Research On EEG And SEMG Integrated Acquisition And Enhancement Technology

EEG(Electroencephalogram)signals and sEMG(Surface Electromyography)signals are important physiological electrical signals of the human body.The human intention and action information contained in their signals are of great significance to the development of humancomputer interaction technology.At present,the fusion interactive technology of EEG and sEMG has become the core technology of the intelligent human-computer interaction revolution.In this thesis,the integrated collection and enhancement technology of EEG and sEMG signals are studied to achieve a portable EEG and sEMG signals collection,obtain high-purity EEG and sEMG signals through the enhanced denoising algorithm,and provide a guarantee for signal pattern recognition.The main research contents are as follows:The characteristics of EEG and sEMG signals and the overall system architecture are analyzed and designed.By analyzing the generating principles of EEG and sEMG signals separately,the amplitude-frequency characteristics and noise types of EEG and sEMG signals are obtained through data analysis.The research ideas of electrodes,hardware circuits and denoising methods are determined and their performance requirements are proposed,and the overall system framework is designed.The flexible dry electrode that meets the requirements of acquisition performance is developed.According to the overall architecture design,the design idea of the flexible dry electrode is determined,and the electrode design scheme is given from the three aspects of structure,material and preparation process design.The impedance test and collection test of two dry electrodes are performed and the test results are compared with the commercial wet electrodes to prove that the flexible dry electrode can meet the collection requirements.The hardware circuit of acquisition system is designed and the denoising algorithm is proposed.The conditioning circuit,analog-to-digital conversion/main control circuit and Bluetooth transmission circuit of the hardware part are designed and their circuit simulations are performed.The simulation results show that the design meets the system requirements.Further,the low power consumption is studied.The EMD(Empirical Mode Decomposition)and EEMD(Ensemble Empirical Mode Decomposition)algorithms are compared and the ICA(Independent Component Analysis)algorithm is researched theoretically.Based on EEMD-ICA,the EEG artifact denoising algorithm is proposed.By analyzing the traditional wavelet threshold denoising method,the threshold function and threshold selection method are improved,and the denoising method of sEMG signal based on the improved wavelet threshold is proposed.The EEG and sEMG acquisition and denoising experiment platform is built and the experiments are conducted.First,the power consumption of the EEG and sEMG integrated acquisition system is tested,and then the EEG and sEMG signal acquisition test experiment is completed.The collected data is compared with the control group to prove that the acquisition system can meet the low power consumption and accuracy performance requirements.The EEMD-ICA algorithm is used for EOG(Electrooculogram)artifact denoising experiments.Compared with the results of the EMD algorithm and the wavelet method,the EEMD-ICA algorithm has the superiority in denoising EOG artifacts.Furthermore,the improved wavelet threshold method is used to denoise the sEMG signal.Compared with the traditional soft and hard threshold method,the improved wavelet threshold denoising method has the superiority in the sEMG signal denoising.