Data Transmission Design And Implementation Of 64 Channels EEG Acquisition System

EEG signal is a direct reflection of neuronal cells electrophysiological activities in the brain,which has been widely used in clinical and scientific researches,So the equipment that is designed to acquit the EEG single called EEG acquisition system has been paid much attention.In order to meet the requirements of EEG in scientific research,this paper designed the data transmission subsystem of the multi-lead,high-performance EEG acquisition system.The EEG acquisition system consists of analog part and data transmission subsystem.The analog part completes the single extraction,amplification,hardware filtering and sampling of all the leads EEG signals in parallel.The data transmission subsystem will collect the EEG data which sampled by the analog part for channel verification,digital filtering,packaging and uploading and so on.Because the EEG acquisition system has a large number of leads,high sampling rate,long bit width of the EEG data,the FIFO is added between the analog part and the data transmission subsystem to realize the high-speed data processing and transmission.The data transfer subsystem is also the master of the EEG acquisition system,which composed of TI's high-performance digital signal processor TMS320C6748 which acts as the main controller and CY7C68013 of Cypress as the USB coprocessor.The main controller reads the EEG data from the FIFO chip in the 8 analog boards respectively,then filtering the data with 100 Hz band trap,finally transfer the data to the USB coprocessor through the DMA channel.USB coprocessor will transmit the EEG data through the USB cable to the PC human-computer interaction software.At the same time the main controller also controls the entire system.PC human-computer interaction software will collect the EEG data from the USB interface,then processing the data for channel identification,waveform display,data storage and so on.In order to verify the performance of the data transmission subsystem,the paper designs the data transfer verification experiment,the digital notch experiment.The result proves that the data transmission system can complete the data transmission and process task of the EEG system correctly,orderly and efficiently.In order to verify the entire EEG acquisition system can carry out scientific research experiments,the thesis designed the spontaneous EEG experiments and evoked EEG experiments.The evoked EEG experiments were mainly carried out by oddball paradigm experiment,steady-state visual evoked potential(SSVEP)experiment,MOVEP visual evoked experiment.Experiments show that the whole EEG acquisition system can meet the needs of scientific research.