Assessment of mechanical properties of human head tissues for trauma modelling

Abstract

Many discrepancies are found in the literature regarding the damage and constitutive models for head tissues as well as the values of the constants involved in the constitutive equations. Their proper definition is required for consistent numerical model performance when predicting human head behaviour, and hence skull fracture and brain damage. The objective of this research is to perform a critical review of constitutive models and damage indicators describing human head tissue response under impact loading. A 3D finite element human head model has been generated by using computed tomography images, which has been validated through the comparison to experimental data in the literature. The threshold values of the skull and the scalp that lead to fracture have been analysed. We conclude that (1) compact bone properties are critical in skull fracture, (2) the elastic constants of the cerebrospinal fluid affect the intracranial pressure distribution, and (3) the consideration of brain tissue as a nearly incompressible solid with a high (but not complete) water content offers pressure responses consistent with the experimental data.

The importance of modeling the human cerebral vasculature in blunt trauma

“…For instance, to identify potential injury thresholds for TBI, two separate research groups have independently developed three-dimensional (3-D) finite element (FE) models of the human head and correlated the simulated responses with injuries observed in computed tomography images [5,6]. Moreover, to evaluate the biomechanical response of the brain to impacts and impulses that generate translation and rotation of the head, different research groups have developed 3-D FE models of the human head, which vary greatly in terms of the number of anatomical components, material properties of the brain tissue, brain anatomy, and description of the cerebral vasculature [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. For example, Tse et al included 13 components in their FE model [20], whereas the FE model developed by Cotton et al consisted of 32 components [8].…”

Effect of different helmet shell configurations on the protection against head trauma

“…A human head numerical model developed from the segmentation of computed tomography (CT) images from a man belonging to the 50th percentile was employed in this work. This model was validated in previous works by Lozano-Mínguez et al 17 against low- to middle-velocity impact tests from the literature 18,19 and against ballistic experimental tests 20 on protected postmortem human surrogate (PMHS) heads. 8 The model comprises six of the main living tissues of the head: cranium (divided into the two compact bone tables and the diplöe core), facial bones, brain, cerebrospinal fluid (CSF) and scalp.…”

“…Therefore, double Figure 1. Numerical head model from Lozano-Mínguez et al 17 and Palomar et al 20 employed for ballistic simulations. precision was required both for the preprocessor and for the processor.…”

Multibody system modelling of unmanned aircraft system collisions with the human head

“…ABS plastic and Aluminium) was obtained from an online source, MATBASE [24]. For a crash dummy, the head contact surface was assumed to have characteristics of a human head scalp and the materials property was obtained from the experiment presented by Lozano-M ınguez et al [25]. Since the materials properties come in ranges of values, the contact curves derived then consist of an upper and lower bound curve, corresponding to the lower and upper values of the materials properties.…”