Communications Link for an Implantable Electrode Array

摘要

The research conducted in this thesis develops an implantable communications (biotelemetry) link for the Air Force Institute of Technology's implantable, multiplexed, multielectrode array used to record electric potentials on the visual cortex of a mammal. A prototype is developed to test the feasibility of transcutaneous data transfer and power transfer for a system relaying 100KHz of data bandwidth. The working system uses a varactor FM modulator, phase locked loop demodulator, and op amp signal amplification. Power transfer is made by a single frequency RF inductive couple to an implanted rechargeable Ni-Cd battery pack. The implanted system draws 18 milliwatts of power and the power supply is capable of supplying 30 milliamps of current at 5 volts for a 2 hour period before recharging is required. Details of the design procedures as well as recommendations for an implantable system realization are included.