| 摘要 |
<p>A steerable guidewire has an elongate main wire (10) having a tapered distal portion (12A) and a helical coil (16) mounted about the distal portion. The distal end (12) of the coil extends beyond the distal tip (14) of the tapered distal portion of the main wire. An inner helical coil (22) is disposed within the outer coil is secured at its proximal end (24) to the distal tip of the tapered distal portion of the main wire and at its distal end to the distal end of the outer coil. The device does not have a separate safety wire, the inner coil serving as the sole safety connection between the main wire and the outer coil. The omission of the conventional safety wire and the use of the dual coil construction provides a tip which is equally flexible in all directions. Gradual selected transitions in stiffness may be achieved by varying the spacing of the individual turns of the inner and outer coils. The guidewire also provides for a change in the radiopacity of the distal portion of the guidewire to provide a more radiopaque segment at the distal portion than at the more proximal portions by forming the inner coil from a more radiopaque material than the outer coil.</p> |
