Fig. 2.

Automatic word recognition to isolate the letters of interest (here, I–S–C plus the preceding and following letters). Data are shown for one trial of subject 12. Top panel, Instantaneous angular velocity over time, summed over all 17 measured joints. The vertical lines mark local minima, indicating hold times. Bottom panel, Distance in discriminant space over time, between the measured joint angle vector and the vectors associated with each letter cluster in the training set. Darker values correspond to shorter distances. White circles indicate the letter cluster to which the measured vector is closest at each of the isolated hold times.