A Johns Hopkins researcher has joined experts from
four other institutions who plan to create
a dynamic electronic surface that would allow blind or
visually impaired people to "feel" mathematical
graphs, diagrams and other visuals now displayed on
computer screens.
Although the prototype is expected to convey
relatively simple graphics, further advances may
someday allow blind people to use the interface to sense
more complex illustrations, including pictures
and maps. The prototype is expected to be completed within
three years.
The project was launched recently with support from a
$330,000 National Science Foundation
grant. The team is led by Ilona Kretzschmar, assistant
professor of chemical engineering at the City
College of New York's Grove School of Engineering. Among
her five primary collaborators is James E.
West, a research professor in the Department of Electrical and
Computer Engineering at Johns
Hopkins. West is a widely respected inventor who received
the National Medal of Technology from
President George W. Bush in a White House ceremony earlier
this year.
West was recruited for the tactile interface team
because of his extensive knowledge of how
to move electrical charges through plastic or polymer
materials. The device is expected to utilize an
electro-active polymer film that can rise slightly and may
even wiggle in response to electronic signals,
enabling the user's fingertips to sense a pattern. The tool
may also feature sound feedback to help
users steer their fingers along the lines of a graph or
diagram. In developing the prototype,
Kretzschmar and West will be joined by other leading
researchers from Baruch College, CCNY,
Northwestern University and the University of Maryland,
College Park.
"This is an excellent team," West said. "Eventually,
if we can show this is feasible, I think this
device will open up the world for people who are blind or
visually impaired. The interface could help
them sense contours and changes in shape and texture and
use their fingers to perceive some of the
computer images that people with normal vision take for
granted."
Currently, people who are blind access computers
either through screen-reading software that
"speaks" the output or via expensive Braille displays that
can handle only text. "We're trying to make a
cheaper device that would receive information tactilely and
also be able to receive graphic
information," said Kretzschmar, who is principal
investigator of the NSF grant.
Kretzschmar first contacted West several years ago to
learn more about his research into the
electronic properties of polymer materials. At Bell Labs in
1962, West and his colleague Gerhard
Sessler patented the electret microphone, in which thin
sheets of polymer film, metal-coated on one
side, are given a permanent charge to help convert sound to
electrical signals with high fidelity.
Almost 90 percent of the more than 2 billion microphones
produced today are based on the principles
developed by West and Sessler. These microphones are used
in most telephones and many other
electronic devices worldwide. In 2002, West joined the
faculty at Johns Hopkins, where he has
continued his research into the behavior of these
polymers.
He is now lending this expertise to the
Kretzschmar-led project, which is called "A Dynamic
Tactile Interface for Visually Impaired and Blind People."
The interface is expected to consist of
three layers: The bottom layer will be a touch screen
connected to a computer for audio feedback to
communicate the position touched on the screen. The middle
layer will have embedded isolated
electrodes to address segments of the polymer top layer.
The top layer will consist of an electro-
active polymer film covered with a thin gold film. Segments
of the top layer will be able to extend out
from the surface as voltage is applied from the
corresponding electrode in the middle layer.
"In a world that increasingly depends on graphical,
pictorial and multimedia technology, visually
impaired and blind people have struggled to keep up,"
Kretzschmar said. "If we can develop a viable
dynamic tactile interface that allows graphic and pictorial
information to be presented in real time in
tactile rather than visual space, the amount of information
available to visually impaired and blind
individuals will increase dramatically."
Kretzschmar is producing Janus particles--particles
with two halves and named for the Roman
god Janus--to be added to the polymer film to increase its
electro-active properties and run
mechanical functions. The film will then be tested to
measure its addressability, maximum elongation,
durability and readability.
Members of her research team have begun to consult
with representatives of the National
Federation of the Blind and with visually impaired faculty
members to obtain advice on how touch can
best convey visual graphic displays, how much the material
needs to change for optimal tactile
detection and what the best way is to receive the
information.
In addition to Kretzschmar and West, the primary
researchers are Karen Gourgey, director of
the Computer Center for Visually Impaired People at Baruch
College; Vivien Tartter, professor of
psychology at CCNY; Thrasos Pappas, associate professor of
electrical engineering and computer
science at Northwestern University; and Leigh R. Abts,
professor of education and engineering at the
University of Maryland, College Park.