A tele-rehabilitation system with bilateral haptic feedback to both the therapist and the patient via time-delay environment

In this paper, a bilateral tele-rehabilitation system capable of providing haptic feedback to both the therapist and the patient is proposed. As internet is used for communication in the proposed system, the problem of time delay must be solved, which may give rise to loss of transparency and even instability. To address the problem, a control strategy is designed, which could deal with not only constant time delay, but also time-varying delay. The feasibility of the proposed method is verified by experiments.