Cable-based parallel manipulator for rehabilitation of shoulder and elbow movements

In this paper a cable-based system is presented for rehabilitation of the shoulder and elbow movements. Cable-based manipulators have very good kinematic and dynamic characteristics, and they also show other properties such as: transportability and low-cost construction, which make them also suitable for medical applications and rehabilitation. The general robotics structure consists of four cables that allow the movement of vertical flexion-extension, abduction-adduction and horizontal flexion-extension with different limits of movement and speed of the shoulder. The structure can also perform the elbow movements of the flexion-extension. The development of this robotic device is justified by the large number of people with upper limb problems. These problems are due of stroke, polio, arthritis, recovery after accidents or trauma and can be applied to movements of physical therapy. The kinematics model of cable-based parallel robots is obtained similarly to the model obtained from traditional parallel structures. The graphical simulations of the cable-based parallel structure for rehabilitation of the movements of the human arm are presented showing the viability of the proposed structure. Finally preliminary experimental tests are presented.