CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is an international application claiming priority to United States Application Serial No. 16/402,749 filed on May 3, 2019, the contents of which are incorporated herein by reference in its entirety.”

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR

DEVELOPMENT

This invention was made with government support under HD074310 awarded by the National Institutes of Health, and 0810029 and 0923861 awarded by the National Science Foundation. The government has certain rights in the invention.

FIELD OF THE INVENTION

The present invention pertains generally to the field of medical devices, and more specifically to a system for in-situ clearing of occlusive material such as secretions in endotracheal tubes and other tubes in the body where secretions or other materials accumulate and negatively impact tube patency.

BACKGROUND

The following is a description of the background of endotracheal tubes (ETTs). It should be understood that the device and method of the present invention is not limited to the clearing of ETTs but is applicable to a range of artificial tubes such as indwelling catheters, pigtail catheters, abscess drains, and chest tubes and that ETTs are being discussed simply by way of example. It should also be understood that the device and method of the present invention is not limited to secretions but is applicable to a range of accumulating and/or occluding materials such as blood, clots, and ingrown tissues/membranes.

Automated mechanical ventilation is often required for patients under anesthesia and for longer-term breathing assistance in compromised patients. Endotracheal tubes are placed in the upper respiratory tract of patients to provide direct airway access when connected to a mechanical ventilator. Annually, 50 million ETTs are sold globally. Patients intubated with ETTs are unable to effectively clear lung secretions, and therefore secretions can accumulate and partially occlude the inside of the ETT. This leads to increased airway resistance and a potentially negative impact on patient health if not remedied. Without proper air humidification, the secretions also potentially become dried, thick, and difficult to remove.

The most routine method to maintain ETT patency is periodic aspiration with a suction catheter. The suction catheter is designed to be momentarily inserted down the ETT manually while attached to a negative pressure source. There are two general types of suction catheters: open and closed. An open suction catheter requires the patient to be disconnected from the ventilator for the suctioning procedure. A closed suction catheter is enclosed in a protective sleeve and remains attached to the ventilator circuit the entire time. Suctioning can occur without having to shut off the ventilator or disconnect the patient, because there is a diaphragm that maintains an air-tight seal around the suctioning catheter. Whether open or closed, the general suction procedure remains the same. With one hand stabilizing the proximal end of the ETT, the suction catheter is fed into the ETT with the opposite hand until the end is reached, being careful to not over-insert the catheter beyond the tip of the ETT. While retracting the suction catheter, a valve is pressed enabling the negative pressure source to apply a vacuum to the inner lumen of the suction catheter to aspirate out secretions accumulated on the inner wall of the ETT. It is generally desired for the entire suction procedure to be performed in 10-15 seconds, or 5 seconds in children to minimize the impact of the suctioning procedure on lung mechanics and respiration. Generally, a patient will require suctioning every 4-6 hours, but the process may be performed with greater regularity if necessary. The procedure is recommended on an as needed basis, not a regular interval, due to the detrimental effect on the patient.

Attempts to clear the ETT using standard techniques are often ineffective, time consuming, expensive, and an agonizing experience for the patients, families, and health care providers. Standard methods can also dislodge bacteria containing particles into the lungs. Ventilator Acquired Pneumonia (VAP) is a major source of infection in hospitals, and is often due to the direct path to the lungs for bacteria from ETT intubation. Standard suctioning has an effect on lung mechanics, including decreased tidal volume and lung compliance. Clinical side effects include hypoxia (low oxygen in blood), bradycardia (low heart rate), or atelectasis (collapse of part of the lung). In general, the long term effects of acute changes in lung mechanics or cumulative exposures to short term clinical side effects of suctioning on long term respiratory health is not known. Still, minimizing the potential negative impacts of the suctioning process on the lungs is desirable.

Negative effects can be minimized with use of smaller diameter suction catheters, which allow improved airflow during the insertion of the catheter and when actively suctioning. Guidelines suggest choosing a suction catheter whose outer diameter is less than half the inner diameter of the ETT. However, with narrow ETTs (such as neo-natal or pediatric patients) this is difficult to achieve without severely limiting secretion aspiration effectiveness using standard methods. Such small diameter suction catheters may easily clog, depending on the consistency of the secretions. In addition to airflow considerations, larger suction catheters may be difficult to insert if the catheter diameter to ETT inner diameter ratio is larger than 0.7.

While the practice is now largely discouraged, occasionally physiologic saline may be first instilled at the inlet to the ETT in an attempt to hydrate and thin the secretions to encourage its removal during the subsequent suctioning procedure. Additional goals of saline instillation may include lubricating and easing the insertion of the catheter itself, and/or elicitation of a cough from the patient to aid secretion removal. The current methods of instilling saline into ETTs are not precise and there is risk of excess fluid entering the lungs and possibly causing dispersion of adherent contaminating material. Reports further suggest saline instillation may cause greater blood oxygen desaturation than suctioning without saline. Despite lack of evidence supporting saline instillation and its potential risks, some clinicians continue the practice.

When suctioning is unable to restore patency quickly, the only recourse is to replace the ETT, further raising the risk of VAP while also depriving the patient of oxygen until the patient is re-intubated and reconnected to the ventilator. In addition, the re-intubation process itself can agitate the patient’ s airway and lead to inflammation and/or injury.

There remains a need to safely and quickly clear ETTs, while reducing the negative impact the suction procedure has on the lung mechanics of an already compromised patient.

SUMMARY OF THE INVENTION The present invention is directed to an occlusion clearing device and system that may be used to clear secretions from ETTs and other tubes in the body more quickly, thoroughly, and with less impact on the patient's lungs or other organs than any current method. The device may operate within a closed system, meaning that the connection to and function of the ventilator is not intermpted when secretion clearing is conducted. Gentle oscillation motion may be applied to assist in the clearing of the secretions or other material.

The occlusion clearing device includes a clearing stem having an aspiration conduit and an irrigation conduit within the aspiration conduit. This dual lumen stem allows distal delivery of low volume, continuous irrigation balanced with aspiration, allowing secretions to be broken up and aspirated. Notably, the irrigation conduit terminates inside the aspiration conduit, and is spaced a distance from the terminal end of the aspiration conduit, such that substantially all of the irrigation fluid provided to the operative end of the clearing stem remains within the clearing stem and is aspirated back up the clearing stem through the aspiration conduit. Therefore, contact of fluid or debris with the endotracheal tube is avoided. A coupler may be used to connect the endotracheal tube to the device, so that the operative distal end of the clearing stem can be moved into the tube for clearing occlusive material. This coupler may also include a port for the ventilator to attach, so that ventilation can continue throughout the process of occlusion clearing. The device also includes a handset having aspiration and irrigation tubing that connects to respective sources, and valves for each to control the aspiration and irrigation flow, respectively. These valves may be activated simultaneously with an actuator, which may also be locked in position to keep the aspiration and irrigation on or off. Reciprocating motion, such as vibration, although not necessary, may also aid the break-up and aspiration of thicker secretions, allow easier insertion (less hang up in tube), and to prevent secretions from getting stuck in the aspiration conduit. Implementing the motion applied to the clearing stem, along with the irrigation and aspiration, while maintaining the closed system, may require the use of custom connections. The present invention is also directed to a handset for use in connection with an occlusion clearing device as described above. The handset includes a body and cover movable relative the to the body. Tubing such as for irrigation and aspiration run through the handset body, and each tubing may have a valve in fluid flow communication therewith to control the flow of fluid, such as irrigant and/or aspirant, therethrough. The valve(s) may be operated between first and second positions by compression or other suitable mechanism to constrict or open the tubing associated therewith, limiting or permitting fluid flow therethrough, respectively. The handset cover may be moved between disengaged and engaged positions that affect the positions of the valve(s) such that the cover in an engaged position applies force to the valve(s) and changes the valve(s) from a first to second position.

The handset further includes a locking mechanism configured to retain the cover at a particular position relative to the body, and thereby also the position of the valve(s). The locking mechanism includes a first component connected to the cover. The first component is selectively movable relative to the cover between an unlocked and locked position. A second component of the locking mechanism is affixed to the handset body and engages a portion of the first component as the first component moves. The second component also includes an engagement surface that retains the first component in a locked position once achieved. The valve(s) may also have a biasing member that provides a biasing force of the first component against the engagement surface of the second component that assists in the retention of the locked position. The second component may have a receiver that receives and movably restrains the first component therein, such as an extension of the first component that extends into the receiver. The receiver preferably has an incline angle that draws the first component in an engagement direction while with first component moves in a locking direction. The overall effect of the interaction of the first and second components of the locking mechanism is to draw and hold the cover in an engagement direction when the locking mechanism is locked.

Application of force is required to overcome the locked position and move the first component to an unlocked position. This movement causes the cover to move to a disengaged position, which in turn allows the valve to change from the second to first positions with the attendant effect on fluid flow through the associated tubing.

The handset and occlusion clearing device, together with their particular features and advantages, will become more apparent from the following detailed description and with reference to the appended drawings. DESCRIPTION OF THE DRAWINGS

Fig. l is a perspective view of one embodiment of the occlusive clearing device.

Fig. 2 is a partial cutaway of the distal end of the clearing stem, positioned in an artificial tube having occlusive material being removed through the clearing stem.

Fig. 3A is a perspective view of one embodiment of the distal end of the clearing stem. Fig. 3B is a cross-section of the distal end of the clearing stem of Figure 3 A.

Fig. 4A is a perspective view of another embodiment of the distal end of the clearing stem.

Fig. 4B is a cross-section of the distal end of the clearing stem of Figure 4A.

Fig. 5A is a partial cross-section of a coupler connected to an endotracheal tube, in which the operative distal end of the occlusion clearing device is positioned within the coupler.

Fig. 5B is a partial cross-section of a coupler connected to an endotracheal tube, in which the operative distal end of the occlusion clearing device is inserted into the tube through the coupler. Fig. 6 is a perspective view of one embodiment of the handset at the proximal end of the clearing stem.

Fig. 7 A is a perspective view of another embodiment of the handset.

Fig. 7B is a perspective view of a third embodiment of the handset. Fig. 7C is a perspective view of a fourth embodiment of the handset.

Fig. 7D and Fig. 7E are perspective views of a fifth embodiment of the handset.

Fig. 8 is a partial cutaway of one embodiment of the handset showing the interior components of the handset.

Fig. 9 is a cross-sectional view of one embodiment of the tubing junction in the handset. Fig. 10A is a schematic elevation view of one embodiment of the aspiration valve in the default position (closed).

Fig. 1 OB is a schematic elevation view of the aspiration valve of Figure 10A in the open position.

Fig. 11 is a partial cutaway of another embodiment of the handset including a motor. Fig. 12 is a perspective view of another embodiment of the handset at the proximal end of a clearing stem.

Fig. 13A is a cross-sectional view of the handset of Figure 12 along line 13-13, shown in an unlocked position.

Fig. 13B is a cross-sectional view of the handset of Figure 13 A, shown in a locked position.

Fig. 14 is a perspective view of one embodiment of the first component of the locking mechanism. Fig. 15 is a perspective view of one embodiment of the second component of the locking mechanism.

Fig. 16A is a perspective view of one embodiment of the locking mechanism in an unlocked position, showing the first component of Fig. 14 (viewed from the opposite side) with the second component of Fig. 15.

Fig. 16B is a perspective view of the locking mechanism of Fig. 16A in a locked position.

Like reference numerals refer to like parts throughout the several views of the drawings.

DETAILED DESCRIPTION

It is hereby noted that the term " in situ " is defined as performing an act on an element while the element is being utilized for its commonly known function. For example, performing the act of clearing fluids or material from an ETT in situ refers to the fluids or material in an ETT while the tube is dwelling within the trachea or respiratory system of a living being, human or other.

As shown in the accompanying drawings, the present invention is directed to an occlusion clearing device which employs several features that, individually and together, enhance aspiration effectiveness while occupying less cross-sectional area compared to existing devices on the market. The need to occupy less cross-sectional area, while remaining similarly or more effective than existing devices is important, but particularly so in small diameter tubes, such as neonatal ETTs with outer diameters less than or equal to 4 mm, for reason mentioned above.

The features of the present invention are aimed primarily at maintaining and improving flow of occlusive material (e.g. secretions, mucus, blood) within the aspiration lumen, which is highly prone to blockage due to the small cross-sectional area. An irrigation lumen is disposed within and mns parallel to the aspiration lumen, and terminates within the aspiration lumen before the clearing stem ends. The irrigation fluid (e.g. saline) sent to the distal end stays entirely within the clearing stem and does not exit into the tube to be cleared. Thus, the irrigation fluid helps lubricate the occlusive material once it is in the aspiration lumen and reduce viscosity of the material, which keeps the occlusive material from clogging the aspiration lumen during removal. In addition, the occlusion clearing device includes a coupler that permits access of the clearing stem to the tube having the occlusion to be cleared while still maintaining a closed system, such that the subject can remain on ventilation while the tube is being cleared.

In some embodiments, vibration may be delivered to the clearing stem of the device to assist in breaking up the occlusive material in the tube being cleared at the distal end, and also providing gentle agitation with irrigation fluid to keep the occlusive material moving during aspiration. The vibration may also reduce interfacial friction between the clearing stem and the inner side of the tube being cleared, making the clearing stem easier to insert, which may be performed with just a single hand. As used herein, the terms “occlusion,” “secretion,” and “clog” may be used interchangeably, and refer to occlusive material in a tube disposed within a living subject, such as a patient. The subject may be a human or any other animal. The tube may be any artificial or natural tube disposed within a subject, and may be resident within the subject for a period of time. For instance, such tubes may include, but are not limited to endotracheal and tracheostomy tubes. Such tube is to be cleared when it has acquired material which is desired to be removed, such as foreign material or an amount of material (foreign or natural, such as secretions, mucus, and build-up of medication) that impairs the function of the tube, creates an unhygienic or uncomfortable situation for the subject, or may otherwise be medically necessary or preferable to remove. Such material is referred to herein as “occlusive material.” Accordingly, occlusive material need not fully block or close off the tube to be cleared, but may refer to any material within the tube that is desired to be removed.

With reference now to the Figures, Fig. 1 shows one embodiment of the occlusion clearing device 100 of the present invention. The device 100 includes a clearing stem 120 having an operative distal end 130 on one end, and a proximal end 135 on the opposite end. The distal end 130 of the clearing stem 120 may be fed into the tube to be cleared (not shown), such as through a coupler 190, in order to reach the occlusion for removal. The clearing stem 120 may include depth markings 137 that aid the user during insertion into the tube to be cleared, to ensure the clearing stem 120 is not inserted beyond the end of the tube.

The clearing stem 120 is made up of an aspiration conduit 121 having an aspiration lumen 122 defined there through, and an irrigation conduit 125 disposed within the aspiration conduit 121. During use, occlusive material is pulled into the aspiration conduit 121 of the clearing stem 120 at the distal end 130, and irrigant from the irrigation conduit 125 keeps the occlusive material sufficiently softened that it continues to move proximally through the clearing stem 120 for removal and does not clog the clearing stem 120. At the proximal end 135, the device 100 includes a handset 150 housing aspiration tubing 121a and irrigation tubing 125a. The aspiration tubing 121a carries the aspiration out of the device through an aspiration port 154. The irrigation tubing 125a carries irrigation into the device from an irrigation port 157. The handset 150 also includes valves controlling the flow of aspiration and irrigation through the respective tubing 121a, 125a, and consequently also controls the flow rate in the clearing stem 120. Accordingly, the handset 150 is intended to be gripped by a clinician or other user for maneuvering and actuation of the device 100 for aspiration of occlusive material from the tube to be cleared.

In at least one embodiment, a protective sleeve 138 may cover the clearing stem 120 and prevent it from being contaminated by the environment. For example, the protective sleeve 138 may maintain a sterile environment for the clearing stem 120 once the device 100 is sterilized. At a minimum, the protective sleeve 138 prevents a user from directly touching the clearing stem 120, and protects it from dirt and debris that may be in the air. The protective sleeve 138 may connect at one end to the coupler 190 and at the other end to the handset 150, such as at an adapter 153, so that the protective sleeve 138 spans the entire length of the clearing stem 120 between each of these components.

As shown in Fig. 2, the distal end of the clearing stem 120 is operative to withdraw occlusive material 5 from a tube 7. The occlusive material 5 may include but is not limited to secretions, mucus, phlegm, blood, etc. In use, the distal end 130, and specifically the distal tip 131, of the aspiration conduit 121 is positioned in close proximity to the occlusive material 5 that is to be removed from the tube 7. Aspiration is applied to draw the occlusive material 5 into the aspiration lumen 122, and is removed from the tube 7 by being pulled in an aspirational flow direction 128 away from the distal end 130 of the device 100.

As is depicted throughout Figures 2-4B, the aspiration conduit 121 includes at least one opening 132 in the distal tip 131. In at least one embodiment, the distal tip 131 includes an opening at the terminal end of the aspiration conduit 121. In some embodiments, as shown in Figures 3A and 4A, the distal tip 131 includes a plurality of openings 132 in the aspiration conduit 121. Any number and placement of openings 132 is contemplated herein. For instance, one of these openings 132 may be located at the terminal end of the aspiration conduit 121, and at least one additional opening 132 may be formed in the wall of the aspiration conduit 121 at the distal tip 131 spaced away from the terminal end of the distal tip 131. Fig. 3 A shows two openings 132 directly opposite each other across the diameter of the aspiration conduit 121. The number and placement of these openings may vary in order to optimize the removal of occlusive material. For instance, two openings 132 may be present and may be set back or proximal from the terminal end of the distal tip 135 by the same distance or different distances, such that the opening on one side is closer to the distal tip of the aspiration conduit 121 than the other opening. Typically the most distal edge of the most distal openings 132 will be a preselected distance from the terminal end, such as at least approximately one-half diameter (one radius) back from the terminal end of the distal tip 135 of the aspiration conduit 121 or farther. For instance, the openings 132 shown in Fig 3A for an aspiration conduit 121 having an internal diameter .036 inches may be spaced back from the terminal end by a distance in the range of 0.009 to 0.100 inches, and may be in the range of 0.012 to 0.050 inches, and may preferably be 0.015 inches. The openings 132 shown in Fig 3A for an aspiration conduit 121 having and internal diameter .057 inches may be spaced back from the terminal end by a distance in the range of 0.012 to 0.125 inches, and may be in the range of 0.018 to 0.060 inches, and may preferably be 0.025 inches.

The opening(s) 132 are dimensioned to permit occlusive material 5 to pass there through, and may be any size and shape as permits passage of occlusive material 5. For instance, in at least one embodiment as shown in Figures 2-4B, the opening(s) 132 are circular. Typical diameters for circular openings 132, such as shown in Fig 3A, for an aspiration conduit 121 having an internal diameter 0.036 inches (such as used to clear a 2.5mm tube) may be in the range of 0.018 to 0.045 inches, or more preferably 0.025 to 0.036 inches, and may be 0.030 inches. Typical diameters for circular openings 132 such as shown in Fig 3 A for an aspiration conduit 121 having an internal diameter of 0.057 inches (such as used to clear a 3.5mm tube) may be in the range of 0.025 to 0.067 inches, or more preferably 0.030 to 0.060 inches, and may be 0.050 inches. In at least one other embodiment, the terminal opening 132 may be circular and additional openings 132 at the distal tip 131 may be oval or oblong in shape, and may have a longer dimension either parallel to the length of the aspiration conduit 121 or in the direction of the circumference of the aspiration conduit 121. For instance, openings 132 in the aspiration conduit 121 may be oval in shape and have a longer dimension perpendicular to the length of the aspiration conduit 121, in the direction of the circumference of the aspiration conduit 121, so as to increase the area for receiving the occlusive material 5 into the aspiration lumen 122.

Regarding size, the opening(s) 132 are generally approximately the same diameter or smaller than the diameter of the aspiration lumen 122. These are only examples provided for illustrative purposes, and should not be considered limiting.

The occlusive material 5 is sucked into the clearing stem 120, specifically the aspiration lumen 122, and aspirated back towards the proximal end of the device as shown by the aspirational flow arrows 123. Suction pressure is applied at the proximal end of the device 100 to establish aspirational flow 123, and may be between 50 and 200mm Hg. In at least one embodiment, the aspiration pressure that drives aspiration flow 123 is preferably between 60 and 150 mm Hg. In still further embodiments, the aspirational pressure is between 80-130 mm Hg, and may preferably be 120mm Hg. Greater and lower aspirational pressures and resulting flow rates are also possible and contemplated herein.

The size or diameter of the clearing stem 120, and specifically the aspiration conduit 121, will vary, but is small enough to be inserted into a tube 7 to be cleared, such as an endotracheal tube (ETT) or tracheostomy tube, although any tube 7 having occlusive material 5 in need of removal is contemplated. Therefore, the aspiration conduit 121 is also large enough to accommodate occlusive material 5 therein as it is aspirated away. The wall of the aspiration conduit 121 is sufficiently thick to provide structure for the clearing stem 120 and will not collapse under the aspirational pressure when applied, and yet is thin enough to be navigated through the tube 7 to reach the occlusive material 5 for clearing. For example, for a 2.5mm ETT, one embodiment of the aspiration conduit 121 has an internal diameter of 0.030 to 0.057 inches. This internal diameter corresponds to the diameter of the aspiration lumen 122. In other embodiments, the internal diameter is in the range of 0.035 to 0.045 inches, and may preferably be 0.036 inches in some embodiments. The wall thickness of the aspiration conduit 121 may be altered to affect the stiffness, ability to withstand higher suction pressures, or to adjust the outside diameter of the aspiration conduit. For example, typically wall thicknesses for the aspiration conduit 121 may be in the range of 0.002 to 0.012 inches in some embodiments. In certain embodiments, the wall thickness of the aspiration conduit 121 may be in the range of 0.004 to 0.010, more preferably may be 0.006 inches in certain embodiments.

In examples where a 3.5mm ETT is to be cleared, the aspiration conduit 121 may have an internal diameter of 0.045 to 0.080 inches. In some embodiments, the internal diameter is the range of 0.055 to 0.070 inches, and may preferably be 0.057 inches. The wall thickness of the aspiration conduit 121 may be in the range of 0.002 to 0.012 inches. In some embodiments, the wall thickness may be in the range of 0.004 to 0.010 inches, and may more preferably be 0.006 inches in some embodiments. Of course, smaller and larger wall thicknesses and lumen diameters are also contemplated herein, depending on the size of the tube 7 to be cleared and the type, character and amount of occlusive material 5 to be removed. As depicted in Figures 2-4B, the clearing stem 120 also includes an irrigation conduit 125 having an irrigation lumen 126 therein. The irrigation conduit 125 is at least partially disposed within the aspiration lumen 122 of the clearing stem 120, and provides irrigant 127 to the distal end of the clearing stem 120. The irrigation conduit 125 ends within the aspiration lumen 122, such that the irrigation conduit 125 is entirely within the aspiration lumen 122 at the distal end 130 of the clearing stem 120. As occlusive material 5 is drawn into the clearing stem 120 through the opening(s) 132, it mixes with irrigant 127 being gently expelled from the irrigation lumen 126 into the aspiration lumen 122, as best shown in Figures 2 and 4B. This mixing of irrigant 127 and the occlusive material 5 helps to lubricate the occlusive material 5 within the device 100 and prevent it from clogging the aspiration lumen 122, and therefore maintain the patency of the clearing stem 120. As most clearly shown in Figures 3B and 4B, the irrigation conduit 125 terminates within the aspiration lumen 122 before, or proximal to, the opening(s) 132 at the distal tip 131. This retracted position allows the irrigant 127 to exit the irrigation lumen 126 and mix with occlusive material 5 while remaining entirely within the clearing stem 120. In other words, the positioning of the irrigation conduit 125 within the aspiration lumen

122 prevents irrigant 127 from leaking out of or exiting the clearing stem 120 through the opening(s) 132. This is particularly important in cases where the tube 7 being cleared is an ETT or tracheostomy tube residing in the subject patient’s respiratory tract, where further fluid added to the tube, and potentially the patient’s lungs or airway, should be avoided. Both the internal diameter of the irrigation conduit 125 (the diameter of the irrigation lumen 126) and the delivery pressure of irrigant 127 provided at the proximal end of the device 100 affect irrigant flow rate to the distal end of irrigation conduit 125. The irrigant flow rate through the irrigation lumen 126 is coordinated with aspiration flow though the aspiration lumen 122 to ensure that no irrigant 127 exits the openings 132 in the distal end 130 of the clearing stem 120. The irrigation lumen 126 may have a diameter in the range of 0.005 to 0.015 in some embodiments. In other embodiments, it may be in the range of 0.008 to 0.013 inches, and may preferably be about 0.010 inches. These are but a few preferred diameters, and other diameters larger and smaller are also contemplated. The irrigation lumen 126 diameter may depend on the size of the aspiration lumen 122 into which the irrigation conduit 125 is placed.

The irrigation conduit 125 may have different wall thicknesses depending on the desired stiffness, ability to withstand higher irrigant pressures, or based on the diameter of the aspiration conduit 121, which may alter the size of the aspiration lumen 122 and aspirant flow rate. For instance, in some embodiments, the irrigation conduit 125 may have a wall thickness in the range of 0.0005 to 0.0030 inches. In some embodiments, the wall thickness is in the range of 0.0008 to 0.0015 inches, and may preferably be 0.0010 inches.

The delivery pressure of irrigant 127 may vary, such as from 1 psi to 20 psi. In some embodiments, the irrigation pressure may be from 2 psi to 15 psi. In still other embodiments, the irrigation pressure may be from 6 psi to 10 psi, and may preferably be 7 psi. Irrigant flow rates may vary, such as from 0.003 g/sec to 0.100 g/sec in some embodiments. In certain embodiments, the irrigant flow rate may be from 0.010 g/sec to 0.050 g/sec. In still other embodiments, it may be from 0.015 g/sec to 0.035 g/sec, and may preferably be 0.025 g/sec.

The physical dimensions of the aspiration conduit 121 and irrigation conduit 125 can be altered to affect the aspiration flow 123 and irrigant flow 128, respectively. If the delivery pressure of irrigant 127 and the aspiration pressure are fixed and unchanging, increasing the diameter of the irrigation lumen 126 will increases the irrigant flow 128 relative to the aspiration flow 123. Likewise, decreasing the diameter of the irrigation lumen 126 will decrease the irrigant flow 128 relative to the aspiration flow 123. The wall thicknesses of the irrigation conduit 125 and aspiration conduit 121 can also affect the relative flows. As an example, if the aspiration conduit 121 inner diameter and irrigant conduit 125 outer diameter remain fixed, increasing the irrigant conduit 125 wall thickness will necessarily reduce the available area in the irrigant lumen 126, thereby reducing the irrigant flow 128.

Both the irrigation conduit 125 and the aspiration conduit 121 may be made of polymeric materials typically used for medical catheter applications including, but not limited to, polyurethane, polyvinylchoride, polyimide, and polyamide including copolymers and blends that can be utilized to adjust the physical properties to balance strength, stiffness, hardness, etc. Additionally, the materials, dimensions or both maybe altered along the length of the clearing stem 120 from the distal end 130 to proximal end 135 to provide a balance of strength, stiffness, hardness, and other factors as may be beneficial at different portions of the clearing stem 120. Reinforcements may be utilized to alter these properties. Such reinforcements may include additives to the polymeric material, such as glass fiber or spiral and braided wire reinforcement. In some embodiments, the clearing stem 120 may have variable stiffness along its length.

For instance, a stiffer material may be used at the proximal end 135 for maximum aspiration lumen 122 diameter while maintaining or improving pushability. The distal end 130, however, may be flexible to prevent tissue damage if contact with biological surfaces occurs. In some embodiments as in Figures 4A and 4B, the distal tip 131 may be made of a different material than the rest of the clearing stem 120. For instance, the distal tip 131 may be made of a softer or more flexible material than the rest of the clearing stem 120. This allows for a more rigid material to be used throughout most of the length of the clearing stem 120 to maximize the pushability of the clearing stem 120 as it is being inserted into the tube 7 and a more flexible material to be used at the distal tip 131 to ensure tissue damage is minimized in the event that the clearing stem 120 is inadvertently over inserted. Examples of a softer material for use in the distal tip 131 may include materials having a Shore hardness or durometer in the range of 30A to 100A (60D), where “A” refers to the Shore A scale and “D” refers to the Shore D scale, which partially overlap. In some embodiments, the softer distal tip 131 material may be in the range of

70A (12D) to 90A (45D). In certain embodiments, it may be about 82A (35D). In contrast, the more rigid material used for the proximal end 135 of the clearing stem 120 may be in the range of 80A (32D) to 90D. In some embodiments, the more rigid material may be in the range of 95A (50D) to 80D, and may preferably be 72D. The particular materials used for either the softer or more rigid sections of the clearing stem 120 may be polymeric materials and blends as are commonly used in medical grade catheters, although any material suitable for medical use may be used. These are illustrative examples, and are not intended to be limiting.

The irrigation conduit 125 and aspiration conduit 121 may be separate components, as shown in Figure 3B. In other embodiments, as in Fig. 4B, the irrigation conduit 125 and aspiration conduit 121 may be integrally formed, such as made from a single multi-lumen extrusion. In still other embodiments, the irrigation conduit 125 and aspiration conduit 121 may be formed separately, but may be secured to one another in the device 100. The multi-lumen extrusion can be a more rigid material, as previously discussed, and the distal tip 131 can be a more compliant material bonded to the end of the extrusion. This configuration allows the irrigation lumen 126 to be set back from the terminal end of the clearing stem 120 so that substantially all of the irrigant 127 that exits the irrigation lumen 126 is aspirated back in the aspiration flow 123 direction to the proximal end of the occlusion clearing device 100 before it can exit the openings 132. As shown in Figures 5 A and 5B, the occlusion clearing device 100 further includes a coupler 190 at the distal end 130 of the clearing stem 120 that provides a connection point for access to the tube 7 having occlusive material to be cleared, such as an ETT. The coupler 190 includes a clearing stem connector 191 having a chamber 194 therein into which the distal end 130 of the clearing stem is passed. The protective sleeve 138 may attach to the clearing stem connector 191 to protect the clearing stem 120 outside of the coupler 190. The coupler 190 also includes a tube connector 195 that attaches to the tube 7. The connection between the tube 7 and tube connector 195 is selectively reversible, such that the device 100 can be attached for use and then removed when clearing is complete. Attachment of the tube 7 and tube connector 195 can be by any suitable means that provides a fluidically tight seal that is selectively reversible. For example, the tube connector 195 may snap on to the tube 7, or may have threading to attach to the tube 7 in a screw-type fashion. The tube connector 195 is in fluid communication with the chamber 194 within the clearing stem connector 191, such that the clearing stem 120 can be moved between the clearing stem connector 191 and the tube connector 195 for accessing the tube 7 for clearing.

In at least one preferred embodiment, the coupler 190 further includes a diaphragm 192 that creates a fluidic seal around the clearing stem 120 when it is positioned inside the coupler 190. For instance, the diaphragm 192 may be located in the clearing stem connector 191, such that the clearing stem 120 must pass through the diaphragm 192 in order to enter the coupler 190, and specifically the chamber 194. The diaphragm 192 seals off the coupler 190, forming a closed system between the tube 7 and the clearing stem 120 during use. Also, in some embodiments, the coupler 190 may also include additional port(s), such as a ventilator port 196 that attaches to the ventilator system on which a patient may be established. Accordingly, when the ventilator system is connected to the ventilator port 196 and the tube 7 is connected to the tube connector 195, the diaphragm 192 creates a seal around the clearing stem 120, forming a closed system such that the patient can continue to be mechanically ventilated through the ventilator port 196 without any air leaks during the occlusion removal process. In other embodiments, however, the occlusion clearing device 100 may be used in an open system in which the patient is not on a ventilator system, or the ventilator system is temporarily suspended for occlusion clearing.

In use, the clearing stem 120 is positioned into the chamber 194 of the clearing stem connector 191, and the tube 7 is connected to the tube connector 195, as depicted in Figure 5A. The clinician or user then moves the clearing stem 120 through the coupler 190 and into the tube 7, as shown in Figure 5B, until the distal end of the clearing stem 120 is in proximity to the occlusive material to be cleared (as in Figure 2). The occlusive material is removed from the tube 7, as shown in Figure 2, and the clearing stem 120 is withdrawn from the tube 7, returning again to the coupler 190 as seen in Figure 5 A. Aspiration and irrigation may occur at any time during this process, including when the clearing stem 120 is being advanced into the tube 7 and as it is withdrawn from the tube 7. The clearing stem 120 may be moved in and out of the tube 7 by grasping the clearing stem 120 through the protective sleeve 138 and inching it forward or back, or it may be moved by pushing on the handset 150 at the proximal end 135 of the clearing stem 120. The coupler 190 may also be held steady with one hand if desired. In some embodiments, the coupler 190 may also include a lavage port 193 on the clearing stem connector 191, as shown in Figures 5 A and 5B. The lavage port 193 allows the user to clean or flush the distal end of the clearing stem 120 after use or between insertions. Accordingly, the lavage port 193 is in fluid communication with the chamber 194 therein. Lavage fluid, such as saline or other biologically suitable wash fluid, may be introduced into the lavage port 193 to remove occlusive material or other matter the clearing stem 120 may have picked up from the tube 7. This lavage fluid may then be aspirated through the aspiration lumen 122 of the clearing stem to remove it from the coupler 190. As shown throughout Figures 1 and 6-8, the occlusion clearing device 100 also includes a handset 150 at the proximal end 135 of the clearing stem 120. The handset 150 is designed to be held in a single hand of the user for positioning and use of the occlusion clearing device 100. Accordingly, the handset 150 includes a body 151 that is gripped by the user, and houses various other components for actuating the device 100. For instance, the handset 150 provides the user the ability to control the aspiration flow 123 and the irrigation flow 128 with one hand, explained in detail below.

As illustrated in Figure 6, the handset 150 is located at the proximal end of the clearing stem 120. The clearing stem 120 connects to the handset 150 through an adaptor 153. The adaptor 153 may connect directly or indirectly to the body 151 of the handset 150. The adaptor 153 also provides a connection point for the protective sleeve 138 (not shown) at the proximal end of the device 100, thus protecting the proximal end of the clearing stem 120.

As depicted in Figure 8, the handset 150 includes an aspiration port 154 that connects to an aspiration source (not shown) such as a vacuum pump or other suitable source of suction. The handset 150 further includes aspiration tubing 121a disposed through at least a portion of the body 151 of the handset 150 and connecting the aspiration port 154 to the aspiration lumen 122 of the clearing stem 120 as it joins to the handset 150 through the adaptor, as shown in Figure 6. The aspiration tubing 121a is in fluid communication with both the aspiration lumen 122 of the clearing stem 120 and the aspiration port 154 such that suction drawn at the source is communicated through the aspiration port 154, through the tubing 121a, and through the aspiration lumen 122 to the distal tip 131 of the clearing stem 120 to draw occlusive material 5 into the clearing aspiration lumen 122 for removal.

Similarly, as seen in Figure 8, the handset 150 also includes an irrigation port 157 that connects to a source of irrigant (not shown), such as saline or other inert fluid. The handset 150 further includes irrigation tubing 125a disposed through at least a portion of the body 151 of the handset 150 and connecting the irrigation port 157 to the irrigation lumen 126 of the clearing stem 120. The irrigation tubing 125a is in fluid communication with the irrigation port 157 and the irrigation lumen 126 so that irrigant provided from the source (not shown) to the irrigation port 157 is moved through the irrigation tubing 125a and through the irrigation lumen 126 to the distal end 130 of the clearing stem 120, where it exits into the aspiration lumen 122 and mixes with occlusive material 5 therein to lubricate it for removal.

In some embodiments, the aspiration port 154 and irrigation port 157 connect directly to the body 151 of the handset. In other embodiments, as in Figure 7D, the aspiration port 154 and irrigation port 157 may be spaced apart from the body 151 of the handset, and connect indirectly through aspiration tubing 121a and irrigation tubing 125a, respectively. Accordingly, at least a portion of aspiration tubing 121a and irrigation tubing 125a is positioned within the body 151 of the handset 150 and connects the aspiration port 154 and irrigation port 157 to the appropriate lumens 122, 126 of the clearing stem 120, and at least a portion of the aspiration tubing 121a and irrigation tubing 125a may be positioned or extend beyond the body 151 of the handset 150 for joining to distanced aspiration port 154 and irrigation port 157. Either or both of the aspiration port 154 and irrigation port 157 may be spaced apart from the body 151 of the handset 150. The handset 150 may also include a viewing window 156 which coincides with a portion of the clearing stem 120 and/or aspiration tubing 121a and permits a user to see and visually monitor the occlusive material 5 as it is aspirated through the device 100. The viewing window 156 may be located anywhere along the clearing stem 120 or aspiration tubing 121a. For instance, in some embodiments, the viewing window 156 is located on the distal side of the handset 150, as shown in Fig. 6. In other embodiments, the viewing window 156 is located proximally of the handset 150 along aspiration tubing 121a, as shown in Fig. 7A. The viewing window 156 may be a portion of tubing, a window set into tubing, or may be an entire segment of tubing. In a preferred embodiment, the viewing window 156 is transparent to allow visual perception of occlusive material 5 and irrigant 127 as it is aspirated through and out of the device 100. For instance, the amount, color and consistency of the occlusive material 5, and whether any blood is also present, may be visually monitored using the viewing window 156.

The handset 150 also includes a tubing junction 180, as shown in Figures 8 and 9. The tubing junction 180 provides a way of combining the irrigation tubing 125a and aspiration tubing 121a in order to get the irrigation conduit 125 inside the aspiration lumen 122 in the clearing stem 120. In other words, the tubing junction 180 joins the proximal portions of the irrigation conduit 125 and aspiration conduit 121 from the clearing stem 120 with their respective distal tubings 125a and 121a in a way that enables separate irrigation and aspiration through a single combined clearing stem 120. With particular reference to Figure 9, the tubing junction 180 includes a first passage 181 that receives the aspiration tubing 121a in the handset 150. This first passage 181 is therefore in fluid communication with the aspiration tubing lumen 122a such that aspirated materials can move from the first passage 181 into the aspiration tubing 121a in the direction of aspiration flow 123. The tubing junction 180 also includes a second passage 182 that receives the irrigation tubing 125a in the handset 150. The second passage 182 is in fluid communication with the irrigation tubing lumen 126a, and therefore also with irrigant moving in the direction of irrigation flow 128. The tubing junction 180 further includes a third passage 184 that receives the aspiration conduit 121 and irrigation conduit 125 of the clearing stem 120.

In the embodiment of Figure 9, the aspiration conduit 121 begins in the third passage 184 of the tubing junction 180, but the irrigation conduit 125 extends into the second passage 182. Irrigant 127 from the irrigation tubing 125a in the second passage 182 enters the irrigation conduit 125 in the second passage 182, and continues in the direction of irrigation flow 128 on into the clearing stem. Since the aspiration conduit 121 of the clearing stem only begins in the third passage 184, the irrigation conduit 125 is able to enter the aspiration lumen 122 in the third passage 184. In some embodiments, as in Figure 9, the irrigation conduit 125 extends into the second passage 182, but is separate from the irrigation tubing 125a that may also be located in the second passage 182. In other embodiments, the irrigation conduit 125 and tubing 125a may join together, such as in the second passage 182 of the tubing junction 180. For instance, at least one of the irrigation tubing 125a or conduit 125 may taper to a common diameter shared between them, so that irrigant 127 pushed from the irrigation tubing 125a into the conduit 125 is directed into the irrigation conduit 125. These are but a few examples. Other embodiments may contemplate other ways of directing the irrigant 127 into the irrigation conduit 125 of the clearing stem 120.

Additionally, a seal 183 is provided in the tubing junction 180, such as in the second passage 182, third passage 184, or the space there between to create a fluid tight or hermetic barrier around the irrigation conduit 125 or tubing 125a within the tubing junction 180. For instance, the seal 183 may be provided in the second passage 182 around the irrigation conduit 125, as depicted in Figure 9. The seal 183 creates a fluid communication between the aspiration lumen 122 from the clearing stem 120, the third passage 184 and first passage 181 of the tubing junction 180, and the aspiration tubing lumen 122a for aspiration. The seal 183 functions to exclude the irrigant 127 from this aspiration fluid communication. The seal 183 may be any material suitable for creating a fluid tight barrier, such as adhesive, gel, or other similar material. Further, it should be appreciated that although the embodiment of Figure 9 shows the aspiration conduit 121 and tubing 121a as separate, in at least one other embodiment, the aspiration conduit 121 and tubing 121a may join or merge at some point in the tubing junction 180. In still other embodiments, the aspiration conduit 121 and tubing 121a may be the same, and the irrigation conduit 125 may penetrate or pass through the wall of the aspiration conduit 121, in which case the seal 183 would be formed around the irrigation conduit 125 at this point.

As shown in Figures 8 and 10A-10B, the handset 150 also includes valves that control each of the aspiration 123 and irrigation 128 flow. Specifically, a first valve 170 is interposed in the aspiration tubing 121a that connects the aspiration port 154 to the aspiration conduit 121 of the clearing stem 120. A second valve 172 is interposed in the irrigation tubing 125a that connects the irrigation port 157 to the irrigation conduit 125 of the clearing stem 120. The valves 170, 172 may be opened or closed to turn the aspiration 123 and irrigation 128 flow on or off, respectively. For instance, the valves 170, 172 may each have a valve top 174, a body 175, and at least one but preferably more than one arm 176, as shown in Figures 10A and 10B. The valve top 174 may be raised or lowered to change the valve 170, 172 between open and closed positions. Additionally, the valves 170, 172 may be any type of valve suitable for opening and closing a fluid flow path, such as but not limited to membrane valves and spring valves. As used herein, “fluid” may mean liquid, gas, combinations thereof, and may further include particulates dispersed therein, such as occlusive material 5.

For instance, in at least one embodiment, the valves 170, 172 are membrane valves that are closed when the valve top 174 is in the raised position, as in Figure 10A, and open when the valve top 174 is lowered or depressed, as in Figure 10B. Here, the first valve 170 is shown for illustrative purposes, but it should be understood that the second valve 172 may work in a similar fashion. For instance, the aspiration tubing 121a connects to each arm 176 of the first valve 170 such that the first vale 170 is interposed in the fluid flow path of aspiration 123. When the first valve 170 is closed, as in Figure 10A, the aspiration flow 123 is halted at the body 175 of the first valve 170 and not permitted to pass. Aspiration is prevented from flowing through the handset 150. When the valve top 174 is lowered, as in Figure 10B, the membrane valve that is the first valve 170 opens, permitting aspiration flow 123 through the valve body 175, into the opposing arm 176, and on into the aspiration tubing 121a on the other side of the first valve 170. Accordingly, aspiration flow 123 is permitted through the handset 150. The example of membrane valves are illustrated here, but it should be appreciated that other types of valves, such as spring valves, may operate in the reverse manner (where the valve is open when the valve top 174 is raised and closed when the valve top 174 is lowered). Various types and operations of valve are contemplated here.

The handset 150 may further include an actuator 161 located on the handset 150, such as on the body 151, that can be pressed, moved, or otherwise activated to engage and/or disengage the first and second valves 170, 172 to move them between operative and inoperative positions. In at least one embodiment, the actuator 161 is a button that is activated by rotation, as in Figure 7A, or by pressing, as in Figures 7B and 7C. In other embodiments, the actuator 161 may be a portion of or the entire top surface 152 of the handset 150, as in Figures 6 and 7D-7E. In such embodiments, the top surface 152 may be movably connected to the body 151, such as by a hinge connection or other suitable mechanism. When the actuator 161 portion is pressed, the entire top surface 152 may pivot down, as indicated by the directional arrow in Figure 6. When not engaged, the top surface 152 of the handset 150 may return to a raised position. In other embodiments, as in Figures 12 - 13B, the handset 150' may include a cover 155 movably connected to the body 151, such as in an engagement direction 213 when a portion of a locking mechanism 200, such as a slide lock 162a is moved in a locking direction 211, as described in greater detail below. In such embodiments, the cover 155 and/or slide lock 162a may act as the actuator 161. These are just a few illustrative examples of the form and operation of the actuator 161, and are not intended to be limiting. For all of these examples, the actuator 161 may be activated or acted on by the hand of the user holding the handset 150, such as by pressing with the heel or edge of the hand or with a finger. Accordingly, the handset 150 may be both held and operated single-handedly by a user. When activated, the actuator 161 engages the first and second valves 170, 172 within the handset 150 to open or close the valve. For instance, the actuator 161 pressing down on the valve tops 174 of the first and second valves 170, 172 will open or close the valves, depending on the type of valve it is. In at least one embodiment, the valves 170, 172 can thus be opened or closed simultaneously; although in other embodiments it is contemplated they may be operated independently of one another. Moreover, in some embodiments it is contemplated that partial opening or closing of the valves 170, 172 may be possible by engaging the actuator 161 variably or by degrees. The handset 150 may also include a lock 162 that retains the actuator 161 in a particular position, and as a result also maintains the first and second valves 170, 172 in a corresponding position. For example, the lock 162 may keep the actuator 161 in a depressed or rotated position, which in turn keeps the first and second valves 170, 172 in the corresponding open or closed position (or partially opened or closed position, depending on the embodiment). Accordingly, a user may select the desired position for the actuator 161 and then lock it in place, thereby keeping the aspiration and irrigation either one or off. The user therefore does not have to continually hold down the actuator 161, but may set it and then turn their attention to the distal end of the device 100 or the viewing window 156 to monitor the occlusion clearing process. The lock 162 is also selectively releasable to permit the actuator 161 to move to another position when desired.

Various types of locks 162 are contemplated. For instance, in at least one embodiment as shown in Figures 6 and 7B, the lock 162a may be a slide lock that moves along a track between positions. In one position, the lock 162a may engage the actuator 161 and keep it in restricted engagement in a particular setting, such as up or down. In another position along the slide track, the lock 162a disengages from the actuator 161, which is then free to move to a different position. The lock and unlock positions of the lock 162a may be anywhere along the track as permits engagement and disengagement of the actuator 161. In at least one other embodiment, as depicted in Figure 7A, the actuator 161 may itself be a lock 162d, such that the actuator 161 may be pressed to activate and rotated to lock in position, or may be rotated to both activate and lock at the same time. In other embodiments, as in Figure 7C, the lock 162b may be a plate or other substantially planar device that may slidingly engage at least part of the actuator 161 to retain it in position. For instance, the lock 162b may be inserted around or under at least a portion of the actuator 161 when it is raised, as indicated by the directional arrow, so as to prevent it from being pressed down. In this case, the lock 162b may prevent the actuator 161 from being depressed, keeping the valves 170, 172 either open or closed depending on the corresponding position. In still other embodiments, as in Figures 7D, the lock 162c may be a pin that is inserted into an aperture 165 in the body 151 of the handset 150 to engage the actuator 161. The lock 162c may be selectively removed from the aperture 165 to release the actuator 161, as in Figure 7E. Accordingly, the lock 162c may be attached to a mount 164 or other structure that movably connects the lock 162c to the handset 150. As shown in Figure 7E, the mount 164 may pivot or swing about a fixed point so as to move the lock 162c into and out of alignment with the aperture 165 for engaging or disengaging the actuator 161, respectively.

It should also be evident that the various types of locks 162a, 162b, 162c may be configured to work with different types of actuators 161. For instance, a slide lock 162a is illustrated for use with both a hinge type actuator (as in Figure 6) and a button type actuator 161 (as in Figure 7B). The lock 162 may be part of a larger locking mechanism 200 that positions and retains the first and second valves 170, 172 in various operative and inoperative positions. For example, in the embodiment shown in Figures 12-16B, the locking mechanism 200 may include a first component 220 and second component 230 that engage one another and coordinate to selectively move and hold the cover 155 of a handset 150' in particular positions. The first component 220 of the locking mechanism 200 is movably connected to the cover 155 of the handset 150' and is selectively movable relative thereto. A portion of the first component 220 may be accessible from outside the handset 150', such as a slide lock 162a as shown in Figure 13 A. The slide lock 162a, and therefore first component 220, may be slidably movable along a track 163 in the cover 155. Movement in a locking direction 211 moves the locking mechanism 200 toward a locked position, and movement in the opposite direction moves the locking mechanism 200 toward an unlocked position. Movement between locked and unlocked positions need not be slidable. In other embodiments, the locking mechanism 200 may be moveable between locked and unlocked positions by rotational motion, linear motion in another direction or axis, or other type of motion.

As depicted in Figures 14 and 16A-16B, the first component 220 may include the lock 162, such as a slide lock 162a though other lock forms are also contemplated. The lock 162 is designed to be actuated by the user to engage and disengage the locking mechanism 200. Accordingly, the lock 162 may be located at the exterior of the handset 150', such as at the cover 155. The lock 162 is preferably integrally formed as part of the first component 220, though in certain embodiments may be affixed to the remainder of the first component 220 if formed separately, such as by adhesive, melting or affixing with fasteners by way of example. The first component 220 is selectively movable relative to the cover 155 and also may extend from the cover 155 into the internal cavity formed by the cover 155 and body 151 of the handset 150'.

The first component 220 may also include one or more extension 222 that is shaped and dimensioned to interact with at least a portion of the second component 230 of the locking mechanism 200. For instance, in at least one embodiment the extension(s) 222 projects from the main body of the first component 220 such as to grab, hook or otherwise engage with a portion of the second component 230. The extension 222 may have any suitable shape for such purpose, including but not limited to a tab, projection, finger, bump(s), protrusion or other similar shape, and may be angular, linear, curved or irregularly shaped. The extension(s) 222 may be located anywhere on the first component 220, though in at least one embodiment the extension 222 may be located proximate to the second component 230, such as at a terminal end of the first component 220. The extension 222 may extend from the first component 220 in any direction and may be integrally formed with or securely attached to the first component 220. In at least one embodiment, the extension 222 may extend laterally or perpendicularly to the main body of first component 220, such as to increase engagement with the second component 230. Other directions and configurations are also contemplated herein.

The locking mechanism 200 also includes a second component 230 configured to engage at least a portion of the first component 220 and selectively retain the first component 220 in a locked position. The second component 230 is preferably affixed or otherwise fixedly secured to a portion of the body 151 of the handset 150', such as to a bottom or side surface of the handset 150'. The second component 230 may be integrally formed with the body 151 of the handset 150' in at least one embodiment, or may be molded, adhered or otherwise securely fastened thereto in other embodiments. It should be noted that in other embodiments, the attachments may be reversed such that the first component 220 may be affixed to the handset 150' and the second component 230 may connected to the cover 155. Regardless of positioning and attachment points, the first and second components 220, 230 extend toward each other from their respective fixed points within the handset 150' and/or cover 155 to interact with one another to lock and unlock the locking mechanism 200.

With reference to Figures 15-16B, the second component 230 may include a receiver 232 which is dimensioned to movably receive and retain at least a portion of the first component 220, such as the extension(s) 222, therein. The receiver 232 may include an incline angle relative to the cover 155 of the handset 150'. The incline angle may extend along any portion of the second component 230 and may have any angle, level or degree of incline, such as up to and including 90° relative to the cover 155 of the handset 150'. In certain embodiments, the receiver 232 may have an incline angle in the range of about 35 - 75°, and preferably about 45°. The incline angle and length of the receiver 232 may be dictated by the overall dimensions of the handset 150' and interior space therein. The receiver 232 may have any shape and dimension to accommodate at least a portion of the first component 220 and also fit within the handset 150'. As shown in the embodiment of Figures 15-16B, the receiver 232 may have a substantially linear path with a fixed incline angle. In other embodiments, the receiver 232 may have a curved path, curvilinear path, angular path, irregularly shaped or other path which still functions to draw the first component 220 in an engagement direction 213 when the first component 220 is moved in the locking direction 211, as shown in Figure 13 A. However, it is not necessary that the entire receiver 232 have an incline angle, or the same incline angle over the entire length of the receiver 232. Indeed, in some embodiments the receiver 232 may be notched or have various discrete levels or segments corresponding to different locking positions. At least a portion of the first component 220, such as at least a portion of the extension(s)

222, may be movably retained within the receiver 232 of the second component 230. In certain embodiments, the extension(s) 222 is movably retained within the receiver 232 even in an unlocked position of the handset 150', although in other embodiments the first and second components 220, 230 may not be interconnected or joined in any way in an unlocked position. Further, the extension 222 may extend into or through the receiver 232 by any amount. For instance, the extension 222 may extend substantially entirely the width of the receiver 232, such as to maximize alignment and retention of the extension 222 therein. In other embodiments, the extension 222 may traverse only part of the width of the receiver 232. As used herein, the width direction of the receiver 232 is perpendicular to the length of the receiver 232 that corresponds with the locking direction 211 shown in Figures 13A-13B.

The second component 230 may also include at least one engagement surface 234, which may be located along the receiver 232. In at least one embodiment, as in Figures 13A-16B, the engagement surface 234 may be located at a terminal end of the receiver 232. In other embodiments, the engagement surface(s) 234 may be located anywhere along the second component 230, such as along the receiver 232. In certain embodiments, there may be multiple engagement surfaces 234 located at different points along the second component 230 and/or receiver 232. Regardless of number, each engagement surface 234 is configured to contact and selectively retain the first component 220 in a locked position and restrict further movement of the first component 220. Indeed, in at least one embodiment the engagement surface 234 may be positioned and dimensioned to restrict further movement of the extension(s) 222 or other portion(s) of the first component 220 in the receiver 232 in the locking direction 211. Accordingly, each engagement surface 234 may define a different locked position of the locking mechanism 200. In some embodiments, the engagement surface 234 may be a flat surface in the receiver 232, such as at the terminal end thereof. In other embodiments the engagement surface 234 may include a dip, recess, bump or protrusion from the surface the receiver 232 that interferes with the movement of the extension(s) 222 or other portion(s) of the first component 220 therein. In certain embodiments, the engagement surface 234 and extension 222 may be at least partially correspondingly shaped to facilitate a snap-fit or frictional fit engagement between the two that may be overcome only with sufficient force. Accordingly, the engagement surface 234 may restrict movement of the first component 220 by frictional force. With reference to Figures 13A-13B, at least a portion of the locking mechanism 200 may be internally housed in the handset 150', with the first and second components 220, 230 extending into the interior space of the handset 150'. The locking mechanism 200 therefore avoids the tubing junction 180, tubing 121a, 125a and valves 170, 172 also located within the handset 150'. For instance, in at least one embodiment the first and second components 220, 230 of the locking mechanism 200 may be positioned between the tubing junction 180 and valves 170, 172 so that the functioning of the locking mechanism 200 does not interfere with the tubing junction 180 and does not constrict the tubing 121a, 125a, except in connection with the action on the valves 170, 172 as described below. A portion of the first component 220 may extend through the cover 155 and may therefore be accessible from outside the handset 150', as shown in Figures 13A-13B. This exteriorly-facing portion of the first component 220 may be engaged by the user to selectively lock and unlock the locking mechanism. In at least one embodiment as shown in Figures 13A-13B, the exterior-facing portion of the first component 220 may be a slide lock 162a as described above, although any of the locks 162 discussed may be used in conjunction with the locking mechanism 200.

To activate the locking mechanism 200 from an unlocked to a locked position, a user applies directional force to the first component 220 in the locking direction 211, shown in Figure 13 A. This causes the first component 220 to move relative to the second component 230, such as along the corresponding track 163 in the cover 155. As the first component 220 is moved in a locking direction 211, the extension 222 of the first component 220 is positioned within the receiver 232 of the second component 230 and traverses through the receiver 232, such as by slidable movement. Because of the incline angle of the receiver 232, the first component 220 is drawn or pulled in an engagement direction 213 as the first component 220 is progressed in the locking direction 211. Because the first component 220 is connected to the cover 155, the cover 155 is similarly drawn in an engagement direction 213 from a disengaged position toward an engaged position, which in this embodiment compresses the overall dimension of the handset 150'. Increased movement of the first component 220 in the locking direction 211 produces increased compression of the handset 150' in the engagement direction 213 according to the degree of incline angle of the receiver 232.

At a certain point during the locking procedure, the cover 155 comes into contact with the valves 170, 172. Further movement of the first component 220 in the locking direction 211, and of the cover 155 in the engagement direction 213, increases force applied to the valves 170, 172 thereby moving them from a first position to a second position. This may occur concurrently for the valves 170, 172 or at different times depending on the configuration, shape and height of the valves 170, 172. Changing of the valves 170, 172 from a first to second position has the result of either opening or constricting the associated tubing 121a, 125a depending on the type and operation of the valve 170, 172 as described above. For example, in at least one embodiment the first position of valves 170, 172 may be an uncompressed position in which the valves 170, 172 are closed and fluid flow through the associated tubing is restricted. A second position of the valves 170, 172 may be a compressed position in which valves the 170, 172 are open and fluid flow is permitted through the associated tubing. There may be any number of positions of the valves 170, 172 which may correspond to various degrees of opened or closed status. The fluid flowing therethrough may be aspirant or irrigant as indicated by the associated tubing and discussed above.

When the first component 220 or extension 222 thereof encounters the engagement surface 234 of the second component 230, such as in the receiver 232, the movement of the first component 220 relative to the second component 230 may be halted. For example, the engagement surface 234 limits further movement of the first component 220 in the locking direction 211. In the embodiment shown in Figures 13A-16B there may be a single engagement surface 234 at the terminal end of the receiver 232. In other embodiments, however, there may be multiple engagement surfaces 234 located at different positions along the second component 230 or receiver 232 that each at least temporarily halt the forward progression of the first component 220 in a locking direction 211. In such embodiments, each engagement surface 234 defines a different locking position.

Furthermore, the valves 170, 172 are also compressed during the locking procedure as described above. Because of this compression to engaged positions, the valves 170, 172 provide a counter-force to the locking mechanism 200 that promotes the retention of the first and second components 220, 230 in fixed relation to one another in the locked position(s) when force is no longer applied to the first component 220. For instance, in the embodiment of Figure 13B, the valves 170, 172 each include at least one biasing member that compresses or otherwise provides a biasing force when pressure or force is applied to the upper surface of the valve 170, 172. This biasing force from changing of the valves 170, 172 from a first to second position pushes in a counter-force direction 215 opposite of the engagement direction 213. The counter force applies pressure to the first component 220 of the locking mechanism 200, biasing it against the second component 230. For instance, the counter force pushes the extension 222 of the first component 220 against the engagement surface 234 of the second component 230. The shape and dimension of the engagement surface 234 keeps the extension 222 from moving out of a locked position. The engagement surface 234 may therefore have a flat or planar shape to facilitate contacting enough of the extension 222 that the counterforce provided by the valves 170, 172 provides a frictional grip for retention. Accordingly, the biasing force of the biasing member of the valves 170, 172 may add to the frictional force between the first and second components 220, 230 that retains the first component 220 in a locked position.

When the locked position is no longer desired, force is again applied to the first component 220, such as in the locking direction 211 to access further locked positions or opposite of the locking direction 211 to transition to an unlocked position. Such action provides sufficient force to overcome the counterforce being supplied by the valves 170, 172 that hold the extension 222 against the engagement surface 234, thereby releasing the frictional hold between the components 220, 230. The extension 222 is again free to move within the receiver 232. Such action may also overcome any other frictional forces between the extension 222 and engagement surface 234, such as but not limited to frictional forces in snap-fit engagement or to overcome bumps or other tractional elements that may define a boundary of the engagement surface 234 as discussed above.

The occlusion clearing device 100 may be used with only aspiration and irrigation. In some embodiments, however, reciprocating motion may also be applied to the clearing stem 120 to assist the distal tip 131 in contacting the occlusive material 5 in the tube 7 to be cleared, and in keeping the occlusive material 5 moving through the aspiration lumen 122 of the clearing stem 120 for removal and maintain patency of the clearing stem 120. Therefore, in some embodiments, as in Figure 11, the handset 150 may also include a motor 160 that generates reciprocating or oscillating motion. As used herein, “reciprocating” and “oscillating” may be used interchangeably to refer to motion that is back and forth in an axial direction. A shaft 167 connects to the motor 160 and transmits the reciprocating motion to the clearing stem 120, such that the clearing stem 120 is gently moved back and forth by the reciprocating motion 168. For instance, the shaft 167 may connect the motor 160 to the tubing junction 180, so as to provide the reciprocating motion 168 to the tubing junction 180, which in turn conveys the motion 168 to the clearing stem 120 attached to and extending from the opposite side of the tubing junction 180. The shaft 167 is therefore made of a rigid material, such as polymer or metal having a hardness sufficient to maintain its structure and avoid bending upon the application of reciprocating motion from the motor 166. The motor 166 may be driven by any suitable power source, such as DC power from a wall-driven power supply connected by a power cord 169, or by battery, or both.

The motor 166 may be any suitable motor capable of generating gentle reciprocating motion, such as, but not limited to, voice coil motors (VCM); DC motors; piezoelectric transducers, including amplified piezoelectric actuator (APA) motors such as those disclosed in U.S. Patent No. 6,465,936 (Knowles, et al.), whose entire disclosure is incorporated by reference herein; piezoelectric actuators; active polymer compound actuators; solenoid motors; pneumatic motors; magnetorestrictive transducers; and electrorestrictive transducers. For instance, in some embodiments the motor 166 may be a voice coil motor (VCM) as are commercially available. For instance, the VCM may include a displaceable motor shaft with magnets mounted thereto and coil windings wound around the VCM body. When activated, an electric current is applied through the coil windings, creating a magnetic field inside the coil windings. The non-uniform magnetic field at the ends exerts a force on the magnets on the shaft. Alternating the current alternates the direction of the magnetic field gradients and results in a reciprocating motion of the motor shaft with respect to the VCM body. The magnitude of the force is determined by the magnetic flux density, which is proportional to the number of turns per length of the coil, current magnitude, cross-sectional area of the coil, as well as the strength of the permanent magnets. Springs in the VCM absorb the energy associated with abrupt changes in the direction of the inertial force of the magnets and VCM body when actuated. By way of example only, the spring constant of the springs can range from 0.5 - 5 lb/in, and more preferably 1.5 - 2.5 lb/in. The relative positions of the coil windings and magnets can be reversed, such that the coil windings are wound directly around the motor shaft and the magnets are positioned around the VCM body and thus do not interfere with the motor shaft’s reciprocation.

Alternatively, the VCM may be a dual coil motor or actuator. Instead of using magnets, two coil windings are used wherein one coil is wound directly around the motor shaft and a second or outer coil is wound around the first or inner coil but without interfering with shaft displacement. Each coil is supplied with respective alternating current sources which generate respective electromagnetic fields that also generate a reciprocating motion of the motor shaft. The inner coil may conduct direct current DC while the outer coil conducts alternating current AC. Alternatively, the inner coil may conduct alternating current AC while the outer coil conducts direct current DC, or both the inner coil and the outer coil may conduct alternating current AC. The VCM may also include a countermass or counterbalance which is driven at an opposite phase (e.g., 180° phase lag) for cancelling some or all of the vibration caused by the motor. This avoids “chatter” from the parts and therefore does not irritate the operator or patient.

In some embodiments, the motor 166 may be a DC or DC brushless motor for creating reciprocating displacement via a scotch yoke or similar mechanism. When activated, the DC motor causes a rotating crank to drive the scotch yoke slider and the scotch yoke shaft in reciprocating motion. An adapter transmits the scotch yoke motion to the scotch yoke shaft. In other embodiments, the motor 166 is an amplified piezoelectric actuator (APA) that creates reciprocating displacement in the lower range, preferably 0.1 to 2.0 mm. One or more APA motors can be used in series to increase displacement. Reciprocating motion is created by APA actuator expansion and contraction. In still other embodiments, a Langevin transducer can be used for the motor 166. A Langevin transducer comprises a plurality of piezoelectric elements arranged to cause a horn to vibrate to produce the reciprocating motion. A power source provides the proper activation energy. Lateral displacement caused by overtones produced from the horn vibrating may be minimized by compressing the piezoelectric elements. Accordingly, a standing wave is generated, which propagates to the clearing stem. In further embodiments, the motor 166 is a solenoid motor. The solenoid is pulsed during activation such that during the pulse, a solenoid shaft is driven in one direction and when the pulse is terminated, a return spring restores the solenoid shaft to the opposite direction. This action is repeated at the operative frequencies. In still other embodiments, the motor 166 may be a pneumatic motor that has a shaft which receives pneumatic pulses from a pneumatic pulse generator via an air supply. A pneumatic motor diaphragm distributes the pneumatic pulse evenly to the pneumatic motor shaft, thereby maintaining its alignment, while at the same time providing a tightly-sealed motor configuration. The pneumatic pulse causes the pneumatic motor shaft to be driven in one direction while compressing a return spring. Once the pneumatic pulse is terminated, the return spring restores the pneumatic motor shaft to the opposite direction. This action is repeated at operative frequencies. Since many modifications, variations and changes in detail can be made to the described preferred embodiments, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents. Now that the invention has been described,