Remotely powered telemetry system with dynamic power-adaptation for freely moving animals

A complete implantable system for monitoring vital parameters via bio-sensors inside freely moving laboratory animals and its experimental verification are presented. The system harvests 2 mW power wirelessly and the power is transmitted at 10 MHz by an array of coils placed under the living space of the animal. Dynamic power-adaptation is used to transfer sufficient power to implanted module by adjusting the base module power with respect to animal position. Results on the micro-modules incorporating custom 0.18 um CMOS circuits verify a 80% power efficiency at 2 mW load and 60 dB of ripple suppression, as required to supply the implanted bio-sensors.