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The literature contains a wide range of response data describing the biomechanics of isolated body regions. Current data for the validation of frontal anthropomorphic test devices and human body computational models lack, however, a detailed description of the whole-body response to loading with contemporary restraints in automobile crashes.

The objective of the current study was to provide a comprehensive characterization of human biomechanical response to whole-body, lateral impact. Three approximately 50th-percentile adult male PMHS were subjected to right-side pure lateral impacts at 4.3 ± 0.1 m/s using a rigid wall mounted to a rail-mounted sled. Each subject was positioned on a rigid seat and held stationary by a system of tethers until immediately prior to being impacted by the moving wall with 100 mm pelvic offset. Displacement data were obtained using an optoelectronic stereophotogrammetric system that was used to track the 3D motions of the impacting wall sled; seat sled, and reflective targets secured to the head, spine, extremities, ribcage, and shoulder complex of each subject. Kinematic data were also recorded using 3-axis accelerometer cubes secured to the head, pelvis, and spine at the levels of T1, T6, T11, and L3. Chest deformation in the transverse plane was recorded using a single chestband.

Two post-mortem human subjects were subjected to dynamic, non-injurious (up to 20% chest deflection) anterior shoulder belt loading at 0.5 m/s and 0.9 m/s loading rates. The human surrogates were mounted to a stationary apparatus that supported the spine and shoulder in a configuration comparable to that achieved in a 48 km/h sled test at the time of maximum chest deformation. A hydraulically driven shoulder belt was used to load the anterior thorax which was instrumented with a load cell for measuring reaction force and uniaxial strain gages at the 4th and 8th ribs. In addition, the deformation of the chest was measured using a 16- camera Vicon 3D motion capture system. In order to investigate the chest deformation pattern and ribcage loading in greater detail, a human finite element (FE) model of the thorax was used to simulate the tests.

This paper presents thoracic response corridors developed using fifteen post-mortem human subjects (PMHS) subjected to single and double diagonal belt, distributed, and hub loading on the anterior thorax. We believe this is the first study to quantify the force-deflection response of the same thorax to different loading conditions using dynamic, non-impact, restraint-like loading. Subjects were positioned supine on a table and a hydraulic master-slave cylinder arrangement was used with a high-speed materials testing machine to provide controlled chest deflection at a rate similar to that experienced by restrained PMHS in a 48-km/h sled test. All loading conditions were tested at a nominally non-injurious level initially. When the battery of non-injurious tests was completed, a single loading condition was used for a final, injurious test (nominal 40% chest deflection).

Injury to the thorax is the predominant cause of fatalities in crash-involved automobile occupants over the age of 65, and many elderly-occupant automobile fatalities occur in crashes below compliance or consumer information test speeds. As the average age of the automotive population increases, thoracic injury prevention in lower severity crashes will play an increasingly important role in automobile safety. This study presents the results of a series of sled tests to investigate the thoracic deformation, kinematic, and injury responses of belted post-mortem human surrogates (PMHS, average age 44 years) and frontal anthropomorphic test devices (ATDs) in low-speed frontal crashes. Nine 29 km/h (three PMHS, three Hybrid III 50th% male ATD, three THOR-NT ATD) and three 38 km/h (one PMHS, two Hybrid III) frontal sled tests were performed to simulate an occupant seated in the right front passenger seat of a mid-sized sedan restrained with a standard (not force-limited) 3-point seatbelt.

Recent field data studies have shown that force-limiting belt systems reduce the occurrence of thoracic injuries in frontal crashes relative to standard (not force-limiting) belt systems. Laboratory cadaver tests have also shown reductions in trauma, as well as in chest deflection, associated with a force-limiting belt. On the other hand, tests using anthropomorphic test devices (ATDs) have shown trends indicating increased, decreased, or unchanged chest deflection. This paper attempts to resolve previous experimental studies by comparing the anterior-posterior and lateral chest deflections measured by the THOR and Hybrid III (H-III) dummies over a range of experimental conditions. The analysis involves nineteen 48-km/h and 57-km/h sled tests utilizing force-limiting and standard seat belt systems, both with an air bag. Tests on both the driver side and the passenger side are considered.

This report describes a series of experiments using Hexcel(TM) to limit the impact force in lateral abdominal impacts. Two hundred fourteen (214) anesthetized New Zealand White rabbits were impacted at 5 to 15 m/s using a pneumatic impactor. Injury responses from tests with a force-limiting impact interface (94 tests) were compared with the responses from tests with a rigid impact interface (120 tests) having the same level of lateral abdominal compression. The Hexcel had a length of 3 inches, the same diameter as the rigid impactor, and crushed at a constant force (pressure level of 232 kPa (33 psi)) once deformation was initiated. The results of these tests showed that the probability of serious abdominal injury did not change significantly with the Hexcel, even though peak pressures were reduced to as little as one third of their previous values.

Seventeen left lateral impact experiments were performed using anesthetized swine to determine the biomechanics of injury production in this impact mode. Two series of eight animals were used and one animal served as a control. In the first series of experiments, rigid thoracic and pelvic loading surfaces were separated by an “interplate gap” of 20.3 cm (8”). In the second series of experiments, the interplate gap was filled by a rigid plate mounted flush with the thoracic and pelvic loading surfaces. Impact velocities ranged from 7.2 to 15.0 m/s (about 15 to 30 mph). Injury patterns for the liver, spleen, and rib cage were significantly different in the two series of experiments (level of significance > 90%). The causative factor responsible for the different injury outcomes was the interplate gap. The conclusion of this report is that loading-surface discontinuities can cause significant injury.

The purpose of this paper is to compare the biofidelity rating schemes of ISO/TR9790 and the NHTSA Bio Rank System. This paper describes the development of new impact response corridors being proposed for ISO/TR9790 from the results of a recent series of side-impact sled tests. The response data were analyzed by methods consistent with ISO/TR9790, including normalization by impulse-momentum analysis and the elimination of subjects that sustained six or more rib fractures. Unlike ISO/TR9790, this paper proposes the elimination of the data from tests in which the timing and the sequence of loading of the individual impact plates were inconsistent compared to other tests conducted with the same impact wall configuration.

Analysis and validation of current scaling relationships and existing response corridors using animal surrogate test data is valuable, and may lead to the development of new or improved scaling relationships. For this reason, lateral pendulum impact testing of appropriate size cadaveric porcine surrogates of human 3-year-old, 6-year-old, 10-year-old, and 50th percentile male age equivalence, were performed at the thorax and abdomen body regions to compare swine test data to already established human lateral impact response corridors scaled from the 50th percentile human adult male to the pediatric level to establish viability of current scaling laws. Appropriate Porcine Surrogate Equivalents PSE for the human 3-year-old, 6-year-old, 10-year-old, and 50th percentile male, based on whole body mass, were established. A series of lateral impact thorax and abdomen pendulum testing was performed based on previously established scaled lateral impact assessment test protocols.

To date, several lateral impact studies (Bolte et al., 2000, 2003, Marth, 2002 and Compigne et al., 2004) have been performed on the shoulder to determine the response characteristics and injury threshold of the shoulder complex. Our understanding of the biomechanical response and injury tolerance of the shoulder would be improved if the results of these tests were combined. From a larger data base shoulder injury tolerance criteria can be developed as well as corridors for side impact dummies. Data from the study by Marth (2002, 12 tests) was combined with data from the previous studies. Twenty-two low speed tests (4.5 ± 0.7 m/s) and 9 high speed tests (6.7 ± 0.7 m/s) were selected from the combined data for developing corridors. Shoulder force, deflection and T1y acceleration corridors were developed using a minimization of cumulative variance technique.

This paper presents the results of biomechanical testing of the SID-IIs beta+-prototype dummy by the Occupant Safety Research Partnership. The purpose of this testing was to evaluate the dummy against its previously established biomechanical response corridors for its critical body regions. The response corridors were scaled from the 50th percentile adult male corridors defined in International Standards Organization Technical Report 9790 to corridors for a 5th percentile adult female, using established International Standards Organization procedures. Tests were performed for the head, neck, shoulder, thorax, abdomen and pelvis regions of the dummy. Testing included drop tests, pendulum impacts and sled tests. The biofidelity of the SID-IIs beta+-prototype was calculated using a weighted biomechanical test response procedure developed by the International Standards Organization.

There has been recent progress over the past 10 years in research comparing 6-year-old thoracic and abdominal response of pediatric volunteers, pediatric post mortem human subjects (PMHS), animal surrogates, and 6-year-old ATDs. Although progress has been made to guide scaling laws of adult to pediatric thorax and abdomen data for use in ATD design and development of finite element models, further effort is needed, particularly with respect to lateral impacts. The objective of the current study was to use the impact response data of age equivalent swine from Yaek et al. (2018) to assess the validity of scaling laws used to develop lateral impact response corridors from adult porcine surrogate equivalents (PSE) to the 3-year-old, 6-year-old, and 10-year-old for the thorax and abdominal body regions.

Rear seat adult occupant protection is receiving increased attention from the automotive safety community. Recent anthropomorphic test device (ATD) studies have suggested that it may be possible to improve kinematics and reduce injuries to rear seat occupants in frontal collisions by incorporating shoulder-belt force-limiting and pretensioning (FL+PT) technologies into rear seat 3-point belt restraints. This study seeks to further investigate the feasibility and potential kinematic benefits of a FL+PT rear seat, 3-point belt restraint system in a series of 48 kmh frontal impact sled tests (20 g, 80 ms sled acceleration pulse) performed with post mortem human surrogates (PMHS). Three PMHS were tested with a 3-point belt restraint with a progressive (two-stage) force limiting and pretensioning retractor in a sled buck representing the rear seat occupant environment of a 2004 mid-sized sedan.

This study continued the biomechanical investigations of forearm fractures caused by direct loading of steering-wheel airbags during the early stages of deployment. Twenty-four static deployments of driver airbags were conducted into the forearms of unembalmed whole cadavers using a range of airbags, including airbags that are depowered as allowed by the new federal requirements for frontal impact testing. In general, the depowered airbags showed a reduction in incidence and severity of forearm fractures compared to the pre-depowered airbags tested. Data from these twenty-four tests were combined with results from previous studies to develop a refined empirical model for fracture occurrence based on Average Distal Forearm Speed (ADFS), and a revised value for fifty-percent probability of forearm-bone fracture of 10.5 m/s. Bone mineral content, which is directly related to forearm tolerance, was found to be linearly related to arm mass.

This paper presents a load distribution-specific viscoelastic structural characterization of the Hybrid III 50th percentile male anthropomorphic test dummy thorax. The dummy is positioned supine on a high-speed material testing machine and ramp-and-hold tests are performed using a distributed load, a hub load, and a diagonal belt load applied to the anterior thorax of the dummy. The force-deflection response is shown to be linear viscoelastic for all loading conditions when the internal dummy instrumentation is used to measure chest deflection. When an externally measured displacement (i.e., a measurement that includes the superficial skin material) is used for the characterization, a quasilinear viscoelastic characterization is necessary. Linear and quasilinear viscoelastic model coefficients are presented for all three loading conditions.

Data from the National Crash Severity Study (NCSS) has been analyzed with respect to lateral impacts. Accident variables, vehicle variables, and occupant variables, and their interactions have been considered. Emphasis has been placed on occupant variables, especially occupant injury patterns. This report is mainly a compendium of the data, including a comparison of the NCSS statistics with those from France, Germany, and Great Britain. Overall, these lateral impact statistics are quite similar to results of other field accident studies, which is an interesting observation given the diverse vehicle and driver populations and the differing traffic situations experienced by those populations. Conclusions have been drawn regarding typical lateral impact situations and the effectiveness of seatbelts in lateral impacts.

In 1998, Rouhana et al. described development of a new device, called the IR-TRACC (InfraRed - Telescoping Rod for Assessment of Chest Compression). In its original concept, the IR-TRACC uses two infrared LEDs inside of a telescoping rod to measure deflection. One LED serves as a light transmitter and the other as a light receiver. The output from the receiver LED is converted to a linear function of chest compression using an analog circuit. Tests have been performed with IR-TRACC units at various labs around the world since 1998. A first-generation IR-TRACC system was retrofit into a Q3 dummy by TNO. Similarly, a mid sized male Hybrid III dummy thorax and a small female Hybrid III dummy thorax have been designed by First Technology Safety Systems (FTSS) such that each contains 4 second-generation IR-TRACC units. The second-generation IR-TRACC is the result of continued development by FTSS, especially in the areas of the analysis circuit, manufacturing and calibration methods.

Airbag deployments are associated with loud noise of short duration, called impulse noise. Research performed in the late 1960's and early 1970's established several criteria for assessment of the risk of impulse noise-induced hearing loss for military weapons and general exposures. These criteria were modified for airbag noise in the early 1970's, but field accident statistics and experimental results with human volunteers exposed to airbags do not seem to agree with the criteria. More recent research on impulse noise from weapons firing, in particular that of Price & Kalb of the US Army Research Laboratory, has led to development of a mathematical model of the ear. This model incorporates transfer functions which alter the incident sound pressure through various parts of the ear. It also calculates a function, called the “hazard”, that is a measure of mechanical fatigue of the hair cells in the inner ear.

High-amplitude, short-duration noise is called impulse noise. A large body of literature on impulse noise has been developed primarily by military researchers for multiple exposures such as those caused by weapons firing. Some research into the impulse noise associated with air bag deployments was performed in the late 1960's and early 1970's to ascertain the risk of hearing loss. Several criteria for risk of noise-induced hearing loss were proposed and much was learned about the sources of the noise. Unfortunately, the instrumentation used to measure the noise in many of those studies lacked adequate low frequency response characteristics. Perhaps more importantly, results from experiments with human volunteers do not seem to agree with the proposed criteria. For this study, a new system consisting of commercially available pressure transducers and microphones was assembled and a new software package was developed.