Abstract

Over the past two decades, battery driven low-power wireless communications deviceshave become common place in everyday life. Yet, over the same time period, the adaptation of these technologies for wireless enablement of implantable medical devices has failed to progress at a similar rate; predominately due to the significant problems associated with the use of chemical power sources within hydrated living tissues. In recent years, several multi-disciplinary research teams have reported limited success at using full custom microelectronic technologies for battery free wireless enablement of a small number of implantable diagnostic sensors. However, it remains unclear as to whether any of these systems would prove commercially viable or meet with the regulatory standards governing the use of non-ionising radiation in such applications. In this work, a battery free wireless enabled implantable microelectronic platform architecture for in-vivo tissue impedance measurement is proposed. The platform architecture has been specifically designed to employ low-cost regulatory compliant commodity technologies; utilising near field magnetic coupling at HF-RFID (High Frequency - Radio Frequency Identification) wavelengths for power delivery and a far-field MedRadio (Medical Radio) transceiver for high-speed low-power data transfer. Top-level schematic simulations were initially used to verify the design. Prototype fabrication and electrical test were subsequently used to demonstrate proof of concept. Careful attention to design best practice has led to the realization of a novel platform architecture that has the potential to facilitate significant unit cost reductions.