Patent 3998215 Issued on December 21, 1976. Estimated Expiration Date: December 21, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
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.