The Zoom Wigner transform and its application to the analysis of blood velocity waveforms

The analysis of blood velocity using noninvasive Doppler ultrasound is now an important clinical technique. The paper discusses the application of the Wigner transform to the estimation of blood velocity from the Doppler signal. A new type of Wigner transform, the Zoom Wigner Transform or ZWT is developed. The ZWT has certain advantages over the standard Wigner transform, particularly in relation to the frequency resolution of specific components, these are discussed. The final section of the paper considers practical aspects of blood velocity estimation and illustrates the use of the WZT in relation to other methods.