VIRTUAL


Thursday, September 16th    2021

3:45 – 4:45 p.m.

WEBEX


Speaker:  Prof. Ricardo Mejia-Alvarez

Assistant Professor, Department of Mechanical Engineering
Engineering Research Complex, Composite Vehicle Research Center

Michigan State University

 

“The Intracranial Mechanics of Traumatic Brain Injury”

 

 

Abstract: 

In this talk, we will address the use of simplified models of the human head to capture localized dynamic loads resulting from exposure to blast and blunt impact. The study finds supporting evidence for stress/strain concentration in material interfaces, and for direct and indirect cavitation damage. These localized dynamic loads are replicated in living tissue and cerebral organoids to study the connection between external loads and mechanical “dose” to tissue and cells.

 

The motivation for this study is that more than 300,000 service members who have returned from conflicts in the Middle East have remained with long-term pathologies that include Post Traumatic Stress Disorder (PTSD), depression, severe anxiety, and suicidal tendencies that in many cases are consummated. In most cases, these pathologies are the result of Traumatic Brain Injury. So far, there is not any clear connection between the incident load, the ensuing intracranial events, and injury at the organ, tissue, and cellular level. A few hypotheses point to the effect of impedance mismatch in the material interfaces of gray and white matter, as well as the direct and indirect effects of inertial cavitation of the Cerebrospinal Fluid (CSF), as the origin of TBI pathology. Some computer simulations lend credence to these attempts to find mechanistic explanations to the origin of TBI, but animal studies and post-mortem human data have been insufficient to validate these results.

 

Bio: 

Dr Ricardo Mejia-Alvarez is an Assistant Professor in the Department of Mechanical Engineering at Michigan State University. He received his PhD degree in Theoretical and Applied Mechanics from the University of Illinois at Urbana-Champaign. He worked in Los Alamos National Laboratory from 2010 to 2016, primarily conducting experimental research in shock-driven instabilities. Dr. Mejia-Alvarez studies shock-matter interactions, with emphasis on their effect on living tissue and the mechanics of TBI. Some of his accolades include the 2011 Francois Frenkiel Award for Fluid Dynamics from the American Physical Society and a Fulbright Fellowship