Wound treatment apparatus and method

• US 8,235,955 B2
• Filed: 04/27/2006
• Issued: 08/07/2012
• Est. Priority Date: 04/27/2005
• Status: Active Grant

• Current Assignee: Smith & Nephew PLC
• Original Assignee: Smith & Nephew PLC
• Inventors: Hartwell, Edward Y., Lee-Webb, Julian, Nicolini, Derek, Blott, Patrick L.
• Primary Examiner(s): Zalukaeva, Tatyana
• Assistant Examiner(s): Hanrahan, Benedict L
• Application Number:
  US11/919,355
• Publication Number:
  US 20090306609A1
• Time in Patent Office: 2,294 Days
• Field of Search: 604/315, 604/19, 604289-290, 604304-308, 604/317, 604319-323, 604/327, 604/540, 604/543
• US Class Current: 604/305
• 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 1/962 having pumping means on the suction site, e.g. miniature pump on dressing or dressing capable of exerting suction
• CPC Class Codes: A61M 3/02 Enemata; Irrigators
• CPC Class Codes: A61M 3/0208 before use
• CPC Class Codes: A61M 3/0212 after use
• CPC Class Codes: A61M 3/0216 Pressure
• CPC Class Codes: A61M 3/022 Volume; Flow rate
• CPC Class Codes: A61M 35/30 Gas therapy for therapeutic treatment of the skin

Abstract

An apparatus for cleansing wounds in which irrigant fluid from a reservoir connected to a conformable wound dressing and wound exudate from the dressing are moved by a device (which may be a single pump or two pumps) for moving fluid through a flow path which passes through the dressing and a means for providing simultaneous aspiration and irrigation of the wound, and means for stressing the wound bed and optionally tissue surrounding the wound. The former removes materials deleterious to wound healing, while distributing materials that are beneficial in promoting wound healing over the wound bed. The latter promotes wound healing. The dressing and a method of treatment using the apparatus.

Claims

1. An apparatus for aspirating, irrigating and/or cleansing a wound, comprising:

a fluid flow path, comprising;

a conformable wound dressing, having a backing layer which is capable of forming a relatively fluid-tight seal or closure over a wound, thereby creating a space between the wound and the backing layer,

an inlet pipe in fluid communication with the space between the wound and the backing layer to allow irrigation of the wound; and

an outlet pipe in communication with the space between the wound and the backing layer to allow aspiration of the wound;

a fluid reservoir that, in use, provides an irrigation fluid directly or indirectly to the inlet pipe;

a first device for directly or indirectly moving fluid through the inlet pipe or the outlet pipe;

a first regulator for directly or indirectly regulating fluid moving through the inlet pipe or the outlet pipe; and

a second device for moving fluid through the other of the inlet pipe or the outlet pipe as compared to the first device and/or a second regulator for regulating fluid moving through the other of the inlet pipe or the outlet pipe as compared to the first regulator;

means for applying stress to the wound bed and/or tissue surrounding the wound comprising at least one expandable and contractible fluid-inflatable body capable of applying pressure to the wound bed;

wherein;

the fluid-inflatable body comprises an inflation inlet, is partially filled with an elastically resilient material, such as an elastomeric foam, and defines a sealed space in communication with the inflation inlet.

2. The apparatus of claim 1 comprising both a second device for moving fluid through the outlet pipe and a second regulator for regulating fluid moving through the outlet pipe and wherein, in use, the first device directly or indirectly moves fluid through the inlet pipe and the first regulator directly or indirectly regulates fluid moving through the inlet pipe.

3. The apparatus of claim 1 comprising a second device for moving fluid through the outlet pipe, wherein, in use, the first device directly or indirectly moves fluid through the inlet pipe while the second device moves fluid through the outlet pipe so as to provide simultaneous aspiration and irrigation of the wound.

4. The apparatus of claim 1 in which the means for applying stress to the wound bed is capable of applying an optionally varying positive and/or negative pressure to the wound bed.

5. The apparatus of claim 1 wherein the fluid-inflatable body is inflatable by a gas, liquid, gas in liquid aerosol and/or a gel.

6. The apparatus of claim 1 wherein the manifold covers and contacts a significant area of the wound bed with openings that deliver the fluid directly to the wound bed over an extended area.

7. The apparatus of claim 1 wherein the manifold comprises of one or more inflatable hollow bodies defined by a film sheet or membrane.

8. The apparatus of claim 1 wherein the manifold covers 50% or greater of the wound bed.

9. The apparatus of claim 1 wherein the fluid-inflatable body comprises a substantially flat film, sheet or membrane, defining a chamber, pouch or other structure of the backing layer.

10. The apparatus of claim 1 comprising an inflation and/or deflation pump for inflating or deflating the fluid-inflatable body.

11. The apparatus of claim 10 wherein the inflation and/or deflation pump is reversible.

12. The apparatus of claim 10 wherein the inflation and/or deflation pump is a piston pump or rotary pump.

13. The apparatus of claim 12 wherein the inflation and/or deflation pump is a peristaltic pump.

14. The apparatus of claim 1 in which the means for applying stress to the wound bed is capable of varying the pressure by up to 50% above and below atmospheric pressure.

15. The apparatus of claim 1 in which the means for applying stress to the wound bed is capable of varying pressure in regular or irregular cycles.

16. The apparatus of claim 15 in which the frequency of regular or irregular cycles is between 1 and 48 per 24 hour period.

17. The apparatus of claim 1 in which the means for applying stress to the wound bed is capable of varying pressure in regular or irregular pulses.

18. The apparatus of claim 17 in which frequencies of regular pulses for the stimulation of the healing of wounds is from 1 to 3000 per minute (0.016- 50 Hz).

19. The apparatus of claim 18 in which maximum amplitude for the pulses is up to 10 mm Hg above and below the baseline pressure.

20. The apparatus of claim 1 in which the means for applying stress to the wound is capable of varying pressure in regular or irregular cycles and regular or irregular pulses, the pulses being superimposed on the cycles.

21. The apparatus of claim 1 wherein the means for applying stress to the wound bed includes a magnetic fluid in a chamber or other hollow structure.

22. The apparatus of claim 1 wherein the means for applying stress to the wound bed comprises means to bleed fluid into the flow path of the apparatus.

23. The apparatus of claim 3 wherein the first and/or second device for moving fluid through the wound is a variable-throughput device.

24. The apparatus of claim 23 wherein the first and/or second device is a variable-speed pump.

25. The apparatus of claim 24 wherein the first and/or second device for moving fluid through is a reciprocating pump or a rotary pump.

26. The apparatus of claim 25 wherein the first device is a diaphragm pump.

27. The apparatus of claim 25 wherein the second device is a peristaltic pump.

28. The apparatus of claim 3 wherein the variable-throughput device is capable of pulsed, continuous, variable and/or automated and/or programmable fluid movement.

29. The apparatus of claim 1 wherein the apparatus is capable of applying a negative pressure within the wound dressing of up to 50% atm.

30. The apparatus of claim 29 comprising at least one body in the flow path to, over and from the wound bed which has sufficient resilience against the pressure to allow any significant compression or decompression of the fluid occur.

31. The apparatus of claim 1 wherein the one or more pipes comprise a manifold which covers and contacts a significant area of the wound bed with openings for delivering and/or receive fluid directly to/from the wound bed over an extended area.

32. The apparatus of claim 1 wherein securing means are provided to secure the wound dressing to the site of the wound.

35. A method of operation of an apparatus for aspirating, irrigating and/or cleansing a wound, said method comprising:

applying the apparatus of claim 1 to the wound;

conforming the backing layer of the wound dressing to the shape of the bodily part in which the wound is to form a relatively fluid tight seal or closure;

activating the first device to move irrigant to the wound; and

activating the means for applying stress to the wound bed and optionally tissue surrounding the wound.

36. The method of claim 35 wherein activating means for applying stress to the wound bed and optionally tissue surrounding the wound comprises activating means to apply optionally varying positive and/or negative pressure to the wound bed.

37. The method of claim 35 wherein activating the first device to move irrigant to the wound comprises activating the first device to move an irrigant fluid through the at least one inlet and to move an aspirant fluid out of the at least one outlet pipe.

38. The method of claim 35 wherein the flow rate of fluid to the dressing is in the range of 1 to 1500 ml/hour.

39. The method of claim 35 wherein the flow rate of total fluid out of the dressing is in the range of 1 to 2000 ml/hour.

40. The method of claim 35 wherein activating the first device to move irrigant to the wound comprises activating simultaneous irrigation and aspiration of the wound.

41. The method of claim 35 wherein activating the first device to move irrigant to the wound comprises activating sequential irrigation and aspiration of the wound.

42. The method of claim 35 wherein the apparatus is run at a negative pressure of up to 50% atm.

43. The method of claim 35 comprising applying the stress intermittently.

44. The apparatus of claim 1 wherein the at least one expandable and contractible body is cyclically inflated and deflated by admitting and releasing a fluid from the module during use.

45. The method of claim 35 comprising stressing the wound by applying a cyclical positive and negative pressure to the wound in accordance with a systolic-diastolic asymmetric sawtooth waveform.

46. The method of treating a wound of claim 45 wherein the systolic-diastolic asymmetric sawtooth waveform has a frequency of about 60 to 100 per minute.

47. The method of claim 35 comprising applying a varying pressure to the wound in accordance with a sinusoidal waveform.

48. The method of claim 35 comprising varying a pressure within the wound cover between a positive and a negative value, wherein the positive value is above atmospheric pressure and the negative value is below atmospheric pressure.

49. The method of claim 35 comprising varying the pressure to the wound between at least two negative pressure values, wherein each negative pressure value is below atmospheric pressure.

33. An apparatus for aspirating, irrigating and/or cleansing a wound comprising:

a wound dressing comprising;

a backing layer with a wound-facing face which is capable of forming a relatively fluid-tight seal or closure over a wound;

an inlet pipe in fluid communication with a space between the wound and the backing layer to allow irrigation of the wound; and

an outlet pipe in communication with the space between the wound and the backing layer to allow aspiration of the wound;

means for applying stress to the wound bed and optionally tissue surrounding the wound comprising at least one expandable and contractible fluid-inflatable body, the fluid inflatable body configured to provide a positive and/or negative pressure to the wound and/or tissue surrounding the wound;

a first device for moving fluid through the wound dressing to the wound and/or moving fluid from the wound; and

a second device for moving fluid through the wound dressing to the wound and/or moving fluid from the wound; and

means for aspirate flow regulation connected to the outlet pipe and/or means for supply flow regulation connected to the inlet pipe;

wherein;

the fluid-inflatable body comprises an inflation inlet, is partially filled with an elastically resilient material, such as an elastomeric foam, and defines a sealed space in communication with the inflation inlet.

34. The apparatus of claim 33, wherein the wound dressing is provided in a bacteria-proof pouch.