Bidirectional telemetry for implantable systems

This paper describes the design, implementation and results of two optimized telemetry links for implantable systems. The goals are to transmit the information and the energy efficiently. The external to internal link has been designed with a novel schema to implement an OOK modulation, based in a class-E amplifier. The receiver used for the implant has a new structure to optimize the energy reception. An internal demodulator for the internal unit has been implemented in an ASIC 0.7/spl mu/m to obtain the information. The results have been of a 43% efficiency in the received-transmitted power at 2cm, a high bit rate 1Mbps with a carrier of 8MHz. The internal to external link has been designed to transmit a high bit rate 1.4Mbps with a few mW. In this case, an external receiver that recovers the signal contaminated for the external to internal link has also been designed.