scholarly journals Factors Affecting the Severity of Placental Abruption in Pregnant Vehicle Drivers: Analysis with a Novel Finite Element Model

Healthcare ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Katsunori Tanaka ◽  
Yasuki Motozawa ◽  
Kentaro Takahashi ◽  
Tetsuo Maki ◽  
Masahito Hitosugi
Keyword(s):  
Finite Element ◽  
Pregnant Woman ◽  
Finite Element Model ◽  
Placental Abruption ◽  
Motor Vehicle ◽  
Human Subjects ◽  
Element Model ◽  
Collision Velocity ◽  
Vehicle Collisions ◽  
Factors Affecting

We clarified factors affecting the severity of placental abruption in motor vehicle collisions by quantitively analyzing the area of placental abruption in a numerical simulation of an unrestrained pregnant vehicle driver at collision velocities of 3 and 6 m/s. For the simulation, we constructed a novel finite element model of a small 30-week pregnant woman, which was validated anthropometrically using computed tomography data and biomechanically using previous examinations of post-mortem human subjects. In the simulation, stress in the elements of the utero–placental interface was computed, and those elements exceeding a failure criterion were considered to be abrupted. It was found that a doubling of the collision velocity increased the area of placental abruption 10-fold, and the abruption area was approximately 20% for a collision velocity of 6 m/s, which is lower than the speed limit for general roads. This result implies that even low-speed vehicle collisions have negative maternal and fetal outcomes owing to placental abruption without a seatbelt restraint. Additionally, contact to the abdomen, 30 mm below the umbilicus, led to a larger placental abruption area than contact at the umbilicus level when the placenta was located at the uterus fundus. The results support that a reduction in the collision speed and seatbelt restraint at a suitable position are important to decrease the placental abruption area and therefore protect a pregnant woman and her fetus in a motor vehicle collision.

A Finite Element Model of Remote Palpation of Breast Lesions Using Radiation Force: Factors Affecting Tissue Displacement

2000 ◽  
Vol 22 (1) ◽  
pp. 35-54 ◽  
Author(s):  
Kathryn R. Nightingale ◽  
Roger W. Nightingale ◽  
Mark L. Palmeri ◽  
Gregg E. Trahey
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Radiation Force ◽  
Element Model ◽  
Breast Lesions ◽  
Factors Affecting

scholarly journals Numerical Assessment of Factors Affecting Waveform Based on Low Strain Testing of Piles

2014 ◽  
Vol 8 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Zegen Wang ◽  
Yifeng Wu ◽  
Zuocheng Xiao
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Testing ◽  
Element Model ◽  
Numerical Analyses ◽  
Factors Affecting ◽  
The Real ◽  
Numerical Assessment ◽  
Strain Testing ◽  
Mesh Density

In this paper dynamic testing of piles using the low strain method is performed by means of numerical analyses based on solid finite element model. To this end, velocity-time curves are presented investigating the influence of various parameters such as mesh density, impulse width, receiving point, and soil modulus on the waveform characteristics. Then, find regularity of waveform affected by different parameters to provide reference of the real project detection.

Influence of Vocal Fold Scarring on Phonation: Predictions from a Finite Element Model

2005 ◽  
Vol 114 (11) ◽  
pp. 847-852 ◽  
Author(s):  
David A. Berry ◽  
Haven Reininger ◽  
Fariborz Alipour ◽  
Diane M. Bless ◽  
Charles N. Ford
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Fundamental Frequency ◽  
Viscoelastic Properties ◽  
Vocal Fold ◽  
Human Subjects ◽  
Vocal Folds ◽  
Element Model ◽  
Acoustic Intensity ◽  
Vocal Fold Vibration

Objectives: A systematic study of the influence of vocal fold scarring on phonation was conducted. In particular, phonatory variables such as fundamental frequency, oral acoustic intensity, and phonation threshold pressure (PTP) were investigated as a function of the size and position of the laryngeal scar. Methods: By means of a finite element model of vocal fold vibration, the viscoelastic properties of both normal and scarred vocal fold mucosae were simulated on the basis of recent rheological data obtained from rabbit and canine models. Results: The study showed that an increase in the viscoelasticity of the scarred mucosa resulted in an increase in fundamental frequency, an increase in PTP, and a decrease in oral acoustic intensity. With regard to positioning of the scar, the PTP increased most significantly when the scar was within ±2 mm of the superior-medial junction of the vocal folds. Conclusions: The systematic data obtained in this investigation agree with the general clinical experience. In the future, these findings may be further validated on human subjects as newly emerging technologies such as linear skin rheometry and optical coherence tomography allow the histologic and viscoelastic properties of the normal and scarred vocal fold mucosae to be measured in the clinic.

ANALYSIS OF LIVER IMPACT RESPONSES THROUGH A CHINESE HUMAN BODY FINITE ELEMENT MODEL

2016 ◽  
Vol 16 (08) ◽  
pp. 1640024 ◽  
Author(s):  
TIANYA DU ◽  
JIQING CHEN ◽  
FENGCHONG LAN
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Human Body ◽  
Human Subjects ◽  
Element Model ◽  
Dynamic Responses ◽  
Peak Strain ◽  
Skeleton Model ◽  
Chinese Adult ◽  
Liver Model

Human liver biomechanical responses associated with frontal impacts, lateral impacts were studied using a simplified Chinese human body Finite Element Model (FEM) with more geometrical-accurate liver model for an average Chinese adult male from high resolution CT data. The developed model in this paper was composed by geometrically detailed liver model, simplified models of thoracic-abdominal organs, and the human skeleton model. Then, the whole model was validated at various velocities by comparing simulation outcomes with Post Mortem Human Subjects (PMHS) experimental results in frontal and lateral pendulum impacts. The force–deflection and force–time characteristics were in good agreement with the test results. The validated model was then applied for studying liver dynamic responses and injuries in simulations. Pressure, tensile stress and peak strain that may induce hepatic injuries was computed from model simulations and were analyzed about the correlation with the global parameters, like thoracic deflection, viscous criterion value, contact force. This study demonstrated that the method of developing a simplified finite element thorax-abdomen model with detailed liver model could be effective of hepatic injury assessment in various impacts reported in literature.

Development of a Finite Element Model of a Pediatric Pelvis and Material Property Estimation

2008 ◽  
Author(s):  
Jong-Eun Kim ◽  
Zuoping Li ◽  
Yasushi Ito ◽  
Christina D. Huber ◽  
Alan M. Shih ◽  
...  
Keyword(s):  
Finite Element ◽  
Computational Models ◽  
Motor Vehicle ◽  
Element Model ◽  
Fe Model ◽  
Motor Vehicle Collisions ◽  
Vehicle Collisions ◽  
Injury Mechanisms ◽  
Sport Activities ◽  
Material Property Estimation

The pediatric pelvis is vulnerable to injuries in motor vehicle collisions, sport activities, and fall accidents. Pelvic fractures and injury mechanisms in children differ substantially from those found in adults [1]. While the injury mechanisms and tolerances of the adult pelvis have been fairly well characterized through cadaveric experiments and computational models, efforts related to the pediatric pelvis have been limited due to difficulties in acquiring and testing pediatric cadavers. The objective of this study was to develop a finite element (FE) model of a 10-year-old (10YO) human pelvis to provide more comprehensive understanding of injury mechanisms experienced by children.

scholarly journals Quantification of Subjective Scaling of Friction Using a Fingertip Biomechanical Model

2012 ◽  
Vol 9 (3) ◽  
pp. 293-302
Author(s):  
Mohammad Abdolvahab
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Discharge Rate ◽  
Human Subjects ◽  
Biomechanical Model ◽  
Element Model ◽  
Contact Forces ◽  
Psychophysical Experiment ◽  
Perceptual Evaluation ◽  
Neural Unit

Subjective scaling of friction is important in many applications in haptic technology. A nonhomogeneous biomechanical finite element model of fingertip is proposed in order to predict neural response of sensitive mechanoreceptors to frictional stimuli (Slowly Adapting SAII receptors under the glabrous skin). In a guided psychophysical experiment, ten human subjects were asked to scale several standard surfaces based on the perception of their frictional properties. Contact forces deployed during the exploratory time of one of the participants were captured in order to estimate required parameters for the model of contact in the simulation procedure. Consequently, the strain energy density at the location of a selective mechanoreceptor in the finite element model as a measure of discharge rate of the neural unit was compared to the subject’s perceptual evaluation of the relevant stimuli. It was observed that the subject’s scores correlate with the discharge rate of the given receptor.

Sign in / Sign up

Export Citation Format

Share Document