VACUUM ASSISTED WOUND DRESSING

• US 20110172615A2
• Filed: 11/20/2008
• Published: 07/14/2011
• Est. Priority Date: 11/21/2007
• Status: Active Grant

• Current Assignee: Smith & Nephew PLC
• Original Assignee: Smith & Nephew PLC
• Inventors: Greener, Bryan
• Granted Patent: US 8,715,256 B2
• Time in Patent Office: Days
• US Class Current: 604/319
• CPC Class Codes: A61F 13/0206 with absorbent fibrous layers, e.g. woven or non-woven absorbent pads or island dressings
• CPC Class Codes: A61F 13/0209 comprising superabsorbent material
• CPC Class Codes: A61F 13/0226 characterised by the support layer
• CPC Class Codes: A61F 13/05 specially adapted for use with sub-pressure or over-pressure therapy, wound drainage or wound irrigation, e.g. for use with negative-pressure wound therapy [NPWT]
• CPC Class Codes: A61F 2013/00536 for draining or irrigating wounds
• CPC Class Codes: A61F 2013/0094 for sensing physical parameters
• CPC Class Codes: A61M 1/78 Means for preventing overflow or contamination of the pumping systems combined with drainage containers A61M1/60
• CPC Class Codes: A61M 1/915 Constructional details of the pressure distribution manifold
• CPC Class Codes: A61M 1/964 having venting means on or near the dressing
• CPC Class Codes: A61M 1/985 the dressing itself forming the collection container
• CPC Class Codes: A61M 39/24 Check- or non-return valves

Abstract

Apparatus for the application of topical negative pressure therapy to a wound site is described, the apparatus comprising: a wound contacting element for retaining wound exudate fluid therein; a wound covering element that provides a substantially airtight seal over the wound contacting element and wound site; a vacuum connection tube connecting a wound cavity to a vacuum source; and a vacuum source connected to a distal end of the vacuum connection tube.

Claims

1. Apparatus for the application of topical negative pressure therapy to a wound site, the apparatus comprising:

a wound contacting element for retaining wound exudate fluid therein;

a wound covering element that provides a substantially airtight seal over the wound contacting element and wound site;

a vacuum connection tube connecting a wound cavity to a vacuum source;

a valve interposed between the wound contacting element and the vacuum connection tube, wherein the valve blocks liquid transport beyond itself;

and a vacuum source connected to a distal end of the vacuum connection tube.

2. Apparatus according to claim 1 wherein the valve blocks liquid transport beyond itself under pressures between atmospheric pressure and 200 mmHg below atmospheric pressure.

3. Apparatus according to claim 2 where the valve blocks liquid transport beyond itself between atmospheric and 250 mmHg below atmospheric pressure.

4. Apparatus according to claim 1 wherein the valve comprises a liquid contact triggered valve to block liquid transport out of the wound cavity.

5. Apparatus according to claim 1 wherein liquid transport is blocked by the wound contacting element being able to absorb but not transmit liquid under the applied negative pressure.

6. An apparatus according to claim 5 wherein the wound contacting element is a self-coalescent material.

7. An apparatus according to claim 6 where the self-coalescent material is selected from the group comprising:

carboxymethylchitosan; and

a derivative of carboxymethylchitosan.

8. An apparatus according to claim 4 wherein the liquid contact-triggered valve is constructed of an absorbent material placed in a restricted aperture.

9. An apparatus according to claim 8 wherein the absorbent material is able to absorb but not transmit fluid under the applied negative pressure.

10. An apparatus according to claim 1 wherein the coupling of the vacuum connection tube to the wound cavity is achieved via an aperture in the wound covering element.

11. An apparatus according to claim 10 wherein the aperture in the wound covering element has a pressure-sensitive valve.

12. An apparatus according to claim 11 wherein the pressure sensitive valve opens when a surface-to-surface pressure differential of 5 to 200 mmHg exists.

13. An apparatus according to claim 1 wherein coupling of the vacuum connection tube to the wound covering element is by non-adhesive means.

14. An apparatus according to claim 13 wherein coupling is achieved by a surface-to-surface pressure differential.

15. An apparatus according to claim 1 wherein the wound contacting element and the wound covering element are combined in a single physical entity.

16. An apparatus according to claim 1 wherein the wound contacting element, the wound covering element and the vacuum connection tube are combined into a single physical entity.

25. Apparatus according to claim 1 wherein the vacuum connection tube may be repeatedly connected and disconnected from the wound covering element without damage thereto.

17. (canceled)

18. (canceled)

19. (canceled)

20. (canceled)

21. (canceled)

22. (canceled)

23. (canceled)

24. (canceled)

26. Apparatus for the application of topical negative pressure therapy to a wound site, the apparatus comprising:

a wound covering element configured to be positioned over a wound;

a cup-shaped member configured to be secured over an aperture in the wound covering element;

a vacuum source connected to the wound covering element through at least a vacuum connection tube connected to the cup-shaped member; and

a wound dressing portion configured to retain wound exudate under the wound covering element and block the flow of exudate away from itself, the wound dressing portion comprising an absorbent material configured to be placed over the wound and under the wound covering element, the absorbent material configured to retain wound exudate therein upon application of negative pressure.

27. The apparatus of claim 26, wherein the wound dressing portion comprises a valve that closes upon contact with wound exudate.

28. The apparatus of claim 26, wherein the wound dressing portion is a wound contacting element.

29. The apparatus of claim 26, wherein the wound dressing portion and the wound covering element form a single element.

30. The apparatus of claim 26, wherein the absorbent material comprises a superabsorbent material.

31. The apparatus of claim 30, wherein the superabsorbent material is capable of absorbing at least five times its own weight in fluid.

32. The apparatus of claim 26, wherein the absorbent material comprises a non-woven material.

33. The apparatus of claim 26, wherein the absorbent material comprises an open-celled foam.

34. The apparatus of claim 26, wherein the absorbent material comprises a knit or woven material.

35. The apparatus of claim 26, wherein the wound covering element additionally comprises an adhesive for adhering to a portion of skin surrounding the wound.

36. The apparatus of claim 26, wherein the wound covering element is fluid impermeable and gas permeable.

37. The apparatus of claim 26, wherein the wound covering element is gas permeable.

38. The apparatus of claim 26, wherein the vacuum source is powered by a battery.

39. The apparatus of claim 38, wherein the vacuum source and battery together weigh less than 200 g.

40. A method for the application of topical negative pressure therapy to a wound site, the method comprising:

placing a wound dressing portion comprising an absorbent material over the wound site;

sealing the wound site with a wound covering element having a cup-shaped member secured over an aperture in the wound covering element and being capable of providing a substantially airtight seal over the wound site;

applying topical negative pressure to the wound site through a conduit connected to the wound covering element via the cup-shaped member;

retaining fluid from the wound site in the absorbent material; and

preventing fluid from the wound site from entering the cup-shaped member.

41. The method of claim 40, wherein the absorbent material is a superabsorber.

42. The method of claim 41, wherein the superabsorber absorbs at least five times its own weight in fluid.

43. The method of claim 40, wherein preventing fluid from entering the cup-shaped member comprises operating a valve that occludes upon contact with fluid from the wound site.

44. The method of claim 40, wherein the wound dressing portion and the wound covering element are placed over the wound site as a single element.

45. The method of claim 40, wherein the wound dressing portion is placed into contact with the wound.

46. The method of claim 40, wherein topical negative pressure is applied with a powered vacuum source.