Download or read book Finite Element Simulation of the Healthy and Degenerated Lumbar Spine Interplay Between Muscle Activity and Intervertebral Disc Multiphysics written by Themis Toumanidou and published by . This book was released on 2017 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: The human spine provides mechanical support to the trunk while it protects the spinal cord and nerves from the external loads transferred during daily activities. Such loads are largely controlled by the spine muscles and influence the biophysical regulation of the intervertebral discs (IVD). Numerical models have been important tools for the translation of the external forces into internal loads that otherwise cannot be easily measured directly. This PhD thesis used the predictive ability of constitutive equations to reflect the mechanical properties of the lumbar IVD and muscles and explore the IVD-muscle interplay on the healthy and degenerated spine. A review of the state-of-the-art reported for the estimation of spine loads was performed, and the Hill¿s mus cle model and the poro-hyperelastic formulations used for IVD modeling were particularly detailed. A new constitutive equation assembly was proposed involving one active parameter controlled via strain-based criteria, and four passive parameters. For the latters, literature-based values were initially defined, and a parametric study was designed for the active parameter by proposing stretch-related activation thresholds. An optimization scheme was then developed to define a full set of calibrated values per fascicle using force estimations from a reported rigid body model based on measured kinematics of the vertebrae. To test the robustness of the method, a generic L3-S1 finite element (FE) model was developed that included 46 muscle fascicles and all passive issues. Simulation of forward flexion showed that the predicted muscle forces increased in caudal direction. The intradiscal pressure (IDP) predictions correlated with previous in vivo measurements showing the ability of the model to capture realistic internal loads. To simulate standing, the gravity loads were defined by considering the heterogeneous distribution of body volumes along the trunk. This simulation was also coupled to a previous 8-hour free IVD swelling to mimic the overnight disc hydration. Disc swelling led to muscle activation and force distributions that seemed particularly appropriate to counterbalance the gravity loads, pointing out the likely existence of a functional balance between stretch-induced muscle activation and IVD multiphysics. A geometrical extension was then performed to incorporate all relevant tissues of the full lumbar spine including in total 96 fascicles. The effect of previous rest (PR) and muscle presence (MS) on internal loads was explored in standing and lying. Muscle force predictions in standing showed that with PR, the total loads transferred were altered from compressive to tensile. Overnight, the computed IDP increase reproduced previous in vivo data. Both PR and MS affected the vertebrae motion particularly between L1-L2. When degenerated discs properties were used, a general IDP decrease and up to 14 times higher activation was predicted in standing with PR.At last, the previous workflow was repeated using a patient L1-S1 FE model with patient-specific (P-SP) and condition-depended material properties. In standing, asymmetric fascicle activation with increased shortening at the left side and lateral bending was predicted. The decreased swelling capacity of the degenerated discs was associated to an increased muscle activation needed to balance the gravity loads that tended to flex forward the trunk. Comparisons of the IDP results in both models with healthy discs showed that introducing P-SP geometries gave better correlations with in vivo data. Given the difficulties to evaluate the predicted muscle forces experimentally, such outcome further contributed to the validation of the method. Despite its limitations, this approach allowed to explicitly and rationally explore the interactions between muscle function and passive tissue biomechanics in the lumbar spine. The information provided could help clinical decision for patients whom source of back pain is unclear.
Download or read book 0820 Different Degrees of Disc Degeneration Alter the Multidirectional Motions and Load Sharing of the Lumbar Spine Parametric Subject Specific Finite Element Simulations written by Chi-Chien Niu and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: INTRODUCTION: Various studies have shown that intervertebral disc degeneration, lumbar stability, flexibility and low back pain are interrelated [1]. Hence, the relationship of lumbar spine flexibility to different grades of disc degeneration is of great interest in clinics. Finite element (FE) modeling has emerged in literature as an advantageous approach to study spinal biomechanics. Although complex exact FE modeling is reliable, its clinical application has been limited as it is time-consuming and constrained to the input geometry, typically based on one or few subjects. Therefore, the objective of this study was (1) to develop a validated parametric subject-specific FE model which can automatically update the geometry of the lumbar spine from different patients; and (2) to evaluate the influence of disc degeneration on the biomechanical response of lumbar spine. METHODS: The geometry of the lumbar spine (L1-S1) was automatically updated by inputting 125 independent parameters using a user-defined code based on defined geometrical constraints obtained from lateral and AP X-Ray images (Fig. 1A). Parametric lumbar FE model consisted of 5 vertebrae, sacral component, 5 IVDs, 7 ligaments and 5 pairs of facet joints and was developed using ABAQUS (SIMULIA, Providence, RI, USA). Five subject-specific FE models were developed based on images of 5 patients from data bank of the Chang Gung Memorial Hospital. The validity of the FE models was evaluated using pure moments of 1 to10 Nm in different directions, subsequent to a compressive preloading with a follower load to mimic the upper body weight. Further, parametric FE models of those lumbar spines were regenerated for L4-L5 disc degeneration in different grades (i.e., healthy, mild, moderate, and severe degeneration), in which the disc height reduction and the increasing of nucleusu2019 compressibility were considered (Fig. 1B) [2]. Biomechanical responses including motion patterns, intradiscal pressure (IDP) and experienced stress in different components were analyzed under the same loading and boundary conditions. The extracted ranges of motion (ROM) were compared using one-way ANOVA. The differences were considered significant at p
Download or read book Finite Element Modeling and Simulation of Healthy and Degenerated Human Lumbar Spine written by Márta Kurutz and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solute Transport in a Healthy and Degenerated Lumbar Intervertebral Disc written by Daniel J. Roig and published by . This book was released on 2011 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Modeling of Intervertebral Disc Degeneration and Repair written by Qiaoqiao Zhu and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Intervertebral disc (IVD) is the largest avascular structure in the human body and its main function is to support mechanical loading and to provide the flexibility for the spine system. Degenerative disc disease (DDD) is related to low back pain which affects more than 600 million people worldwide. One of the challenges in modeling DDD is that the biological, mechanical, chemical, and electrical events in IVD are coupled at different levels. It is important to develop a numerical model to understand the biophysics and pathophysiology in IVD (a biological system). A multiscale and multi-physics model was developed based on a cell-activity-coupled mechano-electrochemical continuum mixture theory. In this model, the phenomena at the solute (or solvent) level (e.g., diffusion and/or reaction of ions, nutrients, growth factors, and interstitial fluid), cellular level (e.g., cell metabolism and viability), and tissue level (e.g., disc volume and shape) are accounted for. The model also includes the interactions among biological (cell activity), chemical [osmolarity, pH, extracellular matrix (ECM) synthesis and degradation], electrical (charges on ECM and solutes), and mechanical (loading and tissue swelling) events in the IVD. Numerical results were obtained by solving a dozen of partial differential equations using a finite element method. This model has been successfully used to simulate the degenerative progression of the IVD (up to 55 years) due to poor nutrition supply. The predicted distributions of water content in the IVD were consistent with those from direct measurements published in the literature. This result was also consistent with those observed in MRI images of IVDs in human patients. The model was also used to study kinetics of charged antibiotics (for treating disc infections) and effects of dynamic loading on cell viability (for preventing degeneration) in the IVD. The model has also been used to investigate the long-term efficacy (up to 10 years) of cell therapies for disc repair (i.e., in silico clinical trials). This model can be used not only to provide insights into the mechanisms of disc degeneration, but also to develop new diagnostic tools and to optimize new therapeutic strategies for degenerated discs.
Download or read book The Intervertebral Disc written by Irving M. Shapiro and published by Springer Science & Business Media. This book was released on 2013-09-02 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: The intervertebral disc is a complex structure that separates opposing vertebrae, permits a wide range of motion, and accommodates high biomechanical forces. Disc degeneration leads to a loss of function and is often associated with excruciating pain. Written by leading scientists and clinicians, the first part of the book provides a review of the basic biology of the disc in health and disease. The second part considers strategies to mitigate the effects of disc degeneration and discusses the possibility of engineering replacement tissues. The final section is devoted to approaches to model normal development and elucidate the pathogenesis of degenerative disc disease using animal, organ and cell culture techniques. The book bridges the gap between the basic and clinical sciences; the target audience includes basic scientists, orthopaedists and neurologists, while at the same time appealing to the needs of graduate students, medical students, interns and fellows.
Download or read book Brain and Human Body Modeling 2020 written by Sergey N. Makarov and published by Springer Nature. This book was released on 2021 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 41st Annual International Conference of the IEEE EMBS, took place between July 23 and 27, 2019, in Berlin, Germany. The focus was on "Biomedical engineering ranging from wellness to intensive care." This conference provided an opportunity for researchers from academia and industry to discuss a variety of topics relevant to EMBS and hosted the 4th Annual Invited Session on Computational Human Models. At this session, a bevy of research related to the development of human phantoms was presented, together with a substantial variety of practical applications explored through simulation.
Download or read book Biomaterials for Spinal Surgery written by Luigi Ambrosio and published by Elsevier. This book was released on 2012-03-12 with total page 645 pages. Available in PDF, EPUB and Kindle. Book excerpt: There have been important developments in materials and therapies for the treatment of spinal conditions. Biomaterials for spinal surgery summarises this research and how it is being applied for the benefit of patients.After an introduction to the subject, part one reviews fundamental issues such as spinal conditions and their pathologies, spinal loads, modelling and osteobiologic agents in spinal surgery. Part two discusses the use of bone substitutes and artificial intervertebral discs whilst part three covers topics such as the use of injectable biomaterials like calcium phosphate for vertebroplasty and kyphoplasty as well as scoliosis implants. The final part of the book summarises developments in regenerative therapies such as the use of stem cells for intervertebral disc regeneration.With its distinguished editors and international team of contributors, Biomaterials for spinal surgery is a standard reference for both those developing new biomaterials and therapies for spinal surgery and those using them in clinical practice. - Summarises recent developments in materials and therapies for the treatment of spinal conditions and examines how it is being applied for the benefit of patients - Reviews fundamental issues such as spinal conditions and their pathologies, spinal loads, modelling and osteobiologic agents in spinal surgery - Discusses the use of bone substitutes and artificial intervertebral discs and covers topics such as the use of injectable biomaterials like calcium phosphate for vertebroplasty and kyphoplasty
Download or read book Biomechanics of the Spine written by Fabio Galbusera and published by Academic Press. This book was released on 2018-04-23 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomechanics of the Spine encompasses the basics of spine biomechanics, spinal tissues, spinal disorders and treatment methods. Organized into four parts, the first chapters explore the functional anatomy of the spine, with special emphasis on aspects which are biomechanically relevant and quite often neglected in clinical literature. The second part describes the mechanics of the individual spinal tissues, along with commonly used testing set-ups and the constitutive models used to represent them in mathematical studies. The third part covers in detail the current methods which are used in spine research: experimental testing, numerical simulation and in vivo studies (imaging and motion analysis). The last part covers the biomechanical aspects of spinal pathologies and their surgical treatment. This valuable reference is ideal for bioengineers who are involved in spine biomechanics, and spinal surgeons who are looking to broaden their biomechanical knowledge base. The contributors to this book are from the leading institutions in the world that are researching spine biomechanics. - Includes broad coverage of spine disorders and surgery with a biomechanical focus - Summarizes state-of-the-art and cutting-edge research in the field of spine biomechanics - Discusses a variety of methods, including In vivo and In vitro testing, and finite element and musculoskeletal modeling
Download or read book Concepts and Principles of Pharmacology written by James E. Barrett and published by Springer Nature. This book was released on 2019-12-24 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: Celebrating 100 years of HEP, this volume will discuss key pharmacological discoveries and concepts of the past 100 years. These discoveries have dramatically changed the medical treatment paradigms of many diseases and these concepts have and will continue to shape discovery of new medicinies. Newly evolving technologies will similarly be discussed as they will shape the future of the pharmacology and, accordingly, medical therapy.
Download or read book Biomedical Composites written by Luigi Ambrosio and published by Elsevier. This book was released on 2009-11-23 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biocomposites are widely used in the medical industry to repair and restore bone, tooth, cartilage skin and other tissues. Biomedical composites, provides a thorough review of the current status, recent progress and future trends in composites for biomedical applications.Part one discusses the fundamentals of biocomposites with chapters on natural composites, design and fabrication of biocomposites, and hard and soft tissue applications of biocomposites. Part two then reviews applications of biocomposites. Chapters discuss composites for bone repair, composite coatings for implants, composites for spinal implants, injectable composites and composites for tissue engineered scaffolds. Chapters in part three discuss the biocompatibility, mechanical behaviour and failure of biocomposites with such topics as cellular response, testing of biocomposites and tribology of biocomposites. Finally part four reviews the future for biocomposites with chapters on nano-structured biocomposites, developing biocomposites as scaffolds and biocomposites in tissue engineering and regenerative medicine.With its distinguished editor and team of international contributors, Biomedical composites is an essential reference to materials scientists and researchers in industry and academia, as well as all those concerned with this increasingly important field. - Provides a thorough review of the current status, recent progress and future trends in composites for biomedical applications - Discusses the fundamentals of biocomposites with chapters on natural composites, design and fabrication of biocomposites and their applications - Chapters address composites for bone repair, spinal implants and various other applications and discuss biocompatability, mechanical behaviour and failure of biocomposites
Download or read book Cardiovascular Biomechanics written by Peter R. Hoskins and published by Springer. This book was released on 2017-02-16 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a balanced presentation of the fundamental principles of cardiovascular biomechanics research, as well as its valuable clinical applications. Pursuing an integrated approach at the interface of the life sciences, physics and engineering, it also includes extensive images to explain the concepts discussed. With a focus on explaining the underlying principles, this book examines the physiology and mechanics of circulation, mechanobiology and the biomechanics of different components of the cardiovascular system, in-vivo techniques, in-vitro techniques, and the medical applications of this research. Written for undergraduate and postgraduate students and including sample problems at the end of each chapter, this interdisciplinary text provides an essential introduction to the topic. It is also an ideal reference text for researchers and clinical practitioners, and will benefit a wide range of students and researchers including engineers, physicists, biologists and clinicians who are interested in the area of cardiovascular biomechanics.
Download or read book EcoMasterplanning written by Ken Yeang and published by Wiley. This book was released on 2009-05-26 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In planning for a sustainable future for our planet, it is vital that we achieve a seamless and benign biointegration of all human interventions in the natural environment. Finding green design solutions for our built environment must start from the wider scale of regional and urban planning and must then be carried right through to infrastructural engineering, architecture and industrial design. Masterplanning affords the chance to redress current environmental imbalances and to reduce the consequences of our built systems on the environment, with the greater and of reversing climate change. Ecomasterplanning presents a groundbreaking integrative and comprehensive approach to masterplanning, illustrated by examples that Ken Yeang – the original pioneer of the ‘green skyscraper’ – has designed in a highly visually driven format, the book examines over 20 of his masterplans from around the world, including those in the Netherlands, china, India, Turkey, Malaysia, Singapore and North America.
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 Piezoelectric Nanomaterials for Biomedical Applications written by Gianni Ciofani and published by Springer Science & Business Media. This book was released on 2012-03-31 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoscale structures and materials have been explored in many biological applications because of their novel and impressive physical and chemical properties. Such properties allow remarkable opportunities to study and interact with complex biological processes. This book analyses the state of the art of piezoelectric nanomaterials and introduces their applications in the biomedical field. Despite their impressive potentials, piezoelectric materials have not yet received significant attention for bio-applications. This book shows that the exploitation of piezoelectric nanoparticles in nanomedicine is possible and realistic, and their impressive physical properties can be useful for several applications, ranging from sensors and transducers for the detection of biomolecules to “sensible” substrates for tissue engineering or cell stimulation.
Download or read book 5th International Conference on Biomedical Engineering in Vietnam written by Vo Van Toi and published by Springer. This book was released on 2014-11-18 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents the proceedings of the Fifth International Conference on the Development of Biomedical Engineering in Vietnam which was held from June 16-18, 2014 in Ho Chi Minh City. The volume reflects the progress of Biomedical Engineering and discusses problems and solutions. I aims identifying new challenges, and shaping future directions for research in biomedical engineering fields including medical instrumentation, bioinformatics, biomechanics, medical imaging, drug delivery therapy, regenerative medicine and entrepreneurship in medical devices.
Download or read book Trauma Biomechanics written by Kai-Uwe Schmitt and published by Springer Science & Business Media. This book was released on 2013-04-09 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 2004 World Health Day is dedicated to the theme of road safety by the World Health Organization (WHO) due mostly to the enormous socio economic costs attributed to trafik accidents. More than 140,000 people are injured, 3,000 killed, and 15,000 disabled for life everyday on the world's roads. The field of trauma biomechanics, or injury biomechanics, uses the principles of mechanics to study the response and tolerance level of biological tissues under extreme loading conditions. Through an understanding of mechanical factors that influence the function and structure of human tissues, countermeasures can be developed to alleviate or even eliminate such injuries. This book, Trauma-Biomechanics, surveys a wide variety of topics in injury biomechanics including anatomy, injury c1assification, injury mechanism, and injury criteria. It is the first collection I am aware of that lists regional injury reference values, or injury criterion, either currently in use or proposed by both U. S. and European communities. Although the book is meant to be an introduction for medical doctors and engineers who are beginners in the field of injury biomechanics, sufficient references are provided for those who wish to conduct further research, and even established researchers will find it useful as a reference for finding the biomechanical background of each proposed injury mechanism and injury criterion.
