| 摘要 |
<p>A shielded tip catheter (10, 12) for use with a pulsed energy source (14) for fracturing deposits such as urinary and biliary stones and atherosclerotic plaque in the human body is disclosed. The flexible catheter (10) has a shielded tip structure (12) which is adapted for insertion through a fluid passage in a living body. The tip structure (12) can contain an impact element (30), a scraping implement (52) or a cutting implement (54). An energy source (14) creates repeated rapid vapor expansions adjacent the element (32) causing it (30) to undergo repeated pulse like movements, imparting a series of high-velocity impulses to an adjacent deposit, thereby fracturing or cutting it. The energy source (14) can be a laser with a fiber optic delivery system (24) in the catheter (10) terminating adjacent the impact element (30), or a spark generator (14) with a conductor (24) within the catheter (10) to deliver a fluid vaporizing spark (28) adjacent the element (30).</p> |
