Effect of coil structures on performance of a four-coil WPT powered medical implantable devices

Wireless power transfer technology (WPT) is rigorously gaining huge prospect in medical implantable devices such as pacemakers, left ventricle assist devices (LVAD), deep brain stimulator etc. The major challenges faced while designing the WPT system for medical implants are the size of the coils and the power transfer efficiency. Hence, alignment of the coils and their structures decides the performance of the overall system. In this paper, a four coil WPT system has been experimentally designed based on the dimensions suitable for LVAD system. The analytical design approach of the system and its parameters are presented in the paper. The performance of the four-coil system is tested at distinct air gaps between the coils and for various source frequencies. The lateral misalignment tolerance of the designed system is also tested for various coil-coil distances. The work presented in this paper, is mainly focused on the analysis of effect of coil structure on various parameters of the WPT system. The comparative results of the system for circular and square coil structures are verified and are documented in this paper.