4 posts found
Your smart ring does not count your breaths. It counts the ripples that breathing leaves on your heart rate, then runs statistics to guess how many times you inhaled. The method is real. The precision is not.
Most wearables compute a stress score by running your heart rate through a black box. Pulsyn does the same thing, but the weights are public, the math is in the repository, and the app tells you exactly how confident it is. Here is the full breakdown.
Every major wearable gives you a stress score between 0 and 100. That number is not a measurement. It is a proprietary blend of heart rate variability and secret sauce with no clinical definition. Pulsyn shows you the raw HRV and the context instead.
HRV is not a score. It is a noisy physiological signal that consumer wearables clean, compress, and repackage as a recovery percentage with no medical validation. This post explains how the sausage is made, why the math does not support the marketing, and what Pulsyn does instead.