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Motor vehicle accidents are statistically the major cause of accidental severe injuries for pregnant women and fetuses fatality. Volunteers, post mortem human surrogates, anthropomorphic crash test devices and computational occupant models are used to improve human safety in motor vehicle accidents. However, due to the ethical issues, pregnant women and their fetuses cannot be used as volunteers or post mortem human surrogates to investigate the effects of crashes on them. The only anthropomorphic test device representing pregnant women is very limited in design and lacks a fetus. There is no computational pregnant occupant model with a fetus other than 'Expecting'. This thesis focuses on understanding the risk of placental abruption for pregnant drivers involved in road accidents, hence assessing the risk to fetus fatality. An extensive review of existing models in general and pregnant women models in particular is reported. The time line of successive development of crash test dummies and their positive effect on automotive passive safety design are examined. 'Expecting', the computational pregnant occupant model with a finite element uterus and a multibody fetus, is used in this research to determine the strain levels in the uteroplacental interface. External factors, such as the effect of restraint systems and crash speeds are considered. Internal factors, such as the effect of placental location in the uterus, and the inclusion and exclusion of a fetus are investigated. The head of the multibody fetus is replaced with a deformable head model to investigate the effects of a deformable fetus head on strain levels. The computational pregnant driver model with a fetus offers a more realistic representation of the response to crash impact hence provides a useful tool to investigate fetus safety in motor vehicle accidents. Seat belt, airbag and steering wheel interact directly with the pregnant abdomen and play an important role on fetus safety in motor vehicle accidents. The results prove that the use of a three-point seat belt with the airbag offer the greatest protection to the fetus for frontal crash impacts. The model without a fetus underestimates the strain levels. The outcome of this research should assist automobile manufacturers to address the potential safety issues at the design level.

This thesis describes the prototype and development of a soft continuum robotic airbag system that is attached to a passive mobility walker. The system can deploy in multiple configurations: to the front, left, or right of the walker depending on the direction of a detected fall. The continuum component of the project is made of nylon fabric with thin cables, allowing it to be compactly stored before deploying. The airbag is inflated in real time during a fall using a novel compression system. Results of experiments with the prototype in each configuration are presented. The system deploys consistently across falls, significantly reducing the g-force of impact.

Although airbags have reduced the incidence of fatal and severe injuries in automobile collisions, they have been shown to increase the risk of less severe injuries. The purpose of this research was to investigate particular occupants and injury types in automobile crashes in order to identify national trends in injury incidence, type, and severity. A statistical analysis was performed in order to determine the effects of airbag deployment on incidence and severity of various injury and occupant types. In addition, a computational modeling study aimed to recreate actual automobile crashes that occurred in order to identify injury mechanisms and occupant kinematics during the crash. The specific studies performed were designed to investigate the effects of frontal airbags on: skin injuries, burn injuries, eye injuries, orbital fractures, severe upper extremity injuries, and pregnant occupant injuries. The statistical analyses revealed several significant findings in injury trends related to occupant exposure to airbag deployment. In particular, occupants in frontal crashes were significantly at a higher risk to sustain a skin injury (p=0.00), a burn injury (p=0.02), a corneal abrasion (p=0.03), and a severe upper extremity injury (p=0.01) when exposed to an airbag deployment, than when not exposed to an airbag deployment. In addition, female occupants were at a statistically higher risk of sustaining an airbag induced skin injury than males (p=0.00). Finally, within a 95% confidence interval, older occupants were at a higher risk for sustaining both airbag induced burn injuries, and severe upper extremity injuries. While occupants in crashes with lower impact velocities were at a higher risk for airbag induced burn injuries, occupants in crashes with higher impact velocities were more likely to sustain a severe upper extremity injury. The airbag increased the incidence of eye injuries for occupants in frontal crashes, however, it also decreased the severity of the associated eye injuries. In particular, occupants who sustained an orbital fracture when exposed to airbag deployment sustained mostly closed, less severe orbital fractures, while occupants not exposed to airbag deployment much more often sustained more severe, open, displaced, or comminuted orbital fractures. While the airbag was shown to increase the risk of some injuries to particular occupants involved in specific crash types, the airbag appears to have provided a beneficial protective effect as it also reduced the severity of all injuries observed.

Airbags have been saving lives in automobile crashes for many years and are now being used in helicopters. The purpose of this study was to investigate the potential for ocular injuries to helicopter pilots wearing night vision goggles when the airbag is deployed. A nonlinear finite element model of the human eye was constructed. Ocular structures never before included in finite element models of the eye, such as the fatty tissue, extraocular muscles, and bony orbit were included in this model. In addition, this model includes material properties up to rupture making the eye suitable for large deformation applications. The model was imported into Madymo and used to determine the worst-case position of a helicopter pilot wearing night vision goggles. This was evaluated as the greatest Von Mises stress in the eye when the airbag is deployed. The worst-case position was achieved by minimizing the distance between the eyes and goggles, having the occupant look directly into the airbag, and making initial contact with the airbag halfway through its full deployment. By removing the extraocular muscles, the stress sustained by the eye decreased. Simulations with both the goggles remaining fastened and breaking away from the aviator helmet were performed. Finally, placing a protective lens in front of the eyes was found to reduce the stress to the eye but increase the force experienced by the surrounding orbital bones. The finite element model of the eye proved effective at evaluating the experimental boundary conditions, and could be used in the future to evaluate impact loading on eyes that have been surgically corrected and to model the geometry of the orbital bones.