There are many other companies building artificial arms. Otto Bock has mechanical and electronic devices, most for below-elbow amputees. Liberating Technologies has powered elbows, as does Hosmer, which makes most of the hooks in use. That's a sister company to Motion Control, both owned by Fillauer, which makes a partial hand.

It's true of all bionic innovation. The fields are crowded with different players, each building on collective knowledge. That's part of what makes it so exciting. It's competition, but it's also collaboration. And everyone's learning.

The eyes have it

Artificial vision is nowhere close to replacing the colors, textures and shapes lost to blindness. Though research in the field is thriving around the country, there are definite hurdles that must be overcome, said Richard Normann, Ph.D, professor of bioengineering and ophthalmology at the U. Still, there's a sense of excitement and possibility regarding the evolving field of neuroprosthetics.

"What we're doing goes well beyond artificial vision," Normann said. "We're creating new ways to talk to and listen to the neurons of the central and peripheral nervous system."

Normann's efforts revolve around the "Utah Electrode Array," created in the mid- to late-'90s. Researchers in laboratories around the world are using this array, which contains 100 needle-shaped electrodes, each of which can talk simultaneously to many individual neurons of the brain.

The array is much smaller than a penny, and the 100 electrodes seem to hold endless possibilities. The arrays are marketed through a spin-off company formed by the U. called Cyberkinetics (formerly Bionic Technologies Inc.).

The Utah Electrode Array enables new therapeutic possibilities that were inconceivable two decades ago, Normann said.

Conventional surface electrode arrays are placed on the brain's surface over the areas they are supposed to stimulate. Dr. William Dobelle, a researcher in artificial vision, put surface electrodes over the visual part of the brain in blind subjects. When he passed currents through the electrodes, they could see points of light.

A group of California scientists are achieving similar results with blind subjects by placing surface electrodes on the retinas and stimulating them.

But though somewhat satisfying, such experiments reveal little that wasn't known back in the late '60 and '70s, Normann said.

Here's why: Surface electrodes are large, each about a millimeter in diameter. However, the neurons they're trying to stimulate are relatively small. These large electrodes can stimulate a lot of neurons at once and are not particularly selective.