WO2021209949A1

WO2021209949A1 - Systems and methods for active evaporation of a wound therapy system

Info

Publication number: WO2021209949A1
Application number: PCT/IB2021/053122
Authority: WO
Inventors: Christopher Brian Locke
Original assignee: Kci Licensing, Inc.
Priority date: 2020-04-16
Filing date: 2021-04-15
Publication date: 2021-10-21

Abstract

A negative pressure wound therapy (NPWT) system includes a canister and a therapy device. The canister includes one or more air inlets and one or more passageways extending through the canister. The therapy device includes a negative pressure pump and a fan. The negative pressure pump is configured to draw a negative pressure at a wound. The fan is configured to operate to draw a flow of air into the one or more air inlets of the canister, through the one or more passageways extending through the canister, and vented out from a passageway of the therapy device to facilitate active evaporation at the canister.

Description

SYSTEMS AND METHODS FOR ACTIVE EVAPORATION OF A WOUND THERAPY SYSTEM

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of priority to U.S. Provisional Application No.

63/011,032, filed on April 16, 2020, which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] The present disclosure relates generally to negative pressure wound therapy (NPWT) systems. More particularly, the present disclosure relates to active or forced evaporation at a canister at a canister of the NPWT system.

SUMMARY

[0003] One implementation of the present disclosure is a NPWT system, according to some embodiments. The system includes a canister and a therapy device. The canister includes one or more air inlets and one or more passageways extending through the canister. The therapy device includes a negative pressure pump and a fan. The negative pressure pump is configured to draw a negative pressure at a wound. The fan is configured to operate to draw a flow of air into the one or more air inlets of the canister, through the one or more passageways extending through the canister, and vented out from a passageway of the therapy device to facilitate active evaporation at the canister. [0004] Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices and/or processes described herein, as defined solely by the claims, will become apparent in the detailed description set forth herein and taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 is a side sectional view of a wound therapy system including a canister and a NPWT device that includes a fan operable to force an evaporative airflow through the canister and the NPWT device, according to some embodiments.

[0006] FIG. 2 is a graph showing an amount of evaporation that occurs from different positions of the fan of the wound therapy system of FIG. 1, according to some embodiments.

[0007] FIG. 3 is a diagram showing the different positions of the fan of the graph of FIG. 2, according to some embodiments.

[0008] FIG. 4 is a block diagram of a control system for the wound therapy system of FIG. 1, according to some embodiments.

[0009] FIG. 5 is a flow diagram of a process for performing active evaporation of a NPWT system, according to some embodiments. [0010] FIG. 6 is a block diagram of a wound therapy system including a therapy device coupled to a wound dressing via tubing, according to some embodiments.

[0011] FIG. 7 is a block diagram illustrating the therapy device of FIG. 6 in greater detail when the therapy device operates to draw a vacuum within a negative pressure circuit, according to some embodiments.

[0012] FIG. 8A is a block diagram illustrating the therapy device of FIG. 6 in greater detail when the therapy device operates to vent the negative pressure circuit, according to some embodiments. [0013] FIG. 8B is a block diagram illustrating the therapy device of FIG. 6 in greater detail when the therapy device uses an orifice to vent the negative pressure circuit, according to some embodiments.

[0014] FIG. 9 is a block diagram illustrating the therapy device of FIG. 6 in greater detail when the therapy device operates to deliver instillation fluid to the wound dressing and/or a wound, according to some embodiments.

DETAILED DESCRIPTION

Overview

[0015] Referring generally to the FIGURES, a NPWT system can include a canister and a NPWT device. The NPWT device may include a negative pressure pump (e.g., a suction pump) that is configured to draw a negative pressure at a wound or a wound site to facilitate improved healing of the wound. The NPWT device may draw wound fluid from the wound or the wound site and store the wound fluid in an inner volume of the canister. The canister can include multiple passageways, filters, and air inlets. The canister can also include an outlet that is surrounded by a seal and is configured to fluidly couple with a correspondingly sized and positioned inlet or opening of the NPWT device. The NPWT device includes a passage that fluidly couples with the passageways of the canister through the opening of the NPWT device and the outlet of the canister. The NPWT device also includes a fan positioned in the passage that operates to draw air through the air inlets of the canister, the passageways of the canister, the outlet of the canister, and through the passage of the NPWT device. The fan can drive the air to discharge or exhaust out of the NPWT device through one or more exhaust port(s) of the NPWT device. The exhaust ports of the NPWT device, the passage of the NPWT device, the opening of the NPWT device, the outlet of the canister, the passageways of the canister, and the air inlets of the canister cooperatively define a fluid flow path. The fan operates to draw air through the air inlets of the canister, along the flow path, and exit the NPWT device through the exhaust port(s).

[0016] Driving air through the canister may cause fluid that is collected and stored in the canister to evaporate, thereby moisturizing the air that flows along the flow path. The evaporated fluid is carried with the air and exhausted from the NPWT device through the exhaust ports. The filters of the canister facilitate sterilizing the moisturized air so that contaminants are not exhausted out of the NPWT device through the exhaust ports. The NPWT device may also include one or more ultraviolet (UV) light emitters that are configured to emit UV light into the moisturized air that flows along the flow path. The UV light emitters may function to provide a secondary sterilization of the moisturized air by disrupting the DNA of various microorganisms that may be present in the moisturized air before the moisturized air is exhausted from the NPWT device.

[0017] Advantageously, actively driving or causing evaporation of the fluid that is stored in the canister can facilitate an improved or increased fluid capacity of the canister. For example, the canister may still collect and store fluid that is drawn from the wound, but some of the fluid may be evaporated and exhausted from the canister (e.g., along the flow path and through the NPWT device) so that the canister does not reach a maximum fill level as soon.

Forced Evaporation Therapy System Wound Therapy System

[0018] Referring particularly to FIG. 1, a wound therapy system 10 is shown, according to some embodiments. Wound therapy system 10 may be an active or forced evaporative system which draws a negative pressure at a wound, collects fluid or wound exudate from the wound at a canister and forces evaporation of the fluid in the canister for discharge to the atmosphere. Wound therapy system 10 can be the same as, similar to, or incorporate any of the functionality of the system of U.S. Patent No. 8,821,458, filed April 12, 2011, orthe dressing/system of U.S. Patent No. 8,604,265, filed April 12, 2011, orthe system of U.S. Patent No. 9,023,002, filed April 9, 2012, orthe system ofU.S. Patent No. 9,433,711, filed November 12, 2012, the entire disclosures of which are incorporated by reference herein.

[0019] Wound therapy system 10 includes a NPWT device 12 and a canister, a container, a tank, a vessel, etc., shown as canister 14. NPWT device 12 can be the same as or similar to therapy device 602 as described in greater detail below with reference to FIGS. 6-9 and canister 14 can be the same as or similar to removed fluid canister 606 as described in greater detail below with reference to FIGS. 6-9. Canister 14 is configured to receive, collect, and store wound fluid that is drawn from a wound or periwound area that wound therapy system 10 treats. Canister 14 can include an inlet 48 that is fluidly coupled with a wound and a wound dressing. For example, inlet 48 may be fluidly coupled with tubing 610 as described in greater detail below with reference to FIGS. 6-9. Wound exudate or fluid (e.g., instillation fluid that is provided to the wound and the wound dressing by wound therapy system 10) can be drawn through inlet 48 and stored in canister 14 (e.g., within a storage volume 50 of canister 14). Storage volume 50 may be the same inner volumes as passageways 60. In some embodiments, wound exudate or fluid is drawn into canister 14 by operation of a negative pressure pump 16 of NPWT device 12. For example, negative pressure pump 16 can operate to draw a negative pressure at the wound and the wound dressing to bias, draw, suck, or drive wound exudate and fluid from the wound to canister 14.

[0020] Canister 14 may be removably coupled with NPWT device 12 so that canister 14 can be disconnected and emptied. For example, wound exudate and/or fluid may accumulate in canister 14 as the wound is treated by wound therapy system 10. In some embodiments, canister 14 includes selectively transparent or opaque material that changes transparency or opacity in response to contact with a fluid so that a caregiver can monitor a level of fluid within canister 14. In other embodiments, canister 14 includes a transparent material or a transparent region so that the caregiver can monitor an amount or level of fluid in canister 14 by visual inspection. Once canister 14 reaches a certain fill level, the caregiver may remove canister 14 from NPWT device 12 and empty the contents.

[0021] Referring still to FIG. 1, NPWT device 12 may include a first opening 52 positioned proximate or near negative pressure pump 16. In some embodiments, first opening 52 is configured to fluidly couple with a corresponding opening 54 of canister 14. A seal 30 (e.g., an O-ring, a flexible member, a rubber member, etc.) can be positioned between NPWT device 12 and canister 14 and may allow air to pass through first opening 52 of NPWT device 12 and the corresponding opening 54 of canister 14.

[0022] Canister 14 can include a filter 32 that is positioned at opening 54 of canister 14. Filter 32 may facilitate removal of various bacteria, fluid, particulate matter, etc., as negative pressure pump 16 operates to draw negative pressure or suction through first opening 52 of NPWT device 12 and the corresponding opening 54 of canister 14.

[0023] NPWT device 12 can include a passage 56 (e.g., a flow path, a passageway, a channel, etc.) that extends through NPWT device 12. Canister 14 also includes one or more passageways 60 (e.g., flow paths, passageways, channels, etc.), and one or more air inlets 28 (e.g., openings, holes, apertures, inlets, etc.) that fluidly couple passageways 60 with the atmosphere so that air can be drawn through air inlets 28 and passageways 60. Passageways 60 fluidly couple with an opening 58 of canister 14. Opening 58 can be aligned with a corresponding opening or inlet 62 of NPWT device 12 so that passageways 60 of canister 14 fluidly couple with passage 56 of NPWT device 12. NPWT device 12 also includes one or more exhaust ports 44 that fluidly couple with passage 56 of NPWT device 12 so that air, or evaporated fluid can be driven out of NPWT device 12. Exhaust ports 44 vent to the atmosphere so that air or fluid can be emitted or ejected from NPWT device 12.

[0024] In some embodiments, air inlets 28, passageways 60, opening 58, inlet 62, passage 56, and exhaust ports 44 define a flow path 40. Flow path 40 begins at air inlets 28, extends along passageways 60 and passage 56, and terminates at exhaust ports 44. It should be understood that while FIG. 1 shows only a single flow path 40 and a single exhaust port 44, NPWT device 12 and canister 14 may include multiple flow paths 40, multiple exhaust ports 44, etc.

[0025] Referring still to FIG. 1, NPWT device 12 can include a fan 20 that is configured to operate to drive, draw, or force air flow along flow path 40. Fan 20 may be driven by a fan motor 38 (shown in FIG. 4) that is operated by controller 18. Controller 18 may operate a speed of fan 20 so that fan 20 operates to draw air along flow path 40 for forced evaporation of fluid at canister 14. Fan 20 can be positioned in passage 56 so that fan 20 operates to draw air to enter canister 14 through air inlets 28, pass through passageways 60 and passage 56, and exit NPWT device 12 through exhaust ports 44. As the air is drawn through passageways 60, the airflow may cause fluid that is stored in canister 14 or drawn from the wound to evaporate, thereby moisturizing the air. The moisturized air is then passed through opening 58 of canister 14 to inlet 62 of NPWT device 12. The moisturized air then passes through passage 56 and exits NPWT device 12 through exhaust ports 44.

[0026] Fan 20 includes a stem member 24 and multiple impeller blades 22. Stem member 24 and impeller blades 22 are driven to rotate by fan motor 38 so that air is drawn into canister 14 through air inlets 28, forces evaporation at canister 14, is passed from canister 14 to NPWT device 12, and is exhausted to the atmosphere through exhaust port(s) 44.

[0027] Referring still to FIG. 1, passageways 60 can include one or more fdms, membranes, filters, etc., shown as filters 36. Filters 36 can be manufactured from a high moisture vapor transmission rate (MVTR) material. For example, filters 36 can include one or more high MVTR films, wicking systems, and/or welding/adhesive bonds to secure a layered structure within passageways 60. Using multiple filters 36 may reduce a statistical likelihood that fluid is discharged from canister 14 if one of filters 36 fails. Filters 36 may have a structure of perforations, lattice openings, etc., that is smaller than a size of various water or fluid molecules. In this way, liquid may be prevented from being exhausted from NPWT device 12 along flow path 40. Filters 36 can be or include a bacterial filter and/or a hydrophobic filter.

[0028] In some embodiments, passage 56 includes a filter 36 along flow path 40. Filter 36 can be configured to prevent large water or fluid molecules from being exhausted through exhaust ports 44. Filter 36 may be positioned upstream of fan 20 so that large water molecules do not impinge on impeller blades 22, thereby reducing a likelihood of cavitation.

[0029] Referring still to FIG. 1, NPWT device 12 can include UV light sources 34 (e.g., UV light emitting diodes (LEDs), UV emitters, short-wavelength UV-C LED emitters, etc.) that are configured to emit UV light into flow path 40 and/or onto fan 20. For example, UV light sources 34 can be configured to emit UV light onto impeller blades 22 and/or stem member 24 and into the flow of air or moist air that travels along flow path 40. UV light sources 34 may be positioned downstream from fan 20 (e.g., between fan 20 and exhaust ports 44, on a discharge side of fan 20, etc.). In some embodiments, UV light sources 34 are configured to emit UV light into the flow of air or moisturized air to kill or mitigate the presence of any bacteria, viruses, or contaminants that may be present in the moisturized air. Based on principles of ultraviolet germicidal irradiation (UVGI), UV light sources 34 can kill or inactivate various microorganisms which may be present in the moist air by destroying nucleic acids and disrupting the microorganisms’ DNA, thereby leaving the microorganisms unable to perform their cellular functions. UV light sources 34 can be configured to emit light at a wavelength of between 225 to 280 nanometers.

[0030] UV light sources 34 may be positioned anywhere along the flow path 40 between canister 14 (e.g., the opening 58 of canister 14) and a suction side of fan 20. In some embodiments, UV light sources 34 are positioned anywhere along flow path 40 between air inlets 28 and exhaust ports 44.

UV light sources 34 may be positioned along and configured to emit UV light along only a portion of flow path 40 (e.g., along a portion of flow path 40 that extends between air inlets 28 of canister 14 and exhaust ports 44 of NPWT device 12). In other embodiments, UV light sources 34 are positioned along and configured to emit UV light along an entirety of flow path 40. In some embodiments, UV light sources are positioned along a portion of flow path 40 that extends between opening 58 of canister 14 and exhaust ports 44 of NPWT device 12 and are configured to emit UV light along the portion of flow path 40 that extends between opening 58 of canister 14 and exhaust ports 44 of NPWT device 12.

[0031] It should be understood that any combination of filters 36 and UV light sources 34 may be provided and positioned along flow path 40. For example, wound therapy system 10 can include only filters 36 but no UV light sources 34, or may include UV light sources 34 only but no filters 36, or may include a combination of both UV light sources 34 and filters 36. Advantageously, UV light sources 34 can be used in addition to filters 36 to ensure that microorganisms are not exhausted to the atmosphere through exhaust port(s) 44.

[0032] Additionally, UV light sources 34 may continue to operate to emit the UV light even after fan 20 has stopped operating. In some embodiments, UV light sources 34 are configured to emit UV light onto impeller blades 22 and stem member 24 to sterilize fan 20. UV light sources 34 can also be configured to emit UV light onto inner sidewalls of passage 56 of NPWT device 12, even after fan 20 has stopped operating to sterilize the inner sidewalls or interior surfaces of passage 56. In this way, UV light sources 34 can operate to emit UV light as fan 20 operates to sterilize air that is driven by fan 20 and exhausted through exhaust port(s) 44, and when fan 20 ceases operating to sterilize various interior surfaces of passage 56. UV light sources 34 can also be configured to provide UV light onto various interior surfaces of passageways 60 even after fan 20 has stopped operating to sterilize interior surfaces of passageways 60. In some embodiments, various components of fan 20 (e.g., impeller blades 22, stem member 24, etc.) and interior surfaces of passage 56 or passageway 60 are manufactured from a plastic or other material that does not disrupt a wavelength of the UV light emitted by UV sources 34. For example, impeller blades 22 of fan 20, and/or interior surfaces of passage 56 and passageways 60 may be manufactured from or coated with a polycarbonate (PC), polydimethylsiloxane (PDMS), or a cyclin olefin copolymer (COC) compound which are optically transparent.

[0033] In some embodiments, UV light sources 34 (e.g., dosing emitters) are in close proximity to interior surfaces of passage 56 or passageways 60 and so exposure to the UV light is brief, which is consistent with an anticipated flow rate of air/fluid along flow path 40.

[0034] Advantageously, forcing evaporation of fluid that builds up in canister 14 to produce a fluid/air mixture, sterilizing/filtering the fluid/air mixture, and exhausting the sterilized and/or filtered fluid/air mixture can facilitate a smaller static volume of canister 14 but a higher fluid management capacity. For example, using the forced evaporation techniques described herein and exhausting fluid/air mixture to the atmosphere may reduce a rate at which fluid builds up in canister 14 and needs to be removed, replaced, or emptied.

[0035] Referring still to FIG. 1, wound therapy system 10 can include a fdm, a membrane, a fdter, etc., shown as film 64. Film 64 can be the same as or similar to filters 36 and is positioned within NPWT device 12 along flow path 40. Film 64 can be positioned downstream of fan 20 between fan 20 and exhaust port 44. Film 64 may be configured to filter contaminants, particulate, viruses, bacteria, etc., or large water molecules from the fluid/air mixture that is driven or drawn by fan 20. Film 64 can be positioned on a discharge side of fan 20. Film 64 and/or filter(s) 36 can include scatter coated OxySalts to increase an anti-microbial strength thereof.

[0036] Film 64 and/or filter(s) 36 can also include a perforated absorbent layer such as an absorbent non-woven material (e.g., a low flow restrictor) to capture and immobilize any fluids that condense.

In some embodiments, film 64 or filter(s) 36 can be replaced or discarded when canister 14 is replaced by a caregiver.

Fan Location and Configurations

[0037] Referring particularly to FIGS. 2-3, graph 200 shows test results indicating fluid loss (in milliliters) over a 24 hour period for various configurations or operations of a fan in an evaporative wound therapy system, such as wound therapy system 10 described in greater detail above with reference to FIG. 1. Graph 200 of FIG. 2 includes a first series 202 that indicates fluid loss for a passive evaporative wound therapy system, a second series 204 that indicates fluid loss for a configuration where the fan is positioned at an end of a film and draws air into a canister, a third series 206 that indicates fluid loss for a configuration where the fan is positioned at the end of the film and forces air out of the canister, a fourth series 208 that indicates fluid loss for a configuration where the fan is positioned at a middle of the film and drives air towards the film, and a third series 210 that indicates fluid loss for a configuration where the fan is positioned at the middle of the film and drives air away from the film.

[0038] FIG. 3 includes a first diagram 304 illustrating the configuration where fan 20 is located at an end of film 300 and operates to draw air into the canister, a second diagram 306 where fan 20 is located at an end of film 300 and operates to draw air out of the canister, a third diagram 308 where fan 20 is located at a middle of film 300 and operates to draw air towards film 300, and a fourth diagram 310 where fan 20 is located at the middle of film 300 and operates to drive air away from film 300. First diagram 304 corresponds to series 204 of graph 200, second diagram 306 corresponds to series 206 of graph 200, third diagram 308 corresponds to series 208 of graph 200, and fourth diagram 310 corresponds to series 210 of graph 200. Film 300 can be film 64 as described in greater detail above with reference to FIG. 1.

[0039] As shown in FIG. 2, series 208, corresponding to diagram 308, indicates a highest amount of fluid loss (and therefore the most evaporation). Specifically, drawing air through the canister and discharging the air towards fdm 300 (as fan 20 of wound therapy system 10 operates) may result in approximately 47 milliliters of fluid loss over a 24 hour period. Table 1, shown below, demonstrates the average amount of fluid loss in a 24 hour period and a percentage of total fluid loss for series 202-

210:

Table 1 - Test Results

Control System

[0040] Referring particularly to FIG. 4, a control system 400 for wound therapy system 10 is shown, according to some embodiments. Control system 400 includes controller 18, negative pressure pump 16, UV light sources 34, fan motor 38, power source 408, and fan 20. Controller 18 can be configured to operate negative pressure pump 16, UV light sources 34, and fan motor 38 to force a negative flow of air (e.g., along fluid flow path 40 as shown in FIG. 1 and described in greater detail above) to force evaporation at canister 14 and exhaust or discharge the evaporated air out of NPWT device 12 (e.g., through exhaust port(s) 44).

[0041] Controller 18 may include a processing circuit 402 including a processor 404 and memory 406. Processor 404 may be a general purpose or specific purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a group of processing components, or other suitable processing components. Processor 404 is configured to execute computer code or instructions stored in memory 406 or received from other computer readable media (e.g., CDROM, network storage, a remote server, etc.).

[0042] Memory 406 may include one or more devices (e.g., memory units, memory devices, storage devices, etc.) for storing data and/or computer code for completing and/or facilitating the various processes described in the present disclosure. Memory 406 may include random access memory (RAM), read-only memory (ROM), hard drive storage, temporary storage, non-volatile memory, flash memory, optical memory, or any other suitable memory for storing software objects and/or computer instructions. Memory 406 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present disclosure. Memory 406 may be communicably connected to processor 404 via processing circuit 402 and may include computer code for executing (e.g., by the processor) one or more processes described herein. When processor 404 executes instructions stored in memory 406, processor 404 generally configures controller 18 (and more particularly processing circuit 402) to complete such activities.

[0043] Controller 18 is configured to generate control signals for UV light sources 34, fan motor 38, and negative pressure pump 16. Controller 18 can generate control signals for negative pressure pump 16 to draw a negative pressure at a wound for which negative pressure pump 16 is configured to provide NPWT. In some embodiments, controller 18 is the same as or similar to controller 618 as described in greater detail below with reference to FIGS. 6-9.

[0044] Controller 18 can also be configured to generate and provide control signals to UV light sources 34 so that UV light sources 34 operate to emit UV light along fluid flow path 40. In some embodiments, the control signals are provided to UV light sources 34 which are positioned along fluid flow path 40 so that UV light sources 34 operate to emit light that has a frequency of 225 to 280 nanometers. Controller 18 may provide the control signals to UV light sources 34 whenever fan 20 is operated (e.g., driven by fan motor 38) and for a time period after fan 20 has ceased operation to sterilize impeller blades 22 or interior surfaces of passageways 60 or passage 56. In some embodiments, UV light sources 34 draw electrical energy from the control signals provided by controller 18. In some embodiments, UV light sources 34 draw electrical energy from power source 408 of control system 400.

[0045] Referring still to FIG. 4, controller 18 is also configured to provide control signals to fan motor 38 so that fan 20 operates to draw air along fluid flow path 40. The control signals may cause fan motor 38, stem member 24, and impeller blades 22 to rotate at an angular speed uy_an which results in a flow rate V of air along flow path 40. In some embodiments, fan motor 38 is rotatably fixedly coupled with stem member 24 and impeller blades 22 through a driveshaft 42. In other embodiments, fan motor 38 drives stem member 24 and impeller blades 22 through multiple gears, belts, pulleys, etc., or any other power transmission system. In such an embodiment, an angular speed of fan motor 38, J_motor. is greater than or less than the angular speed u _an of fan 20.

[0046] Controller 18 can be configured to operate fan motor 38 at a single, predetermined speed, or at multiple different angular speeds. For example, controller 18 may operate fan motor 38 to rotate at different speeds to achieve different values of the flow rate V of air along flow path 40 (e.g., to facilitate different amounts of forced evaporation of fluid tha tis collected and stored in canister 14). Active Evaporation Process

[0047] Referring particularly to FIG. 5, a process 500 for providing forced or active evaporation of a NPWT system is shown, according to some embodiments. Process 500 includes steps 502-508 and optional steps 510-514. Process 500 can be performed using wound therapy system 10. In some embodiments, process 500 is performed to force evaporation of fluid that is collected in a canister of the NPWT system (e.g., in canister 14 of therapy system 10). Air may be drawn through air inlets in the canister, passed through internal passageways of the canister, where fluid in the canister evaporates and discharged through a therapy device of the NPWT system.

[0048] Process 500 includes providing a NPWT system (e.g., NPWT device 12) including a therapy device (e.g., NPWT device 12) having a fan (e.g., fan 20) positioned along a passage (e.g., passage 56) and a canister (e.g., canister 14) including one or more filters (e.g., filters 36) positioned along passageways (e.g., passageways 60) (step 502), according to some embodiments. Step 502 can be performed by a patient’s caregiver. The NPWT system may be therapy system 10 as described in greater detail above with reference to FIGS. 1-4. The fan may be configured to draw air through one or more inlets, openings, apertures, etc., of the canister so that air forces an evaporation of the fluid in the canister and is exhausted through one or more exhaust ports of the therapy device.

[0049] Process 500 includes operating a suction pump of the therapy device to draw a negative pressure at a wound site and drawing fluid from the wound site into the canister (step 504), according to some embodiments. Step 504 can be performed by controller 18 and negative pressure pump 16. For example, NPWT device 12, or more particularly, negative pressure pump 16, can be configured to draw a negative pressure at a wound site through inlet 48 so that fluid exuded by the wound at the wound site is drawn into and collected by canister 14.

[0050] Process 500 includes operating the fan to draw air along a flow path, the flow path defined by an air inlet of the canister, the passageways of the canister, the passage of the therapy device, and an exhaust port of the therapy device, whereby operation of the fan drives evaporation of the fluid in the canister (step 506), according to some embodiments. Step 506 can be performed by controller 18 and fan 20. For example, controller 18 may generate control signals for fan 20 so that fan 20 operates to draw air along flow path 40. The air may pass through the canister, driving or actively forcing evaporation of the fluid in the canister into the air flow. The air is then passed through the passage in the therapy device and exhausted (e.g., to the atmosphere) out of the therapy device. Various filters, membranes, films, etc., may be positioned along the flow path so that the air is sterilized before being exhausted. The various filters, membranes, films, etc., may be filters 36, film 64, filter 32, or any combination thereof.

[0051] Process 500 includes exhausting the moisturized air through the exhaust port of the therapy device (step 508), according to some embodiments. In some embodiments, the moisturized air carries various fluid that is drawn from the wound, collected in the canister, and evaporated into the airflow. The exhaust ports are positioned on the therapy device and the air inlet is positioned on the canister.

In this way, air is drawn through the canister, forces evaporation of the fluid at the canister, and is exhausted through the exhaust ports of the therapy device. Step 508 can be performed by fan 20 which operates to draw air into the canister and exhaust moisturized air from the therapy device. [0052] Process 500 includes operating one or more UV light sources (e.g., LEDs, emitters, etc.) that are positioned along the flow path to emit UV light into the flow of air along the flow path (step 510), according to some embodiments. In some embodiments, step 510 is optional. Step 510 can be performed by controller 18 and UV light sources 34 as described in greater detail above with reference to FIGS. 1-4. For example, controller 18 may operate UV light sources 34 to emit UV light into the flow path so that any contaminants, bacteria, viruses, germs, etc., that are present in the moisturized air are killed or otherwise deactivated (e.g., by disrupting their DNA). Step 510 can be performed if the NPWT system includes UV light sources positioned along the flow path.

[0053] Process 500 includes ceasing operation of the fan (step 512), according to some embodiments. In some embodiments, operation of the fan is ceased by controller 18. Controller 18 may cease providing control signals to the fan or may provide control signals to the fan that cause the fan to cease operating to draw air through the canister and the therapy device. Controller 18 can cease operation of the fan in response to a user input that is received at a user interface or a human machine interface (e.g., by pressing a button on a user interface of the therapy device, operating a touchscreen of the therapy device, receiving a signal from a communicably coupled device such as a smartphone, etc.), in response to the fan operating for a predetermined time duration, or in response to determining or detecting that fluid is not present in the canister. Step 512 may be optional.

[0054] Process 500 includes continuing to operate the UV light sources to emit the UV light for a time period after the operation of the fan is ceased (step 514), according to some embodiments. In some embodiments, step 514 is performed by UV light sources 34 and controller 18. For example, controller 18 may continue providing control signals to UV light sources 34 so that the UV light sources 34 continue emitting UV light even after fan 20 has ceased operating to draw air along the flow path (e.g., flow path 40). UV light sources can continue emitting UV light onto impeller blades of the fan or onto interior surfaces of the passageways or the passage to sterilize the impeller blades of the fan and/or the interior surfaces of the passageways or the interior surfaces of the passage.

Therapy Device

[0055] Referring now to FIGS. 6-9, a negative pressure wound therapy (NPWT) system 600 is shown, according to an exemplary embodiment. NPWT system 600 is shown to include a therapy device 602 fluidly connected to a wound dressing 100 via tubing 608 and 610. Wound dressing 100 may be adhered or sealed to a patient’s skin 102 surrounding a wound 122. Several examples of wound dressings 100 which can be used in combination with NPWT system 600 are described in detail in U.S. Patent No. 7,651,484 granted January 26, 2010, U.S. Patent No. 8,394,081 granted March 12, 2013, and U.S. Patent Application No. 14/087,418 filed November 22, 2013. The entire disclosure of each of these patents and patent applications is incorporated by reference herein.

[0056] It should be understood that NPWT system 600 as described herein may be configured to perform any of the functionality of therapy system 10 as described in greater detail above with reference to FIGS. 1-5. For example, therapy device 602 can be the same as or similar to therapy device 12 as described in greater detail above with reference to FIGS. 1-4, or vice versa, and may include any of the components, features, configurations, members, etc., of therapy device 12 (e.g., fan 20, controller 18, UV light sources 34, passage 56, film 64, inlet 62, etc.). Uikewise, removed fluid canister 606 can be the same as or similar to canister 14 as described in greater detail above with reference to FIGS. 1-4, or vice versa, and may include any of the components, features, configurations, members, etc., of canister 14 (e.g., filters 36, air inlets 28, passageways 60, storage volume 50, opening 58, etc.).

[0057] Therapy device 602 can be configured to provide negative pressure wound therapy by reducing the pressure at wound 122. Therapy device 602 can draw a vacuum at wound 122 (relative to atmospheric pressure) by removing wound exudate, air, and other fluids from wound 122. Wound exudate may include fluid that filters from a patient’s circulatory system into lesions or areas of inflammation. For example, wound exudate may include water and dissolved solutes such as blood, plasma proteins, white blood cells, platelets, and red blood cells. Other fluids removed from wound 122 may include instillation fluid 605 previously delivered to wound 122. Instillation fluid 605 can include, for example, a cleansing fluid, a prescribed fluid, a medicated fluid, an antibiotic fluid, or any other type of fluid which can be delivered to wound 122 during wound treatment. Instillation fluid

605 may be held in an instillation fluid canister 604 and controllably dispensed to wound 122 via instillation fluid tubing 608. In some embodiments, instillation fluid canister 604 is detachable from therapy device 602 to allow canister 606 to be refdled and replaced as needed.

[0058] The fluids 607 removed from wound 122 pass through removed fluid tubing 610 and are collected in removed fluid canister 606. Removed fluid canister 606 may be a component of therapy device 602 configured to collect wound exudate and other fluids 607 removed from wound 122. In some embodiments, removed fluid canister 606 is detachable from therapy device 602 to allow canister 606 to be emptied and replaced as needed. A lower portion of canister 606 may be filled with wound exudate and other fluids 607 removed from wound 122, whereas an upper portion of canister

606 may be filled with air. Therapy device 602 can be configured to draw a vacuum within canister 606 by pumping air out of canister 606. The reduced pressure within canister 606 can be translated to wound dressing 100 and wound 122 via tubing 610 such that wound dressing 100 and wound 122 are maintained at the same pressure as canister 606.

[0059] Referring particularly to FIGS. 7-9, block diagrams illustrating therapy device 602 in greater detail are shown, according to an exemplary embodiment. Therapy device 602 is shown to include a pneumatic pump 620, an instillation pump 622, a valve 632, a filter 628, and a controller 618. Pneumatic pump 620 can be fluidly coupled to removed fluid canister 606 (e.g., via conduit 636) and can be configured to draw a vacuum within canister 606 by pumping air out of canister 606. In some embodiments, pneumatic pump 620 is configured to operate in both a forward direction and a reverse direction. For example, pneumatic pump 620 can operate in the forward direction to pump air out of canister 606 and decrease the pressure within canister 606. Pneumatic pump 620 can operate in the reverse direction to pump air into canister 606 and increase the pressure within canister 606. Pneumatic pump 620 can be controlled by controller 618, described in greater detail below.

[0060] Similarly, instillation pump 622 can be fluidly coupled to instillation fluid canister 604 via tubing 609 and fluidly coupled to wound dressing 100 via tubing 608. Instillation pump 622 can be operated to deliver instillation fluid 605 to wound dressing 100 and wound 122 by pumping instillation fluid 605 through tubing 609 and tubing 608. Instillation pump 622 can be controlled by controller 618, described in greater detail below.

[0061] Filter 628 can be positioned between removed fluid canister 606 and pneumatic pump 620 (e.g., along conduit 636) such that the air pumped out of canister 606 passes through fdter 628. Filter 628 can be configured to prevent liquid or solid particles from entering conduit 636 and reaching pneumatic pump 620. Filter 628 may include, for example, a bacterial filter that is hydrophobic and/or lipophilic such that aqueous and/or oily liquids will bead on the surface of filter 628.

Pneumatic pump 620 can be configured to provide sufficient airflow through filter 628 that the pressure drop across filter 628 is not substantial (e.g., such that the pressure drop will not substantially interfere with the application of negative pressure to wound 122 from therapy device 602).

[0062] In some embodiments, therapy device 602 operates a valve 632 to controllably vent the negative pressure circuit, as shown in FIG. 8A. Valve 632 can be fluidly connected with pneumatic pump 620 and filter 628 via conduit 636. In some embodiments, valve 632 is configured to control airflow between conduit 636 and the environment around therapy device 602. For example, valve 632 can be opened to allow airflow into conduit 636 via vent 634 and conduit 638, and closed to prevent airflow into conduit 636 via vent 634 and conduit 638. Valve 632 can be opened and closed by controller 618, described in greater detail below. When valve 632 is closed, pneumatic pump 620 can draw a vacuum within a negative pressure circuit by causing airflow through filter 628 in a first direction, as shown in FIG. 7. The negative pressure circuit may include any component of system 600 that can be maintained at a negative pressure when performing negative pressure wound therapy (e.g., conduit 636, removed fluid canister 606, tubing 610, wound dressing 100, and/or wound 122). For example, the negative pressure circuit may include conduit 636, removed fluid canister 606, tubing 610, wound dressing 100, and/or wound 122. When valve 632 is open, airflow from the environment around therapy device 602 may enter conduit 636 via vent 634 and conduit 638 and fill the vacuum within the negative pressure circuit. The airflow from conduit 636 into canister 606 and other volumes within the negative pressure circuit may pass through filter 628 in a second direction, opposite the first direction, as shown in FIG. 8A.

[0063] In some embodiments, therapy device 602 vents the negative pressure circuit via an orifice 158, as shown in FIG. 8B. Orifice 158 may be a small opening in conduit 636 or any other component of the negative pressure circuit (e.g., removed fluid canister 606, tubing 610, tubing 611, wound dressing 100, etc.) and may allow air to leak into the negative pressure circuit at a known rate. In some embodiments, therapy device 602 vents the negative pressure circuit via orifice 158 rather than operating valve 632. Valve 632 can be omitted from therapy device 602 for any embodiment in which orifice 158 is included. The rate at which air leaks into the negative pressure circuit via orifice 158 may be substantially constant or may vary as a function of the negative pressure, depending on the geometry of orifice 158.

[0064] In some embodiments, therapy device 602 includes a variety of sensors. For example, therapy device 602 is shown to include a pressure sensor 630 configured to measure the pressure within canister 606 and/or the pressure at wound dressing 100 or wound 122. In some embodiments, therapy device 602 includes a pressure sensor 613 configured to measure the pressure within tubing 611. Tubing 611 may be connected to wound dressing 100 and may be dedicated to measuring the pressure at wound dressing 100 or wound 122 without having a secondary function such as channeling installation fluid 605 or wound exudate. In various embodiments, tubing 608, 610, and 611 may be physically separate tubes or separate lumens within a single tube that connects therapy device 602 to wound dressing 100. Accordingly, tubing 610 may be described as a negative pressure lumen that functions apply negative pressure wound dressing 100 or wound 122, whereas tubing 611 may be described as a sensing lumen configured to sense the pressure at wound dressing 100 or wound 122. Pressure sensors 630 and 613 can be located within therapy device 602, positioned at any location along tubing 608, 610, and 611, or located at wound dressing 100 in various embodiments. Pressure measurements recorded by pressure sensors 630 and/or 613 can be communicated to controller 618. Controller 618 use the pressure measurements as inputs to various pressure testing operations and control operations performed by controller 618.

[0065] Controller 618 can be configured to operate pneumatic pump 620, instillation pump 622, valve 632, and/or other controllable components of therapy device 602. In some embodiments, controller 618 operates pneumatic pump 620, instillation pump 622, valve 632, and/or other controllable components of therapy device 602 to draw a negative pressure at wound 122 and/or to provide instillation fluid to wound 122.

[0066] In some embodiments, therapy device 602 includes a user interface 626. User interface 626 may include one or more buttons, dials, sliders, keys, or other input devices configured to receive input from a user. User interface 626 may also include one or more display devices (e.g., UEDs, UCD displays, etc.), speakers, tactile feedback devices, or other output devices configured to provide information to a user. In some embodiments, the pressure measurements recorded by pressure sensors 630 and/or 613 are presented to a user via user interface 626. User interface 626 can also display alerts generated by controller 618. For example, controller 618 can generate a “no canister” alert if canister 606 is not detected.

[0067] In some embodiments, therapy device 602 includes a data communications interface 624 (e.g., a USB port, a wireless transceiver, etc.) configured to receive and transmit data.

Communications interface 624 may include wired or wireless communications interfaces (e.g., jacks, antennas, transmitters, receivers, transceivers, wire terminals, etc.) for conducting data communications external systems or devices. In various embodiments, the communications may be direct (e.g., local wired or wireless communications) or via a communications network (e.g., a WAN, the Internet, a cellular network, etc.). For example, communications interface 624 can include a USB port or an Ethernet card and port for sending and receiving data via an Ethernet-based communications link or network. In another example, communications interface 624 can include a Wi-Fi transceiver for communicating via a wireless communications network or cellular or mobile phone communications transceivers.

Configuration of Exemplary Embodiments

[0068] As utilized herein, the terms “approximately,” “about,” “substantially,” and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims. [0069] It should be noted that the term “exemplary” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, and/or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

[0070] The term “coupled,” as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using a separate intervening member and any additional intermediate members coupled with one another, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. Such members may be coupled mechanically, electrically, and/or fluidly.

[0071] References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below,” etc.) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.

[0072] The hydrophobicity of a material may vary, but to be considered hydrophobic, generally the material can have an average contact angle with water of at least 90 degrees in some embodiments.

To be considered hydrophilic, generally the material can have a contact angle of most 90 degrees in some embodiments. In some embodiments the contact angle with water can be no more than 150 degrees. For example, in some embodiments, the contact angle of the hydrophobic material may be in a range of at least 70 degrees to about 120 degrees with an average contact angle of at least 90 degrees, or in a range of at least 120 degrees to 150 degrees. Water contact angles can be measured using any standard apparatus. Although manual goniometers can be used to visually approximate contact angles, contact angle measuring instruments can often include an integrated system involving a level stage, liquid dropper such as a syringe, camera, and software designed to calculate contact angles more accurately and precisely, among other things. Non-limiting examples of such integrated systems may include the FTAl25, FTA200, FTA2000, and FTA4000 systems, all commercially available from First Ten Angstroms, Inc., of Portsmouth, Va., and the DTA25, DTA30, and DTA100 systems, all commercially available from Kruss GmbH of Hamburg, Germany. Unless otherwise specified, water contact angles herein are measured using deionized and distilled water on a level sample surface for a sessile drop added from a height of no more than 5 cm in air at 20-25° C and 20- 50% relative humidity. Contact angles reported herein represent averages of 5-9 measured values, discarding both the highest and lowest measured values. The hydrophobicity of a material herein may be further enhanced with a hydrophobic coating of other materials, such as silicones and fluorocarbons, and by any means known, such as by coating by the other material (e.g., coated using a liquid that may be subsequently dried on the material) or plasma coated.

[0073] A hydrophobic material can be any material having a solubility in water of less than 10 mg/L at standard temperature and pressure. A hydrophilic material can be any material having a solubility in water of 10 mg/L and greater at standard temperature and pressure.

[0074] It is important to note that the construction and arrangement of the wound dressing with optional status indicator as shown in the various exemplary embodiments is illustrative only.

Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure.

[0075] Additionally, any element disclosed in one embodiment may be incorporated or utilized with any other embodiment disclosed herein. For example, the configuration and construction of the flow path 40 of the exemplary embodiment described in at least paragraph [0023] may be incorporated in the NPWT system 600 of the exemplary embodiment described in at least paragraph [0055] Although only one example of an element from one embodiment that can be incorporated or utilized in another embodiment has been described above, it should be appreciated that other elements of the various embodiments may be incorporated or utilized with any of the other embodiments disclosed herein.

Claims

WHAT IS CLAIMED IS:

1. A negative pressure wound therapy (NPWT) system, the system comprising: a canister comprising one or more air inlets and one or more passageways extending through the canister; a therapy device comprising a negative pressure pump configured to draw a negative pressure at a wound and a fan configured to operate to draw a flow of air into the one or more air inlets of the canister, through the one or more passageways extending through the canister, and vented out from a passageway of the therapy device to facilitate active evaporation at the canister.

2. The NPWT system of Claim 1, wherein the fan is configured to draw air out of the therapy device through one or more exhaust ports.

3. The NPWT system of Claim 2, wherein the fan is configured to drive a flow of air along a flow path, the flow path defined by the one or more air inlets of the canister, the one or more passageways extending through the canister, and the one or more exhaust ports of the therapy device.

4. The NPWT system of Claim 3, wherein the canister is removably coupled to the therapy device and the flow path includes aligned openings in the canister and the therapy device, the aligned openings surrounded by a seal between the canister and the therapy device.

5. The NPWT system of Claim 2, further comprising one or more filters positioned between the fan and the one or more exhaust ports.

6. The NPWT system of Claim 5, wherein the one or more filters are bacterial filters.

7. The NPWT system of Claim 6, wherein the one or more bacterial filters comprise a flow facing surface comprising silver coated foam.

8. The NPWT system of Claim 5, wherein the one or more filters comprise a foam material.

9. The NPWT system of Claim 4, further comprising one or more ultraviolet (UV) light sources, wherein the one or more UV light sources are configured to emit UV light into the flow of air to sterilize the air.

10. The NPWT system of Claim 9, wherein the one or more UV light sources emit light at a frequency of 225 to 280 nanometers to kill or inactivate microorganisms in the air.

11. The NPWT system of Claim 9, wherein the one or more UV light sources are configured to emit the UV light along a portion of or an entirety of the flow path.

12. The NPWT system of Claim 9, wherein the one or more UV light sources are configured to emit the UV light onto the fan to sterilize the fan.

13. The NPWT system of Claim 12, wherein the one or more UV light sources are configured to emit the UV light even after the fan is inoperational or is not operating to draw the flow of air.

14. The NPWT system of Claim 1, further comprising a controller configured to operate the fan to facilitate the active evaporation at the canister.