Laser-based analyzer may be able to detect compounds in breath associated with various diseases.

| February 20, 2008

I have posted previous notes about the use of breath testing to detect diseases.  Here is another one.

         Reuters (2/20) reports that according to a paper appearing in the journal Optics Express, researchers at the University of Colorado-Boulder (CU) have developed a "new laser analyzer [that] might be able to help doctors detect cancer, asthma, or other diseases by sampling a patient’s breath." Using "mirrors to bounce the laser’s light back and forth until it has touched every molecule a patient exhales in a single breath," the device may be able to "detect minute traces of compounds that can point to various diseases." The new technique, developed in collaboration with the National Institute of Standards and Technology," is "called cavity-enhanced direct optical frequency comb spectroscopy."

        According to an article appearing on the ABC (2/19, Dye) website, "It has been well established that people exhale a complex mixture of gases, including oxygen, nitrogen, carbon dioxide, and others," said lead researcher Jun Ye. Moreover, some "1,000 different compounds are contained in human breath," and "along with those common gases and compounds, people also exhale certain molecules that are considered ‘biomarkers’ indicating specific conditions, such as diseases." Ye added, "If you go to the medical literature you will see tons of studies that correlate certain diseases with particular molecules found in the breath," noting that "one common example is nitrous oxide, which is associated with asthma."

        Contributing to MSNBC‘s (2/19) website, Steve Mitchell reports that "[b]reath analysis systems have been around for several years, but a common problem with previous methods is they could only detect one or a few types of compounds in the breath." According to Ye, "[t]his doesn’t provide enough information to determine if a person has a specific disease because they could have elevated levels of a single compound for other reasons." Yet, the "new laser technique provides a way to assess the levels of many different compounds in the breath at once, offering a more accurate picture of whether a person has a particular disease." Ye added, "It’s like seeing the entire forest, rather than just individual trees."

        Terence Risby, of Johns Hopkins Medical Institutions, "has worked on breath analysis for years, and helped develop devices that can detect liver disease by measuring sulfurous molecules in the breath," noted the Denver Post (2/19, Human). But "Risby said he had some doubts about the immediate use of the new laser method, because it’s far easier to measure chemicals in the breath than it is to understand why they are there." For instance, ethane "can show up in the breath of a person who is developing cancer, he said — or the chemical’s presence could instead signal an absence of fruit and vegetables in the diet." Risby said, "If you don’t understand what you’re doing, you can do more a disservice than anything else." Still, the new technique may be an alternative to other techniques that "rely on either the expensive and time-intensive technique of mass spectrometry — a set-up can cost $1 million," said CU graduate research assistant Mike Thorpe — "or on devices that measure only one or two constituents of breath."

        For the month-long study, "volunteers breathed into what is called a ‘detection chamber,’" reported Colorado’s CBS affiliate KCNC-TV (2/19, Walsh). Then using the spectroscopy technique, the team "blasted the breath with ultra fast invisible laser pulses that can recognize individual molecules," and the resulting "information was recorded on a camera, allowing researchers to actually see what was in the breath on a computer." They discovered that they could identify trace amounts of methane, ammonia, and carbon monoxide in the breaths’ of some of their participants. Although the "technique has yet to be tested in clinical trails," the researchers are "already getting calls from entrepreneurs hoping to get in on this promising laser technology." Thorpe added, "I hope it means a cheaper method for health screening," because "[t]hat would be the ultimate goal."


Category: General Healthcare News

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