Patent ID: 8974446
Filing Date: 2015-03-10
Classification: A61B,A61N

Abstract:
1. An ablation apparatus comprising an ultrasonic transducer which includes: a piezoelectric element having a cylindrical shape with a longitudinal axis, an inner surface facing inwardly toward the longitudinal axis, and an outer surface facing outwardly away from the longitudinal axis, wherein the piezoelectric element is housed inside a bore formed within a tubular wall of a non-compliant and non-porous cap; a plurality of external electrodes disposed on the outer surface of the piezoelectric element; and at least one internal electrode disposed on the inner surface of the piezoelectric element; wherein the at least one internal electrode provides corresponding internal electrode portions that are disposed opposite the plurality of external electrodes with respect to the piezoelectric element, the external electrodes and the at least one internal electrode to be energized to apply an electric field across the piezoelectric element between the external electrodes and the corresponding internal electrode portions, so as to produce ultrasonic ablation zones extending from the energized external electrodes outwardly away from the longitudinal axis; and wherein the ultrasonic ablation zones of the external electrodes are distributed in a staggered configuration so as to span one or more open arc segments around the longitudinal axis, and the ultrasound ablation zones of all the external electrodes projected longitudinally onto any lateral plane which is perpendicular to the longitudinal axis span a substantially closed loop around the longitudinal axis.