Peak detector for resolution enhancement of ultrasonic visualization

Abstract

A digital electronic system for improving the resolution of dynamic range-handling capacity for received ultrasound in reflection or transmission imaging systems. This system provides a means for preventing loss of structural detail in the display by minimizing the overlapping of signals resulting from the transducer bandwidth and pulse length. It also makes use of a (positive or negative) peak detector to recognize and print as a single point the presence of point targets. With the present technology, a point target may be represented in a B-mode display on several successive scan lines resulting in an abnormally large representation on the display. The actual target is represented by the peak point of the envelope of a series of scan lines in which the point target is displayed. The objective is to print only one point which corresponds with the actual position of the point target with an intensity that corresponds to the intensity of the received signal. To accomplish this objective the received signal amplitudes are continually digitized and stored so that three successive lines of data can be compared. When a legitimate maximum is identified, a corresponding six-bit word is coupled to a PROM. Within the PROM are eight transfer functions, one of which is selected by a three-bit word address to the PROM and the selected function performs dynamic range compression of the received ultrasound. The four-bit PROM output couples first to a converter and from there to a suitable display means.