Philip V. Bayly, Ph.D.

When the human head experiences any kind of movement — from nodding yes or no to heading a soccer ball or being jolted in a car crash — the brain moves inside the skull, leading to deformation of the tissue. Such deformations are key to understanding traumatic brain injury but are challenging to study since the brain is hidden inside the skull.

Philip V. Bayly, the Lee Hunter Distinguished Professor and chair of the Department of Mechanical Engineering & Materials Science at the McKelvey School of Engineering at Washington University in St. Louis, and Jordan D. Escarcega, a mechanical engineering doctoral student in Bayly’s lab, led a multi-institutional team to compare how the human brain deforms in response to movement using two types of magnetic resonance imaging (MRI). Their work is published in the August issue of the ASME Journal of Biomechanical Engineering… Continue reading.

During the third trimester, a baby’s brain undergoes rapid development in utero. The cerebral cortex dramatically expands its surface area and begins to fold. Previous work suggests that this quick and very vital growth is an individualized process, with details varying infant to infant.

Research from a collaborative team at Washington University in St. Louis tested a new, 3-D method that could lead to new diagnostic tools that will precisely measure the third-trimester growth and folding patterns of a baby’s brain.

The findings, published online March 5 in PNAS, could help to sound an early alarm on developmental disorders in premature infants that could affect them later in life.

“One of the things that’s really interesting about people’s brains is that they are so different, yet so similar,” said Philip Bayly, the Lilyan & E. Lisle Hughes Professor of Mechanical Engineering at the School of Engineering & Applied Science. “We all have the same components, but our brain folds are like fingerprints: Everyone has a different pattern. Understanding the mechanical process of folding — when it occurs — might be a way to detect problems for brain development down the road… Continue reading.

Traumatic brain injury, or TBI, can be devastating and debilitating. Despite intense interest and years of study, the exact mechanisms linking force and neurological injury remain unclear. Researchers know that the membranes separating the skull from the brain play a key role in absorbing shock and preventing damage caused during a head impact, but the details remain largely mysterious.

New research from a team of engineers at Washington University in St. Louis takes a closer look at this “suspension system” and the insight it could provide to limit or perhaps prevent TBI.

“The idea was to find out how protective are the layers of membranes that connect the brain to the skull,” said Philip Bayly, the Lilyan & E. Lisle Hughes Professor of Mechanical Engineering and chair of the Mechanical Engineering & Materials Science Department at the School of Engineering & Applied Science. “They serve the same function as the suspension in your car. When you go over a bump in a car, there’s a big oscillation of the wheels but you get very little motion in your body because the suspension absorbs it.

“We know that the membranes are there to cushion the brain, but by how much, and what’s the variation from person to person?”

During the study, researchers used an imaging technique called magnetic resonance elastography, or MRE, on six volunteers. During MRE, tiny skull vibrations are introduced through a vibrating pillow and measured with sensors embedded in a mouthguard. The motion of the brain was then measured via magnetic resonance imaging. When compared to a gelatin model that showed significant force transfer, the six subjects’ skull-brain interface significantly delayed and weakened the transfer of motion from skull to brain.

The human body has a lot of jobs to do, and its mechanical features, such as strength and flexibility, are important to how well it does them. Washington University in St. Louis engineers are now applying a new imaging technique to a model of brain tissue to see how stiff or soft it might be.

Philip Bayly, PhD, the Lilyan and E. Lisle Hughes Professor of Mechanical Engineering and chair the Department of Mechanical Engineering & Materials Science, has received a three-year, $429,222 grant from the National Science Foundation to study directionally dependent mechanical properties in muscle, white matter in the brain or artificial tissue.

In the brain, white matter holds the nerve fibers that wire cells together. Fibers in tissue also determine mechanical stiffness and strength and influence in which direction waves travel during motion. But these fibers also make it difficult to measure the properties without taking invasive measures.

Bayly and Joel Garbow, PhD, research associate professor of radiology at the School of Medicine, plan to use magnetic resonance elastrography (MRE), a noninvasive technique, to view and measure different properties of waves when they travel in different directions in the fibrous materials. There are a variety of factors that come into play.

The American Academy of Neurology issued new guidelines last week for assessing school-aged athletes with head injuries on the field. The message: if in doubt, sit out.

With more than 3 million sports-related concussions occurring in the U.S. each year, from school children to professional athletes, the issue is a burgeoning health crisis.
While concussions may not be difficult to diagnose initially, the longer one waits, the more difficult treatment can be.

The efforts of a researcher and his colleagues at Washington University in St. Louis’ School of Engineering & Applied Science are helping to unravel the many mysteries of traumatic brain injury.

“There’s and urgent need to understand the problem of traumatic brain injuries, for the sake of athletes, military personnel and accident victims,” says Philip Bayly, PhD, the Lilyan and E. Lisle Hughes Professor of Mechanical Engineering.

“Anyone who has met someone who’s had a head injury knows how scary it is, and how frustrating it is that we know so little about the causal pathways, and thus the best therapeutic opportunities,” he says.

Bayly, chair of the Department of Mechanical Engineering & Materials Science, researches the mechanics of brain injury. He recently received a $2.25 million grant from the National Institutes of Health to better understand traumatic brain injuries.

Washington University in St. Louis engineering researchers have received a five-year $2.25 million grant to better understand traumatic brain injuries in efforts to improve methods for prevention and treatment.

Philip Bayly, PhD, the Lilyan and E. Lisle Hughes Professor of Mechanical Engineering and chair of the Department of Mechanical Engineering & Materials Science, is principal investigator for the grant from the National Institutes of Health.
The grant will allow Bayly and his research team to develop 3-D computer models of brain biomechanics that will give researchers and clinicians a better understanding about what happens to the brain during traumatic brain injury. Previously, Bayly and his research team measured brain motion and mechanical properties of the brain in 2-D.

Head injuries, concussions and the resulting trauma have been in public discussion recently as the National Football League (NFL) deals with a lawsuit regarding head injuries by about one-third of living former NFL players. The league is accused of not providing information connecting football-related head injuries to brain damage, memory loss and other long-term health issues.

“We are concerned about everyone who hits their head,” Bayly says. “It’s not only a factor for NFL players, but anyone who’s had a traumatic brain injury is at greater risk for Alzheimer’s disease and potentially other neurological disorders. We’re also concerned about basketball players or soccer players who also get concussions, so it’s a widespread problem.”