Determination of the envelope function (maximum velocity curve) in Doppler ultrasound flow velocity diagrams

Abstract

This paper presents a new approach for the evaluation of Doppler flow velocity diagrams, obtained during brachial artery flow mediated dilatation (FMD) studies. The velocity diagrams are stored as image sequences on VCR tape. For this reason standard signal processing methods can not be used. A method for determination of blood velocity envelopes from image data is reported that uses Doppler-data specific heuristics to achieve high accuracy and robustness. The approach was tested in 40 Doppler blood flow images. Comparisons with manually defined independent standards demonstrated a very good correlation in determined peak velocity values (r = 0.993) and flow envelope areas (r = 0.996). The method is currently tested in a large volume clinical study.