Designing sensor systems capable of differentiating children from adults

INTRODUCTION: Injury prevention systems intended to prevent children from entering hazardous locations (or at least alert caregivers if that occurs) often respond to every instance of a person's presence, regardless of whether the intruder is a child. This performance results in a high nuisance alarm rate that sometimes causes adults to disable or circumvent the safety system. If a child safety system can accurately identify intruders as adults or children, nuisance alarm rates can be decreased. METHOD: This analysis selects three human factors (height, foot length, and cognition) amenable to adult/child differentiation and describes likely sensor strategies, advantages, and disadvantages. RESULTS: Preliminary testing of prototypes systems shows that simple sensor systems are capable of acquiring adequate data for adult/child differentiation. The discussion addresses requirements for discriminator systems and the effects of various sensor combinations on overall performance.     

Predicting pool safety habits and intentions of Australian parents and carers for their young children

Introduction: Children under five years are most at risk of experiencing fatal and nonfatal drowning. The highest proportion of drowning incidents occur in private swimming pools. Lapses in adult supervision and failures in pool barriers are leading contributory factors for pool drowning in this age group. Methods: We investigated the role of the theory of planned behavior social cognitions (attitude, subjective norm, and perceived behavioral control) as well as perceived barriers, planning, role construction, and anticipated regret on parents’ and carers’ intentions and habits toward two pool safety behaviors: restricting access and supervising children around private swimming pools. The study adopted a cross-sectional correlational design. Participants (N = 509) comprised Australian parents or caregivers with children aged under five years and access to a swimming pool at their residence. Participants completed a battery of self-report measures of social cognitive variables with respect to the swimming pool safety behaviors for their children. Results: Path analytic models controlling for past behavior indicated that subjective norm, planning, anticipated regret, and role construction were important predictors of habit, and subjective norm was a consistent predictor of intentions, for both behaviors. Planning predicted intentions in the restricting access sample, while attitudes, barriers, and role construction also predicted intentions in the supervising sample. Both models controlled for past behavior. Conclusion: Current findings indicate the importance of psychological factors for restricting access and supervising behaviors, with normative factors prominent for both reasoned (intentions) and non-conscious (habits) behavioral antecedents. It seems factors guiding restricting access, which likely require regular enactment of routine behaviors (e.g., ensuring gate is not propped open, pool fence meets standards), may be governed by more habitual than intentional processes.     

Swimming obstructed by dead-water

In nautical literature, ‘dead-water’ refers to the obstructive effect encountered by ships moving in stratified water due to the ship generating waves on an interface that separates different water masses. To investigate the hypothesis that open water swimming may also be obstructed by an encounter of dead-water, possibly causing drowning, we performed two experiments that assess the impact of stratified water on swimming. In the first experiment, subjects made a single front-crawl stroke while lying on a carriage that was rolling just above the water surface. The gain in kinetic energy, as a result of the stroke, was far less in stratified than in homogeneous water. In the second experiment, four subjects swam a short distance (5 m) in homogeneous and in two different settings of stratified water. At the same stroke frequency, swimming in stratified conditions was slower by 15%, implying a loss in propulsive power by 40%. Although in nature stratification will be less strong, extrapolation of the results suggests that dead-water might indeed obstruct swimming in open water as well. This effect will be most pronounced during fair weather, when stratification of a shallow surface layer is most easily established. Our findings indicate that swimmers’ anecdotal evidence on ‘water behaving strangely’ may have to be taken more seriously than previously thought.     

Ecology of drowning risk at a public swimming pool

INTRODUCTION: The fourth-leading cause of death in middle childhood is drowning, but there is remarkably little known about swimmer or lifeguard behavior patterns at public swimming pools. METHOD: This study used non-intrusive observational methodology to examine risk-taking by swimming patrons (predominantly children) and surveillance habits of lifeguards at a public swimming pool. The study also examined whether risk-taking behavior might be associated with density of swimmers, temperature, or lifeguard behaviors. RESULTS: Results suggested risk-taking behavior was common, with dangerous incidents observed over 90 times per hour. Particularly high were rates of running on the deck, which exceeded 100 incidents per hour near the deepest water of the pool, and jumping into the water dangerously close to other swimmers, which was witnessed about once every two minutes in the shallow water of the pool. Lifeguards tended to scan the pool well, and remain attentive to the areas under their responsibility, but they were distracted about 10 times per hour and warned patrons only about once for every 14 dangerous incidents observed. CONCLUSIONS: No consistent correlates to risk-taking behavior by swimming pool patrons were identified. Results are discussed with respect to previous findings and implications for intervention. Impact on Industry: Findings emphasize the need to increase awareness and adherence to safety rules by swimmers at swimming pools; to educate and remind lifeguards about proper swimming pool surveillance techniques; and to consider environmental changes at public swimming pools that might increase swimmer safety.