- Taste buds can only distinguish between five basic flavours:
sweet, sour, salty, bitter, and savoury. The sensors in your nose,
by contrast, can sense as many as 10,000 different odors.
- The “Electronic Nose” is a relatively new tool that
may be used for safety, quality, or process monitoring, accomplishing
in a few minutes procedures that may presently require days to
complete.
- People spend some 95% of their time indoors, at home, at the
office, in schools, shopping malls, roadway vehicles, airports
and aircraft. Since the 1980s, indoor air quality investigations
have found school classrooms are often poorly ventilated; low-level
air intakes can be sources of combustion-fumes ingestion.
- While humans are very good at detecting odours, we are not very
good at identifying them. Everyone has experienced the “tip-of-the-nose”
phenomenon, when we know we’re familiar with an odour, but
just can’t remember the name. The sensory impact of an odour
(both quality and intensity) can be quite ambiguous, causing us
to rely on context to help figure out what we’re smelling.
- Odors--whether emanating from a sweet-smelling gardenia or a
rank sweat sock--are volatile chemicals that can kill olfactory
neurons.
- According to a forecast by Germany’s Intotech Consulting
Group, the market for these products will be $1.1 billion by 2004.
The United States, Europe, and Japan are expected to be the biggest
consumers of the sensing technologies. “Sensing is a hot
topic”, said Britton.
- Odor can induce: bad mood, interfere with falling asleep, disturb
sleep, induce headache, nausea, fits of coughing, interfere with
reading and thinking, interfere with recreation, induce vomiting,
and interfere with bad breathing.
- Studies show that familiar odours revive old memories more readily
than do familiar sights or sounds.
- We smell by a chemical and physiological process. The keys to
this process have only recently been discovered. Smells are carried
on objects, air, and water. We smell by certain molecules dissolving
onto hair-like cilia receptors that extend down from the olfactory
bulb of the brain and into the nasal cavity.
- The nose can distinguish more than 10,000 different odours found
in nature with only about 1000 different odour nerve receptors
available in the nose for that purpose.
- We detect odours by using at least a thousand different special
genes that are active exclusively in the cells of our odour nerve
receptors. These special genes help our odour nerve receptors
“paint a picture” for each odour. Any slight change
in the molecular “picture” can change a sweet smell
into a foul one—and vice versa.
- The market for electronic nose technology is poised for massive
growth over the next few years. While current sales have been
relatively small (approximately $15 million with unit costs in
the $25,000 to $100,000 range in 1999), the advent of lower cost
technology will dramatically alter the market size and scope.
As the definitive industry study by John Wiley & Sons states:
“After about a decade of development and a few commercializations,
the market is expected to take off and grow as the number of commercial
noses and applications increase.”
- “Scientists have endowed computers with eyes to see, thanks
to digital cameras, and ears to hear, via microphones and sophisticated
recognition software. Now they’re taking computers further
into the realm of the senses with the development of an artificial
nose.”
- “Just as a police dog comes to recognize cocaine by repeated
exposure to that smell, an electronic nose must be “trained”
to recognize an odor abnormality. Electronic noses combined with
artificial neural (ANN) technology allow these instruments to
be trained. ANNs are artificial intelligence networks which, like
humans, can “learn” through exposure to stimuli.”
- The human nose: “It’s the best chemical detector
on the planet”. (Firestein)
- “The nose does a lot more than just hold up our eyeglasses”.
(Firestein)
- The nose was very important to England’s King George III.
He believed that the sense of smell could get you into real trouble.
He changed the law to include the provision that if a man believed
that he’d been seduced into matrimony by his wife’s
perfume, he had sufficient grounds for divorce.
- “The nose knows”
- The benefits of electronic noses include compactness, portability,
real-time analysis, and automation.
- In some instances electronic noses can be used to augment or
replace panels of human experts. In other cases, electronic noses
can be used to reduce the amount of analytical chemistry that
is performed in food production especially when qualitative results
will do.
- Because the sense of smell is an important sense to the physician,
an electronic nose has applicability as a diagnostic tool. An
electronic nose can examine odors from the body (e.g., breath,
wounds, body fluids, etc.) and identify possible problems.
- It would be difficult to imagine life without smell. Early experiments
by NASA found that the efficiency of astronauts was reduced when
confined to the near odor-free environment of a one-person space
capsule. Astronauts found a smell-free environment so disturbing
that they carried scented chemicals with them to counteract any
negative effects of “odor-boredom”. NASA integrates
a variety of smells into the air conditioning system of the space
shuttle.
|
|
