A paralyzed 28-year-old man has walked 475 feet by using a brain-controlled robot suit, CNN reported. The device resembles a set of external limb braces and moves in response to his thoughts. It shows potential for the field of neuroprosthetics.
According to CNN, the patient’s name is Thibault and he was paralyzed from the neck down after a 40-foot fall several years ago. In 2017, he began working with researchers from the University of Grenoble, in France. The researchers developed a pair of recording devices that are placed under the skin on each side of the head. The devices can then read signals in the brain’s sensorimotor cortex, which controls motor function. In the last two years, Thibault has trained a computer algorithm program to translate his thoughts into movements, which are then fed to the robotic exoskeleton. Strapped into the exoskeleton, Thibault recently made it walk a total of 475 feet. This story shows the enormous potential for neuroprosthetics—artificial body parts that can be operated by thought.
Neuroprosthetics for Beginners
The shortest definition for neuroprosthetics is “prosthetics using neural signals of the human body,” said Dr. John Long, Professor of Biology and a Professor of Cognitive Science on the John Guy Vassar Chair of Natural History at Vassar College.
Although most of us use our thoughts to control our body parts every waking moment of our lives—from walking down the street to typing on a keyboard—we do so with a direct line from our brain sending electrical signals through the nervous system to a muscle. So how do we do the same thing with an artificial limb without intensive science fiction surgery? It starts with the equipment that’s hooked up to the patient.
“The idea here is to tap directly into the human’s nervous system for control,” Dr. Long said. “This is done with what amounts to a special antenna, called an electrode, designed to pick up and amplify the electrical signals generated by nerves and muscles. The electrode can be on the surface of the skin; under the skin-touching muscle; or in the body right next to, or even inside of, the nervous system.”
Next comes the hard part. “Once you have that electrode in the right place to detect nerve signals, then you have to train the human how to voluntarily make and control the electrical signals that the electrode reads,” Dr. Long said. This is what Thibault and the researchers, who headed the experiment, have been doing since 2017.
EMG Signals and the DEKA Arm
A prosthetic called the DEKA Arm also puts this into practice. “The signals that command the DEKA Arm come from electrodes that detect electrical signals called EMG signals that muscles make near where the robotic arm is attached,” Dr. Long said. “EMG stands for ElectroMyoGraphy.”
The difference compared to any other robotic device, then, is that the human operator isn’t using his or her hands on an input device like a controller. If they were, it would be similar to an automobile, a crane, or a video game. The key is that the input is the body’s electrical signals, whether measured in the brain like Thibault’s exosuit or in the muscles like the DEKA Arm.
“Those muscle signals come from the nerves, and that’s why this device is called neuroprosthetic,” Dr. Long said. Even more exciting is the level of sensitivity someone has when using a neuroprosthetic device. Dr. Long pointed out that the DEKA Arm is so delicate that a person operating it can pick up an egg from one carton, transfer it to another, and place it there without breaking it.
Researchers say that commercially available exosuits are still many years off, but thought-controlled robotics are advancing at a promising rate.
Dr. John Long contributed to this article. Dr. Long is a Professor of Biology and a Professor of Cognitive Science on the John Guy Vassar Chair of Natural History at Vassar College. Professor Long received his Ph.D. in Zoology from Duke University.