摘要: A two-stage state recognition method is proposed for asynchronous SSVEP (steady-state visual evoked potential) based brain-computer interface (SBCI) system. The two-stage method is composed of the idle state (IS) detection and control state (CS) discrimination modules. Based on blind source separation and continuous wavelet transform techniques, the proposed method integrates functions of multi-electrode spatial filtering and feature extraction. In IS detection module, a method using the ensemble IS feature is proposed. In CS discrimination module, the ensemble CS feature is designed as feature vector for control intent classification. Further, performance comparisons are investigated among our IS detection module and other existing ones. Also the experimental results validate the satisfactory performance of our CS discrimination module.