Abstract :
This article describes how a device developed by engineers for engineering applications ¿ the ultrasonic transducer ¿ was slowly converted to medical research and application. Like the X ray, ultrasonics can penetrate the living body, and can be used for studying inner structures, with the advantage that it avoids the hazards of X radiation. The development of appropriate ultrasonic systems, many of whose problems parallel those encountered in early radiology, has brought ultrasonics to the point where it can be used almost routinely in the study of conditions in the eye, brain, heart, and abdomen.
