Walking for paralyzed man is a matter of using his brain

Twenty-eight-year-old Adam Fritz knew if he was willing to step up to the challenge, he might actually be able to take a few steps on his own — something he couldn’t do for seven years.

Years after a spinal cord injury left him paralyzed in both legs, Fritz just walked again using the power of his mind — and a whole lot of technology.

It was only a 12-foot journey, but for Fritz and the UC Irvine researchers he has been working with for three years, it was a hard-fought breakthrough.

The research team, led by biomedical engineer Zoran Nenadic and neurologist An Do, developed brain-computer technology designed to get someone with paralyzed limbs walking again.

“We had Adam walk slowly for 12 feet with a break midway just to see the walking,” Nenadic said. “What we have right now is a proof-of-concept. We were able to show that you can restore intuitive and brain-controlled walking, even after a spinal cord injury.”

Fritz was injured when he was 21 while riding his motorcycle from Orange County to his hometown of Claremont. A table slid off of a truck in front of him and Fritz hit the table and then the road.

His T6 vertebrae, located in the middle of his spine, shattered from the impact.

“No one wants to hear the words ‘I’m sorry, you’re paralyzed and you’ll never walk again’ but that was what motivated me to participate in the study,” he said. “There’s huge desire to walk again and every person who’s paralyzed will tell you that.”

Fritz first heard of the study three years ago while attending a recovery center for spinal cord injuries in Carlsbad, Project Walk.

“When I heard [researchers] were interested in volunteers, I went ahead and signed up,” Fritz said. “I see this whole project as the first step in the road to finding a cure for paralysis.”

The whole study was broken up into four phases at a UCI campus lab, he said.

First, in the middle of 2013, Fritz put on an EEG cap and sat in front of a computer screen that showed a video game character. The goal was to get the character to budge by thinking of moving.

“It sounds very simple, but when I tried to get it to move I couldn’t do it,” Fritz said. “Then instead of forcing it to move, I thought about myself walking and that concentration is what did it. I thought ‘walk forward’ and ‘stop’ and so forth.”

Later that year, the team moved on to the second phase. Fritz wore the cap again, only instead of moving a video game character he needed to think of moving a pair of robotic legs suspended over a treadmill. The point was to see if the cap could make a machine move, he said.

The third phase in 2014 involved using the cap with Fritz’s muscles.

“The cap records brainwaves and sends those signals wirelessly to a computer,” Nenadic said. “Then the computer recognizes the intention to walk and that data is sent to a pack he’s wearing.”

The pack then sends electrical impulses to pads that are attached to his quadriceps and tibial muscles, Fritz said.

The fourth and final phase was to have Fritz walk the 12-foot distance. While walking, he also wore a body harness suspended from the lab’s ceiling and used a walker to prevent any falls.

The team recorded a video of this big step forward in their research and posted it on YouTube.

Like the video game character he first had to maneuver, Fritz needed complete concentration to get his legs to move.

“The first time I did it, I was elated but I knew if I did celebrate it would ruin it,” Fritz said with a laugh. “I couldn’t be happy or excited because I had to focus so much. It took a long time to get to that video, but it’s actual, visual proof that something like this is working.”

When he’s not testing the technology, Fritz said he still uses his wheelchair.

He has signed up to participate in the next phase of the study where the researchers will work on creating a miniaturized version of the technology. Nenadic and Do said the goal is to create something that is implantable for patients.

The team will also begin to recruit more volunteers to see if the technology is compatible with more than one subject.

“We were really lucky to have a very dedicated volunteer like Adam,” Nenadic said. “A study like this is a joint effort that involves a whole community, not just the scientist.”

Fritz said before his accident he spent years playing soccer and one of things he misses is going outside to kick the ball around.

“But hopefully, he said, “someday that’ll change.”