Development Of Walking-Assisted Lower Limb Rehabilitation Exoskeleton For Hemiplegia Patients

With the rapid development of robotic technology and the inter-discipline, the research on powered rehabilitation exoskeleton has become a hot field in recent years. Aiding in working-assisted for hemiplegia patients with lower exoskeleton is one of the important applications. Hemiplegia is caused by brain injury and result in motor dysfunction in the same side. The two major symptoms of hemiplegia are time contraction in support phase on affected side and abnormal circle gait in swing phase during walking. The application of exoskeleton technology in rehabilitation for hemiplegia patients can not only restrain abnormal circle gait and promote the recovery of normal walking ability of patients, but also liberate the physical therapist from the heavy manual labor.First of all, based on the investigations of the walking-assisted lower extremity rehabilitation exoskeletons around the world, this study designed a single exoskeleton that had two freedoms in hip joint and knee joint which were driven by motors. The mechanical structure of exoskeleton was based on the existed system and used ball screw as transmission mechanism to simulate the contraction of muscles.Secondly, this study established a control hardware system based on DSP and EPOS2motor driver. The reliable communication was achieved based on CANopen protocol and Zigbee wireless technology. On the basis of this hardware system, a control program and PC user interface were developed to control joint motors accurately and interacted friendly. In addition, according to the different needs of hemiplegic patients in different walking training stages, passive control strategy and autonomous control strategy were proposed. With the gait phase feedback and motion intention detection, it could help patients train by themselves and improved the walking comfort.Finally, based on the prototype system, some preliminary experiments including the no-load experiment and normal human walking experiment were conducted to test the performance of the system. The results verify the safety and reliability of the system. This study realized walking-assisted function of the designed system and proved the feasibility of autonomous control on walking training. It also provided the theoretical and practical basis for the study in the future.