Development of an Assisting Instrument of Standing-Up Motion Using Driving Springs for Elderly Persons

To assist standing-up motion from the deep flexion state, an assisting instrument using driving springs on the hip and knee joints has been developed. This instrument consists of an assisting mechanism for the hip joint which has an oscillating follower type cam with a spring drive, and an assisting mechanism for the knee joint which has a non-circular gear, two grooved cams and a loading flat spiral spring. Especially, to apply it to the deep flexion and extension motions of the hip and knee joints, a motion of standing-up from a flat floor is analysed. As a result, it is clear that the assisting force on the hip joint are needed in case of an extension from the deep flexion state, and that force on the knee joint are needed during all extension motion state. Furthermore, the prototype instrument has been tested, and it is confirmed that the instrument is useful for the standing-up motion.