A man has been able to move all four of his paralyzed limbs with a brain-controlled exoskeleton suit, French researchers have said.
The 28-year-old man from Lyon, France, is known as Thibault was paralyzed from shoulders down after he fell 40 feet from a balcony, injuring his spinal cord. He is tetraplegic, denoting to the partial or total loss of use of all four limbs and upper body.
He had some flexibility in his biceps and left wrist and was capable of maneuvering a wheelchair with a joystick in his left arm. He said he felt like the first man on the Moon while taking his first steps in the suit. His movements, mainly walking, are far from perfect, and the robo-suit is being used only in the lab.
However, the researchers are hopeful that the approach could one day improve patients’ quality of life.
How does it work?
Researchers from the biomedical research center Clinatec, the University of Grenoble in France, and the CEA research center inserted recording devices on each side of Thibault’s head, between the brain and skin, to cover the sensorimotor cortex, the area of the brain that controls sensation and motor function.
Electrode grids gathered the man’s brain signals and passed them on to a decoding algorithm, which transformed the signals into movements and directed a robotic exoskeleton to complete them. Throughout the study, Thibault covered a total of 145 meters (around 476 feet) with 480 steps using the avatar, video, and exoskeleton together, researchers said in the paper, which was published in the Lancet Neurology journal on 4th October.
How easy was it to use?
Thibault was an optician before he fell 15m in an incident at a night club four years ago which left him paralyzed. However, in 2017, he participated in the exoskeleton experiment with Clinatec and the University of Grenoble.
In the beginning, he practiced using the brain implants to control an avatar or virtual character, in a computer game, then he switched to walking in the suit. He said that since he didn’t walk for two years, he forgot what was it like to stand and also forgot he was taller than the other people in the room. He struggled for quite some time in learning how to control his arms.
“It was very problematic because it is a grouping of multiple muscles and movements. This is the most exciting thing I do with the exoskeleton.”
Weighing 65kg, the sophisticated robotics is not totally restoring function. However, it is a noticeable advance on similar approaches that let people control a single limb with their thoughts.
Thibault does need to be fastened to a ceiling-harness to reduce the risk of him falling over in the exoskeleton which means the device is still not ready to move outside the laboratory.
“This is far from independent walking,” said Prof Alim-Louis Benabid, the president of the Clinatec executive board. “He does not have the swift and accurate movements not to fall, nobody on earth does this.”
In tasks where Thibault had to touch particular targets by using the exoskeleton to move his upper and lower arms and turn his wrists, he was successful 71% of the time. According to Prof Benabid, who made deep brain stimulation for Parkinson’s disease: “We have resolved the problem and shown the principle is correct. This is proof we can enhance the movement of patients in an exoskeleton.
“This is in the route of giving a better quality of life.”
The French scientists say they can continue to hone the technology. At the instant, they are restricted by the amount of data they can read from the brain, send to a computer, infer, and direct to the exoskeleton in real-time.
They have 350 milliseconds to move from thought to movement, or else the system becomes difficult to control. This means the researchers are using only 32 out of the 64 electrodes on each implant.
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So there is still the ability to read the brain in more detail utilizing more powerful computers and AI to understand the information from the brain. There are also preparations to develop finger control to enable Thibault to pick up and move objects.
He has already used the implantation to control a wheelchair.
Technology to be misused?
There are scientists exploring ways of using exoskeletons to improve human abilities, a field identified as transhumanism, rather than conquer paralysis. This includes many military applications.
“We are categorically not going in the direction of these stupid and extreme applications,” said Prof Benabid. “Our job is to treat the injured patients who have lost function.”
What do experts think?
Professor Tom Shakespeare, from the London School of Hygiene and Tropical Medicine, said while this study presents a “exciting and welcoming advance”, proof of concept has still a long way to go from functional clinical possibility.
“A danger of publicity always exists in this field. Cost limitations mean that hi-tech options are never going to be accessible to most people in the world with spinal cord damage.”
Merely 15% of people with disabilities had a wheelchair or other assistive devices, he said.