Analysis of low leakage magnetic field transcutaneous energy transfer for ventricular assist devices

A three-phase transcutaneous energy transfer (three-phase TET) is proposed to reduce the leakage magnetic field when transmitting power to implantable medical devices such as pacemakers, capsule-endoscopes, biological sensors, and ventricular assist devices. A previous study by the authors found that the magnetic field strength of a three-phase TET, which consists of six pancake coils, is lower than that of a typical TET and below the CISPR 11 regulation level when transmitting 15 W of power. In this study, the authors redesign the coils to be fan-shaped for power transmissions between 1-15 W. The theoretical energy transmission efficiency is calculated, and the magnetic field strength is analyzed using a method-of-moments simulation. The magnetic field of the redesigned three-phase TET is 15.6 dBμA/m lower than the regulation limit at frequencies of 1454 kHz.