Breaking News
August 17, 2018 - Bacterial activity in child’s mouth may serve as biomarkers for autism spectrum disorder
August 17, 2018 - Scripps Research scientists uncover new approach for treating thrombocytopenia
August 17, 2018 - Mathematical model shows the influence of human behavior on spread of infectious diseases
August 17, 2018 - Valley Hospital achieves Magnet recognition for fourth consecutive time
August 17, 2018 - Researchers describe link between poor oocyte development and oxidative stress in obese mice
August 17, 2018 - Hospitals battle for control over fast-growing heart-valve procedure
August 17, 2018 - AHA: Home-Delivered Meals Keep Heart Failure Patients Out of Hospital
August 17, 2018 - In Southern Mozambique, only half of people diagnosed with HIV enroll in medical care
August 17, 2018 - Researchers discuss techniques to help combat growing epidemic of obesity
August 17, 2018 - Researchers develop novel statistical method to evaluate gene-to-gene interactions linked with cancer
August 17, 2018 - Island Fertility joins Stony Brook Community Medical to provide comprehensive fertility care
August 17, 2018 - Study shows link between thinning of the retina and early sign of Parkinson’s disease
August 17, 2018 - Digital birth control app gets FDA nod
August 17, 2018 - FDA grants approval for first generic version of epinephrine auto-injector
August 17, 2018 - Federal advisory group publishes recommendations on prevention of acute, chronic pain
August 17, 2018 - 3D-printed human body parts to be used as teaching aids for surgical training
August 17, 2018 - U.S. murder, suicide rates climbing again
August 17, 2018 - This is your brain on… roller coasters?
August 17, 2018 - Report discusses whether all newborns should undergo genetic sequencing
August 17, 2018 - UCR receives 2018 Inspiring Programs in STEM Award from INSIGHT Into Diversity magazine
August 17, 2018 - Researchers publish new paper on developing vaccine candidates for Helminthic parasites
August 17, 2018 - Researchers develop new method to diagnose broad range of cancers using malaria protein
August 17, 2018 - Female mosquitoes quickly evolve selective mating behavior when faced with threats
August 17, 2018 - FDA Grants Breakthrough Therapy Designation to Daiichi Sankyo’s FLT3 Inhibitor Quizartinib for Relapsed/Refractory FLT3-ITD AML
August 17, 2018 - Resistance training and exercise motivation go hand-in-hand
August 17, 2018 - A lesson for future doctors: Listen to and learn from your patients
August 17, 2018 - NUS study discovers a bidirectional regulator and shines light on A-to-I RNA editing in cancer cells
August 17, 2018 - Research shows link between high blood levels of omega-3s and better brain function in children
August 17, 2018 - Researchers propose new theory for how rare gene mutations cause Alzheimer’s disease
August 17, 2018 - New project to combat DMD-related fibrosis receives major funding boost
August 17, 2018 - Digital psychiatric therapy can ‘rewire’ the brain in children with ADHD, study shows
August 17, 2018 - Psychologist to assess how the brain maintains precise short-term and long-term memories
August 17, 2018 - Eating white button mushrooms could improve regulation of glucose in the liver
August 17, 2018 - Scientists identify mutational signatures in ovarian cancer
August 17, 2018 - Sun Pharma receives U.S. FDA approval for CEQUA to treat patients with dry eye disease
August 17, 2018 - Teva Announces Updated Indication and Vial Presentation for Granix (tbo-filgrastim) Injection in United States
August 17, 2018 - Study shows DNA methylation related to liver disease among obese patients
August 17, 2018 - Life on the border: Back at Stanford, ready to pitch in
August 17, 2018 - New device for accurately placing hemodialysis catheters on kidney patients
August 17, 2018 - New strategy accelerates, automates process of prototype molecule optimization
August 17, 2018 - Study finds role of autoimmunity in development of COPD
August 17, 2018 - Researchers transform research tool to study neuronal function
August 17, 2018 - Cognitive impairment does not equate to unhappiness in older adults
August 17, 2018 - Peer Comparisons Can Decrease Risky Prescribing Patterns
August 17, 2018 - Susceptible genes identified for childhood chronic kidney disease
August 17, 2018 - Research uncovers miscarriage cause, identifies potential targets for treatment
August 17, 2018 - Bacterial armor could be new target for antibiotics | News Center
August 17, 2018 - FDA expands approval of Vertex’ cystic fibrosis medicine to treat children aged 12 to
August 17, 2018 - Give Your Child a Head Start With Math
August 17, 2018 - Ground-breaking study tests whether rejected livers can be made viable for transplantation
August 16, 2018 - New algorithm could improve diagnosis of rare diseases | News Center
August 16, 2018 - SCHILLER introduces latest generation of ECG device, CARDIOVIT AT-102 G2
August 16, 2018 - Proper treatment, refraining from smoking can reduce heart disease risk from type 2 diabetes
August 16, 2018 - Mount Sinai study could transform treatment for patients with retinal degenerative diseases
August 16, 2018 - Penn researchers develop first mouse model of idiopathic pulmonary fibrosis
August 16, 2018 - Four tips to help prevent fall allergy symptoms
August 16, 2018 - Women’s Preventive Services Initiative says screen all women annually for urinary incontinence
August 16, 2018 - At Stanford, patient discovers the source of her headaches, nausea | News Center
August 16, 2018 - To Prevent Injuries in Young Baseball Players, Chris Ahmad Reaches Out to Parents
August 16, 2018 - Restoring blood flow may be linked to longer survival in patients with critical limb ischemia
August 16, 2018 - New model of genetically engineered immune cells may help fight solid tumors
August 16, 2018 - Maternal stress increases anxious and depressive-like behaviors in female offspring
August 16, 2018 - Childhood exposure to secondhand smoke increases risk of COPD death in adulthood
August 16, 2018 - Scientists uncover key control mechanism of DNA replication
August 16, 2018 - NIH begins first-in-human trial of experimental live, attenuated Zika virus vaccine
August 16, 2018 - Two diabetes medications don’t slow progression of type 2 diabetes in youth
August 16, 2018 - 5 Questions: How Stanford research is making MRI scans safer for kids | News Center
August 16, 2018 - Columbia Celebrates 25th Anniversary of White Coat Ceremony
August 16, 2018 - Phonak’s new smallest and most discreet Virto B-Titanium hearing aid
August 16, 2018 - New project aims to study growth of water-based microorganisms
August 16, 2018 - Immune cell found to play important role in photosensitivity
August 16, 2018 - Higher social dominance linked to faster decision-making in men
August 16, 2018 - Blood test in early pregnancy could determine a woman’s later risk for gestational diabetes
August 16, 2018 - New research confirms link between DDT exposure and autism
August 16, 2018 - Neurodevelopmental Anomalies, Birth Defects Linked to Zika ID’d
August 16, 2018 - Risk of heart failure up in ALVSD patients with diabetes
August 16, 2018 - Exercise reduces symptoms and fatigue in patients with chronic kidney disease
August 16, 2018 - Study reveals role of RUNX proteins in DNA repair
August 16, 2018 - New research finds no harm from average salt consumption
August 16, 2018 - Researchers develop new way of testing bacterial resistance to antibiotics
Computer modeling and simulation may help characterize injury from blasts on a battlefield

Computer modeling and simulation may help characterize injury from blasts on a battlefield

image_pdfDownload PDFimage_print

Sandia National Laboratories is developing specialized computer modeling and simulation methods to better understand how blasts on a battlefield could lead to traumatic brain injury and injuries to vital organs, like the heart and lungs.

Researchers at Sandia have studied the mechanisms behind traumatic brain injury for about a decade. Their traumatic injury modeling and simulation project began with a head-and-neck representation, and now they’ve created a high-fidelity, digital model of a man from the waist up to study the minute mechanisms behind trauma.

“We’re also concerned about the possibility of injury to the life-support systems in the torso. Everything’s interconnected,” said Paul Taylor, who leads the project. “Clearly, we would love to have a representation of a full human but certainly capturing all the regions where life-critical organs are located is a very good start.”

The information could help manufacturers develop better designs for helmets and body armor.

“Protection of the soldier, sailor or marine is essential, and well aligned with our national security mission against challenging and new lethal threats,” said program manager Doug Dederman. “It is a privilege for our integrated military systems staff to team with the Department of Defense and medical communities to improve both diagnostic capabilities and mitigation of risk with improved protective equipment.”

Sandia’s most recent work grew from a Laboratory Directed Research and Development-funded project that wrapped up in late 2016. Along the way, the team conducted both macroscale and microscale traumatic brain injury simulations, began working with doctors to correlate simulation predictions with clinical assessments of people with brain injury and increased the size of their team.

They theorize that a phenomenon called fluid cavitation can lead to traumatic brain injury. They’ve developed macroscale simulations to test the hypothesis and extended their work into microscale studies to examine whether blast and short-pulse blunt impact, such as a projectile hitting body armor, could lead to fluid cavitation, forming bubbles whose collapse could damage sensitive brain and lung tissue, Taylor said.

Cavitation is the formation of vapor cavities -; bubbles -; caused by rapid pressure changes in fluid, which can occur from blast exposure. Bubbles form and, because they’re unstable, immediately collapse, generating a microjet or miniature localized shock wave. It’s a physics phenomenon commonly seen at the leading edge of spinning ship propellers, eroding those propellers.

Studying the mechanisms behind damage to brain, organs

“We’ve been able to demonstrate, at least theoretically, that the individual experiences fluid cavitation in the brain. We’ve subjected our head-neck model to blasts from the front, from the side, from the rear, and what we see are what looks like peppered regions in the brain,” localized regions experiencing cavitation, Taylor said, pointing to the occipital, temporal and brain stem areas on a slide from a simulation.

“Does cavitation occur, and if so, where might it be occurring?” said team member Candice Cooper, who developed the macroscale simulation. “Then we look at those areas on the microscale to see if cavitation is indeed occurring, how might it damage these tissues and lead to traumatic brain injury.”

The smallest area in the macroscale simulation is 1 cubic millimeter, which isn’t small enough to capture the physics of fluid cavitation very well, Taylor said.

Enter Shivonne Haniff, who performs microscale modeling and simulation to complement Cooper’s macroscale work, simulating the formation and collapse of cavitation bubbles in the brain in scales below 1 millimeter.

One of Haniff’s models represents axonal fiber bundle tracks within the brain’s white matter. Typically, white matter axons have myelin sheaths, a protective coating, similar to how insulation protects electric wiring. Myelin sheathing accelerates neurological pulses, allowing humans to process information very quickly. Diseases, such as multiple sclerosis, degrade myelin sheathing and drastically reduce pulse transmission.

The team hypothesizes that blast- and impact-induced cavitation and subsequent bubble collapse also could damage myelin sheathing.

Haniff’s video of a microscale simulation of cavitation bubble collapse within the white matter axon fiber bundle introduces a pressure pulse from one side, causing asymmetric collapse of the bubbles, generating highly localized pressure pulses and microjetting that damages neighboring axons and their myelin sheathing.

The team studied how compressive wave amplitude and bubble size influenced microjetting strength.

“To assess damage potential from bubble collapse-induced microjetting, we looked at pressures and shear stresses downstream of the bubbles. The shear stresses in the myelin sheathing were considerably higher than the shear stresses in the axon core, indicating the myelin acts as a protective barrier,” Haniff said. “However, damage to this myelin sheathing could impair the transmission of nerve signals, which can lead to neurological problems.”

She’s focusing now on modeling cavitation damage within the blood-brain barrier, a semi-permeable vascular system that allows passage of nutrients and gases needed by the brain but blocks harmful toxins. A video simulation shows cavitation bubbles suddenly collapsing under pressure, drastically increasing pressure and shear loading on surrounding tissue, which can damage it. Simulations look at the effects of different bubble diameters, bubble density and pressure wave amplitudes on the degree of damage.

Working out how to model damage mechanisms

Cooper also conducted modeling and simulations for a generic body armor configuration. The work was aimed at understanding the modeling problem rather than reaching conclusions applicable to specific armor. Her simulation studied pressures within the heart, lungs and other organs in different scenarios, such as a soldier standing about 10 feet from a roadside bomb blast.

“We looked at pressure as well as the shearing stress that can lead to tissue tearing, and found that in this notional case, having padding behind the armor actually increased peak pressures in life-critical organs, the heart and the liver, which could lead to damage,” Cooper said. “It also led to an increase in shear stresses in all of the organs that we looked at.

“This is just an example of how we can use our modeling and simulation tools. If someone came to us with their armor design and said, ‘Would you take a look at this,’ we could vary the materials of the foam padding, the positioning of the foam padding, the size or geometry of the foam padding or of the armor plate itself,” she said. “We could look at variations on their design and let them know this change makes it better, that change makes it worse.”

Source:

Blast, impact simulations could lead to better understanding of injuries and body armor

Tagged with:

About author

Related Articles