Lead quality monitoring for detection of the Optimal Snapshot Time to record resting ECG

This study presents a multichannel ECG quality monitoring system, which continuously scans the leads´ status (valid/lead-off) and quality (0-100%), according to the ECG components in the low, medium and high frequency bands. The system aims to detect the optimal moment to start the record of a 10s resting ECG within the 1^st minute of signal acquisition - the earliest in time, the best in all leads´ quality, named `Optimal Snapshot Time´ (OST) and `Best Snapshot Quality´ (BestSQ). The system compares the current leads´ quality to an adaptive quality threshold (AQT) whose decreasing trend is trained on 375 ECGs. The validation over 267 ECGs in the test database shows that: 87.2% of the ECGs would be recorded with a quality ≥ 95%BestSQ; 33.1% at the optimal moment OST±2.5s; 29.3% would be started earlier due to their sufficient quality >AQT; 37.2% would be recorded with a delay >2.5s due to their compromised BestSQ, not reaching the AQT level in the vicinity of OST.