Blast-induced traumatic brain injury (bTBI) has been widely accepted as a “signature” wound affecting military service members in modern conflicts. When a blast-wave generated by an improvised explosive device explosion propagates through the human head, it is hypothesized to cause direct mechanical damage to the brain tissue leading to vascular injury, cerebral edema as well as less detectable but persistent deficits. However, the exact mechanisms and pathophysiology of bTBI still remain poorly understood. One of the main reasons for such poor understanding is the technical challenge of reproducing the typical time-varying loading cycles induced on brain tissue after a blast event under controlled laboratory conditions. Blast events have a sub-millisecond onset of high pressure followed by complex dynamics resulting from the interaction between the blast wave and the intricate anatomical structure of the human head. This interaction gives rise to time-varying intracranial pressure profiles, dynamic shear loads, and cavitation events, which are hypothesized to cause mechanical insults to the brain tissue.To tackle these experimental challenges, we have developed four experimental devices that can reproduce the dominant intracranial effects induced by blast loading onto the brain. These experimental devices are: (1) Multi-material Hopkinson bar (MMHB) actuator, (2) Generator of broadband pressure cycles, (3) Rig for controlled-cavitation events, and (4) Generator of dynamic shear cycles. This dissertation details the design and development of the aforementioned experimental systems along with the preliminary ex-vivo and in-vitro experiments performed to test their applicability. The designed apparatuses are comparably inexpensive, compact, easily portable, and highly controllable, making them well suited for biomedical applications. These devices can be used to conduct ex-vivo and in-vitro experiments involving animal brain tissue specimens, cell cultures, and organoids to explore their pathophysiological response to the blast-like loadings observed during a bTBI event.
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