HIGH RESOLUTION PULSE ECHO ULTRASONIC DISPLAY SYSTEM

摘要

An improvement to a pulse-echo ultrasonic-imaging system employing an acoustic focusing device occupying a fixed aperture to both illuminate internal structure of a visually opaque object with a scanning focused beam of ultrasonic energy and for returning a reflected signal portion of the scanning focused beam passed therethrough for detection. The improvement makes it possible to employ a large numerical aperture spherical lens exhibiting aberration as the focusing device by utilizing a corrector plate. The corrector plate causes the lens to image a flat transducer in a flat image field. Were it not for the corrector plate, the lens aberration would provide an undesired curved image field. The improved system is suitable for displaying deep soft tissue of a living human being for a medical diagnostic purpose.