Pulsed transmission waveform to mitigate tissue thermal effects in transcutaneous wireless energy supply systems for high-power rated medical implants

Therapeutic options in end stage heart failure include cardiac transplantation or mechanical circulatory support: Left Ventricular Assist Device (LVAD) or Total Artificial Heart (TAH). These devices have relatively high power requirements (5-80W). Existing power supplies to LVAD and TAH are via percutaneous drivelines with a high frequency of complications including infection. We have developed a wireless Transcutaneous Energy Transmission (TET) waveform protocol and system technology which address the major clinical drawbacks of existing systems: skin tissue thermal effect and system durability. Conventional single-channel TET solutions have significant limitations, including inefficient energy transfer characteristics and high energy density levels producing tissue thermal effects. A reduced lifetime of the internal rechargeable battery is an additional drawback. In the proposed novel system, a multi-channel, time-space multiplexed and pulsed RF transmission waveform transcutaneous power delivery approach, is presented for sustained internal energy supply to high-power rated implantable devices. The bench system prototype performance evaluation results, revealed excellent high-energy transfer efficiency and safer management of lower energy density levels. In conclusion, the proposed pulsed transmission waveform protocol and multi-channel concepts can be configured for individual high-power rated LVAD devices to effectively mitigate tissue thermal effects and to prolong backup battery lifetime.