Circuit Design for a 4-Channel EEG Pre-processing System with Programmable Output Control Capability

The design of a 4-channel Electro-encephalography (EEG) pre-processing circuit using 0.6m CMOS technology is proposed in this paper. The circuit is divided into two parts. To amplify and differentiate the Alpha, Beta, Delta, and Theta waves from the original EEG signal, a mixed-mode EEG pre-processing system with high gain, low power, and low input noise amplifier and four Gm-C band-pass filters driven by a 1V single power supply are designed. The 4-channel pre-processing system is implemented by connecting four of them in parallel. Second, a digital control circuit consisting of a Serial Input Parallel Output (SIPO) Shift Register and SRAM array is constructed and used to control the output of the pre-processing system, which is powered by a 3.8V power supply.