[Enhanced automatic collision notification system. First field experience]. / Automatische Unfallmelder. Erste Erfahrungen aus der Anwendung.

Motor vehicle accidents are the leading cause of severe injuries. Outcome of these victims is substantially influenced by rescue time and primary trauma centre care. Nowadays, automatic crash notification systems (ACN) are available offering the major possibility of immediate initiation of the rescue chain and thereby shortening rescue time up to 50%. According to the EU commission a nationwide equipping of motor vehicles with automatic crash notification systems could save up to 2,500 lives per year. Therefore, all new vehicles should be equipped with an automatic crash notification system by 2014. BMW is the first manufacturer to install an enhanced automatic crash notification system (eACN), which could optimize the rescue triage by estimating the risk for severe injuries (MAIS3+) based on telemetric transmitted accident data.

The SceneScore for improved pre-hospital triage of motor-vehicle crash victims.

The SceneScore is a simple mechanism of injury scoring system designed to facilitate the appropriate triage of crash victims. It comprises 7 variables including age, collision type, impact location, airbag deployment, steering wheel deformity, intrusion, and restraint use. A cutoff value of 7 or 8 provides the maximum balance between sensitivity and specificity, with sensitivities of 75% to 83% and specificities of 29% to 46%. For cases triaged to the trauma center based only on high suspicion of injury, the SceneScore reduces the overtriage rate by almost half. Proper application of the SceneScore may lead to improved triage and enhanced communication of mechanism of injury criteria.

Age appropriate restraints for the right front passenger.

This study applies NASS/CDS, GES and FARS data to examine occupant exposure plus injury and fatality rates for belted occupants in frontal crashes by seating position, age and gender. The NASS data was used to examine the distributions by crash severity. The GES data showed that when two elderly occupants (age 65+) were present, the female occupied the right front passenger position 73% of the time. A paired comparison analysis using FARS data showed that, for elderly occupants (age 65+), the fatality risk for elderly right front passengers is 42% higher than for elderly drivers. The NASS/CDS analysis found 74% of the seriously injured vulnerable passengers with MAIS 3+ injuries were in crashes less severe than 26 mph. This group of injured occupants was made up of 43% aged 50 and older and 42% younger females. The injury rates for the older (age 50+) right front passengers were 1.8 times the rates for the elderly drivers. These results suggest the need for more benign safety systems for the right front passenger that are appropriate for the lower injury tolerance of the predominant occupants of that seating position.

Residual injuries after recent safety improvements.

This study examines the residual injuries reported in NASS/CDS 1997-2004 by crash mode, crash severity, body region and occupant age. It examines how serious injuries are distributed in present day crashes and identifies opportunities for further injury reduction. In planar crashes, approximately 66% of the MAIS 3+ injuries occur in crashes less severe than 25 mph delta-V. Chest injuries predominate in these crashes, particularly among elderly occupants. A reduction in chest injuries to belted elderly occupants during low severity frontal crashes offers a prime opportunity for further improvement of safety systems. Younger occupants could also benefit from improved chest protection.

Real world crash evaluation of vehicle stability control (VSC) technology.

This study quantifies the effect of Vehicle Stability Control (VSC) in reducing crash involvement rates for a subset of vehicles in the US fleet. Crash rates for a variety of impact types before and after VSC technology was implemented are compared. Police-reported crashes from six available US state files from 1998-2002 were analyzed including 13,987 crash-involved study vehicles not equipped with the technology and 5,671 crashes of vehicles equipped with VSC as a standard feature. Overall, an 11.2% (95% CI: 2.4%, 21.1%) reduction in multi-vehicle frontal crash involvement was identified for VSC-equipped vehicles. A 52.6% (95% CI: 42.5%, 62.7%) reduction in single-vehicle crash rates was found.

Investigation of the performance of safety systems for protection of the elderly.

This study investigates injury occurrence for belted occupants as a function of age. An analysis of NASS/CDS 1997-2003 data was conducted to determine crash involvement rates and injury rates for front seat occupants versus mean occupant age. In frontal and near-side crashes, the average age of MAIS 3+ belted front seat occupants injured in crashes less severe than 15 mph is of the order of 50 years. The average age of the population exposed to crashes less severe than 15 mph is under 40 years old. The crash exposure and frequency if injuries to the elderly were both found to be the highest in low severity crashes. The chest is the most frequent body region injured for the elderly. These findings suggest the need for more benign safety systems to protect the elderly in low severity crashes. Design of safety systems for the elderly should give priority to reducing the chest loading in low severity frontal and near-side crashes.

Frequency of injuries in multiple impact crashes.

NASS 1998-2000 was queried to determine the frequency of serious injuries in multiple impact crashes and the distribution of injuries by crash sequence. The data set included all passenger cars and light trucks in NASS/CDS. The results showed that 42% of the MAIS 3+ injuries were in crashes that involved more than one harmful event. Approximately 24% of the MAIS 3+ injuries involved two harmful events, and 18% involved 3 or more harmful events. For multiple crashes with serious injuries, the most frequent initial impact direction was frontal (50%) followed by side (44.9%). The most frequent second impact was side (48.4%) followed by frontal (27.6%). The most harmful sequences were side-side (27.7%), front-side (15.8%) and front-front (14.9). The data suggests the need for further investigation and classification complex multiple impact crashes to aid in the in the design of safety systems.

Validation of the urgency algorithm for near-side crashes.

The URGENCY algorithm uses vehicle crash sensor data in Automatic Crash Notification (ACN) systems to assist in instantly identifying crashes that are most likely to have time critical injuries. The algorithm also provides the capability of improving injury identification, using data obtained from the scene. The prime purpose of the algorithm is to automatically provide emergency medical responders with objective information on crash severity to assist in detecting the approximately 1% of crashes with serious injuries needing the most urgent medical care. The algorithm calculates the risk of a MAIS 3+ injury being present in the crashed vehicle, instantly at the time of the crash. The prediction can be subsequently updated as more information becomes available. The algorithm was based on a multiple regression analysis using data from the National Accident Sampling System/Crashworthiness Data System, (NASS/CDS) years 1988-95. In this paper, the accuracy of the algorithm was evaluated for near side crashes by applying it retrospectively to the population of injured occupants in NASS 1997-2000. URGENCY was applied to the population of injured occupants in near side crashes. Using an injury risk criterion of 50%, URGENCY identified 69% of the crashes with MAIS 3+ injuries. By lowering injury risk criterion to 40%, URGENCY identified 78% of the crashes with MAIS 3+ injuries. Vehicle side intrusion was found to be a highly influential variable. By changing side intrusion from a binary to a continuous variable, the correctly identified crashes increased from 69% to 81%. Examination of the consequence of missing variables found that unknown values of occupant height and weight had a negligible effect on the ability to capture the MAIS 3+ injured. However, lack of knowledge of these variables did increase the magnitude of the false positives.