Most strokes damage the part of the brain that controls movement. After suffering one, many patients struggle to walk normally, with one side of the body more greatly impacted than the other. As people relearn how to walk, they typically only have canes and walkers to rely on.
Now, the exoskeleton company ReWalk is working on an assistive system called Restore to help stroke patients walk normally again. ReWalk has partnered with the Wyss Institute at Harvard, which focuses on developing new technology based on biological design principles. At Wyss, associate professor Conor Walsh and his team have been developing a soft exoskeleton–which resembles a belt and a leg brace–for stroke patients for the past five years.
“The existing exoskeleton technology can actually work for some of these patients, but it’s not designed for that,” says Larry Jasinski, ReWalk’s CEO. “It’s too big, it’s too heavy, it dominates the body.”
There are several different exoskeletons on the market geared toward helping paraplegics walk again–sometimes even for the price of a car. These models, including one produced by ReWalk, tend to be heavy, mechanical, and expensive. But Walsh’s design focuses only on what people who struggle with walking need. Because stroke patients tend to experience difficulty walking with one of their legs, Restore consists of a belt connected to a single leg brace that targets the ankle–the joint that’s most impacted by a stroke, Walsh says.
Restore is designed to work like a swing. “If you imagine someone on a swing, if you give a little tap at the right time, they’ll keep moving back and forth on that swing,” Walsh says. “We can still help that person move in a way that doesn’t impair them more.”
Restore also uses sensors to monitor movement so that if someone starts to walk faster or slower, it can adapt to changes in speed. While it automatically adapts to each person’s walking pattern, some of the parameters of the brace are also adjustable, so a physical therapist would be able to adjust the amount of support it provides over time. For instance, a therapist might want Restore to give maximum support initially, and then slowly scale back as a patient gets stronger. The sensors also provide detailed information about the person’s progress to the therapist.
While Walsh and his team have handled the design process–which included bringing patients into their lab to test prototypes–Jasinski and ReWalk will focus on bringing the product to market. Jasinski says that Restore will start undergoing FDA clinical trials early next year, with the aim that it will be on the market by the end of the year. Additionally, Jasinski says that this exoskeleton will be significantly less expensive than the company’s flagship exoskeleton, which costs an astronomical $77,000, though the company hasn’t decided on a price yet.
Initially, Restore will be targeted at stroke patients. But Jasinski and Walsh believe that it will also be helpful to people with multiple sclerosis, cerebral palsy, and even Parkinson’s. Because the technology is modular, it could potentially be adjusted to support different joints than the ankle, depending on what patients need.