There are already mechanical devices that correct foot drop, including metal and plastic braces that wrap around the leg and ankle. Wagman isn’t a fan. “All of these mobility devices are all pretty much the same since the 1940s,” Wagman said. “They’re very cumbersome.”
In contrast, he says their system is comfortable and practically invisible.
Sole1 just won the US James Dyson Award, a competition for engineering students sponsored by the British inventor best known for his best-selling vacuum cleaners. Wagman and Bokisch hope to eventually bring it to market at a price between $1,000 and $2,000.
Clearly not the kind of sock you want to lose in the dryer.
Bokisch is an undergraduate at Harvard’s Paulson School of Engineering, while Wagman is working on a master’s degree in design engineering, having earned a bachelor’s in industrial design at Savannah College of Art and Design.
Both men paid a price for their army service. Wagman never saw combat. “I was sent to the border wall,” he said. But as an airborne soldier, he made 30 parachute drops and was badly injured in one of them. Today, he’s partially disabled.
“I was fortunate enough to work in Afghanistan,” Bokisch said. He served as a sniper during a single nine-month tour and cherishes the memory of a friend in a special forces unit, who wore a prosthetic leg and joked about his “bulletproof foot.” Bokisch himself was never wounded. But he suffered several serious injuries and, like Wagman, is partially disabled.
“Our backs are [screwed up] from the army,” Wagman said. “Our legs are messed up, because of falling out of planes, being deployed.”
When the two met at Harvard in a bioengineering class, they discovered a shared concern about improving assistive technologies for soldiers and others with serious physical challenges.
“I feel like it’s our place to give back to this community,” Bokisch said.
They began with foot drop because the problem is serious, yet relatively simple.
Foot drop happens when the front part of the foot droops forward when it’s lifted from the ground, instead of tilting slightly upward. When the foot is lowered, the toes hit first and drag across the ground. This often causes trips and falls. People with foot drop compensate by raising one leg higher than the other when walking. This gives them an awkward gait and can lead to joint and spine trouble.
Foot drop isn’t a disease in itself but a common symptom of diseases that afflict millions, including stroke, muscular dystrophy, Parkinson’s disease, and cerebral palsy.
“It basically unravels people’s lives,” Wagman said.
The Sole1 device uses an ankle bracelet with a computer and an inertial measuring unit to measure the exact position of the ankle. The bracelet plugs into electrical contacts on the sock, which are connected to filaments that run toward the toe of the sock. The filaments are made of “shape memory alloy,” a springlike metal that flexes when heated. The sock also contains another inertial measuring unit to track the position of the foot.
With every step, the computer uses a predictive algorithm to measure the angle of the forefoot relative to the ankle. If it’s drooping, it sends power to the filaments, flexing them to pull the foot upright. The sock’s software uses an artificial intelligence system that’s supposed to track the owner’s gait to improve the sock’s performance over time.
Alan Asbeck, an associate professor of engineering at Virginia Tech, said that Bokisch and Wagman may have found a way to make a foot drop device that’s more comfortable and less obtrusive than existing systems.
“It looks like the design of this one is really low profile,” Asbeck said. “I do think there is a need for this general sort of thing.” But he added that he hasn’t tested the Sole1 to determine if it works as advertised.
The two veterans are now recruiting volunteers to test Sole1 in real-world conditions. If it works out, Wagman and Bokisch hope to create more ambitious robotic devices for the arms and legs that will be powerful but almost invisible. The goal, Bokisch said, is “cool cyberpunk gear that young men and women are stoked to wear.”
Hiawatha Bray can be reached at hiawatha.bray@globe.com. Follow him @GlobeTechLab.
