Conductive adhesive and biomedical electrode

Claim 2

In an ECG electrode comprising an electrode plate having an upper surface and a lower skin-directed surface, means for electrically-connecting said electrode plate to the lead wire of an electrocardiograph, and a layer of an electrically-conductive pressure-sensitive adhesive on the lower surface of electrode plate, the improvement wherein said adhesive comprises a nonionic swellable, conformable, cohesive, dermally-non-irritating hydrophilic synthetic cross-linked acrylic acid polymer; polyhydric alcohol which is liquid at about 20° C.; and an ionizable salt in an amount effective to render said adhesive electrically-conductive; said polymer being polymerized and cross-linked after formation into said layer to form a continuous covalently-bonded network throughout said layer.

Claim 3

The electrode according to claim 1 wherein said ionizable salt contains a halide ion.

Claim 4

The electrode according to claim 2 wherein said halide ion is chloride.

Claim 5

The electrode according to claim 3 wherein said salt is potassium chloride.

Claim 6

The electrode according to claim 1 wherein said polyhydric alcohol comprises from about 10 to about 90 parts per weight of said adhesive.

Claim 7

The electrode according to claim 5 wherein said polyhydric alcohol is glycerol.

Claim 8

The electrode according to claim 1 wherein said adhesive further comprises a tackifier selected from the group consisting of polyacrylic acid and soluble salts thereof.

Claim 9

The electrode according to claim 1 wherein said electrode plate comprises a layer of metal foil.

Claim 10

The electrode according to claim 8 wherein said metal is tin.

Claim 11

The electrode according to claim 1 wherein said electrode plate comprises a non-woven web having metallic silver vapor-coated on the lower surface thereof.

Claim 12

In a biomedical electrode comprising an electrode plate having an upper surface and a lower skin-directed surface, said electrode plate having means for electrical connection to a lead wire of an electro-medical device, and a layer of an electrically-conductive pressure-sensitive adhesive on said lower surface of said electrode plate for enhancing electrical connection with the skin, the improvement wherein said adhesive layer comprises a swellable, dermally-nonirritating, conformable, cohesive, hydrophilic polymer formed by the in situ photo-polymerization of an adhesive precursor comprising (1) a water-soluble polyhydric alcohol which is a liquid at about 20° C.; (2) acrylic acid (3) a photo-initiator soluble in said polyhydric alcohol; (4) a crosslinking agent of a multifunctional unsaturated free radically-polymerizable material soluble in said polyhydric alcohol; and (5) an ionizable salt in an amount effective to render said conductive material electrically conductive; whereby said adhesive layer is a continuous covalently bonded network throughout said adhesive layer.

Claim 13

In a biomedical electrode comprising an electrode plate having an upper surface and a lower skin-directed surface, said electrode plate having means for electrical connection to a lead wire of an electro-medical device, and a layer of an electrically-conductive pressure-sensitive adhesive on said lower surface of said electrode plate for enhancing electrical connection with the skin, the improvement wherein said adhesive layer comprises a swellable, dermally-nonirritating, conformable, cohesive, hydrophilic polymer formed by the in situ photo-polymerization of an adhesive precursor comprising (1) a water-soluble polyhydric alcohol which is a liquid at about 20° C.; (2) acrylic acid (3) a photo-initiator soluble in said polyhydric alcohol; (4) a crosslinking agent of a multifunctional unsaturated free radically-polymerizable material soluble in said polyhydric alcohol; and (5) an ionizable salt in an amount effective to render said conductive material electrically conductive; whereby said adhesive layer is a continuous covalently bonded network throughout said adhesive layer.

Claim 14

The essentially dry biomedical electrode according to claim 11 wherein the photo-initiator is benzildimethylketal.