A new study conducted by researchers at the University of Waterloo, Canada has discovered that Apple Watch’s ECG sensor can detect stress, precisely, a new health monitoring feature untapped by Apple.
Apple Watch Series 6 and later models are equipped with an ECG sensor for users to monitor their heart rate at any place and at any time via the ECG app. The app also automatically detects undiagnosed atrial fibrillation (AFib), a form of irregular rhythm.
Data collected by the Apple Watch heart rate sensor accurately predicts stress scores
Researchers used the data collected by the ECG app to determine Heart Rate Variability (HRV) which indicates health problems related to heart conditions and mental health issues like depression and anxiety. In this case, HRV data was used to deduce the stress score.
For two weeks, participants took ECG recordings 6 times a day at three-hour intervals via an iPhone 7 on iOS 15 and an Apple Watch Series 6. The ECG data was converted into a CSV format and loaded into kubios to determine HRV. The researchers found:
“In general, the “stress” models had a high level of precision but lower recall. The “no stress” models performed generally well with a recall typically above 60%. Considering the ultra-short duration of the ECG measurements performed here compared to the standard, as well as the nature of real-life measurements, the results presented were quite promising.”
Researchers believe that the additional data collected by Apple Watch with an electrical heart sensor like physical and sleep activity can increase the model’s predictive power because they complement the ECG data.
They concluded that a wearable device capable of stress monitoring like the Apple Watch has the potential of improving users’ mental health.
The researchers contend that a wearable device capable of continuous, real-time stress monitoring would enable individuals to respond early to changes in their mental health. Furthermore, large-scale data collection from such devices would inform public health initiatives and policies.