Download or read book The Biomechanics of Ascending Aortic Aneurysms written by Evan Wener and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "An ascending aortic aneurysm is a pathologic enlargement of the ascending portion of the aorta. Comorbidities of dilation include aortic valve disease and connective tissue disorders. If the ascending aorta exceeds a threshold diameter, open heart surgery is recommended. This is a traumatic procedure and the recovery is demanding. As our population ages and with improved technologies to diagnose the disease, the number of cases will increase every year. Understanding the mechanics of ascending aortic tissue will help cardiac surgeons make timely decisions on when to intervene. There are many ways to characterize the mechanical properties of aortic tissue. In this study, we used biaxial and uniaxial tensile testing with an optical tracking system to record the Green-Lagrangian (Green strain) strain. Engineering and true stiffness values were calculated and compared along with patient characteristics. Aortas were classified by valve type as healthy, tricuspid, bicuspid type 1 and bicuspid type 2. The results show that diseased tissue does behave differently than healthy tissue indicating that a local remodeling does occurs to the aortic wall. There are also differences in the mechanics between the types of diseased valves suggesting that valve type also affects the way the aortic wall responds to the disturbed hemodynamic environment. Correlations between stiffness and patient characteristics show that no matter which experimented technique or method of stiffness calculation is used, relationships are generally conserved. The only difference is the magnitude of the elastic modulus. The conclusions drawn from the data would not change whether biaxial or uniaxial experiments were performed. However when comparing engineering and true stiffness, only 7/12 covariances were similar and therefore the conclusions are inconsistent. " --
Download or read book Biomechanics and Mechanobiology of Aneurysms written by Tim McGloughlin and published by Springer Science & Business Media. This book was released on 2011-09-15 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cardiovascular disease is the leading cause of morbidity and premature death of modern era medicine. It is estimated that approximately 81 million people in the United States (US) currently have one or more of the many forms of cardiovascular disease, resulting in 1 in every 2.8 deaths, or 900,000 deaths per year. 40% of all deaths in Europe are a result of cardiovascular disease in people under the age of 75. Aneurysms form a significant portion of these cardiovascular related deaths and are defined as a permanent and irreversible localised dilation of a blood vessel greater than 50% of its normal diameter. Although aneurysms can form in any blood vessel, the more lethal aneurysms develop in the cranial arteries, and in the thoracic aorta and abdominal aorta. Frequently aneurysms are undetected and if left untreated may eventually expand until rupture with very high levels of morbidity and mortality. The biomechanics and mechanobiology of aneursymal diseases are not fully understood and this monograph aims to provide new insights into aneurysm aetiology and behavior based on the most recent biomechanics research related to this important topic. The contributors to this volume bring together a unique blend of expertise in experimental, computational and tissue biomechanics relating to aneurysm behavior and enable the reader to gain a fresh understanding of key factors influencing aneurysm behavior and treatment. Biological risk factors such as tobacco smoking, sex, age, hypertension, family history and mechanobiological risk factors such as aneurysm geometry and shape as well as mechanical properties of the diseased tissues are considered in detail as are many of the diagnostic and treatment options.
Download or read book Biomechanics of Ascending Aortic Aneurysms written by Alexander Emmott and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The aorta is the largest artery in the body and serves as the conduit for systemic blood flow from the heart. Its central property is its passive elastic behaviour that converts fluid energy to elastic potential during systole and subsequently returns that stored potential to maintain systemic circulation during diastole. With disease the pathological remodelling of the wall can result in an impairment of its elastic function, particularly in the case of an aortic aneurysm. If left unrepaired, aortic aneurysms carry significant risk of tearing and often result in death or serious disability. Clinical guidelines for surgical intervention are based on aortic diameter thresholds, but unfortunately these criteria are insufficient and an estimated 40% of dissection and rupture cases occur at diameters below the surgical guidelines. Aortic diameter criteria do not fully relay the risk that elastic impairment and pathological remodelling contribute to dissection or rupture. Herein, this thesis tested the hypothesis that the elastic or mechanical properties of the aortic wall can be used as a marker of ascending aortic dysfunction and contribute added information beyond size to identify at-risk patients. In this work we used transesophageal echocardiography, an application of ultrasound imaging to the heart and great vessels, to assess the mechanical properties of the ascending aorta and subsequently validated this methodology with ex vivo tensile analysis on resected tissue. Specifically, we developed novel in vivo stiffness metrics termed the Cardiac Cycle Pressure Modulus (CCPM) and the Cardiac Cycle Stress Modulus (CCSM) that were compared with aortic wall histology and ex vivo stiffness and energy loss parameters that have been widely reported, previously. This approach was applied globally (i.e., circumference averaged) and regionally at four distinct foci around the aortic circumference. Global CCPM and CCSM were significantly predictive of ex vivo mechanical indices and histopathology and could be used to identify patients with adverse aortic remodelling who did not meet standard surgical criteria of ≥5.5 cm diameter. Regional analysis demonstrated that heterogeneity in CCPM and CCSM increased with medial degeneration creating uneven distribution of physiological stress in the aortic wall. Furthermore, both tensile and compressive strain patterns were observed simultaneously in neighbouring regions of some patients suggesting a more complex physio-mechanical environment than had previously been appreciated. Ultimately, this work proposes a novel assessment technique to follow patients with ascending aortic aneurysms that may provide a crucial added dimension to surgical management of patients." --
Download or read book Biomechanics of Human Ascending Aorta and Aneurysm Rupture Risk Assessment written by Siyu Lin and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ascending aortic aneurysms (AsAA) and aortic dissections are life-threatening cardiovascular diseases. The main criteria for determining surgical intervention of AsAA are the maximum diameter or the increasing annual rate of the aneurysm. The mortality of the untreated aortic dissection can be 21% to 74%, depending on the delay of hospital admission.Our study aims to characterize the biomechanical properties of the ascending aorta and propose a patient-specific approach to assess the risks of rupture. The purpose of this PhD work is multifold.On the one hand, biaxial tensile tests were performed on AsAA samples obtained from one hundred patients with surgery of AsAA. The impact on the different characteristics and risks was evaluated and cross-compared. We have shown that the risk factors of gender, age, diameter, and aortic valve disorders have a major impact on the stiffness of AsAA. On the other hand, eleven acute type A aortic dissection samples were collected. We have confirmed that the adventitia shows a significant stiffness than the intimomedial layer. Meanwhile, a rare case of AsAA associated with the quadricuspid aortic valve displays similar biomechanical properties to AsAA associated with the bicuspid aortic valve than with the tricuspid aortic valve. In order to make synthetic modeling from 3D printed aorta in 4D flow magnetic resonance imaging (MRI) study, three three-dimensional printable materials were tested to compare with an undilated aortic wall. The biomechanical properties of the 50 SH (shore stiffness) RGD450+TangoPlus is the most aorta-alike material.To conclude, from our result from one hundred patients, gender, age, diameter, and aortic valve disorders are the key to aortic stiffness.
Download or read book Biomechanics of the Aorta written by T. Christian Gasser and published by Elsevier. This book was released on 2024-06-18 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomechanics of the Aorta: Modelling for Patient Care is a holistic analysis of the aorta towards its biomechanical description. The book addresses topics such as physiology, clinical imaging, tissue and blood flow modeling, along with knowledge that is needed in diagnostics, aortic rupture prediction, assist surgical planning, and more. It encompasses a wide range of topics from the basic sciences (Vascular biology, Continuum mechanics, Image analysis) to clinical applications, as well as describing and presenting computational studies and experimental benches to mimic, understand and propose the best treatment of aortic pathologies. The book begins with an introduction to the fundamental aspects of the anatomy, biology and physiopathology of the aorta and proceeds to present the main computational fluid dynamic studies and biomechanical and mechanobiological models developed over the last decade. With approaches, methodologies and findings from contributors all over the world, this new volume in the Biomechanics of Living Organs series will increase understanding of aortic function as well as improve the design of medical devices and clinical interventions, including surgical procedures. Represents a comprehensive means for those involved in the aortic research and the related developments in the industry Introduces the most recent imaging technologies to characterize factors, such as aortic geometry, mechanical properties of the aortic tissue, and the local cellular activity in the vessel wall Synthesizes advances in vascular biomechanics, medical imaging and computational finite element fluid and solid models to increase understanding of aorta function
Download or read book Biomechanics of abdominal aortic aneurysms an experimental approach towards a better understanding of pathological progression written by Jianhua Tong and published by . This book was released on 2013 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Calcific Aortic Valve Disease written by Elena Aikawa and published by BoD – Books on Demand. This book was released on 2013-06-12 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to population aging, calcific aortic valve disease (CAVD) has become the most common heart valve disease in Western countries. No therapies exist to slow this disease progression, and surgical valve replacement is the only effective treatment. Calcific Aortic Valve Disease covers the contemporary understanding of basic valve biology and the mechanisms of CAVD, provides novel insights into the genetics, proteomics, and metabolomics of CAVD, depicts new strategies in heart valve tissue engineering and regenerative medicine, and explores current treatment approaches. As we are on the verge of understanding the mechanisms of CAVD, we hope that this book will enable readers to comprehend our current knowledge and focus on the possibility of preventing disease progression in the future.
Download or read book Transport in Biological Media written by Sid M. Becker and published by Newnes. This book was released on 2013-05-21 with total page 575 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transport in Biological Media is a solid resource of mathematical models for researchers across a broad range of scientific and engineering problems such as the effects of drug delivery, chemotherapy, or insulin intake to interpret transport experiments in areas of cutting edge biological research. A wide range of emerging theoretical and experimental mathematical methodologies are offered by biological topic to appeal to individual researchers to assist them in solving problems in their specific area of research. Researchers in biology, biophysics, biomathematics, chemistry, engineers and clinical fields specific to transport modeling will find this resource indispensible. Provides detailed mathematical model development to interpret experiments and provides current modeling practices Provides a wide range of biological and clinical applications Includes physiological descriptions of models
Download or read book Aortic Dissection and Related Syndromes written by Ragavendra Baliga and published by Springer Science & Business Media. This book was released on 2007-04-03 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: This state-of the-art publication is a result of the combined efforts of participants from the International Registry of Aortic Dissection (IRAD). It is the most comprehensive reference on aortic dissection The book has been divided into sections. Each chapter provides a succinct overview of the current clinical literature and incorporates illustrations for further explanation.
Download or read book Surgical Management of Aortic Pathology written by Olaf H. Stanger and published by Springer. This book was released on 2019-04-15 with total page 1223 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book follows the concept of perceiving the entire aorta as one functional organ assuming that all individual pathologies and local interventional procedures affect the up- and downstream segments with consequences for complications and disease progression. Thus any preventive or surgical strategy must recognize the aortic disease in its entirety. The book intends to cover the full spectrum of aortic pathologies, mechanisms and functional interplay. The latest available diagnostic tools and options for surgical treatment are presented by the foremost experts in their field in state-of-the-art reviews. The reader is provided with the most current and comprehensive insight into all fundamental and clinical aspects of aortic disease. All chapters are carefully complemented with figures and illustrations.
Download or read book Aortopathy written by Koichiro Niwa and published by Springer. This book was released on 2017-02-09 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first textbook to focus on Aortopathy, a new clinical concept for a form of vasculopathy. The first section of the book starts from discussing general concept and history of Aortopathy, and then deals with its pathophysiology, manifestation, intrinsic factor, clinical implication, management and prevention. The second part closely looks at various disorders of the Aortopathy such as bicuspid aortic valve and coarctation of aorta. The book editors have published a lot of works on the topic and have been collecting relating data in the field of congenital heart disease for the past 20 years, thus present the book with confidence. The topic - an association of aortic pathophysiological abnormality, aortic dilation and aorto-left ventricular interaction - is getting more and more attention among cardiovascular physicians. This is the first book to refer for cardiologists, pediatric cardiologists, surgeons, ACHD specialists, etc. to acquire thorough knowledge on Aortopathy.
Download or read book Diseases of the Aorta written by Robert S. Dieter and published by Springer Nature. This book was released on 2019-08-27 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines various aspects of the aorta, both healthy and diseased states, in 40 chapters of in-depth research by experts in cardiovascular disease. It begins with chapters on the embryology, anatomy, genetics, and physiology of the aorta along with imaging studies used to visualize its structure. The bulk of the book focuses on acute and chronic disorders such as coarctation of the aorta, inflammatory and connective tissue disorders, acute aortic thrombosis, infections, tumors, related ocular diseases, and various aneurysms and fistulas. In addition, it explores aortic disease in pregnancy, fetal aortic disorders, and aortic trauma in children. The book highlights the epidemiology and natural history as well as medical, endovascular, and surgical treatments for each disease. It also discusses valve repair, 3D printing applications, and the role of multidisciplinary aortic centers. Diseases of the Aorta is an indispensable and authoritative resource for cardiologists, cardiovascular surgeons, interventional radiologists, radiologists, and vascular medicine specialists.
Download or read book Mechanisms of Vascular Disease written by Robert Fitridge and published by University of Adelaide Press. This book was released on 2011 with total page 589 pages. Available in PDF, EPUB and Kindle. Book excerpt: New updated edition first published with Cambridge University Press. This new edition includes 29 chapters on topics as diverse as pathophysiology of atherosclerosis, vascular haemodynamics, haemostasis, thrombophilia and post-amputation pain syndromes.
Download or read book Computational Modeling and Simulation Examples in Bioengineering written by Nenad Filipovic and published by John Wiley & Sons. This book was released on 2021-12-14 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: A systematic overview of the quickly developing field of bioengineering—with state-of-the-art modeling software! Computational Modeling and Simulation Examples in Bioengineering provides a comprehensive introduction to the emerging field of bioengineering. It provides the theoretical background necessary to simulating pathological conditions in the bones, muscles, cardiovascular tissue, and cancers, as well as lung and vertigo disease. The methodological approaches used for simulations include the finite element, dissipative particle dynamics, and lattice Boltzman. The text includes access to a state-of-the-art software package for simulating the theoretical problems. In this way, the book enhances the reader's learning capabilities in the field of biomedical engineering. The aim of this book is to provide concrete examples of applied modeling in biomedical engineering. Examples in a wide range of areas equip the reader with a foundation of knowledge regarding which problems can be modeled with which numerical methods. With more practical examples and more online software support than any competing text, this book organizes the field of computational bioengineering into an accessible and thorough introduction. Computational Modeling and Simulation Examples in Bioengineering: Includes a state-of-the-art software package enabling readers to engage in hands-on modeling of the examples in the book Provides a background on continuum and discrete modeling, along with equations and derivations for three key numerical methods Considers examples in the modeling of bones, skeletal muscles, cartilage, tissue engineering, blood flow, plaque, and more Explores stent deployment modeling as well as stent design and optimization techniques Generates different examples of fracture fixation with respect to the advantages in medical practice applications Computational Modeling and Simulation Examples in Bioengineering is an excellent textbook for students of bioengineering, as well as a support for basic and clinical research. Medical doctors and other clinical professionals will also benefit from this resource and guide to the latest modeling techniques.
Download or read book Diagnosis and Treatment of Aortic Diseases written by C.A. Nienaber and published by Springer Science & Business Media. This book was released on 1999-03-31 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes recent surgical techniques developed to improve prognosis in aortic diseases, and discusses recent interventional strategies such as endovascular stent-graft placement and non-surgical reconstruction of the aorta. Chapters deal with aortic dissection, aortic aneurysm, surgical treatment of aortic aneurysms and dissections, inherited disorders of the aorta, aortic trauma, aortitis, and etiology and pathology of aortic malformations. Each chapter is organized in a similar fashion, with information on demographic aspects, pathology, clinical presentation, and diagnostic and therapeutic approaches. Annotation copyrighted by Book News, Inc., Portland, OR
Download or read book Biomechanics of Living Organs written by Yohan Payan and published by World Bank Publications. This book was released on 2017-06-09 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomechanics of Living Organs: Hyperelastic Constitutive Laws for Finite Element Modeling is the first book to cover finite element biomechanical modeling of each organ in the human body. This collection of chapters from the leaders in the field focuses on the constitutive laws for each organ. Each author introduces the state-of-the-art concerning constitutive laws and then illustrates the implementation of such laws with Finite Element Modeling of these organs. The focus of each chapter is on instruction, careful derivation and presentation of formulae, and methods. When modeling tissues, this book will help users determine modeling parameters and the variability for particular populations. Chapters highlight important experimental techniques needed to inform, motivate, and validate the choice of strain energy function or the constitutive model. Remodeling, growth, and damage are all covered, as is the relationship of constitutive relationships of organs to tissue and molecular scale properties (as net organ behavior depends fundamentally on its sub components). This book is intended for professionals, academics, and students in tissue and continuum biomechanics. Covers hyper elastic frameworks for large tissue deformations Considers which strain energy functions are the most appropriate to model the passive and active states of living tissue Evaluates the physical meaning of proposed energy functions
Download or read book Material Parameter Identification and Inverse Problems in Soft Tissue Biomechanics written by Stéphane Avril and published by Springer. This book was released on 2016-10-12 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: The articles in this book review hybrid experimental-computational methods applied to soft tissues which have been developed by worldwide specialists in the field. People developing computational models of soft tissues and organs will find solutions for calibrating the material parameters of their models; people performing tests on soft tissues will learn what to extract from the data and how to use these data for their models and people worried about the complexity of the biomechanical behavior of soft tissues will find relevant approaches to address this complexity.
