In Vivo Human Skull-Brain Dynamics During Mild Sagittal Skull Acceleration
Abstract/Contents
- Abstract
- Mild traumatic brain injury, or concussion, is one of the greatest medical challenges facing our society today, with diagnosed cases more prevalent than ever before, especially in contact sports. Previous studies have shown increased risk of neurodegenerative diseases such as Alzheimer’s in patients with a history of concussions, signifying the importance of better diagnostic tools and preventative equipment. Global kinematic variables and their variants have been historically used as indicators of concussion. The field of brain injury biomechanics rests on the assumptions that the brain is an almost incompressible material with little shear resistance. Together with the geometry of the relatively rigid skull, these assumptions have led to hypotheses that the brain is much more vulnerable to rotational rather than translational motions of the head. Previous animal experiments have shown higher rates of injury when rotational head accelerations were applied. Detailed finite element models have also predicted that rotational head motions lead to higher deformations in the brain. However, never before has this difference of dependence on skull input been shown experimentally. Here, we present the first study to experimentally investigate the decoupled effect of rotation and translation of the head on relative brain-skull displacement in live humans. Using high-speed fluoroscopy, we measured the brain's displacement as a result of head motions of up to 10g translational and 6 rad/s rotational velocities, which reach head motions near median soccer headers. Our results suggest that brain motion occurs predominantly due to the rotational head motion and relative motion of the brain is a function of the skull's rotational velocity. Furthermore, this experiment will allow us to validate our previous finding that skull–brain dynamics can be approximated by an under-damped system with a low-frequency resonance of less than 20 Hz. Our findings provide insight and suggest a new direction into designing smarter protective helmets based on the understanding of the complex dynamics of brain deformation rather than ad hoc injury correlations.
Description
| Type of resource | text |
|---|---|
| Date created | May 11, 2016 |
Creators/Contributors
| Author | Hammoor, Bradley |
|---|---|
| Advisor | Camarillo, David |
| Advisor | Pelc, Norbert J. |
| Advisor | Deisseroth, Karl |
| Degree granting institution | Stanford University. Department of Bioengineering. |
Subjects
| Subject | Concussion |
|---|---|
| Subject | Traumatic Brain Injury |
| Subject | Firestone Medal for Excellence in Undergraduate Research |
| Genre | Thesis |
Bibliographic information
Access conditions
- Use and reproduction
- User agrees that, where applicable, content will not be used to identify or to otherwise infringe the privacy or confidentiality rights of individuals. Content distributed via the Stanford Digital Repository may be subject to additional license and use restrictions applied by the depositor.
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Preferred citation
- Preferred Citation
- Hammoor, Bradley. (2016). In Vivo Human Skull-Brain Dynamics During Mild Sagittal Skull Acceleration. Stanford Digital Repository. Available at: http://purl.stanford.edu/tv003sr5716
Collection
Undergraduate Theses, School of Engineering
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- Contact
- hammoorb@stanford.edu
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