Download or read book A Computational Stress Deformation Analysis of Arterial Wall Tissue written by Ryan Taylor Krone and published by . This book was released on 2010 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the mechanical behavior of arterial walls under various physiological loading and boundary conditions is essential for achieving the following: (1) improved therapeutics that are based on mechanical procedures (e.g. arterial segmenting and suturing), (2) study of mechanical factors that may trigger the onset of arterial aneurysms (i.e. focal blood-filled dilatation of the vessel wall caused by disease) and (3) investigations on tissue variations due to health, age, hypertension and atherosclerosis, all of which hold immense clinical relevance. In general, the physiological conditions on an any arterial segment can include axial stretch, torsional twist and transmural (internal, radial) pressure which often provoke large wall-tissue deformations that require theories of continuum hyperelasticity. Further, the presence of collagen fibers throughout the two structural layers (media, adventitia) of the arterial wall require anisotropic strain energy functions for more histological accurate models. Nonlinear computational methods are therefore essential for this class of boundary-value-problems (BVPs) which often do not contain closed-form solutions. We begin by modeling the arterial vessel wall as a thin sheet in the form of a circular cylinder in the reference configuration. We seek to employ a bio-type strain energy function on this constitutive framework to investigate the onset of non-linear instabilities in a thin-walled, hyperelastic tube under (remote) axial stretch and internal pressure. Viscoelastic effects are also considered in this model. We then build to investigating the effects of various combinations of axial stretch and transmural pressure on the global deformation and through-thickness stress and strain fields of an arterial segment modeled as a two-layer, fiber-reinforced composite and idealized as a thick-walled cylinder in the reference configuration. We further consider (in both models) the presence of local tissue lesions, or portions of the arterial wall having either stiffer (i.e. thrombosis or scar tissue) or softer (i.e. diseased tissue) material characteristics, relative to the surrounding tissue. We account for this by appropriately scaling the elastic constants of the strain energy functions for regions with a lesion and without. For the three-dimensional model, we employ the strain energy function of Holzapfel et al. which has been modified by constraints on the principal invariants by Balzani et al. in order to ensure material polyconvexity. We choose a particular vessel, the human common carotid (HCC) artery, with appropriate geometric and material properties found from various experimentally-based studies (e.g. Fung et al.). We focus on distinct elastic constants for each layer (media, adventitia) that have been obtained through biaxial (i.e. not simply uniaxial data - reasons for this are discussed later) testing of in vitro HCC arteries. The loading conditions are combinations of axial extension and transmural pressure, in the presence and absence of material lesions. The loading is consistent with in vivo conditions on a general segment of the vessel wall. We find that as a two-dimensional surface, the overall deformation from internal pressure (i.e. the bulge) depends on the magnitude and, more importantly, the rate of axial stretch and transmural pressure, the elastic material parameters of the bio-strain energy function, and of course local inhomogeneities in the material description of the tissue. When modeled as a three-dimensional solid undergoing pure axial stretch, the majority of the stress is in the medial tissue, which displays a significant gradient in the axial direction, whereas the stress in the adventitia is constant throughout the length of the vessel. For supra-physiological pressures (i.e. 20-30 kPa, or about 50% higher than in vivo conditions) the adventitia contributes to the load sharing and the gradient in the medial layer evens out. For narrow (2% of the length), stiff (100x stiffer than surrounding tissue), ring-like lesions under the same pressures and axial stretch, the overall vessel deformation is considerably smaller in the radial direction. The overall segment shape is stabilized by this type of material abnormality. For local spot-like stiff (100x stiffer than surrounding tissue) lesions, the deformation leads to an inward bulge (i.e. a clot) that will likely affect fluid flow characteristics, hence growth and remodeling of the tissue at the wall. For these loading conditions, when the spot-like and ring-like lesions are approximately two-times softer than the surrounding tissue, no significant differences appear in the stress and strain fields.

Download or read book Cardiovascular Soft Tissue Mechanics written by Stephen C. Cowin and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: This special volume of the Journal of Elasticity represents the first in a new p- gram dedicated to the occasional publication of collections of invited, reviewed papers of topical interest. The purpose of this program is to spotlight the dev- opments and applications in the mechanics of materials within specific areas that can enhance growth and provide insight for the advancement of the field as well as promote fundamental understanding and basic discovery. Soft Tissue Mechanics is an area of biomechanics that draws heavily upon f- damental ideas and material models from nonlinear elasticity and viscoelasticity. A major goal of this research is to understand those mechanics properties of heart, artery, collagen and skeletal muscle tissue that can be used for the diagnosis of health problems and the improvement of human life. This volume illustrates how experiment, modeling and computation is currently employed in this emerging field. May 2001 ROGER FOSDICK Editor-in-Chief Journal of Elasticity 61: ix–xii, 2000. ix Preface There are two primary areas for the application of elasticity in the biomechanics of tissues: hard tissue mechanics (e.g., bone, teeth, horns, etc.) and soft tissue - chanics (e.g., skin, tendons, arteries, etc.). The distinguishing feature between these tissue types is the amount of physiological “normal” deformation they experience. While “hard” tissues only experience small deformations, soft tissues typically experience large deformations. From a biomechanics viewpoint soft tissues fall within the realm of finite elasticity.

Download or read book Structure Based Mechanics of Tissues and Organs written by Ghassan S. Kassab and published by Springer. This book was released on 2016-01-28 with total page 491 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book portrays the commonality of tissue micro-structure that dictates physiological function in various organs (microstructure-function relation). Tissue and organ models are used to illustrate physiological functions based on microstructure. Fiber scale properties such as orientation and crimp are described in detail. Structurally-based constitutive models are given throughout the book, not only to avoid ambiguities in material characterization, but also to offer insights into the function, structure, and mechanics of tissue components. A statement of future directions of the field is also given, including how advancements, such as state-of-the-art computational modeling and optical measurements of tissue/cells structures, are taking structure-based modeling to the next level. This book also: Provides a comprehensive view of tissue modeling across multiple systems Broadens readers’ understanding of state-of-the-art computational modeling and optical measurements of tissue/cells structures Describes in detail fiber scale properties such as orientation and crimp

Download or read book Nonlinear Elasticity written by Y. B. Fu and published by Cambridge University Press. This book was released on 2001-05-07 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive introduction to nonlinear elasticity for graduates and researchers, covering new developments in the field.

Download or read book Biomechanical Modelling at the Molecular Cellular and Tissue Levels written by Gerhard A. Holzapfel and published by Springer Science & Business Media. This book was released on 2009-06-05 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computational Modeling for Assessing Coronary Artery Pathophysiology written by Christos Bourantas and published by Frontiers Media SA. This book was released on 2022-09-27 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computational Hemodynamics Theory Modelling and Applications written by Jiyuan Tu and published by Springer. This book was released on 2015-02-24 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses geometric and mathematical models that can be used to study fluid and structural mechanics in the cardiovascular system. Where traditional research methodologies in the human cardiovascular system are challenging due to its invasive nature, several recent advances in medical imaging and computational fluid and solid mechanics modelling now provide new and exciting research opportunities. This emerging field of study is multi-disciplinary, involving numerical methods, computational science, fluid and structural mechanics, and biomedical engineering. Certainly any new student or researcher in this field may feel overwhelmed by the wide range of disciplines that need to be understood. This unique book is one of the first to bring together knowledge from multiple disciplines, providing a starting point to each of the individual disciplines involved, attempting to ease the steep learning curve. This book presents elementary knowledge on the physiology of the cardiovascular system; basic knowledge and techniques on reconstructing geometric models from medical imaging; mathematics that describe fluid and structural mechanics, and corresponding numerical/computational methods to solve its equations and problems. Many practical examples and case studies are presented to reinforce best practice guidelines for setting high quality computational models and simulations. These examples contain a large number of images for visualization, to explain cardiovascular physiological functions and disease. The reader is then exposed to some of the latest research activities through a summary of breakthrough research models, findings, and techniques. The book’s approach is aimed at students and researchers entering this field from engineering, applied mathematics, biotechnology or medicine, wishing to engage in this emerging and exciting field of computational hemodynamics modelling.

Download or read book Computational Modeling in Biomechanics written by Suvranu De and published by Springer Science & Business Media. This book was released on 2010-03-10 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: Availability of advanced computational technology has fundamentally altered the investigative paradigm in the field of biomechanics. Armed with sophisticated computational tools, researchers are seeking answers to fundamental questions by exploring complex biomechanical phenomena at the molecular, cellular, tissue and organ levels. The computational armamentarium includes such diverse tools as the ab initio quantum mechanical and molecular dynamics methods at the atomistic scales and the finite element, boundary element, meshfree as well as immersed boundary and lattice-Boltzmann methods at the continuum scales. Multiscale methods that link various scales are also being developed. While most applications require forward analysis, e.g., finding deformations and stresses as a result of loading, others involve determination of constitutive parameters based on tissue imaging and inverse analysis. This book provides a glimpse of the diverse and important roles that modern computational technology is playing in various areas of biomechanics including biofluids and mass transfer, cardiovascular mechanics, musculoskeletal mechanics, soft tissue mechanics, and biomolecular mechanics.

Download or read book Nonlinear Solid Mechanics written by Gerhard A. Holzapfel and published by . This book was released on 2000-04-06 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a modern and comprehensive coverage of continuum mechanics, this volume includes information on "variational principles"--Significant, as this is the only method by which such material is actually utilized in engineering practice.

Download or read book Multiscale Biomechanics written by Jean-Francois Ganghoffer and published by Elsevier. This book was released on 2018-02-03 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiscale Biomechanics provides new insights on multiscale static and dynamic behavior of both soft and hard biological tissues, including bone, the intervertebral disk, biological membranes and tendons. The physiological aspects of bones and biological membranes are introduced, along with micromechanical models used to compute mechanical response. A modern account of continuum mechanics of growth and remodeling, generalized continuum models to capture internal lengths scales, and dedicated homogenization methods are provided to help the reader with the necessary theoretical foundations. Topics discussed include multiscale methods for fibrous media based on discrete homogenization, generalized continua constitutive models for bone, and a presentation of recent theoretical and numerical advances. In addition, a refresher on continuum mechanics and more advanced background related to differential geometry, configurational mechanics, mechanics of growth, thermodynamics of open systems and homogenization methods is given in separate chapters. Numerical aspects are treated in detail, and simulations are presented to illustrate models. This book is intended for graduate students and researchers in biomechanics interested in the latest research developments, as well as those who wish to gain insight into the field of biomechanics. Provides a clear exposition of multiscale methods for fibrous media based on discrete homogenization and the consideration of generalized continua constitutive models for bone Presents recent theoretical and numerical advances for bone remodeling and growth Includes the necessary theoretical background that is exposed in a clear and self-contained manner Covers continuum mechanics and more advanced background related to differential geometry, configurational mechanics, mechanics of growth, thermodynamics of open systems and homogenization methods

Download or read book Mechanics of Biological Tissue written by Gerhard A. Holzapfel and published by Springer Science & Business Media. This book was released on 2006-06-03 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanics of biological tissues is a multidisciplinary and rapidly expanding area of research. This book points to important directions combining mechanical sciences with the new developments in biology. It delivers articles on mechanics of tissues at the molecular, cellular, tissue and organ levels.

Download or read book Biomechanics of Soft Tissue in Cardiovascular Systems written by Gerhard A. Holzapfel and published by Springer. This book was released on 2014-05-04 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is written by leading experts in the field presenting an up-to-date view of the subject matter in a didactically sound manner. It presents a review of the current knowledge of the behaviour of soft tissues in the cardiovascular system under mechanical loads, and the importance of constitutive laws in understanding the underlying mechanics is highlighted. Cells are also described together with arteries, tendons and ligaments, heart, and other biological tissues of current research interest in biomechanics. This includes experimental, continuum mechanical and computational perspectives, with the emphasis on nonlinear behaviour, and the simulation of mechanical procedures such as balloon angioplasty.

Download or read book Patient Specific Modeling of the Cardiovascular System written by Roy C.P. Kerckhoffs and published by Springer Science & Business Media. This book was released on 2010-09-03 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: Peter Hunter Computational physiology for the cardiovascular system is entering a new and exciting phase of clinical application. Biophysically based models of the human heart and circulation, based on patient-specific anatomy but also informed by po- lation atlases and incorporating a great deal of mechanistic understanding at the cell, tissue, and organ levels, offer the prospect of evidence-based diagnosis and treatment of cardiovascular disease. The clinical value of patient-specific modeling is well illustrated in application areas where model-based interpretation of clinical images allows a more precise analysis of disease processes than can otherwise be achieved. For example, Chap. 6 in this volume, by Speelman et al. , deals with the very difficult problem of trying to predict whether and when an abdominal aortic aneurysm might burst. This requires automated segmentation of the vascular geometry from magnetic re- nance images and finite element analysis of wall stress using large deformation elasticity theory applied to the geometric model created from the segmentation. The time-varying normal and shear stress acting on the arterial wall is estimated from the arterial pressure and flow distributions. Thrombus formation is identified as a potentially important contributor to changed material properties of the arterial wall. Understanding how the wall adapts and remodels its material properties in the face of changes in both the stress loading and blood constituents associated with infl- matory processes (IL6, CRP, MMPs, etc.

Download or read book Computational Biomechanics written by Kozaburo Hayashi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: The combination of readily available computing power and progress in numerical techniques has made nonlinear systems - the kind that only a few years ago were ignored as too complex - open to analysis for the first time. Now realistic models of living systems incorporating the nonlinear variation and anisotropic nature of physical properties can be solved numerically on modern computers to give realistically usable results. This has opened up new and exciting possibilities for the fusing of ideas from physiology and engineering in the burgeoning new field that is biomechanics. Computational Biomechanics presents pioneering work focusing on the areas of orthopedic and circulatory mechanics, using experimental results to confirm or improve the relevant mathematical models and parameters. Together with two companion volumes, Biomechanics: Functional Adaptation and Remodeling and the Data Book on Mechanical Properties of Living Cells, Tissues, and Organs, this monograph will prove invaluable to those working in fields ranging from medical science and clinical medicine to biomedical engineering and applied mechanics.

Download or read book Cardiovascular Solid Mechanics written by Jay D. Humphrey and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text presents a general introduction to soft tissue biomechanics. One of its primary goals is to introduce basic analytical, experimental and computational methods. In doing so, it enables readers to gain a relatively complete understanding of the biomechanics of the heart and vasculature.

Download or read book A Computational Approach to Arteriolar Bifurcations written by Charles L. Robinson and published by . This book was released on 2003 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research attempts to improve the computational methodology used for arterial blood flow analysis to predict and characterize wall shear stress. This analysis also includes a characterization of wall shear stress effects as a result of changing model geometry and the physical composition of the blood as a particle-laden fluid which better represents the physical features of these microcirculatory vessels.

Download or read book Computational biomechanics for ventricle arterial dysfunction and remodeling in heart failure volume II written by Yunlong Huo and published by Frontiers Media SA. This book was released on 2023-01-09 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: