D.C. epidermal biopotential sensing electrode assembly and apparatus for use therewith

• US 5,560,357 A
• Filed: 01/27/1995
• Issued: 10/01/1996
• Est. Priority Date: 11/04/1991
• Status: Expired due to Fees

• Current Assignee: Biofield Corporation
• Original Assignee: Biofield Corporation
• Inventors: Hahn, deceased, Steven, Faupel, Mark L.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US08/379,994
• Time in Patent Office: 613 Days
• Field of Search: 128/635, 128/639, 128/640, 128/642, 128/641, 128/657, 128/734, 604/20, 607/901
• US Class Current: 600/345
• CPC Class Codes: A61B 2562/0238 Optical sensor arrangements for performing transmission measurements on body tissue
• CPC Class Codes: A61B 2562/08 Sensors provided with means for identification, e.g. barcodes or memory chips
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/2415 Measuring direct current [DC] or slowly varying biopotentials
• CPC Class Codes: A61B 5/25 Bioelectric electrodes therefor
• CPC Class Codes: A61B 5/259 using conductive adhesive means, e.g. gels
• CPC Class Codes: Y10S 607/901 Cancer detection

Abstract

The apparatus and method for screening and diagnosing trauma or disease in body tissues involves the use of DC biopotential sensing electrodes having DC offset potentials within an acceptable range and electrical characteristics which enhance the accuracy of the biopotential measurement. The apparatus checks the electrodes connected thereto prior to a measurement cycle and will not initiate the measurement cycle if improper electrodes are present. The electrodes may be formed to selectively pass only certain ions thereby enhancing the sensitivity of the electrodes.

Claims

1. A D.C. epidermal biopotential sensing electrode assembly for use with an apparatus for determining a cancerous condition at a test site on a human or animal subject as a function of an electromagnetic field present in the subject at that test site comprising:

a base,

an electrode element mounted upon said base,

an electrical terminal connected to said electrode element to conduct an electrical potential therefrom, and

contact means mounted in contact with the electrode element for contacting the skin of the subject at the test site to facilitate the migration of ions associated with cancerous growth between the subject and the electrode element, said contact means including a conductive gel and a selective ion exchange means in contact with said conductive gel and operative to permit only ions having a particular electrical change to migrate between said subject and said electrode element while excluding other ions, said selective ion exchange means including an ion exchange membrane formed of an ion exchange resin mounted in contact with said conductive gel in spaced relationship to the electrode element.

2. The D.C. epidermal biopotential sensing electrode of claim 1 wherein said ions permitted to migrate between said subject and the electrode are only positively charged ions, said ion exchange resin being a solid polymer cation exchange material.

3. An apparatus for indicating a cancerous condition at a test site on a human or animal subject by measuring D.C. electrical biopotentials which are a function of an electromagnetic field present in the subject at said test site comprising:

a selective electrode sensing means which operates at a point of skin contact at the test site where a change in chemical composition may arise due to the presence of cancerous cells to detect D.C. biopotentials indicative of said electromagnetic field and provide output test potentials, said selective electrode sensing means including at least one epidermal D.C. biopotential sensing electrode to provide a reference electrode for contacting the skin of the subject at a reference site and at least one epidermal D.C. biopotential sensing electrode to provide a test electrode for contacting the skin of the subject at said test site, said test electrode including a base, an electrode element mounted upon said base, an electrical terminal connected to said electrode element to conduct an electrical potential therefrom, and contact means mounted in contact with the electrode element for contacting the skin of the subject at the test site to facilitate the selective migration of ions between the subject and the electrode element, said contact means including a conductive gel and a selective ion exchange means in contact with said conductive gel and operative to permit only predetermined ions to migrate between the subject and said electrode element, said selective ion exchange means including an ion exchange membrane mounted in contact with said conductive gel in spaced relationship to the electrode element, and

processing means connected to receive said test potentials from said selective electrode sensing means, said processing means operating during a test period to sample a plurality of test potentials from said selective electrode sensing means.

4. The apparatus of claim 3 wherein said reference electrode and sensing electrode form a D.C. biopotential sensing electrode pair having a D.C. offset potential within a limited range of from 0 to 1.0 millivolts D.C.

5. The apparatus of claim 4 wherein said selective ion exchange membrane is formed of ion exchange resin, said ion exchange means operating to permit only ions having a particular electrical change to migrate between said subject and said electrode element.

6. The apparatus of claim 3 wherein said ion exchange membrane is a solid polymer cation-exchange membrane which permits only positively charged ions to migrate between said subject and the electrode element.