RF-Powered Cage System for Implant Biotelemetry

A radio-frequency-powered rectangular cage (1 m ×0.75 m ×0.75 m) has been designed to power a biotelemetry transmitter implanted in animals. Electromagnetic coupling is used in place of conventional batteries to supply dc power to the implant, thus extending the lifetime of the implant unit indefinitely. The same frequency is used for both RF powering and signal transmisision by a time-sharing scheme. The result of the design, construction, and testing of the RF powering system in the laboratory as well as an animal evaluation with a rabbit to telemeter ECG under "normal" living conditions over 24 months are reported.