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We evaluated the accuracy of two types of 3D body scanners and scan-derived measurements using three types of test objects: a gauge; an anthropomorphic dummy; and human subjects. To provide the background data to show the necessity of such evaluation, repeatability of landmarking by a measurer and the repeatability of the landmark locations determined manually using a mouse were evaluated. The results showed that (1) repeatability of scan-derived body dimensions were not always better than manual measurements obtained by traditional methods, (2) the errors in landmarking by a measurer were not always the main cause of measurement errors in scan-derived measurements, (3) accuracy of whole-body scanners was not uniform within the scanning volume, and (4) evaluation using a dummy could underestimate the measurement errors in the human scan-derived data. This protocol may be available for other scanner systems.

The influence of the head shape on intracranial responses under impact was investigated by using Finite Element Method. Head shape models of 52 young adult male Japanese were analyzed by Multi Dimensional Scaling (MDS), and a 2 dimensional distribution map of head shapes was obtained. Five finite element models of the Japanese head were constructed by a transformed finite element model of an average European adult male (H-Head model) using Free Form Deformation (FFD) technique. The constructed models represent the 5th and 95th percentile of the first 2 scales obtained by MDS. The same acceleration pulse was applied to the H-Head model and the five finite element models. The cause of the difference was considered to be differences in pressure distribution in the brain caused by the differences in the head shape. Variation in the head shape should be taken into account in simulating the effects of impact using a finite element model.