September 24, 2015
Breakthrough: Paralyzed man regains ability to walk using direct brain control
Given recent advances in technology, it isn’t unusual for a previously paralyzed man or woman regaining the ability to walk thanks to manually-controlled robotic limbs, but now University of California-Irvine researchers have accomplished the feat without such aids.
In a preliminary proof-of-concept study, Dr. An Do, Dr. Zoran Nenadic and colleagues showed that it is possible to use direct brain control to allow a spinal cord injury patient to use his or her own legs to walk again without having to rely upon mechanical aids for locomotion.The research, which was published in the Journal of NeuroEngineering and Rehabilitation, is said to mark the first time that direct brain control has enabled a person to walk without use of robotic devices following complete paralysis in both legs following a spinal cord injury.
The individual had been a paraplegic for five years, and thanks to an EEG-based brain control system, he was able to walk along a 3.66m long course 30 times over a 19 week span, the study authors said. Periods of mental training and physical conditioning were required, they added.
Dr. Nenadic, the senior lead researcher of the study and an associate professor in the UC-Irvine Department of Biomedical Engineering, told redOrbit that the study “is a culmination of a five-year work that started with able-bodied subjects learning to operate a brain-computer interface (BCI) system,” using brain waves to control the movement of a virtual-reality avatar.
Initial research could lead to fully-implantable BCI units
He and his colleagues then recruited people with paraplegia due to spinal cord injuries, and demonstrated that they could compete the VR tasks as well if not better than able-bodied men and women. Encouraged by those results, he explained that they decided to test the function of the BCI system in a real-world environment.
They started by demonstrating that a paralyzed subject could successfully walk on a treadmill using a BCI-controlled robotic leg orthosis. Following that successful experiment, they took the BCI system and integrated it with an electrical muscle stimulator. Eventually, this set-up allowed the subject to walk across a room, stopping at designed points along a course, by controlling the entire system using only his brain waves, Dr. Nenadic explained in an email to redOrbit.
On the heels of this successful proof-of-concept test, he said that he and his colleagues plan to test the system with additional individuals suffering from paraplegia due to spinal cord injuries. He noted that they are currently “in the process of developing a simplified, more portable and more practical version of the system. Ideally, we would want to test the function of this new system in multiple subjects with paraplegia.”
Based on the success of their initial tests, “we expect the system to work at the population level,” Dr. Nenadic added. “Given the success of the current non-invasive system, one of our research trusts is to pursue the development of invasive (fully implantable) BCI system.”
“This would circumvent some of the impracticalities of the current system, such as putting the electrodes on and off, or being dependent on external electronics,” he concluded. “The invasive system would also yield brain waves of higher quality, which would likely translate into more accurate control. Finally, the implant could also be used to deliver sensory feedback to the subjects and allow them to feel their legs as they are walking.”
Feature Image: University of California, Irvine