A Taste of Progress

A blind man focuses intently on a sheet of paper upon which his daughter has written a word. The camera situated on his head relays its vision to the device sitting on his tongue, and within moments he proclaims, “dad.”

Erik Weihenmayer lost his vision at the age of 13, but in spite of his loss went on to amount many accomplishments that certainly don’t fail to impress. To name a few: he was the first blind man to scale Mount Everest (for which he was recognized by Time Magazine); he’s earned countless awards including a ESPY award and a Helen Keller Lifetime Achievement award; he’s even carried the Olympic Torch. And now, thanks to BrainPort Vision, he was able to get a glimpse of sight once more.

Wicab’s BrainPort Vision is a device used for sensory substitution that utilizes one of the more unique and non-invasive methods available. Erik was able to read the notecard by feeling the letters on his tongue, somewhat analogous to brail. Electrotactile stimulation is the basis for the technology. In a nutshell, a camera feeds information to an encoding device connected to a square array of electrodes that lies on the tongue. The user feels controlled and harmless pulses of current attempting to simulate what the camera sees in a tactile fashion. The sensation has been described as feeling like pop rocks or a carbonated beverage. “Hundreds of pixels on the plate tingle on my tongue, and together they form patterns and shapes that my brain interprets as the space around me,” said Erik. In addition to  “seeing” two-dimensional objects, users are able to navigate in three dimensions to some extent. In fact, Erik was able to walk through a forest, only aided by the device, to find his wife.

This technology is effective for more than just the vision impaired, it’s beneficial for those with inner ear issues as well—and perhaps more so. Maintaining balance is obviously of great concern, and this tends to be a problem for those with damaged inner ears. For this task, the same design is employed, but instead of a camera, the device contains an accelerometer. An accelerometer, used to measure tilt with respect to Earth’s gravity (found commonly in modern technology like the iPhone), is responsible for sending data to the BrainPort’s plate. The plate contains five stimulation points: left, right, front, back, and center. If the user tilts their head right, the right side (user’s right) of the plate is triggered. Those testing the device were told to keep the current as near to the center as possible. Wicab conducted a study of five individuals suffering from various forms of vestibular loss, or the loss of some ability to control balance. All subjects trained for 60 minutes, two times a day, for five consecutive days. They were tested before and after the trial:

• All five subjects improved on at least one of the given standard balance assessment tests
• Two subjects improved notably on the Activities-specific Balance Confidence (ABC) test, revealing a 23% increase in performance (from 77% to 100%) and a 26% increase in performance (from 58% to 84%)
• One subject’s inability to drive in most traffic was effectively erased — a job saving transition

This device may have military application as well. Sight is sometimes difficult underwater, and BrainPort may be able to provide help with a soldier’s orientation and positioning. Perhaps if infrared cameras were used, enemies could be located more easily–proving especially helpful if radio contact is lost.

BrainPort has been compared to learning to ride a bike; in just minutes, spatial orientation is within reach.  And as with anything, practice makes perfect. Dr. Bach-y-Rita, the chief scientist at Wicab, phrased it:

…we do not see with the eyes; the optical image does not go beyond the retina where it is turned into spatio-temporal patterns of action potentials along the optic nerve fibers. The brain then recreates the images from analysis of the impulse patterns. Thus, for a sensory substitution event to occur, one need only to accurately entrain action potentials in an alternate information channel, which do not differ significantly for the individual senses. With training, the brain learns to appropriately interpret that information and utilize it to function as it would with data from the intact natural sense.

The eye is just one means of transportation to the visual world. Science is searching for methods to replicate the eye, and so far this technology has a lot to offer as an easily implemented, non-surgical option. While the idea of substituting senses is a bit out of the ordinary, it’s an entirely realistic portal for vision restoration to take.

mmiller12 studies engineering in Columbus, Ohio.

Advertisement