Researchers in California have successfully connected an electroencephalogram (EEG)-based brain-computer interface (BCI) to a robotic leg, an accomplishment that may give new hope to people with spinal cord injuries (SCI).
The research was led by An Do, MD, at the Veterans Affairs (VA) Long Beach Medical Center, along with help from colleagues at the University of California, Irvine (UC Irvine). The robotic lower limb is controlled in real time by EEG signals fed into a computer.
“This ﬁnding represents the ﬁrst successful demonstration of a BCI-controlled lower extremity prosthesis for independent ambulation,” say the researchers.
The project began by building on the team’s previous research that developed a way to use EEG signals to control the walking motion of a character in a virtual world. To accomplish this, they recorded EEG data from able-bodied participants. The participants alternated between walking and standing while the data was recorded, which was used to generate an EEG prediction model for online operation via a brain-controlled interface.
A serious concern during the testing phase was the possibility of “false alarm rates,” which are unintended steps. In the real world, an unintended step, especially when crossing the street or facing another hazard, could be deadly. Luckily, the system showed no false alarms during testing.
The next stage in the development of the project will be to test the system on a subject that has a spinal cord injury. The focus of the future of the project will be to restore walking to those with paraplegia resulting from a spinal cord injury, and the possible rehabilitation of people with incomplete motor injuries.
The team stated, “these results provide preliminary evidence that restoring brain-controlled ambulation may be possible. However, future work is necessary to test this system in individuals with paraplegia due to SCI.”