Tuesday, July 31, 2007

That's no ordinary okay sign being flashed by John German of Altoona, Pa.; this one is produced by a bionic hand.

David Gow, director of technology for Touch Bionics of Scotland, the maker of the i-Limb Hand, says the device is the first commercially available prosthetic in which each jointed finger is controlled by its own motor.

Five years in development, the hand operates myoelectrically -- through a nerve signal relayed from muscles in the arm to the replacement hand. The device retails for $18,000, twice the price of the average prosthetic, says Phil Newman, head of sales and marketing for Touch Bionics. He says it will allow injured Iraq war veterans and those with certain medical conditions to "return to a more or fully active level" of life. (German lost part of his left arm to a nerve disorder.)

Because each finger can move independently, users can exercise a more natural grip, sensitive enough to pick up delicate objects. The prosthetic also allows users to point an index finger and to grasp and turn a key -- tasks that were impossible with earlier prosthetics.

Although the buzz of the motors and the jerky mechanical maneuvers betray the i-Limb Hand as a machine, its range of movement restores function and expressiveness to users, says its maker.

"The hand is a mirror to a soul; it's not just a functional device," Gow says. "It's used for gestures, used for body language that [the able-bodied] take for granted."

-- Kathleen Hom