Hybrid biological power cells for cardiac pacemakers--materials evaluation.

A number of cathode and anode materials for an implantable hybrid biogalvanic fuel cell have been evaluated. Results of in vitro polarization tests and in vivo experiments with a voltagesensing transmitter are presented. Experiments performed in an artificial interstitial-fluid (AIF) electrolyte are also discussed. A Pt activated-carbon cathode and zinc anode have exhibited the most suitable characteristics when all aspects of this type of power source are considered. This electrode pair has been used to power a cardiac pacemaker in two dogs with surgically created A-V blocks.