[Use of acoustic rhinometry for determining segmental airway geometry with nasal positive or negative pressure].

The investigations show an application of nasal acoustic rhinometry for determination of segmental naso- and oropharyngeal airway cross-section during negative or positive pressure breathing. The investigations show in 16 patients with obstructive sleep apnoea (AI = 21.5), that negative pressure produces a segmentally different reduction of naso-oropharyngeal cross-section which is weakly correlated to the Broca index. But the amount of cross-sectional reduction is highly significantly correlated to the apnoea index (r = 0.64). The functional relationship between pressure load of the airways during wakefulness and the severe nature of the disease reveals the possibility of diagnostic use.