A Method to Calculate the AIS Trauma Score from a Finite Element Model

In the real world, traumatic injuries are measured using the Abbreviated Injury Scale (AIS), however, such a scale cannot be computed to date or the injury precisely located by using human computer models. These models use stresses and strains to evaluate whether serious or fatal injuries are reached, which unfortunately bear no direct relation to AIS. This paper proposes to overcome this deficiency and suggests a unique Organ Trauma Model (OTM) able to calculate the risk to life of any organ injury, focussing in this case on real-life pedestrian head injuries. The OTM uses a power method, named Peak Virtual Power (PVP), and defines a brain white and gray matters trauma response as a function of impact direction and impact speed. The OTM was tested against four real-life pedestrian accidents and proved to predict the head trauma severity and location. In some cases, the method did however under-estimate the trauma by 1 AIS level because of post-impact haemorrhage which cannot be captured with Lagrangian Finite Element solvers. The OTM has the potential to create an important advance in vehicle safety by adding more information on the risk of head trauma.