Figure 2. Flow dependence of exhaled NO.

Exhaled NO at three different flows (50 ml/s, 100 ml/s and 200 ml/s) in an asthmatic patient. This plot demonstrates the inverse relationship between the exhaled concentration of NO and the exhalation flow. Vex/Vaw is the airway volume turnover, where Vex is the exhaled volume, and Vaw is the subjects airway volume and is estimated in milliliters as the sum of the subjects ideal body weight in pounds plus age in years (Tsoukias et al., 2001).