| 摘要 |
<p>Ultrasonic apparatus for clot dissolution and plaque ablation includes a radiator (44, 144) for coupling ultrasonic waves into plaque and a piezoelectric crystal (24), connected with said radiator means (44, 144), for the intravascular generation of ultrasonic waves; said ultrasonic waves being propagated along a longitudinal axis of said piezoelectric crystal means (24) and having an inertial node position within said piezoelectric crystal means (24). The piezoelectric crystal (24) is constructed in order to prevent significant power loss caused by a shifting of the inertial node of the generated ultrasonic waves to a position exterior to said piezoelectric crystal (24) due to loading of the radiator means (44, 144) caused by the coupling of ultrasonic waves into the clot or plaque.</p> |
