Transcutaneous Energy Transfer System for Cardiac Assist Devices by Use of Inhomogeneous Biocompatible Core Material

A novel magnetic liquid silicone rubber composite core design applicable to wireless power transfer (WPT) for medical applications is presented. As a case study, the integration of WPT, including the proposed cores for the coils, with ventricular-assist devices (VADs) was investigated. This facilitates transferring 4.6 W of power wirelessly through the skin layer, which, thus, allows to disposal of the transcutaneous cable that connects the extracorporal batteries to the implanted blood pump. To enhance the coupling coefficient and consequently increase the WPT efficiency, the geometry of the cores was optimized. This reduces the temperature increase in the implant area. The field and thermal simulations were carried out with CST software. The electrical properties of the proposed design as obtained by simulation were validated by measurements. The simulation results perfectly coincide with the measured results. Finally, a new optimized design with additional high permeability core inserts is introduced to further increase the coupling coefficient. The results indicate that the coupling coefficient is increased from 0.31 to 0.52 with the optimized design compared to the case without cores. Moreover, by fixing the initial temperature as 37 °C, the maximum temperature is decreased from 38.19 °C to 37.27 °C while keeping the transferred power fixed. Its high magnetic conductivity, biocompatibility, low-loss property, flexibility, and Qi-standard compatibility make the proposed WPT design an excellent candidate for the wireless powering of heart-assist devices, such as VADs.