Indoor Location Tracking Using Bluetooth Proximity Beacons
Paul N. Kizakevich, Michael McCartney, Ann Zhang, Robert Daniel Furberg, Steve Duncan, Roy W. Whitmore · Epidemiology · 2006
SS7-05 Introduction: The purpose of this work is to develop methods for collecting longitudinal data on human exposure-related activities. Methods and instruments are being developed for a broad range of data types: activity, location, energy expenditure, environmental conditions, diet, and use of 3 types of consumer products: pesticides, cleaning products, and personal care products. Integration of data streams through a common ambulatory platform is integral to our strategy for collecting information all day each day for a week. Our goal is to achieve low enough participant burden that people will sustain participation in longitudinal studies for 1 week in each quarter of the year. Methods: To relieve the participant burden of noting presence in residential microenvironments, we developed an automated monitoring system for indoor location tracking using Bluetooth wireless technology. Autonomous beacons are placed in key residential microenvironments (eg, kitchen, bedroom, bathroom, garage, vehicle) and range-adjusted to the perimeter of each room. The range is determined according to room size, beacon placement within the room, and potential interference with adjacent rooms. Throughout the 7-day monitoring session, each beacon periodically tests (eg, 30-econd intervals) whether the participant's pocket PC is within range. When the participant's pocket PC is detected, the beacon sends a time-stamped microenvironment location code to the pocket PC for data logging. The resulting data log records a weeklong history of the time spent in each residential microenvironment. Controlled bench tests are being conducted to establish reliability, longevity, sensitivity, and specificity of the tracking methodology. Observational field tests are being conducted by placing beacons in investigators’ homes and logging automated and manually affirmed presence in various rooms throughout the day. A pilot field test of our overall system, including location tracking, will be conducted during the spring of 2006. Five pilot test subjects will be randomly assigned to each of 8 experimental treatments. Each subject will participate for 7 consecutive days. Results: Results will be available after the controlled bench, observational field, and pilot field tests have been conducted in the spring of 2006. Discussion and Conclusions: Preliminary results have shown that automated detection is closely aligned with manual data. Technical elements of the system design will be presented, along with results of the various test methodologies. Results from this project will determine a set of collection methods that will produce accurate estimates of human exposure-related activities in future longitudinal studies.