JPH04300523A - Portable type electrocardiograph - Google Patents

Abstract

PURPOSE:To enable a doctor to display the trend graph and histogram relating to the number of heart beats and its ST level on the spot in the unsulting and to provide a macrodisplay/microdisplay function. CONSTITUTION:The electrocardiogram signal which is obtd. by a body surface electrode 1 and is amplified by an electrocardiograph amplifier 2 is converted by an A/D converter 3 to electrocardiogram data which is temporarily stored via CPU 4 into a RAM 6. The CPU 4 stores the number of heat beats and the max. value, min. value and average value relating to the ST level as trend graph data within respective blocks with 5 seconds, 30 seconds and 12 minutes as one block unit time into the RAM 6. The histogram data relating to the number of the heart beats and the ST level upon lapse of every 10 minutes, upon lapse of every 60 minutes and upon lapse of 24 hours are stored into the RAM 6. The selective display of the trend graphs or histograms of plural groups is possible in reproduction display.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable electrocardiograph that is carried by a patient on a daily basis and is configured to constantly measure electrocardiogram waveform data and store it in a memory.

0002

[Prior Art] Conventionally, when attempting to create a trend graph or histogram of electrocardiogram parameters such as heart rate and electrocardiogram ST level related to electrocardiogram data over a long period of time (for example, 24 to 48 hours), Holter electrocardiographs and It was common to use a separate analysis device.

[0003] The Holter electrocardiograph samples and A/D converts electrocardiogram signals detected by body surface electrodes and stores them on magnetic tape as digital electrocardiogram data. Then, the magnetic tape that stores the electrocardiogram data over the entire measurement time obtained by the Holter electrocardiograph is set in a separate dedicated analysis device, and the electrocardiogram data is reproduced from the magnetic tape and processed by the computer as required. I created trend graphs and histograms related to electrocardiogram parameters such as heart rate and ST level. A histogram divides heart rate and ST level into several levels, and the number of objects belonging to each level (
weight).

[0004] In this case, since all sampling data over the entire measurement time range is stored on the magnetic tape, when creating trend graphs and histograms,
This method has the advantage of being able to freely set any time as the unit time that divides the total measurement time.

[0005]

[Problems to be Solved by the Invention] As described above, in the past, a Holter electrocardiograph was used to collect electrocardiogram data, and a dedicated analysis was used to create trend graphs and histograms related to electrocardiogram parameters such as heart rate and ST level. Because the analysis equipment is generally large-scale, it is often installed in a separate room from the examination room, making it impossible to make an immediate diagnosis in the examination room.

[0006] It takes a considerable amount of time to transport the magnetic tape, play it back to the analyzer, and transfer the data, and it also takes a considerable amount of time to obtain trend graphs and histograms using the analyzer. As a result, there were difficulties in terms of use, operation, and efficiency.

In the medical field, under the above-mentioned circumstances, there is a portable type that can immediately reproduce and display trend graphs and histograms related to electrocardiogram parameters such as heart rate and ST level so that doctors can immediately use them for diagnosis in the examination room. An electrocardiograph is required.

[0008] The present invention aims to provide a portable electrocardiograph that can meet the above-mentioned demands and has an enlarged display/reduced display function so that multiple types of trend graphs and histograms can be reproduced and displayed. purpose.

[0009]

[Means for Solving the Problems] A first portable electrocardiograph according to the present invention includes an electrocardiogram amplifier that amplifies an electrocardiogram signal obtained from a body surface electrode attached to a patient, and an electrocardiogram amplifier that amplifies an electrocardiogram signal obtained from a body surface electrode attached to a patient. An A/D converter for converting into digital electrocardiogram data, means for temporarily storing the obtained electrocardiogram data, and calculation of electrocardiogram parameters such as heart rate and electrocardiogram ST level based on the stored electrocardiogram data. means for temporarily storing the electrocardiogram parameters, and creating trend graph data of a block group in which one block is a predetermined value within the electrocardiogram parameter group in a predetermined unit time, means for dividing and creating trend graph data consisting of block groups into a plurality of groups having different unit times; and means for individually storing the trend graph data of the plurality of groups having different block unit times; The present invention is characterized by comprising means for arbitrarily selecting any one of the plurality of groups of trend graph data, and means for displaying the selected trend graph data.

A second portable electrocardiograph according to the present invention includes an electrocardiogram amplifier that amplifies electrocardiogram signals obtained from body surface electrodes worn on a patient, and converts the amplified electrocardiogram signals into digital electrocardiogram data. an A/D converter for converting the electrocardiogram data into an A/D converter, a means for temporarily storing the obtained electrocardiogram data, and a means for calculating electrocardiogram parameters such as heart rate and electrocardiogram ST level based on the stored electrocardiogram data; Means for temporarily storing the electrocardiogram parameters, and creating histogram data for a group of electrocardiogram parameters for each predetermined elapsed time from the start of measurement, and storing such histogram data at different elapsed repeat times. means for individually storing the histogram data of the plurality of groups having different elapsed times; and arbitrarily selecting any one of the histogram data of the plurality of groups. and means for displaying the selected histogram data.

[0011]

[Operation] One of the problems to be solved is how to store trend graph data or histogram data within a limited storage capacity.

[0012] Both the first and second portable electrocardiographs include
Unlike conventional Holter electrocardiographs, A/D converted electrocardiogram data itself is not stored as final data.

That is, first, electrocardiogram parameters such as heart rate and electrocardiogram ST level are calculated from temporarily stored electrocardiogram data, and then further temporarily stored.

[0014] In the first portable electrocardiograph,
Based on the electrocardiogram parameters, a plurality of groups of trend graph data having different block unit times are individually created and stored. Further, in the second portable electrocardiograph, multiple groups of histogram data having different elapsed times from the start of measurement are individually created and stored.

That is, instead of requiring a dedicated analysis device separate from the portable electrocardiograph as in the conventional case, the portable electrocardiograph itself has a means for creating and storing trend graph data or histogram data. Built-in.

[0016] Therefore, when displaying a playback, the first portable electrocardiograph already stores trend graph data necessary for displaying the playback, and the second portable electrocardiograph This means that the histogram data necessary for playback display has already been stored.

[0017] In the first portable electrocardiograph,
It is possible to select and display any trend graph data from among the multiple groups of stored trend graph data, but these multiple groups of trend graph data have different block unit times. Therefore, the longer the time per block of trend graph data, the coarser the resolution and the reduced display.
The shorter the block unit time of trend graph data, the finer the resolution of the enlarged display.

[0018] Furthermore, in the second portable electrocardiograph, any one of the plurality of stored histogram data groups can be selected and displayed. A histogram with a long elapsed time allows a general trend to be grasped, and a histogram with a short repetition elapsed time allows a detailed trend in a shorter time range to be grasped.

[0019]

[Embodiment] First Embodiment The first embodiment relates to the above-described first portable electrocardiograph of the present invention, and FIG. 1 is a block diagram showing the configuration of its main parts.

In the figure, 1 is a body surface electrode attached to a patient, 2 is an electrocardiogram amplifier that amplifies the electrocardiogram signal obtained from the body surface electrode 1, and 3 is an electrocardiogram amplifier that converts the amplified analog electrocardiogram signal into digital electrocardiogram data. 4 is a CP which is the central processing unit of the microcomputer.
U, 5 is a ROM that stores programs, and 6 is a RAM (IC memory) as a working memory.

The RAM 6 has a storage area for temporarily storing electrocardiogram data obtained by the A/D converter 3 via the CPU 4. The CPU 4 calculates the heart rate and electrocardiogram ST based on the electrocardiogram data temporarily stored in the RAM 6.
It has a function to calculate electrocardiogram parameters such as levels. The RAM 6 has an area for temporarily storing data on calculated electrocardiogram parameters, ie, heart rate and ST level.

The CPU 4 determines maximum values h5max, st5max, and minimum values h5min, which are predetermined values in the heart rate group and the ST level group, respectively, every 5 seconds.
, st5min , average value h5ave , st5ave
A function to create trend graph data for a group of 5-second blocks, with 1 block being the maximum value h30max, st30max, and minimum value h3, which are predetermined values in the heart rate group and ST level group, respectively, every 30 seconds.
0min, st30min, average value h30ave
, st30ave as one block, and a function to create trend graph data of a group of 30-second blocks, and ■ maximum value h12max, which is a predetermined value in each heart rate group and ST level group every 12 minutes.
st12max, minimum value h12min, st12m
in , the average value h12ave , st12ave is 1
It also has a function to create trend graph data for a group of 12-minute blocks. However, these plural block unit times of 5 seconds, 30 seconds, and 12 minutes are only examples.

The RAM 6 has a capacity sufficient to store at least two heartbeats worth of electrocardiogram data and 24 hours (or 48 hours worth) of trend graph data related to heart rate and ST level. It is constructed as a thing. Further, the CPU 4 has a function of selectively reading trend graph data of 5 seconds, 30 seconds, or 12 minutes related to the heart rate or ST level from the RAM 6 and converting it into display data.

7 is a liquid crystal driver driven and controlled by the CPU 4; 8 is a liquid crystal display device configured to have minute liquid crystal display elements arranged in a matrix vertically and horizontally so that various data can be displayed in the form of numerical values, graphs, or waveforms; 9 is a touch key for inputting various commands.

Next, the operation of the portable electrocardiograph according to the first embodiment will be explained based on the flowcharts shown in FIGS. 2 and 3.

Control operations by the CPU 4 are started when the power is turned on. Detected by body surface electrode 1 and sent to electrocardiogram amplifier 2
The electrocardiogram signal amplified by is input to the A/D converter 3. The CPU 4 performs the following control operations according to the program imported from the ROM 5.

First, in step S1, it is determined whether or not the measurement key on the touch key 9 has been operated, and if it is determined that the measurement key has been operated, the routine of steps S2 to S12 is executed, and if not, the touch key is not pressed in step S13. It is determined whether or not the playback key in key 9 has been operated, and if it is determined that it has been operated, steps S14--
The routine of S19 or the routine of S20 to S25 is executed (details will be described later).

Generally, the measurement key is operated first. Therefore, the process advances to step S2 to control the A/D converter 3, sample the amplified electrocardiogram signal inputted by the A/D converter 3 at regular intervals, convert it into digital electrocardiogram data by A/D conversion, Incorporate into. Then, the CPU 4 transfers the continuously sampled electrocardiogram data to the RAM 6 and temporarily stores it in step S3.

[0029] Next, in step S4, the CPU 4
The electrocardiogram waveform is analyzed based on the electrocardiogram data read from M6 to search for the peak of the R wave that marks the end of one heartbeat. The R wave apex is the part with the sharpest rise in the QRS complex, which is a characteristic point of the electrocardiogram waveform. The method of searching for the peak of the R wave is, for example, by determining that the electrocardiogram data at a certain point exceeds 70% of the maximum value of the previous electrocardiogram data group and is the maximum point. can. When it is recognized that it is the R wave peak, step S5
If not, the process returns to step S2 via steps S11 and S12, and hereafter steps S2 to S4
, S11, and S12 are repeated.

[0030] Once the R-wave peak is found, the process proceeds to step S5, where the heart rate is calculated. That is, the reciprocal of the time from the R-wave apex of the previous heartbeat to the R-wave apex of the current heartbeat is determined, and this is taken as the heart rate. The time is determined by [sampling number x sampling period] between the peaks of both R waves. Next, the CPU 4 transfers the trend graph data regarding the heart rate to the RAM 6 and stores it in step S6. In this step S6 transfer, 5 seconds,
We will create trend graph data (maximum value, minimum value, average value) for heart rate with 30 seconds and 12 minutes as one block unit time (for details, see Figure 4 and Figure 5).
(Explained below)

[0031] In step S7, it is determined whether or not the calculation of the ST level has been completed, and if it has been completed, the process proceeds to step S11.
However, if it is not calculated, skip to steps S8 and S9.
Proceed to calculate the ST level. That is, step S
In step 8, it is determined whether a certain period of time (for example, 60 msec) has elapsed since the R wave peak, and if it has elapsed, step S is performed.
Proceed to step 9 to calculate the ST level. The ST level can be determined as a value obtained by subtracting the value of electrocardiogram data at that time from the value of electrocardiogram data a certain time before the R-wave peak (for example, 120 msec before).

[0032] When the calculation of the ST level is completed, the RAM6
Of the electrocardiogram data stored in , the heart rate and S
Since it is not necessary for calculating the T level, also RA
Considering the effective use of M6, erase those data.

Then, in step S10, the trend graph data regarding the ST level is transferred to the RAM 6 and stored therein. In this step S10 transfer, 5 seconds, 30
Trend graph data (maximum value, minimum value, average value) will be created for the ST level with each block unit time being 1 second and 12 minutes (see Figures 6 and 7 for details).
(Explained below)

As described above, trend graph data relating to the heart rate and ST level for each one block unit time has been created and stored in the RAM 6. Calculation and calculation of trend graph data related to heart rate and ST level
Storage continues repeatedly until the abort key is operated or 24 hours have elapsed from the start of the measurement. That is, step S
When it is determined in Step 11 that the cancel key on the touch key 9 has been operated, the process returns to Step S1, and when it is determined in Step S12 that the measurement time has elapsed for 24 hours, the power is automatically turned off and the electrocardiogram is started. End data measurement. Unless the abort key is operated during the process,
Trend graph data relating to heart rate and ST level for each unit time over a maximum of 24 hours will be stored in the RAM 6.

[0035] After the abort key is operated, or 24
When the power is turned on again after a period of time has elapsed, the determination in step S1 is usually negative, and step S1 in FIG.
Proceed to step 3. That is, in step S13, the touch key 9
Wait for the playback key to be pressed, and then, in steps S14 and S20, it is determined whether the heart rate trend key or the ST level trend key in the touch key 9 is selected. Step S14~
Execute the routine of S19, and in the latter case, step S19.
The routine from S20 to S25 is executed.

When the heart rate trend is selected in step S14, the process proceeds to step S15, where the heart rate trend graph data is read into the CPU 4 from the RAM 6, and the heart rate trend graph data is converted into display data in step S16. This heart rate/trend graph is a graph that shows temporal fluctuations in heart rate, with time on the horizontal axis and heart rate on the vertical axis. Then, in step S17, the CPU 4 transfers the display data of the heart rate/trend graph to the liquid crystal driver 7, and in step S18, controls the liquid crystal driver 7 to display the heart rate/trend graph on the liquid crystal display device 8 (FIG. 8 (see below for details). The display continues until it is determined in step S19 that the cancel key on the touch keys 9 has been operated.

[0037] In addition, each heart rate for 5 seconds, 30 seconds, and 12 minutes.
Step S1 determines which trend graph to display.
Determine according to the instructions in 4.

On the other hand, when the ST level trend is selected in step S20, the process proceeds to step S21, where the ST level trend graph data is loaded from the RAM 6 into the CPU 4, and in step S22, the ST level trend graph data is converted into display data. . This ST level trend graph is a graph showing temporal fluctuations in the ST level, with time plotted on the horizontal axis and ST level plotted on the vertical axis. Then, in step S23, the CPU 4 transfers the display data of the ST level trend graph to the liquid crystal driver 7, and in step S24 controls the liquid crystal driver 7 to display the ST level trend graph on the liquid crystal display device 8. The display continues until it is determined in step S25 that the stop key has been operated.

It should be noted that which of the ST level trend graphs for 5 seconds, 30 seconds, and 12 minutes is to be displayed is determined by the instruction in step S20.

The calculation of the trend graph data (maximum value, minimum value, average value) for one block unit time, which is the key point of this embodiment, is performed in step S6 of the flowchart of FIG. 2 regarding the heart rate, and ST The level is determined in step S10.

First, calculation of heart rate trend graph data will be explained based on the flowcharts of FIGS. 4 and 5.

In step S60, only when this routine is reached for the first time after the start of measurement with the portable electrocardiograph, the count register, buffer memory, timer, etc. necessary for calculation are initialized. Step S60 will be skipped from the second time onwards. Here, h5s, h30s, h12s
is the cumulative addition memory of heart rate when one block unit time is 5 seconds, 30 seconds, and 12 minutes, respectively, n5, n30, n1
Similarly, 2 is a heartbeat count register.

[0043] Next, in step S61, it is determined whether the internal timer of the CPU 4 that measures unit time has counted the elapse of 5 seconds. If it has not elapsed, the process proceeds to step S62, and the heart rate h calculated in step S5 is The heart rate h is added to the cumulative addition memory h5s to increase the cumulative value, and the heart rate h is compared with the maximum value h5max and minimum value h5min of the 5 second interval, and if the latest heart rate h is larger, or If it is smaller, it is set as the new maximum value h5max or minimum value h5min, but otherwise it is set as the original maximum value h5max.
and leave the minimum value h5min as is. Furthermore, the number of heartbeats n5 in the 5-second interval is incremented by 1, and the process of step S62 is ended.

On the other hand, when it is determined in step S61 that 5 seconds have elapsed, the process proceeds to step S63, where the cumulative sum h5s of heartbeats up to that point is calculated as the number of heartbeats n5 up to that point.
By dividing by, the average heart rate for 5 seconds h5a
Calculate ve. Then, the maximum value h5max, minimum value h5min, and average value h5ave of the heart rate for 5 seconds are transferred to and stored in the RAM 6. Then,
In preparation for the next 5 seconds of calculation, n5, h5max, h5
Initialize min and h5ave and proceed to step S6
Finish the process in step 3.

Steps S64 to S66 show calculations for a 30 second period, and steps S67 to S69 show calculations for a 12 minute period. These operations are basically the same as those for the 5 second period.

[0046] In step S64, it is determined whether 30 seconds have elapsed. If 30 seconds have not elapsed, the process proceeds to step S65, where the heart rate h is added to the cumulative addition memory h30s of the heart rate h calculated in step S5. While increasing the cumulative value, heart rate h is compared with the maximum value h30max and minimum value h30min of the 30 second interval, and if the latest heart rate h is larger or smaller, it is set as the new maximum value h30max or minimum value. Value h30min
Set as . Furthermore, the number of heartbeats in a 30 second interval n30
is incremented by 1, and the process of step S65 is ended.

On the other hand, if it is determined in step S64 that 30 seconds have elapsed, the process proceeds to step S66, and the cumulative sum h30s of the heartbeats up to that point is divided by the number of heartbeats n30 up to that point, thereby calculating the heartbeats for 30 seconds. Calculate the number average value h30ave. Then, the maximum value h30max and minimum value h30min of heart rate for 30 seconds
and the average value h30ave are transferred to the RAM 6 and stored therein. Then, in preparation for the next 30 seconds of calculation, n30
, h30max, h30min and h30ave
is initialized, and the process of step S66 is ended.

In step S67, it is determined whether 12 minutes have elapsed. If 12 minutes have not elapsed, the process proceeds to step S68, where the heart rate h is added to the cumulative addition memory h12s for the heart rate h calculated in step S5. While increasing the cumulative value, heart rate h is compared with the maximum value h12max and minimum value h12min of the 12-minute interval, and if the latest heart rate h is larger or smaller, it is set as the new maximum value h12max or minimum value. Value h12min
Set as . Furthermore, the number of heartbeats in a 12-minute interval n12
is incremented by 1, and the process of step S68 is ended.

On the other hand, if it is determined in step S67 that 12 minutes have elapsed, the process proceeds to step S69, and the heartbeats for 12 minutes are calculated by dividing the cumulative addition value h12s of heartbeats up to that point by the number of heartbeats n12 up to that point. Calculate the number average value h12ave. Then, the maximum value h12max and the minimum value h12min of the heart rate for 12 minutes
and the average value h12ave are transferred to the RAM 6 and stored therein. Next, in preparation for the next 12 minutes of calculation, n12
, h12max, h12min and h12ave
is initialized, and the process of step S69 is ended.

[0050] As a result of the above, the trend graph data (maximum value, minimum value, average value) for heart rate with 1 block unit time of 5 seconds, 30 seconds, and 12 minutes are each 1 block.
This means that the number of times has been stored in the RAM 6. By repeating this, trend graph data of heart rate for 5 seconds, 30 seconds, and 12 minutes will be stored in the RAM 6 for up to 24 hours.

FIGS. 6 and 7 show step S10 in FIG.
A detailed flowchart is shown, but the data handled is S.
The operation is the same as that for the heart rate in FIGS. 4 and 5, except that the ST level is changed to the T level, and the counter and memory for the ST level are used, so the explanation will be omitted.

By the routines shown in FIGS. 6 and 7, 5 seconds, 3
ST where 0 seconds and 12 minutes are each one block unit time
This means that the trend graph data (maximum value, minimum value, average value) for each level is stored in the RAM 6 once. By repeating this, you can create up to 24 ST level trend graph data for 5 seconds, 30 seconds, and 12 minutes.
An amount corresponding to the time will be stored in the RAM 6.

FIG. 8 shows an example of a heart rate/trend graph displayed on the liquid crystal display device 8. As shown in FIG.

FIG. 9 is an explanatory diagram of enlarged/reduced display of a trend graph related to heart rate.

[0055] The shorter the block unit time is, the more the display is enlarged, and the longer it is, the smaller the display is. For example, for a trend graph with one block unit time of 30 seconds, which is the middle, if you switch to a trend graph with a shorter unit time of 5 seconds, the display will be enlarged, and if you switch to a trend graph with a longer unit time of 12 minutes, the display will be reduced. becomes.

It is assumed that the number of display pixels of the trend graph on the liquid crystal display device 8 is 120 dots, and each dot displays one block of data. Regarding the time width that can be displayed on one screen of the liquid crystal display device 8, if one block unit time is 12 minutes, 12 minutes x 120 = 24 hours, 3
In the case of 0 seconds, 30 seconds x 120 = 1 hour, and in the case of 5 seconds, 5 seconds x 120 = 10 minutes. Since the maximum measurement time of the portable electrocardiograph is 24 hours, the capacity of RAM6 required to store trend graph data is as follows.
If one block unit time is 12 minutes, 120 pieces, 30 pieces
In the case of seconds, the number is 120×24=2880, and in the case of 5 seconds, the number is 120×24×6=17280.

Now, as shown in FIG. 9(a),
Displaying a 24-hour screen with a unit time of 12 minutes,
Assume that the cursor 10a is located at the sixth block. There is only one screen available for 24 hours. From this state,
Assume that an enlarged display is performed on the screen for one hour in which the unit time shown in FIG. 9(b) is 30 seconds. Then, the second 1-hour screen out of 24 1-hour screens is displayed, and the cursor 10a
is located in the first block (121st block in total). The reason is as follows.

In the 24-hour screen, the first block shows a trend graph for 0 minutes≦t≦12 minutes after the start of measurement. Considering the same way, the 6th block is 60 minutes<t≦
A trend graph for 72 minutes is shown. Since this time exceeds one hour, it does not fit in the first screen in the enlarged one-hour screen, but becomes the second screen. The reason why it is set as the first is because 60 minutes<t≦72 minutes is regarded as 60 minutes<t≦61 minutes (after all, t=61 minutes). Since one sheet has 120 blocks, the first block of the second sheet is the 121st block (120+1=121) in total.

Next, the unit time shown in FIG. 9(c) is 5.
Suppose that 10 minutes, which is seconds, is enlarged and displayed on the screen. Then, 1
The seventh 10-minute screen out of the 44 10-minute screens is displayed, and the cursor 10a is positioned at the first block (721st block in total). The reason is as follows.

In the 1-hour screen, the first block of the second screen shows the trend graph for t=61 minutes after the start of measurement, as described above. This is over an hour. Exactly one hour is 60 minutes ÷ 10 minutes = 6, which is the 6th photo.
It's 61 minutes long, over an hour, so it's the 7th piece. One sheet contains 120 blocks, so six sheets contain 72 blocks.
This will be 0 blocks. Therefore, the first block of the seventh sheet becomes the 720+1=721st block in total.

Next, contrary to the above, the case of switching to reduced display will be explained. Now, suppose that the 10-minute screen shown in FIG. 9(c) is displayed, and that the displayed screen is the fifth 10-minute screen, and that the cursor 10b is positioned at the 50th screen. The total position of this cursor 10b is (5
-1)×120+50=530th block. In terms of time, 5 x 530 = 2650, so 264
It belongs to 5 seconds<t≦2650 seconds. Suppose that from this state, the reduced display is performed on the screen for 1 hour with a unit time of 30 seconds as shown in FIG. 9(b). Then, the first one-hour screen out of the twenty-four one-hour screens is displayed, and the cursor 10b is positioned at the 89th block.

The reason is as follows.

[0063] 2645÷30≒88.2, which is smaller than 120, so it belongs to the first sheet. cursor 1
0b is the 89th.

Suppose that the one-hour screen shown in FIG. 9(b) is then reduced to the 24-hour screen shown in FIG. 9(a). The 89th point in the first one-hour screen corresponds to 2640 seconds<t≦2670 seconds in terms of time. Expressed in minutes, 44 minutes<t≦44.4 minutes. 44 minutes ÷ 12 ≒ 3
．． 7, the cursor 10b is positioned at the fourth block.

FIGS. 10A to 10C show a method of displaying a trend graph on a liquid crystal display screen. However, in each case, only one block is shown. FIG. 10(a) is a general case, where the maximum value (max) and the minimum value (mi
n) are connected with a bar line, and the portion corresponding to the average value (ave) is outlined. In (b) of FIG. 10, the maximum value (max) and the minimum value (min) are different, but in calculation, the average value (ave) is the maximum value (max) or the minimum value (
This shows the case where the value becomes equal to min). Also, Figure 1
0 (c) indicates the case where maximum value=minimum value=average value.

Second Embodiment The second embodiment relates to the second portable electrocardiograph of the present invention described above, and the block diagram showing the configuration of the main parts is similar to that of the first embodiment. This is similar to FIG. 1.

The CPU 4 has the function of () creating histogram data regarding the heart rate and ST level every 10 minutes from the start of measurement of electrocardiogram data;
Ability to create similar histogram data every minute,
It also has a function to create similar histogram data 24 hours after the start of measurement. however,
These 10 minutes, 60 minutes, and 24 hours are just examples.

[0068] The RAM 6 has a capacity sufficient to store at least two heartbeats worth of electrocardiogram data and the above-mentioned histogram data relating to heart rate and ST level for 24 hours (or 48 hours). It is configured as. The CPU 4 also has a function of selectively reading out histogram data related to heart rate and ST level every 10 minutes, every 60 minutes, or after 24 hours from the RAM 6, and converting it into display data. have.

The basic operation of the portable electrocardiograph of the second embodiment, as shown in FIGS. 11 and 12, basically follows the flow chart of FIGS. 2 and 3 used in the first embodiment. It is similar to However, since the processing target is different from the first embodiment, steps S6a, S10a, S14a to S18
a, the expressions of S20a to S24a are different.

That is, in step S6a, histogram data regarding the heart rate is created every 10 minutes, every 60 minutes, and after 24 hours, and is transferred to and stored in the RAM 6 (for details, refer to the figure). 13, explained in FIG. 14). In addition, in step S10a, ST level histogram data is created every 10 minutes, every 60 minutes, and after 24 hours, and this is transferred to and stored in the RAM 6 (see FIGS. 15 and 16 for details). (explained in)
. In step S14a, instead of determining whether the heart rate trend key is operated, it is rewritten as whether the heart rate histogram key is operated. Further, step S20a is “S
Instead of determining whether to operate the T level trend key,
Is this a T-level histogram key operation?''

[0071] In step S15a, heart rate histogram data is read from the RAM6 into the CPU4. Step S16a converts the heart rate histogram data into display data. As shown in FIG. 17, this heart rate histogram data is obtained by dividing the heart rate into several levels and counting the number of heartbeats at each level as a weight. The histogram displayed on the display screen is shown in Figure 19.
As shown in , the horizontal axis represents the level of heart rate, and the vertical axis represents the number (weight) of heartbeats at each level. Step S17a transfers the heart rate histogram data to the liquid crystal driver 7. Step S18a displays a heart rate histogram on the liquid crystal display device 8.

In step S21a, ST level histogram data is read from the RAM 6 into the CPU 4. Step S22a converts the ST level histogram data into display data. As shown in FIG. 18, this ST level histogram data is obtained by dividing the ST level into several levels and counting the number of ST levels in each level as a weight. Step S23a transfers the ST level histogram data to the liquid crystal driver 7. Step S18a displays the ST level histogram on the liquid crystal display device 8.

[0073] Furthermore, every 10 minutes, every 60 minutes, 24
Which heart rate/histogram to display after the elapse of time is determined by the instruction in step S14a.

[0074] Also, every 10 minutes, every 60 minutes, 24
Which of the ST level histograms to display after the elapse of time is determined by the instruction in step S20a.

[0075] Every 10 minutes, which is the key point of this example,
Calculation of histogram data of heart rate every 60 minutes and after 24 hours is performed in step S6a of FIG. 11, and histogram data of ST level is performed in step S10a.

First, calculation of heart rate histogram data will be explained based on the flowcharts of FIGS. 13 and 14.

Before that, the memory structure of the heart rate histogram data shown in FIG. 17 will be explained. The heart rate is divided into two levels from 30 to 199, and the heart rate below 29 and the heart rate above 200 are grouped together because the number of heartbeats is small. Then, as a memory for the histogram of heart rate every 10 minutes, mh10-29 is 29 or less.
, 30-31 mh10-30, 32-33 mh10
-32, 198-199 mh10-198, 2
00 or more is defined as mh10-200. As the memory for the histogram of heart rate every 60 minutes, 29 or less is m.
h60-29, 30-31 mh60-30, 32-3
3 is mh60-32, 198-199 is mh60
-198, 200 or higher is defined as mh60-200. As memory for the histogram of heart rate after 24 hours, 29 or less is mh24-29, 30-31 is mh24-
30, 32-33 mh24-32, 198-1
99 is mh24-198, 200 or more is mh24-20
It is set to 0.

In step S60a, all the above-mentioned histogram memories necessary for calculation are initialized only when this routine is reached for the first time after the start of measurement with the portable electrocardiograph.

Step S60a will be skipped from the second time onwards.

In step S61a, the internal timer of the CPU 4 determines whether 10 minutes have elapsed since the start of measurement.
If the elapsed time has not elapsed, the process advances to step S62a, where it is determined to which histogram level the value of the heart rate h calculated in step S5 belongs, and the count value of the histogram memory mh10-x is calculated every 10 minutes. Increment by 1. When it is determined in step S61a that 10 minutes have elapsed, the process advances to step S63a, and the 1 stored in each histogram memory mh10-x obtained in step S62a up to that point is
All the histogram data every 0 minutes are transferred to a predetermined storage area of the RAM 6 and stored therein. Then, all of the histogram memories mh10-x for each 10-minute period are initialized to prepare for creating histogram data for the next 10-minute period.

[0081] In step S64a, it is determined whether 60 minutes have elapsed. If 60 minutes have not elapsed, the process proceeds to step S65a, and it is determined to which histogram level the value of the heart rate h calculated in step S5 belongs, and the corresponding histogram level is determined. 60 to do
The count value of the histogram memory mh60-x is incremented by 1 every minute. If it is determined in step S64a that 60 minutes have elapsed, step S66
Proceeding to step a, all the histogram data for every 60 minutes stored in each histogram memory mh60-x obtained in step S65a are transferred to a predetermined storage area of the RAM 6 and stored therein. Then, all of the histogram memories mh60-x for each 60-minute period are initialized to prepare for creating histogram data for the next 60-minute period.

[0082] In step S67a, it is determined whether 24 hours have elapsed. If 24 hours have not elapsed, the process proceeds to step S68a, and it is determined to which histogram level the value of the heart rate h calculated in step S5 belongs, and the corresponding histogram level is determined. do 2
The count value of the histogram memory mh24-x is incremented by 1 every four hours. Step S67
When it is determined that 24 hours have elapsed in step a, the process advances to step S69a, and each histogram memory mh24-x obtained by performing step S68a up to that point is
All the histogram data stored in the 24-hour period are transferred to a predetermined storage area of the RAM 6 and stored therein. And the histogram memory mh every 24 hours
24-x to prepare for creating histogram data every 24 hours.

[0083] As a result of the above, the histogram data regarding the heart rate every 10 minutes, every 60 minutes, and 24 hours has been stored in the RAM 6 once. By repeating, every 10 minutes, every 60 minutes, 2
Histogram data of heart rate for each 4-hour period will be stored in the RAM 6 for up to 24 hours.

FIGS. 15 and 16 show a detailed flowchart of step S10a in FIG. 11, but the only difference is that the data handled has changed to the ST level, and that the memory for the ST level is used, and the histogram Points where the level classification values are different (see Figure 18)
The rest is the same as the operation regarding the heart rate in FIGS. 13 and 14, so the explanation will be omitted.

By the routines shown in FIGS. 15 and 16, 10
Histogram data for ST level at every minute, every 60 minutes, and 24 hours, RAM6
It will be stored in . By repeating the ST, every 10 minutes, every 60 minutes, and every 24 hours.
Level histogram data for up to 24 hours, R
It will be stored in AM6.

FIG. 19 shows an example of a histogram regarding heart rate displayed on the liquid crystal display device 8. As shown in FIG.

FIG. 20 is an explanatory diagram of enlarged/reduced display of a histogram related to heart rate.

Considering the histogram when the measurement time is 24 hours, the histogram after 24 hours is 1
There are 24 histograms for every 60 minutes, and 144 histograms for every 10 minutes.

[0089] By switching the screen from (a) to (b) to (c) in Fig. 20, the display becomes enlarged, and from (c) to (b) to (
By switching the screen to a), the display becomes reduced.

[0090]

As described above, according to the first portable electrocardiograph of the present invention, electrocardiogram parameters such as heart rate and electrocardiogram ST level related to electrocardiogram data measured over a relatively long period of time can be improved. Multiple groups of trend graph data with different block unit times can be collected and stored in the portable electrocardiograph itself, allowing doctors to instantly display and display trend graphs in a reduced size or at will with the necessary display commands in the examination room. Can be enlarged,
Diagnosis of heart disease can be performed quickly and accurately.

Further, according to the second portable electrocardiograph according to the present invention, the repeated progress from the start of measurement of electrocardiogram parameters such as heart rate and electrocardiogram ST level related to electrocardiogram data measured over a relatively long period of time is also possible. Multiple groups of histogram data at different times can be collected and stored in the portable electrocardiograph itself, and the doctor can instantly reduce or enlarge the histogram in the examination room according to the necessary display commands. This makes it possible to quickly and accurately diagnose heart disease.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of main parts of a portable electrocardiograph according to a first embodiment.

FIG. 2 is a flowchart for explaining the overall operation of the first embodiment.

FIG. 3 is a flowchart for explaining the overall operation of the first embodiment.

FIG. 4 is a flowchart for creating trend graph data regarding heart rate in the first embodiment.

FIG. 5 is a flowchart for creating trend graph data regarding heart rate in the first embodiment.

FIG. 6 is a flowchart for creating trend graph data regarding the ST level in the first embodiment.

FIG. 7 is a flowchart for creating trend graph data regarding the ST level in the first embodiment.

FIG. 8 is a diagram showing a display example of a heart rate/trend graph according to the first embodiment.

FIG. 9 is an explanatory diagram of enlarged display/reduced display according to the first embodiment.

FIG. 10 is an explanatory diagram of a method of displaying a trend graph according to the first embodiment.

FIG. 11 is a flowchart for explaining the overall operation of the second embodiment.

FIG. 12 is a flowchart for explaining the overall operation of the second embodiment.

FIG. 13 is a flowchart for creating histogram data regarding heart rate in the second embodiment.

FIG. 14 is a flowchart for creating histogram data regarding heart rate in the second embodiment.

FIG. 15 is a flowchart for creating histogram data regarding the ST level in the second embodiment.

FIG. 16 is a flowchart for creating histogram data regarding the ST level in the second embodiment.

FIG. 17 is a map diagram of a histogram memory for heart rate in the second embodiment.

FIG. 18 is a map diagram of a histogram memory for ST levels in the second embodiment.

FIG. 19 is a diagram illustrating a display example of a histogram regarding heart rate according to the second embodiment.

FIG. 20 is an explanatory diagram of enlarged display/reduced display according to the second embodiment.

[Explanation of symbols]

1 Body surface electrode

Claims (2)

[Claims] Claim 1: An electrocardiogram amplifier that amplifies an electrocardiogram signal obtained from a body surface electrode attached to a patient, and an amplifier that converts the amplified electrocardiogram signal into digital electrocardiogram data.
a D converter, a means for temporarily storing the obtained electrocardiogram data, a means for calculating electrocardiogram parameters such as heart rate and electrocardiogram ST level based on the stored electrocardiogram data, and a means for temporarily storing the electrocardiogram parameters. creating trend graph data of a block group in which one block is a predetermined value within a group of electrocardiogram parameters in a predetermined unit time; and creating trend graph data consisting of such a block group. means for dividing and creating a plurality of groups having different unit times; means for individually storing the plurality of groups of trend graph data having different block unit times; A portable electrocardiograph comprising means for arbitrarily selecting any trend graph data, and means for displaying the selected trend graph data. 2. An electrocardiogram amplifier that amplifies an electrocardiogram signal obtained from a body surface electrode attached to a patient, and an amplifier that converts the amplified electrocardiogram signal into digital electrocardiogram data.
a D converter, a means for temporarily storing the obtained electrocardiogram data, a means for calculating electrocardiogram parameters such as heart rate and electrocardiogram ST level based on the stored electrocardiogram data, and a means for temporarily storing the electrocardiogram parameters. creating histogram data for a group of electrocardiogram parameters for each predetermined repeated elapsed time from the start of measurement, and creating such histogram data for a plurality of groups having different said repeated elapsed times; means for individually storing a plurality of groups of histogram data having different repetition elapsed times; a means for arbitrarily selecting any one of the histogram data from the plurality of groups; A portable electrocardiograph comprising means for displaying selected histogram data.