Multi-Channel EMS-Based Interface for Perceptual Sharing of Joint Stiffness in Telerehabilitation

In recent years, the demand for telerehabilitation has been increasing, and its effectiveness has been verified for various diseases and injuries. However, especially in the field of physical rehabilitation, manual assessment is commonly used, and the therapist cannot touch the patient remotely. Therefore, we developed an interface using multi-channel electrical muscle stimulation (EMS) for the evaluation of joint stiffness, which is difficult to judge visually. The performance evaluation showed that the elbow joint drag force tended to increase as the stimulation intensity of the EMS increased. In the perceptual study, the proposed method significantly improved discrimination performance compared to the video meeting system for the individuals without disabilities ($p=0.0051$, the Wilcoxon signedrank test). The results suggest that the proposed method can be applied to clinical practice by establishing a calibration method that is tailored to the individual characteristics of the users.