Fig. 6
The separation effect of the same data from Fig. 3 by using SOBI based on dual ROI: a shows subject’s high-quality video and the dual ROI, then b displays 6-channels observations; c displays the source signals separated by using 6-channels SOBI; after filters out residual noises, d obtains the target signals (note: the purple and green column on spectrum respectively denote RR band and HR band)