Development and validation of a head/brain FE model and investigation of influential factor on the brain response during head impact

2016 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
Noritoshi Atsumi ◽  
Yuko Nakahira ◽  
Masami Iwamoto
2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Miao Na ◽  
Timothy J. Beavers ◽  
Abhijit Chandra ◽  
Sarah A. Bentil

Abstract Finite element (FE) method has been widely used for gaining insights into the mechanical response of brain tissue during impacts. In this study, a coupled Eulerian−Lagrangian (CEL) formulation is implemented in impact simulations of a head system to overcome the mesh distortion difficulties due to large deformation in the cerebrospinal fluid (CSF) region and provide a biofidelic model of the interaction between the brain and skull. The head system used in our FE model is constructed from the transverse section of the human brain, with CSF modeled by Eulerian elements. Spring connectors are applied to represent the pia-arachnoid connection between the brain and skull. Validations of the CEL formulation and the FE model are performed using the experimental results. The dynamic response of brain tissue under noncontact impacts and the brain regions susceptible to injury are evaluated based on the intracranial pressure (ICP), maximum principal strain (MPS), and von Mises stress. While tracking the critical MPS location on the brain, higher likelihood of contrecoup injury than coup injury is found when sudden brain−skull motion takes place. The accumulation effect of CSF in the ventricle system, under large relative brain−skull motion, is also identified. The FE results show that adding relative angular velocities, to the translational impact model, not only causes a diffuse high strain area, but also cause the temporal lobes to be susceptible to cerebral contusions since the protecting CSF is prone to be squeezed away at the temporal sites due to the head rotations.


2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Ryan D. M. Packett ◽  
Philip J. Brown ◽  
Gautam S. S. Popli ◽  
F. Scott Gayzik

Tissue cooling has been proven as a viable therapy for multiple conditions and injuries and has been applied to the brain to treat epilepsy and concussions, leading to improved long-term outcomes. To facilitate the study of temperature reduction as a function of various cooling methods, a thermal brain phantom was developed and analyzed. The phantom is composed of a potassium-neutralized, superabsorbent copolymer hydrogel. The phantom was tested in a series of cooling trials using a cooling block and 37 deg water representing nondirectional blood flow ranging up to 6 gph, a physiologically representative range based on the prototype volume. Results were compared against a validated finite difference (FD) model. Two sets of parameters were used in the FD model: one set to represent the phantom itself and a second set to represent brain parenchyma. The model was then used to calculate steady-state cooling at a depth of 5 mm for all flow rates, for both the phantom and a model of the brain. This effort was undertaken to (1) validate the FD model against the phantom results and (2) evaluate how similar the thermal response of the phantom is to that of a perfused brain. The FD phantom model showed good agreement with the empirical phantom results. Furthermore, the empirical phantom agreed with the predicted brain response within 3.5% at physiological flow, suggesting a biofidelic thermal response. The phantom will be used as a platform for future studies of thermally mediated therapies applied to the cerebral cortex.


2005 ◽  
Vol 297-300 ◽  
pp. 1333-1338
Author(s):  
Chang Min Suh ◽  
Sung Ho Kim ◽  
Byung Won Hwang

Brain damage by the impact force was evaluated by the numerical analysis with a three dimensional Finite Element (FE) model. The FE model was constructed from the MRI data of a subject, and visco-elastic behavior for constitutive equation was applied to the brain tissue. From the FE simulation, brain damage and deformation of the frontal head impacted by a steel impactor were analyzed. The variations of head acceleration and Intra-Cranial Pressure (ICP) during the impact were analyzed in order to evaluate Traumatic Brain Injury (TBI). In addition, relative displacement between the skull and the brain due to head impact was investigated. And, pathological severity was evaluated according to Head Injury Criterion (HIC) from the FE simulation. The analytic results of brain damage showed a good agreement with those of the cadaver test performed by Nahum et al. (1977) and other medical reports. And then, the variation of the HIC value was evaluated according to various impact conditions. This study would provide useful data and methodology in the field of biomechanics for analyzing the brain damage by head impact.


Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 286
Author(s):  
Soheil Keshmiri

Recent decades have witnessed a substantial progress in the utilization of brain activity for the identification of stress digital markers. In particular, the success of entropic measures for this purpose is very appealing, considering (1) their suitability for capturing both linear and non-linear characteristics of brain activity recordings and (2) their direct association with the brain signal variability. These findings rely on external stimuli to induce the brain stress response. On the other hand, research suggests that the use of different types of experimentally induced psychological and physical stressors could potentially yield differential impacts on the brain response to stress and therefore should be dissociated from more general patterns. The present study takes a step toward addressing this issue by introducing conditional entropy (CE) as a potential electroencephalography (EEG)-based resting-state digital marker of stress. For this purpose, we use the resting-state multi-channel EEG recordings of 20 individuals whose responses to stress-related questionnaires show significantly higher and lower level of stress. Through the application of representational similarity analysis (RSA) and K-nearest-neighbor (KNN) classification, we verify the potential that the use of CE can offer to the solution concept of finding an effective digital marker for stress.


Author(s):  
Jeffrey S. Brooks ◽  
Adam Redgrift ◽  
Allen A. Champagne ◽  
James P. Dickey

AbstractThis study sought to evaluate head accelerations in both players involved in a football collision. Players on two opposing Canadian university teams were equipped with helmet mounted sensors during one game per season, for two consecutive seasons. A total of 276 collisions between 58 instrumented players were identified via video and cross-referenced with sensor timestamps. Player involvement (striking and struck), impact type (block or tackle), head impact location (front, back, left and right), and play type were recorded from video footage. While struck players did not experience significantly different linear or rotational accelerations between any play types, striking players had the highest linear and rotational head accelerations during kickoff plays (p ≤ .03). Striking players also experienced greater linear and rotational head accelerations than struck players during kickoff plays (p = .001). However, struck players experienced greater linear and rotational accelerations than striking players during kick return plays (p ≤ .008). Other studies have established that the more severe the head impact, the greater risk for injury to the brain. This paper’s results highlight that kickoff play rule changes, as implemented in American college football, would decrease head impact exposure of Canadian university football athletes and make the game safer.


Author(s):  
M. S. Chafi ◽  
V. Dirisala ◽  
G. Karami ◽  
M. Ziejewski

In the central nervous system, the subarachnoid space is the interval between the arachnoid membrane and the pia mater. It is filled with a clear, watery liquid called cerebrospinal fluid (CSF). The CSF buffers the brain against mechanical shocks and creates buoyancy to protect it from the forces of gravity. The relative motion of the brain due to a simultaneous loading is caused because the skull and brain have different densities and the CSF surrounds the brain. The impact experiments are usually carried out on cadavers with no CSF included because of the autolysis. Even in the cadaveric head impact experiments by Hardy et al. [1], where the specimens are repressurized using artificial CSF, this is not known how far this can replicate the real functionality of CSF. With such motivation, a special interest lies on how to model this feature in a finite element (FE) modeling of the human head because it is questionable if one uses in vivo CSF properties (i.e. bulk modulus of 2.19 GPa) to validate a FE human head against cadaveric experimental data.


2020 ◽  
Author(s):  
Katja Junttila ◽  
Anna-Riikka Smolander ◽  
Reima Karhila ◽  
Anastasia Giannakopoulou ◽  
Maria Uther ◽  
...  

Learning is increasingly assisted by technology. Digital games may be useful for learning, especially in children. However, more research is needed to understand the factors that induce gaming benefits to cognition. In this study, we investigated the effectiveness of digital game-based learning approach in children by comparing the learning of foreign speech sounds and words in a digital game or a non-game digital application with equal amount of exposure and practice. To evaluate gaming-induced plastic changes in the brain function, we used the mismatch negativity (MMN) brain response that reflects the activation of long-term memory representations for speech sounds and words. We recorded auditory event-related potentials (ERPs) from 37 school-aged Finnish-speaking children before and after playing the “Say it again, kid!” (SIAK) language-learning game where they explored game boards, produced English words aloud, and got stars as feedback from an automatic speech recognizer to proceed in the game. The learning of foreign speech sounds and words was compared in two conditions embedded in the game: a game condition and a non-game condition with the same speech production task but lacking visual game elements and feedback. The MMN amplitude increased between the pre-measurement and the post-measurement for the word trained with the game but not for the word trained with the non-game condition, suggesting that the gaming intervention enhanced learning more than the non-game intervention. The results indicate that digital game-based learning can be beneficial for children’s language learning and that gaming elements per se, not just practise time, support learning.


2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Chuanfu Li ◽  
Jun Yang ◽  
Jinbo Sun ◽  
Chunsheng Xu ◽  
Yuanqiang Zhu ◽  
...  

In recent years, neuroimaging studies of acupuncture have explored extensive aspects of brain responses to acupuncture in finding its underlying mechanisms. Most of these studies have been performed on healthy adults. Only a few studies have been performed on patients with diseases. Brain responses to acupuncture in patients with the same disease at different pathological stages have not been explored, although it may be more important and helpful in uncovering its underlying mechanisms. In the present study, we used fMRI to compare brain responses to acupuncture in patients with Bell’s palsy at different pathological stages with normal controls and found that the brain response to acupuncture varied at different pathological stages of Bell’s palsy. The brain response to acupuncture decreased in the early stages, increased in the later stages, and nearly returned to normal in the recovered group. All of the changes in the brain response to acupuncture could be explained as resulting from the changes in the brain functional status. Therefore, we proposed that the brain response to acupuncture is dependent on the brain functional status, while further investigation is needed to provide more evidence in support of this proposition.


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