Researchers at the Ecole Polytechnique Federale Lausanne (EPFL) in Switzerland, together with Brown University, Medtronic and Fraunhofer ICT-IMM in Germany, have made headlines with an implantable device that helped a paralyzed monkey walk. Meanwhile, at UMC Utrecht, a brain implant is helping a fully paralyzed woman communicate through a computer operated with her mind.

It’s the latest evolution in Brain Computer Interfaces, or BCI. The idea will transform treatment for injuries that disrupt the brain’s communication within a body, though the extent – and the timeline – are still hard to pin down. There are hurdles ahead, but these developments could make new milestones in computer interaction seem tantalizingly close. 

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Think of implantable tech as WiFi for your nervous system. 

To understand how BCI works, consider that the brain is already electric. To reduce a lot of complexity, let’s just say that neurons carry data, encoded as chemical and electrical activity. 

Try making a fist. From the moment you decide to make a fist, you’re sending bursts of information through your neural pathways, into your hand. That’s roughly parallel to how a computer transmits data throughout a network. Visit a website, and the website quickly sends back little packets of information until nextrends appears in your browser window.

In a computer network, that information can bounce around different points to get to your computer quickly. If one point in the network is down, or broken, it simply finds another path.

A body can’t do that. Neurons are confined to the central nervous system. Injuries such as spinal damage can disrupt the path that neurons take to get from your brain to your legs. A spinal cord injury can lead to paralysis because there’s no alternative path for your neurons to connect to the muscles in your legs.

What’s important here is that the brain is still sending that information. It’s like writing emails when the internet is down: you can hit send, but if the connection is blocked, the command never gets where it needs to go. Researchers needed to find a way to deliver that message through a broken spine. 

Connect the dots

What if those neurons had another path? That’s what researchers at EPFL have asked, and answered, with their implantable BCI device.

Those researchers implanted a microelectrode array into the primate’s brain. That implant helped translate spikes in motor activity signal, the same “commands” that the primate would have sent if it had a fully functional leg.

Instead, the array sent those translated commands to a pulse generator. That generator, in turn, sent these signals to spinal implant just below the injury’s damaged bit of pathway. That implant triggered the same neurons that would control that leg’s motion before the pathway was damaged.

Suddenly, the brain could communicate with its legs again. Think of it as the brain using a smartphone to send an e-mail because the WiFi went down. When EPFL researchers tried this, the effect was instantaneous.

“The primate was able to walk immediately once the brain-spine interface was activated. No physiotherapy or training was necessary,” said neuroscientist Erwan Bezard of Bordeaux University, who oversaw the experiment.

Implantable tech in humans

A similar technology was recently tested on a 58-year-old woman with amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease. With ALS, neurons controlling muscle movements gradually weaken, then die, causing oftentimes fatal paralysis. Researchers created a device that could detect and amplify those weak signals, allowing the neurons associated with the movement of her right hand to function as a communications device.

This was a common technique for granting independence to those with ALS. Functional muscle groups are maximized for communication, often relying on extremely complex and time-consuming typing.

Stephen Hawking, the brilliant physicist who was diagnosed with the disease in 1963, communicates through messages translated by tiny movements of his cheek muscles. This approach speeds that up by removing the physical requirement for typing.

After the implant, the woman was able to play simple video games (Pong) using only her mind, and the “messages” that the mind could still send to unresponsive muscles. Those impulses were translated into a control device for an interactive keyboard, speeding up her ability to communicate.

She’s now living outside of the hospital, the first patient with such a device to be able to do so. A team from UMC Utrecht has been supervising her progress, and published the results in the New England Journal of Medicine.

Challenges ahead

“There are many challenges ahead and it may take several years before all the components of this intervention can be tested in people,” said Grégoire Courtine, who led the EPFL collaboration.

One of those challenges? Getting the technology to help two-legged creatures walk. The current model works because the monkey walks on four legs, meaning that stabilizing its gravity is a simpler computational process. While this experiment is a remarkable proof of concept, it has ways to go before it can fully restore bipedal motion in humans. The first steps for this technology in humans is likely to be an aid for therapy, rather than an outright cure.

Likewise, the tech behind the ALS case is still slow, and researchers are working on improving the speed and complexity of possible actions. But before that, they need to test the product in two more patients, and then conduct an international clinical trial.

What’s NEXT?

These challenges haven’t stopped many people from dreaming about technology that would make voice-recognition seem as cutting-edge as a rotary phone. In fact, big ideas for BCI have been considered since the 1970s, when research first started at the University of California.

Because BCI operates off of translated electrical current, any system involving touch or sight could be controlled by thought. That could include data storage: imagine a program that makes a map of areas as you move through them, collecting input from others who move around the space. Rescue workers in dangerous environments could benefit from instantaneous, collective eyesight. 

The interface also highlights the benefits of human processing against machine processing. The advantage of networking the two is bringing the simultaneous, rapid processing of the human mind to the quick-as-lightning execution of commands made possible by a machine. Those who dream of biological enhancements see this as a perfect pairing for cyborg technologies.

Of course, right now, those schemes are grounded by reality. Products built with the technology’s limited functions have existed since the mid-1990s for a variety of purposes, emphasizing wearable (rather than implanted) devices. That market currently includes projects as diverse as piloting a miniature plane to training young “Jedi Knights” to use the Force.

Far-off evolutions of these technologies could produce applications such as educational software that avoids the most difficult material if it senses a student is fatigued. Even that degree of complexity is much further away. Experts suggest we may not see this application of the tech until 2032, at the earliest. A full cyborg interface might just have to wait. 

In the meantime, processing complex output from the human brain, and allowing synapses to leap-frog over damage in the nervous system, is quite a remarkable achievement. There’s no doubt that these developments have opened the door to bring these dreams even closer.


Illustration by Jemere Ruby, courtesy of EPFL.