SINGLE ELEMENT ULTRASONIC COLLIMATING TRANSDUCERS AND A METHOD AND APPARATUS UTILIZING ULTRASONIC TRANSDUCERS IN 3D TOMOGRAPHY

摘要

A single element resonant or wideband collimating ultrasound piezotransducer with and without electronic scanning capabilities, which can be electronically optimized for far or near field imaging. In a resonant implementation, a plurality of concentric ring electrodes (further subdivided into segments to provide electronic scanning capability) are provided on both surfaces of the piezoelement. In the alternative implementation a plurality of sector shaped electrodes is placed on the front and back surface of non-homogeneously polarized piezoelement. The geometry of the electrodes is determined by calculation of pressure distribution on the working surface of the piezoelement which maximizes specific optimization criterion. Similarly, polarization vector in non-uniformly polarized element is calculated to maximize specific optimization criterion. In a wide band implementation the body of the piezoelement forms an acoustic trap. The plurality of electrodes of various geometries on working and side surfaces of the piezoelement provide collimating and electronic scanning capabilities.