Running Specification and Fall Prevention of a Slide-On-Ceiling type Walking Assistive Device (Design and Safety Evaluation of Slide-On-Ceiling Mechanism)

Abstract

Many kinds of walking assistive devices have been developed for aged or disabled persons to rehabilitate their walking as far as they can. Most of the devices are lifts moving on the floor or hoists with trolley wheels along rails fixed to the ceiling. Both, however, have limitations on their mobilities. This paper describes a novel sliding-on-ceiling type of walking assistive device with much higher mobility than the conventional devices. It suspends a rehabilitated person by means of three pairs of a permanent magnet/wheel combination system moving freely on a ceiling covered with a steel plate. The magnets attract the device to the steel plate on the ceiling and the suspending or supporting force depends on the attraction force of magnets, which is adjustable by varying the gap between the magnets and the steel plate. However, this device has a serious level of risk of the combination system being torn off and falling down on the rehabilitated person. Thus, criteria for the safety measures for falling are discussed on the basis of both the force and moment balances. Finally, the design conception is given for the scaling up the device, and a drawing of the magnet gap distance against the weight of the rehabilitated person is constructed, as a function of supporting force.