JPH03218729A - Electrocardiograph - Google Patents

Abstract

PURPOSE:To continuously attain the storage for many hours, and also, to miniaturize a electrocardiograph itself, to contrive the reduction in weight, and to improve the portability by storing electrocardiogram waveform data in a changeable card, and storing it temporarily in the built-in buffer at the time of changing the card. CONSTITUTION:To a memory card 50 which can be attached/detached to/from an electrocardiograph main body 80, electrocardiogram waveform data is inputted from a control part 30, and when it reaches its capacity limit, the control part 30 displays its fact on a display part 70, and also, sends a sign by a sound from a notice part 75. Simultaneously, the memory is switched to a built-in buffer memory 40 from the memory card, and the electrocardiogram waveform data is stored therein tentatively. A person to be examined replaces the memory card 50 with a new one during this time. When the replacement is ended, the control part 30 transfers the electrocardiogram waveform data stored temporarily in the buffer memory 40 to the new memory card and stores it therein, and thereafter, electrocardiogram waveform data inputted to the control part is stored successively in the new memory card.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrocardiogram waveform II and an improvement in an electrocardiograph for analyzing it.

[Conventional technology]

In recent years, clinical tests that measure electrocardiograms, blood pressure, etc. are routinely performed in the medical field.

These tests are usually performed within a very limited time in medical facilities such as clinics and hospitals under the supervision of a doctor or clinical laboratory technician. However, there are some diseases that cannot be detected by testing within such a limited time.

For example, in the case of a transient heart disease (arrhythmia), abnormal waveforms do not always appear on the electrocardiogram, and the time intervals at which they appear are irregular, so the probability of detection in a short test is low. , it is often difficult to make a definitive diagnosis with a short test.

Therefore, in order to detect such diseases, methods have been devised to measure electrocardiograms over a long period of time. This method is called a long-term electrocardiogram (usually referred to as a Holter electrocardiogram), in which a portable electrocardiograph is worn on the subject's body for 24 hours a day during daily life, and electrocardiogram waveforms are collected on magnetic tape. The electrocardiogram waveform is recorded and later reproduced by a magnetic tape reproducing device for observation by an examiner such as a doctor to discover abnormalities and diagnose transient heart diseases. In this case, the electrocardiogram waveform recorded on the magnetic tape is reproduced at high speed because of its large volume. Therefore, it has become a burdensome task for examiners such as doctors to view and diagnose a large number of electrocardiogram waveforms that are reproduced at high speed.

In this way, it is a waste of time to replay all 24-hour ECG waveforms and spend a lot of time analyzing them in order to discover arrhythmias that occur only occasionally and transiently. The efficiency of inspection is low.

In order to solve this irrationality, a large amount of recorded magnetic tape is played back at high speed (for example, 60 times or 120 times faster playback) and the waveform is automatically analyzed using a predetermined method by the device.As a result, abnormalities are detected. There is also a method in which only the determined portion is displayed and the inspector inspects it. However, since the magnetic tape is played back at high speed and the electrocardiogram waveform data is input at high speed, if you try to analyze it using a microcomputer, you will not have enough time for analysis, making it difficult to improve the accuracy of analysis. This is the current situation.

Therefore, recently, electrocardiogram waveform analysis has been automatically performed simultaneously while collecting electrocardiograms for a long time, that is, in real time.As a result,
Record only the electrocardiogram waveforms judged to be abnormal on magnetic tape or
These abnormal waveforms and analysis results are stored in a C memory or the like, displayed on a display device at a later date by the doctor, and printed out if necessary so that the doctor can confirm the results. This method provides sufficient analysis time (60 or 120 times longer) than the above-mentioned methods, and improves analysis accuracy.

In real-time analysis of such long-term electrocardiogram measurement, all electrocardiogram waveforms for 24 hours are not retained, but only waveforms determined to be abnormal by automatic analysis of the device are stored. Therefore, since the waveforms determined to be normal by automatic analysis are not stored in memory, even if there are abnormal waveforms among them, the examiner cannot inspect them.

For this reason, in real-time analysis, it is extremely important that no abnormal waveforms are overlooked, and it is also important that normal waveforms are not determined to be abnormal in order to reduce the labor of the examiner during testing.

As a method to simultaneously solve the problem of automatic analysis accuracy in the real-time analysis method mentioned above and the poor diagnostic efficiency (efficiency) of the method of recording on magnetic tape and analyzing it later (long-term electrocardiogram storage method), Recently, a method has been devised that combines two methods: real-time analysis and long-term electrocardiogram recording (Japanese Patent Application Laid-Open No. 62-233145.62-261339).

In other words, in this combination method, electrocardiograms are measured over a long period of time, and all electrocardiograms are recorded on magnetic tape. At the same time, the electrocardiograms are automatically analyzed in real time by a microcomputer built into the main body, and the results of this analysis are recorded magnetically. It records on a tape or another memory module (e.g. semiconductor memory), and when a 24-hour measurement is completed, the analyzed results can be obtained in a short time using real-time analysis.
Four hours' worth of electrocardiograms are also obtained, and a doctor can perform analysis and diagnosis as necessary, improving overall accuracy.

However, the purpose of long-term electrocardiograms is to obtain information that cannot be obtained from regular 12-lead electrocardiograms or exercise stress tests.
In other words, it is important to obtain electrocardiograms in daily life, and it is therefore strongly desirable that the electrocardiograph used for testing be portable, small, and lightweight so as not to be a burden on the subject. ing.

However, current Holter electrocardiographs that use magnetic tape recording are large and heavy, and strongly restrict the subject, which poses a major practical problem (hindrance).

By the way, the above-mentioned method of combining real-time analysis and long-term electrocardiogram recording is a system that adds another memory module to record real-time analysis results to the current magnetic tape recording type Holter electrocardiograph, and the overall The shape and perspective of the monitor have also become larger and heavier, and although improvements have been made in terms of diagnostic accuracy and efficiency, no improvements have been made in terms of the restrictiveness of long-term electrocardiogram examinations, which is the original purpose. Not only is this method not effective, but on the contrary, it is a method that strengthens the restraint, and therefore, it can be said that the value of the electrocardiograph is greatly diminished as a long-term electrocardiograph.

On the other hand, long-term electrocardiographs that do not use magnetic tape at all have been devised. For example, in Japanese Unexamined Patent Publication No. 19229/1983, a semiconductor memory or a digital memory such as a magnetic bubble memory is used as the memory. however,
If we try to store 24 hours worth of electrocardiogram waveforms on these digital memories in the same way as magnetic tape, a fairly large capacity memory will be required, and in reality, the size of the device will be too large, which will hinder its portability. Therefore, the electrocardiogram data is compressed before being stored to reduce the data volume. However, although increasing the compression rate reduces the data capacity, there is a risk that the important electrocardiogram waveform will be distorted, which will adversely affect accurate diagnosis.

[Problem to be solved by the invention]

As described above, high-speed playback/automatic analysis methods have varying degrees of analysis accuracy, and real-time analysis methods may miss abnormal waveforms. In addition, devices that use a combination method that combines both high-speed playback/automatic analysis and real-time analysis methods are large and heavy, and place greater restraint on the patient, while those that use digital memory If an attempt is made to increase the memory capacity, the device becomes bulky and heavy and lacks portability, and if data is compressed to solve this problem, the electrocardiogram waveform becomes distorted.

The present invention is intended to solve the above-mentioned problems, and improves the poor portability of conventional long-term electrocardiographs, that is, the restraint of the subject, without impairing the efficiency and accuracy of diagnosis. The purpose of the present invention is to provide an electrocardiograph that is small, lightweight, and highly portable.

[Means to solve the problem]

To this end, the present invention provides an A/D converter that converts a detected electrocardiogram waveform analog signal into a digital signal;
An electrocardiograph comprising a control section that reads digital signals from a converter and performs control to store them in a semiconductor storage section, comprising a buffer memory that is controlled by the control section and can temporarily store digital signals; The semiconductor storage section is configured as a separate semiconductor storage medium that is removable from the electrocardiograph, and when the digital signal is not stored in the storage medium, the digital signal read from the A/D conversion is stored in the buffer memory. It is characterized by being temporarily memorized.

[Effect]

The present invention constantly stores electrocardiogram waveform data in a semiconductor memory that is detachable from the electrocardiograph and is configured separately from the electrocardiograph, and when the memory becomes full or is not stored during insertion and removal. , the storage of data is switched from the removable semiconductor memory to the buffer memory built into the electrocardiograph for temporary storage, and when a new memory card is inserted, the data temporarily stored in the buffer is transferred to the new semiconductor memory. By storing the electrocardiogram waveform data continuously and sequentially on the memory card,
Therefore, the electrocardiogram waveform data can be stored without being compressed, eliminating limitations on examination time and improving diagnostic accuracy. Furthermore, the electrocardiograph itself can be made smaller and lighter, improving portability. It becomes possible.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of the electrocardiograph of the present invention;
FIG. 2 is a block diagram showing the configuration of the reproducing device, and FIG. 3 is a perspective view for explaining the electrocardiograph of the present invention. In the figure, 5
is a human power terminal, 10 is an amplifier, 20 is an A/D converter, 30
is a control unit, 40 is a buffer memory, 50 is a memory card, 60 is a power supply unit, 70 is a display unit, 75 is a notification unit, 80 is a main body, 100 is an input unit (interface unit), 150 is a control unit, 170 is an output Section 200 is a display section.

The electrocardiograph of the present invention is comprised of a portable long-term electrocardiograph main body 80 and a memory card 50, as shown in FIG. The memory card 50 is composed of a semiconductor memory such as SRAM, DRAM, or writable ROM, and is removably attached to the main body 80.

The configuration of the main body 80 and the relationship with the memory card 50 are explained in the first section.
This will be explained using figures.

An electrocardiogram waveform (cardiac potential) from an electrocardiogram electrode (not shown) attached to the subject is input to the amplifier 10 of the main body 80 from the input terminal 5, is converted into a digital quantity by the A/D converter 20, and is sent to the CPU. The information is read into the control unit 30 consisting of the following. The read electrocardiogram waveform data is stored in the memory card 50 by the control unit 30. The buffer memory 40 is
This is for temporarily storing electrocardiogram waveform data while the memory card is not being stored to the memory card until its storage capacity is full or the card is being inserted or removed for replacement.

In addition, the content of the read data or the data that has been processed in a predetermined manner can be displayed on the display unit 70 at any time, and a notification will be sent when the remaining memory capacity of the memory card is exhausted or below a predetermined remaining capacity. The test subject is informed by the section 75 by sound. Each part of the device is supplied with power from a power supply section 60 that uses a battery as a power source.

By the way, in order for the memory card 50 to have a capacity sufficient to store all 24 hours worth of electrocardiogram waveforms, the shape of the memory card 50 must be made large, but on the other hand, the portability of the electrocardiograph 80 for long periods of time can be improved. In order to achieve this, it is desirable to make the overall shape (length, width, thickness) as small as possible. Therefore, the shape and thickness of the memory card 50 must necessarily be kept below a certain thickness, and the memory capacity that can store electrocardiogram waveforms is limited, and as a result, the time that data can be read is also limited to a certain time b. will be done.

Thus, it is an object of the present invention to eliminate the limitation on the storage time of electrocardiogram waveform data due to the capacity limitation of the memory card 50. That is, when electrocardiogram waveform data is manually input to the memory card 50 by the control unit 30 and the capacity limit of the memory card 50 is reached, the control unit 30 displays on the display unit 70 that the memory card is saturated, and The notification section 75 sends a sound signal so that the person can understand. At the same time, the controller 30 switches the memory for storing data from the memory card to the buffer memory 40, and after the memory card 50 is saturated, the electrocardiogram waveform data is temporarily stored in the buffer memory 40. Of course, switching may be performed before the memory is completely saturated to prevent data loss during memory switching for some reason.

When the subject is notified that the memory card 50 is saturated, the subject removes the memory card 50 from the main body 80 and inserts a new memory card into the main body 80.

When a new memory card is inserted into the main body 80, the control unit 30 transfers the electrocardiogram waveform data temporarily stored in the buffer memory 40 to the new memory card and stores it.
Thereafter, electrocardiogram waveform data input manually to the control unit 30 is sequentially stored in new memory cards.

In this way, even if the memory card becomes saturated, by replacing it with a new memory card, you will not be limited to the capacity of one memory card, and you will be able to sequentially record ECG waveforms for the required time (usually 24 hours) with a new memory card. Furthermore, since electrocardiogram waveform data is temporarily stored in the buffer memory 40 even when the memory card is replaced, electrocardiogram waveform data can be stored continuously.

Next, reading out the stored electrocardiogram waveform data will be explained with reference to FIG.

The electrocardiogram waveform data stored in the memory card 50 is read and reproduced by the reproduction device 500 shown in FIG. That is, when a memory card storing electrocardiogram waveform data is set in the playback device 500, the data stored in the memory card is sequentially read through the human power unit (interface) 100 and predetermined processing is performed in the control unit 150. The electrocardiogram information is displayed on the display section 200, and the electrocardiogram information is output to a printer from the output section 170 as necessary.

The electrocardiogram information output to the printer at this time is, for example, 24
Information equivalent to a regular long-term electrocardiograph can be obtained, such as analysis results for all waveforms and abnormal electrocardiograms for an hour.

FIG. 4 and FIG. 5 are diagrams showing other embodiments of the present invention,
The same numbers as in FIGS. 1 and 2 indicate the same contents. Note that 90 is an event switch.

In this embodiment, an event switch 90 is provided on the electrocardiograph main body 80, as shown in FIG.
This embodiment is similar to the embodiment shown in FIG. 1 in that a memory card 50 is removably attached to the electrocardiograph main body.

The event switch 90 is connected to the control section 30 as shown in FIG.
It is connected to the electrocardiograph to notify the electrocardiograph when the subject experiences any subjective symptoms related to the heart, such as chest pain, palpitations, shortness of breath, or dizziness, during the test.
When this switch is pressed, a signal is input to the control unit 30, indicating that there was a subjective symptom and that the time is recorded on the memory card 30.
0, and is stored in the buffer memory 40 when the memory card 50 is removed during exchange. Therefore, the correspondence between the electrocardiogram waveforms stored in the memory card and the subjective symptoms is accurately stored and reproduced by the reproducing device shown in FIG. 2, which is extremely useful for diagnosis.

Note that as another testing method, the function of the control unit 30 may be set so as to store only the electrocardiogram waveforms before and after pressing the event switch 90 instead of storing all the electrocardiogram waveforms. As a result, the amount of information of the electrocardiogram waveform to be stored is reduced, and electrocardiogram examinations can be performed for a longer period of time, which is very useful for diagnosis. In this case as well, according to the present invention, it is possible to sequentially store electrocardiogram waveforms at the time of occurrence of an event switch in a memory card without any time limit.

〔Effect of the invention〕

As described above, according to the present invention, electrocardiogram waveform data is stored in a memory card, and when the capacity of the memory card is saturated, the subject is notified of this, and the subject knows that the capacity has been saturated, and a new memory card is stored. Testing can be continued by replacing the memory card, and by storing the ECG waveform data in the buffer when the memory card is replaced, long-term ECG waveform data can be stored in the memory card continuously and sequentially. It eliminates the test time limitations of long-term electrocardiographs that use digital memory, and also improves diagnostic accuracy because the original waveform can be faithfully stored without the need to compress ECG waveform data. Furthermore, by using a memory card, the electrocardiograph itself becomes smaller and lighter, improving portability and reducing the burden on the subject. In addition, by combining it with an event switch, it becomes even more useful for diagnosis, and by storing only the electrocardiogram waveforms before and after the event switch is imitated, it becomes possible to perform an electrocardiogram examination for a longer period of time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the overall configuration of the electrocardiograph of the present invention;
Fig. 2 is a block diagram showing the configuration of the playback device, Fig. 3 is a perspective view for explaining the electrocardiograph of the invention, and Fig. 4 is a diagram showing another embodiment of the invention provided with an event switch. , 5th
The figure is a perspective view of another embodiment of the present invention in which an event switch is provided. 30...control unit, 40...buffer memory, 50...
...Memory card, 70...Display section, 75...Notification section, 90...Event switch.

Claims (2)

[Claims] (1) An A/D converter that converts a detected electrocardiogram waveform analog signal into a digital signal, and a control unit that reads the digital signal from the A/D converter and performs control to store it in a semiconductor storage unit. The electrocardiograph has a buffer memory which is controlled by the control section and is capable of temporarily storing digital signals, and the semiconductor storage section is constituted separately by a semiconductor storage medium that is removable from the electrocardiograph, and the storage An electrocardiograph characterized in that the digital signal read from the A/D conversion is temporarily stored in the buffer memory when it is not stored in a medium. (2) The electrocardiograph according to claim 1, wherein the contents of the buffer memory are transferred to and stored in the attached storage medium.