Coil Optimization Techniques for Power Transfer in Medical Implantable

Abstract

Bionic eye (Retinal prosthesis) is an electronic device designed to treat patients who are suffered from Retinitis Pigmentosa (RP). A consistent energy supply for the bionic eye should be achieved in order to maintain high efficiency of the device. In attempt to optimize the maximum power transfer and the misalignment tolerance, two coil structures are presented in this paper. Four parameters including mutual inductance, efficiency, voltage gain and power were measured experimentally and simulated by matlab. The experimental data showed close correlation with the theoretical simulations. At first, two single coils were placed in parallel. Although the power transfer obtained was the highest using this structure, the misalignment tolerance was low. This result did not align with the objective of this project that is to maximize the misalignment tolerance. As a result, a new coil structure of the receiver was proposed. It was made of two receiver coils either in square form or in circular form placed orthogonally. The result of the misalignment tolerance showed improvement in this coil structure. The experimental and simulation techniques proposed in this project could be applied to other inductive wireless power transfer links without limitations imposed by numerical methods.