Harnessing Dermal Blood Flow to Mitigate Skin Heating Effects in Wireless Transdermal Energy Systems for Driving Heart Pumps

Abstract

This work focuses on the thermal analysis of a transdermal wireless radiofrequency (RF) energy transfer system, to power artificial heart pumps, particularly left-ventricular assist devices (LVADs). We aim to understand the blood perfusion factors to mitigate the skin heating effects and thermal injury to subcutaneous tissue under the RF coupling area. A 2-channel RF power loss emulator (RFPLE) system was developed to conduct a study independent of the wireless RF supply coupling method. The heating coils were implanted subcutaneously 6–8 mm beneath the porcine model skin. Heating effects due to RF coupling inefficiency power losses for conventional and our novel pulsed transmission waveform protocol were emulated. The thermal profiles were studied for varying levels of LVAD power requirement. An in-silico model was developed in parallel with the in-vivo experiments to aid the interpretation of results.