April 15, 2003
The Sound of One-Hand Signing
GW Engineering Doctoral Candidate Jose Hernandez-Rebollar
Creates an Electronic Translation Device for American Sign Language
American Sign Language (ASL) is one of the most used languages in the
United States. Yet communications between the ASL-fluent and those unfamiliar
with the deaf communitys chosen parlance are a constant dilemma.
Its especially problematic in emergency situations because no
electronic translation methods exist for ASL. Its a problem that
GW doctoral candidate Jose Hernandez-Rebollar has devoted three years
of his life to solving how to construct a device that translates
the sometimes complex movements of ASL into written and spoken form.
To that end Hernandez-Rebollar, who studies electrical and computer
engineering at the School of Engineering and Applied Science (SEAS),
devised the AcceleGlove. His ASL translation device uses accelerometers,
a microcontroller, and algorithms he wrote especially to translate ASL
into the written and spoken word in two basic steps.
First, the AcceleGlove is placed on the hand and strapped to the arm,
allowing the accelerometers on the glove to act as sensors that generate
signals from the movement, orientation, and positioning of the hand
and the fingers in relation to the body. These signals are analyzed
by a microcontroller to find the position of the fingers and hand trajectory.
The second step of the process is to take the recorded position and
trajectory and find what they mean. To do so, the position of the fingers
and the trajectory of the hand are run through Hernandez-Rebollars
algorithms to detect the gesture and classify the gesture in a certain
category, to find the correct word associated with the hand movement.
This entire process takes milliseconds from the time the sign is made,
to recognition of the sign, and the computerized voice saying the corresponding
Hernandez-Rebollar realized that while there are dictionaries to translate
almost every spoken language, there is no electronic means of translating
ASL. According to Thomas E. Allen of the Gallaudet Research Institute,
the accepted range for numbers of speakers of ASL in the United States
is between 500,000 to two million people, leading some to refer to ASL
as the fourth most-used language in the United States.
I started thinking about an electronic translation method for
ASL before I came to GW, says Hernandez-Rebollar. The language
has been around for almost 200 years, yet unlike most other languages
we do not have electronic translation for ASL.
A native of Mexico, Hernandez-Rebollar came to the United States and
GW in 1998 on a Fulbright scholarship after completing his undergraduate
and masters work at University of Puebla, and later working at
the National Institute for Astrophysics, Optics, and Electronics (INAOE).
At INAOE, Hernandez-Rebollar was involved in building the largest millimeter
telescope in the world. His specific area of interest involved the control
of the telescopes antenna. INAOE encouraged Hernandez-Rebollar
to go overseas to obtain an advanced degree and training, which led
him to apply for a Fulbright scholarship.
The Fulbright provided Hernandez-Rebollar funding for two years of coursework
and one year of work on his dissertation. In 2000, he presented Nicholas
Kyriakopoulos, professor of electrical and computer engineering at GW
and Hernandez-Rebollars dissertation director, with the preliminary
idea of creating a method of electronic translation of ASL for his doctoral
research. Kyriakopoulos cautioned him about the difficulties of undertaking
the project because Hernandez-Rebollar had no experience in that area.
I thought it would be very hard and that the topic was mostly
covered by others anyways, shrugs Kyriakopoulos. People
who undertake experimental dissertations are generally risking more,
there is less opportunity to change direction midstream.
Undeterred by Kyriakopoulos warnings, Hernandez-Rebollar developed
the primary circuits for the AcceleGlove while his dissertation director
was on sabbatical during the spring 2000. Over the summer, he developed
the first algorithm, or program, to identify ASL gestures. When Kyriakopoulos
returned and saw the work Hernandez-Rebollar had already put into the
project, he gave Hernandez-Rebollar his blessing to go forward with
the AcceleGlove project. Now, Hernandez-Rebollar is on course to earn
his PhD in May or the following semester.
For Hernandez-Rebollar, this research is the combination of two of his
passions: helping others and inventing new devices by experimenting
with electronics. In high school, he was actually more interested in
being a doctor or a lawyer. However, as time passed, he realized the
benefits of an engineering career. In electrical engineering if
I blow up something, I can buy another one and its no problem,
Hernandez-Rebollar says. It also doesnt hurt to get paid
to do something you enjoy, he chuckles.
When Robert Lindeman, assistant professor of computer science, realized
Hernandez-Rebollars ability to build and test electronic products,
Lindeman hired him as a research assistant to help with his work in
Professor Lindeman really came to the rescue when my Fulbright
scholarship was running out, says Hernandez-Rebollar.
Without his research assistantship Hernandez-Rebollar could not have
afforded to stay in the United States and in all likelihood would have
been unable to continue work on the AcceleGlove.
It is still a question as to whether the deaf community would embrace
a device like the AcceleGlove. In Hernandez-Rebollars research
and testing of his glove he found two distinct feelings in the deaf
community. Some feel that being deaf is not a handicap, it is simply
another way of life and you should not use artificial means to overcome
loss of hearing.
Meanwhile, others feel that if new technologies can help improve your
life or make you feel better about yourself, why not make use of what
However, the AcceleGlove is not a new technology that would simply be
useful for deaf people in emergency situations. The ability to communicate
through hand gestures could also be used to teach ASL, along with being
modified for use in virtual reality, military settings, and in different
forms of sign language. The thing that makes Joses research
so interesting is that it is applicable to so many different areas,
Of course, at this point the AcceleGlove is not viable as a commercial
product and there is room for improvement and growth. The AcceleGlove
currently only recognizes 173 words, although new signs may be added
to the lexicon and recognized without Hernandez-Rebollar having to change
the code. The algorithms used to recognize hand and finger movements
can always be improved to become more reliable in their detection of
Hernandez-Rebollar is proud to say that the AcceleGlove correctly translates
easy words more than 95 percent of the time, but what he
calls hard words have only a 6070 percent success
rate. If he can extend the research, development and testing to gloves
to both hands, Hernandez- Rebollar would be able to work with an even
larger dictionary of words in ASL.
Although there is more work to be done with the AcceleGlove, Hernandez-Rebollar
is not sure if he will have the necessary financial support to continue
his research after his dissertation. He is not sure if other pursuits,
such as one of the small side projects he is always working on, will
eventually pull him away from the AcceleGlove project.
If the project continues it will keep Hernandez-Rebollar busy; a language
is not something easy to catalogue and translate. When James Murray
set out to create the Oxford English Dictionary, he did not know it
was a project that would consume 40 years of his life, and that he would
not live to see it completed. Does Hernandez-Rebollar want the AcceleGlove
and make it his lifelong project? Right now he looks at everything as
a blank slate. Fortunately for Hernandez-Rebollar, that is when he does
his best work.
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