In the summer of 2000, Wicab hired Yuri Danilov, a neurophysiologist with vast knowledge of the nervous system, who helped the team envision all kinds of applications for its nascent technology. The scientists began mapping a “star chart” of all the possible uses. Nearest and most obvious were “first order” stars, such as a system to augment hearing, vision substitution for the blind, and an assistive device to help people with damage to the vestibular system, a region of the inner ear critical to balance. From these core applications, the group traced logical paths to scores of more distant possibilities, such as treatments for Parkinson’s disease or for children with sensory-motor integration disorders. Eventually, the star chart held more than 170 applications scribbled on several taped-together pages.
Among all the stars, the scientists believed two shone the brightest: vision and, thanks to Mitch Tyler’s timely illness, balance. In the lab, they built and tested prototypes for each application. To make the balance device, Tyler purchased a green plastic hard hat and attached a miniature accelerometer, which relayed information through a computer to the tongue display’s electrodes. Someone wearing the helmet and standing upright would feel a buzz at the center of his or her tongue. But if the individual swayed, the accelerometer sensed the deviation and sent an error signal, causing the sensation to move left, right, backward, or forward, depending on the direction of the tilt. The person’s task was to move in space until the signal became centered again.
“It’s like having someone place a finger on top of your head to indicate you’re upright,” says Tyler. “If you tip your head, you feel the finger slide off to one side, and you naturally move your head back to compensate. It’s a very simple concept. You’re just correcting for a deviation in your position relative to a marker.”