Systems And Methods For Electrically Detecting The Presence Of Exudate In Dressings

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.

1 - 16 . (canceled) 
     
     
         17 . A method for treating a tissue site, the method comprising:
 providing a dressing, wherein the dressing comprises:
 an absorbent layer for placing in fluid communication with the tissue site, the absorbent layer for receiving and retaining ionic fluids, the absorbent layer having a first side and a second, patient-facing side, 
 a sealing member for covering the first side of the absorbent layer, and 
 a first galvanic cell associated with the absorbent layer and configured to produce a voltage indicative of a full state when a portion of the absorbent layer proximate to the first galvanic cell is substantially saturated with the ionic fluid; 
   deploying the dressing proximate to the tissue site; and   electrically coupling the first galvanic cell to a monitoring unit, wherein the monitoring unit is configured to produce a dressing-full signal when receiving the voltage indicative of a full state from the first galvanic cell.   
     
     
         18 . The dressing of  claim 17 , wherein the galvanic cell comprises:
 a first electrode and a second electrode, the first electrode and second electrode in fluid communication with a portion of the absorbent layer, and the first electrode and second electrode spaced from one another;   a first electrical lead coupled to the first electrode;   a second electrical lead coupled to the second electrode; and   wherein the first electrode and second electrode are configured to produce measurable electrical voltage when the ionic fluid covers the first electrode and second electrode.   
     
     
         19 . The method of  claim 18 , wherein the first electrode comprises copper and the second electrode comprises tin. 
     
     
         20 . The method of  claim 18 , wherein the first electrode comprises copper and the second electrode comprises tin, and wherein the ionic fluid comprises exudate from a patient. 
     
     
         21 . The method of  claim 18 , wherein the first electrode comprises copper and the second electrode comprises zinc. 
     
     
         22 . The method of  claim 17 , wherein the dressing further comprises a plurality of galvanic cells associated with the absorbent layer and configured to provide voltage proportional to the saturation of the absorbent layer of the dressing. 
     
     
         23 . A dressing for treating a tissue site on a patient, the dressing comprising:
 an absorbent layer for placing in fluid communication with the tissue site, the absorbent layer for receiving and retaining ionic fluids, the absorbent layer having a first side and a second, patient-facing side;   a sealing member for covering the absorbent layer; and   a conductive loop fluidly coupled to the absorbent layer and having a first terminal, a second terminal, and at least one conductive gap, wherein the conductive gap is sized and configured to be electrically bridged when covered with the ionic fluid.   
     
     
         24 . A dressing for treating a tissue site on a patient, the dressing comprising:
 an absorbent layer for placing in fluid communication with the tissue site, the absorbent layer for receiving and retaining fluids, the absorbent layer having a first side and a second, patient-facing side;   a dye associated with the absorbent layer, wherein the dye is operable to change optical properties when becoming wet;   a sealing member for covering the first side of the absorbent layer; and   an electrical optical sensor associated with the absorbent layer and configured to detect a change in optical properties of the dye and to produce an electrical signal when the change has been sensed.   
     
     
         25 . A dressing for receiving an ionic fluid, the dressing comprising:
 a treatment manifold for placing in fluid communication with a tissue site and for receiving ionic fluids, the treatment manifold having a first side and a second, patient-facing side;   a sealing member for covering the first side of the treatment manifold;   a first galvanic cell associated with the treatment manifold and configured to produce a voltage when a portion of the treatment manifold proximate to the first galvanic cell is substantially saturated with the ionic fluid.   
     
     
         26 . A reduced-pressure treatment system comprising:
 a treatment manifold for placing in fluid communication with a tissue site and for receiving ionic fluids, the treatment manifold having a first side and a second, patient-facing side;   a sealing member for covering the first side of the treatment manifold;   an absorbent layer disposed between the sealing member and the treatment manifold;   an electronic detection device associated with the absorbent layer for producing an electrical signal indicative of at least a fully saturated state; and   a wireless-communication-and-power subsystem comprising:
 an antenna, communication, and processing unit associated with the electronic detection device, and 
 a remote wireless communication and power unit configured to transmit power to the antenna, communication, and processing unit and to receive a signal therefrom. 
   
     
     
         27 . A dressing for treating a tissue site, comprising
 a tissue dressing member for location adjacent to the tissue being treated; and   at least one liquid sensor for detecting the presence of liquid at a location on or in the tissue dressing member.   
     
     
         28 . The dressing according to  claim 27 , wherein the dressing member comprises a treatment manifold. 
     
     
         29 . The dressing according to  claim 27 , wherein the dressing member comprises an absorbent member. 
     
     
         30 . The dressing according to  claim 27 , further comprising a sealing member for covering the tissue dressing member. 
     
     
         31 . A dressing according to  claim 27 , wherein the at least one liquid sensor is a galvanic cell. 
     
     
         32 . The dressing according to  claim 27 , wherein the at least one liquid sensor is a selectively conductive loop, the loop comprising conductive material having spaces which may be bridged by an ionic liquid contacting a surface of the loop thereby electrically completing the loop. 
     
     
         33 . The dressing according to  claim 27 , wherein an optical property of the tissue dressing member is configured to change upon absorption of a liquid, and wherein the sensor is an optical sensor for detecting that change. 
     
     
         34 . The dressing according to  claim 33 , wherein the optical property is color. 
     
     
         35 . The dressing according to  claim 27 , comprising a plurality of sensors. 
     
     
         36 . The dressing according to  claim 27 , wherein the at least one sensor is located on a surface of the tissue dressing. 
     
     
         37 . The dressing according to  claim 27 , wherein the at least one sensor is located within the tissue dressing. 
     
     
         38 . The dressing according to  claim 33 , wherein the sensor is located on the outside of a sealing member covering the tissue dressing member. 
     
     
         39 . The dressing according to  claim 27 , further comprising a pump located with the dressing for applying a reduced pressure to the tissue site. 
     
     
         40 . The dressing according to  claim 27 , further-comprising:
 a monitoring device electrically connected to the at least one liquid sensor and configured to provide an indication of detection of liquid by the at least one liquid sensor.