A researcher working for the National Institute of Standards and Technology has demonstrated an optical technique for identifying tiny amounts of a broad range of molecules in the breath, potentially enabling a fast, low-cost screening tool for disease.

In this approach, NIST researchers analyze human breath with "frequency combs," which are generated by a laser specially designed to produce a series of very short, equally spaced pulses of light. Each pulse may be only a few millionth billionths of a second long. The laser generates light as a series of very narrow frequency peaks equally spaced, like the teeth of a comb, across a broad spectrum.

The tool sounds like yet another example of a Star Trek-like device making its reality debut. On Star Trek, Tricorders had multiple functions but the medical version used by Bones McCoy could scan a body and help diagnose and heal injured or sick patients.

To test frequency combs, student volunteers exhaled breath that entered an optical cavity where it was "combed" by the light pulses. By detecting which colors of light were absorbed and in what amounts-essentially looking for light absorbed near the "teeth" of the comb- the researchers could detect specific molecules and their concentrations, NIST said. According to researchers over 1000 different compounds contained in human breath have already been identified. For example, a student smoker who participated in the experiment had a level of carbon monoxide that was five times greater than a nonsmoker in the experiment, NIST said. The optical comb approach allows the researchers to simultaneously analyze a very broad spectrum, covering many possible molecular compounds, with high precision, frequency resolution and sensitivity. The technique is in early phases, and would require clinical trials before it could become available at a doctor's office, but it could lead to one of the first widespread applications of frequency combs, NIST said in a release. "For example, nitric oxide can indicate asthma, but it also appears in breath with many other lung diseases, including chronic obstructive pulmonary disease, cystic fibrosis and bronchiectasis. However, if we simultaneously monitor nitric oxide, carbon monoxide, hydro-peroxide, nitrites, nitrates, pentane, and ethane, all important biomarkers for asthma, we can be much more certain for a definitive diagnosis of this important disease," said Jun Ye, a physicist at JILA who cowrote the research. JILA is a joint institute of the NIST and the University of Colorado at Boulder. Existing methods for detecting trace amounts of molecules from the breath are either bulky, slow, limited to specific molecules, unable to distinguish very well between multiple compounds or inaccurate at measuring their concentrations, NIST said. Layer 8 in a box See these related stories: Top 10 real-life Star Trek inventions 5 Trek inventions I'd like to see... Star Trek-like Ion engines to rocket space agency's Mercury shot Star Trek-like 'Phraselator' device helps police communicate