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 a car accident left him paralyzed, Zuniga is making significant strides. Using a surgically implanted brain-computer interface (BCI) that can decipher his thoughts, Zuniga recently drove an adapted NASCAR racecar around Pikes Peak International Raceway in Colorado, just by thinking about grasping the accelerator. He also connects his BCI to an adaptive glove each day to help him regain some control of his right hand to open doors, feed himself, write short notes, and brush his teeth.
In 2018, as part of a research study, Zuniga volunteered to have the BCI surgically implanted to see if the technology could improve the lives of people like himself, who are living with spinal cord injuries. It was the first time that doctors at The Miami Project to Cure Paralysis, a Center of Excellence at the University of Miami Miller School of Medicine, had implanted a BCI just for research purposes, said David McMillan, director of education and outreach for The Miami Project, as well as an assistant professor of neurological surgery. “Finding someone brave enough to get a brain implant when they don’t need it was tricky,” said McMillan, who facilitates many Miami Project clinical trials for people with spinal cord injuries. “There was no guaranteed benefit, but German’s courage and exploratory spirit were amazing.”
Two weeks after his surgery, Zuniga met with the research team, which includes study leader Abhishek Prasad, a biomedical engineering associate professor; Dr. Jonathan Jagid, professor of clinical neurosurgery; Dr. Michael Ivan, associate professor of neurosurgery; Dr. Iahn Cajigas, a former neurosurgery resident; and Kevin Davis, a graduate student in Prasad’s neural interfaces lab at The Miami Project, and a 2021-2022 IDSC Fellow. By prompting Zuniga to think about the natural task 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 was wearing the glove, Zuniga could move his thumb, pointer finger and middle finger of his right hand. “It meant a lot to see my fingers moving again,” said Zuniga, now 25. “It gave me more faith that what I did was right, and it made me happy to know that this is not just for me, but this research could help people everywhere who are suffering from spinal cord injuries.”
The progress Zuniga has made is a result of his own determination, along with the diligent work of researchers at The Miami Project, who share a goal of helping people with spinal cord injuries regain movement. Jagid, who implanted Zuniga’s BCI, said his team searched for more than six years for a candidate for this experimental surgery, and they were fortunate to find Zuniga. “German is a very driven, selfless individual who wants to help anyone he can to overcome spinal cord injury,” Jagid said. “I wasn’t surprised he was able to drive that car because if you know German, he is going to make it happen.” Now the team has other goals for the BCI: Help Zuniga use both of his hands—and possibly his legs too. Zuniga may also get the chance to drive an adaptive boat one day.
It has been a long journey though. After the car accident paralyzed him, Zuniga spent six months in the hospital and a year of his life in rehabilitation while working to complete his junior year of high school. But like other survivors of spinal cord injury, Zuniga tries to stay active to prevent more muscle spasms or atrophy. He was working out in the gym of The Miami Project and participating in other clinical trials when he read a newsletter about a study looking for people with spinal cord injuries to volunteer to get a BCI implanted. Since it could help him regain some independence, Zuniga was intrigued.
Zuniga was vetted for the study, which included meeting strict qualification criteria. And once he turned 21, he went in for surgery. Jagid said his team chose this specific BCI because it was less invasive than others and is designed to sense brain signals. The actual device is just a tiny strip of sensors that sits on the brain—along with a generator placed just below the shoulder bone and small wire that connects the two. Another advantage is that the BCI is completely concealed within 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 over a small area of the brain that controls hand movement, called the hand motor knob. “Our thought was if we could just allow him to initiate hand movement again by thinking about it, that could substantially help him, and that’s how this came to be,” 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. In time, their work allowed Zuniga to not only control the glove, but Zuniga was also able to use his BCI to control a robotic walking device on a treadmill at The Miami Project in 2019.
“It felt good to be back on my feet and to see my legs move when I thought about it,” Zuniga said. “It was incredible.”
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 out of the lab. Davis even developed a cell phone app that connects to the BCI via Bluetooth and prompts Zuniga to think about opening and closing his hand. Then, a minicomputer in Zuniga’s backpack connects his brain signals to control a device—typically the adaptive glove. “The BCI extracts the data from the brain, and then it sends information to another device like the glove, or in the most recent case, a car accelerator,” said Davis, a student in the M.D./Ph.D. Medical Scientist Training Program, currently doing his graduate work in biomedical engineering.
Just before the COVID-19 pandemic began, Davis finished refining the portable BCI decoder. This was particularly fortuitous because Zuniga could practice his new skills at home throughout the past two years, and Davis could refine the software remotely when needed. He is also able to collect data on Zuniga from home now and is gathering evidence about how useful the BCI setup could be for others with spinal cord injuries.
Jagid said that Zuniga is the only person with a spinal cord injury he knows of with this mobile setup, while other BCI patients typically have a visible device protruding from their head and must be in a lab to connect it to a machine that decodes their brain signals. “What’s nice about this device and the current setup is that it can be used at home, so he can actually benefit from the renewed use of his hand,” Jagid added. “German has gotten very good at being able to do that seamlessly.”
There are myriad benefits to the flexibility of Zuniga’s transportable BCI, McMillan added. “Currently, other people may have BCIs that have a wider signal and could send more advanced commands [from their brain], but because this one is simpler, and allows German to use it in a variety of contexts, he is able to explore more and further than others,” McMillan said. “He is using it to do simple activities of daily living, and to control really advanced robotics, like an 850-horsepower NASCAR race car.”
To drive the car this spring, an opportunity made possible by Falci Adaptive Motorsports, there were a few tweaks made to the BCI software so it would work with the car’s technology, but not much, Davis said. Zuniga still needed to think about opening and closing his hand to engage the throttle, 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 handful of times before we left, but German was still just using the same motor imagery of opening and closing his hand, which he’s quite familiar with,” Davis said. “He just needed to figure out the sensitivity of it to apply to the gas.”
While there was a safety driver in the car with him, Zuniga was exhilarated by the experience of driving a racecar. “After the first lap, I lost my fear and the sense of freedom was amazing,” he said. “To see how I was able to control a car—it’s something I never would’ve thought that this device could make 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 could allow for more complex function, like the use of both hands. At the same time, the team is looking into other brain-computer interfaces that may allow future patients to have more freedom and restoration of function.
Zuniga had always hoped to go to college after graduating from high school in 2015. After seeing the power of technology through his own experience, he decided to become a computer science major 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 an interest in me 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 to create a new device one day.”
Additional members of the BCI study team from the Miami Project include: Annie Palermo, Noeline Prins, Jasim Ahmad, Steven Vanni, Sebastian Gallo, Audrey Wilson, and Letitia Fisher.
MASTHEAD PHOTO CREDIT: (Left to right) Associate professor of biomedical engineering Abhishek Prasad, graduate student Kevin Davis, and professor of clinical neurosurgery, Dr. Jonathan Jagid, watch as German Aldana Zuniga uses his adaptive glove and brain computer interface (BCI) to grasp a permanent marker. Photo by Robert Camarena/University of Miami.