Gert-Jan and Michel share with most people their love of socializing, ideally toasting with their friends. “The simple act of raise a glass It is something that people do without giving it importance.” But for them it is. Both are paraplegics, having had two separate accidents. and the two have managed to rise and toast again with your colleagues. And thanks to spinal implants, a brain-spinal bridge and artificial intelligence (AI) trained for each paraplegic.
In 2022 we met Michel, who was able to get up again after four years in a wheelchair, due to a motorcycle accident. Remotely controlled electrodes and artificial intelligence allow him a certain amount of mobility, although somewhat ‘robotic’. Gert-Jan’s case has just been published in Nature and mark a new milestone. “Last week, nobody could help me, and I was able to get up with the walker [electrónico] and paint [una pared]”, exemplifies the patient in an encounter with the media.
The patient became a paraplegic after practically breaking his neck in a cycling accident in China. On his return, his doctor told him that a colleague from Lausanne wanted to try a digital brain-cord bridge. An experimental device to reconstruct the nerve wiring between neurons in the brain and the legs and hands and until a part is regenerated. The doctor Gregoire Courtine (Federal Polytechnic School of Lausanne, EPFL, in Switzerland) worked training personalized artificial intelligence so that paraplegics can walk again.
Today, Gert-Jan not only paints walls and toasts with her friends. I control my movements with my mind,going 100 or 200 meters, depends on the day”. But what is truly “interesting about his case” is that, one day they tested disconnect the implanted device and see if you could get up. She picked up her crutches and took a few steps. “The patient,” says Dr. Courtine, “has somehow managed to reestablish part of the neural connections,” thanks to the stimulation.
Another novelty regarding the case of Michel is that the movement “feels more natural”. Michel would press a series of buttons on his electronic walker or tablet to trigger the commands his brain would issue to move his legs, step by step. One leg after the other, which resembles “walking like a robot”. In the case of Gert-Jan, the brain-spinal bridge allows her legs to “capture a thought” and thus, the movement, after training him and the associated AI, is more natural.
“With this brain-controlled spinal stimulation,” Courtain continues, “we have a given model, which can control hip flexion, ankle extension or flexion on both sides, which was not possible before.”
A brain-spinal bridge that is not valid for any paraplegic
In paraplegic people, a spinal cord injury interrupts communication between the brain and the nerve region of the spine that controls walking. Some previous approaches to restoring movement involve electrically stimulated regions of the spinal cord, as in Michel’s case. However, this required the use of motion sensors, and patients showed limited ability to adapt leg movements to changing terrain and demands. The brain-cord bridge could improve control over the timing and amplitude of muscle activity.
And although it is a success that Gert-Jan can even stand without manual support for almost 3 minutes at a time, all this is still in progress. an experimental phase. This follow-up study was opened to a very restricted group of patients. Less than ten could see results in their studies of brain-spinal cord interfaces in paraplegics.
To date, four patients have benefited from similar implants but only on an experimental level.
The presentation of Gert-Jan’s case, made in great detail by a company spin off of the University, it is still far from being a marketable reality for everyone. courtine is behind this startup of biomedical engineering. The 44-year-old Frenchman, passionate about climbing and extreme sports, trusts that his company will achieve, at least, that after an accident while practicing one of these sports -for example- the sentence to a wheelchair is not directly assumed. forever.
He has the technology, but to land it on a clinical level, people specialized in relatively complex neurosurgeries and physical trainers and technical engineers and linked to artificial intelligence. Behind these success stories is Jocelyne Bloch, a neurosurgeon at Lausanne University Hospital.
“When everything is installed -explains the doctor-, the patient has to learn to manage his brain signals and we, to correlate those signals with the stimulation of the spinal cord”, he explains. “This is all quite fast, in just a few sessions everything connects and the patient starts training.”
After receiving these implants, the patient is asked to imagine moving their legs; In doing so, your brain emits signals that, through algorithms, are converted into binary data with the electrodes and device inserted into the brain. This is how the AI is trained. This, in turn, becomes movement instructions for the medullary implant.
Michel, the young paraplegic we met in 2022, could be the next to undergo this brain-spinal bridge… “if we convince him to let Jocelyne drill a hole in his skull, with the beautiful long hair he has,” Courtain jokes.