A Portable System For EEG Measurements Which Based On The Full Bandwidth

Considering most of the current EEG acquisition system can only collect and recordEEG signal who’s bandwidth lie0.5Hz to50Hz, which limit scientists put more effortinto the low-frequency EEG signal for the further research.Therefore, the developmentand design of the new full-bandwidth EEG instrument has gradually become one of thefocuses of the research at home and abroad.Above all, after comparisoning andanalysising the principles, techniques and performance of the the traditional EEGacquisition system and the full-bandwidth EEG system,we could develop and design aportable full bandwidth EEG acquisition system.This paper first summarizes the the development status of the EEG amplifier and thesignificance of developing full-bandwidth EEG system.In addition,this paper makecomparative analysis of EEG acquisition system technology for conventional EEGacquisition system and the full bandwidth, and referred to several problems that need tobe solved in the development and design to the portable devices.Then this paper put forward the designe scheme of the analog circuit of the entireacquisition system combined the EEG acquisition technology at home and abroad as wellas the latest development of analog circuits technology.The scheme mainly include thedesign work of amplifier circuit (preamplifier, main amplifier circuit andpost-amplification circuit) and filter circuit (high pass filter circuit, low pass filter circuitand the power frequency trap circuit).The system’s digital circuits part will carry out some necessary analysis andprocesse to EEG signal after it pass the amplification and filtering processing in theanalog circuits.We choose STM32microcontroller as the main controller of the digitalcircuit part,and it works by using its own12-bit ADC to complete AD sampling.TheSTM32microcontroller also need to complete the work of serial communication betweenSTM32and the computer and the work of SD memory of EEG signal.Besides,thisresearch also accomplish the compile of PC interface to display EEG signal’s waveformwhiche collected by EEG amplifier.Finally,this paper also put forward the direction of future research and someproblems which need to be rsolved...