Abstract: A surgical tool for use in implanting a heart pacer. The tool includes a handle from whose one end an Allen wrench extends and in whose other end an O-ring plug having a stem is removably held by the stem. The wrench serves to screw an Allen-head set screw into the pacer to secure the terminal of the catheter which connects the pacer to the heart electrically. The plug seals the hole in which the set screw is inserted preventing electrical leakage by reason of penetration of body fluids to the terminal. The stem is removed from the plug and may serve to seal the suture hole in the pacer when the pacer is not sutured in place.

Abstract: A heart pacer to be implanted between the pectoralis major muscle and the skin a short distance below the clavicle having an outer container in the shape of an ovaloid. Such a heart pacer adapts itself positionally, cosmetically and with a minimum of discomfort to implantation.

Abstract: A nuclear heart pacer having a heat-to-electricity converter including a solid-state thermoelectric unit embedded in rubber which is compressed to impress hydrostatic precompression on the unit. The converter and the radioactive heat source are enclosed in a container which includes the electrical circuit components for producing and controlling the pulses; the converter and components being embedded in rubber. The portions of the rubber in the converter and in the container through which heat flows between the radioactive primary source and the hot junction and between the cold junction and the wall of the container are of thermally conducting silicone rubber.The primary radioactive source material Pu.sub.238 is encapsuled in a refractory casing of WC-222 (T-222) which in turn is encapsuled in a corrosion-resistant casing of platinum rhodium, a diffusion barrier separating the WC-222 and the Pt-Rh casings. The Pt-Rh casing is in a closed basket of tantalum.