Researchers hope a laser system they are developing will one day be able to
rapidly screen for diseases like cancer, diabetes and infections using exhaled
breath.
Our breath contains molecular byproducts of our metabolism.
The team from the University of Adelaide in Australia say the “optical dog’s nose”
they have created has the potential to detect disease fast, noninvasively and on
site.
The system uses a special laser spectrometer to analyze the molecular composition of a
sample of gas.
Dr. James Anstie, a researcher at Adelaide’s Institute for Photonics and Advanced
Sensing, says:
“Rather than sniffing out a variety of smells as a dog would, the laser
spectrometry system uses light to ‘sense’ the range of molecules that are present in the
sample.”
In the journal Optics Express, he and his colleagues describe how they used
optical spectroscopy to measure the light-absorption patterns of different molecules fast
and accurately.
More and more scientists are working in the new field of breath analysis. Our breath
contains molecular byproducts of our body’s metabolism – the work that goes on in cells
to keep us alive and healthy.
When things go wrong – like disease – the mix of metabolic byproducts in our breath
changes.
Dr. Anstie explains that teams around the world have published a number of studies
describing how it may be possible to use breath analysis to detect diseases like lung and
esophageal cancer, asthma and diabetes, even before they show external symptoms.
‘Optical frequency comb’
Dr. Anstie says the system he and his team are developing offers a number of potential
advantages: near-instant results, high sensitivity, and the ability to test for a range
of molecules at the same time. This would make it attractive for broad-scale health
screening, he notes.
A key feature of the system is the “optical frequency comb” – a highly
accurate spectrometer that records the spectral result of shining a million different
light frequencies on the gas sample in parallel.
Different molecules absorb light at different frequencies, giving each a unique
optical fingerprint. Dr. Anstie explains what they have to do next:
“We now have a robust system to be able to detect the presence and
concentrations of molecules in a sample. The next step is to work out how to accurately
sample and interpret the levels which will naturally vary from person to
person.”
He and his team hope to have a prototype system up and running in 2-3 years, and a
commercial “plug and play” product in 3-5 years.
Dr. Anstie gives an account of their “optical dog’s nose” laser system in the
following video.
Funds from the study came from the Australian Research Council, the Premier’s Research
and Industry Fund and a South Australian Government Catalyst Research Grant.
Meanwhile, Medical News Today recently learned how another group of
researchers is wondering if a different kind “sniff test” might help diagnose autism. In a Current
Biology paper, Noam Sobel, of the Weizmann Institute of Science in Israel, and
colleagues describe how they identified differences in the way people with autism
respond to smells, suggesting this could be used for early diagnosis of the
condition.
Written by Catharine Paddock PhD