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Abstract This article explores the value of simulation for autonomous-vehicle research and development. There is ample research that details the effectiveness of simulation for training humans to fly and drive. Unfortunately, the same is not true for simulations used to train and test artificial intelligence (AI) that enables autonomous vehicles to fly and drive without humans. Research has shown that simulation “fidelity” is the most influential factor affecting training yield, but psychological fidelity is a widely accepted definition that does not apply to AI because it describes how well simulations engage various cognitive functions of human operators. Therefore, this investigation reviewed the literature that was published between January 2010 and May 2022 on the topic of simulation fidelity to understand how researchers are defining and measuring simulation fidelity as applied to training AI.

Abstract In this study, a parametric thoracic spine (T-spine) model was developed to account for morphological variations among the adult population. A total of 84 CT scans were collected, and the subjects were evenly distributed among age groups and both sexes. CT segmentation, landmarking, and mesh morphing were performed to map a template mesh onto the T-spine vertebrae for each sampled subject. Generalized procrustes analysis (GPA), principal component analysis (PCA), and linear regression analysis were then performed to investigate the morphological variations and develop prediction models. A total of 13 statistical models, including 12 T-spine vertebrae and a spinal curvature model, were combined to predict a full T-spine 3D geometry with any combination of age, sex, stature, and body mass index (BMI). A leave-one-out root mean square error (RMSE) analysis was conducted for each node of the mesh predicted by the statistical model for every T-spine vertebra.

Abstract The ability of senior citizens as well as other members of the general population to engage in an effective manner with technology is of increasing importance as new and innovative technologies become available. While recognizing the challenges that technologies can have on different populations, the ability to interact successfully with new technologies will, for seniors, have important consequences that can affect their quality of life and those of their families in numerous and important ways. This study, building upon previous research, examines the major dimensions of decision-making regarding attitudes toward autonomous vehicle technologies (ATVs) and their use. The study utilized data from a study of senior citizens in the Dallas-Fort Worth (DFW) area and compared the results with a sample of graduate students from a local university.

Abstract Motion sickness is a human health issue that has existed for many years and now serves as the primary hindrance to the very existence of self-driving technology in Autonomous Vehicles (AV). This technology promises to transform drivers into passengers and simple cars into entertainment transportation pods. This potentially increases the likelihood of passengers getting motion sick and threatens the acceptance of commercial AV. The study presents a practical solution using ergonomic paths designed by transition curves such as 3-point B-splines and Non-Uniform Rational B-Splines (NURBS) to study their impact on passenger motion sickness and vehicle-handling behavior. Modern path-tracking models and algorithms equipped with Model Predictive Controller (MPC) and Sliding-Mode Controller (SMC) together with an eight degree of freedom (8 DOF) vehicle model have been used to simulate vehicle motions.

Abstract We model neck loading as a function of impact severity in aligned rear impacts. Neck loading is understood and expected to vary as a function of factors including crash severity, occupant compartment design, and occupant metrics. Within occupant compartment design, seat and restraint characteristics are expected to influence the biomechanical response and occupant kinematics. We investigated the relationship between biomechanical neck-loading metrics and impact severity expressed as speed change (delta-V) by examining 47 low to moderate speed rear-impact crash and sled tests utilizing the Hybrid III (HIII) 50th male Anthropomorphic Test Device (ATD). Our hypothesis was that the relationship between severity expressed as delta-V and the neck metrics examined could be modeled as linear consistent with an understanding that neck loading in a rear impact results from the acceleration of the vehicle.

Abstract The critical intercepts used for the Neck Injury Criterion (Nij) have not been assessed in computational human body models. Under matched-pair conditions, the response of the head-neck complex was compared between the Livermore Software Technology Corporation (LSTC) Hybrid III (HIII) and Global Human Body Models Consortium’s (GHBMC) 50th percentile, detailed male occupant (M50-O) models. The head and neck of the M50-O and HIII were subjected to the dummy performance calibration test procedure for flexion and extension. As a nominal condition, the HIII model met all calibration specifications. Operationalization of the M50-O’s initial position was defined by equivalent head CG location to the HIII and subsequently compared at nominal, ±10%, ±20%, and ±30% of pendulum displacement. Kinematics of the head CG, forces and moments of the upper neck, and changes in neck angle were post processed and compared between the models.

Abstract Compared to other age groups, older adults are at more significant risk of hip fracture when they fall. In addition to the higher risk of falls for the elderly, fear of falls can reduce this population’s outdoor activity. Various preventive solutions have been proposed to reduce the risk of hip fractures ranging from wearable hip protectors to indoor flooring systems. A previously developed rubberized asphalt mixture demonstrated the potential to reduce the risk of head injury. In the current study, the capability of the rubberized asphalt sample was evaluated for the risk of hip fracture for an average elderly male and an average elderly female. A previously developed human body model was positioned in a fall configuration that would give the highest impact forces toward regular asphalt.

Abstract Vehicles with automated driving systems (ADS) may allow nontraditional seating arrangements, such as a reclined seat that is rear facing in a frontal impact. Currently, there is not a widely accepted, commercially available, anthropomorphic test device (ATD) that is designed for a reclined, rear-facing, high-speed crash situation. To begin to identify what modifications are needed for candidate ATDs to exhibit human-like characteristics in these nontraditional scenarios, ATDs should be tested and compared to available postmortem human subject (PMHS) biofidelity response corridors in these seating arrangements. The first objective of this study was to present and discuss updates to the Biofidelity Ranking System (BRS). The second objective was to use the updated BRS to evaluate the responses of the THOR 50th percentile male (THOR-50M) ATD in the rear-facing condition.

Abstract The objective of this study was to compare head, neck, and chest injury risks between front and rear-seated Hybrid III 50th-percentile male anthropomorphic test devices (ATDs) during matched frontal impacts. Seven vehicles were converted to rear seat test bucks (two sedans, three mid-size SUVs, one subcompact SUV, and one minivan) and then used to perform sled testing with vehicle-specific frontal NCAP acceleration pulses and a rear seated (i.e., second row) Hybrid III 50th male ATD. Matched front seat Hybrid III 50th male ATD data were obtained from the NHTSA Vehicle Crash Test Database for each vehicle. HIC15, Nij, maximum chest acceleration, and maximum chest deflection were compared between the front and rear seat tests, as well as between vehicles with conventional and advanced three-point belt restraint systems in the rear seat. Additionally, a modified version of the NCAP frontal star rating was calculated for the front and rear seat tests.

Abstract Bilateral knee impacts were conducted on Hybrid III and THOR 5th percentile female anthropomorphic test devices (ATDs), and the results were compared to previously reported female PMHS data. Each ATD was impacted at velocities of 2.5, 3.5, and 4.9 m/s. Knee–thigh–hip (KTH) loading data, obtained either via direct measurement or through exercising a one-dimensional lumped parameter model (LPM), was analyzed for differences in loading characteristics including the maximum force, time to maximum force, loading rate, and loading duration. In general, the Hybrid III had the highest loading rate and maximum force, and the lowest loading duration and time to peak force for each point along KTH. Conversely, the PMHS generally had the lowest loading rate and maximum force, and the highest loading duration and time to peak force for each point along KTH.

Abstract The outbreak of COVID-19 pandemic in the beginning of 2020 has made it necessary to review many practices in countless areas, changing our lifestyles drastically. Humanity has put health issues in priority to deal with the disease effectively. While health systems are having difficult times in terms of patient care, vaccination, and treatment protocols, existing designs in many areas have proven to be inefficient in preventing or decelerating the pandemic. As the disease is transmitted mainly by particle transfer through coughing, sneezing, and even with speaking, wearing face masks and keeping a distance of 2 m as well as hygiene (especially hand) are shown to be effective methods. However, long exposure to indoor air populated with people is still a major risk due to the possibility of high concentration of virus-contaminated air.

Abstract Traumatic brain injury is a leading cause of global death and disability. Clinically relevant large animal models are a vital tool for understanding the biomechanics of injury, providing validation data for computation models, and advancing clinical translation of laboratory findings. It is well-established that large angular accelerations of the head can cause TBI, but the effect of head impact on the extent and severity of brain pathology remains unclear. Clinically, most TBIs occur with direct head impact, as opposed to inertial injuries where the head is accelerated without direct impact. There are currently no active large animal models of impact TBI. Sheep may provide a valuable model for studying TBI biomechanics, with relatively large brains that are similar in structure to that of humans. The aim of this project is to develop an ovine model of impact TBI to study the relationships between impact mechanics and brain pathology.

Abstract Some anthropomorphic test devices (ATDs) currently being developed are equipped with abdominal pressure twin sensors (APTS) for the assessment of abdominal injuries and as an indicator of the occurrence of the submarining of an occupant during a crash event. The APTS is comprised of a fluid-filled polyurethane elastomeric bladder which is sealed by an aluminum cap with an implanted pressure transducer. It is integrated into ATD abdomens, and fluid pressure is increased due to the abdomen/bladder compression due to interactions with the seatbelt or other structures. In this article, a nonlinear dynamic finite element (FE) model is constructed of an APTS using LS-PrePost and converted to the LS-Dyna solver input format. The polyurethane bladder and the internal fluid are represented with viscoelastic and isotropic hypoelastic material models, respectively. The aluminum cap was considered a rigid part since it is significantly stiffer than the bladder and the fluid.

Abstract Human thoracic injury under frontal collisions is an inevitable problem in vehicle safety research. Compared with the Multiple Rigid-Body Models (MRBMs) and Finite Element Human Body Models (FEHBMs), Mathematical Equivalent Models (MEMs) can not only provide important data but also improve the research efficiency. The current thoracic MEMs usually adapted the mechanical isolation method to isolate the thorax from the human body; therefore, the effects of the head, neck, and lower body internal organs on the mechanical responses of the thorax are not considered. In this article, a new thoracic MEM, named as Improved Consistent Lobdell Model (ICLM), is developed based on the concentrated mass-spring-damping system to consider the energy absorbed by the deformation of the internal soft tissue and the motion hysteresis of the head, neck, and lower body.

Abstract Introduction: This study evaluates driving ability in those with Charcot Marie Tooth Disease Type 1A, a hereditary peripheral neuropathy. Methods: Individuals with Charcot Marie Tooth Disease Type 1A (n = 18, age = 42 ± 7) and controls (n = 19; age = 35 ± 10) were evaluated in a driving simulator. The Charcot Marie Tooth Neuropathy Score version 2 was obtained for individuals. Rank Sum test and Spearman rank correlations were used for statistical analysis. Results: A 74% higher rate of lane departures and an 89% higher rate of lane deviations were seen in those with Charcot Marie Tooth Disease Type 1A than for controls (p = 0.005 and p < 0.001, respectively). Lane control variability was 10% higher for the individual group and correlated with the neuropathy score (rS = 0.518, p = 0.040), specifically sensory loss (rS = 0.710, p = 0.002) and pinprick sensation loss in the leg (rS = 0.490, p = 0.054).

Abstract Through connectivity with the electric grid, electric vehicles (EVs) minimize or eliminate the need for fossil fuels. Despite the rapid adoption of EVs in recent times, most government adoption objectives have not been attained. This article aims to comprehend the reasons behind the limited uptake of electric scooters in India and the driving aspects. This research used a grounded theory methodology. Using a snowball sampling technique, we conducted 25 in-depth interviews with EV owners, mainly based in Delhi and Mumbai. As an outcome of the study, four drivers and four impediments to the adoption of EVs have been formulated. The study shows that there are Financial, Technological, Operational, and Psychological drivers and Technological/Infrastructural, Operational, and Psychological impediments to the adoption. The study identifies the key concern areas in the form of categories of drivers and impediments, which can be considered in industrial and public policymaking.

Erratum.

Abstract Computational and experimental studies have been undertaken to investigate injurious head-first impacts (HFI), which can occur during automotive rollovers. Recent studies assume a torso surrogate mass (TSM) boundary condition, wherein the first or first two thoracic vertebrae are potted and constrained to only move in the vertical loading direction. The TSM boundary condition has not been compared with a full body (FB) model computationally or experimentally for HFI. In this study, the Global Human Body Models Consortium 50th percentile male detailed human body model (M50-O, Version 6.0) was applied to compare the kinematic, kinetic, and injury response of an HFI with a TSM boundary condition (M50-TSM), and a full body boundary condition (M50-FB). Impacts (to M50-TSM and M50-FB) were simulated between the head and a rigid plate using a commercial FE code (LS-DYNA).

Abstract The objective of this study was to evaluate the thoracic response and injury metrics of the Hybrid III (HIII-50M) and THOR (THOR-50M) 50th-percentile male Anthropomorphic Test Devices (ATDs) during frontal, rear-seated sled tests using modern vehicles with various rear seat characteristics. Test bucks were fabricated from seven vehicles (two sedans, three midsize sport utility vehicles [SUVs], one subcompact SUV, and one minivan) that represented varying levels of rear seat designs and safety technologies, e.g., three vehicles had advanced restraints with pretensioners (PT) and load limiters (LL). Twenty-five frontal sled tests were conducted using three sled pulses derived from the vehicle-specific New Car Assessment Program (NCAP) crash pulses (NCAP85 ΔV = 56 kph, Scaled ΔV = 32 kph, and Generic ΔV = 32 kph). The HIII-50M and THOR-50M ATDs were positioned in the right and left rear seats, respectively.

Abstract Introduction: The use of less lethal impact munitions (LLIMs) by law enforcement has increased in frequency, especially following nationwide protests regarding police brutality and racial injustice in the summer of 2020. There are several reports of the projectiles causing severe injuries when they penetrate the skin including pulmonary contusions, bone fractures, liver lacerations, and, in some cases, death. The penetration threshold of skin in different body regions is due to differences in the underlying structure (varying degree of muscle, adipose tissue, and presence or absence of bone). Objective: The objective of this study was to further investigate what factors affected the likelihood of skin penetration in various body regions and to develop corresponding penetration risk curves.