Peripheral Nerve Block and Stimulation for Controlling Rat Ankle Joint Angle using Visual Feedback System*

Abstract

Spasticity is a condition in which the muscles of the limbs continuously contract. High-frequency alternating current (HFAC) is a method of blocking nerve signals, which can be applied to prevent spasticity. Functional motions can be reconstructed by controlling limb muscles using functional electrical stimulation (FES) during HFAC treatment for spastic paralysis. In this study, we conducted signal blocking and stimulation of rat peripheral nerve as a potential method for reconstructing the functional motion of limbs in spastic paralysis patients and investigated the effect of HFAC at different stimulation frequencies on the prevention of muscle contraction. FES with visual feedback was also performed to control the angle of the rat ankle joint. The HFAC experiments showed that nerve block was achieved with nerve stimulation frequencies at 1 Hz and 60 Hz when a l-kHz block signal was used. Visual feedback control of the ankle joint angle was achieved using the proportional-integral (PI) control method. The findings of this study will contribute to the establishment of new methods for reconstructing functional motion in spastic paralysis patients.