Application posture

Abstract: Finite element analyses of the human body for seat interaction simulation require accurate and precise prediction of the tissue-level response. To achieve this, the human anatomy must be represented with high fidelity. Current practices for constructing subject-specific models based on magnetic resonance images (MRI) in supine postures have reduced the error in the geometric representation of subjects' anatomy relative to reconstructions based on cadaveric data from previous studies. Nonetheless, the significant differences in bone orientation and soft-tissue contour between seated and supine postures create a need for data obtained in postures more similar to the application posture. In this study, we present a novel method for creating digital human models based on seated MR data. An adult-male volunteer was scanned in a simulated driving posture using a positional MRI scanner. A combination of transverse and sagittal images were used to reconstruct the major anatomical features from the buttocks through to the knees, including bone, muscle and fat tissue perimeters, using Solidworks software. MRI-based reconstruction of the pelvis was enhanced using a template model developed in previous work. A non-rigid registration algorithm was used to fit the pelvis template into the MRI data. Both the left and the right sides of the model were constructed due to the intended asymmetric posture of the volunteer during the MRI measurements. The presented subject-specific model of the buttocks and thighs will add value to optimisation cycles in automotive seat development when used in simulating human interaction with automotive seats.