Heart Rate Variability - Pro

- Real time display of LF/HF
- Enhanced ectopic beat elimination
- All data saved to files for offline analysis
- Improved stability

Ectopic beats are captured by Lagrangian interpolation of the data stream.

LF/HF is calculated by resampling the dataset at 4Hz them applying Welch's periodogram through a 256 point FFT using a 16 sample wide window and an 8 sample overlap.

The uncorrected raw R-R samples are saved in a file named "year-month-day-hour-minute-second-r2r.txt"
The HRV parameters calculated and displayed during operation are saved in a file named "year-month-day-hour-minute-second-sd1.txt"

The filenames are the time the program was started and are saved in the directory HRVpro/data.

Both files can be imported into Excel and the r2r file can be directly opened in Kubios.

Next steps: Plot LF/HF as skinny bars withing the SD1 plot

Notes
1. This app is for general interest only and SHOULD NOT be used for any clinical purpose.
2. CONSULT YOUR PHYSICIAN before undertaking any strenuous activity
3. This app requires a Polar Wearlink+ Transmitter With Bluetooth (Available from Amazon)
- NOTE If you have a Bluetooth Low Energy Chest-strap such as Polar H7 or Zephyr HxM check out the new app HRVxt
4. App was developed and tested on Samsung S3
5. Some users of the free version of the app have reported odd behavior such as failing to connect properly (with the display remaining at 'listening') and the app displaying improbably high values. Both of these conditions have been seen during development of the app and appear to be an Andriod related issue ( when the device gets itself in this state, 'Cardio Training' fails as well).
Recovery from this condition can be achieved by shutting the device down completely then restarting.