Elbow training device using the Mechanically Adjustable Stiffness Actuator(MASA).

This paper presents an elbow training device using the Mechanically Adjustable Stiffness Actuator(MASA) for stroke survivors with hemiplegia. The MASA is a series elastic actuator whose mechanical stiffness is variable. Stiffness and the neutral position of the spring is mechanically changed using two identical actuators. Since assisting torque of the actuators is transmitted through the springs, changing stiffness of the MASA results in different level of assistance by the actuators. Then, according to the performance of the patients during given tracking tasks, the level of assistance is controlled via changing stiffness. A prototype of the rehabilitation device using the MASA is introduced and a preliminary experiments with 10 healthy subjects show the level of assistance changes.