Expiratory flow rate and closing volumes.
D000328:Adult; D000403:Airway Resistance; D006371:Helium; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000175:diagnosis; D009584:Nitrogen; D012123:Pulmonary Ventilation; D012119:Respiration; D012907:Smoking; D013147:Spirometry; D014797:Vital Capacity
D006371:Helium; D009584:Nitrogen