AU2013200814B2

AU2013200814B2 - Negative pressure wound therapy device

Info

Publication number: AU2013200814B2
Application number: AU2013200814A
Authority: AU
Inventors: John Buan
Original assignee: Smith and Nephew Inc
Current assignee: Smith and Nephew Inc
Priority date: 2008-05-27
Filing date: 2013-02-14
Publication date: 2014-05-01
Anticipated expiration: 2029-05-27
Also published as: AU2013200814A1

Abstract

Abstract The present invention provides a wound therapy device (10) having a port or port hole (20), an absorptive material (22) and at least one viewing portal (56). In addition, a method determining a saturation level of a wound therapy device is also provided by the invention. Fig. 2 qT C~jN o cq C\,, N N% t (M0 (\j coj C, / - - - - -- - - - -

Description

- 1 NEGATIVE PRESSURE WOUND THERAPY DEVICE RELATED APPLICATIONS [0001] This application is a divisional application of Australian Patent Application No. 2009251810, whose specification as filed is hereby incorporated by reference in its entirety. The invention in the present application relates, generally, in subject matter to the devices disclosed in Applicant's own U.S. Patent Pre-Grant Publication Nos. 2007/0265585 and 2007/0265586. TECHNICAL FIELD [0002] The present invention relates, in general, to a device and method for wound therapy that is capable of treating a variety of chronic and acute wound types, including, but not limited to, infection wounds, venous ulcers, arterial ulcers, diabetic ulcers, burn wounds, post amputation wounds, surgical wounds, and the like. Specifically, the present disclosure is related to wound treatment devices and methods that utilize negative pressure therapy. BACKGROUND [0003] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. [0004] Negative pressure therapy has been one method used for the treatment of a variety of wounds by practitioners in the art. Conventional negative pressure therapy devices are generally large in size and often require the use of complicated equipment such as suction pumps, vacuum pumps and complex electronic controllers. [0005] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. [0006] Since the negative pressure therapy devices (e.g., dressings) utilize negative pressure, it is an object of the invention, in at least one preferred form, to minimize the -2 opportunity for leaks in same, so as to prevent increased damage to the patient and/or wound, or unnecessarily prolonged damage to the patient and/or wound. [0007] Additionally, since negative pressure therapy devices (e.g., dressings) are usually wrapped with, for example, gauze, ace bandages, compression stockings, etc., it is an object of the invention, in at least one preferred form, for the connection point between the pump and the negative pressure therapy device to be disposed distally from the negative pressure therapy device. This may increase the comfort of the patient, as well as allow for a limited amount of access to the negative pressure therapy device while it is wrapped. BRIEF SUMMARY OF THE INVENTION [0008] A first aspect of the invention provides a wound therapy device for treating a wound using negative pressure, comprising: a backing material having a shape with an edge, a first side and a second side, the backing material configured to maintain negative pressure under the first side of the backing material; a port hole disposed in the backing material; an adaptor disposed at least partially over the port hole configured to communicate negative pressure to the first side of the backing material from a source of negative pressure; an absorptive material disposed underneath the first side of the backing material; and at least one viewing portal disposed over the absorptive material allowing the absorptive material to be seen from the second side of the backing material. [0009] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to". [0010] Preferably, the device further comprises a fluid impermeable membrane disposed above the absorptive material configured to prevent exudate from flowing to a source of negative pressure. In one preferred form, the fluid impermeable membrane is disposed on the adaptor. In another preferred form, the device further comprises a fluid -3 impermeable membrane above the absorptive material configured to prevent exudate from flowing into the tube. [0011] Preferably, the device further comprises a negative pressure source configured to be connected to the adaptor. [0012] Preferably, the device further comprises a tube connected to the adaptor and configured to be in fluid communication with a source of negative pressure. [0013] Preferably, the at least one viewing portal is covered by a transparent material. [0014] Preferably, the at least one viewing portal is covered by a semi-transparent material. [0015] The device of any one of the preceding claims, wherein the at least one viewing portal is circular. [0016] Preferably, the device comprises at least three viewing portals. [0017] Preferably, the device comprises two or more viewing portals, wherein the viewing portals are arranged in a pattern. [0018] Preferably, the device comprises two or more viewing portals, wherein the viewing portals are arranged randomly. [0019] Preferably, the backing material is non-transparent. [0020] Preferably, the at least one viewing portal is disposed in the backing layer. [0021] Preferably, the viewing portal changes colour based on the level of saturation of the absorptive material. [0022] Preferably, the device further comprises a wound interface layer disposed underneath at least a portion of the first side of the backing material.

-4 [0023] Preferably, the first side of the backing material comprises an adhesive. More preferably, the device further comprises one or more liners removeably attached to the first side of the backing material. [0024] Preferably, the backing layer has a circular shape. Alternatively, the backing layer has a square shape. In another alternative form, the backing layer has an oblong shape. [0025] Preferably, the absorptive material comprises an absorptive pad. More preferably, the absorptive pad comprises a super-absorbent polymer. [0026] In accordance with an embodiment of the invention, a wound therapy device includes a backing material, a port hole disposed in the backing material, an absorptive pad disposed on the first side of the backing material such that a portion of the absorptive pad is disposed under the port hole, and, a gasket disposed on the backing material distally between the absorptive pad and the edge. [0027] The use and position of the gasket, along with other factors, are believed to decrease the chances for air pressure leaks. Thus, this will increase the effectiveness and usefulness of the negative pressure therapy device. [0028] In another embodiment of the invention, the gasket is a hydrogel material. [0029] In yet another embodiment of the invention, a wound therapy device also includes a wound interface layer, such as a silver plated mesh, disposed around an exposed portion of the absorptive pad. [0030] A second aspect of the invention provides a wound therapy device for treating a wound using negative pressure, comprising: a wound dressing configured to maintain negative pressure over a wound, the wound dressing comprising: a wound interface layer; an absorptive material above the wound interface layer; and a non-transparent material covering the absorptive material and having at least one viewing portal to allow viewing of the absorptive material through the at least one viewing portal; and -5 a port over the non-transparent material configured to communicate negative pressure to the wound dressing from a source of negative pressure. [0031] Preferably, the wound dressing further comprises a semi-transparent material over the at least one viewing portal. [0032] Preferably, the wound dressing further comprises a backing layer further comprising a semi-transparent material over the at least one viewing portal. [0033] Preferably, the port is provided over an opening in the non-transparent material. [0034] Preferably, the non-transparent material has at least three viewing portals. [0035] A third aspect of the invention provides a method of determining a saturation level of a wound therapy device, comprising: placing a wound dressing over a wound, the wound dressing comprising an absorptive pad; applying negative pressure to the wound dressing through a port positioned over the absorptive pad; absorbing wound exudate in the absorptive pad; and monitoring saturation of the absorptive pad through at least one viewing portal provided over the absorptive pad. [0036] Preferably, the method further comprises monitoring saturation of the absorptive pad through at least three viewing portals provided over the absorptive pad. [0037] Preferably, the at least one viewing portal is covered with a transparent or semi transparent material. [0038] Preferably, the wound dressing comprises a non-transparent material covering the absorptive pad, wherein the at least one viewing portal extends through the non transparent material. [0039] Preferably, the method further comprises preventing fluid from flowing from the dressing to a source of negative pressure with a fluid impermeable membrane.

-6 BRIEF DESCRIPTION OF THE DRAWINGS [0040] The present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that the accompanying drawings depict only typical embodiments, and are, therefore, not to be considered to be limiting of the scope of the present disclosure, the embodiments will be described and explained with specificity and detail in reference to the accompanying drawings as provided below. [0041] Figure 1 is a cutaway side view of an embodiment of a wound healing device according to the present invention. [0042] Figure 2 is a top view of an embodiment of a wound healing device according to the present invention. [0043] Figure 3 is an exploded view of an embodiment of a wound healing device according to the present invention. [0044] Figure 4 is a back view of an embodiment of a wound healing device according to the present invention. DETAILED DESCRIPTION OF THE DRAWINGS [0045] It will be readily understood that the components of the embodiments as generally described and illustrated in the Figures herein could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of various embodiments, as represented in the Figures, is not intended to limit the scope of the present disclosure, but is merely representative of various embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated. [0046] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing -7 description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. [0047] Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment. [0048] Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention. [0049] Reference throughout this specification to "one embodiment," "an embodiment," or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment," "in an embodiment," and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. [0050] In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations such as vacuum sources are not shown or described in detail to avoid obscuring aspects of the invention. [0051] Referring now to Figures 1-4, a wound therapy device 10 is shown. A wound therapy device 10 includes a backing material 12 having a shape with an edge 14 and a -8 first side 16 having an adhesive and a second side 18. The present invention contemplates multiple shapes including, but not limited to, circles, ovals, squares, and oblongs. The backing material 12 may be flexible to allow the device 10 to be contoured to the appropriate location of a wound. In addition, it is preferred that the backing material 12 be semi-permeable. What is meant by the term semi-permeable is that the backing material has breathability aspects that do not impact the ability to hold negative pressure relative to appropriate therapeutic treatment, as would be understood by those of ordinary skill in the art. [0052] It is contemplated that a liner 34 is removably attached to a portion of the first side 16 of the backing material 12. In a preferred embodiment, a second liner 50 and a third liner 52 each disposed on a portion of the edge 14. This is to facilitate quick deploy and use of the device 10. For example, the liner 34 can be removed. The clinician or patient placing the device 10 can utilize second liner 50 and third liner 52 while placing the device 10 without touching the adhesive on the first side 16. [0053] A port hole 20 is disposed in the backing material 18. The port hole 20 can have any shape and size. In an embodiment of the present invention, an adaptor 28 is disposed within the port hole 20. In a preferred embodiment of the invention, a fluid impermeable membrane 54 is disposed on the adaptor 28. The fluid impermeable membrane 54 prohibits fluids and other exudates from flowing from the device 10 to the source of the negative pressure. In a preferred embodiment, the fluid impermeable membrane 54 is GORE-TEX@; however, other materials are contemplated to be used. [0054] A tube segment 30 allows for communication between the adaptor 28 and a connector 32. The connector 32 is connected (either directly or indirectly) to the source of the negative pressure (not shown). The tube segment 30 is long enough that the connector 32 is distally spaced from the adaptor 28 and/or port hole 20. Non-kinking tube material may be used. It is contemplated that the adaptor 28, tube segment 30 and connector 32 is comprised of one structure or multiple structures connected. By moving the connector 32 away from the port hole 20, it is believed that the device will increase the comfort of the patient, since the connection between the device and pump does not have to be located under gauze or other wrapping material such as Unna Boot or COBAN@ which typically wraps around the device. Additionally, if the connection between the pump and device needs to be broken, the wrapping material does not need to be removed.

-9 [0055] Returning to Figures 1-4, an absorptive pad 22 is disposed adjacent the first side 16 of the backing material 12. The absorptive pad 22 is capable of absorbing exudates and liquid from a wound, while continuing to allow the device to communicate negative pressure to the wound. The absorptive pad 22 may be a material such as sponges, foams, fibers, wicking fibers, hollow fibers, beads, fabrics, or gauzes, super absorbent materials including super-absorbent polymers in various forms, absorbent foams, gelling agents such as sodium carboxy methyl cellulose, packing materials, and/or combinations thereof. Since the absorptive pad 22 allows the communication of the negative pressure from a pump to the wound, the absorptive pad 22 is disposed under the port hole 20. By used of the term "under," it is meant that when the device 10 is viewed from a top view (such as in Figure 2), a portion of the absorptive pad 22 is disposed beneath the port hole 20. In addition, it is contemplated that the absorptive pad 22 need not be directly beneath or under the port hole 20, i.e., other structures may be disposed between the two structures. [0056] In addition to the port hole 20, it is contemplated that the device 10 includes at least one viewing portal 56 in the backing material 12. Since the absorptive pad 22 retains the exudates and fluids removed from the wound, the viewing portal 56 allows a clinician or patient to determine if the absorptive pad 22 is saturated or not. It is preferred that the viewing portal 56 be disposed between the wound and the port hole 20. In addition, since certain backing materials are non-transparent it is contemplated that a semi-transparent material be disposed over the viewing portal 56 so as to prevent any exudates from leaking out. [0057] It is contemplated that the device 10 also includes wound interface layer 26, or other similar structure, disposed around a portion of the absorptive pad 22. The wound interface layer 26 will allow epithelialization and reduce wound tissue adherence to the device. In one embodiment, the wound interface layer 26 may comprise a silver plated mesh, such as one that is currently commonly available and known as SILVERION@. [0058] A gasket 24 is disposed on the backing material 12, and more particularly on the first side 16 of the backing material 12 with the adhesive. The gasket 24 is disposed distally between the edge 14 of the backing material 12 and the absorptive pad 22. It is contemplated that the gasket 24 be disposed immediately adjacent to the absorptive pad 22.

-10 [0059] The gasket 24 has a thickness, and it is contemplated that the thickness of the gasket 24 is between 3 to 5 mils and the width of the gasket 24 is approximately 3/8 of an inch. [0060] In one embodiment of the invention the gasket 24 is a hydrogel. Such materials are currently available from Katecho, in Des Moines, Iowa (USA). It is preferred that the gasket 24 be a material that be biocompatible with skin. In addition the gasket 24 material should mildly adhere to the skin, but not adhere to the skin in the same manner as the adhesive on the backing material. In addition, the gasket 24 material should be mildly flowable. Furthermore, the gasket 24 material should be non-reactive to normal medical device sterility processes. Another contemplated material is a silicone gel; however, it is currently believed to be too cost prohibitive to utilize the silicone gel. [0061] It is preferred that the gasket 24 and the absorptive pad 22 have the same (relatively) shape. It is most preferred that the shape is an oval. Moreover, it is important that the gasket 24 be sized such that the wound is entirely disposed within the gasket 24. [0062] Such a gasket 24 is believed to minimize the possibility of air pressure leaks, and thus increase the efficiency of the device. [0063] In addition to the devices described here, an embodiment of the invention is a method of making a wound therapy device. The method includes the steps of: * applying a port hole to adhesive substrate; * using the port hole as a registration point for applying a gasket material; * applying a predetermined thickness of the gasket material in a predetermined shape at a distance around the port hole; * applying a liner to the adhesive substrate; . rolling the adhesive substrate. [0064] The step of applying a port hole to an adhesive substrate may include punching, cutting, slicing, removing or any other action that results in a port hole being made in an adhesive substrate. The adhesive substrate may be the backing material described above. [0065] By using the port hole as a registration point, it is meant that the port hole location is used as the position to determine where the gasket material is to be applied.

- 11 Once it is determined where the gasket material is to be applied, the gasket material can be applied at a distance in a predetermined shape around the port hole. It is contemplated that the gasket material is applied by being poured. Additionally, the gasket can be applied in any number of predetermined shapes and thickness. [0066] A liner can be applied to the adhesive substrate and the combination of the adhesive substrate and liner can be rolled and subsequently stored. The resulting combination of adhesive substrate and liner material can then be cut into smaller individual wound therapy devices, and further steps such as providing an absorptive pad and/or providing an adaptor can be accomplished. [0067] It is also contemplated that the method includes the steps of providing the second liner and third liner each on a portion of an edge of the adhesive substrate, such as described above. [0068] Since after use the wound therapy devices usually contain bodily waste typically comprising exudates and liquid from a wound, they are disposable, and thus, decreasing the costs of manufacturing, would be beneficial and is believed to be desirable. Additionally increasing the manufacturability may also be desirable. [0069] Currently, the devices that are described herein are manufactured with a hybrid method, involving some steps that are performed by machine, and other steps that are performed by hand. Such a process may include taking stock material for the gasket and, after cutting the stock material, placing the gaskets by hand onto the backing material. However, it is contemplated that the entire method of manufacture be performed by machines, by hand or a hybrid thereof. [0070] Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the present disclosure to its fullest extent. The examples and embodiments disclosed herein are to be construed as merely illustrative and not a limitation of the scope of the present disclosure in any way. It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles of the disclosure provided herein. In other words, various modifications and improvements of the embodiments specifically disclosed in the description above are within the scope of the appended -12 claims. Note that elements recited in means-plus-function format are intended to be construed in accordance with 35 U.S.C. § 112 16. The scope of the invention is therefore defined by the following claims.

Claims

1. A wound therapy device for treating a wound using negative pressure, comprising: a backing material having a shape with an edge, a first side and a second side, the backing material configured to maintain negative pressure under the first side of the backing material; a port hole disposed in the backing material; an adaptor disposed at least partially over the port hole configured to communicate negative pressure to the first side of the backing material from a source of negative pressure; an absorptive material disposed underneath the first side of the backing material; and at least one viewing portal disposed over the absorptive material allowing the absorptive material to be seen from the second side of the backing material.

2. The device of claim 1, further comprising a fluid impermeable membrane disposed above the absorptive material configured to prevent exudate from flowing to a source of negative pressure.

3. The device of claim 2, wherein the fluid impermeable membrane is disposed on the adaptor.

4. The device of claim 2, further comprising a fluid impermeable membrane above the absorptive material configured to prevent exudate from flowing into the tube.

5. The device of any one of the preceding claims, further comprising a negative pressure source configured to be connected to the adaptor.

6. The device of any one of the preceding claims, further comprising a tube connected to the adaptor and configured to be in fluid communication with a source of negative pressure.

7. The device of any one of the preceding claims, wherein the at least one viewing portal is covered by a transparent material. - 14

8. The device of any one of the preceding claims, wherein the at least one viewing portal is covered by a semi-transparent material.

9. The device of any one of the preceding claims, wherein the at least one viewing portal is circular.

10. The device of any one of the preceding claims, wherein the device comprises at least three viewing portals.

11. The device of any one of claims 1 to 9, wherein the device comprises two or more viewing portals, wherein the viewing portals are arranged in a pattern.

12. The device of any one of claims 1 to 9, wherein the device comprises two or more viewing portals, wherein the viewing portals are arranged randomly.

13. The device of any one of the preceding claims, wherein the backing material is non-transparent.

14. The device of any one of the preceding claims, wherein the at least one viewing portal is disposed in the backing layer.

15. The device of any one of the preceding claims, wherein the viewing portal changes colour based on the level of saturation of the absorptive material.

16. The device of any one of the preceding claims, further comprising a wound interface layer disposed underneath at least a portion of the first side of the backing material.

17. The device of any one of the preceding claims, wherein the first side of the backing material comprises an adhesive.

18. The device of claim 17, further comprising one or more liners removeably attached to the first side of the backing material.

19. The device of any one of the preceding claims, wherein the backing layer has a circular shape. -15

20. The device of any one of claims 1 to 18, wherein the backing layer has a square shape.

21. The device of any one of claims 1 to 18, wherein the backing layer has an oblong shape.

22. The device of any one of the preceding claims, wherein the absorptive material comprises an absorptive pad.

23. The device of claim 22, wherein the absorptive pad comprises a super absorbent polymer.

24. A wound therapy device for treating a wound using negative pressure, comprising: a wound dressing configured to maintain negative pressure over a wound, the wound dressing comprising: a wound interface layer; an absorptive material above the wound interface layer; and a non-transparent material covering the absorptive material and having at least one viewing portal to allow viewing of the absorptive material through the at least one viewing portal; and a port over the non-transparent material configured to communicate negative pressure to the wound dressing from a source of negative pressure.

25. The device of claim 24, wherein the wound dressing further comprises a semi transparent material over the at least one viewing portal.

26. The device of claim 24 or 25, wherein the wound dressing further comprises a backing layer further comprising a semi-transparent material over the at least one viewing portal.

27. The device of any one of claims 24 to 26, wherein the port is provided over an opening in the non-transparent material.

28. The device of any one of claims 24 to 27, wherein the non-transparent material has at least three viewing portals. -16

29. A method of determining a saturation level of a wound therapy device, comprising: placing a wound dressing over a wound, the wound dressing comprising an absorptive pad; applying negative pressure to the wound dressing through a port positioned over the absorptive pad; absorbing wound exudate in the absorptive pad; and monitoring saturation of the absorptive pad through at least one viewing portal provided over the absorptive pad.

30. The method of claim 29, comprising monitoring saturation of the absorptive pad through at least three viewing portals provided over the absorptive pad.

31. The method of claim 29 or 30, wherein the at least one viewing portal is covered with a transparent or semi-transparent material.

32. The method of any one of claims 29 to 31, wherein the wound dressing comprises a non-transparent material covering the absorptive pad, wherein the at least one viewing portal extends through the non-transparent material.

33. The method of any one of claims 29 to 32, further comprising preventing fluid from flowing from the dressing to a source of negative pressure with a fluid impermeable membrane.

34. A wound therapy device or a method of making a wound therapy device, substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.