(a) Identification. A breath nitric oxide test system is a device intended to measure fractional nitric oxide in human breath. Measurement of changes in fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to anti-inflammatory therapy, as an adjunct to established clinical and laboratory assessments of asthma. A breath nitric oxide test system combines chemiluminescence detection of nitric oxide with a pneumotachograph, display, and dedicated software.

(b) Classification. Class II (special controls). The special control is FDA's guidance entitled “Class II Special Controls Guidance Document: Breath Nitric Oxide Test System.” See § 862.1(d) for the availability of this guidance document.