Research On P300 Mode Enhancement And Recognition For Portable Brain Computer Interface

Brain computer interface(BCI)is a way to enable people to interact with the external environment by analyzing their EEG(Electroencephalography)signals.It does not rely on the muscles or the nervous system itself,but realizes the interaction between the human brain with the outside world through EEG and external auxiliary equipment,that is to say,the brain computer interface provides a possible scheme for human beings to use consciousness to control and change the external environment.In recent years,the study of brain computer interface ushers in the rapid development period.Based on some kinds of EEG signals(such as P300,Steady State Visually Evoked Potential(SSVEP),Mu rhythm,etc.),BCI research have made great progress,and the safe,real-time and simple brain computer interface technologies are gradually going out of the laboratory.In this context,how to apply the brain computer interface to the real life becomes the research focus and future direction in the BCI field.The traditional EEG acquisition equipment has some problems such as high cost,long acquisition time,low efficiency,complicated operation and low signal to noise ratio,and inconvenient for practical application.With the development of related technologies,various wearable BCI devises,such as Emotiv EPOC,MindWave,Muse,have entered the market.They have some significant advantages such as small size,low cost,convenient operation,and good user experience,etc.,leading to a research direction of portable BCI.On the other hand,P300 is an event-evoked potential generated after 300ms of the presentation of a small probability event,and is one of the EEG signals that have been deeply studied and widely used.However,the traditional BCI systems based on P300 have some disadvantages such as complex signal acquisition,time consuming and weak P300 signal,so it is not convenient for practical application.In this paper,portable brain computer interface based on P300 was studied.EEG data are collected efficiently and conveniently by Emotiv EPOC,and the event-related potential P300 is enhanced by the improved P300 stimulation paradigm.The results show that compared with the classical paradigm,the improved paradigm can more effectively evoke the relevant brain areas and enhance the characteristics of P300.This research demonstrates that by only using a few electrodes,a good classification result can be obtained through the classification algorithm LDA(Linear discriminant analysis)and SVM(Support vector machine),showing a promising future of the portable brain computer interface.