Self-test for negative pressure wound therapy devices

Abstract

A negative pressure wound treatment apparatus can include a negative pressure source configured to be connected to a wound by a fluid flow path, a valve in the fluid flow path and configured to allow supply of negative pressure from the negative pressure source upstream of the valve in an open state and to block supply of negative pressure from the negative pressure source upstream of the valve in a closed state, a flow restrictor in the fluid flow path, and a pressure sensor configured to measure a pressure differential across the flow restrictor. The apparatus can include a control circuit configured to cause the valve to be in the open state in a normal operating mode and to perform at least one of a leak test, a flow test, or an overpressure test in a test mode.

Description

TECHNICAL FIELD

[0001] Embodiments described herein relate to apparatuses, systems, and methods for treating a wound, for example, using a dressing in combination with negative pressure wound therapy. BACKGROUND

[0002] Many different types of wound dressings are known for aiding the healing process of a human or animal. These different types of wound dressings include many different types of materials and layers, such as gauze, pads, foam pads, or multi-layer wound dressings. Topical negative pressure (TNP) therapy, also sometimes referred to as vacuum assisted closure, negative pressure wound therapy, or reduced pressure wound therapy, is widely recognized as a beneficial mechanism for improving the healing rate of a wound. Such treatment is applicable to a wide range of wounds, such as incisional, open, and abdominal wounds, among others. TNP therapy aids in the closure and healing of a wound by reducing tissue edema, promoting blood flow, stimulating the formation of granulation tissue, removing excess exudate, and can reduce bacterial load. As a result, wound infection is reduced. Moreover, TNP treatment allows the wound to be subjected to less external disturbance and promotes more rapid healing. SUMMARY

[0003] A negative pressure wound treatment apparatus can include a negative pressure source configured to be connected by a fluid flow path to a wound covered by a wound dressing and to provide negative pressure to the wound. The apparatus can include a valve in the fluid flow path. The valve can be structured to allow supply of negative pressure from the negative pressure source upstream of the valve in an open state. The valve can be structured to block supply of negative pressure from the negative pressure source upstream of the valve in a closed state. The apparatus can include a flow restrictor in the fluid flow path, which can be downstream of the valve. The apparatus can include a pressure sensor configured to measure pressure in the fluid flow path and a pressure differential across the flow restrictor. The apparatus can include a control circuit configured to cause the valve to be in the open state in a normal operating mode in which negative pressure is provided to the wound. The control circuit can be configured to perform at least one of a leak test, a flow test, or an overpressure test in a test mode in which performance of the apparatus is verified. The leak test can include the control circuit being configured to cause the valve to close, cause the negative pressure source to operate at a first intensity level, cause the negative pressure source to pause operation for a duration, and in response to determining that a change in negative pressure measured by the pressure sensor after expiration of the duration satisfies a threshold indicative of a leak, indicate that a leak is present in the fluid flow path. The flow test can include the control circuit being configured to cause the valve to open, cause the negative pressure source to operate at a second intensity level, and in response to determining that a pressure differential across the flow restrictor measured by the pressure sensor satisfies a pressure differential threshold indicative of insufficient flow, indicate insufficient flow. The overpressure test can include the control circuit being configured to cause the valve to close, cause the negative pressure source to operate at a third intensity level, and in response to determining that pressure in the fluid flow path satisfies a threshold indicative of unsafe negative pressure and a system configured to prevent unsafe negative pressure has not been activated, indicate a fault in the system configured to prevent unsafe negative pressure in the fluid flow path.

[0004] The negative pressure wound therapy apparatus of any of the preceding paragraphs and / or any of the apparatuses, devices, or systems disclosed herein can include one or more of the following features. The second intensity level can be greater than the first intensity level. The first intensity level can be equal to the third intensity level. The valve can be a solenoid valve. The pressure sensor can include a first pressure sensor located upstream of the flow restrictor and a second pressure sensor located downstream of the flow restrictor. The apparatus can include a canister configured to be located in the fluid flow path and to collect fluid aspirated from the wound. The control circuit can be configured to verify, in the test mode, that the canister has been removed from the fluid flow path. The control circuit can be configured to, in the test mode, in response to determining that the canister has not been removed and that the wound dressing has not been disconnected, not perform the leak test, the flow test, and the overpressure test. The control can be configured to, in the test mode, provide an indication that at least one of the canister has not been removed or the wound dressing has not been disconnected.

[0005] The negative pressure wound therapy apparatus of any of the preceding paragraphs and / or any of the apparatuses, devices, or systems disclosed herein can include one or more of the following features. The system configured to prevent unsafe negative pressure in the fluid flow path can include at least one of: another valve located in the fluid flow path, the control circuit configured to cause the another valve to open in response to pressure in the fluid flow path satisfying a threshold indicative of unsafe negative pressure; or the control circuit configured to deactivate the negative pressure source in response to pressure in the fluid flow path satisfying a threshold indicative of unsafe negative pressure. The overpressure test can include the control circuit configured to indicate a fault in the system configured to prevent unsafe negative pressure in the fluid flow path in response to determining that the system configured to prevent unsafe negative pressure has been activated when pressure in the fluid flow path does not satisfy a threshold indicative of unsafe negative pressure. The apparatus can include a check valve located in the fluid flow path. The check valve can be configured to allow fluid to flow downstream toward the negative pressure source or an air vent and to prevent fluid from flowing in the opposite direction.

[0006] The negative pressure wound treatment apparatus of any of the preceding paragraphs and / or any of the apparatuses, devices, or systems disclosed herein can include one or more of the following features. The control circuit can be configured to perform a health test in the test mode, the health test comprising determining an efficiency of the negative pressure source and indicating a sufficient health condition in response to determining that the efficiency satisfies an efficiency threshold. The control circuit can be configured to determine the efficiency of the negative pressure source by determining a ratio of an amount of power output by the negative pressure source to an amount of power provided to the negative pressure source. The control circuit can be configured to determine the amount of power output by the negative pressure source based on determining a product of a mass flow rate and a specific work of the negative pressure source. The control circuit can be configured to determine at least one of the mass flow rate or the specific work based on determining a differential pressure across the flow restrictor. The control circuit can be configured to determine the mass flow rate based on determining a volumetric flow rate. The control circuit can be configured to perform the health test after successfully completing the flow test. The valve can function as the flow restrictor.

[0007] A negative pressure wound treatment apparatus can include a negative pressure source configured to be connected to a wound covered by a wound dressing by a fluid flow path and to provide negative pressure to the wound. The apparatus can include a valve located in the fluid flow path. The valve can be structured to allow supply of negative pressure from the negative pressure source upstream of the valve in an open state. The valve can be structured to block supply of negative pressure from the negative pressure source upstream of the valve in a closed state. The apparatus can include a flow restrictor located in the fluid flow path. The apparatus can include a pressure sensor configured to measure pressure in the fluid flow path. The apparatus can include a control circuit configured to cause the valve to be in the open state in a normal operating mode in which negative pressure is provided to the wound. The control circuit can be configured to perform at least one of a leak test or a flow test in a test mode in which performance of the apparatus is verified. The leak test can include the control circuit being configured to cause the valve to close, cause the negative pressure source to operate at a first intensity level, cause the negative pressure source to pause operation for a duration, and in response to determining that a change in negative pressure measured by the pressure sensor after expiration of the duration satisfies a threshold indicative of a leak, indicate that a leak is present in the fluid flow path. The flow test can include the control circuit being configured to cause the valve to open, cause the negative pressure source to operate at a second intensity level, and in response to determining that a differential pressure across the flow restrictor measured by the pressure sensor satisfies a differential pressure threshold indicative of an insufficient flow, indicate that the flow is insufficient.

[0008] The negative pressure wound therapy apparatus of any of the preceding paragraphs and / or any of the apparatuses, devices, or systems disclosed herein can include one or more of the following features. The control circuit can be configured to perform, in the test mode, at least one of the leak test, the flow rate test, or an overpressure test. The overpressure test can include the control circuit being configured to cause the valve to close, cause the negative pressure source to operate at a third intensity level, and in response to determining that a pressure in the fluid flow path satisfies a threshold indicative of unsafe negative pressure and an overpressure protection has not been activated, indicate a fault in the overpressure protection. The overpressure protection can include at least one of: another valve located in the fluid flow path, the control circuit being configured to cause the another valve to open (or vent overpressure to ambient) in response to the pressure in the fluid flow path satisfying the threshold indicative of unsafe negative pressure; or the control circuit being configured to deactivate the negative pressure source in response to the pressure in the fluid flow path satisfying the threshold indicative of unsafe negative pressure. The overpressure test can include the control circuit being configured to indicate a fault in the overpressure protection in response to determining that the overpressure protection has been activated when the pressure in the fluid flow path does not satisfy the threshold indicative of unsafe negative pressure.

[0009] The negative pressure wound therapy apparatus of any of the preceding paragraphs and / or any of the apparatuses, devices, or systems disclosed herein can include one or more of the following features. The second intensity level can be greater than the first intensity level. The valve can be a solenoid valve. The pressure sensor can include a first pressure sensor located upstream of the flow restrictor and a second pressure sensor located downstream of the flow restrictor. The apparatus can include a canister configured to be located in the fluid flow path and to collect fluid aspirated from the wound. The control circuit can be configured to verify, in the test mode, that the canister has been removed from the fluid flow path. The control circuit can be configured to not perform the leak test and the flow rate test in the test mode in response to determining that the canister has not been removed and that the wound dressing has not been disconnected. The control circuit can be configured to provide, in the test mode, an indication of at least one of that the canister has not been removed or that the wound dressing has not been disconnected. The apparatus can include a check valve located in the fluid flow path. The check valve can be configured to allow fluid to flow downstream toward the negative pressure source or an exhaust and to prevent fluid from flowing in the opposite direction.

[0010] The negative pressure wound therapy apparatus of any of the preceding paragraphs and / or any of the apparatuses, devices, or systems disclosed herein can include one or more of the following features. The control circuit can be configured to perform a health test in the test mode, the health test comprising determining an efficiency of the negative pressure source and indicating a sufficient health condition in response to determining that the efficiency satisfies an efficiency threshold. The control circuit can be configured to determine the efficiency of the negative pressure source by determining a ratio of an amount of power output by the negative pressure source to an amount of power provided to the negative pressure source. The control circuit can be configured to determine the amount of power output by the negative pressure source based on determining a product of a mass flow rate and a specific work of the negative pressure source. The control circuit can be configured to determine at least one of the mass flow rate or the specific work based on determining a differential pressure across the flow restrictor. The control circuit can be configured to determine the mass flow rate based on determining a volumetric flow rate. The control circuit can be configured to perform the health test after successfully completing the flow test. The valve can function as the flow restrictor.

[0011] Disclosed herein are methods of operating the negative pressure wound therapy apparatus of any of the preceding paragraphs and / or any of the apparatuses, devices, or systems disclosed herein. Kits comprising the negative pressure wound therapy apparatus of any of the preceding paragraphs and / or any of the apparatuses, devices, or systems disclosed herein and one or more wound dressings or canisters are disclosed.

[0012] Any feature, component, or detail of any arrangement or embodiment disclosed in the present application, including but not limited to any of the device embodiments and any of the negative pressure wound therapy embodiments disclosed herein, can be combinable with any other feature, component, or detail of any arrangement or embodiment disclosed herein to form new arrangements and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1A A negative pressure wound therapy system is shown.

[0014] Figure 1B Another negative pressure wound therapy system is shown.

[0015] Figure 2A Is an isometric view of a negative pressure wound therapy apparatus and canister, showing the canister detached from a pump assembly of the apparatus.

[0016] Figure 2B Is Figure 2A A rear view of the negative pressure wound therapy apparatus shown in

[0017] Figure 2C Shows Figure 2A A top surface of the negative pressure wound therapy apparatus shown in

[0018] Figure 3 A schematic of a control system of a negative pressure wound treatment apparatus is shown.

[0019] Figure 4 Another negative pressure wound treatment system is shown.

[0020] Figure 5 A negative pressure wound treatment apparatus configured to perform a self-test is shown.

[0021] Figures 6 to 9 A flowchart of tests that can be performed by a negative pressure wound treatment apparatus of Figure 5 is shown.

[0022] Figure 10 A manifold that can be utilized by a negative pressure wound treatment apparatus of Figure 5 is shown.

[0023] Figure 11 A graph of several tests performed by a negative pressure wound treatment apparatus of Figure 5 is shown. DETAILED DESCRIPTION

[0024] Embodiments disclosed herein relate to systems and methods for treating and / or monitoring a wound. Some embodiments of the negative pressure wound treatment apparatuses disclosed herein can include a negative pressure source configured to be connected and / or fluidically coupled to a wound covered by a wound dressing via a fluid flow path and to provide negative pressure to the wound.

[0025] Throughout this specification the term wound is mentioned. The term wound should be interpreted broadly and encompasses open and closed wounds where the skin has been torn, cut or punctured, or where trauma has caused a bruise or any other surface or other condition or defect on the skin of a patient, or other wounds that benefit from pressure treatment. Thus, a wound is broadly defined as any area of damaged tissue that can or can not produce fluid. Examples of such wounds include, but are not limited to, abdominal or other large or incised wounds, either resulting from surgery, trauma, sterniotomies, fasciotomies, or resulting from other conditions, dehisced wounds, acute wounds, chronic wounds, subacute and dehisced wounds, traumatic wounds, flaps and skin grafts, lacerations, abrasions, contusions, burns, diabetic ulcers, pressure ulcers, stoma, surgical wounds, traumatic ulcers, venous ulcers, and the like.

[0026] Embodiments of the systems and methods disclosed herein can be used with topical negative pressure ("TNP") or reduced pressure wound treatment systems. Briefly, reduced pressure wound treatment helps to close and heal many forms of "hard-to-heal" wounds by reducing tissue edema, promoting blood flow and granulation tissue formation, or removing excess exudate, and can reduce bacterial load (and thus the risk of infection). Additionally, this treatment allows for reduced disturbance of the wound, leading to faster healing. TNP treatment systems can also assist in healing surgically closed wounds by removing fluid. TNP treatment can help stabilize tissue at apposed closure sites. Another beneficial use of TNP treatment can be found in grafts and flaps, in which case it is important to remove excess fluid and to bring the graft into close approximation with the tissue to ensure tissue viability.

[0027] As used herein, a reduced pressure level or negative pressure level (e.g., -X mmHg) refers to a pressure level relative to normal ambient atmospheric pressure, which can correspond to 760 mmHg (or 1 atm, 29.93 inHg, 101.325 kPa, 14.696 psi, etc.). Thus, a negative pressure value of -X mmHg reflects a pressure that is X mmHg lower than 760 mmHg, or in other words, a pressure of (760 - X) mmHg. Further, a negative pressure that is "less" or "smaller" than X mmHg corresponds to a pressure that is closer to atmospheric pressure (e.g., -40 mmHg is smaller than -60 mmHg). A negative pressure that is "more" or "larger" than -X mmHg corresponds to a pressure that is further from atmospheric pressure (e.g., -80 mmHg is larger than -60 mmHg). In some cases, a local ambient atmospheric pressure is used as a reference point, which can not necessarily be, for example, 760 mmHg.

[0028] In addition to or instead of reduced pressure therapy, the systems and methods disclosed herein can be used with other types of therapy, e.g., irrigation, ultrasound, heating or cooling, nerve stimulation, etc. In some cases, the disclosed systems and methods can be used for wound monitoring without the application of additional therapy. The systems and methods disclosed herein can be used in conjunction with dressings including compression dressings, reduced pressure dressings, etc.

[0029] A healthcare provider, e.g., a clinician, a nurse, etc., can provide a TNP prescription that specifies, for example, a pressure level or an application time. However, the healing process is different for each patient, and this prescription can affect the healing process in ways that the clinician or healthcare provider did not intend when designing the prescription. The healthcare provider can attempt to adjust the prescription as the wound heals (or does not heal), but such a process can require various appointments that can be time-consuming and repetitive. Embodiments disclosed herein provide systems, devices, or methods that efficiently adjust TNP prescriptions and deliver effective TNP therapy.

[0030] Wound treatment system

[0031] Figure 1A A negative pressure wound treatment system 100 (sometimes referred to as a reduced pressure or negative pressure wound treatment system, TNP system, or wound treatment system) is schematically shown. In any of the embodiments disclosed herein, although not required, the negative pressure wound treatment system 100 can include a wound filler 102 placed on or in a wound 104 (which can be a cavity). The wound 104 can be sealed by a wound cover 106 (which can be a drape) such that the wound cover 106 can be in fluid communication with the wound 104. The wound filler 102 in combination with the wound cover 106 can be referred to as a wound dressing. A tube or conduit 108 (also referred to herein as a flexible suction adapter or fluid connector) can be used to connect the wound cover 106 with a wound treatment device 110 (sometimes referred to as a "pump assembly" in whole or in part) that is configured to supply reduced pressure or negative pressure. The conduit 108 can be a single lumen tube or a multi-lumen tube. A connector 112 can be used to removably and selectively couple the conduit or tube 142 with the conduit 108.

[0032] In any of the systems disclosed herein, the wound treatment device can be canisterless, where, for example and without limitation, wound exudate is collected in the wound dressing or diverted via a conduit for collection at another location. However, any of the wound treatment devices disclosed herein can include or support a canister.

[0033] Additionally, for any of the wound treatment systems disclosed herein, any of the wound treatment devices can be mounted to or supported by or adjacent to a wound dressing. The wound filler 102 can be of any suitable type, such as a hydrophilic or hydrophobic foam, gauze, an inflatable bag, or the like. The wound filler 102 can conform to the wound 104 such that the wound filler 102 substantially fills the cavity of the wound 104. The wound cover 106 can provide a fluid substantially impermeable seal over the wound 104. The wound cover 106 can have a top side and a bottom side. The bottom side can be sealed (or in any other suitable manner) to the wound 104, such as by sealing to the skin surrounding the wound 104. The conduit 108 or any of the other conduits disclosed herein can be formed of polyurethane, PVC, nylon, polyethylene, silicone, or any other suitable material.

[0034] The wound cover 106 can have a port (not shown) configured to receive an end of the conduit 108. In some cases, the conduit 108 can otherwise pass through or beneath the wound cover 106 to supply reduced pressure to the wound 104 in order to maintain a desired reduced pressure level in the wound 104. The conduit 108 can be any suitable article configured to provide at least a substantially sealed fluid flow path or passageway between the wound therapy device 110 and the wound cover 106 in order to supply reduced pressure provided by the wound therapy device 110 to the wound 104.

[0035] The wound cover 106 and the wound filler 102 can be provided in a single article or in the form of an integrated single unit. In some cases, no wound filler is provided and the wound cover itself can be considered a wound dressing. The wound dressing can then be connected to a source of negative pressure of the wound therapy device 110 via the conduit 108. In some cases, although not required, the wound therapy device 110 can be miniaturized and portable, although larger conventional sources of negative pressure (or pumps) can also be used.

[0036] The wound cover 106 can be positioned over a wound site to be treated. The wound cover 106 can form a substantially sealed cavity or enclosure over the wound site. The wound cover 106 can have a film with high water vapor permeability to enable excess fluid to evaporate and can have a superabsorbent material contained therein to safely absorb wound exudate. In some cases, the components of the TNP system described herein can be particularly suitable for incisions that exude small amounts of wound exudate.

[0037] The wound therapy device 110 can operate with or without the use of an exudate canister. In some cases, as shown, the wound therapy device 110 can include an exudate canister. In some cases, the wound therapy device 110 and the conduit 108 are configured such that the conduit 108 can be quickly and easily removed from the wound therapy device 110 can facilitate or improve the process of wound dressing or pump replacement if needed. Any of the pump assemblies disclosed herein can have any suitable connection between the conduit 108 and the pump.

[0038] The wound treatment device 110 can deliver a negative pressure of about -80 mmHg, or between about -20 mmHg and -200 mmHg. It should be noted that these pressures are relative to normal ambient atmospheric pressure, and thus, -200 mmHg would actually be about 560 mmHg. In some cases, the pressure range can be between about -40 mmHg and -150 mmHg. Alternatively, a pressure range of up to -75 mmHg, up to -80 mmHg, or more than -80 mmHg can be used. Additionally, in some cases, a pressure range of less than -75 mmHg can be used. Alternatively, the wound treatment device 110 can supply a pressure range of more than about -100 mmHg, or even -150 mmHg.

[0039] As will be described in greater detail below, the negative pressure wound treatment system 100 can be configured to provide a connection 332 with a separate or remote computing device 334. The connection 332 can be wired or wireless (e.g., Bluetooth, NFC, WiFi, or cellular). The remote computing device 334 can be a smartphone, tablet, laptop, or another standalone computer, a server (e.g., a cloud server), another pump device, etc.

[0040] Figure 1B Another negative pressure wound treatment system 100’ is shown. The negative pressure wound treatment system 100’ can have any of the components, features, or other details of any other negative pressure wound treatment system disclosed herein, including but not limited to Figure 1A the negative pressure wound treatment system 100 shown in Figure 4 the negative pressure wound treatment system 400 shown in Figure 1B the negative pressure wound treatment system 100’ shown in and / or any of the components, features, or other details of the negative pressure wound treatment system 100’ described herein. The negative pressure wound treatment system 100’ can have a wound cover 106 over a wound 104, which can seal the wound 104. A conduit 108’ such as a single lumen or multi-lumen tube can be used to connect the wound cover 106 with a wound treatment device 110’ (sometimes referred to as a “pump assembly” as a whole or in part) that is configured to supply reduced or negative pressure. The wound cover 106 can be in fluid communication with the wound 104.

[0041] Referring to Figure 1B , the conduit 108’ can have a bridge portion 130 and an applicator 132 at a distal end of the bridge portion 130, forming a flexible suction adapter (or conduit) 108’ that can have a proximal portion and a distal portion (the distal portion closer to the wound 104 than the proximal portion). A connector 134 can be provided at a proximal end of the bridge portion 130 for connection to at least one of the channels, which can run along Figure 1BThe length of the bridge portion 130 of the conduit 108 shown in the middle extends. The cap 140 can be coupled with a portion of the conduit 108, and in some cases, as shown, can be attached to the connector 134. The cap 140 can be used to prevent leakage of fluid from the proximal end of the bridge portion 130. The conduit 108' can be a soft port manufactured by Smith & Nephew. As mentioned, the negative pressure wound treatment system 100' can include a source of negative pressure, such as the device 110', capable of supplying negative pressure to the wound 104 through the conduit 108'. Although not required, the device 110' can also include a canister or other container for storing wound exudate and other fluids that can be removed from the wound.

[0042] The device 110' can be connected to the connector 134 via a conduit or tube 142. In use, the applicator 132 can be placed over an orifice formed in the cover 106, which is placed over a properly prepared wound or wound 104. Subsequently, with the wound treatment device 110' connected to the connector 134 via the tube 142, the wound treatment device 110' can be activated to supply negative pressure to the wound. The application of negative pressure can be applied until a desired level of healing of the wound is achieved.

[0043] The bridge portion 130 can include an upper channel material or layer between the upper layer and the middle layer, with a lower channel material or layer between the middle layer and the bottom layer. Preferably, the upper layer, the middle layer, and the lower layer can have an elongate portion extending between a proximal end and a distal end, and can comprise a material that is impermeable to fluid, such as a polymer such as polyurethane. Of course, it should be recognized that the upper layer, the middle layer, and the lower layer can each be comprised of different materials including semi-permeable materials. In some cases, one or more of the upper layer, the middle layer, and the lower layer can be at least partially transparent. In some cases, the upper layer and the lower layer can be curved, rounded, or outwardly convex over a majority of their length.

[0044] The upper and lower channel layers can be elongated layers that extend from the proximal end to the distal end of the bridge 130, and can each preferably comprise a porous material, including for example an open cell foam, such as polyethylene or polyurethane. In some cases, one or more of the upper and lower channel layers can be constructed of a fabric (e.g., a knitted or woven spacer fabric (such as a knitted polyester 3D fabric, Baltex 7970.RTM., or Gehring 879.RTM.)) or a nonwoven material or a terry-knit or terry pile material. The fibers can not necessarily be woven, and can include felted and flocked (including materials such as Flotex.RTM.) fiber materials. The selected materials are preferably adapted to channel wound exudate away from the wound, and for transmitting negative pressure or exhaust air to the wound site, and can also impart a degree of kink or occlusion resistance to the channel layers. In one example, the upper channel layer can comprise an open cell foam, such as polyurethane, and the lower channel layer can comprise a fabric. In another example, the upper channel layer is optional, and the system can instead be provided with an open upper channel. The upper channel layer can have a curved, rounded, or upwardly convex upper surface and a substantially flat lower surface, and the lower channel layer can have a curved, rounded, or downwardly convex lower surface and a substantially flat upper surface.

[0045] The fabric or material of any of the components of the bridge 130 can have a three-dimensional (3D) structure, in which one or more types of fibers form a structure in which the fibers extend in all three dimensions. In some cases, such a fabric can assist in wicking, transmitting fluid, or transmitting negative pressure. In some cases, the fabric or material of the channel can include several layers of material that are stacked or laminated on one another, which can in some cases be used to prevent the channel from collapsing under the application of negative pressure. The materials used in some embodiments of the conduit 108' can be conformable and pliable, which in some cases can help to avoid pressure ulcers and other complications that can be caused by a wound therapy system being pressed against a patient's skin.

[0046] The distal ends of the upper, middle, and lower layers, as well as the channel layers, can be enlarged at their distal ends (to be placed over the wound site), and can form a "teardrop" or other enlarged shape. At least the distal ends of the upper, middle, and lower layers, as well as the channel layers, can also be provided with at least one through-going aperture. Such apertures can be used not only to exhaust wound exudate and apply negative pressure to the wound, but also during the manufacture of the device, as these apertures can be used to properly align these respective layers.

[0047] In some embodiments, a controlled gas leak 146 (sometimes referred to as a gas leak, air leak, or controlled air leak) can be provided on the bridge portion 130, for example at its proximal end. This air leak 146 can include an opening or passage extending through the upper layer of the bridge portion 130, such that the air leak 146 is in fluid communication with the upper channel of the bridge portion 130. Upon application of suction to the conduit 108, gas (e.g., air) can enter through the air leak 146 and move along the upper channel of the bridge portion 130 from the proximal end of the bridge portion to the distal end of the bridge portion. The gas can then be suctioned into the lower channel of the bridge portion 130 by passing through the aperture through the distal end of the upper, middle, and lower layers.

[0048] The air leak 146 can include a filter. Preferably, the air leak 146 is located at the proximal end of the bridge portion 130 in order to minimize the likelihood that wound exudate or other fluids will contact and possibly clog or interfere with the air leak 146 or the filter. In some cases, the filter can be a microporous membrane capable of excluding microorganisms and bacteria, and can be capable of filtering out particles larger than 45 microns. Preferably, the filter can exclude particles larger than 1.0 micron, and more preferably, particles larger than 0.2 microns. Advantageously, some embodiments can provide a filter that is at least partially chemically resistant to common household liquids such as water, shampoos, and other surfactants. In some cases, reapplying a vacuum to the suction adapter or wiping the exposed outer portion of the filter can be sufficient to clear any foreign matter clogging the filter. The filter can be composed of a polymer of suitable resistance such as acrylic, polyether sulfone, or polytetrafluoroethylene, and can be oleophobic or hydrophobic. In some cases, the gas leak 146 can supply a relatively constant flow of gas that does not significantly increase with the application of additional negative pressure to the conduit 108'. In examples of the negative pressure wound therapy system 100, the flow of gas through the gas leak 146 increases with the application of additional negative pressure, preferably this increased flow of gas will be minimized and will not increase in proportion to the negative pressure applied thereto. Further descriptions of such bridges, conduits, air leaks, and other components, features, and details that can be used with any embodiment of the negative pressure wound therapy system disclosed herein can be found in U.S. Patent No. 8,801,685, which is incorporated by reference herein in its entirety as if fully set forth herein.

[0049] Any of the wound treatment apparatuses disclosed herein (e.g., apparatus 110 or 110’) can provide continuous or intermittent negative pressure therapy. Continuous therapy can be delivered at a higher than 0 mmHg, -25 mmHg, -40 mmHg, -50 mmHg, -60 mmHg, -70 mmHg, -80 mmHg, -90 mmHg, -100 mmHg, -120 mmHg, -140 mmHg, -160 mmHg, -180 mmHg, -200 mmHg, or lower than -200 mmHg. Intermittent therapy can be delivered between a low negative pressure and a high negative pressure setpoint (sometimes referred to as a setpoint). The low setpoint can be set to be higher than 0 mmHg, -25 mmHg, -40 mmHg, -50 mmHg, -60 mmHg, -70 mmHg, -80 mmHg, -90 mmHg, -100 mmHg, -120 mmHg, -140 mmHg, -160 mmHg, -180 mmHg, or lower than -180 mmHg. The high setpoint can be set to be higher than -25 mmHg, -40 mmHg, -50 mmHg, -60 mmHg, -70 mmHg, -80 mmHg, -90 mmHg, -100 mmHg, -120 mmHg, -125 mmHg, -140 mmHg, -160 mmHg, -180 mmHg, -200 mmHg, or lower than -200 mmHg. During intermittent therapy, negative pressure at the low setpoint can be delivered for a first duration, and upon expiration of the first duration, negative pressure at the high setpoint can be delivered for a second duration. Upon expiration of the second duration, negative pressure at the low setpoint can be delivered. The first duration and the second duration can be the same or different values.

[0050] In operation, the wound filler 102 can be inserted into the cavity of the wound 104, and the wound cover 106 can be placed so as to seal the wound 104. The wound treatment apparatus 110’ can provide negative pressure to the wound cover 106, which can be transmitted to the wound 104 via the wound filler 102. Fluid (e.g., wound exudate) can be suctioned by the conduit 108’ and stored in the canister. In some cases, the fluid is absorbed by the wound filler 102 or one or more absorbent layers (not shown).

[0051] Wound dressings that can be used with the pump assemblies and systems of the present application include Renasys-F, Renasys-G, Renasys AB, and Pico Dressings available from Smith & Nephew. Additional descriptions of such wound dressings and other components of negative pressure wound therapy systems that can be used with the pump assemblies and systems of the present application can be found in U.S. Patent Publication Nos. 2012 / 0116334, 2011 / 0213287, 2011 / 0282309, 2012 / 0136325, U.S. Patent No. 9,084,845, and International Application No. PCT / EP2020 / 078376, each of which is incorporated by reference herein in its entirety as if fully set forth herein. In some cases, other suitable wound dressings can be used.

[0052] Figures 2A-2C A negative pressure wound therapy device 110’ is shown. As shown, a pump assembly 160 and a canister 162 can be connected, thereby forming the wound therapy device 110’. Referring to Figure 2C The pump assembly 160 can include an interface panel 170 having a display 172, one or more indicators 174, or one or more controls or buttons, including, for example and without limitation, a therapy start and pause button 180 or an alarm / alert mute button 182. The interface panel 170 can have one or more input controls or buttons 184 (three are shown) that can be used to control any function of the pump assembly 160 or the interface panel 170. For example and without limitation, one or more of the buttons 184 can be used to turn the pump assembly 160 on or off, start or pause therapy, operate and monitor the operation of the pump assembly 160, scroll through menus displayed on the display 172, or control or perform other functions. In certain cases, the command buttons 184 can be programmable and can be made of a soft-touch rubber.

[0053] Additionally, the interface panel 170 can have a visual indicator 186 that can indicate which of the one or more buttons 184 is active. The interface panel 170 can also have a lock / unlock control or button 188 that can be configured to selectively lock or unlock the functionality of various buttons (e.g., the buttons 184) or the display 172. When the lock / unlock button 188 is in the locked state, pressing one or more of the various other buttons or the display does not cause the pump assembly 160 to change any display or performance function of the device. In this way, the interface panel 170 will be protected from inadvertent bumping or touching of the various buttons or display. The interface panel 170 can be located on an upper portion of the pump assembly 160, such as, but not limited to, on a surface of the pump assembly 160 that faces upward.

[0054] A display 172, which may be a screen (e.g., an LED screen), may be mounted in the middle portion of the interface panel 170. The display 172 may be a touchscreen display. The display 172 may support playback of audiovisual (AV) content (e.g., instructional videos) and present multiple screens or a graphical user interface (GUI) for configuring, controlling, and monitoring the operation of the pump assembly 160.

[0055] One or more indicators 174 may be lights (e.g., LEDs) and may be configured to provide visual indications of alarm conditions and / or pump status. For example, and without limitation, one or more indicators 174 may be configured to provide visual indications of the status of the pump assembly 160 or other components of the negative pressure wound therapy system 100' (including, but not limited to, catheter 108' or wound covering 106) (e.g., to provide indications of normal operation, low battery, leak, full tank, blockage, overpressure, etc.). Any one or more suitable indicators, such as visual, audio, tactile indicators, etc., may be used additionally or alternatively.

[0056] Figure 2B It shows Figure 2A The image shows a rear or rear view of the wound treatment device 110'. As shown, the pump assembly 160 may include a speaker 192 for generating sound. For example, but not limited to, the speaker 192 may generate an audible alarm in response to deviations in treatment delivery, non-compliance in treatment delivery, or any other similar or suitable conditions or combinations thereof. The speaker 192 may provide audio to accompany one or more instructional videos that may be displayed on the display 172.

[0057] Pump assembly 160 may be configured to provide easy access (e.g., an access door on the housing of the pump assembly) to one or more filters (e.g., antibacterial filters) of the pump assembly 160. This allows a user (e.g., a healthcare provider or patient) to more easily access, inspect, or replace such filters. Pump assembly 160 may also include a power socket 196 for supplying power to the pump assembly 160 or for charging and recharging an internal power source (e.g., a battery). Some embodiments of pump assembly 160 may include a disposable or renewable power source, such as one or more batteries, eliminating the need for a power socket. Pump assembly 160 may have a recess 198 formed therein to facilitate gripping of the pump assembly 160.

[0058] Canister 162 can hold fluid aspirated from wound 104. For example, canister 162 can have a capacity of 800 mL (or approximately 800 mL), or a capacity from 300 mL or less to 1000 mL or more, or any capacity level within that range. Canister 162 may include tubing for connection to conduit 108' to form a fluid flow path. Canister 162 can be replaced by another canister, e.g., when canister 162 is filled with fluid. ReferenceFigure 2A The wound treatment device 110’ can include a canister inlet tube 200 (also referred to herein as a dressing port connector) in fluid communication with the canister 162. For example, and without limitation, the canister inlet tube 200 can be used to connect with the conduit 108’.

[0059] The canister 162 can be selectively coupled and removable from the pump assembly 160. Referring to FIG. 10, the canister 162 can be selectively coupled to the pump assembly 160 by a canister release button 202. The canister release button 202 can be configured to selectively release the canister 162 from the pump assembly 160. Figure 2A In some cases, the canister release button 202 can be configured to selectively release the canister 162 from the pump assembly 160. Referring to FIG. 10, Figure 2B The canister 162 can have one or more fill lines or graduations 204 to indicate to a user the amount of fluid or exudate stored within the canister 162.

[0060] The wound treatment device 110’ can have a handle 208 that can be used to lift or carry the wound treatment device 110’. The handle 208 can be coupled with the pump assembly 160 and can be rotatable relative to the wound treatment device 110’ such that the handle can be rotated upward to lift or carry the wound treatment device 110’ or the pump assembly 160 or rotated into a lower profile in a more compact position when the handle is not in use. In some cases, the handle 208 can be coupled with the pump assembly 160 in a fixed position. The handle 208 can be coupled with an upper portion of the pump assembly 160 or can be removable from the wound treatment device 110’.

[0061] Figure 3 A schematic of a control system 300 is shown that can be used in any of the wound treatment devices described herein, such as in the wound treatment device 110’. The electrical components are operable to accept user input, provide output to a user, operate a pressure source, provide connectivity, and the like. A first processor (e.g., a main controller 310) can be responsible for user activity and a second processor (e.g., a pump controller 370) can be responsible for controlling another device, such as a pump 390.

[0062] Input / output (I / O) module 320 can be used to control input and / or output to another component or device, such as pump 390, one or more sensors (e.g., one or more pressure sensors 325 configured to monitor pressure in one or more locations of a fluid flow path), etc. For example, the I / O module can receive data from one or more sensors through one or more ports, such as serial (e.g., I2C), parallel, hybrid ports, etc. Any of the pressure sensors can be part of a wound therapy device or can. In some cases, any of the pressure sensors 325 can be remote from the wound therapy device, such as located at or near a wound (e.g., in a dressing or catheter that connects the dressing to the wound therapy device). In such embodiments, any of the remote pressure sensors can communicate with the I / O module through a wired connection or with one or more transceivers 340 through a wireless connection.

[0063] Main controller 310 can receive data from and provide data to one or more expansion modules 360, such as one or more USB ports, SD ports, compact disc (CD) drives, DVD drives, FireWire ports, Thunderbolt ports, PCI Express ports, etc. Main controller 310, along with other controllers or processors, can store data in memory 350 (e.g., one or more memory modules), which can be internal or external to main controller 310. Any suitable type of memory can be used, including volatile or non-volatile memory, such as RAM, ROM, magnetic memory, solid-state memory, magnetoresistive random access memory (MRAM), etc.

[0064] Main controller 310 can be a general purpose controller, such as a low-power processor or a special purpose processor. Main controller 310 can be configured as a "central" processor in the electronic architecture of system 300, and main controller 310 can coordinate activities of other processors, such as pump controller 370, communication controller 330, and one or more additional processors 380. Main controller 310 can run a suitable operating system, such as Linux, Windows CE, VxWorks, etc.

[0065] The pump controller 370 can control operation of a pump 390, which can generate negative pressure or reduced pressure. The pump 390 can be a suitable pump, such as a diaphragm pump, a peristaltic pump, a rotary pump, a rotary vane pump, a rolling pump, a screw pump, a liquid ring pump, a diaphragm pump operated by a piezoelectric transducer, a voice coil pump, or the like. The pump controller 370 can measure pressure in the fluid flow path using data received from one or more pressure sensors 325, calculate a rate of fluid flow, and control the pump. The pump controller 370 can control a pump actuator (e.g., a motor) such that a desired negative pressure level is achieved in the wound 104. The desired negative pressure level can be a pressure set or selected by a user. The pump controller 370 can use pulse width modulation (PWM) or pulsatile control to control the pump (e.g., a pump motor). The control signal to drive the pump can be a 0-100% duty cycle PWM signal. The pump controller 370 can perform flow calculations and detect alarms. The pump controller 370 can communicate information to the main controller 310. The pump controller 370 can be a low-power processor.

[0066] The communication controller 330 can provide connectivity (e.g., wired or wireless connectivity 332). The communication controller 330 can utilize one or more transceivers 340 to transmit and receive data. The one or more transceivers 340 can include one or more antennas, optical sensors, optical emitters, vibrating motors or transducers, vibration sensors, acoustic sensors, ultrasonic sensors, or the like. The communication controller 330 can provide one or more of the following types of connectivity: global positioning system (GPS), cellular connectivity (e.g., 2G, 3G, LTE, 4G, 5G, or the like), near-field communication (NFC), Bluetooth connectivity, radio-frequency identification (RFID), wireless local area network (WLAN), wireless personal area network (WPAN), WiFi connectivity, internet connectivity, optical connectivity (e.g., using infrared light, barcodes, QR codes, or the like), acoustic connectivity, ultrasonic connectivity, or the like. The connectivity can be used for various activities, such as pump assembly location tracking, asset tracking, compliance monitoring, remote selection, log uploading, alarm and other operational data, as well as adjustment of therapy settings, upgrades of software or firmware, pairing, or the like.

[0067] The communication controller 330 can provide dual GPS / cellular functionality. The cellular functionality can be, for example, 3G, 4G, or 5G functionality. The communication controller 330 can communicate information to the main controller 310. The communication controller 330 can include internal memory or can utilize memory 350. The communication controller 330 can be a low-power processor.

[0068] The control system 300 can store data, such as GPS data, therapy data, device data, and event data. Such data can be stored, for example, in the memory 350. Such data can include patient data collected by one or more sensors. The control system 300 can track and record therapy and other operational data. Such data can be stored, for example, in the memory 350.

[0069] Using the connection provided by the communication controller 330, the control system 300 can upload any data stored, maintained, or tracked by the control system 300 to a remote computing device, such as the device 334. The control system 300 can also download various operational data, such as therapy selections and parameters, firmware and software patches and upgrades, etc., (e.g., via the connection with the device 334). One or more additional processors 380 can be used, such as processors for controlling one or more user interfaces (e.g., one or more displays). In certain instances, depending on the embodiment of the wound monitoring or therapy system in which the control system 300 is used, any of the illustrated or described components of the control system 300 can be omitted.

[0070] Any of the negative pressure wound therapy devices described herein can include one or more features disclosed in U.S. Patent No. 9,737,649 or U.S. Patent Publication No. 2017 / 0216501, each of which is incorporated by reference in its entirety.

[0071] Multiple dressing negative pressure wound therapy

[0072] Figure 4 Another negative pressure wound therapy system 400 is shown. The system 400 can include a wound therapy device, such as the wound therapy device 110’, capable of supplying negative pressure to one or several wound sites. The wound therapy device 110’ can be in fluid communication with one or more wound dressings 406a, 406b (collectively, 406) in order to supply negative pressure to one or more wounds, such as the wounds 104a and 104b. A first fluid flow path can include components that provide fluid connection from the wound therapy device 110’ to the first wound dressing 406a. By way of non-limiting example, the first fluid flow path can include a path from the wound dressing 406a to the wound therapy device 110’ or a path from the first wound dressing 406a to an inlet 446 of a branch accessory (or connector) 444 that is in fluid connection with the wound therapy device 110’. Similarly, a second fluid flow path can include components that provide fluid connection from the wound therapy device 110’ to the second wound dressing 406b.

[0073] The system 400 can be similar to the system 100’, except that multiple wounds 104a and 140b are being treated by the system 400. The system 400 can include any one or more components of the system 100’, which are described above in connection with the system 100’, except that the system 400 is configured to treat multiple wounds 104a and 140b. Figure 4The first and second wounds are distinguished by the additional letters "a" or "b" (e.g., wounds 104a and 104b, coverings 106a and 106b). As shown, the system 400 can include multiple wound dressings 406a, 406b (and corresponding fluid flow paths) in fluid communication with the wound therapy device 110' via multiple suction adapters (e.g., adapters 108'). The suction adapters can include any one or more components of the adapters 108', which are described in more detail in Figure 4 The first and second wounds are distinguished by the additional letters "a" or "b" (e.g., bridge portions 130a and 130b, connectors 134a and 134b, and caps 140a and 140b).

[0074] The wound therapy device 110' can be fluidly coupled to the inlet 446 of the connector 444 via the tube 142. The connector 444 can be fluidly coupled to the connectors 134a, 134b via the branches 445a, 445b and tubes or conduits 442a, 442b, which can be fluidly coupled to the tubes or conduits 130a, 130b. The tubes or conduits 130a, 130b can be fluidly coupled to the dressings 406a, 406b. Once all of the conduit and dressing components are coupled and operably positioned, the wound therapy device 110' can be activated, thereby supplying negative pressure to the wounds 430a, 430b via the fluid flow paths. The application of negative pressure can be applied until a desired level of healing of the wounds 430 is achieved. Although Figure 4 Two wounds and wound dressings are shown, but some embodiments of the wound therapy device 110' can provide therapy to a single wound (e.g., by closing the unused branch 445a or 445b of the connector 444) or to more than two wounds (e.g., by adding branches to the connector 444).

[0075] The system 400 can include one or more features disclosed in U.S. Patent Publication No. 2020 / 0069850 or International Publication No. WO 2018 / 167199, each of which is incorporated by reference in its entirety.

[0076] Self-testing of a negative pressure device

[0077] In certain instances, it can be desirable to test a negative pressure wound therapy device (e.g., device 110) to ensure that it is able to safely and efficiently provide negative pressure wound therapy. Such testing can involve verifying one or more of the following: that the leak rate of the device is within acceptable limits, that the negative pressure source provides sufficient flow, that the overpressure safety system is operable, that the efficiency (or health) of the negative pressure wound therapy device, etc. The testing can additionally or alternatively involve one or more of the following: prompting the user to press one or more of the buttons (e.g., buttons 184) of the user interface to confirm normal operation, confirming that the display (e.g., display 172) is illuminated, confirming that one or more of the status indicators (e.g., status indicators 174) are illuminated, confirming that the speaker (e.g., speaker 192) is operable, etc. The testing can be performed periodically (e.g., once every half year), etc. when the device is used with a new patient. The testing parameters, such as timing and pressure settings, can vary to accommodate different self-test hardware designs. For example, the pressure can vary from about -40 mmHg to about -250 mmHg. Existing devices are typically sent to the device manufacturer or a third party for testing by the user (e.g., the patient or a healthcare provider (HCP), etc.). However, this approach is time consuming, expensive, and disruptive.

[0078] Figure 5 A negative pressure wound therapy device 500 configured to perform a self-test is shown. Device 500 can include one or more features of any of the devices described herein (e.g., device 110). Device 500 is capable of performing a self-test in the field without the need to send the device to the manufacturer or a third party. For example, a user can cause device 500 to perform a self-test. The self-test can be activated, for example, via the user interface of the device, such as by display 206. The self-test can be initiated remotely. Device 500 can provide an indication to the user (which can be local or remote) or a remote computing system that the self-test has been successfully or unsuccessfully completed. The indication can be provided using any of the methods described herein, such as visually, aurally, haptically, via a remote transmission, etc. The indication can include information about which particular test or tests have been successfully completed or failed. In some instances, the indication can include a prohibition to provide negative pressure wound therapy in response to a determination that the self-test has not been successfully completed.

[0079] Device 500 can include an inlet 510, a canister 520 (which can be optional), and a negative pressure source (in the direction indicated by arrow 560). In a canisterless system, inlet 510 can be similar to inlet 210 Figure 4The connector 444 can be a connector as shown in FIG. 4. A one-way valve or check valve 550 can be included to ensure that fluid flows downstream toward the negative pressure source (in the direction indicated by arrow 560) and not in the opposite direction, for example, when the negative pressure source is deactivated or stopped. The check valve 550 can stop any reverse flow when the negative pressure source is stopped. The device 500 can include the valve 530, the flow restrictor 540, and pressure sensors 532, 534 in the fluid flow path upstream and downstream of the flow restrictor 540. In some cases, the pressure sensors 532, 534 can be replaced with a differential pressure sensor configured to measure the pressure across the flow restrictor 540 and the pressure in the fluid flow path. The fluid flow path can include the negative pressure source and other components inside or integral with the negative pressure source, such as one or more connectors, manifolds, lumens, tubes, valves (e.g., one or more valves of the negative pressure source), etc. In some embodiments, the flow restrictor 540 can be a valve, such as a solenoid valve (or solenoid) or a manually operated valve. The valve 530 can also be a flow restrictor, for example.

[0080] During normal operation of the device 500 providing negative pressure to a wound covered by a wound dressing fluidly connected to the inlet 510, the valve 530 can remain open. The device 500 can adjust the negative pressure in the fluid flow path based on pressure signals from the pressure sensor 532 (and / or the pressure sensor 534). During a self-test, the valve 530 can be closed. The valve 530 can be a solenoid valve or a manually operated valve that is opened and closed by a controller (or controllers) of the device 500. During normal operation, the pressure sensors 532, 534 can be checked to confirm that similar pressure values are detected. A limit (or threshold) can be set for changes in pressure detected by the pressure sensors 532, 534. In response to determining that the limit has been met, a determination of a self-test failure can be made, and an indication can be provided.

[0081] Figure 6A process 600 of performing a self-test is shown. The process 600 can be implemented by the device 500, for example, under the control of the controller (or controllers) of the device 500. In block 602, the process 600 can verify whether the canister or wound dressing is disconnected. In some cases, the wound dressing can be connected to the canister. The process 600 can verify in block 602 that one or more of the wound dressing (e.g., in a canister-less system) or the canister (e.g., in a system with a canister) has been disconnected. This can be performed via one or more of the sensors, such as optical sensors, electromagnetic sensors (e.g., Hall effect sensors), electrical switches, mechanical switches, etc. In certain cases, the self-test can be performed without removing the canister. This can provide the benefit of having the canister filter act as protection from particulates (e.g., dust or debris) entering the system and potentially causing damage to any of the components 530, 532, 534, 540, 550, or the source of negative pressure.

[0082] It can be advantageous to remove one or more of the wound dressing or canister during the self-test in order to ensure that there is no restriction to fluid flow, establish a fixed volume in the fluid flow path subject to the self-test, etc. For example, because the volume of fluid absorbed by the wound dressing is unknown, a wound dressing fluidly connected to the device 500 can create a substantial restriction to the flow of fluid, which can result in inaccurate performance of the self-test. As another example, when a canister is present, the self-test can be inaccurately performed because the volume of fluid (e.g., fluid aspirated from a wound) that can be present in the canister is unknown. As yet another example, when the device is fluidly connected to a patient, safety can be promoted by not performing an overpressure test. In some cases, the process 600 can prompt the user to remove one or more of the canister or wound dressing. The process 600 can generate an indication in response to determining in block 602 that one or more of the wound dressing or canister has not been removed. The process 600 can terminate the self-test in response to determining in block 602 that one or more of the wound dressing or canister has not been removed.

[0083] The process 600 can transition to block 604, in which a leak test can be performed on the device. The leak test can be used to verify that the device has a leak rate within acceptable limits for negative pressure wound therapy. If the leak test fails, the process 600 can transition to block 614. If the leak test passes, the process 600 can transition to block 606 and perform a flow test on the device. The flow test can be used to verify that the negative pressure source of the device provides sufficient flow for negative pressure wound therapy. If the flow test fails, the process 600 can transition to block 614. If the flow test passes, the process 600 can transition to block 608 and verify that the overpressure safety system of the device is operable. The overpressure safety system can prevent unsafe levels of negative pressure from being applied to a wound (e.g., negative pressures of about -235 mmHg or less, about -240 mmHg or less or more, about -245 mmHg or less or more, about -250 mmHg or more, etc.). In some cases, the overpressure safety system can include a valve or another mechanism configured to release negative pressure in response to detecting an excessive level of negative pressure. For example, a valve can be opened to release excessive negative pressure to the atmosphere. The overpressure safety system can alternatively or additionally include deactivating the negative pressure source or the device 500 in response to detecting an excessive level of negative pressure. If the overpressure test fails, the process 600 can transition to block 614. If the overpressure test passes, the process 600 can transition to block 612. In block 612, the process 600 can provide an indication that the self-test has been successfully completed. In certain cases, the order of the tests 604-608 can be different. For example, the flow test in block 606 can be performed before the leak test in block 604.

[0084] In block 614, the process 600 can provide an indication that the self-test has not been successfully completed. Such an indication can include information about which of the one or more tests was not successfully completed, as described herein.

[0085] Figure 7 A process 700 for a leak test is shown. The process 700 can be performed by a device such as the device 500, for example. The process 700 can be performed in response to a user input, such as a user input to initiate a self-test of the device 500. Figure 6performed in block 604 of the process 600. The process 700 can be implemented by the device 500, for example, performed under the control of a controller (or controllers) of the device 500. The process 700 can begin in block 702, in which the valve 530 can be closed. In block 704, the process 700 can activate the negative pressure source. The process 700 can cause the negative pressure source to run at a low intensity or low level of activity (e.g., about 10% or less or more of a duty cycle (e.g., PWM), about 20% or less or more of a duty cycle (e.g., PWM), about 30% or less or more of a duty cycle, etc.). For example, the process 700 can cause a low level of power to be supplied to an actuator (e.g., motor, piezoelectric transducer, etc.) of the negative pressure source. The process 700 can remain in block 704 until a first negative pressure threshold level has been established in the fluid flow path. This can be verified by the pressure sensor 532 (or the pressure sensor 534). The first negative pressure threshold level can be at least about -100 mmHg, about -150 mmHg or less or more, about -160 mmHg or less or more, about -170 mmHg or less or more, about -180 mmHg or less or more, about -190 mmHg or less or more, about -200 mmHg or more, etc. The first negative pressure threshold level can depend on various factors, such as the type of negative pressure source that the device 500 is utilizing, the type of wound that the device 500 is configured to treat (e.g., treating a large wound can require the device 500 to be configured to provide a greater level of negative pressure and greater flow than treating a small wound), etc.

[0086] In some cases, the volume of the fluid flow path can be very small after the valve 530 has been closed. Activating the negative pressure source and deactivating the negative pressure source when the first negative pressure threshold level has been established (as can typically be performed during the application of negative pressure wound therapy to a wound) can cause the negative pressure in the fluid flow path to reach a level that satisfies an excessive negative pressure level. This can undesirably cause the overpressure safety system to be activated. To avoid such a result, the actuator of the negative pressure source can be activated for a fixed period of time or a fixed duty cycle, after which the pressure in the fluid flow path can be verified. Subsequently, the actuator can be activated again, if necessary, to determine the first negative pressure threshold level. For example, the actuator can be a motor that can be pulsed for a fixed period of time or pulsed for a single rotation (or multiple rotations). Subsequently, the pressure in the fluid flow path can be verified, and if the first negative pressure threshold level has not been established, the motor can be pulsed again.

[0087] The process 700 can transition to block 706, in which it can be verified that the first negative pressure threshold level has been established in the fluid flow path. For example, the process 700 can verify that the pressure sensor 532 reads a negative pressure level that is greater than (a more negative value) or equal to the first negative pressure threshold level. If the verification in block 706 is unsuccessful, the process 700 can transition to block 714, in which an indication can be provided that the leak test has failed. For example, the leak test can fail due to the presence of one or more leaks in the fluid flow path that prevent the process 700 from establishing the first negative pressure threshold level in the fluid flow path.

[0088] If the verification in block 706 is successful, the process 700 can transition to block 708. In block 708, the process 700 can implement a delay for a threshold period of time. The threshold period of time can be, for example, 1 second or less, 2 seconds or less or more, 5 seconds or less or more, 10 seconds or more, etc. In block 708, the negative pressure source can be deactivated so as to allow the negative pressure in the fluid flow path to decrease (or become more positive). Such negative pressure decay can be due to the presence of one or more inherent leaks in the fluid flow path (e.g., one or more connectors, manifolds, or valves such as the valve 530 in the fluid flow path can have inherent leaks). As described herein, the threshold period of time for the delay can depend on various factors, such as the type of negative pressure source being utilized by the device 500, the type of wound that the device 500 is configured to treat, etc.

[0089] After the threshold period of time has elapsed, the process 700 can transition to block 710, in which it can be verified that the negative pressure in the fluid flow path has decreased by an amount that satisfies a pressure decay threshold. Even if one or more inherent leaks are present in the fluid flow path, such leaks should not be too large or too severe so as to cause a large decrease in negative pressure in the fluid flow path during the delay in block 708. The pressure decay threshold can be set to a relatively small value, such as, for example, 1 mmHg or less, 2 mmHg or less, 3 mmHg or less, 4 mmHg or less, 5 mmHg or less or more, 10 mmHg or less or more, 20 mmHg or less or more, 25 mmHg or less or more, etc. As described herein, the pressure decay threshold can depend on various factors, such as the type of negative pressure source being utilized by the device 500, the type of wound that the device 500 is configured to treat, etc. In block 710, the process 700 can utilize readings from the pressure sensor 532 or 534.

[0090] If process 700 verifies in box 710 that the negative pressure in the fluid flow path meets the pressure decay threshold, then process 700 may transition to box 712, where a successful leak test can be indicated. For example, in box 710, process 700 may verify that the negative pressure in the fluid flow path is greater than (or more negative) or equal to the difference between a first threshold negative pressure level and the pressure decay threshold. If the verification in box 710 is unsuccessful, process 700 may transition to box 714, where an indication that the leak test has failed can be provided. This could be due to one or more leaks in the flow path causing the pressure decay to be too steep.

[0091] Figure 8 The process 800 for flow testing is shown. Process 800 can be performed in... Figure 6 The process 800 is performed in block 606. Process 800 can be implemented by device 500, for example, under the control of a controller (or one or more controllers) of device 500. Process 800 can begin in block 802, in which valve 530 can be opened. In block 804, process 800 can activate a negative pressure source. Process 800 can cause the negative pressure source to operate at a high intensity or maximum activity level. For example, process 800 can supply a maximum power level to the actuator of the negative pressure source. In block 804, the process can cause the negative pressure to operate for a threshold duration, which is, for example, about 1 second or less, about 2 seconds or less or longer, about 3 seconds or less or longer, about 4 seconds or less or longer, about 5 seconds or less or longer, about 6 seconds or less or longer, about 7 seconds or less or longer, about 8 seconds or less or longer, about 9 seconds or less or longer, about 10 seconds or longer, etc.

[0092] Executable block 804 causes the negative pressure source to operate at its highest or maximum flow rate (e.g., highest or maximum duty cycle (e.g., approximately 95% PWM or more)). Because such operation can significantly increase the negative pressure in the fluid flow path, process 800 can execute block 802 (to open valve 530) so as not to activate the overpressure safety system as described herein.

[0093] Process 800 can transition to block 806, where the pressure differential across flow restrictor 540 can be verified to satisfy a pressure differential threshold indicative of adequate flow. Flow restrictor 540 can have a cross-sectional area that is narrower than the cross-sectional area of other components in the fluid flow path. For example, flow restrictor 540 can be one or more of a thin, relatively long tube or conduit, a small hole or orifice, etc. As another example, flow restrictor 540 can be a variable area flow restrictor whose cross-sectional area can be changed or adjusted (e.g., by one or more controllers) such that an undue burden is not placed on the negative pressure source to overcome the flow restriction caused by the flow restrictor during normal operation. For example, flow restrictor 540 can be a butterfly valve, a needle valve, a ball valve, a solenoid valve, etc. As yet another example, a bypass tube or conduit having an unrestricted cross-sectional area can be placed across the flow restrictor. During normal operation, fluid can flow through the bypass conduit. During self-test, fluid can flow through flow restrictor 540. Using one or more valves, such as one or more solenoid valves, etc., fluid flow can be directed to the bypass conduit or flow restrictor 540. Additional details of flow restrictors are disclosed in U.S. Patent Nos. 8,974,429 and 9,636,440, each of which is incorporated by reference in its entirety.

[0094] As a result of restricting fluid flow, a pressure differential can be generated across flow restrictor 540. Such a pressure differential can be determined by pressure sensors 532, 534. The pressure differential measurement can be used to determine flow in the fluid flow path, as the pressure differential can be proportional to flow. For example, the pressure differential can be proportional to flow such that an increase in flow can cause an increase in pressure differential. In some cases, pressure sensor 532 can measure atmospheric pressure due to valve 530 having been opened in block 802. Pressure sensor 534, located downstream of flow restrictor 540, can measure a more negative pressure due to the flow restriction caused by the flow restrictor. In block 806, the measured pressure differential can be compared to a pressure differential threshold. The pressure differential threshold can be about 5 mmHg or less, 10 mmHg or less or more, about 15 mmHg or less or more, about 20 mmHg or more, etc. The pressure differential threshold can depend on various factors, such as the type of negative pressure source that device 500 is utilizing, the type of wound that device 500 is configured to treat, the flow through the flow path, etc.

[0095] If the process 800 determines that the pressure differential across the flow restrictor 540 satisfies the pressure differential threshold, then it can transition to block 812, in which an indication of a successful completion of the flow test can be provided. For example, the process 800 can transition to block 812 in response to determining that the pressure differential is greater than or equal to the pressure differential threshold. If the verification in block 806 is unsuccessful, then the process 800 can transition to block 814, in which an indication that the flow test has failed can be provided. For example, the process 800 can transition to block 814 in response to determining that the pressure differential is less than the pressure differential threshold. The failure of the flow test can be due to a malfunction of one or more components of the negative pressure source (e.g., the actuator), a blockage in the fluid flow path, etc.

[0096] In some cases, after transitioning to block 812, the process 800 can test the health of the negative pressure wound therapy device. The device health can be determined based on the efficiency of the negative pressure source (e.g., the pump). The efficiency can be determined as the ratio of the power output to the power input using Equation 1.

[0097]

[0098] The power input can reflect the power consumed by the negative pressure source. The power input can be determined as the product of the current and the voltage supplied to the negative pressure source. In some embodiments, the current can be measured and calculated via a sense resistor and an optional amplifier. The sense resistor can be placed in series with the negative pressure source. The output from the sense resistor, which can be the voltage across the resistor, can be fed into the amplifier. The amplifier can amplify the voltage, which can be small due to the small resistance of the resistor. The current supplied to the negative pressure source can be calculated using Ohm’s law (the voltage output of the amplifier / the resistance of the resistor).

[0099] The power output can indicate the actual performance of the negative pressure source (e.g., the power output by the negative pressure source). According to Equation 1, the power output can be calculated by determining the mass flow rate and the specific work. The mass flow rate can be calculated using Equation 4. To determine the mass flow rate, the volume flow rate (V) and the air density (p 空气 ). The volume flow rate can indicate the volume of fluid that passes over time. As described herein (e.g., in connection with block 806), the change in pressure across the flow restrictor 540 can indicate the volume flow rate, which can be measured as the difference between the pressure readings of the pressure sensors 532, 534. In some cases, the flow restrictor 540 can be modeled to determine a relationship between the flow (or volume flow rate) and the change in pressure. For example, the Bernoulli equation can be used. In some cases, the relationship can be linear.

[0100]

[0101] In some cases, the mass flow rate can be measured directly, for example, by using a flow sensor (or flow meter). For example, a hot wire sensor can be used.

[0102] Air density can vary with temperature and altitude. Equation 5 can be used to determine the density at a particular temperature and altitude. In this equation, Pabs (atmos) is the atmospheric pressure (in Pascals), Rratio is the specific gas constant for dry air (287.058 JKg - 1 K -1 ), and T is the temperature (in Kelvin). In some cases, the air density at room temperature (20 degrees Celsius) and mean sea level atmospheric pressure (101.325 kPa), which is equal to 1.2041 kg / m 3 According to Equation 3, the specific work (W) can be determined as the ratio of the pressure difference (between the pressures measured by pressure sensors 532, 534) and the air density. In some cases, the pressure difference can be compared to a threshold, which can indirectly provide a measure of the specific work. For example, the negative pressure source can be operated at maximum strength (to provide maximum flow rate), and the pressure difference can be compared to a threshold associated with the specific work when maximum flow rate is provided. The threshold can be adjusted for air density, as explained herein. If the threshold is satisfied (e.g., met or exceeded), the predetermined value of the specific work (associated with providing maximum flow rate) can be used to calculate the efficiency.

[0103] In block 816, the process can determine the mass flow rate. By determining the mass flow rate, the efficiency of the negative pressure source can be calculated under various temperature and pressure conditions (e.g., at different altitudes). In some cases, an indication of the mass flow rate can be provided (e.g., displayed).

[0104] Process 800 can transition to box 818, where the efficiency of the negative pressure source can be determined. As described above, the efficiency can be calculated using Equation 1. Process 800 can transition to box 820, where the efficiency determined in box 818 can be compared to an efficiency threshold. The efficiency threshold can indicate the efficiency of the device determined before the negative pressure wound therapy device has been put into use. For example, the efficiency threshold can indicate the efficiency of the device determined at the time of manufacture. If the determined efficiency meets the efficiency threshold (e.g., equal to 1%, 2%, 5%, or 10% of the efficiency threshold or within it), the process can transition to box 822, indicating that the device has passed a health test. For example, a diaphragm pump can have an efficiency of approximately 20%. The efficiency threshold can be set to an efficiency of 15% (or more or less). Failure to meet the efficiency threshold can indicate that the negative pressure source cannot deliver negative pressure wound therapy or can deliver negative pressure wound therapy while generating excessive heat. If, in box 818, it is determined that the efficiency does not meet the efficiency threshold, then process 800 can transition to box 824, indicating that the negative pressure wound therapy device has failed a health test. The health status can be determined as the ratio between the device's efficiency, as determined before the negative pressure wound therapy device was put into use, and the efficiency determined in block 818. The determined health value can be provided to the user, for example, displayed to the user. The process of checking the device's health status can advantageously allow the user to determine the device's health status and whether the device should be repaired without having to send it to a repair center. In some implementations, health testing can be performed separately from flow testing.

[0105] Figure 9 The overpressure test process 900 is shown. Process 900 can be performed in... Figure 6 The process is executed in block 608. Process 900 can be implemented by device 500, for example, under the control of a controller (or one or more controllers) of device 500. Process 900 can begin in block 902, in which valve 530 can be closed. In block 904, process 900 can activate a negative pressure source. Similar to... Figure 7 In block 704, and in block 904, process 900 can cause the negative pressure source to operate at a low intensity or low activity level. For example, process 900 can cause a low level of electrical power to be supplied to the actuator of the negative pressure source. As in block 704, the same or different intensity levels or low activity levels can be used.

[0106] The process 900 can remain in block 904 until a second threshold level of negative pressure has been established in the fluid flow path. This can be verified by the pressure sensor 532 (or the pressure sensor 534). The second negative pressure threshold level can correspond to a negative pressure that is only slightly below (or more positive) than an over (or excessive) pressure threshold that indicates an unsafe negative pressure level (e.g., a negative pressure of about -235 mmHg or less, about -240 mmHg or less or more, about -245 mmHg or less or more, about -250 mmHg or more, etc.). For example, the second negative pressure threshold level can be about -200 mmHg or less, about -210 mmHg or less or more, about -220 mmHg or less or more, about -230 mmHg or less or more, -250 mmHg or less or more, etc.

[0107] When the second negative pressure threshold level has been established in the fluid flow path, the process 900 can transition to block 906 where it can be verified that the overpressure safety system has not been activated. Unless there is a malfunction, the overpressure safety system should not be activated because the negative pressure in the fluid flow path has not reached the overpressure threshold. If such verification fails, the process 900 can transition to block 914 where an indication can be provided that the overpressure test has failed.

[0108] If the verification in block 906 is successful, the process 900 can transition to block 908 and activate the negative pressure source. Block 908 can be similar to block 904, except that the process 900 can remain in block 908 (with the negative pressure source active) until the negative pressure level in the fluid flow path meets the overpressure threshold. For example, the process 900 can remain in block 908 until the negative pressure in the fluid flow path reaches or exceeds the overpressure threshold. This verification can be performed by the pressure sensor 532 (or the pressure sensor 534). Subsequently, the process 900 can transition to block 910 where it can be verified that the overpressure safety system has been activated (e.g., the negative pressure source has been deactivated). In cases where the overpressure safety system includes another valve configured to vent overpressure to the ambient environment, the process 900 can include activating the negative pressure source in block 908 at a different intensity level (e.g., a maximum intensity level) to verify that the overpressure threshold cannot be achieved. For example, the intensity level can be higher than the intensity level described herein in connection with section 1130. If such verification fails, the process 900 can transition to block 914. If the verification in block 910 is successful, then the process 900 can transition to block 912 where it can be indicated that the overpressure test was successfully completed. Figure 11

[0109] ​In some cases, the process 900 can additionally or alternatively perform the flow test of the process 800. If the flow test fails (e.g., the process 800 reaches the block 814), it can be concluded that the overpressure safety system has been activated. If the flow test is successfully completed (e.g., the process 800 reaches the block 812), it can be concluded that the overpressure safety system has not been activated. In some cases, the flow test can be performed prior to transitioning from the block 910 to the block 912. Performing the flow test can provide additional or alternative verification regarding activation of the overpressure safety system.

[0110] Figure 10 A manifold 1000 that can be utilized by a negative pressure wound therapy device of Figure 5 is shown. The manifold 1000 can include one or more of a valve 1030 (which can correspond to the valve 530), pressure sensors 1032 and 1034 (which can correspond to the pressure sensors 532 and 534), a flow restrictor 1090 (which can correspond to the flow restrictor 540), a check valve 1050 (which can correspond to the check valve 550), or connections between any of these components. The manifold 100 can include an electronics board 1072 (e.g., a circuit board) that supports the pressure sensors 1032, 1034, which can respectively correspond to the pressure sensors 532 and 534. The electronics board 1072 can support the valve 1030, which can correspond to the valve 530. The valve 1030 can be a solenoid valve.

[0111] The manifold 1000 can be formed of portions or housings 1074 and 1078 that are separated by a gasket or grommet 1076. The grommet 1076 can be designed to provide a fluid-tight seal when the housings 1074, 1078 are connected. The housings 1074, 1078 can be glued together, welded together (e.g., using ultrasonic welding), etc. The housing 1074 can support the electronics board 1072. The grommet 1076 can support the check valve 1050, which can correspond to the check valve 550. In some cases, the check valve 1050 can be located outside of the manifold 1000.

[0112] The housing 1078 can include an inlet 1012, which can be fluidly connected to the canister (if present, or to the dressing in a canisterless system) and located downstream of the canister. With reference to Figure 5 , the inlet 1012 can be located on an opposite side of the canister 520 from the inlet 510. The inlet 1012 can be similar to the connector 444 shown in Figure 4 . The housing 1078 can include an outlet 1062, which can be fluidly connected to the source of negative pressure. The outlet 1062 can be located Figure 5The housing 1078 can include an outlet 1082 fluidly connected to an outlet of the exhaust port of the negative pressure source. The housing 1078 can include a muffler configured to reduce noise, vibration, etc. generated by the negative pressure source during operation, or one or more filters configured to prevent one or more of odor, bacteria, etc. from being released into the surrounding environment. The housing 1078 can include an outlet 1084 fluidly connected to the exhaust port (e.g., the external atmosphere) to exhaust gas after the gas passes through the muffler. In some cases, the muffler can be external to the manifold, and the outlets 1082, 1084 can be omitted. Additional details of the muffler and one or more filters are disclosed in U.S. Patent No. 8,845,603 and U.S. Patent Publication No. 2018 / 0318476, each of which is incorporated by reference in its entirety.

[0113] A flow restrictor 1090, which can correspond to the flow restrictor 540, can be integrated into the manifold 1000. For example, the flow restrictor 1090 can be located in the housing 1074. The flow restrictor can be placed between the inlet 1012 and the outlet 1062. In some cases, the flow restrictor 1090 can be a solenoid valve. In cases where the valve 1030 functions as a flow restrictor, the component 1090 can be omitted.

[0114] Additional details of the manifold are disclosed in U.S. Patent Nos. 9,084,845 and 9,427,505, and U.S. Patent Publication No. 2018 / 0318476, each of which is incorporated by reference in its entirety.

[0115] Use of the manifold 1000 or another modular unit can advantageously allow for efficient troubleshooting, for example, in the event that one or more tests performed during self-testing fail. For example, the manifold 1000 or another modular unit can be replaced in response to one or more of the execution of one or more of the blocks 614, 714, 814, or 914 in one or more of the processes 600, 700, 800, or 900. Such a design can allow a user to quickly replace one or more potentially faulty components that can have caused the self-test to fail. The manifold 1000 or another modular unit can be detached from the device 500. During repair or service, removing the potentially faulty manifold 1000 or another modular unit and attaching a different manifold 100 or another modular unit to the device 500 can result in successful completion of the self-test. In some cases, the negative pressure source can be replaced along with the manifold 1000 or another modular unit. For example, the negative pressure source can be attached to the manifold 1000 or integrated in the manifold to form a replaceable modular unit.

[0116] Figure 11Graphical output 1100 is shown that performs a flow test, a leak test, and an overpressure test. The X-axis can represent time. The Y-axis can represent pressure and duty cycle of the negative pressure source. Curve 1102 can represent pressure in the fluid flow path (as measured by one or more of pressure sensors 532 or 534, for example pressure sensor 534). Curve 1104 can represent the duty cycle of the negative pressure source.

[0117] A flow test is shown in section 1110. Valve 530 can be open. The negative pressure source can be run at a high or maximum flow as described herein. As shown, curve 1104 can be at about 100% duty cycle (e.g., at 95% PWM). The pressure in the fluid flow path is shown by curve 1102, which shows a steady pressure of about 35 mmHg. The flow test results can also be used to determine device health or negative pressure source efficiency.

[0118] A leak test is shown in section 1120. Valve 530 can be closed. The negative pressure source can be run at a low intensity or low activity level as described herein. The negative pressure source can be pulsed at 20% PWM (or less or more as described herein) as shown by curve 1104. The pulses can be separated by a delay in time in order to protect pressure sensors 532 or 534 from damage (e.g., to prevent a high negative pressure from being established in a small volume of the fluid flow path with valve 530 closed). The leak can manifest as a large drop in pressure in the fluid flow path as shown by curve 1102. In some cases, pressure sensor 534, which is located on the negative pressure source side of flow restrictor 540, can be monitored to determine a leak.

[0119] Section 1130 shows an overpressure test. Valve 530 can be closed. The negative pressure source can be run at a low intensity or low activity level as described herein. The negative pressure source can be pulsed at 20% PWM (or less or more as described herein) as shown by curve 1104. Each pulse can increase the negative pressure in the fluid flow path. The pulses can be separated by a delay in time to protect pressure sensors 532 or 534 from damage as described herein. At the end of section 1130, the pressure in the fluid flow path can meet an overpressure threshold.

[0120] Advantageously, the self-testing improvements described herein can allow for more efficient and reliable self-testing of negative pressure devices. This can shorten negative pressure wound therapy interruptions and improve patient care.

[0121] Other variations

[0122] Although some embodiments describe negative pressure wound therapy, the systems, devices, and / or methods disclosed herein can be applied to other types of therapy that can be used alone or in addition to TNP therapy. The systems, devices, and / or methods disclosed herein can extend to any medical device, in particular, to any wound treatment device. For example, the systems, devices, and / or methods disclosed herein can be used with a device that provides one or more of ultrasound therapy, oxygen therapy, nerve stimulation, microwave therapy, active agents, antibiotics, antimicrobial agents, etc. Further, such devices can provide TNP therapy. The systems and methods disclosed herein are not limited to medical devices and can be used by any electronic device.

[0123] Any of the controllers or processors disclosed herein can include electronic circuitry (sometimes referred to as control circuitry). The electronic circuitry can be configured to implement programmable control or hardwired control.

[0124] Any values of thresholds, limits, durations, etc. provided herein are not intended to be absolute, and thus can be approximate. Further, any thresholds, limits, durations, etc. provided herein can be fixed or automatically or user- changeable. Further, relative terms with respect to a reference value, as used herein, such as exceed, greater than, less than, etc. are intended to also cover equal to the reference value. For example, exceeding a positive reference value can include being equal to or greater than the reference value. Additionally, relative terms with respect to a reference value, as used herein, such as exceed, greater than, less than, etc. are also intended to cover the inverse of the disclosed relationship, such as below, less than, greater than, etc. with respect to the reference value.

[0125] Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, can be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. Protection is sought for any novel or inventive feature disclosed in this specification (including any accompanying claims, abstract and drawings) and / or any novel or inventive combination of the steps of any method or process so disclosed. The scope of the protection is not limited to the specific embodiments disclosed in the specification, but is intended to cover any development of the features disclosed in this specification (including any accompanying claims, abstract and drawings) and / or any novel or inventive combination of the steps of any method or process so disclosed.

[0126] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of protection. Indeed, the novel methods and systems described herein can be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein can be made without departing from the spirit of the disclosure. Those skilled in the art will appreciate that the specific sequential steps disclosed in the methods shown and / or disclosed can be different, and that other steps can be provided, or provided in a different sequence. According to the embodiments, some of the steps can be removed, others can be added, or some of them can be substituted by other steps. For example, the actual steps taken in the disclosed processes can differ from those described in the specification. According to the embodiments, some of the steps can be removed, others can be added, or some of them can be substituted by other steps. For example, the various components illustrated in the figures or described herein can be implemented as software and / or firmware on a processor, controller, ASIC, FPGA, and / or dedicated hardware. The software or firmware can include instructions stored in non-transitory computer-readable storage. The instructions can be executed by a processor, controller, ASIC, FPGA, or dedicated hardware. The hardware components, such as controllers, processors, ASICs, FPGAs, etc., can include logic circuits. Furthermore, features and attributes of the specific embodiments disclosed above can be combined in different manners to form additional embodiments, all of which fall within the scope of the present disclosure.

[0127] The user interface screens illustrated and described herein can include additional and / or alternative components. These components can include menus, lists, buttons, text boxes, labels, radio buttons, scroll bars, sliders, check boxes, combo boxes, status bars, dialog boxes, windows, etc. The user interface screens can include additional and / or alternative information. The components can be arranged, grouped, displayed in any suitable order.

[0128] Conditional language used herein, such as “can,” “may,” “can,” “may,” “e.g.,” etc., unless otherwise expressly stated or otherwise understood in the context in which they are used, is generally intended to express that certain embodiments include certain features, elements, and / or states, while other embodiments do not. Therefore, such conditional language is not generally intended to imply that one or more embodiments require features, elements, and / or states in any way, or that one or more embodiments must include logic for determining whether such features, elements, and / or states are included in or will be performed in any particular embodiment, with or without user input or prompting. The terms “comprising,” “including,” “having,” etc., are synonymous and used in an open-ended manner, and do not exclude additional elements, features, actions, operations, etc. Furthermore, the term “or” is used in its inclusive sense (but not in its proprietary sense) so that, when used, for example, to connect lists of elements, the term “or” indicates one, some, or all of the elements in the list. In addition, besides having its ordinary meaning, the term “each” as used herein may mean any subset of the set of elements to which the term “each” is applied. Additionally, when used in this application, the terms “in this text,” “above,” “below,” and similar terms refer to the application as a whole, and not to any particular part of the application.

[0129] Unless otherwise specifically stated, connective language such as the phrase “at least one of X, Y, and Z” should be understood in conjunction with the commonly used context to express that an item, term, etc., may be X, Y, or Z, or a combination thereof. Therefore, such connective language is not generally intended to imply that certain embodiments require the separate presence of at least one of X, at least one of Y, and at least one of Z.

[0130] The degree language used herein, such as the terms “about,” “approximately,” “generally,” and “roughly,” indicates a value, quantity, or characteristic that is close to a specified value, quantity, or characteristic, which still performs the desired function or achieves the desired result. For example, the terms “about,” “approximately,” “generally,” and “roughly” may refer to a quantity that is less than 10%, less than 5%, less than 1%, less than 0.1%, and less than 0.01% of a specified quantity. As another example, in some embodiments, the terms “generally parallel” and “roughly parallel” refer to a value, quantity, or characteristic that deviates from exact parallelism by less than or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degrees.

[0131] Unless otherwise explicitly stated, articles such as “a” or “an” should generally be interpreted as including one or more of the described items. Thus, phrases such as “a device configured to…” are intended to include one or more of the described devices. Such devices of one or more descriptions may also be collectively configured to perform the description.

[0132] While the present disclosure includes certain embodiments, examples, and applications, it will be appreciated that the present disclosure is not limited to those explicit disclosures but extends to other alternative embodiments and / or uses and obvious modifications and equivalents thereof, including embodiments that do not provide all of the features and advantages set forth herein. Accordingly, the scope of the present disclosure is not intended to be limited to the specific embodiments described herein but rather the scope of the present disclosure is to be defined according to the following claims and their equivalents.

Claims

1. A negative pressure wound therapy device, comprising: A negative pressure source, configured to be connected to a wound covered by a wound dressing via a fluid flow path and to provide negative pressure to the wound; A valve located in the fluid flow path and configured to allow the supply of negative pressure from a negative pressure source upstream of the valve in an open state and to prevent the supply of negative pressure from a negative pressure source upstream of the valve in a closed state; A flow limiter, wherein the flow limiter is located in the fluid flow path; A pressure sensor configured to measure the pressure in the fluid flow path and the pressure difference across the flow limiter; as well as Control circuit, the control circuit being configured to: In the normal operating mode of providing negative pressure to the wound, the valve is in the open state; as well as In the test mode for verifying the performance of the device, a leakage test is performed, wherein: The leak test includes the control circuit being configured to: close the valve, operate the negative pressure source at a first intensity level, suspend the operation of the negative pressure source for a duration, and indicate the presence of a leak in the fluid flow path in response to determining that a change in negative pressure measured by the pressure sensor after the duration has expired meets a threshold indicating a leak.

2. The apparatus according to claim 1, wherein, The control circuit is configured to perform a flow test or an overvoltage test in a test mode that verifies the performance of the device, wherein: The flow test includes the control circuit being configured to: open the valve, operate the negative pressure source at a second intensity level, and, in response to determining that the pressure differential across the flow limiter measured by the pressure sensor meets a pressure differential threshold indicating insufficient flow, indicate insufficient flow; and The overpressure test includes the control circuit being configured to: close the valve, operate the negative pressure source at a third intensity level, and, in response to determining that the pressure in the fluid flow path meets a threshold indicating an unsafe negative pressure and that the system configured to prevent unsafe negative pressure has not been activated, indicate a fault in the system configured to prevent unsafe negative pressure in the fluid flow path.

3. The apparatus of claim 2, wherein the second strength level is greater than the first strength level.

4. The apparatus of claim 2, wherein the first intensity level is equal to the third intensity level.

5. The apparatus according to any one of claims 2 to 4, wherein the pressure sensor comprises a first pressure sensor located upstream of the flow limiter and a second pressure sensor located downstream of the flow limiter.

6. The apparatus according to any one of claims 2 to 4, further comprising a canister configured to be located in the fluid flow path and to collect fluid aspirated from the wound, wherein the control circuitry is further configured to verify, in the test mode, that the canister has been removed from the fluid flow path.

7. The apparatus of claim 6, wherein the control circuitry is further configured to, in the test mode, not perform the leakage test, the flow test, and the overpressure test in response to determining that the can has not been removed and the wound dressing has not been disconnected.

8. The apparatus of claim 6, wherein the control circuitry is further configured to provide an indication, in the test mode, that at least one of the canister has not been removed or the wound dressing has not been disconnected.

9. The apparatus according to any one of claims 2 to 4, wherein the system configured to prevent unsafe negative pressure in the fluid flow path comprises at least one of the following: Another valve located in the fluid flow path, the control circuit being configured to open the other valve in response to the pressure in the fluid flow path meeting a threshold indicating an unsafe negative pressure; or The control circuit is also configured to deactivate the negative pressure source in response to the pressure in the fluid flow path meeting a threshold indicating an unsafe negative pressure.

10. The apparatus according to any one of claims 2 to 4, wherein the overpressure test includes the control circuit being further configured to activate in response to determining that the system configured to prevent unsafe negative pressure has a pressure in the fluid flow path that does not meet a threshold indicating unsafe negative pressure, indicating a failure in the system configured to prevent unsafe negative pressure in the fluid flow path.

11. The apparatus according to any one of claims 2 to 4, wherein the control circuitry is further configured to perform a health test in the test mode, the health test comprising determining the efficiency of the negative pressure source and indicating sufficient health status in response to determining that the efficiency meets an efficiency threshold.

12. The apparatus of claim 11, wherein the control circuit is configured to determine the efficiency of the negative pressure source by determining the ratio of the amount of power output by the negative pressure source to the amount of power supplied to the negative pressure source.

13. The apparatus of claim 12, wherein the control circuit is configured to determine the amount of power output by the negative pressure source based on the product of the mass flow rate and specific work of the negative pressure source.

14. The apparatus of claim 13, wherein the control circuit is configured to determine at least one of the mass flow rate or the specific work based on determining the pressure difference across the flow limiter.

15. The apparatus of claim 13, wherein the control circuitry is configured to determine the mass flow rate based on a determined volumetric flow rate.

16. The apparatus of claim 11, wherein the control circuitry is configured to perform the health test after the flow test is successfully completed.

17. The apparatus according to any one of claims 2 to 4, wherein the valve acts as the flow limiter.

18. The apparatus according to any one of claims 2 to 4, further comprising a check valve located in the fluid flow path, the check valve being configured to allow fluid to flow downstream toward the negative pressure source or the outside atmosphere and to prevent fluid from flowing in the opposite direction.

19. A negative pressure wound therapy device, comprising: A negative pressure source, configured to be connected to a wound covered by a wound dressing via a fluid flow path and to provide negative pressure to the wound; A valve located in the fluid flow path and configured to allow the supply of negative pressure from a negative pressure source upstream of the valve in an open state and to prevent the supply of negative pressure from a negative pressure source upstream of the valve in a closed state; A flow limiter, wherein the flow limiter is located in the fluid flow path; A pressure sensor configured to measure pressure in the fluid flow path; as well as Control circuit, the control circuit being configured to: In the normal operating mode of providing negative pressure to the wound, the valve is in the open state; as well as In the test mode for verifying the performance of the device, a leakage test is performed, wherein: The leak test includes the control circuit being configured to: close the valve, operate the negative pressure source at a first intensity level, suspend the operation of the negative pressure source for a duration, and indicate the presence of a leak in the fluid flow path in response to determining that a change in negative pressure measured by the pressure sensor after the duration has expired meets a threshold indicating a leak.

20. The apparatus of claim 19, wherein the control circuit is further configured to perform a flow test or an overvoltage test in the test mode, wherein: The flow test includes the control circuit being configured to: open the valve, operate the negative pressure source at a second intensity level, and indicate insufficient flow in response to determining that the pressure difference across the flow limiter measured by the pressure sensor meets a pressure difference threshold indicating insufficient flow. as well as The overpressure test includes the control circuit being configured to: close the valve, operate the negative pressure source at a third intensity level, and, in response to determining that the pressure in the fluid flow path meets a threshold indicating an unsafe negative pressure and that overpressure protection has not been activated, indicate a fault in the overpressure protection.

21. The apparatus of claim 20, wherein the overvoltage protection comprises at least one of the following: Another valve located in the fluid flow path, the control circuit being configured to open the other valve in response to the pressure in the fluid flow path meeting a threshold indicating an unsafe negative pressure; or The control circuit is also configured to deactivate the negative pressure source in response to the pressure in the fluid flow path meeting a threshold indicating an unsafe negative pressure.

22. The apparatus of claim 20, wherein the overpressure test includes the control circuit being further configured to indicate a fault in the overpressure protection in response to determining that the overpressure protection has been activated when the pressure in the fluid flow path does not meet a threshold indicating an unsafe negative pressure.

23. The apparatus according to any one of claims 20 to 22, wherein the second strength level is greater than the first strength level.

24. The apparatus of any one of claims 20 to 22, wherein the control circuitry is further configured to perform a health test in the test mode, the health test comprising determining the efficiency of the negative pressure source and indicating sufficient health status in response to determining that the efficiency meets an efficiency threshold.

25. The apparatus of claim 24, wherein the control circuit is configured to determine the efficiency of the negative pressure source by determining the ratio of the amount of power output by the negative pressure source to the amount of power supplied to the negative pressure source.

26. The apparatus of claim 25, wherein the control circuit is configured to determine the amount of power output by the negative pressure source based on the product of the mass flow rate and specific work of the negative pressure source.

27. The apparatus of claim 26, wherein the control circuitry is configured to determine at least one of the mass flow rate or the specific work based on determining the pressure difference across the flow limiter.

28. The apparatus of claim 26, wherein the control circuitry is configured to determine the mass flow rate based on a determined volumetric flow rate.

29. The apparatus of claim 24, wherein the control circuitry is configured to perform the health test after the flow test has been successfully completed.

30. The apparatus according to any one of claims 20 to 22, wherein the valve comprises a solenoid valve.

31. The apparatus according to any one of claims 20 to 22, wherein the valve acts as the flow limiter.

32. The apparatus according to any one of claims 20 to 22, wherein the pressure sensor comprises a first pressure sensor located upstream of the flow limiter and a second pressure sensor located downstream of the flow limiter.

33. The apparatus of any one of claims 20 to 22, further comprising a canister configured to be located in the fluid flow path and to collect fluid aspirated from the wound, wherein the control circuitry is further configured to verify, in the test mode, that the canister has been removed from the fluid flow path.

34. The apparatus of claim 33, wherein the control circuitry is further configured to not perform the leakage test and the flow test in the test mode in response to determining that the can has not been removed and the wound dressing has not been disconnected.

35. The apparatus of claim 33, wherein the control circuitry is further configured to provide an indication, in the test mode, that at least one of the canister has not been removed or the wound dressing has not been disconnected.

36. The apparatus according to any one of claims 20 to 22, further comprising a check valve located in the fluid flow path, the check valve being configured to allow fluid to flow downstream toward the negative pressure source or the outside atmosphere and to prevent fluid from flowing in the opposite direction.

37. A kit comprising the means according to any one of the preceding claims.

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