A Range-Doppler Flowmeter for Imaging of Blood Velocity Profiles in Arteries

Abstract

Range-Doppler detection in a pulsed ultrasound flowmeter has been performed using a SAW-CZT spectrum analyzer, providing adequate speed for realtime sequential Doppler analysis in a large number of range cells. In vitro experiments using a prototype 32 range cell system, first presented at the 1983 Symposium, demonstrated the capability of providing the instantaneous flow velocity profiles across a vessel. Recent work is reported, directed to make the system clinically experimentable in vivo. Impressive real-time images of blood flow profiles in fimjor human vessels have been obtained. D oppler signal output at 3 MHz rate from the SAW-CZT spectrum analyzer has been digitally processed to extract the mean velocity for each range cell. A microprocessor has been used to estimate the dynamic evolution of blood flow in detail.