| abstract |
An ultrasonic catheter (8) comprises a coaxial cable of electrical conductors (10, 12) with a piezoelectric element (16) at its distal end. The piezoelectric element (16) is shaped, and disposed according to the desired ultrasonic field. When an electrical signal is connected to the conductors (10, 12) the piezoelectric element (16) generates ultrasonic energy. An alternative embodiment is a hollow tubular polymeric catheter (30) with a cylindrical piezoelectric element (36) at its distal end connected to conductors (32, 34) running the length of the catheter (30). The piezoelectric cylinder (36) may be tapered, segmented, or shortened according to the desired focusing of the ultrasonic field. In either embodiment the catheter is threaded through a patient's vasculature, and brought in close proximity to a vascular occlusion. Thrombolytic agents are released from the ultrasonic catheter or a second catheter in close proximity. These agents, and the ultrasonic energy result in breakup of the occlusion through sono-phoresis. |