Development of a Detailed Multi-Body Computational Model of an ATV to Address and Prevent Child Injuries

2011 ◽  
Author(s):  
Chandrashekhar K. Thorbole ◽  
Mary Aitken ◽  
James Graham ◽  
Beverly Miller ◽  
Samantha Hope Mullins ◽  
...  
Keyword(s):  
Computational Model ◽  
The United States ◽  
Suspension System ◽  
Computational Technique ◽  
Adult Size ◽  
Tilt Table Test ◽  
Tilt Table ◽  
Effective Prevention ◽  
Rigid Body Model ◽  
Hybrid Iii

Better insights into ATV crash mechanisms are needed to facilitate effective prevention strategies. Rollover crashes and resulting injuries represent major problems associated with ATVs. These problems are aggravated with the rider is a young child, since all ATVs are rider active machines. Serious injuries associated with child use of adult ATVs are an increasing problem in the United States and other countries. The computational technique is used to develop a detailed adult size ATV. The computational model is developed using the biodynamic code MADYMO. Laboratory tests are conducted on the ATV to extract the dynamic characteristics of the ATV. The ATV model developed features a detailed suspension system. The computational model confidence is increased using a digitized surface to create the rigid body model. The computational ATV model is validated for its lateral stability using a laboratory tilt table test. The suspension system is validated using a drop test on a rigid floor. This validated model is used to simulate and understand crashes and parameters affecting the injury outcome. A Hybrid III six year old dummy is used during the laboratory tilt table test and for initial crash simulations. This paper demonstrates the methodology used to develop a crash analysis for an ATV driven by a six year old child. The computation model is used to recreate a forward flip rollover crash scenario.

Identification of the Best Possible Configuration of the Shoulder Strap of a Three-Point Restraint for Motor Coach Occupant Rollover Protection

2011 ◽  
Author(s):  
Chandrashekhar K. Thorbole ◽  
David A. Renfroe ◽  
Hamid M. Lankarani
Keyword(s):  
Seat Belt ◽  
Essential Element ◽  
The United States ◽  
Computational Technique ◽  
Hybrid Iii ◽  
Roll Rate ◽  
Occupant Injury ◽  
Occupant Injuries ◽  
Serious Injuries ◽  
The Impact

The motor coach is an essential element of the mass transportation system in the United States and all around the globe. Rollover accidents associated with any motor coach without an adequate occupant protection system may result in serious or fatal occupant injuries. The seat belt is an essential safety device in protecting an occupant in a rollover accident. It has been observed that just a quarter roll of a bus results in fatal injuries to an unbelted occupant. This severe nature of occupant injury in a less severe bus roll is attributable to the large flying distance within the unpadded interior and the impact with other fellow occupants. In this situation the presence of a seat belt is mandatory to protect the occupants from serious injuries by preventing their ejection from their seats. The three-point restraint is the best possible solution for the motor coach seat belt requirement. The understanding of shoulder strap placement with respect to the occupant is important information. This information facilitates the best possible seat belt configuration for all occupants which will minimize the slippage of the shoulder strap during a rollover accident. The slipping of the shoulder strap is a function of rollover type, rollover direction, roll rate and the occupant location in a vehicle with respect to roll direction. A Finite Element bus model is used to conduct a trip rollover simulation at two different trip velocities. The motion file, as obtained from this simulation, is used to prescribe motion to a MADYMO facet bus model. The standard Hybrid III 50th percentile ATD (Anthropomorphic Test Device) is used to model all the belted occupants. The FE belt model is used to facilitate the simulation of slippage on the shoulder. This study demonstrates the best possible configuration of the three-point restraints for motor coach occupants in a rollover accident using the computational technique. Knowledge of this kind will help the industry to identify and implement seat belts with the best configuration for occupant rollover protection.

scholarly journals Correlation of head-up tilt table test time interval with risk of recurrent syncope

2015 ◽  
Vol 67 ◽  
pp. S77
Author(s):  
R.K. Gokhroo ◽  
Kumari Priti ◽  
A. Avinash ◽  
Bhanwar Lal Ranwa ◽  
Kamal Kishor ◽  
...  
Keyword(s):  
Test Time ◽  
Time Interval ◽  
Tilt Table Test ◽  
Tilt Table ◽  
Head Up Tilt

Repolarization disparity as a predictor of response to Head Up Tilt‐table Test in pediatric syncope

2021 ◽  
Author(s):  
Mohammad Reza Khalilian ◽  
Abdolrahim Ghasemi ◽  
Narges Khazaei ◽  
Sara Khoshkhou ◽  
Elham Mahmoudi
Keyword(s):  
Tilt Table Test ◽  
Tilt Table ◽  
Head Up Tilt

scholarly journals Modelling human skull growth: a validated computational model

2017 ◽  
Vol 14 (130) ◽  
pp. 20170202 ◽  
Author(s):  
Joseph Libby ◽  
Arsalan Marghoub ◽  
David Johnson ◽  
Roman H. Khonsari ◽  
Michael J. Fagan ◽  
...  
Keyword(s):  
Computational Model ◽  
Three Dimensional ◽  
Basic Knowledge ◽  
Fe Model ◽  
Adult Size ◽  
Fe Method ◽  
Percentage Difference ◽  
Skull Growth

During the first year of life, the brain grows rapidly and the neurocranium increases to about 65% of its adult size. Our understanding of the relationship between the biomechanical forces, especially from the growing brain, the craniofacial soft tissue structures and the individual bone plates of the skull vault is still limited. This basic knowledge could help in the future planning of craniofacial surgical operations. The aim of this study was to develop a validated computational model of skull growth, based on the finite-element (FE) method, to help understand the biomechanics of skull growth. To do this, a two-step validation study was carried out. First, an in vitro physical three-dimensional printed model and an in silico FE model were created from the same micro-CT scan of an infant skull and loaded with forces from the growing brain from zero to two months of age. The results from the in vitro model validated the FE model before it was further developed to expand from 0 to 12 months of age. This second FE model was compared directly with in vivo clinical CT scans of infants without craniofacial conditions ( n = 56). The various models were compared in terms of predicted skull width, length and circumference, while the overall shape was quantified using three-dimensional distance plots. Statistical analysis yielded no significant differences between the male skull models. All size measurements from the FE model versus the in vitro physical model were within 5%, with one exception showing a 7.6% difference. The FE model and in vivo data also correlated well, with the largest percentage difference in size being 8.3%. Overall, the FE model results matched well with both the in vitro and in vivo data. With further development and model refinement, this modelling method could be used to assist in preoperative planning of craniofacial surgery procedures and could help to reduce reoperation rates.

scholarly journals Sex-Related Differences of Acute and Chronic Pancreatitis in Adults

2021 ◽  
Vol 10 (2) ◽  
pp. 300
Author(s):  
Madeline Drake ◽  
Shah-Jahan M. Dodwad ◽  
Joy Davis ◽  
Lillian S. Kao ◽  
Yanna Cao ◽  
...  
Keyword(s):  
Chronic Pancreatitis ◽  
The United States ◽  
Prevention Strategies ◽  
Endoscopic Retrograde ◽  
Effective Prevention ◽  
Type 1 Autoimmune Pancreatitis ◽  
Acute And Chronic Pancreatitis ◽  
Effective Prevention Strategies

The incidence of acute and chronic pancreatitis is increasing in the United States. Rates of acute pancreatitis (AP) are similar in both sexes, but chronic pancreatitis (CP) is more common in males. When stratified by etiology, women have higher rates of gallstone AP, while men have higher rates of alcohol- and tobacco-related AP and CP, hypercalcemic AP, hypertriglyceridemic AP, malignancy-related AP, and type 1 autoimmune pancreatitis (AIP). No significant sex-related differences have been reported in medication-induced AP or type 2 AIP. Whether post-endoscopic retrograde cholangiopancreatography pancreatitis is sex-associated remains controversial. Animal models have demonstrated sex-related differences in the rates of induction and severity of AP, CP, and AIP. Animal and human studies have suggested that a combination of risk factor profiles, as well as genes, may be responsible for the observed differences. More investigation into the sex-related differences of AP and CP is desired in order to improve clinical management by developing effective prevention strategies, diagnostics, and therapeutics.

scholarly journals Ca2+/calmodulin-dependent kinase II-dependent regulation of atrial myocyte late Na+ current, Ca2+ cycling, and excitability: a mathematical modeling study

2017 ◽  
Vol 313 (6) ◽  
pp. H1227-H1239 ◽  
Author(s):  
Birce Onal ◽  
Daniel Gratz ◽  
Thomas J. Hund
Keyword(s):  
Protein Kinase ◽  
Computational Model ◽  
Ryanodine Receptor ◽  
The United States ◽  
Atrial Myocytes ◽  
Open Probability ◽  
Dependent Protein Kinase ◽  
Protein Kinase Ii ◽  
Dependent Protein ◽  
Atrial Myocyte

Atrial fibrillation (AF) affects more than three million people per year in the United States and is associated with high morbidity and mortality. Both electrical and structural remodeling contribute to AF, but the molecular pathways underlying AF pathogenesis are not well understood. Recently, a role for Ca2+/calmodulin-dependent protein kinase II (CaMKII) in the regulation of persistent “late” Na+ current ( INa,L) has been identified. Although INa,L inhibition is emerging as a potential antiarrhythmic strategy in patients with AF, little is known about the mechanism linking INa,L to atrial arrhythmogenesis. A computational approach was used to test the hypothesis that increased CaMKII-activated INa,L in atrial myocytes disrupts Ca2+ homeostasis, promoting arrhythmogenic afterdepolarizations. Dynamic CaMKII activity and regulation of multiple downstream targets [ INa,L, L-type Ca2+ current, phospholamban, and the ryanodine receptor sarcoplasmic reticulum Ca2+-release channel (RyR2)] were incorporated into an existing well-validated computational model of the human atrial action potential. Model simulations showed that constitutive CaMKII-dependent phosphorylation of Nav1.5 and the subsequent increase in INa,L effectively disrupt intracellular atrial myocyte ion homeostasis and CaMKII signaling. Specifically, increased INa,L promotes intracellular Ca2+ overload via forward-mode Na+/Ca2+ exchange activity, which greatly increases RyR2 open probability beyond that observed for CaMKII-dependent phosphorylation of RyR2 alone. Increased INa,L promotes atrial myocyte repolarization defects (afterdepolarizations and alternans) in the setting of acute β-adrenergic stimulation. We anticipate that our modeling efforts will help identify new mechanisms for atrial NaV1.5 regulation with direct relevance for human AF. NEW & NOTEWORTHY Here, we present a novel computational model to study the effects of late Na+ current ( INa,L) in human atrial myocytes. Simulations predict that INa,L promotes intracellular accumulation of Ca2+, with subsequent dysregulation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) signaling and ryanodine receptor 2-mediated Ca2+ release. Although INa,L plays a small role in regulating atrial myocyte excitability at baseline, CaMKII-dependent enhancement of the current promoted arrhythmogenic dynamics. Listen to this article’s corresponding podcast at http://ajpheart.podbean.com/e/camkii-dependent-regulation-of-atrial-late-sodium-current-and-excitability/ .

scholarly journals Patients with reflex syncope have a higher prevalence of atrial fibrillation than general population which is predicted by the type of the tilt table test response

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
J M Farinha ◽  
L Parreira ◽  
A F Esteves ◽  
M Fonseca ◽  
A Pinheiro ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
General Population ◽  
Tilt Test ◽  
Tilt Table Test ◽  
Tilt Table ◽  
Test Response ◽  
Reflex Syncope ◽  
Vasodepressor Response

Abstract Introduction Reflex syncope is the result of an imbalance between the sympathetic and parasympathetic nervous system. The autonomic nervous system has been associated to some forms of atrial fibrillation (AF). Objective The aim of this study was to assess the prevalence of AF in patients with reflex syncope and a positive tilt table test and to identify the type of tilt test response in patients with AF in comparison to patients without AF. Methods We retrospectively studied consecutive patients that underwent a tilt table test at our institution between 2016 and 2019. We selected those patients with a positive test. Patients with an implanted pacemaker at the time of the tilt test and patients followed in a different institution were excluded. Previous diagnoses of AF episodes were assessed. We analysed the clinical characteristics and the tilt table test results according to previous history of AF. Results We studied 49 patients with a positive tilt test. Seven (14.3%) patients had previously diagnosed paroxysmal AF at the time of the tilt table test. Patients with AF were older, had more frequently hypertension, and the tilt test response was more frequently a vasodepressor than mixed or cardioinhibitory response (71.4% vs. 28.6%) (Table). In univariate analysis, age and hypertension were associated with AF, respectively, OR 1.08 (95% CI 1.01–1.17), p=0.034 and OR 10.80 (95% CI 1.19–98.36), p=0.035. A vasodepressor response was also associated with AF (OR 6.25, 95% CI 1.06–36.74, p=0.043). Conclusions Patients with reflex syncope and a positive tilt table test had a higher prevalence of AF than the general population. A vasodepressor response was associated with AF as were age and hypertension, demonstrating the possible impact of the autonomic nervous system and the multifactorial nature of AF. FUNDunding Acknowledgement Type of funding sources: None.

scholarly journals Forensic Engineering Analysis Of Dot Verses Non-Dot Helmet Performance As A Function Of Velocities Exceeding Standardized Testing As A Function Of Velocities Exceeding Standardized Testing

2012 ◽  
Vol 29 (2) ◽  
Author(s):  
Laura L. Liptai
Keyword(s):  
Standardized Testing ◽  
The United States ◽  
Department Of Transportation ◽  
Impact Performance ◽  
Performance Improvements ◽  
Motorcycle Helmet ◽  
Road Surfaces ◽  
Hybrid Iii ◽  
Forensic Engineering ◽  
Testing Standards

Motorcyclists Suffer Serious Trauma More Often Than Automotive Occupants Tracing To Contact With Non-Yielding Road Surfaces And/Or Direct Impact From Other Vehicles. A Motorcycle Helmet Is The Principal Defense To Head Impact. If A Motorcycle Helmet Passes Dot, Department Of Transportation, Approval, What Performance Improvements Correlate? Dot And Non-Dot Helmets Were Tested To Determine Impact Performance At Velocities Exceeding Standardized Testing Velocities. Three Types Of Dot Approved And Three Types Of Non-Dot Approved Helmets Were Tested At Two Speeds Outside Of The Federal Testing Standards In The United States. The Analysis Was Performed Using An Inverted Pendulum Sub-System Experimental Device With A Hybrid-Iii Anthropometric Dummy Cranium And Neck. Results Quantify The Performance By Category, Model, And Experiment By Test Metric.

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