Steady-state transfer function analysis of portions of the circulatory system using indicator dilution techniques

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Title Steady-state transfer function analysis of portions of the circulatory system using indicator dilution techniques
Publication Type thesis
School or College College of Engineering
Department Biomedical Engineering
Author Coulam, Craig Merrill
Date 1967-06
Description A digital computer program has been developed whereby the distribution of dye particle transit times across circulatory pathways can be found from recordings of upstream and downstream indicator dilution curves. This distribution, or transfer function is computed from Fourier series representations of the upstream and downstream indicator curves and makes possible, for the first time, the calculation of transit time distributions independent of the effects of recirculating dye. Since a discontinuity is introduced into the tails of the upstream and downstream curves at the end o£ the indicator sampling, the method requires an iterative approach in the termination of the upstream and downstream curves. The precision of the calculated distribution pattern is determined by comparison of the recorded downstream curve with the results of the convolution of the recorded upstream curve and computed transfer function. The effects of noise, bandwidth, sampling rate and aliasing have been investigated through the use of analog computer models of circulatory pathways. These studies show that the, transfer function description is limited to the bandwidth of the upstream (input) curve. Noise, or variations in magnitude and phase angle o£ input and output curve frequencies, and aliasing effects can introduce oscillations into the time-domain representation of the transfer function as does the use of too few harmonic terms. Two physiological studies are present which show the applicability of using the above method in the analysis of circulatory dispersion properties. The first study is concerned with the vascular responses (coronary, renal and systemic circuits) to the drugs adenosine triphos-phage, acetylcholine and angiotensin II, The second study shows the circulatory dispersion relationships which exist between lower extremity, renal and systemic circuits before, during and following moderate treadmill exercise. A third section of the thesis is devoted to the study of catheter-sampling distortion conditions and to the development of means of correcting for such. Transfer function relationships which describe catheter geometry configurations [bends and coils) and blood hematocrit effects are presented.""
Type Text
Publisher University of Utah
Subject Computers Modes; Circulatory Pathways
Subject MESH Automatic Data Processing; Blood; Oscillometry
Dissertation Institution University of Utah
Dissertation Name PhD
Language eng
Relation is Version of Digital reproduction of "A steady-state transfer function analysis of portions of the circulatory system using indicator dilution techniques". Spencer S. Eccles Health Sciences Library. Print version of "A steady-state transfer function analysis of portions of the circulatory system using indicator dilution techniques". available at J. Willard Marriott Library Special Collection
Rights Management © Craig Merrill Coulam.
Format application/pdf
Format Medium application/pdf
Format Extent 2,579,222 bytes
Identifier undthes,4403
Source Original: University of Utah Spencer S. Eccles Health Sciences Library (no longer available).
Funding/Fellowship Fellowship from the National Institutes of Health.
Master File Extent 2,579,269 bytes
ARK ark:/87278/s6x92d5z
Setname ir_etd
ID 191606
Reference URL https://collections.lib.utah.edu/ark:/87278/s6x92d5z
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