THIS WEEK:                                                           30 Aug 97
 #18  Robots lead the blind.

   By JONATHAN BEARD
An Intelligent white cane that blind people can use to find their way has
been developed by researchers in Michigan. The cane is arobot that will
gently lead them around any obstacles in their path.
'Many industrial robots are strong and capable, but almost blind,' says
Johann Borenstein of the University of Michigan, Ann Arbor. 'The intelligent
cane we have created for the blind is the opposite.'
The prototype GuideCane looks a little like an upright vacuum cleaner. In
its base is a crescent-shaped array of ultrasonic sensors that scan the area
ahead. A built-in computer interprets the data from the sensors, calculates
the best route every 50 milliseconds, and steers the device accordingly.
All a blind person has to do is follow. 'It was immediately intuitive, there
was nothing to learn,' says Carroll Jackson, one of the first blind people
to try the prototype. 'Indoors,' he says, 'I was comfortable using it within
a few minutes.'
The GuideCane weighs about 4 kilrm.Bresen andJackson say that
unlike a guide dog it requires no maintenance other than recharging its
batteries. 'The majority of blind and visually impaired Americans are over
60,' says Jackson, 'and few of them can care for a dog or provide enough
activity to keep it healthy.' At the moment the device cannot sense
overhanging obstacles and it can only operate on smooth surfaces. It also
can't cope with stairs. 'The first thing we want to add to the cane is some
upward-pointing sensors,' says Borenstein. 'Ultimately, we would like to
incorporate a global positioning satellite receiver, so that users could
choose a destination, and the GuideCane would steer them along the best
course.'

New Scientist
Volue  155.   Issue   2097.
 IN BRIEF:                                                            13 Sep 97
 #39  Blindness creates extra sensory perception.

The visual cortex of a blind person's brain does not remain idle-other
senses take it over, say scientists at the National Institutes of Health in
Bethesda, Maryland.
Leonardo Cohen and his colleagues asked ten blind and five sighted
volunteers to identify Braille letters or raised Roman letters by touch. As
they did so, the researchers used magnetic pulses to disrupt various regions
of their brains. When they gave pulses to the visual cortex at the back of
the head, the blind subjects felt extra dots or had trouble making out the
Roman letters. The same stimulation had no effect on sighted readers, the
team says in this week's Nature (vol 389, p 180).
Cohen believes that blind people almost certainly use the visual cortex for
hearing, taste and smell as well. 'This demonstration takes us one step
further towards explaining the improved sensory abilities of blind people,'
he says.

New Scientist
Volume  155.   Issue   2099.
 THIS WEEK:                                                           20 Sep 97
 #12  Every move you make: A compass that knows where you've been.

   By JONATHAN BEARD
For more than 2000 years the magnetic compass has remained unchanged. Now
Directional Robotics of Fresno, California, has updated the device so that
it remembers the movements of anyne carrying it.
The compass 'needle' in the company's Homer Hiker is fixed to a
free-floating disc. Cut into the disc, and running all round it close to the
edge, satee ap. This is widest at the East position and becomes
narrower as it goes round the disc, tapering away to nothing when it has
gone full circle. A fixed light beneath the disc shines through the gap to
strike a photocell mounted above it. The amount of light received by the
photocell is proportional to the position of the needle. This allows the
device to work out which way the person carrying the compass is heading. The
bearing is logged by a memory chip, which also records how long the needle
points in any particular direction.
Harold Gallagher, president of Directional Robotics, says that the key to
the Homer Hiker's success is the use of light to detect the position of the
needle. Previous 'electronic magnetic compasses' failed because of the
electromagnetic fields created by their circuit boards. Using light and
mounting the memory chip away from the needleavoids producing fields strong
enough to affect it.
Homer Hiker will go on sale next year at a price of around Dollars 50, says
Gallagher. It will consume much less power than location devices that rely
on Global Positioning System (GPS) satellites. 'Batteries that power a GPS
unit for one day would run Homer for a month,' Gallagher says.
Directional Robotics expects divers, potholers and loggers working in dense
woodland to be especially interested in Homer Hiker. GPS only works in open
areas because it needs to receive signals from at least three satellites.
Gallagher thinks blind people may also find a use for his compass. Once
someone has walked a certain route, the compass can guide them-or anyone
else-along the same path through a speech synthesiser connected to it.

New Scientist
Volume  155.   Issue   2100.
Copyright (C) IPC Magazines Ltd, 1985-1997
Copyright (C) IPC Magazines Ltd, 1985-1997
Copyright (C) IPC Magazines Ltd, 1985-1997


Bud Kennedy
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