1A2-F13 脳卒中リハビリテーション支援のための股関節一体幹ロボット装具の開発

Abstract

The purpose of this study is to develop the robotic orthosis for post stroke rehabilitation. Robotic therapy system is expected for more intensive, quantitative rehabilitation setting. For upper arm therapy, therapists often facilitate trunk and shoulder girdle to stabilize a root of the upper arm kinematics. Therefore, therapists also request a robotic system to stabilize and control seated posture before they move to upper arm and hand facilitation. So, authors thought that we should develop the robotic system for shoulder and trunk control in reach-to-grasp rehabilitation. The mechanics of the shoulder part of the robotic orthosis was designed by utilizing the trajectory analysis of the scapula orthosis. The analysis found the mean axis around the motion of the scapula orthosis, of which the axis was estimated as a simple pin joint within acceptable residual. The mechanics of trunk part has 3-degrees of freedom for forward bending, lateral bending and twisting of trunk motions. The mechanics of the twisting motion was realized by trapezoidal link mechanism to follow a definite motion range. The robotic orthosis was installed on seating frame to support seated reach-to-grasp therapy in post stroke rehabilitation. The shoulder and trunk orthosis was connected to the frame with additional hip joint, and forward trunk bending was driven by link mechanism extended from seating frame structure. Here, the robotic orthosis has 5-degrees of freedom for driving axis in scapula, 3 motions for trunk motion and hip joint. Joints were driven by servomotors with force sensor, in which the motors were controlled by admittance based method to follow subject's motion. Additional recording system was developed to analyze reach-to-grasp motion with a force plate for detecting reaction force from feet and a goniometer for capturing upper arm angle. In this report, we present the robotic orthosis for stroke rehabilitation and show a preliminary result of reach-to-grasp analysis using the robotic orthosis.