Geometrical Characteristics of a 50^th Anthropometric Head Finite Element Model: Literature Review

Military forces are confronted with an increasing threat of small caliber rounds and fragments (HE projectile, IEDs, etc.) in current operational theatres. This had led to the development of adapted body armour solutions. But, these solutions when impacted may lead to head blunt injuries (behind helmet blunt trauma (BHBT)) that can be severe, even fatal. Apart from the conventional missions, military forces are more and more called to intervene in homeland or abroad in policing missions in which the Kinetic Energy Non-Lethal Weapon (KENLW) solutions are widely used to avoid severe injuries to the targeted people. In both cases, there is a need to make an injury risk assessment in order to prevent or avoid severe or life-threatening injuries. For that purpose, one of the tools that are used is head biofidelic finite element models. The first step in developing a head model is to generate the head geometry. Most of the developed head models are based on the geometry of one specific subject derived from MRI or CT imaging, and the baseline model that is generally considered is the 50^th percentile adult male corresponding to an average adult male. Therefore, it is important before any modelling to gather information on the human head characteristics like organ’s size and shape. The basic geometric characteristics that are mostly taken into account to build the models are the head external dimensions. In this paper, the goal is to gather information on head organs of an average adult male by taking into account not only the external dimensions but also mean geometric characteristics of the head (size of different head organs, skull thickness, etc.) in order to build an averaged geometry of the head.