UBC Reports | Vol. 50 | No. 3 | Mar.
4, 2004
Mini sensors provide maximum data
By Celine Horner
Just as James Bond was always armed with amazing gadgets
that Q secreted in his pens, watches, and Aston Martin cars,
researchers at UBC’s new Centre for Health and Environment
Research (CHER) can now equip themselves with high-tech micro
gadgets provided by the centre’s micro sensor specialist,
Winnie Chu.
CHER researchers rely on accurate measures of human exposure
to air pollutants, noise, water pollutants, and workplace
hazards among others to predict health outcomes and identify
control strategies.
“One of the challenges in measuring personal exposure
to environmental threats is taking measurements as unobtrusively
as possible. Sensors must be discreet and lightweight so as
to allow the wearer to continue their normal activity,”
according to Prof. Paul Demers, CHER’s acting director.
In other words, there’s no point in giving an ice hockey
player a heavy briefcase-sized sensor to assess his exposure
to gas from a Zamboni machine during a match.
Designing micro sensors to help researchers overcome these
types of sampling obstacles is all in a day’s work for
Chu, who is CHER’s fabrication specialist.
Top of her list at the moment is the development of a sensor
that Prof. Kay Teschke can use to assess the impact of whole
body vibration on truck drivers and other workers in heavy
industry. Such a sensor would have to be worn comfortably
by the driver and measure forces acting on the back muscles
without changing the driver’s posture or position. The
sensor must also measure the vibration that the driver is
exposed to from the jostling and jolting of the truck cab.
Chu explains that she will build two accelerometer sensors:
one is worn on a belt that positions the sensor next to the
muscle and measures its mechanomyographic frequency changes,
and one that will be placed in the driver’s seat to
measure the forces due to vibration of the vehicle.
Mechanomyography measures the vibration frequency of individual
muscle fibre contractions as the muscle moves. Each movement
registers at a different frequency, but the higher the frequency
the more likely that the muscle won’t return to its
original size or shape, much like a spring that has been pulled
beyond its elastic limit.
“Accelerometers have been perfected and fine tuned in industry
for use in crash impact air bags. They open at forces indicating
a collision — not if you slap the dash at the sight of yet
another traffic jam. The back injury sensor, which will be
smaller than the size of an aspirin, will yield data about
muscle movement and the effects of external forces that will
allow us to predict muscle strain and therefore avoid back
injury,” explains Chu.
Chu, who has a PhD in chemistry from Simon Fraser University,
is likely to be in high demand by CHER’s 31 researchers
over this first year of the centre’s operation. She
is already working with Prof. Susan Kennedy on analytical
lab methods to detect indications of inflammation in the exhaled
breath of workers exposed to grain dust.
Asst. Prof. Karen Bartlett has enlisted Chu’s help
in building a sensor to monitor airborne fungal spores of
the deadly Cryptococcus neoformans var. gattii, which has
been the cause of a number of deaths on Vancouver Island.
Another long-term plan is to build an indoor air quality sensor
that will use artificial intelligence to eliminate background
contamination and produce reliable readings for contaminants
such as carbon monoxide.
The Michael Smith Foundation for Health Research has provided
the funds for CHER which, in addition to micro sensors and
state-of-the-art sampling techniques, provides researchers
with assistance in grant facilitation, knowledge transfer
and biostatistics.
The hope is that CHER research will involve few high speed
car chases or gun battles and that, unlike Q’s spy craft
devices, Chu’s micro sensors will not be destroyed in
the line of duty.
