| 摘要 |
The present invention relates to a guidewire which comprises an elongated core of a substantially solid cross-section having a distal end portion, the distal end portion having a plurality of notches therein, the notches having a depth of 5-25% of the diameter of the proximal end. The proximal end of the guidewire has a diameter in the range of 0.005-0.040 inches, the notches defining a continuous helix with a constant depth. The guidewire also comprises a helically wound spring, the spring having a plurality of coils defining a lumen. At least part of the distal end portion of the elongated core being received within the lumen. That part of the distal end portion of the elongated core being received within the lumen forming with the helically wound spring an intermediate portion, at least a portion of the coils being disposed within the continuous helix of the elongated core, the helically wound spring being sized and positioned on the elongated core such that a smooth continuous outer diameter is attained over the length of the guidewire. The guidewire also has a means for bonding the coils to the distal end portion so that the guidewire has a continuous stiffness gradient along the length of the guidewire from a stiffest point at the proximal end to a more flexible portion in the distal end portion proximal to the intermediate portion, to a still more flexible portion in the intermediate portion to a most flexible point at the distal end of the helically wound spring. In an alternative embodiment the notches define a continuous helix with a constant depth. This alternative embodiment also has a rounded tip connected to the distal end of the spring and a safety wire connecting the distal end portion and the rounded tip.
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