Wound cleansing apparatus with stress

• US 9,452,244 B2
• Filed: 07/07/2010
• Issued: 09/27/2016
• Est. Priority Date: 04/27/2004
• Status: Active Grant

• Current Assignee: Smith & Nephew PLC
• Original Assignee: Smith & Nephew PLC
• Inventors: Blott, Patrick Lewis, Greener, Bryan, Hartwell, Edward Yerbury, Walker, Tina Michelle, Lee-Webb, Julian, Nicolini, Derek, Green, Clare, Martin, Robin Paul
• Primary Examiner(s): Zalukaeva, Tatyana
• Assistant Examiner(s): TREYGER, ILYA Y
• Application Number:
  US12/832,002
• Publication Number:
  US 20110004171A1
• Time in Patent Office: 2,274 Days
• Field of Search: 604/305, 604/306, 604/307, 604/308
• US Class Current: 1/1
• 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: A61H 9/0057 Suction suction kneading A61H7/008
• CPC Class Codes: A61M 1/75 Intermittent or pulsating suction A61M1/63, A61M1/772 take precedence
• CPC Class Codes: A61M 1/77 Suction-irrigation systems aspiration tips supplying fluids A61M1/85; specific for negative pressure wound therapy A61M1/92; combined with tracheal tubes A61M16/0463
• CPC Class Codes: A61M 1/85 with gas or fluid supply means, e.g. for supplying rinsing fluids or anticoagulants for negative pressure wound therapy A61M1/92, A61M1/94; combined with tracheal tubes A61M16/0463; dental instruments with combined rinsing and aspirating A61C17/0208
• CPC Class Codes: A61M 1/915 Constructional details of the pressure distribution manifold
• CPC Class Codes: A61M 1/916 specially adapted for deep wounds
• CPC Class Codes: A61M 1/92 with liquid supply means
• CPC Class Codes: A61M 1/94 with gas supply means
• CPC Class Codes: A61M 1/96 Suction control thereof
• CPC Class Codes: A61M 35/30 Gas therapy for therapeutic treatment of the skin

Abstract

An apparatus for cleansing wounds with means for stressing the wound bed and optionally tissue surrounding the wound, in which irrigant fluid from a reservoir connected to a conformable wound dressing and wound exudate from the dressing are recirculated by a device for moving fluid through a flow path which passes through the dressing and a means for fluid cleansing and back to the dressing. The cleansing means (which may be a single-phase, e.g. micro-filtration, system or a two-phase, e.g. dialytic system) removes materials deleterious to wound healing, and the cleansed fluid, still containing materials that are beneficial in promoting wound healing, is returned to the wound bed. The means for stressing the wound bed and optionally tissue surrounding the wound promotes wound healing. The dressing and a method of treatment using the apparatus.

Claims

1. A method of treating a wound, comprising:

applying a cyclically varying negative pressure to the wound in accordance with a sinusoidal waveform that varies relative to a baseline pressure, wherein the wound is covered at least partially by a conformable wound dressing configured to form at least a relatively fluid tight seal around at least a portion of the wound,

wherein applying the cyclically varying negative pressure to the wound in accordance with the sinusoidal waveform comprises varying the sinusoidal waveform to include first and second maximum amplitudes of negative pressure, the first maximum amplitude different from the second maximum amplitude, wherein the cyclically varying negative pressure applied to the wound is below atmospheric pressure.

2. The method of treating a wound of claim 1, comprising varying the cyclically varying negative pressure to the wound between at least two negative pressure values, wherein each negative pressure value is below atmospheric pressure.

3. The method of treating a wound of claim 1, further comprising varying the cyclically varying negative pressure to the wound between at least a positive pressure value and a negative pressure value, wherein the positive pressure value is above atmospheric pressure and the negative pressure value is below atmospheric pressure.

4. The method of treating a wound of claim 1, further comprising pumping fluid through at least an inlet conduit in communication with the wound dressing, the wound dressing, and an outlet conduit in communication with the wound dressing.

5. The method of treating a wound of claim 4, further comprising cleansing the fluid that flows out of the wound dressing to reduce the amount of deleterious components in the fluid that flows out of the dressing without substantially reducing the amount of the components in the fluid that flows out of the dressing that are beneficial to wound healing.

6. The method of treating a wound of claim 5, further comprising recirculating at least a portion of the fluid that flows out of the wound dressing back to the dressing after being cleansed so that nutrients, molecules, factors, and/or other components from the wound exudate that aid in proliferation or that are favorable to the wound healing process are returned to the wound.

7. The method of treating a wound of claim 1, comprising varying a pressure provided to a wound filler positioned adjacent to the wound.

8. The method of treating a wound of claim 1, further comprising varying the cyclically varying negative pressure between a first negative pressure value below atmospheric pressure and a second value below atmospheric pressure, wherein the second value is between 5 percent and 40 percent of atmospheric pressure.

9. The method of treating a wound of claim 8, wherein the second value is between 10 percent and 15 percent of atmospheric pressure.

10. The method of treating a wound of claim 1, further comprising applying a cyclically varying positive pressure to the wound.

11. The method of treating a wound of claim 1, further comprising applying a cyclically varying positive and negative pressure to the wound.

12. The method of treating a wound of claim 1, further comprising applying a cyclically varying positive and negative pressure to the wound in accordance with a sinusoidal waveform.

13. The method of treating a wound of claim 1, wherein applying the cyclically varying negative pressure to the wound comprises stressing the wound such that the wound is subject to strain.

14. The method of treating a wound of claim 1, wherein the cyclically varying negative pressure is applied to the wound at a controlled frequency.

15. The method of treating a wound of claim 1, wherein the baseline pressure is a constant negative pressure.

16. The method of treating a wound of claim 1, wherein the baseline pressure is varied below atmospheric pressure.

17. A method of treating a wound, comprising:

applying a varying pressure to the wound in accordance with a waveform selected from the group consisting of sinusoidal, random white noise, sawtooth, and square, the wound covered at least partially by a conformable wound dressing configured to form at least a relatively fluid tight seal around at least a portion of the wound,

wherein the varying pressure is applied at a frequency between 1 and 3000 cycles per minute,

wherein the waveform varies relative to a baseline pressure, and

wherein applying the varying pressure to the wound in accordance with the waveform comprises varying the waveform to include first and second maximum amplitudes of negative pressure, the first maximum amplitude different from the second maximum amplitude.

18. The method of treating a wound of claim 17, comprising:

stressing the wound by applying a cyclical varying negative pressure to the wound in accordance with a systolic-diastolic asymmetric sawtooth waveform,

wherein the cyclical varying negative pressure applied to the wound is below atmospheric pressure.

19. The method of treating a wound of claim 18, wherein stressing the wound comprises varying a pressure provided to a wound filler positioned adjacent to the wound.

20. The method of treating a wound of claim 18, wherein stressing the wound comprises means for varying the pressure of a fluid applied to the wound.

21. The method of treating a wound of claim 18, wherein the systolic-diastolic asymmetric sawtooth waveform has a frequency of about 60 to 100 per minute.

22. The method of treating a wound of claim 17, further comprising pumping fluid through at least an inlet conduit in communication with the wound dressing, the wound dressing, and an outlet conduit in communication with the wound dressing.

23. The method of treating a wound of claim 22, further comprising cleansing the fluid that flows out of the wound dressing to reduce the amount of deleterious components in the fluid that flows out of the dressing without substantially reducing the amount of the components in the fluid that flows out of the dressing that are beneficial to wound healing.

24. The method of treating a wound of claim 23, further comprising recirculating at least a portion of the fluid that flows out of the wound dressing back to the dressing after being cleansed so that nutrients, molecules, factors, and/or other components from the wound exudate that aid in proliferation or that are favorable to the wound healing process are returned to the wound.

25. The method of treating a wound of claim 17, further comprising cyclically varying the varying pressure below atmospheric pressure.

26. The method of treating a wound of claim 17, wherein the varying pressure is applied to the wound in accordance with a sinusoidal waveform.

27. The method of treating a wound of claim 17, wherein applying the varying pressure to the wound comprises stressing the wound such that the wound is subject to strain.

28. The method of treating a wound of claim 17, wherein applying the varying pressure to the wound comprises applying the varying pressure at a controlled frequency.

29. The method of treating a wound of claim 17, wherein the baseline pressure is a constant negative pressure.

30. The method of treating a wound of claim 17, wherein the baseline pressure is varied below atmospheric pressure.