An electrocardiographic electrode is disclosed, which is to be held in close contact with a person's skin for deriving a weak voltage from an inner part of the person. The electrode includes a viscous base member to be held in close contact with the person's skin and having a central opening, a reinforcement...http://www.google.es/patents/US4773424?utm_source=gb-gplus-sharePatente US4773424 - Electrocardiographic electrode
