Design of a soft ankle-foot orthosis exosuit for foot drop assistance

Carly M. Thalman, Joshua Hsu, Laura Snyder, Panagiotis Polygerinos

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This paper presents the design of a soft ankle-foot orthosis (AFO) exosuit to aid natural gait restoration for individuals suffering from foot drop. The sock-like AFO is comprised of soft actuators made from fabric-based, thermally-bonded nylon and designed to be worn over the users shoes. The system assists dorsiflexion during swing phase of the gait cycle utilizing a contracting soft actuator, and provides ankle joint proprioception during stance with a variable stiffness soft actuator. A computational model is developed using finite element analysis to optimize the performance characteristics of the fabric actuators prior to fabrication, maximize contraction, and minimize overall volume. The dorsiflexion actuator is able to achieve a linear tensile force of 197 N at 200 kPa. The variable stiffness actuator generates up to 1. 2 Nm of torque at the same pressure. The computational model and soft AFO are experimentally validated and with a healthy participant through kinematic and electromyography studies. When active the AFO is capable of reducing by 13.3% the activity of the muscle responsible for ankle dorsiflexion during the swing phase.

Original languageEnglish (US)
Title of host publication2019 International Conference on Robotics and Automation, ICRA 2019
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages8436-8442
Number of pages7
ISBN (Electronic)9781538660263
DOIs
StatePublished - May 1 2019
Event2019 International Conference on Robotics and Automation, ICRA 2019 - Montreal, Canada
Duration: May 20 2019May 24 2019

Publication series

NameProceedings - IEEE International Conference on Robotics and Automation
Volume2019-May
ISSN (Print)1050-4729

Conference

Conference2019 International Conference on Robotics and Automation, ICRA 2019
CountryCanada
CityMontreal
Period5/20/195/24/19

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ASJC Scopus subject areas

  • Software
  • Control and Systems Engineering
  • Artificial Intelligence
  • Electrical and Electronic Engineering

Cite this

Thalman, C. M., Hsu, J., Snyder, L., & Polygerinos, P. (2019). Design of a soft ankle-foot orthosis exosuit for foot drop assistance. In 2019 International Conference on Robotics and Automation, ICRA 2019 (pp. 8436-8442). [8794005] (Proceedings - IEEE International Conference on Robotics and Automation; Vol. 2019-May). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/ICRA.2019.8794005