A multi-functional mobility assist device for sit-to-stand motion

This paper presents a multi-functional Sit-to-Stand (STS) assistive device1, which seeks to improve the mobility of individuals with lower extremity weaknesses. While originally designed for a person suffering from post-polio syndrome who could not rise from a seated position unassisted, the device found its utility among overweight and elderly persons and physical therapists. There is a growing population aged 65 and up for whom this essential activity of daily life can be a painful task. Lack of availability of fully-assistive Sit-to-Stand devices, which provide the STS motion and also aid in ambulation presents an unmet need for such individuals. In this paper, we present a novel 6-bar Sit-to-Stand (STS) linkage mechanism integrated into the device, which follows the motion trajectory of the hip joint and provides a comfortable orientation of the supporting bar during the motion. The device is positioned both as a functional assistive device meant for end-users constrained to stay at home due to their disability as well as an ambulation therapy aid to assist physical therapists and care providers to help them lift patients. The device, during the development stage, was tested at several assisted living facilities and nursing homes and is currently being used nationwide.