Warren Tryon - US grants

SHB: Small: Cell Phone-Based Activity Monitoring for Telehealth

Abstract

Contemporary smart cell phones contain a tri-axial accelerometer, which makes it possible to measure the acceleration of a smart phone user in all three spatial dimensions. Modern data mining methods permit the construction of an activity recognition classifier from this acceleration data, so that a user's physical activity (e.g., walking, jogging, standing, etc.) can be automatically inferred from the accelerometer values. This research project will build an activity recognition system that can be deployed as a downloadable cell phone application. Users will then be able to access a description of their activities via a web interface and can use this information to monitor and change their behavior. Thus this research can be used to address the many health-related problems that result from physical inactivity. It can also assist with other health-related problem, such as falling in the elderly, by detecting falls and providing automatic notification to caregivers. The data generated via the cell phone activity recognition system will also enable large scale epidemiological studies of activity levels and health that, due to prohibitive costs, were not previously possible.

Building a successful activity recognition system will require addressing many technical challenges. This research will require improved feature construction methods for transforming time-series data into representations suitable for example-oriented classification algorithms. It will also require the evaluation of alternate architectures for performing wide-scale real-time data mining, in order to determine how much of the activity recognition work should be performed on the client (i.e., smart phone) versus a centralized server. The adequacy of smart cell phones for performing reliable activity recognition will also be evaluated given the many constraints (e.g., limited battery life) imposed by these devices.

Sleep is essential for health, daily functioning, and development. Yet, nearly 80% of 9th- and 97% of 12th-grade adolescents are chronically sleep-deprived. The adverse effects of sleep disturbance are especially pronounced for racial/ethnic minorities who consistently report poorer sleep hygiene. Hence, sleep can be added to a long list of areas in which racial/ethnic minorities suffer from disparities. Sleep disturbance may be a major cause of health and academic disparities among racial/ethnic minority adolescents. Sleep disturbance, health, and academic outcomes are also correlated with experiences of racial/ethnic discrimination, particularly among African American and Hispanic/Latino youth. This study explores whether sleep disturbance influences the relationships among racial discrimination, health and academic outcomes in this high-risk population.

Are youth with greater sleep disturbance more likely to exhibit a negative impact of discrimination on health and achievement? This 4-year study will follow adolescents through high school to understand the ways that social and sleep-related factors influence the associations among racial/ethnic discrimination, health and academic outcomes. By collecting daily reports of discrimination, actigraphy (wristband monitor) measures of sleep, tri-annual reports of health and academic outcomes, and an index of school racial/ethnic diversity, the study investigates: (a) the effects of racial/ethnic discrimination on health and academic outcomes, (b) if sleep disturbance explains the link between racial discrimination and health and academic outcomes, (c) whether having a positive racial/ethnic identity influences how racial discrimination is related to sleep disturbance, and (d) how school ethnic/racial diversity is related to health and academic outcomes. Today, ethnic minorities already comprise 53% of Americans under age 18 and this number is projected to grow. The fact that historically minority groups are experiencing numerical majority status has the potential to redefine race relations. This study explores whether sleep may help protect minority adolescents against the negative effects of racial discrimination and stress.