A Windowless Si Radiation Detector and Biomedical Telemetry System for Studying the Function of Organs of Free-Ranging Animals

A windowless silicon radiation detector and biotelemetry system has been developed and used in the study of the function of organs of free ranging animals. The system consists of an implantable silicon radiation probe, a transmitter package, an FM receiver, and a data handling unit. The intensity of radioisotopes (RI) taken in the organs is measured continuously with an implantable probe with a 5 mm diameter sensitive area. The transmitter package is composed of an RI signal conditioner, and a transmitter. The prototype transmitter package is made of aluminum, and 2 × 6 × 9.5 cm in size. With electronic components included, it weighs 170 gm. The power consumption of the transmitter is about 100 mW, and is furnished from three 5 V mercury batteries. Two of them are used as the detector bias supply. The system was made of discrete electronic components because of their more reliability, lower operating voltage, and lower power consumption. The fundamental characteristics and field performance of the system were carried out using several dogs with the aid of radioisotopes. The application of the system like the study of liver metabolism of dog is discussed.