A new laser analyzer might be able to help doctors detect cancer,
asthma or other diseases by sampling a patient’s breath, researchers
reported on Tuesday. The device uses mirrors to bounce the laser’s light back and forth
until it has touched every molecule a patient exhales in a single
breath, the team reported in the journal Optics Express.

University of Colorado at Boulder physics doctoral
student Michael Thorpe holds a detection chamber while standing next to
a laser apparatus in a photo released by the university on Tuesday. A
new laser analyzer might be able to help doctors detect cancer, asthma
or other diseases by sampling a patient’s breath

This can help detect minute traces of compounds that can point to
various diseases, including cancer, asthma, diabetes and kidney
malfunction, they said.

"This technique can give a broad picture of many different molecules
in the breath all at once," Jun Ye, who led the research at the
University of Colorado, said in a statement.

Ye’s team at a joint institute of the National Institute of
Standards and Technology and the university developed a new technique,
called cavity-enhanced direct optical frequency comb spectroscopy.

When animals and people breathe out, they exhale not only gases that
are not needed, such as carbon dioxide, but also compounds that result
from the metabolism of cells.

"To date, researchers have identified over 1,000 different compounds
contained in human breath," Ye’s team wrote in the report, published on
the Internet" here

Some point to abnormal function — such as methylamine, produced
in higher amounts by liver and kidney disease, ammonia produced when
the kidneys are failing or elevated acetone caused by diabetes.

People with asthma may produce too much nitric oxide, exhaled in the
breath, while smokers produce high levels of carbon monoxide.

Last February, a team at the Cleveland Clinic in Ohio reported they
could use a mass spectrometer breath test to detect lung cancer in
patients. Tumor cells produce compounds called volatile organic
compounds at higher levels than healthy cells.

In 2006, researchers found dogs could be trained to smell cancer on the breath of patients with 99 percent accuracy.

Ye’s team used their method to analyze the breath of several student
volunteers and found they could detect trace signatures of ammonia,
carbon monoxide, and methane in breath.

Their volunteers breathed into an optical cavity, which is a space
between two mirrors. When a pulsed laser light was shone into this
space, it bounced back and forth multiple times, striking all the
molecules in the sample, Ye’s team said.

Spectrometry analysis showed which frequencies of light were
absorbed, in turn an indirect measure of which molecules were in the
sample.

Via Reuters