ACOUSTIC IMAGING WITH THIN ANNULAR APERTURES.

Abstract

It was shown in a previous analysis that a mosaic of piezoelectric acoustic detectors would be sensitive enough to image tissue structures deep within the body and would be able to resolve details as small as one millimeter. A method is discussed here for achieving the effect of a full piezoelectric aperture without having to build one. The basic idea is to measure the amplitude and phase of a wavefront on the annulus bounding an aperture, and to use these measurements to produce an image of the object producing that wavefront. The theory of imaging with thin annular apertures is discussed, the experimental implementation is described, and the resulting images are presented.