Determining canister status for negative pressure wound therapy devices

Abstract

The negative pressure wound therapy device may include one or more fluid detection systems. The canister fluid level detection system may incorporate various fluid detection devices and communicate data related to the fluid level of the canister. In some cases, the negative pressure wound therapy device may include a device housing, a negative pressure source, and a canister configured to be in fluid communication with the negative pressure source. The canister may include a canister housing configured to store fluid aspirated from the wound, a cap connected to the canister housing, and a fluid level sensor supported by the cap. The fluid level sensor may be configured to detect a closed electrical circuit when fluid aspirated from the wound contacts the sensor. An electronic circuit may be configured to detect the state of the sensor and indicate the state of the canister.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to UK Provisional Patent Application No. 2205753.3, filed April 20, 2022, entitled “CANISTER STATUS DETERMINATION FOR NEGATIVE PRESSURE WOUND THERAPY DEVICES,” which is incorporated by reference in its entirety and forms part of this disclosure.

[0002] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments described herein relate to devices, systems and methods for the treatment of wounds, for example, using bandages in combination with negative pressure wound therapy. [Background technology]

[0003] Many different types of wound dressings are known to aid in the healing process of humans or 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, such as incisional wounds, open wounds, and abdominal wounds. TNP therapy can reduce tissue edema, promote blood flow, stimulate the formation of granulation tissue, and aid in wound closure and healing by removing excess exudate, and reduce bacterial load. Thus, reducing infection in the wound. Moreover, TNP therapy reduces external disturbances to the wound, promoting faster healing. Summary of the Invention

[0004] In one aspect, a negative pressure wound therapy device includes a device housing, a negative pressure source supported by the device housing, the negative pressure source configured to provide negative pressure to a wound covered by the wound dressing, a canister configured to be in fluid communication with the negative pressure source and the wound dressing, the canister housing configured to store fluid aspirated from the wound, a cap connected to the canister housing and configured to be connected to the device housing when the canister is removably attached to the device housing, and a fluid level sensor supported by the cap, extending into the canister housing and configured to store fluid aspirated from the wound. The canister may include a fluid level sensor having first and second arms configured to be in fluid communication with the fluid, the fluid level sensor configured to detect a closed electrical circuit when fluid aspirated from the wound contacts the first and second arms of the fluid level sensor, and configured to detect a full condition of the canister when the electrical circuit is closed; and electronic circuitry configured to detect a state of the fluid level sensor and indicate a state of the canister, the first and second arms having lengths, the length of the first arm being different from the length of the second arm, or the first arm being positioned non-parallel to the second arm.

[0005] The negative pressure wound therapy device of any of the preceding paragraphs and / or any of the devices, systems, or apparatus disclosed herein may include one or more of the following features: In some cases, the length of the first arm may be longer than the length of the second arm. In some cases, the first arm and the second arm may have the same length. In some cases, the first arm and the second arm may be parallel to one another. In some cases, the first arm and the second arm may be angled relative to one another. In some cases, the fluid level sensor may include one or more sets of arms. In some cases, the fluid level sensor may include an NFC tag.

[0006] In another aspect, a negative pressure wound therapy device includes a device housing, a negative pressure source supported by the device housing, the negative pressure source configured to provide negative pressure to a wound covered by the wound dressing, a canister configured to be in fluid communication with the negative pressure source and the wound dressing, the canister housing configured to store fluid aspirated from the wound, a cap connected to the canister housing and configured to be connected to the device housing when the canister is removably attached to the device housing, and a fluid level sensor supported by the cap, the arm extending into the canister housing and configured to be in fluid communication with the fluid aspirated from the wound, the fluid level sensor configured to the canister includes a fluid level sensor configured to detect a closed electrical circuit when fluid aspirated from the wound contacts an arm of the fluid level sensor, the fluid level sensor configured to detect a full condition of the canister when the electrical circuit is closed; an electronic circuit configured to detect a state of the fluid level sensor and indicate a state of the canister; and a mechanical shield including an inner surface, an outer surface opposite the inner surface, and an interior, the mechanical shield being positioned inside the canister, the inner surface of the mechanical shield facing the fluid level sensor, the mechanical shield being configured to protect the fluid level sensor from liquid inside the canister.

[0007] The negative pressure wound therapy device of any of the preceding paragraphs and / or any of the devices, systems, or apparatus disclosed herein may include one or more of the following features. In some cases, the mechanical shield may include a first opening along a top of the mechanical shield and a second opening along a bottom of the mechanical shield. In some cases, the mechanical shield may surround the fluid level sensor. In some cases, the mechanical shield may include a cone shape surrounding the fluid level sensor or an arm of the fluid level sensor. In some cases, the mechanical shield may include a truncated square pyramid shape surrounding the fluid level sensor or an arm of the fluid level sensor. In some cases, the mechanical shield may include a truncated rectangular pyramid shape surrounding the fluid level sensor or an arm of the fluid level sensor. In some cases, the mechanical shield may include one or more guards extending from at least a portion of an interior surface of the mechanical shield and positioned along at least one of the first opening and the second opening of the mechanical shield, the one or more guards configured to reduce a likelihood of liquid accessing an interior of the mechanical shield. In some cases, the one or more guards can form a fluid pathway from an exterior of the mechanical shield to an interior of the mechanical shield, thereby allowing fluid aspirated from the wound to access the interior of the mechanical shield when the fluid level in the canister reaches a threshold fluid level. In some cases, the fluid level sensor can include an NFC tag.

[0008] In another aspect, a negative pressure wound therapy device includes a device housing, a negative pressure source supported by the device housing, the negative pressure source configured to provide negative pressure to a wound covered by the wound dressing, a canister configured to be in fluid communication with the negative pressure source and the wound dressing, the canister housing configured to store fluid aspirated from the wound, a cap connected to the canister housing and configured to be connected to the device housing when the canister is removably attached to the device housing, a first fluid level sensor and a second fluid level sensor, the first fluid level sensor detecting a first closed state when fluid aspirated from the wound contacts the first fluid level sensor. the canister may include a first fluid level sensor and a second fluid level sensor configured to detect a second closed electrical circuit when fluid aspirated from the wound contacts the second fluid level sensor, a first mechanical shield and a second mechanical shield each including a top opening and a bottom opening, the first mechanical shield surrounding the first fluid level sensor and the second mechanical shield surrounding the second fluid level sensor, and electronic circuitry configured to detect a status of the first fluid level sensor and the second fluid level sensor to indicate a status of the canister.

[0009] The negative pressure wound therapy device of any of the preceding paragraphs and / or any of the devices, systems, or apparatus disclosed herein may include one or more of the following features: In some cases, the first and second fluid level sensors may be positioned at different heights relative to a base of the canister; In some cases, the first and second fluid level sensors may be positioned at the same height and different lateral positions relative to a base of the canister; In some cases, the first and second mechanical shields may each include an inner surface, comprising an outer surface opposite the inner surface and an interior, the first and second mechanical shields being positioned within the canister, the inner surfaces of the first and second mechanical shields facing the first and second fluid level sensors, respectively, and the first and second mechanical shields being configured to protect the first and second fluid level sensors, respectively, from liquid within the canister. In some cases, the top opening of the first shield may be smaller than the top opening of the second shield, and the bottom opening of the first shield may be smaller than the bottom opening of the second shield. In some cases, the top opening of the second shield may be smaller than the top opening of the first shield, and the bottom opening of the second shield may be smaller than the bottom opening of the first shield. In some cases, the negative pressure wound therapy may include a third fluid level sensor configured to detect a closed electrical circuit when fluid aspirated from the wound contacts the first fluid level sensor, and a third mechanical shield including a top opening and a bottom opening, the third mechanical shield surrounding the third fluid level sensor. In some cases, the top opening of the third shield may be smaller than the top openings of the first shield and the second shield, and the bottom opening of the third shield may be smaller than the bottom openings of the first shield and the second shield. In some cases, the top opening of the third shield may be larger than the top openings of the first shield and the second shield, and the bottom opening of the third shield may be larger than the bottom openings of the first shield and the second shield.In some cases, the fluid level sensor may include an NFC tag.

[0010] In another aspect, a canister for negative pressure wound therapy may include a canister housing configured to store fluid aspirated from the wound, a fluid level sensor configured to be in fluid communication with the fluid aspirated from the wound, the fluid level sensor further configured to detect a closed electrical circuit when the fluid aspirated from the wound contacts the fluid level sensor, a mechanical shield surrounding the fluid level sensor, and electronic circuitry configured to detect a state of the fluid level sensor and indicate a state of the canister.

[0011] The canister for negative pressure wound therapy of any of the preceding paragraphs and / or any of the devices, systems, or apparatus disclosed herein may include one or more of the following features: In some cases, the fluid level sensor may include an arm extending into the interior of the canister housing. In some cases, the mechanical shield may include an inner surface, an outer surface opposite the inner surface, and an interior, the mechanical shield positioned within the canister, the inner surface of the mechanical shield facing the fluid level sensor, and the mechanical shield configured to protect the fluid level sensor from liquid in the canister. In some cases, the fluid level sensor may include an NFC tag.

[0012] Disclosed herein is a negative pressure wound therapy device of any of the preceding paragraphs, and / or a method of operating any of the devices, apparatus, or systems disclosed herein.

[0013] Disclosed is a kit including any of the negative pressure wound therapy devices of the preceding paragraphs, and / or any of the devices, instruments, or systems disclosed herein, and one or more wound dressings.

[0014] Any of the features, components, or details 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 features, components, or details of any of the arrangements or embodiments disclosed herein to form new arrangements and embodiments. [Brief description of the drawings]

[0015] [Figure 1A] FIG. 1A shows a negative pressure wound therapy system. [Figure 1B] FIG. 1B illustrates another negative pressure wound therapy system. [Figure 2A] FIG. 2A 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] FIG. 2C illustrates the top surface of the negative pressure wound therapy device shown in FIG. 2A showing a graphical user interface. [Diagram 3] FIG. 3 illustrates a schematic diagram of a control system for a negative pressure wound therapy device. [Figure 4] FIG. 4 illustrates another negative pressure wound therapy system. [Figure 5A] FIG. 5A shows an exploded view of the canister top and associated components. [Figure 5B] 5B, 5C, 5D, and 5E show exploded views of the canister top and pump assembly components. [Figure 5C] 5B, 5C, 5D, and 5E show exploded views of the canister top and pump assembly components. [Figure 5D] 5B, 5C, 5D, and 5E show exploded views of the canister top and pump assembly components. [Figure 5E]5B, 5C, 5D, and 5E show exploded views of the canister top and pump assembly components. [Figure 6A-6B] 6A, 6B, 6C, and 6D show a canister status detection system for a negative pressure wound therapy system. [Figure 6C-6D] 6A, 6B, 6C, and 6D show a canister status detection system for a negative pressure wound therapy system. [Figure 6E] FIG. 6E shows multiple views of a fluid level sensor. [Figure 7] 7, 8, and 9 show examples of fluid level sensors. [Figure 8] 7, 8, and 9 show examples of fluid level sensors. [Figure 9] 7, 8, and 9 show examples of fluid level sensors. [Figure 10] FIG. 10 shows a cross-sectional view of the fluid level sensor and mechanical shield. [Figure 11] 11, 13 and 15 show an embodiment of a mechanical shield. [Figure 12] 12, 14, 16, and 17 show cross-sectional views of the embodiments of the mechanical shield shown in FIGS. [Figure 13] 11, 13 and 15 show an embodiment of a mechanical shield. [Figure 14] 12, 14, 16, and 17 show cross-sectional views of the embodiments of the mechanical shield shown in FIGS. [Figure 15] 11, 13 and 15 show an embodiment of a mechanical shield. [Figure 16] 12, 14, 16, and 17 show cross-sectional views of the embodiments of the mechanical shield shown in FIGS. [Figure 17] 12, 14, 16, and 17 show cross-sectional views of the embodiments of the mechanical shield shown in FIGS. [Figure 18]18, 26, 27, 30 and 31 show cross-sectional views of embodiments of the mechanical shield. [Figure 19] 19 and 20 show an embodiment of a canister cap that includes a window that defines a mechanical shield. [Figure 20] 19 and 20 show an embodiment of a canister cap that includes a window that defines a mechanical shield. [Figure 21A] 21A and 21B show cross-sectional views of an embodiment of a canister cap that includes one or more windows. [Figure 21B] 21A and 21B show cross-sectional views of an embodiment of a canister cap that includes one or more windows. [Figure 22] FIG. 22 illustrates an embodiment of a portion of a cap assembly including a window that defines a mechanical shield. [Figure 23A] 23A and 23B show cross-sectional views of one example of a canister cap that includes one or more windows that define a mechanical shield. [Figure 23B] 23A and 23B show cross-sectional views of one example of a canister cap that includes one or more windows that define a mechanical shield. [Figure 24] FIG. 24 shows a cross-sectional view of a canister including a canister cap assembly. [Figure 25A] 25A, 25B, and 25C show different views of an embodiment of a canister cap assembly that includes one or more windows that define a mechanical shield. [Figure 25B] 25A, 25B, and 25C show different views of an embodiment of a canister cap assembly that includes one or more windows that define a mechanical shield. [Figure 25C] 25A, 25B, and 25C show different views of an embodiment of a canister cap assembly that includes one or more windows that define a mechanical shield. [Figure 26] 18, 26, 27, 30 and 31 show cross-sectional views of embodiments of the mechanical shield. [Figure 27]18, 26, 27, 30 and 31 show cross-sectional views of embodiments of the mechanical shield. [Figure 28A] 28A and 28B show cross-sectional views of the canister in a stable position. [Figure 28B] 28A and 28B show cross-sectional views of the canister in a stable position. [Figure 28C] FIG. 28C shows a cross-sectional view of the canister in an unstable position. [Figure 29A] 29A and 29B show examples of an NFC reader and an NFC tag antenna. [Figure 29B] 29A and 29B show examples of an NFC reader and an NFC tag antenna. [Diagram 30] 18, 26, 27, 30 and 31 show cross-sectional views of embodiments of the mechanical shield. [Diagram 31] 18, 26, 27, 30 and 31 show cross-sectional views of embodiments of the mechanical shield. [Diagram 32] FIG. 32 illustrates a cross-sectional view of one embodiment of a mechanical shield and multiple fluid level sensors. [Diagram 33] FIG. 33 shows a top cross-sectional view of the mechanical shield of FIG. [Figure 34A] 34A and 34B show an embodiment of a fluid level sensor. [Figure 34B] 34A and 34B show an embodiment of a fluid level sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016]

[0002] 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.

[0017] Throughout this specification, reference is made to wounds. The term wound is broadly interpreted and includes open and closed wounds where the skin is torn, incised, or perforated, or where trauma causes bruising, or any other surface or other pathology or incomplete condition in the skin of a patient, or others that benefit from reduced pressure treatment. Thus, a wound is broadly defined as any damaged area of ​​tissue where fluid may or may not be produced. Examples of such wounds include, but are not limited to, abdominal wounds, or other large wounds or incisions resulting from surgery, trauma, sternotomy, fasciotomy, or other conditions, dehiscence wounds, acute wounds, chronic wounds, subacute wounds and dehiscence wounds, traumatic wounds, flaps and skin grafts, lacerations, abrasions, bruises, burns, diabetic ulcers, decubitus ulcers, stomas, surgical wounds, traumatic wounds, and venous ulcers.

[0018] The embodiments of the systems and methods disclosed herein may 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 "hard to heal" wounds by reducing tissue edema, promoting blood flow and granular tissue formation, or removing excess exudate, and can reduce bacterial load (and thus infection risk). Furthermore, this therapy can lead to less wound injury and more rapid healing. TNP therapy systems can also assist in the healing of surgically closed wounds by removing fluids. 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 grafts are required to be in close proximity to tissue to ensure tissue viability.

[0019] As used herein, a reduced pressure or negative pressure level, such as -XmmHg, represents a pressure level relative to normal ambient atmospheric pressure, which may correspond to 760mmHg (or 1 atm, 29.93 inHg, 101.325 kPa, 14.696 psi, etc.). Thus, a negative pressure value of -XmmHg reflects a pressure that is XmmHg lower than 760mmHg, or in other words, a pressure of (760-X)mmHg. Additionally, a negative pressure that is "lower" or "less" than XmmHg corresponds to a pressure that is closer to atmospheric pressure (e.g., -40mmHg is lower than -60mmHg). A negative pressure that is "higher" or "greater" than -XmmHg corresponds to a pressure that is further from atmospheric pressure (e.g., -80mmHg is higher than -60mmHg). 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.

[0020] The systems and methods disclosed herein may be used in addition to or in place of reduced pressure therapy, such as irrigation, ultrasound, heating or cooling, neurostimulation, etc. 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 in conjunction with dressings, including compression dressings, reduced pressure dressings, etc.

[0021] A healthcare provider, such as a doctor, nurse, etc., may provide a TNP prescription that specifies, for example, pressure levels or application times. 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 devising 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 that may be time-consuming and repetitive. The embodiments disclosed herein provide a system, device, or method that efficiently adjusts the TNP prescription and delivers an effective TNP therapy.

[0022] Wound Therapy Systems FIG. 1A illustrates a schematic of a negative pressure wound treatment system 100 (also referred to as a reduced pressure or negative pressure wound therapy system, TNP system, or wound treatment system). Although not required in any implementation disclosed herein, the negative pressure wound treatment system 100 can include a wound packing 102 placed on or inside 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 in combination 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 (which may be referred to in whole or in part as a "pump assembly") configured to provide reduced pressure or negative pressure. The conduit 108 may be a single lumen tube or a multi-lumen tube. A connector may be used to removably and selectively connect the conduit or tube 142 to the conduit 108 .

[0023] In any of the systems disclosed herein, the wound therapy device may be canister-less, for example and without limitation, wound exudate is 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.

[0024] Additionally, in any of the wound therapy systems disclosed herein, any of the wound therapy devices may be attached to or supported by the wound dressing or adjacent to the wound dressing. The wound filler 102 may be of any suitable type, such as hydrophilic or hydrophobic foam, gauze, inflatable bag, or the like. The wound filler 102 may be conformable to the wound 104 such that the wound filler 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 (or in any other suitable manner) sealed to the wound 104, for example, by sealing with the skin around 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.

[0025] The wound cover 106 may have a port (not shown) configured to receive an end of the conduit 108. In some cases, the conduit 108 may otherwise pass through or under the wound cover 106 to supply reduced pressure to the wound 104 to maintain a desired level of reduced pressure within the wound 104. The conduit 108 may be any suitable article configured to provide at least a substantially sealed fluid flow path or passage between the wound therapy device 110 and the wound cover 106 to supply reduced pressure provided by the wound therapy device 110 to the wound 104.

[0026] The wound cover 106 and wound packing 102 may be provided as a single item or integral single unit. In some cases, no wound packing may be provided and the wound cover itself may be considered a wound dressing. The wound dressing may then be connected via conduit 108 to a negative pressure source of the wound therapy device 110. In some cases, although not required, the wound therapy device 110 can be miniaturized and portable, although a larger conventional negative pressure source (or pump) could also be used.

[0027] The wound cover 106 may be placed over the wound site to be treated. The wound cover 106 may form a substantially sealed cavity or enclosure over the wound. The wound cover 106 may have a film with high water vapor permeability to allow evaporation of excess fluids, and may contain 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 incised wounds that exude a small amount of wound exudate.

[0028] The wound therapy device 110 can be operated with or without the use of an exudate canister. In some cases, as illustrated, the wound therapy device 110 can include an exudate canister. In some cases, configuring the wound therapy device 110 and the conduit 108 such that the conduit 108 can be quickly and easily detached from the wound therapy device 110 can facilitate or improve the process of changing wound dressings or pumps, if necessary. Any of the pump assemblies disclosed herein can have any suitable connection between the conduit 108 and the pump.

[0029] The wound therapy device 110 can 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, i.e., -200 mmHg may actually be about 560 mmHg. In some cases, the pressure range may be between about -40 mmHg and -150 mmHg. Alternatively, a pressure range of -75 mmHg or less, -80 mmHg or less, or greater than -80 mmHg may be used. Also, in some cases, a pressure range below -75 mmHg may be used. Alternatively, a pressure range of approximately -100 mmHg, or even greater than -150 mmHg may be provided by the wound therapy device 110.

[0030] 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 remote computing device 334. The connection 332 may be wired or wireless (e.g., Bluetooth, Bluetooth Low Energy (BLE), Near Field Communication (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, or the like.

[0031] FIG. 1B illustrates another negative pressure wound treatment system 100'. The negative pressure wound treatment system 100' may have any of the components, features, or other details of any of the other negative pressure wound treatment systems disclosed herein, including, but not limited to, the negative pressure wound treatment system 100 illustrated in FIG. 1A or the negative pressure wound treatment 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 treatment system 100' shown in FIG. 1B and / or described herein. The negative pressure wound treatment 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 tube or a multi-lumen tube, may be used to connect the wound cover 106 to a wound therapy device 110' (which may be referred to as a "pump assembly" in whole or in part) configured to provide reduced pressure or negative pressure. The wound cover 106 may be in fluid communication with the wound 104 .

[0032] 1B, the conduit 108' can have a bridge portion 130, which can 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 can 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 can be coupled to a portion of the conduit 108, and in some cases can be attached to the connector 134, as shown. The cap 140 can be useful in preventing fluid from leaking out the proximal end of the bridge portion 130. The conduit 108' can be a Soft Port manufactured by Smith & Nephew. As mentioned above, the negative pressure wound treatment system 100' can include a source of negative pressure, such as device 110', which can provide negative pressure through conduit 108' to the wound 104. Although not required, the device 110' can also include a canister or other container for storing wound exudate and other fluids that may be removed from the wound.

[0033] The device 110' may be connected to the connector 134 via a conduit or tube 142. In use, the applicator 132 may be placed over a suitably prepared wound or an opening formed in the cover 106 placed over the wound 104. With the wound therapy device 110' connected to the connector 134 via the tube 142, the wound therapy device 110' may then be operated to provide negative pressure to the wound. Negative pressure may be applied until a desired level of healing of the wound is achieved.

[0034] 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 the 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 cases, 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 the length of the upper and lower layers.

[0035] The upper and lower channel layers may be elongated layers extending from the proximal end to the distal end of the bridge 130, and each may 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 comprise, for example, a knitted or woven spacer fabric (such as a knitted polyester 3D fabric, Baltex 7970.RTM., or Gehring 879.RTM.), or a nonwoven material, or a terry or loop pile material. The fabric is not necessarily woven and may include felt and flocked fiber materials (including materials such as Flotex.RTM.). 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 include 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.

[0036] 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 aid in wicking, fluid transport, or negative pressure transmission in some cases. 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 be useful in some cases in preventing the channel from collapsing under application of negative pressure. The material used in some implementations of the conduit 108' may be conformable and flexible, which may help in some cases to avoid decubitus ulcers and other complications that may arise from a wound treatment system pressed against a patient's skin.

[0037] 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 include at least one aperture therethrough. This aperture may be useful during manufacture of the device, 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.

[0038] In some implementations, a controlled gas leak 146 (sometimes referred to as a gas leak, air leak, or controlled air leak) may be disposed on the bridge portion 130, e.g., at its proximal end. The 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 may then be drawn into the lower channel of the bridge portion 130 by passing the opening through the upper layer, the middle layer, and the distal end of the lower layer.

[0039] The air leak 146 may include a filter. The air leak 146 may be located at the proximal end of the bridge portion 130 to minimize the possibility of wound exudate or other fluids contacting the air leak 146 or the filter and blocking or impeding the air leak 146 or the filter. In some instances, the filter may be a microporous membrane that may be capable of filtering out microorganisms and bacteria and filtering out particles larger than 45 μm. Preferably, the filter may filter out 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, for example, to 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 out any foreign matter that blocks 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, the gas leak 146 may provide a relatively constant gas flow that does not increase appreciably when additional negative pressure is applied to the conduit 108'. In the example of the negative pressure wound treatment system 100, the gas flow through the gas leak 146 increases when additional negative pressure is applied, and preferably this increased gas flow is minimized and does not increase proportionately 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 treatment system disclosed herein may be found in U.S. Patent No. 8,801,685, the entirety of which is incorporated by reference herein as if fully set forth herein.

[0040] Any of the wound therapy devices disclosed herein (such as device 110 or 110') can provide continuous or intermittent negative pressure therapy. Continuous therapy may be delivered above 0 mmHg, -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. Intermittent therapy may be delivered between a low negative pressure set point and a high negative pressure set point (sometimes referred to as set points). The lower set point may be set above 0mmHg, -25mmHg, -40mmHg, -50mmHg, -60mmHg, -70mmHg, -80mmHg, -90mmHg, -100mmHg, -120mmHg, -125mmHg, -140mmHg, -160mmHg, -180mmHg, or below -180mmHg. The high set point can be set above -25mmHg, -40mmHg, -50mmHg, -60mmHg, -70mmHg, -80mmHg, -90mmHg, -100mmHg, -120mmHg, -125mmHg, -140mmHg, -160mmHg, -180mmHg, -200mmHg, or below -200mmHg. During intermittent therapy, negative pressure at the low set point can be delivered for a first duration, and at the end of the first duration, negative pressure at the high set point can be delivered for a second duration. At the end of the second duration, negative pressure at the low set point can be delivered. The first and second durations can be the same or different values.

[0041] 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 transferred 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).

[0042] Wound dressings that may be used with the pump assembly and system of the present application include Renasys-F, Renasys-G, RenasysAB, and Pico Dressing available from Smith & Nephew. Further description of 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 can be found in U.S. Patent Publication Nos. 2012 / 0116334, 2011 / 0213287, 2011 / 0282309, 2012 / 0136325, U.S. Patent No. 9,084,845, and International 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 used.

[0043] 2A, 2B, and 2C show a negative pressure wound therapy device 110'. As illustrated, a pump assembly 160 and a canister 162 can be connected, thereby forming 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 / alarm mute button 182. The interface panel 170 can have one or more input controls or buttons 184 (three shown) that may be used to control any function of the pump assembly 160 or the interface panel 170. For example, and without limitation, one or more of the buttons 184 can be used to turn the pump assembly 160 on or off, start or pause therapy, operate and monitor the operation of the pump assembly 160, scroll through menus displayed on the display 172, or control or perform other functions. In some cases, the command buttons 184 may be programmable and may be made from a tactile soft rubber.

[0044] Additionally, the interface panel 170 can have a visual indicator 186 that can indicate which of the one or more buttons 184 is active. The interface panel 170 can also have a lock / unlock control or button 188 that can be configured to selectively lock or unlock the functionality of the various buttons (e.g., buttons 184) or display 172. For example, adjustments to therapy settings may be locked / unlocked via the lock / unlock control 188. When the lock / unlock button 188 is in a locked state, pressing one or more of the various other buttons or displays will not cause the pump assembly 160 to change any display or performance functions of the device. In some cases, when the lock / unlock button 188 is in a locked state, some buttons or portions of the display may be available and can cause the pump assembly 160 to change any display or performance functions of the device, while other buttons or portions of the display can cause the pump assembly 160 to change any display or performance functions of the device. For example, and without limitation, when the lock / unlock button 188 is in the locked state, menu navigation is still available and can be used or activated, but commands that adjust therapy settings are grayed out and cannot be used or cause a change in the functionality of the device. In this manner, the interface panel 170 protects the various buttons or displays from being accidentally bumped or touched. The interface panel 170 may be located on a top portion of the pump assembly 160, for example, and without limitation, on an upwardly facing surface of the pump assembly 160.

[0045] A display 172, which may be a screen such as an LCD screen, may be mounted in a central portion of the interface panel 170. The display 172 may be a touch screen display. The display 172 supports the playback of audiovisual (AV) content, such as instructional videos, and can render a number of screens or graphical user interfaces (GUIs) for configuring, controlling, and monitoring the operation of the pump assembly 160.

[0046] The one or more indicators 174 may be illuminating (e.g., LEDs) and may be configured to provide a visual indication of an alarm condition and / or pump status. For example, without limitation, the one or more indicators 174 may be configured to visually indicate a 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 wound cover 106 (e.g., to indicate normal operation, low battery, leakage, canister full, blockage, overpressure, etc.). Any one or more suitable indicators may additionally or alternatively be used, such as visual, audible, tactile indicators, etc.

[0047] 2B illustrates a rear or back view of the wound therapy device 110' shown in FIG. 2A. As shown, the pump assembly 160 can include a speaker 192 for generating audio. For example, and without limitation, the speaker 192 can 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 combinations thereof. The speaker 192 can provide audio to accompany one or more instructional videos that may be displayed on the display 172.

[0048] The pump assembly 160 may be configured to allow 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 healthcare provider 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 required. The pump assembly 160 may have a recess 198 formed therein to facilitate gripping the pump assembly 160.

[0049] The canister 162 may hold fluid 104 aspirated from the wound. 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. With reference 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 limited to, the canister inlet tube 200 may be used to connect to the conduit 108'.

[0050] The canister 162 may be selectively connectable and removable to the pump assembly 160. With reference to FIG. 2A, in some cases a canister release button 202 may be configured to selectively release the canister 162 from the pump assembly 160. With reference to FIG. 2B, the 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 the canister 162.

[0051] The wound therapy device 110' can have a handle 208 that can be used to lift or carry the wound therapy device 110'. The handle 208 can be coupled to the pump assembly 160 and can be rotatable relative to the wound therapy device 110' such that the handle can be rotated upward to lift or carry the wound therapy device 110' or pump assembly 160, or rotated to a lower profile to a more compact position when the handle is not in use. In some cases, the handle 208 can be coupled to the pump assembly 160 in a fixed position. The handle 208 can be coupled to an upper portion of the pump assembly 160 or can be detachable from the wound therapy device 110'.

[0052] 3 illustrates a schematic diagram of a control system 300 that may be used with 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 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 a pump 390.

[0053] 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 a fluid flow path), or the like. For example, the I / O module can 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 can communicate with the I / O module via a wired connection or one or more transceivers 340 via a wireless connection.

[0054] 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 can 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.

[0055] The main controller 310 may be a general-purpose controller, such as a low-power processor or an application-specific processor. The main controller 310 may be configured as the "central" processor within the electronic architecture of the control system 300, and the main controller 310 may coordinate the activities of other processors, such as a pump controller 370, one or more communication controllers 330, and one or more additional processors 380. The main controller 310 may run a suitable operating system, such as Linux, WindowsCE, VxWorks, or the like.

[0056] The pump controller 370 can control the operation of a pump 390 that can generate a 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, and the like. The pump controller 370 can measure the pressure in the fluid flow path, calculate the fluid flow rate, and control the pump using data received from one or more pressure sensors 325. The pump controller 370 can control a pump actuator (e.g., a motor) such that a desired level of negative pressure is achieved in the wound 104. The desired level of negative pressure can be a pressure setting or can be selected by 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 rate 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.

[0057] Any of the one or more communication controllers 330 can provide a connection (such as a wired or wireless connection 332). The one or more communication controllers 330 can utilize one or more transceivers 340 to transmit and receive data. The one or more transceivers 340 can include one or more antennas, optical sensors, optical transmitters, vibration motors or transducers, vibration sensors, acoustic sensors, ultrasonic sensors, or the like. Any of the one or more transceivers 340 can function as a communication controller. In such cases, the one or more communication controllers 330 can be omitted. Any of the one or more transceivers 340 can be connected to one or more antennas that facilitate wireless communication. The one or more communication controllers 330 can provide one or more of the following types of connections: Global Positioning System (GPS), cellular connectivity (e.g., 2G, 3G, LTE, 4G, 5G, etc.), NFC, Bluetooth connectivity (or BLE), 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 connectivity may 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.

[0058] Any of the one or more communication controllers 330 may provide dual GPS / cellular functionality. The cellular functionality may be, for example, 3G, 4G, or 5G functionality. The one or more communication controllers 330 may communicate information to the main controller 310. Any of the one or more communication controllers 330 may include internal memory or may utilize memory 350. Any of the one or more communication controllers 330 may be a low power processor.

[0059] 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.

[0060] Using connections provided by one or more communications controllers 330, the control system 300 can upload any of the data stored, maintained, or tracked by the control system 300 to a remote computing device, such as device 334. The control system 300 can also download (e.g., via connections 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 (such as one or more displays). In some cases, any of the illustrated or described components of the control system 300 can be omitted depending on the embodiment of the wound monitoring or treatment system in which the control system 300 is used.

[0061] 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.

[0062] Multiple Dressing Negative Wound Therapy 4 illustrates another negative pressure wound treatment system 400. The system 400 can include a wound therapy device capable of delivering negative pressure to a wound site(s), such as wound therapy device 110'. The wound therapy device 110' can 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. The first fluid flow path can include components that provide a fluid connection from the wound therapy device 110' to the first wound dressing 406a. As a non-limiting example, the first fluid flow path can include a passageway from the wound dressing 406a to the wound therapy device 110' or a passageway from the first wound dressing 406a to an inlet 446 of a bifurcated fitting (or connector) 444 in fluid connection with the 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.

[0063] System 400 may be similar to system 100', except that multiple wounds 104a and 104b are 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 the letter "a" or "b" appended to distinguish the first wound from the 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.

[0064] The wound therapy device 110' may be fluidly coupled to the inlet 446 of the connector 444 via the tube 142. The connector 444 may be fluidly coupled to the connectors 134a, 134b which may be fluidly coupled to the tubes or conduits 130a, 130b via the branches 445a, 445b and the tubes or conduits 442a, 442b. The tubes or conduits 130a, 130b may be fluidly coupled to the dressings 406a, 406b. Once all the conduit and dressing components are connected and operatively positioned, the wound therapy device 110' may be operated, thereby providing negative pressure to the wounds 430a, 430b via the fluid flow paths. The application of negative pressure may be applied until a desired level of healing of the 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 unused branches 445a or 445b of connector 444) or to three or more wounds (e.g., by adding branches to connector 444).

[0065] System 400 may include one or more features disclosed in U.S. Patent Publication No. WO2020 / 0069850 or International Publication No. WO2018 / 167199, each of which is incorporated by reference in its entirety.

[0066] Canister Status Detection The negative pressure therapy system may utilize a canister status detection system. The canister status detection system may function as a fluid detection system to detect the volume of fluid (or liquid) in the canister (or canister fill level), or whether the canister has reached a full or near-full level of fluid (or liquid). One or more alarms or alerts may be generated in response to the detection. A canister full or near-full alarm may be important to a negative pressure therapy system because it may allow a medical professional or user to replace the canister and continue treatment with minimal interruption (e.g., without having to worry about the device suddenly sounding a canister full or canister clogged alarm).

[0067] A canister fluid detection system may rely on comparing a peak-to-peak voltage measurement obtained from a pressure sensor to a threshold over a period of time to activate a canister full or near full alarm. In some cases, this approach may be unreliable and less tolerant to varying conditions. For example, a nuisance alarm may be generated if the canister is empty but there is a restriction in the flow from the filter assembly.

[0068] Therefore, it may be useful to have a more accurate detection method for detecting a full or nearly full canister condition that reduces nuisance alarms. The canister may have a canister detection system that allows for fluid detection using a device that communicates with the fluid in the canister to detect when the fluid reaches a threshold level in the canister. The canister may incorporate a fluid level sensor device within the surface of the canister. For example, the canister may incorporate a fluid level detector (also referred to as a fluid level sensor) within the cap portion of the canister system. FIG. 5A shows a canister cap 510 that may be positioned on the surface of the canister that is configured to mate or be mated with a negative pressure wound therapy device, such as the pump assembly 160. The canister cap 510 may be positioned to provide fluid communication between a negative pressure source and the interior of the canister. For example, the canister cap 510 may be positioned on top of the canister 162, as shown in FIG. 2A. The pump assembly 160 may be removably attached to the canister cap 510.

[0069] The canister cap 510 may include a housing formed from a cap top 512 and a cap bottom 514. The canister cap 510 may include a filter 516 positioned between the cap top 512 and the cap bottom 514. A fluid level sensor 518 may be included within the canister cap 510 and in communication with the interior of the canister. The fluid level sensor 518 may include two arms 520 extending from the cap bottom 514 to the interior of the canister. The arms 520 may be made from a conductive material (such as a conductive metal). The arms 520 may be used to interact with the fluid within the canister and create a closed circuit when the arms of the fluid level sensor 518 communicate with the fluid within the canister, thereby detecting a full condition of the canister. The fluid level sensor may detect a closed electrical circuit when fluid within the canister is in contact with the arms of the fluid level sensor. For example, a fluid level sensor can collect fluid in the canister when the circuit is open and detect a full canister condition when the circuit is closed. In other examples, a fluid level sensor can collect fluid in the canister when the circuit is closed and detect a full canister condition when the circuit is open. A reader within the negative pressure wound therapy device can communicate with the fluid level sensor and indicate the status of the canister in response to detecting a full canister condition. In response to detecting a full canister condition by the fluid level sensor, the reader can cause a change in the delivery of negative pressure wound therapy (e.g., ceasing application of negative pressure) or an alarm (e.g., a full canister alarm). A reader may be located within a housing of a negative pressure wound therapy device, such as pump assembly 160.

[0070] Although the fluid level sensor 518 is shown with two downwardly extending arms, the fluid level sensor may include only one arm or any number of arms that extend into the interior of the canister to detect fluid therein. In some cases, the fluid level sensor may have any number or extensions or arms, so long as there are at least two separate tracks of conductive material (or electrodes) that form a closed electrical circuit.

[0071] 5B and 5C show exploded views of a canister body or canister housing having a canister cap assembly 1820 similar to the canister cap and components described with reference to FIG. 5A. The canister cap assembly can be assembled and attached to a canister body, which may be coupled to the pump assembly 160 or pump housing, as shown in FIG. 2A. The cap assembly 1820 can be configured to be removably coupled (for example, and without limitation, threadedly coupled) with an opening (such as 1903 shown in FIG. 5B) of the canister body 1902. In some arrangements, the cap assembly 1820 can be welded to the canister body 1902 or otherwise non-removably coupled to the canister body. Some arrangements of the cap assembly 1820 can include a cover or first cap member 1822 having a connector interface 1823 that can have an opening 1824 extending axially through a central portion of the first cap member 1822. The connector interface 1823 may project axially away from the first major surface of the first cap member 1822. The connector interface 1823 may have a generally cylindrical shape and an annular flange formed thereon which may be configured to receive a seal, such as an O-ring 1825. The opening 1824 may be configured to provide a fluid passageway for air and / or other gases within the canister body 1902 to pass through and exit the canister body 1902.

[0072] The cap assembly 1820 may include a top filter 1826 and an odor filter 1828. The top filter 1826 may be a hydrophobic filter and / or a dust filter. The odor filter 1828 may also be configured to filter bacteria from the air flowing through the filter 1828. The top filter 1826 may be used to prevent any liquid from leaking out of the canister body 1902 through the opening 1824 of the first cap member 1822 and may be positioned on one or both sides of the odor filter 1828. The odor filter 1828 may include any suitable filter membrane or material, including carbon. For example, and without limitation, some configurations of the odor filter 1828 may include compressed carbon.

[0073] The cap assembly 1820 may also include a base cap support 1830 that may be configured to provide a support surface for one or more of the filters 1826, 1828 and / or other components of the cap assembly 1820. The base cap support 1830 is configured to insulate or shield the one or more filters 1826, 1828 from exudates and / or other liquids in the canister. In some arrangements, the base cap support 1830 may have a major surface 1840 that may overlap or cover at least a portion of the filter 1828 to inhibit or prevent liquids or exudates in the canister 1902 from splashing onto at least a portion of the odor filter 1828 and / or top filter 1826. For example, and without limitation, major surface 1840 may overlap at least 80% of the surface area of ​​the lower major surface of odor filter 1828, or at least 90% of the surface area of ​​the lower major surface of filter 1828, or at least 60% or approximately 60% to 90% or approximately 90% of the surface area of ​​the first major surface of filter 1828.

[0074] The base cap support 1830 may have one or more openings 1844 formed therein through which air and / or other gases may pass as the air and / or other gases are drawn through the cap assembly 1820 when the pump is operating. The cap assembly 1820 may be configured such that all, or substantially all, air or gas coming from the canister body 1802, 1902 must pass through the filter 1828 before passing through the openings 1844 in the cap assembly 1820. In some arrangements, there may be three or more, or four or more, or five or more openings 1844 formed in the base cap support 1830. The openings 1844 may be formed in a wall perpendicular to the upper major surface of the canister body 1802, 1902 such that exudate is less likely to splash or pass through the openings 1844, for example, the openings 1844 may be formed in a vertical wall of the base cap support 1830.

[0075] The cap assembly 1820 may include a fluid level sensor 1834 for detecting the fluid level in the canister and / or for detecting whether the canister is full or nearly full. The fluid level sensor 1834 may include two downwardly extending arms 1832. The fluid level sensor 1834 and arms 1832 may be similar to the fluid level sensor 518 and arms 520 described with reference to FIG.

[0076] 5D and 5E show exploded views of the canister assembly 1700. The canister assembly 1700 can have a canister body 1702 having a first body portion 1702a and a second body portion 1702b. The canister assembly can include a filter assembly 1620. The filter assembly 1702 can include a hydrophobic filter 1640, an odor filter 1642, and a dust filter 1644, which may be used to block (e.g., prevent) dust or other particles from passing through the pump assembly. The odor filter 1642 may also be configured to filter bacteria from the air flowing through the filter assembly 1620. The hydrophobic filter 1640 may be used to prevent any liquid from leaking out of the canister body 1702 and contacting the odor filter 1642. The odor filter 1642 can include any suitable filter membrane or material, including carbon. For example, and without limitation, some configurations of the odor filter 1642 may include compressed carbon. The filter assembly 1620 is also shown in Figures 5D and 5E.

[0077] The filter assembly 1620 may be supported at a lower or inner end by a base support 1650, which may be configured to provide a support surface for the hydrophobic filter 1640 and / or other components of the filter assembly 1620. The base support 1650 may have one or more openings 1652 through its main surface 1653 through which air and / or other gases can pass as the air and / or other gases are drawn by a pump through the filter assembly 1620.

[0078] Some arrangements of the base support 1650 may optionally be configured to support a sensor or sensors and / or other electronic components. With reference to FIG. 5D, some arrangements of the base support 1650 may have a support surface 1654 configured to support a sensor 1658 and / or other electronic components. For example, and without limitation, the base support 1650 may have a support surface 1654 that is generally parallel to the top surface of the canister assembly 1700. In some arrangements, the base support 1650 may also have one or more support tabs 1655 (two shown) to provide additional support for the sensor or sensors and / or other electronic components. For example, the sensor may include a pair of electrodes configured to determine the fill level of the canister or detect that the canister is full responsive to detection of a current conducted between the electrodes through a liquid (e.g., wound exudate) aspirated into the canister as described herein. The support tab 1655 may support a pair of electrodes that may be positioned on an outwardly facing side of the support tab 1655.

[0079] The support tabs 1655 can extend away from the support surface 1654 towards the bottom of the canister. The support tabs 1655 can have a flange or shield 1657 at a distal end of each of the support tabs 1655 to prevent liquids (e.g., wound exudate) within the canister from splashing onto the support tabs 1655 and / or the electronic components 1658 (such as electrodes) and exposing the gel packets 1622 or gelling agent mounds. In some arrangements, the flanges 1657 can each extend at an angle (e.g., a perpendicular angle) away from the support tabs 1655. In other arrangements, the flanges 1657 can extend at an angle that is greater than or less than 90 degrees relative to the support tabs 1655.

[0080] In some arrangements, the electronics 1658 may optionally be a fill level sensor or a canister full sensor as described herein. For example, the fill level sensor may have a wireless transmitter (which may optionally be a short-range communication transmitter) that may be configured to communicate status information (such as the detected fill level or whether the canister is full) to the pump assembly or other wireless receiver, or may have a wired connection through the canister that communicates with the pump assembly. The flange or shield 1657 may reduce or prevent fluid from splashing onto the fill level sensor or canister full sensor to prevent false positives. In some cases, the flange or shield 1657 may be utilized to shield the electronics from the gelling agent bag or fluid solidifier in the canister. The fill level sensor or canister full sensor may be glued or otherwise secured to or attached to the support surface 1654 and / or support tabs 1655. In other cases, a fill level sensor or canister full sensor may remain on at least a portion of the support surface 1654 and / or support tabs 1655.

[0081] The base support 1650 may have an annular flange 1660 about its periphery and a recess 1662 that may be configured to receive and support at least the hydrophobic filter 1640. The base support 1650 may optionally be welded, glued, or otherwise coupled within an interior surface of the first body portion 1702a of the canister body 1702 of the canister assembly 1700 before the first and second portions 1702a, 1702b of the body 1607 are coupled together.

[0082] The fill level or canister full sensor may be overmolded into the canister assembly. In other cases, the fill level or canister full sensor may be insert molded into the canister assembly. The fill level or canister full sensor may be screen printed onto the canister assembly, for example, an electrical track may be screen printed onto the canister assembly. These techniques may be useful during assembly and manufacturing, as these methods may eliminate the need to place the fill level or canister full sensor inside the canister. The fill level or canister full sensor may be attached to the support surface and / or support tabs by ultrasonic welding or adhesives. This method may utilize manufacturing methods for ultrasonic welding and adhesive applications used for other components of the canister.

[0083] The fluid level sensor may include or be part of a detection system configured to communicate wired or wirelessly (using NFC, RFID, etc.). The detection system may utilize a fluid level sensor incorporating a communication device to communicate information from the canister to the device or another remote computing device 334 (e.g., remote computing device 334). The detection system may utilize a communication device to communicate information from the canister to the device using NFC. NFC is a collection of short-range wireless technologies, typically requiring a separation of 10 cm or less (in some cases, 4 cm or less). NFC may include an initiator (or active tag) and a target (or passive tag). The initiator may actively generate a radio frequency (RF) field that can power the passive tag. In some cases, NFC communication may utilize an NFC reader that communicates with the passive NFC tag. The NFC reader may obtain information stored in the passive NFC tag. The pump assembly 160 may include an NFC reader (which may be located at or near the bottom of the pump assembly 160 housing), and the canister detection system may include a passive NFC tag. When a conductive portion of the NFC tag contacts the fluid in the canister and a circuit is closed, information (such as a flag) may be stored in the memory of the NFC tag. The NFC reader may read such information by communicating with the NFC tag. The NFC reader and the NFC tag may include one or more antennas to facilitate wireless communication (e.g., facilitate transmission and reception of data). In some cases, the range of communication between the NFC reader and the NFC tag may be about 20 mm (or more), which may exceed the distance between the NFC reader and the NFC tag.Additional details of using NFC communications to determine the status of a canister are disclosed in co-pending International Patent Application No. PCT / EP2022 / 060464 entitled COMMUNICATION SYSTEMS AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY DEVICES, filed on April 20, 2022 (Atty. Docket SMNPH.654WO), which was filed on the same day as UK Provisional Application No. 2205753.3, from which this application claims priority, and is incorporated by reference in its entirety.

[0084] As described herein, a negative pressure wound therapy device, such as pump assembly 160, or a remote computing device, can include an NFC reader. The NFC reader can have an antenna configured to facilitate communication with a canister, such as canister 162. Pump assembly 160 can receive data regarding the status of the canister, such as whether the canister is full, the level of fluid in the canister, etc. Additional approaches for communicating with pump assemblies are disclosed in the above-mentioned International Patent Application PCT / EP2022 / 060464 (Atty. Docket SMNPH.654WO), entitled COMMUNICATION SYSTEMS AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY DEVICES.

[0085] To detect the fluid level in the canister, the detection system may utilize a tamper detection system to detect when the fluid in the canister reaches a threshold level. The tamper detection system may detect a change in impedance or resistance in a circuit to determine if the system has been tampered with. For example, when used in packaging, detection of an open circuit in the tamper detection system may indicate tampering with the device, such as opening a parcel. The fluid detection system may utilize a tamper detection system to detect that the canister is full when the tamper detection system detects a closed circuit caused by the fluid level in the canister reaching (or exceeding) a threshold fluid level. Thus, the tamper detection system may detect a full canister in response to a closed circuit, which may indicate no tamper detection (as opposed to tamper detection detected with an open circuit used in the case of packaging solutions).

[0086] 6A and 6B show an exemplary tamper detection system circuit and the state of the tamper detection circuit. The illustrated tamper detection system can be configured to communicate using NFC (using the antenna illustrated on the left). FIG. 6A shows the tamper detection system in a "no tamper detected" state, which corresponds to a closed circuit state (nodes TD0 and TD1 are electrically connected). FIG. 6B shows the tamper detection system in a tamper detected state or an open circuit state (nodes TD0 and TD1 are not electrically connected). The state of the system may be stored in a dedicated register. For example, "01h" (or "1") may indicate a closed circuit, and "00h" (or "0") may indicate an open circuit. Fluid in the canister can be used to close the circuit that creates the no tamper detected state illustrated in FIG. 6A. When the tamper detection system is incorporated into a fluid detection system (such as the fluid level sensor 518), the fluid detection system can have a first state which can be a "canister empty" state corresponding to an open circuit (such as "tamper detected" as shown in FIG. 6B), and a second state can be a "canister full" state corresponding to a closed circuit (e.g., "no tamper detected" as shown in FIG. 6A) with the fluid in the canister closing the circuit. For example, when the fluid in the canister reaches a particular level, the arm 520 of the fluid level sensor 518 can contact the fluid in the canister, thereby completing the circuit and causing the fluid level sensor to detect a canister full condition.

[0087] The tamper detection system can detect that the circuit is closed based on monitoring the impedance or resistance between nodes TD0 and TD1. In some cases, the threshold impedance for detecting a closed circuit should correspond to the impedance of the fluid (such as wound exudate) expected to fill the canister. Testing of a variety of fluids, including tap water, saturated salt water, and irritant exudate (0.9% saline), has revealed impedances of approximately 460 Ω, approximately 34 Ω, and approximately 66 Ω, respectively. The threshold impedance can be set to a value equal to or greater than these impedances. For example, the threshold impedance can be set at about 35Ω (or more), about 50Ω (or less or more), about 70Ω (or less or more), about 100Ω (or less or more), about 0.5 kΩ (or less or more), about 1 kΩ (or less or more), about 2 kΩ (or less or more), about 3 kΩ (or less or more), about 4 kΩ (or less or more), about 5 kΩ (or less or more), about 6 kΩ (or less or more), or less than about 7.5 kΩ. In some cases, the threshold impedance can correspond to an average impedance of at least a portion of the fluid expected to fill the canister.

[0088] In some instances, the threshold impedance may be a preset value. The area of ​​one or more of the electrodes of the fluid level sensor may be adjusted to ensure that the impedance of the closed circuit matches such current threshold impedance. For example, assume that the preset threshold impedance is 50Ω or less. In such a case, the area of ​​one or more electrodes may be increased to ensure that the closed circuit impedance does not exceed 50Ω.

[0089] In some cases, reliable canister detection can be implemented. The fluid detection system can communicate an identifier, which can be a unique value (e.g., a unique canister identifier). For example, if an NFC protocol is used (which operates over a short range), the negative pressure wound therapy device can be configured to not allow the delivery of therapy if an identifier (indicating that the canister is attached to the device) is not received from the canister.

[0090] In some cases, the pump assembly may be used with canisters of various volumes or sizes. In such cases, canisters of different volumes or sizes can be identified by changing the location (or number) of a fluid level sensor (e.g., NFC tag) in the canister on different types of fluid-containing canisters. For example, a canister of a first size can have a fluid level sensor or NFC tag in a first location (such as the top center of the canister body) and a second canister of a second size can have a fluid level sensor or NFC tag located in a second location (such as the top side of the canister body). This can be identified by a reader on the pump assembly to indicate the type of canister attached to the pump assembly, rather than reading a coded message on the sensor to determine the canister type. Additionally, using sensors located at different locations on the canister to determine the volume or size of the canister allows for identification of the canister type even if the data written to the sensor is written in error.

[0091] The state of the tamper detection system 502 supporting NFC communications (e.g., functioning as a passive NFC tag) can be detected by an NFC reader 504, as shown in Figures 6C-6D. As described herein, the NFC reader 504 may be located within a negative pressure wound therapy device (labeled as "tNPWT device" in Figures 6A, 6B, 6C, and 6D), such as the pump assembly 160. Additional details on how an NFC reader can be incorporated within a negative pressure wound therapy device are disclosed in the above-referenced International Patent Application No. PCT / EP2022 / 060464 (Atty. Docket SMNPH.654WO), entitled COMMUNICATION SYSTEMS AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY DEVICES.

[0092] In some cases, the tamper detection system can include a memory that stores additional information related to the status of the canister. For example, the additional information can include information about the canister size (e.g., 300 ml or 800 ml). In some cases, the additional information can include an indication of whether the same canister has been previously installed in the negative pressure wound therapy device. For example, the unique canister identifier can indicate if the same canister is removed and placed back into the negative pressure system. The unique canister identifier can enable tracking of the use of the canister. In some cases, the additional information stored in the tamper detection device in the canister can include tracking information entered into the device, such as the time and / or date when the canister was connected to the pump assembly, when the canister was removed from the pump assembly, and / or the number of operating hours. Additional details regarding the condition of the canister are disclosed in International Patent Application No. PCT / EP2022 / 060459, entitled INTELIGENT DISPOSABLE DEVICES FOR WOUND THERAPY AND TREATMENT, filed on April 20, 2022 (Atty. Docket SMNPH.683WO), which was filed on the same day as UK Provisional Application No. 2205753.3, from which this application claims priority, and is incorporated by reference in its entirety.

[0093] In some cases, the tamper detection system can be used in combination with other canister fullness detection methods. Using two or more redundant systems can promote accuracy. For example, the tamper detection system can be used in combination with peak-to-peak voltage measurements from pressure pulses to avoid false positive alarms from a peak-to-peak voltage measurement system. This can be particularly advantageous when estimating the fill rate of the canister. For example, in some cases, the peak-to-peak voltage measurements can give a rough indication of the fill level and therefore the flow rate of the wound drainage. The tamper detection system can be used to activate an alarm when the canister is near or full to the full level. Additionally, a third check by the user can be performed to increase the accuracy of the system. This third check can consist of a user interface input of the canister level (e.g., "low", "half full", "almost full"). In some cases, the user interface can utilize buttons or other user input modes as described herein. For example, images or text can be used on the buttons (e.g., three buttons each corresponding to a particular fluid level with an image and / or text).

[0094] The fluid detection system may include a fill level sensor or canister full sensor that includes multiple sets of electrode pairs. In some cases, multiple sets of electrode pairs may be positioned on multiple arms. Additionally or alternatively, the fluid detection system may utilize multiple fill level sensors or canister full sensors (e.g., multiple NFC tags) in the canister. For example, in some cases, multiple pairs of arms or multiple sensors may be used rather than a single pair of arms or a single sensor extending into the canister as shown in FIG. 5A. Multiple pairs of arms or multiple sensors may be used at different lengths to measure the fluid level as the canister fills with liquid and before it is full or nearly full. In some cases, as described herein, the sensor may include multiple pairs of arms at multiple distances from the top or cap of the canister. In some cases, multiple sensors may be used and stacked or arranged in an arrangement that allows for detection at different fill levels as the canister fills with liquid. This allows detection at various levels within the canister, allowing a user to determine the remaining volume of the canister or to determine the rate at which the canister is to be filled, as described herein.

[0095] For example, there may be three pairs of arms positioned on or extending into the canister body at different locations within the canister. The first pair of arms (the longest pair of arms) may extend into the canister to a position indicating the canister is half full with liquid. The second pair of arms may be shorter than the first pair, but longer than the third pair, and may extend into the canister to a position between the position indicating the canister is half full and the position indicating the canister is full. The third pair of arms may be the shortest pair of arms and is located in a position indicating the canister is full or nearly full. If only the first pair of arms detects fluid, the canister is half full. If the second pair of arms detects fluid, the canister may be 3 / 4 full, or some volume between midway between full and full or nearly full. If the third pair of arms detects fluid, the canister is full or nearly full. Multiple pairs of arms may also be used to measure the "time to full" of a canister as described further herein. The pairs of arms may be on the same sensor device (or the same support substrate) or may be in the form of multiple sensors (e.g., multiple NFC tags), each having a pair of arms, each pair of arms having a different length than another pair of arms. Although three pairs of arms are described, any number of pairs of arms or any number of sensor devices may be used to detect any number of levels in the canister. Fill level resolution may be increased with more sensors or pairs of arms at various levels.

[0096] In some cases, multiple sensor devices can be positioned at the top of the canister, the same distance from the filter, but on multiple axes. Multiple sensors can provide redundancy against tag failure. Multiple sensors also provide the ability to generate a fill gauge by staggering the sensor locations. The spacing of the tag read paths to generate the fill gauge may be set to a fixed interval for a given amount of fluid, or an appropriate interval for an expected time interval (tags can be spaced more widely at the start or when the container is filled to the bottom, to accommodate a bolus of fluid being delivered to the canister, and then more closely spaced as the canister is filled, as the fluid flow rate is expected to decrease). The latter provides the most granular picture of whether the wound is following the "expected" course with a minimum of trace paths.

[0097] FIG. 6E illustrates an NFC tag that can be used as a fill level sensor assembly. The NFC tag may be used to detect the fluid level in the canister described herein. The canister can be an important part of negative pressure therapy. In some cases, the pump assembly cannot perform negative pressure therapy on the patient without the canister present. The canister must be pneumatically connected and attached to the pump assembly and / or wound dressing. Any of the canister cap embodiments described herein can include an NFC tag fill level sensor assembly, as shown in FIG. 6E. In some cases, as described herein, short-range wireless NFC communication can verify the attachment of the canister to the pump assembly and verify that the canister is properly attached. The primary function of the canister's NFC tag fill level sensor assembly is to enable a passive NFC device in the canister to wirelessly communicate to an NFC reader located in the pump assembly. The wireless function of the NFC tag sensor assembly can transmit data related to canister detection, fluid detection, and programmed canister data. The NFC tag device illustrated in FIG. 6E includes the anti-tamper detection features described herein. In some cases, the NFC tag device can include specific modes to protect tag access, such as an untraceable mode. In some cases, the NFC device can include a digital signature used to prove the origin of the chip in cloning detection, can be embedded with a configurable EEPROM with 60-year data retention, and / or can operate from a 13.56 MHz long-range RFID reader.

[0098] Canister Fill Rate Detection It may be advantageous to detect and indicate the fill rate in a negative pressure system of a canister, such as canister 162. This detection may be performed in addition to, or as an alternative to, the full or nearly full canister detection described herein.

[0099] The canister fill rate may be used to estimate wound drainage or the amount of exudate flowing out of the wound. The flow rate of fluid from the wound can be calculated based on the duration between an empty canister being placed and the time it is full, using the time it took to fill the canister. The volume of the canister can then be divided by the time it takes to fill the canister to calculate the wound fluid flow rate. For example, the following formula can be used:

[0100]

number

[0101] In some cases, the canister volume may be entered by a user or may be detected (e.g., retrieved from the canister's memory as described herein). The exact flow rate may be calculated using a fluid level sensor as described herein. The fill time of the canister may be accurately determined by taking into account any interruptions or halts in treatment and determining whether the same container is still connected when treatment is resumed or if the canister has been removed and reattached. These determinations may be made using a unique canister identifier as described herein.

[0102] In some cases, the flow rate can then be used by a healthcare provider to determine the best treatment route and whether the patient can be moved to another system, for example, Smith & Nephew's Pico Single Use Negative Pressure Wound Therapy System.

[0103] In some cases, the canister can be removed before the canister is full. In these situations, the flow rate can be estimated by a manual input into the user interface indicating the level of fluid in the canister. In some cases, if the canister is removed before it is full or before the canister full alarm is activated, this input may be an input indicating "low," "half full," or "almost full." This input can be used to adjust the canister volume variable in Equation 1.

[0104] In some cases, information obtained from the canisters, canister fill rates, and / or canister usage and therapy usage can provide information to medical professionals and enable understanding of trends and behaviors within a single patient or across different patients to aid in medical decisions.

[0105] In some cases, a flow meter can be positioned in the fluid flow path (such as conduit 108 or 108') to determine the flow rate. For example, a Venturi tube may be used.

[0106] Inductively Coupled Fluid Detection System The canister full detection system can use an inductively coupled fluid detection system that can detect a full or nearly full canister and provide a warning to the user as a result. As described herein, a canister full or nearly full warning can be important for a negative pressure therapy system because it allows a medical professional or user to replace the canister and continue treatment with minimal interruption (e.g., without having to worry about the device suddenly sounding a canister full / shutoff warning).

[0107] The negative pressure wound therapy system can use an inductively coupled fluid detection system to determine if the canister is nearly full. To do this, the system can use spaced electrodes in the canister that can detect the presence of fluid by a change in electrical characteristics when the fluid in the canister is at a certain level and the electrodes are submerged. The canister fluid level information can then be relayed back to the negative pressure therapy system, for example, via inductive coupling (such as NFC) or another wireless or wired communication protocol. For example, an inductively coupled fluid detection system can include one coil on the device (device side) and another coil on the canister (canister side). In some cases, this configuration can provide isolation by avoiding direct electrical connections between the canister, the device, and ultimately the user. The device coil may be located in the bottom portion of the housing of the negative pressure wound therapy device, as described in the above-mentioned International Patent Application No. PCT / EP2022 / 060464 (Atty. Docket SMNPH.654WO) entitled COMMUNICATION SYSTEMS AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY DEVICES. Further details regarding the inductively coupled fluid detection system are disclosed in co-pending International Patent Application No. PCT / EP2022 / 060463 (Atty. Docket SMNPH.672WO) entitled CANISTER STATUS DETERMINATION FOR NEGATIVE PRESSURE WOUND THERAPY DEVICES, filed on the same day as UK Provisional Application No. 2205753.3, from which this application claims priority, and is incorporated by reference in its entirety.

[0108] Additional details of utilizing fluid level sensors and NFC communications to determine canister status are disclosed in co-pending International Patent Application No. PCT / EP2022 / 060463 entitled CANISTER STATUS DETERMINATION FOR NEGATIVE PRESSURE WOUND THERAPY DEVICES (Atty. Docket SMNPH.672WO), filed on the same day as UK Provisional Application No. 2205753.3, from which this application claims priority, and is incorporated by reference in its entirety.

[0109] Fluid Level Sensor Configurations The arms 520 of the fluid level sensor 518 can be configured in different ways. For example, in some cases, the fluid level sensor 518 can include two arms 520. Each arm can include a planar path surface. In some cases, the planar path surfaces of the arms 520 are opposite each other, as shown in FIG. 7. The arms 520 of the fluid level sensor 518 can also include planar path surfaces that are parallel to each other. The planar path surfaces of the arms 520 can also be coplanar. That is, each planar path surface of the arms 520 can be located substantially on the same plane. In other cases, the fluid level sensor 518 can include two offset arms 520, i.e., two arms 520 of different lengths, as shown in FIG. 8. The length of the arms can include the distance between two points A and B. Point A can be a point located along the canister top, and point B can be a point furthest from the canister top. The arms 520 can include planar path surfaces that are parallel to each other and / or coplanar to each other. In yet other cases, the fluid level sensor 518 may include two arms 520 of similar or different lengths, where the arms 520 are angled with respect to each other, as shown in FIG. 9. In some cases, the arms 520 of the fluid level sensor 518 are not mechanically fixed in place. In such cases, the position of the arms 520 inside the canister 162 may vary according to the orientation of the canister 162 (shown in FIGS. 2A, 2B) or any other canister described herein. Although this specification describes the canister 162, the fluid level sensor may be used with any other canister described herein. The distance between the arms 520 may also vary. In some cases, the arms 520 may be closer together than in other cases. Beneficially, the different configurations of the arms 520 may improve the ability of the fluid sensor 518 to accurately detect the state of the fluid level sensor 518 even when the canister 162 is tilted or not in an upright position. The canister 162 of the negative pressure wound therapy device may be configured so that the canister 162 can be seated in one or more positions.The fluid sensor 518 may be positioned to detect a condition (eg, a canister full condition) regardless of where the canister 162 is located.

[0110] An important feature of the fluid sensor may be to alert the user when the canister is full or nearly full, thus preventing fluid from blocking the filter which would lead to loss of negative pressure. The movement of a portion of the sensor that is not mechanically fixed in place under gravity allows the sensor to give a "full" indication at the same (or similar) point below the filter in multiple orientations. Additionally, a fluid sensor that is not mechanically fixed in place can alert the user if the canister is inverted. This alert may occur if an arm of the fluid sensor contacts the top of the canister, which in turn contacts any fluid and / or conductive paths on the canister itself.

[0111] In some cases, the negative pressure wound therapy system includes a single fluid level sensor 518 with one or more sets of arms 520, each set of arms 520 configured to detect a state of the fluid level sensor 518. In some cases, the negative pressure wound therapy system includes one or more fluid level sensors 518. Each fluid level sensor 518 of the one or more fluid level sensors 518 can include one or more sets of arms 520 configured to detect a state of the fluid level sensor 518. Multiple detection points within the canister achieved with multiple sensors or multiple sets of arms 520 can also be achieved by utilizing a fluid level sensor 518 with one common long arm. For example, multiple arms of different lengths seeking connections with one common long arm can detect fluid at multiple levels.

[0112] If the fluid level sensor 518 includes an NFC tag, a single NFC tag having a single antenna and a single chip (e.g., IC chip) can include multiple paths located at different elevations and / or locations within the canister 162 to detect different conditions within the canister 162. In some cases, a single NFC tag can include a single path for detecting conditions inside the canister 162. A negative pressure wound therapy device can include multiple NFC tags. If multiple NFC tags are used, multiple NFC readers, a moving (e.g., rotating, vibrating) single NFC reader, or a multi-frequency NFC reader can be used with channels of different frequencies (e.g., 3.56 (+ / - 0.9) MHz plus 865-868 or 902-928 MHz, e.g., following the EPC Gen2 protocol).

[0113] Fluid Level Sensor Shielding The fluid level sensor 518 may include a mechanical shield 522, as shown in FIG. 10. The mechanical shield 522 may protect the fluid level sensor 518 from splashing and tilting. Beneficially, the mechanical shield 522 may reduce the likelihood of the fluid level sensor 518 malfunctioning, for example, caused by splashing and / or tilting of the canister 162. The mechanical shield 522 may be disposed inside the canister 162. In some cases, the mechanical shield 522 may be supported by a portion of the canister cap, such as, but not limited to, the cap bottom 514 shown in FIG. 5A, the base cap support 1830 shown in FIGS. 5B and 5C, the base support 1650 shown in FIGS. 5D and 5E, or any other component on the inside top surface of the canister. For example, the mechanical shield 522 may be glued or otherwise attached to a portion of the canister cap or to a surface inside the canister. In other cases, the mechanical shield 522 is structurally integral with a portion of the canister cap or with an interior surface of the canister.

[0114] In some cases, the mechanical shield 522 can include an interior surface 522a and an exterior surface 522b and may be configured to surround the fluid level sensor 518, as shown in FIGS. 11-17. In some cases, the mechanical shield 522 includes an opening along a bottom 522c of the mechanical shield 522 and an opening along a top 522d of the mechanical shield 522. As used herein, the term bottom may refer to a portion of the canister furthest from the canister cap 510 or where the canister 162 connects to the pump assembly, and the term top may refer to a portion of the canister 162 closer to the canister cap 510 or where the canister 162 connects to the pump assembly. The top 522d of the mechanical shield 522 may be a portion of the canister closer to the canister top or top surface of the canister than the bottom 522c. The mechanical shield 522 may be configured such that the width of the opening along the bottom 522c of the mechanical shield 522 is equal to or less than the width of the opening along the top 522d of the mechanical shield 522 in at least one plane. The opening along the bottom portion 522c of the mechanical shield 522 may be configured to allow fluid to flow into the interior of the mechanical shield 522, thereby allowing the fluid to contact the arm 520 of the fluid level sensor 518 as the fluid is collected in the canister 162. In some cases, wound fluid may be introduced into the canister 162 through the opening along the top 522d of the mechanical shield 522, as shown by arrow 523 in FIG.

[0115] 10 shows a front cross-sectional view of an example of a mechanical shield 522 for the fluid sensor 518. Beneficially, the mechanical shield 522 of the fluid level sensor 518 can prevent the fluid sensor 518 from malfunctioning when splashing occurs or when the canister 162 is tilted. Splashed fluid may enter the interior of the mechanical shield 522 through an opening along the bottom 522c of the mechanical shield 522, but the angular profile of the wall of the mechanical shield 522 can cause the splashed fluid to drain along the interior wall of the mechanical shield 522, exit the interior of the mechanical shield 522 through the opening, and collect in the bottom of the canister 162, away from the mechanical shield. In some cases, the fluid may splash into the interior of the mechanical shield and come into contact with one of the two arms 520. However, if one of the two arms is splashed or contacted in this manner, it will not activate the canister full or near full alarm, as both arms would need to be in contact with fluid to complete the electrical circuit and activate the canister full or near full alarm.

[0116] Because splashed fluid may contact the arm 520 of the fluid sensor 518 as it drains along the interior wall of the mechanical shield 522, the fluid level sensor 518 may be positioned in any configuration that maximizes the distance between the arm 520 and the interior wall of the shield 522, thereby reducing the chance of the fluid level sensor 518 malfunctioning. For example, the fluid level sensor 518 shown in FIG. 16 may be positioned as shown in FIG. 17 to increase the distance between the arm 520 of the fluid level sensor 518 and the interior wall of the mechanical shield 522.

[0117] In some cases, the mechanical shield 522 can include a cone shape, as shown in FIGS. 11 and 12. In other cases, the mechanical shield 522 can include an inverted truncated square pyramid shape, as shown in FIGS. 13 and 14. In still other cases, the mechanical shield 522 can include an inverted truncated rectangular pyramid shape, as shown in FIG. 15. Although cone shapes, inverted truncated square pyramid shapes, and inverted truncated rectangular pyramid shapes are disclosed herein as possible shapes for the mechanical shield 522, the mechanical shield 522 can include other shapes, including non-continuous and asymmetric shapes. Additionally, in some cases, the wall thickness of the mechanical shield 522 can be the same across all portions of the mechanical shield 522. However, in other cases, the wall thickness can vary depending on the portion of the mechanical shield 522. In some cases, the mechanical shield may surround the fluid level sensor 518 on all sides, as shown in Figures 11-17, but may be left open at the top and bottom to allow fluid communication between the fluid level sensor and the interior of the canister.

[0118] In some cases, as shown in FIGS. 19 and 20, the mechanical shield (similar to the mechanical shield 522 shown in FIGS. 10-18) may be defined by a structure surrounding a window 515 positioned on a support surface 510a extending from a cap 510 of the canister. The support surface 510a may extend downwardly from a bottom surface of the canister cap into the interior of the canister. The dimensions and shapes of the support structure 510a and the window 515 may vary. For example, and without limitation, the support structure 510a may have various widths, lengths, and / or angles relative to the plane of the cap 510. Similarly, the size of the window 515 may vary, with some embodiments having narrower windows 515 than other embodiments. Additionally, in some cases, the plane of the window 515 may be parallel or substantially parallel to the plane of the cap 510. The window 515 and the plane of the cap 510 may be angled relative to one another, as shown in FIG. 19. In some cases, the planes of the window 515 and the cap 510 may be perpendicular to each other, as shown in FIG.

[0119] In some cases, the support surface 510a may extend vertically or substantially vertically into the canister interior, as shown in Figures 21A and 21B. As shown in Figure 21A, the first and second contacts 511a, 511b (also referred to herein as first and second pads, respectively) of the fluid level sensor may be disposed on one side of a window 515 on the support surface 510a, with the contacts 511a, 511b positioned back to back. In other cases, the first and second contacts 511a, 511b of the fluid level sensor may be positioned on different sides of the support surface 510a, as shown in Figure 21B. Figure 22 shows another example of a support structure 510a extending from a portion of a canister cap bottom 514 having an opening along its top surface. The opening may define an edge that may facilitate attachment of a portion of the cap bottom 514 to a canister and / or other components of the canister. In Figures 19-25C, the canister cap 510 is shown in simplified form, however, the canister cap 510 may have any of the features of the previously described embodiments shown in Figures 5A-5E, including, but not limited to, a central port or structure for communicating with the pump assembly.

[0120] As shown in Figures 23A-23B, the support surface 510a may extend from the bottom surface of the canister cap 510, and the support surface 510a may extend at an angle relative to the top surface of the canister cap 510. A non-perpendicular orientation relative to the top surface of the cap 510 and the support surface 510a may beneficially reduce manufacturing costs. For example, the embodiment of Figure 19 may be manufactured using a two-part compression plastic molding tool as opposed to a more complex plastic molding tool. The cap 510 may be positioned inside the top of the canister 162 as shown in Figure 24. Wound fluid within the canister may contact a fluid level sensor positioned within a window 515 of the support surface 510a. The fluid level sensor may be positioned within a window 515 of the support surface as shown in Figures 23A and 23B. For example, when the fluid level in the canister reaches a threshold fluid level, the fluid contacts the fluid level sensor (shown in FIGS. 21A and 21B, 23A and 23B) in a window 515 in the support surface 510a of the cap 510. As shown in FIGS. 23A and 23B, a first contact surface (also referred to herein as a first pad) 511a of the fluid sensor 518 may be positioned on an outwardly facing surface of the fluid level sensor 518, and a second contact surface (also referred to herein as a second pad) 511b may be positioned on the window 515 opposite the support surface 510a. In some cases, the second contact surface 511b may be exposed through the window 515. The fluid level sensor may then extend along the support surface 510a to a top surface of the canister cap 510. An antenna 513 associated with the conductive contact surface of the fluid level sensor may be positioned on the top surface of the canister cap 510, as shown in FIGS. 23A and 23B.

[0121] 25A-25C, the support surface 510a of the cap 510 can include one or more windows 515a, 515b, and 515c along the support surface 510a of the cap 510, each window defining an area of ​​a mechanical shield. For example, in some cases, the area of ​​one or more of the windows 515a, 515b, and 515c can correspond to the area of ​​the mechanical shield 522, discussed in more detail herein, shown as 522', 522'', 522''' in FIG. 30. The area of ​​the one or more openings along the bottom surface of the support surface 510a associated with the one or more windows 515a, 515b, and 515c can vary. For example, similar to the various sizes of the mechanical shield structures described herein, the size of the opening associated with window 515a may be smaller than the size of the opening associated with window 515b, which may be smaller than the size of the opening associated with window 515c, as shown in FIG. 25B. Alternatively, the size of the opening associated with window 515a may be larger than the size of the opening associated with window 515b, which may be larger than the size of the opening associated with window 515c. The various sizes may enable detection or determination of the fluid characteristics described herein. As shown in FIG. 25C, one or more of windows 515a, 515b, and 515c may be positioned at different heights. For example, window 515a may be at a height closer to the cap 510 than windows 515b and 515c. As described in further detail below, these configurations can beneficially enable one or more fluid level sensors 518, and / or a single fluid level sensor 518 having one or more sets of arms 520, to indicate the composition of wound exudate, the amount of fluid collected within the canister 162, the rate at which fluid is collected within the canister 162, and / or a fault condition of the negative pressure wound treatment system.

[0122] In some cases, the mechanical shield 522 includes a splash guard element, as shown in FIGS. 26 and 27. The splash guard element can include a first set of guards 524 including one or more guards configured to prevent splashing fluid from entering the interior of the mechanical shield 522 through an opening along a bottom portion 522c (shown in FIG. 10) of the mechanical shield 522. In some cases, the splash guard element can include one or more guards positioned substantially along the bottom portion 522c of the mechanical shield 522. For example, the splash guard can include a first guard 524a extending from a first portion of the interior surface 522a of the mechanical shield 522 and a second guard 524b extending from a second portion of the interior surface 522a of the mechanical shield 522. In some cases, the second portion of the interior surface 522a (shown in FIG. 10) of the mechanical shield 522 is an opposite portion of the first portion. At least a portion of the first guard 524a may overlap a portion of the second guard 524b. In other cases, the first guard 524a does not overlap the second guard 524b. The first set of guards 524 may be arranged to create a fluid path from the exterior of the mechanical shield 522 to the interior of the mechanical shield 522. Beneficially, the fluid path can facilitate the flow of fluid from the interior of the canister 162 to the interior of the mechanical shield 522 as the canister 162 is filled, while preventing splashed fluid from tripping the fluid level sensor 518.

[0123] In yet other cases, the splash guard element includes a second set of guards 526 including one or more guards positioned substantially along the top 522d (shown in FIG. 10) of the mechanical shield 522, as shown in FIG. 27. The second set of guards 526 can prevent splash fluid from entering the interior of the mechanical shield 522 through the top 522d of the mechanical shield 522 and contacting the arm 520 of the fluid sensor 518, thereby reducing the possibility of the fluid sensor 518 malfunctioning. In some cases, the second set of guards 526 can include a first guard 526a extending from a first portion of the interior surface 522a of the mechanical shield 522 and a second guard 526b extending from a second portion of the interior surface 522a of the mechanical shield 522. Similar to the first guard 524a of the first set of guards 524, at least a portion of the first guard 526a can overlap a portion of the second guard 526b. In other cases, the first guard 526a does not overlap the second guard 526b. The second set of guards 526 may be arranged to create a fluid path from the exterior of the mechanical shield 522 to the interior of the mechanical shield 522. In other cases, the splash guard element includes a single guard with an opening. The single guard can be positioned / shaped to cover at least a top portion of the fluid sensor 518.

[0124] The canister 162 of the negative pressure wound therapy device may be configured to allow the canister 162 to sit in one or more stable positions. The fluid sensor 518 may be positioned to detect a condition (e.g., a canister full condition) regardless of the stable position in which the canister 162 is located. The mechanical shield 522 disclosed herein may be positioned to protect the fluid level sensor 518 from splashing and / or tilting of the canister 162 regardless of the stable position in which the canister 162 is located, as shown in Figures 28A-28C. Figures 28A and 28B show cross sections of the canister 162 in a first stable position and a second stable position, respectively. When the canister 162 is in the first or second stable position, the mechanical shield 522 may protect the fluid level sensor 518 from splashing. Beneficially, the angle of the walls of the mechanical shield 522 when the canister 162 is in the first or second stable position can cause fluid within the mechanical shield 522 to drain and continue to collect inside the canister 162. If the canister 162 is not in the stable position as shown in FIG. 28C, the fluid level sensor 518 may not be able to detect a condition inside the canister 162 (e.g., a full canister condition). The angle of the walls of the mechanical shield 522 can direct at least a portion of the fluid within the mechanical shield 522 toward the filter 516 instead of directing the fluid to the bottom of the canister 162. This can cause the filter 518 to block and / or leak fluid before the fluid level sensor 518 detects the condition inside the canister 162, either of which can prevent treatment.

[0125] Fluid Level Sensor Placement In some instances of the negative pressure wound therapy apparatus, an NFC tag having a first end and a second end opposite the first end may be disposed inside the canister 162. The first end of the NFC tag may be secured to the inside base of the canister 162. The chip and / or antenna of the NFC tag may be located along the second end of the NFC tag. The second end of the NFC tag may be configured to float when fluid begins to collect inside the canister 162. The more fluid collects in the canister 162, the higher the second end of the NFC tag floats relative to the base of the canister 162. The NFC tag may be configured to communicate with an NFC reader located in the negative pressure wound therapy apparatus when the second end of the NFC tag reaches a threshold fluid level in the canister 162 (e.g., when the fluid in the canister 162 reaches a threshold level). Communications from the NFC tag to the NFC reader may indicate the state inside the canister 162 (eg, canister full or almost full).

[0126] The negative pressure wound therapy device may include a guide disposed within the canister 162. The guide may be configured to extend from the bottom of the canister 162 to the top of the canister 162 to at least partially surround the NFC tag. In some cases, the guide may be formed along an interior wall of the canister 162. Beneficially, the guide may guide the second end of the NFC tag from the bottom of the canister 162 to a known position on the top of the canister 162 as fluid begins to collect, preventing the second end of the NFC tag from floating freely within the canister 162.

[0127] The negative pressure wound therapy device can include one or more NFC tags disposed within the canister 162. Each NFC tag of the one or more NFC tags and the NFC reader can be configured to communicate based at least in part on each NFC tag reaching a threshold fluid level within the canister 162. Additionally, each NFC tag of the one or more NFC tags can be of a different density such that each NFC tag can float as fluid collects inside the canister 162 if the density of the fluid inside the canister 162 is greater than the density of each individual NFC tag. Beneficially, the one or more NFC tags can be indicative of the composition of the fluid collected within the canister 162.

[0128] In some cases, the NFC tag antenna 503 and NFC reader 504 are positioned perpendicular to the direction of removal of the canister 162 (e.g., the direction in which the canister 162 is removed from the pump assembly 110), as shown in FIG. 29A. In this configuration, the NFC tag antenna 503 and NFC reader 504 can continue to communicate even if the distance between the NFC antenna 403 and the NFC reader 504 increases. This can occur if the canister 162 is tilted or moved. In some cases, the NFC tag antenna 503 and NFC reader 504 are positioned non-perpendicular to the direction of removal of the canister 162, as shown in FIG. 29B. The non-perpendicular configuration can result in the signal to the NFC tag antenna 503 and NFC reader 504 being dropped (or at least at a shorter distance than the signal would be dropped in the perpendicular arrangement shown in FIG. 29A) as the distance between the NFC tag antenna 503 and the NFC reader 504 increases. The non-vertical configuration allows for a more sensitive sensor configuration by dropping the signal over a shorter distance, as shown in Figure 29B. This allows for a strong signal when the antenna and reader are properly coupled, and a quick drop in signal when the canister and pump assembly are separated. This can reduce the acceptance of unstable conditions and make the system more sensitive to detecting any loosening in the coupling of components that may lead to leaks.

[0129] The negative pressure wound therapy device may include one or more fluid level sensors 518, as shown in Figures 30-33. The negative pressure wound therapy device may also include a single fluid level sensor 518 with one or more sets of arms 520, as shown in Figures 30 and 31. For example, the fluid level sensor 518 may include a first set of arms 520a, a second set of arms 520b, and a third set of arms 520c, as shown in Figure 30. The lengths of the first set of arms 520a, the second set of arms 520b, and the third set of arms 520c may vary. The first set of arms 520a may be shorter than the second set of arms 520b, and the second set of arms 520b may be shorter than the third set of arms 520c. However, other combinations are possible. The different lengths of the first set of arms 520a, the second set of arms 520b, and the third set of arms 520c enable the fluid level sensor 518 to detect one or more conditions inside the canister 162 as fluid collects inside the canister 162.

[0130] In some cases, one or more fluid level sensors 518, or one or more sets of arms 520 of a single fluid level sensor 518, may be positioned at different heights relative to the canister cap 510. This means that some fluid level sensors 518 may be closer to the canister cap 510 than other fluid level sensors 518. Beneficially, using one or more fluid level sensors 518, or one or more sets of arms 520 of a single fluid level sensor 518, at different vertical positions (e.g., heights) may allow for the calculation of a measurement of inflow rate. The fluid level sensors 518 may be configured such that, as the canister fills with fluid, fluid level sensors 518 positioned further from the canister cap 510 are actuated before fluid level sensors 518 positioned closer to the canister cap 510. A measurement of the inflow rate may be obtained by measuring the time it takes each fluid level sensor 518 to actuate. Actuation of an out-of-array fluid level sensor 518 may indicate a failure of one or more of the fluid level sensors 518. For example, activating a first fluid level sensor 518 before a second fluid level sensor located further from the canister cap 510 than the first fluid level sensor 518 can indicate that the first and / or second fluid level sensor 518 are faulty. Because a negative pressure wound therapy device may remove fluid from a wound at a higher rate when therapy begins and at a lower rate as therapy progresses, it may be desirable to vary the spacing between one or more fluid level sensors 518. That is, one or more fluid level sensors 518, and / or fluid level sensors 518 having one or more sets of arms 520 can be positioned at different heights, with the fluid level sensors 518 closer to each other at the top of the canister 162 than at the bottom of the canister 162. Beneficially, this can suggest whether the wound is progressing as expected (e.g., if a particular fluid level sensor 518 is activated earlier than expected, meaning that the fluid velocity is higher than expected).

[0131] 32, one or more fluid level sensors 518, or one or more sets of arms 520 of a single fluid level sensor 518, may be positioned at different lateral positions relative to the walls of the canister 162, but at the same height relative to the canister cap 510. One or more fluid level sensors 518 may be configured to operate simultaneously. Beneficially, the failure of at least one of the fluid level sensors 518 will indicate that at least one of the one or more fluid level sensors 518 has failed.

[0132] In some cases, as shown in FIGS. 18, 30-33, one or more of the fluid level sensors 518, or one or more sets of arms 520 of a single fluid level sensor 518, can include a mechanical shield 522. For example, each set of arms of a fluid level sensor 518 is associated with at least one region of the mechanical shield. As shown in FIG. 30, a first set of arms 520a can be protected by a first region 522' of the mechanical shield 522, a second set of arms 520b can be protected by a second region 522'' of the mechanical shield 522, and a third set of arms 520c can be protected by a third region 522''' of the mechanical shield 522. The mechanical shield 522 can include different shapes and / or sizes, including non-continuous and asymmetric shapes, and any shapes or sizes described for other embodiments of the mechanical shields described herein.

[0133] The width of the openings along the bottom and top of each region of the mechanical shield 522 may vary. For example, the width of the openings along the top and bottom of the first region 522' of the mechanical shield 522 may be smaller than the openings along the top and bottom of the second region 522'' of the mechanical shield 522. Similarly, the width of the openings along the top and bottom of the second region 522'' of the mechanical shield 522 may be smaller than the openings along the top and bottom of the third region 522''' of the mechanical shield 522. If the width of the openings along the top and bottom of the first region 522' of the mechanical shield 522 is smaller than the openings along the top and bottom of the second region 522'' and the third region 522''' of the mechanical shield 522, free-flowing fluid may drain along the interior surfaces of the different mechanical shield regions 522', 522'', 522''' without actuating any of the sets of arms 520a, 520b, 520c of the fluid level sensor 518. However, if the concentration of the fluid is high, the fluid may begin to collect inside the first region 522' of the mechanical shield 522, thereby activating the first set of arms 520a of the fluid level sensor 518. At least a portion of the overflow from the first region 522' may flow to the next region of the mechanical shield 522, i.e., region 522''. Depending on the concentration of the fluid, the overflow may either fill the second region 522'' and thereby activate the second set of arms 520b, or drain along the interior surface of region 522'' without activating the second set of arms 520b. The concentration of the fluid in the canister may be measured by the order in which one or more sets of arms 520a, 520b, 520c are activated. Beneficially, this can be indicative of the composition of the fluid collected in the canister.

[0134] The mechanical shield 522 may also be configured such that the width of the opening along the top and bottom of the first region 522' of the mechanical shield 522 is greater than the width of the opening along the top and bottom of the second region 522'' of the mechanical shield 522. Similarly, the width of the opening along the top and bottom of the second region 522'' of the mechanical shield 522 may be greater than the width of the opening along the top and bottom of the third region 522''' of the mechanical shield 522. In this case, fluid drains along an interior surface of the one or more regions 522', 522'', 522''' of the mechanical shield 522 until and unless the fluid begins to fill one of the one or more regions 522', 522'', 522'''. The mechanical shield may be configured such that overflow from one of the regions 522', 522'', 522''' continues to collect within the canister 162. Discharged fluid from one or more of the regions 522', 522'', 522''' may flow to a region below (if there is one) or to the canister 162. The size of the openings along the bottom of one or more of the regions 522', 522'', 522''' of the mechanical shield 522 may affect how the fluid is collected or discharged to the next region. For example, fluid may be collected faster in a region 522', 522'', 522''' with smaller openings than in a region 522', 522'', 522''' with larger openings. The concentration of the fluid in the canister may be measured by the order in which the set of one or more arms 520a, 520b, 520c are actuated. Beneficially, this can indicate the composition of the fluid collected in the canister. Although the mechanical shield 522 in FIGS. 30 and 31 shows a mechanical shield having three mechanical shield regions 522', 522'', and 522'''', the mechanical shield 522 can include more than three mechanical shield regions or less than three mechanical shield regions.

[0135] In some cases, the mechanical shield 522 may include openings along the top 522d of the mechanical shield and openings along the bottom 522c of the mechanical shield, as shown in FIG. 31. In these cases, wound fluid may enter the mechanical shield 522 through the openings along the top 522d of the mechanical shield 522, drain and exit the mechanical shield 522 through openings along the bottom 522c of the mechanical shield 522, and / or spill (e.g., overflow) and exit the mechanical shield 522 through openings along the top 522d of the mechanical shield 522, as shown by arrow 523. In this configuration, fluid spilling from the openings along the top 522d of the mechanical shield 522 or draining from the openings along the bottom 522c of the mechanical shield 522 may continue to collect in the canister 162. 31 may also include at least one opening, such as opening 525 of FIG. 30, located between the top 522d of the mechanical shield 522 and the bottom 522c of the mechanical shield 522. The at least one opening may provide an additional path for fluid within the mechanical shield 522 to spill (e.g., overflow), exit the mechanical shield 522, and continue to collect in the canister 162.

[0136] In some cases, the mechanical shield 522 can include one or more openings 525 along two regions of the mechanical shield 522, as shown in FIG. 30. For example, the one or more openings 525 can be located between a first region 522' of the mechanical shield 522 and a second region 522'' of the mechanical shield 522, as shown in FIG. 30. The one or more openings can also be located between a second region 522'' of the mechanical shield 522 and a third region 522''' of the mechanical shield 522, as shown in FIG. 30. When the mechanical shield 522 includes one or more openings 525, wound fluid can drain and flow out of each region of the mechanical shield 522 (e.g., 522', 522'', 522''') and / or spill (e.g., overflow) and flow out of each region of the mechanical shield 522 (e.g., 522', 522'', 522''') through the one or more openings 525. With one or more openings 525 between each region of the mechanical shield 522, at least a portion of the fluid that overflows each region of the mechanical shield 522 can continue to collect in the canister 162, and at least a portion of the fluid that drains from each region of the mechanical shield 522 can continue to collect under the canister 162 (if any) or in the region of the mechanical shield 522 within the canister 162. Beneficially, the angular profile of the walls of the mechanical shield 522 can allow any fluid that enters the interior of the mechanical shield 522 to drain along the interior walls of the mechanical shield 522.

[0137] The mechanical shield 522 can indicate the composition of the fluid collected inside the canister 162. For example, in some cases, fluid may be introduced into the mechanical shield 522 through the top of the mechanical shield 522, as shown by arrow 523 in FIGS. 30 and 31. Depending on the surface tension and density of the collected fluid, any fluid that enters the interior of the mechanical shield 522 can either drain from the respective region of the mechanical shield 522 or fill the interior of the respective region of the mechanical shield 522, thereby activating the fluid level sensor 518 corresponding to that region of the mechanical shield 522. By identifying which regions of the mechanical shield 522 drain and which regions of the mechanical shield 522 fill, the composition of the fluid inside one or more regions of the mechanical shield 522 can be identified. Beneficially, this can indicate the condition of the wound, for example, the density of the fluid can indicate whether the wound exudate has excessive blood, or other characteristics that can indicate that negative pressure wound therapy may need to be paused or discontinued. Additionally, the same one or more fluid level sensors 518 may also be actuated to indicate a canister full condition by actuating the same one or more fluid level sensors 518 .

[0138] In some cases, a single mechanical shield 522 having any of the shapes, dimensions, or characteristics of the mechanical shields disclosed herein, with an opening along the top of the mechanical shield 522 and an opening along the bottom 522c of the mechanical shield 522, can protect one or more fluid level sensors 518 and / or fluid level sensors 518 with one or more sets of arms 520. In this configuration, the one or more fluid level sensors 518 and / or fluid level sensors 518 with one or more sets of arms 520 may be positioned at different heights above the openings along the bottom 522c of the mechanical shield 522. Pressure of the fluid inside the mechanical shield 522 against the surface tension of the interior walls of the mechanical shield 522 creates a level of fluid within the mechanical shield 522. The level of fluid inside the mechanical shield 522 may be detected by one or more fluid level sensors 518 and / or fluid level sensors 518 with one or more sets of arms 520. It may also be operable to indicate a canister full condition by activating one or more fluid level sensors 518 and / or a fluid level sensor 518 having one or more sets of arms 520. In some cases, the fluid level sensors may be positioned within a cylindrical mechanical shield having one or more circular cross-section holes in the bottom.

[0139] In some cases, the mechanical shield 522 can include openings of varying cross-section along the bottom of the mechanical shield 522, as shown in FIGS. 32-33. The openings along the bottom of the mechanical shield 522 can define a channel 527 along the interior of the mechanical shield 522, as shown in FIG. 33. Fluid may be introduced into the canister 162 through an opening along the top of the mechanical shield 522 at the end of the smallest cross-section. A property of the fluid, such as its density and / or surface tension, may define how many of the one or more fluid level sensors 518 are activated as the fluid flows through the channel 527. In some cases, one end of the arm 520 of the one or more fluid level sensors 518 can be positioned above the channel 527 to activate the one or more fluid level sensors 518 when the fluid fills the interior of the mechanical shield 522. In some cases, the one or more fluid level sensors 518 are positioned below the channel 527 of the mechanical shield 522. In this configuration, one fluid level sensor 518 of the one or more fluid level sensors 518 is activated at a time, thereby indicating the location on the channel 527 where fluid has dropped and come into contact with that one fluid level sensor 518 .

[0140] 34A and 34B show an example of a fluid level sensor 518. In some cases, the fluid level sensor 518 shown in FIG. 34A and 34B may be similar to the fluid level sensor 518 shown in FIG. 23A and 23B. The fluid sensor 518 may include an antenna 513 and at least two contact points or areas (also referred to herein as pad 1 and pad 2, respectively) 511a, 511b that can activate the fluid level sensor 518 when both contact points 511a, 511b are in contact with a fluid. In some cases, the contact points 511a, 511b may have a conductive material. The contacts 511a, 511b may be in electrical communication with the antenna through their respective tracks as shown in FIG. 34A and 34B. In some cases, the respective tracks shown in FIG. 34A and 34B may be coated with a non-conductive material. For example, the first track 519a can connect the first contact 511a to the antenna 513, and the second track 519b can connect the second contact 511b to the antenna 513. The first track 519a and the second track 519b can be coated with a non-conductive material between the first contact 511a and the antenna 513 and between the second contact 511b and the antenna. This can prevent fluid from activating the fluid level sensor 518 if the fluid comes into contact with a portion of the fluid level sensor 518 where the respective track (first track 519a and / or second track 519b) is located. In some cases, the fluid level sensor 518 can also include an adhesive surface 518a along at least a portion of the fluid level sensor 518. The adhesive surface 518a can be located at or near at least one of the two contacts 511a, 511b, for example, as shown in FIG. 34A. In some cases, the adhesive surface 518a can completely or at least partially surround at least one of the first and second contacts 511a, 511b. The underside of at least one of the two contacts 511a, 511b can also include an adhesive surface.The adhesive surface 518a can facilitate attachment of the fluid level 518a sensor to one or more components disposed inside or within a canister, for example, but not by way of limitation, as shown in Figures 23A and 23B. Figure 34B illustrates a fluid sensor 518 with a second contact (pad 2) 511b folded behind the sensor and therefore not visible in Figure 34B.

[0141] 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, activators, antibiotics, antimicrobial agents, etc. Such devices may further provide TNP therapy. The systems and methods disclosed herein are not limited to medical devices and may be utilized by any electronic device.

[0142] Any transmission of data described herein may be performed securely, for example using one or more of encryption, https protocol, secure VPN connection, error checking, delivery confirmation, etc.

[0143] Any values ​​of thresholds, limits, periods, etc. provided herein are not intended to be absolute values ​​and may therefore be approximate values. In addition, any thresholds, limits, periods, etc. provided herein may be fixed or changed automatically or by a user. Furthermore, as used herein, terms expressing a relative degree, such as exceeding, over, or under, in relation to a reference value, are intended to encompass equality to the reference value. For example, exceeding a positive reference value can encompass being equal to or greater than the reference value. Additionally, as used herein, terms expressing a relative degree, such as exceeding, over, or under, in relation to a reference value, are intended to encompass the inverse of the disclosed relationship, such as under, under, or over, in relation to a reference value.

[0144] It is to be understood that a property, substance, feature, or group described in connection with a particular aspect, embodiment, or example may be applied to any other aspect, embodiment, or example described herein, unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract, and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive. The subject matter is not limited to the details of any of the foregoing embodiments. The subject matter extends to any novel, or any novel combination, of the properties disclosed in this specification (including any accompanying claims, abstract, and drawings), and / or to any novel, or any novel combination, of the steps of any method or process similarly disclosed.

[0145] Although specific embodiments have been described, these embodiments are presented merely as examples 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. Furthermore, 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 shown in the figures or disclosed herein may be implemented as software and / or firmware on a processor, controller, ASIC, FPGA, and / or dedicated hardware. The software or firmware may include instructions stored in a non-transitory computer-readable memory. The instructions may be executed by a processor, controller, ASIC, FPGA, or dedicated hardware. Hardware components may include logic circuitry, such as controllers, processors, ASICs, FPGAs, and the like.Furthermore, the features and characteristics of the 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.

[0146] 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, and the like. The user interface screens may include additional and / or alternative information. The components may be arranged, grouped, and labeled in any suitable order.

[0147] Conditional language such as "can," "could," "might," or "may," unless specifically stated otherwise or interpreted otherwise within the context in which it is used, is typically intended to convey that certain embodiments include certain features, elements, and / or conditions, while other embodiments do not. Thus, such conditional language is not necessarily intended to suggest that the features, elements, and / or conditions are in any way required by one or more embodiments, or that one or more embodiments necessarily include logic for determining, with or without author input or instruction, whether those features, elements, and / or conditions are included in or should be implemented in any particular embodiment. Terms such as "include," "comprise," and "having" are synonymous and are 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 (not an exclusive sense), e.g., when used to join a list of elements, it 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 set of elements to which the term "each" applies. 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.

[0148] Unless otherwise indicated, conjugated language such as the phrase "at least one of X, Y, and Z" should be understood in the context in which it is used to generally convey that an item, term, etc. can be either X, Y, or Z, or combinations thereof. Thus, such conjugated language is not generally 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, respectively, be present.

[0149] As used herein, degree-expressing phrases such as "approximately," "about," "generally," and "substantially" refer 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 mean 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 15 degrees or less, 10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degrees.

[0150] 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 "an apparatus configured to" are intended to include one or more listed apparatus. Such one or more listed apparatuses may also be collectively configured to perform the stated enumeration.

[0151] Although the present disclosure includes specific embodiments, examples, and applications, it should be understood by those skilled in the art that the present disclosure extends beyond the scope of the specifically disclosed embodiments to other alternative embodiments and / or uses and obvious modifications and equivalents thereof, including embodiments that do not provide all of the features and advantages 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.

Claims

1. A negative pressure wound therapy device, Device housing and A negative pressure source supported by the aforementioned device housing, configured to provide negative pressure to a wound covered with a wound bandage, A canister configured to communicate fluidly with the negative pressure source and the wound bandage, A canister housing configured to store the fluid aspirated from the wound, A cap connected to the canister housing, and configured to connect to the device housing when the canister is removably mounted to the device housing, A fluid level sensor supported by the cap, wherein the fluid level sensor includes first and second arms extending into the canister housing and configured to communicate with the fluid drawn from the wound, the fluid level sensor is configured to detect a closed electrical circuit when the fluid drawn from the wound comes into contact with the first and second arms of the fluid level sensor, and the fluid level sensor is configured to detect a full state of the canister when the electrical circuit is closed, A canister comprising: an electronic circuit configured to wirelessly communicate with the fluid level sensor, detect the state of the fluid level sensor, and indicate that the canister is full; Includes, A negative pressure wound therapy device in which the length of the first arm is different from the length of the second arm, or the first arm is positioned in a non-parallel arrangement with respect to the second arm.

2. The negative pressure wound therapy device according to claim 1, wherein the length of the first arm is longer than the length of the second arm.

3. The negative pressure wound therapy device according to claim 1, wherein the first arm and the second arm have the same length.

4. The negative pressure wound therapy apparatus according to claim 1, wherein the first arm and the second arm are parallel to each other.

5. The negative pressure wound therapy apparatus according to claim 1, wherein the first arm and the second arm are angled relative to each other.

6. The negative pressure wound therapy apparatus according to claim 1, wherein the fluid level sensor includes a set of one or more arms.

7. The negative pressure wound therapy apparatus according to claim 1, wherein the fluid level sensor includes an NFC tag.

8. A negative pressure wound therapy device, Device housing and A negative pressure source supported by the aforementioned device housing, configured to provide negative pressure to a wound covered with a wound bandage, A canister configured to communicate fluidly with the negative pressure source and the wound bandage, A canister housing configured to store the fluid aspirated from the wound, A cap connected to the canister housing, and configured to connect to the device housing when the canister is removably mounted to the device housing, A fluid level sensor supported by the cap, wherein the fluid level sensor includes an arm extending into the canister housing and configured to communicate with the fluid drawn from the wound, the fluid level sensor is configured to detect a closed electrical circuit when the fluid drawn from the wound comes into contact with the arm of the fluid level sensor, and the fluid level sensor is configured to detect a full state of the canister when the electrical circuit is closed, An electronic circuit configured to communicate wirelessly with the fluid level sensor, detect the state of the fluid level sensor, and indicate that the canister is full; A mechanical shield comprising an inner surface, an outer surface opposite the inner surface, and an interior, wherein the mechanical shield is positioned within the canister, the inner surface of the mechanical shield faces the fluid level sensor, and the mechanical shield is configured to protect the fluid level sensor from the liquid in the canister. Including canisters, A negative pressure wound therapy device, including one.

9. The negative pressure wound therapy apparatus according to claim 8, wherein the mechanical shield further includes a first opening along the top of the mechanical shield and a second opening along the bottom of the mechanical shield.

10. The negative pressure wound therapy apparatus according to claim 8, wherein the mechanical shield surrounds the fluid level sensor.

11. The mechanical shield has a conical shape, a truncated square pyramidal shape, or a truncated rectangular pyramidal shape, The negative pressure wound therapy device according to claim 8, wherein the conical shape, truncated square pyramidal shape, or truncated rectangular pyramidal shape surrounds the fluid level sensor or the arm of the fluid level sensor.

12. The negative pressure wound therapy apparatus according to claim 9, wherein the mechanical shield further comprises one or more guards extending from at least a portion of the inner surface of the mechanical shield and positioned along at least one of the first opening and the second opening of the mechanical shield, the one or more guards being configured to reduce the possibility of the liquid accessing the interior of the mechanical shield.

13. The negative pressure wound therapy apparatus according to claim 12, wherein one or more guards form a fluid path from the outside of the mechanical shield to the inside of the mechanical shield, thereby allowing fluid drawn from the wound to access the inside of the mechanical shield when the fluid level in the canister reaches a threshold fluid level.

14. The negative pressure wound therapy apparatus according to claim 8, wherein the fluid level sensor is equipped with an NFC tag.

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