A method of creating a biological feedback for correction of cardiac activity and device for its implementation
(57) Abstract:The invention relates to medicine, cardiology. On the surface of the thorax of the patient at points corresponding standardized vectorcardiographic leads, measure electric potentials which determine the 3 components of the total electric dipole moment of the heart. After appropriate mathematical treatment of these quantities the calculation results show the patient in a visual, such as a map, that allows you to identify the electrophysiological characteristics of the heart, which are subject to correction. The proposed method is implemented using a device different from the known presence of two-way telemetry communication channel that enables the creation of fully closed loop biofeedback when a patient of various activities, including exercise-related movement. 2 S. and 1 C.p. f-crystals, 3 ill. The invention relates to medicine, particularly cardiology.Known system with biofeedback, based on the measurement of patient-specific physiological characteristics, carried out is abode in the form of visual or auditory images, reflecting the dynamics of the changes of some physiological characteristics to facilitate optimization by the patient of this characteristic, for example, through self-regulation.In [1 - 3] describes how to create a biofeedback based on the measurement of electrical potentials on the surface of the patient's head (EEG), mathematical processing of the measured data and the presentation to the patient of the results of this processing.In  describes a system programmable rehabilitation of patients with heart disease, in which the patient is given a physical exercise using the treadmill. Electrocardiogram is entered into the computer, and the results of mathematical processing sets the optimal speed of the track.The problem with the above analogy is the inability to determine the electrophysiological characteristics of the heart, which can be optimally carried out the correction of cardiac activity, in particular, correction of the electrophysiological state of the walls of the ventricles in the excitation process. In addition, in these methods, there is no visualization of the results.
rdca, determined by non-invasive measurements, taken as a prototype  . This method involves the following sequence of operations:
1. In a large number of points on the surface of the thorax of the patient is measured electric potentials generated by the heart.
1) rest (unexcited or polarized infarction) or newsradio tissue corresponding to the field, where no one came to the front depolarization after the start of the cycle of excitation of the ventricles (the torque maps Fig. 1 shows in black);
2) the activation state of the corresponding region, where at the moment is the front depolarization, passing through the wall of the heart (white color);
3) state the full excitation (depolarization), corresponding to the area where the front depolarization was in the previous period of time, but the data is acceptable given time is called the moment map of the excitation of the heart, or torque desertorum depolarization. The sequence of the torque desertorum depolarization from the beginning to the end of the period of the QRS with a sufficiently short time interval provides a continuous picture of the overall process of ventricular depolarization in the form of a film. Through the use of relative values of the module of the vector of the heart, which are related to the maximum module, these cards are in some sense be normalized relative to the total size of the ventricles, and we can assume that information about these dimensions expresses himself Max. module. The numbers on the torque maps, shown in Fig. 1 shows the time from the beginning of QRS complex in milliseconds.A more compact representation of the process of excitation of the ventricles is obtained in the form of total cards excitation of the heart, which is calculated according to the torque maps and represent the most significant properties of this process. These include endocardial isochronous map (map of the parish of excitation), epicardial isochronous map (map care excitation) and map the duration of the activation. Endocardial isochronous map depicts the position of the boundaries of the projection of the front depolarization in the field of uobrazenosti ventricles. According to the topological structure of the model, for each time endocardial isochrone is determined by the points where the transition from quiescence to activation state, while the epicardial isochrone is determined by the points where there is a transition from a state of activation in a state of complete depolarization. Map the duration of the activation depicts the distribution on the sphere display of time values within which each point maintains the activation state.In the analysis phase of recovery or repolarization of the excited heart ventricle myocardium (the period of the ST-T cardiac cycle on the electrocardiogram) take into account the spatial distribution of the generation current in the entire volume of the myocardium (unlike the depolarization phase, when the generator is distributed only on the surface of the front depolarization), and use the corresponding spatially-distributed model of the generator. It is assumed that during the period of repolarization this process in every moment is characterized by the sum of a constant space mid-level polarization and AC on the space level, which is determined by the vector of interest is in, moreover, the distribution of the level of polarization on the surface of a sphere display will coincide in form with the potential distribution consisting of the constant component of the dipole component. The first component is set above the average level of polarization, which is determined by the specified parametrically a function of time, reflecting known from electrophysiology average speed repolarization process in myocardial cells, and the second component is calculated as a value proportional to the potential of a dipole with dipole moment equal measured at the moment of the dipole moment of cardioventilatory. The distribution of the levels of polarization in the field of display at a given moment of time is called torque card recovery heart, or torque desertorum repolarization. The sequence of the torque desertorum repolarization from the beginning to the end of the period, ST-T with a sufficiently short time interval provides a continuous picture of the overall process of ventricular repolarization in the form of a film.For evaluation and topographic representation of the distribution of the duration repolarization process on the space of ventricular myocardium ispolzovaniem the average for the entire myocardium value and the dipole component, which is calculated as a value proportional to the potential of a dipole with dipole moment whose components are defined as integrals over time of the measured orthogonal components of the vector of the dipole moment of the heart for the whole period of excitation of the ventricles or ventricular QRST complex. The resulting integral vector known in electrocardiography as ventricular (ventricular) gradient, characterized by irregularity repolarization properties of the myocardium; in accordance with that specified distribution on the sphere display is called card accelerate repolarization.For evaluation and topographic representation of the characteristics of stable focal lesions of the myocardium of the ventricles using the model of the generator disk type, a similar model for the phase of depolarization. Generator, reflecting such pathological changes presented in the form of a disk, the location on the sphere display and dimensions of which are determined by the direction and value of the module of the vector, found by averaging vectors a heart for a period corresponding to the area ST of the electrocardiogram, which in the presence of such focal changes more or less evenly offset Nui deposited on desertorum of any type.All desertorum are represented in the same format on flat oval projection of the spherical quetiapina. If desired, they can be represented with color coloring or numeric designations for convenience of visual and quantitative interpretation of data.Visual interpretation of various desertorum allows you to evaluate the following electrophysiological characteristics of the heart:
a) torque desertorum provide a visual representation of the most General properties of the dynamics of the coverage of ventricular depolarization and repolarization; b) isochronous maps reflect mainly the speed and trajectory of the front spreading depolarization in the tangential direction with respect to the surfaces of the walls of the heart with simultaneous display resizing front; C) map of the duration of the activation reflects mainly the speed of front propagation of depolarization in the radial or normal direction with respect to the surfaces of the wall of the heart; d) map accelerate repolarization reflects the value and the main direction in the space of gradient duration excited (depolarized) state of the myocardium; d) marked on desktopname regionAs shown by the physico-physiological analysis of the used model and experimental clinical research, isochronous maps can be especially useful for recognition of ventricular blockage syndrome predopredeny ventricle, and areas of necrosis and postinfarction cardiosclerosis. Map the duration of the activation is particularly useful for detection of ventricular hypertrophy and blockades; map accelerate repolarization is particularly useful in detecting conditions of the myocardium, heralding the emergence of a dangerous heart rhythm disturbance; image areas of focal changes help to identify local tissue damage (acute myocardial infarction, postinfarction cardiosclerosis) and transient ischemia in limited areas of the ventricles of the heart.The proposed method of data interpretation using desertorum gives the opportunity to assess the state of the heart and diagnose many complex cardiac abnormalities doctor with medium and low skilled and even professional.This allows you to create a system with closed loop biofeedback, when a doctor, and in some cases the patient himself (after appropriate training) will be able svoevremennyy, occurring in a patient during exercise, after emotional stress, in the course of his employment, as well as on the background of the medication and during the functional load tests.The advantage and distinctive feature of the proposed method is that through the use of significantly more informative system electrocardiographic cardiac mapping and the original diagnostic algorithms, the determination of the functional state of the heart muscle is not limited to traditional check its integral functions (heart rate, rhythm, blood pressure, etc.), and reflects a more subtle characteristics that are critical for the diagnosis of heart disease, assessing the effectiveness of therapy and to select the most optimal mode of exercise, emotional stress and work, providing:
1) assessment of the level of electrical activity of the right and left ventricles of the heart, including the isolated and combined hypertrophy of the myocardium of the ventricles and electrical overload of the ventricles;
2) identify local itelnych with chronic forms of ischemic heart disease;
3) quantitative determination of the sizes of the zones of ischemic damage (so-called "periinfarct zone") and necrosis in patients with acute myocardial infarction, as well as increase or decrease the size of these zones in the dynamics under the action of the drug and other therapy;
4) more accurate diagnosis of the extent and level of destruction of the conducting system of the heart in patients with a variety of disorders intraventricular conduction (blockages of the heart);
5) a quantitative assessment of the degree of electrical inhomogeneity of the heart muscle that allows high accuracy to diagnose patients with various heart diseases increased risk of dangerous ventricular arrhythmias, including arrhythmias high gradations.The original algorithms electrocardiographically diagnostics will allow us to obtain not only the visual quality picture of the electric field of the heart, which usually requires complex interpretation by an experienced specialist in the field of electrocardiography cardiac mapping, but also give the ability to automatically in real time to interpret the found changes of the electric field of the heart in the form of specific medical sakila statistical data for each clinical and electrocardiographic syndrome can be calculated differential function, reflecting the significant and specific changes in the electrophysiological properties of cardiac muscle, which will allow the circuit biofeedback to show the doctor and the patient not desertorum, and these differential functions in the form of simplified visual and/or sound images.This will allow us to automatically diagnose these disorders electrophysiological properties of cardiac muscle in patients suffering from various diseases of the circulatory system (ischemic heart disease, acute myocardial infarction, arterial hypertension, congenital and acquired heart diseases, cardiomyopathies, myocardial dystrophy, and others), as well as to perform the correction of these disorders with the help of drugs and non-pharmacological methods of treatment, informed selection of the most optimal modes of physical activity and work, and in some cases - using systems of motivational and self-regulation.The proposed method is implemented using the device depicted in Fig. 2 and Fig. 3. In Fig. 2 shows the layout of electrodes and measuring-emitting unit on the patient, Fig. 3 - structure is polagaemsa on the patient, and receiving and processing complex 2, which is located away from the patient in the coverage area of the electromagnetic signals used to transmit information. In the measuring-emitting unit 1 includes electrodes 3-1...3-7 for removal of biopotentials, biopotential amplifiers 4-1...4-3 connected to the electrodes by Frank, the switch 5, an analog-to-digital Converter (ADC) 6, the encoder (the encoder) 7, the electromagnetic signal transmitter 8, the electromagnetic signal receiver 9, a decoder (decoding device) 10, a block feedback 11 audiomonitor 12. The power of all nodes measuring transmitting unit activates the auxiliary power supply 13. Part of receiving and processing complex includes: a receiver of electromagnetic signals 14, the computer 15 and the electromagnetic signal transmitter 16. For the transmission of information using electromagnetic signals can be used as radio frequency and electromagnetic signals in other spectral regions, for example, in the field of infrared frequencies. In the latter case, the transmitter of electromagnetic signals may be led, and the receiver is a phototransistor. Using electrodes 3-1...3-7 located in tocque Frank, which allows to obtain the components of total dipole moment electric generator hearts on 3 axes: X, Y and Z. Thus, the voltage at the output of each of amplifiers 4-1. . . 4-3 will be proportional to the corresponding component of the electric dipole of the heart. The outputs of the amplifiers are connected to inputs of the switch 5, which sequentially connects the outputs of the amplifiers to the input of the ADC Converter 6, which converts the output voltages of amplifiers in parallel binary code.The outputs of the ADC 6 is connected to the inputs of the encoder 7, which converts the parallel binary code in a consistent, for example, code in Manchester P". This code is modulated carrier frequency of the transmitter 8. The electromagnetic signals radiated by the transmitter 8, are accepted by the receiver 14. After decoding, and decoding the received signal information transmitted electromagnetic signals, is entered in the computer 15, which is the mathematical processing of this information in accordance with the above-described method. The result of mathematical processing is displayed on the monitor screen of the computer in the form of desertorum (torque, total and differential). For each disease type selects the type of your desertorum, allowing you to get on the od supervision of a physician or under the control of the patient. In the latter case, the patient received appropriate instructions, with the doctor through self-regulation, and other factors (physical activity, medications) seek to change desertorum in a positive direction. Another option biofeedback can be carried out using a differential function, which is calculated for each type of disease and reflects the dynamics of changes of cardiac activity when carrying out correction. In this case, the signal biofeedback may be presented to the patient in a more simple and understandable form, for example, using sound signals. In this embodiment, feedback information is transmitted to the patient via the second communication channel. This information is converted into a serial binary code, which is modulated carrier frequency of the transmitter 16. The signal radiated by the transmitter 16 is received by the receiver 9, detectable by the decoder 10 and is supplied to the actuator feedback 11, which converts it into a readable patient, for example, sound images. In this embodiment biofeedback, the patient is not connected with the manufacturing equipment and whether to raise the bar, while receiving information indicating in which direction (positive or negative) from the point of view of correction directed these steps.In comparison with analogues and the prototype of the proposed method for the creation of biofeedback and device for its implementation have the following advantages:
1. Provides the ability to view the electrophysiological characteristics of the heart based on the measured electrical potentials in a small number of points corresponding standardized vectorcardiographic leads, for example, leads the system Franca that enables to implement this method using a simple and cheap equipment.2. Provides a visual representation of the electrophysiological characteristics of the excitation of the heart not only during depolarization (QRS), but in the period of repolarization (ST-T) of the ventricles of the heart, thereby allowing reliable identification of short-term, long-term and chronic physiological and pathological changes of the heart to be adjusted (including acute ischemic lesions). You can also assess the electrophysiological state of fibrillation.3. Nagadi to diagnose difficult cases of cardiac activity, but also gives the opportunity to the patient, following the appropriate instructions to correct his heart.4. Calculation of differential functions in conjunction with a telemetry channel two-way communication enables the creation of fully closed loop biofeedback when a patient of various activities, including exercise-related movement.Literature
1. EEG feedback. A PCT application, A 61 B 5/0482 N 90/15571, 1990.2. The method of training the brain activity and device for its implementation. A 61 B 5/04, U.S. patent N 4928704, 1990.3. How to create a rhythmic feedback. A 61 B 5/04, U.S. patent N 5007430, 1991.4. Programmable rehabilitation of patients with heart disease. A 61 B 5/04, U.S. patent N 4860763, 1989.5. To visually represent the electrophysiological characteristics of the heart determined by non-invasive measurements, and device for its implementation. A 61 B 5/04 RF Application N 5045723 from 13.04.92. 1 1. A method of creating a biological feedback for correction of cardiac activity, consisting in the fact that on the surface is s calculate the electrophysiological characteristics of the heart and the result of the calculation have the patient in a readable form, characterized in that the electric potentials measured at points corresponding standardized vectorcardiographic leads, for example, the system Franca, these potentials determine the three components of the total electric dipole moment of the heart, then, using the disk model of a wave of depolarization and distributed dipole model of repolarization in combination with a spherical model of the ventricles of the heart as an electrical generator, calculate basic electrophysiological characteristics of the heart, and the calculation result to present to the patient, for example, in a map form for the performance of acts aimed at changing their cardiac activity in a positive direction. 2 2. The method according to p. 1, characterized in that in addition to determining the absolute values of the electrophysiological characteristics of the heart compute the differential function, reflecting the dynamics of changes in these characteristics for the correction of cardiac activity due to the impact of various factors (drugs dosed physical load systems, auditory training, and other), and the calculation result of differential functions have the patient in a form suitable DL the military due for correction of cardiac activity, contains placed on the patient's body measuring transmitting unit, made in the form of electrodes for removal of biopotentials, United standardized vectorcardiographic the lead system with the appropriate biopotential amplifiers whose outputs are connected respectively to the inputs of the unit's continuous switching and transmitter of electromagnetic signal and located at a distance from the patient in the coverage area of electromagnetic signals pravobranitelj block is executed on the receiver of the electromagnetic signal, the output of which is connected to the input of the computer, characterized in that the measuring transmitting unit entered the United sequentially ADC and the encoder, the output of the latter of which is connected to the transmitter input electromagnetic signal, and the first input - output unit serial switching and series-connected receiver electromagnetic signal, the decoder and audiomonitor and pravobranitelj unit entered a transmitter, connected to the output of the computer.