SW-SiStA2: A New-Generation Semi-Wearable Device for Sit-to-Stand Assistance

Abstract

Mobility impairment is a major problem that affects the quality of life of numerous older adults. With impaired mobility, such individuals usually have significant difficulty in standing up from a seated position, and thus often suffer from the lack of physical activities in their daily life. To address this problem, the authors present a new assistive device, namely Semi-Wearable Sit-to-Stand Assist Generation-2 (SW-SiStA2), in this paper. Similar to the original (first generation) SW-SiStA, this novel semi-wearable device can be easily attached to the user to provide sit-to-stand assistance, and can also be easily detached after reaching the standing posture to facilitate the subsequent ambulation. The new SW-SiStA2 is powered with a remote-release gas spring, which serves the dual purpose of actuation and energy storage (i.e., storing the energy accumulated during compression and powering the sit-to-stand assistance through extension). The remote release feature enables a user to easily control the SW-SiStA2 assistance through the locking and unlocking of the gas spring. The SW-SiStA2 was experimentally tested with human participants. Under the device's assistance, the participants were able to stand up much more easily, with significant reduction (up to 28% compared with the unassisted condition) of the muscle efforts in the process.

Design and Evaluation of the Sit-to-Stand Movement Assistive Device for Elderly

“…SW-SiStA2 is an STS movement assistive device characterized by quick donning and easy doffing, using air springs as the power source to assist the lower limbs. Experiments have shown that this device significantly aids in promoting the standing action, reducing muscle activation by up to 28% [18]. Purwar et al have designed a new type of six-bar mechanism assistive device for the elderly that aids in standing up and walking.…”