A New Automatic QT-Interval Measurement Method for Wireless ECG Monitoring System Using Smartphone.

Area of Science:

• Biomedical Engineering
• Cardiology
• Signal Processing

Background:

• QT interval prolongation is a key indicator for diagnosing heart arrhythmias.
• Manual QT interval measurement from electrocardiograms (ECGs) is time-consuming, especially for 12-lead ECGs.
• Automated QT interval measurement is essential for efficient cardiac monitoring.

Purpose of the Study:

• To develop and validate a novel, automated method for accurate QT interval measurement.
• To assess the performance of the proposed method against manual measurements and existing techniques.

Main Methods:

• The automated method involves three stages: QRS-complex detection using a modified Pan-Tompkins algorithm, QRS-onset determination, and T-end determination based on Region of Interest (ROI) maximum limit.
• The system was implemented on a smartphone-based ECG monitoring system.
• Performance was evaluated using correlation coefficient and 95% Limits of Agreement (LoA).

Main Results:

• The automated QT interval measurement achieved a correlation coefficient of 0.575 and a 95% LoA range of 0.290 when compared to reference measurements.
• The QRS-complex detection demonstrated high accuracy (99.70%), positive predictive value (99.78%), and sensitivity (99.92%).
• The smartphone system achieved a 95% LoA range of 0.216 for QT interval measurements compared to manual methods.

Conclusions:

• The proposed automated QT interval measurement method is reliable and accurate for ECG analysis.
• This method offers superior performance in terms of correlation coefficient and 95% LoA compared to other existing techniques.
• The successful implementation on a smartphone highlights its potential for practical clinical applications and remote patient monitoring.