Acute pathophysiology of blast injury-from biomechanics to experiments and computations: Implications on head and polytrauma

Traumatic brain injury (TBI) has been a major public health concern in the United States for decades; with an average of 1.4 million sustaining TBI, leading to 50,000 deaths, 235,000 hospitalizations, and 1.1 million emergency department visits. Among the several causes of TBI including fall accidents, motor vehicle crashes, sports collisions, and firearm assaults, explosions-induced TBI, commonly referred to as Blast-Induced Neurotrauma (BINT) has been frequently observed in recent warfare. In this chapter, we will discuss the origin, mechanics, mechanisms of BINT, and focus on the current state-of-the-art in terms of protection, diagnostics, prognostics and therapeutics involved in BINT. In addition, we will outline novel research approaches currently underway in terms of: experiments in laboratory-on animals, surrogate heads, cadaveric heads; as well as computer models of head-brain system. Finally, an analysis on the protective capabilities that have been introduced in BINTs against blast loading will be evaluated. TBI has been a major public health concern in the United States for decades; from 1995 to 2001 there was an average of 1.4 million Americans a year who sustained TBI, leading to 50,000 deaths, 235,000 hospitalizations, and 1.1 million emergency department visits (Langlois et al., 2004). Of these, an estimated 80,000-90,000 experienced the onset of long-term disability (Langlois et al., 2004; Thurman et al., 1999). These TBIs were largely caused by falls, motor vehicle crashes, sports collisions, and firearm assaults (Langlois et al., 2004). However, in this chapter, we are concerned with a new type of brain injury arising from explosions commonly referred to as BINT. We will focus on the origin, mechanics, and mechanisms of BINT, and the current state-of-the-art in terms of protection, diagnostics, prognostics, and therapeutics of the injury. We will outline the research approaches currently under way in terms of experiments in laboratory on animals, surrogate heads, cadaveric heads, computer models of the head-brain system, and finally an analysis on the protective capabilities of the current helmets against blast loading.