Download or read book Evaluation of the Impact of Lumbar Spine Morphology on Loading with the Application of Biomedical Image based Computational Modeling written by Gregory G. Knapik and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational spine modeling has been employed as a research tool for more than 50 years to better understand the spine and the causes and development of various low back disorders. However, most spine models feature significant limitations that inhibit their utility for research. Clinically focused studies often featured highly detailed finite element models of the spine with great computational complexity that were used to evaluate individual tissue deformations, stresses, and even the impact of surgical instrumentation. Unfortunately, their great complexity limits the types of analyses performed, often requires significant simplifications, and limits the number of models created. Industrial biomechanics studies typically use much lower fidelity musculoskeletal models that evaluate whole body motions and deformations and typically include muscles and other soft tissues. Their simpler nature enables larger numbers of subjects to be evaluated. However, they do not include the same level of spinal detail as finite element models and are limited in the types of possible analyses. A few newer models combine elements of both types, but many still feature significant simplifications, specifically the geometric representation of the vertebrae. Additionally, no models are able to effectively evaluate large numbers of individual subjects to understand the variation of responses in the population. This study sought to address these voids in the use of computational modeling for the study of the biomechanics of the lumbar spine. Given the variability of spine geometry in the population and its ties to various spine disorders, biomechanical models require detailed representation of the structures of the spine and must include sufficient numbers of subjects to account for variability in the population. To that end, an extensive database of detailed digital spine models was developed. CT imaging was used to create three-dimensional geometric models of sixty subjects using a combination of algorithms and manual refinement specifically tuned to minimize partial volume effect errors and capture accurate information from both the anterior and posterior portions of each vertebral body. Geometric measures describing the database showed that there was substantial variability between subjects and as a function of vertebral level, subject age, and gender. A computational study was conducted to evaluate the impact of this subject-specific spine geometry on spinal loads. Biomechanical analysis demonstrated that the variability in spine geometry had a considerable impact on facet joint contact forces and corresponding intervertebral disc endplate moments, forces, and loading sharing between tissues. For most measures, there was a large range of values present in the subject population. Furthermore, there were significant differences in loading as a function of vertebral level, subject age, and between the left and right sides of the vertebrae. The highly complex loading patterns exhibited in each subject demonstrate the importance of including subject-specific geometry and representing numerous subjects in spine modeling in order to accurately understand spinal loads and their variation within the population.

Download or read book Biomedical Imaging and Computational Modeling in Biomechanics written by Ugo Andreaus and published by Springer Science & Business Media. This book was released on 2012-10-09 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book collects the state-of-art and new trends in image analysis and biomechanics. It covers a wide field of scientific and cultural topics, ranging from remodeling of bone tissue under the mechanical stimulus up to optimizing the performance of sports equipment, through the patient-specific modeling in orthopedics, microtomography and its application in oral and implant research, computational modeling in the field of hip prostheses, image based model development and analysis of the human knee joint, kinematics of the hip joint, micro-scale analysis of compositional and mechanical properties of dentin, automated techniques for cervical cell image analysis, and biomedical imaging and computational modeling in cardiovascular disease. The book will be of interest to researchers, Ph.D students, and graduate students with multidisciplinary interests related to image analysis and understanding, medical imaging, biomechanics, simulation and modeling, experimental analysis

Download or read book Computational Modeling for the Assessment of the Biomechanical Properties of the Healthy Diseased and Treated Spine written by Enrico Dall’Ara and published by Frontiers Media SA. This book was released on 2022-09-22 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of a Computational Methodology for Evaluating in Vivo Vertebral Mechanics in Subjects Having Various Conditions of the Lumbar Spine written by Christopher Brian Carr and published by . This book was released on 2013 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Treating and evaluating the causes of low back pain (LBP) is difficult and not fully understood. However, assessing the in vivo motions and loading characteristics in the lumbar spine may provide important data for progressing the diagnosis and treatment of pathologies linked with LBP. This dissertation describes the development of a comprehensive approach for collecting both the kinematics and kinetics of the lumbar vertebrae under in vivo conditions. Forty-four subjects representing healthy, symptomatic, pathological, and surgically implanted (pre- and post-operative) conditions of the lumbar spine were evaluated using dynamic fluoroscopy and 3D-to-2D image registration to assess the motions of the five lumbar vertebrae while patients performed an active flexion-extension, lateral flexion, and axial rotation of the spine. 3D kinematics were extracted describing the relative in-plane and coupled out-of-plane motions of the intervertebral joints. A computational methodology was then utilized for the development of a multi-body, inverse mathematical model based on principles from Kane's dynamics. The kinematics, as well as patient-specific bone geometries, recreated from CT, and ground reaction forces, collected using force plates, served as inputs to the model. Vertebral bones were defined as rigid bodies, while massless frames represented non-specific bone geometries for the lower body, torso and abdominal wall. Soft tissue attachment sites were selected on the vertebral bones allowing for ligaments to be defined for constraint and modeled as linear springs. Relevant muscle groups were also included and solved for using the pseudo-inverse algorithm, which enabled for decoupling of the derived resultant torques and ultimately defined the kinetic trajectory for the muscles. These methodologies allowed for the theoretical modeling of the entire lumbar region and prediction of joint reaction contact forces, ligament constraint forces, and applied musculotendon forces. Results from the model were validated for the prescribed motions using experimental loading data measured directly using telemetrized vertebral implants and intervertebral disc pressure sensors. A comparative analysis of the predicted forces from the model with experimentally collected data showed good agreement in the force profiles and an average combined error around 6.9%. This demonstrated the use of this methodology for in vivo analyses of the lumbar spine.

Download or read book In Vitro Biomechanical Testing and Computational written by Mageswaran Prasath and published by . This book was released on 2012 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Two separate in vitro biomechanical studies were conducted on human cadaveric spines (Lumbar) to evaluate the stability following the implantation of two different spinal fixation devices; interspinous fixation device (ISD) and Hybrid dynamic stabilizers. ISD was evaluated as a stand-alone and in combination with unilateral pedicle rod system. The results were compared against the gold standard, spinal fusion (bilateral pedicle rod system). The second study involving the hybrid dynamic system, evaluated the effect on adjacent levels using a hybrid testing protocol. A robotic spine testing system was used to conduct the biomechanical tests. This system has the ability to apply continuous unconstrained pure moments while dynamically optimizing the motion path to minimize off-axis loads during testing. Thus enabling precise control over the loading and boundary conditions of the test. This ensures test reliability and reproducibility. We found that in flexion-extension, the ISD can provide lumbar stability comparable to spinal fusion. However, it provides minimal rigidity in lateral bending and axial rotation when used as a stand-alone. The ISD with a unilateral pedicle rod system when compared to the spinal fusion construct were shown to provide similar levels of stability in all directions, though the spinal fusion construct showed a trend toward improved stiffness overall. The results for the dynamic stabilization system showed stability characteristics similar to a solid all metal construct. Its addition to the supra adjacent level (L3- L4) to the fusion (L4- L5) indeed protected the adjacent level from excessive motion. However, it essentially transformed a 1 level into a 2 level lumbar fusion with exponential transfer of motion to the fewer remaining discs (excessive adjacent level motion). The computational aspect of the study involved the development of a spine model (single segment). The kinematic data from these biomechanical studies (ISD study) was then used to validate a finite element model of the spine.

Download or read book An Investigation of the Finite Element Simulation of Spaceflight induced Gravitational Unloading of the Whole Human Spine written by Molly Townsend and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Substantial strides are being made in fields supporting human spaceflight, making re-usable and robust flight systems for missions to new and exciting destinations. However, the human body is not capable of withstanding long-duration spaceflight, which involves gravitational unloading as well as extreme loading conditions. In the dynamic loading environment projected on space missions, the potential for injury will likely be high due to the creation of irreversible changes to the musculoskeletal system. Therefore, the specific goals of this research were to (1) determine the appropriate material models to simulate gravitational unloading, (2) determine the loading and boundary conditions in the simulation of gravitational unloading, and (3) investigate the response of the whole human spine under several representative gravitational unloading test cases. A high fidelity computational model and simulation of the space adapted whole human spine was generated and validated for the purpose of investigating the mechanical integrity of the spine in crewmembers during exploratory space missions. Simulation of intervertebral disc poro-hyperelastic response to mechanical unloading was conducted through the application of boundary conditions to approximate the osmotic conditions of the system. Morphology of this gravitational unloading spine model was compared to a control terrestrial-based finite element model. Additionally, the morphology of the lumbar spine was compared to a validation data set generated from head down tilt bed rest studies, a ground-based analog of human spaceflight, and spaceflight experiments. The results were compared to tissue injury limits to implicate bone micro-fractures and intervertebral disc herniations, indicating potential locations of injuries. Five test cases were conducted to offer an overview of the influence of certain boundary and loading conditions on the gravitational unloading responses of the system. Simulations captured straightening of the spinal column under gravitational unloading, a result observed in some of the experimental investigations into this phenomenon. Each intervertebral disc exhibited a swelling response, increasing in height. Unavailability of controlled experimental studies with a large number of subjects created a validation data set with large standard deviations. Injury limits for annular tears were exceeded in the lower cervical and upper thoracic spine and bony micro-fractures occurred throughout the spine on each of the investigated test cases. Additionally, the influence of certain boundary conditions on the deformed shapes of the spinal column was determined. This work offers the first complete review of spaceflight-induced changes in spinal morphology to date. A full derivation of the constitutive equations for poro-hyperelastic materials is presented, offering the framework for the development and implementation of higher fidelity formulations of biphasic swelling as it relates to biological tissues. Additionally, this whole spine finite element model is presented as the only investigation of the spine to long duration gravitational unloading, with a time duration longer than those in diurnal simulations. It is also the only investigation into the response of the whole spine to an analog of spaceflight gravitational unloading. This thorough gravitational unloading study offers a tool that can be used to conduct more robust investigations of human spaceflight.

Download or read book On the Lumbosacral Spine Geometry Variation and Spinal Load sharing written by Sadegh Naserkhaki and published by . This book was released on 2016 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational modeling of the lumbar spine provides insights on kinematics and internal load development and distribution along the spine. Geometry (size and shape) of the spinal structures and more particularly sagittal curvature of the spine governs its response to mechanical loading. Thus, understanding how inter-individual sagittal curvature variation affects the spinal load-sharing between spinal components (discs, ligaments and facet joints) becomes of high importance. The load-sharing is an indicator of how spinal components interact together in a harmonic synergy to maintain its normal function. This study aimed to investigate how the inter-individual sagittal curvature variation affects spinal load-sharing in flexed and extension postures using geometrically personalized Finite Element (FE) modeling. This research used three lumbosacral spines with different curvatures: one hypo-lordotic (Hypo-L), one normal-lordotic (Norm-L) and one hyper-lordotic (Hyper-L) spines with low, normal and high lumbar lordosis (LL), respectively. A 3D nonlinear detailed FE model for the Norm-L spine with realistic geometry was developed and validated against a wide range of numerical and experimental (in-vivo and in-vitro) data. The model was subjected to compressive Follower Load (FL) combined with moment to simulate flexed and extended postures. Load-sharing was expressed as percentage of total internal force/moment developed along the spine that each spinal component carried. These internal forces and moments were determined at the discs centers using static equilibrium approach and included the applied load and the resisting forces in the ligaments and facet joints. Sensitivity of the model predictions to a wide range of FL (500-1100N) and moment (0-20Nm) magnitudes was performed. Optimal magnitudes that minimized the deviation of the model predictions from in-vivo data were determined by optimization. Additional FE models were developed for the Hypo-L and Hyper-L spines. Their kinematics and load-sharing in flexed and extended postures were compared. The kinematics, intradiscal pressure (IDP) and articular facet joint force (FJF) predicted by the FE model were in a good agreement with previous FE results and in-vivo and in-vitro data. The sensitivity analysis revealed that the intervertebral rotations (IVRs), disc moment, and the increase in disc force and moment from neutral to flexed posture were more sensitive to moment magnitude than FL magnitude in case of flexion. The disc force and IDP were more sensitive to the FL magnitude than moment magnitude. The optimal ranges of FL and flexion moment magnitudes were 900N-1100N and 9.9Nm-11.2Nm, respectively. To obtain reasonable compromise between the IDP and disc force, our findings recommend that FL of low magnitude must be combined with flexion moment of high intensity and vice versa. The Hypo-L spine demonstrated stiffer behavior in flexion but more flexible response in extension compared to the Norm-L and Hyper-L spines. The excessive LL stiffened response of the Hyper-L spine to extension but did not affect its resistance to flexion compared to the Norm-L spine. Result showed that contribution of the facet joints and ligaments in supporting bending moments produced additional forces and moments in the discs. Results demonstrated that internal forces produced by FL and flexion were mainly carried by the discs (75%) and posterior ligaments (25%) while contribution of ligaments in supporting internal moment was higher (70%) compared to the discs (20%). Role of the facet joints was negligible except at level L5-S1. This force-sharing was almost similar in all the three spines. In the case of FL and extension, the discs, ligaments and facet joints shared spinal force with proportion of 55%, 20%, 25% respectively in the Hypo-L spine while facet joints contribution did not exceed 10% at levels L1-4 and reached up to 30% at levels L5-S1 in the Norm-L and Hyper-L spines. The facet joints carried up to 63% of the internal moment in the Hyper-L spine. This study demonstrated that spinal load-sharing depends on applied load and varies along the spine. It also depends on spinal curvature. The three spines studied demonstrated that inter-individual curvature variation affects spinal load-sharing only in extended posture while no noticeable difference between the spines was found in flexed posture. Analyzing response of additional spines in each category under different loading conditions such as gravity load in future studies may reveal more significant effects of inter-individual curvature variations.

Download or read book Computational Modeling and Validation of the Deformation and Failure Response of Human Metastatic Vertebrae written by Michelle Xu (Researcher in aeronautics and astronautics) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We show that the proposed approach provides quantitative predictions of the experimental stiffnesses and failure strengths of metastatic vertebrae with good accuracy regardless of the type of metastases the vertebrae exhibit. In addition, we show that by capturing the unique, spatially varying bone volume density in the vertebrae, we are able to obtain detailed descriptions of the local stress and damage responses. From this, we achieve a better understanding of the role metastases play in the deformation and damage response of metastatic vertebrae.

Download or read book Cumulated Index Medicus written by and published by . This book was released on 1989 with total page 1506 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Innovations in Spinal Deformities and Postural Disorders written by Josette Bettany-Saltikov and published by BoD – Books on Demand. This book was released on 2017-09-27 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Innovations in Spinal Deformities and Postural Disorders presents a compendium of innovative work in the management of spinal deformities and postural disorders. The chapters were carefully selected with clinicians, researchers, patients and parents in mind. All of these stakeholders are important links in the management of spinal deformities and disorders. It is our hope that all will remain open to new ideas in the field and will be able to evaluate the material carefully and in ways that are objective and evidence based. We hope that the different chapters in the book will stimulate readers to be original and innovative in their own centers in order to help our patients in the best way possible. This book contains new information on the 3D measurement of, as well as new approaches to, the 3D conservative, including exercises and braces, and surgical treatments for patients with spinal deformities and postural disorders.

Download or read book Handbook of Human Motion written by and published by Springer. This book was released on 2018-04-24 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Handbook of Human Motion is a large cross-disciplinary reference work which covers the many interlinked facets of the science and technology of human motion and its measurement. Individual chapters cover fundamental principles and technological developments, the state-of-the-art and consider applications across four broad and interconnected fields; medicine, sport, forensics and animation. The huge strides in technological advancement made over the past century make it possible to measure motion with unprecedented precision, but also lead to new challenges. This work introduces the many different approaches and systems used in motion capture, including IR and ultrasound, mechanical systems and video, plus some emerging techniques. The large variety of techniques used for the study of motion science in medicine can make analysis a complicated process, but extremely effective for the treatment of the patient when well utilised. The handbook descri bes how motion capture techniques are applied in medicine, and shows how the resulting analysis can help in diagnosis and treatment. A closely related field, sports science involves a combination of in-depth medical knowledge and detailed understanding of performance and training techniques, and motion capture can play an extremely important role in linking these disciplines. The handbook considers which technologies are most appropriate in specific circumstances, how they are applied and how this can help prevent injury and improve sporting performance. The application of motion capture in forensic science and security is reviewed, with chapters dedicated to specific areas including employment law, injury analysis, criminal activity and motion/facial recognition. And in the final area of application, the book describes how novel motion capture techniques have been designed specifically to aid the creation of increasingly realistic animation within films and v ideo games, with Lord of the Rings and Avatar just two examples. Chapters will provide an overview of the bespoke motion capture techniques developed for animation, how these have influenced advances in film and game design, and the links to behavioural studies, both in humans and in robotics. Comprising a cross-referenced compendium of different techniques and applications across a broad field, the Handbook of Human Motion provides the reader with a detailed reference and simultaneously a source of inspiration for future work. The book will be of use to students, researchers, engineers and others working in any field relevant to human motion capture.

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2000 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Clinical Anatomy of the Lumbar Spine and Sacrum written by Nikolai Bogduk and published by Elsevier Health Sciences. This book was released on 2005-01-01 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bogduk aims to provide a foundation of knowledge upon which an understanding of the various treatment and therapy techniques of the different specialities involved can be built. This edition includes discussion of the sacrum and sacro-iliac joint.

Download or read book Innovations in Biomedical Engineering written by Marek Gzik and published by Springer Nature. This book was released on 2022-05-31 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest developments in the field of biomedical engineering and includes practical solutions and strictly scientific considerations. The development of new methods of treatment, advanced diagnostics or personalized rehabilitation requires close cooperation of experts from many fields, including, among others, medicine, biotechnology and finally biomedical engineering. The latter, combining many fields of science, such as computer science, materials science, biomechanics, electronics not only enables the development and production of modern medical equipment, but also participates in the development of new directions and methods of treatment. The presented monograph is a collection of scientific papers on the use of engineering methods in medicine. The topics of the work include both practical solutions and strictly scientific considerations expanding knowledge about the functioning of the human body. We believe that the presented works will have an impact on the development of the field of science, which is biomedical engineering, constituting a contribution to the discussion on the directions of development of cooperation between doctors, physiotherapists and engineers. We would also like to thank all the people who contributed to the creation of this monograph—both the authors of all the works and those involved in technical works.

Download or read book Mechanical Properties of Aging Soft Tissues written by Brian Derby and published by Springer. This book was released on 2014-10-08 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring the structure and mechanics of aging soft tissues, this edited volume presents authoritative reviews from leading experts on a range of tissues including skin, tendons, vasculature and plantar soft tissues. It provides an overview of in vivo and in vitro measurement techniques including state-of-the-art methodologies, as well as focusing on the structural changes that occur within the main components of these tissues resulting in detrimental mechanical property changes. It also highlights the current challenges of this field, and offers an insight into future developments. Age-related changes in the mechanical properties of soft tissues have a profound effect on human morbidity and mortality, and with changing global demographics, there is growing interest in this area. There has been increasing interest in robustly characterizing these mechanical changes to develop structure-property relationships, and growing awareness of the need for enhanced predictive models for computational simulations. This book seeks to address the challenges involved in applying these engineering techniques to reliably characterize these tissues. Focusing on a wide range of tissues and presenting cutting-edge techniques, this book provides an invaluable reference to academics and researchers in a range of disciplines including biomechanics, materials science, tissue engineering, life sciences and biomedicine.

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 Medical Image Processing written by Geoff Dougherty and published by Springer Science & Business Media. This book was released on 2011-07-25 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is designed for end users in the field of digital imaging, who wish to update their skills and understanding with the latest techniques in image analysis. The book emphasizes the conceptual framework of image analysis and the effective use of image processing tools. It uses applications in a variety of fields to demonstrate and consolidate both specific and general concepts, and to build intuition, insight and understanding. Although the chapters are essentially self-contained they reference other chapters to form an integrated whole. Each chapter employs a pedagogical approach to ensure conceptual learning before introducing specific techniques and “tricks of the trade”. The book concentrates on a number of current research applications, and will present a detailed approach to each while emphasizing the applicability of techniques to other problems. The field of topics is wide, ranging from compressive (non-uniform) sampling in MRI, through automated retinal vessel analysis to 3-D ultrasound imaging and more. The book is amply illustrated with figures and applicable medical images. The reader will learn the techniques which experts in the field are currently employing and testing to solve particular research problems, and how they may be applied to other problems.