Restoration of reaching and grasping in a person with tetraplegia through brain-controlled muscle stimulation: a proof-of-concept demonstration

Lancet, 2017 · DOI: 10.1016/S0140-6736(17)30601-3 · Published: May 6, 2017

Simple Explanation

This study explores a way to help people with tetraplegia (paralysis of all four limbs) regain the ability to reach and grab objects. It uses a combination of Functional Electrical Stimulation (FES) to stimulate muscles and an intracortical brain-computer interface (iBCI) to control the stimulation with brain signals. The participant had electrodes implanted in his brain and muscles. He used his thoughts to control the electrical stimulation, which in turn moved his arm and hand. A mobile arm support helped with gravity. The participant was able to perform tasks like drinking coffee and feeding himself using this system, showing the potential for restoring important daily activities.

Study Duration

Not specified

Participants

1 participant (53 years old, C4, ASIA A)

Evidence Level

Level IV, Proof-of-concept demonstration

Key Findings

1
The participant could control single-joint and multi-joint arm movements with 80-100% accuracy using both a virtual arm and his own arm stimulated by FES.
2
The participant successfully completed 11 out of 12 attempts to drink a mug of coffee and was also able to feed himself using the system.
3
The system allowed the participant to make meaningful movements that were impossible without it, demonstrating that no substantial motor recovery occurred due to the FES and/or iBCI.

Research Summary

This study demonstrates that a person with chronic tetraplegia can regain limb movements through coordinated electrical stimulation of muscles, commanded using their own cortical signals via an intracortical brain-computer-interface (iBCI). The participant was able to cortically command his paralyzed arm to perform single-joint and coordinated multi-joint arm movements for point-to-point target acquisitions with high accuracy. The study shows the potential of a combined FES+iBCI neuroprosthesis for restoring both reaching and grasping for people with SCI, representing a major advance for clinically viable neuroprostheses.

Practical Implications

Restoration of Function

The combined FES+iBCI system offers the possibility of regaining lost arm and hand function to perform activities-of-daily-living for people with chronic tetraplegia from SCI.

Technological Advancement

Continued clinical translation of this technology will be aided by iBCI and FES technological advances resulting in smoother and more dexterous arm and hand movements.

Increased Independence

Future systems inspired by this work may provide full-time and more accurate control of the arm and hand, enabling restoration of a wider range of functional activities and resulting in increased independence and quality-of-life.

Study Limitations

1
FES movements were moderately slower and less accurate than the same movements of the VR arm under brain control.
2
The percutaneous FES electrodes limited the number of joints that could be restored and their ranges-of-motion.
3
The participant required continuous visual feedback of his arm movements due to lack of proprioception.

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