Development of a Biofeedback Therapeutic Exercise Supporting Manipulator for Lower Limbs

Although equipments that support physical therapy have been developed, there are few types of equipment to improve quality of physical therapy. This paper proposes a new concept of robotic biofeedback exercise equipment that displays human muscle force during training. The concept tries to have therapeutic value through grasping of condition for trainee during exercise and giving an incentive to perform training. The machine is not only for convalescent patients but also for athletes and ordinary persons with a physical trouble. The manipulator is designed to support lower limb rehabilitation of knee and hip joints in sagittal plane where a three-degree-of-freedom manipulator is adopted in order to realize low height equipment. Since the manipulator has redundant degree-of-freedom, collision avoidance is performed based on acceleration control by disturbance observer. Moreover, simultaneous isokinetic movement for knee and hip joints that has an adjustment capability of maximum speed and acceleration degree is realized in order to realize safe training by isokinetic muscular contraction. Desired motion of the proposed manipulator is confirmed experimentally.