Abstract:
Realistic biomechanical assessments of liver injury risk across the entire occupant population necessitate the comprehensive incorporation of inter-subject variations into numerical human models. The primary objective of this biomechanical study was to quantify the variations in both the shape and material properties of the human liver, crucial for enhancing the biofidelity of computational injury prediction tools. To address the geometrical variability, statistical shape analysis was rigorously applied to analyze the morphological variation using a surface dataset derived from 15 adult human livers, recorded in an occupant posture. Principal component analysis was then skillfully utilized to extract the dominant modes of variation, establish a mean liver model, and define a set of 95% statistical boundary shape models, thereby providing a robust biomechanical representation of anatomical diversity.
Furthermore, to characterize the mechanical behavior, specimen-specific finite element (FE) models were meticulously employed to quantify the intricate material and failure properties of human liver parenchyma. This involved a detailed analysis of the liver tissue's response under various loading conditions. The mean material model parameters, representing the average biomechanical response, were precisely determined from the stress-strain curve averages obtained for each loading rate. This comprehensive characterization of both shape and material property variations is a critical step in developing predictive human FE models that can more accurately simulate injury outcomes for a diverse population. The findings and methodology presented in this research establish a robust biomechanical framework, representing a significant advancement in assessing liver injury risk within human FE models, ultimately contributing to improved occupant safety.
