Figure 1.

Prosthetic hand control flowchart. When the hand is fully open, the LDA classifier must select between no movement, hand open, and one of N hand-grasps (grasp selection). The use of a longer feature extraction window reduces class variance and, therefore, increases inter-class separability. If a grasp has been selected and the hand is not fully open, all N hand-grasps are mapped to hand close, and the classifier selects between these three classes (grasp maintenance). Because all hand-grasps are mapped to a common class, a shorter feature extraction window can be used to reduce system delay.