MEDICAL DEVICE INNOVATION - Medical Device Daily

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BrainPort helps blind mountainclimber
learn to ‘see’ via tongue
By AMANDA PEDERSEN
Medical Device Daily Staff Writer
Erik Weihenmayer has climbed the Seven Summits – the
highest peaks on each of the seven continents – including
Mount Everest. This world adventurer’s quests are made
even more remarkable by the fact that he has conquered
them all while visually guided by others.
In addition to making headlines for being the first blind
man in history to reach the top of Everest in 2001,
Weihenmayer has also been in the spotlight lately for his
involvement with BrainPort, a device designed to allow
blind people to “see” with their tongue.
The device, being developed by Wicab (Middleton,
Wisconsin) and funded by the National Eye Institute (NEI;
Bethesda, Maryland) uses sensory substitution – stimulating
one sense, such as touch, to take the place of another,
such as sight – an idea introduced in the late 1960s by Paul
Bach-y-Rita, MD. Bach-y-Rita died in 2006 but his research
lives on through Wicab, a company he established in 1998.
In addition to the BrainPort vision device, the company is
also developing a BrainPort balance device based on the
same technology.
“There are two different pieces to what [Bach-y-Rita]
believed and what I think is true,” Bob Beckman, president/CEO
of Wicab told Medical Device Daily. “The sensors
– your eyes or your ears – can be replaced with alternate
sensors and also the brain is not hardwired. You do not
have to go through the optic nerve to relay visual information
to the brain . . . you can go through the tongue.”
Recently Weihenmayer demonstrated the BrainPort on
the Today Show, using the device to read numbers on black
and white flash cards. With a camera mounted on his head
sending pulses to his tongue, he is able to interpret and
thereby determine the field of vision in front of him.
According to his web site, he has also used the device to
read words on note cards, play games with his daughter
such as tic-tac-toe, and find holds while rock climbing.
The camera acts as the user’s eyes, gathering white,
gray and black pixels of visual information. A computer
translates this information to electrical impulses, which it
then displays on the tongue in the form of an array of electrodes.
Strong vibrations on the tongue represent white
pixels, medium-strength vibrations represent gray pixels
and no vibrations represent black pixels. Blind people learn
to use that information to gain perception about their surroundings,
Beckman said. A few examples of what a blind
person could learn to do with the device are walk a sidewalk,
read signs in a hallway, and throw a ball into a basket.
Aimee Arnoldussen, a neuroscientist and BrainPort
researcher who worked with Bach-y-Rita, appeared on the
Today Show with Weihenmayer. She said that eventually the
MEDICAL DEVICE INNOVATION 2010
camera part of the device could be shrunk to fit in a pair of
glasses and that the visual information it collects might be
transmitted wirelessly to a retainer-like device that sits on
the roof of the person’s mouth.
Michael Oberdorfer, PhD, of the Division of Extramural
Research at the NEI told MDD that the tongue – aside from
serving us for taste – is very sensitive to touch. “If you’ve
ever had a small seed stuck between your teeth you know
what I’m talking about,” he said.
Oberdorfer said the technology behind the BrainPort
vision device delivers a “very gentle stimulation” to the
user’s tongue, which that person can adjust to get input
from the video camera.
The device would not work for a person who is considered
legally blind but has some vision, Oberdorfer said,
because the user would get competing input from their
eyes and the device. Thus, it only works for individuals like
Weihenmayer who are completely blind.
While only about 3% or less of the U.S. population are
totally blind, according to Oberdorfer, he says that is still a
significant number of people who could someday benefit
from this and other technologies.
But using the device takes practice, Beckman said. He
likened it to learning a new language and noted that it
requires training in order for the blind person to interpret
the tactile images being displayed on their tongue and
transmitted to their brain.
Wicab’s balance device is based on the same sensory
substitution technology as the vision device, only it is
designed for training patients with balance deficits due to
chronic vestibular disorders. The BrainPort balance device
provides information about head position through electrotactile
stimulation of the tongue, Beckman said. That device
consists of a controller – which includes patient controls,
signal processors and microcontroller – and an intra-oral
device, which includes a tilt sensor and an electrode array.
Instead of a camera, the BrainPort balance device uses
an accelerometer. During training sessions with this device,
the patient places the electrode array on the tip of their
tongue and slowly adjusts the signal intensity to a comfortable
level, Wicab said. The accelerometer detects head
and body movement when the patient leans forward, backward
or to either side. This information is relayed by microprocessors
directly to the tongue through the electrode
array, according to the company. For example, if the patient
sways to the left, the stimulus moves to the left side of the
patient’s tongue. If the patient sways to the right, the stimulus
moves to the right side of the tongue, Beckman said.
Patients are told to focus on the stimulus and to adjust their
body position with the goal of maintaining the stimulus on
the center of their tongue.
Beckman said Wicab has found that people learning to
use the BrainPort balance device train best with their eyes
closed and in a position which they find challenging. They
are asked to maintain their balance for 20 minutes, he said.
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