Psychological and Physiological Effects of Muzzle and Breech Blast

Understanding blast-induced neurotrauma: how far have we come?

“…The subsequent interaction between the primary and reflecting waves augments the initial pressure wave and makes it more complex. It has been estimated that the reflected pressure of a blast wave as a function of shock strength can, for an infinite shock strength, achieve eight-times that of the incident blast wave [ 8 ].…”

“…The seminal works from 1950s to 1970s [ 6 , 8 , 10–13 ] posited that the severity of the injuries and the extent of damage caused by a blast wave depend on five main factors [ 14 ]: the peak of the initial positive-pressure wave (e.g., the overpressure ranges from 690 to 1724 kPa, e.g., 100–250 psi, is considered potentially lethal); the duration of overpressure; the density of the medium in which the explosion occurred (air or water); the distance from the incident blast wave, namely, the intensity of the blast overpressure declines with the cubed root of the distance from the explosion (e.g., a person 3 m/10 ft from an explosion is subjected to nine-times more overpressure than a person 6 m or 20 ft away); and the degree of the blast wave’s reflection, namely, in complex environments and confined spaces, the intensity of the blast wave can be augmented between two- and nine-times due to reflection from surrounding objects or walls (e.g., victims positioned between blast and a building often suffer from injuries two- to three-times more severe than a person in an open space). Although there are many discussions about other circumstances and elements that could influence the blast effects, the importance of the above mentioned factors remains irrefutable.…”

“…The works of Shardin [ 6 ], Rössle [ 10 ], Benzinger [ 29 ] and Desaga [ 11 ], published in the German Aviation Medicine World War II in 1950, provided a significant impetus for experimental blast research. However, interestingly, in an attempt to better control the conditions of exposure, the research studies performed during the period of 1950–1980, changed their approach to the experimental design: instead of mimicking the ‘war environment’, they shifted to ‘artificial’ but more controllable technological solutions [ 8 ]. To avoid variations in peak pressures due to fluctuations in charge performances, compressed gas operated shock tubes have been designed and used with increasing frequency in experimental studies [ 48 , 49 ].…”