| 1. |
- Ydenius, Anders, et al.
(författare)
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Fatal car to moose collisions : Real-world in-depth data, crash tests and potential of different countermeasures
- 2017
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Ingår i: Proceedings 25th International Technical Conference on the Enhanced Safety of Vehicles (ESV). - : NHTSA.
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Konferensbidrag (refereegranskat)abstract
- Vehicle collisions with large animals constitute a high risk of serious or fatal injuries, for example in northern America, Europe and Japan. In Sweden approximately 5,000 car collisions with moose occur annually. The change of velocity and acceleration is in general very low, but the car structure is not designed for collision with large animals at high speed. The objectives were to evaluate occupant response and vehicle structure in crash tests; to investigate the factors involved in real-world fatal crashes in Sweden; and to evaluate the potential of Autonomous Emergency Braking (AEB) to increase moose car collision avoidance and survivability. Five crash tests were conducted with cars with different size and characteristics, such as glass and sun roof. A moose crash dummy was impacted at 70 km/h. The Swedish Transport Administration (STA) national database of fatal collisions was used to study fatalities (n=47) in collisions with moose during the period 2005-2016. The analysis focused on collisions where the primary cause of fatality was the collision with a moose. The crash tests showed that a moose collision could be survivable at 70 km/h with an acceptable distance to the header structure. None of the tested cars had an intrusion by the moose into the occupant compartment. The results of the in-depth data analysis showed that a critical factor for a fatal injury was whether the roof was partly or completely ripped off. Downward deformation of the front header structure was also critical together with Apillar deformation. In 24% of the accidents the moose was partly or completely trapped inside the occupant compartment. In 90% of the fatal collisions it was darkness or twilight. In more than 85% of the collisions, no evidence of braking could be detected prior to collision. All of the collisions occurred on rural roads and 83% of the fatalities occurred on roads with speed limits of 90 km/h or above. In eight accident scenes there were moose fences to prevent the moose to access the road. In those accidents, however, the fence was either damaged or had open sections. The analysis of road-side area showed that in many of the moose accidents the side view was enough to allow detection of the moose by an AEB sensor. A critical issue is the ability of the sensors to detect the moose in darkness. The study of the potential for AEB with moose detection was conducted under the assumption that night vision sensors are available, such as infrared sensors or light amplifying technique. With a threshold of 70 km/h for car-moose collision survivability, the results of the analysis showed that AEB had a potential to save (~40%) 18 out of 47 lives. It is suggested that road fencing is preferable on roads with speed limits above 90 km/h, and below 100 km/h, moose AEB has a potential to avoid fatal moose crashes.
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| 2. |
- Alexiou, Eirini, et al.
(författare)
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The impact of facility relocation on patients' perceptions of ward atmosphere and quality of received forensic psychiatric care
- 2016
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Ingår i: Journal of Forensic and Legal Medicine. - : Elsevier BV. - 1752-928X. ; 42, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, large groups of forensic psychiatric patients have been relocated into new medium-and maximum-security forensic psychiatric facilities in Sweden, where a psychosocial care approach is embedded. From this perspective and on the assumption that physical structures affect the therapeutic environment, a prospective longitudinal study was designed to investigate the impact of the facility relocation of three forensic psychiatric hospitals on patients' perceptions of ward atmosphere and quality of received forensic psychiatric care. Participants were patients over 18 years of age sentenced to compulsory forensic psychiatric treatment. Data were obtained by validated questionnaires. Overall, 58 patients (78%) answered the questionnaires at baseline with a total of 25 patients (34%) completing follow-up 1 at six months and 11 patients (15%) completing follow-up 2, one year after relocation. Approximately two-thirds of the participants at all time-points were men and their age range varied from 18 to 69. The results of this study showed that poor physical environment features can have a severe impact on care quality and can reduce the possibilities for person-centered care. Furthermore, the study provides evidence that the patients' perceptions of person-centered care in forensic psychiatric clinics are highly susceptible to factors in the physical and psychosocial environment. Future work will explore the staff's perception of ward atmosphere and the possibilities to adapt a person-centered approach in forensic psychiatric care after facility relocation. (C) 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.
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| 3. |
- Brolin, Karin, 1974, et al.
(författare)
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Aiming for an average female virtual human body model for seat performance assessment in rear-end impacts
- 2015
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Ingår i: The 24th ESV Conference Proceedings.
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Konferensbidrag (refereegranskat)abstract
- The female part of the population suffers more Whiplash Associated Disorders (WAD) in car crashes than males. Several studies have illustrated the need to consider the female population when developing and assessing the WAD prevention performance of advanced restraint systems in rear-end collisions. Presently only one crash test dummy is available, the average sized male BioRID. Recently a virtual dummy model of an average female, EvaRID, was developed and used in rear impact simulations. The results stressed the need for models representing the female part of the population, as well. Virtual crash simulations have become essential in traffic safety and with models of both an average male and female, further steps in addressing improved assessment of WAD prevention can be taken. The present paper presents a starting point of research aiming to develop an open-source average female Finite Element (FE) model with an anatomically detailed cervical spine. This paper provides a review of the literature to identify gender specific neck biomechanics and anatomical differences, followed by a review of published FE models of the cervical spine. Data on vertebral body dimensions (height, width, depth, spinal canal diameter, facet joint angles) have been compiled from biomechanical literature. Significant gender differences exist for the vertebral body depth and width, the spinal curvature in the seated posture, and the spinal stiffness and range of motion. All have the potential to influence the outcome of an impact and should be accounted for in the development of WAD prevention. The review of FE models of the cervical spine presented 17 models based on male geometry but only one model scaled to represent a female. An overview of the models are given with respect to the solver, geometry source, number of elements, and implementation of the facet joints, ligaments, and muscles. It is recommended that an average female model is developed with focus on; 1) the shape of the female vertebral body, especially the depth and width that provides less support area than for males,2) defining the spinal curvature representative of seated female volunteers who generally display less lordosis than males, 3) the dimensions of the spinal ligaments, rather than the material properties, to capture the larger range of motion and less spinal stiffness of female subjects compared to males, and validation to female volunteers and PMHS tests for range of motion, while failure prediction seem less gender sensitive.
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| 4. |
- Carlsson, Anna K, 1966, et al.
(författare)
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Real World Adjustments of Driver Seat and Head Restraint in Saab 9-3 Vehicles
- 2017
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-957X .- 1538-9588. ; 18:4, s. 398-405
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveWhiplash-associated disorder (WAD), commonly denoted whiplash injury, is a worldwide problem. These injuries occur at relatively low changes of velocity (typically
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| 5. |
- Gustafsson, Markus, et al.
(författare)
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Risk of Permanent Medical Impairment (RPMI) in Car Crashes Correlated to Age and Gender
- 2015
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-9588 .- 1538-957X. ; 16:4, s. 353-361
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Tidskriftsartikel (refereegranskat)abstract
- Objective:As fatalities from car crashes decrease, focus on medical impairment following car crashes becomes more essential. This study assessed the risk of permanent medical impairment based on car occupant injuries. The aim was to study whether the risk of permanent medical impairment differs depending on age and gender.Methods:In total, 36,744 injured occupants in car crashes that occurred between 1995 and 2010 were included. All initial injuries (n = 61,440) were classified according to the Abbreviated Injury Scale (AIS) 2005. If a car occupant still had residual symptoms 3years after a crash, the case was classed as a permanent medical impairment. In total, 5,144 injuries led to permanent medical impairment. The data were divided into different groups according to age and gender as well as levels of permanent impairment. The risk of permanent medical impairment was established for different body regions and injury severity levels, according to the AIS.Results:The cervical spine was the body region that had the highest number of diagnoses, and occupants who sustained injuries to the upper and lower extremities had the highest risk of medical impairment for both genders. Females aged 60 and above had a higher risk of permanent medical impairment from fractures in the extremities compared to males in the same age group and younger females. Females aged 44 or younger had a higher risk of permanent medical impairment from whiplash-associated disorders (WAD) than males in the same age group. Minor and moderate injuries (AIS 1-2) had a higher risk of permanent medical impairment among older car occupants compared to younger ones.Conclusions:Differences in long-term outcome were dependent on both gender and age. Differences between age groups were generally greater than between genders. The vast majority of permanent medical impairments resulted from diagnoses with a low risk of fatality. The results emphasize the impact of age and gender in long-term consequences from car crashes. They could be used when designing safety technology in cars as well as to improve health care by contributing to better allocation of rehabilitation resources following trauma.
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| 6. |
- Kullgren, Anders, 1963, et al.
(författare)
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The potential of vehicle and road infrastructure interventions in fatal bicyclist accidents on Swedish roads—What can in-depth studies tell us?
- 2019
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-9588 .- 1538-957X. ; 20:sup1, s. S7-S12
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of this article is to describe the characteristics of fatal crashes with bicyclists on Swedish roads in rural and urban areas and to investigate the potential of bicycle helmets and different vehicle and road infrastructure interventions to prevent them. The study has a comprehensive approach to provide road authorities and vehicle manufacturers with recommendations for future priorities. Methods: The Swedish Transport Administration’s (STA) in-depth database of fatal crashes was used for case-by-case analysis of fatal cycling accidents (2006–2016) on rural (n = 82) and urban (n = 102) roads. The database consists of information from the police, medical journals, autopsy reports, accident analyses performed by STA, and witness statements. The potential of helmet use and various vehicle and road infrastructure safety interventions was determined retrospectively for each case by analyzing the chain of events leading to the fatality. The potential of vehicle safety countermeasures was analyzed based on prognoses on their implementation rates in the Swedish vehicle fleet. Results: The most common accident scenario on rural roads was that the bicyclist was struck while cycling along the side of the road. On urban roads, the majority of accidents occurred in intersections. Most accidents involved a passenger car, but heavy trucks were also common, especially in urban areas. Most accidents occurred in daylight conditions (73%). Almost half (46%) of nonhelmeted bicyclists would have survived with a helmet. It was assessed that nearly 60% of the fatal accidents could be addressed by advanced vehicle safety technologies, especially autonomous emergency braking with the ability to detect bicyclists. With regard to interventions in the road infrastructure, separated paths for bicyclists and bicycle crossings with speed calming measures were found to have the greatest safety potential. Results indicated that 91% of fatally injured bicyclists could potentially be saved with known techniques. However, it will take a long time for such technologies to be widespread. Conclusions: The majority of fatally injured bicyclists studied could potentially be saved with known techniques. A speedy implementation of important vehicle safety systems is recommended. A fast introduction of effective interventions in the road infrastructure is also necessary, preferably with a plan for prioritization.
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| 7. |
- Lübbe, Nils, 1982, et al.
(författare)
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Assessment of Integrated Pedestrian Protection Systems with Forward Collision Warning and Automated Emergency Braking
- 2015
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Ingår i: 2015 IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury. ; , s. 385-397
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Konferensbidrag (refereegranskat)abstract
- Automated Emergency Braking systems reduce impact speeds, and consequently, injuries in car‐ to‐pedestrian impacts. The development of assessment methods for these systems has received considerable attention. Forward Collision Warning systems similarly aim at reducing impact speed, but have received less attention. Casualty cost reductions of several simplified but realistic Forward Collision Warning and Automated Emergency Braking systems were calculated using simulations and a modified AsPeCSS method. Automated Emergency Braking systems were assessed to result in approximately 25% casualty cost reductions. Forward Collision Warning effectiveness ranged from “no benefit” for an audio‐visual warning system with late activation, to a benefit of 25 % casualty cost reduction for an early activating warning system including an additional short brake pulse. As Forward Collision Warning seems to have the potential to reduce pedestrian casualties of the same magnitude as Automated Emergency Braking, the authors suggest including a Forward Collision Warning assessment in a modified AsPeCSS method to rate pedestrian protection of cars.
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| 8. |
- Pazoki, Meysam, et al.
(författare)
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Photoinduced Stark Effects and Mechanism of Ion Displacement in Perovskite Solar Cell Materials
- 2017
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Ingår i: ACS Nano. - : AMER CHEMICAL SOC. - 1936-0851 .- 1936-086X. ; 11:3, s. 2823-2834
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Tidskriftsartikel (refereegranskat)abstract
- Organometallic halide perovskites (OMHPs) have recently emerged as a promising class of materials in photovoltaic technology. Here, we present an in-depth investigation of the physics in these systems by measuring the photoinduced absorption (PIA) in OMHPs as a function of materials composition, excitation wavelength, and modulation frequency. We report a photoinduced Stark effect that depends on the excitation wavelength and on the dipole strength of the monovalent cations in the A position of the ABX(3) perovskite. The results presented are corroborated by density functional theory calculations and provide fundamental information about the photoinduced local electric field change under blue and red excitation as well as insights into the mechanism of light induced ion displacement in OMHPs. For optimized perovskite solar cell devices beyond 19% efficiency, we show that excess thermalization energy of blue photons plays a role in overcoming the activation energy for ion diffusion.
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| 9. |
- Pazoki, Meysam, et al.
(författare)
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Photon Energy-Dependent Hysteresis Effects in Lead Halide Perovskite Materials
- 2017
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 121:47, s. 26180-26187
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Tidskriftsartikel (refereegranskat)abstract
- Lead halide perovskites have a range of spectacular properties and interesting phenomena and are a serious candidate for the next generation of photovoltaics with high efficiencies and low fabrication costs. An interesting phenomenon is the anomalous hysteresis often seen in current-voltage scans, which complicates accurate performance measurements but has also been explored to obtain a more comprehensive understanding of the device physics. Herein, we demonstrate a wavelength and illumination intensity dependency of the hysteresis in state-of-the-art perovskite solar cells with 18% power conversion efficiency (PCE), which gives new insights into ion migration. The perovskite devices show lower hysteresis under illumination with near band edge (red) wavelengths compared to more energetic (blue) excitation. This can be rationalized with thermalization-assisted ion movement or thermalization-assisted vacancy generation. These explanations are supported by the dependency of the photovoltage decay with illumination time and excitation wavelength, as well as by impedance spectroscopy. The suggested mechanism is that high-energy photons create hot charge carriers that either through thermalization can create additional vacancies or by release of more energetic phonons play a role in overcoming the activation energy for ion movement. The excitation wavelength dependency of the hysteresis presented here gives valuable insights into the photophysics of the lead halide perovskite solar cells.
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| 10. |
- Rizzi, Matteo, 1979, et al.
(författare)
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Effectiveness of Motorcycle Antilock Braking Systems (ABS) in Reducing Crashes, the First Cross-National Study
- 2015
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-957X .- 1538-9588. ; 16:2, s. 177-183
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: This study set out to evaluate the effectiveness of motorcycle antilock braking systems (ABS) in reducing real-life crashes. Since the European Parliament has voted on legislation making ABS mandatory on all new motorcycles over 125 cc from 2016, the fitment rate in Europe is likely to increase in the coming years. Though previous research has focused on mostly large displacement motorcycles, this study used police reports from Spain (2006-2009), Italy (2009), and Sweden (2003-2012) in order to analyze a wide range of motorcycles, including scooters, and compare countries with different motorcycling habits. Methods: The statistical analysis used odds ratio calculations with an induced exposure approach. Previous research found that head-on crashes were the least ABS-affected crash type and was therefore used as the nonsensitive crash type for ABS in these calculations. The same motorcycle models, with and without ABS, were compared and the calculations were carried out for each country separately. Crashes involving only scooters were further analyzed. Results: The effectiveness of motorcycle ABS in reducing injury crashes ranged from 24% (95% confidence interval [CI], 12-36) in Italy to 29% (95% CI, 20-38) in Spain, and 34% (95% CI, 16-52) in Sweden. The reductions in severe and fatal crashes were even greater, at 34% (95% CI, 24-44) in Spain and 42% (95% CI, 23-61) in Sweden. The overall reductions of crashes involving ABS-equipped scooters (at least 250 cc) were 27% (95% CI, 12-42) in Italy and 22% (95% CI, 2-42) in Spain. ABS on scooters with at least a 250 cc engine reduced severe and fatal crashes by 31% (95% CI, 12-50), based on Spanish data alone. Conclusions: At this stage, there is more than sufficient scientific-based evidence to support the implementation of ABS on all motorcycles, even light ones. Further research should aim at understanding the injury mitigating effects of motorcycle ABS, possibly in combination with combined braking systems.
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