Effect of Electrical Stimulation to Vibration-induced Kinesthetic Illusion

The vibration-induced kinesthetic illusion has been studied as a technique to generate the sense of movement in a human for rehabilitation and virtual reality. Although the kinesthetic illusion is a potentially promising method to induce a pseudo sense of movement in a human, there is a problem that the amount of the kinesthetic illusion varies from a parson to a parson. To address this problem, it is necessary to propose a method that increases the amount of illusion even under conditions where the illusion is unlikely to be generated. In this study, the authors tried to enhance the amount of kinesthetic illusion by combining vibration and electrical stimulation. Vibration stimulation was applied to antagonist muscle to generate the kinesthetic illusion and electrical stimulation was given to agonist muscle to generate isometric contraction of a muscle. To investigate the effect of the combined method of vibration and electrical stimulation, the authors carried out experiments under three conditions. The first condition was with vibration stimulation only and the second one and third one were with vibration and low or high voltage electrical stimulation. The experimental results show that the combine of electrical and vibration stimulation increases occurrence rate of illusion. In addition, statistical analysis shows that the amount of illusion was enhanced by combined stimulation method.