| 摘要 |
<p>A coil is located at the distal working end of an electrode catheter. The coil includes two parallel electrically conductive strips separated by a narrow gap. The strips are covered with insulation, and are connected respectively to electrical leads having opposite polarity. Electrodes are formed by removing portions of the insulation from the strips. The coil can be expanded to define an increased effective diameter at the working end of the catheter. An RF field produced along the helical path defined by the strips of the coil is unaffected by the expanded state of the coil. The energy from the RF field heats the surrounding venous tissue and causes a reduction in the diameter of the vein. The expanded coil mechanically prevents the vein from shrinking beyond the effective diameter defined by the expanded coil and the patency of the vein is maintained for venous function.</p> |
