Comparison of Estimation Strategies for the Determination of Blood Velocity Using Ultrasound

A number of estimation strategies for the determination of blood velocity have been proposed using narrowband and wideband transmitted signals. Traditional strategies include narrowband “doppler” based estimation techniques, and strategies involving the transmission of a wideband signal with the use of cross correlation for the velocity estimate. We compare the performance of these strategies with two new mixed time-frequency strategies which use both position and phase in order to estimate the blood velocity. The first new mixed estimation strategy utilizes a maximum likelihood estimator which is derived for a wideband periodic transmitted signal. The second new mixed estimation strategy is based upon the concept of cyclic correlation. In each case, results which have been derived previously are cited, and methods which have not been explored are presented in greater detail.