Medical Biomathematics and Biometrics Commons^™

Development Of A Mathematical Model Of Renal Function For Clinical Application, Barbara A. Holshouser

Loma Linda University Electronic Theses, Dissertations & Projects

This model describes the orthoiodohippurate (OIH) distribution and clearance in the renovascular system. The model is described by five compartments: the blood, left and right kidneys, bladder and the red blood cell compartment. Data for these compartments, except the RBC compartment, are collected with scintillation detectors monitoring OIH tagged with 1-131 as the radiopharmaceutical passes through each compartment. Time/ activity curves are plotted for the data and used as inputs to the model parameter estimation routine. The compartments are described by a set of first order ordinary differential equations solved using the Adam's methods. For parameter estimation, an iterative predictor-corrector …

The Coronary Distribution Zone : Mathematical Modelling Of The Left Ventricular Epicardial Surface For Area Calculation, Three-Dimensional Rotaton And Display, S. Matts E. Sjölander

Loma Linda University Electronic Theses, Dissertations & Projects

A computer model of the left ventricular (LV) epicardial surface was developed from Jang’s truncated ellipsoidal model, which has a minor to major axis ratio of 6:10. The model was applied in calculating the area of a segment of the myocardium, jeopardized by an impending occlusion of its associated artery. The endangered segment of the LV muscle was also visualized in different projections by rotations in three space and graphical displays simulating the three dimensions.

The area formula for the surface of the ideal model , a truncated prolate spheroid, was derived and used in producing maps for manual calculations …

Distribution Of Maternal And Fetal Blood Flow Within Cotyledons Of The Sheep Placenta, Gordon G. Power, P. Steven Dale, Paul S. Nelson

Loma Linda University Electronic Theses, Dissertations & Projects

These studies explore the distribution of blood flow among small samples of placental tissue. Labeled microspheres (14 ± 1 pm) were Injected Into the left ventricle of six un-anesthetized ewes and Into the jugular vein of the fetus In utero. A total of 3,576 samples weighing 31. +11. (S.D.) mg were taken from seventeen cotyledons and counted for flow labels. Maternal and fetal flow within the cotyledons were both normally distributed with standard deviations of 44%. The maternal/ fetal flow ratio was less than 0.5 In 9% of the cotyledon, between 0.5 and 1.5 In 70%, and greater than 1.5 …

Computer Modeling Of Cardiac Electrical Activity By Polarcardiogram Patterns, Daniel K. Berry

Loma Linda University Electronic Theses, Dissertations & Projects

The objective of this thesis is to provide for the cardiologist polarcardiograms and additional diagnostic criteria which will enable him to diagnose heart disease more easily. Other contributions are those of: (a) providing a system of data acquisition and (b) analyzing Dr. Gordon Dower’s criteria for myocardial infarction using the programs provided in this thesis.

The problem inherent in the reading of a polarcardiogram is the identification of the "loop" patterns with the associated heart disease. This can be accomplished by reading and interpreting both vectorcardiograms and electrocardiograms as well as angiograms, then relating the interpretation to the polarcardiogram patterns. …

Computer Assisted Electron Spin Resonance Spectral Analysis Of Trapped Radicals, Philip Mook Wah Law

Loma Linda University Electronic Theses, Dissertations & Projects

A set of general purpose FORTRAN IV programs have been written during this study to assist in the analysis of complex spectra. An interactive approach is adopted, utilizing the computer and graphics terminals of the Scientific Computation Facility at Loma Linda University. Some procedures carried out are inversion, coordinates scaling, smoothing, differentiation and integration, correction for slanting baseline, addition and subtraction, and spectral simulation.

As an application, the programs are used to assist in the study of free radicals in gamma-irradiated single crystals of 1,2,3,- benzene tricarboxylic acid dihydrate by electron spin resonance spectroscopy. Is is found that the predominant …

Mathematical Model Of Placental Oxygen And Carbon Dioxide Exchange, Ester P. Hill

Loma Linda University Electronic Theses, Dissertations & Projects

This model of placental CO₂ and O₂ exchange calculates the time course of changes in P_^CO2, [HCO₃^-], and [H⁺] in each of four "compartments" of placental exchange vessels: maternal erythrocytes, maternal plasma, fetal plasma and fetal erythrocytes. The changes in hemoglobin-bound CO₂ (carbamate) and oxyhemoglobin contents within the erythrocytes are also calculated, permitting consideration of the Haldane and Bohr effects. Equations were written to represent one-dimensional steady state CO₂ and O₂ diffusion between concurrent maternal and fetal capillaries and the subsequent hydration, carbamino and oxyhemoglobin reactions. The equations …