Wound dressing

• US 9,220,822 B2
• Filed: 05/13/2014
• Issued: 12/29/2015
• Est. Priority Date: 11/21/2007
• Status: Active Grant

• Current Assignee: Smith & Nephew PLC
• Original Assignee: Smith & Nephew PLC
• Inventors: Hartwell, Edward Yerbury
• Primary Examiner(s): Wiest, Philip R
• Assistant Examiner(s): KLEIN, BENJAMIN JACOB
• Application Number:
  US14/276,983
• Publication Number:
  US 20140249493A1
• Time in Patent Office: 595 Days
• US Class Current: 1/1
• CPC Class Codes: A61F 13/00063 comprising medicaments or additives, e.g. odor control, PH control, debriding, antimicrobic drug delivery dressings A61K9/70; chemical aspect of the additives A61L15/00
• CPC Class Codes: A61F 13/01029 made of multiple layers
• CPC Class Codes: A61F 13/01046 Air-vapor permeability
• CPC Class Codes: A61F 13/02 Adhesive bandages or dressings
• 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 13/022 having more than one layer with different fluid retention characteristics
• CPC Class Codes: A61F 13/0226 characterised by the support layer
• CPC Class Codes: A61F 13/0246 characterised by the skin-adhering 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 2013/00246 in a special way pervious to air or vapours
• CPC Class Codes: A61F 2013/00536 for draining or irrigating wounds
• CPC Class Codes: A61M 1/71 Suction drainage systems containers therefor A61M1/60, A61M1/64; negative pressure wound therapy systems A61M1/90
• 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 1/784 by filtering, sterilising or disinfecting the exhaust air, e.g. swellable filter valves
• CPC Class Codes: A61M 1/882 Draining devices provided with means for releasing antimicrobial or gelation agents in the drained fluid
• CPC Class Codes: A61M 1/915 Constructional details of the pressure distribution manifold
• CPC Class Codes: A61M 1/962 having pumping means on the suction site, e.g. miniature pump on dressing or dressing capable of exerting suction
• 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 2205/7527 : liquophilic, hydrophilic
• CPC Class Codes: A61M 2205/7536 : allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes
• CPC Class Codes: A61M 27/00 : Drainage appliance for wounds or the like , i.e. wound drains, implanted drains negative pressure wound therapy devices A61M1/90; implements for holding wound open A61B17/02 ; middle ear drainage A61F11/202

Abstract

A method and apparatus are disclosed for dressing a wound. The apparatus comprises a sealing layer comprising at least one orifice, an absorbent layer over the sealing layer, absorbing wound exude and a liquid impermeable, gas permeable filter layer over the absorbent layer.

Claims

1. A negative pressure apparatus to generate negative pressure at a wound site, comprising:

a wound dressing comprising an adhesive to adhere the wound dressing to skin around a wound site, the wound dressing having a border region;

a lower chamber surrounded by the border region and having a wound contact layer;

an upper chamber separated from the lower chamber by a sealing layer formed of gas impermeable material, the upper chamber comprising at least one hole into the chamber and a gas permeable and liquid impermeable filter positioned to prevent the passage of fluids from the upper chamber through the at least one hole so that fluids drawn from the lower chamber are stored in the upper chamber; and

a pump inlet in flow communication with the lower chamber, the pump inlet being operably connected with a negative pressure pump to apply negative pressure to the lower chamber to suck fluids therefrom and deliver the sucked fluids into the upper chamber, wherein the pump is integral within the wound dressing.

2. The apparatus of claim 1, wherein the sealing layer comprises a single orifice.

3. The apparatus of claim 1, wherein the sealing layer comprises a plurality of through holes.

4. The apparatus of claim 1, wherein the upper chamber comprises a cover layer comprising the at least one hole.

5. The apparatus of claim 1, wherein the at least one hole is configured to vent air from the upper chamber.

6. The apparatus of claim 1, wherein the lower chamber further comprises a porous layer configured to allow transmission of fluid away from the wound site and distribute negative pressure over at least a portion of the wound contact layer.

7. The apparatus of claim 1, wherein the upper chamber comprises an absorbent material configured to form a reservoir for fluid removed from the wound site.

8. The apparatus of claim 7, wherein the upper chamber comprises a cover layer configured to cover the absorbent material, wherein the cover layer comprises an edge region extending around a perimeter of the cover layer that surrounds the absorbent material.

9. The apparatus of claim 1, wherein the sealing layer comprises an edge region extending around a perimeter of the sealing layer that surrounds the lower chamber, the sealing layer configured to form a substantially air-tight seal over the wound site.

10. A negative pressure apparatus to generate negative pressure at a wound site, comprising:

a wound dressing comprising an adhesive to adhere the wound dressing to skin around a wound site, the wound dressing comprising;

a lower chamber defined between a wound contact layer and a gas impermeable sealing layer;

an upper chamber separated from the lower chamber by the gas impermeable sealing layer, the upper chamber defined between the gas impermeable sealing layer and a cover layer;

one or more holes into the upper chamber to exhaust air from the upper chamber; and

a filter positioned to prevent the passage of liquid from the upper chamber;

a pump inlet in fluid communication with the lower chamber, the pump inlet being operable to apply negative pressure to the lower chamber so that fluids drawn through the pump inlet are delivered into the upper chamber for storage therein; and

a pump connected to the pump inlet to apply negative pressure to the lower chamber, the pump configured to extract fluids from the lower chamber and discharge the fluids into the upper chamber.

11. The apparatus of claim 10, wherein the wound dressing comprises a border region that surrounds the lower chamber.

12. The apparatus of claim 10, wherein the one or more holes are provided in the cover layer.

13. The apparatus of claim 10, wherein the sealing layer comprises one or more holes.

14. The apparatus of claim 10, wherein the pump is positioned within the wound dressing.

15. The apparatus of claim 14, wherein the pump is positioned within the upper chamber.

16. The apparatus of claim 10, further comprising an absorbent material within the upper chamber configured to collect and store wound exudate.

17. The apparatus of claim 10, wherein the filter is positioned at the one or more holes to permit passage of gas through the holes and prevent the passage of liquid from the upper chamber.

18. Apparatus for dressing a wound for topical negative pressure therapy, comprising:

a wound contact layer;

a porous layer arranged on the wound contact layer;

a gas impermeable sealing layer arranged on the porous layer and comprising at least one orifice;

an absorbent layer over the sealing layer for absorbing wound exudate;

a liquid impermeable, gas permeable filter layer over the absorbent layer, wherein the filter layer is between the absorbent layer and an overlying cover layer; and

a pump element, located between the cover layer and the sealing layer, comprising an inlet in fluid communication with the sealing layer orifice and an outlet in fluid communication with the absorbent layer.

19. The apparatus as claimed in claim 18, further comprising an adhesive layer on an upper and/or lower side of the wound contact layer.

20. The apparatus as claimed in claim 18, wherein the wound contact layer is sealed together with the sealing layer and cover layer in a border region.