Design And Research Of EEG Signals Acquisition And Processing System

Electroencephalogram(EEG)signal is a typical signal of bioelectricity.When nerve cells of a brain transmit information,it is a general reflection of electrical activities in the cortical layer and on the scalp,which contains much physiological and pathological information.We can learn the relationship between the electrical activities of nerve cells and the physiological and pathological states of people,and this relationship has great significance in the province of the clinical medicine and the cognitive science.EEG is so weak.The background noise of EEG is very strong and the characteristic of non-stationary random bioelectricity of EEG is outstanding.The valuable data of EEG only can be got from statistical result from large numbers of experimental data.The traditional EEG analyzers are expensive,and usually worked inaccurate,which is not convenient to use.On the foundation of basic EEG knowledge,this dissertation originally researched acquisition and analysis of EEG.The main job including:1.Study the generation,assortment,lead,placement of electrode detailedly.2.An adjustable amplifier of gain and frequency in EEG acquisition system was designed according to the features of EEG.Filters comprise EEG low pass filter,EEG High pass filter,EEG band elimination filter.3.An EEG acquisition and control procedures was designed based on LabVIEW virtual instrument development platform and"NI-DAQmx-Data Acquisition"toolkit,it used to collect EEG signal,save the signal to computer and playback it in waveform mode.4. The advantages of wavelet analysis in the processing of EEG was discussed based on the introduction of the basic theory of wavelet transform.An EEG analysis system was designed on LabVIEW,using wavelet analysis to filter EEG signal and extract EEG rhythms. Based on the EEG power spectrum analysis,BEAM was drawn ,according to the principle of data interpolation.