CROSS-REFERENCE TO REUATED APPUICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Application

No. 62/952,933, filed on December 23 ,2020, which is incorporated herein by reference in its entirety.

TECHNICAU FIEUD

[0002] The invention set forth in the appended claims relates generally to tissue treatment systems and more particularly, but without limitation, to pump optimization in a negative- pressure therapy environment.

BACKGROUND

[0003] Clinical studies and practice have shown that reducing pressure in proximity to a tissue site can augment and accelerate growth of new tissue at the tissue site. The applications of this phenomenon are numerous, but it has proven particularly advantageous for treating wounds. Regardless of the etiology of a wound, whether trauma, surgery, or another cause, proper care of the wound is important to the outcome. Treatment of wounds or other tissue with reduced pressure may be commonly referred to as "negative-pressure therapy," but is also known by other names, including "negative- pressure wound therapy," "reduced-pressure therapy," "vacuum therapy," "vacuum-assisted closure," and "topical negative-pressure," for example. Negative-pressure therapy may provide a number of benefits, including migration of epithelial and subcutaneous tissues, improved blood flow, and micro deformation of tissue at a wound site. Together, these benefits can increase development of granulation tissue and reduce healing times.

[0004] While the clinical benefits of negative-pressure therapy are widely known, improvements to therapy systems, components, and processes may benefit healthcare providers and patients.

BRIEF SUMMARY

[0005] New and useful systems, apparatuses, and methods for generating fluid flow and pressure in a negative-pressure therapy environment are set forth in the appended claims. Illustrative embodiments are also provided to enable a person skilled in the art to make and use the claimed subject matter.

[0006] In some embodiments, a pump system is described. The pump system can include a first pump chamber and a second pump chamber. A valve can be fluidly coupled to the first pump chamber and the second pump chamber. The valve can be selectively operable to fluidly couple the first pump chamber and the second pump chamber in a series configuration and in a parallel configuration.

[0007] More generally, a method for providing negative-pressure is described. A negative-pressure source can be provided. The negative-pressure source can have a first pump and a second pump. A valve system can be fluidly coupled to the first pump and the second pump. The valve system can be selectively operable to fluidly couple the first pump and the second pump in a first configuration and in a second configuration. A mode of the negative -pressure source can be determined. In response to determining the mode of the negative-pressure source, the valve system can be actuated to fluidly couple the first pump and the second pump in at least one of the first configuration and the second configuration.

[0008] Alternatively, other example embodiments may describe a negative-pressure therapy system. The negative-pressure therapy system can include a housing having a vacuum port and an exhaust. A valve system can be disposed in the housing and fluidly coupled to the vacuum port and the exhaust. A pump module can be provided and configured to be coupled to the housing and fluidly coupled to the valve system. The valve system can be configured to selectively fluidly couple the pump module to the vacuum port and the exhaust.

[0009] Objectives, advantages, and a preferred mode of making and using the claimed subject matter may be understood best by reference to the accompanying drawings in conjunction with the following detailed description of illustrative embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a functional block diagram of an example embodiment of a therapy system that can provide negative-pressure treatment in accordance with this specification;

[0011] Figure 2 is a schematic diagram of a therapy unit illustrating additional details that may be associated with some embodiments of the therapy system of Figure 1;

[0012] Figure 3 is a schematic diagram of a portion of the therapy unit in a first configuration illustrating additional details that may be associated with some embodiments of the therapy system of Figure 1 ;

[0013] Figure 4 is a schematic diagram of a portion of the therapy unit in a second configuration illustrating additional details that may be associated with some embodiments of the therapy system of Figure 1;

[0014] Figure 5 is a schematic diagram of a portion of an exemplary therapy unit having a standard configuration; and

[0015] Figure 6 is a graph illustrating a relationship between pressure and flow rate that may be associated with pump modes of the flow chart of Figure 7; [0016] Figure 7 is a flow chart representing operational steps that can be associated with the determination of an operating mode of the flow chart of Figure 7;

[0017] Figure 8 is a flow chart representing operational steps that can be associated with a standard operating mode of the flow chart of Figure 7;

[0018] Figure 9 is a flow chart representing operational steps that can be associated with a draw down mode of the flow chart of Figure 7;

[0019] Figure 10 is a flow chart representing operational steps that can be associated with a gross leak mode of the flow chart of Figure 7;

[0020] Figure 11 is a flow chart representing operational steps that can be associated with low leak mode of the flow chart of Figure 7;

[0021] Figure 12 is a flow chart representing operational steps that can be associated with blockage mode of the flow chart of Figure 7; and

[0022] Figure 13 is a flow chart representing operational steps that can be associated with a peristaltic offset mode of the flow chart of Figure 7.

DESCRIPTION OF EXAMPLE EMBODIMENTS

[0023] The following description of example embodiments provides information that enables a person skilled in the art to make and use the subject matter set forth in the appended claims, but it may omit certain details already well-known in the art. The following detailed description is, therefore, to be taken as illustrative and not limiting.

[0024] The example embodiments may also be described herein with reference to spatial relationships between various elements or to the spatial orientation of various elements depicted in the attached drawings. In general, such relationships or orientation assume a frame of reference consistent with or relative to a patient in a position to receive treatment. However, as should be recognized by those skilled in the art, this frame of reference is merely a descriptive expedient rather than a strict prescription.

[0025] The term “tissue site” in this context broadly refers to a wound, defect, or other treatment target located on or within tissue, including but not limited to, a surface wound, bone tissue, adipose tissue, muscle tissue, neural tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendons, or ligaments. The term “tissue site” may also refer to areas of any tissue that are not necessarily wounded or defective, but are instead areas in which it may be desirable to add or promote the growth of additional tissue. For example, negative pressure may be applied to a tissue site to grow additional tissue that may be harvested and transplanted. A surface wound, as used herein, is a wound on the surface of a body that is exposed to the outer surface of the body, such as injury or damage to the epidermis, dermis, and/or subcutaneous layers. Surface wounds may include ulcers or closed incisions, for example. A surface wound, as used herein, does not include wounds within an intra-abdominal cavity. A wound may include chronic, acute, traumatic, subacute, and dehisced wounds, partial thickness bums, ulcers (such as diabetic, pressure, or venous insufficiency ulcers), flaps, and grafts, for example.

[0026] Figure 1 is a simplified functional block diagram of an example embodiment of a therapy system 100 that can provide negative-pressure therapy to a tissue site in accordance with this specification. The therapy system 100 may include a source or supply of negative pressure, such as a negative-pressure source 102, a dressing 104, a fluid container, such as a container 106, and a regulator or controller, such as a controller 108, for example. Additionally, the therapy system 100 may include sensors to measure operating parameters and provide feedback signals to the controller 108 indicative ofthe operating parameters. As illustrated in Figure 1, for example, the therapy system 100 may include a pressure sensor 110, an electric sensor 112, or both, coupled to the controller 108. As illustrated in the example of Figure 1, the dressing 104 may comprise or consist essentially of a tissue interface 114, a cover 116, or both in some embodiments.

[0027] Some components of the therapy system 100 may be housed within or used in conjunction with other components, such as sensors, processing units, alarm indicators, memory, databases, software, display devices, or user interfaces that further facilitate therapy. For example, in some embodiments, the negative-pressure source 102 may be combined with the container 106, the controller 108, and other components into a therapy unit 118.

[0028] In general, components of the therapy system 100 may be coupled directly or indirectly. For example, the negative-pressure source 102 may be directly coupled to the container 106, and may be indirectly coupled to the dressing 104 through the container 106. Coupling may include fluid, mechanical, thermal, electrical, or chemical coupling (such as a chemical bond), or some combination of coupling in some contexts. For example, the negative-pressure source 102 may be electrically coupled to the controller 108, and may be fluidly coupled to one or more distribution components to provide a fluid path to a tissue site. In some embodiments, components may also be coupled by virtue of physical proximity, being integral to a single structure, or being formed from the same piece of material. For example, the tissue interface 114 and the cover 116 may be discrete layers disposed adjacent to each other, and may be joined together in some embodiments.

[0029] A distribution component is preferably detachable, and may be disposable, reusable, or recyclable. The dressing 104 and the container 106 are illustrative of distribution components. A fluid conductor is another illustrative example of a distribution component. A "fluid conductor," in this context, broadly includes a tube, pipe, hose, conduit, or other structure with one or more lumina or open pathways adapted to convey a fluid between two ends. Typically, a tube is an elongated, cylindrical structure with some flexibility, but the geometry and rigidity may vary. Moreover, some fluid conductors may be molded into or otherwise integrally combined with other components. Distribution components may also include or comprise interfaces or fluid ports to facilitate coupling and de-coupling other components. In some embodiments, for example, a dressing interface may facilitate coupling a fluid conductor to the dressing 104.

[0030] A negative-pressure supply, such as the negative-pressure source 102, may be a reservoir of air at a negative pressure, or may be a manual or electrically-powered device, such as a vacuum pump, a suction pump, a wall suction port available at many healthcare facilities, or a micro pump, for example. “Negative pressure” generally refers to a pressure less than a local ambient pressure, such as the ambient pressure in a local environment external to a sealed therapeutic environment. In many cases, the local ambient pressure may also be the atmospheric pressure at which a tissue site is located. Alternatively, the pressure may be less than a hydrostatic pressure associated with tissue at the tissue site. Unless otherwise indicated, values of pressure stated herein are gauge pressures. References to increases in negative pressure typically refer to a decrease in absolute pressure, while decreases in negative pressure typically refer to an increase in absolute pressure. While the amount and nature of negative pressure applied to a tissue site may vary according to therapeutic requirements, the pressure is generally a low vacuum, also commonly referred to as a rough vacuum, between -5 mm Hg (-667 Pa) and -500 mm Hg (-66.7 kPa). Common therapeutic ranges are between - 50 mm Hg (-6.7 kPa) and -300 mm Hg (-39.9 kPa).

[0031] The container 106 is representative of a container, canister, pouch, or other storage component, which can be used to manage exudates and other fluids withdrawn from a tissue site. In many environments, a rigid container may be preferred or required for collecting, storing, and disposing of fluids. In other environments, fluids may be properly disposed of without rigid container storage, and a re-usable container could reduce waste and costs associated with negative-pressure therapy.

[0032] A controller, such as the controller 108, may be a microprocessor or computer programmed to operate one or more components of the therapy system 100, such as the negative- pressure source 102. In some embodiments, for example, the controller 108 may be a microcontroller, which generally comprises an integrated circuit containing a processor core and a memory programmed to directly or indirectly control one or more operating parameters of the therapy system 100. Operating parameters may include the power applied to the negative-pressure source 102, the pressure generated by the negative-pressure source 102, or the pressure distributed to the tissue interface 114, for example. The controller 108 is also preferably configured to receive one or more input signals, such as a feedback signal, and programmed to modify one or more operating parameters based on the input signals.

[0033] Sensors, such as the pressure sensor 110 or the electric sensor 112, are generally known in the art as any apparatus operable to detect or measure a physical phenomenon or property, and generally provide a signal indicative of the phenomenon or property that is detected or measured. For example, the pressure sensor 110 and the electric sensor 112 may be configured to measure one or more operating parameters of the therapy system 100. In some embodiments, the pressure sensor 110 may be a transducer configured to measure pressure in a pneumatic pathway and convert the measurement to a signal indicative of the pressure measured. In some embodiments, the pressure sensor 110 may be a piezoresistive strain gauge. The electric sensor 112 may optionally measure operating parameters of the negative-pressure source 102, such as the voltage or current, in some embodiments. Preferably, the signals from the pressure sensor 110 and the electric sensor 112 are suitable as an input signal to the controller 108, but some signal conditioning may be appropriate. For example, the signal may need to be filtered or amplified before it can be processed by the controller 108. Typically, the signal is an electrical signal, but may be represented in other forms, such as an optical signal.

[0034] The tissue interface 114 can be generally adapted to partially or fully contact a tissue site. The tissue interface 114 may take many forms, and may have many sizes, shapes, or thicknesses depending on a variety of factors, such as the type of treatment being implemented or the nature and size of a tissue site. For example, the size and shape of the tissue interface 114 may be adapted to the contours of deep and irregular shaped tissue sites.

[0035] In some embodiments, the cover 116 may provide a bacterial barrier and protection from physical trauma. The cover 116 may also be constructed from a material that can reduce evaporative losses and provide a fluid seal between two components or two environments, such as between a therapeutic environment and a local external environment. The cover 116 may be, for example, an elastomeric film or membrane that can provide a seal adequate to maintain a negative pressure at a tissue site for a given negative-pressure source. The cover 116 may have a high moisture- vapor transmission rate (MVTR) in some applications. For example, the MVTR may be at least about 300 g/m ² per twenty-four hours in some embodiments. In some example embodiments, the cover 116 may be a polymer drape, such as a polyurethane film, that is permeable to water vapor but impermeable to liquid. Such drapes typically have a thickness in the range of about 25 microns to about 50 microns. For permeable materials, the permeability generally should be low enough that a desired negative pressure may be maintained.

[0036] The cover 116 may comprise, for example, one or more of the following materials: hydrophilic polyurethane; cellulosics; hydrophilic polyamides; polyvinyl alcohol; polyvinyl pyrrolidone; hydrophilic acrylics; hydrophilic silicone elastomers; an INSPIRE 2301 material from Coveris Advanced Coatings of Wrexham, United Kingdom having, for example, an MVTR (inverted cup technique) of about 14400 g/m ² /24 hours and a thickness of about 30 microns; a thin, uncoated polymer drape; natural rubbers; polyisoprene; styrene butadiene rubber; chloroprene rubber; polybutadiene; nitrile rubber; butyl rubber; ethylene propylene rubber; ethylene propylene diene monomer; chlorosulfonated polyethylene; polysulfide rubber; polyurethane (PU); EVA film; co polyester; silicones; a silicone drape; a 3M Tegaderm® drape; a polyurethane (PU) drape such as one available from Avery Dennison Corporation of Glendale, California; polyether block polyamide copolymer (PEBAX), for example, from Arkema, France; INSPIRE 2327; or other appropriate material. [0037] An attachment device may be used to attach the cover 116 to an attachment surface, such as undamaged epidermis, a gasket, or another cover. The attachment device may take many forms. For example, an attachment device may be a medically-acceptable, pressure-sensitive adhesive configured to bond the cover 116 to epidermis around a tissue site. In some embodiments, for example, some or all of the cover 116 may be coated with an adhesive, such as an acrylic adhesive, which may have a coating weight between about 25 grams per square meter (g.s.m.) and about 65 g.s.m. Thicker adhesives, or combinations of adhesives, may be applied in some embodiments to improve the seal and reduce leaks. Other example embodiments of an attachment device may include a double sided tape, paste, hydrocolloid, hydrogel, silicone gel, or organo gel.

[0038] The fluid mechanics of using a negative-pressure source to reduce pressure in another component or location, such as within a sealed therapeutic environment, can be mathematically complex. However, the basic principles of fluid mechanics applicable to negative-pressure therapy are generally well-known to those skilled in the art, and the process of reducing pressure may be described illustratively herein as “delivering,” “distributing,” or “generating” negative pressure, for example.

[0039] In general, exudates and other fluids flow toward lower pressure along a fluid path. Thus, the term “downstream” typically implies a position in a fluid path relatively closer to a source of negative pressure or further away from a source of positive pressure. Conversely, the term “upstream” implies a position relatively further away from a source of negative pressure or closer to a source of positive pressure. Similarly, it may be convenient to describe certain features in terms of fluid “inlet” or “outlet” in such a frame of reference. This orientation is generally presumed for purposes of describing various features and components herein. However, the fluid path may also be reversed in some applications (such as by substituting a positive-pressure source for a negative-pressure source) and this descriptive convention should not be construed as a limiting convention.

[0040] Negative pressure applied across the tissue site through the tissue interface 114 in the sealed therapeutic environment can induce macro-strain and micro-strain in the tissue site. Negative pressure can also remove exudate and other fluid from a tissue site, which can be collected in container 106.

[0041] In some embodiments, the controller 108 may receive and process data from one or more sensors, such as the pressure sensor 110. The controller 108 may also control the operation of one or more components of the therapy system 100 to manage the pressure delivered to the tissue interface 114. In some embodiments, controller 108 may include an input for receiving a desired target pressure and may be programmed for processing data relating to the setting and inputting of the target pressure to be applied to the tissue interface 114. In some example embodiments, the target pressure may be a fixed pressure value set by an operator as the target negative pressure desired for therapy at a tissue site and then provided as input to the controller 108. The target pressure may vary from tissue site to tissue site based on the type of tissue forming a tissue site, the type of injury or wound (if any), the medical condition of the patient, and the preference of the attending physician. After selecting a desired target pressure, the controller 108 can operate the negative-pressure source 102 in one or more control modes based on the target pressure and may receive feedback from one or more sensors to maintain the target pressure at the tissue interface 114.

[0042] A negative-pressure source can include a pump having a pump head. A pump head may be a chamber or cavity in a pump where mechanical action can generate fluid flow. For example, a diaphragm pump may have a chamber partially formed by a diaphragm. Movement or deflection of the diaphragm causes a change in pressure in the chamber. If the diaphragm deflects into the chamber, the pressure in the chamber can increase, and if the diaphragm deflects away from the chamber, the pressure in the chamber can decrease. The change in pressure in the chamber can force fluid out of the chamber through a one-way valve or draw fluid into the chamber through another one way valve. Cyclically deflecting the diaphragm toward and away from the chamber can generate a fluid flow through the chamber.

[0043] A shape of the pump head or the pump itself can influence the capability of the pump. For example, the pump head can be shaped to develop high pressure differentials, high fluid flow rates, or a hybridization between a pressure differential gain and a fluid flow rate gain. For example, in some portable negative-pressure therapy systems a flow rate of about 2 L/min at ambient pressure and about 250 mL/min at 125 mm Hg of negative pressure can be considered a high fluid flow rate. A negative pressure of about 300 mm Hg can be considered a high pressure differential gain or high negative pressure. Often, a pump head optimized for relatively high pressure differentials may be limited to relatively lower fluid flow rates. Similarly, a pump optimized for relatively high fluid flows may be limited to relatively lower pressure differentials. Pump cavity size, volume and displacement volume can influence the ability of any individual pump to produce a suitable flow rate and negative pressure. As the pump cavity size, volume, and displacement volume increase, the pump becomes louder, larger, and more power consuming. Pumps used as sources of negative pressure, for example diaphragm pumps and piezoelectric pumps, may have pump heads that are optimized to a mid-point between relatively high pressure differentials and relatively high flow rates. During negative -pressure therapy, both high flow and high pressures can be required. For example, at the initiation of therapy, a higher fluid flow rate may be needed to remove fluid from the dressing area at a faster rate. As fluid is removed and the pressure at the tissue site begins to approach the therapy pressure, the pump may need to generate a higher negative pressure to successfully reach the therapy pressure. If a leak develops during therapy, a higher fluid flow rate may again be beneficial. Once the dressing is evacuated, a high pressure may be needed to move a lower volume of fluid. At other times during the negative-pressure therapy cycle, a balance between fluid flow and pressure may be needed.

[0044] Some users of negative-pressure therapy may be sensitive to the sound produced by a pump. The sound produced by a pump can be caused by the vibration of the operating components of the pump, such as the oscillation of the diaphragm and/or the valves opening and closing in a diaphragm pump. Generally, users can tolerate the sound produced by a pump operating at lower frequencies better than the same pump operating at a higher frequency. One method to reduce the volume of sound produced by a pump is to provide a smaller pump having a smaller pump head and associated components. However, providing a smaller pump reduces the total amount of fluid that can be moved for each pump cycle, requiring longer operation of the pump to move a total volume of fluid. Longer operation of the pump can result in the need for a dense source of energy to power the negative- pressure source. Sound reduction is achieved by operating the pump more slowly and for longer periods, requiring more energy to achieve the desired flow rates and pressures. For negative-pressure therapy provided in a medical facility, power is readily available for long term operation of the device. Where negative -pressure is provided to a mobile patient or in an in-home setting, the reliability of the power source is not necessarily assured. Thus, pumping systems may benefit from balancing energy efficiency with the provision of the appropriate flow rates and pressures.

[0045] Some pumping systems may optimize the various parameters in a therapy device that is disposable or that requires disassembly and replacement of the component parts. Such devices often result in expensive devices that must be replaced often and at significant cost to the user. It is also preferred that a pump system be capable of greater than 5000 hours of operation before failure, generally giving the pump system a twelve month lifespan. A pump having a brushless motor may have a longer life, but suffer from increased cost. A pump driven by a brush driven motor may have a lower cost, but may be louder and have a shorter life. As such, development of pumps and methods of operating a pump within a negative-pressure context that are low cost, highly efficient, simple to drive and control while providing high fluid flow rates and high pump pressure differentials may be useful.

[0046] Some pumping systems may provide more than one pump to increase flow or the pressurization. Generally, therapy systems having more than one pump or a pump with two heads are configured during manufacturing to have either a serial configuration or a parallel configuration. The configuration cannot be altered and is generally optimized for the overall system performance. The optimized system can provide either a maximum flow rate desired or a maximum pressure desired but cannot adapt if the system requires either a pressurization or flow rate that the system is not configured to provide. Systems having a parallel configuration can have a greater net flow capacity but develop a lower pressure, and systems having a serial configuration can develop a higher pressure but have a lower net flow capacity. For example, two small pumps fluidly coupled in a series configuration in a negative-pressure therapy context may provide up to about 250 mm Hg to about 300 mm Hg. However, the fluid flow rate at about 125 mm Hg of negative pressure for the example pump system may be only about 150 mL/min. Pressure can refer to the pressure differential across the pump that can be developed by the pump during its operation. Net flow rates or net flow capacity can refer to the largest volume of fluid a pump is capable of moving within a specified period of time. Static systems having either a parallel or serial configuration often fall short of the desired design criteria or are unable to maintain a greater than 5000 hour lifespan.

[0047] Figure 2 is a schematic diagram of the therapy unit 118 illustrating additional details that may be associated with some embodiments of the therapy system 100 of Figure 1. The therapy unit 118 can provide a pumping system optimized to produce high flow and high pressures in response to the needs of the negative-pressure therapy cycle. In particular, the therapy unit 118 can operate a dual head pump that can fluidly couple the dual pump heads in a serial configuration and a parallel configuration dynamically during therapy. The selective fluid coupling can optimize the flow and pressure performance for efficient operation of the dual head pump given the demands placed on the therapy unit 118 by the negative-pressure therapy cycle.

[0048] In some embodiments, the therapy unit 118 can include a housing 202, the negative-pressure source 102, and the container 106. The housing 202 can have a vacuum port 204 and an exhaust 206. The vacuum port 204 and the exhaust 206 may comprise an opening in a wall 203 of the housing 202. A seal may be coupled to the wall 203 of the housing 202 at each opening. In some embodiments, the seal may be a flexible material, such as rubber, silicone, or other similar material configured to contact and form a fluid seal with the wall 203 of the housing 202 and an object pressed against the wall 203 of the housing 202. In some embodiments, the seal may have a concertinaed shape to permit some movement of the seal. In some embodiments, each of the vacuum port 204 and the exhaust 206 can include a filter disposed over the vacuum port 204 and the exhaust 206.

[0049] In some embodiments, the housing 202 can have a cavity 207 in an exterior of the housing 202. In some embodiments, the cavity 207 may be disposed in a same wall 203 as the vacuum port 204 and the exhaust 206. In other embodiments, the cavity 207 can be disposed in other walls of the housing 202. The cavity 207 can depend into the housing 202 and have four sidewalls 209 and an interior wall 211. The four sidewalls 209 can each be perpendicular to the wall 203 of the housing and have ends coupled to an adjacent sidewall 209. The interior wall 211 can be perpendicular to the four sidewalls 209 in some embodiments. The interior wall 211 can be coupled to each of the four sidewalls 209 to provide a physical barrier into an interior space of the housing 202.

[0050] The housing 202 can further comprise a first housing port 210, a second housing port 212, a third housing port 214, and a fourth housing port 216. The first housing port 210, the second housing port 212, the third housing port 214, and the fourth housing port 216 can be disposed on the interior wall of the cavity 207. The first housing port 210 can be fluidly coupled to the vacuum port 204. The second housing port 212 and the third housing port can be fluidly coupled to the valve assembly 208, and the fourth housing port can be fluidly coupled to the exhaust 206. The first housing port 210, the second housing port 212, the third housing port 214, and the fourth housing port 216 can be fluid couplings disposed on an exterior of the housing 202. In some embodiments, each of the first housing port 210, the second housing port 212, the third housing port 214, and the fourth housing port 216 can be an opening in the interior wall 211 of the housing 202. In some embodiments, the opening can have an annular wall depending into the housing 202 and be configured to receive a mating component. The mating component can seal to the annular wall to prevent fluid communication with an ambient environment between the annular wall and the mating component. Each of the first housing port 210, the second housing port 212, the third housing port 214, and the fourth housing port 216 can provide fluid communication across a boundary of the housing 202 if an external device is attached to the respective port. Similarly, each of the first housing port 210, the second housing port 212, the third housing port 214, and the fourth housing port 216 can provide a fluid seal at the boundary of the housing 202 if an external device is not attached to the respective port.

[0051] In some embodiments, the therapy unit 118 can include a valve or valve system such as a valve assembly 208. The valve assembly 208 can be disposed in the housing 202. The valve assembly 208 can be fluidly coupled to the vacuum port 204 and the exhaust 206. The valve assembly 208 can include a first valve 218 and a second valve 220. The first valve 218 can have a fluid inlet 222, a first fluid outlet 224, and a second fluid outlet 226. The fluid inlet 222 can be fluidly coupled to the second housing port 212. The first fluid outlet 224 of the can be fluidly coupled to the exhaust 206. The first valve 218 can be a three way valve, such as a three-way solenoid valve having three fluid couplings where a one of the couplings can be fluidly coupled to either of the other two. An exemplary three-way valve can have a flow rate between about 0 standard liters per minute (splm) and about 11 slpm at an operating pressure between about 0 pounds per square inch (psi) and about 100 psi. In some embodiments, the first valve 218 can be a three-way solenoid valve system having two X-Valve ^® Miniature Pneumatic Solenoid Valves provided by Parker Hannifin Corp. In other embodiments, the first valve 218 can be a linear-actuated three-way valve having a mechanical assembly configured to slide in response to motor actuation to select between the first fluid outlet 224 and the second fluid outlet 226. In still other embodiments, the first valve 218 can be a rotary-actuated valve configured to actuate a mechanical assembly to select between the first fluid outlet 224 and the second fluid outlet 226. The first valve 218 can be configured to require power to transition between the first fluid outlet 224 and the second fluid outlet 226 and require minimal or no power to remain fluidly coupled to the selected outlet.

[0052] The second valve 220 can have a fluid outlet 228, a first fluid inlet 230, and a second fluid inlet 232. The second fluid outlet 226 of the first valve 218 can be fluidly coupled to the first fluid inlet 230. The second fluid inlet 232 can be fluidly coupled to the vacuum port 204, and the fluid outlet 228 can be fluidly coupled to the third housing port 214. The second valve 220 can be a three way valve, such as a three-way solenoid valve having three fluid couplings where a one of the couplings can be fluidly coupled to either of the other two. An exemplary three-way valve can have a flow rate between about 0 standard liters per minute (splm) and about 11 slpm at an operating pressure between about 0 pounds per square inch (psi) and about 100 psi. In some embodiments, the second valve 220 can be a three-way solenoid valve system having two X-Valve ^® Miniature Pneumatic Solenoid Valves provided by Parker Hannifin Corp. In other embodiments, the second valve 220 can be a linear actuated three-way valve having a mechanical assembly configured to slide in response to motor actuation to select between the first fluid inlet 230 and the second fluid inlet 232. In still other embodiments, the second valve 220 can be a rotary actuated valve configured to actuate a mechanical assembly to select between the first fluid inlet 230 and the second fluid inlet 232. The second valve 220 can be configured to require power to transition between the first fluid inlet 230 and the second fluid inlet 232 and require minimal or no power to remain fluidly coupled to the selected outlet.

[0053] Each of the first valve 218 and the second valve 220 can be communicatively coupled to the controller 108. The controller 108 can selectively actuate the first valve 218 and the second valve 220. For example, the controller 108 can actuate the first valve 218 to selectively couple the first fluid outlet 224 to the fluid inlet 222 or the second fluid outlet 226 to the fluid inlet 222. Similarly, the controller 108 can actuate the second valve 220 to selectively couple the first fluid inlet 230 to the fluid outlet 228 or the second fluid inlet 232 to the fluid outlet 228. In some embodiments, the first valve 218 and the second valve 220 are proportional valves. A proportional valve permits proportional flow through the flow paths within the valve. For example, the first valve 218 may be a proportional valve. Fluid flow from the fluid inlet 222 can be distributed to both the first fluid outlet 224 and the second fluid outlet 226. In some embodiments, a portion of the fluid entering the fluid inlet 222 may flow through the first fluid outlet 224, and a portion of the fluid entering the fluid inlet 22 may flow through the second fluid outlet 226.

[0054] A ratio of fluid flow between the first fluid outlet 224 and the second fluid outlet

226 or the first fluid inlet 230 and the second fluid inlet 232 may be variable as needed or selected by the controller 108. The controller 108 may actuate the first valve 218 and the second valve 220 to select the proportion between the first fluid outlet 224 and the second fluid outlet 226 and the first fluid inlet 230 and the second fluid inlet 232, respectively. For example, 60% of the fluid entering the fluid inlet 222 may flow through the first fluid outlet 224, and 40% of the fluid entering the fluid inlet 222 may flow through the second fluid outlet 226. In some embodiments, the portion of the fluid flow through the first fluid outlet 224 may be between 0% and about 100% of the fluid flow through the fluid inlet 222. Similarly, the portion of the fluid flow through the second fluid outlet 226 may be between 0% and about 100% of the fluid flow through the fluid inlet 222. The fluid flow through the first fluid outlet 224 and the second fluid outlet 226 may have an inverse relationship, an increase in fluid flow through the second fluid outlet 226 corresponds to a decrease in fluid flow through the first fluid outlet 224 and vice versa. In some embodiments, the portion of the fluid flow through the first fluid inlet 230 may be between 0% and about 100% of the fluid flow through the fluid outlet 228. Similarly, the portion of the fluid flow through the second fluid inlet 232 may be between 0% and about 100% of the fluid flow through the fluid outlet 228. The fluid flow through the first fluid inlet 230 and the second fluid inlet 232 may have an inverse relationship, an increase in fluid flow through the second fluid inlet 232 corresponds to a decrease in fluid flow through the first fluid inlet 230 and vice versa. [0055] The housing 202 can also include a power coupling 234. The power coupling

234 can be disposed on exterior of the housing 202 and communicatively coupled to the controller 108. In some embodiments, the controller 108 can provide or control the flow of electrical power to the power coupling 234 to power an external device coupled to the power coupling 234. The power coupling 234 can be a spring loaded assembly configured to maintain a mechanical force against a body inserted into or positioned adjacent the power coupling 234. In other embodiments, the power coupling 234 can be a male or female electrical coupling configured to be connected to a corresponding female or male electrical coupling, respectively, of another device. Similarly, the power coupling 234 can be disposed on the interior wall 211 of the cavity 207. In some embodiments, the cavity 207 can be configured to receive the negative-pressure source 102 and couple the negative-pressure source 102 to the housing 202.

[0056] In some embodiments, the negative-pressure source 102 can be configured to be removably coupled to the housing 202. For example, the negative-pressure source 102 can be a user replaceable module capable of being attached to the housing 202 and the container 106. The negative- pressure source 102 may latch in place and be pneumatically sealed to the housing 202. The negative- pressure source 102 can be communicatively coupled to the controller 108 through the power coupling 234. In some embodiments, the negative-pressure source 102 can be replaced at preset intervals. The negative-pressure source 102 can be a pump module having a two pumps or two pump chambers. The first pump chamber can have a fluid inlet 238 and a fluid outlet 240 providing a fluid path through the first pump chamber, and the second pump chamber can have a fluid inlet 241 and a fluid outlet 244 providing a fluid path through the second pump chamber. The negative-pressure source 102 can also have a power coupling 246. The power coupling 246 can be configured to prove motive energy to the operative components within the negative-pressure source 102. For example, if the negative-pressure source has two pumps, the power coupling 246 can provide power and control signals for the operation of the two pumps. Similarly, if the negative-pressure source is a single pump with two chambers, the power coupling 246 can provide power and control signals for the operation of the pump.

[0057] The valve assembly 208 can be fluidly coupled to a pump module, such as the negative-pressure source 102. For example, the negative-pressure source 102 can be configured to be inserted into the cavity 207 and fluidly couple the fluid inlet 238 to the first housing port 210, the fluid outlet 240 to the second housing port 212, the fluid inlet 242 to the third housing port 214, and the fluid outlet 244 to the fourth housing port 216. Similarly, the power coupling 246 can be received by and communicatively coupled with the power coupling 234. For example, the power coupling 246 can be a male or female electrical coupling configured to engage or receive, respectively, the power coupling 234.

[0058] The container 106 can also be removably coupled to the housing 202. For example, the container 106 can be coupled to the housing 202 so that the vacuum port 204 is fluidly coupled to the container 106 and fluidly coupled to the dressing 104 through the container 106. In some embodiments, the container 106 can include a fdter configured to be disposed in the fluid path to the vacuum port 204. In some embodiments, the container 106 may provide a fluid path for the flow of fluid through the exhaust 206 to the ambient environment. In other embodiments, the exhaust 206 may be fluidly coupled to the ambient environment by a fluid path disposed between the container 106 and the housing 202. In some embodiments, the container 106 may contain a separate pressure sensing fluid pathway that can be fluidly coupled to the dressing 104 and the housing 202 to determine a pressure at the tissue site.

[0059] In some embodiments, the therapy unit 118 can have at least one pressure sensor

110 and at least one electric sensor 112. The pressure sensor 110 can be fluidly coupled to the vacuum port 204. In some embodiments, the pressure sensor 110 can determine a pressure a therapy pressure. The therapy pressure can be a pressure at the tissue site, and a targeted therapy pressure or target pressure can be the desired pressure at the tissue site. In some embodiments, a flow meter may also be fluidly coupled to the vacuum port 204. The flow meter can determine a fluid flow rate at the vacuum port 204. The pressure sensor 110 and the flow meter can be communicatively coupled to the controller 108. The controller 108 can receive signals from the pressure sensor 110 and the flow meter indicative of the therapy pressure and a fluid flow rate at the vacuum port 204. The electric sensor 112 can be communicatively coupled to the power coupling 234 and if the negative-pressure source 102 is coupled to the housing 202, communicatively coupled to the negative-pressure source 102. In some embodiments, the electric sensor 112 can determine an operational status of the negative-pressure source 102. For example, the electric sensor can determine how much power is being drawn by the negative-pressure source 102 during operation. The electric sensor 112 can be communicatively coupled to the controller 108. The controller 108 can receive signals from the electric sensor 112 indicatively of the operationl status of the negative-pressure source 102.

[0060] Figure 3 is a schematic diagram of a portion of the therapy unit 118 in a first pump mode illustrating additional details that may be associated with some embodiments of the therapy system 100 of Figure 1. The negative -pressure source 102 can have a first pump chamber or first pump head 302 and a second pump chamber or second pump head 304. In some embodiments, first pump head 302 is a first pump, and the second pump head 304 is a second pump. In other embodiments, the first pump head 302 is a chamber disposed on a first side of a diaphragm or piezoelectric actuator, and the second pump head 304 is a chamber disposed on a second side of the diaphragm or piezoelectric actuator. In some embodiments, the first side and the second side of a diaphragm are opposite facing sides of the diaphragm. In some embodiments, the negative -pressure source 102 can comprise an actuator operable to drive the first pump head 302 and the second pump head 304. The first pump head 302 can be on a first side of the actuator and the second pump head 304 can be on a second side of the actuator opposite the first side. Operation of the actuator can generate a fluid flow in each of the pump heads. In some embodiments, the first pump head 302 and the second pump head 304 can be a dual headed diaphragm pump. For example, the first pump head 302 and the second pump head 304 may each be a head on an opposite side of a dual head pump that is capable of providing fluid flow greater than 1100 mL/min and a vacuum pressure of greater than 140 mbar or 105 mm Hg during continuous operation. In other embodiments, the first pump head 302 and the second pump head 304 can be an XP Series DP-P2-007 or XP-P2-028 disc pump by TTP Ventus Ltd having two pump heads driven by a common actuator. In other embodiments, the first pump head 302 and the second pump head 304 can be separate pumps having a no-load flow rate of about 200 mL/min and capable of developing a pressure of 60kPa or 450 mm Hg. For example, each of the first pump head 302 and the second pump head 304 could be a Microblower MZB3004T04 by Murata Manufacturing Co., Ltd.

[0061] The first pump head 302 can be mounted in a housing so that a fluid inlet of the first pump head 302 is fluidly coupled to the fluid inlet 238, and a fluid outlet of the first pump head 302 is fluidly coupled to the fluid outlet 240. The fluid inlet 238 and the fluid outlet 240 can be fluid ports providing a fluid coupling across a boundary of the negative-pressure source 102 for fluid communication from an exterior of the negative -pressure source 102 with the first pump head 302. The second pump head 304 can be mounted in a housing so that a fluid inlet of the second pump head 304 is fluidly coupled to the fluid inlet 242, and a fluid outlet of the second pump head 304 is fluidly coupled to the fluid outlet 244. The fluid inlet 242 and the fluid outlet 244 can be fluid ports providing a fluid coupling across a boundary of the negative-pressure source 102 for fluid communication from an exterior of the negative-pressure source 102 with the second pump head 304. Operation of the first pump head 302 can draw fluid through the first pump head 302 from the fluid inlet 238 to the fluid outlet 240. Operation of the second pump head 304 can draw fluid through the second pump head 304 from the fluid inlet 242 to the fluid outlet 244.

[0062] The negative-pressure source 102 can be disposed in the cavity 207. If the negative-pressure source 102 is disposed in the cavity 207, the fluid inlet 238 can be fluidly coupled to the vacuum port 204 through the first housing port 210, fluidly coupling the fluid inlet of the first pump head 302 to the vacuum port 204. Similarly, the fluid outlet 240 can be fluidly coupled to the fluid inlet 222 of the first valve 218 through the second housing port 212, fluidly coupling the fluid outlet of the first pump head 302 to the fluid inlet 222 of the first valve 218. The fluid inlet 242 can be fluidly coupled to the fluid outlet 228 of the second valve 220 through the third housing port 214, fluidly coupling the fluid outlet 228 to the fluid inlet of the second pump had 304. Similarly, the fluid outlet 244 can be fluidly coupled to the exhaust 206 through the fourth housing port 216, fluidly coupling the fluid outlet of the second pump head to the exhaust 206.

[0063] The valve assembly 208 can have a first mode and a second mode. In some embodiments, the first mode can be a series mode or series configuration. The second mode can be a parallel mode or parallel configuration. In some embodiments, the valve assembly 208 is configured to be selectively switched between the first mode and the second mode. As illustrated in Figure 3, the valve assembly 208 is in the first mode or the series configuration. In the series configuration, the second fluid outlet 226 of the first valve 218 is fluidly coupled to the fluid inlet 222 of the first valve 218, and the first fluid inlet 230 of the second valve 220 is fluidly coupled to the fluid outlet 228. Actuation of the first pump head 302 and the second pump head 304 will draw fluid from the vacuum port 204 into the first pump head 302, and force fluid from the first pump head 302 into the first valve 218. The first valve 218, having the fluid inlet 222 fluidly coupled to the second fluid outlet 226 will direct fluid into the second valve 220 through the first fluid inlet 230. The second valve 220 having the first fluid inlet 230 fluidly coupled to the fluid outlet 228 will direct fluid into the second pump head 304 from the first valve 218. The second pump head 304 can then force fluid from the second pump head 304 through the exhaust 206.

[0064] While in the series configuration, operation of the first pump head 302 and the second pump head 304 raises a fluid to a first pressurization with the first pump head 302, and then, the fluid can be elevated to a second pressurization by the second pump head 304. In some embodiments, in the series configuration, the first pump head 302 and the second pump head 304 have a stall pressure of about 218 mm Hg. Stall pressure can refer to the effective maximum pressure a pump is capable of generating and can be dependent on the motor torque of the particular pump. In some embodiments, in the series configuration, the first pump head 302 and the second pump head 304 have a max net flow rate of about 1.1 L/min or 1100 mL/min.

[0065] Figure 4 is a schematic diagram of a portion of the therapy unit 118 in a second pump mode illustrating additional details that may be associated with some embodiments of the therapy system 100 of Figure 1. As illustrated in Figure 4, the valve assembly 208 is in the second mode or the parallel configuration. In the parallel configuration, the first fluid outlet 224 of the first valve 218 is fluidly coupled to the fluid inlet 222 of the first valve 218, and the second fluid inlet 232 of the second valve 220 is fluidly coupled to the fluid outlet 228. Actuation of the first pump head 302 will draw fluid from the vacuum port 204 into the first pump head 302, and force fluid from the first pump head 302 into the first valve 218. The first valve 218, having the fluid inlet 222 fluidly coupled to the first fluid outlet 224 will direct fluid into the exhaust 206. Actuation of the second pump head 304 will draw fluid from the fluid outlet 228 and force fluid from the second pump head 304 through the exhaust 206. The second valve 220 having the second fluid inlet 232 fluidly coupled to the fluid outlet 228 will also draw fluid from the vacuum port 204 and direct fluid into the second pump head 304. The second pump head 304 can then force fluid from the second pump head 304 through the exhaust 206.

[0066] In operation, the first pump head 302 and the second pump head each draw fluid through the vacuum port 204, increasing the total flow rate drawn through the vacuum port 204. In some embodiments, in the parallel configuration, the first pump head 302 and the second pump head 304 have a stall pressure of about 160 mm Hg. In some embodiments, in the parallel configuration, the first pump head 302 and the second pump head 304 have a max net flow rate of about 1.67 L/min to about 2 L/min.

[0067] In some embodiments, the first valve 218 and the second valve 220 can be proportional valves. For example, the first valve 218 and the second valve 220 can be configured for partial fluid coupling between the first fluid outlet 224 and the second fluid outlet 226 and the fluid inlet 222; similarly the second valve 220 can be configured for partial fluid coupling between the first fluid inlet 230, the second fluid inlet 232, and the fluid outlet 228. The controller 108 may actuate the first valve 218 and the second valve 220 to provide one or more hybrid configurations having the first pump head 302 and the second pump head 304 partially coupled in a serial configuration and partially coupled in a parallel configuration. In this manner, the controller 108 may gradually switch between the modes and provide hybrid pressure and flow rates.

[0068] Figure 5 is a schematic diagram of a standard pump illustrating additional details that may be associated with some embodiments. A standard pump for a negative-pressure therapy system may have a pump head 502. The pump head 502 may have a fluid inlet 504 and a fluid outlet 506. The fluid inlet 504 can be fluidly coupled to a vacuum port to draw fluid from a distribution component such as a canister or a dressing. The fluid outlet 506 can be fluidly coupled to an exhaust or otherwise coupled to the ambient environment. Operation of the pump head 502 can draw fluid through the pump head 502 from the fluid inlet 504 to the fluid outlet 506. In some embodiments, the pump head 502 may be operated without external valves.

[0069] Figure 6 is a graph illustrating a relationship between pressure and flow rate that may be associated with the therapy system 100 of Figure 1. In the graph of Figure 6, increasing pressure is represented on the Y-axis and increasing flow in represented on the X-axis. Three curves are illustrated in Figure 6, a curve 602, a curve 604, and a curve 606. The curve 602 represents the relationship between pressure and flow in a standard pump head, for example, the pump head 502 of Figure 5. As illustrated by the curve 602, the pump head 502 can provide reasonable flow rates and pressures. The maximum pressure of the pump head 502 is where the curve 602 intersects the Y-axis. As pressure decreases along the curve 602, the net flow provided by the pump head 502 increases. The maximum net flow rate of the pump head 502 is where the curve 602 intersects the X-axis, and the pressure is at a minimum. In some embodiments, the maximum pressure along the curve 602 can be about 160 mm Hg, and the maximum net flow rate can be about 1.1 L/min. In other embodiments, the maximum pressure and flow rate along the curve 602 can be greater or lesser.

[0070] The curve 604 represents the relationship between pressure and flow for the first pump head 302 and the second pump head 304 where the valve assembly 208 is in the serial configuration of Figure 3. As illustrated by the curve 604, the first pump head 302 and the second pump head 304 can provide higher pressures in the serial mode than the pump head 502. In the serial configuration, the first pump head 302 and the second pump head 304 may provide a maximum flow rate similar to the maximum flow rate of the pump head 502, as illustrated by the intersection of the curve 602 and the curve 604 at the X-axis. In the serial configuration, the first pump head 302 and the second pump head 304 may provide a maximum pressure that is higher than the maximum pressure of the pump head 502, as illustrated by the intersection of the curve 602 and the curve 604 at the Y-axis. In some embodiments, the maximum pressure along the curve 604 can be about 218 mm Hg, and the maximum net flow rate can be about 1.1 L/min. In other embodiments, the maximum pressure and flow rate along the curve 604 can be greater or lesser.

[0071] The curve 606 represents the relationship between pressure and flow for the first pump head 302 and the second pump head 304 where the valve assembly 208 is in the parallel configuration of Figure 4. As illustrated by the curve 606, the first pump head 302 and the second pump head 304 can provide higher flow rates in the parallel mode than the pump head 502. In the parallel configuration, the first pump head 302 and the second pump head 304 may provide a maximum pressure similar to the maximum pressure of the pump head 502, as illustrated by the intersection of the curve 602 and the curve 606 at the Y-axis. In the parallel configuration, the first pump head 302 and the second pump head 304 may provide a maximum net flow rate that is higher than the maximum net flow rate of the pump head 502, as illustrated by the intersection of the curve 602 and the curve 604 at the X-axis. In some embodiments, the maximum pressure along the curve 606 can be about 160 mm Hg, and the maximum net flow rate can be about 1.67 L/min to about 2 L/min. In other embodiments, the maximum pressure and flow rate along the curve 606 can be greater or lesser.

[0072] By operating the valve assembly 208 to fluidly couple the first pump head 302 and the second pump head 304 in the serial configuration and the parallel configuration, both the pressure and the flow rate can be maximized to address the particular need of negative-pressure therapy at a particular moment. For example, if the valve assembly 208 is in the series configuration of Figure 3 and the controller 108 determines that a higher flow rate is desired, the controller 108 can operate the first pump head 302 and the second pump head 304 to increase the flow rate along the curve 604. As the flow rate approaches an intersection 608 of the curve 604 and the curve 606, the controller 108 can actuate the first valve 218 and the second valve 220 to transition the valve assembly 208 from the series configuration of Figure 3 to the parallel configuration of Figure 4. The flow rate can continue to increase along the curve 606. In this manner, the first pump head 302 and the second pump head 304 can be operated to provide greater fluid flow rates than if the first pump head 302 and the second pump head 304 were statically coupled in the series configuration. Similarly, if the valve assembly 208 is in the parallel configuration of Figure 4 and the controller 108 determines that a higher pressure is desired, the controller 108 can operate the first pump head 302 and the second pump head 304 to increase the pressure along the curve 606. As the pressure approaches the intersection 608 of the curve 604 and the curve 606, the controller 108 can actuate the first valve 218 and the second valve 220 to transition the valve assembly 208 from the parallel configuration of Figure 4 to the series configuration of Figure 3. The pressure can continue to increase along the curve 604. In this manner, the first pump head 302 and the second pump head 304 can be operated to provide greater pressures than if the first pump head 302 and the second pump head 304 were statically coupled in the parallel configuration.

[0073] Figure 7 is a flow chart 700 illustrating exemplary operations that can be associated with some embodiments of the therapy system 100 of Figure 1. For example, the flow chart 700 can provide operations for determining an operating mode of the therapy unit 118. In some embodiments, the controller 108 may receive input from a user input device, such as a keypad, touch screen, microphone, or other input device. In other embodiments, the controller 108 may determine an operating mode in response to an internal timer or signals from the pressure sensor 110 or the electric sensor 112. At block 701, the therapy system 100 can determine if the mode of the therapy system 100 is a standard mode. For example, the controller 108 can determine if the therapy system 100 should be operated in the standard operating mode in response to signals from the pressure sensor 110 and the electric sensor 112. In some embodiments, the therapy system 100 may be in a standard operating mode if the negative pressure at the tissue site is about 125 mm Hg and a leak rate of the therapy system 100 is less than about 400 mL/min. If the mode of the therapy system is the standard mode, the process can continue on the YES path to block 702, where the therapy system can operate in the standard operating mode. For example, the controller 108 can execute the standard operating mode, and the process ends.

[0074] If the mode ofthe therapy system is not the standard operating mode, the process can continue on the NO path to block 703, where the therapy system can determine if the mode of the therapy system 100 is the draw down mode. For example, the controller 108 can determine if the therapy system 100 should be operated in the draw down mode in response to signals from the pressure sensor 110 and the electric sensor 112. In some embodiments, the therapy system 100 may be in the draw down mode if the negative pressure at the tissue site is less than about 50 mm Hg and a leak rate of the therapy system 100 is less than about 400 mL/min. If the mode of the therapy system 100 is the draw down mode, the process can continue on the YES path to block 704, where the therapy system can operate in the draw down mode, and the process ends.

[0075] If the mode of the therapy system 100 is not the draw down mode, the process can continue on the NO path to block 705, where the therapy system 100 can determine if the mode of the therapy system 100 is the leak mode. For example, the controller 108 can determine if the therapy system 100 should be operated in the leak mode in response to signals from the pressure sensor 110 and the electric sensor 112. In some embodiments, the therapy system 100 may be in the leak mode if the negative pressure at the tissue site is about 125 mm Hg and a leak rate of the therapy system 100 is greater than about 400 mL/min. If the mode of the therapy system 100 is the leak mode, the process can continue on the YES path to block 706, where the process can determine if the therapy system is in the gross leak mode. For example, the controller 108 can determine if the therapy system 100 should be operated in the gross leak mode in response to signals from the pressure sensor 110 and the electric sensor 112. In some embodiments, the therapy system 100 may be in the gross leak mode if the negative pressure at the tissue site is about 125 mm Hg and a leak rate of the therapy system 100 is greater than about 800 mL/min. If the mode of the therapy system 100 is the gross leak mode, the process can continue on the YES path to block 707, where the therapy system 100 can operate in the gross leak mode, and the process ends. For example, the controller 108 can operate the therapy system 100 in the gross leak mode. At block 706, if the mode of the therapy system is not the gross leak mode, the therapy system 100 can continue on the NO path to block 708, where the therapy system can operate in the leak mode and the process ends. For example, the controller 108 can operate the therapy system 100 in the leak mode.

[0076] At block 705, if the mode of the therapy system 100 is not the leak mode, the process continues on the NO path to block 709, where the method determines if the mode of the therapy system is the blockage mode. For example, the controller 108 can determine if the therapy system 100 should be operated in the blockage mode in response to signals from the pressure sensor 110 and the electric sensor 112. In some embodiments, the therapy system 100 may be in the blockage mode if the negative pressure at the tissue site does not increase in response to operation of the first pump head 302 and the second pump head 304 for a predetermine period of time and the leak rate of the therapy system 100 is negligible. For example, if the therapy pressure is less than about 50% of the target pressure for a given period of time and the first pump head 302 and the second pump head 304 generate a pressure that is greater than 150% of the target pressure, the therapy system 100 may have a blockage. If the mode of the therapy system 100 is the blockage mode, the method follows the YES path to block 710, where the therapy system operates in the blockage mode and the process ends.

[0077] At block 709, if the mode of the therapy system 100 is not the blockage mode, the therapy system follows the NO path to block 711, where the method determines if the mode of the therapy system is the offset mode. For example, the controller 108 can determine if the therapy system 100 should be operated in the offset mode in response to signals from the pressure sensor 110 and the electric sensor 112. In some embodiments, the therapy system 100 may be in the offset mode if the negative pressure at the tissue site, the therapy pressure, is less than about 25% of the target pressure, and a leak rate of the therapy system 100 is about 25% of a leak rate configured to trigger an alarm of the therapy system 100. If the mode of the therapy system 100 is the offset mode, the process continues on the YES path to block 712, where the therapy system operates in the offset mode, and the process ends. At block 711 if the mode of the therapy system is not the offset mode, the process can continue on the NO path to block 713. At block 713, the therapy system provides an error message, and the process ends.

[0078] Figure 8 is a flow chart 800 illustrating exemplary operations that can be associated with some embodiments of the standard operating mode of the flow chart 700 of Figure 7. For example, the flow chart 800 can illustrate exemplary operations of a standard operating routine that can be performed by the therapy system 100. At block 801, the therapy system can fluidly couple a first pump head and a second pump head in serial configuration. For example, the fluid outlet 240 of the first pump head 302 can be fluidly coupled to the fluid inlet 242 of the second pump head 304 by actuating the first valve 218 to fluidly couple the fluid inlet 222 to the second fluid outlet 226 and actuating the second valve 220 to fluidly couple the first fluid inlet 230 to the fluid outlet 228. At block 802, the first pump head and the second pump head can be operated. For example, the controller 108 can actuate the negative-pressure source 102 to operate the first pump head 302 and the second pump head 304, drawing fluid from the vacuum port 204 through the first pump head 302, the first valve 218, the second valve 220, and the second pump head 304 through the exhaust 206.

[0079] At block 803, the therapy system can determine if there is a leak. For example, the controller 108 can determine if there is a leak in response to signals received from the pressure sensor 110 and the electric sensor 112. If the therapy system determines that there is no leak, the process can continue on the NO path to block 802, where the process can continue to operate the first pump head and the second pump head.

[0080] If the therapy system determines that there is a leak, the process can continue on the YES path to block 804. At block 804, the therapy system determines if the leak rate is more than 400 mL/min. For example, the controller 108 can determine if the leak rate from the dressing 104 exceeds 400 mL/min in response to signals from the pressure sensor 110 and the electric sensor 112. If the therapy system determines that the leak does not exceed 400 mL/min, the process can continue on the NO path to block 802, where the process can continue to operate the first pump head and the second pump head.

[0081] If the therapy system determines that the leak exceeds 400 mL/min, the process continues on the YES path to block 805, where the therapy system determines if the leak is a gross leak. For example, the controller 108 can determine if the leak rate is greater than 800 mL/min at 125 mm Hg of negative pressure in response to signals received from the pressure sensor 110 and the electric sensor 112. If the therapy system determines that the leak is a gross leak, the process can continue on the YES path to block 806, where the therapy system operates in the gross leak mode, and the process ends. At block 805, if the therapy system determines that the leak is not a gross leak, the process can continue on the NO path to block 807, where the therapy system operates in the leak mode, and the process ends.

[0082] Figure 9 is a flow chart 900 illustrating exemplary operations that can be associated with some embodiments of the draw down operating mode of the flow chart 700 of Figure 7. For example, the flow chart 900 can illustrate exemplary operations of a draw down operating mode that can be performed by the therapy system 100. At block 901, the therapy system can fluidly couple a first pump head and a second pump head in a parallel configuration. For example, the fluid outlet 240 of the first pump head 302 can be fluidly coupled to the exhaust 206 by actuating the first valve 218 to fluidly couple the fluid inlet 222 to the first fluid outlet 224, and the second pump head 304 can be fluidly coupled to the vacuum port 204 by actuating the second valve 220 to fluidly couple the second fluid inlet 232 to the fluid outlet 228. At block 902, the first pump head and the second pump head can be operated. For example, the controller 108 can actuate the negative-pressure source 102 to operate the first pump head 302 and the second pump head 304. The first pump head 302 can draw fluid from the vacuum port 204 through the first pump head 302 and the first valve 218 and through the exhaust 206. Similarly, the second pump head 304 can draw fluid from the vacuum port 204 through the second pump head 304, the second valve 220, and through the exhaust 206.

[0083] At block 903, the therapy system can determine the therapy pressure. For example, the controller 108 can determine the pressure at the tissue site, i.e., the therapy pressure from a signal received from the pressure sensor 110. At block 904, the therapy system can determine if the therapy pressure is greater than 50 mm Hg of negative pressure. For example, the controller 108 can process a signal received from the pressure sensor 110 to determine if the pressure at the tissue site is greater than 50 mm Hg. If the therapy pressure is less than 50 mm Hg negative pressure the process can continue on the NO path to block 902, where the process can continue to operate the first pump head and the second pump head.

[0084] At block 904, if the therapy pressure is greater than 50 mm Hg negative pressure, the process can continue on the YES path to block 905, where the therapy system can determine if the therapy pressure is less than 75 mm Hg. For example, the controller 108 can process a signal from the pressure sensor 110 to determine if the pressure at the tissue site is less than 75 mm Hg of negative pressure. If the therapy pressure is less than 75 mm Hg, the process can continue on the YES path to block 902, wherein the process can continue to operate the first pump head and the second pump head. At block 905, if the therapy pressure is greater than 75 mm Hg of negative pressure, the process can continue on the NO path to block 906, where the therapy system operates in the standard operating mode, and the process ends.

[0085] Figure 10 is a flow chart 1000 illustrating exemplary operations that can be associated with some embodiments of the gross leak operating mode of the flow chart 700 of Figure 7. For example, the flow chart 1000 can illustrate exemplary operations of a gross leak mode that can be performed by the therapy system 100. At block 1001, the therapy system can fluidly couple a first pump head and a second pump head in a parallel configuration. For example, the fluid outlet 240 of the first pump head 302 can be fluidly coupled to the exhaust 206 by actuating the first valve 218 to fluidly couple the fluid inlet 222 to the first fluid outlet 224, and the second pump head 304 can be fluidly coupled to the vacuum port 204 by actuating the second valve 220 to fluidly couple the second fluid inlet 232 to the fluid outlet 228. At block 1002, the first pump head and the second pump head can be operated. For example, the controller 108 can actuate the negative-pressure source 102 to operate the first pump head 302 and the second pump head 304. The first pump head 302 can draw fluid from the vacuum port 204 through the first pump head 302 and the first valve 218 and through the exhaust 206. Similarly, the second pump head 304 can draw fluid from the vacuum port 204 through the second pump head 304, the second valve 220, and through the exhaust 206.

[0086] At block 1003, the therapy system can reduce the pressure at a vacuum port to about 75 mm Hg of negative pressure. For example, the controller 108 can operate the first pump head 302 and the second pump head 304 to maintain a pressure of about 75 mm Hg negative pressure at the vacuum port 204 as determined by the pressure sensor 110. At block 1004, the therapy system can increase the flow rate at the vacuum port to a maximum flow rate. In some embodiments, the maximum flow rate may be about 2 L/min. For example, the controller 108 can operate the first pump head 302 and the second pump head 304 to generate a flow rate of about 2 L/min at the vacuum port 204.

[0087] At block 1005, the therapy system can determine if a leak rate at the tissue site is greater than 800 mL/min. For example, the controller 108 can determine if a leak rate at the tissue site is greater than 800 mL/min in response to signals received from the pressure sensor 110 and the electric sensor 112. If the leak rate is greater than 800 mL/min, the process continues on the YES path to block 1002, where the process can continue to operate the first pump head and the second pump head. At block 1005, if the leak rate is less than 800 mL/min, the process can continue on the NO path to block 1006, where the therapy system can operate in a leak mode or leak routine, and the process ends.

[0088] Figure 11 is a flow chart 1100 illustrating exemplary operations that can be associated with some embodiments of the leak operating mode of the flow chart 700 of Figure 7. For example, the flow chart 1100 can illustrate exemplary operations of a leak mode or leak routine that can be performed by the therapy system 100. At block 1101, the therapy system can fluidly couple a first pump head and a second pump head in a parallel configuration. For example, the fluid outlet 240 of the first pump head 302 can be fluidly coupled to the exhaust 206 by actuating the first valve 218 to fluidly couple the fluid inlet 222 to the first fluid outlet 224, and the second pump head 304 can be fluidly coupled to the vacuum port 204 by actuating the second valve 220 to fluidly couple the second fluid inlet 232 to the fluid outlet 228. At block 1102, the first pump head and the second pump head can be operated. For example, the controller 108 can actuate the negative-pressure source 102 to operate the first pump head 302 and the second pump head 304. The first pump head 302 can draw fluid from the vacuum port 204 through the first pump head 302 and the first valve 218 and through the exhaust 206. Similarly, the second pump head 304 can draw fluid from the vacuum port 204 through the second pump head 304, the second valve 220, and through the exhaust 206.

[0089] At block 1103, the therapy system can maintain the pressure at a vacuum port at about 125 mm Hg of negative pressure. For example, the controller 108 can operate the first pump head 302 and the second pump head 304 to maintain a pressure of about 125 mm Hg negative pressure at the vacuum port 204 as determined by the pressure sensor 110. At block 1004, the therapy system can determine if a leak rate at the tissue site is greater than about 400 mL/min. For example, the controller 108 can determine if the leak rate at the tissue site is greater than about 400 mL/min in response to signals received from the pressure sensor 110 and the electric sensor 112. If the leak rate is not greater than about 400 mL/min, the process can continue on the NO path to block 1106. At block 1106, the therapy system can operate in the standard operating mode, and the process ends.

[0090] At block 1104, if the leak rate is greater than about 400 mL/min, the process can continue on the YES path to block 1105. At block 1105, the therapy system can determine if the leak rate of the therapy system is less than about 800 mL/min. For example, the controller 108 can determine if the leak rate at the tissue site is less than about 800 mL/min in response to signals received from the pressure sensor 110 and the electric sensor 112. If the leak rate at the tissue site is less than about 800 mL/min, the process can continue on the YES path to block 1102, wherein the process can continue to operate the first pump head and the second pump head. At block 1105, if the leak rate at the tissue site is not less than about 800 mL/min, the process continues on the NO path to block 1107. At block 1107, the therapy system operates in the gross leak mode, and the process ends.

[0091] Figure 12 is a flow chart 1200 illustrating exemplary operations that can be associated with some embodiments of the blockage operating mode of the flow chart 700 of Figure 7. For example, the flow chart 1200 can illustrate exemplary operations of a blockage operating routine or blockage mode that can be performed by the therapy system 100. At block 1201, the therapy system can fluidly couple a first pump head and a second pump head in serial configuration. For example, the fluid outlet 240 of the first pump head 302 can be fluidly coupled to the fluid inlet 242 of the second pump head 304 by actuating the first valve 218 to fluidly couple the fluid inlet 222 to the second fluid outlet 226 and actuating the second valve 220 to fluidly couple the first fluid inlet 230 to the fluid outlet 228. At block 1202, the first pump head and the second pump head can be operated. For example, the controller 108 can actuate the negative-pressure source 102 to operate the first pump head 302 and the second pump head 304, drawing fluid from the vacuum port 204 through the first pump head 302, the first valve 218, the second valve 220, the second pump head 304, and through the exhaust 206.

[0092] At block 1203, the therapy system determines if a blockage has cleared. For example, the controller 108 can determine if the therapy system 100 has cleared the blockage. In some embodiments, if the therapy pressure determined by the pressure sensor 110 is within about 10% of the target pressure, the controller 108 can identify that the blockage is cleared. If the blockage has cleared, the process continues on the YES path to block 1205, where the therapy system determines an operating mode of the therapy system, and the process ends. At block 1203, if the blockage has not cleared, the process continues on the NO path to block 1204, where the therapy system provides an alarm, and the process ends. For example, the controller 108 can provide an alarm on a user interface of the therapy system 100.

[0093] Figure 13 is a flow chart 1300 illustrating exemplary operations that can be associated with some embodiments of an offset operating mode of the flow chart 700 of Figure 7. For example, the flow chart 1300 can illustrate exemplary operations of a peristaltic offset routine or peristaltic offset mode that can be performed by the therapy system 100. At block 1301, the therapy system can fluidly couple a first pump head and a second pump head in serial configuration. For example, the fluid outlet 240 of the first pump head 302 can be fluidly coupled to the fluid inlet 242 of the second pump head 304 by actuating the first valve 218 to fluidly couple the fluid inlet 222 to the second fluid outlet 226 and actuating the second valve 220 to fluidly couple the first fluid inlet 230 to the fluid outlet 228. At block 1302, the first pump head and the second pump head can be operated. For example, the controller 108 can actuate the negative-pressure source 102 to operate the first pump head 302 and the second pump head 304, drawing fluid from the vacuum port 204 through the first pump head 302, the first valve 218, the second valve 220, and the second pump head 304 through the exhaust 206.

[0094] At block 1303, the therapy system determines if the peristaltic offset should be maintained. For example, the controller 108 can determine if the therapy system 100 should maintain the peristaltic offset. In some embodiments, if the therapy pressure is within about 25% of the target pressure and a leak rate of the therapy system 100 is about 25% of a leak rate at which the system alarms, the therapy system can maintain the peristaltic offset. If the peristaltic offset should be maintained, the process continues on the YES path to block 1302, where the process can continue to operate the first pump head 302 and the second pump head 304. At block 1303, if the peristaltic offset should not be maintained, the process continues on the NO path to block 1304, where the therapy system determines an operating mode of the therapy system, and the process ends.

[0095] The therapy systems, apparatuses, and methods described herein may provide significant advantages. For example, the therapy system 100 can provide a single pump therapy system that is silent and can provide both a relatively high net flow rate and a relatively high pressure. The therapy system 100 can also have a life span of just less than about one year at 100% duty. Ifthe therapy system 100 is operated at about 70% duty, the therapy system 100 can have a life span of greater than a year. The therapy system 100 may also provide an easily replaceable pump module to allow the therapy system 100 to be easily and cheaply refurbished. The therapy system 100 provides the benefits of both serial and parallel configurations by selectively actuating a valve assembly to fluidly couple a first pump head and a second pump in a series configuration or a parallel configuration based on the prevailing conditions of the negative-pressure therapy. The therapy system 100 can provide efficiency gains by having two pump chambers formed and driven around a single piezoelectric actuator. The therapy system 100 can also be about twice as pneumatically efficient compared to a standard piezoelectric pump, and the ability to switch between serial and parallel configurations can leverage the efficiency further by allowing a customizable drive level and life. For example, the therapy system can adjust the power level for the therapy system from 0.6W when at nominal low leak settings to a peak of 1.4W for short periods of extreme pressure or flow need. [0096] While shown in a few illustrative embodiments, a person having ordinary skill in the art will recognize that the therapy systems, apparatuses, and methods described herein are susceptible to various changes and modifications that fall within the scope of the appended claims. Moreover, descriptions of various alternatives using terms such as “or” do not require mutual exclusivity unless clearly required by the context, and the indefinite articles "a" or "an" do not limit the subject to a single instance unless clearly required by the context. Components may be also be combined or eliminated in various configurations for purposes of sale, manufacture, assembly, or use. For example, in some configurations the dressing 110, the container 106, or both may be eliminated or separated from other components for manufacture or sale. In other example configurations, the controller 108 may also be manufactured, configured, assembled, or sold independently of other components.

[0097] The appended claims set forth novel and inventive aspects of the subject matter described above, but the claims may also encompass additional subject matter not specifically recited in detail. For example, certain features, elements, or aspects may be omitted from the claims if not necessary to distinguish the novel and inventive features from what is already known to a person having ordinary skill in the art. Features, elements, and aspects described in the context of some embodiments may also be omitted, combined, or replaced by alternative features serving the same, equivalent, or similar purpose without departing from the scope of the invention defined by the appended claims.