Ag/AgCl electrode assembly for thin smooth muscle electromyography.

An electrode assembly for in vivo recording of the electrical activities of thin muscular layers is described. It comprises an active electrode surrounded by a ring, which avoids the recording of interfering signals. An improved technique for chlorinating the silver electrodes is presented: a partial electrolytic removal of an initial thick deposit is performed. This decreases the impedance, and lowers the ageing degradation of the electrodes in vivo. Recordings of extremely low frequency signals are allowed, whereas standard Ag/AgCl electrodes are inefficient when recording signals in the frequency domain under 0.1 Hz. The technical features which are described can be adapted to any Ag/AgCl electrode developed for in vivo measurements.