A Dual-Arm Participated Human-Robot Collaboration Method for Upper Limb Rehabilitation of Hemiplegic Patients

Upper limb rehabilitation robots are mainly used as a physical therapy method to passively or actively train the affected side. However, they are rarely implemented in accordance with the occupational therapy theory, which is dedicated to improving the sensorimotor coordination of hemiplegic patients by considering both healthy and affected limbs. To realize the occupational therapy concept in robot-assisted upper limb rehabilitation, we propose a new human-robot collaboration framework for hemiplegic patients that integrates healthy/affected limbs and robot. The strategy aims at achieving patient-specific movement capabilities and improving the participation of the affected limb during rehabilitation. To accomplish this task, we have addressed two essential issues: accurate motion estimation of the healthy limb and the rehabilitation trajectory learning technique. The posture estimation is achieved by introducing the calibration model to reduce static and time dependent errors during the measurement. We also introduce a force term to the conventional imitation learning method to improve the adaptability in integrating the affected side in cooperation with the robot. Various experiments have been conducted to validate the feasibility and effectiveness of our proposed dual-arm collaboration strategy.