| 1. |
- Antona, Jacobo, 1981, et al.
(författare)
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Correlation of Global Head and Brain Tissue Injury Criteria to Experimental Concussion derived from Monkey Head Trauma Experiments
- 2013
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Ingår i: IRCOBI Conference. - 2235-3151. ; :IRC-13-55, s. 509-522
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Konferensbidrag (refereegranskat)abstract
- A series of 24 frontal head traumatic impacts on macaques carried out in the past were simulatedwith a validated finite element model of the specimens. From these simulations, brain tissue response and headaccelerations were extracted. Based on the accelerations, global head injury criteria were calculated.Correlation between the brain tissue mechanical parameters, the global head injury criteria and the concussionscored in the experiments were analyzed. Based on this analysis, global head injury criteria that best correlatewith concussion score for frontal impacts were identified and injury risk functions for brain tissue that can beused for human FE models are proposed. In addition, the new results were compared to a previous study basedon simulations of 19 occipital head impacts from the same data source.
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| 2. |
- Antona, Jacobo, 1981, et al.
(författare)
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Reanalysis of Monkey Head Concussion Experiment Data Using a Novel Monkey Finite Element Model to Develop Brain Tissue Injury Reference Values
- 2012
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Ingår i: Proceeding of the 2012 International IRCOBI Conference on the Biomechanics of Impact. - 2235-3151. ; 2012, s. 441-454
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Konferensbidrag (refereegranskat)abstract
- A new method has been applied to develop a Finite Element (FE) model of the head‐ neck complexof Macaque monkey from medical images. The skull, brain and flesh have been validated based on tissue andcomponent experimental data from literature. The kinematics of the head during occipital impacts have beenvalidated against a sub‐set of head impact experiments carried out in the past at the Japan AutomobileResearch Institute (JARI). The validated model has been used to simulate 19 occipital impacts case‐by‐case. Thecorrelation between obtained peak values for a number of mechanical parameters of the different brain regionsand the occurrence of concussion in the experiments was analysed. Maximum principal strain in the brainstemshowed significant correlation to concussion; 21% strain was associated with a probability of 50% risk forconcussion. The developed model and the presented results constitute the first step towards the developmentof a tissue level injury criterion for humans that is based on experimental animal data.
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| 3. |
- Baker, Gretchen H., et al.
(författare)
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Comparison of Self-Selected, Holding Device, and Nominal Conditions on the Belt Fit and Posture of Children on Belt-Positioning Boosters
- 2023
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; , s. 665-689
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Konferensbidrag (refereegranskat)abstract
- Children assume a range of postures when utilising belt-positioning boosters, which may influence belt fit and have implications for dynamic performance. This study evaluates the belt fit and posture of children on boosters while assuming different postures: self-selected, holding device, and nominal. Children (n=25) were recruited (4–11 years, 103.0–146.5 cm, 17.8–33.6 kg) and evaluated on two of five randomised boosters. A 3D coordinate measurement device and an inertial measurement unit-based motion capture system quantified posture, e.g., head, torso, and pelvis positions and orientations, and belt fit, e.g., shoulder belt score, lap belt score, maximum gap size, gap length. Outcomes were compared across postural conditions and boosters using repeated-measures ANOVA. The device condition produced significantly more forward and flexed head postures compared to self-selected and nominal (by 58 mm and 15.0° on average). Variation was small in terms of belt fit and belt gap metrics between postural conditions, suggesting that belt routing features provided similar belt placement despite postural adjustment; however, greater variation is expected in naturalistic settings. This study is the first to directly evaluate the posture and belt fit of children while holding electronic devices and to investigate the influence of different postural conditions on belt fit and postural outcomes.
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| 4. |
- Baker, Gretchen, et al.
(författare)
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Kinematics and Shoulder Belt Engagement of Children on Belt-Positioning Boosters during Emergency Braking Events
- 2017
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; 2017-September:IRC-17-51
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Konferensbidrag (refereegranskat)abstract
- Emergency braking can influence children’s posture and seatbelt interaction. To better protect children in crashes preceded by emergency braking, this study a ims to quantify kinematics and seatbelt engagement during braking events . Eighteen rear‐seated children were exposed to braking events with 1 g deceleration in a passenger vehi cle, restrained by the seatbelt on a booster cushion and an integrated booster cushion. Vehicle acceleration and video data were analysed to m easure head displacement and shoulder belt position. On the booster cushion the belt was generally mid‐sho ulder and lower on the torso with a gap, while on the integrated booster cushion i t was closer to the neck and hi gher on the torso without a gap. Average forward head displacement was 160 mm on the booster cushion and 150 mm on the integrated booster cushion. Generally, the belt maintained the same position on the shoulde r throughout braking, with exceptions influenced by shifted initial positions or non‐standard motions. Braking e vents placed the head approximately 150‐190 mm forward from the initial position, influenced by booster, statu re, and initial seatbelt positioning. This reinforces the importance of maintaining mid‐shoulder or close to neck bel t positions and upright, centred postures prior to emergency braking, which may influence the likelihood of imp acting the vehicle interior and sustaining head injuries in a subsequent crash.
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| 5. |
- Brynskog, Erik, 1989, et al.
(författare)
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Population Variance in Pelvic Response to Lateral Impacts - A Global Sensitivity Analysis
- 2022
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; 2022-September, s. 173-196
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Konferensbidrag (refereegranskat)abstract
- Pelvic fracture remains the third most common moderate to severe injury in motor vehicle crashes, and the dominating lower extremity injury in lateral impacts. An essential tool for analysis of injury, and real-world occupant protection, are finite element human body models. However, today's state-of-the-art pelvis models do not adequately consider the variability in shape and size naturally occurring in human populations. In this study, we developed a new detailed pelvis finite element model, morphable to enable representation of the population shape variance. The model was validated using force-displacement data from post-mortem human subjects, in lateral loading of the denuded pelvis, followed by a global sensitivity analysis. The results suggests that in lateral impacts to the pelvis, pelvic shape contributes to the model response variance by the same magnitude as pelvic bone material stiffness, and that each of these contributions are approximately twice that of the cortical bone thickness. Hence, to model pelvic response for a general population accurately, future studies must consider both pelvic shape and the material properties in the analysis. Increased knowledge about population variability, and inclusion in safety evaluations, can result in more robust systems that reduce the risk of pelvic injuries in real-world accidents.
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| 6. |
- Cutcliffe, Hattie, et al.
(författare)
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Gender differences in Occupant Posture during Driving and Riding
- 2017
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; Antwerp, 2017, September 13-15:IRC-17-12, s. 23-33
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Konferensbidrag (refereegranskat)abstract
- The aim of this study was to compare postures of male and female vehicle occupants, tested in both front seat positions, during normal driving and deceleration onset. These data are useful for the development and initialisation of computational human body models. A secondary aim was to examine the effect of reversible, motorised seat belts in these events. Kinematics were analysed for volunteers driving on rural roads, prior to autonomous braking (11 m/s2 deceleration). Two restraint configurations were tested: a standard versus a motorized belt, activated 200 ms before braking initiation. Kinematic metric comparison via ANCOVA was performed to understand postural differences across gender, role (driver/passenger), and belt type (standard/motorised). Data was analysed prior to and at vehicle deceleration, termed typical riding and initial braking, respectively.While males and females displayed similar postures during typical riding, differences existed between driversand passengers, especially with respect to neck posture. Drivers displayed more protracted neck postures, withsignificantly smaller (by 22‐27 mm, depending on gender) head‐to‐sternum horizontal distances, than passengers.Motorised belts significantly changed posture during initial braking, notably of the chest (which was shiftedposteriorly by approximately 13 mm, depending on gender and role), while standard belts did not. Within a given belt type, occupants’ change in posture was similar across gender and role during initial braking.
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| 7. |
- Davidsson, Johan, 1967, et al.
(författare)
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Evaluation of Seat Performance Criteria for Rear‐End Impact Testing BioRID II and Insurance Data
- 2013
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Ingår i: IRCOBI Conference. - 2235-3151. ; :IRC-13-15, s. 63-76
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Konferensbidrag (refereegranskat)abstract
- The BioRID is recommended for legislative rear‐end impact seat tests. Recommendedinjury criteria are, however, lacking; biomechanical data are limited and confines any evaluation ofproposed criteria.This study aimed at addressing these limitations by comparing BioRID II data from sled tests withreal‐life accident data. Results will evaluate injury predictability of the complete sled test method, whichincludes performance criteria, the use of a generic acceleration pulse, and the BioRID, etc.Real‐life injury risk was calculated for 17 groups of similar seat designs from data provided byFolksam. The number of insurance cases range from 150 to 1136 per group. Regression coefficientswere calculated. Two types of injury risks were used: those leading to documented symptoms of morethan one month’s duration and those classified as leading to permanent medical impairment as aconsequence of a rear‐end impact. These risks were compared to parameter values from sled testsperformed with a BioRID II at 16 km/h pulses.NIC, the maximum rearward Occipital Condyle relative T1 x‐displacements and L1 x‐acceleration bestpredicted the risk of developing permanent medical impairment and symptoms of more than onemonth, given the occupant had initial symptoms following a rear‐end impact.
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| 8. |
- Davidsson, Johan, 1967
(författare)
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Volunteer Shoulder Range of Motion and Stiffness: Data for Evaluation of Crash Test Dummies and Human Body Models
- 2013
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Ingår i: IRCOBI Conference. - 2235-3151. ; :IRC-13-30, s. 230-244
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Konferensbidrag (refereegranskat)abstract
- The shoulder complex has low priority in the development of frontal impact crash test dummiesand Human Body Models. It is rarely exposed to injuries in frontal collisions but it does influence belt interactionand, as such, the thorax compression and head kinematics. Therefore, this study establishes responserequirements for the shoulder complex in terms of range of motion and stiffness.Six male volunteers were seated and belted, with minimum belt‐clavicle interaction, and shoulders werestatically loaded with increasing load; 0 ̶ 200 N/shoulder. Shoulders were pulled straight forward, forwardupward,upward and rearward. Three repetitions per direction were carried out.Resultant shoulder range of motion, at maximum loads, ranged from 44 to 73 mm. The volunteers providedmeasurements with reasonable repeatability.The applied loads were lower than those commonly seen in frontal crashes; however, the shoulder is highlymobile and its response is largely dependent on muscle characteristics. As such, these studies of volunteerresponses may be complimentary to tests with post mortem human subjects. Also, the volunteers curved theirspines only slightly in these tests. Hence, shoulder motion was successfully isolated and results reflect pureshoulder relative to chest motions. As such the data are suitable for dummy and Human Body Modelevaluations.
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| 9. |
- Elrud, Rasmus, et al.
(författare)
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Sickness absence among passenger car occupants following a Crash
- 2017
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; 2017-September, s. 79-90
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Konferensbidrag (refereegranskat)abstract
- Sickness absence is a common consequence of road traffic crashes, with high costs for the individual and society. Yet, scarcely studied, therefore, the aim was to describe sickness absence among injured car occupants. A population-based study using register data was conducted, including all car occupants of working age living in Sweden, who in 2010 had specialised in-or outpatient healthcare due to a car crash (n=9427). Individuals were categorised based on age, sex, and injury type. Odds ratios with 95% confidence intervals for a new sickness absence spell >14 days were estimated. After excluding the 9% already on sickness absence or disability pension, 10% had a new sickness absence spell >14 days. Sex and crash type were not associated with new sickness absence, while old age and being born outside Europe were associated with higher odds ratios. Odds ratios varied with the type of injury and injured body region. The odds ratio for sickness absence was highest for injuries to the spine and spinal cord odds ratio: 8.64 (95% confidence interval 6.45-11.57). Traumatic brain injuries except concussion had an odds ratio of 6.99 (4.04-12.08) while concussions had an odds ratio of 2.66 (1.80-3.93).
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| 10. |
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| 11. |
- Genzel, Jonny, et al.
(författare)
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An Open-Source Finite Element Model of a Generic Car Seat: Development and Validation for Low-Severity Rear Impact Evaluations
- 2022
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - : IRCOBI. - 2235-3151. ; 2022-September, s. 229-242, s. 229-242
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Konferensbidrag (refereegranskat)abstract
- A Finite Element model of a generic Laboratory Seat was developed to replicate a physical counterpart used in rear-impact volunteer tests. The Laboratory Seat has a simplified design, developed to facilitate replication in computational models. The seat has a flat rigid base and the seatback consists of four horizontal panels attached to side posts by coil springs. The seat model was validated with results from component tests and sled tests, including the Anthropomorphic Test Device, BioRID II. An initial test series was carried out to generate data for component validation: the first set of tests to characterise the coil spring properties; and the second set comprising Impactor Tests on Head Restraint Foam to assess the head restraint material properties. For system level validation, sled tests were conducted both with the empty Laboratory Seat and with the BioRID II. The BioRID II tests were conducted in conjunction with an earlier volunteer test study. Both the component and the sled tests were reproduced in a virtual environment. Good agreement was achieved between the mechanical tests and the computational simulations. The seat model is freely available to use: https://openvt.eu/fem/open-access-laboratory-seat-model.
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| 12. |
- 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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| 13. |
- 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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| 14. |
- Ghaffari, Ghazaleh, 1985
(författare)
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Passenger kinematics in Lane change and Lane change with Braking Manoeuvres using two belt configurations: standard and reversible pre‐pretensioner
- 2018
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; 2018-September, s. 493-511
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Konferensbidrag (refereegranskat)abstract
- The development of integrated safety technologies in modern cars demands comprehensive research to predict human occupant response in pre‐crash and crash situations. The aim of this study is to investigate occupant kinematics and to provide validation data for Human Body Models (HBMs) in simulations of evasive events potentially occurring prior to a crash. Nine front‐seat male passengers, wearing a seat belt in either standard or pre‐tensed configuration prior to the event, were exposed to multiple repeatable lane change and lane change with braking manoeuvres while travelling at 73 km/h. The focus of the study was to analyze the occupant kinematics and belt characteristics. The presented data can be used for validation of HBMs in both sagittal and lateral loading scenarios in simulation of pre‐crash events. Corridors comprising mean ±one standard deviation indicated lower sideways and forward displacements for head centre of gravity and T1, with the prepretensioner belt versus the standard belt. Upper torso and head lateral excursion were similar for lane change and lane change with braking manoeuvres, while the longitudinal excursions were highly influenced.
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| 15. |
- Heurlin, Fredrik, et al.
(författare)
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Front passenger airbag benefits for restrained forward‐facing children
- 2016
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Ingår i: IRCOBI Conf Proc - International Research Council on the Biomechanics of Injury, Sept, Malaga, Spain (IRC-16-43). - 2235-3151.
-
Tidskriftsartikel (refereegranskat)abstract
- This study investigates whether the front passenger airbag disabling strategy, developed based onfirst‐generation airbags, is valid for modern airbag designs and restrained forward‐facing children fromthree‐year‐old (3YO) size. In total, 19 different frontal impact situations were evaluated, comparing with andwithout airbag activation, using one vehicle model. Restrained child crash test dummies (3YO, 6YO, 10YO), ofvaried seat positions, booster types, crash pulses and sitting postures (up‐right and forward leaning), weretested in sled tests representative of a modern airbag and seatbelt technology. In addition, some typical misusecases were evaluated.To different extents, all 19 situations tested demonstrated relative positive, or comparable, effect foractivated airbag compared to no airbag. The influence of the airbag was relatively more pronounced in themore forward seat adjustment positions. In the misuse situations, it was clearly more robust using the airbag tohelp protect the child. Based on the results, Volvo Cars is revising its recommendations for restrained forwardfacing children travelling in car models with front passenger airbag designs as tested in this study. For thesespecific car models it is revised to recommend that the airbag should be Enabled for all forward‐facingrestrained child occupants (as for adults), while kept Disabled for all rearward‐facing children.
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| 16. |
- Iraeus, Johan, 1973, et al.
(författare)
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A new open-source finite element lumbar spine model, its tuning and validation, and development of a tissue-based injury risk function for compression fractures
- 2023
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; , s. 1048-1072
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Konferensbidrag (refereegranskat)abstract
- Lumbar spine fractures have been identified as a problem in motor vehicle crashes, and it is expected that this problem might increase with the introduction of reclined postures in autonomous vehicles. Human body models provide a means to address this issue and develop countermeasures. In this study a new open-source finite element lumbar spine model and an associated tissue-based injury risk function were developed and validated. The injury risk function was based on trabecular bone compressive strain in the superior-inferior direction. The kinematic and kinetic validation showed that the model compared reasonably to experimental data, with axial compression and flexion predictions being closest to experimental results. The new risk function was found to have a good quality index. Even though the model evaluations indicated that the fracture risk was somewhat overpredicted, it was judged that the current model, together with the associated injury risk function, can be used to estimate the risk for compressive fractures in the lumbar spine, with the knowledge that these estimates are most likely somewhat conservative.
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| 17. |
- Iraeus, Johan, 1973, et al.
(författare)
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Comparison of Average Female and Male Active HBM Responses in Whole-Sequence Frontal Crash Simulations
- 2023
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; , s. 819-842
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Konferensbidrag (refereegranskat)abstract
- Active human body models (HBMs) are important enablers for the simulation of occupant kinematics in pre-crash manoeuvres in whole-sequence crash scenarios. Pre-crash kinematics as well as injury risks have been shown to vary with sex. In this study, an average-sized female version (F50) of the active M50 SAFER HBM was developed using parametric mesh morphing, complemented with scaling of the muscle cross-sectional area. The active F50 model was validated with respect to volunteer pre-crash kinematics in braking and evasive turning manoeuvres, for two different belt systems (standard/pre-tensioned). Overall, the active F50 model predictions were slightly on the compliant side, compared to the volunteer test data. However, quantitatively using the CORA method, the active F50 model showed good biofidelity (0.81/0.89) for the pre-crash braking manoeuvre and fair biofidelity (0.60/0.75) for the evasive turning manoeuvre. Whole-sequence, combined, pre-crash and in-crash simulations were run with the active F50 and M50 models. They revealed some differences between the models, for which the active F50 model showed lower upper body forward displacements, and higher pelvis displacements, for two crash configurations and belt systems, compared to the active M50 model. Overall, however, the differences were small between the two HBMs.
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| 18. |
- Iraeus, Johan, 1973, et al.
(författare)
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Development and Validation of a Generic Finite Element Ribcage to be used for Strain-based Fracture Prediction
- 2019
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; :S1-5, s. 193-210
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Konferensbidrag (refereegranskat)abstract
- Finite element human body models, comprising detailed anatomical descriptions, can complement anthropomorphic test devices (ATDs) in the development of new restraint systems. Human body models (HBMs) can evaluate injury on tissue level, i.e. rib strain can be used to evaluate the risk of rib fracture, although the HBM must accurately predict the rib strain distribution to be effective. Current HBMs are not validated for rib strain, and it remains unknown if any represent an average-shaped ribcage. Thus, a new generic ribcage was created, representing an average male, based on a combination of averaged geometrical and material data from in-vivo and in-vitro datasets. The ribcage was incorporated into the THUMS AM50 Version 3, resulting in the SAFER HBM Version 9. Validation of ribcage kinetic, kinematics and strain distribution was carried out at three levels of complexity: anterior-posterior rib bending tests; rigid impactor table-top test; and a 40 km/h frontal sled test. The rib strains in the single rib load case were predicted within ± one standard deviation for 91% of the measuring points. The biofidelity for the rib strains in the table-top and sled test load cases was deemed ‘fair’ using CORA analysis. This study is an important step in the development and validation process of strain-based rib fracture criteria for HBMs.
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| 19. |
- Jakobsson, Lotta, 1967, et al.
(författare)
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Rear-End Impact Assessment expanded with Pre-Impact Posture Variations
- 2021
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; 2021-September, s. 753-770
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Konferensbidrag (refereegranskat)abstract
- Present whiplash injury assessment tests, reflecting the seat performance only, provide limited insights into real-world whiplash injury protection needs. Virtual testing of braking followed by a rear-end impact, in addition to alternative initial sitting postures, were conducted to investigate if the current anthropomorphic test device can be used to cover a larger scope of the real-world context. Reconstruction of published 1.1 g braking volunteer tests showed that a BioRID FE model was capable of recreating human-like kinematics; with head and T1 kinematics just within a 1 SD corridor on the low side of the volunteer response, while vertical displacements and lap-belt forces were underpredicted. A simulation series including pre-impact braking prior to rear-end impact investigated two strategies to vary the backset, as well as pre-impact means of intervention, exemplified by pre-impact seatbelt pretensioning. Using virtual testing, the study demonstrates examples of expanding the whiplash assessment test setup, enabling inclusion of a variety of occupant sitting postures and a braking event preceding the rear-end impact, while still being feasible to execute. As a next step, a human body model capable of seamless pre-crash and crash prediction could even allow for more in-depth investigations, as well as inclusion of ranges of occupant sizes and posture setting possibilities.
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| 20. |
- John, Jobin, 1989, et al.
(författare)
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Finite Element Human Body Models to study Sex-differences in Whiplash Injury: Validation of VIVA+ passive response in rear-impact
- 2022
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; 2022-September, s. 215-226
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Konferensbidrag (refereegranskat)abstract
- Neck whiplash injury in rear impact is known to affect females more than males. However, there is a lack of female human body models (HBM) to study whiplash. This paper reports the low-speed passive head-neck kinematic response of a new lineup of models representing an average female and an average male, called VIVA+. The female model serves as the baseline model in the HBM lineup, and the male model is a morphed derivative from the base model. The head-neck kinematics of these two models were evaluated at multiple levels: from cervical spine functional spine unit (FSU) level to head-neck response to mini-sled rear impacts, and finally, whole-body response to rear-impacts. In general, the female FSU were more compliant in moment-rotation responses. In the head-neck mini-sled simulation, the female upper-cervical spine segments responded with more flexion than male segments, resulting in a more pronounced S-Curve formation. In the whole-body rear impact, although the head responded with rearward retraction and rotation and so also T1 with smaller magnitudes, these responses showed considerable differences when compared to the experiments. This could be attributed to the uncertainties in posture and anthropometrical characteristics of the post-mortem human subjects. These evaluations serve as the first step toward providing models to study sex-differences in whiplash injury risks.
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| 21. |
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| 22. |
- Lamy, Michael, et al.
(författare)
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Traumatic Brain Injury Investigation Using FE Modeling of the Rat and Experimental High Amplitude Rotations in the Sagittal Plane
- 2013
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Ingår i: IRCOBI Conference. - 2235-3151. ; :IRC-13-51, s. 456-469
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Konferensbidrag (refereegranskat)abstract
- A combined approach of numerical modeling and animal experiments was used to study themechanisms of traumatic brain injury (TBI). A three‐dimensional finite element model (FEM) of the rat brainwas submitted to experimental sagittal plane rotational acceleration pulses. The experimental setup providedhistological analysis of injured brain tissues for a range of severities. The biomechanical response parameterswere extracted from the FEM in the anatomical regions identified by experiments as prone to injuries. VonMises stresses and first principal strains proved to increase with both the amplitude of acceleration loadings andthe tissue injuries severities. Further comparison between mechanical responses and experimental histologicalscores allowed proposing tissue thresholds for the occurrence of TBI, namely 1.5 kPa and 4% approximately forVon Mises stresses and first principal strains, respectively. Those values can be used for further investigationsof the mechanisms of TBI.
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| 23. |
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| 24. |
- Larsson, Emma, 1991, et al.
(författare)
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Active Human Body Model Predictions Compared to Volunteer Response in Experiments with Braking, Lane Change, and Combined Manoeuvres
- 2019
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; :S1-9, s. 349-369
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Konferensbidrag (refereegranskat)abstract
- Active human body models are an important tool to study occupant interaction with safety systems in evasive manoeuvres such as braking and/or steering. In this study a finite element human body model with and without closed-loop active muscle control in the neck and lower trunk was compared to volunteer occupants in six different load cases with lane change, braking, and combined manoeuvres using standard and prepretensioned seat belts. Seven different muscle controllers, using two different muscle activation strategies based either on head and torso displacements or muscle length, and one with the controller turned off have been compared to volunteer kinematics. Cross-correlation analysis with CORA was used to evaluate the model biofidelity. The results show an improvement in CORA scores when using active muscles, compared to the model with muscle activity turned off, for one load case and similar CORA scores between the models for five load cases. CORA scores ranged from 0.78 to 0.88 for the active models and 0.70 to 0.82 from the model with muscles turned off. The active model gave a kinematic response with good biofidelity in lane change with braking, pure braking, and lane change with pre-pretensioned seat belt, but the biofidelity of the model was rated as fair in lane change with standard seat belt.
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| 25. |
- Larsson, Emma, 1991, et al.
(författare)
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Passenger Kinematics Variance in Different Vehicle Manoeuvres - Biomechanical Response Corridors Based on Principal Component Analysis
- 2022
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; 2022-September, s. 793-843
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Konferensbidrag (refereegranskat)abstract
- This study explores the influence of occupant characteristics and belt type on occupant kinematics in evasive manoeuvres and provides models for construction of response corridors. Data originated from evasive manoeuvres with male and female volunteers. Principal component analysis and linear mixed models were used on selected data to create predictive models for kinematics and belt time histories, using belt configuration, sex, age, stature, and BMI as co-variates. Monte Carlo simulations of resulting models were used to generate upper and lower response corridor limits around the predicted responses. For translational and rotational displacements of the head and the torso, the first three principal components together captured 91%-99% of the variance in the responses. Belt configuration, sex, age, stature, BMI, and their interaction effects were found statistically significant (p < 0.05) in the linear mixed model analysis in lane changes, braking and U-turns at 40 km/h but not in U-turns at 30 km/h or when aware of turn. Response corridors for average sex, stature and BMI, were provided. In conclusion, the models and data provided can be used for validation of human body models with a range of anthropometries and in different manoeuvres and belt configurations potentially occurring in pre-crash manoeuvres.
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