Two probes for tissue impedance measurement each have first and second conductive rings unitarily arranged with an insulative member separating the rings. The conductive rings are coaxially arranged and have individual lead wires connected thereto which extend from one end of the probe for connection...http://www.google.com/patents/US4729385?utm_source=gb-gplus-sharePatent US4729385 - Probe and method of use for detecting abnormal tissues
