Fully automated method for QT interval measurement in ECG

Fully automated method for QT interval measurement is presented. It includes ours: QRS detection algorithm and ECG signals preprocessing allowing suppression of power-line interference, electromyographic noise and baseline drift guaranteeing accurate preservation of the QRS-onset and T-end locality. Representative heart beat is automatically selected at the smallest difference between two consecutive RR intervals. Our method for automatic detection of QRS-onset and T-end is based on the minimum value of the angle between two segments having a common mid point and equal lengths of 10 ms. The minimum of the angle is searched in defined time intervals delineated separately for the Q and T. The method is developed with a feedback to published experts´ markings for Q and T. The mean and standard deviations of the QT differences between our method and the experts´ markings are 3.86 + 12.52 ms. The score 25.19 for the Challenge 2006 is the second best in Division 3.