Two paralyzed people have been able to operate a robotic arm through thought control, using a cutting-edge technology for the first time that taps into the mind to overcome limitations of the body, scientists announced Wednesday.
Dr. John P. Donoghue of Brown University and his colleagues reported the feat in the online edition of the journal Nature, calling it the first use of a prosthetic device by those who have lost nerve connections between brain and limbs.
The two paralyzed subjects were able to move objects through thought control by way of a tiny implant in the brain that gathers neural information -- thoughts -- and transmits the data to a receiver fixed to the scalp, which communicates with the computerized robotic arm.
The aspirin-size device, part of the system called BrainGate, must be put in place by a neurosurgeon in the brain's motor cortex, an active site for limb movement. Attached to the tiny disc in the brain are nearly 100 sensors that retrieve brain signals.
"The hope here is to make someone who is paralyzed not be," Donoghue told Newsday last month following Stony Brook University's 16th annual Swartz Foundation Mind Brain Lecture, where he was the featured speaker.
Donoghue noted his work brings to life what science fiction writers have fantasized about for decades -- using thoughts to control the movement of prosthetics. Better than science fiction, Donoghue noted, is the possibility of creating independence for a population who otherwise would be confined and reliant on others.
Donoghue noted that even though injury and disease can disconnect mind and body, the neural signals that allow limb movement are still intact and remain active in the brain. The system allows scientists to tap into that neural energy and focus it in a new way.
One of Donoghue's test subjects, a 56-year-old woman paralyzed 15 years ago after a stroke, was able to use her thoughts to command the large robotic arm placed nearby to lift a bottle of coffee. Her thoughts powered the device to bring the bottle close enough to her face to sip its contents, allowing her to serve herself for the first time since she had become paralyzed.
The other test subject in the study is a 66-year-old man who also suffered a stroke and lost use of all four limbs. His use of thoughts to control the robotic arm was his first use of any kind of prosthetic device since his paralysis three years ago, according to the research.
During his Stony Brook lecture, Donoghue showed a video of the woman revealing even more potent examples of how thought control can be used. She was asked by one of the researchers to move a filled wineglass from one side of a table to the other using the robotic arm. The table was a few feet away, so she had to process the request, then use her thoughts to move the glass -- which she did without spilling a drop.
"The brain works as an electrical communication device," said Donoghue, a professor of neuroscience and engineering at Brown, where he directs the Institute for Brain Science. He's also a senior research scientist for the Veterans Affairs department.
"In the brain, signals are coded and specific, and the only way to pick them up is put a sensor in the brain about the size of a baby aspirin," he said.
In the journal paper, Donoghue's team says the new system is aimed at people paralyzed from spinal cord injuries, brainstem stroke, amyotrophic lateral sclerosis (Lou Gehrig's disease) and other disorders.