Bio-inspired upper limb soft exoskeleton to reduce stroke-induced complications.

Journal: Bioinspiration & biomimetics
Published Date:

Abstract

Stroke has become the leading cause of disability and the second-leading cause of mortality worldwide. Dyskinesia complications are the major reason of these high death and disability rates. As a tool for rapid motion function recovery in stroke patients, exoskeleton robots can reduce complications and thereby decrease stroke mortality rates. However, existing exoskeleton robots interfere with the wearer's natural motion and damage joints and muscles due to poor human-machine coupling. In this paper, a novel ergonomic soft bionic exoskeleton robot with 7 degrees of freedom was proposed to address these problems based on the principles of functional anatomy and sports biomechanics. First, the human motion system was analysed according to the functional anatomy, and the muscles were modelled as tension lines. Second, a soft bionic robot was established based on the musculoskeletal tension line model. Third, a robot control method mimicking human muscle control principles was proposed and optimized on a humanoid platform manufactured using 3D printing. After the control method was optimized, the motion trajectory similarities between humans and the platform exceeded 87%. Fourth, the force-assisted effect was tested based on electromyogram signals, and the results showed that muscle signals decreased by 58.17% after robot assistance. Finally, motion-assistance experiments were performed with stroke patients. The joint movement level increased by 174% with assistance, which allowed patients to engage in activities of daily living. With this robot, stroke patients could recover their motion functions, preventing complications and decreasing fatality and disability rates.

Authors

  • Ning Li
    Department of Respiratory and Critical Care Medicine, Center for Respiratory Medicine, the Fourth Affiliated Hospital of School of Medicine, and International School of Medicine, International Institutes of Medicine, Zhejiang University, Yiwu, China.
  • Tie Yang
  • Peng Yu
    College of Life Science, Northwest Normal University, Lanzhou, 730070, Gansu, People's Republic of China.
  • Junling Chang
  • Liang Zhao
    Graduate School of Advanced Integrated Studies in Human Survivability (Shishu-Kan), Kyoto University, Kyoto, Japan.
  • Xingang Zhao
  • Imad H Elhajj
    Vascular Medicine Program, American University of Beirut Medical Center, Riad el Solh, PO Box 11-023, Beirut, 11072020, Lebanon.
  • Ning Xi
    Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, 48824, USA. Electronic address: xin@egr.msu.edu.
  • Lianqing Liu