基于脑电alpha波及运动想象的在线脑机接口系统设计

On-line brain-computer interface system design based on alpha wave and motor imagery

背景:目前在线脑机接口系统绝大多数采用同步式设计,无法区分"工作"状态与"空闲"状态。目的:设计一种能够自由在"工作"与"空闲"状态间切换,方便灵活的脑机接口系统。方法:设计了综合睁眼产生的alpha波阻断现象,以及进行运动想象时产生事件相关同步及去同步现象这些生理特征的在线脑机接口系统。通过检测使用者枕部脑电信号alpha波状况,来切换"空闲"与"工作"状态;在"工作"状态下,通过想象不同的肢体运动,分析运动皮质脑电信号的频率特征,来实现对外界的信息传输。结果与结论:实验证明,经过训练的使用者在该在线脑机接口平台上可以自如的在不同状态间进行切换,并且能以很高的分类正确率发出控制命令。采用此方法进行设计,脑机接口系统的实用性得到了增强。

BACKGROUND：At present,most of on-line brain-computer interface（BCI） systems adopt synchronous design,which cannot tell the switch between active state and idle state.OBJECTIVE：To design an effective BCI system design,which is free to switch between active state and idle state.METHODS：In this paper,an on-line BCI system was designed based on a series of physiological phenomenon,such as alpha wave-block,event related synchronization（ERS） and event related desynchronization（ERD）.Through detecting the EEG recorded from occipital area,the two states being active and idle could be switched.Under the statement of active,EEG captured from motor cortex was processed,and the frequency feature was extracted during different motor imagery tasks,in the end,the mind that user wanted to express was estimated.RESULTS AND CONCLUSION：The results show that the subject can switch freely between the two states by using this on-line BCI system after training.Using this method,the practicability of on-line BCI system is getting improved greatly.