Using the BrainGate system and a robotic arm, a woman paralyzed by a brainstem stroke nearly 15 years ago serves herself coffee without human assistance. Photo/BrainGate2.org
Study volunteers with paralysis use thoughts to operate robotic arms
Department of Veterans Affairs (VA) researchers and colleagues report in the May 16 online edition of Nature that two study volunteers with tetraplegia — paralysis of all four limbs and the torso — were able to grasp objects with robotic arms they controlled with their own thoughts. They used an investigational system called BrainGate, which harnesses brain signals to command external devices.
One of the participants, a 58-year-old woman, was able to pick up a bottle of coffee and bring it to her lips to drink. This was the first time she served herself since she became paralyzed nearly 15 years ago.
The woman and a 66-year-old man, who is a veteran, took part in the research. They each had been paralyzed by a brainstem stroke years earlier that robbed them of control of their arms and legs.
The research involved two different robotic arms. One, the DLR arm, was developed as an assistive device by the DLR Institute of Robotics and Mechatronics. The other, the DEKA arm, was developed as a prosthetic arm by DEKA Research and Development, through funding from the Defense Advanced Research Project Agency. VA and DARPA have worked with DEKA engineers and veterans with limb loss in a separate study designed to optimize the arm’s design and function.
Early work on BrainGate took place at Brown University, and VA helped fund its continuing development. The system uses a tiny brain implant about the size of a baby aspirin, with nearly 100 electrodes. It is placed just under the skull on the brain’s motor cortex, which helps control movement. The electrodes, or sensors, are close enough to individual brain cells to pick up their impulses. A wire bundle runs from the electrodes and outside the body to a computer that translates the signals into commands for devices.
The new findings are the first demonstration and peer-reviewed report of people with tetraplegia using brain signals to control a robotic arm in three-dimensional space — as opposed to a two-dimensional computer screen.
Source: VA Research Currents, May 2012. Used by permission.