Transcutaneous Energy Transmission for Artificial Heart

Abstract

Transcutaneous energy transmission is a noninvasive method for supplying power to an implantable artificial heart. However, it is necessary to continue energy transmission using a transcutaneous transformer during bathing because an implantable battery is not yet commercially available. In this study, we evaluated the electromagnetic safety, transmission efficiency, and temperature rise of two types of transformers (air-core-flat type and externally coupled type) immersed in various conductive liquids, with the assumption of bathing and sweating. It was found that, as the liquid conductivity increased, the transmission efficiency decreased; and as the transmission frequency increased, the efficiency decreased significantly. When the transformers were immersed in 0.9% NaCl solution with the assumption of bathing and sweating, the transmission efficiency of each transformer was higher than 94.4% for a transmission frequency of 400 kHz, and the temperature rise was less than 0.3°C. These findings indicate that our transcutaneous transformers can transmit energy to artificial hearts even when immersed in 0.9% NaCl solution.