Objective : To discuss the difference of vital capacity ( VC ), expiratory reserve volume ( ERV ) and inspiratory capacity ( IC ) in chronic obstructive pulmonary disease ( COPD ) patients and the normal subjects after breathing helium-oxygen mixtures ( heliox ). 目的探讨慢性阻塞性肺病(COPD)患者呼吸氦氧混合气(He-O2)后肺活量(VC)及其组成补呼气容积(ERV)和深吸气量(IC)的变化与健康人的差异。