System for treating a wound with suction and method detecting loss of suction

• US 20070016152A1
• Filed: 11/07/2005
• Published: 01/18/2007
• Est. Priority Date: 07/14/2005
• Status: Active Grant

• Current Assignee: Paul Hartmann AG (Schwenk Zement KG)
• Original Assignee: Boehringer Laboratories, Inc.
• Inventors: Karpowicz, John, Norton, Derek, Klocek, Kevin, Boehringer, John, Radl, Christopher
• Granted Patent: US 7,438,705 B2
• Time in Patent Office: Days
• US Class Current: 604/326
• CPC Class Codes: A61M 1/60 Containers for suction drainage, adapted to be used with an external suction source containers not adapted for subjection to vacuum A61M1/69
• CPC Class Codes: A61M 1/72 Cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 1/73 comprising sensors or indicators for physical values
• CPC Class Codes: A61M 1/74 Suction control underwater drainage A61M1/61
• CPC Class Codes: A61M 1/784 by filtering, sterilising or disinfecting the exhaust air, e.g. swellable filter valves
• CPC Class Codes: A61M 1/80 Suction pumps A61M1/64, A61M1/71, A61M60/00 take precedence
• CPC Class Codes: A61M 1/86 Connectors between drainage tube and handpiece, e.g. drainage tubes detachable from handpiece
• 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 1/92 with liquid supply means
• CPC Class Codes: A61M 1/96 Suction control thereof
• CPC Class Codes: A61M 1/964 having venting means on or near the dressing
• CPC Class Codes: A61M 1/982 with means for detecting level of collected exudate
• CPC Class Codes: A61M 2205/123 with incorporated reservoirs
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/8206 battery-operated
• CPC Class Codes: A61M 2205/8237 Charging means
• 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 system for applying suction to a wound uses a reference airflow for monitoring system operation. A reference airflow (or “controlled leak”) to the suction source is provided when the system is in operation, such that deviation from the reference airflow can be monitored as an indication of a change in operation, such as a leak in the seal of the wound cover, a blockage of airflow from crimping of the suction conduit or overfill of the waste collector, or an inadvertent turn off or disconnect from the suction source.

Claims

1. A system for applying suction to a wound, comprising;

(a) a source of suction;

(b) a conduit having one end operatively associated with the wound to communicate suction to the wound, and an opposite end operatively associated with the source of suction;

(c) a reference airflow provided to the suction source when the system is in operation, such that deviation from the reference flow can be monitored as an indication of a change in operation of the system.

2. A system as in claim 1, further comprising a vent in fluid communication with the conduit to provide the reference airflow.

3. A system as in claim 1, further comprising a source of therapeutic mixture vent in fluid communication with the conduit to provide the reference airflow.

4. A system as in claim 1, further comprising a flow rate monitor to monitor airflow through the conduit and indicate deviation from the reference flow.

5. A system as in claim 4, wherein the flow rate monitor may be direct airflow measuring device or a device to measure airflow indirectly.

6. A system as in claim 5, wherein a direct airflow measuring device may be a float meter, a target meter, a hot wire anemometer, a rotameter, mass flow meter, differential pressure meter or a turbine meter.

7. A system as in claim 5, wherein an indirect airflow measuring device may be a means for measuring suction pump input as a surrogate for airflow rate.

8. A system as in claim 2, wherein the vent is located near the wound.

9. A system as in claim 8, wherein the vent is an aperture into the conduit that is sealed sterile with a porous material.

10. A system as in claim 1, further comprising a wound cover overlying the wound.

11. A system as in claim 10, further comprising a vent in the wound cover to provide the reference airflow.

12. A system as in claim 10, wherein the wound cover is a semi permeable material, and the reference airflow is in excess of a natural permeation through the wound cover but below about 1000 cubic centimeters per minute.

13. A system as in claim 1, wherein the reference airflow is in the range of about 50-300 cubic centimeters per minute.

14. A system as in claim 1, further comprising a filter/drier unit in the conduit between the source of suction and the wound.

15. A system as in claim 1, further including a waste collector canister between the wound and the source of suction for collecting liquids aspirated from the wound, wherein the canister includes gelling agent.

16. A system as in claim 4, wherein the flow rate monitor is a float meter indicating by the position of a float when the airflow through the meter is in a normal range associated with the reference airflow, and when the airflow through the meter is outside of the normal range.

17. A system as in claim 16, further comprising the float meter having a plurality of inner chambers with discrete diameters, the chambers being arranged such that the chamber lowest in the meter has the least diameter, and the chamber or chambers above it have progressively larger diameters.

18. A system as in claim 17, further comprising the float meter chambers being color coded to indicate normal and abnormal positions of the float meter.

19. A system as in claim 4, wherein the suction source is a portable pump having a visual indicator of airflow marked to display normal airflow and deviation from normal airflow as detected by the flow rate monitor.

20. A system as in claim 3, further comprising a flow rate monitor to measure flow of the therapeutic mixture to the wound and indicate deviation from the reference flow as an indication of a change in operation of the system.

21. A system for suction wound therapy, comprising;

(a) a source of suction;

(b) a wound dressing, including a wound cover that is sealable to skin surrounding a wound;

(c) an air conduit having one end operatively associated with the wound dressing to communicate suction to the wound, and an opposite end operatively connected with the source of suction;

(d) an air vent in fluid communication with the conduit to allow a reference airflow through the conduit to the suction source when the system is in normal operation, such that deviation from the reference airflow can be monitored as an indication of abnormal operation; and

(e) a flow rate monitor to detect deviation from the reference flow.

22. A system as in claim 21, wherein the reference airflow is below about 1000 cubic centimeters per minute.

23. A system as in claim 22, wherein the reference airflow is in the range of about 50-300 cubic centimeters per minute.

24. A system as in claim 21, further including a supply system for providing therapeutic mixture to the wound.

25. A system as in claim 24, further including a flow rate monitor to monitor the flow of therapeutic mixture.

26. A system as in claim 21, wherein the source of suction is a portable pump unit.

27. A system as in claim 26, wherein the pump unit is connected directly to a waste collection canister.

28. A system as in claim 27, wherein the pump unit has a docking station to support the canister.

29. A system as in claim 27, wherein the canister contains stacked disks of gelling agent.

30. A system as in claim 27, including a connection fitting on the canister adapted to be received into a connection port of the pump unit, wherein the fitting has a sealing element.

31. A method of detecting leaks in a suction therapy wound dressing system that includes a wound cover sealed to skin surrounding the wound and a conduit operably connecting the dressing to a source of suction, the method comprising the steps of:

creating a reference airflow through the system when the wound cover is properly sealed to the skin;

monitoring the airflow though the system; and

associating an increase in airflow above the reference flow as an indication of probable air leakage in the system.

32. A method as in claim 31, wherein the step of creating a reference airflow includes placing a vent in the conduit outside of the wound cover.

33. A method as in claim 31, wherein the step of creating a reference airflow includes placing a vent in the wound cover.

34. A method as in claim 31, wherein the step of creating a reference airflow includes the step of providing a therapeutic mixture to the wound.

35. A method as in claim 34, further comprising the step of aspirating therapeutic liquid and liquid wound exudate from the would

36. A method as in claim 35, further comprising collecting the aspirated liquids in a waste collection canister.

37. A method as in claim 31, further comprising the step of associating a decrease of airflow below the reference airflow as an indicator of possible blockage in the system.

43. A method as in claim 37, including the further step of providing an aural indication of abnormal operation of the system as detected from monitoring airflow through the system.

38. A method of detecting leaks and blockages in a suction therapy wound dressing that includes a wound cover sealed to skin surrounding the wound and a conduit operably connecting the dressing to a source of suction, the method comprising the steps of:

creating a reference airflow through the conduit when the wound cover is properly sealed to the skin;

monitoring the airflow through the conduit;

associating an increase in airflow above the reference flow as an indication of probable air leakage in the system; and

associating a decrease in airflow below the reference flow as an indication of probable blockage in the conduit or loss of suction at the source.

39. A method as in claim 38, wherein the step of creating a reference airflow includes placing a vent in the conduit outside of the wound cover.

40. A method as in claim 38, wherein the reference airflow is below 1000 cubic centimeters per minute.

41. A method as in claim 40, wherein the reference airflow is in the range of about 50-300 cubic centimeters per minute.

42. A method as in claim 38, including the further step of providing a visual indication of normal and abnormal operation of the system as detected from monitoring airflow through the system.