A 3-DOF Cable-Driven Robotic Ankle Rehabilitation Device

With the ankle considered as one of the more complex joints in the body, it can rotate about all three anatomical axes of rotation and it is crucial for balance and propulsion during walking. However, disabilities and physical injuries to the ankle joint can severely affect normal daily tasks of standing and walking. Currently, several robotic devices have been developed to assist in physical rehabilitation of the ankle. However, most designs only facilitate the dorsi-plantarflexion motion of the ankle which is just one of its three possible axes of rotation. The study prototype uses a cable-driven mechanism that attaches to the foot and routed to an actuation unit through cable guides. This mechanism allows for the separation of the motors and other bulky components from the ankle. A wooden mock ankle with a ball joint was used to simulate the 3-DOF ankle movements. Several experiments have been performed for validation such as if the device can reach the maximum angles of a natural ankle and if the GUI delivers calibrated movements. Overall, the development of a 3-DOF ankle rehabilitation device was successful. This prototype provides a new design concept to the current state of the art in robotic ankle devices that can facilitate a more naturalistic movement during therapy.