User-friendly negative pressure wound therapy device and method of operating such device - Patents.com

Abstract

The negative pressure wound therapy device may be configured to monitor movement and determine that the device is falling, as well as the duration and height of the fall. Flat falls and rolling falls can be accurately detected. The device may provide an indication of the fall, including stopping therapy. The device may monitor the amount of exudate removed from the wound and determine whether or not to transition to low exudate rate negative pressure wound therapy, and suggest such a transition. The device may utilize a proportional-integral-derivative (PID) control loop to drive the negative pressure source of the device. The PID control loop may utilize different proportional and integral gains for different negative pressure set points to achieve the target pressure quickly and without significant overshoot.

Description

[Technical field]

[0001] 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.

[0002] 2. Description of Related Art Many different kinds 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

[0003] The negative pressure wound therapy device can include a housing and a negative pressure source supported by the housing and configured to be connected via a fluid flow path to a wound covered by the wound dressing, the negative pressure source further configured to provide negative pressure to the wound. The device can include an electronic circuit supported by the housing, the electronic circuit configured to detect movement of the housing. The electronic circuit can be configured to detect that the housing is falling and determine a duration of the fall based on the movement of the housing. The electronic circuit can be configured to provide a first indication in response to determining that the duration of the fall meets a duration threshold.

[0004] 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: The electronic circuit may include an accelerometer. The electronic circuit may be configured to detect that the housing is falling in response to determining that the acceleration detected by the accelerometer meets a first acceleration threshold indicative of low acceleration. The acceleration detected by the accelerometer may include one or more of an acceleration along a z-axis, or a magnitude of acceleration along multiple axes. The electronic circuit may be configured to determine a duration of the fall in response to detecting a duration that the acceleration detected by the accelerometer meets the first acceleration threshold. The electronic circuit may be configured to determine a first time that the acceleration detected by the accelerometer first meets the first acceleration threshold. The electronic circuit may be configured to determine a second time that the housing makes a first impact with the surface. The electronic circuit may be configured to determine the duration of the fall based on a time difference between the second time and the initial time, where determining the duration of the fall is based on a time difference that accounts for possible rotation of the housing during the fall. The electronic circuitry can be configured to determine the second time in response to detecting that the acceleration detected by the accelerometer meets a second acceleration threshold indicative of a high acceleration threshold.

[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: The device may include an electronic processing circuit configured to operate the negative pressure source. The electronic circuit may be configured to transition the electronic processing circuit from a non-operating state to an operating state in response to determining that the duration of the drop meets a duration threshold. The electronic circuit may be configured to determine a height of the drop based on the duration of the drop. The first indication may include one or more of stopping the negative pressure source or performing one or more tests of the device. The electronic circuit may be configured to detect that the housing is tilted based on movement of the housing and provide a second indication in response to detecting that the housing is tilted. The electronic circuit may include an accelerometer. The electronic circuit may be configured to detect that the housing is tilted in response to determining that the acceleration detected by the accelerometer meets a tilt threshold. The acceleration may be acceleration along the z-axis. The first indication may include stopping the negative pressure source.

[0006] The negative pressure wound therapy device may include a negative pressure source configured to be connected to a wound covered with a wound dressing via a fluid flow path, the negative pressure source further configured to provide negative pressure to the wound. The device may include a canister configured to be fluidly connected to the negative pressure source via a fluid flow path and further configured to store fluid aspirated from the wound, the canister further configured to be disconnected from the negative pressure source and replaced by a replacement canister. The device may include electronic processing circuitry configured to monitor aspiration rate of fluid from the wound based on monitoring replacement of the canister. The electronic circuitry may be configured to provide an indication that a transition is recommended in response to determining that the aspiration rate meets a threshold indicative of a transition to treating the wound with a low exudate rate negative pressure wound therapy system.

[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: The low exudate rate negative pressure wound therapy system may be configured to store fluid aspirated from the wound in an absorbent dressing and does not utilize a canister. The electronic processing circuit may be configured to determine that the aspiration rate meets the threshold in response to detecting that at least one canister change has occurred outside of a threshold duration without the canister being full. The threshold duration may include three days. The at least one canister change may include two consecutive canister changes. The sizes of the canister and the replacement canister may include a first size and a second size larger than the first size. The electronic processing circuit may be configured to determine that the aspiration rate meets the threshold in response to detecting that the canister is of the first size. The electronic processing circuit may be configured to ignore the replacement canister from monitoring canister changes in response to determining that the replacement canister was previously used with a different negative pressure wound therapy device. The electronic processing circuitry may be configured to detect when the canister is disconnected from fluid connection to the negative pressure source and then reconnecting the canister, and to ignore the reconnection of the canister from monitoring for canister replacement.

[0008] The negative pressure wound therapy device may include a negative pressure source configured to be connected to a wound covered with a wound dressing via a fluid flow path, the negative pressure source further configured to provide a negative pressure to the wound. The device may include an electronic processing circuit configured to operate the negative pressure source to establish a target negative pressure at the wound, the target negative pressure being selected from a plurality of negative pressure set points. The electronic processing circuit may be configured to control the negative pressure source using a proportional-integral-derivative (PID) control loop using a first pair of integral and proportional gains associated with a first negative pressure set point and a second pair of integral and proportional gains associated with a second negative pressure set point different from the first negative pressure set point, where the first pair of integral and proportional gains are different from the second pair of integral and proportional gains.

[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: The PID control loop may use a different pair of integral and proportional gains for each negative pressure set point of the plurality of negative pressure set points. The electronic processing circuit may be configured to increase the first and second pairs of integral gains in response to determining that the target negative pressure has been reached. The first and second pairs of proportional gains may be related to the first and second negative pressure set points by a linear or square relationship.

[0010] The negative pressure wound therapy device may include a negative pressure source configured to be connected to a wound covered with a wound dressing via a fluid flow path, the negative pressure source further configured to provide negative pressure to the wound. The device may include an electronic processing circuit configured to operate the negative pressure source to provide negative pressure to the wound. The device may include a canister positioned within the fluid flow path and configured to store fluid drawn from the wound. The electronic processing circuit may be configured to shut off the negative pressure source in response to detecting that the canister is full and that an obstruction exists within the fluid flow path.

[0011] The negative pressure wound therapy device of any of the preceding paragraphs and / or any of the instruments, systems, or devices disclosed herein may include one or more of the following features: The electronic processing circuitry may be configured to activate the negative pressure source after deactivating the negative pressure source in response to at least one of detecting that the canister is not full or that no occlusion is present in the fluid flow path.

[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 this 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 shows the top surface of the negative pressure wound therapy device shown in FIG. 2A, showing the 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. [Diagram 5] Figures 5, 6, 7 and 8 show plots of acceleration versus time. [Figure 6] Same as above. [Figure 7] Same as above. [Figure 8] Same as above. [Figure 9] FIG. 9 illustrates the process of migrating to a canisterless wound therapy system. [Figure 10A] 10A, 10B, 10C, 10D, 11A, 11B, 11C, and 11D provide graphical user interface screens. [Figure 10B] Same as above. [Figure 10C] Same as above. [Figure 10D] Same as above. [Figure 11A] Same as above. [Figure 11B] Same as above. [Figure 11C] Same as above. [Figure 11D-1] Same as above. [Figure 11D-2] Same as above. [Figure 11D-3] Same as above. [Figure 12] FIG. 12 shows a plot of proportional gain versus target pressure. [Figure 13] 13 and 14 show the process for transitioning to a canisterless wound therapy system. [Figure 14] Same as above. 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 to include 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 or incisional wounds 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 ulcers, 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 may 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 may reduce bacterial load (and thus infection risk). Furthermore, this therapy may lead to less wound injury and more rapid healing. TNP therapy systems may also assist in the healing of surgically closed wounds by removing fluids. TNP therapy may help stabilize tissues in opposition to closure. Further beneficial uses of TNP therapy may 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, nerve stimulation, or the like, with other types of treatments. In some cases, the disclosed systems and methods may be used for wound monitoring without the application of additional therapy. The systems and methods disclosed herein may be used with dressings, including compression dressings, reduced pressure dressings, or the like.

[0021] A healthcare provider, such as a doctor, nurse, or the like, can 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′ may include a wound packing 102 placed on or within a wound 104 (which may be a cavity). The wound 104 may be sealed by a wound cover 106, which may be a drape, such that the wound cover 106 may be in fluid communication with the wound 104. The wound packing 102 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 deliver reduced pressure or negative pressure. The conduit 108' can be a single lumen or a multi-lumen conduit. A connector can be used to removably and selectively couple the conduit or tube of the device 110' 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 a wound dressing or adjacent to a 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 is provided and the wound cover itself may be considered a wound dressing. The wound dressing may then be connected to a negative pressure source of the wound therapy device 110' via conduit 108. In some cases, although not required, the wound therapy device 110' may be miniaturized and portable, although a larger conventional negative pressure source (or pump) may 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 have a superabsorbent material contained therein to safely absorb wound exudate. In some cases, the components of the TNP system described herein may be particularly suitable for 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 shown, the wound therapy device 110' may include an exudate canister. In some cases, the wound therapy device 110' and the conduit 108' may be configured such that the conduit 108' can be quickly and easily detached from the wound therapy device 110' to facilitate or improve the process of changing wound dressings or pumps, if necessary. Any of the pump assemblies disclosed herein may have any suitable connection between the conduit 108' and the pump.

[0029] The wound therapy device 110' may deliver a negative pressure of approximately -80 mmHg, or between about -20 mmHg and -200 mmHg. Note that these pressures are relative to normal ambient atmospheric pressure, 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 computing device 334. The connection 332 may be wired or wireless (such as 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 (such as 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′ shown in FIG. 1A or the negative pressure wound treatment system 400 shown 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 or multi-lumen tubing, may be used to connect the wound cover 106 to a wound therapy device 110 (sometimes 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 may have a bridge portion 130, which may have a proximal end portion and a distal end portion (the distal end portion is closer to the wound 104 than the proximal end portion), and an applicator 132 at the distal end of the bridge portion 130, which forms a flexible suction adapter (or conduit) 108. A connector 134 may be disposed at the proximal end of the bridge portion 130 to extend along the length of the bridge portion 130 of the conduit 108 shown in FIG. 1B and connect to at least one of the channels. A cap 140 may be coupled to a portion of the conduit 108, and in some cases may be attached to the connector 134, as shown. The cap 140 may be useful in preventing fluid from leaking out the proximal end of the bridge portion 130. The conduit 108 may be a Soft Port manufactured by Smith & Nephew. As mentioned above, the negative pressure wound treatment system 100 may include a negative pressure source, such as device 110, capable of supplying negative pressure to the wound 104 through conduit 108. Although not required, the canister or device 110 may also include other containers 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. The application of 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 preferably comprise a porous material including an open cell foam such as, for example, polyethylene or polyurethane. In some cases, one or more of the upper and lower channel layers may be comprised of, 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 floppy fabric 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 may include an open cell foam such as polyurethane, and the lower channel layer may include a fabric. In another example, the upper channel layer is optional and the system may instead include an open upper channel. The upper channel layer may have a curved, rounded, or upwardly convex upper surface and a substantially flat lower surface, and the lower channel layer may 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 fabrics 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 the application of negative pressure. The materials used in some implementations of the conduit 108 may be conformable and flexible, which may help in some cases to avoid bed sores 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 (which may also be referred to as a gas leak, air leak, or controlled air leak) may be disposed on the bridge portion 130, for example, at a proximal end of the bridge portion 130. This air leak 146 may include an opening or channel extending through an upper layer of the bridge portion 130 such that the air leak 146 is in fluid communication with the upper channel of the bridge portion 130. Upon application of suction to the conduit 108, gas (such as air) may enter through the gas leak 146 and travel along the upper channel of the bridge portion 130 from the proximal end of the bridge portion 130 to the distal end of the bridge portion. 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. Preferably, the air leak 146 is located at the proximal end of the bridge portion 130 to minimize the possibility of wound exudate or other fluids contacting the air leak 146 or filter and blocking or impeding the air leak 146 or filter. In some instances, the filter may be a microporous membrane that may be capable of excluding microorganisms and bacteria and filtering particles larger than 45 μm. Preferably, the filter may be capable of filtering 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 instances of negative pressure wound treatment systems 100 where the gas flow through the gas leak 146 increases when additional negative pressure is applied, preferably this increased gas flow will be minimized and will 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') may 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 transmitted to the wound 104 via the wound packing 102. Fluid (such as wound exudate) may be drawn through the conduit 108' and stored in the canister. In some cases, the fluid is absorbed by the wound packing 102 or one or more absorbent layers (not shown).

[0042] Wound dressings that may be used with the pump assembly and system of the present application may include Renasys-F, Renasys-G, Renasys AB, 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 may be found in U.S. Patent Publication Nos. 2012 / 0116334, 2011 / 0213287, 2011 / 0282309, 2012 / 0136325, U.S. Patent No. 9,084,845, and International Patent No. PCT / EP2020 / 078376, each of which is incorporated herein by reference in its entirety as if fully set forth herein. In some cases, other suitable wound dressings may be used.

[0043] 2A, 2B, and 2C illustrate a negative pressure wound therapy device 110'. As shown, 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 can be used to control any function of the pump assembly 160 or the interface panel 170. For example, and without limitation, one or more of the buttons 184 can be used to turn the pump assembly 160 on or off, start or pause therapy, operate and monitor the operation of the pump assembly 160, scroll through menus displayed on the display 172, or control or perform other functions. In some cases, the command buttons 184 may be programmable and may be made from a tactile soft rubber.

[0044] Additionally, the interface panel 170 may have a visual indicator 186 that may indicate which of the one or more buttons 184 is active. The interface panel 170 may also have a lock / unlock control or button 188 that may be configured to selectively lock or unlock the functionality of 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 this manner, the interface panel 170 will protect 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 lights (e.g., LEDs) and may be configured to provide a visual indication of an alarm condition and / or the status of the pump. For example, and without limitation, the one or more indicators 174 may be configured to provide a visual indication of the status of the pump assembly 160 or other components of the negative pressure wound therapy system 100, including, but not limited to, the conduit 108 or wound cover 106 (e.g., providing an indication of normal operation, low battery, leakage, canister full, blockage, overpressure, etc.). Any suitable one or more 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 may include a speaker 192 for generating audio. For example, and without limitation, the speaker 192 may generate an audio alarm in response to deviations in therapy delivery, non-compliance with therapy delivery, or any other similar or suitable medical condition, or combinations thereof. The speaker 192 may 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 provide easy access (such as 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 (such as a healthcare provider or 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 (such as 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 aspirated from the wound 104. For example, the canister 162 may have a capacity of 800 mL (or approximately 800 mL), or a capacity of 300 mL or less to 1000 mL or more, or any capacity level within this range. The canister 162 may include tubing for connecting 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 142 (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 142 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 may have a handle 208 that can be used to lift or carry the wound therapy device 110. The handle 208 may be coupled to the pump assembly 160 and may be rotatable relative to the wound therapy device 110 so that the handle can be rotated upwards for lifting or carrying the wound therapy device 110 or pump assembly 160, or rotated to a lower profile for a more compact position when the handle is not in use. In some cases, the handle 208 may be coupled to the pump assembly 160 in a fixed position. The handle 208 may be coupled to an upper portion of the pump assembly 160 or may 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 the fluid flow path), etc. 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 can be part of the wound therapy device or the canister. In some cases, any of the pressure sensors 325 can 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 with one or more transceivers 340 via a wireless connection.

[0054] The one or more motion sensors 328 can monitor the movement of the wound therapy device. The one or more motion sensors 328 can include one or more acceleration sensors or accelerometers (e.g., one or more MEMS accelerometers that may be part of a MEMS accelerometer integrated circuit), gyroscopes, etc. Any of the accelerometers can be a three-axis accelerometer, a piezoelectric accelerometer, etc. The one or more motion sensors 328 can provide motion data to the main controller 310. The one or more motion sensors 328 can be powered by an internal power source. For example, the one or more motion sensors 328 can receive power directly from the internal power source such that the one or more motion sensors 328 remain operational when the device is off (such as when the device is in storage, in transit, or otherwise not being used). In some cases, the one or more motion sensors 328 can be powered by another power source such that the one or more motion sensors 328 remain operational when the internal power source is depleted. The one or more motion sensors 328 can be a low power device (such as a low power MEMS accelerometer integrated circuit).

[0055] 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.

[0056] 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, Windows CE, VxWorks, or the like.

[0057] The pump controller 370 can control the operation of a pump 390 that can generate negative pressure or reduced pressure. The pump 390 can be any suitable pump, such as a diaphragm pump, a peristaltic pump, a rotary pump, a rotary vane pump, a scroll pump, a screw pump, a liquid ring pump, a diaphragm pump operated by a piezoelectric transducer, a voice coil pump, 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 the 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 selected by a pressure setting or a user. The pump controller 370 can control the pump (e.g., a pump motor) using pulse width modulation (PWM) or pulse control. The control signal for driving the pump can be a 0-100% duty cycle PWM signal. The pump controller 370 can perform flow 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.

[0058] Any of the one or more communication controllers 330 may provide a connection (such as a wired or wireless connection 332). The one or more communication controllers 330 may utilize one or more transceivers 340 to transmit and receive data. The one or more transceivers 340 may include one or more antennas, optical sensors, optical transmitters, vibration motors or transducers, vibration sensors, acoustic sensors, ultrasonic sensors, and the like. Any of the one or more transceivers 340 may function as a communication controller. In such cases, the one or more communication controllers 330 may be omitted. Any of the one or more transceivers 340 may be connected to one or more antennas that facilitate wireless communication. The one or more communication controllers 330 may 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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 WO 2017 / 0216501, each of which is incorporated by reference in its entirety.

[0063] Multiple Dressing Negative Wound Therapy 4 illustrates another negative pressure wound treatment system 400. The system 400 may include a wound therapy device capable of delivering negative pressure to a wound site, such as wound therapy device 110. The wound therapy device 110 may be in fluid communication with one or more wound dressings 406a, 406b (collectively referred to as 406) to deliver negative pressure to one or more wounds, such as wounds 104a and 104b. The first fluid flow path may 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 may 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 branch attachment (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.

[0064] System 400 may be similar to system 100, except that multiple wounds 104a and 140b 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) shown in FIG. 4 with the letter "a" or "b" added to distinguish between the first and second wounds.

[0065] 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 of 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 104a, 104b via the fluid flow paths. The application of negative pressure may be applied until a desired level of healing of the wounds 104a, 104b 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).

[0066] 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.

[0067] Drop detection and device orientation detection It may be advantageous to monitor the movement of a negative pressure wound therapy device to determine if the device has been crashed (or misplaced, etc.), to monitor the movement of the device, or to monitor the movement of the patient. To accomplish this, one or more motion sensors (such as one or more motion sensors 328) may be utilized. Data from the one or more motion sensors may provide one or more controllers (such as main controller 310), which may detect that the device has been crashed (or otherwise misused). In some cases, the one or more motion sensors may be part of a device or package (such as an integrated circuit) that provides processing capabilities for analyzing data detected by the one or more motion sensors. An indication of a crash (or misuse) may be provided as described herein.

[0068] A fall (or free fall) may be associated with reduced gravity as measured by one or more motion sensors, such as one or more accelerometers or gyroscopes. FIG. 5 shows a plot of acceleration versus time as measured by a triaxial accelerometer of a negative pressure wound therapy device. Such an accelerometer may measure acceleration along the x-axis (shown as 502 in FIG. 5), the y-axis (shown as 504 in FIG. 5), and the z-axis (shown as 506 in FIG. 5). During a period 510, the device is placed on a surface (such as a desk). During this period, the acceleration along the x-axis and the y-axis is 0 g (g=9.8 m / s 2 ), and a constant gravitational acceleration of -1g is observed along the z-axis (due to the orientation of the device, the acceleration is negative, and in some cases the acceleration along the z-axis may be 1g). During period 512, the device is pushed off the surface. During this period, the acceleration along the x-, y-, and z-axes does not change.

[0069] During time period 514, the device falls freely. The acceleration along the x-axis and y-axis does not change, while the acceleration along the z-axis decreases to 0g (as the device is in free fall). In some cases, the free fall causes a "near zero G" state (or event), which may be an indication of a crash or misuse. Such a near zero G state may be preceded by a "low G" state (or event), when the acceleration along the z-axis decreases. During the free fall, the acceleration values ​​along the three axes remain zero until impact with the floor (or another surface) occurs (at approximately 4 seconds as shown in FIG. 5).

[0070] During time period 516, the device makes a first impact with the floor (or another surface). During this time period, the acceleration values ​​along the three axes are large (positive or negative) values ​​as gravity increases as the device lands on the surface. Such a "high G" event (or condition) indicates that the device decelerates upon contact with a hard surface. During time period 518, the device makes one or more second impacts with the floor (or another surface). These one or more second impacts may be due to the device bouncing or rolling. The device makes several second impacts with the surface, as illustrated by the multiple peaks during time period 518. During this time period, the acceleration values ​​along the three axes are large (positive or negative) values. Finally, during time period 520, the device is stationary on the floor (or another surface). Similar to time period 510, during this time period, the acceleration along the x-axis and y-axis is 0g, while a constant gravitational acceleration of -1g is observed along the z-axis.

[0071] FIG. 6 shows a plot of acceleration magnitude versus time as measured by a three-axis accelerometer. The acceleration magnitude (|g|) is given by the following equation (g x , g y , and g z are the acceleration values ​​along the x-axis, y-axis, and z-axis, respectively) according to:

[0072]

number

[0073] One or more of the filters or threshold analyses can be applied to the acceleration data (e.g., the magnitude of the acceleration data) to determine whether the device is in free fall or detects smaller movements (e.g., lifting the device or placing the device down on a surface). Careful consideration of the threshold (also called a low acceleration threshold) may be required to avoid false positives (e.g., a potential trigger may occur too early when lifting or lowering the device). In some cases, the threshold for detecting free fall from the acceleration magnitude can be about 0.5 to 0.4 (or another suitable value indicative of a low G condition). For example, the device can be determined to be in free fall while the acceleration magnitude meets the threshold (e.g., while the acceleration magnitude meets and / or remains below the threshold). FIG. 6 illustrates a threshold 630 of about 0.5. For a duration 614 (when the device is in free fall), the acceleration magnitude is equal to or less than the threshold 630.

[0074] In some implementations, the height of the fall (or drop) can be determined. This can be accomplished by determining the duration (such as duration 614) of the device in free fall. The height of the fall (h) can be calculated using the following formula, where g is the free fall acceleration (9.8 m / s 2 ) where t is the duration of the free fall: h=(1 / 2)gt 2 An indication of one or more of the duration of the drop or the drop height may be provided.

[0075] Measuring the duration (and / or height) of the free fall can provide advantages over approaches that rely on detecting an instantaneous impact at impact for fall detection. For example, the duration of the free fall can serve as a check to detect whether the device is in free fall. A threshold duration can be used to distinguish a false positive from an actual free fall. In some cases, a false positive determination can be made if the determined duration of the free fall does not meet (e.g., is less than) the threshold duration. Advantageously, the accuracy of fall detection can be improved.

[0076] In some cases, the location of the accelerometer may be offset from the center of mass of the device. For example, with reference to Figure 3, the accelerometer (shown as 328) may be located on a substrate (such as a printed circuit board (PCB)) of the control system 300. With reference to Figure 2B, the PCB may be located within the housing of the pump assembly 160 at a location offset from the center of mass of the device. The center of mass of the device may change depending on the fill level of the canister.

[0077] Because the center of mass of the device may be offset from the location of the accelerometer, a crash or fall may be either flat (when the device does not rotate) or rotational (when the device rotates about its center of mass). In practice, many falls may be rotational falls. As described herein, a flat fall may be detected by determining that the magnitude of acceleration meets a threshold indicative of a low G condition. This is illustrated in FIG. 7, which is similar to FIG. 5. A free fall is indicated by the duration 714 that the magnitude of acceleration remains below the threshold. The first and second impacts are indicated by 716 and 718. The duration that the device bounces off a surface (such as a floor) after the first impact is illustrated as 722.

[0078] A rotational drop allows the accelerometer to detect the centripetal acceleration (a) given by the device rotation rate (v) and the accelerometer offset (r) from the axis of rotation: a=v 2 / r This acceleration value may be significant enough to discontinue the threshold analysis as shown in FIG. 8 (similar to FIG. 7 but showing a plot incorporating rotational falls). As shown by duration 814 where the device is in free fall, the acceleration magnitude may exceed the low acceleration threshold due to the extra contribution of centripetal acceleration. The acceleration values ​​during duration 814 are not as flat and constant as those during duration 714. For example, a bump in the acceleration values ​​is shown during duration 714. Such centripetal acceleration contribution may cause the fall to be missed or the duration (and fall height) to be inaccurately determined (e.g., underestimated).

[0079] To account for the possibility that the device may rotate (or spin) during a fall, the free-fall detection can be refined as follows: 1. Detect the time of first impact, as evidenced by a high G event. 2. Because these events are likely to be caused by a second impact, prevent any further incoming data from triggering for 1 second (or another suitable period of time). 3. Search the data captured by the accelerometer for the start time of the low G event. 4. Calculate the fall height based on the time separation of 1 to 3.

[0080] In some cases, some of the steps (eg, step 2) may be omitted and / or the steps may be performed in a different order.

[0081] The first impact may be detected by detecting that the acceleration (e.g., the magnitude of the acceleration) meets a high acceleration threshold. For example, with reference to FIG. 6, during the first impact shown as 616, the magnitude of the acceleration reaches a large value (e.g., about 4.5). The high acceleration threshold may be set to 4.0 or another suitable value. As another example, during the impact, the rate of change of the magnitude of the acceleration is large (as shown by the slope of the peak 616). A rate of change threshold may be used to detect the impact. Once the duration between the detection of the free fall (step 3 above) and the first impact (step 1 above) is determined, the height of the fall may be calculated as described above.

[0082] Selecting an appropriate frequency at which the accelerometer is sampled (or accelerometer data is acquired) can be important to ensure accuracy and resolution of the drop height calculation. However, there is a trade-off, as higher sampling frequencies increase the power consumption of the accelerometer. For example, MEMS accelerometers can be sampled at a variety of frequencies, from 10 Hertz to several kilohertz. In some configurations, testing has revealed that a sampling rate of approximately 50 Hertz can provide sufficient resolution and accuracy without consuming excessive power. In some implementations, other suitable sampling rates can be used.

[0083] As described herein, in response to detecting a fall, an indication of the fall can be provided. In some cases, the indication can include pausing delivery of the negative pressure wound therapy (e.g., by turning off the negative pressure source) or reducing the intensity of the therapy (e.g., by reducing the power provided to the negative pressure source) in response to detecting a fall. Advantageously, this can reduce patient discomfort (e.g., which may be caused by the negative pressure source attempting to maintain a desired pressure at the wound when the wound dressing or another portion of the fluid flow path becomes dislodged or disconnected as a result of the fall) and reduce noise (e.g., from the operation of the negative pressure source or the activation of one or more audible alarms, such as a leak alarm).

[0084] In certain cases, in response to detecting a fall, the device may initiate one or more self-tests to ensure that the device can properly provide negative pressure wound therapy. Additional details of the self-tests are disclosed in International Publication No. WO 2021 / 191203, entitled "Self-Test of Negative Pressure Wound Therapy Device," which is incorporated by reference in its entirety. In some cases, the device may prevent the provision of negative pressure wound therapy in response to detecting a fall (e.g., in response to detecting a fall from a large height, which may increase the likelihood of damage to the device) and / or in response to determining that one or more self-tests have failed. Additional or alternative safety mechanisms may be activated in response to detecting a fall.

[0085] In some instances, fall detection may be performed when the device is off (e.g., in storage, transport, shipping, or otherwise not in use). As described herein, the accelerometer may receive power directly from an internal power source (or another power source). In this way, the accelerometer may monitor the movement of the device even when other electronic components (such as the main controller 310) are not operating (e.g., are turned off or are asleep). As described herein, the accelerometer may be part of a package that provides processing capabilities. Detection of one or more of the low-G or high-G events may cause the accelerometer package to wake up the main controller 310 or one or more other electronic components of the device (e.g., via asserting or triggering one or more interrupts). As described herein, one or more corrective actions (such as providing an indication, pausing therapy, etc.) may be taken.

[0086] The orientation of the device may be detected using any of the approaches described herein. For example, an inverted device orientation may be detected through analysis of acceleration values ​​along one or more of the x-axis, y-axis, or z-axis. The acceleration value along the z-axis is 1g when the device is placed upside down on a surface (rather than -1g, as illustrated during duration 510 of FIG. 5). If one or more (or more than one) accelerometer axes meet (e.g., equal and / or exceed) a threshold, an undesirable tilt may be detected. For example, when the device is upright on a surface, the acceleration value along the z-axis is about 1 (or in some cases, -1, depending on the calibration of the accelerometer). If the device is tilted at 45 degrees, the acceleration value along the z-axis is about 0.5 (or in some cases, -0.5). If the device is lying on its side, the acceleration value along the z-axis is approximately zero. If the acceleration along the z-axis is negative (or in some cases, positive), the device may be tilted beyond lying on its side. When the acceleration along the z-axis is -1 (or in some cases +1), the device is fully flipped. As a result, tilt detection can be performed based on determining that the acceleration along the z-axis meets (e.g., falls below / exceeds / below) a tilt threshold. In some cases, the tilt threshold can be 0.5 (or in some cases -0.5). The determination can be made using the absolute value of the acceleration along the z-axis and the tilt threshold to eliminate any dependency on accelerometer calibration.

[0087] Detection of an undesirable tilt may cause the device to generate an indication to the user to place the device in a proper orientation (such as an audible warning, visual message, or the like). In some cases, delivery of negative pressure wound therapy may be paused until the device is in a proper orientation. This may prevent blockage of one or more filters (such as blockage of a filter in a canister, which may unnecessarily require a canister change). Additional or alternative safety mechanisms may be activated in response to detection of an incorrect device orientation.

[0088] Patient activity can be monitored using any of the approaches disclosed herein. For example, patient mobility can be detected by examining the magnitude of acceleration to determine if a significant level of movement (compared to a threshold) is detected for a significant time interval (compared to a threshold). The levels of activity can be summed to provide a cumulative activity level index. Tracking a patient's mobility (or lack of mobility) can be beneficial to medical personnel to determine or adjust the patient's treatment. Data related to the patient's activity can be communicated to a remote computing device as described herein.

[0089] Accelerometer data can be analyzed to understand the frequency with which the device is moving or mobile versus stationary (e.g., bedside). This analysis can lead to a more user-optimized design for the negative pressure wound therapy device. For example, if the accelerometer data suggests that the user of the device is highly mobile, it may be desirable to focus on portability in the design. As another example, if fall detection is frequently triggered, a design focused on durability may be preferred. Accelerometer data may allow investigations to be conducted to understand sources of user error or misuse, such as inaccurate device orientation. Tracking patient mobility may also provide useful information to healthcare professionals (HCPs) in determining the best course of treatment for the patient.

[0090] Advantageously, the approach described in this section can provide improved fall or misuse detection, which can promote patient comfort and safety. In addition, patient mobility can be monitored, which can be used to refine treatment, develop more reliable and patient-friendly negative pressure wound therapy devices, and determine the best course of treatment for the patient.

[0091] Transitioning to a different therapy system It may be advantageous to be able to determine and suggest that a patient may transition from a larger, heavier canister-compatible negative pressure wound therapy system (typically configured to treat larger wounds) to a smaller, more portable canisterless negative pressure wound therapy system (typically configured to treat smaller wounds). As a patient's wound is healing with the application of negative pressure wound therapy, the size of the wound may be reduced and the amount of wound exudate may be reduced. As a result, the patient may be able to transition to a canisterless system at some point during treatment. One example of a canisterless system is the Pico system available from Smith & Nephew.

[0092] In some cases, the amount of fluid (such as exudate) produced by the wound can be monitored. If the rate of fluid produced by the wound is low enough, transition to a canisterless system (or mode) can be suggested. Approaches to achieving these goals are described below.

[0093] Any of the negative pressure wound therapy devices, such as device 110, can be in communication with any of the canisters disclosed herein, such as canister 162. The device can obtain data from the canister. Such data can include one or more of status data (such as whether the canister is full or the level of fluid in the canister), configuration data (e.g., canister volume or size, such as 300 mL or 800 mL), identification data (such as a canister identifier, batch code, or canister serial number), canister manufacturing date (which can be a timestamp), date / time of first use of the canister (which can be a timestamp), etc.

[0094] The acquisition of data can be performed by or under the control of one or more controllers of the device. The acquisition of data can be performed via a wired connection or wirelessly, such as using one or more transceivers 340. For example, the device can acquire data using a near field protocol (such as NFC), RFID, Bluetooth, etc. The data can be acquired prior to initiating negative pressure wound therapy.

[0095] Any of the canisters disclosed herein, such as canister 162, may include electronics having memory (capable of storing any of the data described in this section) and communication capabilities. The electronics may be located partially or completely within the canister housing. The electronics may be powered by a power source, such as a coin cell battery or one or more capacitors. In some cases, external power may be provided, such as via NFC, RFID, or other wireless charging protocols.

[0096] Further details of communication with the canister and data acquisition are disclosed in International Patent Application No. PCT / EP2022 / 060464, filed April 20, 2022, entitled "Communication Systems and Methods for Negative Pressure Wound Therapy Devices," International Patent Application No. PCT / EP2022 / 060463, filed April 20, 2022, entitled "Canister Status Determination for Negative Pressure Wound Therapy Devices," and International Patent Application No. PCT / EP2022 / 060459, filed April 20, 2022, entitled "Intelligent Disposable Devices for Wound Therapy and Treatment," each of which is incorporated by reference in its entirety.

[0097] In some cases, the device may detect the presence of the canister. For example, the device may attempt to communicate with the canister and determine if a response is received. As another example, the device may utilize a sensor, such as an optical sensor, a resistive sensor, a capacitive sensor, a magnetic sensor, etc., to determine the presence of the canister. As described herein, the device may obtain data from the canister, including one or more of the canister serial number, the canister capacity or size (e.g., 300 mL or 800 mL), the canister fill detection (e.g., not full or full), and the date / time of first use of the canister (which may be stored in the canister memory in response to the canister being connected to the device and / or in response to the initiation of negative pressure wound therapy).

[0098] The rate of fluid removal from the wound can be monitored directly (e.g., by using a flow sensor) or indirectly (e.g., by monitoring the speed or duty cycle of the negative pressure source). The rate of fluid removal can be monitored indirectly using data obtained from the canister. In some cases, the rate of fluid removal can be monitored by monitoring canister changes. Having the canister changed frequently when it is full may indicate a higher rate of fluid removal than having the canister changed less frequently or changing the canister when it is not full. In some cases, if the rate of fluid removal meets (e.g., meets and / or falls below) a fluid flow threshold (e.g., about 100 mL / day), transitioning to a canisterless system may be appropriate and suggested.

[0099] A determination that a transition to a canisterless system is appropriate may be made when two (or more) successive canister exchanges are performed, each occurring for a period longer than a threshold period (e.g., three days or less or more), and each occurring with the canister not full. In some examples, the successive canister exchanges may need to be associated with a particular canister size (such as a smaller 300 mL canister). Some implementations may take into account an actual determination of the canister fill level, rather than a determination that the canister is full or not full.

[0100] In some cases, the exchange of a single unfilled canister outside of a threshold period may trigger a decision to transition to a canisterless system. For example, the exchange of a larger canister (such as an 800 mL canister) outside of six days (or less or more) may trigger a decision. Monitoring canister change trends may be used to make the decision. For example, canister changes may be made daily and a subsequent change after three days (or less or more), or several such changes, may trigger a decision.

[0101] When a canister (such as canister 162) is connected to an apparatus (such as apparatus 110), the canister can be checked to see if it is included in the process for determining whether to transition to a canisterless system. The determination can include one or more of verifying that the canister is fresh (e.g., not having been used in another apparatus, which can be determined by verifying that the canister memory does not store a first use date / time), verifying that the canister is the correct size (e.g., 300 mL), and verifying that the canister identification (e.g., serial number) is recognized as having been previously connected to the apparatus. In some instances, the first two of these verifications need to be met for a canister to be included in the process for determining whether to transition to a canisterless system. To overcome the problem of the process erroneously reacting to a canister being inadvertently disconnected and then reconnected, the latter verification (verifying the canister as having been previously connected to the apparatus) can be used after an initial verification that the canister should be included in the process (e.g., when the canister is connected to the apparatus for the first time). If a canister is included in the process, monitoring can be performed of the frequency of canister removal and whether the canister was not full (or had a fluid level below a threshold fill level) when removed.

[0102] If the 300 mL canister does not register as full for, say, three days, the rate of fluid removal from the wound may be assumed to be less than 100 mL / day (or 120 mL / day, 80 mL / day, 50 mL / day, or less or more). Making two such canister changes consecutively may indicate a fluid removal rate of less than 600 mL over six days. As another example, a smaller canister, such as a 100 mL, may be used, and not filling such a canister for two (or more) days may indicate a removal rate of less than 100 mL / day. Such a low removal rate may indicate a wound that is healed enough to be treated by a canisterless system. As a result, a transition to a canisterless system may be suggested. The actual threshold rate of removal may be determined based on the capabilities of the proposed therapy. The decision to send to a canisterless system may be made by one or more controllers (such as the main controller 310) of the device.

[0103] FIG. 13 illustrates a process 1300 for transitioning to a canisterless mode. The process 1300 may be implemented by one or more controllers of the device, such as the main controller 310. The process 1300 may be executed in response to detecting that a canister is not connected, which may be indicated by a missing canister alarm (or warning). The process 1300 may begin at block 1302, where the process may detect the installation of a new canister. The process 1300 may transition to block 1304, where it may determine whether the canister has been changed. This determination may be performed using any of the approaches described herein, such as those described in connection with FIG. 14. If, at block 1304, the process 1300 detects that the same canister has been reinstalled, the process 1300 may end by transitioning to block 1314.

[0104] If, at block 1304, the process 1300 detects that a different canister has been installed, the process may proceed to block 1306, where it may determine whether the number of canister changes counted towards a transition to a canisterless system (e.g., as described in connection with FIG. 14) meets a threshold. The threshold may be, for example, two consecutive canister changes. If not, the process 1300 may proceed to block 1308, where a missing canister alarm may be cleared, after which the process may end by proceeding to block 1314. If, at block 1306, the process 1300 determines the number of canister changes when the canister meets the threshold, the process may proceed to block 1310, where a missing canister alarm may be cleared. The process may then proceed to block 1312, where a notification may be provided that a decision to transition to a canisterless system has been made. Such a notification may be described, for example, in connection with FIG. 9. After the notification is provided, the process 1300 may end by proceeding to block 1314.

[0105] 14 shows a process 1400 for verifying that a canister has been changed and should be included to determine whether to transition to a canisterless system. The process 1400 may be implemented by one or more controllers of the device, such as the main controller 310. The process 1400 may be performed in block 1304 of FIG.

[0106] At block 1402, the process 1400 may analyze the identity of the installed canister to determine if the canister has not been previously installed in the device. At block 1404, the process 1400 may determine if the previously installed canister (which was replaced) was not full (or had a particular fill level). At block 1406, the process may determine if a canister change was performed outside of a certain period of time (such as 3 days). At block 1408, the process 1400 may determine if each of the conditions at blocks 1402, 1404, and 1406 have been met. If so, the process 1400 may move to block 1412 where the number of canister changes may be increased toward a transition to a canisterless system. This number may be utilized at block 1306 of FIG. 13. The process 1400 may then end at block 1414. If the process 1400 determines at block 1408 that any one or more of the conditions at blocks 1402, 1404, and 1406 are not satisfied, the process 1400 may move to block 1410 where the number of canister changes may be reset. The process 1400 may then end at block 1414.

[0107] Once a decision to transition to a canisterless system is made, a notification (or indication) may be provided, as shown in FIG. 9, which illustrates a process 900 for transitioning to a canisterless mode. Process 900 may be performed by one or more controllers of the device, such as main controller 310. User interface screens illustrated in blocks 902, 904, 908, 910, 912, and 920 may be displayed on display 172. Block 902 illustrates an example user interface screen for prompting a user to connect a canister. Block 904 illustrates an example user interface screen for an alert that a canister is not connected. Once a canister is connected, the process may transition to block 906, where a decision regarding transitioning to a canisterless system may be made. This decision may be made using any of the approaches described herein.

[0108] If a decision to transition to a canisterless system is not made at block 906, the process 900 may transition to block 920, where an exemplary user interface screen is illustrated for beginning to provide negative pressure wound therapy using a device with a canister. If a decision to transition to a canisterless system is made at block 906, the process 900 may transition to block 908, where an exemplary user interface screen is illustrated for suggesting a transition to a canisterless system. As illustrated, once a decision to transition to a canisterless system is made, the transition message may not explicitly state that the patient is suitable for transition. Rather, the message may suggest that the HCP consider transitioning. Blocks 910 and 912 depict additional user interface screens for suggesting such a transition. A user may advance the user interface screens from block 908 to block 910 and from block 910 to block 912 by manipulating one or more inputs or components on the interface panel 170. For example, a user may press one or more buttons of the set of buttons 184.

[0109] 9, BTIN1 corresponds to a first button in the set of buttons 184, and BTN3 corresponds to a third button in the set of buttons 184. For example, pressing a button associated with the action "Next" (e.g., BTN3) may cause a transition to the next block (910 or 912). A user can transition to block 920 from any of blocks 908, 910, and 912 by pressing one of the buttons from the set of buttons 184. For example, pressing a button associated with the action "Reject" (e.g., BTN1) may cause a transition to block 920.

[0110] In some cases, the notification may be sent to a remote computing device. For example, the notification may be sent wirelessly to the device 334.

[0111] Advantageously, monitoring the rate of fluid removal from the wound can be used to determine that a transition to a canisterless system can be made, which, among other things, can promote patient comfort, improve patient mobility, and increase patient compliance with negative pressure wound therapy.

[0112] Further details on the transition to canisterless systems can be found in U.S. Patent No. 10,143,785, entitled "Systems and Methods for Applying Reduced Pressure Therapy," U.S. Patent Publication No. 2019 / 0358372, entitled "Negative Pressure Wound Therapy Apparatuses and Methods for Using the Same," U.S. Patent Publication No. 2021 / 0106735, entitled "Power Source Charging for Negative Pressure Wound Therapy Apparatus," U.S. Patent Publication No. 2020 / 0230302, entitled "Negative Pressure Wound Therapy Apparatus with Removable Panels," U.S. Patent Publication No. 2021 / 0106736, entitled "Systems and Methods for Determining Blockages in a Negative Pressure Wound Therapy System," and U.S. Patent Publication No. 2021 / 0106737, entitled "Securing Control of Settings of Wound Therapy Apparatus," all of which are incorporated herein by reference in their entirety. No. 2020 / 0330662, entitled "Negative Pressure Wound Therapy Apparatuses," U.S. Patent Publication No. 2021 / 0038776, entitled "Systems and Methods for Controlling Dual Mode Negative Pressure Wound Therapy Apparatus," and International Publication No. WO 2019 / 211732, entitled "Exhaust Vent for a Negative Pressure Wound Therapy System," each of which is incorporated by reference in its entirety.

[0113] Although specific examples are presented in the context of transitioning to a canisterless negative pressure wound therapy system, the approaches described herein are generally applicable to determining (and proposing) a transition from a first treatment system to a second treatment system different from the first treatment system. The first treatment system may be a less transportable, larger, and heavier system. The second treatment system may be a more transportable, smaller, and lighter system. In some cases, the first treatment system may be a high exudate rate (or high exudate) negative pressure wound therapy system and the second treatment system may be a low exudate rate (or low exudate) negative pressure wound therapy system (one or more of a canisterless system, a mechanically powered system, a compact system with a canister, etc.).

[0114] Multi-parameter PID control A negative pressure wound therapy system may need to be able to maintain a desired pressure set point over a wide variety of operating conditions, taking into account one or more of internal device variations (such as voltage or pump-to-pump variations), external environmental variations (such as temperature or atmospheric pressure), various user-selectable pressure set points, and wound conditions (such as wound volume, dressing air leaks, or exudate liquid volume and viscosity). Such variations may make it difficult to design a system that uses a fixed drive signal to control the negative pressure source (e.g., a drive signal applied to the motor or another actuator of the negative pressure source). In some cases, a proportional-integral-derivative (PID) control loop (sometimes referred to as a PID loop) may be used. The PID loop may need to be stable and yet responsive over all conditions (such as one or more of the variations described herein) under which the system operates.

[0115] A PID loop may have a set of fixed parameters that control the gains within the loop. These parameters may include: A proportional gain (P-Gain) that can be used to drive a PID loop whose output is based on the ratio of the output error (e.g. the difference between the current pressure compared to the target pressure) Integral Gain (I Gain) that can be used to drive a PID loop whose output is based on a ratio of the system integral error (i.e. the sum of the current and the previous output error) A differential gain (D-Gain) that can be used to drive a PID loop whose output is based on the ratio of the difference between the current output error and the previous error.

[0116] In some cases, a negative pressure wound therapy system may implement proportional and integral gains, but may not implement differential gains. Such control loops may be referred to as PI loops (which may be a special case of PID loops).

[0117] The proportional gain may be more important than the other gains and may account for the main drive when the output error is very large. The integral gain may correct for steady state errors once the system is nearly at the target pressure. The differential gain may handle acceleration / deceleration towards the target pressure and may account for the inertia of the system.

[0118] A single set of PID parameters can be used to control a symmetric system. An example of a symmetric system is driving a pointer to a target angle (such as a speedometer needle). In such a system, the correction of the output requires the same drive regardless of the target position. However, a negative pressure wound therapy system cannot be symmetric for at least the following reasons: First, establishing a higher negative pressure level set point (or a higher vacuum level) may require more power than establishing a lower negative pressure level set point. For example, the power required to reduce pressure from 0 mmHg to -50 mmHg is much less than the power required to reduce pressure from -150 mmHg to -200 mmHg, even if the error in both cases is 50 mmHg. This may be due to the following: The flow rate in the fluid flow path may increase as the negative pressure increases (or becomes more negative), which may be due to the negative pressure source power.

[0119] This may cause a proportional square increase, with the extra pressure on the negative pressure source component increasing the power required to maintain the higher negative pressure. Second, the system can only drive the negative pressure source in one direction (e.g., reduce but not increase pressure). If the negative pressure overshoots, the drive signal to control the negative pressure source is turned off and the system must wait until the negative pressure decays naturally, for example, due to one or more leaks in the fluid flow path.

[0120] Thus, in some instances, a PID loop optimized for good performance for a target set point of, for example, -200 mmHg will not perform as well for a target set point of, for example, -50 mmHg. The reason can be seen by inspection of the proportional gain (P-gain). If the system is in an initial state (such as when the fluid flow path is at atmospheric pressure) and the target set point is -200 mmHg, the initial error is -200. Assuming a P-gain of -1, converting the error to a fractional power for driving the negative pressure source (which may be expressed as a percentage) means that the PID loop will initially attempt to drive the negative pressure source at 200% (this may be determined using the formula (error*P-gain), which corresponds to -200*1=200%). Since the negative pressure source can be driven at a maximum of 100%, the negative pressure source will continue to be driven at 100% until the pressure in the fluid flow path reaches, for example, -100 mmHg. At this point, the proportional gain can linearly decrease the proportional drive power (as the error decreases) until the target set point is achieved. Assume the target set point is -25 mmHg and the same P-gain of -1 is used. The initial error is -25 and only 25% of the negative pressure source power is applied (-25 x -1 = 25%). As a result, the system will be very slow to reach the target set point. This can be due to the negative pressure source having to overcome a fixed volume of gas (such as air) in the system that needs to be evacuated before it can achieve any negative pressure value in the fluid flow path.

[0121] Assume the system is optimized to reduce pressure to -25mmHg. A much higher P-gain can be selected, such as -8, since the expected error will be smaller. This allows for an initial source power of 100% at start-up (-25 x -8 = 200%, which is limited to 100%). The power is reduced linearly towards the target pressure. However, if a P-gain value of -8 is applied to the system to reduce pressure to -200mmHg, the PID loop will attempt to drive the source at 1600% (-200 x 8). This will be limited to 100% for the majority of the duration of driving the source to establish the set point, reducing to less than 100% drive very close to the target pressure. Undesirably, the inertia of the system will likely cause a large overshoot of the target pressure.

[0122] To address these issues, individual PID loop parameters for each target pressure set point can be used. In some cases, different P-gain, I-gain, or D-gain values ​​can be determined for one or more different negative pressure set points. For example, when a PI loop is used, different P-gain and I-gain values ​​can be determined for each negative pressure set point (or at least some different set points). The ratio of P-gain to I-gain can be about 0.1 (or 1%). The P-gain value can be linearly proportional to the set point, as shown in FIG. 12. Using such P-gain and I-gain values, the PID loop can provide good control at both high and low pressures. The target pressure can be achieved in a reasonable time without significant overshoot.

[0123] For example, the following P-gain and I-gain values ​​for each negative pressure set point may be determined (eg, through testing) and used in the PI loop:

[0124] [Table 1]

[0125] In some cases, instead of a linear relationship between P gain and set point (such as in the table above and in FIG. 12), a squared relationship can be used. Such a relationship may more closely model the pressure vs. power curve. In some instances, line or curve fitting can be used. Such an approach may further account for asymmetries in negative pressure wound therapy systems.

[0126] To compensate for the asymmetric nature of the negative pressure wound therapy system, the I-gain may be adjusted when the pressure in the fluid flow path is above the set point (or more negative than the set point). This may reduce the size and duration of the overshoot. The adjustment factor may be a constant, e.g., an integer value (such as 2, 3, 5, or more than 5). The adjustment may be multiplicative (in such cases, the adjustment factor may be referred to as a multiplier). For example, assume the set point is -125 mmHg and the multiplier is M. When the actual pressure in the fluid flow path is below the set point (or more positive than -125 mmHg), the I-gain used to raise the actual pressure to the target may be X (which may be an integer value). When the actual pressure is above the set point (or more negative than -125 mmHg), the I-gain may be adjusted by the multiplier to M*X. This may reduce any overshoot and, as a result, reduce the risk of providing the patient with too much negative pressure, which may cause discomfort or pain.

[0127] Adjustments to I-gain can be made after the set point is achieved to reduce the size and duration of any pressure overshoot and reduce the risk of overpressurizing the wound. In some cases, adjustments to I-gain can be made before the set point is achieved to facilitate faster achievement of the target pressure (which may come with the risk of causing a pressure overshoot).

[0128] If the multiplier is selected too large, it can cause the integral term (or integral sum) of the PI or PID loop to collapse rapidly even with small pressure fluctuations that may naturally occur, for example, due to air bubbles in the exudate being aspirated, causing small disturbances in the pressure in the fluid flow path. Using too large a multiplier can produce uneven and undesirable pressure regulation accompanied by periodic drops in the drive signal power.

[0129] The PID (or PI) loop may be implemented by one or more controllers, such as pump controller 370. The P gain and I gain values ​​for different set points may be stored in a memory, such as memory 350. For example, a lookup table indexed by the set points may be used.

[0130] In some cases, the pressure at the wound may be measured directly, for example by one or more pressure sensors positioned at or near the wound, in which case references to pressure within the fluid flow path used in this section may be replaced with pressure at the wound.

[0131] Advantageously, the approach described in this section can facilitate good control of the negative pressure source at both high and low negative pressure set points. The target pressure can be achieved quickly and without significant overshoot.

[0132] Tutorial for operating a negative pressure wound therapy device Any of the negative pressure wound therapy devices disclosed herein (such as device 110) may be configured to provide one or more tutorials for operating the device. The one or more tutorials may be provided in an AV format. For example, the one or more tutorials may be selected from a user interface displayed on display 172. The one or more tutorials may include a device overview, applying negative pressure wound therapy, resolving alarms, etc. One or more controllers (such as main controller 310) may control the provision of the one or more tutorials.

[0133] As described herein, a device may include a user interface (such as interface 170) for operating the device. The user interface may include one or more indicators 174 or one or more controls or buttons (e.g., including but not limited to, a therapy start and pause button 180 or an alarm / alert mute button 182 and one or more input controls or buttons 184). To further facilitate a user learning how to operate the device, one or more tutorials may be provided that the user can activate to highlight (e.g., illuminate) one or more user interface components necessary to cause the device to perform a particular function.

[0134] For example, with reference to user interface screen 1010 shown in FIG. 10A, one (or more) of buttons 184 may be used to change the intensity of negative pressure wound therapy. User interface screen 1010 may be displayed on display 172. The associated button 184 may be illuminated (or otherwise highlighted to a user) while user interface screen 1010 is displayed. As another example, with reference to user interface screen 1020 shown in FIG. 10B, one of buttons 184 may be used to access a menu on display 172. The associated button 184 may be illuminated (or otherwise highlighted to a user) while user interface screen 1020 is displayed on display 172.

[0135] As yet another example, with reference to user interface screen 1030 shown in FIG. 10C, button 188 may be operable to lock or unlock functionality of various other controls (e.g., one or more buttons for adjusting therapy settings). Button 188 may be illuminated (or otherwise highlighted to a user) while user interface screen 1030 is displayed. As yet another example, with reference to user interface screen 1040 illustrated in FIG. 10D, button 202 may be operable to disconnect and remove a canister. Button 202 may be illuminated (or otherwise highlighted to a user) while user interface screen 1040 is displayed. Similarly, start and pause buttons 180 may be illuminated (or otherwise highlighted to a user).

[0136] Therapy Summary and Log Any of the negative pressure wound therapy devices disclosed herein (such as device 110) may be configured to record data associated with the delivery of therapy and provide one or more summaries to a user. For example, the one or more summaries may be displayed on display 172. One or more controllers (such as main controller 310) may control the recording of data and provide the one or more summaries.

[0137] 11A shows a user interface screen 1110 providing a therapy summary for several days. The screen 1110 may include a bar graph 1112 showing therapy time for several days captured by the summary. The days may include the current day (which in the illustrated example may be Sunday) and three days prior (e.g., Saturday, Friday, and Thursday). In some implementations, formats other than or in addition to the bar graph 1112 may be displayed (e.g., pie chart, line graph, etc.). The user interface screen 1110 may include daily averages 1114 determined for several days (e.g., four days in the illustrated example).

[0138] FIG. 11B illustrates a user interface screen 1120 that provides a therapy summary for a particular day (which may correspond to a current day, such as a Sunday, for example). The therapy summary of screen 1120 may be described in more detail than the summary of screen 1110. User interface screen 1120 may be accessed from screen 1110 by selecting option 1102 (labeled "Next") of FIG. 11A. As described herein, option 1102 may be activated by one of buttons 184. User interface screen 1120 may illustrate a graph 1132 of negative pressure levels over time for a particular day. Various alarms or other events 1134 may be illustrated and positioned to coincide with the time of occurrence. This may facilitate a user's analysis and understanding of how negative pressure wound therapy was provided on a particular day.

[0139] Selecting option 1104 (labeled "Log") in FIG. 11B (or FIG. 11A) displays user interface screen 1130, shown in FIG. 11C. As described herein, option 1104 may be activated by one of buttons 184. User interface screen 1130 may provide a more detailed listing of various alarms or other events 1134. As shown, times of occurrence of various alarms or other events 1134 may be provided.

[0140] FIG. 11D illustrates a transition between therapy summaries for several days (e.g., four days, Sunday, Saturday, Friday, and Thursday) as illustrated in FIG. 11A. The transition may begin with a user interface screen 1110 that provides a therapy summary for several days. Selecting option 1102 (labeled "Next") on screen 1110 may display a user interface screen 1120 that provides a more detailed therapy summary for the current day (e.g., Sunday). Selecting option 1102 (labeled "Next") on screen 1120 may launch a user interface screen 1122 that provides a more detailed therapy summary for the previous day (e.g., Saturday). Selecting option 1102 (labeled "Next") on screen 1122 may launch a user interface screen 1124 that provides a more detailed therapy summary for the day before yesterday (e.g., Friday). Finally, selecting option 1102 (labeled "Next") on screen 1124 can launch user interface screen 1126, which provides a more detailed therapy summary from three days ago (e.g., Thursday). User interface screens 1122, 1124, and 1126 can be similar to user interface screen 1120. Selecting option 1102 (labeled "Next") on screen 1126 can display user interface screen 1110, which provides a therapy summary for several days.

[0141] Advantageously, the approach described in this section can provide data relevant to therapy delivery in a user-friendly and easy-to-understand format.

[0142] Inhibition of delivery of negative pressure wound therapy In some cases, the delivery of negative pressure may be inhibited by any of the pump assemblies disclosed herein (such as pump assembly 160) in response to detecting one or more operating conditions. For example, the delivery of negative pressure may be inhibited in response to detecting that one or more canister filters are blocked with fluid. Although the canister may contain one or more hydrophobic filters that inhibit the passage of liquid into the pump assembly 160, when the canister is completely filled with fluid and more filters are blocked, continued application of negative pressure (especially at higher negative pressure set points such as about -200 mmHg) may mechanically stress one or more filter membranes and cause mechanical failure (such as tearing or detachment) of one or more filters. As a result, there may be a risk of damaging the pump assembly 160 with liquid. To mitigate this risk, it may be advantageous to inhibit the delivery of negative pressure (such as by shutting off the negative pressure source) in response to detecting that one or more filters are blocked.

[0143] Detection of the blockage of the filter(s) may be performed as follows: The pump assembly 160 (e.g., via the controller(s) 310 or 370) may not be configured to directly detect the blockage of the filter(s). In some cases, this may be performed indirectly in response to detecting that the canister is full and there is a blockage in the fluid flow path. These two conditions may be detected independently by the pump assembly 160, for example, to distinguish between a blockage due to the canister being full (proximal blockage) and a blockage upstream of the canister (distal blockage). Detection of both of these conditions may indicate that the filter(s) is blocked, since both a proximal and distal blockage are detected. Delivery of negative pressure may be inhibited in response to detecting that the canister is full and there is a blockage in the fluid flow path.

[0144] In some implementations, canister full detection can be performed by detecting a fluid connection using two electrodes placed inside the canister. Further details of canister full detection are disclosed in International Patent Application No. PCT / EP2022 / 060463, filed April 20, 2022, entitled "Canister Status Determination for Negative Pressure Wound Therapy Devices," which is incorporated by reference in its entirety. Occlusion detection can be performed by monitoring activity of the negative pressure source (e.g., by monitoring the speed of a motor of the negative pressure source, by monitoring the duty cycle of an actuator of the negative pressure source, or the like) and comparing the activity to one or more activity thresholds indicative of an occlusion in the fluid flow path. Further details of occlusion detection are disclosed in U.S. Pat. No. 9,737,649, issued on August 22, 2017, and entitled "Systems and Methods for Applying Reduced Pressure Therapy," and U.S. Pat. No. 10,744,239, issued on August 18, 2020, and entitled "Leak Detection in Negative Pressure Wound Therapy System," each of which is incorporated by reference in its entirety.

[0145] Delivery of negative pressure may be resumed in response to clearing at least one of a canister full or an occlusion in the fluid flow path. While it is unlikely that an occlusion would clear with the negative pressure source being stopped, a canister full may clear if the canister full detection was triggered as a result of incorrect orientation of the pump assembly 160 (rather than due to the canister being full). For example, the pump assembly 160 may be tilted or placed upside down, triggering the canister full detection. Placing the pump assembly 160 in an upright position may clear the canister full condition, thereby allowing delivery of negative pressure wound therapy to continue.

[0146] Other Variations Any of the negative pressure wound therapy systems and / or devices disclosed herein may implement any combination of the features disclosed in the various preceding sections, for example, any of the systems and / or devices described in one or more of the "Fall Detection and Device Orientation Detection" section, the "Transitioning to Different Therapy Systems" section, the "Multi-Parameter PID Control" section, the "Tutorial for Negative Pressure Wound Therapy Device Operation" section, the "Therapy Overview and Logs" section, or the "Negative Pressure Wound Therapy Delivery Impairments" section.

[0147] 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, or the like. 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.

[0148] Any transmission of data described herein may be performed securely, for example utilizing one or more of encryption, https protocol, a secure VPN connection, error checking, delivery confirmation, or the like.

[0149] Although some embodiments describe the use of an accelerometer and accelerometer data, any other motion sensor may be used. For example, one or more shock or impact sensors may be utilized.

[0150] Values ​​such as thresholds, limits, periods, etc. provided herein are not intended to be absolute values ​​and therefore may 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, less than, etc., 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, less than, etc., in relation to a reference value are intended to encompass the inverse of the disclosed relationship, such as less than, under, over, etc., in relation to a reference value.

[0151] 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.

[0152] 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, such as controllers, processors, ASICs, FPGAs, and the like, may include logic circuitry. Furthermore, the features and characteristics of specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] Unless expressly stated otherwise, articles such as "a" or "an" should generally be construed to include one or more of the listed items. Thus, phrases such as "an apparatus configured to" are intended to include one or more of the listed apparatus. Such one or more listed apparatuses may also be collectively configured to perform the stated enumeration.

[0158] 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 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. Thus, 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. 1. A negative pressure wound therapy device comprising: Housing and a negative pressure source supported by the housing and configured to be connected via a fluid flow path to a wound covered by the wound dressing, the negative pressure source being further configured to provide negative pressure to the wound; an electronic circuit supported by the housing and configured to detect movement of the housing; Detecting that the housing is falling based on the movement of the housing and determining a duration of the fall; and and electronic circuitry further configured to provide a first indication in response to determining that the duration of the drop meets a duration threshold.

2. the electronic circuitry includes an accelerometer, the electronic circuitry being configured to detect that the housing is being dropped in response to determining that acceleration detected by the accelerometer satisfies a first acceleration threshold indicative of low acceleration; and optionally: the acceleration detected by the accelerometer includes one or more of a magnitude of acceleration along a z-axis or a magnitude of acceleration along multiple axes; 10. The negative pressure wound therapy device of claim 1.

3. 3. The negative pressure wound therapy device of claim 2, wherein the electronic circuit is configured to determine the duration of the fall in response to detecting a duration during which the acceleration detected by the accelerometer meets the first acceleration threshold.

4. determining a first time at which the acceleration detected by the accelerometer first meets the first acceleration threshold; determining a second time during which the housing makes a first impact with the surface; 3. The negative pressure wound therapy device of claim 2, configured to determine the duration of the drop based on a time difference between the second time and an initial time, wherein determining the duration of the drop is based on the time difference taking into account possible rotation of the housing during the drop.

5. 5. The negative pressure wound therapy device of claim 4, wherein the electronic circuit is configured to determine the second time period in response to detecting that the acceleration detected by the accelerometer satisfies a second acceleration threshold indicative of a high acceleration threshold.

6. 10. The negative pressure wound therapy device of claim 1, further comprising an electronic processing circuit configured to operate the negative pressure source, the electronic circuit configured to transition the electronic processing circuit from a non-operating state to an operating state in response to determining that the duration of the drop meets the duration threshold.

7. The negative pressure wound therapy device of claim 1 , wherein the electronic circuitry is further configured to determine the height of the drop based on the duration of the drop.

8. A negative pressure wound therapy device according to any preceding claim, wherein the first indication includes one or more of stopping the negative pressure source or performing one or more tests on the device.

9. 10. The negative pressure wound therapy device of claim 1, wherein the electronic circuitry is further configured to detect that the housing is tilted based on the movement of the housing and to provide a second indication in response to detecting that the housing is tilted.

10. the electronic circuitry includes an accelerometer, the electronic circuitry being configured to detect that the housing is tilted in response to determining that acceleration detected by the accelerometer satisfies a tilt threshold; and optionally, the acceleration includes acceleration along the z-axis; 10. The negative pressure wound therapy device of claim 9.

11. The negative pressure wound therapy device of claim 10 , wherein the first indication includes shutting off the negative pressure source.

12. 1. A negative pressure wound therapy device comprising: a negative pressure source configured to be connected to a wound covered with a wound dressing via a fluid flow path, the negative pressure source further configured to provide negative pressure to the wound; a canister configured to be fluidly connected to the negative pressure source via the fluid flow path and further configured to store fluid aspirated from the wound, the canister being further configured to be disconnected from the negative pressure source and replaced by a replacement canister; and an electronic processing circuit configured to monitor the rate of fluid suction from the wound based on monitoring the replacement of the canister, and in response to determining that the suction rate meets a threshold indicating a transition to treating the wound with a low exudate rate negative pressure wound therapy system, provide an indication that the transition is recommended.

13. 13. The negative pressure wound therapy device of claim 12, wherein the low exudate rate negative pressure wound therapy system is configured to store fluid aspirated from the wound in an absorbent dressing and does not utilize a canister.

14. 13. The negative pressure wound therapy device of claim 12, wherein the electronic processing circuit is configured to determine that the suction rate meets the threshold in response to detecting that at least one canister change has occurred outside a threshold duration when the canister is not full.

15. 13. The negative pressure wound therapy device of claim 12, wherein the sizes of the canister and replacement canister include a first size and a second size larger than the first size, and the electronic processing circuit is configured to determine that the suction rate meets the threshold in response to detecting that the canister is the first size.

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