Co.Design

How An Amputee Built The World's First Functional Prosthetic Finger

The hands-on mechanic and amputee who gave the world the finger (made out of bike parts) adapts it to a touch-screen world.

Former bike mechanic and navy veteran Colin MacDuff made national headlines this spring for the incredible cycle shop feat of essentially turning eight hours of middle-of-the-night sawing and welding handlebar parts into a fully functional prosthetic finger.

The revelatory invention pointed MacDuff, who’d lost the first two digits of his middle finger in an explosives accident in 2010, on a new career trajectory, as product designer and entrepreneur. He now runs RCM Enterprise, LLC, a business that produces the world’s first Bio-mechanical Prosthetic Finger (BPF), made “for amputees, by an amputee.” Amazingly, it’s also simply the first functional prosthetic finger. This is a missing body part people are generally expected to just live without, to compensate with other digits.

In only four months since the debut of the product (which is no longer made of bike handlebars), MacDuff’s 12-person company is receiving thousands of orders and "way more attention than we ever expected,” says RCM CEO Jon Bengtsson, who’s trying to fulfill hundreds of back orders.

While the company gears up to meet customer demand for a high-performance prosthetic finger, it’s also addressing the demands of our more and more digit-meets-digital interfacing world. One of MacDuff’s most critical design considerations hardly existed 10 years ago and is now somewhat of a holy grail in prosthetics: making the finger touch-screen-friendly. This had become, after all, one of the most important everyday functions of our fingers.

RCM has such a next-generation upgrade to the BPF in development. Bengtsson tells Co.Design they’ve "already identified and tested the material" that can successfully mimic human skin and heat conductance. “Now it’s just a matter of how to integrate it into the product and make it durable enough for everyday use," he says, estimating that the smartphone- and iPad-friendly product will be available in six to 12 months.

The other modern challenge is expanding from prosthetic finger into prosthetic thumb, as the human-distinguishing opposable digit has a much greater range of motion that calls for a much more complicated functionality. The thumb is in the works, says Bengtsson. Seeing as it took humans thousands of years of evolution to get those thumbs up to speed, though, RCM is presumably on the fast track, whatever the release date.

As for the original BPF, the company has streamlined the production process so that it takes just three weeks to deliver a customized finger to a patient after fitting. They’re also developing technology that allows a patient to send a scan of their hand and follow through digitally for the life of the product. “This would make the ordering process completely online, from cradle to grave,” says Bengtsson.

He emphasizes that MacDuff has filled a major gap in the medical world. In the past, Bengtsson says that when people sought help after a finger injury, “a lot of surgeons recommended just completely amputating the remaining digits. There haven’t been a lot of options. There was no product like this.” In Japan, members of the organized crime syndicate Yakuza have a brutal ritual, called Yubitsume, of cutting off the fingers of transgressors. Victims there created a high demand for cosmetic silicone fingers, to hide the very visible and very stigmatized amputation. But despite being carefully painted to match skin colors, with convincing nails and knuckle wrinkles, these were cosmetic, not functional, prosthetics.

Driven by the natural biomechanics and flexion of the human hand, the BPF “works as an exoskeleton device,” using a “roll-cage” concept. “We look forward to giving you the finger!” says their website.

MacDuff sure gave it to himself. He now wears his own invention 24/7--while chopping wood, racing mountain bikes, and working on cars. One person the company fitted plays guitar with the BPF, another plays piano. In some ways, it’s an improvement over the human version, even. Says Bengtsson, “We ran the finger over with a car to test it, and it didn’t break.”

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1 Comments

  • MBerka

    The news often has reports of the first prosthetic - first to fully work, first to really feel. The orders clearly indicate this product's progress beyond past concepts, but how does it compare to other leaders in the field?