Kinematic analysis of an upper extremity stroke rehabilitation orthosis

• Main Author: Yang, Fang
• Other Authors: Heng Kok Hui, John Gerard
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Mechanical engineering::Assistive technology
• Online Access: http://hdl.handle.net/10356/17340
• Institution: Nanyang Technological University

This study is part of a long term project, which aims to build a reliable and cost-efficient upper arm orthosis for stroke patient rehabilitation purpose. In this paper, two topics are covered. The first one is to simulate the hand and orthosis’ motion in virtual environment, and found the optimistic design for the orthosis linkages. With the aid of computer software Catia, the virtual model for the hand and orthosis system was built. A dummy exoskeleton hand is used to control the motion of the system, several daily living activities are simulated on the system, after a series of trail and error experiments, the best linkage length was found and the linkages was modified accordingly, the updated system’s motion range was increased and was able to cover most of the hand daily living activities such as cylindrical grasp, pinch and hook. The second topic is to conduct kinematic analysis on the orthosis for better motion control purpose. A 4-step kinematic analysis method is proposed to solve the problem in a convenient and cost efficient way. The proposed method reveals the relationship between hand’s joint angle and motor’s turning angle. Using this method, the designer could predict the motion of the hand and thus gain better control over the system. Cylindrical grasp is used as an example. This method also has some deficiencies, due to lack of the actual hand anatomy data for Singapore’s stroke patient, especially the joint angle of each finger bone, some assumptions and estimations are made. Hence the motor rotating angle obtained though this method is a rough value, the accuracy of the analysis could be improved if live experiments are conducted and actual joint angle is measured and obtained from the patient.