Effect of data censoring on thoracic injury risk curves.

Objective: The first objective was to evaluate the effect of using less censored (i.e., exact and interval-censored) data on thoracic injury risk curves and the resulting injury probabilities.

Frontal-Crash Occupant Protection in the Rear Seat: Submarining and Abdomen/Pelvis Response in Midsized Male Surrogates.

Frontal-crash sled tests were conducted to assess submarining protection and abdominal injury risk for midsized male occupants in the rear seat of modern vehicles. Twelve sled tests were conducted in four rear-seat vehicle-bucks with twelve post-mortem human surrogates (PMHS). Select kinematic responses and submarining incidence were compared to previously observed performance of the Hybrid III 50th-percentile male and THOR-50M ATDs (Anthropomorphic Test Devices) in matched sled tests conducted as part of a previous study.

Comparison of Adult Female and Male PMHS Pelvis and Lumbar Response to Underbody Blast.

The goal of this study was to gather and compare kinematic response and injury data on both female and male whole-body Post-mortem Human Surrogates (PMHS) responses to Underbody Blast (UBB) loading. Midsized males (50th percentile, MM) have historically been most used in biomechanical testing and were the focus of the Warrior Injury Assessment Manikin (WIAMan) program, thus this population subgroup was selected to be the baseline for female comparison. Both small female (5th percentile, SF) and large female (75th percentile, LF) PMHS were included in the test series to attempt to discern whether differences between male and female responses were predominantly driven by sex or size.

Effects of loading rate, age, and morphology on the material properties of human rib trabecular bone.

The material and morphometric properties of trabecular bone have been studied extensively in bones bearing significant weight, such as the appendicular long bones and spine. Less attention has been devoted to the ribs, where quantification of material properties is vital to understanding thoracic injury. The objective of this study was to quantify the compressive material properties of human rib trabecular bone and assess the effects of loading rate, age, and morphology on the material properties.

Comparative biofidelity of the Hybrid III and THOR 50th male ATDs under three restraint conditions during frontal sled tests.

Objective: The purpose of this study was to provide a whole-body biofidelity assessment of the Hybrid III (HIII) and THOR 50th percentile male anthropomorphic test devices (ATDs) during frontal sled tests, incorporating data from kinematics, chest deflection, and test buck reaction load cells. Additionally, the accuracy of the injury risk prediction capabilities for each ATD was evaluated against injuries observed in matched postmortem human surrogate (PMHS) tests.

Methods: Sled tests, designed to simulate a United States New Car Assessment Program (US-NCAP) frontal test, were conducted using the HIII, THOR, and 8 approximately 50th percentile male PMHS under 3 restraint conditions.

Response of small female and midsize male models with active musculature in pre-crash maneuvers and low-speed impacts.

Objective: The objectives of this study were to evaluate computationally efficient small female (54.1 kg, 149.9 cm) and midsize male (78.

Implementation and calibration of active small female and average male human body models using low-speed frontal sled tests.

Objective: The objective of this study was to implement active muscles in a computationally efficient small female finite element model (54.1 kg, 149.9 cm) suitable for predicting occupant response during precrash braking and low-speed frontal sled tests.

A comparison of rib cortical bone compressive and tensile material properties: Trends with age, sex, and loading rate.

The objectives of this study were to develop novel methods for quantifying human rib cortical bone material properties in compression and to compare the compressive material property data to existing tensile data for matched subjects. Cylindrical coupons were obtained from the rib cortical bone of 30 subjects (M = 19, F = 11) ranging from 18 to 95 years of age (Avg. = 48.

Subject-specific rib finite element models with material data derived from coupon tests under bending loading.

Rib fractures are common thoracic injuries in motor vehicle crashes. Several human finite element (FE) human models have been created to numerically assess thoracic injury risks. However, the accurate prediction of rib biomechanical response has shown to be challenging due to human variation and modeling approaches.

Stiffness of a type II external skeletal fixator and locking compression plate in a fracture gap model.

Objective: To compare the stiffness of constructs fixed with a type II external skeletal fixator (ESF) or a 3.5-mm locking compression plate (LCP) in axial compression and bending with a fracture gap model.

Study Design: Quasi-static four-point bending and axial compression tests.

Effects of sex, age, and two loading rates on the tensile material properties of human rib cortical bone.

The objective of this study was to evaluate the effects of sex, loading rate, and age on the tensile material properties of human rib cortical bone over a wide range of subject demographics. Sixty-one (n = 61) subjects (M = 32, F = 29) ranging in age from 17 to 99 years of age (Avg. = 56.

Detailed subject-specific FE rib modeling for fracture prediction.

The current state of the art human body models (HBMs) underpredict the number of fractured ribs. Also, it has not been shown that the models can predict the fracture locations. Efforts have been made to create subject specific rib models for fracture prediction, with mixed results.

Assessment of Thoracic Response and Injury Risk Using the Hybrid III, THOR-M, and Post-Mortem Human Surrogates under Various Restraint Conditions in Full-Scale Frontal Sled Tests.

A total of 20 full-scale frontal sled tests were conducted using the Hybrid III (HIII), THOR-M and post-mortem human surrogates (PMHSs) to evaluate the thoracic biofidelity of the HIII and THOR-M under various belted restraint conditions. Each surrogate was tested under three belted restraint conditions: knee bolster, knee bolster and steering wheel airbag, and knee bolster airbag and steering wheel airbag. In order to assess the relative biofidelity of each ATD, external thoracic deflections were quantitatively compared between the ATDs and PMHSs using an objective rating metric.

Evaluation of Hybrid III and THOR-M neck kinetics and injury risk under various restraint conditions during full-scale frontal sled tests.

Objective: The objective of this research was to compare the kinetics and predicted injury risks of the Hybrid III (HIII) and Test device for Human Occupant Restraint (THOR)-M necks during full-scale frontal sled tests under 3 safety restraint conditions: knee bolster (KB), knee bolster and steering wheel airbag (KB/SWAB), and knee bolster airbag and steering wheel airbag (KBAB/SWAB).

Methods: Twelve sled tests were performed for the HIII and THOR-M, and 8 matched sled tests were performed using postmortem human surrogates (PMHSs). The tests were designed to match the 2012 Toyota Camry New Car Assessment Program (NCAP) full-scale crash test.

Effects of postmortem time and storage fluid on the material properties of bovine liver parenchyma in tension.

In motor vehicle collisions (MVCs), liver injuries are one of the most frequently reported types of abdominal organ trauma. Although finite element models are utilized to evaluate the risk of sustaining an abdominal organ injury in MVCs, these models must be validated based on biomechanical data in order to accurately assess injury risk. Given that previous studies that have quantified the tensile failure properties of human liver parenchyma have been limited to testing at 48 h postmortem, it is currently unknown how the material properties change between time of death and 48 h postmortem.

Occupant kinematics of the Hybrid III, THOR-M, and postmortem human surrogates under various restraint conditions in full-scale frontal sled tests.

Objective: The objective of this research was to compare the occupant kinematics of the Hybrid III (HIII), THOR-M, and postmortem human surrogates (PMHS) during full-scale frontal sled tests under 3 safety restraint conditions: knee bolster (KB), knee bolster and steering wheel airbag (KB/SWAB), and knee bolster airbag and steering wheel airbag (KBAB/SWAB).

Methods: A total of 20 frontal sled tests were performed with at least 2 tests performed per restraint condition per surrogate. The tests were designed to match the 2012 Toyota Camry New Car Assessment Program (NCAP) full-scale crash test.

Neck forces and moments of human volunteers and post mortem human surrogates in low-speed frontal sled tests.

Objective: The objective of this study was to quantify the effects of active muscles (e.g. conscious bracing, resting tone, and reflex response) and acceleration severity on the neck forces and moments generated during low-speed frontal sled tests with adult male human volunteers and post mortem human surrogates (PMHSs).

Non-censored rib fracture data during frontal PMHS sled tests.

Objective: The purpose of this study was to obtain non-censored rib fracture data due to three-point belt loading during dynamic frontal post-mortem human surrogate (PMHS) sled tests. The PMHS responses were then compared to matched tests performed using the Hybrid-III 50(th) percentile male ATD.

Methods: Matched dynamic frontal sled tests were performed on two male PMHSs, which were approximately 50(th) percentile height and weight, and the Hybrid-III 50(th) percentile male ATD.

Comparison of ATD to PMHS Response in the Under-Body Blast Environment.

A blast buck (Accelerative Loading Fixture, or ALF) was developed for studying underbody blast events in a laboratory-like setting. It was designed to provide a high-magnitude, high-rate, vertical loading environment for cadaver and dummy testing. It consists of a platform with a reinforcing cage that supports adjustable-height rigid seats for two crew positions.

Finite element comparison of human and Hybrid III responses in a frontal impact.

The improvement of finite element (FE) Human Body Models (HBMs) has made them valuable tools for investigating restraint interactions compared to anthropomorphic test devices (ATDs). The objective of this study was to evaluate the effect of various combinations of safety restraint systems on the sensitivity of thoracic injury criteria using matched ATD and Human Body Model (HBM) simulations at two crash severities. A total of seven (7) variables were investigated: 3-point belt with two (2) load limits, frontal airbag, knee bolster airbag, a buckle pretensioner, and two (2) delta-v's - 40kph and 50kph.

Effects of Filtering on Experimental Blast Overpressure Measurements.

When access to live-fire test facilities is limited, experimental studies of blast-related injuries necessitate the use of a shock tube or Advanced Blast Simulator (ABS) to mimic free-field blast overpressure. However, modeling blast overpressure in a laboratory setting potentially introduces experimental artifacts in measured responses. Due to the high sampling rates required to capture a blast overpressure event, proximity to alternating current (AC-powered electronics) and poorly strain-relieved or unshielded wires can result in artifacts in the recorded overpressure trace.

Membrane characteristics for biological blast overpressure testing using blast simulators.

Blast simulators often use passive-rupture membranes to generate shock waves similar to free-field blasts. The purpose of this study was to compare rupture patterns and pressure traces of three distinct membrane materials for biological and biomechanical blast studies. An Advanced Blast Simulator (ABS) located at the Center for Injury Biomechanics at Virginia Tech was used to test membrane characteristics.

Human occupants in low-speed frontal sled tests: effects of pre-impact bracing on chest compression, reaction forces, and subject acceleration.

Objectives: The purpose of this study was to investigate the effects of pre-impact bracing on the chest compression, reaction forces, and accelerations experienced by human occupants during low-speed frontal sled tests.

Methods: A total of twenty low-speed frontal sled tests, ten low severity (∼2.5g, Δv=5 kph) and ten medium severity (∼5g, Δv=10 kph), were performed on five 50th-percentile male human volunteers.