VENTILATOR WITH INTEGRATED COUGH-ASSIST

BACKGROUND OF THE INVENTION Field of the Invention

The present invention is directed generally to an active exhalation valve for use with a ventilator having a pressure source usable to control operation of the valve and thereby the flow of patient exhaled gases. Description of the Related Art

Respiration may be characterized as including both an inspiratory phase and an exhalation phase. During the inspiratory phase, inspiratory gases are drawn into the lungs, and during the exhalation phase, exhalation gases are expelled from the lungs.

Mechanical ventilators are used to assist with breathing.

Conventional ventilators typically push inspiratory gases including oxygen into the patient's lungs. Many patients who use a ventilator also need other types of assistance related to treating and maintaining their airways and lungs. For example, some patients may use a nebulizer to deliver drugs to their lungs and/or airways. Further, some patients may need help clearing secretions from their lungs and/or airways. Such assistance is typically provided by a conventional suction device. Thus, in additional to a ventilator, many patients require multiple devices and traveling with such equipment can be particularly problematic.

Currently, to receive cough assistance, a patient must be disconnected from mechanical ventilation, and connected to a separate cough assist device. After a cough assist maneuver is performed, the patient must be disconnected from the cough assist device, and reconnected to the mechanical ventilation. Often, suctioning of the patient airway is also performed after the patient has been disconnected from the cough assist device and reconnected to the mechanical ventilation to remove secretions not adequately cleared from the patient airway during the cough assist maneuver. To minimize risk of patient hypoxemia during the period of time that the patient is not receiving mechanical ventilation, it is a common practice to deliver an elevated level of inspired oxygen before removing mechanical ventilation from the patient. Because this process may be tedious, it is often not performed in a manner that is most advantageous to the patient.

Thus, a need exists for ventilators configured to be portable and/or provide additional functionality beyond delivering inspiratory gases into the patient's lungs. The present application provides these and other advantages as will be apparent from the following detailed description and accompanying figures.

SUMMARY OF THE INVENTION

An embodiment includes a method of providing a breath to a human patient. The human patient has a patient connection connected, by a patient circuit, to a ventilator device. The breath has an inspiratory phase with a beginning and an end. The method includes delivering a bolus of oxygen to the patient circuit at or before the beginning of the inspiratory phase of the breath, terminating the delivery of the bolus of oxygen before the end of the inspiratory phase of the breath, and delivering breathing gases including air to the patient circuit before the end of the inspiratory phase of the breath. The patient circuit delivers the bolus of oxygen and the breathing gases to the patient connection. Optionally, the method may further include waiting until after the delivery of the bolus of oxygen delivered for the breath has been terminated before delivering the breathing gases.

Optionally, the method may further include receiving a bolus volume value. In such embodiments, the bolus of oxygen delivered for the breath has a volume substantially equal to the bolus volume value.

Optionally, delivering the breathing gases to the patient circuit includes providing the breathing gases to the patient circuit at a first input location of the patient circuit, and delivering the bolus of oxygen to the patient circuit includes providing the bolus of oxygen to the patient circuit at a second input location of the patient circuit closer than the first input location to the patient connection.

Combined the bolus of oxygen and the breathing gases delivered for the breath have a total inspiratory volume. Optionally, the bolus of oxygen delivered for the breath has a volume that is less than about 75% of the total inspiratory volume. Optionally, the bolus of oxygen delivered for the breath has a volume that is between about 50% of the total inspiratory volume and about 75% of the total inspiratory volume.

Optionally, the method may further include receiving an oxygen flow equivalent value associated with an oxygen flow rate which if applied to the patient circuit continuously from the beginning of the inspiratory phase of the breath to an end of an expiratory phase of the breath would produce a first volume of oxygen. In such embodiments, the bolus of oxygen delivered for the breath has a second volume that is less than the first volume of oxygen.

Optionally, the method may further include detecting the beginning of the inspiratory phase of the breath has been initiated by the patient. In such embodiments, the method may further include initiating delivery of the bolus of oxygen to the patient circuit in response to having detected the beginning of the inspiratory phase of the breath has been initiated by the patient.

The method may be used with an oxygen source connected to a valve. In such embodiments, delivering the bolus of oxygen at or before the beginning of the inspiratory phase of the breath includes opening the valve to thereby allow a flow of oxygen from the oxygen source to the patient circuit.

Further, terminating the delivery of the bolus of oxygen before the end of the inspiratory phase of the breath includes closing the valve to thereby discontinue the flow of oxygen from the oxygen source to the patient circuit.

The method may be used with an oxygen generator connected to the oxygen source. In such embodiments, the oxygen source is configured to store oxygen generated by the oxygen generator, the method further includes detecting a value including at least one of a concentration of the oxygen stored by the oxygen source and a pressure of the oxygen stored by the oxygen source, determining if the detected value is below a threshold value, operating the oxygen generator when the detected value is determined to be below the threshold value, and delivering oxygen generated by the oxygen generator to the oxygen source.

The method may be used with a user specified total tidal volume. In such embodiments, the breathing gases delivered for the breath have a first volume, the bolus of oxygen delivered for the breath has a second volume, and combined the first and second volumes are substantially equal to the user specified total tidal volume. The method may be used with a user specified peak inspiratory pressure value. In such embodiments, a combined pressure of the breathing gases and the bolus of oxygen delivered for the breath does not exceed the user specified peak inspiratory pressure value.

The method may be used with a breathing gases delivery conduit and an oxygen delivery conduit. The breathing gases delivery conduit has a breathing gases output located at a first end portion of the patient circuit away from the patient connection. The oxygen delivery conduit has an oxygen output located at a second end portion of the patient circuit adjacent to the patient connection. Delivering the breathing gases to the patient circuit may include providing the breathing gases to the breathing gases output via the breathing gases delivery conduit. Further, delivering the bolus of oxygen to the patient circuit includes providing the bolus of oxygen to the oxygen output via oxygen delivery conduit, to thereby isolate the bolus of oxygen delivered for the breath from the breathing gases delivered for the breath along at least a majority portion of the patient circuit prior to the patient connection.

Optionally, the patient circuit includes a breathing gases delivery conduit and an oxygen delivery conduit. In such embodiments, delivering the breathing gases to the patient circuit includes providing the breathing gases to the breathing gases delivery conduit, which delivers the breathing gases to the patient connection. Further, delivering the bolus of oxygen to the patient circuit includes providing the bolus of oxygen to the oxygen delivery conduit, which delivers the bolus of oxygen to the patient connection, thereby isolating the bolus of oxygen delivered for the breath from the breathing gases delivered for the breath along at least a portion of the patient circuit prior to the patient connection. Optionally, the bolus of oxygen exits the oxygen delivery conduit and enters the breathing gases delivery conduit at a location adjacent to the patient connection. Optionally, the bolus of oxygen exits the oxygen delivery conduit and enters the breathing gases delivery conduit at a location within about two centimeters of the patient connection.

The method may be used with a compressor operable to compress breathing gases. In such embodiments, delivering breathing gases to the patient circuit includes delivering at least a portion of the breathing gases compressed by the compressor. An embodiment includes a ventilator device for use with an oxygen source and a patient circuit. The patient circuit is configured to receive breathing gases and oxygen to provide a breath to a human patient having a patient connection couplable to the patient circuit. The breath has an inspiratory phase with a beginning and an end. The ventilator device includes a compressor configured to deliver breathing gases to the patient circuit, and a control system configured to (a) allow the oxygen to flow from the oxygen source to the patient circuit at or before a beginning of an inspiratory phase of a breath, (b) prevent the oxygen from flowing from the oxygen source to the patient circuit before an end of the inspiratory phase of the breath, and (c) cause the compressor to deliver the breathing gases to the patient circuit before the end of the inspiratory phase of the breath.

Optionally, the ventilator device may include an input configured to receive a user specified total tidal volume. In such embodiments, the breathing gases delivered to the patient circuit for the breath have a first volume, the oxygen allowed to flow to the patient circuit for the breath has a second volume, and combined the first and second volumes are substantially equal to the user specified total tidal volume.

Optionally, the ventilator device may include an input configured to receive a user specified peak inspiratory pressure value. In such embodiments, a combined pressure of the breathing gases delivered to the patient circuit and the oxygen allowed to flow to the patient circuit for the breath does not exceed the user specified peak inspiratory pressure value.

Another embodiment includes a ventilator device for use with a patient circuit. The patient circuit is configured to receive breathing gases and oxygen to provide a breath to a human patient having a patient connection couplable to the patient circuit. The breath has an inspiratory phase with a beginning and an end. The ventilator device includes a compressor configured to deliver breathing gases to the patient circuit, a patient oxygen outlet couplable to the patient circuit, an oxygen source configured to deliver oxygen to the patient circuit, and a control system configured to (a) allow the oxygen to flow from the oxygen source to the patient circuit at or before a beginning of an inspiratory phase of a breath, (b) prevent the oxygen from flowing from the oxygen source to the patient circuit before an end of the inspiratory phase of the breath, and (c) cause the compressor to deliver the breathing gases to the patient circuit before the end of the inspiratory phase of the breath. Optionally, the ventilator device may include an input configured to receive a user specified total tidal volume. In such embodiments, the breathing gases delivered to the patient circuit for the breath have a first volume, the oxygen allowed to flow to the patient circuit for the breath has a second volume, and combined the first and second volumes are substantially equal to the user specified total tidal volume. Optionally, the ventilator device may include an input configured to receive a user specified peak inspiratory pressure value. In such embodiments, a combined pressure of the breathing gases delivered to the patient circuit and the oxygen allowed to flow to the patient circuit for the breath does not exceed the user specified peak inspiratory pressure value.

An embodiment includes a ventilation system for use with a human patient having a patient connection couplable to a patient circuit. The system includes a control system, an oxygen source configured to deliver oxygen to a patient oxygen outlet couplable to the patient circuit, and a compressor configured to deliver breathing gases to a ventilator connection couplable to the patient circuit. The ventilator connection is different from the patient oxygen outlet. The control system is configured to identify an inspiratory phase of a breath, and instruct the oxygen source to deliver the oxygen to the patient oxygen outlet before or during the inspiratory phase. The oxygen source is configured to deliver the oxygen to the patient oxygen outlet in response to the instruction to deliver the oxygen to the patient oxygen outlet. The control system is further configured to instruct the compressor to deliver the breathing gases to the ventilator connection during the inspiratory phase. The compressor is configured to deliver the breathing gases to the ventilator connection in response to the instruction to deliver the breathing gases to the ventilator connection.

Optionally, the compressor and the ventilator connection may be components of a ventilator, and the oxygen source may be external to the ventilator.

Optionally, the oxygen source is an internal oxygen source of a ventilator. The internal oxygen source has an oxygen inlet in fluid communication with the internal oxygen source. In such embodiments, the ventilation system may include an external oxygen source in fluid communication with the oxygen inlet to deliver oxygen from the external oxygen source to the internal oxygen source.

Optionally, the ventilation system also includes an oxygen generator in fluid communication with the oxygen source, the oxygen generator delivering oxygen to the oxygen source. The compressor, the oxygen source, and the oxygen generator may each be components of a ventilator. Alternatively, the compressor and the oxygen source are each components of a ventilator, and the oxygen generator is external to the ventilator.

Optionally, the ventilation system also includes a user interface having an input configured to receive a user specified total tidal volume. The user interface is configured to provide the user specified total tidal volume to the control system. The control system is configured to determine a first volume and a second volume. In such embodiments, the breathing gases delivered for the breath have the first volume, the oxygen delivered for the breath has the second volume, and combined the first and second volumes are substantially equal to the user specified total tidal volume.

Optionally, the ventilation system also includes a user interface having an input configured to receive a user specified peak inspiratory pressure value. In such embodiments, the user interface is configured to provide the user specified peak inspiratory pressure value to the control system, and a combined pressure of the breathing gases and the oxygen delivered for the breath does not exceed the user specified peak inspiratory pressure value.

An embodiment includes a method of providing a breath to a human patient. The patient has a patient connection connected by a patient circuit to a ventilator having a first ventilator connection and a different second ventilator connection. Each of the first and second ventilator connections is in fluid communication with the patient circuit. The method includes identifying, with the ventilator, initiation of an inspiratory phase of the breath, delivering a bolus of oxygen to the first ventilator connection before or during the inspiratory phase, and delivering breathing gases including air to the second ventilator connection during the inspiratory phase. The ventilator isolates the bolus of oxygen delivered to the first ventilator connection from the breathing gases delivered to the second ventilator connection. Optionally, the ventilator may deliver the bolus of oxygen at the initiation of the inspiratory phase of the breath. Optionally, the ventilator may determine a volume of the bolus of oxygen delivered for the breath.

The method may further include identifying, with the ventilator, an end of the inspiratory phase of the breath, and terminating the delivery of the bolus of oxygen before the end of the inspiratory phase. The breathing gases may be delivered after the delivery of the bolus of oxygen has been terminated.

The method may be used with a user specified total tidal volume. In such embodiments, the breathing gases delivered for the breath have a first volume, the bolus of oxygen delivered for the breath has a second volume, and combined the first and second volumes are substantially equal to the user specified total tidal volume.

The method may be used with a user specified peak inspiratory pressure value. In such embodiments, a combined pressure of the breathing gases and the bolus of oxygen delivered for the breath does not exceed the user specified peak inspiratory pressure value.

An embodiment includes a ventilator device for use with a human patient having a patient connection couplable to a patient circuit. The ventilator device includes a ventilator connection couplable to the patient circuit, one or more first flow conduits in fluid communication with the ventilator connection, and a compressor configured to deliver breathing gases to the one or more first flow conduits. The one or more first flow conduits deliver the breathing gases to the ventilator connection. The ventilator device also includes a patient oxygen outlet couplable to the patient circuit, one or more second flow conduits in fluid communication with the patient oxygen outlet, and an oxygen source configured to deliver oxygen to the one or more second flow conduits. The one or more second flow conduits deliver the oxygen to the patient oxygen outlet. The patient oxygen outlet and the one or more second flow conduits isolate the oxygen from the breathing gases delivered to the one or more first flow conduits and the ventilator connection.

Optionally, the one or more second flow conduits include a first conduit and a second conduit, and the ventilator device further includes a valve. The first conduit is in fluid communication with the valve to deliver oxygen from the oxygen source to the valve. The second conduit is in fluid communication with the valve to deliver oxygen from the valve to the patient oxygen outlet. Opening the valve allows the oxygen to flow from the oxygen source to the patient oxygen outlet through the first and second conduits. On the other hand, closing the valve prevents the oxygen from flowing from the oxygen source to the patient oxygen outlet through the first and second conduits. Optionally, the ventilator device includes a control system configured to: (a) open the valve at or before a beginning of an inspiratory phase of a breath to thereby allow the oxygen to flow from the oxygen source to the patient oxygen outlet; (b) close the valve before an end of the inspiratory phase of the breath to thereby prevent the oxygen from flowing from the oxygen source to the patient oxygen outlet; and (c) instruct the compressor to deliver the breathing gases before the end of the inspiratory phase of the breath. Optionally, the control system may be configured to instruct the compressor to deliver the breathing gases after the valve has been closed.

Optionally, the ventilator device includes an input configured to receive a user specified total tidal volume. In such embodiments, the breathing gases delivered for the breath have a first volume, the oxygen allowed to flow for the breath has a second volume, and combined the first and second volumes are substantially equal to the user specified total tidal volume.

Optionally, the ventilator device includes an input configured to receive a user specified peak inspiratory pressure value. In such embodiments, a combined pressure of the breathing gases delivered and the oxygen allowed to flow for the breath does not exceed the user specified peak inspiratory pressure value.

Optionally, the ventilator device includes a user input configured to receive a user selected parameter value. In such embodiments, the control system is configured to leave the valve open until a volume of oxygen determined based at least in part on the user selected parameter value has flowed through the valve.

The oxygen source may be configured to store oxygen. In such embodiments, the ventilator device may optionally include an oxygen generator in fluid communication with the oxygen source, and a sensor configured to provide a signal to the control system. The signal encodes at least one of a concentration of oxygen stored by the oxygen source and a pressure of the oxygen stored by the oxygen source. In such embodiments, the control system is configured to use the signal to determine whether an amount of oxygen stored by the oxygen source is less than a threshold value, and to operate the oxygen generator to deliver oxygen to the oxygen source when the control system determines the amount of oxygen stored by the oxygen source is less than the threshold value.

The patient circuit may have a sensor configured to detect a flow rate within the patient circuit and send a signal encoding the flow rate. In such embodiments, the control system may be configured to receive the signal from the sensor and use the signal to detect when the patient has initiated the beginning of the inspiratory phase.

Optionally, the ventilator device includes a sensor configured to detect a flow rate within one of the one or more first flow conduits and send a signal to the control system encoding the flow rate. In such embodiments, the control system is configured to use the signal to detect when the patient has initiated the beginning of the inspiratory phase.

Optionally, the ventilator device includes an accumulator configured to deliver at least a portion of the breathing gases to the compressor via at least one of the one or more first flow conduits, and a sensor configured to (a) detect a flow rate inside the at least one of the one or more first flow conduits and (b) send a signal to the control system encoding the flow rate. In such embodiments, the control system is configured to use the signal to detect when the patient has initiated the beginning of the inspiratory phase.

An embodiment of a pressure swing adsorption oxygen generator to separate oxygen from air for use with a pressure source generating a high pressure and a low pressure, includes an adsorption bed having a bed of nitrogen absorbent material; and a multi-position rotary valve for controlling pressure swing adsorption of the adsorption bed, and being couplable to the pressure source for fluid communication therewith and in fluid communication with the adsorption bed. The rotary valve includes a cam having first and second rotary positions, in the first rotary position of the cam the rotary valve communicating high pressure generated by the pressure source to the adsorption bed and in the second rotary position of the cam the rotary valve communicating low pressure generated by the pressure source to the adsorption bed.

Optionally, the pressure swing adsorption oxygen generator may include an oxygen storage unit connected to the adsorption bed; a first regulator which upon a sensed first condition when the cam is in the first rotary position permits oxygen generated within the adsorption bed to pass to the oxygen storage unit; and a second regulator which upon a sense second condition when the cam is in the second rotary position permits a portion of the oxygen in the oxygen storage unit to enter the adsorption bed to assist in purging nitrogen from the adsorption bed.

Optionally, the pressure swing adsorption oxygen generator may include an oxygen storage unit; a first pressure regulator connected to the adsorption bed and to the oxygen storage unit, and in response to pressure in the adsorption bed rising to a preselected first pressure, the first pressure regulator regulating the pressure in the adsorption bed to the preselected first pressure and permitting oxygen generated within the adsorption bed to pass through the first pressure regulator to the oxygen storage unit; and a second pressure regulator connected to the adsorption bed and to the oxygen storage unit, and in response to pressure in the adsorption bed falling to a preselected second pressure that is lower than the preselected first pressure, the pressure regulator regulating the pressure in the adsorption bed to the preselected second pressure and permitting stored oxygen within the oxygen storage unit to pass through the second pressure regulator to the adsorption bed.

Optionally, the pressure swing adsorption oxygen generator may be constructed such that the first pressure regulator prevents fluid communication through the first pressure regulator between the adsorption bed and the oxygen storage unit when the pressure in the adsorption bed is below the preselected first pressure, and the second pressure regulator prevents fluid communication through the second pressure regulator between the oxygen storage unit and the adsorption bed when the pressure in the adsorption bed is above the preselected second pressure.

Another embodiment of a pressure swing adsorption oxygen generator to separate oxygen from air, includes a pressure source generating a high pressure and a low pressure; an adsorption bed having a bed of nitrogen absorbent material; and a multi-position rotary valve for controlling pressure swing adsorption of the adsorption bed, and being in fluid communication with the pressure source and the adsorption bed, the rotary valve including a cam having first and second rotary positions, in the first rotary position of the cam the rotary valve communicating high pressure generated by the pressure source to the adsorption bed and in the second rotary position of the cam the rotary valve communicating low pressure generated by the pressure source to the adsorption bed.

Optionally, the pressure source is a compressor, and the high pressure generated is a positive pressure and the low pressure generated is a negative pressure.

Another embodiment of a pressure swing adsorption oxygen generator to separate oxygen from air for use with a pressure source generating a high pressure and a low pressure, includes an adsorption bed having a bed of nitrogen absorbent material; and a multi-position rotary valve for controlling pressure swing adsorption of the adsorption bed, and being couplable to the pressure source for fluid communication therewith and in fluid communication with the adsorption bed. The rotary valve having a cam having at least first and second rotary positions; a rotary actuator configured to rotate the cam; and a plurality of valves operative in response to the rotary position of the cam. In the first rotary position of the cam at least one of the valves communicating high pressure generated by the pressure source to the adsorption bed and in the second rotary position of the cam at least one of the valves communicating low pressure generated by the pressure source to the adsorption bed.

Optionally, when the pressure swing adsorption oxygen generator is for use with the pressure source being a compressor with the high pressure being at an output port and the low pressure being at an input port, the plurality of valves may include first, second, third and fourth valves, each having a first port and a second port which are in fluid communication with each other in a first state and out of fluid communication with each other in a second state, and selectively movable between the first and second states. The first port of the first valve being in fluid communication with the compressor output port and the second port of the first valve being in fluid communication with atmosphere. The first port of the second valve being in fluid communication with the adsorption bed and the second port of the second valve being in fluid communication with the compressor output port. The first port of the third valve being in fluid communication with the adsorption bed and the second port of the third valve being in fluid communication with the compressor input port. The first port of the fourth valve being in fluid communication with the compressor input port and the second port of the fourth valve being in fluid communication with a supply of air from which oxygen is to be separated. The first, second, third and fourth valves being moved between the first and second states in a repeated sequence in response to rotation of the cam, wherein when the cam is in the first rotary position the second and fourth valves are in the first state and the first and third valves are in the second state, and when the cam is in the second rotary position the first and third valves are in the first state and the second and fourth valves are in the second state.

Optionally, the first and third valves are moved by the cam between the first and second states in unison, and the second and fourth valves are moved by the cam between the first and second states in unison.

Optionally, the cam has first and second cam lobes, and further has third and fourth rotary positions, wherein when the cam is moved to the first rotary position the first cam lobe moves the fourth valve to the first state and the second cam lobe moves the second valve to the first state, and the first and third valves are in the second state, when the cam is moved to the second rotary position the first cam lobe moves the first valve to the first state and the second cam lobe moves the third valves to the first state, and the second and fourth valves are in the second state, when the cam is moved to the third rotary position the first cam lobe moves the second valve to the first state and the second cam lobe moves the fourth valve to the first state, and the first and third valves are in the second state, and when the cam is moved to the fourth rotary position the first cam lobe moves the third valve to the first state and the second cam lobe moves the first valves to the first state, and the second and fourth valves are in the second state.

Optionally, each of the valves may include a poppet member; a seat having a seat aperture; and a pushrod member having a cam follower abutting the cam for movement of the pushrod in response to rotation of the cam between the first and second rotary positions of the cam, the poppet member being coupled to the pushrod member for movement therewith to move the poppet member into and out of seated arrangement with the seat to close and open the seat aperture in response to rotation of the cam.

Further, each of the valves may further include a housing with an end opening toward the cam, the poppet member and seat being positioned in the housing with the pushrod extending through the housing end opening, and further include a flexible diaphragm positioned between the seat and the cam and having an opening through which the pushrod extends. The diaphragm closing the housing end opening, and having a peripheral portion coupled to the housing and a central portion coupled to the pushrod for movement therewith. The diaphragm may further have an effective area and the poppet valve having a closure area closing the seat aperture. The effective area of the diaphragm and the closure area of the poppet valve being sized to offset the force on the pushrod resulting from the pressure within the chamber between the seat and the diaphragm when the poppet valve is in seated arrangement with the seat, thereby reducing the force on the cam follower of the pushrod member.

Another embodiment of a pressure swing adsorption oxygen generator to separate oxygen from air, includes a compressor having an input port and an output port; an adsorption bed having a bed of nitrogen absorbent material; and a multi-position rotary valve for controlling pressure swing

adsorption of the adsorption bed, and being in fluid communication with the compressor and the adsorption bed. The rotary valve has a cam; a rotary actuator configured to rotate the cam; and first, second, third and fourth valves. Each valve having a first port and a second port which are in fluid communication with each other in a first state and out of fluid communication with each other in a second state, and being selectively movable between the first and second states in response to the rotary position of the cam. The first port of the first valve being in fluid communication with the compressor output port and the second port of the first valve being in fluid communication with atmosphere. The first port of the second valve being in fluid communication with the adsorption bed and the second port of the second valve being in fluid communication with the compressor output port. The first port of the third valve being in fluid communication with the adsorption bed and the second port of the third valve being in fluid communication with the compressor input port. The first port of the fourth valve being in fluid communication with the compressor input port and the second port of the fourth valve being in fluid communication with a supply of air from which oxygen is to be separated in the adsorption bed. The first, second, third and fourth valves being moved between the first and second states in a repeated sequence in response to rotation of the cam, wherein during a first period the second and fourth valves are in the first state and the first and third valves are in the second state, whereby air at high pressure is communicated to the adsorption bed to separate nitrogen from the air and generate oxygen, and during a second period occurring after the first period the first and third valves are in the first state and the second and fourth valves are in the second state, whereby nitrogen is purged from the adsorption bed.

Optionally, the pressure swing adsorption oxygen generator includes an oxygen storage unit connected to the adsorption bed; a first regulator which upon a sensed first condition during the first period permits the generated oxygen within the adsorption bed to pass to the oxygen storage unit; and a second regulator which upon a sense second condition during the second period permits a portion of the oxygen in the oxygen storage unit to enter the adsorption bed to assist in purging the nitrogen from the adsorption bed.

Optionally, the pressure swing adsorption oxygen generator may include an oxygen storage unit; a first pressure regulator connected to the adsorption bed and to the oxygen storage unit, and in response to pressure in the adsorption bed rising to a preselected first pressure, the first pressure regulator regulating the pressure in the adsorption bed to the preselected first pressure and permitting the generated oxygen within the adsorption bed to pass through the first pressure regulator to the oxygen storage unit; and a second pressure regulator connected to the adsorption bed and to the oxygen storage unit, and in response to pressure in the adsorption bed falling to a preselected second pressure that is lower than the preselected first pressure, the pressure regulator regulating the pressure in the adsorption bed to the preselected second pressure and permitting stored oxygen within the oxygen storage unit to pass through the second pressure regulator to the adsorption bed.

Optionally, the first pressure regulator prevents fluid communication through the first pressure regulator between the adsorption bed and the oxygen storage unit when the pressure in the adsorption bed is below the preselected first pressure, and the second pressure regulator prevents fluid communication through the second pressure regulator between the oxygen storage unit and the adsorption bed when the pressure in the adsorption bed is above the preselected second pressure.

The pressure swing adsorption oxygen generator wherein during a third period occurring after the second period the second and fourth valves are in the first state and the first and third valves are in the second state, whereby air at high pressure is communicated to the adsorption bed to separate nitrogen from the air and generate oxygen, and during a fourth period occurring after the third period the first and third valves are in the first state and the second and fourth valves are in the second state, whereby nitrogen is purged from the adsorption bed.

Optionally, the first and third valves are positioned opposite each other on opposing sides of the cam, and the second and fourth valves are positioned opposite each other on opposing sides of the cam.

Optionally, the cam has first and second cam lobes, and during the first period the first cam lobe moves the fourth valve to the first state and the second cam lobe moves the second valve to the first state, and the first and third valves are in the second state, during the second period the first cam lobe moves the first valve to the first state and the second cam lobe moves the third valves to the first state, and the second and fourth valves are in the second state, during the third period the first cam lobe moves the second valve to the first state and the second cam lobe moves the fourth valve to the first state, and the first and third valves are in the second state, and during the fourth period the first cam lobe moves the third valve to the first state and the second cam lobe moves the first valves to the first state, and the second and fourth valves are in the second state.

An embodiment of a ventilator with an integrated cough assist for use with a patient circuit in fluid communication with a patient connection of a patient, the ventilator being operable in a ventilation mode and in a cough-assist mode. The ventilator includes a ventilator connection to which the patient circuit is connectable for fluid communication therewith, a ventilator portion directing a flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode, a user input for selectively switching operation of the ventilator from ventilation mode to cough-assist mode without disconnecting the ventilator from the patient, and a controller operable in response to the user input for switching the ventilator from operation in the ventilation mode to operation in the cough-assist mode, and controlling operation of the ventilator in cough-assist mode to provide for at least one cough assist to the patient having an insufflation phase followed by an exsufflation phase. The ventilator further including a cough- assist valve which is in a first state for the insufflation phase of the cough assist and then moved to a second state for the exsufflation phase of the cough assist. When the cough-assist valve is in the first state for the insufflation phase of the cough assist, the cough-assist valve communicates a positive pressure to the ventilator connection, and when the cough-assist valve is in the second state for the exsufflation phase of the cough assist, the cough-assist valve communicates a negative pressure to the ventilator connection.

Optionally, the cough-assist valve communicates a positive pressure to the ventilator connection sufficient to generate a patient airway pressure of 10 to 70 cmH2O, and when the cough-assist valve is in the second state for the exsufflation phase of the cough assist, the cough-assist valve communicates a negative pressure to the ventilator connection sufficient to generate a patient airway pressure of -10 to -70 cmH2O.

Another embodiment of a ventilator with an integrated cough assist for use with a patient circuit in fluid communication with a patient connection of a patient, where the ventilator is operable in a ventilation mode and in a cough- assist mode, includes a controller controlling operation of the ventilator in the cough-assist mode to provide for at least one cough assist to the patient having an insufflation phase followed by an exsufflation phase, a ventilator connection to which the patient circuit is connectable for fluid communication therewith, a ventilator subsystem directing a flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode, and a compressor having a compressor inlet and a compressor outlet, the compressor being operable to accelerate gaseous fluid input to the compressor inlet and deliver the accelerated gaseous fluid out the compressor outlet. The ventilator further including a cough- assist valve which is in a first state for the insufflation phase of the cough assist and then moved to a second state for the exsufflation phase of the cough assist. When the cough-assist valve is in the first state for the insufflation phase of the cough assist, the cough-assist valve directs a flow of air to the compressor inlet and directs the flow of the accelerated air from the compressor outlet to the ventilator connection for delivery to the patient, and when the cough-assist valve is in the second state for the exsufflation phase of the cough assist, the cough- assist valve directs the flow of exsufflation gases from the patient to the

compressor inlet and exhausts the flow of the accelerated exsufflation gases from the compressor outlet. Optionally, when the ventilator is in the ventilation mode, the cough- assist valve is retained for operation in the first state.

Optionally, the ventilator portion directs the flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode by directing the ventilation air to the compressor inlet with the cough-assist valve being retained for operation in the first state.

Yet another embodiment of a ventilator with an integrated cough assist for use with a patient circuit in fluid communication with a patient connection of a patient, with the ventilator being operable in a ventilation mode and in a cough-assist mode, includes a controller controlling operation of the ventilator in the cough-assist mode to provide for at least one cough assist to the patient having an insufflation phase followed by an exsufflation phase, a ventilator connection to which the patient circuit is connectable for fluid communication therewith, a ventilator portion directing a flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode, a compressor having a compressor inlet and a compressor outlet, the compressor being operable to accelerate gaseous fluid input to the compressor inlet and deliver the accelerated gaseous fluid out the compressor outlet, and a cough-assist valve which is in a first state for the insufflation phase of the cough assist and then moved to a second state for the exsufflation phase of the cough assist. The cough-assist valve includes a first chamber, a second chamber, a third chamber, a valve air intake aperture in fluid communication with a supply of air, a valve exhaust outlet aperture, a valve-to-compressor outlet aperture in fluid communication with the compressor input, a compressor-to-valve inlet aperture in fluid communication with the compressor output, a first aperture through which the first chamber and second chamber are in fluid communication, a second aperture through which the second chamber and third chamber are in fluid communication, a third aperture in fluid communication with the ventilator connection, a first valve member movable between a first position closing the first aperture and a second position closing the valve air intake aperture, and a second valve member movable between a first position closing the valve exhaust outlet aperture and a second position closing the second aperture. When the cough-assist valve is in the first state for the insufflation phase of the cough assist, the first valve member is in the first valve member first position, and the second valve member is in the second valve member first position, and when the cough-assist valve is in the second state for the exsufflation phase of the cough assist, the first valve member is in the first valve member second position, and the second valve member is in the second valve member second state. The cough-assist valve further includes a valve actuator configured to move the first and second valve members to their first positions for the insufflation phase of the cough assist and to move the first and second valve members to their second positions for the exsufflation phase of the cough assist.

Optionally, when the ventilator is in the ventilation mode, the cough- assist valve is retained for operation in the first state.

Optionally, the ventilator portion directs the flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode by directing the ventilation air to the compressor inlet with the cough-assist valve being retained for operation in the first state.

Optionally, the first and second valve members are attached to a connection member and the valve actuator is configured to move the connection member to a first position to move the first and second valve members to their first positions for the insufflation phase of the cough assist and to a second position to move the first and second valve members to their second positions for the exsufflation phase of the cough assist.

Optionally, the valve actuator includes an electromagnetic coil and a permanent magnet with one of the electromagnetic coil and the permanent magnet being attached to the connection member for movement therewith as a unit, and the other of the electromagnetic coil and the permanent magnet being stationary, the electromagnetic coil and the permanent magnet magnetically interacting when the electromagnetic coil is selectively energized to move the first and second valve members between their first and second positions.

Optionally, the ventilator further includes first and second permanent latching magnets, and first and second ferromagnetic member portions, one of the first permanent latching magnet and the first ferromagnetic member portion being attached to the connection member for movement therewith as a unit and the other being stationary, and one of the second permanent latching magnet and the second ferromagnetic member portion being attached to the connection member for movement therewith as a unit and the other being stationary, with the first permanent latching magnet being positioned sufficiently close to the first ferromagnetic member portion when the first and second valve members are in their first positions to hold the first and second valve members in their first positions when the electromagnetic coil is de-energized, and with the second permanent latching magnet being positioned sufficiently close to the second ferromagnetic member portion when the first and second valve members are in their second positions to hold the first and second valve members in their second positions when the electromagnetic coil is de-energized.

Optionally, the ventilator further includes a permanent latching magnet, and a ferromagnetic member portion, one of the permanent latching magnet and the ferromagnetic member portion being attached to the connection member for movement therewith as a unit and the other being stationary, with the permanent latching magnet being positioned sufficiently close to the ferromagnetic member portion when the first and second valve members are in one of their first and second positions to hold the first and second valve members in such one of their first and second positions when the electromagnetic coil is de-energized.

Optionally, the valve actuator includes a stationary electromagnetic coil and a movable permanent magnet, the electromagnetic coil being positioned in a stationary coil housing through which the connection member extends, and the permanent magnet being positioned within the coil housing with the

electromagnetic coil extending thereabout, with the permanent magnet being attached to the connection member for movement therewith as a unit and positioned for magnetic interaction with the electromagnetic coil, the

electromagnetic coil and the permanent magnet magnetically interacting when the electromagnetic coil is selectively energized to move the first and second valve members between their first and second positions.

Optionally, the ventilator further includes first and second permanent latching magnets, and first and second ferromagnetic member portions, one of the first permanent latching magnet and the first ferromagnetic member portion being attached to the connection member for movement therewith as a unit and the other being stationary, and one of the second permanent latching magnet and the second ferromagnetic member portion being attached to the connection member for movement therewith as a unit and the other being stationary, with the first permanent latching magnet being positioned sufficiently close to the first ferromagnetic member portion when the first and second valve members are in their first positions to hold the first and second valve members in their first position when the electromagnetic coil is de-energized, and with the second permanent latching magnet being positioned sufficiently close to the second ferromagnetic member portion when the first and second valve members are in their second positions to hold the first and second members in their second positions when the electromagnetic coil is de-energized.

Optionally, the ventilator further includes first and second permanent latching magnets attached to the connection member within the coil housing for movement with the connection member as a unit, and first and second

ferromagnetic member portions, with the first permanent latching magnet being positioned sufficiently close to the first ferromagnetic member portion when the first and second valve members are in their first positions to hold the first and second valve members in their first positions when the electromagnetic coil is de- energized, and with the second permanent latching magnet being positioned sufficiently close to the second ferromagnetic member portion when the first and second valve members are in their second positions to hold the first and second valve members in their second positions when the electromagnetic coil is de- energized.

Optionally, the first ferromagnetic member portion is a first end portion of the coil housing and the second ferromagnetic member portion is a second end portion of the coil housing.

Optionally, the ventilator further includes a permanent latching magnet attached to the connection member within the coil housing for movement with the connection member as a unit, and a ferromagnetic member portion, with the permanent latching magnet being positioned sufficiently close to the

ferromagnetic member portion when the first and second valve members are in one of their first and second positions to hold the first and second valve members in such one of their first and second positions when the electromagnetic coil is de- energized.

Optionally, the connection member is an elongated shaft extending fully through the second chamber and having a first end portion extending through the first aperture into the first chamber and a second end portion extending through the second aperture into the third chamber, with the first valve member attached to the first end portion of the shaft within the first chamber between the valve air intake aperture and the first aperture, and with the second valve member attached to the second end portion of the shaft within the third chamber between the valve exhaust outlet aperture and the second aperture.

Optionally, the valve actuator includes an electromagnetic coil and a permanent magnet with one of the electromagnetic coil and the permanent magnet being attached to and concentrically arranged with the connection member for movement therewith as a unit, and the other of the electromagnetic coil and the permanent magnet being stationary, with the electromagnetic coil and the permanent magnet magnetically interacting when the electromagnetic coil is selectively energized to move the first and second valve members between their first and second positions.

Optionally, the other of the electromagnetic coil and the permanent magnet is concentrically arranged with the connection member.

Optionally, the first, second and third chambers are within a valve body.

Optionally, the first, second and third chambers are in a linear arrangement within the valve body, and the connection member is an elongated shaft extending fully through the second chamber and having a first end portion extending into the first chamber and a second end portion extending into the third chamber.

Optionally, the valve air intake aperture, the first aperture, the second aperture and the valve exhaust outlet aperture are in linear alignment, and the connection member is an elongated shaft in coaxial alignment with the valve air intake aperture, the first aperture, the second aperture and the valve exhaust outlet aperture, with the shaft extending fully through the second chamber and having a first end portion extending through the first aperture into the first chamber with the first valve member attached thereto within the first chamber and movable with the shaft between the first aperture and the valve air intake aperture, and a second end portion extending through the second aperture into the third chamber with the second valve member attached thereto within the third aperture and movable with the shaft between the valve exhaust outlet aperture and the second aperture. Optionally, the area of the first aperture closed by the first valve member when in the first valve member first position and the area of the valve exhaust outlet aperture closed by the second valve member when in the second valve member first position are sized to produce substantially equal and

oppositely directed forces on the first and second valve members resulting from air pressure in the second chamber transmitted from the third aperture, and the area of the valve air intake aperture closed by the first valve member when in the first valve member second position and the area of the second aperture closed by the second valve member when in the second valve member second position are sized to produce substantially equal and oppositely directed forces on the first and second valve members resulting from air pressure in the second chamber transmitted from the third aperture.

An additional embodiment of a ventilator with an integrated cough assist for use with a patient circuit in fluid communication with a patient connection of a patient, with the ventilator being operable in a ventilation mode and in a cough-assist mode, includes a controller controlling operation of the ventilator in the cough-assist mode to provide for at least one cough assist to the patient having an insufflation phase followed by an exsufflation phase, a ventilator connection to which the patient circuit is connectable for fluid communication therewith, a ventilator portion directing a flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode, a compressor having a compressor inlet and a compressor outlet, the compressor being operable to accelerate gaseous fluid input to the compressor inlet and deliver the accelerated gaseous fluid out the compressor outlet, and a cough-assist valve which is in a first state for the insufflation phase of the cough assist and then moved to a second state for the exsufflation phase of the cough assist. The cough-assist valve further includes a valve air intake in fluid communication with a supply of air, a valve exhaust outlet, a valve-to-compressor outlet in fluid communication with the compressor input, a compressor-to-valve inlet in fluid communication with the compressor output, a first valve member movable between a first valve member first position and a first valve member second position, a second valve member movable between a second valve member first position and a second valve member second position, and a third aperture in fluid communication with the ventilator connection. When the cough-assist valve is in the first state for the insufflation phase of the cough assist, the first valve member is in the first valve member first position permitting the flow of air from the supply of air entering the valve air intake to flow through the valve-to-compressor outlet and enter the compressor inlet while blocking the flow of air entering the valve air intake from flowing directly to the third aperture, and the second valve member is in the second valve member first position permitting the flow of the accelerated air from the compressor outlet entering the compressor-to-valve inlet to flow through the third aperture for flow to the ventilator connection for delivery to the patient while blocking the flow of the accelerated air from the compressor outlet entering the compressor-to-valve inlet from flowing through the valve exhaust outlet. When the cough-assist valve is in the second state for the exsufflation phase of the cough assist, the first valve member is in the first valve member second position permitting the flow of exsufflation gases from the patient entering the third aperture to flow through the valve-to-compressor outlet and enter the compressor inlet while blocking the flow of exsufflation gases from the patient entering the third aperture from flowing through the valve air intake, and the second valve member is in the second valve member second state permitting the flow of the accelerated exsufflation gases entering the compressor-to-valve inlet to flow through the valve exhaust outlet while blocking the flow of accelerated exsufflation gases entering the compressor-to-valve inlet from flowing to the third aperture. A valve actuator is configured to move the first and second valve members to the first and second valve member first positions for the insufflation phase of the cough assist and to move the first and second valve members to the first and second valve member second positions for the exsufflation phase of the cough assist.

An embodiment of a secretion trap is for use between a patient connection and a patient circuit. The secretion trap includes a first connection portion connectable to the patient connection for fluid communication with the patient connection, a second connection portion connectable to the patient circuit for fluid communication with the patient circuit, and a central portion located between the first and second connection portions. The central portion having a first end portion in fluid communication with the first connection portion, a second end portion in fluid communication with the second connection portion, and a secretion collection well located between the first and second end portions sized to capture and retain secretions therein entering the central portion.

Optionally, the first connection portion has a first cross-sectional area, the second connection portion has a second cross-sectional area, and the secretion collection well is a chamber located between the first and second end portions having a lengthwise portion thereof with at least a third cross-sectional area sufficiently greater than the first cross-sectional area of the first connection portion to capture and retain secretions in the secretion collection chamber entering the central portion.

Optionally, the trap includes a drain in fluid communication with the secretion collection well for removal of secretions captured and retained by the secretion collection well.

Optionally, the secretion trap, when used with a source of suction, further includes a drain having a first end portion in fluid communication with the secretion collection well and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the secretion collection well for removal of secretions captured and retained by the secretion collection well.

Optionally, the first end portion of the drain is in fluid communication with the secretion collection well at a location nearer to the first end portion than to the second end portion of the secretion collection well.

Another embodiment of a secretion trap is for use between a patient connection with a connection portion having an interior passageway and a cough assist conduit with a connection portion having an interior passageway. The secretion trap includes a first connection portion connectable to the connection portion of the patient connection for fluid communication with the patient connection, the first connection portion having an interior passageway, a second connection portion connectable to the connection portion of the cough assist conduit for fluid communication with the cough assist conduit, the second connection portion having an interior passageway, and a secretion collection chamber located between the first and second connection portions. The secretion collection chamber has a chamber first end portion located toward the first connection portion and a chamber second end portion located toward the second connection portion. One of the passageways of the first connection portion and the connection portion of the patient connection define a flow aperture for the secretion collection chamber at the chamber first end portion and one of passageways of the second connection portion and the connection portion of the cough assist conduit define a flow aperture for the secretion collection chamber at the chamber second end portion. The secretion chamber has a well portion sized to capture and retain secretions therein entering the central portion.

Optionally, the secretion chamber has a lengthwise portion with a cross-sectional area sized such that a fluid flow with a flow rate entering the secretion chamber through the flow aperture at the chamber first end portion is sufficiently reduced in flow rate within the secretion chamber for the secretion collection chamber to capture and retain therein secretions carried by the fluid flow.

Optionally, the secretion trap includes a drain in fluid communication with the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

Optionally, the secretion trap when used with a source of suction further includes a drain having a first end portion in fluid communication with the secretion collection chamber and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

Optionally, the first end portion of the drain is in fluid communication with the secretion collection chamber at a location nearer to the chamber first end portion than to the chamber second end portion.

Yet another embodiment is a patient connection with an integrated secretion trap for use with a patient circuit. The patient connection includes a patient breathing conduit portion and a secretion collection chamber with chamber first and second end portions. The chamber first end portion is in fluid

communication with the patient breathing conduit portion and the chamber second end portion is connectable with the patient circuit for fluid communication with the patient circuit. The patient breathing conduit portion and chamber first end portion define a first end flow aperture for the secretion collection chamber at the chamber first end portion. The secretion chamber has a lengthwise portion with a cross-sectional area sized such that a fluid flow with a flow rate entering the secretion chamber through the first end flow aperture is sufficiently reduced in flow rate within the secretion chamber for the secretion collection chamber to capture and retain therein secretions carried by the fluid flow.

Optionally, the patient connection further includes a drain in fluid communication with the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

Optionally, the patient connection when used with a source of suction further includes a drain having a first end portion in fluid communication with the secretion collection chamber and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

Another embodiment is a patient circuit with an integrated secretion trap for use with a patient connection. The patient circuit includes a patient circuit conduit portion and a secretion collection chamber with chamber first and second end portions. The chamber first end portion is connectable with to the patient connection for fluid communication with the patient connection and the chamber second end portion is in fluid communication with the patient circuit conduit portion. The patient connection and chamber first end portion when connected together define a first end flow aperture for the secretion collection chamber at the chamber first end portion. The secretion chamber has a lengthwise portion with a cross-sectional area sized such that a fluid flow with a flow rate entering the secretion chamber through the first end flow aperture is sufficiently reduced in flow rate within the secretion chamber for the secretion collection chamber to capture and retain therein secretions carried by the fluid flow.

Optionally, the patient circuit further includes a drain in fluid communication with the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

Optionally, the patient circuit when used with a source of suction further includes a drain having a first end portion in fluid communication with the secretion collection chamber and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber. An additional embodiment of a patient connection has an integrated secretion trap and patient circuit. The secretion trap includes a patient breathing conduit portion, a patient circuit conduit portion, and a secretion collection chamber with chamber first and second end portions. The chamber first end portion is in fluid communication with the patient breathing conduit portion and the chamber second end portion is in fluid communication with the patient circuit conduit portion. The patient breathing conduit portion and chamber first end portion define a first end flow aperture for the secretion collection chamber at the chamber first end portion. The secretion chamber has a lengthwise portion with a cross-sectional area sized such that a fluid flow with a flow rate entering the secretion chamber through the first end flow aperture is sufficiently reduced in flow rate within the secretion chamber for the secretion collection chamber to capture and retain therein secretions carried by the fluid flow.

Optionally, the patient connection further includes a drain in fluid communication with the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

Optionally, the patient connection when used with a source of suction further includes a drain having a first end portion in fluid communication with the secretion collection chamber and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

Yet in another additional embodiment is a ventilator with an integrated cough assist and a secretion trap for use in fluid communication with a patient connection. The ventilator being operable in a ventilation mode and in a cough-assist mode. The ventilator includes a ventilator connection and a secretion trap having a first connection portion connectable to the patient connection for fluid communication with the patient connection, a second connection portion in fluid communication with the ventilator connection, and a central portion located between the first and second connection portion. The central portion has a first end portion in fluid communication with the first connection portion, a second end portion in fluid communication with the second connection portion, and a secretion collection well located between the first and second end portions sized to capture and retain secretions therein entering the central portion. The ventilator also includes a ventilator portion directing a flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode, a user input for selectively switching operation of the ventilator from ventilation mode to cough-assist mode without disconnecting the ventilator from the patient, and a controller operable in response to the user input for switching the ventilator from operation in the ventilation mode to operation in the cough-assist mode, and controlling operation of the ventilator in the cough-assist mode to provide for at least one cough assist to the patient.

Optionally, the controller, when controlling operation of the ventilator in the cough-assist mode, controls operation of the ventilator to provide for at least one cough assist to the patient having an insufflation phase followed by an exsufflation phase. The ventilator further includes at least one cough-assist valve to communicate a positive pressure to the ventilator connection during at least a portion of the insufflation phase of the cough assist and to communicate a negative pressure to the ventilator connection during at least a portion of the exsufflation phase of the cough assist.

Optionally, the ventilator further includes a drain in fluid communication with the secretion collection well for removal of secretions captured and retained by the secretion collection well.

Optionally, the ventilator when used with a source of suction further include a drain having a first end portion in fluid communication with the secretion collection well and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the secretion collection well for removal of secretions captured and retained by the secretion collection well.

An embodiment of a secretion trap is for use between a patient connection and a patient circuit. The secretion trap includes a first connection portion connectable to the patient connection for fluid communication with the patient connection, a second connection portion connectable to the patient circuit for fluid communication with the patient circuit, and a central portion located between the first and second connection portion and having a first end portion in fluid communication with the first connection portion and a second end portion in fluid communication with the second connection portion. The secretion trap further includes a secretion collection drain located in fluid communication with the central portion sized and positioned for removal of secretions entering within the central portion.

The secretion trap may be used with a source of suction. In which case the secretion collection drain may have a first end portion in fluid

communication with the central portion and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the central portion for removal of the secretions entering within the central portion. One embodiment of a passive valve is for use as a fixed leak valve with a ventilator by connection to a patient connection. The passive valve includes a valve body having an internal chamber, a first valve body port in fluid communication with the internal chamber and configured for fluid communication with the patient connection, a second valve body port in fluid communication with the internal chamber and configured for fluid communication with the ventilator, a valve body passageway in communication with the internal chamber and with ambient air exterior of the valve body, and a check valve seal positioned to seal the valve body passageway to permit the flow of gas within the internal chamber through the valve body passageway to the exterior of the valve body and to prevent the flow of ambient air exterior of the valve body through the valve body passageway into the internal chamber.

Optionally, the valve body passageway is an elongated circumferentially extending channel extending at least partially about the valve body.

Optionally, the passive valve further includes a plurality of first passageways in fluid communication with the internal chamber and the channel.

Optionally, the check valve seal is an elongated circumferentially extending flexible seal positioned within the channel and flexibly movable between a closed position closing the first passageways to prevent fluid communication between the internal chamber and the channel through the first passageways when pressure in the internal chamber is below a threshold pressure, and an open position opening the first passageways to allow fluid communication between the internal chamber and the channel through the first passageways when pressure in the internal chamber is above the threshold pressure and thereby providing a fluid communication path between the internal chamber and ambient air exterior of the valve body.

Another embodiment of a passive valve is for use as a fixed leak valve with a ventilator by connection to a patient connection. The passive valve includes a body having a first body portion, a second body portion and a third body portion positioned between the first and second body portions. The first body portion has a first fluid passageway extending therethrough with an outward end portion configured for fluid communication with the patient connection, the second body portion has a second fluid passageway extending therethrough with an outward end portion configured for fluid communication with the ventilator, and the third body portion has a third fluid passageway extending therethrough in fluid communication with the first and second fluid passageways. The first, second and third fluid passageways in combination define a body fluid passageway. The third body portion has a chamber extending at least partially thereabout, with the chamber having at least one interior opening in fluid communication with the body fluid passageway, and at least one exterior opening in fluid communication with the exterior of the body. A seal is included which has at least a portion thereof located within the chamber and movable between a closed position closing the at least one interior opening of the chamber when pressure in the body fluid passageway is below a threshold pressure, and an open position opening the at least one interior opening when pressure in the body fluid passageway is above the threshold pressure.

Optionally, the portion of the seal is a first peripheral portion of the seal.

Optionally, the first peripheral portion of the seal is flexible and moves from the closed position to the open position by flexing away from the at least one interior opening in response to the pressure in the body fluid

passageway being above the threshold pressure.

Optionally, the seal further includes a second peripheral portion of the seal held stationary relative to the body.

Optionally, the seal is flexible and moves from the closed position to the open position by flexing away from the at least one interior opening in response to the pressure in the body fluid passageway being above the threshold pressure. Optionally, the at least one interior opening includes at least two interior openings and the portion of the seal extends between the at least two interior openings of the chamber and is movable between a closed position covering and closing the at least two interior openings to prevent fluid

communication between the body fluid passageway and the chamber through the at least two interior openings when pressure in the body fluid passageway is below a threshold pressure, and an open position opening the at least two interior openings to allow fluid communication between the body fluid passageway and the chamber through the at least two interior openings when pressure in the body fluid passageway is above the threshold pressure and thereby providing a fluid communication path between the body fluid passageway and the at least one exterior opening of the chamber.

Optionally, the seal has a first peripheral portion and a second peripheral portion with one of the first and second peripheral portions being located outward of the other of the first and second peripheral portions. The first peripheral portion of the seal extending between the at least two interior openings, and being flexible and moving from the closed position to the open position by flexing away from the at least two interior openings in response to the pressure in the body fluid passageway being above the threshold pressure. The second peripheral portion of the seal being held stationary relative to the body.

Optionally, the chamber is an annular chamber extending fully about the third fluid passageway, and the seal is an annular seal.

Yet another embodiment of the passive valve is for use as a fixed leak valve with a ventilator by connection to a patient connection. The passive valve includes a seal having a seal central opening, first and second body portions and a chamber. The first body portion has a first fluid passageway extending therethrough with an outward first end portion configured for fluid communication with the patient connection and an inward second end portion, and the second body portion has a second fluid passageway extending therethrough with an outward first end portion configured for fluid communication with the ventilator and an inward second end portion. The inward second end portions of the first and second body portions are joined together with the seal positioned therebetween with the seal central opening aligned with the first and second fluid passageways to define a body fluid passageway extending between the outward first end portions of the first and second body portions. The chamber extends about the body fluid passageway and has at least one interior opening in fluid

communication with the body fluid passageway, and at least one exterior opening in fluid communication with the exterior of the body. The seal has a first peripheral portion located within the chamber and movable between a closed position closing the at least one interior opening when pressure in the body fluid passageway is below a threshold pressure, and an open position opening the at least one interior opening when pressure in the body fluid passageway is above the threshold pressure.

Optionally, the first peripheral portion of the annular seal is flexible and moves from the closed position to the open position by flexing away from the at least one interior opening in response to the pressure in the body fluid passageway being above the threshold pressure.

Optionally, the annular seal further has a second peripheral portion held stationary relative to the body.

Optionally, the at least one interior opening is formed by at least one gap between joined inward second end portions of the first and second body portions.

Optionally, the at least one exterior opening is formed in a flange portion of at least one of the joined inward second end portions of the first and second body portions.

Another embodiment is a ventilator with an integrated cough assist for use with a patient. The ventilator includes a passive patient circuit for fluid communication with a patient connection, a ventilator portion having a ventilator connection to which the patient circuit is connectable for fluid communication therewith, with the ventilator portion being operable in a ventilation mode and in a cough-assist mode. The ventilator portion directs a flow of ventilation air to the ventilator connection for delivery to the patient via the patient circuit when the ventilator is in the ventilation mode, with the ventilation air producing a pressure in the patient circuit above a threshold pressure. The ventilator further includes a user input for selecting switching operation of the ventilator from the ventilation mode to the cough-assist mode without disconnecting the ventilator from the patient, and a controller operable in response to the user input for switching the ventilator from operation in the ventilation mode to operation in the cough-assist mode, and controlling operation of the ventilator in cough-assist mode to provide for at least one cough assist to the patient having an insufflation phase followed by an exsufflation phase. The ventilator also includes a cough-assist valve which is in a first state for the insufflation phase of the cough assist and then moved to a second state for the exsufflation phase of the cough assist. When the cough- assist valve is in the first state for the insufflation phase of the cough assist, the cough-assist valve communicates a positive pressure to the ventilator connection for delivery to the patient via the patient circuit at a pressure in the patient circuit above the threshold pressure, and when the cough-assist valve is in the second state for the exsufflation phase of the cough assist, the cough-assist valve communicates a negative pressure to the ventilator connection for delivery to the patient via the patient circuit at a pressure in the patient circuit below the threshold pressure. The patient circuit of the ventilator includes a passive valve usable as a fixed leak valve. The passive valve includes a valve body having an internal chamber, a first valve body port in fluid communication with the internal chamber and configured for fluid communication with the patient connection, a second valve body port in fluid communication with the internal chamber and configured for fluid communication with the ventilator connection, a valve body passageway in communication with the internal chamber and with ambient air exterior of the valve body, and a check valve seal positioned to seal the valve body passageway to permit the flow of gas within the internal chamber through the valve body passageway to the exterior of the valve body and to prevent the flow of ambient air exterior of the valve body through the valve body passageway into the internal chamber.

Optionally, the valve body passageway comprises a passageway chamber extending at least partially about the internal chamber of the valve body with the first valve body port comprising at least two interior openings of the passageway chamber providing fluid communication between the passageway chamber and the internal chamber of the valve body, and the second valve body port comprising at least one exterior opening of the passageway chamber providing fluid communication between the passageway chamber and the exterior of the valve body. The check valve seal is at least in part located within the passageway chamber and extends between the at least two interior openings of the passageway chamber. The portion of the seal is movable between a closed position closing the at least two interior opening of the passageway chamber when pressure in the internal chamber of the valve body is below the threshold pressure, and an open position opening the at least two interior opening of the passageway chamber when pressure in the internal chamber of the valve body is above the threshold pressure.

Optionally, the portion of the seal located within the passageway chamber is flexible and moves from the closed position to the open position by flexing away from the at least two interior openings of the passageway chamber in response to the pressure in the internal chamber of the valve body being above the threshold pressure.

Optionally, the seal further includes a portion held stationary relative to the valve body.

Another embodiment is a patient connection for use with a ventilator and a patient having at least one lung. The patient connection includes a patient interface portion having a fluid passageway couplable to the patient in fluid communication with the at least one lung of the patient; and a passive valve portion operable as a fixed leak valve. The valve portion includes a valve body having an internal chamber, a first valve body port in fluid communication with the internal chamber and configured for fluid communication with the fluid

passageway of the patient interface, a second valve body port in fluid

communication with the internal chamber and configured for fluid communication with the ventilator, a valve body passageway in communication with the internal chamber and with ambient air exterior of the valve body, and a check valve seal positioned to seal the valve body passageway to permit the flow of gas within the internal chamber through the valve body passageway to the exterior of the valve body and to prevent the flow of ambient air exterior of the valve body through the valve body passageway into the internal chamber.

Optionally, the valve body passageway is an elongated circumferentially extending channel extending at least partially about the valve body.

Optionally, the patient connection further includes a plurality of first passageways in fluid communication with the internal chamber and the channel.

Optionally, the check valve seal is an elongated circumferentially extending flexible seal positioned within the channel and flexibly movable between a closed position closing the first passageways to prevent fluid communication between the internal chamber and the channel through the first passageways when pressure in the internal chamber is below a threshold pressure, and an open position opening the first passageways to allow fluid communication between the internal chamber and the channel through the first passageways when pressure in the internal chamber is above the threshold pressure and thereby providing a fluid communication path between the internal chamber and ambient air exterior of the valve body.

One embodiment of an active exhalation valve is for use with a ventilator to control flow of patient exhaled gases. The active exhalation valve includes a patient circuit connection port, a patient connection port, an exhaled gas port, a pilot pressure port, a valve seat, and a movable poppet. The movable poppet includes an inner bellows member, an outer bellows member and a bellows poppet face. The pilot pressure port is configured such that an activation pressure applied to the pilot pressure port extends the inner and outer bellows members to move the bellows poppet face into engagement with the valve seat and restrict flow of patient exhaled gases to the exhaled gas port, and the reduction of the activation pressure to the pilot pressure port allows the inner and outer bellows members to move the bellows poppet face away from the valve seat and out of engagement with the valve seat to permit flow of patient exhaled gases to the exhaled gas port, thereby controlling the flow of patient exhaled gases from the valve.

Optionally, the inner and outer bellows members define an interior bellows chamber therebetween and the pilot pressure port is in fluid

communication with the interior bellows chamber.

Optionally, the inner bellows member has an inner bellows fluid passageway extending therethrough in fluid communication with the patient circuit connection port and the patient connection port.

Optionally, the inner bellows fluid passageway is in continuous fluid communication with the patient circuit connection port and the patient connection port during operation of the exhalation valve, and out of fluid communication with the interior bellows chamber between the inner and outer bellows members. Optionally, the inner bellows member has an inner bellows fluid passageway extending therethrough in continuous fluid communication with the patient circuit connection port and the patient connection port.

Another embodiment of an active exhalation valve is for use with a patient connection and a ventilator having a pressure source usable to control operation of the valve to control flow of patient exhaled gases. The active exhalation valve includes a patient circuit connection port for fluid communication with the ventilator, a patient connection port for fluid communication with the patient connection, an exhaled gas port for fluid communication with air exterior to the valve to remove patient exhaled gases from the valve, a pilot pressure port for fluid communication with the pressure source, a valve seat, and a movable poppet. The movable poppet includes an inner bellows member, an outer bellows member and a bellows poppet face. The pilot pressure port is configured such that an activation pressure applied by the pressure source to the pilot pressure port extends the inner and outer bellows members to move the bellows poppet face into sealing engagement with the valve seat and restrict flow of patient exhaled gases to the exhaled gas port, and the reduction of the activation pressure applied by the pressure source to the pilot pressure port allows the inner and outer bellows members to move the bellows poppet face away from the valve seat and out of sealing engagement with the valve seat to permit flow of patient exhaled gases to the exhaled gas port, thereby controlling the flow of patient exhaled gases from the valve.

Optionally, the inner and outer bellows members define an interior bellows chamber therebetween and the pilot pressure port is in fluid

communication with the interior bellows chamber.

Optionally, the inner bellows member has an inner bellows fluid passageway extending therethrough in fluid communication with the patient circuit connection port and the patient connection port.

Optionally, the inner bellows fluid passageway is in continuous fluid communication with the patient circuit connection port and the patient connection port during operation of the exhalation valve, and out of fluid communication with the interior bellows chamber between the inner and outer bellows members. Optionally, the inner bellows member has an inner bellows fluid passageway extending therethrough in continuous fluid communication with the patient circuit connection port and the patient connection port.

Yet another embodiment of an active exhalation valve is for use with a ventilator to control operation of the valve to control flow of patient exhaled gases. The active exhalation valve includes a patient circuit connection port, a patient connection port, an exhaled gas port, a pilot pressure port, a valve seat, and a movable poppet. The movable poppet includes an inner member, an outer member and a poppet face. The pilot pressure port is configured such that an activation pressure applied to the pilot pressure port moves the inner and outer members toward the valve seat to move the poppet face into engagement with the valve seat and restrict flow of patient exhaled gases to the exhaled gas port, and the reduction of the activation pressure to the pilot pressure port allows the inner and outer members to move away from the valve seat to move the poppet face out of engagement with the valve seat to permit flow of patient exhaled gases to the exhaled gas port, thereby controlling the flow of patient exhaled gases from the valve.

Optionally, the inner and outer members define an interior chamber therebetween and the pilot pressure port is in fluid communication with the interior chamber.

Optionally, the inner member has an inner member fluid passageway extending therethrough in fluid communication with the patient circuit connection port and the patient connection port.

Optionally, the inner member fluid passageway is in continuous fluid communication with the patient circuit connection port and the patient connection port during operation of the exhalation valve, and out of fluid communication with the interior bellows chamber between the inner and outer bellows members.

Optionally, the inner member has an inner member fluid passageway extending therethrough in continuous fluid communication with the patient circuit connection port and the patient connection port.

Another embodiment of an active exhalation valve is for use with a patient connection and a ventilator having a pressure source usable to control operation of the valve. The active exhalation valve includes a valve body having an internal body chamber with gasses therein having a body chamber pressure, a first body port in fluid communication with the body chamber and configured for fluid communication with the patient connection, a second body port in fluid communication with the body chamber and configured for fluid communication with the ventilator, a passageway in fluid communication with the body chamber and with ambient air exterior of the valve body, and a valve seal movable between a closed position sealing the passageway and an open position opening the passageway. The valve seal has an outer member, an inner member positioned within the outer member, an internal seal chamber located between the outer and inner members and in fluid communication with the pressure source, and a seal member extending between the inner and outer members and movable therewith. The seal member has a first surface portion inside the seal chamber configured for movement of the valve seal toward the closed position in response to pressure applied thereto by the pressure source and a second surface portion outside the seal chamber configured for movement of the valve seal toward the open position in response to pressure applied thereto by the body chamber pressure, with the amount and direction of movement of the valve seal being responsive to a resultant force generated by the pressure source and the body chamber pressure on the first and second surface portions.

Optionally, the inner member has an inner member fluid passageway extending therethrough in fluid communication with the body chamber and having a first end in fluid communication with the first body port and a second end in fluid communication with the second body port.

Optionally, the inner member fluid passageway is in continuous fluid communication with the first and second body ports during operation of the exhalation valve, and out of fluid communication with the seal chamber between the inner and outer members.

Optionally, the inner member has an inner member fluid passageway extending therethrough with a first opening in continuous fluid communication with the first body port and a second opening in continuous fluid communication with the second body port.

Optionally, the body has a wall portion positioned outward of the valve seal and defining another chamber positioned outward of the valve seal with the passageway being in the wall portion. Optionally, the body has a perimeter wall portion extending circumferentially about the body chamber and positioned outward of the valve seal, and defining an elongated perimeter chamber extending at least partially about the body chamber, with the passageway being in the perimeter wall portion.

Optionally, the passageway comprises a plurality of apertures in an external wall of the body in fluid communication with the body chamber and with ambient air exterior of the valve body.

An additional embodiment of an active exhalation valve is for use with a patient connection and a ventilator having a pressure source usable to control operation of the valve. The active exhalation valve includes a valve body having an internal body chamber with gasses therein having a body chamber pressure and a body wall portion with a channel therein for fluid communication with the pressure source and an aperture in fluid communication with the channel, a first body port in fluid communication with the body chamber and configured for fluid communication with the patient connection, a second body port in fluid communication with the body chamber and configured for fluid communication with the ventilator, a passageway in fluid communication with the body chamber and with ambient air exterior of the valve body, and a valve seal movable between a closed position sealing the passageway and an open position opening the passageway. The valve seal has an outer longitudinally extending and

longitudinally compressible wall, an inner longitudinally extending and

longitudinally compressible wall positioned within the outer wall, each of the outer and inner walls having a first end and a second end, a seal end wall closing a space between the first ends of the outer and inner walls and being longitudinally movable with the first ends of the outer and inner walls, with the body wall portion closing a space between the second ends of the outer and inner walls, and an internal seal chamber located between the outer and inner walls and extending between the seal end wall and the body wall portion. The aperture of the body wall portion is in fluid communication with the seal chamber to provide fluid communication with the pressure source. The seal end wall is longitudinally movable within the valve body between the closed position with the outer and inner walls being in an extended configuration and the open position with the outer and inner walls being compressed into at least a partially longitudinally compressed position. The seal end wall has a first surface portion inside the seal chamber configured for movement of the valve seal toward the closed position in response to pressure applied thereto by the pressure source and a second surface portion outside the seal chamber configured for movement of the valve seal toward the open position in response to pressure applied thereto by the body chamber pressure, with the amount and direction of movement of the valve seal being responsive to a resultant force generated by the pressure source and the body chamber pressure on the first and second surface portions of the seal end wall.

Optionally, the inner wall has an inner wall fluid passageway extending therethrough in fluid communication with the body chamber and having a first end in fluid communication with the first body port and a second end in fluid communication with the second body port.

Optionally, the inner wall fluid passageway is in continuous fluid communication with the first and second body ports during operation of the exhalation valve, and out of fluid communication with the seal chamber between the inner and outer walls.

Optionally, the inner wall has an inner wall fluid passageway extending therethrough with a first opening in continuous fluid communication with the first body port and a second opening in continuous fluid communication with the second body port.

Optionally, the longitudinally compressible outer and inner walls are corrugated with a plurality of corrugations, and when in the at least partially longitudinally compressed position more than one of the corrugations is longitudinally compressed.

A final embodiment of an active exhalation valve is for use with a patient connection and a ventilator having a pressure source usable to control operation of the valve. The active exhalation valve includes a valve body having an internal body chamber with gasses therein having a body chamber pressure and a channel therein for fluid communication with the pressure source and an aperture in fluid communication with the channel, a first body port in fluid communication with the body chamber and configured for fluid communication with the patient connection, a second body port in fluid communication with the body chamber and configured for fluid communication with the ventilator, a passageway in fluid communication with the body chamber and with ambient air exterior of the valve body, and a valve seal movable between a closed position sealing the passageway and an open position opening the passageway. The valve seal has a seal chamber defined by first and second longitudinally spaced apart ends, and by an outer longitudinally extendable wall and an inner longitudinally extendable wall positioned within the outer wall. The aperture of the valve body is in fluid communication with the seal chamber to provide fluid communication with the pressure source. The first end of the seal chamber is longitudinally movable within the valve body between the closed position of the valve seal whereat the outer and inner walls are in a longitudinally extended configuration and the open position of the valve seal whereat the outer and inner walls are in a longitudinally retracted configuration. The valve seal is moved toward the closed position in response to pressure applied by the pressure source and toward the open position in response to pressure applied by the body chamber pressure, with the amount and direction of movement of the valve seal being responsive to a resultant force generated by the pressure source and the body chamber pressure.

Optionally, the inner wall has an inner wall fluid passageway extending therethrough in fluid communication with the body chamber and having a first end in fluid communication with the first body port and a second end in fluid communication with the second body port.

Optionally, the inner wall fluid passageway is in continuous fluid communication with the first and second body ports during operation of the exhalation valve, and out of fluid communication with the seal chamber between the inner and outer walls.

Optionally, the inner wall has an inner wall fluid passageway extending therethrough with a first opening in continuous fluid communication with the first body port and a second opening in continuous fluid communication with the second body port.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Figure 1 is a block diagram illustrating an exemplary system that includes a ventilator for use by a human patient.

Figure 2A is an illustration of a first embodiment of a passive patient circuit for use with the ventilator of Figure 1. Figure 2B is a cross-sectional view of a second embodiment of a passive patient circuit for use with the ventilator of Figure 1 .

Figure 2C is an enlarged cross-sectional view of a valve assembly of the passive patient circuit of Figure 2B illustrated in a closed configuration.

Figure 2D is an enlarged cross-sectional view of the valve assembly of the passive patient circuit of Figure 2B illustrated in an open configuration.

Figure 2E is an exploded view of a valve assembly of the passive patient circuit of Figure 2B.

Figure 2F is an illustration of an alternative embodiment of the first embodiment of the passive patient circuit shown in Figure 2A with the leak valve incorporated into the patient connection.

Figure 3A is a cross-sectional view of an embodiment of an active patient circuit for use with the ventilator of Figure 1 .

Figure 3B is an exploded view of a multi-lumen tube assembly of the active patient circuit of Figure 3A.

Figure 3C is an exploded view of an active exhalation valve assembly of the active patient circuit of Figure 3A.

Figure 3D is an enlarged perspective view of a double bellows member of the active exhalation valve assembly of Figure 3C.

Figure 3E is an enlarged cross-sectional view of the active patient circuit of Figure 3A illustrated with the double bellows member of the active exhalation valve assembly in a closed position.

Figure 3F is a first enlarged cross-sectional view of the active patient circuit of Figure 3A illustrated with the double bellows member of the active exhalation valve assembly in an open position.

Figure 3G is a second enlarged cross-sectional view of the active patient circuit of Figure 3A illustrated with the double bellows member of the active exhalation valve assembly in the open position.

Figure 4 is block diagram illustrating some exemplary components of the ventilator of Figure 1 .

Figure 5A is a schematic diagram illustrating some exemplary components of a ventilator assembly of the ventilator of Figure 1 with a cough assist valve of the ventilator assembly depicted in a first configuration. Figure 5B is a schematic diagram illustrating the cough assist valve of the ventilator assembly in a second configuration.

Figure 5C is an enlarged portion of the schematic diagram of Figure 5A showing the cough assist valve in the first configuration.

Figure 5D is an enlarged portion of the schematic diagram of Figure

5B showing the cough assist valve in the second configuration.

Figure 5E is block diagram illustrating exemplary components of a control system of the ventilator, control signals sent by the control system to exemplary components of the ventilation assembly, and the data signals received by the control system from exemplary components of the ventilation assembly.

Figure 6 is block diagram illustrating some exemplary components of a user interface of the ventilator of Figure 1 .

Figure 7 A is a schematic diagram illustrating some exemplary components of an oxygen assembly of the ventilator of Figure 1 .

Figure 7B is block diagram illustrating exemplary control signals sent by the control system to exemplary components of the oxygen assembly, and the data signals received by the control system from exemplary components of the oxygen assembly.

Figure 8A is a block diagram illustrating an adsorption bed of the oxygen assembly during a first phase of a vacuum pressure swing adsorption ("VPSA") process.

Figure 8B is a block diagram illustrating the adsorption bed of the oxygen assembly during a second phase of the VPSA process.

Figure 8C is a block diagram illustrating the adsorption bed of the oxygen assembly during a third phase of the VPSA process.

Figure 8D is a block diagram illustrating the adsorption bed of the oxygen assembly during a fourth phase of the VPSA process.

Figure 9 is an illustration of a metering valve of the oxygen assembly.

Figure 10A is a perspective view of a first side of a first rotary valve assembly of the oxygen assembly.

Figure 10B is a perspective view of a second side of the first rotary valve assembly. Figure 10C is a perspective view of the first side of the first rotary valve assembly including a shaft of a motor assembly and omitting other parts of the motor assembly.

Figure 10D is a perspective view of the second side of the first rotary valve assembly with its outer housing and printed circuit board removed.

Figure 10E is an exploded perspective view of one of four poppet valves of the first rotary valve assembly illustrated with an end cap and fasteners.

Figure 10F is a cross-sectional view of the first rotary valve assembly with its second and fourth poppet valves open.

Figure 10G is a cross-sectional view of the first rotary valve assembly with its first and third poppet valves open.

Figure 1 1 is a graph showing pressure and feed flow experienced by a bed of nitrogen adsorbent material of the oxygen generator during the four phases of the VPSA process.

Figure 12 is a flow diagram of a method performed by the control system of the ventilator of Figure 1 .

Figure 13A is an illustration of an optional second rotary valve assembly of the oxygen assembly depicted with a first one of its four poppet valves open.

Figure 13B is an illustration of the optional second rotary valve assembly of the oxygen assembly depicted with a second one of its four poppet valves open.

Figure 13C is an illustration of the optional second rotary valve assembly of the oxygen assembly depicted with a third one of its four poppet valves open.

Figure 13D is an illustration of the optional second rotary valve assembly of the oxygen assembly depicted with a fourth one of its four poppet valves open.

Figure 14A is a graph showing patient airway flow using a prior art ventilator during both inspiratory and expiratory phases.

Figure 14B is a graph showing patient airway pressure using the prior art ventilator during both the inspiratory and expiratory phases.

Figure 15A is a graph showing patient airway flow using the ventilator of Figure 1 during both inspiratory and expiratory phases. Figure 15B is a graph showing patient airway pressure using the ventilator of Figure 1 during both the inspiratory and expiratory phases.

Figure 16 is a block diagram illustrating an exemplary suction assembly for use with the ventilator of Figure 1 .

Figure 17A is a perspective view of a cough assist valve of the ventilator assembly showing an air intake side of the cough assist valve.

Figure 17B is a perspective view of the cough assist valve showing an exhaust outlet side of the cough assist valve.

Figure 18A is a cross-sectional view of the cough assist valve in a first configuration used during normal ventilation and an insufflation phase of a cough.

Figure 18B is a cross-sectional view of the cough assist valve in a second configuration used during an exsufflation phase of a cough.

Figure 19A is an exploded perspective view of an end cap assembly of the cough assist valve.

Figure 19B is an enlarged perspective view of a second side of a seat member of the end cap assembly of Figure 19A.

Figure 19C is an enlarged perspective view of a first side of a seat member of the end cap assembly of Figure 19A.

Figure 20 is a perspective view of a subassembly of the cough assist valve including a moving coil actuator, a shaft, and a pair of poppet valve assemblies.

Figure 21 is an exploded perspective view of one of the poppet valve assemblies of the cough assist valve.

Figure 22 is an exploded perspective view of a subassembly of the cough assist valve including the shaft, a guide member, and retaining rings.

Figure 23A is a perspective view of the air intake side of the cough assist valve omitting both its end cap assembly and poppet valve assembly.

Figure 23B is a perspective view of the exhaust outlet side of the cough assist valve omitting its end cap assembly.

Figure 24A is a perspective view of a first side of an intake body portion of a housing of the cough assist valve.

Figure 24B is a perspective view of a second side of the intake body portion of the housing of the cough assist valve. Figure 25 is a perspective view of an exhaust body portion of a housing of the cough assist valve.

Figure 26 is a pair of graphs with the top graph showing airway pressure during both insufflation and exsufflation phases of a cough assist maneuver performed using the ventilator, and the bottom graph showing airway flow rate during both the insufflation and exsufflation phases of the cough assist maneuver performed using the ventilator.

Figure 27 is a side view of a secretion trap.

Figure 28 is a side view of the secretion trap of Figure 27 connected to both a patient connection and a patient circuit connection.

Figure 29 is a side view of an embodiment of the secretion trap of Figure 28 including a drain.

Figure 30 is an exploded view of an alternate embodiment of a valve assembly for use in the passive patient circuit of Figure 2B.

Figure 31 A is an enlarged longitudinal cross-sectional view of the valve assembly of Figure 30 illustrated in a closed configuration.

Figure 31 B is an enlarged longitudinal cross-sectional view of the valve assembly of Figure 30 illustrated in an open configuration.

Figure 31 C is an enlarged longitudinal cross-sectional view of the valve assembly of Figure 31A rotated approximately 45° about its longitudinal axis from the position depicted in Figure 31 A.

Figure 32 is a perspective view of a first valve housing of the valve assembly of Figure 30.

Figure 33 is a perspective view of a second valve housing of the valve assembly of Figure 30.

Figure 34A is a longitudinal cross-sectional view of an alternate embodiment of a cough assist valve for use with the ventilator assembly of Figure 5A depicted in a first configuration used during normal ventilation and an insufflation phase of a cough.

Figure 34B is a longitudinal cross-sectional view of the cough assist valve of Figure 34A depicted in a second configuration used during an exsufflation phase of a cough.

Figure 35 is an exploded perspective view of an end cap assembly of the cough assist valve of Figure 34A. Figure 36 is a perspective view of a subassembly of the cough assist valve of Figure 34A including a movable magnet subassembly of an actuator, a shaft, and a pair of poppet valve assemblies.

Figure 37 is a perspective view of an intake body portion of a housing of the cough assist valve of Figure 34A.

Figure 38 is a perspective view of an exhaust body portion of a housing of the cough assist valve of Figure 34A.

Like reference numerals have been used in the figures to identify like components.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 is a block diagram illustrating an exemplary system 10 that includes a ventilator 100 with integrated cough assist functionality for use by a patient 102. The ventilator 100 may be configured to provide both traditional volume controlled ventilation and pressure controlled ventilation. The

ventilator 100 has an optional multi-lumen tube connection 103, a main ventilator connection 104, and a patient oxygen outlet 105. The patient 102 has a patient connection 106 (e.g., a tracheal tube, a nasal mask, a mouthpiece, and the like) that is connectable to the main ventilator connection 104 and/or the patient oxygen outlet 105 by a patient circuit 1 10.

As will be described below, the patient circuit 1 10 may be implemented as an active patient circuit or a passive patient circuit. Optionally, when the patient circuit 1 10 is implemented as an active patient circuit, the patient circuit 1 10 may include one or more ports 1 1 1 configured to be connected to the optional multi-lumen tube connection 103. The port(s) 1 1 1 allow one or more pressure signals 109 to flow between the optional multi-lumen tube

connection 103 and the patient circuit 1 10. As is apparent to those of ordinary skill in the art, a pressure signal may be characterized as gas(es) obtained from a fluid (and/or gas) source for which a pressure is to be measured. The gas(es) obtained are at the same pressure as the fluid (and/or gas) source.

The main ventilator connection 104 is configured to provide gases

1 12 that include room air 1 14 optionally mixed with oxygen. While identified as being "room air," those of ordinary skill in the art appreciate that the room air 1 14 may include air obtained from any source external to the ventilator 100. The gases 1 12 may be used as inspiratory gases (during the inspiratory phase of a breath) or insufflation gases used during the insufflation phase of a cough. The main ventilator connection 104 is configured to receive gases 1 13, which may include exsufflation gases exhaled by the patient 102 during an exsufflation phase of a cough.

The air 1 14 is received by the ventilator 100 via a patient air intake 1 16. The oxygen that is optionally mixed with the air 1 14 may be generated internally by the ventilator 100 and/or received from an optional low pressure oxygen source 1 18 (e.g., an oxygen concentrator), and/or an optional high pressure oxygen source 120. When the oxygen is generated internally, the ventilator 100 may output exhaust gases (e.g., nitrogen-rich gas 122) via an outlet vent 124. Optionally, the ventilator 100 may include a low pressure oxygen inlet 126 configured to be coupled to the optional low pressure oxygen source 1 18 and receive optional low pressure oxygen 128 therefrom. The ventilator 100 may include an optional high pressure oxygen inlet 130 configured to be coupled to the optional high pressure oxygen source 120 and receive optional high pressure oxygen 132 therefrom.

The patient oxygen outlet 105 is configured to provide doses or pulses of oxygen 140 to the patient connection 106 (via the patient circuit 1 10) that are synchronized with the patient's breathing. Unlike the gases 1 12 provided by the main ventilator connection 104, the pulses of oxygen 140 do not include the air 1 14.

The gases 1 12 and/or the pulses of oxygen 140 delivered to the patient circuit 1 10 are conducted thereby as inspiratory or insufflation gases 108 to the patient connection 106, which at least in part conducts those gases into the patient's lung(s) 142. Whenever the patient exhales during the exhalation phase of a breath or exsufflation phase of a cough, exhaled gases 107 enter the patient circuit 1 10 via the patient connection 106. Thus, the patient circuit 1 10 may contain one or more of the following gases: the gases 1 12 provided by the ventilator 100, the pulses of oxygen 140, and the exhaled gases 107. For ease of illustration, the gases inside the patient circuit 1 10 will be referred to hereafter as "patient gases."

Optionally, the ventilator 100 includes a suction connection 150 configured to be coupled to an optional suction assembly 152. The ventilator 100 may provide suction 154 to the optional suction assembly 152 via the optional suction connection 150. The suction assembly 152 may be configured to be connected to the patient connection 106, a suction catheter 812 (see Figure 16) positionable inside the patient connection 106, and/or a drain 1280 (see Figure 29).

Referring to Figure 1 , optionally, the ventilator 100 includes a nebulizer connection 160 configured to be coupled to an optional nebulizer assembly 162. The ventilator 100 may provide gases 164 (e.g., the air 1 14) to the optional nebulizer assembly 162 via the optional nebulizer connection 160. The optional nebulizer assembly 162 may be configured to be connected to the patient circuit 1 10. However, this is not a requirement.

Optionally, the ventilator 100 may include an outlet port 166 through which exhaust 167 may exit from the ventilator 100.

The ventilator 100 may be configured to be portable and powered by an internal battery (not shown) and/or an external power source (not shown) such as a conventional wall outlet.

PASSIVE PATIENT CIRCUITS

Figure 2A is an illustration of a first embodiment of a passive patient circuit 170 that may be used to implement the patient circuit 1 10. Referring to Figure 2A, the passive patient circuit 170 has a first end portion 172 opposite a second end portion 174. The first end portion 172 is configured to be connected or coupled (e.g., directly or using a hose, flow line, conduit, or tube) to the main ventilator connection 104. The second end portion 174 is configured to be connected or coupled to the patient connection 106 (e.g., directly or using a hose, flow line, conduit, or tube). Optionally, a secretion trap 1250 (described below with respect to Figures 27 - 29) may be positioned between the second end portion 174 and the patient connection 106. The passive patient circuit 170 conducts the gases 1 12 (that include the air 1 14 optionally mixed with oxygen) from the main ventilator connection 104 into the patient connection 106 (optionally via the secretion trap 1250 illustrated in Figures 27 - 29).

In the embodiment illustrated, the passive patient circuit 170 includes an optional bacterial filter 176, a leak valve 177, and a flexible tube segment 178. The optional bacterial filter 176 may be positioned between the first end portion 172 and the flexible tube segment 178. The gases 1 12 may flow through the optional bacterial filter 176 and on to the patient connection 106. When present, the bacterial filter 176 helps prevent bacteria (e.g., received from the patient connection 106) from entering the ventilator 100 (via the main ventilator connection 104).

The leak valve 177 is coupled to the flexible tube segment 178 near the second end portion 174. The leak valve 177 is configured to allow gases to flow out of the passive patient circuit 170 and into the environment outside the passive patient circuit 170. The leak valve 177 may be implemented as a conventional fixed leak valve configured to allow at most a threshold amount of pressure inside the passive patient circuit 170 during both the inspiratory and exhalation phases.

The leak valve 177 may be implemented as a positive pressure valve that allows a portion of the patient gases to flow out of the passive patient circuit 170 and into the environment outside the passive patient circuit 170 whenever the pressure inside the passive patient circuit 170 is above the threshold amount (e.g., environmental pressure). The leak valve 177 includes a flexible member or flap 179 that covers and seals an outlet opening 180 when the pressure inside the passive patient circuit 170 is below the threshold amount. Thus, the leak valve 177 is closed when the pressure inside the passive patient circuit 170 is below the threshold amount.

On the other hand, the flap 179 is configured to be pushed outwardly and away from the outlet opening 180 when the pressure inside the passive patient circuit 170 exceeds the threshold amount (e.g., environmental pressure). Thus, the leak valve 177 is open when the pressure inside the passive patient circuit 170 is above the threshold amount. During normal ventilation, the leak valve 177 is open during both the inspiratory and exhalation phases. This means a portion of the patient gases inside the passive patient circuit 170 flow out of the passive patient circuit 170 through the outlet opening 180 and into the

environment outside the passive patient circuit 170 during both the inspiratory and exhalation phases. On the other hand, as explained below, during an exsufflation phase of a cough, the leak valve 177 closes. This prevents the patient gases inside the passive patient circuit 170 from flowing out of the passive patient circuit 170 through the outlet opening 180. It also prevents air from entering the passive patient circuit 170 through the outlet opening 180. Figure 2F is an illustration of an alternative embodiment of the first embodiment of the passive patient circuit 170 shown in Figure 2A with the leak valve 177 incorporated into the patient connection 106 and to which the second end portion 174 of the flexible tube segment 178 is connected or coupled.

Alternatively, the leak valve 177 may be constructed as a separate part connected or coupled both to the second end portion 174 of the flexible tube segment 178 and to the patient connection 106.

Figure 2B is an illustration of a second embodiment of a passive patient circuit 440 that may be used to implement the patient circuit 1 10. The passive patient circuit 440 includes a connector 442, a flexible tube segment 444, an open-ended oxygen pulse delivery tube 446, and a valve assembly 448. The flexible tube segment 444 may be implemented using a conventional corrugated or expanding ventilation hose or tubing (e.g., circuit tubing). The flexible tube segment 444 has a first end portion 450 opposite a second end portion 451 . The first end portion 450 is configured to be connected or coupled to the

connector 442. The second end portion 451 is configured to be connected or coupled to the valve assembly 448.

The connector 442 has a generally tube-shaped connector housing 452 with a first end portion 454 configured to be connected to the main ventilator connection 104 (e.g., directly or using a hose, flow line, conduit, or tube) and to receive the gases 1 12 (that include the air 1 14 optionally mixed with oxygen) from the main ventilator connection 104. Optionally, the bacterial filter 176 (see Figure 2A) may be positioned between the connector 442 and the main ventilator connection 104. In such embodiments, the gases 1 12 flow through the bacterial filter 176 on their way to the connector 442. The bacterial filter 176 helps prevent bacteria (e.g., received from the patient connection 106) from entering the ventilator 100 (via the main ventilator connection 104).

The connector housing 452 has a second end portion 456 configured to be coupled to the first end portion 450 of the flexible tube

segment 444 and to provide the gases 1 12 received by the first end portion 454 to the flexible tube segment 444. The flexible tube segment 444 conducts the gases

1 12 to the valve assembly 448.

The connector 442 includes a hollow tube section 458 that extends outwardly from the connector housing 452. In the embodiment illustrated, the tube section 458 is substantially transverse to the connector housing 452.

However, this is not a requirement. The tube section 458 has an open free end portion 459 configured to be connected to the patient oxygen outlet 105 (e.g., directly or using a hose, flow line, conduit, or tube) and to receive the pulses of oxygen 140 therefrom. Inside the connector housing 452, the tube section 458 is connected to the oxygen pulse delivery tube 446 and provides the pulses of oxygen 140 thereto. In the embodiment illustrated, the tube section 458 is connected to or includes a branch tube 460 that extends longitudinally inside the connector housing 452. The branch tube 460 has an open free end 462 configured to be coupled to the oxygen pulse delivery tube 446 and provide the pulses of oxygen 140 thereto. While the tube section 458 extends into the connector housing 452, the tube section 458 only partially obstructs the flow of the gases 1 12 through the connector housing 452. In other words, the gases 1 12 pass by or alongside the tube section 458 and the branch tube 460, if present.

In the embodiment illustrated, the oxygen pulse delivery tube 446 extends through the flexible tube segment 444 and at least part way into the valve assembly 448. Thus, the oxygen pulse delivery tube 446 isolates the pulses of oxygen 140 from the gases in the flexible tube segment 444 along a majority portion of the passive patient circuit 440. The oxygen pulse delivery tube 446 has a first end portion 464 configured to be coupled to the branch tube 460. The oxygen pulse delivery tube 446 has a second end portion 465 that terminates at or near the patient connection 106. By way of a non-limiting example, the second end portion 465 may terminate within about two centimeters of the patient connection 106. The oxygen pulse delivery tube 446 conducts the pulses of oxygen 140 from the branch tube 460 to the patient connection 106. At the same time, the passive patient circuit 440 conducts the gases 1 12 (that include the air 1 14 optionally mixed with oxygen) from the main ventilator connection 104 into the patient connection 106.

In alternate embodiments, the oxygen pulse delivery tube 446 may be connected to the patient oxygen outlet 105 (e.g., directly or using a hose, flow line, conduit, or tube) to receive the pulses of oxygen 140 from the patient oxygen outlet 105. In such embodiments, the oxygen pulse delivery tube 446 may extend along the outside of the flexible tube segment 444. The second end portion 465 of the oxygen pulse delivery tube 446 may be connected to a portion of the passive patient circuit 440 at or near the patient connection 106 to provide the pulses of oxygen 140 from the branch tube 460 to the patient connection 106.

Figures 2C-2E illustrate exemplary components of the valve assembly 448. In the embodiment illustrated, the valve assembly 448 includes a first valve housing 468, a second valve housing 469, and a flexible ring-shaped leaf 470.

The first valve housing 468 is configured to be coupled to the patient connection 106 (see Figure 2A). Optionally, the secretion trap 1250 (see Figures 27 and 28) may be coupled between the first valve housing 468 and the patient connection 106. The second valve housing 469 is configured to be coupled to the second end portion 451 of the flexible tube segment 444. The first and second valve housings 468 and 469 are configured to be coupled together with the ring- shaped leaf 470 positioned therebetween. A peripheral portion 473 of the leaf 470 is positioned within a ring-shaped chamber 474 defined by the first and second valve housings 468 and 469. One or more openings 476 are formed in the second valve housing 469 and connect the chamber 474 with the environment outside the passive patient circuit 440 (see Figure 2B). Additionally, one or more openings 478 are formed in the second valve housing 469 and connect the patient gases inside the passive patient circuit 440 (see Figure 2B) with the chamber 474.

Like the flap 179 (see Figure 2A), the peripheral portion 473 of the leaf 470 is configured to transition or deflect from a closed position (see Figure 2C) and an open position (see Figure 2D) when the pressure inside the passive patient circuit 440 (see Figure 2B) exceeds the threshold amount (e.g.,

environmental pressure). When the peripheral portion 473 of the leaf 470 is in the closed position depicted in Figure 2C, the leaf 470 blocks off the one or more openings 478 and isolates the chamber 474 from the environment inside the passive patient circuit 440 (see Figure 2B). On the other hand, when the peripheral portion 473 of the leaf 470 is in the open position depicted in Figure 2D, the leaf 470 no longer blocks off the one or more openings 478 and allows the chamber 474 to communicate with the patient gases inside and outside the passive patient circuit 440 (see Figure 2B). Thus, gases may exit the interior of the passive patient circuit 440 (see Figure 2B) through the opening(s) 478, the chamber 474, and the opening(s) 476. During the inspiratory phase, the ventilator 100 adjusts the pressure inside the passive patient circuit 440 to achieve a preset inspiratory pressure, which places or maintains the peripheral portion 473 of the leaf 470 in the open position with the peripheral portion 473 of the leaf leaving the openings 478 unblocked. Some of the patient gases flow to the patient 102 (see Figure 1 ), and some of the patient gases flow out through the openings 476.

During the exhalation phase, the ventilator 100 adjusts the pressure inside the passive patient circuit 440 to achieve a baseline or positive end- expiratory pressure ("PEEP"), which places or maintains the peripheral portion 473 of the leaf 470 in the open position. Some of the exhaled gases 107 (see Figure 1 ) from the patient 102 flow out through the openings 476, and some of the exhaled gases 107 flow into the passive patient circuit 440 (e.g., into the flexible tube segment 444).

The breath may pause between the end of the exhalation phase and the beginning of the inspiratory phase. This pause may be characterized as a dead time that occurs between the phases. During a pause, the ventilator 100 adjusts the pressure inside the passive patient circuit 440 to PEEP, which places or maintains the peripheral portion 473 of the leaf 470 in the open position, and causes the flow of the gases 1 12 from the ventilator 100 to flow out of the passive patient circuit 440 through the openings 476. Also, during this time, at least a portion of the exhaled gases 107 that flowed into the passive patient circuit 440 during the exhalation phase is "purged" out through the openings 476 by the forward moving flow of the gases 1 12 from the ventilator 100.

As explained below, during an exsufflation phase of a cough, the pressure inside the passive patient circuit 440 (see Figure 2B) is less than the threshold amount (e.g., environmental pressure). This places the peripheral portion 473 of the leaf 470 in the closed position with the peripheral portion 473 of the leaf blocking the openings 478, which prevents the patient gases inside the passive patient circuit 440 from flowing out of the passive patient circuit 440 through the opening(s) 476. It also prevents air from entering the passive patient circuit 440 through the opening(s) 476.

The combined areas of the openings 476 may be characterized as providing a fixed orifice. Thus, the valve assembly 448 may be characterized as being a one-way valve with a fixed orifice. If the combined areas of the openings 476 is too large, most of the inspiratory flow will leak out through the openings 476, leaving little for the patient 102. Conversely, if the combined areas of the openings 476 is too small, the exhaled gases 107 will not be fully purged from the passive patient circuit 440 during the exhalation phase and the pause between the inspiratory and exhalation phases. By way of a non-limiting example, the valve assembly 448 may be configured to leak about 20-50 liters per minute ("LPM") when the pressure inside the passive patient circuit 440 is about 10 centimeters of water ("cmH20").

Figure 30 is an exploded view of an alternate embodiment of a valve assembly 1448 that may be used in the passive patient circuit 440 (see Figure 2B) instead of the valve assembly 448. In such embodiments, the flexible tube segment 444 (see Figure 2B) conducts the gases 1 12 (see Figure 2B) to the valve assembly 1448 and the oxygen pulse delivery tube 446 may extend through the flexible tube segment 444 (see Figure 2B) and at least part way into the valve assembly 1448.

In the embodiment illustrated, the valve assembly 1448 includes a first valve housing 1468, a second valve housing 1469, and a flexible ring-shaped leaf 1470. As shown in Figures 31A-31 C, the first and second valve housings 1468 and 1469 are configured to be coupled together with the ring-shaped leaf 1470 positioned therebetween.

Referring to Figure 32, in the embodiment illustrated, the first valve housing 1468 has a first end portion 1480 opposite a second end portion 1482. An open ended through channel 1484 extends through the first valve housing 1468 between its first and second end portions 1480 and 1482. The first end portion 1480 is configured to be coupled to the patient connection 106 (see Figure 2B). Optionally, the secretion trap 1250 (see Figures 27-29) may be coupled between the first end portion 1480 of the first valve housing 1468 and the patient connection 106 (see Figure 2B).

The second end portion 1482 is configured to be coupled to the second valve housing 1469 (see Figures 30-31 C and 33). The second end portion 1482 includes a ring-shaped longitudinally extending inner wall 1486 positioned alongside the channel 1484 and defining a portion thereof. The second end portion 1482 includes a first wall portion 1488 that extends radially outwardly from the inner wall 1486 and terminates at a ring-shaped longitudinally extending outer wall 1489. The outer wall 1489 is concentric with and spaced apart from the inner wall 1486 by the first wall portion 1488. A distal edge portion 1487 of the inner wall 1486 is configured to abut the leaf 1470 (see Figures 30- 31 C) and press the leaf 1470 against the second valve housing 1469 (see Figures 30-31 C and 33) to form an annular seal between the first and second valve housings 1468 and 1469 along the distal edge portion 1487 of the ring-shaped inner wall 1486. Near the location whereat the outer wall 1489 terminates the first wall portion 1488, the outer wall 1489 has a ring-shaped groove 1490 formed along its inner surface that opens toward the inner wall 1486. The outer wall 1489 has a longitudinally extending notch or keyway 1491 formed therein.

Referring to Figure 33, in the embodiment illustrated, the second valve housing 1469 has a first end portion 1420 opposite a second end

portion1422. An open ended through channel 1424 extends through the second valve housing 1469 between its first and second end portions 1420 and 1422. The second end portion 1422 of the second valve housing 1469 is configured to be coupled to the second end portion 451 (see Figure 2B) of the flexible tube segment 444 (see Figure 2B).

The first end portion 1420 is configured to be coupled to the first valve housing 1468 (see Figures 30-32). The first end portion 1420 of the second valve housing 1469 includes a radially outwardly extending second wall portion 1428 having a distal portion 1429. A plurality of tabs 1430A-1430D are positioned along the distal portion 1429 of the second wall portion 1428. The tabs 1430A- 1430D are configured to be received inside the ring-shaped groove 1490 (see Figure 32) formed in the outer wall 1489 (see Figure 32) of the first valve housing 1468 (see Figures 30-32). Engagement between the tabs 1430A-1430D and the groove 1490 couples the first and second valve housings 1468 and 1469 together. The tab 1430D includes a key member 1432 configured to be received inside the keyway 1491 (see Figure 32) formed in the outer wall 1489 (see Figure 32) of the first valve housing 1468 (see Figures 30-32). When the first and second valve housings 1468 and 1469 are coupled together, the key member 1432 is received inside the keyway 1491 to prevent rotation of the first valve housing 1468 relative to the second valve housing 1469.

The second valve housing 1469 includes a plurality of leaf

positioning projections 1434A-1434D configured to be received inside a central through-hole 1436 (see Figure 30) formed in the leaf 1470 (see Figures 30-31 B). Referring to Figure 31 C, the leaf positioning projections 1434A-1434D help position the leaf 1470 with respect to the first and second valve housings 1468 and 1469. When the first and second valve housings 1468 and 1469 are coupled together, the leaf positioning projections 1434A-1434D extend into the channel 1484 (see Figure 32) alongside the inner wall 1486 (see Figure 32).

Referring to Figures 31A-31 C, a peripheral portion 1473 of the leaf 1470 is positioned within a ring-shaped chamber 1474 defined by the first and second valve housings 1468 and 1469. Referring to Figures 31 A and 31 B, in the embodiment illustrated, the chamber 1474 is defined by the inner wall 1486, the first wall portion 1488, the outer wall 1489, and the second wall portion 1428.

One or more openings 1476 are defined between the first and second valve housings 1468 and 1469. In the embodiment illustrated, the second wall portion 1428 extends only partway toward the outer wall 1489 of the first valve housing 1468. However, as shown in Figure 31 C, the tabs 1430A-1430D (see Figure 33), which are mounted on the distal portion 1429 (see Figure 33) of the second wall portion 1428, contact the outer wall 1489 of the first valve housing 1468. Thus, referring to Figures 31 A and 31 B, the openings 1476 are defined between the distal portion 1429 (see Figure 33) of the second wall portion 1428 and the outer wall 1489 of the first valve housing 1468 and positioned between the tabs 1430A-1430D (see Figure 33).

The one or more openings 1476 connect the chamber 1474 with the environment outside the passive patient circuit 440 (see Figure 2B). Additionally, one or more openings 1478 are formed in the second valve housing 1469 and connect the patient gases inside the passive patient circuit 440 (see Figure 2B) with the chamber 1474. Referring to Figure 33, the one or more openings 1478 are positioned between the distal portion 1429 of the second wall portion 1428 and the leaf positioning projections 1434A-1434D.

Referring to Figures 31A-31 C, the flexible ring-shaped leaf 1470 is substantially similar to the flexible ring-shaped leaf 470 (see Figures 2C-2E). The peripheral portion 1473 of the leaf 1470 is configured to transition or deflect from a closed position (see Figures 31 A and 31 C) and an open position (see Figure 31 B) when the pressure inside the passive patient circuit 440 (see Figure 2B) exceeds the threshold amount (e.g., environmental pressure). When the peripheral portion 1473 of the leaf 1470 is in the closed position depicted in Figures 31A and 31 C, the leaf 1470 blocks off the one or more openings 1478 into the chamber 1474 thereby isolating the chamber 1474 from the environment inside the passive patient circuit 440 (see Figure 2B). On the other hand, when the peripheral portion 1473 of the leaf 1470 is in the open position depicted in Figure 31 B, the leaf 1470 no longer blocks off the one or more openings 1478 and allows the chamber 1474 to communicate with the patient gases inside the passive patient circuit 440 (see Figure 2B). Thus, gases may exit the interior of the passive patient circuit 440 (see Figure 2B) through the opening(s) 1478, the chamber 1474, and the opening(s) 1476.

As mentioned above, during the inspiratory phase, the ventilator 100 adjusts the pressure inside the passive patient circuit 440 to achieve a preset inspiratory pressure, which places or maintains the peripheral portion 1473 of the leaf 1470 in the open position (see Figure 31 B). Some of the patient gases flow to the patient 102 (see Figure 1 ), and some of the patient gases flow out through the openings 1476.

During the exhalation phase, the ventilator 100 adjusts the pressure inside the passive patient circuit 440 to achieve a baseline or positive end- expiratory pressure ("PEEP"), which places or maintains the peripheral portion 1473 of the leaf 1470 in the open position (see Figure 31 B). Some of the exhaled gases 107 (see Figure 1 ) from the patient 102 flow out through the openings 1476, and some of the exhaled gases 107 flow into the passive patient circuit 440 (e.g., into the flexible tube segment 444).

During a pause between the end of the exhalation phase and the beginning of the inspiratory phase, the ventilator 100 adjusts the pressure inside the passive patient circuit 440 to PEEP, which places or maintains the peripheral portion 1473 of the leaf 1470 in the open position (see Figure 31 B), and causes the flow of the gases 1 12 from the ventilator 100 to flow out of the passive patient circuit 440 through the openings 1476. Also, during this time, at least a portion of the exhaled gases 107 that flowed into the passive patient circuit 440 during the exhalation phase is "purged" out through the openings 1476 by the forward moving flow of the gases 1 12 from the ventilator 100.

The combined areas of the openings 1476 may be characterized as providing a fixed orifice. Thus, the valve assembly 1448 may be characterized as being a one-way valve with a fixed orifice. If the combined areas of the openings 1476 is too large, most of the inspiratory flow will leak out through the openings 1476, leaving little for the patient 102. Conversely, if the combined areas of the openings 1476 is too small, the exhaled gases 107 will not be fully purged from the passive patient circuit 440 during the exhalation phase and the pause between the inspiratory and exhalation phases. By way of a non-limiting example, the valve assembly 1448 may be configured to leak about 20-50 LPM when the pressure inside the passive patient circuit 440 is about 10 cmH20.

As explained below, during an exsufflation phase of a cough, the pressure inside the passive patient circuit 440 (see Figure 2B) is less than the threshold amount (e.g., environmental pressure). When the passive patient circuit 440 (see Figure 2B) includes the valve assembly 1448 (instead of the valve assembly 448), the peripheral portion 1473 of the leaf 1470 is placed in the closed position (see Figures 31 A and 31 C) when the pressure inside the passive patient circuit 440 (see Figure 2B) is less than the threshold amount, which prevents the patient gases inside the passive patient circuit 440 from flowing out of the passive patient circuit 440 through the opening(s) 1476. It also prevents air from entering the passive patient circuit 440 through the opening(s) 1476.

It should be noted that the passive valve assemblies described herein may be integrated into the patient connection 106, such as into a patient mask serving as the patient connection, rather than being part of the passive patient circuit 170 or the passive patient circuit 440. As stated above and as shown in FIG. 1 , the patient 102 has a patient connection 106 which may be a tracheal tube, a nasal mask, a mouthpiece or the like, that is connectable to the main ventilator connection 104 and/or the patient oxygen outlet 105 by a patient circuit 1 10.

ACTIVE PATIENT CIRCUIT

Figure 3A depicts an active patient circuit 600 that may be used to implement the patient circuit 1 10 (see Figure 1 ). Referring to Figure 3A, the active patient circuit 600 includes the connector 442, the flexible tube segment 444, the oxygen pulse delivery tube 446, a multi-lumen tube assembly 602, and an active exhalation valve assembly 604.

Like in the passive patient circuit 440 (see Figure 2B), the connector 442 is coupled to both the first end portion 450 of the flexible tube segment 444 and the oxygen pulse delivery tube 446. The connector 442 receives the gases 1 12 and provides them to the flexible tube segment 444.

Further, the connector 442 receives the pulses of oxygen 140 and provides them to the oxygen pulse delivery tube 446. The pulses of oxygen 140 exit the oxygen pulse delivery tube 446 at or near the patient connection 106. By way of a non- limiting example, the pulses of oxygen 140 may exit the oxygen pulse delivery tube 446 within about 10 centimeters of the patient connection 106. In the embodiment illustrated, the pulses of oxygen 140 exit the oxygen pulse delivery tube 446 at or near the active exhalation valve assembly 604.

Optionally, the bacterial filter 176 (see Figure 2A) may be positioned between the connector 442 and the main ventilator connection 104. In such embodiments, the gases 1 12 flow through the bacterial filter 176 on their way to the connector 442. When present, the bacterial filter 176 helps prevent bacteria (e.g., received from the patient connection 106) from entering the ventilator 100 (via the main ventilator connection 104).

The second end portion 451 of the flexible tube segment 444 is configured to be coupled to the active exhalation valve assembly 604. As mentioned above with respect to Figure 1 , the patient circuit 1 10 may include one or more ports 1 1 1 configured to allow the one or more pressure signals 109 to flow between the optional multi-lumen tube connection 103 and the patient circuit 1 10. Referring to Figure 3C, in the embodiment illustrated, the ports 1 1 1 (see Figure 1 ) include ports 1 1 1 A-1 1 1 C spaced apart from one another longitudinally. The ports 1 1 1 A-1 1 1 C are each formed in the active exhalation valve

assembly 604. The port 1 1 1 C is referred to hereafter as the pilot port 1 1 1 C.

Figure 3B is exploded perspective view of the multi-lumen tube assembly 602. Referring to Figure 3B, the multi-lumen tube assembly 602 includes a coupler 608, an elongated tube segment 610, and a connector member 612. The coupler 608 is configured to couple a first end portion 620 of the tube segment 610 to the optional multi-lumen tube connection 103 (see Figure 3A). The tube segment 610 has a second end portion 622 opposite the first end portion 620. The second end portion 622 is connected to the connector member 612. Three separate and continuous open-ended channels 626A-626C extend longitudinally through the tube segment 610. The connector member 612 has three connectors 630A-630C configured to connected to the ports 1 1 1 A-1 1 1 C (see Figure 3C), respectively. The connectors 630A and 630B receive pressure signals 109A and 109B (see Figure 5A), respectively, from the ports 1 1 1 A and 1 1 1 B, respectively. The connector 630C conducts a pressure signal 109C (see Figure 5A) to and from the pilot port 1 1 1 C.

Continuous channels 632A-632C extend from the connectors 630A- 630C, respectively, to an end portion 634 of the connector member 612. When the connector member 612 is connected to the tube segment 610, the continuous channels 626A-626C of the tube segment 610 are aligned and communicate with the continuous channels 632A-632C, respectively. Thus, the multi-lumen tube assembly 602 may be used to conduct the separate pressure signals 109A and 109B, respectively, from the ports 1 1 1A and 1 1 1 B, respectively, to the optional multi-lumen tube connection 103. Further, the multi-lumen tube assembly 602 may be used to conduct the pressure signal 109C to the pilot port 1 1 1 C from the optional multi-lumen tube connection 103 and vice versa.

Referring to Figure 3C, the active exhalation valve assembly 604 includes a first valve housing member 640, a double bellows member 644, and a second valve housing member 642. The ports 1 1 1 A and 1 1 1 B are formed in the first valve housing member 640 and extend laterally outwardly therefrom. The pilot port 1 1 1 C is formed in the second valve housing member 642 and extends laterally outwardly therefrom.

Figure 3E and 3F are enlarged longitudinal cross sectional views that each show a portion of the active patient circuit 600 that includes the active exhalation valve assembly 604. The oxygen pulse delivery tube 446 has been omitted from Figure 3E and 3F. In the embodiment illustrated, the first valve housing member 640 includes an internal obstruction 646 positioned between the ports 1 1 1 A and 1 1 1 B and configured to partially restrict flow through the first valve housing member 640. Further, as shown in Figures 3E and 3F, the interior of the first valve housing member 640 includes a first narrowed portion 647A that is adjacent to the obstruction 646 and the port 1 1 1 A, and a second narrowed portion

647B that is adjacent to the obstruction 646 and the port 1 1 1 B. Thus, the first and second narrowed portions 647A and 647B are positioned opposite one another longitudinally with respect to the obstruction 646 with the first narrowed portion 647A being nearer to the patient connection 106 (see Figure 3A) than the second narrowed portion 647B. The ports 1 1 1 A and 1 1 1 B open into the first and second narrowed portions 647A and 647B, respectively.

Referring to Figure 3G, together the obstruction 646, the first and second narrowed portions 647A and 647B, and the ports 1 1 1 A and 1 1 1 B define an airway flow transducer 648 (e.g., a fixed orifice differential pressure type flow meter) inside the interior of the first valve housing member 640. During the inspiration phase, the gases 1 12 may flow around the obstruction 646 along flow paths identified by curved arrows 649A and 649B. During the exhalation phase, the exhaled gases 107 may flow around the obstruction 646 along flow paths opposite those identified by the curved arrows 649A and 649B.

Referring to Figure 3C, the first valve housing member 640 has a first end portion 650 configured to be coupled to the patient connection 106 (see Figure 3A). Optionally, the secretion trap 1250 (see Figures 27 and 28) may be coupled between the first end portion 650 and the patient connection 106. The first valve housing member 640 has a second end portion 652 configured to be coupled to the second valve housing member 642. The second valve housing member 642 has a first end portion 654 configured to be coupled to the second end portion 652 of the first valve housing member 640, and a second end portion 656 configured to be coupled to the second end portion 451 of the flexible tube segment 444. The first end portion 654 of the second valve housing member 642 has a generally cylindrical shaped bellows connector portion 657. An opening 658 of the pilot port 1 1 1 C is formed in the bellows connector portion 657 of the second valve housing member 642.

Referring to Figure 3D, the double bellows member 644 has a generally ring-like outer shape with a centrally located through-channel 660. The double bellows member 644 has a hollow interior 662 with a ring-shaped open end 664 opposite a ring-shaped closed end 666 (see Figure 3C). In the

embodiment illustrated, the double bellows member 644 has concertinaed inner and outer sidewalis 668 and 669. The inner sidewall 668 extends between the open end 664 and the closed end 666 along the centrally located through-channel 660. The outer sidewall 669 extends between the open end 664 and the closed end 666 and is spaced radially outwardly from the inner sidewall 668. The hollow interior 662 is defined between the inner and outer sidewalis 668 and 669. Each of the inner and outer sidewalls 688 and 669 have bellows portions 668A and 669A (see Figure 3C), respectively, which each have an undulating longitudinal cross-sectional shape (also referred to as a corrugated or convoluted tubular shape). In alternate embodiments, the inner and outer sidewalls 668 and 669 may include different numbers of convolutions that define a single convolute or more than two convolutes.

The open end 664 is configured to fit over the bellows connector portion 657 of the second valve housing member 642 like a sleeve. When the bellows connector portion 657 of the second valve housing member 642 is received inside the open end 664 of the double bellows member 644, the bellows portions 668A and 669A (see Figure 3C) of the inner and outer sidewalls 668 and 669, respectively, are positioned adjacent to the bellows connector portion 657 of the second valve housing member 642. Thus, the opening 658 of the pilot port 1 1 1 C is in communication with a portion of the hollow interior 662 positioned between the bellows portions 668A and 669A (see Figure 3C) of the inner and outer sidewalls 668 and 669, respectively.

Referring to Figure 3C, when the bellows connector portion 657 of the second valve housing member 642 is received inside the open end 664 of the double bellows member 644, the opening 658 of the pilot port 1 1 1 C may provide the pressure signal 109C to the interior of the double bellows member 644.

Referring to Figures 3E and 3F, as mentioned above, the second end portion 652 of the first valve housing member 640 is configured to be coupled to the first end portion 654 of the second valve housing member 642. When so coupled together, a ring-shaped chamber 670 is defined between the second end portion 652 of the first valve housing member 640 and the first end portion 654 of the second valve housing member 642. One or more openings 672 (see Figure 3C) are formed in the first valve housing member 640 and connect the chamber 670 with the environment outside the active patient circuit 600 (see Figure 3A). The bellows portion 668A and 669A (see Figure 3C) of the outer sidewall 669 and a peripheral portion 674 of the closed end 666 is positioned within the chamber 670.

The double bellows member 644 is constructed from a flexible material (e.g., silicone rubber and the like). The bellows portions 668A and 669A (see Figure 3C) of the inner and outer sidewalls 668 and 669, respectively, are configured to compress to transition the closed end 666 from a closed position (see Figure 3E) to an open position (see Figure 3F). When the bellows portions 668A and 669A (see Figure 3C) are not compressed, the closed end 666 is in the closed position depicted in Figure 3E. In this configuration, the closed end 666 of the double bellows member 644 abuts a ring-shaped seat 680 formed in the first valve housing member 640 and defining a portion of the chamber 670. This seals the chamber 670 from the interior of the active patient circuit 600. On the other hand, when the bellows portions 668A and 669A (see Figure 3C) are compressed toward the second valve housing member 642, the closed end 666 is in the open position depicted in Figure 3F. In this configuration, the closed end 666 is spaced away from the seat 680. This opens the chamber 670 by connecting the chamber 670 with the inside of the active patient circuit 600. Thus, when the closed end 666 of the double bellows member 644 is in the open position, patient gases inside the active patient circuit 600 may exit therefrom through the chamber 670 and the opening(s) 672 (see Figure 3C).

The closed end 666 of the double bellows member 644 is selectively moved between the open and closed positions by controlling the pressure inside the double bellows member 644 using the pilot port 1 1 1 C. For example, the closed end 666 of the double bellows member 644 may be placed in the closed position (see Figure 3E) during the inspiratory phase, and in the open position during the expiratory phase. In such embodiments, at the start of the inspiratory phase, the pilot port 1 1 1 C provides a flow of gases (as the pressure signal 109C) having the same pressure as the gases 1 12 (provided to the active patient circuit 600) to the hollow interior 662 of the double bellows member 644. An area of the double bellows member 644 exposed to a pressure provided by the patient 102 (see Figure 1 ) via the patient connection 106 is less than an area exposed to the pressure of the pressure signal 109C, so that even if the two pressures are equal, the closed end 666 of the double bellows member 644 will move to or remain in the closed position against the seat 680. At the end of the inspiratory phase, the pilot port 1 1 1 C provides a flow of gases (as the pressure signal 109C) having a pilot pressure to the hollow interior 662 of the double bellows

member 644. The pilot pressure is less than the pressure provided by the patient

102 (see Figure 1 ) via the patient connection 106 and causes the closed end 666 of the double bellows member 644 to move to or remain in the open position (see Figure 3F) spaced apart from the seat 680. Thus, during normal ventilation, the pressure inside the hollow interior 662 of the double bellows member 644 may be alternated between a closed pressure that is the same pressure as the gases 1 12 (provided to the active patient circuit 600), and an open pressure that is equal to the pilot pressure. If desired, the pressure inside the hollow interior 662 of the double bellows member 644 may be adjusted by allowing the flow of gases (in the pressure signal 109C) to flow from the hollow interior 662 to the pilot port 1 1 1 C.

As explained below, during an exsufflation phase of a cough, the closed end 666 of the double bellows member 644 may be placed in the closed position (see Figure 3E). This prevents exsufflation gases (exhaled by the patient 102) into the active patient circuit 600 from exiting the active patient circuit 600 through the opening(s) 672 (see Figure 3C). It also prevents air from entering the active patient circuit 600 through the opening(s) 672 (see Figure 3C). It is noted that during the beginning of the exsufflation phase, when the pressure is still positive, the double bellows member 644 is in the open position and automatically closes when the pressure provided by the patient 102 drops below ambient.

VENTILATOR

Figure 4 is a block diagram illustrating some exemplary components of the ventilator 100. Referring to Figure 4, in addition to the components discussed with respect to Figure 1 , the ventilator 100 includes a ventilation assembly 190, a user interface 200, an oxygen assembly 210, a control system 220, and conventional monitoring and alarm systems 221 . Because those of ordinary skill in the art are familiar with conventional monitoring and alarm systems 221 , they will not be described in detail herein.

The control system 220 receives input information 196 (e.g., settings, parameter values, and the like) from the user interface 200, and provides output information 198 (e.g., performance information, status information, and the like) to the user interface 200. The user interface 200 is configured to receive input from a user (e.g., a caregiver, a clinician, and the like associated with the patient 102 depicted in Figure 1 ) and provide that input to the control system 220 in the input information 196. The user interface 200 is also configured to display the output information 198 to the user.

As mentioned above, referring to Figure 1 , the patient circuit 1 10 may include the optional port(s) 1 1 1 configured to allow one or more pressure signals 109 to flow between the optional multi-lumen tube connection 103 and the patient circuit 1 10. Referring to Figure 3, the optional multi-lumen tube connection 103 is configured to provide the pressure signal(s) 109 to the ventilation

assembly 190.

As will be explained below, the ventilation assembly 190 may receive one or more control signals 192 from the control system 220, and the ventilation assembly 190 may provide one or more data signals 194 to the control system 220. Similarly, the oxygen assembly 210 may receive one or more control signals 260 from the control system 220, and the oxygen assembly 210 may provide one or more data signals 262 to the control system 220. The control signals 192 and 260 and the data signals 194 and 262 may be used by the control system 220 to monitor and/or control internal operations of the ventilator 100.

VENTILATION ASSEMBLY

Figures 5A and 5B are schematic diagrams illustrating some exemplary components of the ventilation assembly 190. Figure 5E is a block diagram illustrating exemplary components of the control system 220, the control signal(s) 192 sent by the control system 220 to exemplary components of the ventilation assembly 190, and the data signals 194 received by the control system 220 from exemplary components of the ventilation assembly 190.

Referring to Figures 5A and 5B, the ventilation assembly 190 includes a cough assist valve 204, an accumulator 202, an internal flow

transducer 212, a blower 222, an airway pressure transducer 224, an airway flow transducer module 225, an exhalation control assembly 226, an oxygen

sensor 227, an ambient pressure transducer 228, an inlet silencer 229, and an internal bacteria filter 230.

The cough assist valve 204 is connected to the accumulator 202 by a conduit or flow line 214. For ease of illustration, a portion of the flow line 214 between the accumulator 202 and the internal flow transducer 212 has been omitted from Figures 5A and 5B.

The cough assist valve 204 is connected to the outlet port 166 by a conduit or flow line 215. For ease of illustration, a portion of the flow line 215 between the cough assist valve 204 and the outlet port 166 has been omitted from Figures 5A and 5B. The cough assist valve 204 is connected to the main ventilator connection 104 by a conduit or flow line 273. For ease of illustration, a portion of the flow line 273 between the cough assist valve 204 and the internal bacteria filter 230 has been omitted from Figures 5A and 5B.

Figure 5A depicts the cough assist valve 204 in a first configuration and Figure 5B depicts the cough assist valve 204 in a second configuration.

Referring to Figure 5A, in the first configuration, the cough assist valve 204 receives a gas 252 from the accumulator 202 (via the flow line 214), and outputs the gas 252 to the main ventilator connection 104 (via the flow line 273). During normal breathing and ventilation, the cough assist valve 204 remains in the first configuration. When cough assist functionality (described below) is used to perform a cough assist maneuver, the cough assist valve 204 is in the first configuration during the insufflation phase of a cough and the cough assist valve 204 is in the second configuration during the exsufflation phase of the cough. Referring to Figure 5B, in the second configuration, the cough assist valve 204 receives exsufflation gases 253 via the flow line 273, and outputs the exsufflation gases 253 (as the exhaust 167) to the outlet port 166 via the flow line 215.

Figure 5C is an enlarged schematic diagram of the cough assist valve 204 in the first configuration. Figure 5C illustrates the gas 252 flowing through both the blower 222 and the cough assist valve 204 during the inspiratory phase of a breath or the insufflation phase of a cough assist maneuver performed by the ventilator 100 (see Figure 1 and 4).

Figure 5D is an enlarged schematic diagram of the cough assist valve 204 in the second configuration. Figure 5D illustrates the exsufflation gases

253 flowing through both the blower 222 and the cough assist valve 204 during an exsufflation phase of a cough assist maneuver performed by the ventilator 100

(see Figure 1 and 4). For ease of illustration, ports 275A-275C (see Figures 5A and 5B) have been omitted from Figures 5C and 5D.

Referring to Figures 5C and 5D, the cough assist valve 204 has a valve-to-blower outlet 1002, a blower-to-valve inlet 1004, an air intake 1006, an exhaust outlet 1008, and an aperture 1010. The aperture 1010 is connected to the main ventilator connection 104 by the flow line 273. As shown in Figure 5C, when the cough assist valve 204 is in the first configuration, the air intake 1006 is in fluid communication with the valve-to-blower outlet 1002, and the blower-to- valve inlet 1004 is in fluid communication with the aperture 1010. Further, the exhaust outlet 1008 is closed, and both the valve-to-blower outlet 1002 and the air intake 1006 are out of fluid communication with the aperture 1010 except via the blower 222. Thus, the gas 252 may flow into the air intake 1006, through a portion of the cough assist valve 204 and out of the valve-to-blower outlet 1002, and into the blower 222. The gas 252 exiting the blower 222 flows into the blower-to-valve inlet 1004, through a portion of the cough assist valve 204, and exits the cough assist valve 204 through the aperture 1010. The aperture 1010 is connected to the flow line 273, which conducts the gas 252 (see Figure 5A) to the main ventilator connection 104.

As shown in Figure 5D, when the cough assist valve 204 in the second configuration, the air intake 1006 is closed, and both the blower-to-valve inlet 1004 and the exhaust outlet 1008 are out of fluid communication with the aperture 1010 except via the blower 222. Further, the aperture 1010 is in fluid communication with the valve-to-blower outlet 1002, and the blower-to-valve inlet 1004 is in fluid communication with the exhaust outlet 1008. Thus, the

exsufflation gases 253 flow into the aperture 1010, through a portion of the cough assist valve 204 and out the valve-to-blower outlet 1002, and into the blower 222. The exsufflation gases 253 exiting the blower 222 flow into the blower-to-valve inlet 1004, through a portion of the cough assist valve 204, and exit the cough assist valve 204 though the exhaust outlet 1008. The exhaust outlet 1008 is connected to the flow line 215 (see Figures 5A and 5B), which conducts the exsufflation gases 253 (as the exhaust 167 illustrated in Figures 5A and 5B) to the outlet port 166.

Figures 17A and 17B are perspective views of the cough assist valve 204. Figures 18A and 18B are cross-sectional views of the cough assist valve 204. Figure 18A depicts the cough assist valve 204 in the first configuration, and Figure 18B depicts the cough assist valve 204 in the second configuration.

Referring to Figure 17A, the cough assist valve 204 includes a generally cylindrically shaped housing 1020. In the embodiment illustrated, the air intake 1006 is formed in a first open end 1022 of the housing 1020 and the exhaust outlet 1008 (see Figure 17B) is located at a second open end 1024 of the housing 1020 with the second open end 1024 being opposite the first open end 1022. The valve-to-blower outlet 1002, the blower-to-valve inlet 1004, and the aperture 1010 (see Figure 17B) are formed in a sidewall 1026 of the housing 1020 extending between the first and second open ends 1022 and 1024 thereof.

A first end cap assembly 1032 may be coupled to the first open end 1022, and a second end cap assembly 1034 may be coupled to the second open end 1024. The first and second end cap assemblies 1032 and 1034 are substantially identical to one another. Referring to Figure 19A, each of the first and second end cap assemblies 1032 and 1034 (see Figures 17A, 17B, 18A and 18B) includes a magnet 1040, a retaining member 1042, a sealing member 1044 (e.g., an O-ring), and a seat member 1046. The sealing member 1044 is positioned between the seat member 1046 and the retaining member 1042. Each of the first and second end cap assemblies 1032 and 1034 may be coupled to the housing 1020 by one or more tabs 1048 and one or more fasteners 1049.

Referring to Figures 17A and 17B, in the embodiment illustrated, the

housing 1020 includes an outwardly extending mounting portion 1050 at each of the first and second open ends 1022 and 1024 of the housing 1020, each configured to receive one of the each fasteners 1049.

In the embodiment illustrated, the magnet 1040 is generally cylindrically or disk shaped. However, this is not a requirement.

Referring to Figure 19A, the retaining member 1042 has a ring- shaped base portion 1052 defining an opening 1053. A sidewall 1054 extends inwardly from the base portion 1052 toward the seat member 1046. Each tab 1048 is configured to abut the base portion 1052 and avoid obstructing the opening 1053. Thus, gas (e.g., the gas 252 or the exsufflation gases 253) may pass through the opening 1053 unobstructed by the tab(s) 1048.

Referring to Figures 19B and 19C, the seat member 1046 has a ring-shaped peripheral portion 1056 defining an opening 1058 therewithin. A central magnet receiving portion 1060 is supported within the opening 1058 by radially extending support arms 1061 -1063 connected to the peripheral portion 1056. Together the magnet receiving portion 1060 and the support arms 1061 , 1062 and 1063 which only partially obstruct or occlude the opening 1058. Thus, gas (e.g., the gas 252 or the exsufflation gases 253) may pass through the opening 1058 around the magnet receiving portion 1060 and the support arms 1061 , 1062 and 1063. The seat member 1046 has an inwardly facing side 1070 (see Figure 19C) opposite an outwardly facing side 1071 (see Figure 19B). Referring to Figure 19C, the peripheral portion 1056 along the inwardly facing side 1070 is configured to be at least partially received inside one of the first and second open ends 1022 and 1024 (see Figures 17A-18B) of the housing 1020. Along the inwardly facing side 1070, the peripheral portion 1056 has an inwardly extending annular projection 1072 positioned adjacent the opening 1058. In the

embodiment illustrated, the peripheral portion 1056 has a longitudinally inwardly facing, annularly extending helical ramp portion 1074 along the inwardly facing side 1070. As will be described in greater detail below, the ramp portion 1074 is used to adjustably longitudinally position the seat members 1046 of the first and second end cap assemblies 1032 and 1034 within the housing 1020.

Referring to Figure 19B, in the embodiment illustrated, the peripheral portion 1056 has an annular shaped recessed portion 1076 along the outwardly facing side 1071 . The recessed portion 1076 is configured to receive the sealing member 1044 and at least a free end portion of the inwardly extending sidewall 1054 of the retaining member 1042 with the sealing member 1044 sandwiched between the seat member 1046 and the retaining member 1042.

At the outwardly facing side 1071 , the magnet receiving portion 1060 is configured to receive the magnet 1040 (see Figure 19A). In the embodiment illustrated, the magnet receiving portion 1060 has been implemented as an open ended cylinder. However, this is not a requirement. Along the inwardly facing side 1070 (see Figure 19C), the magnet receiving portion 1060 has an inner stop wall 1066 configured to prevent the magnet 1040 from passing through the central magnet receiving portion 1060 into the housing 1020. By way of a non-limiting example, the magnet 1040 (see Figure 19A) may be retained inside the magnet receiving portion 1060 by friction or an adhesive.

Referring to Figure 23A, the first open end 1022 of the housing 1020 has a longitudinally outward facing, annularly extending first inside helical ramp portion 1092 configured to mate with the helical ramp portion 1074 (see Figure 19C) of the first end cap assembly 1032 (see Figures 17A, 18A and 18B). A ring- shaped inner seat member 1096 is positioned inside the housing 1020 at a circumferentially extending, radially projecting, inner wall 1 185 near but inward of the first open end 1022. The inner seat member 1096 has a longitudinally outwardly extending annular projection 1097 substantially similar to the inwardly annular projection 1072 (see Figure 19C).

Referring to Figure 19C, the annular projection 1072 formed on the inwardly facing side 1070 of the seat member 1046 of the first end cap assembly 1032 functions as a first seat "S1" (see Figures 18A and 18B). The annular projection 1097 within the housing 1020 at the first open end 1022 functions as a second seat "S2" (see Figures 18A and 18B). As may be seen in Figures 18A and 18B, the second seat "S2" is positioned longitudinally inward from the first cap assembly 1032. The first and second seats "S1 " and "S2" extend toward and face one another.

Referring to Figure 23B, the second open end 1024 of the housing 1020 has a longitudinally outward facing, annularly extending second inside helical ramp portion 1094 configured to mate with the helical ramp portion 1074 (see Figure 19C) of the second end cap assembly 1034 (see Figures 17B, 18A and 18B). The housing 1020 has circumferentially extending, radially inwardly projecting, inner wall 1 100 near but inward of the second open end 1024. The inner wall 1 100 has a longitudinally outwardly extending annular projection 1 102 substantially similar to the annular projection 1072 (see Figure 19C). The annular projection 1 102 within the housing 1020 at the second open end 1024 functions as a third seat "S3" (see Figure 18A and 18B). As shown in Figures 18A and 18B, the third seat "S3" is positioned longitudinally inward from the second end cap assembly 1034. The annular projection 1072 (see Figure 19C) of the seat member 1046 (see Figure 19C) of the second end cap assembly 1034 functions as a fourth seat "S4." The third and fourth seats "S3" and "S4" extend toward and face one another.

The first seat "S1 " is positioned adjacent to the air intake 1006, and the fourth seat "S4" is positioned adjacent to the exhaust outlet 1008. The valve- to-blower outlet 1002 is positioned between the first seat "S1" and the second seat "S2" inside the housing 1020. Similarly, the blower-to-valve inlet 1004 is positioned between the third seat "S3" and the fourth seat "S4" formed in the housing 1020.

The cough assist valve 204 includes first and second poppet valve assemblies 1 1 12 and 1 1 14 connected together by a shaft 1 1 16 so as to move together in unison. The cough assist valve 204 has first, second and third interior chambers, as will be described below. The first poppet valve assembly 1 1 12 is located in the first chamber between the first and second seats "S1 " and "S2," and moves longitudinally between the first and second seats "S1" and "S2," and the second poppet valve assembly 1 1 14 is located in the third chamber between the third and fourth seats "S3" and "S4," and moves longitudinally between the third and fourth seats "S3" and "S4." The second chamber is located between the second and third seats "S2" and "S3," respectively, and hence is located between the first and third chambers. The second seat "S2" defines a first aperture through which the first and second chambers are in fluid communication and the first poppet valve assembly 1 1 12 controls flow through the first aperture, and the third seat "S3" defines a second aperture through which the second and third chambers are in fluid communication and the second poppet valve assembly 1 1 14 controls flow through the second aperture. As shown in Figure 18A, when the first poppet valve assembly 1 1 12 is pressed against the second seat "S2," the cough assist valve 204 is in the first configuration illustrated in Figures 5A and 5C. In the first configuration, the first poppet valve assembly 1 1 12 permits the flow of gas 252 from the accumulator 202 to flow through the air intake 1006 into the first chamber and then to the valve-to-blower outlet 1002, and enter the blower 222, while blocking flow of the gas 252 directly to the aperture 1010, thus sealing the aperture 1010 from both the air intake 1006 and the valve-to-blower outlet 1002. At the same time, the second poppet valve assembly 1 1 14 is pressed against the fourth seat "S4," so that the second poppet valve assembly 1 1 14 closes the exhaust outlet 1008 and directs the flow of the gas 252 into the third chamber and then through the second aperture into the second chamber for exit through the aperture 1010 to the main ventilator connection 104. In this configuration, the gas 252 from the accumulator 202 entering the air intake 1006 is directed to the blower 222 through the valve-to-blower outlet 1002. The gas 252 is then blown by the blower 222 into the blower-to-valve inlet 1004 and exit the cough assist valve 204 through the aperture 1010 to the main ventilator connection 104.

As shown in Figure 18B, when the first poppet valve assembly 1 1 12 is pressed against the first seat "S1 ," the cough assist valve 204 is in the second configuration illustrated in Figures 5B and 5D. In the second configuration, the first poppet valve assembly 1 1 12 permits the flow of exsufflation gases 253 from the main ventilator connection 104 to flow through the aperture 1010 into the second chamber and then through the first aperture into the first chamber for exit through the valve-to-blower outlet 1002, and entry to the blower 222, while blocking flow of the exsufflation gases to the air intake 1006 and also preventing gas 252 from the accumulator 202 reaching the valve-to-blower outlet 1002. At the same time, the second poppet valve assembly 1 1 14 is pressed against the third seat "S3," so that the second poppet valve assembly 1 1 14 opens the exhaust outlet 1008 and blocks the flow of the exsufflation gases 253 through the second aperture into the second chamber and to the aperture 1010. In this configuration, the exsufflation gases 253 from the main ventilator connection 104 entering the aperture 1010, pass through the first chamber and are directed to the blower 222 through the valve-to-blower outlet 1002. The exsufflation gases 253 are then blown by the blower 222 into the blower-to-valve inlet 1004 and into the third chamber and exit the cough assist valve 204 through the exhaust outlet 1008 to the outlet port 166.

The first and second poppet valve assemblies 1 1 12 and 1 1 14 are coupled to opposite ends of the shaft 1 1 16 to move therewith as a unit in unison. Referring to Figure 22, in the embodiment illustrated, a guide member 1 120 (e.g., a pin, dowel, and the like) extends laterally outwardly from the shaft 1 1 16. The shaft 1 1 16 may include one or more circumferentially extending grooves 1 122 and 1 124 each configured to receive a different retaining ring 1 126. The shaft 1 1 16 has a first end portion 1 132 opposite a second end portion 1 134. Longitudinal channels 1 136 and 1 138 extend inwardly into the shaft at the first and second end portions 1 132 and 1 134, respectively. Each of the channels 1 136 and 1 138 is configured to receive a fastener 1 140 (see Figure 21 ).

The shaft 1 1 16 is configured to move longitudinally within the housing 1020 between a first position (see Figure 18A) whereat the cough assist valve 204 is in the first configuration and a second position (see Figure 18B) whereat the cough assist valve 204 is in the second configuration. Referring to Figures 18A and 18B, as the shaft 1 1 16 moves, the first poppet valve assembly 1 1 12 moves between the first and second seats "S1 " and "S2," and the second poppet valve assembly 1 1 14 moves between the third and fourth seats "S3" and "S4." When the shaft 1 1 16 is in the first position (see Figure 18A), the first poppet valve assembly 1 1 12 is in sealing position against the first seat "S1 ," and the second poppet valve assembly 1 1 14 is in sealing position against the third seat "S3." When the shaft 1 1 16 is in the second position (see Figure 18B), the first poppet valve assembly 1 1 12 is in sealing position against the second seat "S2," and the second poppet valve assembly 1 1 14 is in sealing position against the fourth seat "S4."

The ramp portion 1074 of seat member 1046 of the first end cap assembly 1032 is in sliding engagement with the ramp portion 1092 within the first open end 1022 of the housing 1020 such that rotation of the seat member 1046 causes adjustable longitudinal movement relative to the housing 1020 to precisely adjust the position of the first seat S1 of the seat member 1046, during assembly and calibration, with respect to the first poppet valve assembly 1 1 12 to achieve the desired seal and seating therebetween. Similarly, the ramp portion 1074 of seat member 1046 of the second end cap assembly 1034 is in sliding

engagement with the ramp portion 1094 within the second open end 1024 of the housing 1020 such that rotation of the seat member 1046 causes adjustable longitudinal movement relative to the housing 1020 to precisely adjust the position of the fourth seat S4 of the seat member 1046, during assembly and calibration, with respect to the second poppet valve assembly 1 1 14 to achieve the desired seal and seating therebetween.

The first and second poppet valve assemblies 1 1 12 and 1 1 14 are substantially identical to one another. Referring to Figure 21 , each of the first and second poppet valve assemblies 1 1 12 and 1 1 14 includes the fastener 1 140, a ferromagnetic member 1 144, a first sealing member 1 146 (e.g., an O-ring), a disk shaped poppet member 1 148, a second sealing member 1 150 (e.g., an O-ring), and an optional washer 1 152.

The fastener 1 140 of the first poppet valve assembly 1 1 12 fastens the other components (namely, the ferromagnetic member 1 144, the first sealing member 1 146, the poppet member 1 148, the second sealing member 1 150, and optionally, the washer 1 152) of the first poppet valve assembly 1 1 12 to the first end portion 1 132 of the shaft 1 1 16. Similarly, the fastener 1 140 of the second poppet valve assembly 1 1 14 fastens the other components of the second poppet valve assembly 1 1 14 to the second end portion 1 134 of the shaft 1 1 16. The first and second sealing members 1 146 and 1 150 of each of the first and second poppet valve assemblies 1 1 12 and 1 1 14 serve to both seal the poppet valve assemblies to the end portion of the shaft 1 1 16 and provide a flexible coupling between the shaft and the poppet members 1 148 of the poppet valve assemblies.

Referring to Figure 18A, the magnet 1040 of the first end cap assembly 1032 attracts the ferromagnetic member 1 144 of the first poppet valve assembly 1 1 12 and when in proximity therewith maintains the shaft 1 1 16 in the first position after the shaft has been moved to the first position and holds the first poppet valve assembly 1 1 12 in place at the first seat S1 of the first end cap assembly 1032. Similarly, referring to Figure 18B, the magnet 1040 of the second end cap assembly 1034 attracts the ferromagnetic member 1 144 of the second poppet valve assembly 1 1 14 and when in proximity therewith maintains the shaft 1 1 16 in the second position after the shaft has been moved to the second position and holds the second poppet valve assembly 1 1 14 in place at the fourth seat S4 of the second end cap assembly 1034. The ferromagnetic members 1 144 holds the poppet valve assemblies 1 1 12 and 1 1 14 in place with respect to the first and fourth seats S1 and S4, respectively, even when power is not being applied to the actuator used to move the poppet valve assemblies.

Referring to Figure 20, the cough assist valve 204 includes an actuator 1 170 configured to selectively move the shaft 1 1 16 between the first position (see Figure 18A) and the second position (see Figure 18B) along longitudinal directions identified by double headed arrow 1 172. In the

embodiment illustrated, the actuator 1 170 is a linear actuator implemented using a voice coil that includes a movable coil subassembly 1 174 and a stationary magnet subassembly 1 176. The shaft 1 1 16 is coupled to the movable coil subassembly 1 174 and moves therewith as a unit. Referring to Figures 18A and 18B, the stationary magnet subassembly 1 176 is coupled to an actuator mounting portion 1 190 of the housing 1020 (e.g., by one or more fasteners 1 178).

Referring to Figure 18A, the movable coil subassembly 1 174 is connected by one or more wires 1059 to a printed circuit board ("PCB") 1064 mounted to the outside of the housing 1020. In the embodiment illustrated, the wire(s) 1059 provide power to the movable coil subassembly 1 174. The housing

1020 includes one or more apertures 1065 (see Figure 24A) through which the wire(s) 1059 may pass. The PCB 1064 is connected to the control system 220

(see Figure 5E) by one or more wires (not shown). The actuator 1 170 is configured to receive a control signal 1 180 (see Figure 5E) from the control system 220 (via the PCB 1064 and the wire(s) 1059) and move in accordance with one or more instructions in the control signal 1 180. The PCB 1064 serves as a connector and passes the control signal 1 180 to the movable coil subassembly 1 174.

The control signal 1 180 (see Figure 5E) selectively powers the movable coil subassembly 1 174 to move toward either the first end cap assembly 1032 or the second end cap assembly 1034. When the movable coil

subassembly 1 174 moves toward the first end cap assembly 1032, the movable coil subassembly 1 174 moves the shaft 1 1 16 toward the first position. Referring to Figure 18A, after the shaft 1 1 16 has moved to the first position, the movable coil subassembly 1 174 is powered down and the magnet 1040 of the first end cap assembly 1032 (which, as described above is attracted to at least a portion of the first poppet valve assembly 1 1 12) maintains the shaft 1 1 16 in the first position. On the other hand, when the movable coil subassembly 1 174 moves toward the second end cap assembly 1034, the movable coil subassembly 1 174 moves the shaft 1 1 16 toward the second position. Referring to Figure 18B, after the shaft 1 1 16 has moved to the second position, the movable coil subassembly 1 174 is powered down and the magnet 1040 of the second end cap assembly 1034 (which, as described above is attracted to at least a portion of the second poppet valve assembly 1 1 14) maintains the shaft 1 1 16 in the second position. Thus, additional power is not needed to maintain the shaft 1 1 16 in either the first position or the second position, which helps extend battery life in embodiments powered by one or more batteries.

Referring to Figure 24B, the housing 1020 (see Figures 18A and 18B) includes a first internal support 1 184 spaced inwardly from the first open end 1022. In the embodiment illustrated, the first internal support 1 184 extends radially inward from the circumferential ly inwardly extending inner wall 1 185. The first internal support 1 184 has a longitudinally extending channel 1 186 formed therein. Referring to Figures 18A and 18B, the channel 1 186 (see Figure 24B) is configured to allow the shaft 1 1 16 to pass fully therethrough to position the first poppet valve assembly 1 1 12 between the first internal support 1 184 and the first end cap assembly 1032. As may be viewed in Figure 23A, the channel 1 186 opens alongside the inner seat member 1096, and as shown in Figures 18A and 18B, positions the first poppet valve assembly 1 1 12 between the first and second seats "S1 " and "S2." A portion of the shaft 1 1 16 near the first end portion 1 132 including the guide member 1 120 (see Figure 22) is positioned inside the channel 1 186 (see Figure 24B) and reciprocates therein. Referring to Figure 24A, an open-ended, longitudinally extending guide groove 1 188 is formed in the first internal support 1 184 alongside the channel 1 186. The guide member 1 120 (see Figure 22) is positioned in and moves within the guide groove 1 188. (This prevents rotation of the poppet assembly, which could damage the wires.)

The first internal support 1 184 has the actuator mounting portion 1 190 which optionally includes one or more through-holes configured to receive the fastener(s) 1 178 (see Figures 18A and 18B). The stationary magnet subassembly 1 176 (see Figures 18A and 18B) is coupled to the actuator mounting portion 1 190 which anchors the stationary magnet subassembly to the housing 1020 (see Figures 18A and 18B). In the embodiment illustrated, the actuator mounting portion 1 190 includes an inwardly extending peripheral sidewall 1 192 configured to extend around a portion of the stationary magnet subassembly 1 176.

Referring to Figure 25, the housing 1020 (see Figures 18A and 18B) includes a second internal support 1 194 spaced inwardly from the second open end 1024. In the embodiment illustrated, the second internal support 1 194 extends radially inward from the inner wall 1 100. The second internal support 1 194 has a through-hole 1 196 formed therein. Referring to Figure 18A and 18B, the through-hole 1 196 (see Figure 25) is configured to allow the shaft 1 1 16 to pass therethrough to position the second poppet valve assembly 1 1 14 between the second internal support 1 194 and the second end cap assembly 1034. As may be viewed in Figure 25, the through-hole 1 196 opens alongside the annular projection 1 102, and as shown in Figures 18A and 18B, positions the second poppet valve assembly 1 1 14 between the third and fourth seats "S3" and "S4."

Referring to Figures 17A, 17B, 18A, 18B, 23A, and 23B, in the embodiment illustrated, the housing 1020 includes an intake body portion 1 198 coupled to an exhaust body portion 1 199. The valve-to-blower outlet 1002, the air intake 1006, the aperture 1010, the first open end 1022, and the first internal support 1 184 are formed in the intake body portion 1 198. The blower-to-valve inlet 1004, the exhaust outlet 1008, the second open end 1024, and the second internal support 1 194 are formed in the exhaust body portion 1 199. In the embodiment illustrated, the cough assist valve 204 includes the ports 275A, 275B and 275C (described below) formed in the housing 1020. The ports 275A and 275B may be formed in the exhaust body portion 1 199, and the port 275C may be formed in the intake body portion 1 198. However, this is not a requirement. Optionally, the cough assist valve 204 includes a port 275D (see Figures 17B and 23A) configured to be connected to a redundant airway pressure transducer (not shown).

Figures 34A and 34B are cross-sectional views of an alternate embodiment of a cough assist valve 2000 that may be used in the ventilation assembly 190 (see Figures 4 and 5A), instead of the cough assist valve 204 (see Figures 5A-5D and 17A-18B). Referring to Figures 5A and 5B, like the cough assist valve 204, the cough assist valve 2000 (see Figures 34A and 34B) is configured to be connected to the accumulator 202 by the flow line 214, to the outlet port 166 by the flow line 215, and to the main ventilator connection 104 by the flow line 273.

Figure 34A depicts the cough assist valve 2000 in a first configuration and Figure 34B depicts the cough assist valve 2000 in a second configuration. The first and second configurations of the cough assist valve 2000 correspond and provide identical functionality to the first and second

configurations, respectively, of the cough assist valve 204 (see Figures 5A-5D and 17A-18B). Thus, during normal breathing and ventilation, the cough assist valve 2000 remains in the first configuration. When cough assist functionality

(described below) is used to perform a cough assist maneuver, the cough assist valve 2000 is in the first configuration during the insufflation phase of a cough and the cough assist valve 2000 is in the second configuration during the exsufflation phase of the cough.

Referring to Figures 34A, 34B, 18A, and 18B, the cough assist valve 2000 has a valve-to-blower outlet 2002, a blower-to-valve inlet 2004, an air intake 2006, an exhaust outlet 2008, and an aperture 2010 substantially identical to the valve-to-blower outlet 1002, the blower-to-valve inlet 1004, the air intake 1006, the exhaust outlet 1008, and the aperture 1010, respectively, of the cough assist valve 204. The valve-to-blower outlet 2002 and the blower-to-valve inlet 2004 are each connected to the blower 222. The air intake 2006 is connected to the accumulator 202 by the flow line 214. The exhaust outlet 2008 is connected to the outlet port 166 by the flow line 215. The aperture 2010 is connected to the main ventilator connection 104 by the flow line 273. The cough assist valve 2000 has seats "S1 "' to "S4"' that are substantially identical to the seats "S1" to "S4," respectively, of the cough assist valve 204.

Referring to Figures 34A and 34B, the cough assist valve 2000 includes a generally cylindrically shaped housing 2020. The air intake 2006 is formed in a first open end 2022 of the housing 2020 and the exhaust outlet 2008 is formed at a second open end 2024 of the housing 2020. The valve-to-blower outlet 2002, the blower-to-valve inlet 2004, and the aperture 2010 are formed in a sidewall 2026 of the housing 2020 extending between the first and second open ends 2022 and 2024 thereof.

First and second end cap assemblies 2032 and 2034 may be coupled to the first and second open ends 2022 and 2024, respectively. The first and second end cap assemblies 2032 and 2034 are substantially identical to one another. Referring to Figure 35, each of the first and second end cap assemblies 2032 and 2034 (see Figures 34A and 34B) includes a retaining member 2042, a sealing member 2044 (e.g., an O-ring), and a seat member 2046. Referring to Figures 34A and 34B, each of the first and second end cap assemblies 2032 and 2034 may be coupled to the housing 2020 by one or more fasteners 2049. In the embodiment illustrated, the housing 2020 includes one or more outwardly extending mounting portions 2050 at each of the first and second open ends 2022 and 2024 of the housing 2020 each configured to receive one of the fasteners 2049.

Referring to Figure 35, the seat member 2046 has a ring-shaped peripheral portion 2056 defining an opening 2058. The seat member 2046 has an inwardly facing side 2070 opposite an outwardly facing side 2071 . Along the inwardly facing side 2070, the seat member 2046 has an inwardly extending annular projection 2072 positioned adjacent the opening 2058. In the

embodiment illustrated, the peripheral portion 2056 has an outside threaded portion 2074 along the inwardly facing side 2070 and an annular shaped recessed portion 2076 along the outwardly facing side 2071 . The recessed portion 2076 is configured to receive the sealing member 2044 and at least a free end portion of an inwardly extending sidewall 2054 of the retaining member 2042 with the sealing member 2044 sandwiched between the seat member 2046 and the retaining member 2042.

The first and second end cap assemblies 2032 and 2034 (see Figures 34A and 34B) do not include the tabs 1048 (see Figure 19A). Instead, the retaining member 2042 of the first end cap assembly 2032 (see Figures 34A and 34B) includes an outwardly extending mounting portion 2057 for each of the outwardly extending mounting portions 2050 (see Figures 34A, 34B, and 37) located at the first open end 2022 (see Figures 34A and 34B) of the housing 2020. Similarly, each mounting portion 2057 of the retaining member 2042 of the second end cap assembly 2034 (see Figures 34A and 34B) corresponds to one of the outwardly extending mounting portions 2050 (see Figures 34A, 34B, and 38) located at the second open end 2024 of the housing 2020. Each mounting portion 2057 is configured to receive one of the fasteners 2049 and be fastened thereby to the mounting portion 2050 (see Figures 34A, 34B, and 38) that corresponds to the mounting portion 2057.

Referring to Figure 37, the first open end 2022 of the housing 2020 (see Figure 34A and 34B) has a first inside threaded portion 2092 configured to mate with the outside threaded portion 2074 (see Figure 35) of the first end cap assembly 2032 (see Figures 34A and 34B). The housing 2020 (see Figure 34A and 34B) has circumferentially extending, radially inwardly projecting, inner wall 2095 near but inward of the first open end 2022. The inner wall 2095 has a longitudinally outwardly extending annular projection 2097 substantially similar to the annular projection 2072 (see Figure 35).

Referring to Figure 35, the annular projection 2072 of the seat member 2046 of the first end cap assembly 2032 (see Figures 34A and 34B) functions as the first seat "S1 "' (see Figures 34A and 34B). Referring to Figure 37, the annular projection 2097 inside the first open end 2022 of the housing 2020 functions as the second seat "S2"' (see Figures 34A and 34B). As may be seen in Figures 34A and 34B, the second seat "S2"' is positioned longitudinally inward from the first cap assembly 2032. The first and second seats "S1 "' and "S2"' extend toward and face one another.

Referring to Figure 38, the second open end 2024 of the housing 2020 (see Figure 34A and 34B) has a second inside threaded portion 2094 configured to mate with the outside threaded portion 2074 (see Figure 35) of the second end cap assembly 2034 (see Figures 34A and 34B). The

housing 2020 (see Figure 34A and 34B) has circumferentially extending, radially inwardly projecting, inner wall 2100 near but inward of the second open end 2024. The inner wall 2100 has a longitudinally outwardly extending annular projection 2102 substantially similar to the annular projection 2072 (see Figure 35).

Referring to Figure 34A and 34B, the annular projection 2102 (see Figure 38) within the housing 2020 at the second open end 2024 functions as the third seat "S3 ¹ ." The third seat "S3"' is positioned longitudinally inward from the second end cap assembly 2034. The annular projection 2072 (see Figure 35) of the seat member 2046 (see Figure 35) of the second end cap assembly 2034 functions as a fourth seat "S4\" The third and fourth seats "S3"' and "S4"' extend toward and face one another.

Referring to Figures 34A and 34B, the cough assist valve 2000 includes first and second poppet valve assemblies 21 12 and 21 14 connected together by a shaft 21 16 so as to move together in unison. The first poppet valve assembly 21 12 is located and moves longitudinally between the first and second seats "S1 "' and "S2 ¹ ," and the second poppet valve assembly 21 14 is located and moves longitudinally between the third and fourth seats "S3"' and "S4\"

Referring to Figures 34A and 34B, the shaft 21 16 is configured to move longitudinally within the housing 2020 between a first position (see Figure 34A) whereat the cough assist valve 2000 is in the first configuration and a second position (see Figure 34B) whereat the cough assist valve 2000 is in the second configuration. As the shaft 21 16 moves, the first poppet valve assembly 21 12 moves between the first and second seats "S1 "' and "S2 ¹ ," and the second poppet valve assembly 21 14 moves between the third and fourth seats "S3"' and "S4\" When the shaft 21 16 is in the first position (see Figure 34A), the first poppet valve assembly 21 12 is in sealing position against the first seat "S1 ¹ ," and the second poppet valve assembly 21 14 is in sealing position against the third seat "S3'." When the shaft 21 16 is in the second position (see Figure 34B), the first poppet valve assembly 21 12 is in sealing position against the second seat "S2 ¹ ," and the second poppet valve assembly 21 14 is in sealing position against the fourth seat "S4\"

Referring to Figure 34A, a longitudinal channel 2136 extends inwardly into the shaft 21 16 at each of its ends. Referring to Figure 36, each of the channels 2136 (see Figure 34A) is configured to receive a fastener 2140 (see Figure 21 ). The first and second poppet valve assemblies 21 12 and 21 14 are substantially identical to one another. Referring to Figure 36, each of the first and second poppet valve assemblies 21 12 and 21 14 includes the fastener 2140, an optional first washer 2146, a disk shaped poppet member 2148, and an optional second washer 2152. While not visible in Figure 36, the first and second poppet valve assemblies 21 12 and 21 14 each include first and second sealing members 1 146 and 1 150, much as shown in Figure 21 , which serve to both seal the poppet valve assemblies to the end portion of the shaft 21 16 and provide a flexible coupling between the shaft and the poppet valve members 2148 of the poppet valve assemblies. The fastener 2140 of the first poppet valve assembly 21 12 fastens the other components (namely, the optional first washer 2146, the disk shaped poppet member 2148, and the optional second washer 2152) of the first poppet valve assembly 21 12 to one of the ends of the shaft 21 16. Similarly, the fastener 2140 of the second poppet valve assembly 21 14 fastens the other components of the second poppet valve assembly 21 14 to the other end of the shaft 21 16.

Referring to Figures 34A and 34B, the cough assist valve 2000 includes an actuator 2170 configured to selectively move the shaft 21 16 between the first position (see Figure 34A) and the second position (see Figure 34B) along longitudinal directions identified by double headed arrow 2172 (see Figure 36). In the embodiment illustrated, the actuator 2170 is a linear actuator that includes a stationary coil subassembly 2174 and a movable magnet subassembly 2176. The shaft 21 16 is coupled to the movable magnet subassembly 2176 and moves therewith as a unit.

Referring to Figures 34A and 34B, the stationary coil subassembly 2174 includes a coil 2177 housed inside an outer housing 2179. The outer housing 2179 is coupled to an actuator mounting portion 2190 of the

housing 2020 (e.g., by one or more fasteners 2178). The outer housing 2179 is constructed from a magnetic material. The coil 2177 is connected by one or more wires 2062 to a printed circuit board ("PCB") 2064 mounted to the outside of the housing 2020. In the embodiment illustrated, the wire(s) 2062 provide power to the coil 2177. The outer housing 2179 and the housing 2020 each include one or more apertures through which the wire(s) 2062 may pass. The PCB 2064 is connected to the control system 220 (see Figure 5E) by one or more wires (not shown). The actuator 2170 is configured to receive the control signal 1 180 (see Figure 5E) from the control system 220 (via the PCB 2064 and the wire(s) 2062) and move in accordance with one or more instructions in the control signal 1 180. The PCB 2064 serves as a connector and passes the control signal 1 180 to the coil 2177.

Referring to Figure 36, the movable magnet subassembly 2176 has a main magnet 2150 with a first end 2151 opposite a second end 2153. A first latch magnet 2156 is mounted to the first end 2151 and a second latch magnet 2158 is mounted to the second end 2153. The first and second latch magnets 2156 and 2158 are each attracted to the magnetic outer housing 2179 (see Figures 34A and 34B). Referring to Figure 34A, attraction between the first latch magnet 2156 (see Figure 36) and the outer housing 2179 maintains the shaft 21 16 in the first position after the shaft 21 16 has been moved to the first position (by powering the coil 2177). Similarly, referring to Figure 34B, attraction between the second latch magnet 2158 (see Figure 36) and the outer housing 2179 maintains the shaft 21 16 in the second position after the shaft 21 16 has been moved to the second position (by powering the coil 2177). Thus, the shaft 21 16 may remain in a desired position after the coil 2177 is powered down.

The control signal 1 180 (see Figure 5E) selectively powers the coil

2177 to move the movable magnet subassembly 2176 toward either the first end cap assembly 2032 or the second end cap assembly 2034. When the movable magnet subassembly 2176 moves toward the first end cap assembly 2032, the shaft 21 16 moves therewith toward the first position. Referring to Figure 34A, after the shaft 21 16 has moved to the first position, the coil 2177 is powered down and attraction between the first latch magnet 2156 (see Figure 36) and the outer housing 2179 maintains the shaft 21 16 in the first position. On the other hand, when the movable magnet subassembly 2176 moves toward the second end cap assembly 2034, the shaft 21 16 moves therewith toward the second position. Referring to Figure 34B, after the shaft 21 16 has moved to the second position, the coil 2177 is powered down and attraction between the second latch magnet 2158 (see Figure 36) and the outer housing 2179 maintains the shaft 21 16 in the second position. Thus, additional power is not needed to maintain the shaft 21 16 in either the first position or the second position, which helps extend battery life in embodiments powered by one or more batteries.

Referring to Figure 37, the actuator mounting portion 2190 is spaced inwardly from the first open end 2022 and optionally includes one or more through-holes configured to receive the fastener(s) 2178 (see Figures 34A and 34B). Referring to Figures 34A and 34B, the outer housing 2179 is coupled to an inwardly facing side of the actuator mounting portion 2190 by the fastener(s) 2178, which anchor the stationary coil subassembly 2174 to the housing 2020. Referring to Figures 34A and 34B, the actuator mounting portion 2190 has a through-hole 2186 (see Figure 37) configured to allow the shaft 21 16 to pass fully therethrough to position the first poppet valve assembly 21 12 between the first and second seats "S1 "' and "S2\"

Referring to Figure 38, the housing 2020 (see Figures 34A and 34B) includes an internal support 2194 spaced inwardly from the second open end 2024. In the embodiment illustrated, the internal support 2194 extends radially inward from the inner wall 2100. The internal support 2194 has a through-hole 2196 formed therein. Referring to Figure 34A and 34B, the through-hole 2196 (see Figure 38) is configured to allow the shaft 21 16 to pass therethrough to position the second poppet valve assembly 21 14 between the third and fourth seats "S3"' and "S4\" Referring to Figures 34A and 34B, the internal support 2194 abuts and helps position the outer housing 2179 of the actuator 2170. In the embodiment illustrated, the actuator mounting portion 2190 is coupled to an end of the outer housing 2179 near the second seat "S2"' and the internal support 2194 abuts an opposite end of the outer housing 2179 near the third seat "S3 ¹ ."

Referring to Figures 34A and 34B, the housing 2020 includes an intake body portion 2198 (also illustrated in Figure 37) coupled to an exhaust body portion 2199 (also illustrated in Figure 38). The valve-to-blower outlet 2002, the air intake 2006, the aperture 2010, the first open end 2022, and the actuator mounting portion 2190 are formed in the intake body portion 2198. The blower-to- valve inlet 2004, the exhaust outlet 2008, the second open end 2024, and the internal support 2194 are formed in the exhaust body portion 2199.

Referring to Figure 34A, in the first configuration, the first poppet valve assembly 21 12 is pressed against the second seat "S2 ¹ ," and the second poppet valve assembly 21 14 is pressed against the fourth seat "S4\" Referring to Figures 5A and 34A, in the first configuration, the first poppet valve assembly 21 12 permits the flow of gas 252 from the accumulator 202 to flow through the air intake 2006, out the valve-to-blower outlet 2002, and into the blower 222. Further, the first poppet valve assembly 21 12 blocks the gas 252 from directly entering the aperture 2010, thus sealing the aperture 2010 from both the air intake 2006 and the valve-to-blower outlet 2002. At the same time, the second poppet valve assembly 21 14, which is pressed against the fourth seat "S4 ¹ ," closes the exhaust outlet 2008 and permits the flow of the gas 252 to the main ventilator connection 104. In this configuration, the gas 252 from the accumulator 202 entering the air intake 2006 is directed to the blower 222 through the valve-to-blower outlet 2002. The gas 252 is then blown by the blower 222 into the blower-to-valve inlet 2004 and out through the aperture 2010 to the main ventilator connection 104.

Referring to Figure 34B, in the second configuration, the first poppet valve assembly 21 12 is pressed against the first seat "S1 ¹ ," and the second poppet valve assembly 21 14 is pressed against the third seat "S3 ¹ ." Referring to Figures 5B and 34B, in the second configuration, the first poppet valve assembly 21 12 permits the flow of exsufflation gases 253 from the main ventilator

connection 104 to flow through the aperture 2010, out the valve-to-blower outlet 2002, and into the blower 222. Further the first poppet valve assembly 21 12 blocks the flow of exsufflation gases to the air intake 2006, thus preventing gas 252 from the accumulator 202 from reaching the valve-to-blower outlet 2002. At the same time, the second poppet valve assembly 21 14, which is pressed against the third seat "S3 ¹ ," opens the exhaust outlet 2008 and blocks the flow of the exsufflation gases 253 to the aperture 2010. In this configuration, the exsufflation gases 253 from the main ventilator connection 104 entering the aperture 2010 are directed to the blower 222 through the valve-to-blower outlet 2002. The

exsufflation gases 253 are then blown by the blower 222 into the blower-to-valve inlet 2004 and out through the exhaust outlet 2008.

In the embodiment illustrated, the cough assist valve 2000 (see Figures 34A and 34B) includes the ports 275A, 275B and 275C (described below and illustrated in Figures 5A and 5B) formed in the housing 2020 (see Figures 34A and 34B). Referring to Figure 38, the ports 275A and 275B may be formed in the exhaust body portion 2199. Referring to Figures 34A and 34B, the port 275C may be formed in the intake body portion 2198. However, this is not a requirement. Optionally, referring to Figure 37, the cough assist valve 2000 includes the port 275D configured to be connected to a redundant airway pressure transducer (not shown).

The cough assist valve, whether it be the cough assist valve 204 or the cough assist valve 2000, is designed so that the pressures working against the first and second poppet valve assemblies 1 1 12 and 1 1 14 of cough assist valve 204 or the first and second poppet valve assemblies 21 12 and 21 14 of cough assist valve 2000, are balanced. This results in the actuator 1 170 of cough assist valve 204 and the actuator 2170 of cough assist valve 2000 never having to work against the patient pressure. Since all of the seat areas of seats S1 -S4 of cough assist valve 204 are the same, as are all of the seat areas of seats S1 '-S4' of cough assist valve 2000, the patient pressure inside the cough assist valve coming through port 1010 (e.g., see Figures 5C and 5D) working against the poppet valve assemblies of the cough assist valve, creates forces that are equal and opposite. Thus, the force on the first and second poppet valve assemblies 1 1 12 and 1 1 14 of cough assist valve 204, when seated against the first and third seats S1 and S3, respectively, and when seated against the second and fourth seats S2 and S4, respectively, are substantially equal and in opposite directions. Similarly, the force on the first and second poppet valve assemblies 21 12 and 21 14 of cough assist valve 2000, when seated against the first and third seats S1 ' and S3', respectively, and when seated against the second and fourth seats S2' and S4', respectively, are substantially equal and in opposite directions. If the forces on the first and second poppet valve assemblies of the cough assist valve were not balanced, the actuator 1 170/2170 of the cough assist valve would need to be much larger, and the power required to actuate the actuator would be greater.

As mentioned above, the ventilation assembly 190 may include either the cough assist valve 204 or the cough assist valve 2000. If the ventilation assembly 190 includes the cough assist valve 204, during normal ventilation, the cough assist valve 204 is in the first configuration shown in Figures 5A and 18A. On the other hand, if the ventilation assembly 190 includes the cough assist valve 2000 (see Figures 34A and 34B), during normal ventilation, the cough assist valve 2000 is in the first configuration shown in Figures 34A. Referring to Figure 5A, at the beginning of the inspiratory phase of a breath (and the beginning of the insufflation phase of a cough), the air 1 14 may be drawn into the ventilator 100 (see Figures 1 and 4) through the patient air intake 1 16, which may be configured to filter dust and/or other types of particles from the air. At least a portion of the air 1 14 flows into the accumulator 202 where the air 1 14 may optionally be mixed with oxygen 250 received from the oxygen assembly 210, the low pressure oxygen 128 (received from the external low- pressure oxygen source 1 18 depicted in Figure 1 ), combinations and/or subcombinations thereof, and the like. As illustrated in Figure 4, the high pressure oxygen 132 (received from the high-pressure external oxygen source 120 depicted in Figure 1 ) flows into the oxygen assembly 210 and may be delivered to the accumulator 202 (see Figure 5A) as the oxygen 250.

Referring to Figure 5A, the accumulator 202 may also serve as a muffler for the patient air intake 1 16.

The inlet silencer 229 helps muffle sounds created by the oxygen assembly 210 (e.g., by a compressor 302 illustrated in Figure 7A).

The oxygen sensor 227 is connected to the accumulator 202 and measures an oxygen concentration value of the gas(es) inside the accumulator 202. This value approximates the oxygen concentration value of the gas 252 that exits the accumulator 202. Referring to Figure 5E, the oxygen sensor 227 provides an oxygen concentration signal 276 encoding the oxygen concentration value to the control system 220. The control system 220 processes the oxygen concentration signal 276 to obtain a measure of how much oxygen is in the gas 252 (e.g., expressed as a percentage). Referring to Figure 4, the output information 198 sent by the control system 220 to the user interface 200 may include the measure of how much oxygen is in the gas 252. The user interface 200 may display this measure to the user (e.g., the patient 102 depicted in Figure 1 ).

Referring to Figure 5A, optionally, the accumulator 202 includes or is connected to the low-pressure oxygen inlet 126. When the low-pressure oxygen 128 is supplied by the external low-pressure oxygen source 1 18 (see Figure 1 ), the control system 220 may not control the resulting oxygen

concentration flowing to the patient 102. In other words, the low-pressure oxygen 128 may simply flow into the accumulator 202, be mixed with the air 1 14, and pushed into the patient circuit 1 10 (see Figure 1 ) by the blower 222. When this occurs, the ventilator 100 does not control the oxygen concentration delivered to the patient 102 in the inspiratory gases 108 (see Figure 1 ), but does control the delivery of the inspiratory gases 108 during the inspiratory phase of each breath.

The gas 252 exiting the accumulator 202 includes the air 1 14 and optionally one or more of the oxygen 250 and the oxygen 128. The gas 252 may be conducted via the flow line 214 to the internal flow transducer 212. The gas 252 flows through the internal flow transducer 212, which measures a flow rate of the gas 252 and provides a flow signal 270 (see Figure 5E) encoding the flow rate to the control system 220 (see Figure 5E). The flow signal 270 may be implemented as an analog electric signal. Referring to Figure 5E, the control system 220 uses the flow signal 270 to control the blower 222. By way of a non- limiting example and as shown in Figure 5A, the internal flow transducer 212 may be implemented using a flow transducer having a fixed orifice differential pressure configuration.

The internal flow transducer 212 may be used to detect when the patient 102 (see Figure 1 ) has initiated a breath. In particular, the internal flow transducer 212 may be used in this manner when the patient circuit 1 10 (see Figure 1 ) is implemented as a passive patient circuit (e.g., the passive patient circuit 170, the passive patient circuit 440, and the like). The flow of gases through the flow line 214 is not determined entirely by the blower 222. Instead, the patient's breathing efforts may cause a change in the flow rate through the flow line 214. Thus, the control system 220 may identify that the patient 102 has initiated a breath by identifying a change in the flow rate (encoded in the flow signal 270) through the flow line 214.

The internal flow transducer 212 may include or be connected to an auto zero solenoid valve SV5 configured to be selectively activated and

deactivated by a control signal 285 (see Figure 5E) sent by the control

system 220. The internal flow transducer 212 may drift over time, causing flow rate measuring errors. To compensate for this error, occasionally (e.g., periodically) the control system 220 energizes (or activates) the auto zero solenoid valve SV5 (using the control signal 285) and determines an offset value for the internal flow transducer 212. After determining the offset value, the control system 220 uses the offset value to compensate future readings (based on the flow signal 270) accordingly.

Referring to Figure 5A, after the internal flow transducer 212, the gas 252 is conducted into the blower 222 via the flow line 214 and the cough assist valve 204 (or the cough assist valve 2000). Referring to Figure 5E, the blower 222 may be implemented as a radial blower driven by a motor 272. By way of a non-limiting example, the motor 272 may be implemented as a brushless direct current motor. By way of additional non-limiting examples, the blower 222 may be implemented as a compressor, a pump, and the like. The motor 272 has an operating speed that is controlled by the control system 220. By way of a non- limiting example, the control system 220 may continuously control the operating speed of the motor 272.

Referring to Figure 5A, the gas 252 flows out of the blower 222 and into the cough assist valve 204 (or the cough assist valve 2000). The ports 275A- 275C are each configured to provide access to the flow of the gas 252 in the cough assist valve 204 (or the cough assist valve 2000). The flow line 273 conducts the flow of the gas 252 from the cough assist valve 204 (or the cough assist valve 2000) to the internal bacteria filter 230.

Referring to Figure 5A, the airway pressure transducer 224 measures airway pressure of the gas 252 flowing out of the blower 222 and toward the main ventilator connection 104. In the embodiment illustrated, the airway pressure transducer 224 is connected to the port 275C. Referring to Figure 5E, the airway pressure transducer 224 provides an electrical pressure signal 274 encoding these pressure values to the control system 220. The electrical pressure signal 274 is used to control patient pressure during the inspiratory and exhalation phases. The electrical pressure signal 274 is also used by the monitoring and alarm systems 221 (see Figure 4). Optionally, the ventilator 100 (see Figures 1 and 4) may include one or more redundant airway pressure transducers (not shown) like the airway pressure transducer 224 to provide a failsafe backup for the airway pressure transducer 224. In embodiments including a redundant airway pressure transducer (not shown), the redundant airway pressure transducer may be connected to the port 275D (see Figure 17B).

The airway pressure transducer 224 may be used by the control system 220 to detect a pressure change and in response to detecting a pressure change, instruct the blower 222 to increase or decrease its speed to adjust the pressure inside the flow line 273. Thus, the control system 220 may use the electrical pressure signal 274 to deliver pressure ventilation and/or help ensure the pressure inside the flow line 273 does not exceed an user supplied peak inspiratory pressure value (e.g., entered via the pressure control input 237 depicted in Figure 6).

Referring to Figure 5A, the airway flow transducer module 225 includes a differential pressure transducer PT4, auto zero solenoid valves SV1 and SV2, and purge solenoid valves SV3 and SV4. Referring to Figure 5E, the control system 220 may selectively activate or deactivate the solenoid valves SV1 -SV4 using control signals 281 -284, respectively.

Referring to Figure 1 , as mentioned above, the patient circuit 1 10 may include the one or more optional ports 1 1 1 . Figure 5A illustrates an implementation of the ventilation assembly 190 configured for use with the patient circuit 1 10 implemented as an active patient circuit (e.g., the active patient circuit 600 depicted in Figure 3A, and the like). In alternate embodiments configured for use with the patient circuit 1 10 implemented as a passive patient circuit (e.g., the passive patient circuit 170 depicted in Figure 2A, the passive patient circuit 440 depicted in Figure 2B, and the like), the ports 275A and 275B, the airway flow transducer module 225, and the exhalation control assembly 226 may be omitted from the ventilation assembly 190.

The airway flow transducer module 225, and the exhalation control assembly 226 illustrated in Figure 5A are configured for use with an active patient circuit (e.g., the active patient circuit 600 depicted in Figure 3A) that includes the airway flow transducer 648 (see Figure 3G). Referring to Figure 5A, the first and second ports 1 1 1 A and 1 1 1 B (see Figure 3C) send first and second pressure signals 109A and 109B, respectively, (e.g., via separate lines or channels) to the differential pressure transducer PT4. The differential pressure transducer PT4 has input ports PA and PB configured to receive the first and second pressure signals 109A and 109B, respectively. The differential pressure transducer PT4 determines a differential pressure based on the first and second pressure signals 109A and 109B, converts the differential pressure to a signal 277 (see Figure 5E), and (as illustrated in Figure 5E) transmits the signal 277 to the control system 220 for further processing thereby. By way of a non-limiting example, the signal 277 may be an analog signal.

The signal 277 may be used to detect when the patient 102 (see Figure 1 ) has initiated a breath. The flow of gases through the active patient circuit 600 (see Figure 3A) is not determined entirely by the blower 222. Instead, the patient's breathing efforts may cause a change in the flow rate through the active patient circuit 600. Thus, the control system 220 may identify that the patient 102 has initiated a breath by identifying a change in the flow rate (encoded in the signal 277) through the active patient circuit 600.

The auto zero solenoid valves SV1 and SV2 are connected to the input ports PA and PB, respectively, of the differential pressure transducer PT4. Further, each of the auto zero solenoid valves SV1 and SV2 is connected to ambient pressure. The differential pressure transducer PT4 can drift over time causing flow measuring errors. To compensate for this error, occasionally (e.g., periodically) the control system 220 energizes (or activates) the auto zero solenoid valves SV1 and SV2 (using the control signals 281 and 282,

respectively) and determines an offset value for the differential pressure transducer PT4. Then, the control system 220 deactivates the auto zero solenoid valves SV1 and SV2 (using the control signals 281 and 282, respectively). After determining the offset value, the control system 220 uses the offset value to compensate future readings (based on the signal 277) accordingly.

The purge solenoid valves SV3 and SV4 are connected to the port 275A. Referring to Figure 5E, the control system 220 occasionally (e.g., periodically) energizes (or activates) the purge solenoid valves SV3 and SV4 (using the control signals 283 and 284, respectively), which allows dry gas from the cough assist valve 204 illustrated in Figure 5A (or the cough assist valve 2000 illustrated in Figure 34A) to flow through the lines, ports, and/or channels (e.g., the optional multi-lumen tube connection 103, the channels 626A and 626B, the channels 632A and 632B, the ports 1 1 1 A and 1 1 1 B, and the like) conducting the pressure signals 109A and 109B to purge those structures of any moisture that may have condensed from the humid patient breathing gas.

Referring to Figure 5E, the exhalation control assembly 226 includes an accumulator A2, a pressure transducer PT8, and solenoid valves SV6-SV8. The accumulator A2 has three ports 267-269 and an internal pressure (referred as the "pilot pressure"). The pressure transducer PT8 is connected to the

accumulator A2, measures the internal pressure inside the accumulator A2, and transmits this value to the control system 220 in an electrical pressure signal 271 (see Figure 5E).

Referring to Figure 5E, the solenoid valves SV6-SV8 are configured to be selectively activated and deactivated by control signals 286-288,

respectively, sent by the control system 220 to the solenoid valves SV6-SV8, respectively. Turning to Figure 5A, the solenoid valve SV6 is connected to the first port 267 of the accumulator A2, the port 275B, and the pilot port 1 1 1 C (see Figure 3C) of the active patient circuit 600 (see Figure 3A). The solenoid valve SV7 is connected to the second port 268 of the accumulator A2 and the port 275B. The solenoid valve SV8 is connected between the third port 269 of the accumulator A2 and the outlet port 166.

The exhalation control assembly 226 provides the pilot pressure (from the accumulator A2) to the pilot port 1 1 1 C (see Figure 3C) of the active patient circuit 600 (see Figure 3A), which as described above, controls the active exhalation valve assembly 604. At the start of the inspiratory phase of a breath, the control system 220 activates the solenoid valve SV6 (using the control signal 286), which connects the pressure of the gases 252 (via the port 275B) to the pilot port 1 1 1 C. This closes the active exhalation valve assembly 604. At the end of the inspiratory phase of a breath, the control system 220 deactivates the solenoid valve SV6 (using the control signal 286), which connects the internal pressure of the accumulator A2 (or the pilot pressure) to the active exhalation valve

assembly 604, which opens the active exhalation valve assembly 604.

Similarly, at the start of the insufflation phase of a cough, the control system 220 activates the solenoid valve SV6 (using the control signal 286), which connects the pressure of the gases 252 (via the port 275B) to the pilot port 1 1 1 C. This closes the active exhalation valve assembly 604. At the end of the

insufflation phase, the control system 220 deactivates the solenoid valve SV6 (using the control signal 286), which connects the internal pressure of the accumulator A2 (or the pilot pressure) to the active exhalation valve

assembly 604. As discussed below, instead of opening the active exhalation valve assembly 604, this maintains the active exhalation valve assembly 604 in the closed configuration. It is noted that during the beginning of the exsufflation phase, the double bellows member 644 may move into the open position as a result of the patient pressure applied to the double bellows member being higher than ambient, but will automatically close when the pressure provided by the patient 102 drops below ambient.

The control system 220 uses the solenoid valves SV7 and SV8 to control the pilot pressure inside the accumulator A2 using feedback provided by the pressure transducer PT8 (via the electrical pressure signal 271 depicted in Figure 5E) to set a pilot pressure for the exhalation phase of a breath that will achieve the desired PEEP. For example, the control system 220 may lower the pilot pressure inside the accumulator A2 by activating the solenoid valve SV8

(using the control signal 288) to vent some of the gases inside the accumulator A2 via the outlet port 166 as the exhaust 167. Conversely, the control system 220 may increase the pilot pressure by activating the solenoid valve SV7 (using the control signal 287) to add some of the gases 252 (obtained via the port 275B) to the inside of the accumulator A2.

Referring to Figure 5E, the control system 220 uses the electrical pressure signal 274 (received from the airway pressure transducer 224) to help control the blower 222. The control system 220 sends a control signal 278 to the motor 272, which directs the blower 222 to provide a desired flow rate and/or a desired amount of pressure to the patient 102. As mentioned above, the flow signal 270 is used to help control the flow rate of the gas 252 during the inspiratory and exhalation phases of a breath. Similarly, the electrical pressure signal 274 is used to control the patient pressure during the inspiratory and exhalation phases of a breath. The flow signal 270 may be used to help control the flow rate of the gas 252 during the insufflation phase and/or the flow rate of the exsufflation gases 253 during the exsufflation phase of a cough. Similarly, the electrical pressure signal 274 is used to control the patient pressure during the insufflation phase and/or the exsufflation phase of a cough.

As explained above, the ventilator 100 adjusts the pressure inside the patient circuit 1 10 (e.g., the passive patient circuit 440 illustrated in Figure 2B) to achieve the preset inspiratory pressure during the inspiratory phase, the baseline pressure or PEEP during the exhalation phase, and PEEP during the pause between the inspiratory and exhalation phases. These adjustments (and adjustments performed during a cough assist maneuver) are made by the control system 220, which monitors the electrical pressure signal 274, and uses the control signal 278 to increase or decrease the speed of the motor 272 to achieve the desired pressure inside the patient circuit 1 10.

The ambient pressure transducer 228 measures an atmospheric pressure value. The ambient pressure transducer 228 provides an ambient electrical pressure signal 280 encoding the atmospheric pressure value to the control system 220. The control system 220 uses the ambient electrical pressure signal 280 to correct the flow rate values (received via the flow signal 270), and/or the exhaled tidal volume value (calculated by the control system 220) to desired standard conditions.

Referring to Figure 5A, as mentioned above, the flow line 273 conducts the flow of the gas 252 from the cough assist valve 204 (or the cough assist valve 2000) to the internal bacteria filter 230. After the gas 252 passes through the internal bacteria filter 230, they exit the internal bacteria filter 230 as the gases 1 12 and enter the patient circuit 1 10 (see Figure 1 ) via the main ventilator connection 104. The internal bacteria filter 230 helps prevent bacteria in the patient circuit 1 10 from contaminating the ventilator 100.

USER INTERFACE

Figure 6 is a block diagram illustrating some exemplary components of the user interface 200. As mentioned above, Figure 4 illustrates the output information 198 sent by the control system 220 to exemplary components of the user interface 200, and the input information 196 received by the control system 220 from exemplary components of the user interface 200.

Referring to Figure 6, the user interface 200 is configured to receive operating parameter values from a user (e.g., a clinician) and to display

information to the user. For example, the user interface 200 may include a display device 240 (e.g., a liquid crystal display), a mode input 235, an inspiratory time input 236, a pressure control input 237, a pressure support input 238, an activate oxygen generator input 239 for activating oxygen generation (described below), a tidal volume input 242, an oxygen flow equivalent 244, a fraction of inspired oxygen ("FI02") input 246, a breath rate input 247, an oxygen pulse volume input 251 , an activate cough assist input 241 , an activate suction input 248 for activing the suction assembly 152 (see Figure 1 ), and an activate nebulizer input 249 for activing the nebulizer assembly 162 (see Figure 1 ). The beginning of the inspiratory phase is referred to as "initiation." The mode input 235 is configured to receive an indication as to whether the ventilator 100 determines when each breath is initiated or the patient 102 determines when each breath is initiated. The breath rate input 247 is configured to receive a rate (e.g., breaths per minute) at which breaths are to be delivered. If the user has indicated (using the mode input 235) that the ventilator 100 determines when each breath is initiated, the ventilator 100 will deliver breaths in accordance with the rate received by the breath rate input 247 (e.g., at regularly timed intervals). On the other hand, If the user has indicated (using the mode input 235) that the patient 102 initiates each breath, the ventilator 100 will automatically deliver breaths as needed to ensure the patient 102 receives breaths at least as frequently as indicated by the rate received by the breath rate input 247.

The ventilator 100 may identify the end of the inspiratory phase using time or a rate of flow of the gases 1 12 to the patient 102. In the latter case, the patient 102 determines when the inspiratory phase ends. The inspiratory time input 236 is configured to receive a value indicating a duration Tj from the initiation of each breath to the end of the inspiratory phase. The ventilator 100 may use the value (indicating the duration Tj) to identify the end of the inspiratory phase. The pressure support input 238 receives an indication that the user would like to use the rate of flow of the gases 1 12 to the patient 102 (instead of the value indicating the duration Tj) to end the inspiratory phase. For example, the ventilator 100 may end the inspiratory phase of a breath when the flow rate of the gases 1 12 is only about 25% of a peak flow rate that occurred during the breath.

The ventilator 100 is configured to deliver the gases 1 12 alone, or a combination of the gases 1 12 and the pulses of oxygen 140. As mentioned above, the ventilator 100 may be configured to provide both traditional volume controlled ventilation and pressure controlled ventilation. To use pressure control, the user may use the pressure control input 237 to enter a peak inspiratory pressure value. The ventilator 100 uses the peak inspiratory pressure value to configure the gases 1 12 alone, or the combination of the gases 1 12 and the pulses of oxygen 140 such that the pressure during the inspiratory phases is at most the peak inspiratory pressure value. The FI02 input 246 is configured to receive an oxygen concentration value. The ventilator 100 uses the oxygen concentration value to configure the gases 1 12 to have an oxygen concentration equal to or approximating the oxygen concentration value.

The oxygen pulse volume input 251 is configured to receive an oxygen pulse volume value (e.g., expressed in milliliters, or a value within a predefined range, such as from 1 to 10, and the like). The ventilator 100 uses the oxygen pulse volume value to configure each of the pulses of oxygen 140 to have a volume equal to or approximating the oxygen pulse volume value.

The tidal volume input 242 is configured to receive a desired total tidal volume value. Referring to Figure 15A, the ventilator 100 uses the desired total tidal volume value to output a volume of the gases 1 12 (illustrated by area 586 and described below) and one of the pulses of oxygen 140 (illustrated by area 584 and described below) during each breath. For each breath delivered, the total tidal volume delivered is the combined volumes of gases 1 12 and the pulse of oxygen 140 delivered during the breath.

The oxygen flow equivalent 244 is configured to receive a desired oxygen delivery rate (expressed in liters per minute) that identifies a rate at which a hypothetical continuous oxygen flow may be bled into a conventional ventilator or the patient circuit 1 10 (see Figure 1 ) from an external source (e.g., a standalone oxygen concentrator). The ventilator 100 uses this value to configure each of the pulses of oxygen 140 (see Figure 1 ) to deliver an amount of oxygen that would provide equivalent oxygenation to the patient 102 (see Figure 1 ) as the hypothetical continuous oxygen flow.

The activate cough assist input 241 indicates that the user would like to perform a cough assist maneuver (discussed below).

OXYGEN ASSEMBLY

Figure 7 A is a schematic diagram illustrating some exemplary components of the oxygen assembly 210. Figure 7B illustrates the control signals 260 sent by the control system 220 to exemplary components of the oxygen assembly 210, and the data signals 262 received by the control system 220 from exemplary components of the oxygen assembly 210.

Referring to Figure 7A, the oxygen assembly 210 is configured to receive the high-pressure oxygen 132 and/or generate oxygen 346 (see Figure 8B) and provide the oxygen 250 to the accumulator 202 (see Figure 5A) of the ventilation assembly 190 and/or provide the pulses of oxygen 140 to the patient oxygen outlet 105. The oxygen assembly 210 may be configured to provide up to about two liters per minute ("LPM") of approximately 90% pure oxygen. In the embodiment illustrated, the oxygen assembly 210 includes an adsorption bed 300, the compressor 302, a first rotary valve assembly 306, two pressure transducers PT2 and PT3, two pressure regulators R1 and R2, an outlet silencer 31 1 , optional solenoid valves SV9 and SV10, an oxygen tank 312, an oxygen sensor 314, a metering valve 320, and an optional second rotary valve assembly 330. Together the compressor 302, the first rotary valve assembly 306, the adsorption bed 300, and the pressure regulators R1 and R2 may be

characterized as being an oxygen generator or oxygen concentrator. The oxygen generator illustrated in the figures and described below implements a vacuum pressure swing adsorption ("VPSA") process. In alternate embodiments, the ventilator 100 may include an oxygen generator that implements at least one of a polymer membrane separation process, an ion transport separation process, a cryogenic process, and the like. Further, the VPSA process described below is a subset of Pressure Swing Adsorption (PSA) and the oxygen generator may be configured to implement a PSA process other than the VPSA process described below.

The adsorption bed 300 is configured to harvest oxygen from the air 1 14 received via the patient air intake 1 16. As will be explained below, the adsorption bed 300 may be configured to at least partially implement a VPSA process that includes a cycle with four phases (described below). The cycle alternately generates the oxygen 346 (see Figure 8B) and the nitrogen-rich gas 122. As the ventilator 100 operates, the cycle is repeated until enough oxygen has been generated to fill the oxygen tank 312. When the oxygen tank 312 is full, the cycles are halted or slowed until a sufficient amount of the oxygen in the oxygen tank 312 has been removed. Then, the cycles are resumed again or sped up as appropriate. The nitrogen-rich gas 122 generated by each cycle is exhausted to the outside environment via the outlet vent 124.

Figures 8A-8D are block diagrams illustrating some exemplary components of the adsorption bed 300. Referring to Figures 8A-8D, in the embodiment illustrated, the adsorption bed 300 includes at least one housing 340 having a first end 341 opposite a second end 343. The housing 340 contains a bed of nitrogen adsorbent material 344 (such as zeolite) between its first and second ends 341 and 343. The bed of nitrogen adsorbent material 344

preferentially absorbs nitrogen. For ease of illustration, the adsorption bed 300 will be described as including a single housing containing a single bed of nitrogen adsorbent material. In alternate embodiments, the adsorption bed 300 may include two or more beds like the bed of nitrogen adsorbent material 344 that are each housed inside separate housings like the housing 340.

As mentioned above, the VPSA process includes a cycle with four phases. Figure 8A illustrates the adsorption bed 300 during a first phase.

Referring to Figure 8A, during the first phase, the air 1 14 is pumped into the housing 340 by the compressor 302 (see Figure 7A). When the housing 340 is pressurized with the air 1 14 (by the compressor 302), nitrogen in the air is preferentially adsorbed by the bed of nitrogen adsorbent material 344, which leaves behind unadsorbed oxygen. The bed of nitrogen adsorbent material 344 may include interstitial spaces in which the unadsorbed oxygen is held or trapped.

Figure 8B illustrates the adsorption bed 300 during a second phase of a cycle of the VPSA process. During the second phase, the oxygen 346 is pumped from the housing 340. The oxygen 346 flows from the interstitial spaces and into the oxygen tank 312 (see Figure 7A).

Figure 8C illustrates the adsorption bed 300 during a third phase of a cycle of the VPSA process. During the third phase, the nitrogen-rich gas 122 is pulled from the bed of nitrogen adsorbent material 344 in the housing 340 (by the compressor 302 illustrated in Figure 7A) and vented to the outside environment via the outlet vent 124 (see Figure 7A).

Figure 8D illustrates the adsorption bed 300 during a fourth phase of a cycle of the VPSA process. During the fourth phase, a flow of "purge" oxygen 348 (e.g., from the oxygen tank 312 illustrated in Figure 7A) may be used to help draw out the nitrogen-rich gas 122 and regenerate the bed of nitrogen adsorbent material 344.

Returning to Figure 7A, the oxygen 346 (see Figure 8B) removed from the adsorption bed 300 flows through the pressure regulator R2, and into the oxygen tank 312 where the oxygen 346 is stored. While this is occurring, the metering valve 320 may be closed, and the pressure regulator R1 may be closed to prevent flow back into the adsorption bed 300. Alternatively, the metering valve 320 may be at least partially open to allow some of the oxygen 346 to flow to the optional second rotary valve assembly 330.

During each cycle, the compressor 302 is configured to alternately push the air 1 14 into the adsorption bed 300 (through the first rotary valve assembly 306) and pull the nitrogen-rich gas 122 out of the adsorption bed 300 (through the first rotary valve assembly 306). The compressor 302 may be driven by a motor 350 and may include a sensor 352 (e.g., an encoder) configured to provide a signal 354 encoding the direction and speed of rotation of the motor 350 to the control system 220. Referring to Figure 7B, the motor 350 is configured to receive instructions from the control system 220 encoded in a control signal 356. The instructions in the control signal 356 instruct the motor 350 to switch on or off and/or indicate in which direction the motor 350 is to rotate when switched on. Further, the control signal 356 may instruct the motor 350 at which speed to run. Referring to Figure 7A, when the motor 350 runs in a first direction, the

compressor 302 pushes air into the adsorption bed 300. On the other hand, when the motor 350 runs in a second direction, the compressor 302 pulls the nitrogen- rich gas 122 (see Figures 8C and 8D) from the adsorption bed 300. By way of a non-limiting example, the motor 350 may be implemented as a brushless direct current motor.

Figure 9 is an illustration of the metering valve 320. Referring to Figure 9, the pressure transducer PT3 is connected across the metering valve 320. Thus, the pressure transducer PT3 may determine a pressure differential value across the metering valve 320. Referring to Figure 7B, the pressure transducer PT3 provides a pressure differential signal 358 encoding the pressure differential value to the control system 220.

Referring to Figures 7B and 9, the metering valve 320 may be driven by a stepper motor 322 configured to receive a control signal 360 from the control system 220 encoding a stepper position value. The stepper motor 322 is configured to move to the stepper position value encoded in the control signal 360. In the embodiment illustrated, the metering valve 320 is a stepper driven proportioning valve characterized by three variables: (1 ) valve position, (2) differential pressure across the valve (as measured by the pressure transducer PT3), and (3) flow rate. When a particular flow rate is desired (e.g., entered by the user via the flow rate input 248 depicted in Figure 6), the control system 220 uses the pressure differential signal 358 (encoding the pressure differential value) and the particular flow rate to "look up" a corresponding stepper position value in a characterization table 362. In other words, the characterization table 362 stores stepper position values each associated with a flow rate value and a pressure differential value. Thus, a particular pressure differential value and a particular flow rate value may be used by the control system 220 to determine a stepper position value. Then, the control system 220 encodes the stepper position value in the control signal 360 and sends it to the stepper motor 322. This process may be repeated occasionally (e.g., every few milliseconds) to provide an

instantaneously desired oxygen flow rate.

Referring to Figure 9, a position sensor 368 may be operatively coupled to the metering valve 320 and used to determine a home position. The position sensor 368 provides a position signal 370 to the control system 220 that encodes whether the metering valve 320 is in the home position (e.g., true or "on") or at a position other than the home position (e.g., false or "off").

Referring to Figure 7A, the pressure regulator R2 may be characterized as being a back pressure regulator. The pressure regulator R2 may be configured to prevent the pressure inside the adsorption bed 300 from exceeding a first threshold pressure value (e.g., approximately 10 pounds per square inch ("PSIG")). For example, the pressure regulator R2 may be configured to allow oxygen to flow automatically from the adsorption bed 300 when the pressure inside the adsorption bed 300 reaches the first threshold value. The pressure regulator R2 may also be configured to prevent gases from flowing into the adsorption bed 300. This allows the pressure regulator R2 to control the pressure during the first phase (see Figure 8A) and the second phase (see Figure 8B).

The pressure regulator R1 may be characterized as being a vacuum regulator. The pressure regulator R1 may be configured to prevent the pressure inside the adsorption bed 300 from falling below a second threshold pressure value (e.g., approximately -7 PSIG). Thus, the pressure regulator R1 regulates the pressure in the adsorption bed 300 to the second threshold pressure during the third phase (see Figure 8C) and the fourth phase (see Figure 8D). For example, the pressure regulator R1 may be configured to allow oxygen to flow automatically into the adsorption bed 300 (e.g., from the oxygen tank 312) when the pressure inside the adsorption bed 300 falls below the second threshold value. The pressure regulator R1 may also be configured to prevent gases inside the adsorption bed 300 from flowing out of the adsorption bed 300 toward the metering valve 320 (see Figure 1 ).

The optional solenoid valves SV9 and SV10 may be configured to maintain the pressure inside the oxygen tank 312 between a minimum threshold pressure value (e.g., approximately 4 PSIG) and a maximum threshold pressure value (e.g., approximately 10 PSIG). The solenoid valves SV9 and SV10 are connected in a parallel arrangement to a conduit or flow line (not shown) that conducts the high-pressure oxygen 132 (e.g., from the high-pressure oxygen source 120 illustrated in Figure 1 ) to the oxygen tank 312. The control

system 220 selectively activates and deactivates the solenoid valves SV9 and SV10 using control signals 380 and 382 (see Figure 7B), respectively, to maintain the pressure in oxygen tank 312 between the minimum and maximum threshold pressure values. Thus, together the control system 220 and the solenoid valves SV9 and SV10 perform the functions of a digital (on/off) regulator.

The control system 220 may automatically stop the oxygen assembly 210 from performing the VPSA process when the high-pressure external oxygen source 120 is connected. For example, the control system 220 may slow or shut down the VPSA process when pressure in the oxygen tank 312 exceeds an upper threshold (e.g., 10 PSIG). In this manner, the control system 220 may slow or shut down the VPSA process when the adsorption bed 300 is operating or the high-pressure external oxygen source 120 is connected. On the other hand, when the pressure inside the oxygen tank 312 falls below a lower pressure threshold (e.g., 4 PSIG), the control system 220 may restart or accelerate the VPSA process.

The oxygen tank 312 may be implemented as a rigid chamber configured to store a predetermined amount of oxygen (e.g., about 56 cubic inches of oxygen). The outlet silencer 31 1 helps muffle sounds created by the compressor 302.

Referring to Figures 7A and 7B, the oxygen sensor 314 measures oxygen concentration in the oxygen tank 312, and encodes an oxygen

concentration value in an oxygen concentration signal 378 provided to the control system 220. The control system 220 may use the oxygen concentration signal 378 to monitor the oxygen assembly 210 to ensure it is working properly. If the oxygen concentration signal 378 indicates the oxygen concentration is too low, the control system 220 may conclude that the oxygen assembly 210 is not functioning properly.

The pressure transducer PT2 monitors the pressure between the first and second rotary valve assemblies 306 and 330 (which may be

characterized as being a pump pressure supplied to the second rotary valve assembly 330). Referring to Figure 7B, the pressure transducer PT2 provides an electrical pressure signal 374 encoding that pressure value to the control system 220.

FIRST ROTARY VALVE ASSEMBLY

Figure 10A is a perspective view of a first side of an exemplary embodiment of the first rotary valve assembly 306. Figure 10B is a perspective view of a second side of the first rotary valve assembly 306 opposite the first side. Referring to Figure 10A, the first rotary valve assembly 306 includes a motor assembly 830 mounted to an outer housing 832. The motor assembly 830 includes a stepper motor 833 (see Figure 7B) and a shaft 836 (see Figures 10B and 10C). The stepper motor 833 is configured to rotate the shaft 836.

Referring to Figure 10B, a position sensor 834 may be mounted on a printed circuit board ("PCB") 837 fastened to the outer housing 832 opposite the motor assembly 830. In such embodiments, the PCB 837 may include an opening through which an end of the shaft 836 opposite the motor assembly 830 may pass.

Figure 10C depicts the first side of the first rotary valve assembly 306 and the shaft 836 of the motor assembly 830. Other parts of the motor assembly 830 have been omitted in Figure 10C. Referring to Figure 10C, in the embodiment illustrated, the outer housing 832 has an outer shape that is generally cross or cruciform-shaped. Thus, the outer housing 832 has four arms 841 -844 that extend outwardly from a central region 845 of the outer housing 832. In the embodiment illustrated, the motor assembly 830 (see Figure 10A) is mounted to the central region 845.

Figure 10D depicts the second side of the first rotary valve assembly 306 with the outer housing 832 and the PCB 837 removed. As shown in Figure 10D, the arms 841 -844 (see Figure 10B) house poppet valves CV1 -CV4, respectively. Inside the outer housing 832 (see Figure 10B), the poppet valves CV1 and CV3 are positioned opposite one another, and the poppet valves CV2 and CV4 are positioned opposite one another. The first rotary valve

assembly 306 includes a cam 850 mounted on the shaft 836 (see Figures 10B and 10C) and configured to selectively actuate the poppet valves CV1 -CV4. The cam 850 rotates with the shaft 836 as the motor assembly 830 (see Figure 10A) rotates the shaft 836. Referring to Figure 7B, the position sensor 834 provides a position signal 835 to the control system 220 that encodes whether the cam 850, the stepper motor 833 (see Figure 10A and 10B), and/or the shaft 836 (see Figure 10B and 10C) is in a home position (e.g., true or "on") or at a position other than the home position (e.g., false or "off").

Referring to Figure 10C, each of the arms 841 -844 is open at its distal end 846. The open distal ends 846 of the arms 841 -844 are closed by end caps 851 -854, respectively. The end caps 851 -854 may be fastened to the outer housing 832 by fasteners 855.

Referring to Figure 10B, the arms 841 -844 include inlet openings 856A-856D, respectively, configured to receive a gas or mixture of gases, and outlet openings 858A-858D, respectively, through which a gas or mixture of gases may exit.

Referring to Figure 10D, each of the poppet valves CV1 -CV4 includes an open ended housing 860 with a lateral inlet 862 and a lateral outlet 864. The lateral inlets 862 of the poppet valves CV1 -CV4 are aligned and in fluid communication with the inlet openings 856A-856D, respectively, of the outer housing 832. Similarly, the lateral outlets 864 of the poppet valves CV1 -CV4 are aligned and in fluid communication with the outlet openings 858A-858D, respectively, of the outer housing 832.

One or more seals 866 and 868 (e.g., O-ring type seals) may be positioned between the outer housing 832 and the housing 860. For example, the seal 868 may be positioned between the lateral inlet 862 and the lateral outlet 864. By way of another non-limiting example, one of the seals 866 may be positioned between each of the open distal ends 846 of the arms 841 -844 and the end caps 851 -854, respectively. The poppet valves CV1 -CV4 are substantially identical to one another. For the sake of brevity, only the poppet valve CV1 will be described in detail. Figure 10E is an exploded perspective view of the poppet valve CV1 , the end cap 851 , and the fasteners 855. Referring to Figure 10E, the housing 860 has an open proximal end portion 870 opposite an open distal end portion 872. The open distal end portion 872 is closed by the end cap 851 when the end cap 851 is fastened to the outer housing 832. Similarly, the housings 860 of the poppet valves CV2-CV4 are closed at their open distal end portions 872 by the end caps 852-853, respectively, when the end caps 852-854 are fastened to the outer housing 832

Figure 10F is a cross sectional view of the first rotary valve assembly 306 with the cam 850 positioned to open the poppet valves CV2 and CV4. Figure 10G is a cross sectional view of the first rotary valve assembly 306 with the cam 850 positioned to open the poppet valves CV1 and CV3.

Referring to Figure 10F, a generally cylindrically shaped guide portion 876 extends inwardly from the open proximal end portion 870 (see Figure 10E) of the housing 860. An open-ended channel 877 is formed in the guide portion 876. A shoulder 878 is formed on the inside the housing 860 between the lateral inlet and outlet 862 and 864.

Turning to Figure 10E, inside the housing 860, the poppet valve CV1 has a pushrod 880 biased away from the end cap 851 by a biasing assembly 884. Referring to Figure 10F, the pushrod 880 extends through the channel 877 and exits the housing 860 though the open proximal end portion 870 (see Figure 10E). Turning to Figure 10E, the pushrod 880 may have a circumferential recess 879 form near its proximal end portion 881 .

A ring-shaped diaphragm 886 may extend around the pushrod 880 near the proximal end portion 881 . In the embodiment illustrated, the diaphragm 886 has a circular central portion P2 having a center aperture 887 through which the pushrod 880 extends with the inner edge portion of the central portion P2 positioned within the recess 879, and thereby the central portion P2 firmly grips the pushrod 880. The diaphragm 886 may close and seal the open proximal end portion 870 of the housing 860. However, the diaphragm 886 may flex or stretch longitudinally to allow the pushrod 880 to move longitudinally with respect to the housing 860. In the embodiment illustrated in Figure 10F, the diaphragm 886 has a circular outer peripheral portion P1 positioned between the open proximal end portion 870 of the housing 860 and the outer housing 832, and thereby the outer peripheral portion P1 is firmly clamped in place.

Referring to Figure 10E, the circular outer peripheral portion P1 of the diaphragm 886 is connected to the circular central portion P2 by a curved or contoured intermediate portion P3. The intermediate portion P3 may be

characterized as being a convolute. A circle positioned midway between the outer peripheral portion P1 and the central portion P2 may be characterized as being located at the center of the convolute. The diaphragm 886 has an effective area which extends from the circle at the center of the convolute to the central portion P2.

Turning to Figure 10E, the pushrod 880 has a distal end portion 882 opposite the proximal end portion 881 . The proximal end portion 881 has a cam follower 883 (see Figures 10C and 10E) formed therein. In the embodiment illustrated, the proximal end portion 881 may taper outwardly and be generally cone-shaped. The cam follower 883 (see Figure 10C) may be implemented as a planar or contoured lower surface of the proximal end portion 881.

A ring-shaped seat 896 is fixedly attached to the shoulder 878 formed on the inside the housing 860. In the embodiment illustrated, the seat 896 has a central through-hole 897 through which the pushrod 880 extends

unobstructed.

The distal end portion 882 of the pushrod 880 has a longitudinally extending channel 885 formed therein. The channel 885 is open at the distal end portion 882 of the pushrod 880. A disc-shaped poppet member 892 is fastened to the distal end portion 882 of the pushrod 880 by a fastener 894 (e.g., a bolt, screw, and the like) that extends into the open end of the channel 885. Thus, the fastener 894 couples the poppet member 892 to the distal end portion 882 of the pushrod 880, which moves therewith as a unit when the pushrod 880 moves inside the housing 860.

Referring to Figure 10F, when the poppet member 892 is pressed against the seat 896, the poppet member 892 closes the central through-hole 897 and divides the interior of the housing 860 into a proximal chamber 900 and a distal chamber 902. Thus, the poppet member 892 may seal the proximal and distal chambers 900 and 902 from one another. The lateral inlet 862 is in communication with the proximal chamber 900, and the lateral outlet 864 is in communication with the proximal chamber 900. On the other hand, referring to Figure 10G, when the poppet member 892 is spaced apart distally from the seat 896, the central through-hole 897 is uncovered and the proximal and distal chambers 900 and 902 are in communication with one another. Thus, in this configuration, a gas or mixture of gases may flow between the proximal and distal chambers 900 and 902. In other words, a pathway is opened between the lateral inlet and outlet 862 and 864.

The distal end portion 882 of the pushrod 880 is adjacent the biasing assembly 884. In the embodiment illustrated, the biasing assembly 884 includes a biasing member 888 (e.g., a coil spring), and an end cap 890. The biasing member 888 applies an inwardly directed force on the pushrod 880, which helps insure the pushrod 880 maintains contact with the cam 850. The end cap 890 rests upon the fastener 894 and is positioned between the disc-shaped poppet member 892 and the end cap 851 . The biasing member 888 extends between the end cap 890 and the end cap 851 and applies the biasing force to the end cap 890, which translates that force to the fastener 894 and/or the poppet member 892. In turn, the fastener 894 and/or the poppet member 892 translates the biasing force to the pushrod 880.

The cam 850 may be characterized as having two lobes or high points 910 and 912 opposite one another. When one of the high points 910 and 912 is adjacent the cam follower 883 (see Figures 10C and 10E) of the pushrod 880 of the poppet valve CV1 , the high point 910 or 912 pushes the pushrod 880 outwardly toward the end cap 851. This pushes the disc-shaped poppet member 892 away from the seat 896 (as illustrated in Figure 10G) and opens the central through-hole 897. This opens the poppet valve CV1 and allows a gas or mixture of gases to flow though the poppet valve CV1 . On the other hand, as illustrated in Figure 10G, when neither of the high points 910 and 912 are adjacent the cam follower 883 (see Figures 10C and 10E) of the pushrod 880 of the poppet valve CV1 , the pushrod 880 is biased inwardly away from the end cap 851 by the biasing assembly 884. The pushrod 880 thereby pulls the disc-shaped poppet member 892 toward the seat 896 causing the poppet member 892 to cover or close the central through-hole 897. This closes the poppet valve CV1 and prevents a gas or mixture of gases from flowing though the poppet valve CV1 . Because the ventilator 100 may be required to function over a long life span (e.g., more than about 30,000 hours), the first rotary valve assembly 306 may experience about 15,000,000 VPSA cycles. To satisfy this requirement, each of the poppet valves CV1 -CV4 may have a "balanced" valve configuration.

Whenever one of the poppet valves CV1 -CV4 is closed, pressure inside the proximal chamber 900 acts upon both the effective area of the diaphragm 886 and a portion of the poppet member 892 covering (or closing) the central through-hole 897 of the seat 896. The area of the portion of the poppet member 892 covering (or closing) the central through-hole 897 of the seat 896 is approximately equal to the effective area of the diaphragm 886. When the pressure inside the proximal chamber 900 is negative (or a vacuum), an inwardly (toward the proximal chamber 900) directed force acts upon the effective area of the diaphragm 886. At the same time, an inwardly (toward the proximal chamber 900) directed force acts on the portion of the poppet member 892 covering the central through-hole 897 of the seat 896. Similarly, when the pressure inside the proximal

chamber 900 is positive, an outwardly (away from the proximal chamber 900) directed force acts upon the effective area of the diaphragm 886 and an outwardly (or distally) directed force acts on the portion of the poppet member 892 covering the central through-hole 897 of the seat 896. Thus, when the proximal

chamber 900 is sealed by the poppet member 892, forces directed in opposite directions act upon the effective area of the diaphragm 886 and the area of the portion of the poppet member 892 covering (or closing) the central through-hole 897 of the seat 896. Because (as mentioned above), the effective area of the diaphragm 886 and the area of the portion of the poppet member 892 covering (or closing) the central through-hole 897 of the seat 896 are approximately equal, net force on the pushrod 880 is zero. This balancing feature helps reduce the force of the pushrod 880 on the cam follower 883 and the cam 850, thereby reducing the wear and extending the life.

As explained above, each of the poppet valves CV1 -CV4 is biased into a closed position by its biasing assembly 884. Each of the poppet valves

CV1 -CV4 includes the cam follower 883 (see Figures 10C and 10E) that abuts the cam 850. As the cam 850 rotates, it pushes opposing ones of the poppet valves CV1 -CV4 outwardly opening them. If the poppet valves CV1 and CV3 are in open positions, the poppet valves CV2 and CV4 are in closed positions and vice versa. Referring to Figure 7B, the first rotary valve assembly 306 (e.g., the stepper motor 833) is configured to receive a control signal 376 from the control system 220 encoding a cam position. The first rotary valve assembly 306 (e.g., the stepper motor 833) is also configured to rotate the cam 850 to the position encoded in the control signal 376.

Referring to Figure 7A, the poppet valve CV3 (see Figures 10G) is connected to the compressor 302 and the adsorption bed 300. The control system 220 makes the pressure inside the distal chamber 902 of the poppet valve CV3 less than the pressure inside the proximal chamber 900 of the poppet valve CV3 by configuring the compressor 302 to provide suction to the distal

chamber 902.

The poppet valve CV1 (Figures 10G) is connected to the compressor 302 and the outlet vent 124. The control system 220 makes the pressure inside the distal chamber 902 of the poppet valve CV1 less than the pressure inside the proximal chamber 900 of the poppet valve CV1 by configuring the compressor 302 to push the nitrogen-rich gas 122 (see Figures 8C and 8D) into the proximal chamber 900.

When the poppet valves CV1 and CV3 are open as illustrated in Figure 10G, the poppet valve CV3 receives the nitrogen-rich gas 122 (see Figures 8C and 8D) from the adsorption bed 300 and provides it to the compressor 302. At the same time, the poppet valve CV1 allows the nitrogen-rich gas 122 pumped from the adsorption bed 300 (via the poppet valve CV3) by the compressor 302 to flow out of the compressor 302 and exit the ventilator 100 via the outlet vent 124. Optionally, the poppet valve CV3 may be connected to the second rotary valve assembly 330. As will be explained below, the compressor 302 may provide the suction 154 to the suction assembly 152 via the second rotary valve

assembly 330.

Referring to Figure 7A, the poppet valve CV4 (see Figures 10F) is connected to the compressor 302 and the patient air intake 1 16. The control system 220 makes the pressure inside the proximal chamber 900 of the poppet valve CV4 less than the pressure inside the distal chamber 902 of the poppet valve CV4 by configuring the compressor 302 to provide suction to the proximal chamber 900. The poppet valve CV2 (see Figure 10F) is connected to the compressor 302 and the adsorption bed 300. The control system 220 makes the pressure inside the distal chamber 902 of the poppet valve CV2 greater than the pressure inside the proximal chamber 900 of the poppet valve CV2 by configuring the compressor 302 to provide the pressurized air 1 14 pumped by the compressor 302 to the distal chamber 902.

When the poppet valves CV2 and CV4 are open as illustrated in Figure 10F, the poppet valve CV4 allows the air 1 14 to be pumped via the patient air intake 1 16 into the compressor 302. At the same time, the poppet valve CV2 provides the pressurized air 1 14 from the compressor 302 to the adsorption bed 300. Optionally, the poppet valve CV2 may be connected to the second rotary valve assembly 330. As will be explained below, the gases 164 provided to the second rotary valve assembly 330 may be used to implement the nebulizer assembly 162.

As mentioned above, in the embodiment illustrated, the oxygen assembly 210 generates the oxygen 364 (see Figure 8B) using the VPSA process, which may have four phases that are labeled "PHASE 1 ," "PHASE 2," "PHASE 3," and "PHASE 4" across the top of Figure 1 1 .

In Figure 1 1 , an upper line 400 depicts pressure experienced by the bed of nitrogen adsorbent material 344 (see Figures 8A-8D) during the four phases of the VPSA process. Referring to Figure 1 1 , the line 400 may be determined by the control system 220 based on the electrical pressure signal 374 (see Figure 7B) provided by the pressure transducer PT2. A lower line 410 depicts feed flow rate through the bed of nitrogen adsorbent material 344 (see Figures 8A-8D) during the four-phases of the VPSA process.

Lines 421 and 423 show that the poppet valves CV1 and CV3, respectively, are transitioned from open ("passing") to closed ("not passing") at the beginning of the first phase and then the poppet valves CV1 and CV3 are transitioned from closed ("not passing") to open ("passing") at the beginning of third phase. Thus, the poppet valves CV1 and CV3 are closed during most of the first phase and all of the second phase. Further, the poppet valves CV1 and CV3 are open during most of the third phase and all of the fourth phase.

Conversely, lines 422 and 424 show that the poppet valves CV2 and CV4, respectively, are transitioned from closed ("not passing") to open ("passing") at the beginning of the first phase and then the poppet valves CV2 and CV4 are transitioned from open ("passing") to closed ("not passing") at the beginning of third phase. Thus, the poppet valves CV2 and CV4 are open during most of the first phase and all of the second phase. Further, the poppet valves CV2 and CV4 are closed during most of the third phase and all of the fourth phase.

Figure 12 is a flow diagram of a method 500 performed by the control system 220. The method 500 at least partially implements the VPSA process. As the method 500 is performed, the pressure transducer PT2 (see Figures 7A and 7B) occasionally obtains pressure values for the adsorption bed 300 and sends the electrical pressure signal 374 to the control system 220.

In first block 502, the control system 220 begins the first phase of the VPSA process by opening the poppet valves CV2 and CV4, and closing the poppet valves CV1 and CV3. At this point, the pressure regulator R2 is closed.

In next block 504, the control system 220 instructs the motor 350 of the compressor 302 to pump the air 1 14 from the patient air intake 1 16 into the adsorption bed 300. The motor 350 of the compressor 302 may run at a relatively high speed while drawing the air 1 14 from the patient air intake 1 16.

In block 506, the control system 220 determines that the pressure inside the adsorption bed 300 has reached the first threshold pressure value (e.g., approximately 10 PSIG). When the pressure inside the adsorption bed 300 reaches the first threshold pressure value, the pressure regulator R2 automatically opens. At this point, the first phase ends and the second phase begins. During the second phase, nitrogen is adsorbed by the adsorption bed 300 from the air 1 14 and referring to Figure 8B, the oxygen 346 (e.g., 90% pure oxygen) flows out of the adsorption bed 300 through the pressure regulator R2. The oxygen that passes through the pressure regulator R2 during the second phase is stored in the oxygen tank 312.

Returning to Figure 12, in next block 508, at the start of the second phase, the control system 220 reduces the speed of the motor 350. Referring to Figure 8B, during the second phase, a mass transfer zone 430 moves away from the first end 341 (in a direction identified by an arrow "D1 ") through to the second end 343. Gas on a first side 432 of the mass transfer zone 430 near the first end 341 is air, and gas on a second side 434 of the mass transfer zone 430 near the second end 343 is about 90% oxygen. The compressor 302 may run relatively slowly during the second phase to facilitate effective nitrogen adsorbtion. In block 510, the control system 220 detects the end of the second phase, which ends when the mass transfer zone 430 reaches the second end 343. The control system 220 may determine the second phase has ended after a predetermined amount of time (e.g., about one second) has elapsed. In some embodiments, the control system 220 may also use a secondary means (e.g., pressure) to help determine when the second phase has ended. At this point, the adsorption bed 300 is fully saturated with nitrogen, the second phase ends, and the third phase begins.

At the start of the third phase, in block 512, the control system 220 opens the poppet valves CV1 and CV3, and closes the poppet valves CV2 and

CV4. At this point, the pressure regulator R1 is closed.

In next block 514, the control system 220 instructs the motor 350 of the compressor 302 to pump the nitrogen-rich gas 122 from the adsorption bed 300 and into the external environment through the outlet vent 124. The compressor 302 may run at a relatively high speed as it draws the nitrogen-rich gas 122 out of the adsorption bed 300.

In block 516, the control system 220 determines that the pressure inside the adsorption bed 300 has reached the second threshold pressure value (e.g., approximately -7 PSIG). At this point, the third phase ends and the fourth phase begins.

At the beginning of the fourth phase, in block 518, the control system 220 may reduce the speed of the motor 350 to a relatively slow speed.

In block 520, the control system 220 purges the adsorption bed 300 with oxygen from the oxygen tank 312. In block 520, the pressure regulator R1 opens automatically to allow the flow of "purge" oxygen 348 (see Figure 8D) from the oxygen tank 312 to flow through the adsorption bed 300 (e.g., in a direction identified by an arrow "D2"). The mass transfer zone 430 also moves away from the second end 343 (in a direction identified by an arrow "D2") through to the first end 341 . The low pressure inside the adsorption bed 300 combined with the flow of purge oxygen 348 draws the nitrogen out and regenerates the adsorption bed 300. When the purge is completed, the fourth phase ends, which completes one four-phase cycle, and the method 500 terminates. The control system 220 may begin another cycle by returning to block 502 of the method 500. Figures 13A-13D are schematic diagrams of the second rotary valve assembly 330. The second rotary valve assembly 330 may be substantially similar to the first rotary valve assembly 306 (see Figures 10A and 10B).

However, the second rotary valve assembly 330 includes a cam 530 with a single lobe or high point 532, which is unlike the cam 850 of the first rotary valve assembly 306, which has two high points 910 and 912 (see Figure 10F) opposite one another.

Referring to Figures 13A-13D, the cam 530 of the second rotary valve assembly 330 is configured to selectively actuate four poppet valves CV5- CV8 one at a time. Each of the poppet valves CV5-CV8 may be substantially similar to the poppet valve CV1 illustrated in Figure 10E.

In the second rotary valve assembly 330, the poppet valves CV5 and CV7 are positioned opposite one another. Similarly, the poppet valves CV6 and CV8 are positioned opposite one another. The poppet valves CV5-CV8 are biased into a closed position. Each of the poppet valves CV5-CV8 has a pushrod 538 (substantially similar to the pushrod 880 depicted in Figure 10E) with a cam follower 540 (substantially similar to the cam follower 883 depicted in Figure 10C) that abuts the cam 530. As the cam 530 rotates, it pushes only one of the pushrods 538 of the poppet valves CV5-CV8 at a time outwardly and into an open position.

Further, as explained above with respect to the first rotary valve assembly 306, each of the poppet valves CV5-CV8 may include a poppet member (substantially identical to the poppet member 892) configured to move with respect to a seat (substantially identical to the seat 896) to selectively connect a proximal chamber (like the proximal chamber 900) with a distal chamber (like the distal chamber 902). In such embodiments, after the cam 530 pushes the pushrod 538 of a selected one of the poppet valves CV5-CV8 outwardly, the selected poppet valve opens.

Referring to Figure 7B, the second rotary valve assembly 330 includes a stepper motor 542 and a position sensor 544 substantially similar to the stepper motor 833 and the position sensor 834 of the first rotary valve

assembly 306. The second rotary valve assembly 330 (e.g., the stepper motor 542) is configured to receive a control signal 546 from the control system 220 encoding a cam position. The second rotary valve assembly 330 (e.g., the stepper motor 542) is also configured to rotate the cam 530 to the position encoded in the control signal 546. The position sensor 544 provides a position signal 548 to the control system 220 that encodes whether the stepper motor 542 and/or the cam 530 is in a home position (e.g., true or "on") or at a position other than the home position (e.g., false or "off").

Referring to Figure 13A, the poppet valve CV5 has an inlet 550 connected to the suction connection 150 and an outlet 552 connected to the poppet valve CV3 (see Figures 10D, 10F, and 10G). When the poppet valves CV1 and CV3 are open, the poppet valve CV5 may be opened (as shown in Figure 13A) to receive the suction 154 from the compressor 302 and provide the suction 154 to the suction connection 150. Any gases received from the suction assembly 152 (see Figure 1 ) via the suction connection 150, may be pumped by the compressor 302 out the outlet vent 124 via the poppet valve CV1. The nitrogen-rich gas 122 may be pumped by the compressor 302 at the same time the suction 154 is provided.

Referring to Figure 13B, the poppet valve CV6 has an inlet 554 connected to the nebulizer assembly 162 and an outlet 556 connected to the poppet valve CV2. When the poppet valves CV2 and CV4 are open, the poppet valve CV6 may be opened (as shown in Figure 13B) to provide the gases 164 to the nebulizer connection 160 instead of providing the air 1 14 to the adsorption bed 300. Thus, the compressor 302 may power the nebulizer assembly 162 (see Figure 1 ).

Referring to Figure 13C, the poppet valve CV7 has an inlet 558 connected to the metering valve 320 and an outlet 560 connected to the accumulator 202. When the poppet valve CV7 is open as shown in Figure 13C, oxygen output from the metering valve 320 is provided to the accumulator 202.

Referring to Figure 13D, the poppet valve CV8 has an inlet 562 connected to the metering valve 320 and an outlet 564 connected to the patient circuit 1 10. When the poppet valve CV8 is open as shown in Figure 13D, the oxygen 364 (from the adsorption bed 300) and/or the oxygen from the oxygen tank 312 is provided directly to the patient circuit 1 10. CONTROL SYSTEM

Referring to Figures 5E and 7B, the control system 220 includes a memory 700 connected to one or more processors 710. The memory stores the table 362 and instructions 720 executable by the processor(s) 710.

The processor(s) 710 may be implemented by one or more microprocessors, microcontrollers, application-specific integrated circuits ("ASIC"), digital signal processors ("DSP"), combinations or sub-combinations thereof, or the like. The processor(s) 710 may be integrated into an electrical circuit, such as a conventional circuit board, that supplies power to the processor(s) 710. The processor(s) 710 may include internal memory and/or the memory 700 may be coupled thereto. The present invention is not limited by the specific hardware component(s) used to implement the processor(s) 710 and/or the memory 700.

The memory 700 is a computer readable medium that includes instructions or computer executable components that are executed by the processor(s) 710. The memory 700 may be implemented using transitory and/or non-transitory memory components. The memory 700 may be coupled to the processor(s) 710 by an internal bus 715.

The memory 700 may include random access memory ("RAM") and read-only memory ("ROM"). The memory 700 contains instructions and data that control the operation of the processor(s) 710. The memory 700 may also include a basic input/output system ("BIOS"), which contains the basic routines that help transfer information between elements within the ventilator 100.

Optionally, the memory 700 may include internal and/or external memory devices such as hard disk drives, floppy disk drives, and optical storage devices (e.g., CD-ROM, R/W CD-ROM, DVD, and the like). The ventilator 100 may also include one or more I/O interfaces (not shown) such as a serial interface (e.g., RS-232, RS-432, and the like), an IEEE-488 interface, a universal serial bus ("USB") interface, a parallel interface, and the like, for the communication with removable memory devices such as flash memory drives, external floppy disk drives, and the like.

The processor(s) 710 is configured to execute software implementing the VPSA process (which may include performing the method 500 illustrated in Figure 12) and/or delivering oxygen in accordance with oxygen delivery methods described below. Such software may be implemented by the instructions 720 stored in memory 700.

OXYGEN DELIVERY

Referring to Figure 1 , as mentioned above, the ventilator 100 delivers the inspiratory gases 108 directly to the patient connection 106 (via the patient circuit 1 10). Oxygen may be delivered to the patient 102 in one of two ways: (1 ) as pulses of oxygen 140 delivered directly to the patient connection 106, or (2) in the gases 1 12 that contain the air 1 14 optionally blended with the oxygen 250 and/or the low pressure oxygen 128 in the accumulator 202.

Figures 14A and 14B are graphs illustrating traditional delivery of oxygen by a conventional portable ventilator connected to an external low pressure continuous flow source, such as a stand-alone oxygen concentrator. In Figure 14A, the conventional portable ventilator is using traditional volume controlled ventilation to deliver breaths. In both Figures 14A and 14B, the x-axis is time. The inspiratory phase occurs during the duration Tj. The exhalation phase occurs during a duration T _E . The pause occurs during a duration T _P .

In Figure 14A, the y-axis is flow rate within the patient's airway.

Referring to Figure 14A, a dashed line 570 illustrates a continuous flow of oxygen delivered during both the inspiratory and expiratory phases. A solid line 572 illustrates a flow of air provided by the conventional portable ventilator during both the inspiratory and expiratory phases. The solid line 572 is determined by a set of desired ventilator settings.

An area 574 illustrates an inspiratory volume of air received by the patient, and an area 575 illustrates an expiratory volume of air expelled by the patient. The area 574 represents the desired total tidal volume selected by the user.

A shaded area 576 illustrates a volume of effective oxygen provided to the patient during the inspiratory phase. An area 578 illustrates a volume of oxygen that is delivered by the conventional portable ventilator during the inspiratory phase but is unusable (e.g., trapped in one or more anatomical dead spaces). Together the areas 576 and 578 form a volume of gases that exceed the desired ventilator settings (e.g., a desired total tidal volume). Specifically, together the areas 574, 576, and 578 form a total inspiratory volume (of oxygen and air) delivered by the conventional portable ventilator that exceeds the desired total tidal volume. An area 580 illustrates a volume of oxygen delivered by the conventional portable ventilator during the exhalation phase that is wasted by the conventional portable ventilator.

In Figure 14B, the conventional portable ventilator is using traditional pressure controlled ventilation to deliver breaths. Referring to Figure 14B, the y- axis is pressure within the patient's airway. A pressure value "PIP" identifies the peak inspiratory pressure input or desired by the user. A solid line 581 illustrates patient airway pressure during both the inspiratory and expiratory phases.

Unfortunately, as Figure 14B illustrates, the continuous flow of oxygen (illustrated in Figure 14A by the dashed line 570) causes the pressure within the patient's airway to exceed the peak inspiratory pressure input by the user (the pressure value "PIP").

As shown in Figures 14A and 14B, the conventional portable ventilator is inefficient. For example, the conventional portable ventilator wastes all of the continuous flow of oxygen (illustrated in Figure 14A by the dashed line 570) delivered during non-inspiratory time. Further, because the continuous flow of oxygen delivered to the patient is not controlled (e.g., by ventilator volume or inspiratory pressure settings), only a portion of the oxygen (illustrated by the shaded area 576) delivered is actually effective. Further, the continuous flow of oxygen causes the peak inspiratory pressure input by the user to be exceeded when pressure controlled ventilation is used. One reason for this problem is that the conventional ventilator does not know how much oxygen (e.g., volume or rate) is being delivered to the patient.

While Figures 14A and 14B depict the conventional portable ventilator using traditional volume controlled ventilation and traditional pressure controlled ventilation, respectively, to deliver breaths, a similar result occurs when the conventional portable ventilator uses other types of ventilation because the ventilator does not know how much oxygen (e.g., volume or rate) is being delivered to the patient. Thus, the ventilator cannot accurately configure the breaths delivered (e.g., to achieve either a desired flow rate or pressure in the patient's airway).

Figures 15A and 15B are graphs illustrating oxygen delivery provided by the ventilator 100 illustrated in Figures 1 and 4. In Figure 15A, the ventilator 100 is using volume controlled ventilation to deliver breaths. In both Figures 15A and 15B, the x-axis is time. The inspiratory phase occurs during the duration Tj. The exhalation phase occurs during the duration T _E . The pause occurs during the duration T _P .

Referring to Figure 15A, a solid line 582 illustrates a flow of air provided by the ventilator 100 during both the inspiratory and expiratory phases. The solid line 582 is determined by a set of desired ventilator settings (e.g., values entered via the user interface 200 illustrated in Figure 6). A shaded area 584 illustrates a volume of effective oxygen provided to the patient 102 at the beginning of the inspiratory phase. An area 586 illustrates a volume of air provided to the patient 102 during the inspiratory phase. Together the areas 584 and 586 form a total inspiratory volume (of oxygen and air) delivered by the ventilator 100. As mentioned above, this volume is also referred to as the total tidal volume. An area 588 illustrates an expiratory volume of air expelled by the patient 102.

Figure 15A illustrates delivering one of the pulses of oxygen 140

(see Figure 1 ) at the start of the inspiration phase before the gases 1 12 (see Figure 1 ) are provided. For example, the ventilator 100 may wait until after the pulse of oxygen has been delivered before delivering the gases 1 12. Thus, at the start of each inspiration phase of each breath, the patient 102 (see Figure 1 ) may be receiving only the pulse (or bolus) of oxygen from the ventilator 100. However, this is not a requirement. In alternate embodiments, the flow of the gases 1 12 may begin before the delivery of the bolus of oxygen has completed. In any event, the flow of the gases 1 12 are started before the end of the inspiration phase.

In Figure 15B, the ventilator 100 is using pressure controlled ventilation to deliver breaths. Referring to Figure 15B, the y-axis is pressure within the patient's airway. A solid line 589 illustrates patient airway pressure during both the inspiratory and expiratory phases. As Figure 15B illustrates, the pressure within the patient's airway does not exceed the peak inspiratory pressure value input by the user (the pressure value "PIP") using the pressure control input 237 (see Figure 6).

As shown in Figures 15A and 15B, the ventilator 100 is more efficient than the conventional portable ventilator. For example, the ventilator 100 does not provide a continuous flow of oxygen and therefore, avoids wasting oxygen during non-inspiratory times. Further, the total inspiratory volume is in accordance with (and does not exceed) the desired ventilator settings. And furthermore, the oxygen is delivered in the first part of the breath where the oxygen provides better oxygenation, as opposed to during the last part of the breath when the oxygen becomes trapped in the anatomical dead spaces.

Further, because the ventilator 100 knows the total tidal volume delivered, the ventilator 100 may configure the breaths not to exceed a user supplied peak inspiratory pressure value (e.g., when pressure ventilation is used). Thus, one of ordinary skill in the art through application of the present teachings could configure the ventilator 100 to deliver any desired type of ventilation in which oxygen is delivered in the first part of the breath. Further, the delivery of the pulses of oxygen 140 (see Figure 1 ) may begin before the initiation of each breath.

Referring to Figure 13D, for pulse dose delivery, the control system 220 instructs the second rotary valve assembly 330 (via the control signal 546 depicted in Figure 7B) to rotate the cam 530 to open the poppet valve CV8. The inspiratory phase may be initiated by either the control system 220 or the patient 102. After detecting the beginning of an inspiratory phase, the control system 220 instructs the stepper motor 322 of the metering valve 320 to deliver a desired dose or pulse of oxygen to the patient circuit 1 10, referred to as a "bolus." Thus, the ventilator 100 is configured to synchronize a bolus of oxygen with the patient's breathing. For example, the ventilator 100 may be configured to provide the volume (or bolus) of oxygen depicted by the area 584 of Figure 15A.

The user interface 200 may be used to determine parameter values for the bolus. For example, if the oxygen flow equivalent input 244 (see Figure 6) allows the user to select a numerical value (e.g., from 1 to 10), each successive number may represent an amount of "equivalent oxygenation" relative to a continuous flow of oxygen. For example, the number "2" may provide a bolus of oxygen at the beginning of a breath that would provide oxygenation equivalent to a bleed-in flow of oxygen at two liters per minute from an external source (e.g., the low pressure oxygen source 1 18 depicted in Figure 1 ). By way of another non- limiting example, the user may select a numerical value within a predetermined range that represents from about 0.2 liters per minute to about 9 liters per minute in increments of about 0.1 liters per minute. Because at least some of the oxygen delivered using a hypothetical continuous flow of oxygen is wasted, the control system 220 is configured to deliver an amount of oxygen in the bolus that is less than an amount of oxygen that would be delivered by the continuous flow of oxygen during the inspiration phase.

In alternate embodiments, the user may enter a pulse volume value using the oxygen pulse volume input 251 (see Figure 6) that specifies the size of the bolus. The pulse volume value may be expressed in milliliters or a

dimensionless value within a predetermined numerical range (e.g., from 1 to 10). In such embodiments, each successive number may represent a greater amount of oxygen.

The control system 220 adjusts the delivery of the breath to account for the bolus, and ensures that the breath is delivered in accordance with the user setting of tidal volume (entered via the tidal volume input 242 depicted in Figure 6) or the peak inspiratory pressure value (e.g., entered via the pressure control input 237depicted in Figure 6). By way of a non-limiting example, the control

system 220 may configure the bolus to have a volume that is less than about 75% of the total tidal volume delivered. By way of another non-limiting example, the control system 220 may configure the bolus to have a volume that is between about 50% and about 75% of the total tidal volume delivered.

Further, the ventilator 100 is configured to adjust the parameter values (e.g., volume, pressure, etc.) of the inspiratory gases 108 to assure the inspiratory gases 108 are delivered correctly. For example, if the user (e.g., a clinician) uses the tidal volume input 242 (see Figure 6) to set the total tidal volume value to 500 ml, and the oxygen pulse volume input 251 (see Figure 6) to set the pulse volume value to 100 ml, the control system 220 will set the air delivery from the accumulator 202 to 400 ml, thus providing the correct total volume (500 ml = 400 ml + 100 ml) to the patient circuit 1 10.

The control system 220 may deliver a user-set bolus of oxygen (e.g., in the gases 1 12 and/or the pulses of oxygen 140) to the patient connection 106. The size of the bolus is controlled by the metering valve 320. The control system 220 reduces the flow of the gases 252 (see Figure 5A) as measured by the internal flow transducer 212 (and encoded in the flow signal 270 illustrated in Figure 5E) to satisfy a user set tidal volume value (when volume ventilation is used) or a user set peak inspiratory pressure value (when pressure ventilation is used).

The total inspiratory flow rate and volume of the gases 1 12 (see Figure 1 ) may be determined using the flow signal 270 (see Figure 5E), and the pulse volume may be determined using the signal 358 (see Figure 7B) and the stepper position value (described above) of the metering valve 320. Further, the control system 220 controls the pulse (or bolus) volume using the control signal 360 (see Figure 7B) sent to the stepper motor 322 (see Figure 7B) of the metering valve 320. The control system 220 sets the air delivery from the accumulator 202 using the control signal 278 (see Figure 5E) sent to the motor 272 of the blower 222.

Referring to Figure 13C, for mixed oxygen delivery, the cam 530 of the second rotary valve assembly 330 is positioned so that the poppet valve CV7 is in the open position. The control system 220 determines the oxygen flow required at a given time to achieve a FI02 input by the user (e.g., via the FI02 input 246 depicted in Figure 6). The FI02 may be expressed within a range (e.g., about 21 % to about 100%). The control system 220 may use the control signal 360 (see Figure 7B) to position the metering valve 320 to achieve the desired oxygen flow. The control system 220 may use the oxygen concentration signal 276 (see Figure 5E) from the oxygen sensor 227 to monitor the gases 252 that pass through the internal bacterial filter 230 and emerge as the gases 1 12.

SUCTION ASSEMBLY

Referring to Figure 16, the suction assembly 152 may include a filter 800, a conventional suction canister 810, a conventional suction catheter 812, and tubing 820 configured to be connected to the suction catheter 812. The suction catheter 812 may be configured to be inserted inside the patient connection 106.

Referring to Figure 1 , the suction assembly 152 provides a means to use the suction 154 provided by the ventilator 100 to "vacuum" secretions from the patient's airway. Referring to Figure 10G, the control system 220 positions the cam 850 of the first rotary valve assembly 306 to open the poppet valves CV1 and CV3, and, referring to Figure 13A, the control system 220 positions the cam 530 of the second rotary valve assembly 330 to open the poppet valve CV5. In this configuration, the compressor 302 pulls gas and secretions from the suction catheter 812 (see Figure 16), through the tubing 820 and into the suction canister 810 (see Figure 16) where the liquid secretions are trapped. The filter 800 (e.g., a hydrophobic filter) may be used to further prevent patient secretions from entering the ventilator 100 through the suction connection 150. However, gas pulled into the ventilator 100 continues through the first and second rotary valve assemblies 306 and 330, and enters the compressor 302. The control system 220 controls the speed of the motor 350 of the compressor 302 to achieve the user set suction pressure, as measured by the pressure transducer PT2.

NEBULIZER ASSEMBLY

Referring to Figure 1 , the nebulizer assembly 162 provides a means to use the gases 164 provided by the ventilator 100 for delivering aerosolized medications to the patient's lung(s) 142. Referring to Figure 10F, the control system 220 positions the cam 850 of the first rotary valve assembly 306 to open the poppet valves CV2 and CV4, and, referring to Figure 13B, the control system 220 positions the cam 530 of the second rotary valve assembly 330 to open the poppet valve CV6. In this configuration, gas flows from the

compressor 302, through the first and second rotary valve assemblies 306 and 330, and on to the nebulizer assembly 162. The control system 220 controls the speed of the motor 350 of the compressor 302 to maintain a desired pressure (e.g., about 12 PSIG) as measured by the pressure transducer PT2. The first rotary valve assembly 306 may be cycled to synchronize medication delivery with the inspiratory phase as desired. In a manner similar to that used for pulse dose oxygen delivery, the control system 220 may compensate (or adjust) the breaths delivered to account for the additional volume delivered by the nebulizer assembly 162.

COUGH ASSIST

As mentioned above, a normal cough may be characterized as having an insufflation phase followed by an exsufflation phase. During the insufflation phase, the patient 102 (see Figure 1 ) draws gases into the patient's lung(s) 142 (see Figure 1 ). During the exsufflation phase, the patient 102 exhales at least a portion of the gases in the patient's lung(s) 142 (which may include secretions from the patient's lung(s) 142) using a peak flow rate and a peak pressure that are both greater than that used during the exhalation phase of normal breathing. The ventilator 100 (see Figures 1 and 4) is configured to provide cough assist functionality that facilitates secretion clearance by creating an exhaled flow rate and/or pressure that simulates a normal cough. Referring to Figure 6, the user may use the activate cough assist input 241 to instruct the ventilator 100 (see Figures 1 and 4) to switch from a normal breathing mode to a cough assist mode during which the cough assist functionality is used to perform a cough assist maneuver with the patient 102 (see Figure 1 ).

As mentioned above, the ventilation assembly 190 may include either the cough assist valve 204 or the cough assist valve 2000. Referring to Figure 5C, if the ventilation assembly 190 includes the cough assist valve 204, at the beginning of the insufflation phase, the control system 220 places the cough assist valve 204 in the first configuration (Figures 5A, 5C and 18A). Thus, the blower 222 can deliver the gas 252 to the main ventilator connection 104 in the same manner that a normal breath is delivered. The control system 220 (see Figure 5E) instructs the blower 222 (using the control signal 1 180) to deliver flow to achieve pressure in accordance with the user input settings for insufflation and exsufflation pressure. These settings are usually for greater flow rate and/or pressure than used during a normal breath but that many not always be the case. In other words, the blower 222 adds energy to the gas 252 (e.g., increases its flow rate and/or pressure) that exits the blower 222 and flows into the blower-to-valve inlet 1004 of the cough assist valve 204. The gas 252 flows through a portion of the cough assist valve 204 and exits the cough assist valve 204 into the flow line 273 via the aperture 1010. The flow line 273 conducts the gas 252 to the main ventilator connection 104. The main ventilator connection 104 is coupled (e.g., directly or using a hose, flow line, conduit, or tube) to the patient circuit 1 10 (see Figure 1 ), which conducts the inspiratory gases 108 to the patient connection 106, which in turn conducts the inspiratory gases 108 on to the patient 102. The inspiratory gases 108 inflate the lung(s) 142 and raise the pressure to a desired insufflation pressure (see Figure 26).

At the end of the insufflation phase, the control system 220 (see Figure 5E) instructs the cough assist valve 204 (using the control signal 1 180) to transition to the second configuration (see Figures 5B, 5D, and 18B). The control system 220 also instructs the blower 222 (using the control signal 1 180) to increase its speed to achieve a desired exsufflation pressure (see Figure 26). This creates a high peak exsufflation flow rate. At the end of the exsufflation phase, if desired, the cough assist maneuver may repeated. If the ventilation assembly 190 includes the cough assist valve 2000 (see Figures 34A and 34B) instead of the cough assist valve 204, at the beginning of the insufflation phase, the control system 220 places the cough assist valve 2000 in the first configuration (see Figure 34A). The control system 220 (see Figure 5E) instructs the blower 222 (using the control signal 1 180) to apply a selected flow rate and/or pressure which often is greater than used during a normal breath. The gas 252 exits the blower 222 and flows into the blower-to- valve inlet 2004 of the cough assist valve 2000. The gas 252 flows through a portion of the cough assist valve 2000 and exits the cough assist valve 2000 into the flow line 273 via the aperture 2010. The flow line 273 conducts the gas 252 to the main ventilator connection 104. The main ventilator connection 104 is coupled (e.g., directly or using a hose, flow line, conduit, or tube) to the patient circuit 1 10 (see Figure 1 ), which conducts the inspiratory gases 108 to the patient connection 106, which in turn conducts the inspiratory gases 108 on to the patient 102. The inspiratory gases 108 inflate the lung(s) 142 and raise the pressure to a desired insufflation pressure (see Figure 26). At the end of the insufflation phase, the control system 220 (see Figure 5E) instructs the cough assist valve 2000 (using the control signal 1 180) to transition to the second configuration (see Figure 34B). The control system 220 also instructs the blower 222 (using the control signal 1 180) to increase its speed to achieve a desired exsufflation pressure (see Figure 26). This creates a high peak exsufflation flow rate. At the end of the exsufflation phase, if desired, the cough assist maneuver may repeated.

Referring to Figure 26, a line 1200 illustrates airway pressure during both the insufflation and exsufflation phases of a cough assist maneuver performed using the ventilator 100. Referring to Figure 26, a line 1202 illustrates airway flow rates during both the insufflation and exsufflation phases of a cough assist maneuver performed using the ventilator 100.

Because the ventilator 100 combines both mechanical ventilation and cough assist functions into one device, it is desirable to use the same tubing for both ventilation and cough assist so the user does not have to change tubing connections between operations. Keeping the tubing connection intact may also provide one or more of the following benefits:

1 . better maintenance of the patient's oxygenation level,

2. reduced likelihood of ventilator-associated pneumonia, and 3. reduced risks associated with possible errors of reconnection. Unfortunately, prior art passive patient circuits are inadequate for use with cough assist because they include a fixed leak valve that reduces the negative pressure in the patient circuit during the exsufflation phase. This reduction in negative pressure causes an undesirable reduction in the flow rate from the patient's lungs, which in turn compromises secretion clearance.

The passive patient circuit 440 illustrated in Figure 2B avoids this problem because the passive patient circuit 440 includes the valve assembly 448 or the valve assembly 1448 (see Figures 30-31 C). When the passive patient circuit 440 includes the valve assembly 448, the peripheral portion 473 of the leaf 470 of the valve assembly 448 is configured to transition or deflect from the open position (see Figure 2D) to the closed position (see Figure 2C) when the pressure inside the passive patient circuit 440 (see Figure 2B) is less than the threshold amount (e.g., environmental pressure). When the peripheral portion 473 of the leaf 470 is in the closed position depicted in Figure 2C, the leaf 470 blocks off the one or more openings 478 and isolates the chamber 474 from the environment inside the passive patient circuit 440 (see Figure 2B). Thus, the leaf 470 prevents a flow of air into the passive patient circuit 440 (through the one or more openings 478) while the patient circuit pressure is less than the threshold amount (e.g., when the patient circuit pressure is negative). The valve assembly 448 may be characterized as being a positive pressure leak valve in embodiments in which the valve assembly 448 is open when the patient circuit pressure is positive and closed when the patient circuit pressure is negative.

Similarly, referring to Figures 31 A and 31 B, when the passive patient circuit 440 (see Figure 2B) includes the valve assembly 1448, the peripheral portion 1473 of the leaf 1470 of the valve assembly 1448 is configured to transition or deflect from the open position (see Figure 31 B) to the closed position (see Figure 31 A) when the pressure inside the passive patient circuit 440 (see Figure 2B) is less than the threshold amount (e.g., environmental pressure).

When the peripheral portion 1473 of the leaf 1470 is in the closed position depicted in Figure 31 A, the leaf 1470 blocks off the one or more openings 1478 and isolates the chamber 1474 from the environment inside the passive patient circuit 440 (see Figure 2B). Thus, the leaf 1470 prevents a flow of air into the passive patient circuit 440 (through the one or more openings 1478) while the patient circuit pressure is less than the threshold amount (e.g., when the patient circuit pressure is negative). The valve assembly 1448 may be characterized as being a positive pressure leak valve in embodiments in which the valve

assembly 1448 is open when the patient circuit pressure is positive and closed when the patient circuit pressure is negative.

When a passive patient circuit (e.g., the passive patient circuit 170, the passive patient circuit 440, and the like) that includes a suitable passive leak valve (e.g., the leak valve 177, the valve assembly 448, the valve assembly 1448, and the like) is used, gas flows to the patient 102 through the passive patient circuit during the insufflation phase. Some of the flow leaks out through the passive leak valve, and the rest travels into the patient's lung(s) 142 (see Figure 1 ). If the ventilation assembly 190 includes the cough assist valve 204 (see Figures 5A-5D and 17A-18B), at the end of the insufflation phase, the control system 220 transitions the cough assist valve 204 to the second configuration (see Figures 5B, 5D, and 18B), and increases the speed of the blower 222 to achieve a desired exsufflation pressure. On the other hand, if the ventilation assembly 190 includes the cough assist valve 2000 (see Figures 34A and 34B), at the end of the insufflation phase, the control system 220 transitions the cough assist valve 2000 to the second configuration (see Figure 34B), and increases the speed of the blower 222 to achieve a desired exsufflation pressure. A check valve component (e.g., the flap 179, the leaf 470, the leaf 1470, and the like) of the passive leak valve prevents external flow from entering the passive patient circuit.

Alternatively, the active patient circuit 600 illustrated in Figure 3A may be used during a cough assist maneuver. When the active patient circuit 600 is used, the active exhalation valve assembly 604 is closed during both the insufflation and exsufflation phases. During the insufflation phase, the control system 220 closes the active exhalation valve assembly 604 by energizing or activates the solenoid valve SV6 (using the control signal 286), which connects the pressure of the gases 252 (via the port 275B) to the pilot port 1 1 1 C. During the exsufflation phase, the control system 220 de-energizes or deactivates the solenoid valve SV6 (using the control signal 286), which connects the internal pressure of the accumulator A2 (or the pilot pressure) to the active exhalation valve assembly 604. This causes the active exhalation valve assembly 604 to remain closed. The active exhalation valve assembly 604 remains closed because the pilot pressure is higher than patient pressure, and (as explained above) the area of the double bellows member 644 exposed to a pressure provided by the patient 102 (see Figure 1 ) via the patient connection 106 is less than an area exposed to the pressure of the pressure signal 109C. Thus, even if the two pressures are equal, the closed end 666 of the double bellows

member 644 will move to or remain in the closed position against the seat 680. It is noted that in the cough assist mode, the pressure in Accumulator A2 is set to zero. At the beginning of exsufflation, the patient pressure is higher than pressure signal 109C, so the exhalation valve opens. This is beneficial since it drops the pressure faster, and creates greater exsufflation flow. When the patient pressure drops below ambient, the active exhalation valve assembly 604 closes, preventing ambient gas from entering into the patient circuit.

SECRETION TRAP

During a conventional cough assist maneuver, the patient connection 106 (e.g., a tracheostomy tube) is pneumatically connected by cough assist tubing (e.g., tubing having an inner diameter of about 22 mm) to a cough assist device. By way of a non-limiting example, the patient connection 106 (e.g., a tracheostomy tube) may have an outer diameter of about 15 mm and an inner diameter of about 8 mm. Current practice is to connect the cough assist tubing to the patient connection 106 utilizing a connector, such as a connector or adapter having an outer diameter of 22 mm and an inner diameter of 15 mm. The connector may be straight, right angled, flexible, or outfitted with a swivel connector. The connector functions as an adaptor that transitions from the outside diameter (e.g., about 15 mm) of the patient connection 106 (e.g., a tracheostomy tube) to the inside diameter (e.g., about 22 mm) of the cough assist tubing. Thus, the flow pathway from the patient connection 106 to the cough assist tubing includes an abrupt transition (e.g., from an inner diameter of about 15 mm to an inner diameter of about 22 mm).

Unfortunately, currently available connectors used to connect the patient connection 106 to the cough assist tubing (which is connected to a cough assist device) are not designed to trap secretions generated by a cough assist maneuver. It is common for patient secretions to exit the patient connection 106

(e.g., a tracheostomy tube) during the exsufflation phase, collect in the connector, and travel back toward and/or into the patient connection 106 during the insufflation phase, which is not desired. This process is typically repeated several times until the secretions eventually migrate into the cough assist tubing. Then, the cough assist tubing is removed and disposed of or cleaned.

Figure 27 illustrates a secretion trap 1250 that may be used instead of a conventional connector to connect the patient connection 106 to a cough assist tube 1252 serving as or as part of the patient circuit 1 10. Alternatively, the secretion trap 1250 may be formed in an end 1254 of the cough assist tube 1252. In Figures 27 and 28, the patient connection 106 has been illustrated as a tracheostomy tube 1260 connected to a patient airway 1262 (see Figure 28). The cough assist tube 1252 may be connected to a conventional cough assist device (not shown).

Alternatively, the secretion trap 1250 may be used to connect the patient connection 106 to the patient circuit 1 10 (e.g., the passive patient circuit 440, the active patient circuit 600, and the like) directly or using a hose, flow line, conduit, or tube. In such embodiments, the patient circuit 1 10 is connected to the main ventilator connection 104 (and optionally to the patient oxygen outlet 105). Alternatively, the secretion trap 1250 may be implemented as a component of the patient circuit 1 10.

In the embodiment illustrated, the secretion trap 1250 has a first end portion 1256 opposite a second end portion 1258. The first end portion 1256 is couplable to the patient connection 106, and the second end portion 1258 is couplable to the cough assist tube 1252 or the patient circuit 1 10 (see Figure 1 ).

Referring to Figure 28, unlike conventional connectors (that may be used to connect the patient connection 106 to the cough assist tube 1252), the secretion trap 1250 is configured to trap patient secretions 1268 during a cough assist maneuver. Referring to Figure 27, internal geometry of the secretion trap 1250 is configured to create first and second inner diameter steps. The first step transitions from an inner diameter " I D 1 " of the patient connection 106 (e.g., about 8 mm) to a significantly larger inner diameter "ID2" (e.g., greater than about 22 mm) of the secretion trap 1250. The second step transitions from the inner diameter "ID2" to a smaller inner diameter "ID3" (e.g., about 15 mm). The second end portion 1258 of the secretion trap 1250 has an outer diameter "OD" (e.g., about 22 mm) configured to mate with the cough assist tube 1252. The small inner diameter "IDT causes exsufflation flows (identified by an arrow 1270 in Figure 28) to have a high first velocity that mobilizes secretions. The first (rapid) step to the larger inner diameter "ID2" causes the velocity of the exsufflation flows to reduce to a slower second velocity. This reduction in velocity causes the secretions 1268 (see Figure 28) to settle or collect in a well 1274 created by the larger inner diameter "ID2." The well 1274 protects the secretions 1268 (see Figure 28) from re-mobilization during inspiratory flows (identified by an arrow 1272 in Figure 28). Further, patient secretions typically have a high surface tension that helps retain them in the well 1274 until they can be removed, which helps prevent contamination of the cough assist tube 1252 or the patient circuit 1 10 (see Figure 1 ).

As mentioned above, because a cough assist maneuver may move secretions during both the exsufflation and insufflation phases, some secretions may remain within the patient connection 106 after the cough assist maneuver. For this reason, the patient connection 106 is often suctioned to remove these remaining secretions after the cough assist maneuver.

Figure 29 illustrates the secretion trap 1250 connected to a drain 1280 configured to provide suction during a cough assist maneuver. Thus, the secretion trap 1250 may be used to provide an improved therapy in which the secretions 1268 are suctioned as they exit the patient connection 106 during a cough assist maneuver. The drain 1280 includes an open-ended tube section 1282 having a first end portion 1284 in fluid communication with the well 1274, and a second end portion (not shown) in fluid communication with a suction device (e.g., the suction assembly 152 illustrated in Figures 1 and 16). The first end portion 1284 may be positioned nearer the patient connection 106 than the cough assist tube 1252 or the patient circuit 1 10 (see Figure 1 ). The suction device provides negative pressure (depicted as an arrow 1290) to the drain 1280 during a cough assist maneuver that suctions the secretions 1268 from the well 1274. The negative pressure draws the secretions 1268 into the open-ended tube section 1282 (via its first end portion 1284) as the secretions exit the patient connection 106, thereby keeping the ventilation airway (e.g., the patient circuit 1 10) clear of secretions that may impede ventilation.

While the drain 1280 has been described and illustrated as being connected to the secretion trap 1250, in alternate embodiments, the drain 1280 may be connected to other structures at or near the patient connection 106. For example, the drain 1280 may be connected directly to the patient connection 106. Alternatively, the drain 1280 may be connected to the patient circuit 1 10.

The drain 1280 may provide one or more of the following features: 1 . improved clearance of the ventilation airway,

2. reduced contamination, and

3. reduced need to disconnect the patient connection 106 from

mechanical ventilation (e.g., provided by the ventilator 100).

Because the drain 1280 provides secretion clearance without disconnecting the patient circuit 1 10 from the patient 102, the drain 1280 may be particularly useful with the ventilator 100, which is configured to provide both mechanical ventilation and cough assist.

Embodiments of the disclosure can be described in view of the following clauses in any combination to define the invention:

A1 . A method of providing a breath to a human patient having a patient connection connected by a patient circuit to a ventilator device, the breath having an inspiratory phase with a beginning and an end, the method comprising:

delivering a bolus of oxygen to the patient circuit at or before the beginning of the inspiratory phase of the breath, the patient circuit delivering the bolus of oxygen to the patient connection;

terminating the delivery of the bolus of oxygen before the end of the inspiratory phase of the breath; and

delivering breathing gases comprising air to the patient circuit before the end of the inspiratory phase of the breath, the patient circuit delivering the breathing gases to the patient connection.

A2. The method of clause A1 , further comprising:

waiting until after the delivery of the bolus of oxygen delivered for the breath has been terminated before delivering the breathing gases.

A3. The method of clause A1 , wherein

combined the bolus of oxygen and the breathing gases delivered for the breath have a total inspiratory volume, and

the bolus of oxygen delivered for the breath has a volume that is less than about 75% of the total inspiratory volume.

A4. The method of clause A1 , wherein combined the bolus of oxygen and the breathing gases delivered for the breath have a total inspiratory volume, and

the bolus of oxygen delivered for the breath has a volume that is between about 50% of the total inspiratory volume and about 75% of the total inspiratory volume.

A5. The method of clause A1 , wherein the breath has an expiratory phase, and the method further comprises:

receiving an oxygen flow equivalent value associated with an oxygen flow rate which if applied to the patient circuit continuously from the beginning of the inspiratory phase to an end of the expiratory phase would produce a first volume of oxygen, and wherein the bolus of oxygen delivered for the breath has a second volume that is less than the first volume of oxygen.

A6. The method of clause A1 for use with an oxygen source connected to a valve, wherein

delivering the bolus of oxygen at or before the beginning of the inspiratory phase of the breath comprises opening the valve to thereby allow a flow of oxygen from the oxygen source to the patient circuit, and

terminating the delivery of the bolus of oxygen before the end of the inspiratory phase of the breath comprises closing the valve to thereby discontinue the flow of oxygen from the oxygen source to the patient circuit.

A7. The method of clause A6 for use with an oxygen generator connected to the oxygen source, and the oxygen source being configured to store oxygen generated by the oxygen generator, the method further comprising:

detecting a value comprising at least one of a concentration of the oxygen stored by the oxygen source and a pressure of the oxygen stored by the oxygen source;

determining if the detected value is below a threshold value;

operating the oxygen generator when the detected value is determined to be below the threshold value; and

delivering oxygen generated by the oxygen generator to the oxygen source.

A8. The method of clause A1 , further comprising:

detecting the beginning of the inspiratory phase of the breath has been initiated by the patient. A9. The method of clause A1 , further comprising: detecting the beginning of the inspiratory phase of the breath has been initiated by the patient, and in response initiating delivery of the bolus of oxygen to the patient circuit.

A10. The method of clause A1 for use with a user specified total tidal volume, wherein the breathing gases delivered for the breath have a first volume,

the bolus of oxygen delivered for the breath has a second volume, and

combined the first and second volumes are substantially equal to the user specified total tidal volume.

A1 1 . The method of clause A1 for use with a user specified peak inspiratory pressure value, wherein a combined pressure of the breathing gases and the bolus of oxygen delivered for the breath does not exceed the user specified peak inspiratory pressure value.

A12. The method of clause A1 , wherein

delivering the breathing gases to the patient circuit comprises providing the breathing gases to the patient circuit at a first input location of the patient circuit, and

delivering the bolus of oxygen to the patient circuit comprises providing the bolus of oxygen to the patient circuit at a second input location of the patient circuit closer than the first input location to the patient connection.

A13. The method of clause A1 for use with a breathing gases delivery conduit having a breathing gases output located at a first end portion of the patient circuit away from the patient connection and an oxygen delivery conduit having an oxygen output located at a second end portion of the patient circuit adjacent to the patient connection, wherein delivering the breathing gases to the patient circuit comprises providing the breathing gases to the breathing gases output via the breathing gases delivery conduit and wherein delivering the bolus of oxygen to the patient circuit comprises providing the bolus of oxygen to the oxygen output via oxygen delivery conduit, to thereby isolate the bolus of oxygen delivered for the breath from the breathing gases delivered for the breath along at least a majority portion of the patient circuit prior to the patient

connection. A14. The method of clause A1 for use with the patient circuit comprising a breathing gases delivery conduit and an oxygen delivery conduit, wherein

delivering the breathing gases to the patient circuit comprises providing the breathing gases to the breathing gases delivery conduit, which delivers the breathing gases to the patient connection, and

delivering the bolus of oxygen to the patient circuit comprises providing the bolus of oxygen to the oxygen delivery conduit, which delivers the bolus of oxygen to the patient connection, thereby isolating the bolus of oxygen delivered for the breath from the breathing gases delivered for the breath along at least a portion of the patient circuit prior to the patient connection.

A15. The method of clause A14, wherein the bolus of oxygen exits the oxygen delivery conduit and enters the breathing gases delivery conduit at a location adjacent to the patient connection.

A16. The method of clause A14, wherein the bolus of oxygen exits the oxygen delivery conduit and enters the breathing gases delivery conduit at a location within about 2 centimeters of the patient connection.

A17. The method of clause A1 , further comprising:

receiving a bolus volume value, and

wherein the bolus of oxygen delivered for the breath has a volume substantially equal to the bolus volume value.

A18. The method of clause A1 , for use with a compressor operable to compress breathing gases, wherein delivering breathing gases to the patient circuit comprises delivering at least a portion of the breathing gases compressed by the compressor.

A19. A ventilator device for use with an oxygen source and a patient circuit configured to receive breathing gases and oxygen to provide a breath to a human patient having a patient connection couplable to the patient circuit, the breath having an inspiratory phase with a beginning and an end, the ventilator device comprising:

a compressor configured to deliver breathing gases to the patient circuit; and

a control system configured such that: (a) at or before a beginning of an inspiratory phase of a breath, the control system allows the oxygen to flow from the oxygen source to the patient circuit;

(b) before an end of the inspiratory phase of the breath, the control system prevents the oxygen from flowing from the oxygen source to the patient circuit; and

(c) before the end of the inspiratory phase of the breath, the control system causes the compressor to deliver the breathing gases to the patient circuit.

A20. The ventilator device of clause A19, further comprising:

an input configured to receive a user specified total tidal volume, wherein the breathing gases delivered to the patient circuit for the breath have a first volume,

the oxygen allowed to flow to the patient circuit for the breath has a second volume, and

combined the first and second volumes are substantially equal to the user specified total tidal volume.

A21 . The ventilator device of clause A19, further comprising:

an input configured to receive a user specified peak inspiratory pressure value, wherein a combined pressure of the breathing gases delivered to the patient circuit and the oxygen allowed to flow to the patient circuit for the breath does not exceed the user specified peak inspiratory pressure value.

A22. A ventilator device for use with a patient circuit configured to receive breathing gases and oxygen to provide a breath to a human patient having a patient connection couplable to the patient circuit, the breath having an inspiratory phase with a beginning and an end, the ventilator device comprising:

a compressor configured to deliver breathing gases to the patient circuit;

a patient oxygen outlet couplable to the patient circuit; an oxygen source configured to deliver oxygen to the patient circuit; and

a control system configured such that:

(a) at or before a beginning of an inspiratory phase of a breath, the control system allows the oxygen to flow from the oxygen source to the patient circuit; (b) before an end of the inspiratory phase of the breath, the control system prevents the oxygen from flowing from the oxygen source to the patient circuit; and

(c) before the end of the inspiratory phase of the breath, the control system causes the compressor to deliver the breathing gases to the patient circuit.

A23. The ventilator device of clause A22, further comprising:

an input configured to receive a user specified total tidal volume, wherein the breathing gases delivered to the patient circuit for the breath have a first volume,

the oxygen allowed to flow to the patient circuit for the breath has a second volume, and

combined the first and second volumes are substantially equal to the user specified total tidal volume.

A24. The ventilator device of clause A22, further comprising:

an input configured to receive a user specified peak inspiratory pressure value, wherein a combined pressure of the breathing gases delivered to the patient circuit and the oxygen allowed to flow to the patient circuit for the breath does not exceed the user specified peak inspiratory pressure value.

A25. A ventilation system for use with a human patient having a patient connection couplable to a patient circuit, the system comprising:

an oxygen source configured to deliver oxygen to a patient oxygen outlet couplable to the patient circuit;

a compressor configured to deliver breathing gases to a ventilator connection couplable to the patient circuit, the ventilator connection being different from the patient oxygen outlet; and

a control system configured to:

identify an inspiratory phase of a breath;

instruct the oxygen source to deliver the oxygen to the patient oxygen outlet before or during the inspiratory phase, the oxygen source being configured to deliver the oxygen to the patient oxygen outlet in response to the instruction to deliver the oxygen to the patient oxygen outlet; and

instruct the compressor to deliver the breathing gases to the ventilator connection during the inspiratory phase, the compressor being configured to deliver the breathing gases to the ventilator connection in response to the instruction to deliver the breathing gases to the ventilator connection.

A26. The ventilation system of clause A25, wherein the compressor and the ventilator connection comprise a ventilator, and the oxygen source is external to the ventilator.

A27. The ventilation system of clause A25, wherein the oxygen source comprises an internal oxygen source of a ventilator having an oxygen inlet in fluid communication with the internal oxygen source, and the ventilation system further comprises an external oxygen source in fluid communication with the oxygen inlet to deliver oxygen from the external oxygen source to the internal oxygen source.

A28. The ventilation system of clause A25, further comprising: an oxygen generator in fluid communication with the oxygen source, the oxygen generator delivering oxygen to the oxygen source.

A29. The ventilation system of clause A28, wherein the compressor, the oxygen source and the oxygen generator comprise a ventilator.

A30. The ventilation system of clause A28, wherein the compressor and the oxygen source comprise a ventilator, and the oxygen generator is external to the ventilator.

A31 . The ventilation system of clause A25, further comprising: a user interface having an input configured to receive a user specified total tidal volume, the user interface being configured to provide the user specified total tidal volume to the control system,

wherein the control system is configured to determine a first volume and a second volume,

the breathing gases delivered for the breath have the first volume, the oxygen delivered for the breath has the second volume, and combined the first and second volumes are substantially equal to the user specified total tidal volume.

A32. The ventilation system of clause A25, further comprising: a user interface having an input configured to receive a user specified peak inspiratory pressure value, the user interface being configured to provide the user specified peak inspiratory pressure value to the control system, wherein a combined pressure of the breathing gases and the oxygen delivered for the breath does not exceed the user specified peak inspiratory pressure value.

B1 . A method of providing a breath to a human patient having a patient connection connected by a patient circuit to a ventilator having a first ventilator connection and a different second ventilator connection, each of the first and second ventilator connections being in fluid communication with the patient circuit, the method comprising:

identifying, with the ventilator, initiation of an inspiratory phase of the breath;

delivering a bolus of oxygen to the first ventilator connection before or during the inspiratory phase; and

delivering breathing gases comprising air to the second ventilator connection during the inspiratory phase, the ventilator isolating the bolus of oxygen delivered to the first ventilator connection from the breathing gases delivered to the second ventilator connection.

B2. The method of clause B1 , wherein the bolus of oxygen is delivered at the initiation of the inspiratory phase of the breath.

B3. The method of clause B1 , further comprising:

identifying, with the ventilator, an end of the inspiratory phase of the breath; and

terminating the delivery of the bolus of oxygen before the end of the inspiratory phase, wherein the breathing gases are delivered after the delivery of the bolus of oxygen has been terminated.

B4. The method of clause B1 , further comprising:

determining, with the ventilator, a volume of the bolus of oxygen delivered for the breath.

B5. The method of clause B1 for use with a user specified total tidal volume, wherein the breathing gases delivered for the breath have a first volume,

the bolus of oxygen delivered for the breath has a second volume, and

combined the first and second volumes are substantially equal to the user specified total tidal volume. B6. The method of clause B1 for use with a user specified peak inspiratory pressure value, wherein a combined pressure of the breathing gases and the bolus of oxygen delivered for the breath does not exceed the user specified peak inspiratory pressure value.

B7. A ventilator device for use with a human patient having a patient connection couplable to a patient circuit, the ventilator device comprising:

a ventilator connection couplable to the patient circuit; one or more first flow conduits in fluid communication with the ventilator connection;

a compressor configured to deliver breathing gases to the one or more first flow conduits, which deliver the breathing gases to the ventilator connection;

a patient oxygen outlet couplable to the patient circuit; one or more second flow conduits in fluid communication with the patient oxygen outlet; and

an oxygen source configured to deliver oxygen to the one or more second flow conduits, which deliver the oxygen to the patient oxygen outlet, wherein the patient oxygen outlet and the one or more second flow conduits isolate the oxygen from the breathing gases delivered to the one or more first flow conduits and the ventilator connection.

B8. The ventilator device of clause B7, wherein the one or more second flow conduits includes a first conduit and a second conduit, and the ventilator device further comprises:

a valve, the first conduit being in fluid communication with the valve to deliver oxygen from the oxygen source to the valve, and the second conduit being in fluid communication with the valve to deliver oxygen from the valve to the patient oxygen outlet, wherein opening the valve allows the oxygen to flow from the oxygen source to the patient oxygen outlet through the first and second conduits, and closing the valve prevents the oxygen from flowing from the oxygen source to the patient oxygen outlet through the first and second conduits.

B9. The ventilator device of clause B8, further comprising a control system configured to: (a) open the valve at or before a beginning of an inspiratory phase of a breath to thereby allow the oxygen to flow from the oxygen source to the patient oxygen outlet;

(b) close the valve before an end of the inspiratory phase of the breath to thereby prevent the oxygen from flowing from the oxygen source to the patient oxygen outlet; and

(c) instruct the compressor to deliver the breathing gases before the end of the inspiratory phase of the breath.

B10. The ventilator device of clause B9, further comprising:

an input configured to receive a user specified total tidal volume, wherein the breathing gases delivered for the breath have a first volume,

the oxygen allowed to flow for the breath has a second volume, and combined the first and second volumes are substantially equal to the user specified total tidal volume.

B1 1 . The ventilator device of clause B9, further comprising:

an input configured to receive a user specified peak inspiratory pressure value, wherein a combined pressure of the breathing gases delivered and the oxygen allowed to flow for the breath does not exceed the user specified peak inspiratory pressure value.

B12. The ventilator device of clause B9, wherein the control system is configured to instruct the compressor to deliver the breathing gases after the valve has been closed.

B13. The ventilator device of clause B9, further comprising:

a user input configured to receive a user selected parameter value, the control system being configured to leave the valve open until a volume of oxygen determined based at least in part on the user selected parameter value has flowed through the valve.

B14. The ventilator device of clause B9, wherein the oxygen source is configured to store oxygen, and the ventilator device further comprises:

an oxygen generator in fluid communication with the oxygen source; and

a sensor configured to provide a signal to the control system, the signal encoding at least one of a concentration of oxygen stored by the oxygen source and a pressure of the oxygen stored by the oxygen source, the control system being configured to use the signal to determine whether an amount of oxygen stored by the oxygen source is less than a threshold value, and to operate the oxygen generator to deliver oxygen to the oxygen source when the control system determines the amount of oxygen stored by the oxygen source is less than the threshold value.

B15. The ventilator device of clause B9, for use with the patient circuit having a sensor configured to detect a flow rate within the patient circuit and send a signal encoding the flow rate, wherein the control system is configured to receive the signal from the sensor and use the signal to detect when the patient has initiated the beginning of the inspiratory phase.

B16. The ventilator device of clause B9, further comprising:

a sensor configured to detect a flow rate within one of the one or more first flow conduits and send a signal to the control system encoding the flow rate, the control system being configured to use the signal to detect when the patient has initiated the beginning of the inspiratory phase.

B17. The ventilator device of clause B9, further comprising:

an accumulator configured to deliver at least a portion of the breathing gases to the compressor via at least one of the one or more first flow conduits; and

a sensor configured to detect a flow rate inside the at least one of the one or more first flow conduits and send a signal to the control system encoding the flow rate, the control system being configured to use the signal to detect when the patient has initiated the beginning of the inspiratory phase.

C1 . A pressure swing adsorption oxygen generator to separate oxygen from air for use with a pressure source generating a high pressure and a low pressure, comprising:

an adsorption bed having a bed of nitrogen absorbent material; and a multi-position rotary valve for controlling pressure swing adsorption of the adsorption bed, and being couplable to the pressure source for fluid

communication therewith and in fluid communication with the adsorption bed, the rotary valve including a cam having first and second rotary positions, in the first rotary position of the cam the rotary valve communicating high pressure

generated by the pressure source to the adsorption bed and in the second rotary position of the cam the rotary valve communicating low pressure generated by the pressure source to the adsorption bed.

C2. The pressure swing adsorption oxygen generator of clause C1 , further including:

an oxygen storage unit connected to the adsorption bed;

a first regulator which upon a sensed first condition when the cam is in the first rotary position permits oxygen generated within the adsorption bed to pass to the oxygen storage unit; and

a second regulator which upon a sense second condition when the cam is in the second rotary position permits a portion of the oxygen in the oxygen storage unit to enter the adsorption bed to assist in purging nitrogen from the adsorption bed.

C3. The pressure swing adsorption oxygen generator of clause C1 , further including:

an oxygen storage unit;

a first pressure regulator connected to the adsorption bed and to the oxygen storage unit, and in response to pressure in the adsorption bed rising to a preselected first pressure, the first pressure regulator regulating the pressure in the adsorption bed to the preselected first pressure and permitting oxygen generated within the adsorption bed to pass through the first pressure regulator to the oxygen storage unit; and

a second pressure regulator connected to the adsorption bed and to the oxygen storage unit, and in response to pressure in the adsorption bed falling to a preselected second pressure that is lower than the preselected first pressure, the pressure regulator regulating the pressure in the adsorption bed to the

preselected second pressure and permitting stored oxygen within the oxygen storage unit to pass through the second pressure regulator to the adsorption bed.

C4. The pressure swing adsorption oxygen generator of clause C3, wherein the first pressure regulator prevents fluid communication through the first pressure regulator between the adsorption bed and the oxygen storage unit when the pressure in the adsorption bed is below the preselected first pressure, and the second pressure regulator prevents fluid communication through the second pressure regulator between the oxygen storage unit and the adsorption bed when the pressure in the adsorption bed is above the preselected second pressure.

C5. A pressure swing adsorption oxygen generator to separate oxygen from air, comprising:

a pressure source generating a high pressure and a low pressure;

an adsorption bed having a bed of nitrogen absorbent material; and a multi-position rotary valve for controlling pressure swing adsorption of the adsorption bed, and being in fluid communication with the pressure source and the adsorption bed, the rotary valve including a cam having first and second rotary positions, in the first rotary position of the cam the rotary valve communicating high pressure generated by the pressure source to the adsorption bed and in the second rotary position of the cam the rotary valve communicating low pressure generated by the pressure source to the adsorption bed.

C6. The pressure swing adsorption oxygen generator of clause C5, wherein the pressure source is a compressor, and the high pressure generated is a positive pressure and the low pressure generated is a negative pressure.

C7. A pressure swing adsorption oxygen generator to separate oxygen from air for use with a pressure source generating a high pressure and a low pressure, comprising:

an adsorption bed having a bed of nitrogen absorbent material; and a multi-position rotary valve for controlling pressure swing adsorption of the adsorption bed, and being couplable to the pressure source for fluid

communication therewith and in fluid communication with the adsorption bed, the rotary valve having:

a cam having at least first and second rotary positions;

a rotary actuator configured to rotate the cam; and

a plurality of valves operative in response to the rotary position of the cam, in the first rotary position of the cam at least one of the valves communicating high pressure generated by the pressure source to the adsorption bed and in the second rotary position of the cam at least one of the valves communicating low pressure generated by the pressure source to the adsorption bed.

C8. The pressure swing adsorption oxygen generator of clause C7 for use with the pressure source being a compressor with the high pressure being at an output port and the low pressure being at an input port, wherein the plurality of valves includes first, second, third and fourth valves, each having a first port and a second port which are in fluid communication with each other in a first state and out of fluid communication with each other in a second state, and selectively movable between the first and second states,

the first port of the first valve being in fluid communication with the compressor output port and the second port of the first valve being in fluid communication with atmosphere,

the first port of the second valve being in fluid communication with the adsorption bed and the second port of the second valve being in fluid

communication with the compressor output port,

the first port of the third valve being in fluid communication with the adsorption bed and the second port of the third valve being in fluid communication with the compressor input port,

the first port of the fourth valve being in fluid communication with the compressor input port and the second port of the fourth valve being in fluid communication with a supply of air from which oxygen is to be separated,

the first, second, third and fourth valves being moved between the first and second states in a repeated sequence in response to rotation of the cam, wherein when the cam is in the first rotary position the second and fourth valves are in the first state and the first and third valves are in the second state, and when the cam is in the second rotary position the first and third valves are in the first state and the second and fourth valves are in the second state.

C9. The pressure swing adsorption oxygen generator of clause C8, wherein the first and third valves are moved by the cam between the first and second states in unison, and the second and fourth valves are moved by the cam between the first and second states in unison.

C10. The pressure swing adsorption oxygen generator of clause C8, wherein the cam has first and second cam lobes, and further has third and fourth rotary positions, wherein when the cam is moved to the first rotary position the first cam lobe moves the fourth valve to the first state and the second cam lobe moves the second valve to the first state, and the first and third valves are in the second state, when the cam is moved to the second rotary position the first cam lobe moves the first valve to the first state and the second cam lobe moves the third valves to the first state, and the second and fourth valves are in the second state, when the cam is moved to the third rotary position the first cam lobe moves the second valve to the first state and the second cam lobe moves the fourth valve to the first state, and the first and third valves are in the second state, and when the cam is moved to the fourth rotary position the first cam lobe moves the third valve to the first state and the second cam lobe moves the first valves to the first state, and the second and fourth valves are in the second state.

C1 1 . The pressure swing adsorption oxygen generator of clause C7, wherein each of the valves includes:

a poppet member;

a seat having a seat aperture; and

a pushrod member having a cam follower abutting the cam for movement of the pushrod in response to rotation of the cam between the first and second rotary positions of the cam, the poppet member being coupled to the pushrod member for movement therewith to move the poppet member into and out of seated arrangement with the seat to close and open the seat aperture in response to rotation of the cam.

C12. The pressure swing adsorption oxygen generator of clause C1 1 , wherein each of the valves further includes a housing with an end opening toward the cam, the poppet member and seat being positioned in the housing with the pushrod extending through the housing end opening, and further includes a flexible diaphragm positioned between the seat and the cam and having an opening through which the pushrod extends, the diaphragm closing the housing end opening, and having a peripheral portion coupled to the housing and a central portion coupled to the pushrod for movement therewith, the diaphragm having an effective area and the poppet valve having a closure area closing the seat aperture, the effective area of the diaphragm and the closure area of the poppet valve being sized to offset the force on the pushrod resulting from the pressure within the chamber between the seat and the diaphragm when the poppet valve is in seated arrangement with the seat, thereby reducing the force on the cam follower of the pushrod member.

C13. A pressure swing adsorption oxygen generator to separate oxygen from air, comprising:

a compressor having an input port and an output port; an adsorption bed having a bed of nitrogen absorbent material; and a multi-position rotary valve for controlling pressure swing adsorption of the adsorption bed, and being in fluid communication with the compressor and the adsorption bed, the rotary valve having:

a cam;

a rotary actuator configured to rotate the cam; and

first, second, third and fourth valves, each having a first port and a second port which are in fluid communication with each other in a first state and out of fluid communication with each other in a second state, and selectively movable between the first and second states in response to the rotary position of the cam, the first port of the first valve being in fluid communication with the compressor output port and the second port of the first valve being in fluid communication with atmosphere,

the first port of the second valve being in fluid communication with the adsorption bed and the second port of the second valve being in fluid

communication with the compressor output port,

the first port of the third valve being in fluid communication with the adsorption bed and the second port of the third valve being in fluid communication with the compressor input port,

the first port of the fourth valve being in fluid communication with the compressor input port and the second port of the fourth valve being in fluid communication with a supply of air from which oxygen is to be separated in the adsorption bed,

the first, second, third and fourth valves being moved between the first and second states in a repeated sequence in response to rotation of the cam, wherein during a first period the second and fourth valves are in the first state and the first and third valves are in the second state, whereby air at high pressure is communicated to the adsorption bed to separate nitrogen from the air and generate oxygen, and during a second period occurring after the first period the first and third valves are in the first state and the second and fourth valves are in the second state, whereby nitrogen is purged from the adsorption bed.

C14. The pressure swing adsorption oxygen generator of clause C13, further including:

an oxygen storage unit connected to the adsorption bed; a first regulator which upon a sensed first condition during the first period permits the generated oxygen within the adsorption bed to pass to the oxygen storage unit; and

a second regulator which upon a sense second condition during the second period permits a portion of the oxygen in the oxygen storage unit to enter the adsorption bed to assist in purging the nitrogen from the adsorption bed.

C15. The pressure swing adsorption oxygen generator of clause C13, further including:

an oxygen storage unit;

a first pressure regulator connected to the adsorption bed and to the oxygen storage unit, and in response to pressure in the adsorption bed rising to a preselected first pressure, the first pressure regulator regulating the pressure in the adsorption bed to the preselected first pressure and permitting the generated oxygen within the adsorption bed to pass through the first pressure regulator to the oxygen storage unit; and

a second pressure regulator connected to the adsorption bed and to the oxygen storage unit, and in response to pressure in the adsorption bed falling to a preselected second pressure that is lower than the preselected first pressure, the pressure regulator regulating the pressure in the adsorption bed to the

preselected second pressure and permitting stored oxygen within the oxygen storage unit to pass through the second pressure regulator to the adsorption bed.

C16. The pressure swing adsorption oxygen generator of clause C15, wherein the first pressure regulator prevents fluid communication through the first pressure regulator between the adsorption bed and the oxygen storage unit when the pressure in the adsorption bed is below the preselected first pressure, and the second pressure regulator prevents fluid communication through the second pressure regulator between the oxygen storage unit and the adsorption bed when the pressure in the adsorption bed is above the preselected second pressure.

C17. The pressure swing adsorption oxygen generator of clause

C13, wherein during a third period occurring after the second period the second and fourth valves are in the first state and the first and third valves are in the second state, whereby air at high pressure is communicated to the adsorption bed to separate nitrogen from the air and generate oxygen, and during a fourth period occurring after the third period the first and third valves are in the first state and the second and fourth valves are in the second state, whereby nitrogen is purged from the adsorption bed.

C18. The pressure swing adsorption oxygen generator of clause C13, wherein the first and third valves are positioned opposite each other on opposing sides of the cam, and the second and fourth valves are positioned opposite each other on opposing sides of the cam.

C19. The pressure swing adsorption oxygen generator of clause C18, wherein the cam has first and second cam lobes, and wherein during the first period the first cam lobe moves the fourth valve to the first state and the second cam lobe moves the second valve to the first state, and the first and third valves are in the second state, during the second period the first cam lobe moves the first valve to the first state and the second cam lobe moves the third valves to the first state, and the second and fourth valves are in the second state, during the third period the first cam lobe moves the second valve to the first state and the second cam lobe moves the fourth valve to the first state, and the first and third valves are in the second state, and during the fourth period the first cam lobe moves the third valve to the first state and the second cam lobe moves the first valves to the first state, and the second and fourth valves are in the second state.

D1 . A ventilator with an integrated cough assist for use with a patient circuit in fluid communication with a patient connection of a patient, the ventilator being operable in a ventilation mode and in a cough-assist mode, the ventilator comprising:

a ventilator connection to which the patient circuit is connectable for fluid communication therewith;

a ventilator portion directing a flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode;

a user input for selectively switching operation of the ventilator from ventilation mode to cough-assist mode without disconnecting the ventilator from the patient;

a controller operable in response to the user input for switching the ventilator from operation in the ventilation mode to operation in the cough-assist mode, and controlling operation of the ventilator in cough-assist mode to provide for at least one cough assist to the patient having an insufflation phase followed by an exsufflation phase; and

a cough-assist valve which is in a first state for the insufflation phase of the cough assist and then moved to a second state for the exsufflation phase of the cough assist, when the cough-assist valve is in the first state for the

insufflation phase of the cough assist, the cough-assist valve communicates a positive pressure to the ventilator connection, and when the cough-assist valve is in the second state for the exsufflation phase of the cough assist, the cough-assist valve communicates a negative pressure to the ventilator connection.

D2. The ventilator of clause D1 , wherein the cough-assist valve communicates a positive pressure to the ventilator connection sufficient to generate a patient airway pressure of 10 to 70 cmH20, and when the cough- assist valve is in the second state for the exsufflation phase of the cough assist, the cough-assist valve communicates a negative pressure to the ventilator connection sufficient to generate a patient airway pressure of -10 to -70 cmH20.

D3. A ventilator with an integrated cough assist for use with a patient circuit in fluid communication with a patient connection of a patient, the ventilator being operable in a ventilation mode and in a cough-assist mode, the ventilator comprising:

a controller controlling operation of the ventilator in the cough-assist mode to provide for at least one cough assist to the patient having an insufflation phase followed by an exsufflation phase;

a ventilator connection to which the patient circuit is connectable for fluid communication therewith;

a ventilator subsystem directing a flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode;

a compressor having a compressor inlet and a compressor outlet, the compressor being operable to accelerate gaseous fluid input to the

compressor inlet and deliver the accelerated gaseous fluid out the compressor outlet; and

a cough-assist valve which is in a first state for the insufflation phase of the cough assist and then moved to a second state for the exsufflation phase of the cough assist, when the cough-assist valve is in the first state for the

insufflation phase of the cough assist, the cough-assist valve directs a flow of air to the compressor inlet and directs the flow of the accelerated air from the compressor outlet to the ventilator connection for delivery to the patient, and when the cough-assist valve is in the second state for the exsufflation phase of the cough assist, the cough-assist valve directs the flow of exsufflation gases from the patient to the compressor inlet and exhausts the flow of the accelerated

exsufflation gases from the compressor outlet.

D4. The ventilator of clause D3, wherein when the ventilator is in the ventilation mode, the cough-assist valve is retained for operation in the first state.

D5. The ventilator of clause D3, wherein the ventilator portion directs the flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode by directing the ventilation air to the compressor inlet with the cough-assist valve being retained for operation in the first state.

D6. A ventilator with an integrated cough assist for use with a patient circuit in fluid communication with a patient connection of a patient, the ventilator being operable in a ventilation mode and in a cough-assist mode, the ventilator comprising:

a controller controlling operation of the ventilator in the cough-assist mode to provide for at least one cough assist to the patient having an insufflation phase followed by an exsufflation phase;

a ventilator connection to which the patient circuit is connectable for fluid communication therewith;

a ventilator portion directing a flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode;

a compressor having a compressor inlet and a compressor outlet, the compressor being operable to accelerate gaseous fluid input to the

compressor inlet and deliver the accelerated gaseous fluid out the compressor outlet; and

a cough-assist valve which is in a first state for the insufflation phase of the cough assist and then moved to a second state for the exsufflation phase of the cough assist, the cough-assist valve comprising:

a first chamber;

a second chamber;

a third chamber; a valve air intake aperture in fluid communication with a supply of air;

a valve exhaust outlet aperture;

a valve-to-compressor outlet aperture in fluid communication with the compressor input;

a compressor-to-valve inlet aperture in fluid communication with the compressor output;

a first aperture through which the first chamber and second chamber are in fluid communication;

a second aperture through which the second chamber and third chamber are in fluid communication;

a third aperture in fluid communication with the ventilator connection; a first valve member movable between a first position closing the first aperture and a second position closing the valve air intake aperture;

a second valve member movable between a first position closing the valve exhaust outlet aperture and a second position closing the second aperture;

when the cough-assist valve is in the first state for the insufflation phase of the cough assist, the first valve member is in the first valve member first position, and the second valve member is in the second valve member first position;

when the cough-assist valve is in the second state for the exsufflation phase of the cough assist, the first valve member is in the first valve member second position, and the second valve member is in the second valve member second state; and

a valve actuator configured to move the first and second valve members to their first positions for the insufflation phase of the cough assist and to move the first and second valve members to their second positions for the exsufflation phase of the cough assist.

D7. The ventilator of clause D6, wherein when the ventilator is in the ventilation mode, the cough-assist valve is retained for operation in the first state.

D8. The ventilator of clause D6, wherein the ventilator portion directs the flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode by directing the ventilation air to the compressor inlet with the cough-assist valve being retained for operation in the first state.

D9. The ventilator of clause D6, wherein the first and second valve members are attached to a connection member and the valve actuator is configured to move the connection member to a first position to move the first and second valve members to their first positions for the insufflation phase of the cough assist and to a second position to move the first and second valve members to their second positions for the exsufflation phase of the cough assist.

D10. The ventilator of clause D9, wherein the valve actuator includes an electromagnetic coil and a permanent magnet with one of the electromagnetic coil and the permanent magnet being attached to the connection member for movement therewith as a unit, and the other of the electromagnetic coil and the permanent magnet being stationary, the electromagnetic coil and the permanent magnet magnetically interacting when the electromagnetic coil is selectively energized to move the first and second valve members between their first and second positions.

D1 1 . The ventilator of clause D10, further including first and second permanent latching magnets, and first and second ferromagnetic member portions, one of the first permanent latching magnet and the first ferromagnetic member portion being attached to the connection member for movement therewith as a unit and the other being stationary, and one of the second permanent latching magnet and the second ferromagnetic member portion being attached to the connection member for movement therewith as a unit and the other being stationary, the first permanent latching magnet being positioned sufficiently close to the first ferromagnetic member portion when the first and second valve members are in their first positions to hold the first and second valve members in their first positions when the electromagnetic coil is de-energized, and the second permanent latching magnet being positioned sufficiently close to the second ferromagnetic member portion when the first and second valve members are in their second positions to hold the first and second valve members in their second positions when the electromagnetic coil is de-energized.

D12. The ventilator of clause D10, further including a permanent latching magnet, and a ferromagnetic member portion, one of the permanent latching magnet and the ferromagnetic member portion being attached to the connection member for movement therewith as a unit and the other being stationary, the permanent latching magnet being positioned sufficiently close to the ferromagnetic member portion when the first and second valve members are in one of their first and second positions to hold the first and second valve members in such one of their first and second positions when the electromagnetic coil is de-energized.

D13. The ventilator of clause D9, wherein the valve actuator includes a stationary electromagnetic coil and a movable permanent magnet, the electromagnetic coil being positioned in a stationary coil housing through which the connection member extends, and the permanent magnet being positioned within the coil housing with the electromagnetic coil extending thereabout, the permanent magnet being attached to the connection member for movement therewith as a unit and positioned for magnetic interaction with the

electromagnetic coil, the electromagnetic coil and the permanent magnet magnetically interacting when the electromagnetic coil is selectively energized to move the first and second valve members between their first and second positions.

D14. The ventilator of clause D13, further including first and second permanent latching magnets, and first and second ferromagnetic member portions, one of the first permanent latching magnet and the first ferromagnetic member portion being attached to the connection member for movement therewith as a unit and the other being stationary, and one of the second permanent latching magnet and the second ferromagnetic member portion being attached to the connection member for movement therewith as a unit and the other being stationary, the first permanent latching magnet being positioned sufficiently close to the first ferromagnetic member portion when the first and second valve members are in their first positions to hold the first and second valve members in their first position when the electromagnetic coil is de-energized, and the second permanent latching magnet being positioned sufficiently close to the second ferromagnetic member portion when the first and second valve members are in their second positions to hold the first and second members in their second positions when the electromagnetic coil is de-energized.

D15. The ventilator of clause D13, further including first and second permanent latching magnets attached to the connection member within the coil housing for movement with the connection member as a unit, and first and second ferromagnetic member portions, the first permanent latching magnet being positioned sufficiently close to the first ferromagnetic member portion when the first and second valve members are in their first positions to hold the first and second valve members in their first positions when the electromagnetic coil is de- energized, and the second permanent latching magnet being positioned sufficiently close to the second ferromagnetic member portion when the first and second valve members are in their second positions to hold the first and second valve members in their second positions when the electromagnetic coil is de- energized.

D16. The ventilator of clause D15, wherein the first ferromagnetic member portion is a first end portion of the coil housing and the second

ferromagnetic member portion is a second end portion of the coil housing.

D17. The ventilator of clause D13, further including a permanent latching magnet attached to the connection member within the coil housing for movement with the connection member as a unit, and a ferromagnetic member portion, the permanent latching magnet being positioned sufficiently close to the ferromagnetic member portion when the first and second valve members are in one of their first and second positions to hold the first and second valve members in such one of their first and second positions when the electromagnetic coil is de- energized.

D18. The ventilator of clause D9, wherein the connection member is an elongated shaft extending fully through the second chamber and having a first end portion extending through the first aperture into the first chamber and a second end portion extending through the second aperture into the third chamber, with the first valve member attached to the first end portion of the shaft within the first chamber between the valve air intake aperture and the first aperture, and with the second valve member attached to the second end portion of the shaft within the third chamber between the valve exhaust outlet aperture and the second aperture.

D19. The ventilator of clause D9, wherein the valve actuator includes an electromagnetic coil and a permanent magnet with one of the electromagnetic coil and the permanent magnet being attached to and

concentrically arranged with the connection member for movement therewith as a unit, and the other of the electromagnetic coil and the permanent magnet being stationary, the electromagnetic coil and the permanent magnet magnetically interacting when the electromagnetic coil is selectively energized to move the first and second valve members between their first and second positions.

D20. The ventilator of clause D19, wherein the other of the electromagnetic coil and the permanent magnet is concentrically arranged with the connection member.

D21 . The ventilator of clause D6, wherein the first, second and third chambers are within a valve body.

D22. The ventilator of clause D21 , wherein the first, second and third chambers are in a linear arrangement within the valve body, and the connection member is an elongated shaft extending fully through the second chamber and having a first end portion extending into the first chamber and a second end portion extending into the third chamber.

D23. The ventilator of clause D6, wherein the valve air intake aperture, the first aperture, the second aperture and the valve exhaust outlet aperture are in linear alignment, and the connection member is an elongated shaft in coaxial alignment with the valve air intake aperture, the first aperture, the second aperture and the valve exhaust outlet aperture, the shaft extending fully through the second chamber and having a first end portion extending through the first aperture into the first chamber with the first valve member attached thereto within the first chamber and movable with the shaft between the first aperture and the valve air intake aperture, and a second end portion extending through the second aperture into the third chamber with the second valve member attached thereto within the third aperture and movable with the shaft between the valve exhaust outlet aperture and the second aperture.

D24. The ventilator of clause D6, wherein:

the area of the first aperture closed by the first valve member when in the first valve member first position and the area of the valve exhaust outlet aperture closed by the second valve member when in the second valve member first position are sized to produce substantially equal and oppositely directed forces on the first and second valve members resulting from air pressure in the second chamber transmitted from the third aperture, and the area of the valve air intake aperture closed by the first valve member when in the first valve member second position and the area of the second aperture closed by the second valve member when in the second valve member second position are sized to produce substantially equal and oppositely directed forces on the first and second valve members resulting from air pressure in the second chamber transmitted from the third aperture.

D25. A ventilator with an integrated cough assist for use with a patient circuit in fluid communication with a patient connection of a patient, the ventilator being operable in a ventilation mode and in a cough-assist mode, the ventilator comprising:

a controller controlling operation of the ventilator in the cough-assist mode to provide for at least one cough assist to the patient having an insufflation phase followed by an exsufflation phase;

a ventilator connection to which the patient circuit is connectable for fluid communication therewith;

a ventilator portion directing a flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode;

a compressor having a compressor inlet and a compressor outlet, the compressor being operable to accelerate gaseous fluid input to the

compressor inlet and deliver the accelerated gaseous fluid out the compressor outlet; and

a cough-assist valve which is in a first state for the insufflation phase of the cough assist and then moved to a second state for the exsufflation phase of the cough assist, the cough-assist valve comprising:

a valve air intake in fluid communication with a supply of air;

a valve exhaust outlet;

a valve-to-compressor outlet in fluid communication with the compressor input;

a compressor-to-valve inlet in fluid communication with the compressor output;

a first valve member movable between a first valve member first position and a first valve member second position;

a second valve member movable between a second valve member first position and a second valve member second position; a third aperture in fluid communication with the ventilator connection; when the cough-assist valve is in the first state for the insufflation phase of the cough assist, the first valve member is in the first valve member first position permitting the flow of air from the supply of air entering the valve air intake to flow through the valve-to-compressor outlet and enter the compressor inlet while blocking the flow of air entering the valve air intake from flowing directly to the third aperture, and the second valve member is in the second valve member first position permitting the flow of the accelerated air from the

compressor outlet entering the compressor-to-valve inlet to flow through the third aperture for flow to the ventilator connection for delivery to the patient while blocking the flow of the accelerated air from the compressor outlet entering the compressor-to-valve inlet from flowing through the valve exhaust outlet;

when the cough-assist valve is in the second state for the exsufflation phase of the cough assist, the first valve member is in the first valve member second position permitting the flow of exsufflation gases from the patient entering the third aperture to flow through the valve-to-compressor outlet and enter the compressor inlet while blocking the flow of exsufflation gases from the patient entering the third aperture from flowing through the valve air intake, and the second valve member is in the second valve member second state permitting the flow of the accelerated exsufflation gases entering the compressor-to-valve inlet to flow through the valve exhaust outlet while blocking the flow of accelerated exsufflation gases entering the compressor-to-valve inlet from flowing to the third aperture; and

a valve actuator configured to move the first and second valve members to the first and second valve member first positions for the insufflation phase of the cough assist and to move the first and second valve members to the first and second valve member second positions for the exsufflation phase of the cough assist.

E1 . A secretion trap for use between a patient connection and a patient circuit, the secretion trap comprising:

a first connection portion connectable to the patient connection for fluid communication with the patient connection;

a second connection portion connectable to the patient circuit for fluid communication with the patient circuit; and a central portion located between the first and second connection portions and having:

a first end portion in fluid communication with the first connection portion,

a second end portion in fluid communication with the second connection portion; and

a secretion collection well located between the first and second end portions sized to capture and retain secretions therein entering the central portion.

E2. The secretion trap of clause E1 , wherein the first connection portion has a first cross-sectional area, the second connection portion has a second cross-sectional area, and the secretion collection well is a chamber located between the first and second end portions having a lengthwise portion thereof with at least a third cross-sectional area sufficiently greater than the first cross-sectional area of the first connection portion to capture and retain secretions in the secretion collection chamber entering the central portion.

E3. The secretion trap of clause E1 , further including a drain in fluid communication with the secretion collection well for removal of secretions captured and retained by the secretion collection well.

E4. The secretion trap of clause E1 for use with a source of suction, further including a drain having a first end portion in fluid communication with the secretion collection well and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the secretion collection well for removal of secretions captured and retained by the secretion collection well.

E5. The secretion trap of clause E4, wherein the first end portion of the drain is in fluid communication with the secretion collection well at a location nearer to the first end portion than to the second end portion of the secretion collection well.

E6. A secretion trap for use between a patient connection with a connection portion having an interior passageway and a cough assist conduit with a connection portion having an interior passageway, the secretion trap

comprising: a first connection portion connectable to the connection portion of the patient connection for fluid communication with the patient connection, the first connection portion having an interior passageway;

a second connection portion connectable to the connection portion of the cough assist conduit for fluid communication with the cough assist conduit, the second connection portion having an interior passageway; and

a secretion collection chamber located between the first and second connection portions and having a chamber first end portion located toward the first connection portion and a chamber second end portion located toward the second connection portion, one of the passageways of the first connection portion and the connection portion of the patient connection defining a flow aperture for the secretion collection chamber at the chamber first end portion and one of passageways of the second connection portion and the connection portion of the cough assist conduit defining a flow aperture for the secretion collection chamber at the chamber second end portion, the secretion chamber having a well portion sized to capture and retain secretions therein entering the central portion.

E7. The secretion trap of clause E6, wherein the secretion chamber has a lengthwise portion with a cross-sectional area sized such that a fluid flow with a flow rate entering the secretion chamber through the flow aperture at the chamber first end portion is sufficiently reduced in flow rate within the secretion chamber for the secretion collection chamber to capture and retain therein secretions carried by the fluid flow.

E8. The secretion trap of clause E6, further including a drain in fluid communication with the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

E9. The secretion trap of clause E6 for use with a source of suction, further including a drain having a first end portion in fluid communication with the secretion collection chamber and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

E10. The secretion trap of clause E9, wherein the first end portion of the drain is in fluid communication with the secretion collection chamber at a location nearer to the chamber first end portion than to the chamber second end portion.

E1 1 . A patient connection with an integrated secretion trap for use with a patient circuit, comprising:

a patient breathing conduit portion; and

a secretion collection chamber with chamber first and second end portions, the chamber first end portion being in fluid communication with the patient breathing conduit portion and the chamber second end portion being connectable with the patient circuit for fluid communication with the patient circuit, the patient breathing conduit portion and chamber first end portion defining a first end flow aperture for the secretion collection chamber at the chamber first end portion, the secretion chamber having a lengthwise portion with a cross-sectional area sized such that a fluid flow with a flow rate entering the secretion chamber through the first end flow aperture is sufficiently reduced in flow rate within the secretion chamber for the secretion collection chamber to capture and retain therein secretions carried by the fluid flow.

E12. The patient connection of clause E1 1 , further including a drain in fluid communication with the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

E13. The patient connection of clause E1 1 for use with a source of suction, further including a drain having a first end portion in fluid communication with the secretion collection chamber and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

E14. A patient circuit with an integrated secretion trap for use with a patient connection, comprising:

a patient circuit conduit portion; and

a secretion collection chamber with chamber first and second end portions, the chamber first end portion being connectable with to the patient connection for fluid communication with the patient connection and the chamber second end portion being in fluid communication with the patient circuit conduit portion, the patient connection and chamber first end portion when connected together defining a first end flow aperture for the secretion collection chamber at the chamber first end portion, the secretion chamber having a lengthwise portion with a cross-sectional area sized such that a fluid flow with a flow rate entering the secretion chamber through the first end flow aperture is sufficiently reduced in flow rate within the secretion chamber for the secretion collection chamber to capture and retain therein secretions carried by the fluid flow.

E15. The patient circuit of clause E14, further including a drain in fluid communication with the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

E16. The patient circuit of clause E14 for use with a source of suction, further including a drain having a first end portion in fluid communication with the secretion collection chamber and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

E17. A patient connection with an integrated secretion trap and patient circuit, the secretion trap comprising:

a patient breathing conduit portion;

a patient circuit conduit portion; and

a secretion collection chamber with chamber first and second end portions, the chamber first end portion being in fluid communication with the patient breathing conduit portion and the chamber second end portion being in fluid communication with the patient circuit conduit portion, the patient breathing conduit portion and chamber first end portion defining a first end flow aperture for the secretion collection chamber at the chamber first end portion, the secretion chamber having a lengthwise portion with a cross-sectional area sized such that a fluid flow with a flow rate entering the secretion chamber through the first end flow aperture is sufficiently reduced in flow rate within the secretion chamber for the secretion collection chamber to capture and retain therein secretions carried by the fluid flow.

E18. The patient connection of clause E17, further including a drain in fluid communication with the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

E19. The patient connection of clause E17 for use with a source of suction, further including a drain having a first end portion in fluid communication with the secretion collection chamber and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the secretion collection chamber for removal of secretions captured and retained by the secretion collection chamber.

E20. A ventilator with an integrated cough assist and a secretion trap for use in fluid communication with a patient connection, the ventilator being operable in a ventilation mode and in a cough-assist mode, the ventilator comprising:

a ventilator connection;

a secretion trap having a first connection portion connectable to the patient connection for fluid communication with the patient connection, a second connection portion in fluid communication with the ventilator connection, and a central portion located between the first and second connection portion, the central portion having a first end portion in fluid communication with the first connection portion, a second end portion in fluid communication with the second connection portion, and a secretion collection well located between the first and second end portions sized to capture and retain secretions therein entering the central portion;

a ventilator portion directing a flow of ventilation air to the ventilator connection for delivery to the patient in the ventilation mode;

a user input for selectively switching operation of the ventilator from ventilation mode to cough-assist mode without disconnecting the ventilator from the patient; and

a controller operable in response to the user input for switching the ventilator from operation in the ventilation mode to operation in the cough-assist mode, and controlling operation of the ventilator in the cough-assist mode to provide for at least one cough assist to the patient.

E21 . The ventilator of clause E20, wherein the controller, when controlling operation of the ventilator in the cough-assist mode, controls operation of the ventilator to provide for at least one cough assist to the patient having an insufflation phase followed by an exsufflation phase, the ventilator further including at least one cough-assist valve to communicate a positive pressure to the ventilator connection during at least a portion of the insufflation phase of the cough assist and to communicate a negative pressure to the ventilator connection during at least a portion of the exsufflation phase of the cough assist.

E22. The ventilator of clause E20, further including a drain in fluid communication with the secretion collection well for removal of secretions captured and retained by the secretion collection well.

E23 The ventilator of clause E20 for use with a source of suction, further including a drain having a first end portion in fluid communication with the secretion collection well and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the secretion collection well for removal of secretions captured and retained by the secretion collection well.

E24. A secretion trap for use between a patient connection and a patient circuit, the secretion trap comprising:

a first connection portion connectable to the patient connection for fluid communication with the patient connection;

a second connection portion connectable to the patient circuit for fluid communication with the patient circuit;

a central portion located between the first and second connection portion and having a first end portion in fluid communication with the first connection portion and a second end portion in fluid communication with the second connection portion; and

a secretion collection drain located in fluid communication with the central portion sized and positioned for removal of secretions entering within the central portion.

E25. The secretion trap of clause E24 for use with a source of suction, wherein the secretion collection drain has a first end portion in fluid communication with the central portion and a second end portion connectable to the source of suction for fluid communication with the source of suction for the application of suction to the central portion for removal of the secretions entering within the central portion.

F1. A passive valve for use as a fixed leak valve with a ventilator by connection to a patient connection, comprising:

a valve body having an internal chamber; a first valve body port in fluid communication with the internal chamber and configured for fluid communication with the patient connection;

a second valve body port in fluid communication with the internal chamber and configured for fluid communication with the ventilator;

a valve body passageway in fluid communication with the internal chamber and with ambient air exterior of the valve body; and

a check valve seal positioned to seal the valve body passageway to permit the flow of gas within the internal chamber through the valve body passageway to the exterior of the valve body and to prevent the flow of ambient air exterior of the valve body through the valve body passageway into the internal chamber.

F2. The passive valve of clause F1 , wherein the valve body passageway is an elongated circumferentially extending channel extending at least partially about the valve body.

F3. The passive valve of clause F2, further including a plurality of first passageways in fluid communication with the internal chamber and the channel.

F4. The passive valve of clause F3, wherein the check valve seal is an elongated circumferentially extending flexible seal positioned within the channel and flexibly movable between a closed position closing the first passageways to prevent fluid communication between the internal chamber and the channel through the first passageways when pressure in the internal chamber is below a threshold pressure, and an open position opening the first

passageways to allow fluid communication between the internal chamber and the channel through the first passageways when pressure in the internal chamber is above the threshold pressure and thereby providing a fluid communication path between the internal chamber and ambient air exterior of the valve body.

F5. A passive valve for use as a fixed leak valve with a ventilator by connection to a patient connection, comprising:

a body having a first body portion, a second body portion and a third body portion positioned between the first and second body portions;

the first body portion having a first fluid passageway extending therethrough with an outward end portion configured for fluid communication with the patient connection; the second body portion having a second fluid passageway extending therethrough with an outward end portion configured for fluid

communication with the ventilator;

the third body portion having a third fluid passageway extending therethrough in fluid communication with the first and second fluid passageways, the first, second and third fluid passageways in combination defining a body fluid passageway, the third body portion having a chamber extending at least partially thereabout, the chamber having at least one interior opening in fluid

communication with the body fluid passageway, and at least one exterior opening in fluid communication with the exterior of the body; and

a seal having at least a portion thereof located within the chamber and movable between a closed position closing the at least one interior opening of the chamber when pressure in the body fluid passageway is below a threshold pressure, and an open position opening the at least one interior opening when pressure in the body fluid passageway is above the threshold pressure.

F6. The passive valve of clause F5, wherein the portion of the seal is a first peripheral portion of the seal.

F7. The passive valve of clause F6, wherein the first peripheral portion of the seal is flexible and moves from the closed position to the open position by flexing away from the at least one interior opening in response to the pressure in the body fluid passageway being above the threshold pressure.

F8. The passive valve of clause F7, wherein the seal further includes a second peripheral portion of the seal held stationary relative to the body.

F9. The passive valve of clause F6, wherein the seal is flexible and moves from the closed position to the open position by flexing away from the at least one interior opening in response to the pressure in the body fluid passageway being above the threshold pressure.

F10. The passive valve of clause F6, wherein the at least one interior opening includes at least two interior openings and the portion of the seal extends between the at least two interior openings of the chamber and is movable between a closed position covering and closing the at least two interior openings to prevent fluid communication between the body fluid passageway and the chamber through the at least two interior openings when pressure in the body fluid passageway is below a threshold pressure, and an open position opening the at least two interior openings to allow fluid communication between the body fluid passageway and the chamber through the at least two interior openings when pressure in the body fluid passageway is above the threshold pressure and thereby providing a fluid communication path between the body fluid passageway and the at least one exterior opening of the chamber.

F1 1 . The passive valve of clause F10, wherein the seal has a first peripheral portion and a second peripheral portion with one of the first and second peripheral portions being located outward of the other of the first and second peripheral portions, the first peripheral portion of the seal extending between the at least two interior openings, the first peripheral portion of the seal being flexible and moving from the closed position to the open position by flexing away from the at least two interior openings in response to the pressure in the body fluid passageway being above the threshold pressure, and the second peripheral portion of the seal being held stationary relative to the body.

F12. The passive valve of clause F5, wherein the chamber is an annular chamber extending fully about the third fluid passageway, and the seal is an annular seal.

F13. A passive valve for use as a fixed leak valve with a ventilator by connection to a patient connection, comprising:

a seal having a seal central opening;

a first body portion having a first fluid passageway extending therethrough with an outward first end portion configured for fluid communication with the patient connection and an inward second end portion;

a second body portion having a second fluid passageway extending therethrough with an outward first end portion configured for fluid communication with the ventilator and an inward second end portion, the inward second end portions of the first and second body portions being joined together with the seal positioned therebetween with the seal central opening aligned with the first and second fluid passageways to define a body fluid passageway extending between the outward first end portions of the first and second body portions; and

a chamber extending about the body fluid passageway, the chamber having at least one interior opening in fluid communication with the body fluid passageway, and at least one exterior opening in fluid communication with the exterior of the body, the seal having a first peripheral portion located within the chamber and being movable between a closed position closing the at least one interior opening when pressure in the body fluid passageway is below a threshold pressure, and an open position opening the at least one interior opening when pressure in the body fluid passageway is above the threshold pressure.

F14. The passive valve of clause F13, wherein the first peripheral portion of the annular seal is flexible and moves from the closed position to the open position by flexing away from the at least one interior opening in response to the pressure in the body fluid passageway being above the threshold pressure.

F15. The passive valve of clause F14, wherein the annular seal further has a second peripheral portion held stationary relative to the body.

F16. The passive valve of clause F13, wherein the at least one interior opening is formed by at least one gap between joined inward second end portions of the first and second body portions.

F17. The passive valve of clause F13, wherein the at least one exterior opening is formed in a flange portion of at least one of the joined inward second end portions of the first and second body portions.

F18. A ventilator with an integrated cough assist for use with a patient, the ventilator comprising:

a passive patient circuit for fluid communication with a patient connection;

a ventilator portion having a ventilator connection to which the patient circuit is connectable for fluid communication therewith, the ventilator portion being operable in a ventilation mode and in a cough-assist mode, the ventilator portion directing a flow of ventilation air to the ventilator connection for delivery to the patient via the patient circuit when the ventilator is in the ventilation mode, the ventilation air producing a pressure in the patient circuit above a threshold pressure;

a user input for selecting switching operation of the ventilator from the ventilation mode to the cough-assist mode without disconnecting the ventilator from the patient;

a controller operable in response to the user input for switching the ventilator from operation in the ventilation mode to operation in the cough-assist mode, and controlling operation of the ventilator in cough-assist mode to provide for at least one cough assist to the patient having an insufflation phase followed by an exsufflation phase;

a cough-assist valve which is in a first state for the insufflation phase of the cough assist and then moved to a second state for the exsufflation phase of the cough assist, when the cough-assist valve is in the first state for the

insufflation phase of the cough assist, the cough-assist valve communicates a positive pressure to the ventilator connection for delivery to the patient via the patient circuit at a pressure in the patient circuit above the threshold pressure, and when the cough-assist valve is in the second state for the exsufflation phase of the cough assist, the cough-assist valve communicates a negative pressure to the ventilator connection for delivery to the patient via the patient circuit at a pressure in the patient circuit below the threshold pressure; and

wherein the patient circuit includes a passive valve usable as a fixed leak valve and having:

a valve body having an internal chamber;

a first valve body port in fluid communication with the internal chamber and configured for fluid communication with the patient connection;

a second valve body port in fluid communication with the internal chamber and configured for fluid communication with the ventilator connection;

a valve body passageway in communication with the internal chamber and with ambient air exterior of the valve body; and

a check valve seal positioned to seal the valve body passageway to permit the flow of gas within the internal chamber through the valve body passageway to the exterior of the valve body and to prevent the flow of ambient air exterior of the valve body through the valve body passageway into the internal chamber.

F19. The ventilator of clause F18, wherein the valve body passageway comprises a passageway chamber extending at least partially about the internal chamber of the valve body with the first valve body port comprising at least two interior openings of the passageway chamber providing fluid

communication between the passageway chamber and the internal chamber of the valve body, and the second valve body port comprising at least one exterior opening of the passageway chamber providing fluid communication between the passageway chamber and the exterior of the valve body, and the check valve seal is at least in part located within the passageway chamber and extends between the at least two interior openings of the passageway chamber, the portion of the seal being movable between a closed position closing the at least two interior opening of the passageway chamber when pressure in the internal chamber of the valve body is below the threshold pressure, and an open position opening the at least two interior opening of the passageway chamber when pressure in the internal chamber of the valve body is above the threshold pressure.

F20. The ventilator of clause F19, wherein the portion of the seal located within the passageway chamber is flexible and moves from the closed position to the open position by flexing away from the at least two interior openings of the passageway chamber in response to the pressure in the internal chamber of the valve body being above the threshold pressure.

F21 . The ventilator of clause F20, wherein the seal further includes a portion held stationary relative to the valve body.

F22. A patient connection for use with a ventilator and a patient having at least one lung, comprising:

a patient interface portion having a fluid passageway couplable to the patient in fluid communication with the at least one lung of the patient; and a passive valve portion operable as a fixed leak valve, the valve portion having:

a valve body having an internal chamber;

a first valve body port in fluid communication with the internal chamber and configured for fluid communication with the fluid passageway of the patient interface;

a second valve body port in fluid communication with the internal chamber and configured for fluid communication with the ventilator;

a valve body passageway in communication with the internal chamber and with ambient air exterior of the valve body; and

a check valve seal positioned to seal the valve body passageway to permit the flow of gas within the internal chamber through the valve body passageway to the exterior of the valve body and to prevent the flow of ambient air exterior of the valve body through the valve body passageway into the internal chamber. F23. The patient connection of clause F22, wherein the valve body passageway is an elongated circumferentially extending channel extending at least partially about the valve body.

F24. The patient connection of clause F23, further including a plurality of first passageways in fluid communication with the internal chamber and the channel.

F25. The patient connection of clause F24, wherein the check valve seal is an elongated circumferentially extending flexible seal positioned within the channel and flexibly movable between a closed position closing the first passageways to prevent fluid communication between the internal chamber and the channel through the first passageways when pressure in the internal chamber is below a threshold pressure, and an open position opening the first

passageways to allow fluid communication between the internal chamber and the channel through the first passageways when pressure in the internal chamber is above the threshold pressure and thereby providing a fluid communication path between the internal chamber and ambient air exterior of the valve body.

G1 . An active exhalation valve for use with a ventilator to control flow of patient exhaled gases, comprising:

a patient circuit connection port;

a patient connection port;

an exhaled gas port;

a pilot pressure port;

a valve seat; and

a movable poppet including an inner bellows member, an outer bellows member and a bellows poppet face, the pilot pressure port being configured such that an activation pressure applied to the pilot pressure port extends the inner and outer bellows members to move the bellows poppet face into engagement with the valve seat and restrict flow of patient exhaled gases to the exhaled gas port, and the reduction of the activation pressure to the pilot pressure port allows the inner and outer bellows members to move the bellows poppet face away from the valve seat and out of engagement with the valve seat to permit flow of patient exhaled gases to the exhaled gas port, thereby controlling the flow of patient exhaled gases from the valve. G2. The exhalation valve of clause G1 , wherein the inner and outer bellows members define an interior bellows chamber therebetween and the pilot pressure port is in fluid communication with the interior bellows chamber.

G3. The exhalation valve of clause G2, wherein the inner bellows member has an inner bellows fluid passageway extending therethrough in fluid communication with the patient circuit connection port and the patient connection port.

G4. The exhalation valve of clause G3, wherein the inner bellows fluid passageway is in continuous fluid communication with the patient circuit connection port and the patient connection port during operation of the exhalation valve, and out of fluid communication with the interior bellows chamber between the inner and outer bellows members.

G5. The exhalation valve of clause G1 , wherein the inner bellows member has an inner bellows fluid passageway extending therethrough in continuous fluid communication with the patient circuit connection port and the patient connection port.

G6. An active exhalation valve for use with a patient connection and a ventilator having a pressure source usable to control operation of the valve to control flow of patient exhaled gases, comprising:

a patient circuit connection port for fluid communication with the ventilator;

a patient connection port for fluid communication with the patient connection;

an exhaled gas port for fluid communication with air exterior to the valve to remove patient exhaled gases from the valve;

a pilot pressure port for fluid communication with the pressure source;

a valve seat; and

a movable poppet including an inner bellows member, an outer bellows member and a bellows poppet face, the pilot pressure port being configured such that an activation pressure applied by the pressure source to the pilot pressure port extends the inner and outer bellows members to move the bellows poppet face into sealing engagement with the valve seat and restrict flow of patient exhaled gases to the exhaled gas port, and the reduction of the activation pressure applied by the pressure source to the pilot pressure port allows the inner and outer bellows members to move the bellows poppet face away from the valve seat and out of sealing engagement with the valve seat to permit flow of patient exhaled gases to the exhaled gas port, thereby controlling the flow of patient exhaled gases from the valve.

G7. The exhalation valve of clause G6, wherein the inner and outer bellows members define an interior bellows chamber therebetween and the pilot pressure port is in fluid communication with the interior bellows chamber.

G8. The exhalation valve of clause G7, wherein the inner bellows member has an inner bellows fluid passageway extending therethrough in fluid communication with the patient circuit connection port and the patient connection port.

G9. The exhalation valve of clause G8, wherein the inner bellows fluid passageway is in continuous fluid communication with the patient circuit connection port and the patient connection port during operation of the exhalation valve, and out of fluid communication with the interior bellows chamber between the inner and outer bellows members.

G10. The exhalation valve of clause G6, wherein the inner bellows member has an inner bellows fluid passageway extending therethrough in continuous fluid communication with the patient circuit connection port and the patient connection port.

G1 1. An active exhalation valve for use with a ventilator to control operation of the valve to control flow of patient exhaled gases, comprising:

a patient circuit connection port;

a patient connection port;

an exhaled gas port;

a pilot pressure port;

a valve seat; and

a movable poppet including an inner member, an outer member and a poppet face, the pilot pressure port being configured such that an activation pressure applied to the pilot pressure port moves the inner and outer members toward the valve seat to move the poppet face into engagement with the valve seat and restrict flow of patient exhaled gases to the exhaled gas port, and the reduction of the activation pressure to the pilot pressure port allows the inner and outer members to move away from the valve seat to move the poppet face out of engagement with the valve seat to permit flow of patient exhaled gases to the exhaled gas port, thereby controlling the flow of patient exhaled gases from the valve.

G12. The exhalation valve of clause G1 1 , wherein the inner and outer members define an interior chamber therebetween and the pilot pressure port is in fluid communication with the interior chamber.

G13. The exhalation valve of clause G12, wherein the inner member has an inner member fluid passageway extending therethrough in fluid communication with the patient circuit connection port and the patient connection port.

G14. The exhalation valve of clause G13, wherein the inner member fluid passageway is in continuous fluid communication with the patient circuit connection port and the patient connection port during operation of the exhalation valve, and out of fluid communication with the interior bellows chamber between the inner and outer bellows members.

G15. The exhalation valve of clause G1 1 , wherein the inner member has an inner member fluid passageway extending therethrough in continuous fluid communication with the patient circuit connection port and the patient connection port.

G16. An active exhalation valve for use with a patient connection and a ventilator having a pressure source usable to control operation of the valve, comprising:

a valve body having an internal body chamber with gasses therein having a body chamber pressure;

a first body port in fluid communication with the body chamber and configured for fluid communication with the patient connection;

a second body port in fluid communication with the body chamber and configured for fluid communication with the ventilator;

a passageway in fluid communication with the body chamber and with ambient air exterior of the valve body; and

a valve seal movable between a closed position sealing the passageway and an open position opening the passageway, the valve seal having: (a) an outer member,

(b) an inner member positioned within the outer member,

(c) an internal seal chamber located between the outer and inner members and in fluid communication with the pressure source, and

(d) a seal member extending between the inner and outer members and movable therewith, the seal member having a first surface portion inside the seal chamber configured for movement of the valve seal toward the closed position in response to pressure applied thereto by the pressure source and a second surface portion outside the seal chamber configured for movement of the valve seal toward the open position in response to pressure applied thereto by the body chamber pressure, with amount and direction of movement of the valve seal being responsive to a resultant force generated by the pressure source and the body chamber pressure on the first and second surface portions. G17. The exhalation valve of clause G16, wherein the inner member has an inner member fluid passageway extending therethrough in fluid communication with the body chamber and having a first end in fluid

communication with the first body port and a second end in fluid communication with the second body port.

G18. The exhalation valve of clause G17, wherein the inner member fluid passageway is in continuous fluid communication with the first and second body ports during operation of the exhalation valve, and out of fluid communication with the seal chamber between the inner and outer members.

G19. The exhalation valve of clause G16, wherein the inner member has an inner member fluid passageway extending therethrough with a first opening in continuous fluid communication with the first body port and a second opening in continuous fluid communication with the second body port.

G20. The exhalation valve of clause G16, wherein the body has a wall portion positioned outward of the valve seal and defining another chamber positioned outward of the valve seal with the passageway being in the wall portion. G21. The exhalation valve of clause G16, wherein the body has a perimeter wall portion extending circumferentially about the body chamber and positioned outward of the valve seal, and defining an elongated perimeter chamber extending at least partially about the body chamber, with the

passageway being in the perimeter wall portion.

G22. The exhalation valve of clause G16, wherein the passageway comprises a plurality of apertures in an external wall of the body in fluid

communication with the body chamber and with ambient air exterior of the valve body.

G23. An active exhalation valve for use with a patient connection and a ventilator having a pressure source usable to control operation of the valve, comprising:

a valve body having an internal body chamber with gasses therein having a body chamber pressure and a body wall portion with a channel therein for fluid communication with the pressure source and an aperture in fluid communication with the channel;

a first body port in fluid communication with the body chamber and configured for fluid communication with the patient connection;

a second body port in fluid communication with the body chamber and configured for fluid communication with the ventilator;

a passageway in fluid communication with the body chamber and with ambient air exterior of the valve body; and

a valve seal movable between a closed position sealing the passageway and an open position opening the passageway, the valve seal having:

(a) an outer longitudinally extending and longitudinally

compressible wall,

(b) an inner longitudinally extending and longitudinally compressible wall positioned within the outer wall, each of the outer and inner walls having a first end and a second end,

(c) a seal end wall closing a space between the first ends of the outer and inner walls and being longitudinally movable with the first ends of the outer and inner walls, (d) the body wall portion closing a space between the second ends of the outer and inner walls, and

(e) an internal seal chamber located between the outer and inner walls and extending between the seal end wall and the body wall portion, the aperture of the body wall portion being in fluid communication with the seal chamber to provide fluid communication with the pressure source, the seal end wall being longitudinally movable within the valve body between the closed position with the outer and inner walls being in an extended configuration and the open position with the outer and inner walls being compressed into at least a partially longitudinally compressed position, the seal end wall having a first surface portion inside the seal chamber configured for movement of the valve seal toward the closed position in response to pressure applied thereto by the pressure source and a second surface portion outside the seal chamber configured for movement of the valve seal toward the open position in response to pressure applied thereto by the body chamber pressure, with amount and direction of movement of the valve seal being responsive to a resultant force generated by the pressure source and the body chamber pressure on the first and second surface portions of the seal end wall.

G24. The exhalation valve of clause G23, wherein the inner wall has an inner wall fluid passageway extending therethrough in fluid communication with the body chamber and having a first end in fluid communication with the first body port and a second end in fluid communication with the second body port.

G25. The exhalation valve of clause G24, wherein the inner wall fluid passageway is in continuous fluid communication with the first and second body ports during operation of the exhalation valve, and out of fluid

communication with the seal chamber between the inner and outer walls.

G26. The exhalation valve of clause G23, wherein the inner wall has an inner wall fluid passageway extending therethrough with a first opening in continuous fluid communication with the first body port and a second opening in continuous fluid communication with the second body port.

G27. The exhalation valve of clause G23, wherein the longitudinally compressible outer and inner walls are corrugated with a plurality of corrugations, and when in the at least partially longitudinally compressed position more than one of the corrugations is longitudinally compressed. G28. An active exhalation valve for use with a patient connection and a ventilator having a pressure source usable to control operation of the valve, comprising:

a valve body having an internal body chamber with gasses therein having a body chamber pressure and a channel therein for fluid communication with the pressure source and an aperture in fluid communication with the channel;

a first body port in fluid communication with the body chamber and configured for fluid communication with the patient connection;

a second body port in fluid communication with the body chamber and configured for fluid communication with the ventilator;

a passageway in fluid communication with the body chamber and with ambient air exterior of the valve body; and

a valve seal movable between a closed position sealing the passageway and an open position opening the passageway, the valve seal having a seal chamber defined by first and second longitudinally spaced apart ends, and by an outer longitudinally extendable wall and an inner longitudinally extendable wall positioned within the outer wall, the aperture of the valve body being in fluid communication with the seal chamber to provide fluid communication with the pressure source, the first end of the seal chamber being longitudinally movable within the valve body between the closed position of the valve seal whereat the outer and inner walls are in a longitudinally extended configuration and the open position of the valve seal whereat the outer and inner walls are in a longitudinally retracted configuration, the valve seal being moved toward the closed position in response to pressure applied by the pressure source and toward the open position in response to pressure applied by the body chamber pressure, with amount and direction of movement of the valve seal being responsive to a resultant force generated by the pressure source and the body chamber pressure.

G29. The exhalation valve of clause G28, wherein the inner wall has an inner wall fluid passageway extending therethrough in fluid communication with the body chamber and having a first end in fluid communication with the first body port and a second end in fluid communication with the second body port.

G30. The exhalation valve of clause G29, wherein the inner wall fluid passageway is in continuous fluid communication with the first and second body ports during operation of the exhalation valve, and out of fluid communication with the seal chamber between the inner and outer walls.

G31. The exhalation valve of clause G28, wherein the inner wall has an inner wall fluid passageway extending therethrough with a first opening in continuous fluid communication with the first body port and a second opening in continuous fluid communication with the second body port.

Features and aspects of the several embodiments described above and illustrated in the different figures of the drawings may be used in various and different combinations, all of which are within the scope of the invention.

The foregoing described embodiments depict different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely exemplary, and that in fact many other architectures can be implemented which achieve the same

functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being

"operably connected," or "operably coupled," to each other to achieve the desired functionality.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from this invention and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of this invention. Furthermore, it is to be

understood that the invention is solely defined by the appended claims. It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be

interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more

recitations).

Accordingly, the invention is not limited except as by the appended claims.