Fig. 6

An illustrative example of the effect of wrist position on the separability of 8 classes in the projected feature space. a Scatter plot of the first three principal components of the feature vectors when including data in neutral position. b Scatter plot of the first three principal components when considering data from all wrist positions. PG power grasp, OP one-finger pinch, TP two-fingers pinch, LG lateral grasp, TP three-fingers pinch, IP index pointing, HO hand open, RE hand rest