eFigure 25-15.

Inspiratory occlusion pressure at 100 msec (0.1 second) in response to hypercapnia.

Each curve is the mean regression of mouth pressure at 0.1 second against Pco₂ for one subject. Inspiratory occlusion pressure may be used to measure the output of the respiratory center in response not only to hypercapnia, but also to hypoxia, exercise, and other factors.

(Modified from Whitelaw WA, Dernne J, Milic-Emili J: Occlusion pressure as a measure of respiratory center output in conscious man. Respir Physiol 23:181–199, 1975.)