Laser Tool May Improve Asthma Diagnoses

ARLINGTON, Va., Oct. 21 -- A novel way to use a laser to analyze breath exhalations opens the door to more accurate diagnosis and prescriptive treatment of asthma, according to the National Science Foundation (NSF).

Patrick McCann at the University of Oklahoma, through an NSF research award, has coupled a laser spectroscopy system to a tunable laser to create a device that can accurately and simultaneously measure carbon dioxide and nitric oxide levels of a single exhalation of breath.

The precise measurements provided by McCann's instrument might help doctors evaluate airway inflammation and prescribe medications with more accuracy, eliminating overmedication.

In diagnosing and treating asthma, physicians must assess how much air is actually flowing through a patient's airways, which is hampered by airway inflammation. Airway inflammation itself is most often assessed by physically invasive procedures. Earlier research found that asthmatics exhale more nitric oxide when their airways are inflamed, making measurement of its levels the preferred method to determine inflammation severity.

At present, nitric oxide levels are measured with devices that analyze chemiluminescence, a photochemical reaction between nitrogen and an ozone sample. Multiple tests are sometimes necessary. Also, chemiluminescence-based devices require periodic recalibration, whereas McCann's laser does not, the NSF said.

The device is currently undergoing clinical trials. His findings are published in two journals of the Optical Society of America: the October edition of Applied Optics and the Jan. 15 edition of Optics Letters.

For more information, visit: www.nsf.gov