Patent ID: 7192782

Claim:
A method for assessing human airway inflammation comprising steps of; collecting an orally exhaled human breath sample over an exhalation interval, wherein said orally exhaled human breath sample comprises orally exhaled NO and orally exhaled CO 2 ; providing a spectrometer including a spectrometer light source, a spectrometer gas sample cell, a spectrometer detector and a spectrometer computer; placing said orally exhaled human breath sample in said spectrometer gas sample cell; illuminating said orally exhaled human breath sample with a spectrometer light source; detecting a transmitted light beam which has passed through said orally exhaled human breath sample with said spectrometer detector to produce a signal sampling; generating a human breath sample spectrum from said signal sampling; analyzing said human breath sample spectrum using said spectrometer computer, said step of analyzing including identifying an absorption characteristic of orally exhaled NO and an absorption characteristic of orally exhaled CO 2 , determining an orally exhaled NO absorption intensity and an orally exhaled CO 2 absorption intensity, storing said orally exhaled NO absorption intensity and said orally exhaled CO 2 absorption intensity as a function of time over the exhalation interval; repeating said analyzing and generating to produce a series of gas mixture spectra, each spectrum having an absorption characteristic of the orally exhaled NO and the orally exhaled CO 2 ; identifying a single signal sampling interval wherein a known concentration CO 2 gas absorption which corresponds to an independently known CO 2 gas concentration and a simultaneous NO absorption occur; calculating a ratio of said simultaneous NO absorption intensity to said known concentration CO 2 gas absorption intensity and multiplying said ratio by a proportionality constant to obtain concentration of said orally exhaled NO thereby providing an assessment of human airway inflammation.