RESUMEN

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.

RESUMEN

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.

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A system of electrode arrangement for localization of zones of small depolarization abnormalities in human myocardium is suggested. Standard electrodes R, L, F and Frank electrodes H, M compatible with standard methods of examination. The total number of electrodes in the system is 15. A technique for reconstruction of the coordinates and orientation angles of the abnormality sources from measured electrode potentials is suggested. Statistical modeling is used to assess the dependence of the reconstruction error on the source position and orientation. The maximal error of coordinate measurement is found to be approximately 1.5 mm; average error, 0.75 mm.

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RESUMEN

Identification of early disturbances in the process of myocardium depolarization and localization of coordinates of these disturbances in the heart contour is an urgent problem of modern electrocardiography. To solve this problem, it is necessary to identify signals of small disturbances in the depolarization process related to particular zones of disturbances in myocardium. Then, the identified signals are used to calculate the disturbance coordinates. In this work, a technique for estimation of partial sensitivity of electrodes to the position and orientation of the dipolar sources in myocardium is suggested. The results of calculation of partial sensitivity presented in this work make it possible to identify effective electrodes and minimize the total number of electrodes. The obtained results enabled us to suggest a system of electrodes for measurement of coordinates of the disturbance sources.

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