Theoretical investigation of effects of flow oscillations on ultrasound Doppler velocity measurements

Effects of flow oscillations on spectrum of Ultrasound Doppler Velocimetry (UDV) signals were investigated theoretically and numerically. A laminar pipe flow with a superimposed oscillating component was considered. Negative impact of oscillation on the ultrasound signal hence on the flow images was observed in the form of spreading of spectral ultrasound signal energy around mean component, leading to image artifacts. Both analytical and numerical results revealed the strong effect of a group of parameters including Doppler frequency, flow oscillation amplitude and frequency. Exceeding a particular value of the group, 1.45, resulted in artifacts in the flow images. Revealing the mechanisms involved in the deteriorations associated with the flow oscillations is potentially useful in UDV studies involving random flow fluctuations such as turbulence.

► Effects of flow oscillations on Ultrasound Doppler Velocimetry are investigated. ► Oscillations lead to spreading of spectral signal energy around mean component. ► A group of flow and UDV parameters plays a critical role on the measurement quality. ► At high frequencies and low amplitudes of flow oscillation signal quality increases.