Design Engineering

Mechanical fingers restore function to amputees

By Design Engineering Staff   

CAD/CAM/CAE Medical CAD mechanical SolidWorks

SolidWorks helps medical inventor craft natural looking and moving prosthetic fingers.

Concord, Mass. – While it may not seem as severe as loosing an arm or leg, the loss of fingers or especially a thumb can be just as debilitating. Struggling to grasp a pen, turn a door knob or carry a suitcase with the affected hand means everyday activities others take for granted become a chore. Complicating the matter is that there are few prosthetics available for digit loss beyond the merely cosmetic.

Ironically, finger loss is also the most common cases of amputation. According to the US Bureau of Labor Statistics, approximately 94 percent of all non-fatal amputations involve fingers. Each year, about 30,000 people lose one or more fingers, often in a door slam or via power tools.

Enter Dan Didrick, founder of Didrick Medical and inventor of X-Fingers, surgical steel fingers which can move, flex, and grasp as naturally as flesh and blood digits. X-Fingers and X-Thumbs are purely mechanical. Criss-crossing surgical steel levers (the “X” in X-Fingers) are actuated by a remaining finger or thumb and covered in lifelike thermoplastic. Fitted with the device, patients can pick up coins, button shirts, tie shoes, type letters, carry buckets – even play the piano.

X-Fingers, notes Didrick, are a huge leap from the traditional cosmetic latex appendages. As such, X-Fingers have earned his company, Didrick Medical, global recognition, including the 2009 Perfect Pitch Award and a finialist showing at the 2009 INDEX: Awards in Copenhagen.


Didrick designed the world’s first active-function artificial finger assemblies in SolidWorks over a two-week period with no engineering experience. In fact, he didn’t know what computer-aided design was before he started using it. He’d whittled his first concept prototype from pine.

Today, hundreds of adult X-Fingers are in use. The mechanical appendages come in 500 different configurations covering five different finger thicknesses, 16 different lengths, and a wide range of injury profiles. Didrick custom manufactures them using electric discharge machining (EDM) driven by SolidWorks files.

“When a patient needs X-Fingers,” he says, “I pick a drawing, save it as STL or IGES, send it to a manufacturer, and it comes back a beautiful part.”

A former medical equipment salesman, Didrick taught himself engineering, patent basics, regulatory relations, manufacturing, and marketing. Even so, getting his product to market wasn’t easy. FDA approval was challenging enough; European approval was excruciating. Applying for the patents alone took a year. “It’s been difficult, but this is my life’s work,” he says. “I do this 80 hours a week. I put everything into this.”


Stories continue below

Print this page

Related Stories