title: Measurement of "closing volume": application and limitations.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006371:Helium; D006801:Humans; D008168:Lung / Q000502:physiology* / Q000503:physiopathology; D008173:Lung Diseases, Obstructive / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009584:Nitrogen; D012907:Smoking / Q000150:complications; D013147:Spirometry; D014978:Xenon
chemical_list: D006371:Helium; D014978:Xenon; D009584:Nitrogen