scholarly journals Finite Element Algorithms for Computational Biomechanics of the Brain

2019 ◽  
pp. 243-272 ◽  
Author(s):  
Adam Wittek ◽  
Grand Roman Joldes ◽  
Karol Miller
Keyword(s):  
Finite Element ◽  
Computational Biomechanics ◽  
The Brain

A finite element model for predicting the distribution of drugs delivered intracranially to the brain

1997 ◽  
Vol 273 (5) ◽  
pp. R1810-R1821 ◽  
Author(s):  
S. Kalyanasundaram ◽  
V. D. Calhoun ◽  
K. W. Leong
Keyword(s):  
Drug Delivery ◽  
Finite Element ◽  
Spin Echo ◽  
Interleukin 2 ◽  
Chemical Species ◽  
Transport Processes ◽  
Proton Density ◽  
Clear Understanding ◽  
Tissue Properties ◽  
The Brain

Drug therapy to the central nervous system is complicated by the presence of the blood-brain barrier. The development of new drug delivery techniques to overcome this obstacle will be aided by a clear understanding of the transport processes in the brain. A rigorous theoretical framework of the transport of drugs delivered locally to the parenchyma has been developed using the finite element method. Magnetic resonance imaging has been used to track the transport of paramagnetic contrast markers in the brain. The information obtained by postprocessing spin-echo, T1-weighted, and proton density images has been used to refine the mathematical model that includes realistic brain geometry and salient anatomic features and allows for two-dimensional transport of chemical species, including both diffusive and convective contributions. In addition, the effects of regional differences in tissue properties, ventricular boundary, and edema on the transport have been considered. The model has been used to predict transport of interleukin-2 in the brain and study the major determinants of transport, at both early and late times after drug delivery.

Influence of Foramen Magnum Boundary Condition on Intracranial Dynamic Response Under Forehead Impact Using Human Body Finite Element Model

2019 ◽  
Vol 17 (07) ◽  
pp. 1950029 ◽  
Author(s):  
Lihai Ren ◽  
Dangdang Wang ◽  
Chengyue Jiang ◽  
Yuanzhi Hu
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Brain Stem ◽  
Axonal Injury ◽  
Human Head ◽  
Foramen Magnum ◽  
Dynamic Responses ◽  
Human Model ◽  
Modeling Methods ◽  
The Brain

The biofidelity is an essential requirement of the application of human head finite element (FE) models to investigate head injuries under mechanical loadings. However, the influence of the foramen magnum boundary condition (FMBC) on intracranial dynamic responses under head impacts has yet to be fully identified until now. This study aimed to investigate the effect of different modeling methods of the FMBC on intracranial dynamic responses induced by forehead impact, especially the axonal injury associated dynamic responses. The total human model for safety (THUMS) was applied in this study. Two FE models with different FMBC modeling methods were developed from the THUMS model. Then, three forehead impact FE models were established respectively, including the original THUMS model. Further FE simulations were conducted to investigate the influence of FMBC modeling methods on intracranial dynamic responses. Though, difference between the intracranial dynamic responses (relative skull-brain motion and strain responses) at areas far from the foramen magnum were slightly, the corresponding difference at the brain stem area were distinctly. Meanwhile, the predicted axonal injury risk of the brain stem white matter was varying among each other. Different modeling methods of FMBC could result in different intracranial dynamic responses of the brain stem, and affect the axonal injury prediction. Therefore, the modeling of the FMBC should be further evaluated for the study of brain stem injury using human head FE models.

Investigation of Stress Wave Propagation in Brain Tissues Through the Use of Finite Element Method

2010 ◽  
Author(s):  
Biaobiao Zhang ◽  
W. Steve Shepard ◽  
Candace L. Floyd
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Brain Injury ◽  
Stress Wave ◽  
Brain Research ◽  
Complex Structure ◽  
Stress Wave Propagation ◽  
Wave Loads ◽  
The Impact ◽  
The Brain

Because axons serve as the conduit for signal transmission within the brain, research related to axon damage during brain injury has received much attention in recent years. Although myelinated axons appear as a uniform white matter, the complex structure of axons has not been thoroughly considered in the study of fundamental structural injury mechanisms. Most axons are surrounded by an insulating sheath of myelin. Furthermore, hollow tube-like microtubules provide a form of structural support as well as a means for transport within the axon. In this work, the effects of microtubule and its surrounding protein mediums inside the axon structure are considered in order to obtain a better understanding of wave propagation within the axon in an attempt to make progress in this area of brain injury modeling. By examining axial wave propagation using a simplified finite element model to represent microtubule and its surrounding proteins assembly, the impact caused by stress wave loads within the brain axon structure can be better understood. Through conducting a transient analysis as the wave propagates, some important characteristics relative to brain tissue injuries are studied.

Finite Element Analysis of Brain Injury due to Head Impact

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1355-1361
Author(s):  
Chang Min Suh ◽  
Sung Ho Kim ◽  
Werner Goldsmith
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Brain Injury ◽  
Head Impact ◽  
Stress And Strain ◽  
Resonance Imaging ◽  
Element Analysis ◽  
External Impact ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

Traumatic Brain Injury (TBI) due to head impact by external impactor was analyzed using Finite Element Method (FEM). Two-dimensiona modeling was performed according to Magnetic Resonance Imaging (MRI) data of Mongolian subject. Pressure variation in a cranium due to external impact was analyzed in order to simulate Nahum et al.'s cadaver test.6 And, analyzed results were compared with Nahum et al.'s experimental data.6 As results, stress and strain behaviors of the brain during impact were accorded with experimental data qualitatively even though there were some differences in quantitative values. In addition, they were accorded with other references about brain injury as well.

Microstructural Hyperelastic Characterization of Brain White Matter in Tension

2019 ◽  
Author(s):  
Mohammadreza Ramzanpour ◽  
Mohammad Hosseini-Farid ◽  
Mariusz Ziejewski ◽  
Ghodrat Karami
Keyword(s):  
Finite Element ◽  
White Matter ◽  
Human Brain ◽  
Volume Fraction ◽  
Fibrous Composite ◽  
Diffuse Axonal Injury ◽  
Stiffness Ratio ◽  
Fibrous Composite Material ◽  
Brain White Matter ◽  
The Brain

Abstract Axons as microstructural constituent elements of brain white matter are highly oriented in extracellular matrix (ECM) in one direction. Therefore, it is possible to model the human brain white matter as a unidirectional fibrous composite material. A micromechanical finite element model of the brain white matter is developed to indirectly measure the brain white matter constituents’ properties including axon and ECM under tensile loading. Experimental tension test on corona radiata conducted by Budday et al. 2017 [1] is used in this study and one-term Ogden hyperelastic constitutive model is applied to characterize its behavior. By the application of genetic algorithm (GA) as a black box optimization method, the Ogden hyperelastic parameters of axon and ECM minimizing the error between numerical finite element simulation and experimental results are measured. Inverse analysis is conducted on the resultant optimized parameters shows high correlation of coefficient (>99%) between the numerical and experimental data which verifies the accuracy of the optimization procedure. The volume fraction of axons in porcine brain white matter is taken to be 52.7% and the stiffness ratio of axon to ECM is perceived to be 3.0. As these values are not accurately known for human brain white matter, we study the material properties of axon and ECM for different stiffness ratio and axon volume fraction values. The results of this study helps to better understand the micromechanical structure of the brain and micro-level injuries such as diffuse axonal injury.

Meshless - The Finite Element of a Direct Coupling Method Mechanical Problems in the Application

2012 ◽  
Vol 548 ◽  
pp. 421-424
Author(s):  
Jin Ping Wang ◽  
Yu Jing Gao ◽  
De Hua Wang
Keyword(s):  
Finite Element ◽  
Shape Function ◽  
Direct Coupling ◽  
Coupling Method ◽  
New Method ◽  
Field Function ◽  
The Core ◽  
Definition Of ◽  
Short Time ◽  
The Brain

Coupling method is developed in recent years to solve numerical problems a new method, meshless - the finite element of a direct coupling method is based on the definition of the generalized unit of coupling of the new method . The core of this method is the use of each unit in the shape function to the assumption that the brain that the whole sub-domain to be seeking to solve the unknown field function. Coupling with other compared with the method is simple to calculate the advantages of a short time.

Patient-specific computational biomechanics of the brain without segmentation and meshing

2012 ◽  
Vol 29 (2) ◽  
pp. 293-308 ◽  
Author(s):  
Johnny Y. Zhang ◽  
Grand Roman Joldes ◽  
Adam Wittek ◽  
Karol Miller
Keyword(s):  
Patient Specific ◽  
Computational Biomechanics ◽  
The Brain
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