PROBLEM TO BE SOLVED: To allow a large filter membrane area to function with a low blood filling level, enabling captured bubbles to be effectively discharged to the outside without allowing leakage of the primary side blood to the secondary side.SOLUTION: An artificial lung allows oxygen-containing gas to flow through hollow fiber membranes 12, and has a blood flow path 4 across the bundle of hollow fiber membranes. A filter 16 is inserted into a filter space 15 adjacent to the bundle of hollow fiber membranes, and an air exhaust port portion 17 is provided to allow the filter space to communicate with the outside space. The filter comprises a sheet-like filter medium 18 folded back into plural leaves, a membrane surface gap 21 is provided between each leaf, and a ridge gap 22 is provided between a pleat ridge 19 and an inner peripheral surface of the blood flow path. A peripheral edge portion of the sheet-like filter medium is in close contact with the inner peripheral surface of the blood flow path, and the filter space is separated into a primary side space 36 and a secondary side space 37. An air exhaust passage penetrating the sheet-like filter medium and communicating the membrane surface gap with the air exhaust port portion, is separated into a primary exhaust passage 40a in communication with the membrane surface gap of the primary side space and a secondary exhaust path 40b in communication with the membrane surface gap of the secondary side space.COPYRIGHT: (C)2015,JPO&INPIT【課題】低血液充填量で大フィルタ膜面積を機能させ、一次側血液を二次側に漏洩させることなく捕捉した気泡を効果的に外部に排出可能とする。【解決手段】中空糸膜12を通して酸素含有ガスが流通し、中空糸膜の束を横断する血液流路4を有する人工肺。中空糸膜の束に隣接するフィルタ空間15にフィルタ16が挿入され、フィルタ空間を外部空間と連通させる排気ポート部17が設けられる。フィルタは複数葉に折り返されたシート状濾材18からなり、各葉間に膜面間隙21を設け、プリーツ稜線19と血液流路内周面の間に稜線間隙22を設ける。シート状濾材の周縁部は、血液流路内周面に密着し、フィルタ空間が一次側空間36と二次側空間37に分離される。シート状濾材を貫通し膜面間隙と排気ポート部を連通させる排気路が、一次側空間の膜面間隙と連通する一次側排気路40aと、二次側空間の膜面間隙と連通する二次側排気路40bとに分離されている。【選択図】図15B
