Systems and methods for electrically detecting the presence of exudate in dressings

• US 8,795,257 B2
• Filed: 07/14/2011
• Issued: 08/05/2014
• Est. Priority Date: 07/19/2010
• Status: Active Grant

• Current Assignee: Solventum Intellectual Properties Company (Solventum Corp.)
• Original Assignee: KCI Licensing Incorporated (3M Company)
• Inventors: Coulthard, Richard Daniel John, Thomson, Malcolm, Jaeger, Rico
• Primary Examiner(s): Hand, Melanie
• Assistant Examiner(s): Craig, Paula L
• Application Number:
  US13/183,245
• Publication Number:
  US 20120016322A1
• Time in Patent Office: 1,118 Days
• Field of Search: 604/313
• US Class Current: 604/541
• CPC Class Codes: A61F 13/00055 Saturation indicators
• 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 13/05 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 2013/00174 possibility of applying pressure
• CPC Class Codes: A61F 2013/00421 with double adhesive layer with cyano-acrylic adhesive A61F2013/00459; with adhesive connecting means A61F2013/00561; adhesives for plasters A61F2013/00655; with absorbent adhesives A61F2013/00757; with permeable adhesive layers A61F2013/00761; different adhesion of different adhesive layers A61F2013/00804; changing the adhesion force with strain value A61F2013/00838
• CPC Class Codes: A61F 2013/00536 for draining or irrigating wounds
• CPC Class Codes: A61F 2013/0054 for deep wounds
• CPC Class Codes: A61F 2013/00961 electrical conductivity
• 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 1/912 Connectors between dressing and drainage tube
• 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 1/966 having a pressure sensor on or near the dressing
• CPC Class Codes: A61M 1/982 with means for detecting level of collected exudate
• CPC Class Codes: A61M 1/985 the dressing itself forming the collection container
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 2205/3317 : Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3341 : stabilising pressure or flow to avoid excessive variation
• CPC Class Codes: A61M 2205/3344 : Measuring or controlling pressure at the body treatment site
• CPC Class Codes: A61M 2205/3569 : sublocal, e.g. between console and disposable
• CPC Class Codes: A61M 2205/3592 : using telemetric means, e.g. radio or optical transmission
• CPC Class Codes: A61M 2205/581 : by audible feedback
• CPC Class Codes: A61M 2205/583 : by visual feedback
• CPC Class Codes: A61M 2205/6081 : Colour codes
• 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
• CPC Class Codes: G08B 21/20 : responsive to moisture

Abstract

Systems and methods are provided for sensing fluid in a dressing on a patient and producing an electrical signal. In one instance, a galvanic cell is used as an electronic detection device. The galvanic cell is placed in the dressing and produces voltage when the dressing is substantially saturated. In one instance, the dressing is a reduced-pressure, absorbent dressing. Other systems, methods, and dressings are presented.

Claims

1. A system for treating a tissue site on a patient with reduced pressure, the system comprising:

an absorbent layer adapted to be disposed at the tissue site to receive fluids from the tissue site in response to reduced pressure;

a sealing member for covering the absorbent layer and a portion of an epidermis of the patient to form a seal;

a reduced-pressure source adapted to be fluidly coupled to the absorbent layer for providing reduced pressure to the absorbent layer;

a galvanic cell comprising a cathode and an anode attached to a base and spaced apart from each other on the base, the cathode and the anode adapted to contact the absorbent layer to form the galvanic cell;

a load electrically coupled across the cathode and the anode to provide a signal when the absorbent layer contacts the cathode and the anode and becomes substantially saturated with fluids from the tissue site; and

a monitoring unit electrically coupled to the load and adapted to receive the signal to provide an indication that the absorbent layer is saturated.

2. The system of claim 1, wherein the monitoring unit is a comparator circuit.

3. The system of claim 1, wherein the monitoring unit comprises an analog-to-digital converter coupled to a microprocessor, and wherein the microprocessor is configured to develop an alarm signal when the signal from the load reaches a signal threshold value.

4. The system of claim 1, wherein the cathode comprises copper and the anode comprises tin.

5. The system of claim 1, wherein the cathode comprises copper and the anode comprises tin, and wherein the fluids comprise exudate.

6. The system of claim 1, wherein the cathode comprises copper and the anode comprises zinc.

7. The system of claim 1, further comprising a plurality of galvanic cells associated with the absorbent layer and configured to provide power proportional to the saturation of the absorbent layer.

8. The system of claim 1, wherein the monitoring unit comprises an electronic detection device and a wireless-communication-and-power subsystem.

9. The system of claim 1, wherein the load comprises a resistive load.

10. The system of claim 1, wherein the load comprises a capacitive load.

11. The system of claim 1, wherein a length of the base is 20 millimeters and a width of the base is 10 millimeters.

12. The system of claim 11, wherein a length of the cathode is 8 millimeters and a width of the cathode is 8 millimeters.

13. The system of claim 11, wherein a length of the anode is 8 millimeters and a width of the anode is 8 millimeters.

14. The system of claim 11, wherein:

a length of the cathode is 8 millimeters;

a width of the cathode is 8 millimeters;

a length of the anode is 8 millimeters; and

a width of the anode is 8 millimeters.

15. The system of claim 1, further comprising:

a manifold adapted to be disposed between the absorbent layer and the tissue site;

wherein the cathode and the anode are adapted to contact the absorbent layer opposite the manifold; and

wherein the reduced-pressure source is adapted to be fluidly coupled to the manifold.