FIGURE 2.

Pictured here are one subject’s myoelectric signals obtained from eight electrode channels during the execution of eight different hand and wrist movements lasting five seconds each. There are observable differences between certain channels during specific movements, but as the number of movements increases, selecting the correct movement simply from threshold comparisons or visual inspection becomes unrealistic. This makes direct or proportional control incapable of controlling a large number of movements, but these distinctions are easily detected with many pattern recognition algorithms.