Session: 01-06-02: New Advances in Acoustics and Vibration: AI and Machine Learning, New Methods and Materials

Paper Number: 143248

143248 - Effect of Skull Sutures on Vibrational Response of a Simplified Head Model 

Traumatic brain injury (TBI) is a frequently studied cause of death and disability. Car crash injuries, contact sports injuries, and combat injuries are typical scenarios for investigating the effects of blunt force impact and acceleration/deceleration events. A related area investigates damage arising from acoustic wave exposure, such as blast wave injuries. This subfield is distinct from auditory damage arising in loud workplace environments, where noise exposure is linked along well characterized pathways to hearing loss, neurodegenerative decline, and dementia.

This work considers aspects of a mechanism by which occupational noise exposure might induce traumatic brain injury, specifically, how sutural connections between the bones of the skull might affect the vibration properties of the head. The skull constitutes armor that surrounds and protects the brain. In typical scenarios like crash modeling, the skull is often treated as a continuous shell, which in some studies includes diploë (the spongy marrow-containing bone layer within the skull). However, the sutures that connect the various skull bones are typically not modeled. Recent work has indicated that the skull may have unanticipated resonant vibration properties if the sutures permit relative motion between the various skull bones. If so, the skull may be responsive to loud airborne sounds, and transmit higher-than-expected sound levels to the brain. Such oscillatory vibrations could induce alternating strains in brain tissues and be a potential mechanism for brain damage.

A typical analysis framework involves creating computational models of human anatomy and then analyzing their response to an injury event. Often this process is numerically treated with finite element methods. Accuracy of numerical results is fundamentally reliant on the level of anatomic detail in the head model. More accurate features can enhance accuracy of the analysis, but the conclusions are then less generalizable to the population (e.g., a unique individual versus all humans).

In this study, we consider a simplified skull model containing the various skull bones connected via cartilaginous sutural networks. We use engineering simulation to investigate the effects the sutures may have on skull acoustic vibrations for a prototypical skull size and shape relative to the properties of a conventional “continuous” skull derived from CT imaging of a particular individual. Results are anticipated to include at least natural frequencies and mode shapes corresponding to these properties. These results are expected to be applicable in occupational safety studies considering risk of injury in loud environments (where sound pressure levels in the range of 90-130 dB exist).

Presenting Author: Marianne Cites University of Pittsburgh

Presenting Author Biography: Marianne Cites is a 4th year PhD candidate in Mechanical Engineering at the University of Pittsburgh. Her research interests include computational acoustics, biological modeling, and reduced-order modeling. She received her B.S. in Aerospace and Mechanical Engineering from the University at Buffalo in 2020.

Authors:

Marianne Cites University of Pittsburgh
Christopher Dumm University of Pittsburgh
George Klinzing University of Pittsburgh
Carey Balaban University of Pittsburgh
Jeffrey Vipperman University of Pittsburgh