JP2002224068A - Body surface added electrocardiogram automatic analyzer for determining electrocardiogram t wave repolarization abnormality - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a body surface average added electrocardiogram device capable of automatically analyzing abnormality of a T a wave for expressing a repolarization process being an index of serious illness arrhythmia on an electrocardiogram. SOLUTION: This body surface added electrocardiogram automatic analyzer for determining electrocardiogram T wave repolarization abnormality is characterized by having an amplifying input means of an electrocardiogram signal led from an electrode installed on a living body, an analog digital converting means connected to the input means, and digitally converting an XYZ lead electrocardiogram, an R wave detecting means for detecting an R wave generating position of the XYZ lead electrocardiogram, an average adding means for adding on average in synchronism with an R wave position detected by the R wave detecting means 3, a storage means for storing an XYZ lead average added electrocardiogram determined by the average adding means, a ventricle delay potential analyzing means for analyzing ventricle delay potential on the basis of the XYZ average added lead electrocardiogram determined by the average adding means, an electrocardiogram T wave analyzing means for analyzing a T wave analyzing section automatically determined from an R wave detecting position, and an output means for outputting an analytical result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrocardiogram device, and more particularly to a ventricular late potential (LP) which is an index of severe arrhythmia causing sudden death.
At the same time, the present invention relates to a body-surface-averaged electrocardiogram device capable of automatically analyzing a T-wave abnormality expressing a repolarization process which is also an index of a severe arrhythmia on an electrocardiogram.

[0002]

2. Description of the Related Art As shown in FIG.
It consists of a T wave and a U wave. It is known that in patients who are susceptible to severe arrhythmias that cause sudden death, abnormalities in the QRS wave representing the depolarization of the electrocardiogram are detected as ventricular delayed potentials, and there are also abnormalities in the T wave representing the repolarization process.
Conventionally, an apparatus for detecting the above-described ECG ventricular delayed potential is known, and an example thereof will be briefly described. FIG. 7 is a block diagram of an ECG ventricular delayed potential detecting apparatus.

In the figure, 1 is an amplifier, 2 is an A / D converter, 3 is an R-wave detector, 4 is an average adder, 5 is a storage, 6
Is an analysis unit, 8 is a display unit, 9 is an input unit, and 10 is a storage unit. XYZ leads (leads from two places on the chest, respectively: X: V5R and V5) Induction, Y induction: V1 and LF, Z: Three inductions of V8 and V3, V5R, V5, V1, LF,
V3 is a known symbol indicating a part on the chest.) The electrocardiogram is amplified by an amplifier 1 and then converted into time-series digital data by an A / D converter 2. All subsequent processing is performed by software. Will be The digital data of the obtained electrocardiogram signal is averaged and added by the average adding section 4 in synchronization with the R-wave position detected by the R-wave detector 3. The XYZ lead averaged electrocardiogram is stored in the storage unit 5 and the analysis unit 6 detects a ventricular delayed potential. In addition, there are the following three types of analyzers for analyzing the repolarization process using an electrocardiogram. Record dozens of lead (body surface mapping) electrocardiograms and attempt to detect abnormalities in the repolarization process from the distribution of the integrated values. Record body surface mapping electrocardiograms and measure the time when the first derivative value is maximum. Some attempt to detect abnormalities in the repolarization process from the distribution, and others attempt to detect abnormalities in the repolarization process by measuring the time until the end of the T-wave of the standard 12-lead ECG. Devices for measuring an electrocardiogram as described above are known. In addition, detection of these repolarization abnormalities is often performed by manual operation by an operator.

[0004]

However, in the detection from the standard 12-lead electrocardiogram, it is difficult to visually determine the end point of the T wave. Also, the method of recording a body surface mapping electrocardiogram has to be equipped with several tens of electrodes, which is complicated. Therefore, the present invention provides a method for predicting severe arrhythmia that causes sudden death on an electrocardiogram.
Simultaneously with the measurement of the ventricular delay potential by the YZ-lead averaged electrocardiogram, the maximum entropy method (MEM: Maximum E) of the T-wave portion using the same XYZ average-lead electrocardiogram.
An object of the present invention is to solve the above-mentioned problem by providing an automatic body surface addition electrocardiogram analysis apparatus capable of performing analysis by tropy method) and displaying an index indicating an abnormality in a repolarization process as a MEM value.

[0005]

Means for Solving the Problems The technical solution adopted by the present invention is an input means for amplifying an electrocardiogram signal induced from an electrode mounted on a living body, and an analog device connected to the input means for digitally converting an XYZ lead electrocardiogram. Digital converting means for detecting an R-wave generation position of the XYZ lead electrocardiogram;
A wave detecting means, an average adding means for performing an average addition in synchronization with the R-wave position detected by the R-wave detecting means 3, a storage means for storing an XYZ lead averaged added electrocardiogram obtained by the average adding means, Ventricular delayed potential analyzing means for analyzing a ventricular delayed potential based on the XYZ average addition lead electrocardiogram obtained by the adding means, and an electrocardiogram T-wave for analyzing a T-wave analysis section automatically determined from the R-wave detection position An automatic body surface addition electrocardiogram analysis apparatus for obtaining an electrocardiogram T-wave repolarization abnormality, comprising an analysis means and an output means for outputting an analysis result. In addition, the electrocardiogram T-wave analysis means performs first-order differentiation of each of the XYZ waveforms in a certain period of time from the R-wave position, analyzes the obtained waveform by the maximum entropy to obtain a prediction error filter coefficient, and An automatic body surface addition electrocardiogram analysis apparatus characterized in that it is configured to obtain a mean square value of a prediction error filter coefficient.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. Components having the same functions as those of the above-described conventional device use the same reference numerals. In FIG. 1, 1 is an amplification input means, 2 is an A / D conversion means, 3 is an R wave detection means, 4 is an average addition means, 5 is a storage means, 6 is a ventricular delayed potential analysis means, and 7 is an electrocardiogram T wave analysis. Means, 8 means display means (output means), 9 means output means, 10 means
Is a storage means (output means), and the present electrocardiogram measuring apparatus is characterized by adding an electrocardiogram T-wave analyzing means as compared with the conventional apparatus. Each of the above units except for the amplification input unit is constituted by a computer.

In this device, the XYZ lead electrocardiograms guided from the electrodes mounted on the body are respectively amplified by the amplifying means 1, then converted into time-series digital data by the A / D converting means 2, and then processed. Are all performed by software. The digital data of the obtained electrocardiogram signal is averagely added in an average adding section in synchronization with the R-wave position detected by the R-wave detecting means 3. The XYZ lead averaged electrocardiogram is stored in the storage means 5. At the same time, the ventricular delayed potential analyzing means 6 detects the ventricular delayed potential, and the electrocardiogram T-wave analyzing means 7 performs abnormal processing of the T-wave repolarization process in a manner described later. When a computer is not used, the device can be configured with a dedicated circuit.

The processing in the electrocardiogram T-wave analysis means 7 will be described with reference to the flowchart shown in FIG. 3 and 4 used in the description here are the output results of the T-wave analysis means. FIG. 3 shows a healthy normal person, and FIG. 4 shows a case of fatal ventricular tachycardia due to myocardial infarction. It belongs to the patient. FIG.
In step 1, a certain time from the R wave position in the XYZ lead averaged ECG is extracted as a T wave analysis section (see A in FIGS. 3 and 4: R between two broken lines).
1, R2 is an analysis section). In step 2, the T wave analysis section is first differentiated. In step 3,
The XYZ waveforms obtained in step S2 are analyzed by the maximum entropy method described later to obtain prediction error filter coefficients. At the same time, the power spectrum by MEM is calculated. XYZ obtained in step 4
A root mean square (RMS) of the prediction error filter coefficient from each of them is obtained (see D in FIGS. 3 and 4). In step 5, output as MEM value (F in FIGS. 3 and 4)
reference). At the same time, the power spectrum (see B and C in FIGS. 3 and 4) and its measured value (see E in FIGS. 3 and 4) by the MEM are output.

_.. Γ _x1 γ _x2 ... Γ _xm , γ _y1 γ _y2 ...
・ If γ _ym , γ _z1 γ _z2・ ・ ・ γ _zm , the mean square value (RM
S) is as follows. √ (γ _x1 ² + γ _y1 ² + γ _z1 ² ) + √ (γ _x2 ² + γ _y2 ² +
^{_{γ z2 2) + ····· + √}} (γ xm 2 + γ ym 2 + γ zm 2) Further, in FIGS. 3 and 4, the power spectrum (see B and C of FIG. 3 and FIG. 4), power spectrum 3 (see FIG. 3 and FIG. 4E), the patient whose F MEMvalue is 5 or less is judged to have an abnormality in the repolarization process. The determination of the analysis section in step 1, the presence or absence of the first-order differentiation process in step 2, and the order of the prediction error filter coefficient in step 3 can be determined by the operator. The analysis by the maximum entropy method was performed by the Burg method. The Burg method algorithm is shown below.

[0010]

(Equation 1)C₀C₁C2 ... C_mIs the m-th order autocorrelation function and the prediction error
Difference filter coefficient γ₁γ _Two... γ_mSignal forward
Average output P when passing in the opposite direction to passing_mMinimize
Solves the above equation and adds the prediction error filter
Find the number. According to the above processing, the present invention
XYZ average addition lead electrocardiogram used for detection of ventricular delayed potential
Analyzing the T-wave part by the maximum entropy method
MEMv
It can be displayed as "alue".

Although the embodiments of the present invention have been described above, the present invention can be embodied in any other forms without departing from the spirit or main features thereof. Therefore, the above-described embodiment is merely an example in every aspect and should not be interpreted in a limited manner. For example, the analysis method of the T-wave is not limited to MEM, and another method (Yule-Walker method) can be adopted as long as it can perform similar analysis.

[0012]

As described above, according to the present invention, a ventricular delayed potential which is an index of ventricular tachyarrhythmia such as ventricular tachyarrhythmia is detected, and a maximum entropy method of the XYZ average addition lead electrocardiogram T wave portion used for the detection is used. By performing the analysis according to the above, it becomes possible to display an index indicating the abnormality as MEMvalue, and it is possible to easily detect abnormalities in the repolarization process of a patient having a severe arrhythmia such as ventricular tachycardia, and to predict sudden death. Useful.

[Brief description of the drawings]

FIG. 1 is a block diagram related to the apparatus of the present invention.

FIG. 2 is a flowchart in the electrocardiogram T-wave analysis means.

FIG. 3 is an output from a T-wave analysis unit (a healthy normal person).

FIG. 4 is an output from a T-wave analysis unit (a patient who developed fatal ventricular tachycardia due to myocardial infarction).

FIG. 5 is an output of a ventricular delayed potential analyzer .

FIG. 6 is a normal electrocardiogram.

FIG. 7 is a block diagram of a conventional ventricular delayed potential detecting device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 amplification input means 2 A / D conversion means 3 R wave detection means 4 average addition means 5 storage means 6 ventricular delayed potential analysis means 7 electrocardiogram T wave detection means 8 display means 9 input means 10 storage means

Claims (2)

[Claims] 1. An amplification input means for an electrocardiogram signal induced from an electrode mounted on a living body, and an XYZ connected to the input means.
Analog-to-digital conversion means for digitally converting a lead electrocardiogram, R-wave detection means for detecting an R-wave generation position of the XYZ lead electrocardiogram, and averaging for averaging in synchronization with the R-wave position detected by the R-wave detection means 3 Addition means, storage means for storing the XYZ lead averaged addition electrocardiogram obtained by the average addition means, and ventricular delay potential analysis means for analyzing a ventricular delay potential based on the XYZ average addition lead electrocardiogram obtained by the average addition means. An electrocardiogram T-wave repolarization abnormality, comprising: an electrocardiogram T-wave analysis means for analyzing a T-wave analysis section automatically determined from an R-wave detection position; and an output means for outputting an analysis result. Surface electrocardiogram automatic analyzer that calculates 2. The electrocardiogram T-wave analysis means first-order differentiates each of the XYZ waveforms in a certain time interval from the R-wave position, analyzes the obtained waveform by the maximum entropy, and obtains a prediction error filter coefficient. 2. The automatic electrocardiogram analyzing apparatus according to claim 1, wherein the apparatus is further configured to obtain a mean square value of the prediction error filter coefficient.