A High-Speed Cineradiographic Technique for Biomechanical Impact

A versatile high-speed cineradiographic system developed in the Biomechanics Department of The University of Michigan's Highway Safety Research Institute has recently been completed, for application to human injury and tolerance and occupant protection research. This system consists of a high-speed motion picture camera which views a 2-inch diameter output phosphor of a high gain 4-stage, magnetically focussed image intensifier tube, gated on and off synchronously with shutter pulses from the motion picture camera. A fast lens optically couples the input photocathode of the image intensifier tube to x-ray images produced on a fluorescent screen by a d-c x-ray generator. The system is adaptable to a wide variety of experimental configurations because: 1) screen size can be easily and inexpensively changed, and can be larger than the largest x-ray intensification tubes made; 2) the image intensifier tube is readily switchable over a wide range of pulse repetition rates and pulse widths, allowing motion picture frame rates closely matched to dynamic events under study; and 3) the system is not limited to a particular x-ray generator, or type of radiation source. Comparison of this system is made with existing high-speed cineradiographic systems, and advantages and disadvantages of this system are described. Examples of x-ray penetration of targeted human cadaver head, neck, knee, and lateral thorax views obtained with the system are shown and discussed.