Date of Award
Summer 1989
Document Type
Thesis - Restricted
Degree Name
Master of Science (MS)
Department
Biomedical Engineering
First Advisor
Linehan, John, H.
Second Advisor
Dawson, Christopher A.
Third Advisor
Petrie, Thomas W.
Abstract
This thesis details the development of a computer model used for simulations of pulmonary arterial input impedance and other aspects of pulsatile pressure flow phenomena applicable to a study of cat lungs. Chapter 1 introduces the thesis and outlines the specific goals of the thesis. One goal is to show that an explicit computer model is able to simulate the pulmonary arterial input impedance spectrum of a cat lung. Another goal is to use the model to examine different aspects of pulse wave transmission through the lung and characterize the changes in the impedance spectra brought about by deviations· from the control or normal situation, examples of which are alterations in arterial mean pressure and vasoconstriction. Chapter 2 establishes the theory on which the computer model is built. This chapter describes the structure of the pulmonary vasculature and introduces the morphometric data which are used in the mathematical expressions for computing the hemodynamic resistance, vessel compliance and fluid inertance. Chapter 2 also explains two methods of determining the input impedance of the model, one based on the expressions derived as an extension of Womersley's analysis[1,2] of oscillatory flow in a long, uniform, rigid tube of circular cross-section, and the other from the simultaneous solution of the set of 48 differential equations used to characterize the deterministic model of the pulmonary vascular bed. Chapter 3 presents the results obtained by employing the model to simulate the pulmonary arterial input impedance spectrum. It includes a comparison of the two methods of impedance determination outlined in Chapter 2 and discusses the usefulness of each of these methods. Chapter 3 also documents the results pertaining to those aspects of pulsatile pressure-flow phenomena that influence the shape of the impedance spectrum. Specifically, pulse wave reflection and transmission aspects within the model are presented. In addition to the above control simulations, Chapter 3 also contains the results obtained when the model is subjected to the influence of a vasoconstrictor, alterations in arterial mean pressure and other deviations from the normal physiologic situation.
Recommended Citation
Rao, Sreesha S., "Analysis of the Pulmonary Arterial Input Impedance of a Computer Model of the Cat Lung" (1989). Master's Theses (1922-2009) Access restricted to Marquette Campus. 3904.
https://epublications.marquette.edu/theses/3904