A data telemetry system for use with implanted medical devices for transmitting digital and analog data to a remote receiver by enabling different combinations of fixed and variable value current sources according to a telemetry logic code to energize a tank coil and produce a ringing type of variable...http://www.google.com.au/patents/US4556063?utm_source=gb-gplus-sharePatent US4556063 - Telemetry system for a medical device
