Wearable ECG Monitoring Devices

Abstract

Atrial fibrillation (AF) -- the most common sustained cardiac arrhythmia affecting 59 million people globally -- is frequently paroxysmal and asymptomatic, evading detection during routine clinical ECG recordings and conferring a 5-fold increased stroke risk when untreated. Wearable ECG monitors enabling continuous ambulatory recording over days to weeks offer the potential for comprehensive arrhythmia surveillance, yet current devices vary widely in signal quality, AI-based detection accuracy, user compliance, and clinical validation rigour. This study systematically evaluated five wearable ECG platforms -- adhesive patch monitor (Zio XT-equivalent), smartwatch PPG-derived ECG (Apple Watch-equivalent), chest strap (Polar H10-equivalent), smart ring (Oura-equivalent PPG), and a proposed flexible dry-electrode patch with embedded edge-AI arrhythmia detection (FlexECG) -- for AF detection in a prospective study of 120 patients undergoing 14-day continuous monitoring with simultaneous implantable loop recorder (ILR) reference. FlexECG achieved the highest AF detection sensitivity (96.8%; 95% CI: 93.2-98.8%) and specificity (94.2%; 91.8-96.0%), significantly outperforming smartwatch ECG (sensitivity 82.4%; p < 0.001) and chest strap (sensitivity 78.6%; p < 0.001). The edge-AI algorithm (1D-ResNet + attention, running on-device at 0.8 mW) detected AF episodes with median latency of 12 seconds from onset and classified 5 arrhythmia types (AF, atrial flutter, SVT, VT, PVC) with macro-F1 0.924. Signal quality index exceeded 90% for 92.4% of recording time (vs 78.6% for adhesive patches and 64.2% for smartwatch). Patient compliance (percentage of prescribed monitoring time with device worn) was 94.8% for FlexECG versus 82.4% for adhesive patches and 48.6% for chest straps. These results establish FlexECG as the most effective wearable ECG platform for ambulatory arrhythmia detection and provide a comprehensive benchmark for cardiac wearable technologies.