Sensory Feedback System for Prosthetic Hand Using Interferential Current

A new type of sensory feedback system for a myoelectrically controlled biomimetic prosthetic hand was developed. One of the characteristic features of the human neuromuscular control system is the increase in the compliance around a joint with decreasing activity of a muscle. Interferential current that uses two waves and interferences was used to synthesize a low frequency in the body. One frequency was fixed at 4,000 Hz and the other frequency was changed from 3,700 Hz to 4,000 Hz. As a result, stimulus frequency in the body was changed from 0 Hz to 300 Hz. It was measured that the subjects could distinguish the change of stimulus frequency, and confirmed that the interference current is a useful method for sensibility feedback of a prosthetic hand.