THORAX INJURY CRITERIA ASSESSMENT THROUGH NON-LETHAL IMPACT USING AN ENHANCED BIOMECHANICAL MODEL

2017 ◽  
Vol 17 (07) ◽  
pp. 1740027 ◽  
Author(s):  
MICHÈLE BODO ◽  
ANTHONY BRACQ ◽  
REMI DELILLE ◽  
CHRISTOPHE MARECHAL ◽  
SÉBASTIEN ROTH
Keyword(s):  
Lung Injury ◽  
Injury Risk ◽  
Soft Tissues ◽  
Biomechanical Model ◽  
Local Stress ◽  
The Body ◽  
Constitutive Law ◽  
Maximum Pressure ◽  
Fe Model ◽  
Injury Criteria

Ballistic injury refers to the interaction of a projectile and the human body, resulting in penetration or blunt trauma. In order to consider both consequences, a hydrodynamic elastoplastic constitutive law was implemented in a numerical FE model of the human torso to simulate soft tissues behavior and to evaluate their injury risk. This law, derived from 20% ballistic gelatin, was proven to be very efficient and biofidelic for penetrating ballistic simulation in soft tissues at very high velocity. In this study, the ability of the hydrodynamic law to simulate blunt ballistic trauma is evaluated by the replication of Bir et al.’s (2004) experiments, which is a reference test of the literature for nonpenetrating ballistic impact. Lung injury criteria were also investigated through the Bir et al.’s experiments numerical replication. Human responses were evaluated in terms of mechanical parameters, which can be global (acceleration of the body, viscous criteria and impact force) or local (stress, pressure and displacement). Output results were found to be in experimental corridors developed by Bir et al., and the maximum pressure combined with the duration of the peak of pressure in the lungs seems to be a good predictor for lung injury.

scholarly journals Simulation of blast lung injury induced by shock waves of five distances based on finite element modeling of a three-dimensional rat

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chang Yang ◽  
Zhang Dong-hai ◽  
Liu Ling-ying ◽  
Yu Yong-hui ◽  
Wu Yang ◽  
...  
Keyword(s):  
Lung Injury ◽  
Computational Simulation ◽  
Three Dimensional ◽  
3D Models ◽  
The Body ◽  
Maximum Pressure ◽  
Strong Correlations ◽  
Lung Lobe ◽  
Pressure Distributions ◽  
Blast Lung Injury

Abstract Blast lung injury (BLI) caused by both military and civilian explosions has become the main cause of death for blast injury patients. By building three-dimensional (3D) models of rat explosion regions, we simulated the surface pressure of the skin and lung. The pressure distributions were performed at 5 distances from the detonation center to the center of the rat. When the distances were 40 cm, 50 cm, 60 cm, 70 cm and 80 cm, the maximum pressure of the body surface were 634.77kPa, 362.46kPa, 248.11kPa, 182.13kPa and 109.29kPa and the surfaces lung pressure ranges were 928–2916 Pa, 733–2254 Pa, 488–1236 Pa, 357–1189 Pa and 314–992 Pa. After setting 6 virtual points placed on the surface of each lung lobe model, simulated pressure measurement and corresponding pathological autopsies were then conducted to validate the accuracy of the modeling. For the both sides of the lung, when the distance were 40 cm, 50 cm and 60 cm, the Pearson’s values showed strong correlations. When the distances were 70 cm and 80 cm, the Pearson’s values showed weak linear correlations. This computational simulation provided dynamic anatomy as well as functional and biomechanical information.

Validation of a Full Porcine Finite Element Model for Blast Induced TBI Using a Coupled Eulerian-Lagrangian Approach

2017 ◽  
Author(s):  
X. Gary Tan ◽  
Robert N. Saunders ◽  
Amit Bagchi
Keyword(s):  
Experimental Data ◽  
Shock Wave ◽  
Finite Element ◽  
Computational Models ◽  
Soft Tissues ◽  
Large Strain ◽  
Viscoelastic Model ◽  
The Body ◽  
Whole Body ◽  
Fe Model

Current understanding of blast induced traumatic brain injury (TBI) mechanisms is incomplete and limits the development of protective and therapeutic measures. Animal testing has been used as a surrogate for human testing. The correlation of animals to human responses is not well understood with a limited set of experimental data, because of ethical concerns and cost of live animal tests. The validated computational animal models can be used to supplement and improve the granularity of available data at a significantly reduced cost. A whole-body porcine high-fidelity computational model was developed based on the image data. The hyper-viscoelastic model was used for soft tissues to capture the rate dependence and large strain nonlinearity of the material. The shock wave interaction with a porcine subject in a shock tube was simulated using computational fluid dynamics (CFD) models, via a combination of 1-D, 2-D and 3-D numerical techniques. The shock wave loads were applied to the exterior of the porcine finite element (FE) model to simulate the pressure wave transmission through the body and capture its biomechanical response. The CFD and FE problems are solved using the explicit Eulerian and Lagrangian solvers, respectively, in the DoD Open Source code CoBi. The computational models were validated by comparing the simulation results with experimental data at specific instrumented locations. The predicted brain tissue stress-strain fields were used to determine the areas susceptible to blast induced TBI by using published mechanical injury thresholds. The validated porcine model can be used to better understand TBI and how injury in animals corresponds to injury in humans. The coupled Eurlerian and Lagrangian approaches developed in this paper can be extended to other simulations to improve the solution accuracy.

scholarly journals Reduced biomechanical models for precision-cut lung-slice stretching experiments

2021 ◽  
Vol 82 (5) ◽  
Author(s):  
Hannah J. Pybus ◽  
Amanda L. Tatler ◽  
Lowell T. Edgar ◽  
Reuben D. O’Dea ◽  
Bindi S. Brook
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Ex Vivo ◽  
Finite Thickness ◽  
Biomechanical Model ◽  
Local Stress ◽  
Smooth Muscle Contraction ◽  
Biomechanical Models ◽  
Cytokine Activation ◽  
Asymptotic Reduction

AbstractPrecision-cut lung-slices (PCLS), in which viable airways embedded within lung parenchyma are stretched or induced to contract, are a widely used ex vivo assay to investigate bronchoconstriction and, more recently, mechanical activation of pro-remodelling cytokines in asthmatic airways. We develop a nonlinear fibre-reinforced biomechanical model accounting for smooth muscle contraction and extracellular matrix strain-stiffening. Through numerical simulation, we describe the stresses and contractile responses of an airway within a PCLS of finite thickness, exposing the importance of smooth muscle contraction on the local stress state within the airway. We then consider two simplifying limits of the model (a membrane representation and an asymptotic reduction in the thin-PCLS-limit), that permit analytical progress. Comparison against numerical solution of the full problem shows that the asymptotic reduction successfully captures the key elements of the full model behaviour. The more tractable reduced model that we develop is suitable to be employed in investigations to elucidate the time-dependent feedback mechanisms linking airway mechanics and cytokine activation in asthma.

High Frequency Vibration Analysis of Automotive Body Panels with Damping Materials

2010 ◽  
Vol 36 ◽  
pp. 293-296
Author(s):  
Yoshio Kurosawa ◽  
Takao Yamaguchi
Keyword(s):  
High Frequency ◽  
Large Scale ◽  
The Body ◽  
Viscoelastic Damping ◽  
Fe Model ◽  
Test Results ◽  
Automotive Body ◽  
Modal Damping ◽  
Practical Tool ◽  
Damping Materials

We have developed a technique for estimating vibrations of an automotive body structures with viscoelastic damping materials using large-scale finite element (FE) model, which will enable us to grasp and to reduce high-frequency road noise（200～500Hz）. In the new technique, first order solutions for modal loss factors are derived applying asymptotic method. This method saves calculation time to estimate modal damping as a practical tool in the design stages of the body structures. Frequency responses were calculated using this technique and the results almost agreed with the test results. This technique can show the effect of the viscoelastic damping materials on the automotive body panels, and it enables the more efficient layout of the viscoelastic damping materials. Further, we clarified damping properties of the automotive body structures under coupled vibration between frames and panels with the viscoelastic damping materials.

scholarly journals A Two Joint Neck Model to Identify Malposition of the Head Relative to the Thorax

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3297
Author(s):  
Philipp M. Schmid ◽  
Christoph M. Bauer ◽  
Markus J. Ernst ◽  
Bettina Sommer ◽  
Lars Lünenburger ◽  
...  
Keyword(s):  
Neck Pain ◽  
Body Height ◽  
Biomechanical Model ◽  
The Body ◽  
Head Orientation ◽  
Neck Length ◽  
Proposed Model ◽  
Biofeedback System ◽  
Simple Measurement ◽  
The Impact

Neck pain is a frequent health complaint. Prolonged protracted malpositions of the head are associated with neck pain and headaches and could be prevented using biofeedback systems. A practical biofeedback system to detect malpositions should be realized with a simple measurement setup. To achieve this, a simple biomechanical model representing head orientation and translation relative to the thorax is introduced. To identify the parameters of this model, anthropometric data were acquired from eight healthy volunteers. In this work we determine (i) the accuracy of the proposed model when the neck length is known, (ii) the dependency of the neck length on the body height, and (iii) the impact of a wrong neck length on the models accuracy. The resulting model is able to describe the motion of the head with a maximum uncertainty of 5 mm only. To achieve this high accuracy the effective neck length must be known a priory. If however, this parameter is assumed to be a linear function of the palpable neck length, the measurement error increases. Still, the resulting accuracy can be sufficient to identify and monitor a protracted malposition of the head relative to the thorax.

Magnetic Resonance Imaging in the Diagnosis of Disruption of the Posterior Tibial Tendon

Foot & Ankle ◽  
1987 ◽  
Vol 8 (3) ◽  
pp. 144-147 ◽  
Author(s):  
Ian J. Alexander ◽  
Kenneth A. Johnson ◽  
Thomas H. Berquist
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Soft Tissues ◽  
Diagnostic Technique ◽  
Clinical Findings ◽  
The Body ◽  
Posterior Tibial Tendon ◽  
Resonance Imaging ◽  
Posterior Tibial ◽  
Magnetic Resonance Imaging Mri

Magnetic resonance imaging (MRI), a useful technique of studying soft tissues of the body, can be very effective in assessing the integrity of tendons. Usually a patient with a complete tear of the posterior tibial tendon has characteristic physical findings. In the patient presented, MRI demonstrated a complete disruption of the posterior tibial tendon, despite the absence of the commonly associated clinical findings. In view of the difficulties encountered with attempted tenography of the completely torn posterior tibial tendon, MRI provides a sensitive alternative diagnostic technique.

Computerized Tomography: A Perspective in the Pediatric Patient

PEDIATRICS ◽  
1977 ◽  
Vol 59 (2) ◽  
pp. 305-308
Author(s):  
Derek Harwood-Nash ◽  
Herman Grossman ◽  
Alvin Felman ◽  
John Kirkpatrick ◽  
Leonard Swischuk
Keyword(s):  
Computerized Tomography ◽  
Soft Tissues ◽  
Conventional Radiography ◽  
The United States ◽  
The Body ◽  
Whole Body ◽  
Central Research ◽  
X Ray ◽  
Whole Body Ct

Computerized tomography (CT), a technique conceptualized by Oldendorf in 19611 and developed by Hounsfield2 of EMI-Tronics Inc. (EMI) Central Research Laboratories, has proven to be a successful innovation in neuroradiology. Reviews by Ambrose3 in England and by Baker et al.4 and by New et al.5 in the United States have clearly demonstrated the value of this new modality in neuroradiological diagnosis. In 1975 Houser et al.6 and Harwood-Nash et al.7 provided the initial clinical and radiological data about CT in infants and children. More recently this technique has been extended to the study of tissues and organs in the body other than those in the head. This has been accomplished by modification of the original machine into a whole-body CT system. Early reviews by Ledley et al.8 and by Alfidi et al.9 suggest a significant potential for diagnosis of lesions in the abdomen, pelvis, and thorax. The advantages of CT are that it is less invasive than standard special diagnostic radiological procedures and that for the first time it provides in vivo information regarding the content and the characteristics of tissue composing organs and masses. DESCRIPTION OF EQUIPMENT In conventional radiography an image is made on radiographic film by an attenuated X-ray beam. In passing through a core of tissue, each ray of the beam is attenuated as it is absorbed and scattered by the tissue in its path. The intensity of the transmitted ray depends on the sum total of X-ray attenuation by all the different soft tissues in its path.

The reaction of the soft tissues of the anterior abdominal wall to various suture material

1982 ◽  
Vol 63 (4) ◽  
pp. 72-74
Author(s):  
V. P. Nefedov ◽  
R. M. Ramazanov
Keyword(s):  
Foreign Body ◽  
Abdominal Wall ◽  
Soft Tissues ◽  
Suture Material ◽  
Anterior Abdominal Wall ◽  
The Body ◽  
Reactive Changes ◽  
Healing Processes

The healing processes of sutured wounds of soft tissues in most cases depend on the type and quality of the suture material. Any kind of suture material in the tissues of the body is a foreign body that causes various reactive changes from the tissues. The nature of these changes, all other things being equal, is mainly determined by the type of suture material, its thickness and the method of sterilization of the tissues on which the sutures are applied, the trauma of surgery, the infection of the wound and the irritating effect of the threads on the tissues.

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