| 摘要 |
<p>An angioplasty balloon catheter (10) particularly adapted for ablation of a stenosis in vivo has a balloon (12) which may be inflated with a conductive contrast fluid (20) injected proximally to the balloon, and is furthermore metallized (22) on the outside of the balloon and catheter shaft. The balloon has piezoelectric properties, and may be excited by application of an ultrasonic signal across the balloon between the metallized surface and the contrast fluid. The catheter is guided by a centrally located guide wire (16) to the site of the stenosis. If the distal tip of the catheter shaft cannot pass through the stenosis, excitation of the piezoelectric balloon in a deflated state at the site of the stenosis causes ultrasonic hammering vibrations at the tip of the catheter shaft which ablate the stenosis. After the tip of the catheter has hammered its way across the stenosis, and while maintaining the ultrasonic excitation signal, the balloon is inflated to keep the vibrating balloon surface in contact with the stenosis. Unlike the case with other inflatable balloon catheters which simply press the stenosis against the blood vessel wall, the stenosis is broken up by ultrasonic vibrations and is carried away by the blood flow, minimizing the risk of re-stenosis. <IMAGE></p> |
