Small steps for a 26-year-old paraplegic man could be a giant step for mankind, as University of California Irvine researchers announced the success of their promising brain-computer interface technology.
Their novel approach permitted the young man, who has complete paralysis of both legs due to spinal cord injury, to take steps without relying on manually controlled robotic limbs.
“Even after years of paralysis, the brain can still generate robust brain waves that can be harnessed to enable basic walking,” said UCI associate professor of biomedical engineering Zoran Nenadic in a statement. “We showed that you can restore intuitive, brain-controlled walking after a complete spinal cord injury. This noninvasive 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.”
This is the latest breakthrough work in the fast-growing field of brain-computer interfaces. Some have been used to control prostheses like a robotic arm. And in 2014, a brain-controlled exoskeleton was used by a person to make the first kick of the 2014 World Cup.
The proof-of-concept study's results were published in the British-based Journal of NeuroEngineering and Rehabilitation. The research team was led by UCI's Nenadic and neurologist An Do, and included Christine King, Po Wang, Colin McCrimmon and Cathy Chou of UCI.
The paralyzed participant was able to walk the 12-foot course using an electroencephalogram-based system that allowed the brain to send messages to the legs by using an algorithm to process the brain's electrical signals and then trigger electrodes around the knees to initiate leg-muscle movements.
The participant had to retrain his brain's walking ability for months using a virtual reality system as well as doing physical therapy to strengthen his body for walking again.
Mental training involved biofeedback via an EEG cap to read brain waves, which were processed through the algorithms to tease out those signals involving leg movement. Once that was accomplished, the subject then practiced in a virtual reality environment to make an avatar walk. This let researchers customize the system to the subject so that when the individual thought of moving a leg, the system could fire signals to the electrodes to make his leg move.
Since the study worked on only a single patient, more research is needed, say researchers.
“Once we’ve confirmed the usability of this noninvasive system, we can look into invasive means, such as brain implants,” said Do. “We hope that an implant could achieve an even greater level of prosthesis control because brain waves are recorded with higher quality. In addition, such an implant could deliver sensation back to the brain, enabling the user to feel his legs.”
