  This paper presents a cloud-connected indoor air quality sensor system that
can be deployed to patients' homes to study personal microenvironmental
exposure for asthma research and management. The system consists of multiple
compact sensor units that can measure residential NO2, ozone, humidity, and
temperature at one minute resolution and a cloud based informatic system that
acquires, stores, and visualizes the microenvironmental data in real time. The
sensor hardware can measure NO2 as low as 10 ppb and ozone at 15 ppb. The cloud
informatic system is implemented using open-source software on Amazon Web
Service for easy deployment and scalability. This system was successfully
deployed to pediatric asthma patients' homes in a pilot study. In this study,
we discovered that some families can have short term NO2 exposure higher than
EPA's one hour exposure limit (100 ppb), and NO2 micropollution episodes often
arise from natural gas appliance usage such as gas stove burning during
cooking. By combining the personalized air pollutant exposure measurements with
the physiological responses from a patient diary and medical record, this
system can enable novel asthma research and personalized asthma management.
