Control of an Ambulatory Exoskeleton with a Brain–Machine Interface for Spinal Cord Injury Gait Rehabilitation

Brain-machine interfaces (BMIs) can be used as a natural control method for rehabilitative technologies in patients suffering from paralysis. BMI provides a continuous association between the brain activity and peripheral stimulation, with the potential to induce plastic changes in the nervous system. This paper proposes a closed-loop BMI system to control an ambulatory exoskeleton—without any weight or balance support—for gait rehabilitation of incomplete spinal cord injury (SCI) patients. The integrated system was validated with three healthy subjects, and its viability in a clinical scenario was tested with four SCI patients. Using a cue-guided paradigm, the electroencephalographic signals of the subjects were used to decode their gait intention and to trigger the movements of the exoskeleton. We designed a protocol with a special emphasis on safety, as patients with poor balance were required to stand and walk.

• 1
  For the three healthy subjects, 84.44 ± 14.56% of the trials were correctly decoded, indicating the viability of the setup.
• 2
  Three out of four patients performed at least one successful BMI session, with an average performance of 77.6 1 ± 14.72%.
• 3
  A shared control strategy was effective in preventing unexpected movements, which could lead to patient falls.