Capacitive Wireless Power and Data Transfer for Implantable Medical Devices

Abstract

Reliable data transmission and sustainable wireless powering are key for a majority of implantable medical devices for performing a multitude of operations. This paper proposes and demonstrates an experimental working bench-top model for the first time of a wireless powering scheme for bio-medical implants through a 2-contact resonant capacitive link where data has been transmitted simultaneously in a hybrid amplitude-frequency shift keying (ASK-FSK) technique over the same channel. This technique is well suited for a high-density micro-stimulation implants and the data telemetry rate is independent of the power carrier frequency. A proof-of-concept table-top setup using 20 mm × 20 mm flexible and conformable capacitive patches with a beef slice of 3 mm thickness demonstrates this idea and helps us carry out preliminary experiments. Experimental results show that for an air-kapton gap between the capacitive patches, the power delivered to the load (PDL) is up to 90 mW with data transfer rate of 170 kbps and power transfer efficiency (PTE) of 70%, whereas for a 3 mm thick beef tissue sample separation with the same setup, the observed PDL was 12 mW with a PTE of 36%.