Design and Evaluation of Cyclic Vibrotactile Funneling Illusion Method for Proprioceptive Position Sense Feedback

The sense of proprioception plays a critical role in motor function by providing a sense of body position and movement. Recent research has highlighted the impact of impaired proprioception on rehabilitation outcomes for stroke patients. To address this issue, various studies have explored the use of vibrotactile feedback to aid and enhance impaired proprioception. Since most studies focused on investigating the characteristics of human proprioceptive position or movement sense, the fixed and cumbersome equipment used for those studies is inappropriate for daily use where compact and portable device is preferred. To address this limitation, we propose a novel vibrotactile feedback method that provides joint-level state information using the cyclic vibrotactile funneling illusion. The proposed method was validated in first experiment with eleven healthy subjects, and the accuracy of proposed method in bi-directional scheme was evaluated through second experiments with three healthy subjects. Our methods demonstrated sufficient ability to transmit proprioceptive position information, making them potentially applicable to various wearable rehabilitation devices, thereby enabling more effective rehabilitation for patients with proprioceptive impairment.