Airbag Deployment Research Articles

A late and failure of airbag deployment case study for drivers of passenger cars in rear-end collisions

The presented study was directed at two types of airbag miss-deployments: late deployment and non-deployment. Late deployment can be a product of override or underride road traffic accidents. Non-deployment can be a product of technical failure or trigger algorithm’s inability to correctly assume the state of the accident to happen. In order to analyse the phenomena through physical tests, a specialized test device was used for a series of 8 non-deployment tests and a series of 4 airbag firing tests, totalling 12 tests. Acceleration based data was recorded and analysed for the movement of the device part simulating the driver head. High speed video recording was used to analyse the mechanics of airbag deployment and correlate with the acceleration based data. It has been determined, in the limitations of the laboratory testing environment, a significant variation of the time frame for the airbag deployments, despite using similar testing conditions and identical tested products. Also, the initial time frame for airbag deployment delay was overshadowed by other factors such as time to impact.

Automotive IC probing challenges –FFI MEMS Technology meets and exceeds expectation

The IC content in automobiles has been steadily increasing for the last twenty years. Emerging automotive applications in the areas of mobile connectivity, automotive safety and electrically powered vehicles are expected to drive semiconductor content well beyond its historic level. Many of these new applications, especially those around automotive safety and electrical power will require extremely high levels of performance and reliability in harsh operating environments. FormFactor and Texas Instruments recently collaborated in a study designed to address new testing challenges presented by these applications. This paper discusses select results from the study.The automotive sector is one of the fastest growing segments in the semiconductor industry. It is projected to outpace established sectors, such as the computer and consumer segments, over the next several years. Per an IC INSIGHTS report [1], the automotive industry is expected to expand at a regular pace of 4.9% from 2015–2020. As shown in Figure 1, the automotive segment is predicted to grow faster than any other semiconductor segment during this time.One of the main reasons for this notable automotive segment growth is that the automotive industry, worldwide, is undergoing some profound changes that are driving an increased dependence on semiconductors. The demand for increasingly versatile electronic systems listed below are believed to be key drivers. These include:Per the World Semiconductor trade statistics [2], the increasing semiconductor content in automobiles will drive the worldwide automotive semiconductor market from its all-time high of $29 billion in 2014 to $44 billion by 2019. This level of growth makes the automotive market highly attractive to many semiconductor manufacturers, since it is being steadier and less cyclical than the consumer and mobile semiconductor markets. This growth outlook is, in part, predicated on the assumption that the future vision of driverless and fully automated cars will soon become reality.These new automotive electronic systems will require specialized ICs that have been tested to guarantee the highest levels of performance and reliability. These various applications will require a range of IC including below examples:ICs used in automotive applications must adhere to the highest performance and quality standards to ensure the safety of both the driver and passengers. Thus, ICs used in these applications must be tested more rigorously and under more extreme conditions than ICs used in most mobile and consumer applications.The electronics incorporated into an automobile, or one of its subsystems, will be expected to operate in a much wider range of temperatures than most mobile consumer devices will experience. A smart phone, for an example, is practically attached to our hands most of our waking hours and, often, is used in an air-conditioned environment. In contrast, cars are used in an outdoor environment. A car's interior can experience a temperature range of −40 to 125°C. In addition, the “hidden” electronics that are mounted under the hood and control the engine, electric power steering, airbag deployment and anti-lock brakes often operate at ambient temperatures of 150°C or higher.When it comes to the deploying electronics, the automotive industry expects zero defects, both for safety and economic reasons. IC manufacturers participating in that sector are expected to use Parts per Million (DPPM) design methodology and manufacture their products using a zero-defect process technology that minimizes early life failures and ensures long MTBF. A 1 ppm IC failure rate can translate to a 1.5% or 15,000 ppm failure rate at the automotive level. Even that low rate can result in a massive recall and serious economic loss for an automotive manufacturer. Thus, automotive IC suppliers are strongly motivated to achieve the goal of zero defects if they want to maintain or grow their share of the automotive IC market.The need for zero defects and the harsh automotive environment create certain challenges for back-end wafer test probing. FormFactor have worked together to address some of these challenges. The two biggest issues concern maintaining thermal agility for wide temperature range probing, and ensuring minimum pad damage with no dielectric punch-through. This section will discuss those challenges and how they were addressed.Emerging automotive applications in the areas of safety, connectivity and electrical power are likely to be the next big area of growth for the semiconductor industry. Many of these new applications, however, present unique challenges for wafer testing automotive ICs, due to formidable dynamics like wide temperature ranges and stringent under-pad cracking requirements to ensure “zero defect” IC performance goals. This study—found that low-force vertical MEMS probe technology and advanced probe card construction design techniques can help to overcome the challenges, while improving production flexibility and uptime.

GLASS Clinical Decision Rule Applied to Thoracolumbar Spinal Fractures in Patients Involved in Motor Vehicle Crashes.

IntroductionThere are established and validated clinical decision tools for cervical spine clearance. Almost all the rules include spinal tenderness on exam as an indication for imaging. Our goal was to apply GLASS, a previously derived clinical decision tool for cervical spine clearance, to thoracolumbar injuries. GLass intact Assures Safe Spine (GLASS) is a simple, objective method to evaluate those patients involved in motor vehicle collisions and determine which are at low risk for thoracolumbar injuries.MethodsWe performed a retrospective cohort study using the National Accident Sampling System-Crashworthiness Data System (NASS-CDS) over an 11-year period (1998–2008). Sampled occupant cases selected in this study included patients age 16–60 who were belt-restrained, front- seat occupants involved in a crash with no airbag deployment, and no glass damage prior to the crash.ResultsWe evaluated 14,191 occupants involved in motor vehicle collisions in this analysis. GLASS had a sensitivity of 94.4% (95% CI [86.3–98.4%]), specificity of 54.1% (95% CI [53.2–54.9%]), and negative predictive value of 99.9% (95% CI [99.8–99.9%]) for thoracic injuries, and a sensitivity of 90.3% (95% CI [82.8–95.2%]), specificity of 54.2% (95% CI [53.3–54.9%]), and negative predictive value of 99.9% (95% CI [99.7–99.9%]) for lumbar injuries.ConclusionThe GLASS rule represents the possibility of a novel, more-objective thoracolumbar spine clearance tool. Prospective evaluation would be required to further evaluate the validity of this clinical decision rule.

Injury Patterns Sustained in Fatal Motor Vehicle Collisions with Driver's Third-Generation Airbag Deployment.

The Office of the Chief Coroner for Ontario database for 2011-2012 was used to compare fatal injury patterns in drivers whose third-generation airbags deployed compared to first- and second-generation airbag deployments and airbag nondeployments with and without seatbelt use. There were 110 frontal and offset frontal crashes analyzed. The small sample size meant that the odds of craniocerebral, cervical spinal, thoracic, and abdominal injuries were not statistically different for airbag generation, deployment status, and seatbelt use; however, the risk of fatal thoracic injuries in third- and second-generation cases was increased. Seatbelt usage in third- and second-generation deployment cases reduced the risk of all injuries except abdominal trauma. High severity impacts and occupant compartment intrusion were frequently observed. The analyses in this retrospective study were challenged by data that were not collated in a standardized way and were limited in details about scene, vehicle, and driver variables.

Association between seatbelt sign and internal injuries in the contemporary airbag era: A retrospective cohort study

BackgroundLiterature predating routine availability of airbags reported an association between seatbelt signs and internal injuries. We measured this association among patients involved in motor vehicle crashes (MVCs) with airbag deployment. MethodsWe conducted a retrospective cohort study by chart review of all MVC patients presenting to our Emergency Department (ED) during 1 January 2008–30 September 2015. We included all adult MVC patients in the driver or front passenger seats with both shoulder and lap seatbelts and airbag deployment. Two trained chart abstractors recorded data regarding restraints and airbag deployment. We obtained all other data via electronic medical record abstraction including demographics, injuries, and survival. We compared the prevalence of cervicothoracic and intra-abdominopelvic injuries between patients with a documented seatbelt sign versus no seatbelt sign using a logistic regression model. ResultsOf 1379 MVC patients, 350 met inclusion criteria. Of these, 138 (39.4%) had a seatbelt sign. The prevalence of cervicothoracic injury was higher among subjects with a documented seatbelt sign (54.3% versus 42.9%, p=0.036) Seatbelt sign predicted cervicothoracic injury with a positive likelihood ratio of 1.3 (95% CI 1.0–1.7) and negative likelihood ratio of 0.8 (95% CI 0.7–1.0). The odds ratio of cervicothoracic injury among patients with a seatbelt sign versus no seatbelt sign was 1.58 (95% confidence interval 1.02–2.46) in the logistic regression model. There was no association between seatbelt sign and intra-abdominopelvic injury (p=0.418). ConclusionsIn the setting of airbag deployment, there is an association between seatbelt sign and cervicothoracic injury but not intra-abdominopelvic injury.

Repeatability testing of a new Hybrid III 6-year-old ATD lower extremity

ABSTRACTObjective: Vehicle safety is improving, thus decreasing the number of life-threatening injuries and increasing the need for research in other areas of the body. The current child anthropomorphic test device (ATD) does not have the capabilities or instrumentation to measure many of the potential interactions between the lower extremity and the vehicle interior. A prototype Hybrid III 6-year-old ATD lower extremity (ATD-LE) was developed and contains a tibia load cell and a more biofidelic ankle. The repeatability of the device has not yet been assessed; thus, the objective was to evaluate the repeatability of the ATD-LE. Additionally, a dynamic assessment was conducted to quantify injury threshold values.Methods: A pneumatic ram impactor was used at 2 velocities to evaluate repeatability. The ATD-LE was fixed to a table and impacted on the plantar aspect of the forefoot. Three repeated trials at 1.3 and 2.3 m/s without shoes and 2.3 m/s with shoes were conducted. The consistency of tibia force (N), bending moment (Nm), ankle range of motion (ROM, °), and stiffness (Nm/°) were quantified. A dynamic assessment using knee bolster airbag (KBA) tests was also conducted. The ATD-LE was positioned to mimic 3 worst-case scenarios: toes touching the mid-dashboard, touching the lower dashboard, and flat on the floor prior to airbag deployment. The impact responses in the femur and tibia were directly collected and compared with published injury threshold values.Results: Ram impact testing indicated primarily excellent repeatability for the variables tested. For all 3 conditions the coefficients of variance (CV) were as follows: tibia force, 1.9–2.7%; tibia moment, 1.0–2.2%; ROM, 1.3–1.4%; ankle stiffness, 4.8–15.6%. The shoe-on condition resulted in a 25% reduction in tibia force and a 56% reduction in tibia bending moment. The KBA tests indicate that the highest injury risk may be when the toes touch the lower dashboard, due to the high bending moments recorded in the tibia at 76.2 Nm, which was above the injury threshold.Conclusions: The above work has demonstrated that the repeatability of the ATD-LE was excellent for tibia force, bending moment, and ankle ROM. The ATD-LE has the ability to provide new information to engineers and researchers due to its ability to directly evaluate the crash response of the ankle and leg. New information on injury mechanism and injury tolerance may lead to injury reduction and thus help advance the safety of children.

Severe soft tissue injuries of the upper extremity in motor vehicle crashes involving partial ejection: the protective role of side curtain airbags

IntroductionPartial ejection (PE) of the upper extremity (UE) can occur in a motor vehicle crash (MVC) resulting in complex and severe soft tissue injuries (SSTI). This study evaluated the relationship between partial ejection and UE injuries, notably SSTIs, in MVCs focusing on crash types and characteristics, and further examined the role of side curtain airbags (SCABs) in the prevention of partial ejection and reducing SSTI of the UE. MethodsWeighted data was analyzed from the National Automotive Sampling System Crashworthiness Data System (NASS-CDS) from 1993 to 2012. Logistic regression models were used to assess the relationship of PE with SSTI of the UE and the effect of SCABs in both nearside impacts and rollover collisions. Crash Injury Research and Engineering Network (CIREN) case studies illustrated PE involving SSTI of the UE, and long term treatment. ResultsRollover and nearside impact collisions had the highest percentages of partial ejection, with over half occurring in rollover collisions. Annually over 800 SSTIs of the UE occurred in all MVCs. For nearside lateral force impacts, a multivariable analysis adjusting for belt use and delta V showed a 15 times (OR 15.35, 95% CI 4.30, 54.79) greater odds of PE for occupants without SCABs compared to those with a SCAB deployment. No occupants (0 of 51,000) sustained a SSTI of the UE when a SCAB deployed in nearside impacts, compared to 0.01% (114 of 430,000) when SCABs were unavailable or did not deploy. In rollover collisions, a multivariable analysis adjusted for number of quarter turns and belt use showed 3 times the odds (OR 3.02, 95% CI 1.22, 7.47) of PE for occupants without SCABs compared to those with a SCAB deployment. Just 0.17% (32 of 19,000) of the occupants sustained a SSTI of the UE in rollovers with a SCAB deployment, compared to 0.53% (2294 of 431,000) of the occupants when SCABs were unavailable or did not deploy. CIREN case studies illustrated the injury causation of SSTI of the UE due to partial ejection, and the long term treatment and medical costs associated with a SSTI to the UE. ConclusionsThe majority of severe soft tissue injuries (SSTI) of the upper extremity (UE) involved partial ejection out the nearside window of outboard seated occupants in nearside impacts and rollover collisions. Real world case studies showed that SSTIs of the upper extremity require extensive treatment, extended hospitalization and are costly. Occupants without a side curtain airbag (SCAB) deployment had an increase in the odds of partial ejection. SCAB deployments provided protection against partial ejection and prevented SSTIs of the UE, with none occurring in nearside impacts, and a small percentage and reduction occurring in rollover collisions compared to those where SCABs were unavailable or did not deploy.

Airbag deployment–related eye injuries

ABSTRACTObjective: We studied the correlation between airbag deployment and eye injuries using 2 different data sets.Methods: The registry of the Finnish Road Accident (FRA) Investigation Teams was analyzed to study severe head- and eyewear-related injuries. All fatal passenger car or van accidents that occurred during the years 2009–2012 (4 years) were included (n = 734). Cases in which the driver's front airbag was deployed were subjected to analysis (n = 409). To determine the proportion of minor, potentially airbag-related eye injuries, the results were compared to the data for all new eye injury patients (n = 1,151) recorded at the Emergency Clinic of the Helsinki University Eye Hospital (HUEH) during one year, from May 1, 2011, to April 30, 2012.Results: In the FRA data set, the unbelted drivers showed a significantly higher risk of death (odds ratio [OR] = 5.89, 95% confidence interval [CI], 3.33–10.9, P = 2.6E-12) or of sustaining head injuries (OR = 2.50, 95% CI, 1.59–3.97, P = 3.8E-5). Only 4 of the 1,151 HUEH patients were involved in a passenger car accident. In one of the crashes, the airbag operated, and the belted driver received 2 sutured eye lid wounds and showed conjunctival sugillation. No permanent eye injuries were recorded during the follow-up. The calculated annual airbag-related eye injury incidence was less than 1/1,000,000 people, 4/100,000 accidents, and 4/10,000 injured occupants.Conclusions: Airbag-related eye injuries occurred very rarely in car accidents in cases where the occupant survived and the restraint system was appropriately used. Spectacle use did not appear to increase the risk of eye injury in restrained occupants.

Numerical modelling and experimental analysis of the passenger side airbag deployment in out-of-position

ABSTRACTIn recent years, many accidents happened with passengers who were out of position when their airbag deployed. Therefore, new safety regulations have come into effect and an airbag now has to meet several requirements that concern out of positioning. In meeting these requirements, simulations of folding and deploying airbags are very useful and are widely used. This paper presents a simulation method for the deploying airbags using three materials in different working conditions. The main aim of this study is evaluate the performance of deploying of passenger side airbag using finite-element methods (FEMs). The model has been validated with experimental tests specifically designed for this task. Although the analysis was limited to linear elastic model, excellent agreements were obtained.

Safety of the rear seat passenger: the importance of a new legislation

The enforcement of law for the front seat occupants to wear seat belts and timely deployment of air bags during crashes has unquestionably reduced front seat occupant morbidity and fatality. However, law does not impose any regulation for the rear seat passengers to wear seat belts in Sri Lanka. As a result an increased incidence of rear seat passenger fatality in high speed crashes is observed in forensic practice. This communication presents four unrestrained rear seat passenger fatalities, in two similar crashes. Imposing of regulations in Sri Lanka to wear seatbelts for rear passengers is strongly recommended as it minimizes fatalities/injuries, not only in rear seat passengers but in all the occupants of a vehicle.

Computational investigation of the effects of knee airbag design on the interaction with occupant lower extremity in frontal and oblique impacts

ABSTRACTObjective: The lower extremity of the occupant represents the most frequently injured body region in motor vehicle crashes. Knee airbags (KABs) have been implemented as a potential countermeasure to reduce lower extremity injuries. Despite the increasing prevalence of KABs in vehicles, the biomechanical interaction of the human lower extremity with the KAB has not been well characterized. This study uses computational models of the human body and KABs to explore how KAB design may influence the impact response of the occupant's lower extremities.Methods: The analysis was conducted using a 50th percentile male occupant human body model with deployed KABs in a simplified vehicle interior. The 2 common KAB design types, bottom-deploy KAB (BKAB) and rear-deploy KAB (RKAB), were both included. A state-of-the-art airbag modeling technique, the corpuscular particle method, was adopted to represent the deployment dynamics of the unfolding airbags. Validation of the environment model was performed based on previously reported test results. The kinematic responses of the occupant lower extremities were compared under both KAB designs, 2 seating configurations (in-position and out-of-position), and 3 loading conditions (static, frontal, and oblique impacts). A linear statistical model was used to assess factor significance considering the impact responses of the occupant lower extremities.Results: The presence of a KAB had a significant influence on the lower extremity kinematics compared to no KAB (P <.05) by providing early restraint and distributing contact force on the legs during airbag deployment. For in-position occupants, the KAB generally tended to decrease tibia loadings. The RKAB led to greater lateral motion of the legs compared to the BKAB, resulting in higher lateral displacement at the knee joint and abduction angle change (51.2 ± 21.7 mm and 15° ± 6.0°) over the dynamic loading conditions. Change in the seating position led to a significant difference in occupant kinematic and kinetic parameters (P <.05). For the out-of-position (forward-seated) occupant, the earlier contact between the lower extremity and the deploying KAB resulted in 28.4° ± 5.8° greater abduction, regardless of crash scenarios. Both KAB types reduced the axial force in the femur relative to no KAB. Overall, the out-of-position occupant sustained a raised axial force and bending moment of the tibia by 0.8 ± 0.2 kN and 21.1 ± 8.7 Nm regardless of restraint use.Conclusions: The current study provided a preliminary computational examination on KAB designs based on a limited set of configurations in an idealized vehicle interior. Results suggested that the BKAB tended to provide more coverage and less leg abduction compared to the RKAB in oblique impact and/or the selected out-of-position scenario. An out-of-position occupant was associated with larger abduction and lower extremity loads over all occupant configurations. Further investigations are recommended to obtain a full understanding of the KAB performance in a more realistic vehicle environment.

A systematic review of otological injuries caused by airbag deployment

A systematic review of otological injuries caused by airbag deployment

Evaluating Airbag Safety Vests for Equestrian Sports

Abstract Thoracic injuries are common in equestrian sports. Advanced safety equipment, including airbag vests, have been introduced to the market to protect this body region. Standard EN13158 [“Protective Clothing—Protective Jackets, Body and Shoulder Protectors for Equestrian Use: For Horse Riders and Those Working with Horses, and for Horse Drivers—Requirements and Test Methods,” European Committee for Standardization, Brussels, 2009 (in German)] defines the minimum requirements for conventional safety vests; however, there is currently no standard related to airbag vests for equestrian sports. The aim of this study is to investigate the applicability of a draft motorcycling standard [prEN1621-4, “Motorcyclists' Protective Clothing Against Mechanical Impact. Part 4: Motorcyclists' Inflatable Protectors—Requirements and Test Methods,” Deutsches Institut für Normung e.V., Berlin, 2010 (in German)] for equestrian airbag vests. Based on EN13158 and prEN1621-4, airbag vests for equestrian sports were tested. In addition to the tests outlined in the above standards, the pressure induced by the inflating airbag on the thorax was measured and the sound level of the deploying airbag was recorded. The use of airbag vests in conjunction with conventional vests was also investigated. Testing airbag vests in accordance with the existing standards was possible without practical issues. The impact tests indicated that airbag vests were able to absorb higher forces compared to conventional vests. The airbag inflation times were recorded to be between 186 and 260 ms. Trigger forces were measured to be between 150 and 593 N. The maximum pressure on the upper body resulted in 20 to 84 kPa. The bang associated with airbag deployment generated a sound level of 87.3 to 98.4 dB(A). The degree of protection offered by airbag vests was demonstrated by applying the procedures prescribed in existing standards. The draft standard for motorcycling proved to be applicable to equestrian sports. However, regarding the interpretation of the test results, it seems necessary to adapt several threshold values of this standard to account for equestrian-specific parameters.

Facial bone fracture with dental injuries from a 4-WD air bag deployment: A case report in Qatar

Background: Injuries from air bag deployment have long been documented and studied like orbital blowout fractures, auditory injuries, etc. However, we report here a case of an alveolar process fracture associated with dental injuries and clear history of face-to-air bag impact only, which has rarely been documented and hence important to be reported. Case report: A 25-year old female front-seat passenger was involved in a head-on collision between her large four-wheel drive vehicle and another similar-sized vehicle. She was unrestrained and suffered facial and dental pain after the air bag was deployed. She denied hitting the dashboard or losing her consciousness. On examination, there was mild skin erythema associated with marked tenderness over her left maxilla and left upper jaw. Her upper left medial incisor was missing, while the lateral incisor and adjacent canine seemed to have been pushed upwards and embedded in their respective sockets. No other injury was elicited and she remained vitally stable. X-ray and CT scan imaging confirmed an alveolar bone fracture with upward displacement of the alveolar margin of the maxilla. Loss of medial upper left incisor, and impaction of the adjacent lateral incisor and canine teeth in the soft tissues at the left naso-labial fold, antero-lateral to the left nasolacrimal bones were also noted. Discussion: It is important to report these to be included in the potential range of injuries associated with air bag impact MVC. It will help widen the physicians range of possible injuries while evaluating an air bag impact MVC patient, hence aiding diagnosis and management. It will also help in the ongoing research for further modifying the techniques and types of protective devices currently used in vehicles to help prevent such injuries, as well as further highlighting the use of restraint along with use of such devices.

Optimized low-risk deployment of a passenger airbag with a passenger protection wrap considering pressure dispersion

The airbag is an occupant protection device widely used in the automotive industry. Federal Motor Vehicle Safety Standard 208 requires the low-risk deployment airbag system to be utilized in vehicles to protect out-of-position occupants. This paper presents a design-for-six-sigma low-risk deployment passenger airbag optimized by adding a passenger protection wrap. The passenger protection wrap reduces the cushion impact force on the passenger by ensuring pressure dispersion. A series of static tests were conducted to demonstrate the proposed system using Federal Motor Vehicle Safety Standard 208 test procedures. The test results shows that the proposed passenger airbag satisfies the criteria established by Federal Motor Vehicle Safety Standard 208 and also presents a significant improvement over conventional airbag systems.

DESIGNING OF DRIVER BEHAVIOR MODEL AND ITS DATA ANALYSIS FOR VEHICULAR APPLICATIONS

Design and Implementation of Evidence Collection System from Event Data Recorder”, deals with collection of Evidence for accident analysis. These evidences are in form of graphs. It includes graph of Speed Vs Time, Engine Temperature Vs Time, Distance Vs Time, Brake Pressure Vs Time, Engine Speed (RPM) Vs Time, Impact Vs Time and Tire Pressure Vs Time. Also it provides single graph merged with all these parameters at the time of accident. One more advantage of system is that, it can also provide Driver Behavior Model. By using this, driver’s driving performance could be found out. This system is nothing but the GUI constructed using Microsoft Visual Studio. All graphs are plotted using this Graphical User Interface. For Data Analysis purpose, B-tree algorithm is used here. Its performance for secondary storage devices and huge data handling capacity makes it more efficient. Data recorded by Event Data Recorder is used here as input. Event Data Recorder is also called as Black box of vehicles. It records vehicular data like speed, date, time, location (latitude, longitude), alcohol content of driver, airbag deployment etc. This data plays an important role detection and analysis of accident if any persists. These EDR are controlled by processors for very accurate operations.

Detection of airbag impact-induced cone photoreceptor damage by adaptive optics scanning laser ophthalmoscopy: a case report

BackgroundThe purpose of this study was to report a case of traumatic maculopathy with para-central visual field defects following an impact by airbag deployment using adaptive optics scanning laser ophthalmoscopy (AO-SLO).Case presentationA 51-year-old man was involved in a motor vehicular accident and his left eye was struck by the deployed airbag, resulting in a para-central scotoma. The patient underwent a full ophthalmologic examination, spectral-domain optical coherence tomography (SD-OCT), and imaging with prototype AO-SLO systems (Canon Inc.) at 14 and 22 months after the injury. Images focused on the photoreceptor layer were recorded in the foveal area, and a montage of AO-SLO images was created. On AO-SLO, focal dark areas could be observed in the left eye at 14 months after the injury. The analysis showed that the cone mosaic (cone density, 16503/mm2; ratio of hexagonal Voronoi domain, 36.3 %; average nearest-neighbor distance (NND)/expected NND, 0.606) was disordered compared with the normal area of the same eye (cone density, 24821/mm2; ratio of hexagonal Voronoi domain, 44.1 %; average NND/expected NND, 0.739). The cone defect area corresponded to the area of the scotoma. A second AO-SLO was performed on the patient at 22 months after the injury and although there were still areas with reduced cone reflectivity, partial improvement of cone mosaic was detected by AO-SLO at this time point.ConclusionPartial recovery of damaged cone photoreceptors following closed globe blunt ocular trauma can be documented using AO-SLO longitudinal tracking.

Analysis of driver injury severity in wrong-way driving crashes on controlled-access highways

For more than five decades, wrong-way driving (WWD) has been notorious as a traffic safety issue for controlled-access highways. Numerous studies and efforts have tried to identify factors that contribute to WWD occurrences at these sites in order to delineate between WWD and non-WWD crashes. However, none of the studies investigate the effect of various confounding variables on the injury severity being sustained by the at-fault drivers in a WWD crash. This study tries to fill this gap in the existing literature by considering possible variables and taking into account the ordinal nature of injury severity using three different ordered-response models: ordered logit or proportional odds (PO), generalized ordered logit (GOL), and partial proportional odds (PPO) model. The findings of this study reveal that a set of variables, including driver’s age, condition (i.e., intoxication), seatbelt use, time of day, airbag deployment, type of setting, surface condition, lighting condition, and type of crash, has a significant effect on the severity of a WWD crash. Additionally, a comparison was made between the three proposed methods. The results corroborate that the PPO model outperforms the other two models in terms of modeling injury severity using our database. Based on the findings, several countermeasures at the engineering, education, and enforcement levels are recommended.

Retinal Tear Related to Air Bag Deployment

Retinal Tear Related to Air Bag Deployment

A comparison of contributing effects on 2-vehicle alcohol-related crashes between impaired and nonimpaired operators

ABSTRACTObjective: Driving under the influence of alcohol is a crime that places the lives of all motorists in danger. Though it is a largely preventable act, impaired driving has accounted for 31 to 38% of fatal crashes across the country over the last decade. When an impaired operator crashes his or her vehicle, there is often a second unit, of which the operator is not impaired, involved in the crash.Methods: This research looks at approximately 14,000 2-unit crashes involving an impaired operator in the State of Ohio from 2008 through 2012. The research is focused on determining the effects of crash and operator characteristics in 2-unit alcohol-related crashes through the use of 2 mixed logit models.Results: It is found that several factors have similar effects on the injury severities of both the impaired and nonimpaired operators, including head-on crashes, the use of seat belts, and the deployment of airbags. There are, however, several factors that affect the 2 operators differently. It is found that the impaired operator's injury severity is based on the type and, more important, the size of the vehicle he or she is driving, the roadway geometry, and the speed of the vehicle driven by the nonimpaired operator. The nonimpaired operator is equally affected by the speed of the impaired vehicle as much as his or her own speed, and the nonimpaired operator's injury severity is virtually independent of the type of vehicle being driven.Conclusions: Researchers may disseminate the results to community groups such as Mothers Against Drunk Driving and Safe Communities to increase awareness of the dangers of drunk driving in an effort to reduce the number of alcohol-related crashes.