The Dutchman Gert-Jan has once again been able to do something he hadn’t been able to do since 2011: walk and climb stairs. This 40-year-old man is in the news because he has tested a device created by Swiss researchers from the University of Lausanne. A kind of wireless ‘digital bridge’ that connects his brain to his back and allows him to send commands to his spinal cord. The advance is published this Wednesday in the magazine Nature.
“We have created a wireless interface between the brain and the spinal cord using brain-computer interface (BCI) technology that transforms thought into action,” summarizes Grégoire Courtine, professor of Neuroscience at the Federal Polytechnic School of Lausanne (EPFL).
The digital bridge has allowed him to regain natural control over the movement of his paralyzed legs, allowing him to stand up, walk and even climb stairs. Gert-Jan explains that she has rediscovered the pleasure of being able to share a beer standing in a bar with her friends: “This simple pleasure represents a significant change in my life.”
Two types of electronic implants are needed to establish this digital bridge. EPFL neurosurgeon Jocelyne Bloch explains: “We have implanted WIMAGINE devices into the region of the brain responsible for controlling leg movements. These developed devices (…) make it possible to decode the electrical signals generated by the brain when we think about walking. We also place a neurostimulator connected to an electrode array over the region of the spinal cord that controls leg movement.”
Guillaume Charvet, head of the BCI program, adds: “Thanks to algorithms based on adaptive artificial intelligence methods, movement intentions are decoded in real time from brain recordings.”
These intentions are then converted into sequences of electrical stimulation of the spinal cord, which in turn activate the leg muscles to achieve the desired movement. This digital bridge works wirelessly, allowing the patient to move autonomously.
Recovery of neurological functions
Rehabilitation with the help of the digital bridge allowed Gert-Jan to recover the neurological functions that she had lost since her accident. The researchers were able to quantify notable improvements in her sensory perceptions and motor skills, even when the digital bridge was turned off. This ‘digital repair’ of the spinal cord suggests that new nerve connections have developed.
So far, the digital bridge has only been tested on one person. In the future, a similar strategy could be used to restore arm and hand function. They add that the digital bridge could also be applied to other clinical indications, such as paralysis derived from stroke.