Implanted device sets thoughts in motion

Using an implanted brain-computer interface, researchers at The Miami Project to Cure Paralysis have been able to help quadriplegic German Aldana Zuniga regain some independence by allowing him to use his hand simply by thinking about it.



When German Aldana Zuniga was 16 years old, doctors told him he would never be able to walk or use his arms properly again.

But Zuniga never gave up on the idea.

Today, nine years after being paralyzed in a serious car accident, Zuniga is making great strides. Using a surgically implanted brain-computer interface (BCI) that can decipher his thoughts, Zuniga recently drove a modified NASCAR race car around Colorado’s Pikes Peak International Raceway just by thinking about hitting the accelerator.

He also connects his BCI with an adaptive glove every day to help him regain some control over his right hand to open doors, feed himself, write short notes and brush his teeth.

“It was amazing to stand there and watch my legs move just thinking about it,” Zuniga said. “It was unbelievable.”

In 2018, as part of a research study, Zuniga offered to have the BCI surgically implanted to see if the technology could improve the lives of people like himself who suffer from spinal cord injuries. It was the first time that doctors in The Miami Project to cure paralysisa Center of Excellence at the University of Miami Miller School of Medicine, had a BCI implanted for research purposes only, said David McMillan, director of education and outreach for The Miami Project, as well as an assistant professor of neurological surgery.

“It was tough to find someone brave enough to get a brain implant when they didn’t need it,” said McMillan, who facilitates many clinical trials at the Miami Project for people with spinal cord injuries. “There was no guaranteed advantage, but German’s courage and inquiring mind were amazing.”

Two weeks after his surgery, Zuniga met with the research team, which included study leader Abhishek Prasad, an associate professor of biomedical engineering; dr. Jonathan Jagid, professor of clinical neurosurgery; dr. Michael Ivan, associate professor of neurosurgery; dr. Iahn Cajigas, a former resident of neurosurgery; and Kevin Davis, a graduate student in Prasad’s neural interface lab at The Miami Project.

German with team at Miami ProjectBy getting Zuniga to think about the natural job of opening and closing his hand, the researchers were able to create software that could read his unique brain signals and send them to the glove. Soon, as long as he wore the glove, Zuniga was able to move his thumb, forefinger, and middle finger of his right hand.

“It meant a lot to see my fingers move again,” says Zuniga, now 25. “It gave me more confidence that what I was doing was right, and it made me happy to know that this isn’t just for me, but that this research could help people everywhere who suffer from spinal cord injuries.”

The progress Zuniga has made is the result of his own determination, along with the diligent work of researchers at The Miami Project, who share a common goal of helping people with spinal cord injuries get back on track. Jagid, who implanted Zuniga’s BCI, said his team spent more than six years looking for a candidate for this experimental surgery, and they were lucky enough to find Zuniga.

“German is a very driven, selfless person who wants to help everyone overcome spinal cord injury,” Jagid said. “I wasn’t surprised he could drive that car because if you know German, he’s going to make it happen.”

Now the team has other goals for the BCI: to help Zuniga use both his hands — and possibly his legs, too. Zuniga may one day get the chance to pilot an adaptive boat.

It has been a long journey.

After being paralyzed by the car accident, Zuniga spent six months in the hospital and a year of his life in rehab as he worked to complete his freshman year of high school. But like other spinal cord injury survivors, Zuniga tries to stay active to avoid more muscle spasms or atrophy. He was working out at The Miami Project’s gym and participating in other clinical trials when he read a newsletter about a study seeking people with spinal cord injuries to volunteer a BCI implant. Because it could help him regain some independence, Zuniga was intrigued.

Zuniga was vetted for the study, which included meeting strict qualification criteria. And when he turned 21, he had surgery. Jagid said his team chose this particular BCI because it was less invasive than others and designed to detect brain signals. The actual device is just a small strip of sensors that sit on the brain — along with a generator placed just below the shoulder bone and a small wire connecting the two. Another advantage is that the BCI is completely hidden in the body. Therefore, if Zuniga decides he wants to remove the BCI later, the surgery is reversible, Jagid said.

Led by Ivan and Jagid, the surgical team mapped out where to place the BCI on Zuniga so it would have the most impact. It now sits above a small part of the brain that controls hand movement, called the hand motor button.

“Our thinking was that if we could just get him to start the hand movements again by thinking about it, that could help him significantly, and that’s how this started,” Jagid added.

Once the BCI was in place, Davis, Prasad and others designed software to decode Zuniga’s brain signals from the device. They asked him to think about opening and closing his hand, then trained the BCI to pick up those unique signals from the part of the brain responsible for moving his right hand. Over time, their work allowed Zuniga to not only control the gauntlet, but Zuniga was also able to use his BCI to control a walking robot on a treadmill at The Miami Project in 2019.

“It felt good to be back on my feet and see my legs move just thinking about it,” Zuniga said. “It was unbelievable.”

Davis, a self-taught software engineer who studied neuroscience in college, then figured out how to make the decoder portable so Zuniga could use the BCI outside the lab. Davis even developed a mobile phone app that connects to the BCI via Bluetooth, prompting Zuniga to think about opening and closing his hand. Then a minicomputer in Zuniga’s backpack connects his brain signals to control a device — usually the adaptive glove.

“The BCI takes the data from the brain and then sends information to another device such as the glove, or in the most recent case, an automobile accelerator,” said Davis, an MD/Ph.D. Medical Scientist Training Program, currently doing his graduate work in Biomedical Engineering.

Just before the COVID-19 pandemic began, Davis completed refining the portable BCI decoder. This was mostly a fluke as Zuniga was able to practice his newfound skills at home for the past two years and Davis was able to fine-tune the software remotely if necessary. He can now also collect data on Zuniga at home and gather evidence about how useful the BCI setup could be for others with spinal cord injury in the future.

Jagid said Zuniga is the only person with spinal cord injury he knows with this mobile setup, while other BCI patients usually have a visible device sticking out of their head and need to be in a lab to connect it to a machine that uses their brains. decodes signals.

“The great thing about this device and its current setup is that it can be used at home so that he can actually benefit from the renewed use of his hand,” added Jagid. “German has gotten really good at being able to do that seamlessly.”

The flexibility of Zuniga’s movable BCI has numerous advantages, McMillan added.

“Currently, other people may have BCIs that have a broader signal and can send more sophisticated commands [from their brain]”But because this one is simpler and allows German to use it in different contexts, it allows him to explore more and further than others,” McMillan said. like an 850 horsepower NASCAR race car.”

German in race car

To drive the car this spring, an opportunity made possible by Falci Adaptive MotorsportThere were a few tweaks made to the BCI software so it would work with the car’s technology, but not many, Davis said. Still having to think about opening and closing his hand to throttle, Zuniga used an adaptive helmet to steer and had a special device attached to the helmet where he inhaled or ‘sipped’ to brake.

“We trained a few times before we left, but German still used the same motor image of opening and closing his hand, which he is quite familiar with,” Davis said. “He just had to figure out its sensitivity to be able to apply to the gas.”

While a safety driver was in the car with him, Zuniga was excited by the experience of driving a race car.

“After the first lap I lost my fear and the feeling of freedom was amazing,” he said. “Seeing how I could drive a car, I never thought that this device would make it possible.”

The next step for the team is to expand the applications of Zuniga’s currently implanted BCI by trying to extract more unique signals from his brain. This can allow for a more complex function, such as using both hands. At the same time, the team is investigating other brain-computer interfaces that may offer future patients greater freedom and function recovery.

Zuniga had always hoped to attend college after graduating from high school in 2015. After seeing the power of technology through his own experience, he decided to major in computer science at Miami-Dade College and now hopes he can program brain devices to help other people like himself gain mobility.

“Working with the BCI sparked my interest because I saw what you could do with technology,” Zuniga said. “It has given me the hunger to want to help make it better and even make a new device one day.”

Additionally members of the Miami Project’s BCI study team include: Annie Palermo, Noeline Prins, Jasim Ahmad, Steven Vanni, Sebastian Gallo, Audrey Wilson, and Letitia Fisher.




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