Blood Viscosity


Book Description







Clinical Aspects of Blood Viscosity and Cell Deformability


Book Description

After many years of relative neglect, the importance of study of factors governing blood flow has at last achieved recognition; in this volume are documented many of the techniques, and the basic scientific and clinical observations, which have helped to open up understanding of this highly important aspect of human physiology and pathology in recent years. The text is logically divided into five sections beginning with blood cell deformability, then moving on to theoretical consideration of blood rheology, followed by accounts of the interrelationships between rheology, blood flow and vascular occlusion. The final two sections deal with blood rheology in clinical practice and therapeutic aspects of the study of blood flow. As regards blood cell deformability (Section A), the basic problem is set out by Kiesewetter and colleagues in the first paragraph of chapter 1 (p. 3), in which they point out that whereas human erythrocytes at rest have a diameter of approxi mately 7. 5 /-tm, nutritive capillaries have diameters ranging from 3-5 /-tm, and chapters in section A give an account of the ways in which the red cell can undergo deformation to permit capillary perfusion and the maintenance of the microcirculation.




Hemorheology in Practice


Book Description

Haemorheology is the study of how the blood, the blood cells and the vessels can function and interact as parts of the living organism. It is presented in this text as a sensitive tool for the recognition of the functional evidences and defects of blood flow.




Hemodynamical Flows


Book Description

This book surveys research results on the physical and mathematical modeling, as well as the numerical simulation of complex fluid and structural mechanical processes occurring in the human blood circulation system. Topics treated include continuum mechanical description; choice of suitable liquid and wall models; mathematical analysis of coupled models; numerical methods for flow simulation; parameter identification and model calibration; fluid-solid interaction; mathematical analysis of piping systems; particle transport in channels and pipes; artificial boundary conditions, and many more. The book was developed from lectures presented by the authors at the Oberwolfach Research Institute (MFO), in Oberwolfach-Walke, Germany, November, 2005.




Blood Viscosity and Shock


Book Description

The hemodynamic significance of the flow properties of blood was put into perspective only during the past decade. Advances in modern technologies today allow the quantitative analy sis of the fluidity of blood and its components under conditions approximating the flow in vivo, particularly those in the microcirculation. The hematocrit is the most important of the determinants of blood fluidity (reciprocal value of blood viscosity); acute increases in the hematocrit exert deleterious effects on circulation and oxygen transport owing to impaired fluidity of blood. High viscosity of plasma due to hyper- or dysproteinemias initiates the microcirculatory dysfunctions in hyperviscosity syndromes. Furthermore, the fluidity or deformability of red cells might be critically diminished and therefore cause redistribution of blood elements and adversely affect the resistance to flow within the microvessels. In low flow states blood fluidity most likely becomes the key determinant for microvessel perfu sion, overriding the neural and local metabolic control mechanisms operative at physiological conditions to adjust blood supply to tissue demand. Microcirculatory disturbances are there fore encountered whenever driving pressures are reduced, as in shock or hypotension, and distal to stenoses of macrovessels, but also in hemoconcentration due to plasma volume con traction, polycythemia, leukemia, and dysproteinemia. Based on experimental studies exploring the possibilities and limitations, with regard to improving the fluidity of blood by reducing the hematocrit, the concept of intentional hemo dilution has been introduced to clinical medicine.




Heart Perfusion, Energetics, and Ischemia


Book Description

The principal purpose of a NATO (North Atlantic Treaty Organization) Advanced Research Workshop, a part of the NATO Advanced Study Institutes Programme, is to: (a) exchange thoughts at the frontiers of knowledge or at the frontiers of two (or more) fields or sectors; (b) review and assess the state of the art; (c) formulate recommendations for future research directions; (d) formulate plans for large international scientific experiments. The aim of the ARW on "Microvascular, rheological, metabolic and heat-transfer aspects of the heart: relation to ischaemia and thrombosis", convened in Chateau de Bonas, July 4-11, 1982, was to describe functions and performance of the heart in an interdisciplin ary effort, involving cardiologists, pathologists, biochemists, haemorheologists, physiologists, pharmacologists and bioengineers; to explore interactions between such subfields as blood rheology, micro circulation and ischaemia of the myocardium, heat transfer, heat work and performance as a pump, effect of -metabolites and ion transfer, mechanism of sudden death, protein synthesis and protein molecular transformations. One of the purposes of the Convenor was to relate clinical haemorheology to the heart energetics and heart metabolism. This was only partly established, as difficulties of communications between different fields, difficulties of semantics and of specialized out looks could not be overcome within a -few days. Nevertheless, a gate was opened for communications interchange in the future. There was even a problem within each specialty, and as is rather common, quite diverse views have been expressed. This, of course, is quite normal in the progress of science.




Clinical Blood Rheology


Book Description

Published in 1988: Study of blood flow properties (rheology) has attracted growing interest from clinicians in recent years. A United Kingdom meeting and a European meeting in 1979 resulted in previous publications summarizing the literature up to that time.




Theoretical and Applied Mechanics


Book Description

The Thirteenth International Congress of Theoretical and Applied Mechanics was held in Moscow from Monday, 21 August, to Saturday, 26 August 1972. About 2500 participants from 37 countries all over the world attended the congress that was convened by the Congress Committee of the International Union of Theoretical and Applied Mechanics. The local or ganization lay in the hands of the Organizing Committee, established by the USSR National Committee on Theoretical and Applied Mechanics. The USSR Academy of Sciences rendered partial financial help to the organization of th8 congress. The Organizing Committee was assisted by the Institute of Problems of Mechanics of the USSR Academy of Sciences, by the Research Institute for Mechanics of Moscow University, and by the Computing Center and the Institute of Applied Mathematics of the USSR Academy of Sciences. The Bureau of IUTAM had allocated a considerable sum for partial financial support of young scientists attending the congress. The Thirteenth Congress was officially opened on Monday morning at the Kremlin Palace of Congresses by Academician N. 1. Muskhelishvili, President of the Congress, and Professor W. T. Koiter, President of IUTAM. Greeting addresses were offered by: Mr. K. N. Rudnev, Minister, member of the Council of Ministers of the USSR, Academician M. V. Keldysh, President of the USSR Academy of Sciences, Mr. L. N.