ABSTRACT
Blast-induced traumatic brain injury (TBI) is a signature, invisible wound of wars, sustained with long-lasting neuropsychiatric and neurological symptoms. The mechanism of blastinduced TBI has been controversial for a long time. Direct cranial transmission of blast waves was considered by most investigators as the mechanical mechanism by which the blast wave causes mild TBI. Only few investigators hypothesized that thoraco-abdominal vascular/hydrodynamic transmission of blast waves could be the major cause of blast-induced TBI. To separate direct cranial transmission of blast waves from thoraco-abdominal vascular/hydrodynamic mechanism to blast-induced TBI, two “iron lung”-like protective devices are designed for protection of desired parts of the animal body against blast waves. One “Iron lung”-like protective device allows only the animal head to expose to blast waves, and another makes the animal thorax and abdomen only expose to blast waves. The use of the “iron lung”-like protective devices in blast injury research will lead to new insight into the mechanisms underlying blast-induced TBI. Shock tubes have been employed to investigate blast injuries in animals since 1940s. However, many uncertainties are associated with the results obtained from the animal models using shock tubes because a series of complex shock waves generated by shock tubes affect
experimental observations and lead to false-positive results in the studies of blast TBI mechanism. A C4 blast generator that generates blast waves by detonation of C4 charge in a free field can be used as a new experimental tool for blast-induced TBI research. A comparative study between two animal models that use traditional shock tube and novel C4 blast generator respectively to induce TBI, will help develop a reliable and valid experimental approach to identify the mechanism of blast-induced TBI. The physical parameters of blast shock waves and the extent and severity of TBI, which are closely associated with the effects of blast shock waves on the brain, need to be analyzed, assessed and compared comprehensively between the two animal models. The two-model comparative approach will contribute to eliminate knowledge gaps regarding blast-induced TBI and to prioritize future TBI research.
