Measurement of Electrocardiographic Signals for Analysis of HeartConditions and Problems

摘要

People who suffer from heart or heart-related diseases mostly experience heart attacks if these diseases are not detected early enough and treated. This underscores the need for a very reliable means of detecting these diseases to save the patients from these attacks which are increasing in proportion all over the world. Electrocardiography (ECG) is the electrical activity of the heart and it generates a biomedical signal referred to as ECG signal or simply ECG, and the appearance of this signal conveys much clinical information regarding the conditions and problems of a patient. Therefore proper interpretation of this signal is very vital in the diagnosis of heart problems. ECG signal amplitude is very small, about 1.0 mV and the signal is naturally contaminated by other biomedical and non-biomedical signals. The biomedical signals are electroencephalogram, electromyogram and baseline wander, while the non-biomedical signal is power line interference. These contaminating signals must be removed from the ECG signal during measurement otherwise it will convey incorrect clinical information concerning the patient's heart conditions and problems. Digital filters are employed in removing these contaminating signals and a good quality digital filter is able to remove these contaminants and still preserve the integrity of the signal. In this paper ECG signal acquisition technique, processing and interpretation are presented. Three different filters are considered: low pass andhigh pass filters and adaptive noise canceller. Matlab software tool is used to observe and record results