A two-dimensional Doppler ultrasonic probe for flow measurement.

The use of a single-transducer pulsed-Doppler ultrasound system in clinical practice has been severely limited, not only by the effects of acoustics and physiologic parameters, but also by inaccuracy because the Doppler angle between the transducer axis and the flow velocity is unknown. In this study, a dual-transducer pulsed-Doppler ultrasound system was used because the Doppler angle could be directly calculated for more accurate determination of the fluid flow velocity vector. From the velocity estimate and velocity profiles, other flow characteristics such as volume flow rates and shear stress can also be estimated. Experimental results indicated that the new transducer model could increase the accuracy of fluid flow velocity measurement and thereby improve the ability to estimate the characteristics of turbulent fluid flow for research and diagnostic purposes.