Oleksandr Solovei ⁽⁵⁾

Abstract The assessment of stress responses requires simultaneous measurement of both cognitive performance and physiological markers. This paper presents a novel methodology for synchronizing browser-based cognitive stress tests with commercial wearable device data (Garmin .fit format) using timestamp alignment. We developed a suite of six…

Abstract The General Data Protection Regulation (GDPR) presents both challenges and opportunities for digital health research. This article examines GDPR compliance considerations in the context of web-based cognitive stress testing synchronized with wearable device data. We present a privacy-first architecture that satisfies GDPR requirements while…

Abstract Heart rate variability (HRV) derived from electrocardiography (ECG) is the established ground truth for physiological stress assessment, yet ECG requires skin-contact electrodes that limit ecological validity and participant comfort. Consumer smartwatches equipped with photoplethysmography (PPG) sensors offer a non-invasive alternative, providing continuous heart rate…

In the realm of wearable technology, stress monitoring has become a “holy grail” for digital health. While most high-end clinical studies rely on Heart Rate Variability (HRV) derived from precise R-R intervals (the time between individual heartbeats), many consumer-grade smartwatches struggle to provide these intervals…

Abstract Heart rate variability (HRV) is a well-established biomarker for autonomic nervous system activity, stress, and emotional regulation. Clinical HRV analysis requires continuous electrocardiogram (ECG) recordings with beat-to-beat (R-R interval) precision—a requirement that off-the-shelf smartwatches fundamentally cannot meet. Consumer wearables such as Garmin devices provide…