Self-Testing Negative Pressure Wound Therapy Devices

Abstract

A negative pressure wound therapy device may include a negative pressure source configured to be connected to a wound via a fluid flow path, a valve positioned within the fluid flow path and configured, in an open state, to allow a supply of negative pressure from a negative pressure source upstream of the valve and, in a closed state, to block a supply of negative pressure from a negative pressure source upstream of the valve, a flow restrictor positioned within the fluid flow path, and a pressure sensor configured to measure a pressure differential across the flow restrictor. The device may include a control circuit configured to cause the valve to be open 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] DETAILED DESCRIPTION OF THE INVENTION The embodiments described herein relate to devices, systems, and methods for treating wounds, for example, using dressings in combination with negative pressure wound therapy. [Background technology]

[0002] Many different types of wound dressings are known to aid in the healing process in humans and animals. These different types of wound dressings include different types of materials and layers, such as gauze, pads, foam pads, or multi-layer wound dressings. Topical negative pressure (TNP) therapy, sometimes referred to as vacuum-assisted closure therapy, negative pressure wound therapy, or reduced pressure wound therapy, is widely recognized as a beneficial mechanism for improving wound healing rates. Such therapy is applicable to a wide range of wounds, including surgical wounds, open wounds, and abdominal wounds. TNP therapy can aid wound closure and healing by reducing tissue edema, promoting blood flow, stimulating granulation tissue formation, and removing excess exudate, and can reduce bacterial load, thus reducing wound infection. Furthermore, TNP therapy allows the wound to tolerate less external disturbance and promotes more rapid healing. Summary of the Invention

[0003] A negative pressure wound therapy device may include a negative pressure source connected to a wound covered by a wound dressing via a fluid flow path and configured to provide negative pressure to the wound. The device may include a valve positioned in the fluid flow path. The valve may be configured to allow the supply of negative pressure from a negative pressure source upstream of the valve in an open state. The valve may be configured to block the supply of negative pressure from a negative pressure source upstream of the valve in a closed state. The device may include a flow restrictor positioned in the fluid flow path downstream of the valve. The device may include a pressure sensor configured to measure the pressure in the fluid flow path and the pressure difference across the flow restrictor. The device may include a control circuit configured to cause the valve to be open in a normal operating mode in which negative pressure is provided to the wound. The control circuit may be configured to perform at least one of a leak test, a flow test, or an overpressure test in a test mode in which the performance of the device is verified. The leak test may include the control circuit being configured to close the valve, operate the negative pressure source at a first intensity level, cease 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 expiration of the duration meets a threshold indicative of a leak. The flow test may include 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 a pressure differential across the flow restrictor measured by the pressure sensor meets a different threshold indicative of insufficient flow. The overpressure test may include the control circuit being configured to close the valve, operate the negative pressure source at a third intensity level, and indicate a fault in the system configured to protect against unsafe negative pressure in the fluid flow path in response to the pressure in the fluid flow path meeting a threshold indicative of an unsafe negative pressure and determining that the system configured to protect against unsafe negative pressure is not operational.

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

[0005] The negative pressure wound therapy device of any of the preceding paragraphs and / or any of the devices, apparatus, or systems disclosed herein may include one or more of the following features: The system configured to protect against unsafe negative pressure in the fluid flow path may include at least one of: a separate valve positioned in the fluid flow path, the control circuit configured to open the separate valve in response to the pressure in the fluid flow path meeting a threshold indicative of an unsafe negative pressure; or the separate valve or the control circuit configured to deactivate the negative pressure source in response to the pressure in the fluid flow path meeting a threshold indicative of an unsafe negative pressure. The overpressure test may include the control circuit configured to indicate a fault in the system configured to protect against unsafe negative pressure in the fluid flow path in response to determining that the system configured to protect against unsafe negative pressure is operational when the pressure in the fluid flow path does not meet the threshold indicative of an unsafe negative pressure. The device may include a check valve positioned in the fluid flow path. The check valve may be configured to allow fluid to flow downstream toward the negative pressure source or exhaust and prevent fluid from flowing in the opposite direction.

[0006] The negative pressure wound therapy device of any of the preceding paragraphs and / or any of the devices, apparatus, or systems disclosed herein may include one or more of the following features. The control circuit may be further configured to perform a health test in a test mode, the health test including determining the efficiency of the negative pressure source and indicating sufficient health in response to determining that the efficiency meets an efficiency threshold. The control circuit may 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 may be configured to determine the amount of power output by the negative pressure source based on determining the product of the mass flow rate and the specific work of the negative pressure source. The control circuit may be configured to determine at least one of the mass flow rate or the specific work based on determining a pressure difference across a flow restrictor. The control circuit may be configured to determine the mass flow rate based on determining a volumetric flow rate. The control circuit may be configured to perform a health test after a flow test is successfully completed. The valve may operate as a flow restrictor.

[0007] A negative pressure wound therapy device may include a negative pressure source connected to a wound covered by a wound dressing via a fluid flow path and configured to provide negative pressure to the wound. The device may include a valve positioned within the fluid flow path. The valve may be configured to allow the supply of negative pressure from a negative pressure source upstream of the valve in an open state. The valve may be configured to block the supply of negative pressure from a negative pressure source upstream of the valve in a closed state. The device may include a flow restrictor positioned within the fluid flow path. The device may include a pressure sensor configured to measure pressure within the fluid flow path. The device may include control circuitry configured to cause the valve to open in a normal operating mode in which negative pressure is provided to the wound. The control circuitry may be configured to perform at least one of a leak test or a flow test in a test mode in which performance of the device is verified. The leak test may include the control circuit being configured to close the valve, operate the negative pressure source at a first intensity level, cease 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 expiration of the duration meets a threshold indicative of a leak. The flow test may include 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 a pressure differential across the flow restrictor measured by the pressure sensor meets a threshold pressure differential indicative of insufficient flow.

[0008] The negative pressure wound therapy device of any of the preceding paragraphs and / or any of the devices, apparatus, or systems disclosed herein may include one or more of the following features: In a test mode, the control circuit may be configured to perform at least one of a leak test, a flow test, or an overpressure test. The overpressure test may include the control circuit being configured to close the valve, operate the negative pressure source at a third intensity level, and indicate a fault in the overpressure protection in response to the pressure in the fluid flow path meeting a threshold indicative of an unsafe negative pressure and determining that the overpressure protection is not operational. The overpressure protection may include at least one of: a separate valve positioned in the fluid flow path, the control circuit being configured to open the separate valve in response to the pressure in the fluid flow path meeting a threshold indicative of an unsafe negative pressure (to vent the overpressure to the surrounding environment); or the control circuit being configured to deactivate the negative pressure source in response to the pressure in the fluid flow path meeting a threshold indicative of an unsafe negative pressure. The overpressure test may include the control circuit being configured to indicate a fault in the overpressure protection in response to determining that the overpressure protection is operational when the pressure in the fluid flow path does not meet a threshold that indicates an unsafe negative pressure.

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

[0010] The negative pressure wound therapy device of any of the preceding paragraphs and / or any of the devices, apparatus, or systems disclosed herein may include one or more of the following features. The control circuit may be further configured to perform a health test in a test mode, the health test including determining the efficiency of the negative pressure source and indicating sufficient health in response to determining that the efficiency meets an efficiency threshold. The control circuit may 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 may be configured to determine the amount of power output by the negative pressure source based on determining the product of the mass flow rate and the specific work of the negative pressure source. The control circuit may be configured to determine at least one of the mass flow rate or the specific work based on determining a pressure difference across a flow restrictor. The control circuit is configured to determine the mass flow rate based on determining a volumetric flow rate. The control circuit may be configured to perform a health test after the flow test is successfully completed. The valve may operate as a flow restrictor.

[0011] Disclosed is a method of operating a negative pressure wound therapy device of any of the preceding paragraphs and / or any of the devices, apparatus, or systems disclosed herein. Disclosed is a kit including a negative pressure wound therapy device of any of the preceding paragraphs and / or any of the devices, apparatus, or systems disclosed herein and one or more dressings or canisters.

[0012] Any feature, component, or detail of any of the arrangements or embodiments disclosed in the present application, including, but not limited to, any of the device embodiments disclosed herein and any of the negative pressure wound therapy embodiments disclosed herein, can be combined with any other feature, component, or detail of any of the arrangements or embodiments disclosed herein to form new arrangements and embodiments. [Brief explanation of the drawings]

[0013] [Figure 1A] 1 illustrates a negative pressure wound therapy system. [Figure 1B] 1 illustrates another negative pressure wound therapy system. [Figure 2A] FIG. 1 is an isometric view of a negative pressure wound therapy device and canister, showing the canister detached from the pump assembly of the device. [Figure 2B] FIG. 2B is a rear view of the negative pressure wound therapy device shown in FIG. 2A. [Figure 2C] 2B illustrates the top view of the negative pressure wound therapy device shown in FIG. 2A showing the user interface. [Figure 3] 1 illustrates a schematic diagram of a control system for a negative pressure wound therapy device. [Figure 4] 1 illustrates another negative pressure wound therapy system. [Figure 5] 1 illustrates a negative pressure wound therapy device configured to perform a self-test. [Figure 6] 6 illustrates a flow chart of a test that may be performed by the negative pressure wound therapy device of FIG. 5. [Figure 7] 6 illustrates a flow chart of a test that may be performed by the negative pressure wound therapy device of FIG. 5. [Figure 8] 6 illustrates a flow chart of a test that may be performed by the negative pressure wound therapy device of FIG. 5. [Figure 9] 6 illustrates a flow chart of a test that may be performed by the negative pressure wound therapy device of FIG. 5. [Figure 10] 6 illustrates a manifold that may be utilized by the negative pressure wound therapy device of FIG. 5. [Figure 11] 6 illustrates graphs of several tests being performed with the negative pressure wound therapy device of FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0014]

[0003] Some embodiments of the negative pressure wound therapy device disclosed herein may include a negative pressure source connected and / or fluidly coupled via a fluid flow path to a wound covered by a wound dressing and configured to provide negative pressure to the wound.

[0015] Throughout this specification, reference is made to wounds. The term wound is broadly construed to include open and closed wounds in which the skin is torn, incised, or perforated, or traumatically induced contusion, or any other surface or other pathological or imperfect state in a patient's skin, or others that would benefit from reduced pressure treatment. Thus, a wound is broadly defined as any damaged area of ​​tissue, which may or may not produce fluid. Examples of such wounds include, but are not limited to, abdominal wounds or other large or incisional wounds resulting from surgery, trauma, sternotomy, fasciotomy, or other pathological conditions, dehiscence wounds, acute wounds, chronic wounds, subacute wounds and dehiscence wounds, traumatic wounds, flaps and skin grafts, lacerations, abrasions, contusions, burns, diabetic ulcers, pressure ulcers, stomas, surgical wounds, traumatic ulcers, and venous ulcers.

[0016] Embodiments of the systems and methods disclosed herein can be used with topical negative pressure ("TNP") or reduced pressure therapy systems. Simply put, negative pressure wound therapy can assist in the closure and healing of many forms of "difficult-to-heal" wounds by reducing tissue edema, promoting blood flow and granular tissue formation, or removing excess exudate, reducing bacterial load (and thus infection risk). Additionally, the therapy can result in less wound disturbance, leading to more rapid healing. TNP therapy systems can also assist in the healing of surgically closed wounds by removing fluid. TNP therapy can help stabilize tissues in opposition to closure. Further beneficial uses of TNP therapy can be found in grafts and flaps, where removing excess fluid is important and graft proximity to tissue is required to ensure tissue viability.

[0017] As used herein, a reduced pressure or negative pressure level, such as -X mmHg, represents a pressure level relative to normal ambient atmospheric pressure, which may 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 less than 760 mmHg, or in other words, a pressure of (760-X) mmHg. Additionally, a negative pressure that is "lower" or "less" than X mmHg corresponds to a pressure that is closer to atmospheric pressure (e.g., -40 mmHg is lower than -60 mmHg). A negative pressure that is "higher" or "greater" than -X mmHg corresponds to a pressure that is further from atmospheric pressure (e.g., -80 mmHg is higher than -60 mmHg). In some cases, the local ambient atmospheric pressure is used as a reference point, and such local atmospheric pressure may not necessarily be, for example, 760 mmHg.

[0018] The systems and methods disclosed herein may be used in addition to or instead of reduced pressure therapy, such as irrigation, ultrasound, heating or cooling, nerve stimulation, or the like. In some cases, the disclosed systems and methods may be used for wound monitoring without the application of additional therapy. The systems and methods disclosed herein may be used with dressings, including compression dressings, reduced pressure dressings, or the like.

[0019] A healthcare professional, such as a doctor, nurse, or the like, can provide a TNP prescription that specifies, for example, pressure level or application time. However, the healing process varies from patient to patient, and the prescription may affect the healing process in ways that the clinician or healthcare provider did not anticipate when designing the prescription. The healthcare provider may attempt to adjust the prescription as the wound heals (or does not heal), but such a process may require various appointments, which can be time-consuming and repetitive. The embodiments disclosed herein provide systems, devices, or methods for efficiently adjusting a TNP prescription and delivering effective TNP therapy.

[0020] Wound Therapy System FIG. 1A schematically illustrates a negative pressure wound therapy system 100 (also referred to as a reduced pressure or negative pressure wound therapy system, TNP system, or wound therapy system). Although not required in any implementation disclosed herein, the negative pressure wound therapy system 100 may include a wound packing 102 placed on or within a wound 104 (which may be a cavity). The wound 104 may be sealed by a wound cover 106, which may be a drape, such that the wound cover 106 may be in fluid communication with the wound 104. The wound packing 102 combined with the wound cover 106 may be referred to as a wound dressing. A tube or conduit 108 (also referred to herein as a flexible suction adapter or fluid connector) may be used to connect the wound cover 106 to a wound therapy device 110 (sometimes referred to in whole or in part as a “pump assembly”) configured to deliver reduced pressure or negative pressure. The conduit 108 may be a single-lumen tube or a multi-lumen tube. Connector 112 may be used to removably and selectively connect conduit or tube 142 to conduit 108 .

[0021] In any of the systems disclosed herein, the wound therapy device may be canisterless, for example, but not limited to, wound exudate being collected in a wound dressing or transferred via a conduit for collection elsewhere, however, any of the wound therapy devices disclosed herein may include or support a canister.

[0022] Additionally, in any of the wound therapy systems disclosed herein, any of the wound therapy devices may be attached to, supported by, or adjacent to a dressing. The wound packing 102 may be of any suitable type, such as hydrophilic or hydrophobic foam, gauze, an inflatable bag, or the like. The wound packing 102 may be conformable to the wound 104 such that the wound packing 102 substantially fills the cavity of the wound 104. The wound cover 106 may provide a substantially fluid-impermeable seal over the wound 104. The wound cover 106 may have a top side and a bottom side. The bottom side may be adhesively sealed (or in any other suitable manner) to the wound 104, for example, by sealing with the skin surrounding the wound 104. The conduit 108, or any other conduit disclosed herein, may be formed from polyurethane, PVC, nylon, polyethylene, silicone, or any other suitable material.

[0023] Wound cover 106 may have a port (not shown) configured to receive an end of conduit 108. In some cases, conduit 108 may otherwise pass through or under wound cover 106 to supply reduced pressure to wound 104 so as to maintain a desired level of reduced pressure within wound 104. Conduit 108 may be any suitable article configured to provide an at least substantially sealed fluid flow path or passageway between wound therapy device 110 and wound cover 106 to supply reduced pressure provided by wound therapy device 110 to wound 104.

[0024] The wound cover 106 and wound packing 102 may be provided as a single item or an integral single unit. In some cases, no wound packing is provided, and the wound cover itself may be considered the wound dressing. The wound dressing may then be connected to a source of negative pressure in the wound therapy device 110 via a conduit 108. In some cases, although not necessary, the wound therapy device 110 may be miniaturized and portable, although a larger conventional negative pressure source (or pump) may also be used.

[0025] The wound cover 106 may be positioned over the wound site to be treated. The wound cover 106 may form a substantially sealed cavity or enclosed space over the wound. The wound cover 106 may have a film with high water vapor permeability to allow evaporation of excess fluids and may have a superabsorbent material contained therein to safely absorb wound exudate. In some cases, the components of the TNP system described herein may be particularly suitable for incisional wounds that exude a small amount of wound exudate.

[0026] Wound therapy device 110 can be operated with or without the use of an exudate canister. In some cases, as illustrated, wound therapy device 110 may include an exudate canister. In some cases, configuring wound therapy device 110 and conduit 108 so that conduit 108 can be quickly and easily removed from wound therapy device 110 can facilitate or improve the process of changing dressings or pumps, if needed. Any of the pump assemblies disclosed herein can have any suitable connection between conduit 108 and the pump.

[0027] The wound therapy device 110 may deliver a negative pressure of approximately -80 mmHg, or between about -20 mmHg and -200 mmHg. Note that these pressures are relative to normal ambient atmospheric pressure; that is, -200 mmHg may actually be approximately 560 mmHg. In some cases, the pressure range may be between about -40 mmHg and -150 mmHg. Alternatively, pressure ranges of -75 mmHg or less, -80 mmHg or less, or greater than 80 mmHg may be used. Also, in some cases, pressure ranges below -75 mmHg may be used. Alternatively, pressure ranges of approximately -100 mmHg or even greater than -150 mmHg may be provided by the wound therapy device 110.

[0028] As described in more detail below, the negative pressure wound therapy system 100 may be configured to provide a connection 332 to a separate or remote computing device 334. The connection 332 may be wired or wireless (e.g., Bluetooth, NFC, WiFi, or cellular). The remote computing device 334 may be a smartphone, tablet, laptop or another standalone computer, a server (e.g., a cloud server), another pump device, etc.

[0029] FIG. 1B illustrates another negative pressure wound therapy system 100′. The negative pressure wound therapy system 100′ may have any of the components, features, or other details of any of the other negative pressure wound therapy systems disclosed herein, including, but not limited to, the negative pressure wound therapy system 100 illustrated in FIG. 1A or the negative pressure wound therapy system 400 illustrated in FIG. 4, in combination with or in place of any of the components, features, or other details of the negative pressure wound therapy system 100′ shown in FIG. 1B and / or described herein. The negative pressure wound therapy system 100′ may have a wound cover 106 over the wound 104 that may seal the wound 104. A conduit 108′, such as a single-lumen or multi-lumen tube, may be used to connect the wound cover 106 to a wound therapy device 110′ (sometimes referred to in whole or in part as a “pump assembly”) configured to supply reduced pressure or negative pressure. The wound cover 106 may be in fluid communication with the wound 104 .

[0030] 1B , the conduit 108′ may have a bridge portion 130, which may have a proximal end portion and a distal end portion (the distal end portion is closer to the wound 104 than the proximal end portion), and an applicator 132 at the distal end of the bridge portion 130, which forms a flexible suction adapter (or conduit) 108′. A connector 134 may be disposed at the proximal end of the bridge portion 130 to extend along the length of the bridge portion 130 of the conduit 108 shown in FIG. 1B and connect to at least one of the channels. A cap 140 may be coupled to a portion of the conduit 108 and, in some cases, attached to the connector 134, as illustrated. The cap 140 may be useful in preventing fluid from leaking out the proximal end of the bridge portion 130. The conduit 108′ may be a Soft Port manufactured by Smith & Nephew. As mentioned above, the negative pressure wound therapy system 100' may include a source of negative pressure, such as a device 110', capable of supplying negative pressure to the wound 104 through a conduit 108'. Although not required, the device 110' may also include a canister or other container for storing wound exudate and other fluids that may be removed from the wound.

[0031] Device 110' may be connected to connector 134 via conduit or tube 142. In use, applicator 132 may be placed over a suitably prepared wound or an aperture formed in cover 106 placed over wound 104. Thereafter, with wound therapy device 110' connected to connector 134 via tube 142, wound therapy device 110' may be operated to provide negative pressure to the wound. The application of negative pressure may be applied until a desired level of healing of the wound is achieved.

[0032] The bridge portion 130 may include an upper channel material or layer positioned between the upper and middle layers, with a lower channel material or layer positioned between the middle and bottom layers. The upper, middle, and lower layers may have elongated portions extending between their proximal and distal ends and may include a fluid-impermeable material, e.g., a polymer such as polyurethane. Of course, it will be understood that the upper, middle, and lower layers may each be constructed from different materials, including semi-permeable materials. In some instances, one or more of the upper, middle, and lower layers may be at least partially transparent. In some instances, the upper and lower layers may be curved, rounded, or outwardly convex over a majority of their lengths.

[0033] The upper and lower channel layers may be elongated layers extending from the proximal to the distal end of the bridge 130, and each may 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 may be constructed from, for example, a knitted or woven spacer fabric (such as a knitted polyester 3D fabric, Baltex 7970®, or Gehring 879®), or a nonwoven material, or a terry or loop pile material. The fabric is not necessarily woven and may include felt and flock fiber materials (including materials such as Flotex®). The material selected is preferably positioned to direct wound exudate away from the wound and transmit negative pressure or evacuated air to the wound site, and may also provide the channel layer with some degree of kink or occlusion resistance. In one example, the upper channel layer can include an open-cell foam such as polyurethane, and the lower channel layer can include 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.

[0034] The fabric or material of any component of the bridge 130 may have a three-dimensional (3D) structure, with one or more types of fibers forming a structure in which the fibers extend in all three dimensions. Such fabric may, in some cases, aid in wicking, fluid transport, or negative pressure transmission. In some cases, the fabric or material of the channel may include several layers of material stacked or layered on top of each other, which may, in some cases, be useful in preventing the channel from collapsing under the application of negative pressure. The material used in some implementations of the conduit 108′ may be conformable and flexible, which may, in some cases, help avoid pressure ulcers and other complications that may arise from a wound treatment system pressed against a patient's skin.

[0035] The distal ends of the top, middle, and bottom layers, as well as the channel layer, may be expanded at the distal ends of the layers (placed over the wound site) to form a "teardrop" or other expanded shape. At least the distal ends of the top, middle, and bottom layers, as well as the channel layer, may also be provided with at least one aperture therethrough. This aperture may be useful during device manufacturing, as it may be used to properly align the respective layers, as well as to drain wound exudate and apply negative pressure to the wound.

[0036] In some implementations, a controlled gas leak 146 (which may also be referred to as a gas leak, air leak, or controlled air leak) may be disposed on the bridge portion 130, for example, at the proximal end of the bridge portion 130. This air leak 146 may include an opening or channel extending through an 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 (such as air) may enter through the gas leak 146 and travel along the upper channel of the bridge portion 130 from the proximal end of the bridge portion 130 to the distal end of the bridge portion. The gas can then be drawn into the lower channel of the bridge portion 130 by passing apertures through the upper layer, middle layer, and the distal end of the lower layer.

[0037] The air leak 146 may include a filter. Preferably, the air leak 146 is located at the proximal end of the bridge portion 130 to minimize the possibility of wound exudate or other fluids contacting and blocking the air leak 146 or filter. In some instances, the filter may be a microporous membrane capable of excluding microorganisms and bacteria and filtering particles larger than 45 μm. Preferably, the filter is capable of filtering particles larger than 1.0 μm, and more preferably, particles larger than 0.2 μm. Advantageously, some implementations may provide a filter that is at least partially chemically resistant to, for example, water, common household liquids such as shampoo, and other surfactants. In some cases, reapplication of vacuum to the suction adapter or wiping the exposed outer portion of the filter may be sufficient to clear any foreign matter blocking the filter. The filter may be constructed of a suitably resistant polymer, such as acrylic, polyethersulfone, or polytetrafluoroethylene, and may be oil-based or hydrophobic. In some cases, gas leak 146 may provide a relatively constant gas flow that does not increase appreciably when additional negative pressure is applied to conduit 108'. In the example of negative pressure wound therapy system 100, gas flow through gas leak 146 increases when additional negative pressure is applied; preferably, this increased gas flow is minimized and does not increase proportionally to the negative pressure applied thereto. Further description of such bridges, conduits, air leaks, and other components, features, and details that may be used in any implementation of the negative pressure wound therapy system disclosed herein can be found in U.S. Patent No. 8,801,685, the entirety of which is incorporated by reference as if fully set forth herein.

[0038] Any of the wound therapy devices disclosed herein (such as device 110 or 110') can provide continuous or intermittent negative pressure therapy. Continuous therapy can be delivered above 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 below −200 mmHg. Intermittent therapy can be delivered between a low and a high negative pressure set point (sometimes referred to as a set point). The low setpoint may be set to above 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 below −180 mmHg. The high setpoint may be set to above −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 below −200 mmHg. During intermittent therapy, negative pressure at a low setting can be delivered for a first duration, and upon expiration of the first duration, negative pressure at a higher setting can be delivered for a second duration. Upon expiration of the second duration, negative pressure at the lower setting can be delivered. The first and second durations can be the same or different.

[0039] In operation, the wound packing 102 may be inserted into the cavity of the wound 104, and the wound cover 106 may be placed to seal the wound 104. The wound therapy device 110' may provide negative pressure to the wound cover 106, which may be transmitted to the wound 104 via the wound packing 102. Fluid (such as wound exudate) may be drawn through the conduit 108' and stored in the canister. In some cases, the fluid is absorbed by the wound packing 102 or one or more absorbent layers (not shown).

[0040] Wound dressings that may be utilized with the pump assembly and system of the present application may include Renasys-F, Renasys-G, Renasys AB, and Pico dressings available from Smith & Nephew. Further descriptions of such wound dressings and other components of negative pressure wound therapy systems that may be used with the pump assembly and system of the present application may 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 Patent No. PCT / EP2020 / 078376, each of which is incorporated herein by reference in its entirety as if fully set forth herein. In some cases, other suitable wound dressings may be utilized.

[0041] 2A-2C illustrate a negative pressure wound therapy device 110'. As illustrated, a pump assembly 160 and a canister 162 can be connected to form the wound therapy device 110'. With reference to FIG. 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, but not limited to, a start and pause therapy button 180 or an alarm / alert mute button 182. The interface panel 170 can have one or more input controls or buttons 184 (three shown) that can be used to control any function of the pump assembly 160 or the interface panel 170. For example, but not limited to, 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 some cases, the command buttons 184 may be programmable and may be made from a tactile, soft rubber.

[0042] Additionally, interface panel 170 may have a visual indicator 186 that can show which of one or more buttons 184 is active. Interface panel 170 may also have a lock / unlock control or button 188 that may be configured to selectively lock or unlock the functionality of various buttons (e.g., buttons 184) or display 172. When lock / unlock button 188 is in a locked state, pressing one or more of the various other buttons or display will not cause pump assembly 160 to change any display or performance features of the device. In this manner, interface panel 170 will protect the various buttons or display from being accidentally bumped or touched. Interface panel 170 may be located on an upper portion of pump assembly 160, for example, but not limited to, on an upward-facing surface of pump assembly 160.

[0043] A display 172, which may be a screen such as an LED screen, may be mounted in a middle portion of the interface panel 170. The display 172 may be a touchscreen display. The display 172 supports the playback of audiovisual (AV) content, such as instructional videos, and can render several screens or graphical user interfaces (GUIs) for configuring, controlling, and monitoring the operation of the pump assembly 160.

[0044] The one or more indicators 174 may be illuminating (e.g., LEDs) and configured to provide a visual indication of an alarm condition and / or the status of the pump. For example, without limitation, the one or more indicators 174 may be configured to provide a visual indication of the status of the pump assembly 160 or other components of the negative pressure wound therapy system 100', including, but not limited to, the conduit 108' or the wound cover 106 (e.g., to provide an indication of normal operation, low battery, leak, canister full, blockage, overpressure, etc.). Any one or more suitable indicators may additionally or alternatively be used, such as visual, audible, tactile indicators, etc.

[0045] 2B shows a rear or back view of the wound therapy device 110' shown in FIG. 2A. As shown, the pump assembly 160 may include a speaker 192 for generating audio. For example, without limitation, the speaker 192 may generate an audio alarm in response to deviations in therapy delivery, non-compliance with therapy delivery, or any other similar or suitable medical condition, or a combination thereof. The speaker 192 may provide audio to accompany one or more instructional videos that may be displayed on the display 172.

[0046] The pump assembly 160 may be configured to provide easy access (e.g., an access door on the casing of the pump assembly) to one or more filters of the pump assembly 160, such as an antibacterial filter. This allows a user (e.g., a medical professional or a patient) to more easily access, inspect, or replace such filters. The pump assembly 160 may also include a power jack 196 for providing power to the pump assembly 160 or for charging and recharging an internal power source (e.g., a battery). Some implementations of the pump assembly 160 may include a disposable or renewable power source, such as one or more batteries, such that a power jack is not necessary. The pump assembly 160 may have a recess 198 formed therein to facilitate gripping the pump assembly 160.

[0047] The canister 162 may hold fluid aspirated from the wound 104. For example, the canister 162 may have a capacity of 800 mL (or approximately 800 mL), or a capacity of 300 mL or less to 1000 mL or more, or any capacity level within this range. The canister 162 may include tubing for connection to the conduit 108′ to form a fluid flow path. The canister 162 may be replaced with another canister, such as when the canister 162 is filled with fluid. Referring to FIG. 2A, the wound therapy device 110′ may include a canister inlet tube 200 (also referred to herein as a dressing port connector) in fluid communication with the canister 162. For example, but not by way of limitation, the canister inlet tube 200 may be used to connect to the conduit 108′.

[0048] Canister 162 may be selectively connectable to and removable from pump assembly 160. With reference to FIG. 2A, in some cases, a canister release button 202 may be configured to selectively release canister 162 from pump assembly 160. With reference to FIG. 2B, canister 162 may have one or more fill lines or markings 204 to indicate to a user and to indicate the amount of fluid or exudate stored within canister 162.

[0049] Wound therapy device 110' may have a handle 208 that can be used to lift or carry wound therapy device 110'. Handle 208 may be coupled to pump assembly 160 and may be rotatable relative to wound therapy device 110' such that the handle can be rotated upward to lift or carry wound therapy device 110' or pump assembly 160, or rotated to a lower profile for a more compact position when the handle is not in use. In some cases, handle 208 may be coupled to pump assembly 160 in a fixed position. Handle 208 may be coupled to an upper portion of pump assembly 160 or may be detachable from wound therapy device 110'.

[0050] 3 illustrates a schematic diagram of a control system 300 that may be used in any of the wound therapy devices described herein, such as wound therapy device 110'. The electrical components may operate to accept user input, provide output to a user, operate a negative pressure source, provide connections, etc. A first processor (such as main controller 310) may be responsible for user activity, and a second processor (pump controller 370) may be responsible for controlling another device, such as pump 390.

[0051] The input / output (I / O) module 320 can be used to control input and / or output to another component or device, such as a pump 390, one or more sensors (e.g., one or more pressure sensors 325 configured to monitor pressure at one or more locations in the fluid flow path), etc. For example, the I / O module may receive data from one or more sensors via one or more ports, such as serial (e.g., I2C), parallel, hybrid ports, and the like. Any of the pressure sensors may be part of the wound therapy device or the canister. In some cases, any of the pressure sensors 325 may be remote to the wound therapy device, such as positioned at or near the wound (e.g., in a dressing or a conduit connecting the dressing to the wound therapy device). In such implementations, any of the remote pressure sensors may communicate with the I / O module via a wired connection or with one or more transceivers 340 via a wireless connection.

[0052] The main controller 310 can receive and provide data to and from 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. The main controller 310, along with other controllers or processors, can store data in memory 350 (e.g., one or more memory modules), which may be internal or external to the 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.

[0053] Main controller 310 may be a general-purpose controller, such as a low-power processor or an application-specific processor. Main controller 310 may be configured as the "central" processor within the electronic architecture of control system 300, and may coordinate the activities of other processors, such as pump controller 370, communication controller 330, and one or more additional processors 380. Main controller 310 may run a suitable operating system, such as Linux, Windows CE, VxWorks, etc.

[0054] The pump controller 370 can control the operation of a pump 390, which can generate negative pressure or reduced pressure. The pump 390 can be any suitable pump, such as a diaphragm pump, a peristaltic pump, a rotary pump, a rotary vane pump, a scroll pump, a screw pump, a liquid ring pump, a diaphragm pump operated by a piezoelectric transducer, a voice coil pump, etc. The pump controller 370 can use data received from one or more pressure sensors 325 to measure the pressure in the fluid flow path, calculate the fluid flow rate, and control the pump. The pump controller 370 can control a pump actuator (e.g., a motor) so that a desired level of negative pressure is achieved within the wound 104. The desired level of negative pressure can be selected by a pressure setting or a user. The pump controller 370 can control the pump (e.g., a pump motor) using pulse-width modulation (PWM) or pulse control. The control signal for driving 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.

[0055] A communications controller 330 may provide connectivity (such as a wired or wireless connection 332). The communications controller 330 may utilize one or more transceivers 340 to transmit and receive data. The one or more transceivers 340 may include one or more antennas, optical sensors, optical transmitters, vibration motors or transducers, vibration sensors, acoustic sensors, ultrasonic sensors, etc. The communications processor 330 may provide one or more of the following types of connectivity: global positioning system (GPS), cellular connectivity (e.g., 2G, 3G, LTE, 4G, 5G, etc.), near field communications (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, barcodes such as QR codes, etc.), acoustic connectivity, ultrasonic connectivity, etc. The connection can be used for a variety of activities, such as pump assembly location tracking, asset tracking, compliance monitoring, remote selection, uploading logs, alarms, and other operational data, as well as adjusting therapy settings, software or firmware upgrades, pairing, etc.

[0056] The communications controller 330 can provide dual GPS / cellular functionality. The cellular functionality can be, for example, 3G, 4G, or 5G functionality. The communications controller 330 can communicate information to the main controller 310. The communications controller 330 can include internal memory or can utilize memory 350. The communications controller 330 can be a low-power processor.

[0057] The control system 300 can store data such as GPS data, therapy data, device data, and event data. This data can be stored, for example, in memory 350. This data can include patient data collected by one or more sensors. The control system 300 can track and log therapy and other operational data. Such data can be stored, for example, in memory 350.

[0058] Using the connection provided by communications controller 330, control system 300 can upload any of the data stored, maintained, or tracked by control system 300 to a remote computing device, such as device 334. Control system 300 can also download (e.g., via connection to device 334) various operational data, such as therapy selections, parameters, firmware and software patches and upgrades. One or more additional processors 380 can be utilized, such as a processor for controlling one or more user interfaces (e.g., one or more displays). In some cases, any of the illustrated or described components of control system 300 can be omitted depending on the embodiment of the wound monitoring or treatment system in which control system 300 is used.

[0059] Any of the negative pressure wound therapy devices described herein may 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.

[0060] Multiple dressing negative wound therapy 4 illustrates another negative pressure wound therapy system 400. System 400 may include a wound therapy device capable of delivering negative pressure to a wound site(s), such as wound therapy device 110′. Wound therapy device 110′ may be in fluid communication with one or more wound dressings 406a, 406b (collectively referred to as 406) to deliver negative pressure to one or more wounds, such as wounds 104a and 104b. A first fluid flow path may include components providing a fluid connection from wound therapy device 110′ to first wound dressing 406a. As a non-limiting example, the first fluid flow path may include a passage from wound dressing 406a to wound therapy device 110′ or a passage from first wound dressing 406a to inlet 446 of branch fitting (or connector) 444 in fluid connection with wound therapy device 110′. Similarly, the second fluid flow path may include components that provide a fluid connection from the wound therapy device 110' to the second wound dressing 406b.

[0061] System 400 may be similar to system 100′, except that multiple wounds 104a and 140b are being treated by system 400. System 400 may include any one or more of the components of system 100′ (wounds 104a and 104b, covers 106a and 106b, etc.) illustrated in FIG. 4 with an appended letter “a” or “b” to distinguish between a first wound and a second wound. As illustrated, system 400 may include multiple wound dressings 406a, 406b (and corresponding fluid flow paths) in fluid communication with wound therapy device 110′ via multiple suction adapters, such as adapter 108′. The suction adapter may include any one or more of the components of adapter 108' (such as bridge portions 130a and 130b, connectors 134a and 134b, and caps 140a and 140b) illustrated in FIG. 4 with the letter "a" or "b" added to distinguish between the first and second wounds.

[0062] Wound therapy device 110' may be fluidly coupled to inlet 446 of connector 444 via tube 142. Connector 444 may be fluidly coupled to connectors 134a, 134b, which may be fluidly coupled to tubes or conduits 130a, 130b via branches 445a, 445b and tubes or conduits 442a, 442b. Tubes or conduits 130a, 130b may be fluidly coupled to dressings 406a, 406b. Once all of the conduit and dressing components are connected and operably positioned, wound therapy device 110' may be operated, thereby providing negative pressure to wounds 430a, 430b via the fluid flow paths. Application of negative pressure may be applied until a desired level of healing of wound 430 is achieved. Although two wounds and wound dressings are illustrated in FIG. 4, some implementations of wound therapy device 110' can provide treatment to a single wound (e.g., by closing an unused branch 445a or 445b of connector 444) or to three or more wounds (e.g., by adding branches to connector 444).

[0063] System 400 may include one or more features disclosed in U.S. Patent Publication No. 2020 / 0069850 or International Publication No. WO2018 / 167199, each of which is incorporated by reference in its entirety.

[0064] Negative Pressure Device Self-Test In some cases, a negative pressure wound therapy device (such as device 110) may need to be tested to ensure it can safely and effectively provide negative pressure wound therapy. Such testing may involve verifying one or more of: that the device's leak rate is within acceptable limits; that the negative pressure source provides adequate flow; that the overpressure safety system is operational; the efficiency (or health) of the negative pressure wound therapy device; etc. Testing may also or alternatively involve one or more of prompting the user to press one or more buttons (such as button 184) on the user interface to confirm normal operation; verifying that a display (such as display 172) is illuminated; verifying that one or more status indicators (such as status indicator 174) are illuminated; verifying that a speaker (such as speaker 192) is operational; etc. Testing may be performed, for example, when the device is used periodically (e.g., every six months) on a new patient. Test parameters, such as time and pressure settings, can be varied to accommodate different self-test hardware designs. For example, the pressure can be varied from approximately -40 mmHg to approximately -250 mmHg. Existing devices are typically sent by the user (such as a patient or healthcare professional (HCP)) to the device manufacturer or a third-party laboratory for testing. However, this approach is time-consuming, expensive, and disruptive.

[0065] FIG. 5 illustrates a negative pressure wound therapy device 500 configured to perform a self-test. The device 500 may include one or more features of any of the devices described herein, such as device 110. The device 500 may be able to perform a self-test on-site without having to send the device to a manufacturer or third-party organization. For example, a user may cause the device 500 to perform a self-test. The self-test may be initiated through a user interface of the device, such as through the display 206. The self-test may be initiated remotely. The device 500 may provide an indication to a user (which may be local or remote) or a remote computing system that the self-test was successfully or unsuccessfully completed. The indication may be provided using any of the approaches described herein, such as visual, auditory, tactile, via remote transmission, etc. The indication may include information regarding which particular test(s) were successfully or unsuccessfully completed. In some cases, in response to determining that the self-test was unsuccessfully completed, the indication may include disabling the delivery of negative pressure wound therapy.

[0066] Device 500 may include inlet 510, a (optional) canister 520, and a negative pressure source (positioned in the direction indicated by arrow 560). In a canisterless system, inlet 510 may be similar to connector 430 illustrated in FIG. 4A. For example, a one-way valve or check valve 550 may be included to ensure that fluid flows downstream toward the negative pressure source (in the direction indicated by arrow 560) rather than in the opposite direction when the negative pressure source is paused or stopped. Check valve 550 can stop any reverse flow when the negative pressure source is stopped. Device 500 may include valve 530, flow restrictor 540, and pressure sensors 532 and 534 positioned in the fluid flow path upstream and downstream of flow restrictor 540. In some cases, pressure sensors 532 and 534 can be replaced with differential pressure sensors configured to measure the pressure across flow restrictor 540 and within the fluid flow path. The fluid flow path may include a negative pressure source and other components within or integral with the negative pressure source, such as one or more connectors, manifolds, lumens, tubing, valves (e.g., one or more valves of the negative pressure source), etc. In some implementations, flow restrictor 540 may be a valve, such as a solenoid valve (or solenoid) or a manually operated valve. For example, valve 530 may also be a flow restrictor. The flow restriction created by flow restrictor 540 may result in a known pressure drop across the pressure measured by pressure sensors 532 and 534.

[0067] During normal operation, when device 500 provides negative pressure to a wound covered by a wound dressing fluidly connected to inlet 510, valve 530 may remain open. Device 500 may regulate the negative pressure in the fluid flow path based on a pressure signal from pressure sensor 532 (and / or pressure sensor 534). During a self-test, valve 530 may be closed. Valve 530 may be a solenoid valve opened and closed by a controller (or one or more controllers) of device 500 or a manually operated valve. Pressure sensors 532 and 534 may be checked during normal operation to verify that similar values ​​of pressure are being detected. Limits (or thresholds) may be set for changes in pressure detected by pressure sensors 532 and 534. In response to a determination that the limit has been met, a determination may be made that the self-test has failed, and an indication may be provided.

[0068] 6 illustrates a process 600 for performing a self-test. Process 600 may be implemented by device 500, such as by being performed under the control of a controller (or one or more controllers) of device 500. In block 602, process 600 may verify that a canister or a wound dressing is disconnected. In some cases, a wound dressing may be connected to a canister. In block 602, process 600 may verify that one or more of a wound dressing (e.g., in a canister-less system) or a canister (e.g., in a system having a canister) is disconnected. This may be performed via one or more sensors, such as an optical sensor, an electromagnetic sensor (e.g., a Hall Effect sensor), an electrical switch, a mechanical switch, etc. In some cases, a self-test may be performed without removing the canister. This may provide the advantage of allowing the canister filter to act as protection from particles (dust or debris) entering the system and potentially causing damage to any of the components 530, 532, 534, 540, 550, or the negative pressure source.

[0069] It may be advantageous to remove one or more of the wound dressings or canisters during a self-test, such as to ensure there are no restrictions on fluid flow or to establish a fixed volume within the fluid flow path that is subject to the self-test. For example, because the volume of fluid absorbed by the wound dressing is unknown, a wound dressing fluidly connected to device 500 may provide a substantial restriction to fluid flow, which may cause the self-test to be performed inaccurately. As another example, if a canister is present, the volume of fluid that may be present in the canister (e.g., fluid being drawn from the wound) is unknown, which may cause the self-test to be performed inaccurately. As yet another example, safety may be promoted by not performing an overpressure test when the device is fluidly connected to a patient. In some cases, process 600 may prompt the user to remove one or more of the canisters or wound dressings. Process 600 may generate an indicator in response to determining that one or more of the wound dressings or canisters have not been removed at block 602. The process 600 may terminate the self-test at block 602 in response to determining that one or more of the wound dressing or the canister has not been removed.

[0070] The process 600 may proceed to block 604, where a leak test of the device may be performed. The leak test may be used to verify that the device's leak rate is within acceptable limits for negative pressure wound therapy. If the leak test fails, the process 600 may proceed to block 614. If the leak test passes, the process 600 may proceed to block 606, where a flow test of the device may be performed. The flow test may be used to verify that the negative pressure source of the device provides adequate flow for negative pressure wound therapy. If the flow test fails, the process 600 may proceed to block 614. If the flow test passes, the process 600 may proceed to block 608, where the overpressure safety system of the device may be verified to be operational. The overpressure safety system may prevent the application of unsafe levels of negative pressure to the wound (e.g., negative pressures below about -235 mmHg, below or above about -240 mmHg, below or above about -245 mmHg, above about -250 mmHg, etc.). In some cases, the overpressure safety system may include a valve or another mechanism configured to release negative pressure in response to detecting an excessive negative pressure level. For example, a valve may open to release the excessive negative pressure to the atmosphere. Alternatively, or in addition, the overpressure safety system may include deactivating the negative pressure source or device 500 in response to detecting an excessive negative pressure level. If the overpressure test fails, the process 600 may proceed to block 614. If the overpressure test passes, the process 600 may proceed to block 612. In block 612, the process 600 may provide an indication that the self-test was successfully completed. In some cases, the order of tests 604-608 may be different. For example, the flow test of block 606 may be performed before the leak test of block 604.

[0071] At block 614, process 600 may provide an indication that the self-test was not completed successfully. Such an indication may include information about which of one or more tests described herein was not completed successfully.

[0072] FIG. 7 illustrates a process 700 for leak testing. Process 700 may be performed in block 604 of FIG. 6. Process 700 may be implemented by device 500, such as being performed under the control of a controller (or one or more controllers) of device 500. Process 700 may begin in block 702, where valve 530 may be closed. In block 704, process 700 may activate a negative pressure source. Process 700 may operate the negative pressure source at a low intensity or a low level of activity (such as a duty cycle (e.g., PWM) of about 10% or less, a duty cycle (e.g., PWM) of about 20% or less, a duty cycle (e.g., PWM) of about 30% or less, etc.). For example, process 700 may provide a low level of power to an actuator (such as a motor, a piezoelectric transducer, etc.) of the negative pressure source. Process 700 may remain in block 704 until a first threshold level of negative pressure is established in the fluid flow path. This can be verified by pressure sensor 532 (or pressure sensor 534). The first threshold level of negative pressure may be at least about −100 mmHg, up to or above about −150 mmHg, up to or above about −160 mmHg, up to or above about −170 mmHg, up to or above about −180 mmHg, up to or above about −190 mmHg, up to or above about −200 mmHg, etc. The first threshold level of negative pressure may depend on various factors, such as the type of negative pressure source utilized by device 500, the type of wound device 500 is configured to treat (e.g., treating a large wound may require device 500 to be configured to provide a greater level of negative pressure and a greater flow rate than treating a small wound), etc.

[0073] In some cases, the volume of the fluid flow path may be significantly reduced after closing valve 530. When a first threshold level of negative pressure has been established (as may typically be done during application of negative pressure wound therapy to a wound), activating the negative pressure source and then deactivating the negative pressure source may allow the negative pressure in the fluid flow path to reach a level that would result in an excessive negative pressure level. This may undesirably activate the overpressure safety system. To avoid such an outcome, the actuator of the negative pressure source may be activated for a fixed period or a fixed duty cycle, after which the pressure in the fluid flow path may be verified. The actuator may then be activated again, as needed, to establish the first threshold level of negative pressure. For example, the actuator may be a motor that may be pulsed for a fixed period or for a single rotation (or multiple rotations). The pressure in the fluid flow path may then be verified, and the motor may again be pulsed if the first threshold level of negative pressure has not been established.

[0074] Process 700 may proceed to block 706, which may verify that a first threshold level of negative pressure has been established in the fluid flow path. For example, process 700 may verify that pressure sensor 532 reads a negative pressure level that is greater than (or more negative than) or equal to the first threshold level of negative pressure. If the verification at block 706 is unsuccessful, process 700 may proceed to block 714, which may provide an indication that the leak test failed. For example, the leak test may fail due to the presence of one or more leaks in the fluid flow path that prevent process 700 from establishing the first threshold level of negative pressure in the fluid flow path.

[0075] If the verification at block 706 is successful, process 700 may proceed to block 708. In block 708, process 700 may implement a delay for a threshold period of time. The threshold period may be, for example, 1 second or less, 2 seconds or less, 5 seconds or more, 10 seconds or more, etc. In block 708, the negative pressure source may be paused to allow the negative pressure in the fluid flow path to decrease (or become more positive). Such negative pressure decay may 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 valve 530, in the fluid flow path may have inherent leaks). As described herein, the threshold period of the delay may depend on various factors, such as the type of negative pressure source utilized by device 500, the type of wound device 500 is configured to treat, etc.

[0076] After the threshold period has elapsed, process 700 may proceed to block 710, where it may verify that the decrease in negative pressure within the fluid flow path meets a pressure decay threshold. While one or more inherent leaks may be present within the fluid flow path, such leaks must not be so large or severe as to cause a large negative pressure drop within the fluid flow path during the delay at block 708. The pressure decay threshold may be set to a relatively small value, such as 1 mmHg or less, 2 mmHg or less, 3 mmHg or less, 4 mmHg or less, 5 mmHg or less, 10 mmHg or less, 20 mmHg or less, 25 mmHg or less, etc. As described herein, the pressure decay threshold may depend on various factors, such as the type of negative pressure source utilized by device 500, the type of wound device 500 is configured to treat, etc. In block 710, process 700 may utilize a reading from pressure sensor 532 or 534.

[0077] If process 700 verifies at block 710 that the negative pressure in the fluid flow path meets the pressure decay threshold, then process 700 may proceed to block 712, which may indicate that the leak test was successfully completed. For example, at block 710, process 700 may verify that the negative pressure in the fluid flow path is greater than (or more negative than) or equal to the difference between a first threshold level of negative pressure and a pressure decay threshold. If the verification at block 710 is unsuccessful, process 700 may proceed to block 714, which may provide an indication that the leak test failed. This may be due to one or more leaks in the flow path causing the pressure to decay too rapidly.

[0078] FIG. 8 illustrates a process 800 for a flow test. Process 800 may be performed in block 606 of FIG. 6. Process 800 may be implemented by device 500, such as being performed under the control of a controller (or one or more controllers) of device 500. Process 800 may begin in block 802, where valve 530 may be opened. In block 804, process 800 may activate a negative pressure source. Process 800 may operate the negative pressure source at a high intensity or maximum level of activity. For example, process 800 may supply a maximum level of power to an actuator of the negative pressure source. In block 804, the process may operate the negative pressure for a threshold duration, such as about 1 second or less, about 2 seconds or less or more, about 3 seconds or less or more, about 4 seconds or less or more, about 5 seconds or less, about 6 seconds or less, about 7 seconds or more, about 8 seconds or less, about 9 seconds or less, about 10 seconds or more, etc.

[0079] Block 804 may be executed to operate the negative pressure source at its highest or maximum flow (such as at its highest or maximum duty cycle (such as about 95% PWM or greater)). Because such operation may cause a significant increase in negative pressure within the fluid flow path, process 800 may execute block 802 (to open valve 530) to prevent activation of the overpressure safety system, as described herein.

[0080] Process 800 may proceed to block 806, where it may verify that the pressure differential across the flow restrictor 540 meets a threshold pressure differential indicative of adequate flow. The flow restrictor 540 may have a cross-sectional area that is narrower than the cross-sectional areas of other components in the fluid flow path. For example, the flow restrictor 540 may be one or more of a thin, relatively long tube or conduit, a small orifice or aperture, or the like. As another example, the flow restrictor 540 may be a variable-area flow restrictor having a cross-sectional area that can be changed or adjusted (e.g., by one or more controllers) to overcome flow restriction caused by the flow restrictor during normal operation so that undue load is not placed on the negative pressure source. For example, the flow restrictor 540 may be a butterfly valve, needle valve, ball valve, solenoid valve, or the like. As yet another example, a bypass pipe or conduit having an unrestricted cross-sectional area can be placed across the flow restrictor. During normal operation, fluid may flow across the bypass conduit. During the self-test, fluid may flow across flow restrictor 540. By using one or more valves, such as one or more solenoid valves, the flow of fluid can be directed to either the bypass conduit or flow restrictor 540. Further 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.

[0081] As a result of restricting the fluid flow, a pressure differential can be created across the flow restrictor 540. Such a pressure differential can be determined by pressure sensors 532 and 534. The pressure differential measurement can be used to determine the flow rate in the fluid flow path, where the pressure differential can be proportional to the flow rate. For example, the pressure differential can be proportional to the flow rate, so an increase in flow rate can cause an increase in the pressure differential. In some cases, because the valve 530 was opened in block 802, the pressure sensor 532 can measure atmospheric pressure. The pressure sensor 534, positioned downstream of the flow restrictor 540, can measure 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 approximately 5 mmHg or less, 10 mmHg or less, 15 mmHg or less, 20 mmHg or more, etc. The pressure differential threshold may depend on various factors, such as the type of negative pressure source utilized by the device 500, the type of wound the device 500 is configured to treat, the flow rate through the flow path, etc.

[0082] If process 800 determines that the pressure differential across flow restrictor 540 meets the pressure differential threshold, it may transition to block 812, which may indicate a successful completion of the flow test. For example, process 800 may 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 at block 806 is unsuccessful, process 800 may transition to block 814, which may provide an indication that the flow test failed. For example, process 800 may transition to block 814 in response to determining that the pressure differential is less than the pressure differential threshold. A failed flow test may be due to a failure of one or more components of the negative pressure source (e.g., an actuator), a blockage of the fluid flow path, etc.

[0083] In some cases, after transitioning to block 812, process 800 may test the health of the negative pressure wound therapy device. The health of the device may be determined based on the efficiency of the negative pressure source (such as a pump). Efficiency may be determined as the ratio of power output to power input using Equation 1:

number

[0084] The power input may reflect the power consumed by the negative pressure source. The power input may be determined as the product of the current and voltage supplied to the negative pressure source. In some implementations, the current may be measured and calculated via a sense resistor and, optionally, an amplifier. The sense resistor may be placed in series with the negative pressure source. The output from the sense resistor (which may be the voltage across the resistor) may be sent to an amplifier. The amplifier may amplify the voltage, which may be small due to the small resistance of the resistor. The current provided to the negative pressure source may be calculated using Ohm's Law (amps of the resistor / voltage output by resistance).

[0085] Power output can indicate the actual performance of a negative pressure source (e.g., the power output by the negative pressure source). Power output can be calculated by determining the mass flow rate and specific work according to Equation 1. Equation 4 can be used to calculate the mass flow rate. To determine the mass flow rate, the volumetric flow rate (V · ) and the density of air (ρ air ) can be utilized. Volumetric flow rate can indicate the volume of fluid passing over time. The change in pressure across flow restrictor 540, which can be measured as the difference between the pressure readings by pressure sensor 532 and sensor 534, as described herein (such as in connection with block 806), can indicate the volumetric flow rate. In some instances, flow restrictor 540 can be modeled to determine the relationship between the flow (or volumetric flow rate) and the change in pressure. For example, Bernoulli's equation can be used. In some instances, the relationship can be linear.

number

[0086] In some instances, mass flow can be measured directly, such as by using a flow sensor (or flow meter). For example, a hot wire sensor can be used.

[0087] The density of air can vary with temperature and altitude. Equation 5 can be used to determine the density at a specific temperature and altitude. In this equation, Pabsolute(atmospheric) is the atmospheric pressure (in Pascals) and Rspecific is the specific gas constant for dry air (287.058 JKg -1 K -1 ), where T is the temperature in Kelvin. In some cases, the density of air at room temperature (20 degrees Celsius) and the mean sea level atmospheric pressure (101.325 kPa) can be used, which is 1.2041 kg / m 3 is equal to. In accordance with Equation 3, specific work (W) can be determined as the ratio of the pressure difference (between the pressure measured by pressure sensor 532 and the pressure measured by pressure sensor 534) to the density of air. In some instances, the pressure difference can be compared to a threshold value, which can indirectly provide a measure of specific work. For example, the negative pressure source can be operated at maximum intensity (to provide maximum flow), and the pressure difference can be compared to a threshold value associated with the specific work when maximum flow is provided. As described herein, the threshold value can be adjusted for the density of air. If the threshold value is met (e.g., met or exceeded), the predetermined value of specific work (associated with providing maximum flow) can be used to calculate efficiency.

[0088] At block 816, the process may determine the mass flow rate. By determining the mass flow rate, the efficiency of the negative pressure source may be calculated under various temperature and pressure conditions (such as at different altitudes). In some cases, an indication of the mass flow rate may be provided (e.g., displayed).

[0089] The process 800 may proceed to block 818, where the efficiency of the negative pressure source may be determined. Efficiency may be calculated using Equation 1, as described above. The process 800 may proceed to block 820, where the efficiency determined in block 818 may be compared to an efficiency threshold. The efficiency threshold may indicate the efficiency of the device, determined before the negative pressure wound therapy device is used. For example, the efficiency threshold may indicate the efficiency of the device, determined at the time of manufacture. If the determined efficiency meets the efficiency threshold (e.g., within 1%, 2%, 5%, or 10% of the efficiency threshold), the process may proceed to block 822, indicating that the device has passed the health test. For example, a diaphragm pump may be approximately 20% efficient. The efficiency threshold may be set at 15% efficiency (or above or below). Failure to comply with the efficiency threshold may mean that the negative pressure source is unable to deliver negative pressure wound therapy, or is able to deliver, but generates too much heat. If, at block 818, it is determined that the efficiency does not meet the efficiency threshold, process 800 may transition to block 824, indicating that the negative pressure wound therapy device failed the health test. The health may be determined as a ratio between the device efficiency determined before the negative pressure wound therapy device was used and the efficiency determined at block 818. The determined health value may be provided to a user, such as displayed. The process of checking the device health may advantageously allow a user to determine the health of the device, and whether the device should be serviced, without having to send the device to a service and repair center. In some implementations, the health test may be performed separately from the flow test.

[0090] FIG. 9 illustrates a process 900 for overpressure testing. Process 900 may be implemented at block 608 of FIG. 6. Process 900 may be implemented by device 500, such as by being performed under the control of a controller (or one or more controllers) of device 500. Process 900 may begin at block 902, where valve 530 may be closed. In block 904, process 900 may activate a negative pressure source. Similar to block 704 of FIG. 7, in block 904, process 900 may operate the negative pressure source at a low intensity or a low level of activity. For example, process 900 may provide a low level of power to an actuator of the negative pressure source. The same or a different intensity level or low activity level as in block 704 may be used.

[0091] Process 900 may remain at block 904 until a second threshold level of negative pressure is established in the fluid-flow path. This can be verified by pressure sensor 532 (or pressure sensor 534). The second threshold level of negative pressure may correspond to a negative pressure that is slightly less (or more positive) than a threshold indicator of excessive (or excessive) pressure or an unsafe level of negative pressure (e.g., a negative pressure of about −235 mmHg or less, about −240 mmHg or less or greater, about −245 mmHg or less or greater, about −250 mmHg or greater, etc.). For example, the second threshold level of negative pressure may be about −200 mmHg or less, about −210 mmHg or less or greater, about −220 mmHg or less, about −230 mmHg or less or greater, about −250 mmHg or less, etc.

[0092] If the second threshold level of negative pressure is established in the fluid flow path, process 900 may proceed to block 906, which may verify that the overpressure safety system is not engaged. Absent a fault, the negative pressure in the fluid flow path has not reached the excessive pressure threshold and therefore the overpressure safety system should not be engaged. If such verification fails, process 900 may proceed to block 914, which may provide an indication that the overpressure test failed.

[0093] If the verification at block 906 is successful, process 900 may proceed to block 908, where the negative pressure source may be activated. Block 908 may be similar to block 904, except that process 900 may remain at block 908 (with the negative pressure source activated) until the negative pressure level in the fluid flow path meets an overpressure threshold. For example, process 900 may remain at block 908 until the negative pressure in the fluid flow path reaches or exceeds an overpressure threshold. This verification may be performed by pressure sensor 532 (or pressure sensor 534). Process 900 may then proceed to block 910, where it may verify that the overpressure safety system is activated (e.g., the negative pressure source is deactivated). If the overpressure safety system includes a separate valve configured to vent the overpressure to the surrounding environment, process 900 may include operating the negative pressure source in block 908 at a different level of intensity (such as a maximum level of intensity) to verify that the excessive pressure threshold cannot be achieved. For example, the level of intensity may be higher than that described herein in connection with segment 1130 of FIG. 11 . If such verification fails, process 900 may proceed to block 914. If the verification in block 910 is successful, process 900 may proceed to block 912, which may indicate that the overpressure test was successfully completed.

[0094] In some cases, process 900 may additionally or alternatively perform a flow test of process 800. If the flow test fails (e.g., process 800 reaches block 814), it can be concluded that the overpressure safety system is operational. If the flow test completes successfully (e.g., process 800 reaches block 812), it can be concluded that the overpressure safety system is not operational. In some instances, the flow test may be performed before transitioning from block 910 to 912. Performing a flow test may provide additional or alternative verification of the operation of the overpressure safety system.

[0095] Figure 10 illustrates a manifold 1000 that may be utilized by the negative pressure wound therapy device of Figure 5. Manifold 1000 may incorporate one or more of valve 1030 (which may correspond to valve 530), pressure sensors 1032 and 1034 (which may correspond to pressure sensors 532 and 534), flow restrictor 1090 (which may correspond to flow restrictor 540), check valve 1050 (which may correspond to check valve 550), or connections between any of these components. Manifold 100 may include an electronics board 1072 (e.g., a circuit board) that supports pressure sensors 1032 and 1034, which may correspond to pressure sensors 532 and 534, respectively. Electronics board 1072 may support valve 1030, which may correspond to valve 530. Valve 1030 may be a solenoid valve.

[0096] Manifold 1000 may be formed from parts or housings 1074 and 1078 separated by a membrane or gasket 1076. Gasket 1076 may be designed to provide a fluid-tight seal when housings 1074 and 1078 are connected. Housings 1074 and 1078 may be glued together, welded together (e.g., using ultrasonic welding), or the like. Housing 1074 may support electronic board 1072. Gasket 1076 may support check valve 1050, which may correspond to check valve 550. In some cases, check valve 1050 may be positioned external to manifold 1000.

[0097] The housing 1078 may include an inlet 1012 that may be fluidly connected to the canister (if present, or the cladding in a canisterless system) and located downstream of the canister. Referring to FIG. 5, the inlet 1012 may be located on the side of the canister 520 opposite the inlet 510. The inlet 1012 may be similar to the connector 430 illustrated in FIG. 4A. The housing 1078 may include an outlet 1062 that may be fluidly connected to a negative pressure source. The outlet 1062 may be located at or near the location indicated by arrow 560 in FIG. 5. The housing 1078 may include an outlet 1082 that is fluidly connected to the exhaust of the negative pressure source. The housing 1078 may include a silencer configured to reduce noise, vibrations, etc. generated by the negative pressure source during operation, or one or more filters configured to prevent odors, bacteria, etc. from being released into the surrounding environment. The housing 1078 may include an outlet 1084 fluidly connected to exhaust (such as outside air) to expel gases after passing through the muffler. In some cases, the muffler may be external to the manifold and the outlets 1082 and 1084 may be omitted. Further 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.

[0098] A flow restrictor 1090, which may correspond to flow restrictor 540, may be integrated into manifold 1000. For example, flow restrictor 1090 may be positioned within housing 1074. The flow restrictor may be installed between inlet 1012 and outlet 1062. In some cases, flow restrictor 1090 may be a solenoid valve. If valve 1030 functions as the flow restrictor, component 1090 may be omitted.

[0099] Further 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.

[0100] The use of manifold 1000 or another modular unit can advantageously enable efficient troubleshooting, for example, if one or more tests performed during a self-test fail. For example, manifold 1000 or another modular unit can be replaced in response to one or more of processes 600, 700, 800, or 900 executing one or more of blocks 614, 714, 814, or 914. Such a design may allow a user to quickly replace one or more potentially defective components that may have caused a self-test to fail. Manifold 1000 or another modular unit may be detachable from device 500. During repair or maintenance, a potentially defective manifold 1000 or another modular unit can be removed and a different manifold 100 or another modular unit installed in device 500, allowing the self-test to be successfully completed. In some cases, the negative pressure source can be replaced along with manifold 1000 or another modular unit. For example, a negative pressure source can be attached to or integrated with manifold 1000 to form a replaceable modular unit.

[0101] 11 illustrates a graphical output 1100 for performing a flow test, a leak test, and an overpressure test. The X-axis may represent time. The Y-axis may represent the pressure and duty cycle of the negative pressure source. Curve 1102 may represent the pressure in the fluid flow path (as measured by one or more of pressure sensors 532 or 534, such as pressure sensor 534). Curve 1104 may represent the duty cycle of the negative pressure source.

[0102] A flow test is illustrated in segment 1110. Valve 530 may be open. As described herein, the negative pressure source may be operated at its highest or maximum flow. As illustrated, curve 1104 may be at approximately 100% duty cycle (e.g., 95% PWM). The pressure in the fluid flow path is illustrated by curve 1102, which shows a stable pressure of approximately 35 mmHg. The results of the flow test may also be used to determine the health of the device or the efficiency of the negative pressure source.

[0103] A leak test is illustrated in segment 1120. Valve 530 may be closed. As described herein, the negative pressure source can be operated at a low intensity or low level of activity. As illustrated by curve 1104, the negative pressure source can be pulsed at a PWM of 20% (or less than or more than 20%, as described herein). Pulses can be separated by a time delay to protect pressure sensor 532 or 534 from damage (such as from establishing high negative pressure in a small volume fluid flow path with valve 530 closed). As illustrated by curve 1102, a leak can manifest itself with a large drop in pressure in the fluid flow path. In some cases, pressure sensor 534, located on the negative pressure source side of flow restrictor 540, can be monitored to determine a leak.

[0104] An overpressure test is illustrated by segment 1130. Valve 530 may be closed. As described herein, the negative pressure source may be operated at a low intensity or low level of activity. As illustrated by curve 1104, the negative pressure source may be pulsed with a PWM of 20% (or less than or more than 20%, as described herein). Each pulse may increase the negative pressure in the fluid flow path. As described herein, the pulses may be separated by a time delay to protect pressure sensor 532 or 534 from damage. At the end of segment 1130, the pressure in the fluid flow path may meet an overpressure threshold.

[0105] Advantageously, the self-testing improvements described herein may allow for more efficient and reliable self-testing of negative pressure devices, which may result in shorter interruptions in negative pressure wound therapy and improved patient care.

[0106] Other variations Although some embodiments describe negative pressure wound therapy, the systems, devices, and / or methods disclosed herein may be applied to other types of therapy that can be used standalone or in addition to TNP therapy. The systems, devices, and / or methods disclosed herein may be extended to any medical device, particularly any wound treatment device. For example, the systems, devices, and / or methods disclosed herein may be used with devices that provide one or more of ultrasound therapy, oxygen therapy, neurostimulation, microwave therapy, active agents, antibiotics, antimicrobial agents, or the like. Such devices may also provide TNP therapy. The systems and methods disclosed herein are not limited to medical devices and may be utilized by any electronic device.

[0107] Any of the controllers or processors disclosed herein may include electronic circuitry (sometimes referred to as control circuitry), which may be configured to implement programmable or hardwired control.

[0108] Any values, such as thresholds, limits, durations, etc., provided herein are not intended to be absolute values ​​and may therefore be approximate. In addition, any thresholds, limits, durations, etc. provided herein may be fixed or variable, either automatically or by a user. Furthermore, as used herein, terms expressing relative degrees, such as greater than, over, and less than, relative to a reference value, are intended to encompass equality with the reference value. For example, exceeding a positive reference value can encompass being equal to or greater than the reference value. In addition, as used herein, terms expressing relative degrees, such as greater than, over, and less than, relative to a reference value, are intended to encompass the inverse of the disclosed relationship, such as less than, under, and over, relative to the reference value.

[0109] It is understood that a property, substance, characteristic, or group described in connection with a particular aspect, embodiment, or example may be applicable to any other aspect, embodiment, or example described herein, to the extent not incompatible therewith. All features disclosed herein (including any claims, abstract, and drawings), and / or all steps of any method or process so disclosed, may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive. Protection is not limited to the details of any of the foregoing embodiments. Protection extends to any novel, or any novel combination, of features disclosed herein (including any accompanying claims, abstract, and drawings), or any novel, or any novel combination of steps of any method or process similarly disclosed.

[0110] Although specific embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of protection. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Additionally, various omissions, substitutions, and changes may be made in the form of the methods and systems described herein. Those skilled in the art will recognize that in some embodiments, the actual steps performed in the illustrated and / or disclosed processes may differ from those shown in the figures. In some embodiments, certain of the steps described above may be omitted, or others may be added. For example, the actual steps and / or order of steps performed in the disclosed processes may differ from those shown in the figures. In some embodiments, certain of the steps described above may be omitted, or others may be added. For example, various components illustrated in the figures or disclosed herein may be implemented as software and / or firmware on a processor, controller, ASIC, FPGA, and / or dedicated hardware. Software or firmware may include instructions stored in non-transitory computer-readable memory. The instructions may be executed by a processor, controller, ASIC, FPGA, or dedicated hardware. Hardware components, such as controllers, processors, ASICs, FPGAs, and the like, may include logic circuitry. Furthermore, the features and characteristics of specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure.

[0111] The user interface screens illustrated and described herein may include additional and / or alternative components. These components may 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 may include additional and / or alternative information. The components may be arranged, grouped, and displayed in any suitable order.

[0112] In particular, conditional language such as "can," "could," "might," "may," "for example," and the like, are generally intended to convey that certain embodiments include certain features, elements, and / or conditions, while other embodiments do not, unless specifically stated otherwise or understood otherwise within the context of use. As such, such conditional language is not necessarily intended to suggest that features, elements, and / or conditions are required in any way for one or more embodiments, or that one or more embodiments necessarily include logic for determining whether those features, elements, and / or conditions are included in or should be implemented in any particular embodiment, with or without author input or instruction. Terms such as "comprise," "include," and "have" are synonymous and used in an inclusive, open-ended manner and do not exclude additional elements, features, acts, operations, etc. Also, the term "or" is used in an inclusive sense (rather than an exclusive sense), such that, for example, when used to connect a list of elements, the term "or" means one, some, or all of the elements in the list. Additionally, the term "each," as used herein, in addition to having its ordinary meaning, can also refer to any subset of the series of elements to which the term "each" is applied. Furthermore, as used herein, the words "herein," "above," "below," and similar words, when used in this application, are meant to refer to the specification as a whole and not to specific portions of the specification.

[0113] Unless otherwise specified, connective language such as the phrase "at least one of X, Y, and Z" should be understood in the context in which it is generally used to convey that an item, term, etc. can be either X, Y, or Z, or combinations thereof. Thus, such connective language is generally not intended to imply that a particular embodiment requires that at least one of X, at least one of Y, and at least one of Z, each be present.

[0114] As used herein, language expressing degrees, such as "approximately," "about," "generally," and "substantially," refers to a value, amount, or characteristic that is close to a given value, amount, or characteristic that still performs a desired function or produces a desired result. For example, the terms "approximately," "about," "generally," and "substantially" can refer to an amount that is within 10%, 5%, 1%, 0.1%, and 0.01% of a given amount. As another example, in certain embodiments, the terms "generally parallel" and "substantially parallel" refer to a value, amount, or characteristic that deviates from exactly parallel by no more than 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degrees.

[0115] Unless expressly stated otherwise, articles such as "a" or "an" should generally be construed to include one or more listed items. Thus, phrases such as "a device configured to" are intended to include one or more listed devices. Such one or more listed devices may also be collectively configured to perform the stated enumeration.

[0116] While the present disclosure includes particular embodiments, examples, and applications, it should be understood by those skilled in the art that the present disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses and obvious modifications and equivalents thereof, including embodiments that may not provide all of the features and advantages described herein. Accordingly, the scope of the present disclosure is not intended to be limited by the specific disclosure of preferred embodiments herein, but may be defined by the claims presented herein or hereafter. [Additional note 1] 1. A negative pressure wound therapy device comprising: a negative pressure source connected via a fluid flow path to a wound covered by the wound dressing and configured to provide negative pressure to the wound; a valve positioned within the fluid flow path, the valve configured, in an open state, to allow a supply of negative pressure from the negative pressure source upstream of the valve and, in a closed state, to block a supply of negative pressure from the negative pressure source upstream of the valve; a flow restrictor positioned within the fluid flow path; a pressure sensor configured to measure a pressure in the fluid flow path and a pressure differential across the flow restrictor; a control circuit, wherein the control circuit in a normal mode of operation in which negative pressure is provided to the wound, causing the valve to be in the open state; and In a test mode in which the performance of the device is verified, the device is configured to perform at least one of a leak test, a flow test, or an overpressure test; the leak test includes the control circuit being configured to: close the valve; operate the negative pressure source at a first intensity level; deactivate 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 the negative pressure measured by the pressure sensor after expiration of the duration meets a threshold indicative of a leak; 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 a pressure differential across the flow restrictor measured by the pressure sensor meets a different threshold indicative of insufficient flow; The negative pressure wound therapy device, wherein the overpressure test includes the control circuit being configured to close the valve, operate the negative pressure source at a third intensity level, and indicate a defect in a system configured to protect against unsafe negative pressure in the fluid flow path in response to the pressure in the fluid flow path meeting a threshold indicative of an unsafe negative pressure and determining that the system configured to protect against unsafe negative pressure is not operating. [Additional note 2] 10. The device of claim 1, wherein the second intensity level is greater than the first intensity level. [Additional note 3] 10. The device of any one of the preceding claims, wherein the first intensity level is equal to the third intensity level. [Additional note 4] 10. The device of any one of the preceding claims, wherein the valve comprises a solenoid valve. [Additional note 5] 10. The device of claim 1, wherein the pressure sensor comprises a first pressure sensor positioned upstream of the flow restrictor and a second pressure sensor positioned downstream of the flow restrictor. [Additional note 6] 10. The device of claim 1, further comprising a canister positioned within the fluid flow path and configured to collect fluid aspirated from the wound, wherein the control circuit is further configured to verify that the canister is removed from the fluid flow path in the test mode. [Additional note 7] 7. The device of claim 6, wherein the control circuit is further configured, in the test mode, to not perform the leak test, the flow test, and the overpressure test in response to determining that the canister has not been removed and the wound dressing has not been disconnected. [Additional note 8] 8. The device of claim 6 or 7, wherein the control circuitry is further configured to provide at least one indication that the canister has not been removed or that the wound dressing has not been disconnected in the test mode. [Additional note 9] the system configured to protect against unsafe negative pressure in the fluid flow path, another valve positioned in the fluid flow path, the control circuit configured to open the another valve in response to the pressure in the fluid flow path meeting the threshold indicative of an unsafe negative pressure; or The system of any one of the preceding paragraphs includes at least one of the following: the control circuit is further configured to deactivate the negative pressure source in response to the pressure in the fluid flow path meeting the threshold indicating an unsafe negative pressure. [Additional Note 10] The device of any one of the preceding clauses, wherein the overpressure test is further configured to indicate a defect in the system configured to protect against unsafe negative pressure in the fluid flow path in response to the control circuit determining that the system configured to protect against unsafe negative pressure is operating when the pressure in the fluid flow path does not meet the threshold indicating an unsafe negative pressure. [Additional Note 11] A device as described in any one of the preceding paragraphs, wherein the control circuit, in the test mode, is further configured to perform a health test, the health test including determining the efficiency of the negative pressure source and indicating sufficient health in response to determining that the efficiency meets an efficiency threshold. [Additional Note 12] The device described in Appendix 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 provided to the negative pressure source. [Additional Note 13] The device described in Appendix 12, wherein the control circuit is configured to determine the amount of power output by the negative pressure source based on determining the product of mass flow rate and the specific work load of the negative pressure source. [Additional Note 14] 14. The device of claim 13, wherein the control circuit is configured to determine at least one of the mass flow rate or the specific work amount based on determining the pressure difference across the flow restrictor. [Additional Note 15] 15. The device of claim 13 or 14, wherein the control circuit is configured to determine the mass flow rate based on determining a volumetric flow rate. [Additional Note 16] 16. The device of any one of clauses 11 to 15, wherein the control circuitry is configured to perform the health test after the flow test is successfully completed. [Additional Note 17] 10. A device according to any one of the preceding clauses, wherein the valve acts as the flow restrictor. [Additional Note 18] The device of any one of the preceding claims, further comprising a check valve positioned within the fluid flow path, the check valve configured to allow fluid to flow downstream toward the negative pressure source or exhaust and to prevent fluid from flowing in the opposite direction. [Additional Note 19] 1. A negative pressure wound therapy device comprising: a negative pressure source connected via a fluid flow path to a wound covered by the wound dressing and configured to provide negative pressure to the wound; a valve positioned within the fluid flow path, the valve configured, in an open state, to allow a supply of negative pressure from the negative pressure source upstream of the valve and, in a closed state, to block a supply of negative pressure from the negative pressure source upstream of the valve; a flow restrictor positioned within the fluid flow path; a pressure sensor configured to measure a pressure in the fluid flow path; a control circuit, wherein the control circuit in a normal mode of operation in which negative pressure is provided to the wound, causing the valve to be in the open state; and In a test mode in which the performance of the device is verified, at least one of a leak test or a flow test is performed; the leak test includes the control circuit being configured to: close the valve; operate the negative pressure source at a first intensity level; deactivate 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 the negative pressure measured by the pressure sensor after expiration of the duration meets a threshold indicative of a leak; 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 differential across the flow restrictor measured by the pressure sensor meets a pressure differential threshold indicative of insufficient flow, a negative pressure wound therapy device. [Additional Note 20] the control circuitry is further configured, in the test mode, to perform at least one of the leak test, the flow test, or the overpressure test; The device of claim 19, wherein the overpressure test includes the control circuit being configured to close the valve, operate the negative pressure source at a third intensity level, and indicate a fault in overpressure protection in response to the pressure in the fluid flow path meeting a threshold indicative of an unsafe negative pressure and determining that the overpressure protection is not operational. [Additional Note 21] The overpressure protection another valve positioned in the fluid flow path, the control circuit configured to open the another valve in response to the pressure in the fluid flow path meeting the threshold indicative of an unsafe negative pressure; or The device described in Appendix 20, including at least one of the following: the control circuit is further configured to deactivate the negative pressure source in response to the pressure in the fluid flow path meeting the threshold indicating an unsafe negative pressure. [Additional Note 22] 22. The device of claim 20 or 21, wherein the overpressure test further comprises the control circuit being configured to indicate a fault in the overpressure protection in response to determining that the overpressure protection is operational when the pressure in the fluid flow path does not meet the threshold indicating an unsafe negative pressure. [Additional Note 23] 23. The device according to any one of appended claims 19 to 22, wherein the second intensity level is greater than the first intensity level. [Additional note 24] The device of any one of claims 19 to 23, wherein the control circuit is further configured to perform a health test in the test mode, the health test including determining the efficiency of the negative pressure source and indicating sufficient health in response to determining that the efficiency meets an efficiency threshold. [Additional note 25] The device described in Appendix 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 provided to the negative pressure source. [Additional note 26] 26. The device of claim 25, wherein the control circuit is configured to determine the amount of power output by the negative pressure source based on determining the product of mass flow rate and the specific work load of the negative pressure source. [Additional note 27] 27. The device of claim 26, wherein the control circuit is configured to determine at least one of the mass flow rate or the specific work amount based on determining the pressure difference across the flow restrictor. [Additional note 28] 28. The device of claim 26 or 27, wherein the control circuit is configured to determine the mass flow rate based on determining a volumetric flow rate. [Additional note 29] 29. The device of any one of clauses 24 to 28, wherein the control circuitry is configured to perform the health test after the flow test is successfully completed. [Additional note 30] 30. The device of any one of clauses 19 to 29, wherein the valve comprises a solenoid valve. [Additional note 31] 31. The device of any one of clauses 19 to 30, wherein the valve operates as the flow restrictor. [Additional note 32] 32. The device of any one of claims 19 to 31, wherein the pressure sensor comprises a first pressure sensor positioned upstream of the flow restrictor and a second pressure sensor positioned downstream of the flow restrictor. [Additional note 33] 33. The device of any one of clauses 19 to 32, further comprising a canister positioned within the fluid flow path and configured to collect fluid aspirated from the wound, wherein the control circuit is further configured to verify that the canister is removed from the fluid flow path in the test mode. [Additional note 34] 34. The device of claim 33, wherein the control circuit is further configured, in the test mode, to not perform the leak test and the flow test in response to determining that the canister has not been removed and the wound dressing has not been disconnected. [Additional note 35] 35. The device of claim 33 or 34, wherein the control circuitry is further configured to provide, in the test mode, at least one indication that the canister has not been removed or that the wound dressing has not been disconnected. [Additional note 36] 36. The device of any one of claims 19 to 35, further comprising a check valve positioned within the fluid flow path, the check valve configured to allow fluid to flow downstream toward the negative pressure source or exhaust and to prevent fluid from flowing in the opposite direction. [Additional note 37] A kit comprising the device of any one of the preceding claims and one or more of the wound dressing or the canister. [Additional note 38] A method of operating a negative pressure wound therapy device according to any one of the preceding claims.

Claims

1. 1. A negative pressure wound therapy device comprising: a negative pressure source connected via a fluid flow path to a wound covered by the wound dressing and configured to provide negative pressure to the wound; a valve positioned within the fluid flow path, the valve configured, in an open state, to allow a supply of negative pressure from the negative pressure source upstream of the valve and, in a closed state, to block a supply of negative pressure from the negative pressure source upstream of the valve; a flow restrictor positioned within the fluid flow path; a pressure sensor configured to measure a pressure in the fluid flow path and a pressure differential across the flow restrictor; a control circuit; The control circuit in a normal mode of operation in which negative pressure is provided to the wound, causing the valve to be in the open state; and In a test mode in which the performance of the negative pressure wound therapy device is verified, at least a leak test is performed; and The negative pressure wound therapy device, wherein the leak test includes the control circuit being configured to close the valve, operate the negative pressure source at a first intensity level, deactivate 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 the negative pressure measured by the pressure sensor after expiration of the duration satisfies a threshold indicative of a leak.

2. The control circuit is further configured to perform a flow test in the test mode in which performance of the negative pressure wound therapy device is verified; 2. The device of claim 1, 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 a pressure differential across the flow restrictor measured by the pressure sensor meets a pressure differential threshold indicative of insufficient flow.

3. The device of claim 2 , wherein the second intensity level is greater than the first intensity level.

4. The control circuit is further configured to perform an overpressure test in the test mode in which performance of the negative pressure wound therapy device is verified; 4. The device of claim 1, wherein the overpressure test includes the control circuit being configured to close the valve, operate the negative pressure source at a third intensity level, and indicate a fault in a system configured to protect against unsafe negative pressure in the fluid flow path in response to the pressure in the fluid flow path meeting a threshold indicative of an unsafe negative pressure and determining that the system configured to protect against unsafe negative pressure is not operational.

5. The device of claim 4 , wherein the first intensity level is equal to the third intensity level.

6. The system configured to protect against unsafe negative pressure in the fluid flow path, comprising: another valve positioned in the fluid flow path, the control circuit configured to open the another valve in response to the pressure in the fluid flow path meeting the threshold indicative of an unsafe negative pressure; or The device of claim 4 or 5, wherein the control circuit is further configured to deactivate the negative pressure source in response to the pressure in the fluid flow path meeting the threshold indicative of an unsafe negative pressure.

7. A device as described in any one of claims 4 to 6, wherein the overpressure test is further configured to indicate a defect in the system configured to protect against unsafe negative pressure in the fluid flow path in response to the control circuit determining that the system configured to protect against unsafe negative pressure is operating when the pressure in the fluid flow path does not meet the threshold indicating an unsafe negative pressure.

8. 8. The device of claim 1, wherein the pressure sensors comprise a first pressure sensor positioned upstream of the flow restrictor and a second pressure sensor positioned downstream of the flow restrictor.

9. 8. The device of claim 4, further comprising a canister positioned within the fluid flow path and configured to collect fluid aspirated from the wound, the control circuitry being further configured to verify that the canister is removed from the fluid flow path in the test mode.

10. 10. The device of claim 9, wherein the control circuit is further configured, in the test mode, to not perform the leak test, the flow test, and the overpressure test in response to determining that the canister has not been removed and the wound dressing has not been disconnected.

11. 11. The device of claim 9 or 10, wherein the control circuitry is further configured to provide, in the test mode, at least one indication that the canister has not been removed or that the wound dressing has not been disconnected.

12. 12. The device of claim 1, wherein the control circuit is further configured to perform a health test in the test mode, the health test including determining an efficiency of the negative pressure source and indicating sufficient health in response to determining that the efficiency meets an efficiency threshold.

13. The device described in claim 12, wherein the control circuit is configured to perform the health test after the flow test is successfully completed.

14. 14. The device of claim 1, further comprising a check valve positioned in the fluid flow path, the check valve configured to allow fluid to flow downstream toward the negative pressure source or exhaust and to prevent fluid from flowing in the opposite direction.

15. 1. A negative pressure wound therapy device comprising: a negative pressure source connected via a fluid flow path to a wound covered by the wound dressing and configured to provide negative pressure to the wound; a valve positioned within the fluid flow path, the valve configured, in an open state, to allow a supply of negative pressure from the negative pressure source upstream of the valve and, in a closed state, to block a supply of negative pressure from the negative pressure source upstream of the valve; a flow restrictor positioned within the fluid flow path; a pressure sensor configured to measure a pressure in the fluid flow path; a control circuit; Equipped with The control circuit in a normal mode of operation in which negative pressure is provided to the wound, causing the valve to be in the open state; and In a test mode in which the performance of the negative pressure wound therapy device is verified, at least a leak test is performed; and The negative pressure wound therapy device, wherein the leak test includes the control circuit being configured to close the valve, operate the negative pressure source at a first intensity level, deactivate 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 the negative pressure measured by the pressure sensor after expiration of the duration satisfies a threshold indicative of a leak.

16. The control circuitry is further configured to perform a flow test in the test mode in which performance of the negative pressure wound therapy device is verified; 16. The device of claim 15, 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 a pressure differential across the flow restrictor measured by the pressure sensor meets a pressure differential threshold indicative of insufficient flow.

17. The device described in claim 16, wherein the second intensity level is greater than the first intensity level.

18. the control circuit is further configured, in the test mode, to perform an overpressure test; 18. The device of claim 15, wherein the overpressure test includes the control circuit being configured to close the valve, operate the negative pressure source at a third intensity level, and indicate a fault in overpressure protection in response to determining that pressure in the fluid flow path meets a threshold indicative of an unsafe negative pressure and the overpressure protection is not operational.

19. The overpressure protection another valve positioned in the fluid flow path, the control circuit configured to open the another valve in response to the pressure in the fluid flow path meeting the threshold indicative of an unsafe negative pressure; or 20. The device of claim 18, wherein the control circuit is further configured to deactivate the negative pressure source in response to the pressure in the fluid flow path meeting the threshold indicative of an unsafe negative pressure.

20. 20. The device of claim 18 or 19, wherein the overpressure test further comprises the control circuit being configured to indicate a fault in the overpressure protection in response to determining that the overpressure protection is operational if the pressure in the fluid flow path does not meet the threshold indicative of an unsafe negative pressure.

21. The device of any one of claims 15 to 20, wherein the control circuit is further configured, in the test mode, to perform a health test, the health test including determining an efficiency of the negative pressure source and indicating sufficient health in response to determining that the efficiency meets an efficiency threshold.

Images