ELLULAR phones, the global positioning
system and wireless alarm technologies have made it possible for hikers
lost on mountains to contact rescue teams. But what about someone who is
knocked unconscious in an accident or cannot make a distress call because
they're being assaulted?
A University of North Carolina researcher has patented a system that
can send a silent distress signal along with the victim's location to emergency
The system is just one of several recently patented innovations that
make use of the global positioning system, an array of 24 satellites orbiting
the earth that transmit signals used to determine the geographic coordinates
of a person or object with a receiving device.
Leandra Vicci, who directs the university's Microelectronic Systems
Laboratory, got the idea for the distress signal after two attempted rapes
in the university area last year. At staff meetings, some faculty members
wondered aloud whether the women could have used their cell phones to summon
"A few days later it occurred to me that while that was a singularly
insensitive comment, they were onto an idea," said Ms. Vicci, a physicist
and engineer who also teaches in the computer sciences department at the
Chapel Hill campus. "If that could be automated, how could it be designed
to get a 911 response team enough information to go on?"
She knew that the components of her idea already existed.
"There is the global positioning system, and G.P.S. technology tells
where you are to within 50 feet or so, and of course there is cell phone
technology, so you could make contact," she said. "Two things were missing.
One, to be able to tell the 911 operator in sensible terms where you are.
The other thing is how to tell them what the problem is."
Ms. Vicci solved those problems by drawing on two other existing technologies.
She designed a small device embedded with a G.P.S. receiver, a cellular
phone chip, a microprocessor and a microphone. The device could be fashioned
into a pendant, or into an accessory worn on a belt or harnessed to a horse
saddle, a ski binding or other equipment that a person might be using when
an accident occurred.
To pass on G.P.S. information to a 911 operator, Ms. Vicci turned to
databases called global information systems. They let users enter longitude
and latitude and get back street names and landmarks.
"It will give you a point on the map, and it could translate that into
`this is in front of the Carolina Union, or 50 feet from the intersection
of Ransom & McCully streets,' " Ms. Vicci said. "That solves the problem
of telling them where the emergency is."
Once the pendant is turned on, "it's basically a G.P.S. receiver that's
getting your coordinates on the fly," Ms. Vicci continued. "Once it's locked
to position and get updates, it can keep quite current."
The receiver would also keep a log of the person's movements.
Some people have questioned whether the device would create a potential
invasion of privacy, Ms. Vicci said.
"This information never leaves this unit unless you have an emergency,
and at that point you want people to know it," she explained.
In a crisis, the system would be triggered with a yank on the pendant's
chain. The wireless phone chip would automatically contact a geographic
information system server. The microprocessor would transmit the G.P.S.
coordinates, and the server would turn those into plain English and pass
them on to a 911 operator.