| 1. |
|
|
| 2. |
|
|
| 3. |
- Carlsson, Anna K, 1966, et al.
(författare)
-
Female volunteer motion in rear impact sled tests in comparison to results from earlier male volunteer tests
- 2008
-
Ingår i: 2008 INTERNATIONAL IRCOBI CONFERENCEONTHE BIOMECHANICS OF INJURY17. – 19. September 2008– BERN (Switzerland)PROCEEDINGS. ; , s. 461-464, s. 461-464
-
Konferensbidrag (refereegranskat)abstract
- Vehicle related crashes causing neck injuries (whiplash) are costly and common, and injury statistic data shows a larger risk of neck injuries for females than for males. This study aims at investigating differences between female and male dynamic response in rear impacts. Rear impact sled tests with female volunteers were carried out and the results were compared with previously performed tests with males in matching test conditions. The volunteer tests were performed at a change of velocity of 7 km/h. The comparison of the average response of the males and the females and their response corridors showed several differences. The horizontal head acceleration peak value was on average 40% higher and occurred on average 18% earlier for the female volunteers compared to the male volunteers. The NIC value was 45% lower and 30% earlier for the females, probably due to a 27% smaller initial head-to-head restraint distance and thereby a 24% earlier head restraint contact. The results provide characteristic differences between dynamic responses of females and males in low speed rear impacts. These results contribute to the understanding of human dynamic response in rear impacts. In addition, they can be used in the process of future development if numerical and/or mechanical human models for crash testing.
|
|
| 4. |
- Davidsson, Johan, 1967, et al.
(författare)
-
Injury threshold for sagittal plane rotational induced diffuse axonal injuries
- 2009
-
Ingår i: 2009 International IRCOBI Conference on the Biomechanics of Injury; York; United Kingdom; 9 September 2009 through 11 September 2009. - 9783033020504 ; , s. 43-55
-
Konferensbidrag (refereegranskat)abstract
- Sagittal plane rotational acceleration induced diffuse axonal injury threshold was investigated using an animal model in which the heads of the rats were exposed to selected rotation accelerations. Post-trauma survival times ranged from 3 to 120 h. Numerous S100 serum concentrations, brain tissue stained for β-Amyloid Precursor Protein (β-APP), and probes for Cyclooxygenase 2 (COX2) mRNA were used to detect affected nerve cells, decaying axons, and cytoskeletal changes, respectively. Scaling laws were applied to estimate injury thresholds for the human brain. Confocal imaging revealed bands of β-APP-positive axons in the corpus callosum and its edges in animals exposed to rotational accelerations >1.1 Mrad/s2. Similarly, for COX2 presence and S100 concentrations at >0.9 Mrad/s2, the numbers of stained cells in the cortex and hippocampus and the concentrations increased. The data clearly indicate that the rat brain is injured at a specific rotational acceleration. Scaled to that of humans this would be 10 krad/s2 with a duration of 4 ms.
|
|
| 5. |
- Davidsson, Johan, 1967
(författare)
-
Sagittal anterior-posterior rotational acceleration induced head injuries in the rat
- 2007
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A new test device to produce sagittal plane rearward rotational acceleration induced diffuse braininjury to the rat has been developed. During trauma, the heads, which were fixed to a rotating barby means of curved plates that were glued to the skull bones, were exposed to rotationalacceleration between 0.3 and 2 Mrad/s2. The animals were sacrificed 3, 24 and 72 hours aftertrauma. Blood samples were collected for serum analyses prior to sacrifice and subsequentdissection of the brains. Transverse cryostat brain tissue sections were cut at three locations inthe brains. The sections were stained with β-Amyliod Precursor Protein (β-APP) andNeurofilament (NF) antibodies and probes for Cyclooxygenase 2 (COX2) mRNA in-situhybridisation to detect decaying axons, cytoskeleton changes and affected nerve cells.Bands of β-APP positive axons, i.e. axons with reduced plasma flow and hence probably dyingaxons, were seen in the corpus callosum, thalamus and hippocampus and in the border of theseregions in most animals exposed to rotational trauma at 1.1 Mrad/s2 or higher. Similarly for theCOX2 marker; above 0.9 Mrad/s2 the numbers of stained cells were large for a number oflocations in the cortex and hippocampus region. Only negligible β-APP and COX2 mRNAupregulation were observed in the sham exposed controls and normal animals. NF changes werenot observed in controls or exposed animals euthanized prior to 3 hours after trauma, but visible24 hours after trauma. The S100 serum analyses indicate that blood vessel and glia cell injuriesoccur at rotational accelerations above 1.1 Mrad/s2.The data clearly indicate that the rat brain is injured at a rearward rotational acceleration of 1.0Mrad/s2 when the rotational acceleration pulse have a duration of 0.4 ms. The scaledrepresentative global head rotational acceleration and duration for humans is estimated to be 9krad/s2 and 4 ms, respectively. However, the study also highlight that these threshold values arehighly influenced by the choice of brain dimensions used in the scaling equations. In addition,differences such as position of the cerebellum, lack of gyruses in the rat brain, and location andshape of the ventricles, etc were not taken into account. In order to improve the understandingthe effect on scaling laws of these differences between the human and the rat, it is recommendedto carry out a parametric study on these issues using detailed FE-models of the rat and humans.
|
|
| 6. |
- Holmqvist, Kristian, 1976, et al.
(författare)
-
EVALUATION OF HYBRID III THORACIC INJURY CRITERIA IN IMPACTS WITH A SIMULATED TRUCK STEERING WHEEL – SUGGESTIONS FOR MODIFICATIONS IN INSTRUMENTATION AND REFERENCE VALUES
- 2009
-
Ingår i: International IRCOBI Conference on the Biomechanics of Impact. ; , s. 201-204
-
Konferensbidrag (refereegranskat)abstract
- Unbelted drivers of heavy commercial vehicles are likely to suffer chest injuries from steering wheel rim contact in frontal impacts. The aim of the present study was to investigate to what extent the current regulatory dummy, the Hybrid III, is capable of assessing the chest deflection in this load case. A Finite Element model of the dummy and its default sensors were evaluated together with chest injury criteria. The THUMS was used as a reference representing the human body. Suggestions on instrumentation and correction factors for injury criteria are proposed for use with the Hybrid III.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Risling, Mårten, et al.
(författare)
-
Diffuse axonal injury induced by rapid rotation
- 2007
-
Ingår i: 37th NeuroSience Conference, San Diego Convention Center, October 14-18, San Diego, USA.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
|
|
