Resolution performance of Doppler ultrasound flowmeters

Abstract

Ultrasonic Doppler flowmeters can simultaneously obtain spatial and velocity distribution patterns of flow in a blood vessel. The factors fixing spatial and velocity resolution, however, must be determined if optimum utilization is to be realized. The parameters influencing spatial resolution are described in the literature, but velocity resolution has received relatively little attention. An attempt is made to show analytically how optimum velocity resolution can be derived with a simple mathematical model and experimental data to verify this theory is presented. A resolution product is offered which characterizes pulsed Doppler flowmeters. This product shows explicitly the necessary compromise between position and velocity resolution for a given instrument.