Biomedical dispersive electrode

Abstract

Herein is disclosed a biomedical dispersive electrode which can redistribute the current in the subject body, increase subject safety, reduce the chance for burns and other tissue damage as well as discomfort experienced by subject during or after usage. Electrodes based on the principles of this invention can be made smaller than electrodes based on the principles of the prior art.

1 . A biomedical electrode adapted for use in combination with an electrical generator, said electrode comprising:
 a. a layer of conductive dielectric;   b. a series of discrete electrical conductors mounted to one side of said conductive dielectric layer, said series electrical conductors comprising one or more inner conductors and at least one outer conductor; and   c. one or more electrical connections for connection to the electrical generator to establish a return current thereto,   wherein said electrical connections are attached exclusively to said one or more of said inner conductors, further wherein said biomedical electrode provides a relatively uniform radial redistribution of current at a subject contacting surface.   
     
     
         2 . The biomedical electrode of  claim 1 , wherein said conductive dielectric layer is of non-uniform thickness. 
     
     
         3 . The biomedical electrode of  claim 2 , wherein the thickness of said conductive dielectric layer increases from its center point to its outer edges. 
     
     
         4 . The biomedical electrode of  claim 2 , wherein the thickness of said conductive dielectric layer tapers from a first thickness at its outer edge to a reduced second thickness at its center point. 
     
     
         5 . The biomedical electrode of  claim 2 , wherein the thickness of said conductive dielectric layer decreases in a stepwise fashion from a first thickness at its outer edge to a reduced second thickness at its center point. 
     
     
         6 . The biomedical electrode of  claim 1 , wherein the outer edges of said conductive dielectric layer extend beyond a perimeter defined by said series of electrical conductors. 
     
     
         7 . The biomedical electrode of  claim 1 , wherein said conductive dielectric has an electrical resistivity ranging from 0.1 to 200 ohm·m. 
     
     
         8 . The biomedical electrode of  claim 1 , further comprising an additional layer of conductive dielectric material disposed over said series of electrical conductors such that the series of electrical conductors are sandwiched between two layers of conductive dielectric material. 
     
     
         9 . A passive dispersive electrode comprising a thin flexible pad adapted to conform to the body of a subject and for use in combination with an electrical generator, collecting current induced by said electrical generator in the body of the subject, said pad comprising:
 a. a layer of conductive dielectric;   b. one or more electrical conductors mounted to one side of said conductive dielectric layer; and   c. one or more electrical connections attached to said one or more of electrical conductors connecting said electrical conductors to said electrical generator to establish a return current thereto,   wherein said conductive dielectric layer is characterized by (a) a non-uniform thickness, (b) outer edges that extend beyond a perimeter defined by said one or more electrical conductors, or (c) both;   further wherein said dispersive electrode provides a relatively uniform radial redistribution of current at a subject contacting surface.   
     
     
         10 . The dispersive electrode of  claim 9 , wherein the thickness of said conductive dielectric layer increases from its center point to its outer edges. 
     
     
         11 . The biomedical electrode of  claim 9 , wherein the thickness of said conductive dielectric layer smoothly tapers from a first thickness at its outer edge to a reduced second thickness at its center point. 
     
     
         12 . The biomedical electrode of  claim 9 , wherein the thickness of said conductive dielectric layer decreases in a stepwise fashion from a first thickness at its outer edge to a reduced second thickness at its center point. 
     
     
         13 . The biomedical electrode of  claim 9 , wherein said conductive dielectric has an electrical resistivity ranging from 0.1 to 200 ohm·m. 
     
     
         14 . The biomedical electrode of  claim 9 , further comprising an additional layer of conductive dielectric material disposed over said one or more electrical conductors such that the one or more electrical conductors are sandwiched between two layers of conductive dielectric material. 
     
     
         15 . A biomedical electrode adapted for use in combination with an electrical generator, said electrode comprising:
 a. a layer of conductive dielectric;   b. one or more discrete electrical conductors mounted to one side of said conductive dielectric layer, wherein at least one of said electrical conductors comprises a multi-turn spiral; and   c. one or more electrical connections for connection to the electrical generator to establish a return current thereto,   wherein said electrical connections are attached to one or more said electrical conductors, further wherein said biomedical electrode provides a relatively uniform radial redistribution of current at a subject contacting surface.   
     
     
         16 . The biomedical electrode of  claim 15 , wherein said one or more discrete electrical conductors comprise a central conducting element circumscribed by a multi-turn spiral. 
     
     
         17 . The biomedical electrode of  claim 16 , wherein said central conducting element is split into two symmetric components. 
     
     
         18 . The biomedical electrode of  claim 15 , wherein said one or more discrete electrical conductors comprise a single spiral composed of a central conducting element connected to one or more intermediate curves that terminate in a single peripheral ring. 
     
     
         19 . The biomedical electrode of  claim 15 , wherein said one or more discrete electrical conductors comprise a pair of mirror-image split spirals symmetrically disposed about the center of said conductive dielectric layer. 
     
     
         20 . The biomedical electrode of  claim 15 , wherein said one or more discrete electrical conductors comprise a pair of nested spirals. 
     
     
         21 . The biomedical electrode of  claim 15 , wherein said multi-turn spiral comprises a curved spiral. 
     
     
         22 . The biomedical electrode of  claim 15 , wherein said multi-turn spiral comprises a polygonal spiral. 
     
     
         23 . The biomedical electrode of  claim 15 , wherein the outer edges of said conductive dielectric layer extend beyond a perimeter defined by said one or more electrical conductors. 
     
     
         24 . The biomedical electrode of  claim 15 , wherein said conductive dielectric has an electrical resistivity ranging from 0.1 to 200 ohm·m. 
     
     
         25 . The biomedical electrode of  claim 15 , further comprising an additional layer of conductive dielectric material disposed over said one or more electrical conductors such that the one or more electrical conductors are sandwiched between two layers of conductive dielectric material.