Development of chest deflection injury risk curve in oblique frontal small female PMHS sled tests

Abstract

Objective

The study's aim is to examine which sternum deflection measure best represents injury in oblique frontal impacts with small female surrogates.

Methods

Data from sixteen PMHS sled tests were used to calculate sternum deflection using displacements in the A-P (x) direction, transverse (xy) plane, sagittal (xz) plane, and triplanar (xyz). Peak deflections were the response variable and were combined with injury outcomes to generate injury risk curves (IRCs) using parametric statistical survival modeling. The IRC with the lowest Brier Score Metric was considered the best deflection measure representing injury.

Results

The triplanar (xyz) deflection metric was the best indicator of injury. At the 10 and 50% probability levels, the magnitudes of this metric were 33 mm and 55 mm, respectively. The quality of the risk curve was fair for 10% and good for 50%, based on the ISO recommendations.

Conclusions

The current study reports on the injury risk to small females in an upright seated position in oblique frontal impacts. The triplanar and transverse plane deflection metrics were similar for this posture; however, occupants in reclined configurations may demonstrate a different response, and further investigations are necessary.

Keywords:

• PMHS
• chest deflection
• survival analysis

Acknowledgments

The authors thank the AAAM for supporting this research through the AAAM Scholar's Program, the National Highway Traffic Safety Administration, and the Office of the Assistant Secretary of Defense for Health Affairs, through the Broad Agency Announcement under Award No. W81XWH-16-1-0010. This study was was also supported by the Department of Veterans Affairs Medical Research. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the Department of Defense or other sponsors.