Application of ultrasound Doppler technique for blood velocity evaluation

Abstract

One of the most important tasks in medicine – increase the quality of blood flow diagnostics. The purpose of this study is development of the application oriented blood flow evaluation methods, based on the ultrasound Doppler signal spectral analysis in real time. In this paper we analyse features of continuous (CW) and pulsed (PW) ultrasound waves Doppler techniques, present main functional electronic modules – hardware of realized instruments, design and characteristics of maked disc-ring Doppler transducers, technique of calculation blood flow evaluation (diagnostic) parameters and experimental Doppler sonograms. Optimal acoustic wave frequency was proposed and it can be applied for determination working frequencies of diagnostic instruments. Novel discreate spatial blood flow multipoint scatterers model developed for modelling new techniques for blood velocity evaluation and optimizing transducer characteristics. It is shown the disc-ring transducer generate in the axial direction quite narrow acoustic beam. In comparison with typical devices additional data for blood flow evaluation and analysis a nature of flow are obtained by visualisation instantaneous distribution (histogram) of amplitudes of Doppler signal spectral components. CW and PW Doppler instruments for evaluation peripheral blood velocities were designed and experimentally tested „in vivo“, they are using for further investigations and other purposes.