An accurate and automatic system for extracting features from ECG paper recordings: its use in clinical studies and telemedicine

The automatic system makes use of mostly generic components like the PC and a desktop colour scanner to perform electronic data capture. Signal processing modules were added to extract relevant statistical and diagnostic information for rapid data abstraction and indexing. The system accepts standard ECG paper records and produces three data files of about 35 KBytes in total consisting of a compressed (lossless) copy of the scanned image, the digitised (recovered) values of the individual leads and a set of features describing the ECG. At each stage of the development, exhaustive tests were carried out to ensure maximum accuracy and speed. The entire operation from scanning to segmentation and signal recovery took less than 2 minutes per record. The system has been installed at the National University Hospital and it incorporates a telemedicine module to classify incoming ECG queries.