RESUMEN
Objective: Various definitions and uses of the term body region can be found in the literature. A definition of body regions using the Abbreviated Injury Scale (AIS) codes not strictly aligned with AIS chapters was developed for use in the European Commission-funded PIONEERS project (Protective Innovations of New Equipment for Enhanced Rider Safety). This work aims to examine the consequences of differently defined body regions on injury priority ranking using the percentage of patients showing at least moderate injury severity (AIS 2+) per regarded body region.Methods: Three different crash investigation data sets of injured riders and/or pillion riders of powered 2-wheelers (PTWs) were used for this analysis. The first contained data for 143 fatalities, the second contained data for 58 severely injured, and the last for contained data for 982 patients from a sample that was close to national representativeness. Frequency of injury was examined using body regions based on the AIS chapters (and first digit of the AIS Unique Identifier) and based on the PIONEERS definition.Results: Though different body region definitions did not result in different top-ranked body regions in terms of injury frequency, different definitions did provide different levels of information that impact priority within AIS chapter-defined regions. For PTW riders, cervical injuries are the highest priority spinal injuries. Thoracic and lumbar spinal injuries seem to occur together with other injuries in the thorax and abdominal region. Severe lower extremity injuries frequently involve the pelvis and the leg.Conclusions: Body regions need to be defined carefully to avoid misinterpretations. Publications that use body regions for their analysis to present injury frequencies should clearly define what they include in each region.
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Escala Resumida de Traumatismos , Accidentes de Tránsito/estadística & datos numéricos , Equipo de Protección Personal/normas , Terminología como Asunto , Unión EuropeaRESUMEN
OBJECTIVE: Autonomous emergency braking (AEB) systems fitted to cars for pedestrians have been predicted to offer substantial benefit. On this basis, consumer rating programs-for example, the European New Car Assessment Programme (Euro NCAP)-are developing rating schemes to encourage fitment of these systems. One of the questions that needs to be answered to do this fully is how the assessment of the speed reduction offered by the AEB is integrated with the current assessment of the passive safety for mitigation of pedestrian injury. Ideally, this should be done on a benefit-related basis. The objective of this research was to develop a benefit-based methodology for assessment of integrated pedestrian protection systems with AEB and passive safety components. The method should include weighting procedures to ensure that it represents injury patterns from accident data and replicates an independently estimated benefit of AEB. METHODS: A methodology has been developed to calculate the expected societal cost of pedestrian injuries, assuming that all pedestrians in the target population (i.e., pedestrians impacted by the front of a passenger car) are impacted by the car being assessed, taking into account the impact speed reduction offered by the car's AEB (if fitted) and the passive safety protection offered by the car's frontal structure. For rating purposes, the cost for the assessed car is normalized by comparing it to the cost calculated for a reference car. The speed reductions measured in AEB tests are used to determine the speed at which each pedestrian in the target population will be impacted. Injury probabilities for each impact are then calculated using the results from Euro NCAP pedestrian impactor tests and injury risk curves. These injury probabilities are converted into cost using "harm"-type costs for the body regions tested. These costs are weighted and summed. Weighting factors were determined using accident data from Germany and Great Britain and an independently estimated AEB benefit. German and Great Britain versions of the methodology are available. The methodology was used to assess cars with good, average, and poor Euro NCAP pedestrian ratings, in combination with a current AEB system. The fitment of a hypothetical A-pillar airbag was also investigated. RESULTS: It was found that the decrease in casualty injury cost achieved by fitting an AEB system was approximately equivalent to that achieved by increasing the passive safety rating from poor to average. Because the assessment was influenced strongly by the level of head protection offered in the scuttle and windscreen area, a hypothetical A-pillar airbag showed high potential to reduce overall casualty cost. CONCLUSIONS: A benefit-based methodology for assessment of integrated pedestrian protection systems with AEB has been developed and tested. It uses input from AEB tests and Euro NCAP passive safety tests to give an integrated assessment of the system performance, which includes consideration of effects such as the change in head impact location caused by the impact speed reduction given by the AEB.
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Accidentes de Tránsito/estadística & datos numéricos , Automóviles , Desaceleración , Equipos de Seguridad , Caminata/lesiones , Heridas y Lesiones/prevención & control , Análisis Costo-Beneficio , Diseño de Equipo , Europa (Continente) , Humanos , Equipos de Seguridad/economíaRESUMEN
OBJECTIVE: The objective of the current study was to estimate the benefit for Europe of fitting precrash braking systems to cars that detect pedestrians and autonomously brake the car to prevent or lower the speed of the impact with the pedestrian. METHODS: The analysis was divided into 2 main parts: (1) Develop and apply methodology to estimate benefit for Great Britain and Germany; (2) scale Great Britain and German results to give an indicative estimate for Europe (EU27). The calculation methodology developed to estimate the benefit was based on 2 main steps: 1. Calculate the change in the impact speed distribution curve for pedestrian casualties hit by the fronts of cars assuming pedestrian autonomous emergency braking (AEB) system fitment. 2. From this, calculate the change in the number of fatally, seriously, and slightly injured casualties by using the relationship between risk of injury and the casualty impact speed distribution to sum the resulting risks for each individual casualty. The methodology was applied to Great Britain and German data for 3 types of pedestrian AEB systems representative of (1) currently available systems; (2) future systems with improved performance, which are expected to be available in the next 2-3 years; and (3) reference limit system, which has the best performance currently thought to be technically feasible. RESULTS: Nominal benefits estimated for Great Britain ranged from £119 million to £385 million annually and for Germany from 63 million to 216 million annually depending on the type of AEB system assumed fitted. Sensitivity calculations showed that the benefit estimated could vary from about half to twice the nominal estimate, depending on factors such as whether or not the system would function at night and the road friction assumed. Based on scaling of estimates made for Great Britain and Germany, the nominal benefit of implementing pedestrian AEB systems on all cars in Europe was estimated to range from about 1 billion per year for current generation AEB systems to about 3.5 billion for a reference limit system (i.e., best performance thought technically feasible at present). Dividing these values by the number of new passenger cars registered in Europe per year gives an indication that the cost of a system per car should be less than â¼80 to â¼280 for it to be cost effective. CONCLUSIONS: The potential benefit of fitting AEB systems to cars in Europe for pedestrian protection has been estimated and the results interpreted to indicate the upper limit of cost for a system to allow it to be cost effective.
Asunto(s)
Accidentes de Tránsito/prevención & control , Automóviles/normas , Desaceleración , Urgencias Médicas , Equipos de Seguridad , Caminata/lesiones , Heridas y Lesiones/prevención & control , Análisis Costo-Beneficio , Europa (Continente) , Alemania , Humanos , Equipos de Seguridad/economía , Riesgo , Reino UnidoRESUMEN
OBJECTIVE: It is commonly agreed that active safety will have a significant impact on reducing accident figures for pedestrians and probably also bicyclists. However, chances and limitations for active safety systems have only been derived based on accident data and the current state of the art, based on proprietary simulation models. The objective of this article is to investigate these chances and limitations by developing an open simulation model. METHODS: This article introduces a simulation model, incorporating accident kinematics, driving dynamics, driver reaction times, pedestrian dynamics, performance parameters of different autonomous emergency braking (AEB) generations, as well as legal and logical limitations. The level of detail for available pedestrian accident data is limited. Relevant variables, especially timing of the pedestrian appearance and the pedestrian's moving speed, are estimated using assumptions. The model in this article uses the fact that a pedestrian and a vehicle in an accident must have been in the same spot at the same time and defines the impact position as a relevant accident parameter, which is usually available from accident data. The calculations done within the model identify the possible timing available for braking by an AEB system as well as the possible speed reduction for different accident scenarios as well as for different system configurations. RESULTS: The simulation model identifies the lateral impact position of the pedestrian as a significant parameter for system performance, and the system layout is designed to brake when the accident becomes unavoidable by the vehicle driver. Scenarios with a pedestrian running from behind an obstruction are the most demanding scenarios and will very likely never be avoidable for all vehicle speeds due to physical limits. Scenarios with an unobstructed person walking will very likely be treatable for a wide speed range for next generation AEB systems.