Bio-medical electrode conductive gel pads

• US 3,998,215 A
• Filed: 04/23/1971
• Issued: 12/21/1976
• Est. Priority Date: 12/18/1968
• Status: Expired due to Term

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Anderson, Clifford J., Gumbusky, James T.
• Primary Examiner(s): Howell, Kyle L.
• Application Number:
  US05/136,768
• Time in Patent Office: 2,069 Days
• Field of Search: 128/2.06, 128/DIG. 4, 128/268, 128/417, 128/418, 252/518, 252/521
• US Class Current: 600/397
• CPC Class Codes: A61B 5/25 Bioelectric electrodes therefor
• CPC Class Codes: A61B 5/257 using adhesive means, e.g. adhesive pads or tapes
• CPC Class Codes: A61B 5/266 containing electrolytes, conductive gels or pastes

Abstract

A gel pad has impregnated in a porous matrix or held within a cavity, an electrically conductive hydrogel capable of transferring electrical signals between the human body and an electrode of an electrical sensing device when the hydrogel is in contact with the body surface. The hydrogel is lightly adherent to the body surface but sufficiently cohesive so that no residue remains when the pad is removed therefrom.

Claims

1. An electrically conductive pad conformable to the surface of the human body and adapted to facilitate the transfer of electrical signals between the body and an electrode, comprising a porous, fibrous carrier having a lightly adherent, conductive hydrogel carried thereby, said hydrogel impregnating and surfacing both sides of said carrier and said hydrogel being more cohesive to said hydrogel than adhesive to the surface of the human body to enable residue-free removal from the skin.

2. The pad of claim 1 wherein said porous, fibrous carrier is a fabric carrier having a substantially porous matrix.

3. The pad of claim 2 wherein said fabric carrier is an absorbent, non-woven fabric.

4. The pad of claim 1 wherein said hydrogel comprises a mixture of water, polyvinyl alcohol, sodium borate decahydrate and a fungicide, said water being present in a concentration of at least about 70% by weight.

5. The pad of claim 1 wherein said carrier has a porosity of from about 300 cc. of air in 0.1 to 50 seconds as measured on a Gurley Densometer and a volume resistivity of from about 5 ohm-cm to 50,000 ohm-cm.

6. The pad of claim 5 wherein said hydrogel comprises a mixture of water, polyvinyl alcohol, sodium borate decahydrate and a fungicide, said water being present in a concentration of at least about 70% by weight.

7. The pad of claim 5 wherein said fibers are rayon fibers.

8. An electrically conductive pad conformable to the surface of the human body and adapted to facilitate the transfer of electrical signals between said body and an electrode, comprising a thin layer of a reinforced, lightly adherent, conductive hydrogel reinforced with from about 0.5 to 10% by weight of a fibrous material, said hydrogel being available for contact with the skin on at least two sides, said hydrogel being more cohesive to said hydrogel than adhesive to the surface of the human body to enable residue-free removal from the skin.