MEDICAL-ELECTRONIC INSTRUMENTS AND ACCESSORIES FOR IMPLANTATION IN AND OPERATION UPON THE HUMAN BODY-NAMELY, [ ELECTRO-COAGULATION FORCEP UNITS; VEIN ERASERS; ] PACEMAKERS AND PACEMAKER SYSTEMS INCLUDING IMPLANTABLE [ AND EXTERNAL ] PACEMAKERS AND SYSTEMS OF BOTH THE DEMAND AND FREE RUNNING TYPES; [ AND ELECTRODES INCLUDING TEMPORARY ENDO-CARDIAC ELECTRODES FOR USE WITH SUCH SYSTEMS ]