A man who is paralyzed in both legs has walked a short distance while hooked up to a brain-interface technology developed by the University of California – Irvine. The unidentified man was able, for the first time, to take steps without the support of manually-controlled robotic limbs. The research participant has been paralyzed for five years after a spinal cord injury. The research was announced on September 24, 2015, and were published in the Journal of NeuroEngineering & Rehabilitation.
The participant walked along a 12 foot course with assistance from an electroencephalogram-based system that allows the brain to bypass the spinal cord and send electrical signals directly to the legs. The system processes the signals through a computer algorithm, and then sends them to electrodes placed around the knees. The electrodes then trigger movement in the leg muscles.
“Even after years of paralysis, the brain can still generate robust brain waves that can be harnessed to enable basic walking,” said Nenadic, an associate professor of biomedical engineering. “We showed that you can restore intuitive, brain-controlled walking after a complete spinal cord injury. This non-invasive system for leg muscle stimulation is a promising method and is an advance of our current brain-controlled systems that use virtual reality or a robotic exoskeleton.”
The participant received mental training for several months to reactivate his walking ability in his brain and had physical therapy. An EEG cap read his brain waves as he thought about moving his legs. The brain waves were processed through the computer algorithm Nenadic formulated to isolate brain waves that were associated with leg movement. When the participant wanted to move his legs, the brain waves were converted into specific signals that stimulated his leg muscles.
The participant required extensive physical therapy to strengthen and recondition his leg muscles. He practiced walking while being suspended five centimeters above the floor, enabling him to move his legs freely without needing to support his body. Eventually, he was able to walk on the ground while wearing a body-weight support system that could pause to keep him from falling.
“Once we’ve confirmed the usability of this noninvasive system, we can look into invasive means, such as brain implants,” said Do, an assistant clinical professor of neurology. “We hope that an implant could achieve an even greater level of prosthesis control because brain waves are recorded with higher quality,” said neurologist and researcher An Do. “In addition, such an implant could deliver sensation back to the brain, enabling the user to feel his legs.” Do said that more research is needed to see if the same results can be achieved in a larger populations of paraplegics.