La Pierre himself is visually impaired, and says being unable to read street
signs frustrated him: ‘I started thinking what I could do to make something
that would tell me where I was.’ He toyed with other ideas, including bar
code readers and a system of FM radio transmitters, before latching onto the
GPS.

He created his own database of the streets at the 20-hectare campus of
Carleton University, Ottawa, by walking around with a GPS receiver and
collecting data points every 10 seconds. The receiver stored each point as
degrees, minutes and seconds of latitude and longitude. To correct for the
GPS’s inherent error (of between 30 and 100 metres) La Pierre used
differential GPS from a fixed transceiver, which rebroadcasts an accurate
reading to the local area, and matched the corrected readings with the
street intersections.

When the user presses a button to ask for location, the system searches the
database for a match with the actual latitude and longitude. The computer
then replays any text or street intersection data matching these coordinates
via a voice synthesiser.

Expanding the technique to other cities should be simple because some
already have street maps which use GPS technology. ‘For updating 911
(emergency) services they are using GPS to map out the city accurately, so
they’ll have all this information – the street intersections, street names
and all the latitudes and longitudes that are coordinated with those.’

La Pierre’s original unit weighed 11 kilograms and consisted of a laptop
computer, battery-operated voice synthesiser and GPS receiver. With over
$500 000 of commercial funding, he is now working on a unit
incorporating the same functions in a package the size of a personal stereo,
weighing less than a kilogram and audible through headphones, unlike the
original which played through the computer speaker.

A hull that is left in the water all year, especially in warm waters,
attracts a living zoo of barnacles, tubeworms, freshwater zebra mussels and
other wildlife.

Scraping or sandblasting the creatures off the hull and applying repeated
coats of toxic antifouling paint is time consuming, messy and expensive.
‘There had to be a better way,’ says Fischer.

Cayenne pepper, shares the same active ingredient as Tabasco sauce,
capsaicin, which is insoluble in water. So Fischer first tested his idea by
putting some double-sided adhesive on one side of a tile and rubbing cayenne
pepper on it.

He dropped the tile over the side of a dock in Florida – ‘The world’s worst
place for barnacles,’ he says. ‘After about three weeks I started to notice
that there were barnacles and tubeworms growing on the back side of this
tile but not where I had treated it.’

He also tried the Tabasco treatment on freshwater zebra mussels in an
aquarium. ‘As soon as they got on they got off right away. They didn’t like
it at all. It was too hot for them,’ he says.

Encouraged by his results he called the spice giant, McCormick, to see if
they would supply the pepper he needed to produce the pepper-based paint he
had in mind. McCormick came up with an extra hot red pepper powder and
derivatives called oleoresins, a resin and oil mix from the capsules and
seeds of the habanero pepper.

‘It’s the hottest pepper known to man,’ says Fischer. ‘To equate the heat
that this pepper gives off, take one measured drop of oleoresin, then add
250 000 drops of water and that will still give you a warm glowing feeling
inside your mouth.’

According to Jon Luikart, of McCormick the results from initial tests have
been very encouraging. The pepper-based paint works well he says, and the
company is conducting further trials on two different formulations at the
Charleston Naval Shipyards in South Carolina to find out how long the
effect lasts.

‘Our goal is to make it last as long as possible which would be about three
or four years,’ says Luikart. ‘Red pepper, being an edible product, is much
more environmentally friendly than a lot of the cuprous oxide type
products,’ he says. ‘The advantage is that we’re not using cuprous oxide or
zinc. We’re using essentially a natural product.’

And that’s good news for the barnacles too. ‘Barnacles are mobile and will
settle on a boat,’ says Luikart. ‘If it’s hot to them they will find some
other place that is more favourable. Rather than kill them it acts as a
°ù±ð±è±ð±ô±ô²¹²Ô³Ù.’

Fischer has obtained a patent for his invention, which will be marketed
under the name of ‘Barnacle Ban’. Fischer says it should be available
commercially in about six months.

Intervertebral discs act as shock absorbers between adjacent vertebrae
and, like a Rolo chocolate, have a tougher outer material and a soft inner
core. If the outer material tears, usually in the lower back where stresses
are greatest, the inner material is squeezed out and pushes against nerves
to cause pain.

Most patients with slipped, or herniated, discs can be treated with
bed rest, heat therapy, painkillers and exercise. Fewer than 1 per cent
require surgery, says John Kostuik, formerly of the Toronto General Hospital
and now professor of orthopaedics and neurosurgery at Johns Hopkins University
in Baltimore. Surgery either removes the extruded material to relieve pressure
on the nerve or takes out the entire disc between the vertebrae and fuses
the two vertebrae together with a bone graft. Spinal fusion requires up
to six months convalescence and more than 15 per cent of operations are
unsuccessful.

The artificial disc consists of a pair of metal plates made from an
alloy of cobalt, chromium, molybdenum and titanium. The two plates are hinged
with a single pin and separated by two coiled titanium springs. Once the
disc has been removed, the device is inserted in its place with the hinge
towards the back, and screwed into the two vertebrae.

The springs mimic the flexing and stretching of a natural disc. The
hinge controls pivoting and keeps both plates and vertebrae aligned in case
an accident or shock jars the spine.

Kostuik estimates only six to ten weeks of convalescence will be needed
because healing involves only soft tissues. Unlike the bone graft, ‘nothing
is being done to restrict motion’, he says. The operation would last ‘a
couple of hours and be no more dangerous than any anterior surgery of the
spine which we currently do’.

Kostuik and his colleagues have put the device through tough endurance
tests over some seven years, testing various combinations of metal and alloy
for wear and fatigue. Plastic and ceramics were rejected because they wore
away over time. As most spinal fusions are performed on people aged 35 to
50, the device needs to last at least 40 years.

They subjected the various moving parts to up to 100 million repetitions
of movement, based on estimates that the average person takes 2 million
strides and makes 125 000 ‘significant bends’ each year.