Miniaturized Optoelectronic Transceiver for Application and Pick-Up of Biological Signals

We present a two-way optoelectronic transmission system for telemetry between a main instrument and a satellite mobile unit to be mounted on a laboratory animal The link employs a pair of LED/photodiode transmitters and receivers operating in regime of diffused infrared radiation from laboratory walls and ceiling.The system offers an accuracy of 0.5% in amplitude and a signal bandwidth of IKHz with a high degree of immunity to electromagnetic noise and ambient illumination.The small size of the mobile unit implemented in surface mount technology (SMT) and the low-voltage, low-power design, make it well-suited for an indoor telemetry link with a freely moving animal of small size. This transceiver system has been routinely utilized for Polarographic in-vivo determination of brain metabolites (DOPAC, 5-HIAA) in rats.