SURFACE METALLIZATION OF DEFRIBRILLATOR LEADS

DEFIBRILLATING ELECTRODES APPLIED DIRECLY TO THE HEART WORK SUCCESSFULLY WHEN THE EFFECTIVE CONTACT AREA BETWEEN ELECTRODE AND MYOCARDIUM IS LARGE. RESEARCHERS HAVE NOTED THAT LARGE PATCH LEADS DEFIBRILLATE MORE EFFECTIVELY THAN SMALL ONES, AND THAT LEADS IN INTIMATE CONTACT WORK BETTER THAT THOSE NOT FIRMLY ATTACHED TO THE HEART. OWING TO THEIR POROUS TITANIUM MESH, CURRENT IMPLANTABLE DEFIBRILLATOR LEADS ELICIT A RELATIVELY HIGH IMPEDANCE AGAINST HEART TISSUE. FURTHERMORE, THE TIO SURFACE THICKENS WITH EACH DISCHARGE, THINNING THE USEFUL TITANIUM SURFACE, AND EVENTUALLY AFFECTING THE MECAHNICAL STABILITY OF THE WOVEN TITANIUM WIRE. PHASE I RESEARCH WILL INVESTIGAGE THE DEVELOPMENT OF LOW-IMPEDANCE, PLATINUM METALLIZED POLYMER TO SAFELY AND EFFECTIVELY DEFILBRILLATE HEART TISSUE. SILICONE RUBBER PATCHES WILL BE ION BEAM TEXTURED TO PROMOTE TISSUE INGROWTH AND INCREASE SURFACE AREA. ION BEAM ASSISTED DEPOSITION (IBAD), WHICH CONSISTS OF METAL DEPOSITION WITH CONCURRENT ION BOMBARDMENT, WILL BE USED TO GROW A PLATINUM COATING ON THE TEXTURED SILICONE RUBBER. THE COATING WILL BE EVALUATED AND SHOWN TO BE DELAMINATION FREE AND ELECTRICALLY CONDUCTIVE (DESPITE SURFACE ELONGATION AND RELAXATION), AS WELL AS BIOCOMPATIBLE. INTEGRATING THIS NOVEL DEFIBRILLATOR PATCH WITH CURRENT LEAD WIRES WILL BE INVESTIGATED, WITH PARTICULAR EMPHASIS UPON THE LEAD WIRE/PLATINUM SURFACE INTERFACE. PHASE II EXTENDS THE SCOPE OF PHASE I TO INCLUDE SYNTHESIS OF ACTUAL LEADS FOR COMPARISON TESTS AGAINST PRESENT LEADS. MORE ANALYTICAL AND COMPREHENSIVE TESTING WOULD BE PERFORMED UNDER SIMULATED IMPLANT CONDITIONS.