Investigation of Anteroposterior Head-Neck Responses during Severe Frontal Impacts Using a Brain-Spinal Cord Complex FE Model

2006 ◽  
Author(s):  
Hideyuki Kimpara ◽  
Yuko Nakahira ◽  
Masami Iwamoto ◽  
Kazuo Miki ◽  
Kazuhiko Ichihara ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Fe Model ◽  
Frontal Impacts ◽  
Head Neck

scholarly journals The Influence of Neck Muscle Activation on Head and Neck Injuries of Occupants in Frontal Impacts

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Fan Li ◽  
Ronggui Lu ◽  
Wei Hu ◽  
Honggeng Li ◽  
Shiping Hu ◽  
...  
Keyword(s):  
Head And Neck ◽  
High Speed ◽  
Muscle Activation ◽  
Neck Muscle ◽  
Fe Model ◽  
Neck Injuries ◽  
Frontal Impact ◽  
Low Speed ◽  
Frontal Impacts ◽  
Head Neck

The aim of the present paper was to study the influence of neck muscle activation on head and neck injuries of vehicle occupants in frontal impacts. A mixed dummy-human finite element model was developed to simulate a frontal impact. The head-neck part of a Hybrid III dummy model was replaced by a well-validated head-neck FE model with passive and active muscle characteristics. The mixed dummy-human FE model was validated by 15 G frontal volunteer tests conducted in the Naval Biodynamics Laboratory. The effects of neck muscle activation on the head dynamic responses and neck injuries of occupants in three frontal impact intensities, low speed (10 km/h), medium speed (30 km/h), and high speed (50 km/h), were studied. The results showed that the mixed dummy-human FE model has good biofidelity. The activation of neck muscles can not only lower the head resultant acceleration under different impact intensities and the head angular acceleration in medium- and high-speed impacts, thereby reducing the risks of head injury, but also protect the neck from injury in low-speed impacts.

Finite Element Study of Spinal Cord Mechanics During Biomechanical Response of Middle Cervical Spine

2010 ◽  
Author(s):  
N. Bahramshahi ◽  
H. Ghaemi ◽  
K. Behdinan
Keyword(s):  
Spinal Cord ◽  
Cervical Spine ◽  
Stress Concentration ◽  
Cervical Spinal Cord ◽  
Axial Strain ◽  
Compressive Load ◽  
Fe Model ◽  
Local Pressure ◽  
Disc Space ◽  
Flexion Extension

The present study is conducted to develop a detailed FE model of spinal cord and to study its behaviour under various loading conditions. To achieve the goal, a previously developed and validated FE model of the middle cervical spine (C3-C5) is utilized. The model is further modified to investigate the stresses that the spinal cord in experiences during cervical spine motion segment in compression and flexion/extension loading modes. The resulting Von Misses stress and axial strain of the anterior and posterior surfaces of the cervical spinal cord are obtained from a set of elements along the C4-C5 disc space of the dural sheath, CSF and cord. The results show that in compression, the anterior surface of spinal cord experiences larger displacement, stress, and strain than those of the posterior surface. Conversely, the analyses show that in flexion\extension, the stresses, strains, and displacements are more pronounced in posterior segment of the spinal cord. In extension, the posterior disc bulge applies pressure onto the Posterior Longitudinal Ligament and thereby, applying local pressure on the spinal cord. The FE results show a stress concentration at the point of contact between disc and spinal cord. Furthermore, the FE results of flexion test show similar stress concentration characteristic at the point of contact. However, the local stress on spinal cord is more pronounced in flexion than extension at the C4-C5 area of spinal cord. It was also determined the compressive load resulted in the highest stress concentration on the spinal cord.

Further Validation of the Ford Human Body FE Model and Use of the Model to Investigate the Effects of Shoulder Belt Force Limiting of 3-Point and 4-Point Restraints in Frontal Impact

2008 ◽  
Author(s):  
Raed E. El-Jawahri ◽  
Jesse S. Ruan ◽  
Stephen W. Rouhana ◽  
Saeed D. Barbat ◽  
Priya Prasad
Keyword(s):  
Human Body ◽  
Ford Motor Company ◽  
Steering Wheel ◽  
Point System ◽  
Fe Model ◽  
Frontal Impact ◽  
Frontal Impacts ◽  
Vehicle Structure ◽  
Impact Simulations ◽  
The Impact

Ford Motor Company human body FE model was validated against 3-point & 4-point belted PMHS tests in frontal impact and PMHS knee impact. The chest deflection, chest acceleration, and belt force in frontal impact simulations were compared with the PMHS test data, while the impact force, femur acceleration, pelvis acceleration, and sacrum acceleration of the knee impact simulations were compared with the respective corridors from PMHS tests. The model used represents a 50th percentile adult male. It was used to study the effects of shoulder belt force limit on 3-point and 4-point restrained occupants in frontal impacts without airbags. A 25 g pulse and a shoulder belt load limit of 1, 2, 3, 4, 6, and 8 kN were used for the 3-point and 4-point restraint systems with a rigid steering wheel, front header, and windshield of a stiffer larger vehicle structure. The results showed that the head acceleration and the chest deflection of the 4-point belt system are less than the respective cases of the 3-point system while the chest acceleration levels were about the same in 3-point and 4-point belt. The mid-shaft femur forces were always higher in the 4-point belt than those of the 3-point belt.

scholarly journals Effects of Impactor Size on Biomechanical Characteristics of Spinal Cord in Hemicontusion Injury Model Using Finite Element Analysis

2020 ◽  
Vol 10 (12) ◽  
pp. 4097
Author(s):  
Batbayar Khuyagbaatar ◽  
Kyungsoo Kim ◽  
Temuujin Batbayar ◽  
Yoon Hyuk Kim
Keyword(s):  
Spinal Cord ◽  
Finite Element ◽  
Infinite Horizon ◽  
Experimental Studies ◽  
Contralateral Side ◽  
Cervical Region ◽  
Fe Model ◽  
New York University ◽  
Ipsilateral Side ◽  
Cord Injury

A cervical hemicontusion spinal cord injury (SCI) produces forelimb deficits on the ipsilateral side of the injury while sparing the function of the limbs on the contralateral side of the injury, allowing for the evaluation of experimental therapeutics for functional recovery. Although the effects of contusion force on the functional and behavioral outcomes were adequately described in previous experimental studies, the size of the impactor tip also had significant effects on the extent of the lesion on the contralateral side of the injury in the hemicontusion rat model. However, studies regarding the effects of impactor size on the spinal cord for the hemicontusion model are limited. In this study, a finite element (FE) model of the rat cervical spinal cord was developed to investigate the effects of impactor size in the hemicontusion SCI model on the stress, strain, and displacement of the spinal cord for the New York University (NYU) and Infinite Horizon (IH) impactors. The impactor tip diameters of 1.2 mm and 1.6 mm with high impact loading resulted in the highest stresses and strains in the right (ipsilateral) side of the spinal cord. Thus, impactor tip diameters between 1.2 mm and 1.6 mm would be convenient to use in the rat hemicontusion SCI models for the cervical region without damaging the left (contralateral) side of the spinal cord. Our findings provide an insight into SCI mechanisms in the rat cervical hemicontusion model.

Development and Validation of A C0–C7 FE Complex for Biomechanical Study

2005 ◽  
Vol 127 (5) ◽  
pp. 729-735 ◽  
Author(s):  
Qing Hang Zhang ◽  
Ee Chon Teo ◽  
Hong Wan Ng
Keyword(s):  
Current Model ◽  
Drop Impact ◽  
Biomechanical Study ◽  
Fe Model ◽  
Midsagittal Plane ◽  
Male Cadaver ◽  
Geometrical Data ◽  
Fe Complex ◽  
Development And Validation ◽  
Head Neck

In this study, the digitized geometrical data of the embalmed skull and vertebrae (C0–C7) of a 68-year old male cadaver were processed to develop a comprehensive, geometrically accurate, nonlinear C0–C7 FE model. The biomechanical response of human neck under physiological static loadings, near vertex drop impact and rear-end impact (whiplash) conditions were investigated and compared with published experimental results. Under static loading conditions, the predicted moment-rotation relationships of each motion segment under moments in midsagittal plane and horizontal plane agreed well with experimental data. In addition, the respective predicted head impact force history and the S-shaped kinematics responses of head-neck complex under near-vertex drop impact and rear-end conditions were close to those observed in reported experiments. Although the predicted responses of the head-neck complex under any specific condition cannot perfectly match the experimental observations, the model reasonably reflected the rotation distributions among the motion segments under static moments and basic responses of head and neck under dynamic loadings. The current model may offer potentials to effectively reflect the behavior of human cervical spine suitable for further biomechanics and traumatic studies.

Intubation biomechanics: validation of a finite element model of cervical spine motion during endotracheal intubation in intact and injured conditions

2018 ◽  
Vol 28 (1) ◽  
pp. 10-22 ◽  
Author(s):  
Benjamin C. Gadomski ◽  
Snehal S. Shetye ◽  
Bradley J. Hindman ◽  
Franklin Dexter ◽  
Brandon G. Santoni ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Finite Element ◽  
Cervical Spine ◽  
Endotracheal Intubation ◽  
Macintosh Laryngoscope ◽  
Element Model ◽  
Fe Model ◽  
Intervertebral Motion ◽  
Model Predictions ◽  
Spine Motion

OBJECTIVEBecause of limitations inherent to cadaver models of endotracheal intubation, the authors’ group developed a finite element (FE) model of the human cervical spine and spinal cord. Their aims were to 1) compare FE model predictions of intervertebral motion during intubation with intervertebral motion measured in patients with intact cervical spines and in cadavers with spine injuries at C-2 and C3–4 and 2) estimate spinal cord strains during intubation under these conditions.METHODSThe FE model was designed to replicate the properties of an intact (stable) spine in patients, C-2 injury (Type II odontoid fracture), and a severe C3–4 distractive-flexion injury from prior cadaver studies. The authors recorded the laryngoscope force values from 2 different laryngoscopes (Macintosh, high intubation force; Airtraq, low intubation force) used during the patient and cadaver intubation studies. FE-modeled motion was compared with experimentally measured motion, and corresponding cord strain values were calculated.RESULTSFE model predictions of intact intervertebral motions were comparable to motions measured in patients and in cadavers at occiput–C2. In intact subaxial segments, the FE model more closely predicted patient intervertebral motions than did cadavers. With C-2 injury, FE-predicted motions did not differ from cadaver measurements. With C3–4 injury, however, the FE model predicted greater motions than were measured in cadavers. FE model cord strains during intubation were greater for the Macintosh laryngoscope than the Airtraq laryngoscope but were comparable among the 3 conditions (intact, C-2 injury, and C3–4 injury).CONCLUSIONSThe FE model is comparable to patients and cadaver models in estimating occiput–C2 motion during intubation in both intact and injured conditions. The FE model may be superior to cadavers in predicting motions of subaxial segments in intact and injured conditions.

Spinal Cord Stress and Strain Predictions in a Ligamentous C5-C6 Segment

2000 ◽  
Author(s):  
J. Scifert ◽  
K. Totoribe ◽  
V. Goel ◽  
C. Clark ◽  
J. Reinhardt ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cervical Spinal Cord ◽  
Experimental Studies ◽  
Stress And Strain ◽  
Fe Model ◽  
Spinal Disorders ◽  
Significant Damage ◽  
Cord Injury ◽  
Bony Segment

Abstract Several spinal disorders and traumatic loading situations are known to inflict damage to neurovascular components of the cervical spinal cord. Studies have shown that damage to the spinal cord can occur regardless of significant damage to surrounding structures. To understand the mechanics of spinal cord injury, one needs to quantify stresses and strains within the spinal cord and its components in response to exterrnal loads applied to the bony spine. Experimental studies can not address this issue. This study presents a Finite Element (FE) model to quantify the physiologic strains and stresses in the cervical spinal cord placed in the ligamentous C5-C6 motion segment, with loads applied to the bony segment and not the the cord itself, as have been done in experimental studies reported in the literature.

Computer Simulation of Head Impact: Estimation of Head-Injury Risk during Soccer Heading

1988 ◽  
Vol 4 (4) ◽  
pp. 358-371 ◽  
Author(s):  
Klaus Schneider ◽  
Ronald F. Zernicke
Keyword(s):  
Head Injury ◽  
Injury Risk ◽  
Cervical Vertebrae ◽  
Rigid Bodies ◽  
Head Impacts ◽  
Frontal Impacts ◽  
Medium Range ◽  
The Impact ◽  
Head Neck ◽  
Soccer Heading

With a validated mathematical model of the head-neck consisting of nine rigid bodies (skull, seven cervical vertebrae, and torso), we simulated head impacts to estimate the injury risk associated with soccer heading. Experimental data from head-linear accelerations during soccer heading were used to validate the nine-body head-neck model for short duration impact loading of the head. In the computer simulations, the mass ratios between head mass and impacting body mass, the velocity of the impacting body, and the impact elasticity were varied. Head-linear and angular accelerations were compared to standard head-injury tolerance levels, and the injury risk specifically related to soccer heading was estimated. Based on our choice of tolerance levels in general, our simulations showed that injury risk from angular head accelerations was greater than from linear head accelerations, and compared to frontal impacts, lateral impacts had greater angular and less linear head accelerations. During soccer heading, our simulations indicated an unacceptable injury risk caused by angular head accelerations for frontal and lateral impacts at relatively low impact velocities for children, and at medium range impact velocities for adults. For linear head accelerations, injury risk existed for frontal and lateral impacts at medium range to relatively larger impact velocities for children, while no injury risk was shown for adults throughout the entire velocity range. For injury prevention, we suggest that head-injury risk can be reduced most substantially by increasing the mass ratio between head and impacting body. In soccer with children, the mass of the impacting body has to be adjusted to the reduced head mass of a child, that is, it must be clearly communicated to parents, coaches, and youngsters to only use smaller soccer balls.

Biomechanical Behaviors in Three Types of Spinal Cord Injury Mechanisms

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Batbayar Khuyagbaatar ◽  
Kyungsoo Kim ◽  
Won Man Park ◽  
Yoon Hyuk Kim
Keyword(s):  
Spinal Cord ◽  
Principal Strain ◽  
Von Mises Stress ◽  
Fe Model ◽  
Maximum Principal Strain ◽  
Stress Peak ◽  
Peak Maximum ◽  
Injury Mechanisms ◽  
Cord Injury ◽  
Von Mises

Clinically, spinal cord injuries (SCIs) are radiographically evaluated and diagnosed from plain radiographs, computed tomography (CT), and magnetic resonance imaging. However, it is difficult to conclude that radiographic evaluation of SCI can directly explain the fundamental mechanism of spinal cord damage. The von-Mises stress and maximum principal strain are directly associated with neurological damage in the spinal cord from a biomechanical viewpoint. In this study, the von-Mises stress and maximum principal strain in the spinal cord as well as the cord cross-sectional area (CSA) were analyzed under various magnitudes for contusion, dislocation, and distraction SCI mechanisms, using a finite-element (FE) model of the cervical spine with spinal cord including white matter, gray matter, dura mater with nerve roots, and cerebrospinal fluid (CSF). A regression analysis was performed to find correlation between peak von-Mises stress/peak maximum principal strain at the cross section of the highest reduction in CSA and corresponding reduction in CSA of the cord. Dislocation and contusion showed greater peak stress and strain values in the cord than distraction. The substantial increases in von-Mises stress as well as CSA reduction similar to or more than 30% were produced at a 60% contusion and a 60% dislocation, while the maximum principal strain was gradually increased as injury severity elevated. In addition, the CSA reduction had a strong correlation with peak von-Mises stress/peak maximum principal strain for the three injury mechanisms, which might be fundamental information in elucidating the relationship between radiographic and mechanical parameters related to SCI.

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