Excitation of natural spinal reflex loops in the sensory-motor control of hand prostheses
File(s)
Accepted version
Author(s)
Alva, Patrick G Sagastegui
Boesendorfer, Anna
Aszmann, Oskar C
Ibanez, Jaime
Farina, Dario
Type
Journal Article
Abstract
Sensory feedback for prosthesis control is typically based on encoding sensory information in specific types of sensory stimuli that the users interpret to adjust the control of the prosthesis. However, in physiological conditions, the afferent feedback received from peripheral nerves is not only processed consciously but also modulates spinal reflex loops that contribute to the neural information driving muscles. Spinal pathways are relevant for sensory-motor integration, but they are commonly not leveraged for prosthesis control. We propose an approach to improve sensory-motor integration for prosthesis control based on modulating the excitability of spinal circuits through the vibration of tendons in a closed loop with muscle activity. We measured muscle signals in healthy participants and amputees during different motor tasks, and we closed the loop by applying vibration on tendons connected to the muscles, which modulated the excitability of motor neurons. The control signals to the prosthesis were thus the combination of voluntary control and additional spinal reflex inputs induced by tendon vibration. Results showed that closed-loop tendon vibration was able to modulate the neural drive to the muscles. When closed-loop tendon vibration was used, participants could achieve similar or better control performance in interfaces using muscle activation than without stimulation. Stimulation could even improve prosthetic grasping in amputees. Overall, our results indicate that closed-loop tendon vibration can integrate spinal reflex pathways in the myocontrol system and open the possibility of incorporating natural feedback loops in prosthesis control.
Date Issued
2024-05-01
Date Acceptance
2024-04-30
Citation
Science Robotics, 2024, 9 (90)
ISSN
2470-9476
Publisher
American Association for the Advancement of Science
Journal / Book Title
Science Robotics
Volume
9
Issue
90
Copyright Statement
Copyright © 2024 Copyright Owner. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy).
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/38809994
Subjects
AFFERENTS
FORCE
HUMAN WRIST
MUSCLE-SPINDLE ENDINGS
RESPONSES
Robotics
Science & Technology
SENSITIVITY
TACTILE FEEDBACK
Technology
TENDON VIBRATION
TONIC VIBRATION REFLEX
VIBRO-ELECTROTACTILE STIMULATION
Publication Status
Accepted
Coverage Spatial
United States
Article Number
eadl0085
Date Publish Online
2024-05-29