title: Comparative study of two hand-held respirators.
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D001993:Bronchodilator Agents / Q000627:therapeutic use; D002245:Carbon Dioxide / Q000097:blood; D002404:Catheterization; D004562:Electrocardiography; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008171:Lung Diseases / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation; D011175:Positive-Pressure Respiration / Q000295:instrumentation*; D012129:Respiratory Function Tests; D012122:Ventilators, Mechanical
chemical_list: D001993:Bronchodilator Agents; D002245:Carbon Dioxide; D010100:Oxygen