JP2938079B2 - Heart disease monitoring device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heart disease monitoring device that monitors a heart condition of a monitoring target (hereinafter, referred to as a patient) by an electrocardiogram.

2. Description of the Related Art Conventionally, a portable electrocardiogram recording apparatus for recording an electrocardiogram has been known. This kind of electrocardiogram recording apparatus records an electric signal obtained from a body surface electrode attached to each part of the body on a magnetic tape or the like. The recorded electric signal is reproduced as an electrocardiogram which can be visually recognized by a well-known reproducing device, and the excitation process of the myocardium, that is, the continuous wave composed of the P wave, the QRS complex, the T wave, and the U wave shown in FIG. The waveform is diagnosed and analyzed by a doctor.

The patient records an electrocardiogram using the above electrocardiogram recording device, and transmits the record at that time to a hospital by telephone or the like when an abnormality is felt. The hospital regenerates and inspects the records sent to diagnose abnormalities.

[Problem to be Solved by the Invention] However, in the conventional electrocardiogram recording apparatus, even if an abnormality appears in the electrocardiogram, the abnormality is not reported to the patient. Therefore, the patient cannot know the abnormality unless there is a subjective symptom. Alternatively, the patient may subjectively judge that even if there is a subjective symptom, the patient is not abnormal. In these cases, the abnormality is not detected and the doctor cannot be diagnosed until the electrocardiogram is transmitted during a regular diagnosis and the doctor examines it, so that it is easy to be too late.

In addition, in the case of myocardial infarction, if it develops, it immediately becomes serious in patients, so it is necessary to accurately grasp changes in the electrocardiogram before the onset. However, the conventional ECG recording device can record the change but cannot notify the patient.

The present invention has been made for the purpose of a heart disease monitoring apparatus that records an electrocardiogram and notifies a patient of an abnormal electrocardiogram.

Means for Solving the Problems The gist of the present invention is that a body surface electrode for detecting a potential difference between each part of the body, and a signal for creating electrocardiogram waveform data from an electric signal output from the body surface electrode A processing device; a buffer memory for temporarily storing the electrocardiogram waveform data at each sampling cycle; an electrocardiogram abnormality determining means for determining whether the temporarily stored electrocardiogram waveform data is abnormal; and an electrocardiogram abnormality. And a storage memory for storing the electrocardiogram waveform data determined to be the following and the electrocardiogram waveform data immediately before and immediately after the electrocardiogram waveform determined to be abnormal.

Further, a notification means for displaying a hospital name and a telephone number to be contacted when it is determined that the electrocardiogram is abnormal may be provided.

[Operation] According to the heart disease monitoring device of the present invention configured as described above, the body surface electrode detects the potential difference between each part of the body, the signal processing device creates electrocardiogram waveform data therefrom, The buffer memory temporarily stores the electrocardiogram waveform data at each sampling period.

When the ECG waveform data is temporarily stored, the ECG abnormality determining means determines whether the ECG is abnormal, and when it is determined that the ECG is abnormal, the storage memory is determined to have the ECG abnormality. The electrocardiogram waveform data and the electrocardiogram waveform data immediately before and immediately after the abnormality is determined are stored.

Thus, the ECG waveform determined to be abnormal can be immediately read from the storage memory.

Embodiment An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the heart disease monitoring device 1 is composed of a body surface electrode 3, a signal processing device 5, and an electronic control device 7, is manufactured in a size that can be carried on a portable device, and has a belt for the patient. Nevertheless, it is always carried and used.

The body surface electrode 3 includes a plurality of electrodes and is connected to the signal processing device 5 by a connector 10. The body surface electrode 3
An electrical change generated by the excitation of the heart muscle is led out of the body as a potential difference between various parts of the body. For example, the body surface electrode 3 is attached to a site of two leads, that is, a right wrist and a left wrist of a patient, and captures a potential difference between the two points and outputs the potential difference to the signal processing device 5 as an electric signal.

The signal processing device 5, as shown in FIG.
An amplifying circuit 20 for amplifying an electric signal input from the A / D to a predetermined level, a sample and hold circuit (hereinafter, referred to as an S / H circuit) 22 for holding the amplified electric signal Sig at a constant period, and a well-known A / D A converter 24, a well-known input / output port 26, a clock signal generation circuit 28 that generates a clock signal Tim that determines the hold timing of the S / H circuit 22,
The aforementioned QRS complex is detected from the electric signal Sig and the reset pulse Re is output.
It comprises a detection circuit 30 for outputting s, a notification device 32 for generating a warning sound in response to a command signal from the electronic control unit 7 when there is an abnormality in the electrocardiogram, and a power supply 34. Further, the signal processing device 5 includes a connector 36 for attaching and detaching the electronic control device 7.

Since the input electric signal is at a level of several millivolts, the amplifier circuit 20 amplifies this to a level of several volts.In order to ensure patient safety, the input side and output side of the amplifier circuit 20 are Insulated. The detection circuit 30
As shown in FIG. 4, the electric signal Sig input from the amplifier circuit 20 is compared with the reference voltage Vref, and when the electric signal Sig exceeds the reference voltage Vref, a reset pulse Res is output.
However, when the voltage exceeds the reference voltage Vref again within the predetermined time, the reset pulse Res is not output. When the reset pulse Res is input, the electric signal Sig is sampled in synchronization with the clock signal Tim and converted into digital waveform data.

Note that the notification device 32 corresponds to the notification means of claim 2.

The electronic control unit 7 includes a well-known CPU 40, a ROM 42, a RAM 44, and a rewritable non-volatile memory (hereinafter referred to as EEPROM).
It comprises a bus and a bus for interconnecting each element. The electronic control unit 7 is integrally molded in the shape of a card, and terminals are collectively arranged in a detachable portion (not shown), and can be detachably attached to the signal processing device 5.

The RAM 44 has areas such as a buffer 44a for temporarily storing data input from the A / D converter 24, a work area 44b for storing various data, and a storage area 44c for storing electrocardiogram waveform data in the event of cardiac abnormalities and dangers. Provided. The data stored in each area is protected by the backup battery 49 even when the electronic control device 7 is separated from the signal processing device 5.

In the EEPROM 46, prediction information set based on a doctor's diagnosis is written. That is, data relating to the predicted cardiac abnormal state and the respective electrocardiogram waveforms in the same critical state, for example, the peak value of the T wave in the predicted cardiac abnormal state and the same dangerous state (hereinafter, the peak value of the cardiac abnormal state) Is referred to as an abnormal value, and the peak value in the dangerous state is referred to as a dangerous value). Each of these peak value data is written to the EEPROM 44 in the electronic control unit 1 dedicated to the patient, and is rewritten at any time according to the condition of the patient.

Note that the electronic control unit 7 corresponds to a buffer memory, an electrocardiogram abnormality diagnosis unit, and a storage memory.

Next, an example of the electrocardiogram waveform data processing executed in the heart disease monitoring device 1 having the above-described configuration will be described with reference to the flowcharts shown in FIGS.

FIG. 6 shows a typical example of a temporal change of an electrocardiogram waveform at the onset of myocardial infarction. As is clear from the figure, the peak level of the T wave becomes abnormally high when myocardial infarction occurs. This abnormal rise is detected by executing the following processing.

That is, the CPU 40 receives the clock signal T from the input / output port 26.
When an interrupt request signal Int synchronized with im is input, an interrupt process shown in the flowchart of FIG. 5 is executed.
That is, data is read from the A / D converter 24 (S
1) and store them sequentially from the head address of the buffer 44a (S
2) End the process.

When the above-described interrupt processing is sequentially executed during the sampling period, data on the electrocardiogram 1 waveform is stored sequentially from the head address of the buffer 44a.

The CPU 40 executes the processing shown in the flowchart of FIG. That is, wait for the reset pulse Res to be input (S10),
When the reset pulse Res is input, the waveform data stored in the buffer 44a is transferred to the work area 44b (S1
1). Subsequently, after clearing the buffer 44a (S12), processing for peak detection of each wave of the electrocardiogram, for example, calculation processing for obtaining the peak of the T wave appearing after the QRS complex is performed (S13). This calculation is performed as follows. The difference between the data of the address and the next address data is obtained in order from the head address of the work area 44b, and the data of the address when the difference changes from negative to positive is selected as peak data. Then, the first peak data and the second peak data are obtained, and the second peak data is recognized as T-wave peak data.

Next, it is determined whether or not the peak data of the T wave is equal to or larger than the abnormal value (S14). If the peak data of the T wave is smaller than the abnormal value, the work area 44b is cleared and the processing is terminated (S15). I do. On the other hand, when the peak value is equal to or larger than the abnormal value, S1
Proceed to 6. In S16, it is determined whether or not the peak data is equal to or more than the risk value. When the above peak data is below the danger value,
An abnormal alarm command is output to the notification device 32 (S17), and the entire data (one waveform) read in the sampling cycle is
The data is stored in the storage area 44c together with the date and time data obtained by a known software timer (S18), and the process proceeds to S15. On the other hand, if the peak data is equal to or greater than the danger value, a danger warning command is output to the notification device 32 (S19), and the process proceeds to S18.

When an abnormal ECG is determined and an abnormal alarm is generated as described above, the doctor is immediately examined. At this time, the electronic control unit 1 is detached from the connector and replaced with a substitute electronic control unit, and the record at that time is transmitted to the hospital by telephone or the like. In a hospital, for example, as shown in FIG. 8, the well-known CPU 50a, ROM 50b, RAM 50c, input / output port 50
d, The electrocardiogram waveform at the time of abnormality can be inspected using the synchroscope 52 and the waveform reproducing device 50 mainly including the D / A converter 50e and the amplifier circuit 50f.

As described in detail above, the heart disease monitoring device 1 of the present embodiment
Records the current ECG and notifies the patient of abnormalities or dangers even when the patient has no subjective symptoms, so that the condition of the heart can be quickly examined and the heart disease can be prevented from becoming worse . In particular, in cases such as the onset of myocardial infarction, it is assumed that the patient's consciousness is lost, but since a danger warning has been issued, it is recognized that the family and surrounding people have myocardial infarction It is effective for saving patients.

In the above embodiment, the peak of the T wave was detected. In addition, the peaks of the P wave, the QRS wave, and the U wave shown in FIG. 9 were also determined according to the patient's symptoms and based on the diagnosis of the doctor. May be detected.

As shown in FIG. 8, a precursor symptom of myocardial infarction such as early contraction (extrasystole) in which the QRS complex appears again immediately after the T wave may be detected. In this case, since the level of the electric signal Sig falls below the base line after the third peak, this is detected and an alarm is issued.

In addition, since the doctor can change various data based on the clinical test, it is needless to say that various detection and comparison / determination processes can be performed according to the patient's current condition and medical condition. For example, based on an electrocardiogram obtained in a two-stage test or an exercise test such as a treadmill, a doctor determines the maximum allowable load (exercise amount) of the patient, and based on the electrocardiogram when this load is applied. Create forecast information. In this case, an appropriate and safe range of the amount of exercise can be known, and the patient can exercise for myocardial activation and health maintenance.

Further, in the above embodiment, only the waveform data when the peak data is equal to or more than the abnormal value and the dangerous value is stored in the storage area. In addition, the waveform data regarding several heartbeats immediately before and after the waveform data is also stored. This will help you with your ECG diagnosis.

If the reset pulse Res is not input even after the lapse of a predetermined time, a danger warning command is immediately output. In addition, since the cycle of the reset pulse Res can be measured based on the clock signal, it may be determined whether the cycle is within a predetermined time band to detect an abnormal heartbeat and add the condition as a condition for generating a warning. .

In addition, if the notification device 32 is provided with a voice synthesizing device or a display device so that the action to be taken and the name and telephone number of the hospital to be contacted can be notified or displayed when a danger alarm occurs, the patient can be saved further. Can help.

[Effects of the Invention] As described above, according to the present invention, the presence / absence of an electrocardiogram abnormality is determined by comparing electrocardiogram information and prediction information on an electrocardiogram abnormality, and if there is an abnormality, the ECG at that time is recorded. Since the patient is notified of the abnormality in the electrocardiogram, even if the patient does not have a subjective symptom of the cardiac abnormality, the patient can be quickly inspected for the electrocardiogram at the time of the abnormality, which is effective in saving the patient's life.

When a doctor wants to see the electrocardiogram waveform when an electrocardiogram abnormality occurs, the doctor can read the electrocardiogram waveform data from the storage memory and immediately see the electrocardiogram waveform data. You can see immediately without searching. Furthermore, if the ECG waveform data at the time of determination of an abnormality is successively stored in the storage memory, even if a new ECG abnormality occurs before the doctor's diagnosis is made, the abnormal ECG waveform data Can be recorded one after another, and the doctor can immediately see the electrocardiogram data and make an appropriate diagnosis.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a heart disease monitoring device of the present invention, FIG. 2 is a block diagram thereof, FIG. 3 is an explanatory diagram showing an electric signal and a reset pulse, and FIG. FIG. 5 is a flowchart showing a waveform data process executed by the electronic control unit, FIG. 6 is an explanatory diagram showing a temporal change of an electrocardiogram waveform at the onset of myocardial infarction, and FIG. FIG. 8 is an explanatory diagram of an electrocardiogram waveform when an early contraction appears, and FIG. 9 is an explanatory diagram showing a basic electrocardiogram waveform. DESCRIPTION OF SYMBOLS 1 ... Heart disease monitoring device, 3 ... Body surface electrode 5 ... Signal processing device, 7 ... Electronic control device 32 ... Notification device, 36 ... Connector 40 ... CPU, 42 ... ROM 44 ... RAM , 46 …… EEPROM

Claims (2)

(57) [Claims] 1. A body surface electrode for detecting a potential difference between each part of a body, a signal processing device for creating electrocardiogram waveform data from an electric signal output from the body surface electrode, and the electrocardiogram waveform data for each sampling period. A buffer memory for temporarily storing; an electrocardiogram abnormality determining means for determining whether the temporarily stored electrocardiogram waveform data is abnormal; and the electrocardiogram waveform data determined to be abnormal. A storage memory for storing electrocardiogram waveform data immediately before and immediately after the electrocardiogram waveform determined to be abnormal; 2. The heart disease monitoring system according to claim 1, further comprising a notifying means for displaying a hospital name and a telephone number to be contacted when it is determined that the electrocardiogram is abnormal. apparatus.