Evaluating the accuracy of wearable heart rate monitors

Heart rate monitors have become a popular tool, which have been built in many different wearable devices, such as Smart Watches and Chest Straps. These wearable monitoring of heart rate (HR) during exercises have given the user some understanding of the heart rate variations. Even though this is not 100% accurate as electrocardiogram (ECG), its being very popular tool for consumers. The technology uses in smart watches is photoplethysmography (PPG) signal and Chest Straps use ECG signal. The main aim of this paper is to compare two wearable devices to monitor heart rate. 50 healthy volunteers participated in this study by completing three different exercises sitting, walking and jogging. The experiment results illustrates that it's harder to get a unique percentage for the variation between the readings of these two devices, however in normal condition both the devices read almost the similar value, but during the exercises it varies and can be with a maximum of 10% variation in the readings. Overall it appears that chest strap utilizing ECG signal appears to be a more accurate than the Apple Watch which utilizes PPG for monitoring heart rates while exercising.