JP6862189B2 - ECG information processing device - Google Patents

Description

The present invention relates to an electrocardiogram information processing device having a TWA analysis function.

The T wave alternans (TWA) phenomenon, in which T waves of different sizes appear every beat on an electrocardiogram, is used as an effective index for evaluating the possibility of sudden death and the prognosis after myocardial infarction. (See Patent Document 1). Since TWA has a measurement potential of several μV and tends to appear when the heart rate rises, it is generally performed by a flank induction method by performing an exercise load test with a subject wearing a measurement electrode. It is performed by measuring an electrocardiogram by the 12-lead method and evaluating this electrocardiogram.

More specifically, in the TWA examination, T waves having different shapes appearing at each beat in each lead of the electrocardiogram are measured, the magnitude of the alternation (that is, the difference between adjacent T waves) is calculated, and the alternation is calculated. It is evaluated that the greater the sex, the higher the possibility of sudden death.

There are roughly two methods for calculating the interactivity of T waves. One is a method called the frequency domain method, and the other is a method called the time domain method. Incidentally, Patent Document 1 describes the frequency domain method.

The frequency domain method is a method in which, for example, the strength of the position of 0.5 (cycle / beat) when the height of the T wave for 128 beats is converted by FFT is set as the strength of the alternation. Incidentally, for example, the average level at the positions of 0.44 to 0.49 (cycle / beat) is used as the noise level. Specifically, for example, by sequentially performing a process of outputting the level at the position of 0.5 (cycle / beat) when FFT-converted in units of 128 beats while shifting each beat, T for a predetermined time. Seeking wave alternation.

The time domain method is a method of detecting an even wave average level of a T wave and an odd wave average level of a T wave by dividing the wave into an even wave and an odd wave.

Further, conventionally, as a method of detecting a T wave, a method of estimating the T wave based on the RR interval of the electrocardiogram (HR (heart rate) tracking type) and a method of detecting the T wave based on the shape of the electrocardiographic waveform of the electrocardiogram. (T wave detection type) and.

Japanese Patent No. 3877761

By the way, in the HR follow-up type, since the T wave position is estimated only by the RR interval, the T wave position may not be captured correctly depending on the shape of the electrocardiographic waveform. On the other hand, the T-wave detection type can correctly detect the T-wave position regardless of individual differences in the electrocardiographic waveform as compared with the HR-following type, but cannot detect the T-wave position when the T-wave height is low. .. As described above, the T wave detection type and the HR follow-up type each have advantages and disadvantages.

The present invention has been made in consideration of the above points, and by utilizing the advantages of the T wave detection type and the HR follow-up type, the reliability of T wave detection is enhanced, and the reliability of TWA inspection is enhanced. Provide an electrocardiogram information processing device capable of

One aspect of the electrocardiogram information processing apparatus of the present invention is
An electrocardiogram information processing device having a TWA analysis function.
A T-wave detector that detects T-waves based on the shape of the electrocardiographic waveform of the acquired electrocardiogram,
A T wave estimation unit that estimates a T wave based on the RR interval of the electrocardiogram, and a T wave estimation unit.
A TWA analysis unit that performs TWA analysis using the T wave detected by the T wave detection unit and / or the T wave estimated by the T wave estimation unit.
To be equipped.

According to the present invention, it is possible to realize an electrocardiogram information processing apparatus capable of enhancing the reliability of T wave detection and, by extension, the reliability of TWA examination by utilizing the advantages of the T wave detection type and the HR follow-up type.

External view of the exercise electrocardiogram examination system according to the embodiment A block diagram showing a main configuration of an electrocardiogram examination device according to an embodiment. The figure which shows the display example of the TWA analysis result when the T wave is detected by the T wave detection type and the T wave can be detected for more than a predetermined period. The figure which shows the display example of the TWA analysis result using the T wave estimated by the HR follow-up type. The figure which shows the display example of the TWA analysis result when the T wave was detected by the T wave detection type and the T wave could not be detected for more than a predetermined period. The figure which shows the display example of the TWA analysis result using the T wave estimated by the HR follow-up type.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Overall configuration>
FIG. 1 is an external view of an exercise electrocardiogram inspection system 10 according to an embodiment of the present invention. The exercise electrocardiogram examination system 10 includes an exercise load device 20 and an electrocardiogram examination device 100 that acquires biological information such as an electrocardiogram and controls the exercise load device 20. In the case of this embodiment, the treadmill is used as the exercise load device 20, but an ergometer or the like may be used instead of the treadmill. The electrocardiogram examination device 100 and the exercise load device 20 are connected by a dedicated cable 30, and the exercise load device 20 is controlled by the electrocardiogram examination device 100. In the case of a treadmill, the rotational speed and inclination of the belt are controlled by the electrocardiogram inspection device 100.

The electrocardiogram examination device 100 includes a device main body 100a, a display 101 made of an LCD (Liquid Crystal Display), an operation unit 102 made of a keyboard, a mouse, and the like, a printer 103, and a sphygmomanometer 104.

FIG. 2 is a block diagram showing a main configuration of the electrocardiogram examination device 100. The control unit 110 of the electrocardiogram examination device 100 controls the overall operation of the electrocardiogram examination device 100. A menu screen and various setting screens are displayed on the display 101. Further, the display 101 shows an electrocardiographic waveform, an analysis result, and the like.

The storage unit 111 is composed of a hard disk drive, a semiconductor memory, or the like. The storage unit 111 stores electrocardiographic waveform data, analysis data thereof, and the like. The storage unit 111 also stores the setting data of the electrocardiogram examination device 100 input by the operator from the operation unit 102.

The printer 103 is a printer of a laser type or a thermal head type, and prints an electrocardiographic waveform obtained by measurement and an analysis result thereof according to an instruction by an operator. The speaker 112 emits an arousing sound or the like in the load inspection mode.

Further, the electrocardiogram examination device 100 has an electrode interface (I / F) 122, a sphygmomanometer interface (I / F) 123, and an exercise load interface (I / F) 124.

The electrode I / F 122 is connected to an electrode portion (that is, an electrode portion for limbs, an electrode portion for chest, etc.) 130 attached to a subject (that is, a subject for electrocardiogram measurement), and is input from this electrode portion 130. The measured voltage is amplified and output to the calculation unit 121. The sphygmomanometer I / F 123 is connected to the sphygmomanometer 104 and outputs a blood pressure value signal input from the sphygmomanometer 104 to the calculation unit 121. Further, the sphygmomanometer I / F 123 outputs a control signal for controlling the pressure supplied to the cuff of the sphygmomanometer 104 to the sphygmomanometer 104.

The calculation unit 121 analyzes the electrocardiographic waveform by executing the electrocardiogram data processing program.

Further, the calculation unit 121 calculates the strength of the alternating T wave by executing the TWA inspection program in the TWA inspection mode. In the case of this embodiment, the interactivity of T waves is evaluated by the frequency domain method. Specifically, the calculation unit 121 sequentially performs a process of outputting a level at a position of 0.5 (cycle / beat) when FFT-converted in units of 128 beats, for example, while shifting the beats one by one. Obtain the T-wave alternative for a predetermined time.

The exercise load I / F 124 is connected to an exercise load device 20 such as a treadmill or an ergometer. A control signal for driving the exercise load device 20 is output from the control unit 110 to the exercise load device 20 via the exercise load I / F 124. Further, a feedback signal from the exercise load device 20 is input via the exercise load I / F 124. The feedback signal includes, for example, a speed signal. The control unit 110 of the electrocardiogram examination device 100 can control the exercise load device 20 to a desired speed based on the speed signal fed back from the exercise load device 20.

<Detection, estimation and selection of T wave according to the embodiment>
The T wave is detected by the calculation unit 121. In the present embodiment, the calculation unit 121 functions as a T wave detection unit that detects a T wave based on the shape of the electrocardiographic waveform of the electrocardiogram, and T wave estimation that estimates the T wave based on the RR interval of the electrocardiogram. It has a function as a unit and a function as a TWA analysis unit that performs TWA analysis using the T wave detected by the T wave detection unit and / or the T wave estimated by the T wave estimation unit. Then, the TWA analysis result obtained by the calculation unit 121 is displayed on the display 101 via the control unit 110.

As described above, in the present embodiment, both so-called T wave detection type T wave detection and so-called HR follow-up type T wave estimation are performed, one or both of them are selected and TWA analysis is performed, and TWA is performed. The analysis result is displayed on the display 101.

Actually, when the T wave can be detected by the T wave detection type for a predetermined period or longer, the TWA is calculated using the T wave detected by the T wave detection type. As a result, the TWA can be calculated based on the highly accurate T wave. On the other hand, when the T wave detection type cannot detect the T wave for a predetermined period or longer, the TWA is calculated using the T wave estimated by the HR follow-up type. As a result, it is possible to prevent the TWA from being unable to be calculated due to the T wave becoming undetectable.

Here, the T wave detection type T wave detection detects the position of the T top from the actual electrocardiographic waveform. As described above, the T wave detection type can detect the T wave more accurately than the HR follow-up type, but when the wave height of the T wave is low, the T wave may not be detected. Generally, the T wave detection type is used when a section with a beautiful waveform can be selected from an electrocardiogram recorded for a long time such as a Holter electrocardiograph. Conversely, the T-wave detection type T-wave detection is likely to be unable to detect the T-wave for a short-term recorded electrocardiogram. For example, in TWA analysis, if 10% or more of T waves are missing out of 128 beats, which is a unit of FFT, measures such as not adopting it as a TWA analysis result may be taken.

On the other hand, in the HR follow-up type, the position of the T wave is estimated from the RR interval, so that the position of the T wave can always be estimated. However, since the positional relationship between the R wave and the T wave fluctuates due to individual differences and diurnal fluctuations, the detection accuracy of the T wave is lower than that of the T wave detection type. It is preferable to be able to detect the level difference at the position of the T-top like the T-wave detection type, but since TWA analysis can be performed even at the level difference at a position slightly off the T-top, the T-wave estimated by the HR follow-up type is used. However, TWA analysis is possible. However, if the T-wave alternation is calculated based on the level difference at a position off the T-top, the strength of the T-wave alternance is calculated to be low.

FIG. 3-FIG. 6 shows a display example on the display 101 in the TWA inspection mode.

3 and 4 show a display example of the TWA analysis result when the T wave can be detected (or estimated) by either the T wave detection type or the HR follow-up type. FIG. 3 is a display example of the TWA analysis result calculated using the T wave detected by the T wave detection type. FIG. 4 is a display example of the TWA analysis result calculated using the T wave estimated by the HR follow-up type. In both the displays of FIGS. 3 and 4, it can be seen that the TWA analysis results are obtained by the V4 lead and the V5 lead.

On the other hand, FIGS. 5 and 6 show a display example of the TWA analysis result when the T wave cannot be detected by the T wave detection type but the T wave can be estimated by the HR follow-up type. FIG. 5 is a display example of the TWA analysis result calculated using the T wave detected by the T wave detection type. FIG. 6 is a display example of the TWA analysis result calculated using the T wave estimated by the HR follow-up type. It can be seen that in the display of FIG. 5, the TWA analysis results are hardly obtained in the V5 lead and the V6 lead, whereas in the display of FIG. 6, the TWA analysis results are obtained in the V5 lead and the V6 lead.

As shown in FIGS. 3 and 4, when the T wave can be detected (or estimated) by either the T wave detection type or the HR follow type, the T wave detection type generally has a T wave rather than the HR follow type. Since the wave detection accuracy is high, it is better to use the TWA analysis result of FIG. 3 than the TWA analysis result of FIG.

On the other hand, as shown in FIGS. 5 and 6, if the T wave detection type cannot detect the T wave but the HR follow-up type can estimate the T wave, the TWA analysis result of FIG. 6 should be used. ..

Here, as for the selection of which TWA analysis result is to be used, a method of selecting by the operator looking at the display screen and a method of selecting by the electrocardiogram examination device 100 can be considered.

In the method of selecting by looking at the operator display screen, the electrocardiogram examination device 100 obtains each TWA analysis result from the T wave detected or estimated by each of the T wave detection type and the HR follow-up type, and displays each TWA analysis result. To do. That is, the calculation unit 121 performs both the TWA analysis using the T wave detected by the T wave detection type and the TWA analysis using the T wave estimated by the HR follow-up type. The analysis results of both of them are displayed as shown in 5 and 6. Then, the operator selects which TWA analysis result to use from the display screen. For example, when the TWA analysis result is obtained in any of the displays as shown in FIGS. 3 and 4, the operator may select the TWA analysis result of FIG. 3 with higher accuracy. On the other hand, when the TWA analysis result is hardly obtained in FIG. 5 as shown in FIGS. 5 and 6, the operator may select the TWA analysis result displayed in FIG.

On the other hand, in the method of selecting which TWA analysis result is used by the electrocardiogram examination device 100, when the T wave can be detected by the T wave detection type for a predetermined period or longer, the T wave detected by the T wave detection type is detected. TWA analysis and display are performed with priority. On the other hand, when the T wave cannot be detected for a predetermined period or longer by the T wave detection type, the T wave estimated by the HR follow-up type is preferentially used for TWA analysis and display. That is, when the T wave detection type can detect the T wave for a predetermined period or longer, the TWA analysis result as shown in FIG. 3 is displayed, and the T wave detection type cannot detect the T wave for a predetermined period or longer. Displays the TWA analysis result as shown in FIG.

As described above, according to the present embodiment, the T wave is detected based on the acquired electrocardiogram waveform shape, and the T wave is estimated based on the RR interval of the electrocardiogram, and this detection and estimation is performed. By performing TWA analysis using T waves, in the case of an electrocardiographic waveform in which T waves can be detected by T wave detection type, high accuracy using T waves detected by T wave detection type is high. The TWA analysis result can be selected, and in the case of an electrocardiographic waveform in which the T wave cannot be detected by the T wave detection type, the TWA analysis result using the T wave estimated by the HR follow-up type can be selected. As a result, by utilizing the advantages of the T wave detection type and the HR follow-up type, the reliability of the T wave detection can be enhanced, and the reliability of the TWA inspection can be enhanced.

The above-described embodiments are merely examples of embodiment of the present invention, and the technical scope of the present invention should not be construed in a limited manner by these. That is, the present invention can be implemented in various forms without departing from its gist or its main features.

In the above-described embodiment, the case where the TWA analysis is performed by the frequency domain method has been described, but the present invention is not limited to this, and the same effect can be obtained when the TWA analysis by the time domain method is performed. Further, in the above-described embodiment, the case where the present invention is applied to the electrocardiogram examination device 100 of the exercise stress electrocardiogram examination system 10 has been described, but the present invention is not limited to this, and the present invention is not limited to this, and the electrocardiogram information processing apparatus having a TWA analysis function Widely applicable.

The electrocardiogram information processing device of the present invention is suitable for an electrocardiogram information processing device having a TWA analysis function.

10 Exercise load electrocardiogram examination system 20 Exercise load device 100 Electrocardiogram examination device 100a Device body 101 Display 102 Operation unit 103 Printer 104 Sphygmomanometer 110 Control unit 121 Calculation unit

Claims (2)

An electrocardiogram information processing device having a TWA analysis function.
A T-wave detector that detects T-waves based on the shape of the electrocardiographic waveform of the acquired electrocardiogram,
A T wave estimation unit that estimates a T wave based on the RR interval of the electrocardiogram, and a T wave estimation unit.
Anda TWA analysis unit for performing TWA analysis using one of the T-wave estimated by the T-wave or the T wave estimation unit detected by the T wave detector,
The TWA analysis unit
When the T wave detection unit can detect the T wave for a predetermined period or longer, TWA analysis is performed using the T wave detected by the T wave detection unit.
If the T wave detection unit cannot detect the T wave for a predetermined period or longer, TWA analysis is performed using the T wave estimated by the T wave estimation unit.
Electrocardiogram information processing device. An electrocardiogram information processing device having a TWA analysis function.
A T-wave detector that detects T-waves based on the shape of the electrocardiographic waveform of the acquired electrocardiogram,
A T wave estimation unit that estimates a T wave based on the RR interval of the electrocardiogram, and a T wave estimation unit.
A TWA analysis unit that performs TWA analysis using the T wave detected by the T wave detection unit and TWA analysis using the T wave estimated by the T wave estimation unit, and a TWA analysis unit.
A display unit that displays the TWA analysis result obtained by the TWA analysis unit, and a display unit that displays the TWA analysis result.
Equipped with
The display unit
The TWA analysis result obtained by the TWA analysis unit using the T wave detected by the T wave detection unit and the TWA obtained by the TWA analysis unit using the T wave estimated by the T wave estimation unit. Display both the analysis result and
ECG information processing apparatus.

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