Wearable lower-limb assistive device for physical load reduction of caregiver on transferring support

This paper introduces a wearable lower-limb assistive device that helps caregivers assisting transfer of an elderly or a physically challenged person between a bed and a wheelchair or between a wheelchair and a toilet. Based on our preliminary survey of the caregivers at a hospital and a nursing home, a wearable assistive device to release caregiver´s physical load should have four functions: (a) to sustain the caregiver´s weight at his/her hip during transferring assistance, (b) to prevent a caregiver from falling backward during transferring assistance, (c) not to interfere with caregiver´s squat motion when the assistance is not needed such as when tying a care receiver´s shoelaces, and (d) to be easy-to-wear and lightweight. This paper proposes the assistive device that satisfies these requirements with novel movable support mechanism and release mechanism. The movable support mechanism prevents a caregiver´s falling backward while bracing the caregiver´s hip part at arbitrary height. The release mechanism disables the weight support function of the device in an easy operation as needed basis. The functions are confirmed through experiments with healthy subjects and physical therapists and through subjective evaluation by therapists.