A laser that analyzes exhalations may aid in the diagnosis and treatment of asthma. Researchers at the University of Oklahoma have created a laser that can accurately and simultaneously measure both carbon dioxide and nitric oxide levels of a single exhalation. Earlier research indicated that asthmatics exhale more nitric oxide when their airways are inflamed; thus, high levels of nitric oxide in exhalations may be used to diagnose asthma. Presently, nitric oxide levels are measured with devices that analyze chemiluminescence, a photochemical reaction between nitrogen and an ozone sample, and multiple tests are sometimes necessary. The findings were published in Applied Optics.