| 主权项 |
1. A stent delivery system, comprising:
a core member having an intermediate portion and an elongate, spiral-cut tube extending proximally of the intermediate portion, the tube having first and second flex zones, the second flex zone being proximal of the first flex zone, and a transition zone between the first and second flex zones; the first flex zone having a bending stiffness of less than 12 N*mm̂2 so as to be navigable through the internal carotid artery bifurcation, the spiral cut of the tube in the first flex zone having a first pitch; the second flex zone having a bending stiffness of greater than 60 N*mm̂2, the spiral cut of the tube in the second flex zone having a second pitch different from the first pitch; wherein the spiral cut of the tube in the transition zone changes from the first pitch to the second pitch in a series of pitch transitions, the spiral cut pitch in the transition zone increasing by an overall percent increase from the first pitch to the second pitch, such that the average overall percent increase achieved per transition is 15% or less; and a stent carried by the intermediate portion. |
