A multichannel biotelemetry transmitter utilizing a PCM subcarrier

Making use of the currently available integrated circuits, a miniature PCM telemetry system operating from one miniature 9-volt battery and drawing less than 5 milliamps has been constructed. The use of this PCM telemetry signal not only provides accurate data transmission, but requires a minimum of RF bandwidth. The serial format that results from multiplexing the input data allows the use of a single channel recorder with its cost savings over a multichannel tape recorder. An additional benefit of the PCM encoding is that the data is in digital format and is directly suitable for computer use.