Degree Type

Dissertation

Date of Award

1982

Degree Name

Doctor of Philosophy

Department

Chemical and Biological Engineering

Abstract

One of the major difficulties in identifying internal tissue structures with current ultrasonic methods if the lack of quantitative and complete retrieval of the acoustical parameters of tissue by a single technique. Therefore, a mathematical model representing the ultrasonic signal modification by a multilayered tissue mass has been developed to quantify the acoustical transfer function of tissue and characterize each tissue layer on the basis of three acoustical parameters;Two reflected signals from the near and far boundaries of each tissue layer were measured and analyzed by Fourier transform methods to obtain the magnitude ratio of the two signals (acoustical transfer function of each tissue layer). Linear regression on the resultant data and simple mathematical computation yield the tissue acoustical parameters: characteristic impedance, propagation, velocity, and amplitude attenuation coefficient;The results indicate that the proposed model is a valid representation of the acoustical transfer function of tissue for normal incidence of the ultrasonic waves since the acoustical parameters predicted by the proposed model agree with those found in the literature.

DOI

https://doi.org/10.31274/rtd-180813-7972

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Mohammad Jamil Mismar

Language

en

Proquest ID

AAI8307773

File Format

application/pdf

File Size

62 pages

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