Real-Time EEG Signal Enhancement Using Canonical Correlation Analysis and Gaussian Mixture Clustering

Figures

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  Figure 1. (a) Experimental paradigm. (b) Experimental setup.

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  Figure 2. Flowchart of proposed artifact removal algorithm.

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  Figure 3. Demonstration of removal of EEG artifacts by BSS-CCA. (a) A 2 s portion of EEG time series that contains blinking. (b) Corresponding CCA component activations. (c) EEG corrected by removing C1, C2, C15, and C16 from (b).

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  Figure 4. Fluctuation of Fisher criterion value from two to 20 clusters.

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  Figure 5. Histogram of artifact and nonartifact significance for extracted features. M, OA, BM, and NA represent muscle artifact, ocular artifact, body movement artifact, and nonartifact activity.

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  Figure 6. Five seconds of EEG data from a representative subject with (a) blinking, (b) chewing, and (c) head rotation. In each subfigure, left and right plots are obtained before and after the proposed artifact removal algorithm is applied.

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  Figure 7. Temporal waveform and power spectrum activities of Oz-EEG channel from a representative subject. (a and c) SSVEP task. (b and d) VEP task. (a and b) Chewing. (c and d) Head rotation. Left and right-hand images in subfigures show EEG waveforms and corresponding log power activity, respectively. Top and middle 2D images show EEG results before and after artifact removal, respectively, and bottom images present averaged results. Each horizontal line in 2D images represents a single trial. The time zero on the x-axis represents the time of onset of the visual stimulus. Blue and red lines in bottom images show averaged results obtained before and after artifact removal, respectively. Note: AR indicates artifact removal.

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  Figure 8. Averaged evoked potentials in Fz, Cz, Pz, and Oz channels during (a) SSVEP and (b) VEP tasks from a representative subject. Each subplot figure shows the averaged waveforms for three artifacts: (i) blinking artifacts, (ii) head rotation artifacts, and (iii) chewing artifacts. In each panel, black line presents averaged waveform without motion, whereas blue and red lines present averaged waveforms before and after artifact removal, respectively.

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  Figure 9. Averaged evoked potentials in Fz, Cz, Pz, and Oz channels during (a) SSVEP and (b) VEP tasks from a representative subject. Each subplot figure shows the averaged waveforms for three artifacts: (i) blinking artifacts, (ii) head rotation artifacts, and (iii) chewing artifacts. In each panel, black line presents averaged waveform without motion, whereas blue and red lines present averaged waveforms after ASR and after proposed artifact removal method, respectively.