Ultrasound in Medicine and Biology
Volume 32, Issue 10, October 2006, Pages 1545-1555
Reliable CFD-based estimation of flow rate in haemodynamics measures
Ponzini, R., Vergara, C., Redaelli, A., Veneziani, A.
Physically useful measures in current clinical practice refer often to the blood flow rate, that is related to the mean velocity. However, the direct measurement of the latter is currently not possible using a Doppler velocimetry technique. Therefore, the usual approach to calculate the flow rate with this technique consists in measuring the maximum velocity and in estimating the mean velocity, making the hypothesis of parabolic profile that in realistic situations results in strongly inaccurate estimates. In this paper, we propose a different way for estimating the flow rate regarded as a function of maximum velocity and Womersley number. This relation is obtained by fixing a parametrised representation and by evaluating the parameters by means of a least-square approach working on the numerical results of CFD simulations (about 200). Numerical simulations are carried out by prescribing the flow rate, not the velocity profile. In this way, no bias is implicitly induced in prescribing boundary conditions. Validation tests based on numerical simulations show that the proposed relation improves the flow rate estimation.
Computational Fluid Dynamics; Doppler technique; Flow rate boundary conditions; Flow rate estimation; Womersley number
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