A Novel Design of a Therapeutic Robot for Hemiplegic Patients

The trend of using therapeutic robots for medical purposes has attracted interest from universities and research centers around the world. One specific area is the rehabilitation of persons with hemiplegia. There are commercial devices called Continuous Passive Motion (CPM) used for purposes of hip and knee rehabilitation. However, these machines are limited to hip rehabilitation due to the restricted number of degrees of freedom. In addition, these machines are not designed for hip and do not achieve full range of motion. In this study, a therapeutic robot with 6 degrees of freedom is proposed for the rehabilitation of persons with hemiplegia. The priority is to design a mechatronic system to perform basic movements of the hip: flexion-extension, abduction-adduction and internal and external rotation. The design process is shown including hardware and software requirements. Furthermore, a robust GPI controller to reject external disturbances caused by the patient's leg is proposed. Finally, to verify the mechanical design, motion tests were performed with the virtual prototype. The proposed rehabilitation system is able to perform the basic movements of the hip with a full range of motion.