Robotic stage for human balance disorder assessment

This paper presents a novel robotic stage for human balance disorder assessment. The proposed robot is composed of top and bottom plates which move perpendicular to each other in x- and y- directions. Both plates can be driven or controlled simultaneously or one at a time. Each of the drive systems for the plates utilize a BLDC motor, ball-screw, force sensor, and motor encoder, which enable various control strategies. Moreover, the force sensor is located between the ball-screw and the load, hence, the load reaction force can be directly measured. To conduct the balance assessment, a human (patient) stands on the top plate of the stage and the robot is driven by either force or position control, from which the force is measured directly by the force sensor. Then, the balance disorder assessment is done by observing the characteristics of the force measurements. This device provides a wider motion strokes which enable the examiner to obtain detailed balance disorder information as compared to the existing techniques. Experiments on both control and actual human balance test are carriedout to verify the effectiveness of the proposed device.