When a patient is completely paralyzed, as sometimes happens after a brain injury or illness, communication can be difficult if not impossible. Research in neuroscience labs all over the world is focused on technology that can assist patients and their caregivers. Recently, a team led by Stanford University scientists, published a clinical research paper on a brain-to-computer interface (BCI) that paralyzed patients can use to communicate. To date, their project is the fastest and most accurate of any other prototypes developed.
The team at Stanford worked with three study volunteers, all of whom had severe limb weakness. Two of the patients were diagnosed with amyotrophic lateral sclerosis (ALS), also called Lou Gehrig’s disease, and the third had a significant spinal cord injury. These patients bravely volunteered to have small electrode arrays surgically implanted in the motor cortices of their brains. The arrays are very small, just the size of a peppercorn. The motor cortex is where signals are sent to arms, hands and fingers to control movement. In the brains of the study volunteers, these signals were picked up by the electrode arrays and transmitted to the computer. Once received by the computer, a set of custom algorithms translated them into commands that moved a cursor on the screen.
The participants needed some training, but it was minimal. Once they were sure of the method of imagining hand movements, seeing what happened, and then adjusting their mental efforts, the results pretty much blew away previous projects on speed and accuracy. Dennis Degray, one of the study volunteers, typed at a rte of 39 correct characters per minute. At that rate, he could theoretically communicate at a typing speed of about 8 words a minute. It might seem slow, but for these patients it’s a significant technological breakthrough that allows them to interact with those around them.
Krishna Shenoy, PhD, professor of electrical engineering at Stanford and co-senior author of the paper stated, “This study reports the highest speed and accuracy, by a factor of three, over what’s been shown before. We’re approaching the speed at which you can type text on your cellphone.” Co-author, Jaimie Henderson, MD, professor of neurosurgery, who performed two of the three device-implantation procedures at Stanford Hospital added, “Our study’s success marks a major milestone on the road to improving quality of life for people with paralysis.”
The system being used in the study is investigational and not available outside clinical research. It’s called the BrainGate Neural Interface System and is being developed in partnership with not only Stanford, but researchers and medical professionals at Massachusetts General Hospital, Case Western Reserve University, Brown University and the U.S. Department of Veterans Affairs. Henderson and Shenoy estimate that in 5-10 years time, the system will be fully wireless, self-calibrating and able to be used without the assistance of a caregiver, a major step for patients who rely on their personal care attendants for almost every task.
Degray, whose paralysis includes everything below the collarbone, was injured in a fall that severed his spinal cord. He described the interface as, “one of the coolest video games I’ve ever gotten to play with and I don’t even have to put a quarter in it.” The research on the project at Stanford is published in the February 21st issue of the journal eLife. Take a look at the video below to see the technology in action.
