ECG waveform data extraction from paper ECG recordings by K-means method

Though modern ECG machine with digital-out has been applied for years, paper recordings are still chosen by medical organizations especially in China. But the recording paper is easily broken. These ECG data were necessarily to be extracted and keep the valuable ECG information as digital type for clinical information sharing, online diagnosing and ECG database establishing. A method based on K-means was proposed to extract ECG data from paper recordings. The ECG waveform and the background grid were separated well.105 patients´ ECG paper recordings were adopted in the experiment. And the recordings are in different damage level, the paper are in different background color and made by different manufacturers. The result shows that ECG waveform can be extracted precisely and smoothly. The precision rate of RR interval, QRS interval, QT interval, ST slope, and R amplitude from ECG data which are digitalized by the approach in the paper could reach 99%.