shows the experimental environment of the meal support mode. When EMG is over the threshold (20% of maximum), the desired angle is up. The desired angle decreases when the patient pushes the support arm downward. Fig. 14 shows the electrode location. The electrode is placed on the line between the medial acromion and the fossa cubit at 1/3 from the fossa cubit [10], and earth electrode is placed on the ulnar styloid process. Processing of the EMG signal is fullwave rectified and is low-pass filtered at 300 Hz. The desired value is given from measurement of the moving range of meals eaten by spoon.
Fig. 15 presents experimentally obtained results. It is apparent that the desired angle is increased by the EMG data of biceps brachii, and that it is reduced by pushing the arm “B” downward. The plant output is followed by the change of the desired angle. Therefore, without causing muscle weakening, it is possible to meal independently using own muscle.