Sensory feedback system for prosthetic hand by using interferential current

The purpose of this study was to develop a new type of sensory feedback system for a myoelectrically controlled biomimetic prosthetic hand. One of the characteristic features of the neuromuscular control system in man is the increase in the compliance around the joint with decreasing activity of the muscle. We used interferential current that uses two waves and interfere to synthesize a low frequency in the body. One frequency was fixed at 4000 Hz and the other frequency was changed from 3700 Hz to 4000 Hz. As the result, stimulus frequency in the body was changed from 0 Hz to 300 Hz. By the experiments, we measured that the subjects could distinguish the change of stimulus frequency and confirmed that the interference current is a useful method for a sensibility feedback device of a prosthetic hand. As a future task, we will try to produce a sensibility feedback device for a prosthetic hand, using the interference current.