A miniature telemetric system base on chip nRF24E1for recording EEG activity in freely moving rat

Abstract

In this paper, we designed a telemetric system to record the electroencephalogram (EEG) from adult freely moving rats. The system has two units: Transmit-end and Receive-end. The Transmit-end is consists of three parts: the preamplifier, which is used instrument amplifier AD620; the LPF (low-pass filter) and the 50 Hz frequency notch filter, which is used the precision amplifier LM324; the transmitter, which is used nRF24E1 chip embedded 8051 core and 8 input ADC transmit the modulated signal at 2.4GHz. The Receive-end is consists of two parts: the receiver, which is used nRF24E1 chip also (nRF24E1 embed RF transmitter and receiver); the interface of Receive-end and PC, which is used MAX3232 (RS-232 chip). The Transmit-end fettered on the back of the rat has light weight (10g including battery) and small size (20mm×50mm).The system can measure the EEG signal of the rat in freely moving over a wireless transmission distance of up to 8 m and also can provide a new platform for behavioral and neurophysiological experiments. © 2008 Springer-Verlag.