Remote Energy Transmission for Powering Artificial Hearts and Assist Devices

Abstract

A high-capacity transcutaneous energy transfer (TET) system has been developed for implantable devices including artificial hearts and ventricular assist devices. The TET system provides more accurate self-tuning capabilities, increased power delivery, improved reliability, and a reduced size, in comparison with previous designs. The design of the TET was optimized with: (1) microprocessor-controlled tuning; (2) a current-sensing transformer; and (3) a reduced component count (4 versus 11 integrated circuits and 15 versus 51 discrete components). Based on these optimisations, the system efficiency has been increased through a 20% reduction in the power required to operate the circuit. The reduced component count has also provided a 40% reduction in the overall footprint of the circuitry. Circuit reliability has been improved by the reduction in complexity and component count. In vitro evaluation of the system has demonstrated its capability to deliver 44–120 watts at a d.c. input of 12–17 volts with coil spacings (in air) from 4 to 14 mm. In the spirit of cooperation, the developed system is also being made available to other research groups, for use with their respective devices. In conclusion, the developed TET delivers increased power (up to 120 watts), with a reliable design, that is efficient, and compact. Further in vitro and in vivo evaluations are ongoing.