An automated data extraction system from 12 lead ECG images

A software based normalized ECG data acquisition system is developed for both normal and abnormal ECG records. This system can transfer wave data recorded on paper to the digital time database. A flatbed scanner is used to form an image database of each 12 lead ECG signal. These TIF formatted gray tone images are then converted into two tone binary images with the help of histogram analysis. Smearing runlength technique is used to remove the vertical and horizontal line segments of graphical papers. Thinning algorithm is applied to each image to obtain the skeleton (1 pixel representation) of each image, which is essential to avoid excess data points in the database. After extracting pixel to pixel co-ordinate information of images of each of the signal of 12 lead ECG records, the data are sorted to regenerate the signal. From standard deviation of the database a graphical analysis is performed to examine the consistency of our database.