Restraint Systems Research Articles

Child Occupant Safety: Towards Implementation of Child Restraint System Law in Malaysia


 
 
 The World Health Organization (WHO) has consistently recommended that all countries regardless of their income add the requirement for Child Restraint System (CRS) to their traffic regulations in order to promote road safety. Malaysia is adopting the CRS regulation in 2020. This paper aims to discuss the readiness and mapping of the roadmap towards the implementation of the law. In a temporal view of road crashes, CRS was part of 'during-crash' passive safety components i.e. to provide protection during the crash impact phase. This analysis includes the CRS benefits and issues, related road safety strategic programmes, the current legal framework, and local research findings based on observational studies. CRS usage and acceptance are on the rise, although still at a nascent stage. This situation can be considered as 'below satisfactory compliance level', hence a more inclusive solution is needed, including the introduction of technology, to influence or compel parents to ensure their children are always secured by CRS while on the road.
 
 

A Study on the Use and Misuse of Child Restraint System (CRS) in Malaysia


 
 
 In car crashes, children are more likely to suffer more severe injuries than adults. For prevention, Child Restraint System (CRS) is normally used. However, inappropriate use of CRS may exacerbate injury risks. This research aims to determine the prevalence of CRS use and misuse among car owners, especially those travelling with children aged 11 years and below. A total of 178 parents were interviewed and 267 children were observed. Overall, only 12.7% children were properly restrained in CRS for their size, with the correct installation and appropriate seating position. Prior to CRS law implementation, initiatives such as awareness campaigns, community based programs and CRS clinics should be introduced.
 
 

Dosimetric Assessment of a High Precision System for Mouse Proton Irradiation to Assess Spinal Cord Toxicity.

The uncertainty associated with the relative biological effectiveness (RBE) in proton therapy, particularly near the Bragg peak (BP), has led to the shift towards biological-based treatment planning. Proton RBE uncertainty has recently been reported as a possible cause for brainstem necrosis in pediatric patients treated with proton therapy. Despite this, in vivo studies have been limited due to the complexity of accurate delivery and absolute dosimetry. The purpose of this investigation was to create a precise and efficient method of treating the mouse spinal cord with various portions of the proton Bragg curve and to quantify associated uncertainties for the characterization of proton RBE. Mice were restrained in 3D printed acrylic boxes, shaped to their external contour, with a silicone insert extending down to mold around the mouse. Brass collimators were designed for parallel opposed beams to treat the spinal cord while shielding the brain and upper extremities of the animal. Up to six animals may be accommodated for simultaneous treatment within the restraint system. Two plans were generated targeting the cervical spinal cord, with either the entrance (ENT) or the BP portion of the beam. Dosimetric uncertainty was measured using EBT3 radiochromic film with a dose-averaged linear energy transfer (LETd) correction. Positional uncertainty was assessed by collecting a library of live mouse scans (n = 6 mice, two independent scans per mouse) and comparing the following dosimetric statistics from the mouse cervical spinal cord: Volume receiving 90% of the prescription dose (V90); mean dose to the spinal cord; and LETd. Film analysis results showed the dosimetric uncertainty to be ±1.2% and ±5.4% for the ENT and BP plans, respectively. Preliminary results from the mouse library showed the V90 to be 96.3 ± 4.8% for the BP plan. Positional uncertainty of the ENT plan was not measured due to the inherent robustness of that treatment plan. The proposed high-throughput mouse proton irradiation setup resulted in accurate dose delivery to mouse spinal cords positioned along the ENT and BP. Future directions include adapting the setup to account for weight fluctuations in mice undergoing fractionated irradiation.

Evaluation of Rotation Reduction Features in Infant and Extended-Use Convertible Child Restraint Systems during Frontal and Rear Impacts.

A correctly used child restraint system (CRS) is associated with a substantial reduction of injury and mortality risks in motor vehicle crashes and epidemiologic data suggests that toddlers are provided greater protection when restrained in a rearward-facing CRS compared to a forward-facing CRS. Some 'extended-use' European CRS models can accommodate children up to six years rearward-facing and have a support (load) leg and/or a pair of lower (Swedish) tethers to reduce rotation during frontal and rear impacts, respectively. Laboratory studies have found that a support leg reduces head and neck injury metrics of anthropomorphic test devices (ATDs) younger than three years in rearward-facing CRS models during frontal impacts. The objectives of the current study were to perform sled tests to: (1) evaluate the effects of using a support leg in rearward-facing infant and extended-use convertible CRS models during frontal impacts, (2) evaluate the effects of using a pair of lower tethers in a rearward-facing extended-use convertible CRS model during rear impacts and (3) compare responses of ATDs in an extendeduse convertible CRS with a support leg and a pair of lower tethers in rearward- and forward-facing configurations during frontal and rear impacts. The presence of a support leg in rearward-facing infant and extended-use convertible CRS models in frontal impacts was associated with reductions in head injury metrics across a range of pediatric ATDs and neck injury metrics were below injury tolerance values. Other strategies in the design of rearward-facing CRS and front row vehicle seatbacks may be available to further reduce head injury metrics. Lower tethers reduced the rearward rotation of an extended-use convertible CRS toward the vehicle seatback in rear impacts and were typically associated with reductions in head and neck injury metrics for the Q6 ATD, but not the Q3 ATD. For frontal impacts, neck injury metrics were typically greater for ATDs in the forward-facing extended-use convertible CRS, whereas head injury metrics were typically greater for the rearward-facing condition (with a support leg and a pair of lower tethers). Interactions of the ATD head and/or the rearward-facing extended-use convertible CRS with the blocker plate in rearward-facing frontal impacts need to be further investigated.

The association between vehicle rim type and risk of occupant injury

Objectives Modern vehicles generally use steel fabricated or alloy blended rims. The manufacturing process and atomic structure of the rim both yield different responses under destructive loading. The aim of this research was to investigate to what extend the type of vehicle rim may influence occupant injury risk. Methods A matched cohort study of frontal German In-Depth Accident Study collisions was devised. The risk of injury to various body regions was compared between vehicles with steel and alloy rims. Results Occupants in vehicles with alloy rims were at a greater risk of thoracic injury (relative risk [RR] = 1.57; 95% confidence interval [CI], 1.01–2.42) and thoracic abdomen injury (RR = 1.62; 95% CI, 1.10–2.39) at the Maximum Abbreviations Injury Scale (MAIS) 2+ severity. Risk of thoracic injury was greatest for the cluster of occupants seated on the nonimpacted side in frontal collisions (RR = 2.21; 95% CI, 1.01–4.86). MAIS 2+ injury to the head/face/neck yielded no association (RR = 0.98; 95% CI, 0.66–1.47). Conclusion Alloy rims are more brittle and, as a result, destructive loading is realized with less severe impact. The critical failure increases the amount of loading that needs to be distributed by the restraint system and results in injury.

Ride-Share Use and Child Passenger Safety Behaviors: An Online Survey of Parents.

Ride-share services are increasingly used for transportation, but little is known about ride-share use and passenger safety behaviors among parents of children for whom child restraint systems (CRS) are recommended. Our objectives were to characterize ride-share use with children and examine passenger restraint use in ride-share. A cross-sectional survey, distributed to the TurkPrime Parent Panel using Amazon Mechanical Turk (MTurk), was designed to assess ride-share and passenger safety behaviors. After screening, adult parents of minor children were invited to complete the full survey about transportation behaviors. Descriptive and chi-square statistics were calculated. Logistic regression was conducted to test for characteristics associated with suboptimal restraint use in ride-share. Of 655 screened parents, 162 had no minor children, 43 had incomplete responses or failed an attention check question. Of 450 parents with minor children, 309 (68.7%) used ride-share in the past year and 73.1% of parents who use ride-share did so with their child(ren). Ride-share use with children was most common on vacation. Among parents of children age ≤8 years, 49% reported always using their child's CRS when traveling in ride-share. Suboptimal restraint use in rideshare was associated with child age (3-8 years compared with <3 years), larger family size, and attitudes and behaviors that tolerate suboptimal CRS use. This study identifies an opportunity to promote use of CRS in ride-share services. Child passenger safety messaging, education, policy, enforcement of legislation, and CRS design will need to be adapted as ride-share services become more widely adopted.

Driver posture monitoring in highly automated vehicles using pressure measurement

Objective Driver posture monitoring is useful for evaluating the readiness to take over from highly automated driving systems as well as for designing intelligent restraint systems to reduce injury. The aim of this study was to develop a real-time and robust driver posture monitoring system using pressure measurement. Methods Driver motion and pressure measurement were collected from 23 differently sized participants performing 42 driving and non-driving activities. Nine typical driver postures were identified by analyzing trunk and feet positions in 3 D space for classification. One deep learning classifier and two Random Forest classifiers were trained respectively on pressure distribution, absolute and relative pressure features extracted from pressure measurement. Leave-One-Out cross-validation was performed to evaluate the performance of the classifiers. Results Without considering feet positions, all the classifiers could provide reliable recognition of the normal trunk position for standard driving with an accuracy around 98%. With help of a reference sitting position, the best performance was achieved by Random Forest classifier trained on the relative pressure features with an average classification accuracy of 80.5% across 9 typical postures and 23 drivers. The main errors were related to the recognition of feet positions when applying braking and relaxing both feet on the floor. Conclusions Pressure measurement could be a good alternative or complementary to camera based driver postural monitoring system. Results show that all classifiers proposed in the work could predict the trunk position for standard driving. With help of an initial posture, Random Forest classifier with relative pressure features could classify trunk positions with high accuracy. However, further effort is needed to improve the accuracy of feet position prediction especially by adding more foot related task data.

Evaluating disparities in child occupant protection using a proportion-eliminated approach to mediation

Objective While there are clear racial/ethnic disparities in child restraint system (CRS) use, to date no studies have identified mediators that quantitatively explain the relationship between race and CRS use. Therefore, the objective of this study was to provide an example of how a proportion-eliminated approach to mediation may be particularly useful in understanding the complex relationship between race and CRS use. Methods Sixty-two mothers with a child between 4-8 years old completed a survey and had their CRS use assessed by a Child Passenger Safety Technician using a structured assessment based on the 2018 American Academy of Pediatrics’ Best Practice guidelines. Recruitment and data collection occurred in Birmingham, Alabama between June 2018 and January 2019. We used chi-squared tests, logistic regressions, and a proportion-eliminated approach to mediation to compare our variables of interest and to estimate the amount of the association between racial group membership and errors in restraint use that may be explained by sociodemographic, psychosocial, and parenting variables. Results Before mediation, Nonwhite mothers in this sample had a 7.38 greater odds of having an error in CRS use than White mothers. Mediation analyses indicated that being married and self-reported seatbelt use explained 47% and 35% of the effect of race on CRS use errors, respectively. Conclusion A proportion-eliminated approach to mediation may be particularly useful in child passenger safety research aiming to inform the development of interventions tailored for racial minority populations.

So much nuance: A qualitative analysis of parental perspectives on child passenger safety

Objective To explore barriers and facilitators to optimal child restraint system (CRS) use for diverse parents of newborn infants and to obtain input from parents on the use of technology-assisted remote car seat checks as tools for promoting optimal CRS use. Methods Parents were recruited using purposive sampling. Interviews were conducted with English- or Spanish-speaking parents with a full term newborn and regular access to a car. Interviews were conducted by phone, and recorded and transcribed verbatim. Interviews were conducted until thematic saturation was reached. Data were organized for analysis using Atlas.ti, and codes grouped by theme using constant comparison. Results 30 parents were enrolled. Barriers and facilitators to optimal CRS use were classified into three themes, as were thoughts on the pros and cons regarding remote car seat checks. Themes on barriers and facilitators included motor vehicle and CRS features (such as age and size of the motor vehicle and presence of the Lower Anchors and Tethers for Children LATCH system), resources (availability, accessibility, and accuracy of resources), and parental factors (parental emotions and characteristics). Themes related to pros and cons of remote car seat checks included the ability (and challenge) of remote car seat checks to identify and correct errors, the potential use of remote car seat checks in certain situations (such as CRS transitions and periods of growth), and convenience of remote car seat checks (including increased availability and ease of access). Subthemes with further detail were arranged within each theme identified. Conclusion From a parent perspective, there are several identified barriers and facilitators of optimal CRS use. Although car seat checks were identified as a resource, in-person accessibility was an issue, and there were mixed opinions on technology-assisted remote car seat checks. These results provide a foundation for additional study on targeted interventions, including remote interventions for which there is an increased need due to the COVID-19 pandemic.

Performance Evaluation of Vehicle Restraint Systems in the Context of Design and Installation

Vehicle Restraint Systems (VRS), a necessary component of the road design, are widely implemented by transport authorities to protect vehicles from severe incidents, mainly colliding to the roadside as well as median obstacles and other potential hazards. The performance evaluation of vehicle restraint systems at the design and installation stages is largely made according to either European or American standards. The local traffic conditions and vehicle compositions in countries, which are noticeably different from Europe and North America, necessitate a customized guideline in which the design and installation of road safety barriers are more adapted to the local conditions of the country. This paper briefly reviews the main features of EN1317, and NCHRP 350/MASH standards, which are predominantly used for the design, installation, and performance evaluation of VRS in Europe and the United States respectively. Moreover, the contribution of these standards in developing the VRS guideline for the State of Qatar is explained. The study recommends customizations to the design and installation of VRS, which are presently implemented according to the guideline developed by the Public Work Authority in Qatar. The present guideline follows European as well as American standards. The recommendations are made based on empirical studies and evidence observed by undertaking a series of site visits, audits, and perform inspections of VRS components installed on Qatari roads and highways. The study findings demonstrate the performance of VRS can be enhanced by incorporating the design and selection of road safety components such as guardrails, terminals, transitions, and crash cushions at the preliminary design stage of roads and highways. This study brings about practical insights and implications for road designers, contractors, supervision teams, and road safety auditors. Doi: 10.28991/cej-2021-03091665 Full Text: PDF

P0213 / #2008: THE EPIDEMIOLOGY OF PEDIATRIC POLYTRAUMA AND ORTHOPEDIC INJURIES: 12-YEAR ANALYSIS OF A LEVEL-1 TRAUMA CENTER (2007-2019)

Aims & Objectives: We present a retrospective study of pediatric polytrauma patients admitted to the pediatric Intensive Care Unit (ICU) of a tertiary university hospital in Europe. Methods: Data retrieved from 2007 to 2019 included mechanism and site of injury, pre-hospital and in-hospital trauma care, ICU length-of-stay (LOS), and in-hospital mortality. Results: 217 patients were included (age 10,7 ± 4,86 years; 66% male). Motor vehicle accidents (MVA) (44,4%) and car-pedestrian accidents (25,9%) were the leading mechanisms of injury, followed by falls from height (21,8%; 4,2% sports-related), penetrating trauma (3,3%) and suicide attempts (2,3%). On pre-hospital assessment, 60% of children had documented loss of consciousness; of these, more than half had severe brain injury (GCS<9). The most frequent injury sites were brain (74%) and skeleton (73%). Vertebral fractures were the most common orthopedic injury (19%), followed by pelvic (16,6%) and femur (15,2%) fractures. Patients with orthopedic trauma had significantly longer ICU LOS (5,1 ± 2,76 vs 3,1 ± 1,16; p=0,007); those with 3 or more fracture sites had greater needs for blood transfusion (20 vs 4 mL/kg; p=0,016). MVA were associated with highest incidence of orthopedic severe injuries (p<0,001). Most children involved in MVA were completely unrestrained (37,5%) or using a restraint system inappropriately (6,3%). Overall ICU trauma-related mortality was 1,8% (three cases of severe brain injury and one cervical spine injury). Conclusions: The great majority of polytrauma children suffer orthopedic injuries, requiring longer ICU admission and higher transfusion volumes. Road traffic accidents remain the leading cause of severe polytrauma. Education-oriented programs are still of crucial importance for prevention.

Rideshare use among parents and their children

Motor vehicle crashes are the leading cause of death for young children. Millions of ridesharing trips are taken each day, and use of these services is predicted to increase. Therefore, it is important to examine the safety of children in these vehicles. We conducted a survey of a nationally representative sample of U.S. adults aged 18 years or older (N = 2017). Of the total sample, 450 respondents reported being a parent or legal guardian of children below the age of 10. Of these, 307 or 68% had ever used ridesharing. Among those who had used ridesharing, a total of 253 or 82% reported using ridesharing with their children below the age of 10 years. Among this group, rideshare use was significantly higher among individuals with college education, and in higher income households. Given that the majority of U.S. states have legislation exempting rideshare vehicles from child restraint system law coverage, our finding of high rates of rideshare use among parents suggests that a large number of children could be at risk of injury due to a lack of appropriate restraint use.

Research on general layout parameters of I-SIZE child safety seat in frontal impact

In order to explore the influence of the general layout parameters of the child restraint system on the evaluation index of child injury in a frontal impact, and to explore the general layout plan that can minimize the child’s injury, this paper selects an I-Size child safety seat that meets the ECE R44 regulations as the research object, in accordance with the ECE R129 regulations, uses the Q3 child dummy to perform a frontal impact sled test on it, and record the test results. On this basis, a simulation concept model of the child safety seat is established, and the parameter combination of the seat back angle and cushion angle and the parameters of the five-point seat belt exit position are studied, and the overall layout design scheme with the best child protection performance is obtained.

Thermodynamic Analysis of Explosive Events in Manholes and Electrical Vaults

A computer code is used to simulate the conditions that exist during a manhole event consisting of an electrical fault and a gas explosion. When energy is generated within the structure, pressures can reach levels sufficient to propel the cover from its frame. The code quantifies the effects of the event and provides guidelines for the design of safety devices that can minimize the potential danger of the event. Differences between chemically-driven and electrically-driven events are shown to require different design criteria for cover restraint systems. Devices designed to restrain the cover must be able to withstand explosive forces and react in sufficient time to reduce internally generated pressures. By understanding the fundamental characteristics of arcing faults and gas explosions and their effect on the internally generated pressures, safety devices can be designed to mitigate the effects of the event in manholes and vaults and thereby reduce the potential danger to maintenance crews, first responders and the public.

Family readiness for evidence-based injury prevention and car seat safety in Jordan

Primary prevention involves developing positive health behaviours designed to avert adverse health outcomes, whereas evidence-based primary prevention adopts practices that reduce illness and injury. This study’s objective was to determine whether families in Jordan would adopt car safety measures after participating in an evidence-based injury prevention programme. Parents of children attending a regional government hospital in Jordan took part in an evidence-based educational class on child car restraints and car safety, six months later follow-up phone calls were made to see if the parents implemented the knowledge obtained in the class. Fifty families participated in the injury prevention class. The results showed that the evidence-based class on child restraint systems led to the adoption of the three interventions by the parents. At the time of the class 45% of parents allowed their infants to sit in the front seat, in the lap of an adult, this was reduced to 12%, being a 33% reduction. In addition, for children aged 6–12 using a seat belt in the back seat, the parents reported that their children using a seat belt increased from 13% to 70%. Finally, parents who participated were more likely to use a child car seat.

Seismic behaviour of reinforced concrete frame structures with all steel assembled Q195 low yield buckling restrained braces

For the traditional buckling restrained braces (BRBs), the core plate is high yield strength steel, and the external restraint system is concrete filled steel tube), it has the disadvantages of high yield strength and large weight, which will produce a large additional effect on the structure. Under the same member deformation, the material with lower strength has larger plastic deformation and more seismic energy absorption, so it is easier to realize the idea that the BRBs is prior to frame structure failure So, an all steel assembled Q195 low yield point buckling restrained braces (LYBRBs), has been proposed in this paper, and the quasi-static low-cycle reciprocating load test was conducted. The results show that the failure mode of the LYBRBS is tensile failure, its hysteretic curve shows good symmetry, stability and fullness, and the LYBRBs has a good energy dissipation capacity. At the same time, based on a reinforced concrete frame (RCF) structure in the area of 8 degree seismic fortification intensity, the RCF structural model was established, and the dynamic characteristics of the RCF structure were compared by PKPM and SAP2000 software to verify the correctness of the model. On this foundation, push-over analysis of the RCF and RCF structure with the arrangement of the LYBRBs (LYBRB-RCF) is performed. The story drift ratio, the curves of the base shear force-top story drift and the plastic hinge condition obtained by push-over analysis are compared. In addition, the structural time history analysis was conducted by SAP2000 software under the action of frequent and rare earthquakes. The story drift ratio, story shear force, time history of the top displacement and acceleration, energy consumption and hysteretic curve of the LYBRBs were analysed.

Experimental Study of Seismic Mitigation of a Large-Span Cable-Stayed Bridge with Elastic Cables by Shaking Table Test

Elastic cables have the advantages of desirable seismic mitigation effect, low cost, and convenient installation, and have been used widely in low-to-mid-span bridges. However, their utilization in long-span cable-stayed bridges has been limited. To study the effect of elastic cable on the seismic response mitigation of long-span cable-stayed bridges, an experimental model (half-bridge model) with a geometric similarity ratio of 1∶40 was established. Both the semifloating system and the elastic restraint system were considered, and the seismic responses of the two systems under earthquake excitation were tested on the shaking table. The results demonstrated the seismic mitigation effect of the elastic restraint system, which is dependent on the characteristics of the seismic wave. The mechanism of the seismic response mitigation of the long-span cable-stayed bridge with longitudinal elastic restraint was discussed.

The Final Tank - A Restraint System Design Tool with High Forecast Quality

The Final Tank - A Restraint System Design Tool with High Forecast Quality

THE INFLUENCE OF IMPACT SPEED ON CHEST INJURY OUTCOME IN WHOLE BODY FRONTAL SLED IMPACTS

While the seatbelt restraint has significantly improved occupant safety, the protection efficiency still needs further enhance to reduce the consequence of the crash. Influence of seatbelt restraint loading on chest injury under 40 km/h has been tested and documented. However, a comprehensive profiling of the efficiency of restraint systems with various impact speeds has not yet been sufficiently reported. The purpose of this study is to analyse the effect of the seatbelt loadings on chest injuries at different impact speeds utilizing a high bio-fidelity human body Finite Element (FE) model. Based on the whole-body frontal sled test configuration, the current simulation is setup using a substitute of Post-Mortem Human Subjects (PMHS). Chest injury outcomes from simulations are analysed in terms of design variables, such as seatbelt position parameters and collision speed in a full factorial experimental design. These outcomes are specifically referred to strain-based injury probabilities and four-point chest deflections caused by the change of the parameters. The results indicate that impact speed does influence chest injury outcome. The ribcage injury risk for more than 3 fractured ribs will increase from around 40 to nearly 100% when the impact speed change from 20 to 40 km/h if the seatbelt positioned at the middle-sternum of this study. Great injuries to the chest are mainly caused by the change of inertia, which indicates that chest injuries are greatly affected by the impact speed. Furthermore, the rib fracture risk and chest deflection are nonlinearly correlated with the change of the seatbelt position parameters. The study approach can serve as a reference for seatbelt virtual design. Meanwhile, it also provides basis for the research of chest injury mechanism.

Development of a detailed human neck finite element model and injury risk curves under lateral impact

Advanced neck finite element modeling and development of neck injury criteria are important for the design of optimal neck protection systems in automotive and other environments. They are also important in virtual tests. The objectives of the present study were to develop a detailed finite element model (FEM) of the human neck and couple it to the existing head model, validate the model with kinematic data from legacy human volunteer and human cadaver impact datasets, and derive lateral impact neck injury risk curves using survival analysis from the upper and lower neck forces and moments. The detailed model represented the anatomy of a young adult mid-size male. It included all the cervical and first thoracic vertebrae, intervening discs, upper and lower spinal ligaments, bilateral facet joints, and passive musculature. Material properties were obtained from literature. Frontal, oblique, and lateral impacts to the distal end of the model was applied based on human volunteer and human cadaver experimental data. Corridor and cross-correlation methods were used for validation. The CORrelation and Analysis (CORA) score was used for objective assessments. Forces and moments were obtained at the occipital condyles (OC) and T1, and parametric survival analysis was used to derive injury risk curves to define human neck injury tolerance to lateral impact. The Brier Score Metric (BSM) was used to determine the hierarchical sequence among the injury metrics. The CORA scores for the lateral, frontal, and oblique impact loading conditions were 0.80, 0.91, and 0.87, respectively, for human volunteer data, and the mean score was 0.7 for human cadaver lateral impacts. Injury risk curves along with ±95% confidence intervals are given for all the four biomechanical metrics. The OC shear force was the optimal metric based on the BSM. A force of 1.5 kN was associated with the 50% probability level of AIS3+ neck injury. As a first step, the presented risk curves serve as human tolerance criteria under lateral impact, hitherto not available in published literatures, and they can be used in virtual testing and advancing restraint systems for improving human safety.