Download or read book Modeling and Simulation of Human Lumbar Spine written by Wilbur Wong and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The human vertebral column serves as the primary protection system to the main spinal cord nerves. By studying a model of how each vertebra reacts under a force applied at different postures would provide valuable information to future medical studies. There is not a standard technique available yet that can be applied to each human. By modeling of the spine using free body diagrams to create equations of motion and using computer software to simulate the lumbar region, the result would allow us to study how the forces and stresses would relate. In addition, this will provide a more precise analysis for vertebral column under different postures. Since each vertebra has a different shape and mass, the model of the spine should be represented using lumped mass, and the tissue and disc surrounding the body of the vertebrae will be represented by spring and dampers. The equations developed is solved using a MATLAB code which plots displacements, while the software, Patran, would output plots of displacement using finite element analysis. With two different modeling approaches, we will be able to determine how different loadings on the spine would affect its deformations.

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 A Two dimensional Human Spine Simulation and Three dimensional Spine Model Construction written by Jianzhi Liu and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: This thesis describes two different, but complementary modeling tasks for the human spine. Methodologies for modeling and simulation of the motion of the human spine vary dramatically in complexity. While providing detailed stress and strain field representations, full finite element modeling of the human spine can be computationally expensive. Alternatively, nonlinear multibody dynamics representations are often used because of their simplicity. These formulations employ rigid models of vertebrae interconnected via conventional mechanical joints. However, it is well documented that inter-vertebral motion can depart significantly from conventional mechanical joint constraints. We present an identification methodology that employs a relaxation technique in which joint mechanical properties are represented via a probability measure. In addition we describe an effort to obtain accurate three-dimensional models of the human spine. These efforts are motivated by considering scoliosis. Scoliosis is defined as abnormal lateral curvature of the spine. It is usually considered as a three-dimensional deformity, because axial rotation will always accompany the lateral curvature. The correction of the deformity is required when the patient risks severe deformity. A three-dimensional spine model is constructed and a computer simulation tool is provided.

Download or read book THREE DIMENSIONAL MODELING OF THE LUMBAR SPINE written by Ayman Kassem and published by . This book was released on 2010-04 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation of the excitation of human lower spinal cord structures with surface electrodes 3D finite element analysis and nerve fiber modeling written by and published by Josef Ladenbauer. This book was released on 2008 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Machines Mechanism and Robotics written by Rajeev Kumar and published by Springer Nature. This book was released on 2021-07-21 with total page 1830 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume includes select papers presented during the 4th International and 19th National Conference on Machines and Mechanism (iNaCoMM 2019), held in Indian Institute of Technology, Mandi. It presents research on various aspects of design and analysis of machines and mechanisms by academic and industry researchers.

Download or read book Three Dimensional Modeling of the Lumbar Spine for Simulation Purposes written by Ayman Hamdy Mohamed Kassem and published by . This book was released on 2002 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this research, a spinal toolbox, for modeling lumbar spine, was built which contains different types of models (i.e. spinal element, Ligaments, discs, and beam models) to be used for specific loading cases.

Download or read book An Analysis of the Effect of Artificial Disc Replacement on the Mechanical Response of the Human Lumbar Spine written by Antonio Jose Gonzalez and published by . This book was released on 2007 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: mathematica model, lumbar spine, matlab simulation, artificial discs, simplified spine model.

Download or read book Biomechanical Models of the Human Thoracic and Lumbar Spine written by Maria Elizete Kunkel and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2012-04 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Severe cases of scoliosis are treated using implants. The effects of different types of implants have been investigated with mathematical models with modifiable geometry. Our aim was perform a nonlinear regression analyses with anatomical data to generate prediction equations for vertebral and intervertebral disc dimensions as a function of only one given dimension measurable by X-ray, the vertebral body height. Third-order polyno-mial regressions provided moderate to high correlation between the vertebral body heights and the endplates and spinal canal; pedicle heights and the spinous process, in addition to a reasonable correlation of the posterior vertebral structures (pedicle and facet). A set of 50 equations was generated for the prediction of the spine dimensions based on the radiographic measurement of the vertebral body height. It was possible to establish useful predictions for all investigated dimensions. This is an efficient approach for obtaining anatomical data for modeling of the human thoracic and lumbar from measurement of only one parameter per vertebra without the need for direct measurement or 3D reconstructions from medical images.

Download or read book Clinical Biomechanics written by Zeevi Dvir and published by . This book was released on 2000 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: Leading authorities provide an exploration of biomechanics focusing on specific issues related to diagnosis and treatment of musculoskeletal problems. Discussions point out the critical significance of biomechanical analysis to the understanding of muscle-joint interactions and the implications for normal and abnormal function.

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 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 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 Finite Element Model Development of the Human Lumbar Spine and Dynamic Stabilization Device Analysis written by Chaudhry Raza Hassan and published by . This book was released on 2015 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Three Dimensional Finite Element Model to Study the Biomechanical and Kinematic Characteristics of the Human Lumbar Spine in Flexion written by Dhruv Jitesh Mehta and published by . This book was released on 2007 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of the research was to develop a three-dimensional finite element model to study the biomechanical and kinematic characteristics of the human lumbar spine in flexion. An analytical model of the lumbar spine capable of taking into consideration the actual geometry, non-linear material properties and realistic loading would be of benefit in studying normal biomechanics, as well as in-vivo behavior in injured and surgically altered spines. Fundamental to this approach is an accurate model of the spine. This was achieved by modeling the lumbar segments L2-L4 from Computed Tomography (CT) data and analyzing them under loading conditions that best approximated the human lumbar segments in flexion. An in-vitro study was performed for validation of the finite element model. Human lumbar cadaveric spinal segments (L2-L4) were loaded based on test conditions similar to those defined in the finite element analysis. The results of the cadaver biomechanical study and finite element analysis were compared. The results suggest that the model is a valid approach to assessing the range of motion of the L3 segment under flexion. Rotation under lateral bending moments was additionally investigated to provide a thorough validation of the model.

Download or read book Experimental and Analytical Modeling of the in Vivo and in Vitro Biomechanical Behavior of the Human Lumbar Spine written by Tov I. Vestgaarden and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: This dissertation has two major parts; Analytical and Experimental. The analytical section contains a study using Finite Element Analysis of dynamic instrumentation to demonstrate stress reduction in adjacent level discs. The experimental section contains biomechanical testing of facet fusion allograft technique and finally a comparison between In Vivo and In Vitro intradiscal pressures to determine forces acting on Lumbar spine segment L4-L5. A comprehensive study of available data, technology and literature was done. Conventional fusion instrumentation is believed to accelerate the degeneration of adjacent discs due to the increased stresses caused by motion discontinuity. A three dimensional finite element model of the lumbar spine was obtained which simulated flexion and extension. Reduced stiffness and increased axial motion of dynamic posterior lumbar fusion instrumentation designs results in a ~10% cumulative stress reduction for each flexion cycle. The cumulative effect of this reduced amplitude and distribution of peak stresses in the adjacent disc may partially alleviate the problem of adjacent level disc degeneration. Traditionally a pedicle screw system has been used for fixation of the lumbar spine and this involves major surgery and recovery time. Facet fixation is a technique that has been used for stabilization of the lumbar spine. The cadaver segments were tested in axial rotation, combined flexion/extension and lateral bending. Implantation of the allograft dowel resulted in a significant increase in stiffness compared to control. Facet fusion allograft provides an effective minimally invasive method of treating debilitating pain caused by deteriorated facet joints by permanently fusing them. An In Vitro biomechanical study was conducted to determine the intradiscal pressure during spinal loading. The intradiscal pressures in flexion/extension, lateral bending and axial rotation was compared to In Vivo published data. There is no data that explains the actual forces acting on the spine during flexion, extension, lateral bending or axial rotation. The functional spinal units were tested in combined axial compression and flexion/extension, combined axial compression and lateral bending and combined axial compression and axial rotation using a nondestructive testing method. Overall, this study found a good correlation between In Vivo and In Vitro data. This can essentially be used to make physiological relation from experimental and analytical evaluations of the lumbar spine. It is important to know how much load needs to be controlled by an implant.