Wireless Power Transfer to Biomedical Implants for Patient Monitoring

Abstract

A real-time active matching circuit (MC) for wireless power transfer applications, especially for
biomedical systems. One prototype of low-cost real-time automatic MC, utilizing a variable circuit topology,
including discrete passives and p-i-n diodes, has been implemented and the principle has been verified by
measurements. One genetic algorithm was introduced to optimize the design over a wide range of impedances
to match. As a result of preliminary operation verification tests, the proposed real-time MC system results in
improving the transfer coefficient. Similar performance improvement results were observed in additional tests
under misaligned conditions, as well as for nonsymmetrical Tx–Rx coil configurations further verifying the
potential applicability of the proposed system to practical biomedical devices.