Some aspects of the relationship between instantaneous volumetric blood flow and continuous wave Doppler ultrasound recordings--III. The calculation of Doppler power spectra from mean velocity waveforms, and the results of processing these spectra with maximum, mean, and RMS frequency processors.

Abstract A method of predicting velocity profiles and hence Doppler relative power spectra (RPS) from mean volumetric flow waveforms using an extension of Womersley's theory is described. The effect on the RPS of using an ultrasound beam which is smaller than the blood vessel is calculated, and comparisons are made between RPS found in this way and experimental RPS measured in a dog model. Finally the effect of making ultrasonic Doppler measurements on complex velocity profiles with different combinations of processing technique and ultrasonic beam size are considered.