DEVICE FOR TREATMENT OF WOUNDS AND A METHOD FOR MANUFACTURING OF WOUND PADS

• US 20110028919A1
• Filed: 04/07/2009
• Published: 02/03/2011
• Est. Priority Date: 04/09/2008
• Status: Active Grant

• Current Assignee: Molnlycke Health Care AB (Mölnlycke Holding AB)
• Original Assignee: Molnlycke Health Care AB (Mölnlycke Holding AB)
• Inventors: Johnnison, Ulf, Frantzich, Sofia
• Granted Patent: US 8,469,915 B2
• Time in Patent Office: Days
• US Class Current: 604/319
• CPC Class Codes: A61F 13/00068 specially adapted for application or removal of fluid, e.g. irrigation or drainage of wounds, under-pressure wound-therapy A61F13/0216 takes precedence; drainage appliances for wounds in general A61M27/00
• CPC Class Codes: A61F 13/00995 for mechanical treatments
• 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 2007/0295 for heating or cooling or use at more than one temperature
• CPC Class Codes: A61F 2013/00174 possibility of applying pressure
• CPC Class Codes: A61F 2013/00412 for use with needles, tubes or catheters
• CPC Class Codes: A61F 2013/00536 for draining or irrigating wounds
• CPC Class Codes: A61F 2013/0054 for deep wounds
• CPC Class Codes: A61F 2013/0074 containing foams
• CPC Class Codes: A61F 2013/00753 superabsorbent fabric of cloth
• CPC Class Codes: A61L 15/26 Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives thereof A61L15/225 takes precedence
• CPC Class Codes: A61L 15/425 Porous materials, e.g. foams or sponges
• 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 1/74 Suction control underwater drainage A61M1/61
• CPC Class Codes: A61M 1/915 Constructional details of the pressure distribution manifold
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: C08L 83/04 Polysiloxanes
• CPC Class Codes: Y10T 428/249969 Of silicon-containing material [e.g., glass, etc.]
• CPC Class Codes: Y10T 428/2962 Silane, silicone or siloxane in coating
• CPC Class Codes: Y10T 428/2971 Impregnation

Abstract

A device for treatment of wounds using reduced pressure, said device comprising

• • a pump
  • a reservoir connected to said pump for collecting exudate from a wound (1),
  • an inlet to the reservoir for connecting the reservoir with the wound so as to allow the pump to expose the wound to the reduced pressure, a wound pad to be arranged in the wound cavity and a sealing covering the wound and said wound pad.

The wound pad consist of an open-cell polyurethane foam which is fully impregnated with a soft hydrophobic silicone gel, and that the foam has a hardness of 1.0-6.0 kPa measured according to ISO 3386-1 at 40% compression. The invention also concerns such a wound pad to be used with an absorbent member. In addition the invention concerns a method for manufacturing the wound pad.

Claims

1. A device for treatment of wounds using reduced pressure, said device comprising

a pump capable of providing a reduced pressure,

a reservoir connected to said pump for collecting exudate from a wound,

an inlet to the reservoir for connecting the reservoir with the wound so as to allow the pump to expose the wound to the reduced pressure, a wound pad to be arranged in the wound cavity and a sealing covering the wound and said wound pad, wherein the wound pad consists of an open-cell polyurethane foam which is fully impregnated with a soft hydrophobic silicone gel, and that the foam has a hardness of 1.0-6.0 kPa measured according to ISO 3386-1 at 40% compression.

2. A device in accordance with claim 1, wherein the hardness of the foam is 1.5-5.0 kPa.

3. A device in accordance with claim 1, wherein the density of the foam is 20-40 kg/m³, measured according to ISO 845.

4. A device in accordance with claim 1, wherein the foam at 25% elongation has a wet elasticity higher than 6 kPa and a dry elasticity higher than 13 kPa measured according to a method described in Appendix A.

5. A device according to claim 1. wherein the silicone gel is homogeneously distributed over the cross-section of the pad of open-cell foam.

6. A device in accordance with claim 1, wherein the open-cell foam is fully impregnated with silicone gel as approved by observing photos taken with an Electron Probe Micro Analyser with Energy Dispersive Spectrometer (EPMA/EDS).

7. A device in accordance with claim 1, wherein the cell diameter is between 500-1800 μ

m, measured according to Visiocell SS-T.013.4E.

8. A device for treatment of wounds, said device comprising a wound pad to be arranged in the wound cavity, an absorbent member for collecting exudate from a wound and a sealing covering the wound, said wound pad and said absorbent member, wherein the wound pad consists of an open-cell polyurethane foam which is fully impregnated with a soft hydrophobic silicone gel, and that the foam has a hardness of 1.0-6.0 kPa measured according to ISO 3386-1 at 40% compression.

9. A device in accordance with claim 8, wherein the foam has a hardness of 1.5-5.0 kPa.

10. A device in accordance with claim 8, wherein the cell diameter is between 500-800 μ

m, measured according to Visiocell SS-T.013.4E.

11. A method for manufacturing of a wound pad of an open-cell polyurethane foam that is impregnated with a soft hydrophobic silicone gel comprising the steps of applying silicone gel in uncured state on one side of a web of an open-cell polyurethane foam, feeding said web with the applied silicone gel between two webs of process paper through a pair of press rolls, squeezing between the press rolls the foam with the applied silicone gel for distributing the gel over the total cross section of the foam, removing said two webs of process paper with excessive silicone gel from the foam web and heating the foam web thereafter for curing of the silicone gel.

12. A method according to claim 11, wherein the curing of the silicone gel is performed in a hot blast furnace at a temperature of about 100°

C. during about 1-5 minutes.

13. A method in accordance with claim 11, wherein the pressure between the press rolls is about 5 bar and that said pressure is adjustable for optimal impregnation and that control of full impregnation of the foam web is performed by inspecting the two webs of process paper, which both paper webs are coated with silicone gel when the foam web is fully impregnated.

14. A method in accordance with claim 11, wherein the velocity of the webs through the press rolls is about 2-5 m/min.