Design and prototyping of exoskeleton system for hand rehabilitation

Loss of the hand's motor abilities results in severe discomfort in the daily life activities that are performed. Rehabilitation is a therapy that has the aim to treat totally or partially the motor function of a patient. This loss of the function can be recovered by muscular functional rehabilitation devices or physical therapy specialists. Research on exoskeletal systems used for rehabilitation has attracted considerable attention in recent years. Within the scope of this study, design and prototyping of exoskeletal system for hand rehabilitation is proposed.Exoskeleton hardware is designed to be positioned on the hand and forearm so that the device is in portable form. It is targeted that the parts should be as light as possible for the purpose of easy mobility. Power transmission of the exoskeleton to the fingertips is a linkage structure which kinematic and kinetic analysis are performed For ergonomic use, the device was modeled in a 3D CAD software and prototype was produced with using a 3D printer. In this study, the exoskeleton mechanisim is designed according to the underactuation principle. This principle makes it adapt itself to whatever grasping object which can do frequent hand movements in daily life. Mechanisim has 3 degree of freedom for each finger that 2 DOFs are passive, and one DOF is active. Active DOF is driven by a servo motor which provides sufficient functional range of motion of the finger. The system is activated by the collective electrical signal generated by the muscles in the forearm, which are responsible for hand flexion motion. These signals are measured by surface electromyography sensors placed on the relevant muscle groups. Acccording to the these signals, embedded software in the microcontroller supports the hand motion by driving the exoskeleton system by servo motors.