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Five anesthetized porcine subjects were exposed to blunt thoracic impact using a 21 kg mass with a flat contact surface traveling at 3.0 to 12.2 m/s. The experiments were conducted to assess the appropriateness of studying in vivo mechanical and physiological response to thoracic impact in a porcine animal model. A comprehensive review of comparative anatomy between the pig and man indicates that the cardiovascular, respiratory and thoracic skeletal systems of the pig are anatomically and functionally a good parallel of similar structures in man. Thoracic anthropometry measurements document that the chest of a 50 to 60 kg pig is similar to the 50th percentile adult male human, but is narrower and deeper. Peak applied force and chest deflection are in good agreement between the animal's responses and similar impact severity data on fresh cadavers.

One of the greatest challenges faced in the design of realistic occupant protection systems is an accurate statistical model of what is really needed. The paucity of data is this realm hinders designers of standards alike. Ideally, a model of crash statistics would correlate, for significant accident modes, injury level (as measured by AMA Abreviated Injury Scale “AIS”) with some adequate measure of crash intensity. Having this information, not only could the required level of safety design be ascertained, but also the justifiable economic expenditure could be estimated. This paper treats the statistical basis for deployment of a data retrival system. It provides a basis for estimates of the amount of data required, the number of vehicles to be instrumented, the crash severity trigger levels, and the economics of recorder installation, for various levels of injury and fatality.

The problem of occupant impact severity reduction by effective use of available space was studied using a two-degree-of-freedom linear mathematical model implemented on a digital computer. An optimum-search method was employed to find the best values of stiffness and damping terms for linear lap and shoulder “belts” corresponding to specific vehicle pulseforms and geometry at speeds 10 to 60 mph. System performance was evaluated on the basis of a severity index comparing occupant deceleration data, and upon penalties imposed for occupant contact with vehicle interior structures. Comparison to biomechanical data indicates that the optimal linear system for 60 mph could produce serious injuries. Comparison to theoretical optimum values indicates considerable room for improvement, using active or nonlinear passive systems.