Spectral analysis of Doppler blood flow velocity measurements.

This study investigates the performance of a parametric method, based on linear prediction analysis, of representing the information in ultrasonic Doppler blood velocity spectra. Previous signal processing applications suggest that this method offers the advantage of characterizing the velocity spectrum in terms of a few meaningful parameters instead of the large number of discrete frequency points required by traditional Fourier analysis. In addition, the method offers increased computational speed, improved frequency resolution, and reduced sensitivity to noise. In this study, the audio output signal of a pulsed Fourier and parametric methods, and the spectra are compared. The parametric method is shown to capable of representing the time course of the Doppler spectrum in terms of just a few numbers. This parametric representation permits simple, flexible display, easy elimination of low frequency 'wall thump' artifacts, and compact storage. (A)