A dual transducer ultrasound system for quantitative Doppler measurements

The possibility of accurately measuring the velocity of blood flowing in human vessels represents a significant opportunity for hemodynamic research and diagnosis. The ultrasound (US) investigation represents a non invasive, diffuse and low cost method capable of evaluating the blood velocity by exploiting the Doppler effect. Unfortunately, the accuracy attainable with standard US equipment is heavily limited by the difficulty of assessing the Doppler angle during in-vivo investigations. In this paper a house-made US system for quantitative velocity measurements is presented. This system relies on an open, full digital architecture appositely designed for research purposes. In particular, the system capability of simultaneously controlling two US probes is shown suitable to implement a novel measurement method which overcomes the above Doppler angle ambiguity. The results of recent in-vitro experiments are reported, showing a velocity measurement accuracy of 0.5% and a precision of 7%.