Calculations



This section summarizes the PALMS data processing functions. Once GPS, accelerometer, and heart-rate (optional) data is uploaded and stored, calculations can be performed to filter, analyze and merge the datasets.

GPS Processing
  • Detect and mark gaps in data
  • Filter invalid and duplicate trackpoints
  • Find location clusters & mark locations
  • Detect trips
  • Classify and number trips
  • Estimate mode-of-transportation based on average speeds
  • Capture trackpoints at locations (optional)
  • Distinguish between indoors and outdoors (when used with QStartz GPS)

Accelerometer Processing
  • Detect and mark non-wearing conditions (defined as X minutes of consecutive zero values)
  • Detect and mark sedentary periods
  • Detect and mark bouts of activity (counts > X for at least Y minutes allowing for Z minutes of counts < X)
  • Classify periods of activity as light, moderate, vigorous, very vigorous based on cutoff values

Heart Rate Processing
  • Filter out dropouts and spikes
  • Detect and mark non-wearing conditions
  • Detect and mark bouts of elevated heart rate (BPM > X for at least Y minutes allowing for Z minutes of BPM < X)
  • Estimate participant's maximum heart rate (based on age)
  • Classify heart rate based in percentage of maximum

Data Fusion (Merge)
  • Align each data stream to desired interval
  • Merge GPS, accelerometer, heart rate data by aligning timestamps
  • Re-classify modes-of-transportation based on accelerometer and heart rate data
  • Calculate Energy Expenditure (EE)
  • Detect and mark gaps in data
  • Collapse / expand gaps as desired by user

Output Variables


Release R2 & R3:


Release R4: