WO2012151359A1

WO2012151359A1 - Negative pressure wound therapy apparatus including one way valve and methods

Info

Publication number: WO2012151359A1
Application number: PCT/US2012/036250
Authority: WO
Inventors: Greg MARN; Pradeep Iyer; Ben Vanmarcke
Original assignee: Avery Dennison Corporation
Priority date: 2011-05-03
Filing date: 2012-05-03
Publication date: 2012-11-08

Abstract

Negative pressure wound therapy apparatus include a flexible membrane with an evacuation port and a one way valve provided by at least one valve membrane mounted to the flexible membrane. The one way valve is configured to permit a fluid within the sealed area to be evacuated out the evacuation port and inhibit a fluid from entering the sealed area. In further examples, methods of treating a wound of a skin layer include the steps of mounting a flexible membrane over the wound and applying negative pressure to a one way valve provided by at least one valve membrane mounted to the flexible membrane.

Description

NEGATIVE PRESSURE WOUND THERAPY APPARATUS INCLUDING ONE WAY VALVE AND METHODS

Cross-Reference to Related Application

[0001] The present application claims the benefit of U.S. Provisional Patent Application No. 61/481, 952 filed May 3, 2011, which is incorporated herein by reference in its entirety.

Field

[0002] The present invention relates to negative pressure wound therapy apparatus, system and methods. More specifically, the present invention relates to a negative pressure wound therapy apparatus including a one way valve provided by at least one valve membrane mounted to a flexible membrane. In further examples, the present invention also more specifically relates to methods of treating a wound of a skin layer with a flexible membrane and a one way valve provided by at least one valve membrane mounted to the flexible membrane.

Background

[0003] Conventional negative pressure wound therapy devices are typically used to facilitate healing of a wound on a layer of skin. Known devices can include relatively complicated installation procedures and/or cumbersome tube configurations used to place the wound in a negative pressure environment.

Brief Summary

[0004] The embodiments of the present invention described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present invention.

[0005] In accordance with one aspect of the disclosure, a negative pressure wound therapy apparatus includes a flexible membrane with an evacuation port extending between a first surface and a second surface of the flexible membrane. The flexible membrane is configured to be mounted over a wound of a skin layer. The negative pressure wound therapy apparatus further includes an adhesive layer on the first surface, wherein the adhesive layer is configured to mount the flexible membrane to the skin layer about the wound to seal the wound within a sealed area. A one way valve is provided by at least one valve membrane mounted to the flexible membrane. The one way valve is configured to permit a fluid within the sealed area to be evacuated out the evacuation port and inhibit a fluid from entering the sealed area.

[0006] In accordance with another aspect of the disclosure, a system for inducing and maintaining a wound of a skin layer in a negative pressure environment comprises a flexible membrane. The flexible membrane includes an evacuation port extending between a first surface and a second surface of the flexible membrane. The flexible membrane is configured to be mounted over a wound of a skin layer. An adhesive layer is provided on the first surface, wherein the adhesive layer is configured to mount the flexible membrane to the skin layer about the wound to seal the wound within a sealed area. A one way valve is also provided by at least one valve membrane mounted to the flexible membrane. The one way valve is configured to permit a fluid within the sealed area to be evacuated out the evacuation port and inhibit a fluid from entering the sealed area. A vacuum device is configured to evacuate a fluid out the evacuation port, wherein the vacuum device is configured to generate a predetermined negative pressure within the sealed area.

[0007] In accordance with still another aspect, a method of treating a wound of a skin layer comprising step of providing a flexible membrane including an evacuation port extending between a first surface and a second surface of the flexible membrane. An adhesive layer is provided on the first surface of the flexible membrane, and a one way valve is provided by at least one valve membrane mounted to the flexible membrane. The method further includes the step of mounting the flexible membrane over the wound by engaging the adhesive layer with the skin layer such that the wound is contained within a sealed area. The method still further includes the step of applying negative pressure to the one way valve such that fluid within the sealed area is evacuated out of the evacuation port. The method also includes the step of maintaining a negative pressure within the sealed area by preventing fluid from entering the sealed area with the one way valve.

[0008] Other features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It is to be understood, however, that the detailed description of the various embodiments and specific examples, while indicating preferred and other embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.

Brief Description of the Drawings

[0009] These, as well as other objects and advantages of this invention, will be more completely understood and appreciated by referring to the following more detailed description of the presently preferred exemplary embodiments of the invention in conjunction with the accompanying drawings, of which:

[0010] FIG. 1 illustrates a negative pressure wound therapy apparatus in accordance with aspects of the disclosure;

[0011] FIG. 2 illustrates a cross sectional view of the negative pressure wound therapy apparatus along line 2-2 of FIG. 1 with the valve flap of the one way valve in a closed position; [0012] FIG. 3 illustrates a cross sectional view similar to FIG. 2 with the valve flap of the one way valve in an open position;

[0013] FIG. 4 illustrates a one way valve in accordance with another example of the disclosure;

[0014] FIG. 5 illustrates a cross sectional view of the negative pressure wound therapy apparatus along line 5-5 of FIG. 4 with the valve flap of the one way valve in a closed position;

[0015] FIG. 6 illustrates a cross sectional view similar to FIG. 5 with the valve flap of the one way valve in an open position;

[0016] FIG. 7 illustrates a one way valve in accordance with yet another example of the disclosure;

[0017] FIG. 8 illustrates a one way valve in accordance with still another example of the disclosure;

[0018] FIG. 9 illustrates a one way valve including a vent layer;

[0019] FIG. 10 illustrates a cross sectional view of a negative pressure wound therapy apparatus with another example one way valve with the valve flap in a closed position;

[0020] FIG. 11 illustrates a cross sectional view similar to FIG. 10 with the valve flap in an open position;

[0021] FIG. 12 illustrates a cross sectional view of a negative pressure wound therapy apparatus with yet another example one way valve with the valve flap in a closed position;

[0022] FIG. 13 illustrates a cross sectional view similar to FIG. 12 with the valve flap in an open position;

[0023] FIG. 14 illustrates a cross sectional view of a negative pressure wound therapy apparatus with another example one way valve with a shell portion in an open position; [0024] FIG. 15 illustrates a cross sectional view similar to FIG. 14 with the shell portion in a closed position;

[0025] FIG. 16 illustrates a cross sectional view of a negative pressure wound therapy apparatus with still another example one way valve with a shell portion in an open position;

[0026] FIG. 17 illustrates a cross sectional view similar to FIG. 16 with the shell portion in a closed position;

[0027] FIG. 18 illustrates a cross sectional view similar to FIG. 16 with the shell portion in a closed position with the gasket exposed;

[0028] FIG. 19 illustrates an exploded view of a negative pressure wound therapy apparatus relative to a wound of a skin layer;

[0029] FIG. 20 illustrates a view similar to FIG. 19 with the flexible membrane attached to the skin layer;

[0030] FIG. 21 illustrates a view similar to FIG. 20 with a negative pressure being applied to the one way valve to evacuate fluid from a sealed area containing the wound of the skin layer;

[0031] FIG. 22 illustrates a cross sectional view of a cup along line 22-22 of FIG. 21;

[0032] FIG. 23 illustrates a method of using a vacuum device in accordance with aspects of the disclosure;

[0033] FIG. 23A illustrates an enlarged schematic view of a one way valve from FIG. 23 located within a connecting tu be of the vacuum device;

[0034] FIG. 24 illustrates another vacuum device in accordance with aspects of the disclosure;

[0035] FIG. 25 illustrates a cup of a vacuum device applying negative pressure to a one way valve;

[0036] FIG. 26 illustrates the cup of FIG. 25 wherein a plunger seals the evacuation port; [0037] FIG. 27 illustrates another negative pressure wound therapy apparatus with fluid being evacuated from the evacuation port of the apparatus; and

[0038] FIG. 28 illustrates the apparatus of FIG. 27 with fluid being introduced into the entrance port of the apparatus.

Detailed Description

[0039] The present invention is now illustrated in greater detail by way of the following detailed description which represents the best presently known mode of carrying out the invention. However, it should be understood that this description is not to be used to limit the present invention, but rather, is provided for the purpose of illustrating the general features of the invention.

[0040] Aspects of the disclosure disclose negative pressure wound therapy apparatus that can facilitate healing of wounds, such as incisions, damage tissue recesses, burns or other skin conditions. Placing the wound under negative pressure within a sealed area can help fight infection, stimulate cellular regeneration, remove contaminants (e.g., liquids, debris, microorganisms) and/or provide other benefits within or around the wound site.

[0041] FIGS. 1-3 illustrate one example of a negative pressure wound therapy apparatus 100 including a flexible membrane 110 with an evacuation port 112 extending between a first surface 114 and a second surface 116 of the flexible membrane 110. The flexible membrane 110 can be precut to a size appropriate for the area of a wound of a skin layer.

[0042] As shown, the evacuation port 112 can be a hole with a relatively small size compared to the overall footprint of the flexible membrane 110. As shown, the hole can be circular although other shapes may be provided in further examples. Moreover, the evacuation port 112 can alternatively be provided as a perforated area, a slit area, a scored area or other structural configuration to allow fluid evacuation from the first surface 114 to the second surface 116 at the location of the evacuation port.

[0043] As shown in FIG. 2, an adhesive layer 120 can also be provided on the first surface 114. As described more fully with respect to FIG. 20 below, the adhesive layer 120 is configured to mount the flexible membrane 110 to a skin layer 1000 about a wound 1002 to seal the wound 1002 within a sealed area 1050.

[0044] The negative pressure wound therapy apparatus 100 can further include a one way valve provided by at least one valve membrane mounted to the flexible membrane 110, wherein the one way valve is configured to permit a fluid within the sealed area 1050 to be evacuated out the evacuation port 112 and inhibit a fluid from entering the sealed area 1050. Various one way valves comprising at least one valve membrane may be used in accordance with aspects of the disclosure. For example, one way valves disclosed in U.S. Patent No. 7,685,793 that issued on May 30, 2010 to Newrones et al. and/or U.S. Patent No. 7,837,387 that issued on November 23, 2010 to Newrones et al. may be used in accordance with aspects of the disclosure although other one way valve configurations with at least one valve membrane may be incorporated with further aspects of the present disclosure. The disclosures of the above-referenced U.S. Patent Nos. 7,685,793 and 7,837,387 are both herein incorporated by reference in its entirety.

[0045] The at least one valve membrane can have a relatively large width (e.g., diameter in the illustrated example) with respect to the height. Therefore, the aspect ratio (width/height) of the at least one valve member can be relatively high when compared to tubing constructions associated with conventional negative pressure therapy devices. For instance, referring to FIG. 2, the at least one membrane can have a width "W" of a bout 0.5 cm (i.e., 50,000 microns) and a height "H" of about 75 microns. As such, the aspect ratio "A" of the illustrated membrane can be about 667 (i.e., 50,000/75). It will be appreciated that other aspect ratios may be provided depending on the particular application. For instance, relatively high aspect ratios "A" can be greater than 1, such as greater than 50, greater than 100, greater 200, greater than 500, greater than 5000 or other aspect ratios to provide various low profile design constructions depending on the particular application. In such an example, the width "W" can be designed to sufficiently cover the evacuation port 112 of the flexible membrane 110. At the same time, the height "H" can be relatively small to provide a low profile construction that may provide the second surface 116 with a substantially flat overall topography. The relatively high aspect ratio with low profile construction can avoid snagging of devices for coupling with an evacuation pump. As such, the patient can avoid damaging the negative pressure wound therapy apparatus by contacting obstacles during normal movement and/or snagging the apparatus against clothing. Moreover, the relatively high aspect ratio with low profile construction can enhance comfort and encourage desirable physical activity that may otherwise be avoided with more cumbersome and uncomfortable apparatus designs.

[0046] The one way valve in accordance with certain examples can include a flap configured to selectively engage a seating area. For example, FIGS. 1-3 illustrate one example one way valve 130 with a valve flap 132 configured to selectively engage a seating area 134. As shown, the at least one valve membrane includes a seat membrane 140 forming a seat platform on which the seating area 134 is located. The seat membrane 140 also includes an evacuation port 142. The seat membrane 140 can be mounted to the second surface 116 of the flexible membrane 110 with the evacuation port 142 of the seat membrane 140 in fluid communication with the evacuation port 112 of the flexible membrane 110. As shown in FIGS. 1-3, the at least one valve membrane of the one way valve 130 can optionally further include a flap membrane 150 mounted to the seat membrane 140. As shown in FIG. 1, the flap membrane 150 can include a cut 152 to define the valve flap 132. The cut 152 comprises an angular cut although rounded cuts or other cut configurations may be provided in further examples.

[0047] As shown in FIGS. 2 and 3, the valve flap 132 includes a movable portion 132a and a hinge portion 132b a bout which the movable portion 132a pivots. Specifically, the movable portion 132a is movable between a closed position (see FIG. 2), wherein the valve flap 132 is seated on the seating area 134 to close the evacuation port 112, and an open position (see FIG. 3), wherein the valve flap 132 is removed from the seating area 134 to open the evacuation port 112.

[0048] The one way valve 130 can be provided as a label structure with a label-to-membrane adhesive 144, a seating adhesive 146, and a film-to-film adhesive 148. When the label structure is incorporated into the flexible membrane 110, the label-to-membrane adhesive 144 secures the label structure to the second surface 116 of the flexible membrane 110, and the seating adhesive 146 holds the movable portion 132a of the valve flap 132 in the closed position. Example seating adhesives 146 can comprise a resealable pressure-sensitive adhesive.

[0049] In the illustrated embodiment, the label-to-membrane adhesive 144 is patterned on the interior surface of the seat membrane 140 in an annular shape aligned to surround the seating area 134. The seating adhesive 146 covers the entire exterior surface seat membrane 140. The film-to-film adhesive 148 is patterned on the seating adhesive 146 in an annular shape aligned to surround the seating area 134.

[0050] Any of the label structures set forth in this disclosure can be efficiently and economically mass-produced by a label-manufacturer at a first location and then supplied to the flexible membrane manufacturer at a second location for convenient incorporation into the flexible membrane 110. For example, the label-manufacturer can provide a web comprising a carrier release liner having a plurality of the label structures temporarily attached thereto. As such, it is possible to mass produce the label structures as a coil of labels with each label including the at least one valve member. The coil of labels can then be loaded into a machine or manual application is possible. The machine can remove the label structure from the carrier release liner and then attach the label structure to the flexible membrane 110 to produce a one way valve associated with the evacuation port. Thus, existing flexible membranes may be retrofitted or otherwise modified to include the at least one valve membrane for the low profile one way valve in accordance with aspects of the present invention.

[0051] As discussed, the flexible membrane 110 can have a single valve flap 132 for its seating area 134 and this valve flap 132 can have a single hinge portion 132b connecting its movable portion 132a to the flexible membrane 110. FIGS. 4-6 illustrate another example one way valve 230 with a flap membrane 250 including a valve flap 232 including two hinge portions 232b on opposite sides of the movable portion 232a.

[0052] FIG. 7 illustrates still another example of a one way valve 330 with a flap membrane 350 including a plurality of radially arranged valve flaps 332 that each includes a movable portion 332a and two hinge portions 332b similar to the movable portion 232a and hinge portions 232b of the valve flap 232 shown in FIGS. 4-6. The valve flaps 232, 332 shown in FIGS. 4-7 allow the movable portion 232a, 332a to lift away from the rest of the seat membrane 240 (e.g., "pucker up") to allow fluid to exit as shown in FIG. 6.

[0053] FIG. 8 illustrates yet another one way valve 430 with a flap membrane 450 including a plurality of radially arranged valve flaps 432 similar in design to the valve flaps 132 illustrated in FIGS. 1- 3. In any event, any combination of movable portion(s) and hinge portion(s) which allow the flap(s) to move between the closed position and the opened position is possible with, and contemplated by, the present disclosure.

[0054] In certain situations, it may be desirable for the evacuation port 112 to prevent liquids or solids (e.g., powders) from exiting the sealed area 1050 by way of the evacuation port 112. In such examples, as shown in FIG. 9, it may be desirable to include a vent layer 160 which is pervious with respect to the expected gasses while, at the same time, it is substantially impervious to the expected liquids or solids (e.g., powders). The vent layer 160 can be positioned in various locations. In one example, as shown in FIG. 9, the vent layer 160 may be positioned between the flexible membrane 110 and the seat membrane 140.

[0055] As described above, the seat membrane 140 may be mounted to the second surface 116 of the flexible membrane 110. In further examples, the seat membrane may be mounted to the first surface 114 of the flexible membrane 110. For example, as shown in FIGS. 10-11, the negative pressure wound therapy apparatus 100 may include a one way valve 530 wherein a seat membrane 540 is mounted to the first surface 114 of the flexible membrane 110, and the flexible membrane 110 includes the valve flap 132. The seat membrane 540 provides a seating platform including a seating area 534 adjacent to an evacuation port 542 of the seat membrane 540. As shown, a cut 111 may be formed in the flexible membrane 110 such that a portion of the flexible membrane 110 forms the valve flap 132 including the movable portion 132a and the hinge portion 132b about which the movable portion 132a pivots. As such, it will be appreciated that the at least one valve membrane comprises only the seat membrane 540 that cooperates with a valve flap 132 formed by the flexible membrane 110 to provide the one way valve. In such an example, in the closed orientation shown in FIG. 10, the seating adhesive layer can hold the valve flap 132 in the closed orientation such that the second surface 116 of the flexible membrane 110 forms a substantially continuous flat surface, thereby providing a particularly desirable seamless one way valve with an enhanced unobstructed low profile design.

[0056] As mentioned in the previous examples, the at least one valve membrane can comprise a seat membrane alone or in combination with a flap membrane. In further examples, the at least one valve membrane can comprise a flap membrane without a seat membrane. For example, as shown in FIGS. 12 and 13, a one way valve 630 can be provided with a flap membrane 650 mounted to the flexible membrane 110, wherein the flap membrane 650 includes the valve flap 132 and the flexible membrane 110 includes a seating area 634. As shown, the seating area 634 is defined by a portion of the flexible membrane 110. [0057] FIGS. 14 and 15 illustrate another example one way valve 730 wherein the at least one valve membrane comprises a casing 170 including a shell portion 180 that is deformable from an open position (shown in FIG. 14) and a closed position (shown in FIG. 15). The shell portion 180 includes gas- releasing holes 182 and a port-sealing adhesive 184. Another adhesive layer 186 can be provided to seal the periphery 188 of the shell portion 180 to the flexible membrane 110 to circumscribe the evacuation port 112. As shown in FIG. 14, in the open position, the casing 170 forms a chamber 190 over the evacuation port 112. During evacuation of the sealed area 1050, gas will pass through the evacuation port 112, through the chamber 190 and out the gas-releasing holes 182. As shown in FIG. 15, in the closed position, the shell portion 180 is deformed (e.g., crushed, flattened) to place the one way valve 730 in the closed position. In the closed position, the port-sealing adhesive 184 adheres the shell portion 180 to the second surface 116 of the flexible membrane 110 to seal the evacuation port 112.

[0058] Referring now to FIGS. 16-18, another one way valve 830 wherein the at least one valve membrane comprises another casing 870 with a shell portion 880 that is deformable from an open position (shown in FIG. 16) and a closed position (shown in FIGS. 17 and 18). Unlike the casing 170 of the one way valve 730 shown in FIGS. 14 and 15, the casing 870 of FIGS. 16-18 is not required to independently maintain the shell portion 880 in the open position. Specifically, the one way valve 830 can include a gasket 890 or other supporting structure that is positioned between the flexible membrane 110 and the casing 870 to hold the shell portion 880 away from the evacuation port 112. The gasket 890 is gas-permeable so that gas can pass therethrough during evacuation and is shaped to at least partially surround the evacuation port 112. For instance, in the illustrated embodiment, the gasket 890 comprises a screen-like material.

[0059] During evacuation, gas passes from the sealed area 1050, through the gasket 890, and through gas-releasing openings 882. To seal the evacuation port 112, the shell portion 880 is pushed into the center of the gasket 890 as shown in FIGS. 17 and 18. If the casing material is flexible enough, the casing 870 can remain intact when the shell portion 880 is pushed to the closed position and the gasket 890 will remain therein after sealing as shown in FIG. 17. Alternatively, the casing 870 can break, tear, or fracture and allow the gasket 890 to be removed once exposed as shown in FIG. 18. Once in the closed position a port-sealing adhesive 884 adheres the shell portion 880 to the second surface 116 of the flexible membrane 110 to seal the evacuation port 112.

[0060] Each of negative pressure wound therapy apparatus can include a release liner attached to the adhesive layer. For example, as shown in FIG. 2, the negative pressure wound therapy apparatus 100 includes a release liner 122 attached to the adhesive layer 120. The release liner 122 is configured to protect the adhesive layer 120 from contamination during storage and/or transport before application of the flexible membrane 110 to the skin layer 1000. The release liner 122 is configured to be peeled off to expose the adhesive layer 120 when preparing to mount the flexible membrane 110 to the skin layer 1000 about the wound 1002. A pull tab or other configuration may be provided to facilitate pealing of the release liner 122 from the adhesive layer 120. For example, the release liner may include one or more pull tabs extending beyond the flexible membrane 110 to allow easy gripping and pealing of the release liner 122 beginning from an edge of the flexible membrane 110.

[0061] As shown in FIGS. 19-21, the negative pressure wound therapy apparatus 100 can also include a packing material 1004 (e.g., foam or gauze) positioned over the evacuation port 112 and engaging the adhesive layer 120. The packing material 1004 can be prepped with a saline solution and may further be provided with an antimicrobial property - e.g., by the material type used or subsequent treatment of the packing material 1004 with an antimicrobial agent. The antimicrobials may be incorporated into the packing material 1004 or other components of the negative pressure wound therapy apparatus 100. Such antimicrobials can reduce bacterial contamination of the apparatus. Example antimicrobials can comprise chorhexidine that may be incorporated into attachment adhesives. In further examples, coatings including antimicrobials may be applied to wetted surfaces of the negative pressure wound therapy apparatus 100. In still further examples, outer surfaces and/or the one-way valve of the negative pressure wound therapy apparatus 100 may be provided with an antimicrobial coating to aid in hygiene.

[0062] As shown in FIGS. 21-26 the negative pressure wound therapy apparatus 100 can also include a vacuum device configured to evacuate a fluid out the evacuation port. Various known vacuum devices may be retrofitted to provide the desired negative pressure to the one way vacuum valve of the present invention. FIGS. 21-23 schematically illustrates just one example vacuum device 1010 that can include a vacuum chamber 1020 with a circumferential seal 1030 configured to selectively engage the flexible membrane 110 to circumscribe and seal the one way valve 130 within the vacuum chamber 1020. In some examples, the circumferential seal 1030 can comprise an adhesive layer, a flexible member (e.g., compressible tube), foam or other material capable of forming to the surface topography of the flexible membrane 110 while providing a fluid tight seal circumscribing the one way valve 130. If provided with an adhesive, the circumferential seal 1030 may be provided with a release liner to preserve the seal until use. The vacuum chamber 1020, in such examples, may be provided by a disposable cup 1032 wherein a connecting tu be 1034 may be attached to a port 1036 of the disposable cup 1032.

[0063] As shown in FIG. 23, the connecting tube 1034 may be attached to a fluid container 1060 configured to trap any liquid or debris 1061 drawn from the sealed area 1050 through the one way valve 130. If provided, the fluid container 1060 may optionally include a pressure release valve 1062 that may be activated (e.g., pressed downward) to release equalize the pressure within the fluid container 1060. Another connecting tube 1070 may also be provided and attached, for example, by way of a coupling 1072 to a pressure regulating device 1080. The connecting tu be 1070 may be provided with a one way valve 1064 (shown schematically in FIG. 23A) and a filter 1066. The one way valve 1064 can be provided such that the pressure regulating device 1080 can be decoupled from the connecting tube 1070 (e.g., by way of the coupling 1072) without loss of pressure within the system.

[0064] The pressure regulating device 1080 of the vacuum device 1010 can include a pump 1082 actuated by a controller 1084. A pressure sensor 1086 can provide pressure information to the controller 1084 to allow proper actuation of the pump 1082 to achieve the desired negative pressure within the system and, consequently, within the sealed area 1050. The pressure sensor 1086 can also send information to a display area 1088 to visually represent the pressure within the system to a user of the vacuum device 1010. Although not shown, a user interface may be provided to allow the user to preselect desired negative pressure levels within the system, equalize pressure within the system, or carry out other functional tasks.

[0065] FIG. 24 illustrates another example vacuum device 2010 that may have similar or identical features as the vacuum device 1010 illustrated in FIG. 23. However, the vacuum device 2010 of FIG. 24 is designed to be a portable system designed to directly engage the flexible membrane 110 by way of a circumferential seal 2012. As shown, in one example, the portable system can comprise a portable hand-held vacuum device. A user may simply grasp the handle 2014 and enter desired pressure characteristics with the user interface 2016 that may also display pressure-related information to the user. Once the desired pressure characteristics are entered in with the user interface 2016 and the circumferential seal 2012 is engaged with the flexible membrane 110, a start button 2018 may be activated to cause suction 2020 to create a negative pressure within the pressure chamber (not shown) to achieve the desired predetermined negative pressure within the sealed area 1050. Once the desired predetermined pressure is achieved, the vacuum device 2010 can be removed and the one way valve 130 can prevent exiting of fluid from the sealed area 1050 and thereby maintain the desired negative pressure within the sealed area. Subsequent applications of the vacuum device 2010 may be periodically conducted to help maintain the desired negative pressure level. [0066] The flexible membrane 110 can comprise various materials depending on the particular application. In one example, the flexible membrane 110 comprises a thin polymeric film (e.g., polyurethane) that can acts as a cover film. In further examples, the flexible membrane 110 can comprise a material that is permeable to water vapor and gases. As such, negative pressure within the sealed area 1050 may diminish over time. At such time, the vacuum device may easily be applied to again evacuate fluid, liquid or other matter from the sealed area 1050 to again provide the sealed area 1050 with the desired negative pressure condition.

[0067] In the above examples, the seat membrane, the flap membrane, and the shell portion can be made from polymer film materials such as polystyrenes, polyolefins, polyamides, polyesters, polycarbonates, polyvinyl alcohol, poly(ethylene vinyl alcohol), polyurethanes, polyacrylates including copolymers of olefins such as ethylene and propylene with acrylic acids and esters, copolymers of olefins and vinyl acetate, ionomers and mixtures thereof.

[0068] The adhesive layer 120 on the first surface 114 of the flexible membrane 110 can comprise a wide range of materials. For example, the adhesive layer 120 can comprise a hydrocolloid such as the hydrocolloid material disclosed in any one of U.S. Patent No 7,335,416 that issued on February 6, 2008, U.S. Patent No 6,710,100 that issued on March 23, 2004, U.S. Patent No 6,583,220 that issued on June 24, 2003, U.S. Patent No 6,326,421 that issued on December 4, 2001, U.S. Patent Application No. 12/866,750 filed August 9, 2010, and U.S. Provisional Patent 61/467,553 filed March 25, 2011, which are herein incorporated by reference in their entireties.

[0069] The label-to-membrane adhesive can be any suitable adhesive, such as a pressure- sensitive adhesive (e.g., acrylic-based, rubber-based, or silicone-based) and, more particularly, a hot melt pressure-sensitive adhesive.

[0070] The seating adhesive can be resealable adhesive to allow repeated sealing procedures. Alternatively the seating adhesive can be a permanent pressure-sensitive adhesive, and/or an energy-activated permanent adhesive to permanently seal the evacuation port once the sealed area is placed under a predetermined negative pressure. A suitable resealable adhesive would have some tack but could be opened/closed repeatedly, preferably without leaving residue. For example, candidates for the resealable adhesive would include acrylic, silicone and/or rubber-based pressure- sensitive adhesives. Suitable permanent adhesives could also comprise acrylic, silicone and/or rubber- based pressure-sensitive adhesives, the difference being that the bond strength would be much higher than with a resealable adhesive. Suitable energy-activated permanent adhesives could include, for example, heat-activated adhesives, such as those with an adhesive-forming resin (e.g., urethane resin, polyether resin, acrylic resin, oxyalkylene resin, and/or vinyl resin).

[0071] The film-to-film adhesive can be any suitable adhesive, such as a pressure-sensitive adhesive (e.g., acrylic-based, rubber-based, or silicone-based) or a curable-adhesive, such as a UV- curable adhesive. It may be noted that if a UV-curable adhesive is used, adjacent membranes (e.g., the flap membrane) may need to be transparent.

[0072] The release and/or carrier liners can be a sheet of paper or polymeric film having a release coating, such as a silicone release coating.

[0073] The vent layer 160 can be made from nylon, polyolefins (e.g., polyethylene, polypropylene, ethylene butylene copolymers), polyurethanes, polyurethane foams, polystyrenes, plasticized polyvinylchlorides, polyesters, polyamides, cotton, or rayon. The vent material can be woven, non-woven, knitted and/or an aperatured (or perforated) film. The material used to fabricate the vent layer should have a porosity or perviousness to accomplish the desired evacuation, for example, at least about 5 cfm (cubic feet per minute), at least about 10 cfm, at least about 15 cfm, at least about 20 cfm and/or at least about 25 cfm with respect to air so that an acceptable level of gas flow can be obtained. [0074] A method of treating the wound 1002 of the skin layer 1000 will now be described. As shown in FIG. 19, the flexible membrane 110 may be provided with the previously described evacuation port 112 extending between the first surface 114 and a second surface 116 of the flexible membrane 110. The release liner 122 may be removed to expose the adhesive layer 120 on the first surface 114 of the flexible membrane 110.

[0075] As shown in FIG. 19, an optional packing material 1004 and/or nonadherent web or other layer 1006 may be provided. A prep wipe 1008 may be used to prep the area around the wound 1002 before or after cleaning the wound 1002 and/or irrigating the wound 1002, e.g., with a sterile saline. As shown in FIG. 20, the nonadherent web may then be used to line the wound 1002 and then the packing material 1004 may be used to fill the wound area.

[0076] As further illustrated in FIG. 20, the flexible membrane 110 can then be mounted over the wound 1002 by engaging the adhesive layer 120 with the skin layer 1000 such that the wound 1002 is contained within a sealed area 1050. Once sealed, negative pressure may be applied to the one way valve 130 such that fluid within the sealed area 1050 is evacuated out of the evacuation port 112.

[0077] Applying the negative pressure to the one way valves illustrated in FIGS. 1-13 can be achieved, for example, with the vacuum devices 1010, 2010 shown in FIGS. 23 and 24. For instance, with reference to FIG. 21, the cup 1032 of the vacuum device 1010 may be positioned relative to the flexible membrane 110 attached to the skin layer 1000. The cup 1032 can be positioned such that the circumferential seal 1030 circumscribes the one way valve 130 while sealing against the flexible membrane 110. Next, a user enters the desired negative pressure and activates the vacuum device 1010. Under instruction from the controller 1084, the pump 1082 is activated to evacuate fluid from the sealed area 1050. Once the desired predetermined negative pressure is sensed within the vacuum chamber 1020 and/or sealed area 1050 by the pressure sensor 1086, the controller 1084 deactivates the pump 1082. The one way valve 1064 and the one way valve 130 can then maintain the negative pressure within the sealed area 1050. As the cup 1032 remains sealed to the flexible membrane 110, debris and liquid may still be evacuated from the wound 1002 area to be stored by the fluid container 1060. Evacuating liquid and/or debris can allow fluid drainage from the wound site that may help fight infection by removing debris and/or microorganisms entrained in the liquid. Removing liquid can further help draw blood flow and consequently oxygen into the wound site to help facilitate healing of the wound.

[0078] If more comfort or mobility is desired, a user may activate the pressure release valve 1062 to equalize the pressure within the fluid container 1060. The cup 1032 may then be removed from the flexible membrane 110. Even after removing the cup 1032, negative pressure may be maintained within the sealed area 1050 by preventing fluid from entering the sealed area 1050 with the one way valve 130. Still further, although not shown, further examples may allow the user to equalize the pressure within the sealed area 1050. For example, although not shown, the valve flap may include a finger tab configured to be grasped by the user to peal the flap to the open position, thereby allowing ambient air to enter the wound site. Alternatively, the tab may not be provided to avoid tempering with the apparatus.

[0079] As mentioned previously, the circumferential seal 1030 can be sealed against the flexible membrane 110. Alternatively, the circumferential seal 1030 may be designed to engage the one way valve. For instance, referring to the broken lines shown in FIG. 3, the circumferential seal 1030 of the vacuum device 1010 can engage the flexible membrane 110 or may engage an outer portion of the flap membrane 150. However, with a flap membrane 150 with a relatively small width "W" (e.g., of 0.5cm) may employ constructions wherein the circumferential seal 1030 has a much larger diameter than the width "W" of the at least one valve membrane. As such, exact coaxial alignment between the cup 1032 and the one way valve is not necessary as long as the one way valve is positioned within the footprint defined by the circumferential seal 1030. [0080] Applying the negative pressure to the one way valves 730, 830 illustrated in FIGS. 14-18 can be achieved, for example, with the modified cup 3032 arrangement shown in FIGS. 25 and 26. Referring to FIG. 25, a negative pressure can be applied by a vacuum cham ber 3020 after a circumferential seal 3030 is sealed against the flexible mem brane 110. Once the fluid is evacuated from the sealed area, a plunger 3040 may be extended in a downward direction 3042 shown in FIG. 26. The plunger 3040 crushes or flattens the shell portion 180 such that the port-sealing adhesive 184 adheres to the second surface 116 of the flexible mem brane 110 to seal the evacuation port 112 (see also FIG. 15).

[0081] FIGS. 27-28 demonstrate another negative pressure wound therapy apparatus 4000 that can include a one way valve 4002 and another one way valve 4004 that operate in opposite directions. The valves 4002, 4004 can be identical to one another although they may comprise different configurations in further examples. Moreover, the one way valves 4002, 4004 can comprise a wide range of configurations, such as any of the membrane valve configurations discussed a bove or other valve configurations. As shown, the one way valve 4002 can be associated with an evacuation port 4006 within the flexible mem brane 4008 that may be similar and operate in a similar manner with the flexible mem brane 110 discussed in previous examples. In addition, as shown, the flexible mem brane 4008 can include an entrance port 4010 to allow fluid to enter the sealed area 1050 and inhibit fluid from exiting the sealed area 1050.

[0082] As shown in FIGS. 27 and 28, one way valve 4002 can be provided together with the another one way valve 4004 with similar features to any of the systems discussed a bove. As shown, the system can include the previously discussed vacuum device 1010. In one example, the vacuum device 1010 can include the d isposa ble cup 1032 that may function with components and in a manner discussed a bove. In addition, as shown in FIG. 28, the system can also include a pressure device 4012 that may include a pressure cup 4014 configured to engage the flexible mem brane 4008 to provide a seal around the entrance port 4010. The pressure device 4012 can be configured to introduce fluid 4016 into the sealed area 1050. In one example, the fluid 4016 may comprise an irrigation fluid (such as a saline solution), antibiotic formula or other fluid designed to promote healing of the wound.

[0083] In operation, the method can include mounting the flexible membrane 4008 over the wound as discussed above and applying a negative pressure to the one way valve 4002 (e.g., with the disposable cup 1032) such that fluid within the sealed area is evacuated out of the evacuation port 4006 as shown in FIG. 27. While negative pressure may act on the flap 4018 of the one way valve 4004, the adhesive portion 4020 may be designed to maintain the flap 4018 in the closed position under the desired negative pressure atmosphere and only temporarily release if the negative pressure passes a predetermined threshold. As such, in one example, the another one way valve 4004 can act as a pressure regulator to allow a desired negative pressure to be maintained while providing a relief valve to limit the extent of the negative vacuum within the sealed area 1050. For instance, flap 4018 can be attached with an adhesive portion 4020 only designed to release the flap 4018 when a sufficiently high predetermined negative pressure threshold is passed, after which the adhesive portion 4020 allows release of the flap 4018 to temporarily pivot in direction 4022 to allow a limited amount of ambient air 4024 to enter the sealed area 1050 until the negative pressure is raised to the point were the flap 4018 pivots back and is again adhered with the adhesive portion 4020 to the flexible membrane 4008.

[0084] Once the desired negative pressure is achieved within the sealed area 1050, the disposable cup 1032 can then be removed wherein the negative pressure is maintained within the sealed area 1050 by preventing fluid from entering the sealed area by way of the one way valve 4002. As shown in FIG. 28 the method can also include engaging a pressure cup 4014 of a pressure device 4012 with the membrane. The pressure device 4012 can then apply positive pressure such that fluid 4016 (e.g., irrigation solution) is introduced within the sealed area 1050. While positive pressure may act on the flap 4005 of the one way valve 4002, the adhesive portion 4003 may be designed to maintain the flap 4005 in the closed position under the desired positive pressure atmosphere and only temporarily release if the positive pressure passes a predetermined threshold. In some examples, the overpressure may be desired to help irrigate the wound, wherein debris and contaminated fluid may be flushed out through the one way valve 4002. After sufficient irrigation and/or sufficient fluid is introduced, the pressure cup 4014 may then be removed wherein the negative pressure can thereafter be maintained by the one way valves 4002, 4004 and or reesta blished by way of the vacuum device 1010 as discussed above.

[0085] As such, the one way valves 4002, 4004 discussed above can act in both directions, i.e., not just to hold vacuum when needed but also allow for infusing irrigating or other fluids periodically as needed. Such infusion or vacuum can be achieved in a variety of ways, such as by way of a vacuum or push device, that may be portable in some examples.

[0086] In still further examples, in addition or alternatively to the valve arrangements discussed above, further examples may include a three-way valve to assist in venting, vacuuming and or irrigation or introducing fluids to the sealed area.

[0087] Any of the vacuum devices or pressure devices (e.g., push device) may comprise an electric pump although manual actuated devices may be provided in further examples. For instance, the pressure or vacuum devices may comprise a syringe-like device to generate a vacuum or provide pressure to introduce fluid to the sealed area. In further examples, the pressure or vacuum device may comprise a hand-cranked or foot-cranked vacuum or pressure device. In still further examples, a manual pump may comprise a bellows-type pump. Providing manual vacuum or pressure devices can allow simple application of the negative pressure wound therapy system in remote locations and/or in instances where electricity is lost or not available - such as environmental disasters. Moreover, manual vacuum or pressure devices may provide a low cost system. A low cost system may, for example, allow a patient to purchase the device for self application. [0088] As discussed above, many types of adhesives may be used for various features of the negative pressure wound therapy apparatus. For example, biocompatible pressure sensitive adhesives or other adhesive types may be used in accordance with aspects of the disclosure. For instance, biocompatible adhesives may be used in all aspects of the device in some examples. In other examples, biocompatible adhesives may be used in areas that have the potential to contact tissues or fluids.

[0089] Various valve configurations may include stand-offs (not shown) below the valve to allow clearance for the valve to function under certain set up configurations. For instance, the flap 4018 in FIG. 28 may include a stand-off to allow the flap to open in the manner shown in FIG. 28 without interference with the wound or skin layer. In further examples the packing material 1004 may be sufficient to permit functionality of the valve although other arrangements may be provided in further examples.

[0090] In further examples, any of the above-referenced negative pressure wound therapy apparatus may include a barrier layer or microporous films incorporated into the valve membrane and/or the one-way valve. For example, a barrier layer may be provided to reduce permea bility of the negative pressure wound therapy apparatus to air, thereby allowing the negative pressure vacuum to be maintained within the sealed area 1050 for longer periods of time. In further examples, the valve membrane and/or the one-way valve may comprise a microporous film configured to allow predetermined vacuum release over time. The barrier layer and/or microporous films, if provided, can allow customization of the valve design depending on the desired application.

[0091] Various features of the negative pressure wound therapy apparatus discussed above may be designed for sterilization. As such, the apparatus may be resistant to high temperature and/or humidity conditions if steam is used for sterilization. In further examples, the negative pressure wound therapy apparatus can be EtO sterilized or sterilized with other procedures. [0092] One way membrane valves in accordance with aspects of the present invention can be incorporated with the flexible membrane at the time of manufacture (e.g., built into the dressing). In further examples, the evacuation port may be created and the membrane valve may be installed by a health care professional when applying the apparatus to the wound of a patient.

[0093] The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of their invention as it pertains to any apparatus, system, method or article not materially departing from but outside the literal scope of the invention as set out in the following claims.

Claims

CLAIMS What is claimed is:

1. A negative pressure wound therapy apparatus comprising:

a flexible membrane including an evacuation port extending between a first surface and a second surface of the flexible membrane, wherein the flexible membrane is configured to be mounted over a wound of a skin layer;

an adhesive layer on the first surface, wherein the adhesive layer is configured to mount the flexible membrane to the skin layer about the wound to seal the wound within a sealed area; and

a one way valve provided by at least one valve membrane mounted to the flexible membrane, wherein the one way valve is configured to permit a fluid within the sealed area to be evacuated out the evacuation port and inhibit a fluid from entering the sealed area.

2. The negative pressure wound therapy apparatus of claim 1, wherein the one way valve comprises a valve flap configured to selectively engage a seating area.

3. The negative pressure wound therapy apparatus according to any one of claims 1 and 2, wherein the at least one valve membrane includes a seat membrane including the seating area and an evacuation port, wherein the seating membrane is mounted to the flexible membrane with the evacuation port of the seat membrane in fluid communication with the evacuation port of the flexible membrane.

4. The negative pressure wound therapy apparatus according to claim 3, wherein the at least one valve membrane further includes a flap membrane mounted to the seat membrane, wherein the flap membrane includes the valve flap.

5. The negative pressure wound therapy apparatus according to any one of claims 3 and 4, wherein the seat membrane is mounted to the second surface of the flexible membrane.

6. The negative pressure wound therapy apparatus of claim 3, wherein the seat membrane is mounted to the first surface of the flexible membrane, and the flexible membrane includes the valve flap.

7. The negative pressure wound therapy apparatus of claim 2, wherein the at least one valve membrane includes a flap membrane mounted to the flexible membrane, wherein the flap membrane includes the valve flap and the flexible membrane includes the seating area.

8. The negative pressure wound therapy apparatus of claim 1, wherein the one way valve comprises a casing including a shell portion that is deformable from an open condition and a closed condition.

9. The negative pressure wound therapy apparatus according to any one of claims 1-8, further comprising a vent layer configured to evacuate gas out the evacuation port while inhibiting evacuation of at least one of a liquid or a solid out of the evacuation port.

10. The negative pressure wound therapy apparatus according to any one of claims 1-9, further comprising a release liner attached to the adhesive layer.

11. The negative pressure wound therapy apparatus according to any one of claims 1-10, further comprising a packing material positioned over the evacuation port and engaging the adhesive layer.

12. The negative pressure wound therapy apparatus according to any one of claims 1-11, further comprising a vacuum device configured to evacuate a fluid out the evacuation port.

13. The negative pressure wound therapy apparatus of claim 12, wherein the vacuum device includes a vacuum chamber with a circumferential seal configured to selectively engage the flexible membrane to circumscribe and seal the one way valve within the vacuum chamber.

14. The negative pressure wound therapy apparatus according to any one of claims 1-7 and 9-13, wherein the at least one valve membrane has an aspect ratio of greater than 1.

15. The negative pressure wound therapy apparatus according to any one of claims 1-14, wherein the adhesive layer on the first surface of the flexible membrane comprises a hydrocolloid.

16. The negative pressure wound therapy apparatus according to any one of claims 1-15, further comprising another one way valve mounted to the flexible membrane, wherein the another one way valve is configured to permit a fluid to enter the sealed area and inhibit a fluid exiting the sealed area.

17. A system for inducing and maintaining a wound of a skin layer in a negative pressure environment comprising:

an adhesive layer on the first surface, wherein the adhesive layer is configured to mount the flexible membrane to the skin layer about the wound to seal the wound within a sealed area;

a one way valve provided by at least one valve membrane mounted to the flexible membrane, wherein the one way valve is configured to permit a fluid within the sealed area to be evacuated out the evacuation port and inhibit a fluid from entering the sealed area; and

a vacuum device configured to evacuate a fluid out the evacuation port, wherein the vacuum device is configured to generate a predetermined negative pressure within the sealed area.

18. The system of claim 17, wherein the vacuum device includes a vacuum chamber with a circumferential seal configured to selectively engage the flexible membrane to circumscribe and seal the one way valve within the vacuum chamber.

19. The system according to any one of claims 17 and 18, wherein the vacuum device comprises a portable hand-held vacuum device.

20. The system according to any one of claims 17-19, wherein the vacuum device includes a cup defining a vacuum chamber, wherein the cup includes a circumferential seal configured to selectively engage the flexible membrane to circumscribe and seal the one way valve within the vacuum chamber.

21. The system according to any one of claims 17-20, wherein the vacuum device includes a pressure regulating device configured to regulate pressure within the vacuum chamber of the cup.

22. The system of claim 21, wherein the vacuum device includes a fluid conduit providing fluid communication between the pressure regulating device and the vacuum chamber of the cup.

23. The system according to any one of claims 17-22, wherein the adhesive layer on the first surface of the flexible membrane comprises a hydrocolloid.

24. The system according to any one of claims 17-23, further comprising:

another one way valve mounted to the flexible membrane, wherein the another one way valve is configured to permit a fluid to enter the sealed area and inhibit a fluid exiting the sealed area; and a pressure device configured to introduce fluid into sealed area with the another one way valve.

25. A method of treating a wound of a skin layer comprising the steps of:

providing a flexible membrane including an evacuation port extending between a first surface and a second surface of the flexible membrane, an adhesive layer on the first surface of the flexible membrane, and a one way valve provided by at least one valve membrane mounted to the flexible membrane;

mounting the flexible membrane over the wound by engaging the adhesive layer with the skin layer such that the wound is contained within a sealed area;

applying negative pressure to the one way valve such that fluid within the sealed area is evacuated out of the evacuation port; and maintaining a negative pressure within the sealed area by preventing fluid from entering the sealed area with the one way valve.

26. The method of claim 25, wherein a vacuum device is used to apply the negative pressure.

27. The method of claim 26, wherein the vacuum device generates a predetermined negative pressure within the sealed area.

28. The method according to any one of claims 26 and 27, further comprising the steps of engaging a circumferential seal of the vacuum device with the flexible membrane to circumscribe the one way seal such that one way valve is sealed within a vacuum chamber.

29. The method of claim 28, further comprising the step of using the vacuum device to achieve a predetermined negative pressure within the vacuum chamber.

30. The method of claim 29, further comprising the step of disengaging the vacuum device from the flexible membrane after achieving the predetermined negative pressure within the vacuum chamber.

31. The method according to any one of claims 25-30 further comprising the steps of:

providing another one way valve mounted to the flexible membrane; and

applying positive pressure to the another one way valve such that fluid enters the sealed area.