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This ground-breaking book provides substantial new analysis and summary data about pregnant occupant biomechanics, and will serve as a critical asset to anyone in the field of automobile safety. The overall goal of this book is to provide the reader with a complete resource for issues relating to the pregnant occupant. This multi-authored book is thoroughly vetted and includes chapter contributions from highly qualified practitioners in the field. A total of 19 technical papers are featured and are broken into six chapters. Each chapter begins with a brief summary and analysis of the research for that topic, and is followed by a selection of references. The remainder of the chapter includes a selection of the very best full-length technical papers on the topic, which are intended to provide depth and compliment the new material.

In order to evaluate a human surrogate, the human and surrogate response must be defined. The purpose of this study was to evaluate the response of cadaver subjects to blunt impacts to the frontal bone, nasal bone and maxilla. Force-displacement corridors were developed based on the impact response of each region. Variation in the force-displacement response of the cadaver subjects due to the occurrence of fracture and fracture severity was demonstrated. Additionally, impacts were performed at matched locations using the Facial and Ocular CountermeasUre Safety (FOCUS) headform. The FOCUS headform is capable of measuring forces imposed onto facial structures using internal load cells. Based on the tests performed in this study, the nasal region of the FOCUS headform was found to be the most sensitive to impact location. Due to a wide range in geometrical characteristics, the nasal impact response varied significantly, resulting in wide corridors for human response.

The objective of this study was to investigate potential for traumatic brain injuries (TBI) using a newly developed, geometrically detailed, finite element head model (FEHM) within the concept of a simulated injury monitor (SIMon). The new FEHM is comprised of several parts: cerebrum, cerebellum, falx, tentorium, combined pia-arachnoid complex (PAC) with cerebro-spinal fluid (CSF), ventricles, brainstem, and parasagittal blood vessels. The model's topology was derived from human computer tomography (CT) scans and then uniformly scaled such that the mass of the brain represents the mass of a 50th percentile male's brain (1.5 kg) with the total head mass of 4.5 kg. The topology of the model was then compared to the preliminary data on the average topology derived from Procrustes shape analysis of 59 individuals. Material properties of the various parts were assigned based on the latest experimental data.

The objective of this study was to investigate the use of a fiber optic based sensor, ShapeTape, as an instrument for measuring abdominal and chest deflection, and to compare it to the current instrument used in impact biomechanics applications, the chestband. Drift, pressure, and temperature tests were conducted for ShapeTape alone, whereas quasi-static and dynamic loading tests were conducted as comparison tests between the chestband and ShapeTape. The effects of drift and temperature on ShapeTape were very small, averaging 0.26% and 1.2% full scale changes respectively. During the pressure test at a load of 1000 N the ShapeTape sensor tested experience a 7.47% full scale voltage change. The average errors in reporting maximum deflection of the chest form during the quasi-static loading tests were 3.35% and 1.64% for ShapeTape and the chestband respectively.

The goal of this project was to evaluate the effect of occupant seating and seatbelt placement on the risk of adverse fetal outcome from a motor vehicle crash. Unrestrained, 3-pt belt, and 3-pt belt plus airbag tests were simulated with the Virginia Tech pregnant occupant computational model in both a driver-side and passenger-side vehicle interior in frontal impacts at 35 kph. The pregnant occupant model is a small female human body model modified to include a finite element uterine model. The model was previously created and validated with abdominal force-deflection responses. Peak uterine strain was reduced by 30% to 50% in passenger-side simulations vs. driver-side simulations. However, in the unrestrained, passenger-side simulation, the pregnant occupant sustained a HIC score of 2820, suggesting immediate maternal death and a high likelihood of fetal death. Additional simulations were run in which the vertical position of the lap-belt was varied through three heights.

A finite element model of a 7-month pregnant uterus was created and integrated into a multi-body human model. The uterine model contains 11,632 elements and 16,335 nodes. The pregnant occupant model was validated using known abdominal response corridors. Unrestrained, 3-pt belt, and 3-pt belt plus airbag tests were simulated at speeds ranging from 13 kph to 55 kph. Peak uterine strain was found to be a good predictor of fetal outcome (R2= 0.85). The strain in the uterine wall exceeded 60%, sufficient to cause placental abruption, in simulations of no restraint at 35 kph and 3-pt belt tests at 45 kph and 55kph. These tests represent a greater than 75% risk of adverse fetal outcome. For matched tests at 35 kph, strains of 60.8% for the unrestrained occupant, 52.6% strain for the 3-pt seatbelt and only 33.0% strain for the 3-pt seatbelt and airbag combination were recorded.

The purpose of this study was to investigate eye injuries and orbital fractures resulting from frontal automobile crashes and to determine the effects of frontal airbags. For this two part study, cases in NASS were selected from the years 1993 through 2000 that include drivers and front seat occupants only, while excluding ejected occupants and rollovers. In addition, only frontal impacts were considered, which are defined as having a primary direction of force (PDOF) of 11, 12, or 1 o'clock. Eye injuries in the NASS database were identified using the current AIS injury codes. An analysis of the cases indicates that 3.1% of occupants exposed to an airbag deployment sustained an eye injury, compared to 2.0% of those occupants not exposed to an airbag deployment. Moreover, there was a significant increase in the risk of corneal abrasion for occupants exposed to an airbag deployment (ρ = 0.03).

The purpose of this study was to investigate severe upper extremity injuries and minor skin injuries resulting from frontal automobile crashes and to determine the effects of frontal airbags. The National Automotive Sampling System database files from 1993 to 2000 were examined in a study that included 25,464 individual cases that occurred in the United States. An analysis of the cases indicated that occupants exposed to an airbag deployment were statistically more likely to sustain a severe upper extremity injury (2.7%), than those occupants not exposed to an airbag deployment (1.6%) (p=0.01). In particular, 0.7% of occupants exposed to an airbag deployment sustained a severe upper extremity injury specifically from the airbag. In addition, when in crashes with an airbag deployment, older occupants were at a higher risk for severe upper extremity injury, as well as occupants in crashes with higher changes in velocity.

The widespread implementation of air bags has increased the incidence of upper extremity injuries in the automotive crash environment. The first step in reducing these injuries is to determine applicable upper extremity injury criteria. The purpose of this paper is to develop injury risk functions for the fifth percentile female forearm, humerus, wrist, and elbow. Injury tolerance data for each anatomical region were gathered from experiments with controlled impact loading of disarticulated small female cadaver upper extremities. This technique allowed for the applied load to be directly quantified. All data were mass scaled to the fifth percentile female. In order to develop the risk functions, the logit distribution was integrated for the uncensored data, while logistic regression and generalized estimating equations statistical analysis techniques were used for censored data.

The purpose of this study was to investigate ocular injuries from high velocity objects projected during an automobile collision. A computational model of the human eye was developed that included ocular structures such as the orbital fatty tissue, extraocular muscles and bony orbit. In order to validate the model, the results predicted by the model were compared to those previously found experimentally. In these experiments, porcine eyes were impacted with foam particles representative of those released during the deployment of an airbag through a seamless module cover. After simulating the identical experimental conditions, the results predicted by the model were in agreement with those found experimentally. A parametric study was conducted to determine the effect of these anatomical boundary conditions. Using MADYMO, a glass particle was projected into the eye. With the fatty tissue and muscles in place, a maximum Von Mises stress of 12.8 MPa occurred in the cornea.

Although filter class specifications have been defined for most anthropomorphic test devices, no recommendation exists for the instrumented upper extremity. A three-part study was performed to determine the best channel filter class (CFC) to use for the instrumented upper extremity. By analyzing frequency content of signals from accelerometers and load cells, filtering data through three of the four possible CFC's to compare effects on the signals, and performing an injury comparison between cadaver data and the filtered load cell data, CFC 600 was chosen and recommended as the optimum filter class to use for upper extremity testing.

This paper presents a parametric study that utilized the CVS/ATB multi-body simulation program to investigate the interaction of the hand and wrist with a door handgrip during side air bag loading. The goal was to quantify the relative severity of various hand and handgrip positions as a guide in the selection of a test matrix for laboratory testing. The air bag was represented as a multi-body system of ellipsoidal surfaces that were created to simulate a prototype seat-mounted thorax side air bag. All simulations were set in a similar static test environment as used in corresponding dummy and cadaver side air bag testing. The occupant mass and geometric properties were based on a 5th percentile female occupant in order to represent a high-risk segment of the adult population. The upper extremity model consisted of wrist and forearm rotations that were based on human volunteer data.