Download or read book Head spine Structure Modeling Enhancements to Secondary Loading Path Model and Validation of Head cervical Spine Model Final Report written by Ted Belytschko and published by . This book was released on 1985 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Head spine Structure Modeling written by Ted Belytschko and published by . This book was released on 1985 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: SAM (for Structural Analysis of Man) is a three-dimensional discrete element mathematical model developed for the prediction of the dynamic response of the head-spine-torso structure to severe impact environments. The model mathematically describes the equations of motion for a system of rigid bodies representing, for example, the head, torso segments and the pelvis, interconnected by deformable elements representing, for example, the intervertebral discs, ligaments and other connective tissues. SAM consists of two distinct components; a general purpose, large displacement, dynamic structural analysis program and a data base containing a number of data sets each which contains material, geometric and inertial property, connectivity and loading environment data. This report describes: the development of a model of the diaphragm which, when incorporated into the HSM, will significantly enhance its ability to replicate the effects of the secondary +Gz loading path through the viscera-abdominal wall/diaphragm/rib-cage system; a discussion of spinal injuries associated with pilot ejection and proposed injury criteria for the cervical spine; an axisymmetric finite element analysis of a lumbar vertebral body with comparisons to other models and specific attention to the question of material distribution effects on stresses; and frontal ( -Gx) and lateral (+Gy) impact simulations using the recently developed Head-Cervical Spine Model and comparisons of simulation results with experimental data.
Download or read book A Dynamic Model of the Cervical Spine and Head written by J. Williams and published by . This book was released on 1981 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: A data base of the head and cervical spine structure for a three- dimensional mathematical model of the human head-spine system has been developed on the basis of recently obtained geometric and stiffness data. The model was developed for predicting detailed head-spine system responses and injury probabilities during, for example, retraction/ejection and ground impact. This model of the head and cervical spine structure treats the cervical spine and head as a collection of rigid bodies and deformable elements; the rigid bodies represent the vertebral bodies and head and the deformable elements represent the intervertebral discs, ligaments, facet joints and muscles. The model is completely three dimensional and can treat nonlinearities due to large displacements and material properties. The geometric data consist of the initial configuration of the vertebrae and the points of attachments of the muscles, discs and ligaments to the vertebrae. Particular attention was devoted to reproducing the orientations of the articular facets. Stiffness data for the intervertebral discs, ligaments and facet joints were developed. A muscle model which includes reflex and voluntary activation was included for the major muscles. Inertial data was developed by estimating the height and cross- sectional area of the sections of the neck associated with each motion segment and multiplying by a uniform density.
Download or read book Refinement and Validation of a Three Dimensional Head Spine Model written by and published by . This book was released on 1978 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: A three dimensional discrete model of human spine, torso and head has been refined and validated by comparison with available experimental results. The model consists of a system of rigid bodies, representing the head, vertebrae, and ribs, interconnected by deformable elements which represent the intervertebral discs, ligaments, and other connective tissues. Four models of varying orders of complexity have been developed, ranging from a complex model to a very simplified model with 32 degrees of freedom. The simplified model is able to closely reproduce many of the response characteristics of the more complex models in G sub z loadings, and, because of its simplicity and short running time, may be well suited for design use. Experimental results for human subjects suitable for validation of models are primarily available in the form of impedance curves for vertical harmonic excitation so techniques were developed which efficiently obtain impedance curves for the model. Comparisons of the impedance curves show good agreement, both in the magnitudes and locations of peaks. Furthermore, it was shown that the primary peaks in the impedance curve in the 5 to 7 Hz range result from a combination of buttock-seat resonance, the flexural response of the spine and visceral resonance. Analogous head-spine models were developed for the chimpanzee, baboon, and rhesus monkey. The objective of this development was to provide a scaling methodology for dynamic response and injury data among these non-human primates and man. Impedance curves are presented for these models and show significant differences in character from that of the human spine models.
Download or read book A Personal Computer Based Head Spine Model written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biodynamic Research Corporation (BRC) of San Antonio, TX, completed an SBIR Phase II project to port the Air Force's Head-Spine Model (HSM) to a personal computer environment, improve certain features of the software, and add a user-friendly interface. The impetus for this project was the Air Force's desire to have a software tool capable of modeling the internal forces and motions of the human head and spine during impulsive acceleration events, particularly aircraft ejections. Although models exist to predict the gross motion of a human under acceleration loading, such as the Air Force Articulated Total Body (ATB) model, Dynaman, and MADYMO, the Head-Spine Model is the only tool able to provide estimates of internal forces. For this reason, the HSM could be valuable to the Air Force and other scientists for simulating acceleration environments.
Download or read book Feasibility Study for a Personal Computer Based Head Spine Model written by and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biodynamic Research Corporation (BRC) of San Antonio, TX, completed an SBIR Phase I project to port the Air Force's Head-Spine Model (HSM) to a PC-DOS environment and provide a recommended roadmap for the future of the HSM. The impetus for this project was the Air Force's desire to have a software tool capable of modeling the internal forces and motions of the human head and spine during impulsive acceleration events, particularly aircraft ejections. Although models exist to predict the gross motion of a human under acceleration loading such as the Air Force Articulated Total Body (ATB) model, Dynaman, and MADYMO, the Head-Spine Model (HSM) is the only tool able to provide estimates of internal forces. For this reason, the HSM could be valuable to the Air Force and other scientists for simulating acceleration environments.
Download or read book Impedance of a Three dimensional Head spine Model written by Eberhart Privitzer and published by . This book was released on 1980 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Refinement and Validation of a Three dimensional Head spine Model Final Report written by Ted Belytschko and published by . This book was released on 1978 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sagittal Balance of the Spine written by Pierre Roussouly and published by Thieme. This book was released on 2019-07-25 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unique resource from internationally renowned experts details the key role of sagittal spine balance Through evolution, human verticality became associated with a wide range of normal pelvic shapes and associated pelvic incidence angles (PIs). While all types of sagittal alignment generally provide adequate support to young adults, age, stress, and related degeneration can progressively lead to sagittal imbalance and contribute to various spinal pathologies. Sagittal Balance of the Spine by Pierre Roussouly, João Luiz Pinheiro-Franco, Hubert Labelle, Martin Gehrchen, and a cadre of esteemed international contributors focuses on the importance of sagittal alignment and spino-pelvic shape identification in clinical practice. Offering the most comprehensive text on sagittal balance to date, this state-of-the-art, richly illustrated book fills a void in the literature, offering clinical pearls throughout seven sections and 24 chapters. Key Highlights The biomechanics of sagittal balance including spine modeling, primary parameters, spinal curves segmentation, and lumbar lordosis classification The role of sagittal balance in low back pain and degeneration, with discussion of spinal orientation and the contact forces theory, spinal degeneration associated with spinopelvic morphotypes, and compensatory mechanisms Comprehensive analysis of the relationship between sagittal imbalance and isthmic lysis spondylolisthesis, degenerative spondylolisthesis, Scheuermann's kyphosis, adolescent idiopathic scoliosis, and adult scoliosis Posterior and anterior treatment approaches – from spinal fixation and spinal fusion – to spinal osteotomy techniques and management of surgical failure This text is essential reading for every neurosurgical and orthopaedic resident, as well as veteran surgeons who evaluate and treat patients with spine conditions. Clinicians will learn why incorporating sagittal balance evaluations into spinal exams is integral to devising more effective treatment strategies and achieving improved outcomes.
Download or read book A PC Based Head Spine Model HSM PC written by and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Head Spine Model (HSM) was originally developed by the USAF Aeromedical Research Laboratory during the late seventies. The HSM was created to aid the solution of problems related to spinal loads resulting from ejection seat acceleration. Unfortunately, the original researchers who developed and used the HSM left the Government and the original code has not been maintained or used in research for several years. Biodynamic Research Corporation contracted with the USAF to create a computer model of the dynamic response of the human head and spine that executes on a PC compatible computer under a Windows environment The HSM-PC is aimed at creating simulations of the biomechanical responses of the head and spine to potentially traumatic impulsive acceleration and impact events.
Download or read book A Model for Analytic Investigation of Three dimensional Head spine Dynamics Final Report written by Ted Belytschko and published by . This book was released on 1976 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling the Biodynamical Response of the Human Head for Injury Analysis written by Danielle N. George and published by . This book was released on 2001-09-01 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study is to develop a finite element model of the human head and neck to investigate the biomechanics of head injury. The finite element model is a two-dimensional, plane strain representation of the cervical spine, skull, and major components of the brain including the cerebrum, cerebellum, brain stem, tentorium and the surrounding cerebral spinal fluid. The dynamic response of the model is validated by comparison with the results of human volunteer sled acceleration experiments conducted by Ewing et al. 10 . To validate the head model, one of the head impact experiments performed on cadavers by Nahum et al. 24, is simulated. The model responses are compared with the measured cadaveric test data in terms of head acceleration, and intracranial pressures measured at four locations including the coup and contrecoup sites. The validated model is used to demonstrate that the Head Injury Criterion (HIC), which is based on resultant translational acceleration of the center of gravity of the head, does not relate to the various mechanisms of brain injury and is therefore insufficient in predicting brain injury.
Download or read book Head and Neck written by Enrico Marani and published by Springer. This book was released on 2018-11-02 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a critical review of the head and neck from an anatomical, physiological and clinical perspective. It begins by providing essential anatomical and physiological information, then discusses historical and current views on specific aspects in subsequent chapters. For example, the anatomy of the skull cap or cranial vault provided in the first chapter is discussed in the context of malformation and identity, as well as the development of the bony skull, in the following chapters. These chapters provide stepping-stones to guide readers through the book. There are new fields of research and technological developments in which Anatomy and Physiology lose track of progress. One of the examples discussed is the automated face recognition. In some respects, e.g. when it comes to cancers and malformations, our understanding of the head and neck – and the resulting therapeutic outcomes – have been extremely disappointing. In others, such as injuries following car accidents, there have been significant advances in our understanding of head and neck dysfunctions and their treatment. Therefore head movements, also during sleep, and head and neck reflexes are discussed. The book makes unequivocal distinctions between correct and incorrect assumptions and provides a critical review of alternative clinical methods for head and neck dysfunctions, such as physiotherapy and lymphatic drainage for cancers. Moreover, it discusses the consequences of various therapeutic measures for physiological and biomechanical conditions, as well as puberty and aging. Lastly, it addresses important biomedical engineering developments for hearing e.g. cochlear implants and for applying vestibular cerebellar effects for vision.
Download or read book A Dynamic Model of the Cervical Spine and Head Final Technical Report written by J. Williams and published by . This book was released on 1981 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Development of EMG Assisted Cervical Spine Biomechanical Model written by Mina Alizadeh and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Annual prevalence rates of neck pain have grown and are expected to continue to rise due to workforce shifting from manufacturing to office work. In spite of the prevalence of neck disorders, the biomechanical mechanism of development remains unclear. Therefore, it is important to better understand the biomechanical forces acting on the cervical spine in order to prevent workplace related neck disorders, decrease the economic burden and improve the quality of life for those suffering. In order to explore these mechanisms, cervical spine computer models have been developed to estimate spine loading, which can be compared with the tolerance limit of intervertebral discs to understand injury risk. Although there are several cervical spine models currently available, mostly are aimed to simulate whiplash situation and are ill-equipped for simulating daily living activities and many limitations associated to the model predictions. Therefore, the objective of this study was to develop a dynamic model, capable of accurate estimation of spinal load during complex occupational and daily living tasks. Hence, the objective of this study was to develop a dynamic biomechanical model of cervical spine capable of simulating complex head and neck motion while accurately estimating spinal tissue loading. Four major steps were conducted to meet this goal. First, a systematic literature review was performed in order to classify existing cervical spine models and to recognize model limitations and the existing gap in the cervical spine modeling area. The most common technique of cervical spine model was multi-body dynamic models. Straight line of action for muscle geometry was commonly developed by attaching muscle origin and insertion, inverse dynamics models were typically used to estimate muscle forces. None of the models had incorporated subject specific muscle activation and properties to accurately estimate both active and passive muscle force components. Several models have attempted to examine their results by comparing their approach with previous studies, however, only limited conditions were able to be examined. Second, the supplication of MRI data in order to develop muscle curved line of action was investigated. Third, the model structure was developed to drive active muscle force by subject specific surface EMG data, curved muscle geometry, separate active and passive muscle forces, and personalized muscle properties. Lastly, model fidelity of the human cervical spine EMG-assisted model was evaluated for 11 subjects (6 males and 5 females) during a wide range of isometric and dynamic neck exertions. The results of this study indicate that personalized EMG-assisted modelling approach is an empirically reasonable approach to accurately estimate spinal moments and spinal tissue loads of the cervical spine. In general, the model predicted at least 80% of the variability in cervical spine moments, and less than 15% of average moment matching error across levels. This model is expected to help quantify neck biomechanical loading during daily living activities and complex occupational postures in order to evaluate risk exposure more accurately, improve patient health and enable the development of interventions that could mitigate risks in occupational jobs.
Download or read book A Model for Analytic Investigation of Three Dimensional Head Spine Dynamics written by T. Belytschko and published by . This book was released on 1976 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: A three dimensional, discrete model of the human spine, torso and head was developed for the purpose of evaluating mechanical response in pilot ejection and it was developed in sufficient generality to be applicable to other body response problems, such as occupant response in aircraft crash and arbitrary loads on the head-spine system. There are no restrictions on the distribution or direction of applied loads, so a wide variety of situations can be treated. Results are presented for a variety of conditions, such as different rates on onset, ejection at angles, effects on lumbar curvature, and eccentric head loadings. It is shown that large initial curvatures and perfectly vertical acceleration loadings result in substantial flexural response of the spine, which cause large bending moments. It is further shown that the combination of the spines low flexural stiffness, initial curvature, and mass eccentricity are such that stability cannot be maintained in a 10 g ejection without restraints or spine-torso-musculature interaction.
Download or read book Structural Modeling of Human Head written by S. H. Advani and published by . This book was released on 1975 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
