ABSTRACT
The challenges of constructing a noninvasive screening system for electrocardiodiagnostics, focused on visualization of electric potential maps on the surface of the epicardium, is addressed. A functional diagram of a module for recording multiple-lead electrocardiosignals is proposed, the essential component of which is a vest (in several standard sizes) worn by the subject and carrying pre-installed electrodes. Results obtained from experimental verification of the operation of the recording module are presented. The issues of computer processing of electrocardiosignals were addressed and led to the ability to obtain 2D maps of the electric potential on a spherical quasi-epicardium, these 2D maps changing synchronously with changes in the position of the time marker on electrocardiograms familiar to cardiologists.
ABSTRACT
BACKGROUND: The actual task of electrocardiographic examinations is to increase the reliability of diagnosing the condition of the heart. Within the framework of this task, an important direction is the solution of the inverse problem of electrocardiography, based on the processing of electrocardiographic signals of multichannel cardio leads at known electrode coordinates in these leads (Titomir et al. Noninvasiv electrocardiotopography, 2003), (Macfarlane et al. Comprehensive Electrocardiology, 2nd ed. (Chapter 9), 2011). RESULTS: In order to obtain more detailed information about the electrical activity of the heart, we carry out a reconstruction of the distribution of equivalent electrical sources on the heart surface. In this area, we hold reconstruction of the equivalent sources during the cardiac cycle at relatively low hardware cost. ECG maps of electrical potentials on the surface of the torso (TSPM) and electrical sources on the surface of the heart (HSSM) were studied for different times of the cardiac cycle. We carried out a visual and quantitative comparison of these maps in the presence of pathological regions of different localization. For this purpose we used the model of the heart electrical activity, based on cellular automata. CONCLUSIONS: The model of cellular automata allows us to consider the processes of heart excitation in the presence of pathological regions of various sizes and localization. It is shown, that changes in the distribution of electrical sources on the surface of the epicardium in the presence of pathological areas with disturbances in the conduction of heart excitation are much more noticeable than changes in ECG maps on the torso surface.
Subject(s)
Electrocardiography , Heart/physiology , Action Potentials , Algorithms , Humans , Pericardium/physiologyABSTRACT
The goal of this work was to suggest a method for improving the efficiency of ECG analysis in measurements of the electrical cardiac activity. The suggested method is based on a solution of the inverse ECG problem. The algorithm for measuring the electrical cardiac activity includes storage of ECG signals from various sources in a database (the body and heart geometry are taken into account), determination of electrically active areas, and determination of the electrical activity at each point of the heart model surface. Test ECG signals available at a free-access web site were used to verify the results of monitoring of the electrical cardiac activity.
Subject(s)
Algorithms , Computer Simulation , Electrocardiography/methods , Heart Conduction System/physiology , Heart/physiology , Body Surface Potential Mapping/methods , Humans , Models, CardiovascularABSTRACT
Wavelet transform is a new tool for analysis of electrocardiographic information. In this work, we consider the procedure for selection of the mother wavelet on the basis of special criteria and substantiate an improved method for ECG analysis based on wavelet transform. An algorithm for selection of mother wavelet and synthesized wavelet providing optimal wavelet transform of ECG signal is developed. It is shown that 3D wavelet spectrograms should be constructed to increase the efficiency of assessment of the state of cardiovascular system.
Subject(s)
Electrocardiography/methods , Signal Processing, Computer-Assisted , Electrocardiography/instrumentation , Humans , MathematicsABSTRACT
The design principles and hardware implementation of Kardiovid computer diagnostic system are considered. The system is intended for diagnosis of the state of cardiovascular system on the basis of the results of electrocardiographic and fluorographic examinations. It provides simulation and visualization of the state of cardiovascular system.
Subject(s)
Cardiovascular Diseases/diagnosis , Electrocardiography/instrumentation , Photofluorography/instrumentation , Diagnosis, Computer-Assisted , Humans , Models, BiologicalABSTRACT
Methods for construction of a model of the surface of the heart and its use for assessing the state of the cardiovascular system are considered. Problems of construction of 3-D models based on Delaney triangulation and Bezier surface are discussed. The necessity for use of computer simulation methods and imaging of the myocardium state at the site of diagnosis is substantiated.
