In 2011, Gert-Jan Oskam was in a motorcycle accident that left him paralyzed below his waist. Now, thanks to special electronics in his brain and spinal cord, he can stand and walk, controlling these actions himself.
The Spinal Cord
The spinal cord is a bundle of nerves that connects the brain to the rest of the body, allowing messages to be sent back and forth. When someone’s spinal cord is hurt, this important pathway can get damaged, meaning information can’t flow between the brain and the lower body.
Mr. Oskam’s spinal cord was partially damaged in 2011. Since that time, he has been paralyzed from the hips down.
(Source: Jimmy Ravier, EPFL.)
In the past, scientists have come up with ways of using electrical devices to send signals to the spinal cord. These treatments have helped some people with spinal cord injuries make some progress. Mr. Oskam tried these methods, but only had limited success.
Now scientists in Switzerland say they have built a “digital bridge” that allows signals from Mr. Oskam’s brain to reach undamaged parts of his spinal cord that control leg movement.
Mr. Oskam said, “For 12 years I’ve been trying to get back my feet. Now I have learned how to walk normal, natural.”
The digital bridge isn’t simple. It required serious surgery and lots of training. Two electrodes – small objects that electricity can pass through – were placed in Mr. Oskam’s skull (the hard bone protecting the brain). Other electrodes were placed in Mr. Oskam’s spine.
(Source: Philippe Getaz, CHUV.)
The researchers first worked to unscramble the signals from Mr. Oskam’s brain. They asked him to think about moving different parts of his legs. Using Artificial Intelligence (AI), they were able to learn which brain signals were supposed to trigger which leg movements.
Next, the scientists used another AI tool to help translate the signals from Mr. Oskam’s brain into signals to send to the electrodes in his spine. Sending these signals to the spinal cord caused Mr. Oskam’s legs to move. The scientists call this a “brain-spine interface”. In his very first session, Mr. Oskam was able to move his hips.
The AI tool was able to make the movements more natural by adjusting the timing of the signals. It also adjusted the strength of the signals so that Mr. Oskam could control how strongly his legs moved.
(Source: Gilles Weber, CHUV.)
In just two days of practicing with the brain-spine interface, Mr. Oskam was able to walk with a walker. The computer that controls the brain-spine interface can be carried in a backpack or on a special walker.
With months of practice, and adjusting the settings of the brain-spine interface, Mr. Oskam was able to stand and walk much more smoothly, and even climb up stairs and steep ramps. The farthest Mr. Oskam has walked at one time is about 330 feet (100 meters), or about the length of a football field.
Perhaps the most surprising change is that now he has some control of his legs, even when the digital bridge is turned off. Grégoire Courtine, who is leading the research, says that nerves in Mr. Oskam’s spinal cord seem to be making new connections.
The digital bridge solution isn’t perfect. It costs a lot, requires difficult surgery, and won’t work for all kinds of spinal cord injuries. But the scientists are hopeful that in the future, this sort of technology will allow many paralyzed people to walk again.