Bio-Potential Signal Extraction from Multi-Channel Paper Recorded Charts

Al-Mejrad Al-Mejrad

doi:10.3844/ajassp.2011.520.524

Abstract

Problem Statement: Almost all of the modern biomedical equipments that record the biopotential actions have digital output but the paper chart records are a must. The volume of these records is significant and increasing rapidly. Keeping a bio-signal chart of a patient make it easy for quick assessment but still create problems in the essence of data storage, archiving , data interchange and communications. Approach: As a solution to all these problems is to convert these paper records to digital form. In this study, a method for bio-potential signal extraction from single or multi-channel paper recorded charts using image processing techniques is developed. Results: After scanning the paper charts and converting them into images using a commercial scanner, the developed algorithm is applied to eliminate the background of the scanned paper chart from any recording device single channel or multi-channel using binary neighborhood morphological operations then converting the extracted waveform image into quantized values representing the waveform recorded paper chart. The extracted signal is then filtered to remove the high frequency effects that result from the morphological operations. A correlation and frequency analysis procedure is then conducted to verify the result against known sampled waveform. Conclusion: A chart paper conversion to digital values that represent only the values for the biopotential waveform and eliminating the other irrelevant information has been achieved. These resulted in a less space occupation of patient records and make it easy for data further processing and manipulations.

Highlights

Due to the advances of information technology in storing, retrieving advance of technology almost all of the modern or processing of information are utilized for creation of biomedical equipments that record the bio-potential database after data extraction from ECG paper records actions have digital output (AlMejrad, 2010a) but the (Lobodzinski, 2003; Mitra, 2004)
After scanning the study charts and converting them into images using a commercial scanner, an algorithm is applied to eliminate the background of the scanned paper chart from any recording device single channel or multi-channel using binary neighborhood morphological operations converting the extracted waveform image into quantized values representing the waveform recorded paper chart
Before the morphological operation a region of interest is being defined that will help in reducing the Algorithm verification: The verification processes starts with collecting real patient information from King Khalid Hospital (KHH) and scan it with the same scanner settings mentioned above applying the algorithm and compare the result to the digital form stored in the hospital central station

Summary

INTRODUCTION

In addition to that the presented ECG scan that is a new digital application that non-digital equipment is still available and in enables the user to convert paper ECGs to digital ECGs widespread use in hospitals The volume of these and validated this study by comparing digital waveforms records is significant and increasing rapidly. Keeping a and measurements with the original From this review, it bio-signal chart of a patient make it easy for quick is clear that most of the study done is for ECG records. After scanning the study charts and converting them into images using a commercial scanner, an algorithm is applied to eliminate the background of the scanned paper chart from any recording device single channel or multi-channel using binary neighborhood morphological operations converting the extracted waveform image into quantized values representing the waveform recorded paper chart. The result is XORed with the image resulted from the subtraction of the threshold image and the image after another threshold stage

MATERIALS AND METHODS

RESULTS

DISCUSSION

CONCLUSION