Artificial hand helps amputees feel just how hard to squeeze

Implanted electrodes allowed the men to feel the same intensity of pressure in the artificial hand as they could in their other hand, scientists at Case Western Reserve University reported Wednesday.

Getting to the point where users respond as they would to a normal limb is key "to moving toward truly creating a replacement for the hand," said Case Western biomedical engineer Dustin Tyler, who leads the project.

Earlier this month, researchers at the University of Pittsburgh reported harnessing brain waves to help a paralyzed man not only move a robotic arm with his thoughts but, in a first, to feel pressure in his own motionless fingers when the artificial ones were touched.

Two years ago, Case Western researchers wired those nerves to a prosthetic outfitted with sensors that let Vonderhuevel and fellow volunteer Igor Spetic of Madison, Ohio, sense different textures.

When the prosthetic sensors were touched, they activated a portable stimulator that sent electrical signals to the nerves, which detected textures like a cotton ball or sandpaper.

Learning how stimulation can produce more realistic sensations is a key step, said University of Pittsburgh rehabilitation specialist Robert Gaunt, who wasn't involved in Wednesday's work but is part of a team developing similar technology for the paralyzed.