Giving 'Sight' to the Blind Through Electricity

Georgios Kefalas/Keystone/Redux

The folding, rubber-tipped white cane used by 4.8 million blind and visually impaired people to navigate could be getting a high-tech makeover.

Researchers at the Monterrey Institute of Technology (ITESM) in Mexico have developed a device that could help the visually impaired better traverse complex, fixed environments like hospitals, offices, schools and shopping centers. Synchronized with virtual maps of indoor settings installed in the device's memory and complemented by global-positioning systems (GPS), the tool emits micro-electric shocks to the user's vestibular system—a part of the body in the inner ear that contributes balance and orientation. The device essentially tells the user when, where and how to maneuver.

The user receives shocks in "currents between 0.15 milliamps and two milliamps in intervals shorter than three seconds when they have to turn left or right," says Alfredo Victor Mantilla Caeiros, the professor of mechatronics at ITESM's Mexico City's campus who led the study.

Unlike other auxiliary tools for the visually impaired (such as smartphone mapping apps with sound output to navigate), this device does not require or interfere with other senses like hearing or touch.

The device can also gauge in which direction the user is moving and count the number of steps he or she takes. Combined with mapping and GPS abilities, this results in a 99 percent accuracy rate, says Mantilla Caeiros. Of course, like all assistive devices, it would require learning, and individual calibration, to guarantee this high accuracy.

Similar technologies that have been developed in the past include the BrainPort V100, which is a nonsurgical assistive device for the blind intended to improve orientation, mobility, object identification and spot reading. It works by translating digital information gathered by a video camera into gentle electrical patterns on the surface of the tongue.

Dr. Richard Rosen, a professor and director of Ophthalmology Research at New York Eye and Ear Infirmary of Mount Sinai, who worked on the BrainPort V100, admits his device was a hit-or-miss with his patients, and is now skeptical about the potential of the ITESM's contraption. One problem, he says, is that "some people have balance issues, and this device may exacerbate those." In the absence of vision, a person's vestibular system may not be fully balanced; in that case, electrically stimulating the system could impact balance and cause debilitating dizziness.

Nevertheless, ITESM is forging ahead. The team has designed and produced the first prototype of its device and has a patent pending. The next step, says Mantilla Caeiros, is to perfect the calibration process, in order to best cater to a user's individual needs.