Swiss researchers develop tech to help person with paralysis walk again

25 May 2023

Gert-Jan, who was the subject of the study. Image: NeuroRestore

Published in Nature, the study involving scientists from NeuroRestore showed how a newly developed wireless interface can ‘transform thought into action’.

Researchers in Switzerland have been able to create a ‘digital bridge’ between the brain and spinal cord enabling a person with paralysis to stand and walk naturally.

In a study published in Nature yesterday (24 May), a team of neuroscientists described how a 40-year-old man who suffered a spinal cord injury that left him paralysed following a bicycle accident was able to walk again using brain-computer interface (BCI) technology.

“We have created a wireless interface between the brain and the spinal cord using BCI technology that transforms thought into action,”, said co-author Grégoire Courtine, a professor of neuroscience at the Swiss Federal Institute of Technology and University Hospital of Lausanne.

The process involved two electronic implants: one on the brain and the other on the spinal cord.

Jocelyne Bloch, a neurosurgeon behind the study, explained that the team implanted one of the sets of devices above the region of the brain that is responsible for controlling leg movements.

“These devices allow to decode the electrical signals generated by the brain when we think about walking. We also positioned a neurostimulator connected to an electrode array over the region of the spinal cord that controls leg movement,” Bloch said.

The wireless interface was co-developed by a team of experts associated with NeuroRestore, a centre set up by the Defitech Foundation, Lausanne University Hospital, the University of Lausanne’s Faculty of Biology and Medicine, and the Swiss Federal Institute of Technology.

Some of the team’s members made headlines in 2018 after helping a man called David Mzee, who had lost the use of his legs following a spinal cord injury, to walk again through continuous electrical stimulation and a pacemaker-like implant.

Cathal Harte, an Irish software engineer who joined NeuroRestore in 2020, told last year that he was excited about the centre’s brain-spine interface study that developed the digital bridge.

“There’s an implanted brain decoder, what you do is you remove parts of the skull, and you replace it with a sensor,” he explained.

“Then you train pattern recognition algorithms to say, OK, think about moving your left leg, think about moving your toe, think about various things and it learns those brain states.

“And so, it’s able to match up then what it’s sensing with intentions, and then we turn those intentions into spinal cord stimulation.”

While the digital bridge has only been tested on one person so far, Bloch and Courtine said that the same technique can be used on patients without hand and arm function, as well as in other clinical conditions such as paralysis due to stroke.

“I’d like to stress the substantial development effort we made to enable the system to be used at home. That’s what makes the achievement all the more real for me,” Harte told about the latest study.

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Vish Gain is a journalist with Silicon Republic