Study On Event Related Potential In The Brain Computer Interface

Brain computer interface does not dependent on peripheral nerve and muscle tissue, and build direct communication and control channel between human brain and electronic devices such as computers. Some severely paralyzed patients because of nerve atrophic disease can use brain computer interface to communicate with the outside world and even do some simple work independently.P300is the object of this study, it is generated by the small probability event trigger event related potential, its peak in about300ms after the events, participants can produce P300without training, therefore P300often used as a kind of brain electrical signal to build brain computer interface system.Evoked electroencephalogram are easily interferenced due to spontaneous electrical.so the SNR is low. Independent component analysis is a kind of algorithm to solve the problem of blind source separation, and it is used on the brain electrical signal denoising and it can avoid multiple superposition average, and less commonly used for brain electrical signal extraction, but it isolates the order in the source signal, phase and amplitude are uncertain, thus refactoring the P300component is unfavorable. The paper use the Pearson correlation coefficient to automatically identify the source signal and interference signal.Paper further analyzes international brain computer interface competition data, in the process of processing EEG data, paper use akind ofjrnproved kernel independent component analysis and the improved fast independent component to analyze P300component for less times, results show that two kinds of improved algorithm can extract well P300component, after comparing the two algorithm we can find fast independent component analysis has advantage.of computational speed compared with kernel independent component analysis.Finally, this paper design a kind of classifier, classification using support vector machine (SVM) on brain electrical signal, training data are chosen random during the design, in test set fault points rate is low. the result shows the effectiveness of the method.