基于盲源分离的运动想象脑电信号特征提取方法的研究

A Research on the Method of Motor Imagery EEG Feature Extraction Based on Blind Source Separation

运动想象脑电信号被广泛应用于脑机接口系统中。针对如何准确有效地提取运动想象脑电信号特征的问题，通过分析运动想象脑电信号时域、频域和头皮空间域的特征，提出了以小波变换为预处理，并利用二阶盲辨识算法和信息论特征提取算法相结合获取的空间滤波器，从时域、频域和头皮空间域对运动想象脑电信号进行特征提取的方法。实验结果表明，采用时域、频域和空间域提取特征的方法性能有明显提高，并且将二阶盲辨识算法和信息论特征提取算法相结合获取的空间滤波器能够反映更真实的大脑源活动。

Motor imagery has been widely used in EEG based brain-computer interface systems. In order to extract feature of the motor imagery EEG accurately and efficiently, the feature of the motor imagery EEG in time, frequency and spatial domain is analysed. Then an approach is put forward that extract feature of the motor imagery EEG from time, frequency and spatial domain, with preprocessing of wavelet transforming and using spatial filter obtained from SOBI and ITFE. Experimental results verify that the proposed method has an obvious improvement in feature extraction compared with the other methods, and the spatial filter obtained from SOBI and ITFE can reflect veridical brains activity.