It lets us converse with others, sing along to the radio and
play a flute. Without it, we couldn't taste that chocolate cake and
lick our lips. But since when can a tongue open a door, operate a
wheelchair or type?
That's exactly what Maysam Ghovanloo, Ph.D., has in mind, with
something he calls the Tongue Drive system. The new assistive
technology dreamed up by this electrical engineer and assistant
professor at the Georgia Institute of Technology (Georgia Tech) in
Atlanta promises to transform the lives of people with severe
disabilities, even those with high-level spinal cord injuries.
With the Tongue Drive, a magnet the size of a grain of rice is
attached to the tip of the tongue with tissue adhesive, or by
implantation or piercing. The person also wears something like a
phone headset, mounted with two extensions along both cheeks, or an
orthodontic brace inside the mouth. Here, an array of magnetic
field sensors detects specific tongue movements for an unlimited
number of different commands, each tailored for the person's
abilities, oral anatomy and personal preferences.
As the tongue (without much thought or effort) quickly and
oh-so-accurately turns and stretches, curls and pokes, the sensor's
signals are immediately transmitted, wirelessly, to a laptop
computer that is programmed to perform a variety of functions
— everything from moving a computer cursor to changing TV
channels. The research team has also begun to develop software to
connect the system to communication tools such as text generators,
speech synthesizers and readers. The user can also switch the
system to standby mode so he or she can eat, talk or sleep, for
instance, without wasting battery power.
Ghovanloo and his graduate research assistant Xueliang Huo are
working on eventually chucking the bulky laptop by connecting the
Tongue Drive system to a smartphone (a mobile phone with
PC-computer capabilities) or PDA (personal digital assistant)
attached to the person's clothing or wheelchair.
“Theoretically, it's also possible to assign a letter of the
alphabet or certain command to each tooth, so just by touching your
tongue to your teeth, you can type or do other things,” says
Ghovanloo, who began the project three years ago.
A motor output, the tongue is similar to the fingers and hands.
But unlike these parts of the body, which are connected directly to
the brain through the spinal cord, the tongue enjoys a direct route
to the brain through a cranial nerve. “So even if someone is
paralyzed all the way up to the neck, they can still use their
tongue,” says Ghovanloo, who notes it generally escapes
damage in severe spinal cord injuries or neuromuscular diseases.
“It's a huge advantage for an assistive technology to rely on
tongue movement because there's a broad spectrum of individuals
with different disabilities that can benefit from it.”
If that little magnet on the tip of the tongue empowers a
disabled person to answer the phone and surf the Internet,
“someone who was isolated can now connect with the rest of
the world. They can get an education and pursue an
occupation,” he continues. And if the Tongue Drive can wheel
them around the house and turn lights on and off, “they
become a lot more independent, relieving a dedicated caregiver of
continuous care.”
So far, with funding from the National Science Foundation and
the Christopher and Dana Reeve Foundation, Ghovanloo's invention
has been tested twice, both times on six able-bodied student
volunteers who tried out its ability to operate a power wheelchair.
The research went off without a hitch. Soon, those with severe
disabilities will get their turn, in trials conducted in
collaboration with the Shepherd Center, an Atlanta-based
catastrophic care hospital.
“I'm really fascinated by doing research at the border of
electrical engineering and medicine,” says Ghovanloo.
“As long as I can remember, I've always liked to help people.
I feel that this is the best area I can do that in.” And if
the Tongue Drive can make it out of the lab and into the world,
“that would be the ultimate satisfaction for me.”
