Self-help standing-up method based on quasi-static motion

When supporting standing-up motion, a caregiver takes advantage of gravity force to make sufficient momentum without bearing heavy burden. The physical abilities or decision-making abilities decrease for many of elderly people who need care. We propose a self-help standing-up method for such people. The method with quasi-static motion in which the acceleration is approximated to zero, so as to keep safety at the time of emergency, is preferable. However, the quasi-static motion gives heavy burden to a caregiver because it cannot make efficient use of inertia force by the help of gravity force. Compared to human assist, mechanical system can easily realize the quasi-static motion, since a mechanical system has an ability to hold a large force. However, a quasi-static motion trajectory has to be newly-developed because it is not well known. Therefore, we propose the mechanical system and a quasi-static method for supporting standing-up motion. As an example, the method using artificial upper body constraint, and fitted to physical characteristics of each patient have been proposed. This system is found to be the effectiveness.