PROBLEM TO BE SOLVED: To provide a closed system extracorporeal circulation circuit capable of suppressing an extracorporeal circulation amount of blood that extracorporeally circulates as much as possible and also reliably catching an air bubble when the air bubble is mixed into the blood that extracorporeally circulates.SOLUTION: A closed system extracorporeal circulation circuit 100 includes: a blood removal line 1 a roller pump 4 an air bubble detection means 6 for detecting an air bubble in the blood removal line 1 an artificial lung 3 being the artificial lung 3 that performs gas exchange, having a first filter and a second filter, and allowing a portion between the first filter and the second filter to function as a flow passage for passing of blood a drainage line 9 communicating with the flow passage and draining a part of the blood a switching means 7 for switching the drainage line 9 between an opened state and a closed state a control means 10 having a function of controlling an actuation of the switching means 7, based on a detection result by the air bubble detection means 6 and a drainage storage container 8 for storing the blood that has flowed down through the opened drainage line 9.COPYRIGHT: (C)2013,JPO&INPIT【課題】体外循環する血液の体外循環量をできる限り抑制することができるとともに、体外循環する血液中に気泡が混入した際、その気泡を確実に捕捉することができる閉鎖系体外循環回路を提供すること。【解決手段】閉鎖系体外循環回路100は、脱血ライン1と、ローラポンプ4と、脱血ライン1内の気泡を検出する気泡検出手段6と、ガス交換を行なう人工肺3であって、第1のフィルタおよび第2のフィルタを有し、第1のフィルタと第2のフィルタとの間が血液が通過する流路として機能する人工肺3と、前記流路と連通し、血液の一部が排出され得る排液ライン9と、排液ライン9を開状態と閉状態とに切り換える切換え手段7と、気泡検出手段6による検出結果に基づいて、切換え手段7の作動を制御する機能を有する制御装置10と、開状態の排液ライン9を流下した血液が収納される排液収納容器8とを備える。【選択図】図1
