title: THE MERITS OF OXYGEN, AIR, AND HELIUM AS SINGLE-BREATH INDICATORS OF NONUNIFORM DISTRIBUTION OF INSPIRED  GAS.
mesh_terms: D000388:Air; D035843:Biomedical Research; D006371:Helium; D006801:Humans; D009584:Nitrogen; D010100:Oxygen; D011656:Pulmonary Emphysema; D012129:Respiratory Function Tests
chemical_list: D006371:Helium; D009584:Nitrogen; D010100:Oxygen
keywords: AIR; CLINICAL RESEARCH; HELIUM; NITROGEN; OXYGEN; PULMONARY EMPHYSEMA; RESPIRATORY FUNCTION TESTS