Abstract

Color Doppler Ultrasound (CDUS) is a method of non-invasive fluid velocity measurement that is used for regular cardiac screenings as well as during complex surgeries such as valve replacements. A Color Doppler image is a contour map of the velocity field and can thereby indicate the presence of abnormal flows or be used to quantitatively measure velocities. CDUS is inexpensive and completely non-invasive. It is for these same reasons that CDUS has the potential to be a powerful tool not only in the medical field, but in the industrial and engineering research fields as well. While there are many devices that use ultrasonic transducers to determine either pipe-wall corrosion or mean flow rate, to date making accurate velocity measurements has required either a clear visualization section or an invasive form of measurement.

An experimental method to quantify the accuracy of Color Doppler Ultrasound velocity measurements in both the laminar and turbulent flow regime through a non-biological media is presented. A clear acrylic tube with a conical nozzle, throat, and a sudden expansion is used to generate a well characterized flow field that includes features typical of physiologic flows and flows within medical devices such as high speed jets and recirculation. The velocity field is measured at three locations using both Color Doppler Ultrasound and Particle Image Velocimetry (PIV) and the measurements are used to generate velocity profiles, which are compared quantitatively.

It was found that although it is possible to resolve phenomena such as recirculation and high speed jets, the media through which the imaging occurs has a significant impact on the accuracy of the Ultrasound generated velocity measurements. Due to the large amount of attenuation of sound through acrylic media, the Color Doppler readings show significant error in velocity measurements. For laminar parabolic flows this shifts both the mean and peak velocities down, with a percent difference in both as high as 42% and 55% respectively. However, at the sudden expansion where high speed jets and recirculation zones occur, the velocity profile becomes wider and flatter, and though the peak velocity measurements have a percent difference of approximately 50%, the percent difference in the mean velocity varied from less than 1% to a maximum of 10%.

Library of Congress Subject Headings

Doppler ultrasonography; Particle image velocimetry

Publication Date

5-2016

Document Type

Thesis

Student Type

Graduate

Degree Name

Mechanical Engineering (MS)

Department, Program, or Center

Mechanical Engineering (KGCOE)

Advisor

Steven Day

Advisor/Committee Member

Michael Schertzer

Advisor/Committee Member

Alexander Liberson

Comments

Physical copy available from RIT's Wallace Library at RC78.7.U4 A64 2016

Campus

RIT – Main Campus

Download

Share

COinS