Methodology to geometrically age human body models to average and subject-specific anthropometrics, demonstrated using a small stature female model assessed in a side impact

Explaining and predicting the increased thorax injury in aged females: age and subject-specific thorax geometry coupled with improved bone constitutive models and age-specific material properties evaluated in side impact conditions

“…Previous studies focusing on geometric age effects on thoracic injury have focused on modifying the rib cage with T1 and T12 as anchor points and modestly modifying the rib angles, potentially missing the full geometric effect. During the morphing process ( 7 ), it was noted that the subject-specific rib angles were not achievable if the subject-specific thoracic posture was not considered, suggesting a strong relationship between posture and rib angles. The present study accounted for the changes in thoracic kyphosis coupled with the changes in rib angle, which had not been previously explored in earlier studies, offering a novel aspect to the investigation of thorax biomechanics.…”

“…The increased injury risk found on the aged models was attributed to the changes in material properties alone and the use of age-adjusted injury risk curves, while the geometry had no effect. Recently, using a hybrid Morphing-CAD methodology, the geometry of a 26-year-old 5 th percentile female model (F05-O) was morphed and repostured into an average 75-year-old (YO) and a subject-specific 86YO HBM (F05-86G) ( 7 ). This approach targeted specific bone positioning and successfully achieved precise morphing targets without compromising the mesh quality.…”

“…Importantly, in the context of this study, the rib angles of the GHBMC 5 th percentile female young model were close to the population values. In a recent study, the young model was morphed to an 84YO subject-specific geometry ( 7 ), and that aged geometry was used in the current study. The resulting rib angles for the aged geometry were higher than the population average for 84YO subjects; however, it is reported that geometric variability increases with increasing age ( 23 ).…”

Personalization of human body models and beyond via image registration

“…Finite element (FE) human body models (HBMs) are becoming increasingly important numerical tools in vehicle safety for understanding injury mechanisms and developing prevention strategies (Östh et al, 2015;Boyle et al, 2019;Hu et al, 2019;Jakobsson et al, 2019;Pipkorn et al, 2019;Boyle et al, 2020;Hwang et al, 2020;Tang et al, 2020;Grebonval et al, 2021;Leledakis et al, 2021;Larsson et al, 2022;Bohman et al, 2022;Booth et al, 2022;Corrales et al, 2022;Erlinger et al, 2022;Mishra et al, 2022;Piqueras et al, 2022;Putra et al, 2022;Östh et al, 2022). HBMs have advantages over crash test dummies, such as representing varying loading directions, different anthropometries and sex, and muscle tonus (Jakobsson et al, 2019).…”

“…The software is accompanied by a 6YO child model that is scalable from a 1.5YO to 12YO through metadata files containing landmarks and control points. The PIPER software has successfully been used to personalize and position various HBMs such as GHBMC (Grebonval et al, 2021;Corrales et al, 2022;Erlinger et al, 2022), THUMS (Germanetti et al, 2020), and VIVA (Kleinbach et al, 2018), demonstrating the versatility of the PIPER software beyond positioning the paired PIPER child model (Giordano et al, 2017;Li and Kleiven, 2018).…”