Estimation of jet flow rate from Doppler proximal velocity acceleration: theoretical predictions from conformal mapping of inviscid flow fields

The influence of finite orifice size and nonplanar global geometry on the calculation of flow rate from color Doppler echocardiography is examined. To investigate these two effects conformal mapping is used to simulate inviscid flow fields. It is found that (1) a finite orifice causes flow rate underestimation, but this error is negligible when the radius is beyond three orifice radii; and (2) a funnel-shaped inlet zone causes flow to be proportional to the amount of a hemisphere subtended by the funnel. These predictions are consistent with findings from previous in vitro and clinical studies