Computer analysis of the electrocardiograms from ECG paper recordings

The volume of electrocardiograms (ECG´s) recorded in hospital is increasing. Although modern electrocardiographs have digital output, most of ECG´s are still recorded on plain papers. Recently, exchanging patients´ clinical information between healthcare facilities has become very important. It will be very helpful, if plane paper type of ECG could be converted to digital form. In general, the background of ECG paper charts can be divided into three types: uniform background, background with colored grid and background with black grid. In this study, we developed a morphological method to retrieve ECG data on paper charts using optical scanner and computer. The results show that our method can erase the background noise and acquire the digital ECG signal from ECG paper charts correctly. Conversion of ECG by optical scanner is of practical use when attempting ECG data exchange between healthcare providers.