Thesis (Ph. D.)--Virginia Commonwealth University, 2009. / Prepared for: Dept. of Public Policy and Administration. Title from title-page of electronic thesis. Bibliography: leaves 128-141.

Research suggests that infants with poor neck and upper torso muscle tone experience lateral slouching and a compromised airway when placed in the semi-upright seating position. Studies reveal that 4-60% of premature infants (born at less than 3-7 weeks gestation) may experience oxygen desaturation events when in their child safety seats (CSS), potentially resulting in adverse neurodevelopmental outcomes. Therefore, the American Academy of Pediatrics recommends that premature infants be tested in their CSS prior to hospital discharge. However, neonatal healthcare providers are concerned that this method of testing might not be reliable. No formal studies have investigated the outcomes of repeat testing of premature infants, and little is known about the risk factors for oxygen desaturation events. Therefore, the purpose of this descriptive, non-experimental, observational study was to explore the stability of the one-point Infant Car Seat Challenge (ICSC) and risk factors that may be associated with oxygen desaturation events. A sample of 49 premature infants was used to explore the following variables: 1) pass/fail rates following two (ICSC) observation points, 2) oxygen saturation and desaturation patterns, sleep/wake activity, and a measure of head lag (using the pull-to-sit maneuver) during two ICSCs, and 3) the association between head lag, chronological age, time spent sleeping in the CSS and oxygen desaturation events. Data were analyzed by descriptive and nonparametric statistical tests. This study's findings indicated that 86% of premature infants had stable results, 8% passed rcsc 1 but not ICSC 2, and 6% failed ICSC l and passed ICSC 2. In addition the odds for oxygen desaturation events increased in infants that are born at a gestational age ≤ 34 weeks, were discharged home at a chronological age of > 7 days and had a corrected gestational age of ≤ 37 weeks. Neither head lag or sleep time influenced the ICSC outcomes. Furthermore the ICSC success rate for identifying at risk infants was equal to or better than that of other screening tests for newborn medical conditions. These findings will assist neonatal healthcare providers in making appropriate recommendations for safe travel.

Whiplash is a neck injury caused by the sudden differential movement between the head and torso. Whiplash injuries are most commonly reported as a consequence of rear impacts in car accidents. They are regarded as minor injuries, but can still lead to long-term disablement and discomfort in the neck. Whiplash injuries can be mitigated by better car seat designs. For this purpose, head restraint geometry must be improved first, and then the dynamic performance of the whole seat must be assessed at all crash seventies. A biofidelic human-body model is a key requirement in designing whiplash mitigating car seats. This thesis presents the development of a 50th percentile male multi-body human model and several energy absorbing car seat designs. The human-body model is specifically designed for rear impact and validated using the responses of seven volunteers from Japanese Automobile Research Institute (JARI) sled tests, which were performed at an impact speed of 8 kph with a rigid seat and without head restraint and seat belt. A generic multi-body car seat model is also developed to implement various seatback and recliner properties, anti-whiplash devices (A WDs) and head restraints. Using the same driving posture and the rigid seat in the JARI sled tests as the basic configuration, several anti-whiplash seats are designed to allow different types of motion for the seatback and seat-pan. The major findings of this research are: -The human-body model simulates the effects of muscle contraction and its overall response is superior in comparison to the currently used models and dummies. -A criterion called the S-shape index (SSI) is developed based on the intervertebral angles of the upper and lower cervical spine. -The car seat design concepts are able to control and use crash energy effectively with the aid of anti-whiplash devices for a wide range of crash seventies. -In order to reduce whiplash injury risk, this study advocates energy absorbing car seats which can also provide head restraint contact as early as possible.

The Master’s thesis deals with development of universal equipment for testing and measurement operating forces of car seats. It describes tests applied on car seats and shows a few examples of equipment for testing. The design part of the thesis deals with development of multipurpose testing equipment using of Modular Function Deployment™ approach. The design of the equipment is done in 5 steps according to mentioned approach. The final part of the thesis includes a risk analysis of the new device and conclusion.