| 摘要 |
A catheter having a shaft with at least two variable layers, in which the relative proportions of the two layers changes along at least a part of the multilayered shaft section. The catheter shaft includes a cotapered transition section having a first layer tapering to a decreased thickness, and a second layer inversely tapering to an increased thickness. In one embodiment, the shaft has one or more tapered outer and/or inner surfaces in addition to the cotapered transition. The tapered outer or inner surface of the shaft is typically longitudinally displaced from the cotapered transition section, and the shaft having a cotapered transition section is coextruded. The shaft of the invention provides improved transitions between shaft sections, to thereby change characteristics such as the shaft stiffness along the length of the catheter. |
