High Resolution Trajectory Mapping of Post-discharge Knee Replacement Patients (TRIPP: Trajectories in Predictive Methods and Alerts to Prevent Asthma)

To determine if particulate matter exposure levels, as measured at the individual level with real-time, data-logging instrumentation, correlate with asthma symptoms.
To determine if particle size (measured in 5 size denominations from 10 micrometers to 300 nanometers), in the context of exposure to particulate matter, correlates with the onset of asthma symptoms.
To determine what time lag, if any, there is between exposure to particulate matter and the onset of symptoms.