SET-UP, IMPROVEMENT, AND EVALUATION OF AN ELECTROHYDRAULIC TOTAL ARTIFICIAL-HEART WITH A SEPARATELY PLACED ENERGY CONVERTER

The authors have been developing an electrohydraulic total artificial heart (TAH) system with a separately placed electrohydraulic energy co nverter to minimize anatomic constraints in the pericardial space. Imp rovements to the system and current status of the development are repo rted. The energy converter was miniaturized to improve implantability, and its thickness was reduced to 54 mm. System efficiency was increas ed by suppressing rush current at the time of motor reversal. Maximum cardiac output of the TAH system was 9 L/min, and maximum system effic iency increased to 10%. The blood pump system was implanted easily in the body of a 57 kg calf, and no significant temperature rise on the e nergy converter surface was observed. As the next step, main component s were integrated into a total system. The transcutaneous energy trans fer system could supply power to the TAH without a decline in pump per formance, and the internal battery could support the system at 6.5 L/m in of cardiac output for 1 hour without a decrease in cardiac output. The authors consider the TAH system with a separately placed energy co nverter the most promising approach to development of a TAH for smalle r sized patients.