| 摘要 |
<p>An expandable atherectomy cutting device comprises a flexible blade (22) having one end connected to a torque tube (24) and the other end connected to a tip (32). The tip and torque tube are rotatably positioned about a guide wire (20), and the torque tube is coupled to a drive element for rotating the flexible blade about the guide wire. A mechanism is associated with the tip and torque tube for pulling the tip toward the torque tube to cause the flexible blade to bow outwardly away from the guide wire to expand its radius of cutting action. The mechanism for causing the flexible blade to bow outwardly includes a base rotatably mounted in slidable relation in the torque tube, and a series of desmodromic filaments (44) connected the base to the tip for pulling the tip toward the torque tube. The flexible blade includes a bend so that it bows outwardly rather than inwardly. The amount of expansion is controlled by a control element coupled to the drive element so that it can be controllably expanded through an infinite variety of positions within a continuous range, and further, can be expanded while the blade is rotating.</p> |
