JPH04322637A - Electrocardiograph - Google Patents

Abstract

PURPOSE:To achieve higher portableness with a smaller size in an electrocardiograph which performs an inspection with a plurality of guidance systems by recording an electrocardiogram waveform higher in quality among the waveforms detected to make the capacity of a recording medium minimum necessary. CONSTITUTION:An electrocardiograph 1 is connected electrically to two electrode sections 2 and 3 for a long time. One electrode section 2 detects an electrocardiogram waveform by a NASA guidance system and the other electrode section 3 detects the electrocardiogram waveform by a CC5 guidance system. A CPU15 compares quality of two electrocardiogram waveforms inputted separately from the electrode sections 2 and 3 and recognizes the waveform less in degrading of quality of the waveform as caused by an electromyogram waveform, a change in base line and the like. A code is recorded with an RAM 17 to indicate which guidance system detects the waveform together with the results of the recognition. In addition, when the CPU15 recognizes that the electrocardiogram waveform detected with the electrode part 2 is the same in quality as the electrocardiogram waveform detected with the electrode section 3, one electrocardiogram waveform, for example, the one detected with the electrode section 2 is adopted in preference.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrocardiograph that performs electrocardiogram testing, and more particularly to an electrocardiograph that performs testing using a plurality of lead methods.

0002

2. Description of the Related Art Among the general electrocardiogram tests for heart disease, there is a long-term electrocardiogram test (commonly known as Holter electrocardiogram test) in which an electrocardiograph is carried around 24 hours a day. This test detects transient abnormal electrocardiogram waveforms that occur irregularly and is difficult to detect with regular electrocardiogram tests, and is intended to be useful for early detection and diagnosis of heart disease.

[0003] For such long-term electrocardiograph examination, NA
One of SA guidance, CM5 guidance, and CC5 guidance is adopted. Also, depending on the purpose of the test,
Among these guidance methods, a combination of two guidance methods is employed, and a combination of NASA guidance and CM5 guidance, or NASA guidance and CC5 guidance is generally selected. Usually, the purpose of this two-lead system is to use two types of lead systems to perform diagnosis for different purposes, such as arrhythmia diagnosis and ST change diagnosis. However, since long-term electrocardiograms are performed during normal daily life, it is often difficult to distinguish between ST changes due to body movement and ST changes due to myocardial ischemia.
Therefore, the reliability of diagnosis of ST changes is extremely low. For this reason, the main purpose of today's long-term electrocardiography is to diagnose arrhythmia such as premature ventricular contraction, and it can be said that the diagnostic content is reliable. When diagnosing arrhythmia, one lead is usually enough to diagnose arrhythmia. However, since an electrocardiogram is a test conducted in daily life, the ECG waveform may be mixed with the EMG waveform due to body movements, or the baseline of the waveform may vary significantly. This results in distortions and deformations that are undesirable for diagnostic purposes. The purpose of the 2-lead system is to use the 2-lead method when the electrocardiogram waveform in one lead is distorted due to such causes and diagnosis is difficult.
When looking at the waveform from one lead and finding that it has little distortion and poses no problem in diagnosis, the waveform from that lead is used instead as the subject of diagnosis.

By the way, such 24-hour electrocardiogram waveforms are recorded on the electrocardiograph body carried by the subject, but semiconductor memory has recently begun to be used as a recording medium instead of magnetic tape. . Semiconductor memory is an excellent recording medium that can record electrocardiogram waveforms digitally, without deteriorating the quality of the waveforms due to frequency distortion, etc., unlike the analog recording method of magnetic tape, which is a conventional recording medium. .

[0005]

[Problems to be Solved by the Invention] However, the electrocardiograph using this semiconductor memory does not have a storage capacity large enough to continuously record all electrocardiogram waveforms over a 24-hour period, unlike conventional long-term electrocardiographs using magnetic tape. does not have. For example, in order to record all electrocardiogram waveforms in digital values using a 2-lead system, the memory capacity should be 8 bits for analog/digital conversion accuracy and 4 ms for sampling time.
If it is ec, it will have a large capacity of 43.2 megabytes. 4 with the largest storage capacity currently in use
Even if you use megabit DRAM (dynamic random access memory), you will need 87 of them.
This led to an increase in the size of the device. For this reason, it is very inconvenient for a subject to carry around 24 hours a day, and there is a problem that portability is poor and it is not practical.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to be able to perform accurate examinations using a plurality of guidance methods using a recording medium with a minimum recording capacity, and to improve the reliability of diagnosis. The object of the present invention is to provide a small-sized electrocardiograph that has improved performance, excellent portability, and is suitable for practical use.

[0007]

[Means for Solving the Problems] The electrocardiograph according to the present invention has the following features:
a plurality of detection units that detect electrocardiogram waveforms using different lead methods; a recognition unit that compares the quality of the electrocardiogram waveforms respectively detected by the plurality of detection units and selects a waveform of good quality; and a recording section for recording electrocardiogram waveforms.

Furthermore, in the electrocardiograph of the present invention, when the recognition section determines that the electrocardiogram waveforms detected by the respective detection sections are of similar quality, the recognition section performs a recognition process using the detection section of a specific guidance method. It is preferable to adopt a configuration in which the detected electrocardiogram waveform is preferentially recorded in the recording section, and when comparing the electrocardiogram waveforms, consideration is given to deterioration in quality due to contamination of the electromyogram waveform with the electromyogram waveform, baseline fluctuation, etc. It is preferable to set it as a structure.

With such a configuration, the electrocardiograph of the present invention compares the electrocardiogram waveforms of each of the plurality of lead methods and records the waveform with less deterioration in waveform quality due to electromyogram waveforms, baseline fluctuations, etc. Therefore, only the electrocardiogram waveform of better quality can be recorded. Therefore, the capacity of the recording medium can be minimized. Therefore, a digital recording type semiconductor memory can be used as the recording medium, and accurate examination can be performed, and the electrocardiograph as a whole can be downsized, and its portability is significantly improved.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic configuration of a long-term electrocardiograph according to an embodiment of the present invention.

The long-term electrocardiograph 1 is electrically connected to two electrode sections 2 and 3 as an electrocardiogram waveform detection section. One electrode part 2 has three electrocardiogram electrodes 2a, 2b, 2c.
The electrocardiogram waveform is detected using, for example, the NASA lead method. The other electrode section 3 is composed of two electrodes 3a and 3b, and detects an electrocardiogram waveform using a different lead method from that of the electrode section 2, for example, a CC5 lead method. As shown in FIG. 3, these electrode parts 2 and 3 are attached to predetermined parts of the subject according to each guidance method. Here, the electrocardiogram electrode 2a
is the reference point (N), which is shared by each guidance method.

The long-term electrocardiograph 1 includes an amplification section 11 for amplifying the electrocardiogram waveform detected by the electrode section 2, an amplification section 12 for amplifying the electrocardiogram waveform detected for the electrode section 3, and an amplification section 1 for amplifying the electrocardiogram waveform detected by the electrode section 3.
an analog/digital conversion unit (hereinafter referred to as A/D conversion unit) 13 that converts the electrocardiogram waveform amplified by the amplifier unit 1 into a digital signal; and an analog/digital conversion unit that converts the electrocardiogram waveform amplified by the amplifier unit 12 into a digital signal. Part 14
and a CPU (central processing unit) 15 which receives as input electrocardiogram waveforms converted into digital signals in A/D converters 13 and 14, respectively.

[0013] The CPU 15 has a ROM (read only).
Memory) 16, RAM (Random Access Memory)
17, an operation section 18, a display section 19, and a communication section 20 are connected, respectively. The CPU 15 executes A according to the control program recorded in the ROM 16 and RAM 17.
The quality of the two electrocardiogram waveforms input from each of the /D converters 13 and 14 is compared, the waveform with less deterioration in waveform quality due to electromyogram waveforms, baseline fluctuations, etc. is recognized, and the recognition results are applied to the electrodes. RA along with a code indicating which waveform was detected by either section 2 or 3, that is, which guidance method.
It is designed to be recorded on M17. This code is
For example, in the case of the NASA guidance system, it is set as "1", and in the case of the CC5 guidance system, it is set as "2".

Further, when the CPU 15 recognizes that the electrocardiogram waveform detected by the electrode section 2 and the electrocardiogram waveform detected by the electrode section 3 are of the same quality, the CPU 15, for example, The electrocardiogram waveform that has been detected is preferentially adopted. The ROM 16 stores a program for controlling the CPU 15 and a program for recognizing electrocardiogram signals in real time. The RAM 17 stores an electrocardiogram waveform converted into a digital signal by the A/D converters 13 and 14, a recognition program for recognizing this electrocardiogram waveform, and data as a result of recognition by the CPU 15 using this recognition program. It has become.

The operation section 18 includes a measurement start switch 41 provided on the outer surface of the long-term electrocardiograph 1 as shown in FIG.
It is composed of etc. The display unit 19 displays a liquid crystal display, and displays, for example, the operating status of the long-term electrocardiograph 1, an alarm for power shortage, and the like. The communication section 20 is a RAM
17 is for outputting the electrocardiogram waveform recorded in the communication section 32 of the reproduction output device 31 to the outside, as shown in FIG.
It is designed to be connected to. Amplifying section 11, 12, A
Necessary power is supplied to each of the /D conversion units 13, 14, CPU 15, ROM 16, and RAM 17 from a power supply unit 21, and a primary battery or a secondary battery is used as the power supply unit 21. .

Next, the operation of the long-term electrocardiograph 1 of this embodiment will be explained. First, the subject wears the long-term electrocardiograph 1 on the waist as shown in FIG. Attach it to the part. Subsequently, the test start switch 41 of the operation unit 18 is turned on to start the test.

In this state, the electrocardiogram waveforms obtained by the electrode sections 2 and 3 are amplified to a predetermined level by the amplifier sections 11 and 12, respectively, and converted into digital signals by the A/D conversion sections 13 and 14. , is input to the CPU 15. C.P.
U15 compares the quality of the two input electrocardiogram waveforms according to the control program stored in the ROM 16 and RAM 17, and selects the waveform with less deterioration in waveform quality due to electromyogram waveforms, baseline fluctuations, etc., such as the electrode section. 2. Recognize the detected waveform. Then, the CPU 15 records the recognition data in the RAM 17 together with a code "1" representing the guidance method of the recognized waveform. Therefore, when the 24-hour test is completed, all of the electrocardiogram waveforms of better quality recognized in this way will have been recorded in the RAM 17. Further, if the CPU 15 determines that the electrocardiogram waveform detected by the electrode part 2 and the electrocardiogram waveform detected by the electrode part 3 are of similar quality, the CPU 15 gives priority to the electrocardiogram waveform detected by the electrode part 2. The recognition data is recorded in the RAM 17.

In order to output the contents recorded in the RAM 17 in this manner, the communication section 20 of the long-term electrocardiograph 1 is connected to the communication section 32 of the reproduction output device 31, as shown in FIG. As a result, the high-quality electrocardiogram waveform recorded in the RAM 17 is transferred to the reproducing/recording device 31 via the communication section 20 and the communication section 32, and is outputted to the recording paper 35 from the output section 34 under the control of the control section 33. . Therefore, by viewing the records by a specialized doctor, an accurate diagnosis can be made, thereby improving the reliability of the electrocardiogram test.

In the above embodiment, two guidance systems, NASA and CC5, were adopted.
The present invention is not limited to this combination, and may also be a combination of other different guidance methods, or may further employ a combination of three or more guidance methods. Furthermore, although the waveforms of better quality may be entirely recorded in the RAM 17 as in the above embodiment, the CPU 15 determines whether these waveforms are normal or abnormal, and the electrocardiogram waveforms determined to be abnormal are Alternatively, high-quality waveforms may be recorded intermittently at fixed time intervals. Further, the time at which the waveform was generated may be recorded together with such a waveform. Furthermore, although the above embodiment has been described using a digital recording type semiconductor memory (RAM 17) as the recording medium, the present invention can of course be applied to an analog recording type electrocardiograph using conventional magnetic tape or the like. It is.

[0020]

[Effects of the Invention] As explained above, according to the electrocardiograph of the present invention, when comparing electrocardiogram waveforms detected by multiple lead methods, there is little deterioration in waveform quality due to electromyogram waveforms, baseline fluctuations, etc. Since only the electrocardiogram waveform of high quality can be recorded, the capacity of the recording medium can be kept to the minimum necessary. Therefore, it is possible to use a digital recording type semiconductor memory as the recording medium, allowing accurate examinations, and making the entire electrocardiograph more compact, significantly improving portability and putting it into practical use. We can provide suitable electrocardiographs.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a long-term electrocardiograph according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration when outputting a recorded waveform of the long-term electrocardiograph in FIG. 1;

FIG. 3 is a front view showing the state in which the long-term electrocardiograph of FIG. 1 is attached to a subject.

[Explanation of symbols]

1 Long-term electrocardiograph 2, 3 Electrode section (electrocardiogram waveform detection section) 11, 12
Amplification sections 13, 14 A/D conversion section 15 CPU (recognition section) 16 ROM 17 RAM (recording section)

Claims (3)

[Claims] 1. A plurality of detection units that detect electrocardiogram waveforms using different lead methods; a recognition unit that compares the quality of the electrocardiogram waveforms respectively detected by the plurality of detection units and selects a waveform with good quality; An electrocardiograph comprising: a recording section that records the electrocardiogram waveform selected by the recognition section. 2. When the recognition unit determines that the electrocardiogram waveforms detected by the respective detection units are of similar quality, the recognition unit records the electrocardiogram waveforms detected by the detection unit of a specific guidance method. 2. The electrocardiograph according to claim 1, wherein the electrocardiograph records data preferentially in the lower part of the body. 3. The recognition unit compares the electrocardiogram waveforms detected by the detection unit by recognizing deterioration in quality due to mixing of electromyogram waveforms or baseline fluctuations in the electrocardiogram waveforms. or an electrocardiograph as described in 2.