Hello, World! VIVA+: A Human Body Model lineup to evaluate Sex-Differences in Crash Protection

Abstract

Finite element Human Body Models are increasingly becoming vital tools for injury assessment and are expected to play an important role in virtual vehicle safety testing. With the aim of realizing models to study sex-differences seen in the injury- and fatality-risks from epidemiology, we developed models that represent an average female and an average male. The models were developed with an objective to allow tissue-based skeletal injury assessment, and thus non-skeletal organs and joints were defined with simplified characterizations to enhance computational efficiency and robustness. The current model lineup comprises female and male representations of (seated) vehicle occupants and (standing) vulnerable road users, enabling the safety assessment of a broader segment of the road user population. In addition, a new workflow utilized in the model development is presented. In this workflow, one model (the seated female) served as the base model while all the other models were generated as closely-linked derivative models, differing only in terms of node coordinates and mass distribution. This approach opens new possibilities to develop and maintain further models as part of the model lineup, representing different types of road users to reflect the ongoing transitions in mobility patterns (like bicyclists and e-scooter users). This paper is the first in a series describing the development and validation of the new Human Body Model lineup, VIVA+. In this paper, we evaluate the kinetic and kinematic responses of the occupant and standing models to blunt impacts, mainly on the torso, in different directions (front, lateral, and back). Moreover, with the inclusion of an average-sized female model as a standard model in the lineup, we seek to foster an equitable injury evaluation in future virtual safety assessments.

Finite Element Human Body Models to study Sex-differences in Whiplash Injury: Validation of VIVA+ passive response in rear-impact

“…A brief overview of the models is given here. Details of the development and workflow is provided elsewhere (John et al, 2022). The anthropometry for the HBMs were based on the recommendations from (Schneider et al, 1983).…”

“…The original VIVA model has recently been rebuilt with a much higher resolution and also morphed into a male counterpart. This newly developed lineup of FE-HBMs is called VIVA+ (John et al, 2022).…”

Finite element human body models with active reflexive muscles suitable for sex based whiplash injury prediction

“…These properties included head mass and inertia properties, densities of soft tissues, as well as knee ligament and quadricep muscle properties (John et al, 2022a). The original, passive, VIVA+ models without active neck muscle responses were validated to blunt impacts in different directions (frontal, lateral and back) (John et al, 2022a;2022b). Specifically, multi-level kinematics Frontiers in Bioengineering and Biotechnology frontiersin.org validations were conducted for the rear-end impact collision starting from the functional spinal unit (FSU) level, isolated head-neck level, and whole-body level.…”

“…Specifically, multi-level kinematics Frontiers in Bioengineering and Biotechnology frontiersin.org validations were conducted for the rear-end impact collision starting from the functional spinal unit (FSU) level, isolated head-neck level, and whole-body level. The details of VIVA+ HBMs developments and validation are described further in John et al (2022a;2022b). In the present study, sub-models that consist only of the head-neck were created by cutting both average female and male models above the first thoracic vertebrae (T1).…”

“…A more sophisticated and robust open-source model called VIVA+ has been developed ( John et al, 2022a ). Its neck model is based on the VIVA OpenHBM’s neck.…”