Design of air-operated spring-based stand assist chair tracking knee joint torque for the elderly
Published in Virtual and Physical Prototyping, 2007
Owing to the reduction of the central pivot function caused by vein motion of the elderly, accidents such as dizziness, and tumble resulting from postural hypotension can occur when the elderly stand quickly from a seated position. In the present paper, an air-operated spring-based stand assist chair is presented, aiming at abating this burden. Through experiments of human pace analysis, the knee joint stress and torque in the standing process are acquired using statistical data from experiments using a simplified model of the human body and expressions of human engineering and theoretical mechanics. Thus the design and parameters of the assistant chair are determined. Two air-operated springs and four roller wheels compose the main part of the actuating mechanism of the proposed chair. The motion analysis of the actuating mechanism, considering the motion restriction and the slight velocity variation of the air-operated spring in the standing process, indicates that the actuating mechanism offers the elderly assistant torque that tracks the knee joint torque in the standing process, and facilitates them to stand up effectively.
Recommended citation: Shi, C. and B. Lin (2007). Design of air-operated spring-based stand assist chair tracking knee joint torque for the elderly. Virtual and Physical Prototyping 2(3), 173-179.