Electrocardiogram, heart rate and temperature monitoring system

Abstract

The purpose of this study is the development of an affordable computer-based electrocardiogram, heart rate and temperature monitoring system, that would complement those that are available on the market and contribute to the reduction of the shortage of these medical instruments in South African hospitals and clinics. Electrocardiogram (ECG) refers to the graph that results from time versus voltage in a patient's chest. It reflects the rhythmic activity of the heart. For this reason the electrocardiogram has a diagnostic value that can be used by medical personnel to examine the biological (hence, clinical) behavior of the heart. The electrocardiogram can also be used to get the heart rate. This thesis explained how to acquire ECG signals from the patient and also how to achieve a cheaper way of providing galvanic isolation, which is required for sensors that are attached to the human body. It also explains computer interfacing using the parallel port and computer-based processing of these ECG signals to determine the instantaneous value of the heart rate and also to reduce the interference that contaminates these signals. In reducing interference, the performance of traditional IIR notch and adaptive filters, as noise cancelers, has been analyzed and compared. Least Mean Squares (LMS) and Normalized Least Mean Squares (NLMS) algorithms are the two algorithms that were considered in this study for adaptive noise canceling and their performance is evaluated and is compared based on their convergence rate, complexity and noise reduction.