These odd-seeming devices are partial finger prostheses, designed to fit over residual portions of amputated fingers. The mechanisms fit into a silicone casing to mimic natural fingers, and, according to the manufacturer, flex and extend naturally.
There’s no power source — the X-Finger is designed to move in response to activity in the residual finger:
The replaced phalanges will follow the natural bending pattern of a finger. Combined lateral and vertical flexion/extension movements can be independently and immediately restored.
Pretty impressive, what? But there’s more!
The X-Finger will allow the user to regain complete control of the articulation of the device simply by moving their residual finger. Benefits will include typing; playing a musical instrument or anything that requires the full dexterity of a hand.
Each is custom made. Didrick Medical, purveyors of this wonderful device, will evaluate each person’s situation without charge, utilizing the charmingly low-tech technique of reviewing a faxed photocopy of the hand in question.
Read more at medGadget
Update 6/3/2007: Image with hand (without cosmetic silicone cover) added