An externally generated myriametric frequency magnetic carrier signal is resonantly reflected by a tuned coil in an implant. The lagging phase angle of the reflected signal is modulated at very low power by varying the impedance across the tuned coil in accordance with a data input signal. An external...http://www.google.fr/patents/US4361153?utm_source=gb-gplus-shareBrevet US4361153 - Implant telemetry system
