From the School of Respiratory Therapy (MYB, CHS, YLY, KJB, JHW), Department of Physiology (YSL), Biostatistics and Research Consultion Center (HWL), and Division of Pulmonary Medicine (MYB, CHS), Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan; Division of Pulmonary Medicine (MYB, KJB), Department of Internal Medicine, Wan Fang Hospital, Taipei, Taiwan; Department of Respiratory Therapy (JHW), Taipei Veterans General Hospital, Taipei, Taiwan; and Institutes of Physiology and Emergency and Critical Care Medicine (TRK), National Yang-Ming University, Taipei, Taiwan.