"Wearable robots” might sound like science fiction, but a research lab at Northern Arizona University is perfecting an ankle exoskeleton to help people who have trouble walking. KNAU’s Melissa Sevigny reports, the project aims to be a giant leap forward for those who struggle to take a step.
Most of us don’t think about walking. Not so for biomechanical engineer Zach Lerner, who says, "It’s actually been something that’s been on my mind for a long time."
When he was growing up his mother had a nerve injury that affected the way her feet moved. That, plus a passion for tinkering with robotics, led to what Lerner calls his dream job. "I’ve been really fortunate enough to create a career where I get to combine these two loves, so the love of robotics and the love of human movement."
One of his current projects is a powered ankle exoskeleton, dubbed the Spark. The research is supported by grants from the National Science Foundation and National Institutes of Health.
Ankle exoskeleton prototype
Melissa Sevigny
/
KNAU
Ankle exoskeleton prototype
In the Human Performance Lab on the NAU campus, Lerner tucks carbon-fiber footplates into his shoes and Velcros in place the wires that link the footplates to the controller around his waist.
When he starts walking, battery powered motors help the foot push off the ground and pick up the toes. The device naturally adjusts when the walker needs more assistance, say for climbing stairs.
"It feels great," Lerner says. "It feels springy. It feels like my calf muscles have just consumed a large espresso and they’re just roaring and ready to go."
Zach Lerner demonstrates the ankle exoskeleton in the Human Performance Lab.
Melissa Sevigny
/
KNAU
Zach Lerner demonstrates the ankle exoskeleton in the Human Performance Lab.
The challenge is to make the device as light and quiet as possible: more like Luke Skywalker’s new hand than Iron Man’s suit. "One thing we’ve heard from potential future users of technology like this, is that they want these devices to be really transparent, so like unnoticeable," Lerner says.
Ryan Richardson is one of those future users who helps test the devices developed in Lerner’s lab. He was born with cerebral palsy and remembers the bulky ankle brace he had to wear as a child."I ended up stopping using that—because at that age… just anything to make you stand out more—'oh, okay.’ I ended up quitting wearing it," he says.
The slimmed down, powered up version is a big improvement, Richardson says. "It’s really cool…. It’s fun for me to get to walk a little bit faster than I normally do."
That’s no small thing. A crosswalk signal rarely gives Richardson enough time to get across the street, and "cars are always antsy to get going," he chuckles.
Then there’s challenges like stairs or uneven sidewalks that might not be cleared of snow. "I often think, okay, how does someone less mobile than me navigate this situation?"
Prototype ankle exoskeletons hanging up in the Human Performance Lab beside an assortment of shoes.
Melissa Sevigny
/
KNAU
Prototype ankle exoskeletons hanging up in the Human Performance Lab beside an assortment of shoes.
Around one million people in the U.S. have cerebral palsy and many more struggle to walk due to muscular dystrophy, stroke, or other conditions.
Master’s student Jackson Truitt, who works in Lerner’s lab, imagines a world where powered exoskeletons are commonplace, "without making you stand out in any particular way, that’d be amazing. Something as normal as throwing on a pair of shoes," he says.
What would that world look like? PhD student Emmanuella Tagoe says: "independence, complete independence."
She joined the lab because she wants to use her engineering skills to benefit others. "I feel like other people have helped me, so if the work that I do is going to help someone else, I feel like it’s paying that back to society and to the community," Tagoe says.
The team also has plans to make a wearable robot for elbows. The ankle exoskeleton is now undergoing clinical trials, and the researchers hope to bring it to market next year.