JBiSE  Vol.4 No.5 , May 2011
Comparison of ICA and WT with S-transform based method for removal of ocular artifact from EEG signals
ABSTRACT
Ocular artifacts are most unwanted disturbance in electroencephalograph (EEG) signals. These are characterized by high amplitude but have overlap-ping frequency band with the useful signal. Hence, it is difficult to remove the ocular artifacts by traditional filtering methods. This paper proposes a new approach of artifact removal using S-transform (ST). It provides an instantaneous time-frequency repre-sentation of a time-varying signal and generates high magnitude S-coefficients at the instances of abrupt changes in the signal. A threshold function has been defined in S-domain to detect the artifact zone in the signal. The artifact has been attenuated by a suitable multiplying factor. The major advantage of ST-fil- tering is that the artifacts may be removed within a narrow time-window, while preserving the frequency information at all other time points. It also preserves the absolutely referenced phase information of the signal after the removal of artifacts. Finally, a com-parative study with wavelet transform (WT) and in-dependent component analysis (ICA) demonstrates the effectiveness of the proposed approach.

Cite this paper
nullSenapati, K. and Routray, A. (2011) Comparison of ICA and WT with S-transform based method for removal of ocular artifact from EEG signals. Journal of Biomedical Science and Engineering, 4, 341-351. doi: 10.4236/jbise.2011.45043.
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