Method:After setting the same MV and enflurane concentration in both circuits, the MV, Paw, circuit anesthetic concentration and the volume of reservoir were measured at different fresh flow rate.

• 方法：在两种麻醉机上分别设定相同分钟通气量(MV)及安氟醚浓度于不同新鲜气流量下测定MV、气道压力、回路内麻醉气体浓度及贮气囊气体量的变化。