Signal processing for brain-computer interface: enhance feature extraction and classification

In this paper we present a new scheme for brain signal processing and classification for electroencephalogram based brain-computer interfaces, by emphasizing the extraction of space-time-frequency feature as well as the combination of classifiers. In particular, we use wavelet packets as a time-frequency analysis tool and employ sparse component analysis to recover source components in the brain signals. We subsequently apply multi-class common spatial pattern filters to the signals and thus obtain important space-time-frequency features for discrimination. Furthermore, a Bayesian method is developed to boost the system, by combining multiple support vector machines in a probabilistic way. We have tested the proposed scheme on real multi-class motor imagery signals, and its efficacy has been demonstrated