| abstract |
A medical electrode (10) adapted for providing electrical contact with a patient's skin and comprises:n a) a conductive member (16) including means (18, 22) for connecting the medical electrode to an external electrical apparatus; and b) interfacing means comprising a solid sheet of a conductive viscoelastic hydrophilic gel (12) which is a homogeneous aqueous mixture, substantially free of unbound water, monomers and cross-linking agents, consisting essentially ofn i) water; ii) an amount dissolved in the water of a water soluble electrolyte effective to reduce the transverse electrical resistance of the sheet to an impedence at 60 Hz of less than 1,000 ohms; and iii) an amount dispersed uniformly throughout the water of from about 2 to 35 wt% of a cross-linked polymer, effective to form with the water a tacky surface viscoelastic adhesive solid which hydrophilic gel is produced by subjecting a liquid film of an aqueous solution having a viscosity of about 2-2,000 × 10³ cps of the electrolyte and a linear water soluble polymer having a weight average molecular weight from about 0.05-10 × 10⁶ Daltons to an amount of high energy radiation effective to convert the liquid film to a sheet of adhesive viscoelastic solid. |