DECONVOLUTION PROCESS IN MEASUREMENT OF ARTERIAL VELOCITY PROFILES VIA AN ULTRASONIC PULSED DOPPLER-VELOCIMETER FOR EVALUATION OF THE WALL SHEAR RATE

A numerically based simulation of pulsed Doppler ultrasound convolutio n and deconvolution of theoretical hemodynamic velocity profiles yield s two major conclusions on performing a deconvolution process. First, the most important parameter to be accounted for is the size of the sa mple volume. Second, a deconvolution process with an overestimated sam ple volume size is revealed by high-frequency noise on the resulting p rofile. A deconvolution process is presented for in vivo arterial velo city profiles, which has the advantage of being systematic and not nee ding experimental testing for determining the size or the shape of the sample volume. It is also independent of the observation angle. Final ly, an example of an application to in vivo human velocity profiles is given. Evaluation of the wall shear rate from the corrected deconvolv ed profiles shows a noticeable improvement with respect to that using the directly convolved Doppler profiles. (C) 1997 World Federation for Ultrasound in Medicine & Biology.