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- Boström, Ola, 1963, et al.
(författare)
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A new neck injury criterion candidate-based on injury findings in the cervical spinal ganglia after experimental neck extension trauma
- 1996
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Ingår i: PROCEEDINGS OF THE 1996 INTERNATIONAL IRCOBI CONFERENCE ON THE BIOMECHANICS OF IMPACT, SEPTEMBER 11-13, DUBLIN, IRELAND. ; , s. 123-136
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Konferensbidrag (refereegranskat)abstract
- In this study a mathematical model, based on Navier Stokes equations, was developed and validated against experimental data. This model predicts the pressure changes in the spinal canal as a function of the volume change inside the canal during neck bending in the x-z (sagittal) plane. Another aim of the study was to investigate pressure phenomena and ganglion injuries at static neck extension loading and dynamic neck extension trauma with a head-restraint present. Experiments on pigs were conducted. Preliminary results indicate that ganglion injuries, as well as pressure transients inside the spinal canal, seem to correlate to the phase shift when the neck passes an s-shape (or maximal retraction) during the rearward motion of the head. That is, when the upper neck quickly changes from a flexion to an extension shape. Static loading of the neck resulted in no signs of injuries to the ganglia. A possible candidate for a neck injury criterion is presented, based on the relative acceleration between the top and the bottom of the cervical spine. A tolerance level based on the pig tests is also discussed.
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| 2. |
- Boström, Ola, 1963, et al.
(författare)
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Comparison of car seats in low speed rear-end impacts using the BioRID dummy and the new neck injury criterion (NIC).
- 2000
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Ingår i: Accident Analysis and Prevention. ; 32:2, s. 321-328
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Tidskriftsartikel (refereegranskat)abstract
- Long-term whiplash associated disorders (WAD) 1-3 sustained in low velocity rear-end impacts is the most common disability injury in Sweden. Therefore, to determine neck injury mechanisms and develop methods to measure neck-injury related parameters are of importance for current crash-safety research. A new neck injury criterion (NIC) has previously been proposed and evaluated by means of dummy, human and mathematical rear-impact simulations. So far, the criterion appears to be sensitive to the major car and collision related risk factors for injuries with long-term consequences. To further evaluate the applicability of NIC, four seats were tested according to a recently proposed sled-test procedure. 'Good' as well as 'bad' seats were chosen on the basis of a recently presented disability risk ranking list. The dummy used in the current tests was the Biofidelic Rear Impact Dummy (BioRID). The results of this study showed that NICmax values were generally related to the real-world risk of long-term WAD 1-3. Furthermore, these results suggested that NICmax calculated from sled tests using the BioRID dummy can be used for evaluating the neck injury risk of different car seats.
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| 3. |
- Boström, Ola, 1963, et al.
(författare)
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Prediction of neck injuries in rear impacts based on accident data and simulations
- 1997
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Ingår i: PROCEEDINGS OF THE 1997 INTERNATIONAL IRCOBI CONFERENCE ON THE BIOMECHANICS OF IMPACT. ; , s. 251-264
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Konferensbidrag (refereegranskat)abstract
- Whiplash associated disorders, occurring in car accidents, are an increasing problem worldwide. According to real-life data from police records, the struck car's velocity change (delta V) and occupant gender are two of the most important factors related to Abbreviated Injury Scale (AIS) 1 neck injuries. In this study, a new rear-impact ranking of cars based on 4432 police reported accidents is presented. The ranking concerns the relative neck injury risk and compensates for the influences of car weight and gender. Moreover, some important factors influencing the risk of AIS 1 neck injury are proposed. These include: the stiffness, damping and yielding characteristics of the seat back, the muscle response of the occupant, and the delta V of the struck car and acceleration pulse. Using a mathematical model it is shown that the influence from these factors can be explained by a recently proposed neck injury criterion (NIC). This criterion is based on the neck motion at the passage of full neck retraction. The NIC, based on a number of volunteer tests, is analysed and validated. The consequence of injury outcome of an observed overall seat back stiffening is also discussed. In conclusion, for delta V below 20 km/h, real-life data show that the geometry of the head restraint is of minor importance. A seat back with low yielding limit or soft performance may be preferable. Moreover, the new NIC seems to be a good predictor of real-life neck injuries.
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| 6. |
- Davidsson, Johan, 1967, et al.
(författare)
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BioRID - A New Biofidelic Rear Impact Dummy
- 1998
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Ingår i: Proceeding of the 1998 International IRCOBI Conference on the Biomechanics of Impact. ; , s. 377-390
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Konferensbidrag (refereegranskat)
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| 7. |
- Davidsson, Johan, 1967, et al.
(författare)
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BioRID P3 – Design and Performance Compared to Hybrid III and Volunteers in Rear Impacts at ΔV=7 km/h
- 1999
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Ingår i: Proceeding of the 43rd STAPP Car Crash Conference, San Diego, USA. ; :SAE paper no. 99SC16, s. 253-265
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Konferensbidrag (refereegranskat)abstract
- Several investigators have noted limitations of the most commonly used dummy in rear impact testing, the Hybrid III. A dummy for rear impact testing, the BioRID I, has previously been presented. It was a step towards an effective tool for seat performance testing, but it was concluded that its neck extension and T1 upward motion were too small and that its user-friendliness could be improved.A new BioRID prototype has been developed. It has new neck muscle substitutes with damping and elastic elements that are independent of each other and fitted inside the torso. The new neck muscle substitutes extend to T3 and thus also load the upper thoracic spine. The new dummy has a softer thoracic spine and a torso made of softer rubber than was used for the original dummy. The BioRID prototype's performance was compared to that of volunteers, the BioRID I and Hybrid III in rear impacts at V=7 km/h. The kinematics response of the new BioRID prototype appears to be more human-like than that of the BioRID I and Hybrid III. The dummy also provides repeatable test results and is more user-friendly than the BioRID I.
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| 8. |
- Davidsson, Johan, 1967, et al.
(författare)
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Human Volunteer Kinematics in Rear-End Sled Collisions
- 1998
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Ingår i: Proceeding of the 1998 International IRCOBI Conference on the Biomechanics of Impact. ; , s. 289-301
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Konferensbidrag (refereegranskat)abstract
- A number of current projects are developing new crash test dummies for rear-end impact testing. The validation of such a dummy design requires human response data from pertinent test situations. The objectives of this study are to quantify human head, neck, chest, pelvis and femur mechanical response in a well defined test seat. Another aim is to see how the response varies with seat design and sled speed change during low-speed rear-end collisions. This data is intended to be used in the validation of the crash test dummy (BioRID I) in rear-end impact situations, with a focus on low delta V (velocity change) collisions. Thirteen human subjects were exposed to 28 rear-end collision sled impacts with velocity changes close to 5 and 7 krn/h respectively. The results showed vertical motion of the subjects' H-point caused by ramping up along the seat, a forward rotat ion of the subjects' femur and maybe a contraction of the subjects' gluteus muscles. A vertical motion of the subjects' torso and head was also observed. This motion was caused by a combination of ramping up along the seat back and the straightening of the thoracic kyphosis. In the first 100 ms after impact, several subjects flexed their head relative T1. These new data have proven to be useful as validation data for new rear-end impact dummies.
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