Download or read book Using Finite Element Modeling to Analyze Injury Thresholds of Traumatic Brain Injury from written by Anna Marie Dulaney and published by . This book was released on 2018 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: A finite element model was developed for a range of human head-sUAS impacts to provide multiple case scenarios of impact severity at two response regions of interest: global and local. The hypothesis was that for certain impact scenarios, local response injuries of the brain (frontal, parietal, occipital, temporal lobes, and cerebellum) have a higher severity level compared to global response injury, the response at the Center of Gravity (CG) of the head. This study is the first one to predict and quantify the influence of impact parameters such as impact velocity, location, offset, and angle of impact to severity of injury. The findings show that an sUAS has the potential of causing minimal harm under certain impact scenarios, while other scenarios cause fatal injuries. Additionally, results indicate that the human head’s global response as a less viable response region of interest when measuring injury severity for clinical diagnosis. It is hoped that the results from this research can be useful to assist decision making for treatments and may offer different perspectives in sUAS designs or operation environments.

Download or read book Biomechanical Analysis of Traumatic Brain Injury by MRI based Finite Element Modeling written by 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 Development of Rat Head Finite Element Model and Tissue Level Biomechanical Threshold for Traumatic Axonal Injury written by Runzhou Zhou and published by . This book was released on 2020 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: The white matter tissues with highly aligned axonal fibers were modeled with transversely isotropic materials to simulate impact direction-dependent injury in the brain. The rat head/body model was validated against in vivo rodent dynamic cortical deformation, brain-skull displacement, and head impact acceleration experimental data. A series of FE parametric studies were conducted to identify various biomechanical factors contributing to the variability of injury severity observed among experiments and across different labs. The FE rat model simulated in vivo TAI in rat brains from closed-head impact acceleration experiments. The correlation of the local biomechanical parameter map with the severity and extent of axonal injury map at tissue levels was established. This improved our understanding of tissue-level injury mechanism for white matter injury. The tissue level thresholds for white matter injury was established by logistic regression analysis. The localized severe TAI in cerebral white matter (corpus callosum region) was best predicted by intracranial pressure (81 kPa) and maximum principal strain (0.26), while the white matter tracts in the brainstem (pyramidal tracts) were best predicted by localized maximum principal strain (0.18) response. The tissue level thresholds developed from this study can be directly translated to the FE human head model. This information will enhance the capability of the human head model in predicting brain injury.

Download or read book Head Injury Simulation in Road Traffic Accidents written by Fábio A. O. Fernandes and published by Springer. This book was released on 2018-04-27 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work the development of a new geometrically detailed finite element head model is presented. Special attention is given to sulci and gyri modelling, making this model more geometrically accurate than others currently available. The model was validated against experimental data from impact tests on cadavers, specifically intracranial pressure and brain motion. Its potential is shown in an accident reconstruction case with injury evaluation by effectively combining multibody kinematics and finite element methodology.

Download or read book A Finite Element Head Injury Model Theory development and results written by T. A. Shugar and published by . This book was released on 1977 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sensitivity Analysis of a Finite Element Head Model to Skull Material Properties in the Study of Traumatic Brain Injury written by Hesam Moghaddam and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Traumatic brain injury (TBI) occurs as result of a sudden trauma to the brain due to impacts or the rapid movement of the head caused by falls, accidents, sports contacts, and physical assaults. TBI can lead to long-term cognitive, physical, and neurological impairments and hence should be prevented. While head kinematics can be experimentally estimated - to a good extent - using dummy heads, assessment of tissue responses of the brain in terms of the intracranial pressure, shear stresses, and strains is technically and morally challenging. Accordingly, due to complications of experimental tests, computational methods such as finite element analysis (FEA) have extensively been used in the last decade to study the injury mechanisms associated with TBI. However, the fidelity of these models is still a concern when conclusions are to be drawn based on numerical results. One major aspect of each computational work is the implementation of accurate material models which can mimic the real behavior of biological tissues. Skull protects the brain against injury by attenuating the transferred load to the intracranial space upon an impact to the head. Several material properties have been used for skull in the literature in the context of impact induced TBI. These studies have used a wide range of densities and Youngu2019s moduli for the skull; however, they have used different head models and loading conditions. Our study aims to investigate the sensitivity of a FE head model to skull material properties. To this end, North Dakota State University Finite Element Head Model (NDSUFEHM) was exposed to an identical impact using three different sets of material properties in terms of density and Youngu2019s modulustaken from the well-substantiated impact TBI studies. A frontal impact scenario was developed by impacting the head moving at 2.5 m/s against a rigid wall 45 degrees about its horizontal plane. Time histories of ICP and shear stress at the location of maximum value were recorded and compared for all three material properties sets. Our primary results predicted noticeable differences among pressure and shear responses both in terms of the peak values and their pattern. Our results suggested the need for a unique set of skull properties in order to improve the biofidelity of FE models.

Download or read book Experimental and Computational Modeling of Traumatic Brain Injury written by David Ira Shreiber and published by . This book was released on 1998 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Modeling of Brain Injury for Performance Evaluation of Football Helmets written by Derek Wallin and published by . This book was released on 2018 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: Football helmets worn today are primarily designed to prevent skull fracture and irreversible brain injury. In that limited respect, today’s helmets are a success with the frequency of reported football-related skull fracture a rare occurrence. In recent decades, however, concussion, mild traumatic brain injury (mTBI), and chronic traumatic encephalopathy (CTE) are being reported with increasing incidence. Helmet manufacturing companies are limited in their performance analysis of helmets, with no standard helmet testing procedures incorporating anatomical data or physiological weaknesses of the brain. Finite Element Modeling of the brain has allowed for analysis of the mechanics of brain injury and can provide injury metrics based on simulated brain injury. In this study the background on current helmet testing procedures is provided as well as a finite element study of brain injury to determine helmet performance. In addition, this modeling will be used to identify what types of impacts are most dangerous.

Download or read book Investigation of Primary Blast Injury and Protection Using Sagittal and Transverse Finite Element Head Models written by Dilaver Singh and published by . This book was released on 2015 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: The prevalence of blast related mild traumatic brain injury (mTBI) in recent military conflicts, attributed in part to an increased exposure to improvised explosive devices (IEDs), requires further understanding to develop methods to mitigate the effects of primary blast exposure. Although general blast injury has been studied extensively since the 1950's, many aspects of mTBI remain unclear, including specific injury mechanisms and injury criteria. The purpose of this work was to develop finite element models to investigate primary blast injury to the head in the loading regimes relevant to mTBI, to use the models to determine the response of the brain tissue, and ultimately to investigate the effectiveness of helmets on response mitigation. Since blast is inherently a wave dominated phenomena, finite element models require relatively small elements to resolve complex pressure wave transmission and reflections in order to accurately predict tissue response. Furthermore, mesh continuity between the tissue structures is necessary to ensure accurate wave transmission. The computational limitations present in analyzing a full three dimensional blast head model led to the development of sagittal and transverse planar models, which provide a fully coupled analysis with the required mesh resolution while remaining computationally feasible. The models consist of a single layer of solid hexahedral elements, and include all of the relevant tissues in the head including the skin, muscle, skull, cerebrospinal fluid, and brain. The sagittal and transverse models were validated using head kinematics against experimental data on Hybrid III head-forms exposed to free-field blast. The peak head accelerations of the models was in close agreement to the experimental data, and the HIC15 predictions were in reasonable agreement. In addition, the models were validated for intracranial pressure using experimental data from cadaveric heads exposed to shock tube loading. The intracranial pressures predicted by the sagittal and transverse models was in good agreement at the frontal, temporal, and parietal locations, and in fair agreement at the occipital location. A simplified three dimensional ellipsoid study was undertaken to verify that sagittal and transverse planar models are capable of representing a three dimensional shape. This investigation confirmed that the pressures predicted by the planar models are accurate at the frontal, temporal, and parietal locations, although underpredicted at the occipital location due to three dimensional wave superposition that becomes significant at the occipital region. The sagittal and transverse models were run at three representative blast load cases, corresponding to 5 kg of C4 at 3, 3.5, and 4 m standoff distances, and the resulting intracranial strains and pressures were investigated. The sagittal and transverse models report peak principal strains of 0.035 - 0.062 and 0.053 - 0.087 respectively. In comparison to the available threshold values of principal strain in the literature, the strains predicted by the models are generally low. While the strains reported by the models in primary blast are small, the strain rates are significantly greater (ranging from 226 - 571 s-1) than those seen in typical automotive or blunt impact scenarios. Furthermore, the models report that significant levels of intracranial pressure, on the order of several atmospheres, can be generated in the brain tissue during primary blast exposure. The peak pressures in the brain tissue for both models typically exceeded the existing injury thresholds for intracranial that are available in the literature. However, these existing criteria were generally developed for automotive crash scenarios, so may not be suitable for the short durations inherent to blast. The magnitudes of intracranial pressure increased significantly with increasing blast load severity, while changes in principal strain were relatively small, and peak strains were low in all three load cases, suggesting that pressure may be a more appropriate injury response metric for blast injury. The sagittal and transverse models were outfitted with various military helmet configurations and materials to investigate the influence of helmet visors, foam lining presence and density, and Kevlar material stiffness on the protective properties of the helmet. The peak head accelerations and intracranial pressures were compared for low and high intensity blast loads. In general, the presence of a helmet resulted in reduced peak head accelerations, and a greater reduction was reported with the addition of a half-visor and full-visor. The presence of a visor significantly reduced positive intracranial pressures in all cases, although increased the maximum negative pressures in some cases. The effects of the foam lining material was not as significant to the model response as the helmet visor configurations, but in general, a lower density foam provided better load mitigation. In cases where there was no foam lining, pressure wave reflections in the air gap between the helmet and head were found to cause greater intracranial pressures in adjacent brain tissue, although the magnitudes of these increased pressures were generally lower than the incident compressive pressures caused by the initial wave impact.

Download or read book Simulation of Traumatic Brain Injury in Children Using Finite Element Modeling written by Ziman Cheng and published by . This book was released on 2017 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traumatic brain injury is the main cause of disability and death in children and infants. This thesis focuses on establishing the consequences of an external force or impact on brain tissues. FE model has been introduced to investigate the consequences of impact force, either dynamic or static, onto the infant brain. Deformable meshes are involved in FE models to generate time-dependent pressure change in various brain tissues. Results demonstrate that our finite element model is capable of investigating brain tissue pressure transmission within certain impact force and can be used for simulation of minor brain injury in infants.

Download or read book Traumatic Brain Injury Thresholds in the Pre adolescent Juvenile written by Matthew R. Maltese and published by . This book was released on 2012 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Finite Element Head Injury Model Volume I Theory Development and Results Final Report written by T. A. Shugar and published by . This book was released on 1977 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Analysis of Traumatic Brain Injury Due to Small Unmanned Aircraft System sUAS Impacts on the Human Head written by Alex Nelson Smith and published by . This book was released on 2019 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: A biofidelic finite element model was developed from an acquired set of CT scans for a range of human head and UAS impacts to provide simulations of multiple velocity scenarios of impact severity at four impact orientations on the human head. The hypothesis was that a correlation existed between the total amounts of kinetic energy of the impact from the UAS and human head collision, as well as that location of impact plays a role in the injury risk sustained. Linear acceleration, angular velocity, and pressure data values were calculated for each individual simulated case and then further correlated to injury risks that represent the severity of damage that would be sustained from the collision. Resulting data proved to show that impact kinetic energy, impact orientation, and impact response of the head and UAS all play vital roles in the amount of damage that is sustained from the impact collisions.

Download or read book Predicting Cognitive Impairment Following Traumatic Brain Injury A Mathematical Approach written by Haojie Mao and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: INTRODUCTIONThe presence of sports related concussions and minor traumatic brain injuries has increase in frequency over the past decade. Where a possible reason for the increase is improved diagnosis methods and general awareness, the overall improvement in helmet safety technology has seemingly not had a significant effect on reducing these concussion symptoms. Short term effects of traumatic brain injuries are known to lead to impairment in cognitive functions. This study looks to provide a quantitative predictor for how the direction of head impact leads to a biomechanical response in the deep brain, more specifically the corpus callosum (CC) and how it affects cognitive aptitude. The CC contains the greatest density of fibril tract connections between the cerebral hemispheres of the brain making it the primary neural connector and an important factor for human cognitive function. The existence of previous literature with defined diffuse axonal injury (DAI) thresholds allows for a comparative study and the ability to use a mathematical approach as a preliminary predictor of injury.METHODSUsing Diffusion Tensor Imaging (DTI) a computed tractography finite element model of the fibril network (Essen et al 2013) was created and inserted into the Global Human Body Model Consortium (GHBMC) head and brain model. Different impact loading cases (n= 4) were simulated with similar time-history impact curves (5k rad/s^2 at 10 ms) to recreate artificial rotational impact scenarios. The four cases presented in this study are: flexion, extension, rotation and lateral bend. The results of these mathematical simulations were then analyzed quantitatively for both magnitude and location of greatest maximum principal strain (MPS) as well as largest Cumulative Strain Damage Measure (CSDM). RESULTSThe GHBMC and DTI fibril network of the CC finite element model showed that the peak MPS was largest in the lateral bend (0.256) that was followed by extension (0.221) and flexion (0.206) and finally rotation (0.192). The Fibril networks had opposing rankings with flexion and extension having an MPS of 0.475 followed by lateral bend at 0.31 and rotation at 0.225. These results were then further analyzed using CSDM to determine more in depth, the extent of the injury. DISCUSSION AND CONCLUSIONThese results help set up the quantitative assessment of the cognitive effects of brain injury, based on previous literature thresholds. The use of computer simulation to both diagnose and identify areas of the brain injured through reverse processing the qualitative symptoms of cognitive tests is a novel approach with many clinical and industry advantages. The future goal of this study is to provide the link between current cognitive tests and the areas affected by traumatic brain trauma while providing a new tool for safety manufactures to quantify the effectiveness of safety equipment designed to protect the brain.

Download or read book The Brain written by Jeffrey A Pike and published by SAE International. This book was released on 2011-09-08 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nearly 50,000 Americans die from brain injuries annually, with approximately half of all Traumatic Brain Injuries (TBI) being transportation-related. TBI is a critical and ever-evolving safety topic, with equally important components of injury prevention, consequences, and treatment. This book is part of a 3-volume set which presents a comprehensive look at recent head injury research and focuses on injury of the head’s contents and features 13 technical papers. These publications are primarily related to injuries to the brain, its surrounding membranes, and its blood supply. Editor Jeffrey A. Pike has selected the most relevant technical papers spanning the early 1990s through the beginning of 2011, including several older papers which provide an essential historical perspective. Each volume in the series also includes a table of references arranged by topic and a new chapter tying together anatomy, injury, and injury mechanism topics. Buy the Set and Save! Head Injury Biomechanics The three-volume set consists of these individual volumes: Head Injury Biomechanics, Volume 1--The Skull Head Injury Biomechanics, Volume 2--The Brain Head Injury Biomechanics, Volume 3--Mitigation

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 Traumatic Brain Injury Assessment Using the Integration of Pattern Recognition Methods and Finite Element Analysis written by Babak Seyed Aghazadeh and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall goal of this research is to develop methods and algorithms to investigate the severity of Traumatic brain injury (TBI) and to estimate the intracranial pressure (ICP) level non-invasively. Brain x-ray computed tomography (CT) images and artificial intelligence methods are employed to estimate the level of ICP. Fully anisotropic complex wavelet transform features are proposed to extract directional textural features from brain images. Different feature selection and classification methods are tested to find the optimal feature vector and estimate the ICP using support vector regression. By using systematic feature extraction, selection and classification, promising results on ICP estimation are achieved. The results also indicate the reliability of the proposed algorithm. In the following, case-based finite element (FE) models are extracted from CT images using Matlab, Solidworks, and Ansys software tools. The ICP estimation obtained from image analysis is used as an input to the FE modeling to obtain stress/strain distribution over the tissue. Three in-plane modeling approaches are proposed to investigate the effect of ICP elevation on brain tissue stress/strain distribution. Moreover, the effect of intracranial bleeding on ICP elevation is studied in 2-D modeling. A mathematical relationship between the intracranial pressure and the maximum strain/stress over the brain tissue is obtained using linear regression method. In the following, a 3-D model is constructed using 3 slices of brain CT images. The effect of increased ICP on the tissue deformation is studied. The results show the proposed framework can accurately simulate the injury and provides an accurate ICP estimation non-invasively. The results from this study may be used as a base for developing a non-invasive procedure for evaluating ICP using FE methods.