Do wearable sensors really measure pulse accurately?

26 Ağu 21:04

There are actually a few pro tips when it comes to precision with optical heart rate sensors. First off, green light (515-545nm wavelength) is less absorbed by melanin (the skin's pigment) but heavily absorbed by hemoglobin, which is why this method tends to be a bit problematic for darker skin tones. If you have darker skin, your wrist sensor can be off by 10-15% even during indoor activities—I’m dark-skinned myself, and when I compared my Polar H10 to my watch during runs, the readings were inconsistent. On top of that, cold weather slows down peripheral circulation, making it harder for the sensor to detect reflected light from the skin. In the cold, wrist sensors can sometimes show up to 20% deviations in heart rate—that’s why I tried placing mine on a bony area under clothing (like the inside of my arm) during outdoor activities, and it gave me more stable results. When compared to ECG sensors, optical sensors show significant differences in synchronization and accuracy. I tested Apple Watch’s ECG sensor (electrocardiographic sensor) and Polar H10 in parallel. While the ECG sensor can detect asystole/ventricular beats, optical sensors only measure periodic heart rate ranges—so they fall short during arrhythmias or sudden changes during exercise. Depending on exercise intensity, the margin of error for optical sensors ranges from 5-25% (worst during high-intensity interval training), whereas ECG sensors stay within 1-3%. So, if you just want quick feedback for fitness/performance tracking, optical sensors can work, but if you need medical precision or suspect arrhythmias, it’s worth investing in a device that can record an ECG alongside it.