The risk of injury as the result of an accident

Science topics February 2015 Road safetyHuman behaviourModelling and computer simulation

David Mitton, Director of  LMBC Laboratory - TS2 Department

The risk of injury as the result of an accident - Ifsttar - [] Vue partielle du modèle éléments finis (Global Human Body Model, GHBM)

Since the beginning of the years 2000, the Laboratory of Impact Mechanics and Biomechanics (Laboratoire de Biomécanique et Mécanique des Chocs − LBMC) started its involvement in European projects aimed at developing models of the human body.

Since that time, this modelling research has taken on a global dimensional with the setting up of a consortium (Global Human Body Model consortium, GHBMC) bringing together the majority of the world’s motor car manufacturers. This consortium asked academic research centres to develop models of parts of the human body and assemble a head-to-toe model. The LBMC has been recognised as « Abdomen Center of Excellence », and then developed the abdominal part of the model.

The first full version of the model represents a man of average height. Since 2013, a licence for this model is available free of charge to all academic institutions. The next phases of the project aim to develop models for other population groups in order to cover all individuals, including children.

 

Models based on medical images

The model of the human body, which includes internal organs such as bones, the heart, the liver, etc., was based on medical images. This permits the construction of morphologically realistic models. Some forms of medical imaging also allow to investigate the influence of subjects’ posture on the form and position of their internal organs (Lafon et al. 2010).

For transport accident applications “average male” models are usually used. However, specific models need to be developed to represent different population groups (Poulard et al. 2012). Research, at the European level, is working towards the development of tools to personalise and position human body models (for example the PIPER project). These will allow to model the bodies of children of different ages and adults of different sizes. The effect of age, during growth then during ageing, should also be taken into account. Nondestructive methods with the potential of exploring this aspect have been evaluated (Mitton et al. 2014).
The ability to create specific models is also a necessity for health-related research. When they are based on medical imaging such models can be more easily personalised, for a given patient. This is one of the topics covered by the laboratory of excellence1 PRIMES (Physics, Radiobiology, Medical Imaging and Simulation − Physique RadiobiologieImagerieMédicaleet Simulation) that brings together 16 research laboratories in Lyon, Saint-Etienne, Grenoble and Clermont-Ferrand, whose the LBMC.

 

 

The risk of injury as the result of an accident - Ifsttar - [] Simulation d’un choc latéral contre un airbag (Global Human Body Model, GHBM).

Advanced models to predict injury risk

 

Once the models have been constructed, their performance must be validated under a variety of loads. Initially, the response of the models is compared with experiments conducted on isolated body segments in laboratory (Vezin et al. 2009). The purpose of these comparisons is to validate the external behaviour of certain parts of the body.
In addition to the external behaviour, internal and local evaluations (Helfenstein-Didier et al. 2016) are necessary to assess the realism of the models. A model’s responses, in terms of local stresses and strains, may be compared with the experimental data. This complex phase can, among other things, allow to define injury criteria. The data are nevertheless limited.
Research at the international level is continuing to improve the predictive capacity of these models. Ultimately, the objective is for the models to predict injuries in the case of an accident and to evaluate protection systems.




1 Labex : Research funding bodies set up as part of the government future investments (Investissementsd’Avenir) programme.

 

Find out more ...

  • Helfenstein-Didier, C., Rongiéras, F., Gennisson, J.-L., Tanter, M., Beillas, P., 2016. A new method to assess the deformations of internal organs of the abdomen during impact. Traffic Injury Prevention 17(8):821-6
  • Lafon Y., Smith F.W., Beillas P., (2010) Combination of a model-deformation method and a positional MRI to quantify the effects of posture on the anatomical structures of the trunk. Journal of Biomechanics 43(7):1269-78.
  • Mitton D., Minonzio J.-G., Talmant M., Ellouz R., Rongieras F., Laugier P., Bruyère-Garnier K., (2014) Non-destructive assessment of human ribs mechanical properties using quantitative ultrasound. Journal of Biomechanics 47(6):1548-53.
  • Poulard D., Bermond F., Dumas R., Bruyère-Garnier K., (2012) Geometrical personalization of human FE model using palpable markers on volunteers. 37e Congrès de la Société de Biomécanique, Toulouse, France, 16-19 octobre. Dans Computer Methods in Biomechanics and Biomedical Engineering 15(S1):298-300.
  • Vezin P., Berthet F., (2009) Structural characterization of human rib cage behaviour under dynamic loading. Stapp Car Crash Journal 53:93-125.