Development of ultra small two-channel system of EEG radio telemetry

The development of a set of ultra small system of EEG radio telemetry was introduced. A whole set of system is divided into three functional parts including EEG conditioning, wireless transmitting and power supply management, link three pieces of circuit together through connector. The EEG conditioning part consists of two analogue circuit modules, one for each channel of EEG. In general, each analogue circuit module carries out differential amplification, active low-pass and high-pass filtering, dc level adjustment and output amplification. The wireless transmitting part includes RF chip and EEPROM used in program store. Battery and power supply management part is composed of li-ion regulator and protection circuit, voltage monitor and power supply management circuit. In this paper, the development strategy of three functional parts is described respectively. In addition, in order to investigate system performance of gathering EEG signal, the test results were given for not only standard signal source with the same amplitude but different frequency but also actual spontaneous and evoked EEG signal. The test results showed that system could meet the demands in researching various kinds of routine EEG in laboratory.