PROBLEM TO BE SOLVED: To provide a catheter assembly which enables blood flashback to be continuously confirmed.SOLUTION: A catheter assembly 10 comprises a catheter 20 and an inner needle 30 which is detachably inserted into the catheter 20, a flow channel 14 in which blood can flow is formed between the catheter 20 and the inner needle 30. A distal end 21 of the catheter 20 comprises a tapered portion 22 which becomes tapered toward a distal end direction. The flow channel 14 comprises a first flow channel part 15 and a second flow channel part 16 which is continuous with a proximal end of the first flow channel part 15 and has a second flow channel cross sectional area larger than that of a first flow channel cross sectional area of the first flow channel part 15, on a distal end side of an axial intermediate part of the catheter 20 and on a proximal end side of the proximal end of the tapered portion 22.SELECTED DRAWING: Figure 2COPYRIGHT: (C)2020,JPO&INPIT【課題】血液のフラッシュバックを継続的に確認可能とするカテーテル組立体を提供する。【解決手段】カテーテル組立体１０は、カテーテル２０と、カテーテル２０内に離脱可能に挿入される内針３０と、を備え、カテーテル２０と内針３０の間に血液を流動可能な流路１４が形成されている。カテーテル２０の先端部２１には、先端方向に向かって先細りとなるテーパ部２２が設けられている。流路１４は、テーパ部２２の基端より基端側且つカテーテル２０の軸方向中間部よりも先端側において、第１流路部１５と、第１流路部１５の基端に連なり且つ第１流路部１５の第１流路断面積よりも大きな第２流路断面積を有する第２流路部１６と、を有する。【選択図】図２
