A method and apparatus for automated detection of a general, non-sinusoidal type of periodicity in ultrasound Doppler signals from pulsatile blood flow is described. The method computes a pulsation index, which is a sum of the normalized powers of the fundamental and several harmonic components in the frequency spectrum of the banded Doppler signal. A weighting function may be applied to the power from each harmonic component in order to suppress contributions due to spurious peaks, as in the case when pulsatile flow is absent.
