| 1. |
- Gepner, B. D., et al.
(författare)
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Comparison of human body models in frontal crashes with reclined seatback
- 2019
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; , s. 293-307
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Konferensbidrag (refereegranskat)abstract
- Reclined seating configurations, relevant to the future of Autonomous Driving Systems is likely to challenge the current state-of-the-art restraint systems. Human body models (HBM) offer an attractive tool to support the design process, however their validity in the reclined scenario remains questionable. The goal of this study is to compare the response of selected HBMs in the frontal, reclined scenario, while utilizing a new prototype restraint system. A sled model with a generic seat, 50 deg seatback recline angle and a prototype 3-point belt system was used in this study. Four different male HBMs were compared, the Global Human Body Model Consortium (GHBMC) simplified occupant model (GHBMC-S), the GHBMC detailed model (GHBMC-D), Total Human Model for Safety SAFER (THUMS-S) model, and THUMS-v5 model. All HBMs showed good pelvis engagement, except GHBMC-D that submarined under the lap belt. Additionally, large differences were observed in pelvis and lumbar spine response between GHBMC and THUMS family models. Since no relevant PMHS data is currently available, it is impossible to evaluate the biofidelity of these models in the reclined scenarios. Evaluating the relative biofidelity of these models can only be accomplished with experimental data capturing detailed 3D skeletal kinematics and all the boundary forces necessary for model evaluation.
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| 7. |
- Gepner, B. D., et al.
(författare)
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Evaluation of GHBMC, THUMS and SAFER Human Body Models in Frontal Impacts in Reclined Postures
- 2022
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; 2022-September, s. 116-143
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Konferensbidrag (refereegranskat)abstract
- Virtual tools, such as human body models (HBMs), can support advances in vehicle development and restraint system design. The goal of this study is to evaluate selected HBMs against data from recent reclined post-mortem human subject (PMHS) tests. Three HBMs - the Global Human Body Modelling Consortium detailed model v.6.0, Total Human Model for Safety v.6.0, and SAFER HBM v.10 - were used in this study. The models were positioned with respect to the average PMHS position and utlised a previously developed environment model. The HBMs were evaluated comparing belt engagement, boundary forces and displacements (in the seat and belt), and the trajectories of the head, T1, T8, T11, L1, L3, and pelvis. The HBMs' belt engagement, boundary forces and displacements, and X-direction (fore-aft) trajectories were all generally consistent with the PMHS. All HBMs predicted more downward motion of the head and T1 compared to the PMHS. The HBMs also showed rearward pelvis pitch at peak lap belt force, opposite to the PMHS. Some of these differences were associated with differences in flexion of the lumbar spine. This is the first study to provide an in-depth evaluation of multiple reclined HBMs in frontal crashes compared to reclined PMHS.
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| 11. |
- Nilsson, Anna-Lena, et al.
(författare)
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Serological Evaluation of Possible Exposure to Ljungan Virus and Related Parechovirus in Autoimmune (Type 1) Diabetes in Children
- 2015
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Ingår i: Journal of Medical Virology. - : Wiley. - 0146-6615 .- 1096-9071. ; 87:7, s. 1130-1140
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Tidskriftsartikel (refereegranskat)abstract
- Exposure to Ljungan virus (LV) is implicated in the risk of autoimmune (type 1) diabetes but possible contribution by other parechoviruses is not ruled out. The aim was to compare children diagnosed with type 1 diabetes in 2005-2011 (n=69) with healthy controls (n=294), all from the Jamtland County in Sweden, using an exploratory suspension multiplex immunoassay for IgM and IgG against 26 peptides of LV, human parechoviruses (HPeV), Aichi virus and poliovirus in relation to a radiobinding assay (RBA) for antibodies against LV and InfluenzaA/H1N1pdm09. Islet autoantibodies and HLA-DQ genotypes were also determined. 1) All five LV-peptide antibodies correlated to each other (P<0.001) in the suspension multiplex IgM- and IgG-antibody assay; 2) The LV-VP1_31-60-IgG correlated with insulin autoantibodies alone (P=0.007) and in combination with HLA-DQ8 overall (P=0.022) as well as with HLA-DQ 8/8 and 8/X subjects (P=0.013); 3) RBA detected LV antibodies correlated with young age at diagnosis (P<0.001) and with insulin autoantibodies (P<0.001) especially in young HLA-DQ8 subjects (P=0.004); 4) LV-peptide-VP1_31-60-IgG correlated to RBA LV antibodies (P=0.009); 5) HPeV3-peptide-IgM and -IgG showed inter-peptide correlations (P<0.001) but only HPeV3-VP1_1-30-IgG (P<0.001) and VP1_95-124-IgG (P=0.009) were related to RBA LV antibodies without relation to insulin autoantibody positivity (P=0.072 and P=0.486, respectively). Both exploratory suspension multiplex IgG to LV-peptide VP1_31-60 and RBA detected LV antibodies correlated with insulin autoantibodies and HLA-DQ8 suggesting possible role in type 1 diabetes. It remains to be determined if cross-reactivity or concomitant exposure to LV and HPeV3 contributes to the seroprevalence. J. Med. Virol. 87:1130-1140, 2015.
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| 12. |
- Perez-Rapela, Daniel, et al.
(författare)
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Comparison of the simplified GHBMC to PMHS kinematics in far-side impact
- 2019
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; , s. 260-281
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Konferensbidrag (refereegranskat)abstract
- Far-side impacts represent 9.5% of all automobile crashes and 8.3% of all MAIS3+ injuries. This type of event generates loads that challenge current restraint systems by setting the occupant in an inward motion. This complex motion, influenced by a number of restraint and impact parameters, often results in a loss of shoulder-to-belt contact. Existing Anthropomorphic Test Devices show limited ability to represent post-mortem human subject kinematics and sensitivity to restraint and impact parameters. Therefore, Human Body Models can play a fundamental role in understanding human response in this impact scenario. This study compares the simplified GHBMC to previously published post-mortem human subject kinematics and sensitivity to restraint and impact parameters. Results show that, in general, the simplified GHBMC captures lateral excursion in oblique impact conditions but overpredicts in purely lateral impact conditions. The simplified GHBMC shows post-mortem human subject like sensitivities to changes in ?V and the use of pretensioner but no sensitivity to changes in impact direction. The human body model performs similarly to other previously published HBMs and obtains a “good” CORA score. However, the surrogate does not represent post-mortem human subject shoulder-to-belt interaction in all configurations.
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| 13. |
- Perez-Rapela, Daniel, et al.
(författare)
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Comparison of WorldSID to PMHS kinematics in far-side impact
- 2018
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; 2018-September, s. 630-654
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Konferensbidrag (refereegranskat)abstract
- Far-side impacts represent 9.5% of all automobile crashes and 8.3% of all MAIS3+ injuries. This type of event generates loads that challenge current restraint systems by setting the occupant on an inward motion. This complex motion, influenced by a number of restraint and impact parameters, often results in a loss of shoulder-to-belt contact. Reducing the negative outcomes of this type of crash requires an ATD capable of correctly representing the kinematics and sensitivity to restraint and impact parameters. The WorldSID is the most advanced ATD for injury evaluation in near-side crashes. However, its suitability for far-side scenarios still needs to be evaluated. This study performed a parametric evaluation of the effect of restraint and impact parameters on WorldSID kinematics. A total of 19 tests in six different test configurations were conducted, matching previously published PMHS tests. The ATD motion was tracked with a 3D high-speed motion-capture system. The parameters varied were: the impact severity and direction; D-ring position; pelvic restraint; and seat belt pretensioning. The ATD response and sensitivity to parameters were evaluated and compared to previously published PMHS data. The results show discrepancies in shoulder-belt engagement, head and torso kinematics and sensitivity to initial conditions.
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| 14. |
- Pipkorn, Bengt, 1963, et al.
(författare)
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Assessment of an Innovative Seatbelt with Independent Control of the Shoulder and Lap Portions Using THOR Tests, the THUMS Model and PMHS Tests
- 2016
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-957X .- 1538-9588. ; 17, s. 124-130
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: What are the potential chest injury benefits and influence on occupant kinematics of a belt system with independent control of the shoulder and lap portions. Methods: This paper investigates the kinematics and dynamics of human surrogates in 35 km/h impacts with two different restraints: a pretensioning (PT), force-limiting (FL) seat belt, a reference belt system, and a concept design with a split buckle consisting (SB) of two separate shoulder and lap belt bands. The study combines mathematical simulations with the THOR dummy and THUMS human body model, and mechanical tests with the THOR dummy and two PMHS tests of similar age (39 and 42 years) and anthropometry (62 kg, 181 cm vs. 60 kg, 171.5 cm). The test setup consisted of a rigid metallic frame representing a standard seating position of a right front passenger. The THOR dummy model predictions were compared to the mechanical THOR dummy test results. The THUMS predicted number of fractured ribs were compared to the number of fractured ribs in the PMHS. Results: THOR sled tests showed that the SB seat belt system decreased chest deflection significantly without increasing the forward displacement of the head. The THOR model and the THOR physical dummy predicted a 13mm and 7mm reduction in peak chest deflection respectively. Peak diagonal belt force in the mechanical test with the reference belt was 5582N while the predicted force was 4770N. The THOR model also predicted lower belt forces with the SB system than the ones observed in the tests (5606N vs. 6085N). THUMS predicted somewhat increased head displacement for the SB system compared to the reference system. Peak diagonal force with the reference belt was 4000N and for the SB system it was 5200N. The PMHS test with the SB belt resulted in improved kinematics and in a smaller number of rib fractures (2 vs. 5 fractures) compared to the reference belt. Conclusion: Concepts for a belt system that can reduce the load on the chest of the occupant in a crash and thereby reduce the number of injured occupants, in particular elderly, was proposed.
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| 16. |
- Tushak, Sophia K., et al.
(författare)
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Evaluation of the GHBMC Lumbar Spine in Sub-injurious and Injurious Loading
- 2022
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; 2022-September, s. 866-883
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Konferensbidrag (refereegranskat)abstract
- Accurate prediction of lumbar spine response and how it relates to kinematics, kinetics, and injury is critical since lumbar spine loading is predicted to be amplified in reclined postures. The objective was to evaluate the Global Human Body Models Consortium (GHBMC) lumbar spine (v5.1.1) model relative to postmortem human subjects (PMHS) in two different loading modes using data from recent experiments. The model's whole ligamentous lumbar spine was first evaluated in sub-injurious quasi-static loading in multiple directions with three different levels of axial compression. Compared to PMHS, the GHBMC responses varied widely across loading direction and axial compression level, exhibiting higher stiffness in some conditions and lower stiffness in other conditions. Then, three-vertebra sections of the model's ligamentous lumbar spine were subjected to high-rate compression-flexion loading to failure. Compared to PMHS, GHBMC responses and stiffness coefficients did not display the same bilinear response behavior, but instead displayed linear behavior. Additionally, the GHBMC and PMHS did not respond similarly when increased levels of axial compression were applied. The outcomes from this study shed light on the usefulness of the model.
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| 18. |
- Valdano, Manuel, et al.
(författare)
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Assessment of Madymo Active Human Body Model Kinematics and Dynamics by means of Human Volunteer Response at Low-Speed Frontal Impacts
- 2021
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; 2021-September, s. 122-135
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Konferensbidrag (refereegranskat)abstract
- The aim of this study was to evaluate the capability of the Madymo active HBM to predict the human response by comparing the predictions from the model with the response from human volunteers in frontal-impact tests at 9km/h. The Madymo active HBM correspond to a 50th percentile male model population (standing height=176cm; weight=75.3kg) and the 13 volunteers were selected to have a similar anthropometry (standing height=173.0±4.3cm; weight=79.1±9.5kg). The influence of a number of important parameters on the Madymo active HBM predictions was evaluated. Those parameters were friction between model and seat pan, reaction time delay and level of co-contraction of neck muscles. The friction was varied between 0.15 and 0.5; the reaction time delay from 0ms to 100ms and the level of co-contraction of neck muscles between a null and full activation. The benchmark considered the displacements of the head, vertebra (C4, T1, T4, T8, T12) and hip, the belt loads, and the estimated upper neck loads in the sagittal plane. It was found that while variations in the RT and CCR levels could cause similar forward excursions, this could also result in an overprediction of the downward excursions; and therefore, the neck muscle controller optimization should always consider both. Two configurations could be implemented in the model to represent the large variation between the volunteers' downward excursion, the first with the closest behaviour to the volunteers' mean and the second closer to the volunteers which showed larger head excursion.
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| 19. |
- Valdano, M., et al.
(författare)
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Evaluation of AIS3+ car occupant injuries using deterministic and probabilistic methods in frontal crashes
- 2024
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Ingår i: Computer Methods in Biomechanics and Biomedical Engineering. - 1476-8259 .- 1025-5842. ; 27:12, s. 1714-1730
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Tidskriftsartikel (refereegranskat)abstract
- Computational modelling was used to assess the capability of a deterministic and a probabilistic method to predict the incidence of AIS3+ injuries in passenger car occupants by comparing the predictions of the methods to the actual injuries observed in real-world crashes. The likelihood of sustaining an injury was first calculated using a computer model for a selected set of injury criteria in different impact conditions based on real-world crashes; AIS3+ injuries were then predicted using each method separately. Regardless of the method, the number of serious injuries was over-predicted. It was also noted that the used injury criteria suggested the occurrence of specific injuries that were not observed in the real world. Although both methods are susceptible to be adapted to improve their predictions, the question of the suitability of using some of the most commonly accepted injury criteria used with crash test dummies for injury assessment with human body models deserves further research.
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| 20. |
- Wågström, Linus, 1977, et al.
(författare)
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Structural adaptivity in frontal collisions: implications on crash pulse characteristics
- 2005
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Ingår i: International Journal of Crashworthiness. - 1358-8265 .- 1754-2111. ; 10:4, s. 371-378
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Tidskriftsartikel (refereegranskat)abstract
- Today's passenger cars protect occupants better than ever against most injury types in passenger car frontal collisions. There is, however, one notable exception: neck injuries. Studies have shown that high mean vehicle deceleration is likely to lead to a greater risk of sustaining neck injuries. In order to design future cars that minimize occupant injury risk, it is suggested that the response of the front structure should be adapted to impact severity. A finite element model was used to predict the implications on acceleration time history by yield-strength variation of the longitudinal rails. Results indicate that lower mean deceleration can be attained by lower-yield-stress material, but caution must be taken to avoid stiff engine-firewall contact as this can create high mean decelerations. Furthermore, results indicate that for an adaptable frontal structure to reduce mean acceleration and neck-injury risk, global load paths must be controlled in frontal impacts.
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