Modeling of the Non-Auditory Response to Blast Overpressure: Gastrointestinal Tract Blast Injury Laboratory Test Techniques

Gastrointestinal tract blast injury involves the interaction of the physical aspect of the blast loading, the dynamics of bubble deformation oscillation, and the physiological properties of the G.I. tract injury threshold. Such interplay is complicated by the random distribution of bubble size and bubble location. Because of these complications, there are several technical hurdles to be overcome before standardized test procedures can be established, JAYCOR has developed several techniques that facilitate the experimental effort. These include 1 the design of a constant temperature test chamber system that can be used to deliver an equivalent intra-abdominal blast signal and facilitate high speed photographic observation of local G.I. deformation 2 an autologous in vitro perfusion technique that allows a complete viable gastrointestinal tract to be isolated in a test chamber for blast injury tests, while under the continued blood supply from the cardiopulmonary system of the same test animal 3 a probe-in-balloon unit that permits gas bubble volume to be placed at desired locations in a G.I. tract for measurement of its corresponding pressure signals 4 an ultrasonic sensing technique for determining the location and length of gas bubbles in the G.I. tract and finally, 5 techniques for indicating the presence, and quantifying the degree, of serosal and mucosal bleeding by Hemastix and microscopic examination. Keywords RA 3, Non-auditory response, Blast overpressure, Explosions, Weapons effectsBiological, StressPhysiology, G.I. Tract injury, Probe-In-Balloon PIB unit.