17th December 2012
Paralysed woman feeds herself with mind-controlled robot arm
Researchers in Pittsburgh have developed a brain-computer interface (BCI) allowing a woman with quadriplegia to maneuver a robotic arm. Using just her thoughts alone, Jan Scheuermann was able to "high five" someone, grasp and move objects of different shapes and sizes, and feed herself chocolate.
In a study published by The Lancet, the team describes how the BCI technology and training programs allowed Ms. Scheuermann, 53, to intentionally move an arm, turn and bend a wrist, and close a hand for the first time in nine years.
Senior investigator Andrew Schwartz, Professor at the Department of Neurobiology, Pittsburgh School of Medicine: "This is a spectacular leap toward greater function and independence for people who are unable to move their own arms. This technology, which interprets brain signals to guide a robot arm, has enormous potential that we are continuing to explore. Our study has shown us that it is technically feasible to restore ability; the participants have told us that BCI gives them hope for the future."
The researchers placed two quarter-inch square electrode grids with 96 contact points each in the regions of Ms. Scheuermann’s brain that would normally control right arm and hand movement. The electrode grids detect signals from individual neurons and then computer algorithms are used to identify the firing patterns associated with particular observed or imagined movements. That intent to move is then translated into actual movement of the robotic arm.
In a separate study, researchers also continue to study BCI technology that uses an electrocortigraphy (ECoG) grid, which sits on the surface of the brain, rather than penetrating the tissue as in the case of the grids used for Ms. Scheuermann.
Senior investigator Michael Boninger, M.D.: "We are learning so much about how the brain controls motor activity, thanks to the hard work and dedication of our trial participants. Perhaps in five to 10 years, we will have a device that can be used in the day-to-day lives of people who are not able to use their own arms."
The next step for BCI technology will likely use a two-way electrode system, that not only captures the intention to move, but also stimulates the brain to generate sensation – potentially allowing a user to adjust grip strength, to firmly grasp a doorknob or gently cradle an egg, for example.
After that, "we're hoping this can become a fully implanted, wireless system that people can actually use in their homes without our supervision," said Jennifer Collinger, Ph.D., assistant professor. "It might even be possible to combine brain control with a device that directly stimulates muscles, to restore movement of the individual's own limb."
For now, Ms. Scheuermann is expected to continue putting the BCI technology through its paces for two more months, then the implants will be removed in another operation.
"This is the ride of my life," she said. "This is the rollercoaster. This is skydiving. It's just fabulous, and I'm enjoying every second of it."