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"Until I created this design," says Dan Didrick of Didrick Medical Inc. in Naples, Florida, "there were no functional replacements for lost fingers. The only option available was cosmetic, silicone, non-bending fingers. Although these devices could mask the condition from others, they offered no functional benefit."

In other words, those with missing digits had little hope of ever having working artificial replacements.

"What the X-System finger does is allow people to regain the flexion and extension (bend and stretch) movements of each replaced finger. Provided they have small portions of the original finger remaining, they can regain independent function of that finger.

"So what this device is, basically is a leverage-controlled assembly. Because of the all the proper locations of the pivot points, it forces the artificial finger to bend in a natural manner, as a finger. So when you stabilize the device to a users hand, and then they move the residual finger around, it will essentially bring that device to life."

Now to understand the importance of what Didrick has just described, consider that in the past, efforts to create working prosthetic fingers were dependent on attempts to connect them to muscles "behind" the locations of the lost fingers, say in the forearm. Here is the essence of the leap forward represented by the development of the X-System.

"We don't have to think about how our fingers move," Didrick says. "If we want to pick up a cup, we simply walk over and our fingers grasp the cup and we can just pick it up.

This device, because it works on the movement when you flex your residual finger -- and because the X-Finger then flexes -- it doesn't require concentration to pick up that cup. So there's no learning curve.

When asked if the X-System is a design in the realm of "bionics," Didrick diligently and graciously steps around claiming the term.

"You know, I actually don't know," he says with a laugh. "Because I don't know the definition of 'bionic,' I'm just not sure. Maybe the word comes from the 1970s and the  television show ('The Bionic Man,' a widely syndicated US-originated show). Maybe it's just a neat term."

Merriam-Webster actually does list "bionic" as a bona fide word, meaning "having normal biological capability or performance enhanced by or as if by electronic or electromechanical devices."

Basically, then, in the strict sense, the X-System of functional finger replacements probably would not qualify as truly bionic, unless you consider the electro-chemical  nerve impulses that guide its movement through residual fingers to fulfill the "electromechanical" aspect of the definition.

Didrick points out, however, that he knows and is a non-competitive "friend" of another INDEX:Award 2009 finalist-design, the i-LIMB prosthetic hand from Scotland's Touch Bionics. You can read designer Hugh Gill's comments on that design here.

"A lot of people think that X-System and Touch Bionics are competitors, but we've been friends for a long time. Touch Bionics helps people who have lost all of their hand, and they've created an incredibly dexterous tool to replace that hand. Our device is for people who have only lost their fingers -- all their fingers, right down to the palm of their hand -- we basically accommodate fingers. Touch Bionics picks up just beyond the fingers."

A challenge the two design companies have in common is the request from some users for a very lifelike look to the prosthetics. "Because our devices are body-powered," 

Didrick says, "any strength needed to bend a glove" which might be stretched over a prosthetic finger to mimic skin "takes away from the strength of the device.

"Until now, silicone was the best material to use to create a prosthetic cover. It can be pigmented to match the translucence, the color, the tone of human flesh. And because there are very few people who are allergic to silicone, it's made it a great product for many years. But one of the problems we've run into with silicone is that it's either too rigid, which decreases the strength of the grip, or -- if you make it too soft -- it tears to easily.

"So we've moved away from attempting to create a perfectly cosmetic cover, and we've moved into thermoplastic. It can't be pigmented as well as silicone to look like skin, but it has great flexibility. This is the stuff used for plastic fishing worms. And if you've ever come across one of those, you know it starts at a length of about 10 centimeters and you can stretch it to about a meter -- and then it comes right back.

"So we've started creating gloves using the best thermoplastic we can get. That cover offers almost no resistance to stretching the distance needed for the finger to bend,  approximately two centimeters, during the flexion of the finger.  We've developed it now to perfectly match the softness of human skin to the touch."

In many cases, Didrick says, workers' compensation insurance programs will pay for both "cosmetic fingers," as they're called -- "they're just going out to dinner and they want a cosmetic replacement," Didrick explains -- and the kind of functional fingers of the X-System technology.

And how does Didrick come to find himself designing the X-System of functional prosthetic fingers?

"I grew up the son of a dentist" in the Midwestern state of Ohio. "And I had access to all sorts of unique mold-making and casting materials" used in dentistry. "So as a child, I aspired to be a special-effects artist in film. 

"As it turns out, the Halloween industry," full of costumes, latex masks and spooky prosthetics for the annual "trick or treat" night on October 31, "was so large in America that I found I  could make Halloween products.

"I started to lose interest in scary movies and things of that nature. And my mom said something interesting. She said, 'You have to find what you love to do, do it every day, and find a way that what you love to do can benefit society.'

"I started to change, having heard her say that. And I learned how to create medical prosthetics, say a nose for people who had had a nasal resection because of cancer, or a replacement of a missing ear.

"And yet it wasn't until I heard of a person who had lost all his fingers in an accident, and was also deaf. So he couldn't use sign language anymore. He was unable to communicate. And even though I'd made cosmetic (non-functional) fingers, like everyone else in the business, I knew I wanted to figure out how to make fingers that would work."

Didrick, without the money for a patent attorney, bought a book on how to apply for patent protection and spent a year getting his X-System work patented in many countries. Then he taught himself next what he needed to know about design engineering to design the device.

His early success with a prosthetic finger for a person he knew who needed one led him to a premature sense of success. About half the people who tested the device had no  success with it. "Little did I know it would take another five years and 60 designs" to get it right.

"But about eight months ago, I had a whole new breakthrough. We created the first round of devices that gave us a 100-percent success rate about six months ago. So we're now gearing up for large-scale release."

The X-System is registered with the US Food and Drug Administration (FDA), with the EU's medical directive for a CE Mark for legal distribution in Europe.

"And with our registration with CCR -- Central Contractor Registration -- our first customer is the Department of Defense of the United States. Very exciting for us. We recently were contacted by someone with the British military, as well."

The next major area of focus for Didrick and his X-System, he says, is pediatrics. Outside of the workplace, children under 5 years old make up the largest group of finger amputees -- car doors slamming, and so on. And too often, children aren't fitted with prosthetics because they outgrow them too quickly.  Ours is such a simple design that we can make the components expandable to last longer for a child."

As hard and long as the process of creating, protecting and introducing the design has been, Didrick says, it's worth it. "It's been long, yes, but we're really excited now and looking forward to the next few years."

Designed by:
Dan Didrick, Naples, Florida, United States.

Produced by:
Didrick Medical Inc.

www.didrickmedical.com

Written by Porter Anderson