Development of biomimetic prosthetic hand

The purpose of this study was to develop a new type of the sensory feedback system for the myoelectrically controlled biomimetic prosthetic hand. One of the characteristic features of the neuromuscular control system in man is an increase in the compliance around the joint, with the decreasing activity of the muscle. For the sensory feedback system the interferential current with two waves was used, and low frequency current in the body was synthesized. Whether the difference of stimulus can be detected by the interference current was examined in our previous study. These results show that the subjects can distinguish the change of the stimulus frequency when one frequency is fixed and the other frequency is changed. The interference current was confirmed to be a useful method for the sensory feedback system of the prosthetic hand. However, this method can transfer only one kind of information. We want to transfer two kinds of information, such as the grasping force and the finger angle. Therefore, the aim of the examination was whether the point of the stimulus could be moved with fixed electrodes. Our experimental results show that the phase change can be successfully used to move the stimulus point.