System monitoring reprogrammable implantable transponder

摘要

A passive transponder including an antenna for receiving an input signal and transmitting an output and a memory for storing the data received by the transponder from an interrogator. The transponder can operate in either a read mode or a programming mode. The transponder includes an integrity circuit for indicating the integrity of the input signal, a monitoring circuit that monitors a characteristic of a host and an impedance modulator that prevents the overmodulation of the output signal.