An Experimental Study of Package Cushioning for the Human Head

Abstract

An experiment was performed to determine the container acceleration and pressure distribution in a Plexiglass cylinder, filled either with water or 3 percent set-gelatin, and impacted against a wall. This experiment serves to quantitatively validate a theoretical model simulating an one-dimensional closed-head impact given earlier. The experiments showed important differences between the theoretical and experimental pressure measurements. When the medium contained within the cylinder was water the coup pressure as found by experiment, was higher than the mathematical model prediction while the contrecoup pressure was in good agreement. When the container was filled with a set gel, the coup pressure was in agreement with the mathematical model but the contrecoup pressure is considerably lower than the calculated result. Since the brain is neither water nor gel, in vivo animal experiments are needed to obtain meaningful tolerance limits for injury due to cavitation at the contrecoup region in closed-head impacts.