JPS6048729A - Cardiograph analytical apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrocardiogram analysis device that can be used for predicting and treating heart diseases.

Conventional configurations and their problems In general, the heart acts as a biological pump and continues to contract and expand without rest. This is called mechanical activity of the heart, but there is actually an activity in the heart that causes this mechanical activity, and this is called electrical activity, and this electrical activity can be detected using an electrocardiograph. What is recorded using this device is the electrocardiogram waveform.

As shown in Figure 1, the electrocardiogram waveform mainly consists of P wave 1, Q wave 2, and so on. R wave 3. S wave 4. It is divided into 5 T waves. Switchless P wave 1
As shown in FIG. 2, this represents the atrial excitatory process in which an excitatory stimulation that begins at the sinus node 6 is transmitted through the atrioventricular node 8 through the intra-atrial conduction fibers 7. The QR9 wave group is Q wave 2. It is a combination of three waves: R wave 3° and S wave 4. Excitation in these waves passes through the atrioventricular node 8, the His bundle 9 in the upper part of the ventricle, and the left leg posterior line 1o. The fibers branch into the left anterior peduncle line 11 and the right anterior peduncle line 12, become Purkinje fibers 13, run on the surface of the endocardium, and spread throughout the ventricular muscle 14, and play a role in the excitatory process of the heart. It shows until the end. That is, the Q wave 2 represents the excitation process of the ventricular septum, the R wave 3 represents the overexcitation of the ventricular muscle, and the S wave 4 represents the excitation process of the ventricular muscle on the opposite side as viewed from the electrode position. The 3-wave group, QR3 wave group, and 3 waves represent the excitation process of the ventricular septum and left and right ventricular muscles. The contractile activity of the ventricle occurs after this electrical stimulation, which appears as the QR3 wave group, passes. Then, the recovery process of the ventricular muscle 14 is expressed as a T wave 5.

Also, from a lamicroscopic perspective, the principle behind the generation of the electrocardiogram south waveform is that the 1π of the sinus node 6, which is a collection of pacing cells, is caused by changes in the intracellular potential of cells in the transmission path (generation of action potentials). , the potential placed on the surface of the human body is observed to be attenuated to about 1/1000 of its value. The waveform that appears on the electrocardiograph is
It can also be said to be a vector representation of the activities of cells on the excitation transmission path within the heart.

For example, to simplify the explanation, if we hypothetically consider only one transmission path, as shown in Figure 3, in the transmission from the atrioventricular node 8 to the Purkinje fibers 13 and the ventricular muscle 14, The action potentials in the constituent cells are slightly different; Figure 4a shows the atrioventricular node, Figure 4 shows the bundle of His, Figure 4C shows the right leg, and Figure 4d shows the Glukinje fiber. Figure 4e shows the action potentials of the ventricular muscle, and these are slightly different. If we look at the intracellular potentials at points A, B, C, D, E, and F on the transmission path on the time axis, they become as shown in Figure 6. As shown in FIG.

In reality, there are many cells from the atrioventricular node 8 to the ventricular muscle 14, and in the transmission of excitement, the observed waveform of the intracellular potential on the human body surface appears as the QR8 wave group of the electrocardiogram, as shown in Figure 7. My thoughts spread.

If there is a disease in the above-mentioned excitement transmission pathway and the cell action potential is not normal, the QR3 wave will have a concave waveform as shown in Figure 8, and will differ from the normal waveform. come.

Conventional electrocardiographs mainly record with a pen recorder, but there are limitations such as the material of the paper and the mechanical movement of the pen, so it is usually
It is only possible to follow a waveform of about 00 Hz, so it is difficult to see changes in the waveform, and even if an electromagnetic oscilloscope is used, it is only able to follow a waveform of 2 to 3 kHz, making it difficult to detect diseases in the excitement transmission path. Only large areas of about 30 to 40 meters in diameter could be detected, which caused a delay in the detection of heart disease and an inability to lower mortality rates.

Purpose of the Invention The present invention has been made to eliminate the above-mentioned conventional problems, and it is possible to discover a diseased area on the transmission path of electrical stimulation (stimulation) of the source of cardiac activity, which could not be discovered in the past. It is an object of the present invention to provide an electrocardiogram analysis device that has improved performance and is capable of estimating the location of diseased areas.

Structure of the Invention In order to achieve the above object, the present invention includes an amplifier that amplifies analog minute biological signals obtained from electrodes attached to the surface of the human body, and an amplifier that converts the analog signal amplified by the amplifier into a digital signal. Creating a trigger point using a D converter and an analog signal amplified by the amplifier,
A CP that stores digital signals before and after the trigger point in an external storage unit based on this trigger point.
and a CRT display that processes and displays the digital signal for all or part of the n time stored in the external storage unit by -1cPU. According to this configuration, the By making the conversion speed of the A/D converter, so-called sampling time, very slow, the waveform corresponding to the QR3 wave part of the electrocardiogram can be broken down into small pieces on both the time and voltage axes of the electrocardiogram, making it possible to imitate the electrocardiogram. This makes it possible to observe minute changes extremely easily and accurately. Also, once the waveform is captured, it is stored in the external storage, so once the waveform is stored,
It can be displayed on the CRT display as many times as necessary, and even arbitrary sections can be displayed as necessary, making it possible to enlarge the whole or parts, and as a result, It can also observe minute changes in waveforms that cannot be observed with conventional electrocardiographs, making it extremely useful for predicting and treating heart disease.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. Fig. 9 shows a block diagram of an electrocardiogram analyzer according to an embodiment of the present invention, where 21 is a human body; human body 21
A total of four electrodes 22 are fixed on the limbs of the person, one each on both hands and feet, and six electrodes 22 are fixed on the chest.
Select one of the four limb leads or the six chest leads. In this case, since the biosignal induced from the human body 21 is very small and only about 1 mV, the biosignal is amplified by the amplifier 24. The biological amplification unit 24 performs these operations.
It is.

The amplified signal is an analog signal, and the amplified signal is an analog signal.
For lcPU processing, the A/D converter 25 converts it into a digital signal. On the other hand, when the memory start switch is pressed, the amplified signal is compared with the preset 1, +7 ga voltage by the voltage comparator 26, and the trigger point is detected. In addition, the external storage unit 27 stores data for a certain period of time (0.1 to 0.4).
The data is stored in the external storage section 27 in a chronologically shifted manner at all times when a storage start signal is input.

In this state, if you press the memory start switch mentioned above,
After the trigger point is detected, the delay device 28 stops capturing the digital signal after a predetermined period of time has elapsed. By making the delay time of the delay device 28 shorter than the storage time determined by the capacity of the external storage section 27, digital signals before the trigger point can also be stored.

When observing the stored electrocardiogram waveform, the CPU 29 reads out the digital signal from the external storage section 27, converts it into an analog signal, and displays it on the CRT display 3o as a two-dimensional figure with a time axis and a voltage axis. indicate. It is also possible to take out any point or section of the shredded external storage section 27 and observe it under magnification.

By setting the conversion speed, so-called sampling time, of the A/D converter 25 that converts the analog signal to a digital signal to, for example, 20μ, a waveform of approximately Q, 1 sec, which corresponds to the QR3 wave portion of an electrocardiogram, is generated on the time axis. and 50
It can be decomposed and converted into 00 points. By decomposing the voltage axis of the A/D converter 25 into, for example, 12 binary bits, the maximum voltage of the QR3 wave portion is approximately 1. ○～
Since it is 1.1mV, the maximum conversion voltage "t" is 1.5mV
Therefore, it has a resolution of 0.37 μV.

In this way, in one embodiment of the present invention, the electrocardiogram QR
It is possible to decompose and convert the 3-wave part into 5000 points (20μ dew interval) on the time axis, and also to convert the 3-wave part into 5000 points (20μ dew interval) on the voltage axis.
Since it can be observed with a resolution of μ■, it is possible to observe minute changes in waveforms that could not be detected with conventional electrocardiographs.

Effects of the Invention As described above, according to the present invention, an amplifier that amplifies analog minute biological signals obtained from electrodes attached to the surface of the human body ← converts the analog signal amplified by the sweat device into a digital signal. By making the conversion speed of the A/D converter, the so-called sampling time, very slow, the waveform corresponding to the CJR3 wave part of the electrocardiogram can be finely decomposed in both the time and voltage axes of the electrocardiogram. Minute changes can be observed extremely easily and accurately. In addition, since the waveform once captured is stored in the external storage unit, the waveform once stored can be displayed on the CRT display as many times as necessary.
Moreover, since any section can be displayed as needed, it is now possible to enlarge the whole or a portion, and as a result, minute changes in waveforms that cannot be observed with conventional electrocardiographs can also be observed. This makes it extremely useful for predicting and treating heart disease.

[Brief explanation of drawings]

Figure 1 is a conventional electrocardiogram waveform diagram, Figure 2 is a vertical cross section of the heart and a model of the electrical impulse transmission path, and Figure 3 is a cross section of the interventricular septum and right ventricle of the heart and a model of the electrical impulse transmission path. figure,
Figure 4 a, b, c, d, and e are waveform diagrams of the intracellular potential at each point on the electrical stimulation transmission path, and Figure 5 shows the overlap of the time axis and voltage axis of the intracellular potential on the electrical stimulation transmission path. Combined waveform diagram, Figure 6 is a waveform diagram of potential n observed on the human body surface, Figure 7 is a waveform diagram of the QR3 wave observed on the human body surface, and Figure 8 is observed on the human body surface with heart disease. Waveform diagram of the third QR wave, No. 9
The figure is a block diagram of an electrocardiogram analysis device showing one embodiment of the present invention. 22... Electrode, 24... Amplifier, 25 ・
...A/D converter, 26...Voltage comparator, 27...
...Data storage section, 29 ...CPU, 30...
・CRT display. Name of agent: Patent attorney Toshio Nakao and 1 other person Figure 2 Figure 3 ((27lb) Ic) /d Figure 5 Figure 7 Figure 8

Claims (1)

[Claims] an amplifier that amplifies analog minute biological signals obtained from electrodes attached to the surface of the human body; and an A/D converter that converts the analog signals amplified by the amplifier into digital signals;
A CPU that creates a trigger point using the analog signal amplified by the amplifier, and stores in an external storage unit the cathode signals before and after the trigger point based on this trigger point; and a CPU that stores the NFC time stored in the external storage unit. The digital signal for a part of the time is CP,
An electrocardiogram analysis device equipped with a CRT display that processes and displays data using U.