Mirror therapy with an exoskeleton upper-limb robot based on IMU measurement system

This paper develops a novel system which includes an exoskeleton upper-limb robot and an inertia motion unit (IMU) measurement system based on mirror therapy concepts with assistive robotics. By integrating the IMU measurement system and the exoskeleton robot, we can execute measurement and control over larger range of motion (ROM) and also improve the safety and user-friendliness of the system. In this paper, two methods using IMU to measure various orientations of parts of the master-side´s upper-limb have been proposed, and then the posture trajectory of the disabled part of the slave´s side will be automatically generated. Conceivably, these two methods can create more complex trajectories than conventional approaches which design specific type of trajectories. Besides that, the accuracy and safety of orientation measurement are very important issues when robot-assisted exercises are conducted. To achieve this objective, we particularly develop a point-to-point control system consisting of two different types of position measurement components along with a PID controller, and both monitor each other to make the system more robust and to prevent the single point of failure problem while the system is working.