How do you calculate the HRV score?

Our HRV score process is broken down as follows:

• We receive the R-R intervals directly from your finger during the reading
• Obvious artifacts are cleaned. The raw, unaltered R-R intervals are backed up securely to the server database. This allows us to improve algorithms for all current and past calculations.
• We apply the RMSSD calculation to the R-R intervals. Root Mean Square of Successive Differences (RMSSD) is the industry standard time domain measurement for detecting Autonomic Nervous System (specifically Parasympathetic) activity in short-term measurements.
• The natural log (ln) is applied to RMSSD. Since RMSSD does not follow a linear trend, conceptualizing the magnitude of its changes can be challenging as it fluctuates. Therefore, it is common practice in the application of RMSSD to apply a natural log to produce a number that behaves in a more linearly distributed fashion.
• The ln(RMSSD) is expanded to generate a useful 0 to 100 score. The ln(RMSSD) value typically ranges from 0 to 6.5. Using over 6,000,000 readings from our database, we have been able to sift out anomalous readings and create a much more accurate scale where everyone fits in a 0 to 100 range – even Olympians and elite endurance athletes.

The final Heart Rate Variability (HRV) score displayed in your reading results is derived from all the raw R-R interval data gathered throughout the entire duration of the measurement.