A wire-driven leg rehabilitation system: development of a 4-DOF experimental system

We proposed and have been studying a multiple-DOF leg rehabilitation system which employs a wire-driven mechanism. Using a parallel wire mechanism, multiple-DOF motion can be achieved with relatively low powered actuators compared with the mechanisms that use conventional rigid links. Also, since wire-driven mechanisms are light and flexible, it makes the system human-friendly. Our eventual goal is to develop a rehabilitation system that carries out 6-DOF motions of hip, knee and ankle joint. In order to achieve this goal, we are taking a gradual approach. In earlier studies, we built and tested a single-DOF experimental system and a 2-DOF experimental system. Currently, we have built and are testing a 4-DOF experimental system. Target motions of the system are hip joint flexion/extension, hip joint abduction/adduction, hip joint external/internal rotation, and knee joint flexion/extension. In this paper, we describe an overview of the 4-DOF experimental system. We also mention experiments using the experimental system.