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A Cheap Prosthetic Knee For The Developing World, Designed From Patient Feedback

Want to make something that people want to use? It turns out, it’s helpful to ask them what they want. That’s why D-Rev’s new knee for people in the developing world is turning into such a big success. Here’s how they did it.

A Cheap Prosthetic Knee For The Developing World, Designed From Patient Feedback

All too often, the prosthetic knees available for amputees in the developing world are clunky and poorly designed. D-Rev, a Bay Area-based nonprofit that designs products for people living on under $4 per day, recently revealed its latest attempt at creating an affordable knee that amputees actually want to wear. That’s because the knee was built with heavy input from its users.

The ReMotion Knee, D-Rev’s first product (we wrote about the second product, Brilliance, in our profile of the company), came into existence when India’s Jaipur Foot Clinic—an organization that provides free limbs and crutches to the disabled— approached a Stanford University class about building a better knee.

As of summer 2012, 3,600 knees had been fitted through a no-cost license with the Jaipur Foot Clinic. Today, the knee, which has an impressive 165-degree range of motion, has been tested with 4,700 patients in nine countries. D-Rev is now getting ready to launch version three of the knee in field trials.

Many of the changes in the latest version were made based on feedback from both patients and prosthetists. Among the tweaks in version three: a curved profile that resembles a real kneecap (instead of a blocky design that looks awkward under clothing); a rubber noise dampener to cut down on the loud clicking noises that occur whenever a patient walks; and a generally sleeker look.

D-Rev also received feedback that the knee was too heavy; the new version is half the weight of version two. And since version three is designed for injection molding, it will be easy to put it into mass production. "We wanted to get to a knee that’s more subtle, less bulky, more something that people would be really proud of," says D-Rev CEO Krista Donaldson.

Field trials for the $80 knee begin this spring and summer in Indonesia, Nicaragua, and the Philippines. Out of the 100 patients in the field trials, 20% have to be women—a requirement born from the low prosthetic fitting rates of women in the developing world. Donaldson explains: "Where a man may get himself to a clinic, it’s harder socially for women to do that. The women we do see tend to be young college students or have more educated families."

Version three of the ReMotion Knee will be available to the public in early to mid-2014.