Stair negotiation made easier using novel interactive energy-recycling assistive stairs.

• Type of Material: Article
• Authors: Yun Seong Song, Missouri University of Science and Technology; Sehoon Ha, Disney Research; Hsiang Hsu, Georgia Institute of Technology; Lena Ting, Emory University; C. Karen Liu, Georgia Institute of Technology
• Language: English
• Date: 2017-07-12
• Publisher: Public Library of Science
• Publication Version: Final Published Version
• Copyright Statement: © 2017 Song et al.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1371/journal.pone.0179637
• Title of Journal or Parent Work: PLoS ONE
• ISSN: 1932-6203
• Volume: 12
• Issue: 7
• Start Page: e0179637
• End Page: e0179637
• Grant/Funding Information: This work was supported by the National Science Foundation (NSF), Grant EFRI-1137229.
• Keywords: Joints (anatomy); Myalgia; Legs; Knee joints; Musculoskeletal system; Ankle joints; Mechanical energy; Walking
• Research Categories: Engineering, Mechanical; Health Sciences, Rehabilitation and Therapy; Engineering, Biomedical

Abstract

Here we show that novel, energy-recycling stairs reduce the amount of work required for humans to both ascend and descend stairs. Our low-power, interactive, and modular steps can be placed on existing staircases, storing energy during stair descent and returning that energy to the user during stair ascent. Energy is recycled through event-triggered latching and unlatching of passive springs without the use of powered actuators. When ascending the energy-recycling stairs, naive users generated 17.4 ± 6.9% less positive work with their leading legs compared to conventional stairs, with the knee joint positive work reduced by 37.7 ± 10.5%. Users also generated 21.9 ± 17.8% less negative work with their trailing legs during stair descent, with ankle joint negative work reduced by 26.0 ± 15.9%. Our low-power energy-recycling stairs have the potential to assist people with mobility impairments during stair negotiation on existing staircases.