Development of Rehabilitation Support Robot with Guidance Control Based on Biarticular Muscle Mechanism

Abstract

This study presents the guidance control provided by a rehabilitation support robot that is intended to assist with the movement of a patient's arm. The guidance control is accomplished using a stiffness ellipse. The characteristic that the direction of force acted upon changes depending on the settings of the stiffness ellipse is used for guiding the movement. The system developed in this study adjusts the stiffness ellipse by using a musculoskeletal manipulator with biarticular mechanism. It was verified that the movement of a subject could be guided by changing the stiffness ellipse and assisting the movement. The experimental results demonstrate that it is possible to guide the movement without any dependency on the control bandwidth of the actuator.

Development of an upper limb rehabilitation robot with guidance control by pneumatic artificial muscles

“…This fact can also be guessed from Hogan's study, which has mentioned that the mechanical stiffness ellipse can be arbitrarily given only when the arm has both biarticular and monoarticular mechanisms [13]. Yokoo et al used a robotic arm to vary the angular stiffness of respective antagonist muscles and conducted an experiment that simulated rehabilitation with deformed stiffness ellipse, which indicated that the induction of movements was possible [12]. The angular stiffness, however, is a ratio of angular change with respect to the load torque and is measured with the unit of Nm/rad.…”

“…It is obvious that the scores of the training improves by guidance control especially when the subject has low motor performance. It has also been shown that guidance control with limited input shows higher accuracy than that with complete input [12]. However, the motor learning effect of guidance control still remains some unclear parts.…”

“…However, the motor learning effect of guidance control still remains some unclear parts. As [12] implies, complete guidance is not effective for a subject with a certain motor skill. On the other hand, active exercise without any guidance control is sometimes too difficult for subjects with low motor skill.…”

Recent advances and outlook in industrial instrumentation and mechatronics control

“…The second type of assist technology is a rehabilitation support robot used for a patient's arm. Research on this robot included developing a mechatronic system using the biarticular muscle mechanism that adjusts the stiffness ellipse .…”

Roles of Mono- and Bi-articular Muscles in Human Limbs: Two-joint Link Model and Applications

“…Therefore, the model has been applied to rehabilitation sciences, robotics, and the fields of mechanical engineering, for example, a development of an externally powered lower limb orthosis ( Saito et al. 2005 ) and a development of a rehabilitation support robot ( Tsuji et al. 2014 ), a development of a lancelet robot ( Tsuji 2010 ), a development of a robotic arm ( Salvucci et al.…”