FIG. 1.

Shock wave delivery apparatus. A: The shock tube is composed of a driver section (behind the diaphragm where gas is compressed) and a driven section (in front of the diaphragm at atmospheric pressure). For characterization purposes, pressure sensors were positioned within (not depicted) and outside the tube. B: After the diaphragm ruptures, the contact surface is initially ahead of the shock wave. C: After traveling a significant distance down the length of the tube, the shock wave outpaces the contact surface and is eventually emitted from the open end of the shock tube, where it strikes the head of the rat positioned a distance equivalent to the shock tube inner diameter for optimal blast conditions (same location as the depicted pressure sensor). D: Representative shock wave recording exhibiting characteristics of an idealized Fried-lander waveform with a rise time of 0.15 msec, maximum overpressure of 150 kPa, overpressure duration of 1.25 msec, maximum underpressure of 20 kPa, and an underpressure duration of 1.25 msec. Waveform properties are tunable by adjusting thickness of the diaphragm and sensor/subject distance from the open end of the shock tube.