| 摘要 |
PURPOSE: To make it possible to percutaneously introduce a catheter introducer and indwelling needle with small resistance into the blood vessel without inflicting more than necessary flaws on the tissues. CONSTITUTION: A diametrally reducing step part 3 and a long circular part 4 which has the diameter increasing toward the base end from this step part until the outside diameter is restored are formed at the front end of an inside tube 1 which is an expanding tube (or inside needle). The front end of an outside tube 5 which is a sheath (or cannula) is put as the convergent circular conical front end 6 on the long circular conical part 4 in tight contact therewith. The front end edge 7 thereof is positioned within nearly the outside diameter of the diametrally reducing step part 3 to form the structure in which angular step parts do not exist. |
