Book Description

The temperature-sensing telemetry system consists of three implanted transmitters (each with its own antenna system and receiver), a scanner to sample in sequence each receiver output, a frequency counter, digital recorder, and tape punch unit. The scanner, synchronized with the digital recorder, permits temperature recording from each of the three transmitters once every 5 minutes. The implant is an FM/FM (frequency-modulated subcarrier/ frequency-modulated transmitter) telemetry unit operating in the 88 to 108 MHz FM broadcast band. Thermistors are used as temperature sensors. Printed circuit boards are used for component interconnection and antenna; mercury batteries are used for power. The sensor, radio frequency transmitter, and batteries are embedded in an epoxy case. Before implantation the unit is calibrated in a water bath over the temperature range of 34 to 42 degrees C. The system has been used to automatically record, digitally and continuously, temperature measurements of three unrestrained rhesus monkeys (Macaca mulatta) for a period of 5 weeks.