JPS61213035A - Apparatus for processing data of electrocardiograph - Google Patents

Abstract

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

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention efficiently records and sets electrocardiogram data measured and detected by an electrocardiogram measuring device, and also enables effective recording and setting of electrocardiogram data measured and detected by an electrocardiogram measuring device, and also enables the use of a telephone line, etc. The present invention relates to an electrocardiogram data processing device that allows electrocardiogram data to be efficiently transmitted and electrocardiogram diagnostic processing to be executed efficiently.

[Background Art] A potential is generated by the electrical excitation that occurs during cardiac muscle activity, and this potential is transmitted to the surface of the body.The state of this transmitted potential is detected by electrodes, What is recorded is an electrocardiogram.

The state of excitation propagation within the myocardium largely depends on the electrical properties of the myocardium, and therefore, even if there is a slight change in the heart rate, the electrocardiogram waveform itself does not change much.

That is, an electrocardiogram waveform starts with a P wave and ends with a T wave, but the process of change from the P wave to the T wave does not change much.

Therefore, in a normal electrocardiogram obtained from the same subject, the waveform states from the P wave to the T wave are very similar to each other.

Such electrocardiogram waveforms are measured and recorded continuously corresponding to the measurement time, and the activity state of the myocardium is diagnosed based on the continuous state of the measured waveforms. However, the recording paper on which this electrocardiogram is recorded becomes long as the measurement time passes, and for example, in order to store and set this electrocardiogram in an electronic storage medium, a large capacity is required in the storage device. Furthermore, when transmitting data to a long distance using a telephone line or the like, a long data transmission time is required. In particular, when trying to manage electrocardiograms at a central hospital, it is necessary to transmit the electrocardiogram waveforms measured in rural areas to the central hospital. In such a situation, it is difficult to perform efficient diagnostic work, and it is difficult to transmit more data to make accurate diagnosis.

[Problems to be Solved by the Invention] This invention has been made in view of the above-mentioned points. In a sufficiently short time range,
It can be transmitted to a remote central diagnosis system, etc., effectively improving diagnostic efficiency, and can be easily stored in an electronic storage device, etc., effectively improving diagnostic effectiveness. It is an object of the present invention to provide an electrocardiogram data processing device that can be used as described above.

[Means for Solving the Problem 1] That is, in the electrocardiogram processing device according to the present invention, the electrocardiogram signal is converted into digital data so that the electrocardiogram waveform for one heartbeat is stored and set. , this digital data is compared with the previous electrocardiographic waveform data stored using the QRS complex as a time reference, and the difference is converted into digital data. Then, data compression such as coating is performed on the differential digital waveform and the data between the waveforms, and the obtained digital data is transmitted as electrocardiogram waveform data using, for example, a telephone line. .

[Function] In the electrocardiogram processing device configured as described above,
The processed electrocardiogram data becomes a data waveform of the difference with each adjacent waveform in the active phase where the change is large, and becomes a waveform with a small range of change.

Since there is originally little change in the rest period, the data as a whole has a very narrow dynamic range, and can be efficiently compressed using existing data compression means. Therefore, the temporally continuous electrocardiogram waveform is converted into a very shortened data signal, which can be easily transmitted over long distances using, for example, a telephone line, making intensive electrocardiogram diagnosis possible. This makes it possible to manage the electrocardiogram data, and such electrocardiogram data can be easily recorded in an electronic recording means, which is extremely effective in improving diagnostic efficiency.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Figure 1 shows the configuration of the electrocardiogram measuring device 1.
The measured electrocardiogram data from 1 is converted into digital data by an A/D converter 12 and supplied to a QRSR8 ratio detection circuit 13. Then, this detection circuit 13 outputs a QRSR8 waveform generated in response to the electrical changes in the myocardium corresponding to a heartbeat. The duration of the signal is determined, and the electrocardiogram data of the active period is supplied to the difference detection circuit 15. The difference detection circuit 15 is further supplied with reference electrocardiogram waveform data from a reference electrocardiogram storage device 16, and is aligned based on, for example, the peak value portion corresponding to the R wave of the electrocardiogram data. For example, the previous electrocardiogram data A and the active phase determination circuit 1 are stored in the storage device.
This difference detection circuit 15 subtracts and detects the difference between electrocardiogram data B from 4 and ECG data B. Then, in the active phase compression circuit 17,
Compressed active phase waveform data is created from the above difference data and is supplied to the compressed electrocardiogram forming circuit 20. Further, this data is supplied to the storage circuit 16 as data for updating the reference electrocardiogram.

Further, electrocardiogram digital data obtained from the A/D converter 12 is supplied to a rest period determination circuit 18. This circuit 18 is supplied with an active phase determination signal from the active phase determination circuit 14, and the portion excluding this active phase is determined to be a rest period. Then, the data corresponding to this idle period is compressed by the idle period compression circuit 19 as a data signal,
Compressed electrocardiogram waveform data is formed in a compressed electrocardiogram data forming circuit 20 in succession with the active phase compressed data from the active phase compression circuit 17. This electrocardiogram waveform data is appropriately recorded and retained, and is also used to transmit it to a distant place via a telephone line or the like.

Here, the electrocardiogram waveform to be measured has a state as shown in Fig. 2 corresponding to the heartbeat, and this waveform has R waves,
It is composed of Q waves, R waves, S waves, and T waves, and the active period is between the ends of the P and T waves.

Next, specific operating states of the electrocardiogram data processing apparatus as described above will be sequentially explained. First, FIG. 3 shows an interrupt routine for the flow of electrocardiogram data compression operation. This routine is started by branching CPIJ to an interrupt program under interrupt control using a pulse signal periodically generated by a timer. . Then, in step 100, the register is saved for interrupt, and in step 101, A/D conversion of input electrocardiogram data is started. In step 102, the and signal is checked,
In step 103, it is determined whether or not the busy state is present, and when it is determined that the busy state is not, the next step 10 is performed.
Proceed to step 4. In this step 104, the A/D converted electrocardiogram data is input, and in the next step 105, this A/D converted data
Store in AD.

Then, in step 106, the counter 5 for the number of unprocessed data is
At step 107, the address 5PLAD is advanced by the number of bytes DL of the stored digital data at r+1JL for PLCNT.

In step 108, the address 5PLAD for storing the input digital data is compared with the address 5PLEND at the end of the storage area for storing the above-mentioned input digital data, and when 5PLEND is larger, the process proceeds to step 109, where the storage address 5PLAD is compared with the input digital data. is set to the first address 5PLST of the storage area, the register is restored in step 120, and this interrupt routine is ended. Also, in step 108, 5PL
If it is determined that ENO is large, the routine directly proceeds to step 120 and ends this routine.

Next, the QRS complex is detected from the sampling data obtained as described above, and FIG. 4 shows the detection routine. That is, first step 20
In order to detect when a certain amount of sampled raw data pooled at 0 has reached a certain amount, the count number of this data is 5PLCNT, and the number of data required to start detecting the QRS complex is NDNQRSD. Contrast.

Then, when the number of unprocessed data is greater than NDNQRSD, the process proceeds to step 201, and the local counter 2 is set to the initial state. Then, in the next step 202, r+1JL is determined for the above (2), and the process proceeds to step 203. In this step 203, the local counter (2) is compared with the sum of the maximum value MAXLP that can be processed as a rest period and the number of data (30a+s) in the active period before the peak position. Normally, the machining is smaller. but,
If data for one heartbeat is missing or if the QRS complex undergoes significant deformation, there is a possibility that ■ will exceed the above-mentioned added value. If 1 is smaller than the above addition value, the process proceeds to step 204, where the secondary difference value Y of the sampling data x1 is
(i) and the threshold value THR82D used for QRS detection are compared. In step 204, this routine ends when the threshold exceeds the secondary difference value, and returns to step 202 when it does not.

If it is determined in step 203 that summer is in a large state, the process proceeds to step 205. In this step 205, the maximum length MAXLP that can be processed as a pause period is set as the data length PLEN to be processed as a pause period, and in the next step 206, the data of this pause period is compressed. and,
In step 207, the number of data P to be processed during the pause period is
LEN is subtracted from the number of unprocessed data to obtain a new number of unprocessed data, and the process returns to step 200.

Here, the data obtained by sampling x1, x2,
...xi..., Y(i)-[x (i-n)-x(i)]-[x
(i)-x(i-n)] -X (i+n)-2x (+)+X (i-n
> is called the second-order difference value of the interval nT. However, the king is the sampling interval. That is, if the sampling rate is 200H2, T is 5 m5ec and r
n-6'', Y(i) is ×(1) 3 Q 1se
This is the second-order difference value of c.

Next, in order to determine the range of the active phase, the maximum value of the QRS complex is determined, and the range of the active phase is determined based on this. That is, as shown in FIG. 5, first in step 300, 0.0
We investigated about 6 m5 ec and found the maximum value
This point is determined as the peak position of the R wave. Here, Q
RS group detection is performed by comparing the difference value and the same value. Also, the width of the QRS complex is approximately 0.081se.
c, it is assumed that the R wave peak position is located 0.06 m5ec after the detection position.

Then, in the next step 301, the start address S of the active period is set based on the number of data DNBP of the active period before the peak position, and in step 302, PLEN is set to the above S, and this routine is ended. That is, the second difference value Y(i) of the sampling data is calculated by computer processing, and the address of the maximum value of the sampling data considered to be the QRS complex is determined by computer processing.

Then, using this as a reference, an address for performing subtraction with the reference electrocardiogram is determined.

In order to compress the data of the idle period, as shown in FIG.
It is determined whether or not is larger than rOJ. If it is determined that PLEN is greater than O, step 40
Proceeding to step 2, the above PLEN is used as is as the suspension period data, and DLEN is set to PLEN. and,
In the next step 403, from O to PL of local counter I
Data compression is performed for sample values up to EN.

Further, if it is determined in step 401 that PLEN is 0 or smaller than 0, step 40
Proceed to step 4, adopt 0 as the idle period data, and set DLEN
Let be 0. Then, in step 405, the absolute value of PLEN is added as data. That is, in a normal case, the compressed data of the rest period waveform becomes the rest period data. When the interval between heartbeats becomes shorter and the processed active phase periods overlap, the length of the overlapping portion becomes resting phase data. By doing this, in the reproduction process, it can be determined whether or not there is an overlap in the processed active period periods by checking whether DLEN is 0 or not. Then, it becomes possible to accurately reproduce the temporal relationship of the active period, whether there is overlap or not.

In order to compress active phase data, an active phase flag is first created in step 500, as shown in FIG.

Then, in step 501, the PLE of local counter I
The difference between the data from N to the active period LAEGC and the previous electrocardiogram waveform stored in the storage device is calculated, and the result is stored in the memory as a difference value W. This stored difference waveform data is used in the next step 5.
02 to perform data compression.

Here, the above data compression is performed using, for example, IEEE TRAN.
SACTION BIOMEDICAL ENGINE
ERING, VOL, BME30°N011. NOVE
Representative points are determined according to the 5APA2 algorithm shown in MBER19831C, and the potential difference and time difference between the representative points are used as data. In other words, the original signal waveform as shown in Figure 8 is approximated by a polygonal line, and only the time and value at the end points of each line segment are used as data, and points on the line segment are substituted between the end points. By doing this, data compression is performed.

This algorithm has a feature in that points on the waveform are given as endpoints of the line segments.

If the time and potential of the representative point are known using the above 5APA algorithm, the electrocardiogram waveform can be reproduced, but the time and potential of this representative point are not absolute values, but may be relative values from the previous representative point. No problem. That is, the first 1
Once a point is set reliably, subsequent points can be determined if the time length and potential difference between them and the previous point are known.
This makes it possible to reproduce waveforms.

A differential electrocardiogram waveform is reproduced from the compressed data of the active phase of the electrocardiogram obtained as described above, and this differential electrocardiogram waveform is added to the reference electrocardiogram waveform and stored and set as a new reference electrocardiogram.

The above is an overview of the processing on the compression side. Reproduction processing for reproducing the original electrocardiogram waveform from compressed data is performed in a state corresponding to this. That is, the differential electrocardiogram waveform is reproduced from the compressed data of the active phase using the method described above, and the reference electrocardiogram waveform in the reproduction process is added to this and stored and set as the reproduced electrocardiogram waveform and the new reference electrocardiogram waveform.

The rest period data is similarly reproduced if DLEN>O.

By sequentially storing these data at the next address in the memory, temporally continuous digital electrocardiogram data can be obtained. If it is found from the DLEN of the resting phase data that the active phase data overlap, the new active phase reproduction data is adopted as the reproduction data in the continuous waveform. That is, the memory address is returned by an amount corresponding to the overlapping length, and the playback data of the new active period is addressed to the memory.

The electrocardiogram digital data obtained in this way is supplied to a D/A converter as it is without any particular reconstruction between samples, where it is converted into analog data, and filtered as appropriate. For example, an electrocardiogram waveform can be reproduced by a pen recorder.

[Effects of the Invention] As described above, in the electrocardiogram processing device according to the present invention, since the electrocardiogram waveform is expressed by taking the difference from the waveform one heartbeat before, it is sufficiently compressed to form a waveform signal. In addition, the pause period will also be expressed as compressed data.

In such electrocardiogram data, especially the waveform data of the active phase is stored and set in the storage device as a reference electrocardiogram, and the new active phase waveform data is calculated by taking the difference with the measured electrocardiogram waveform. It allows the waveform to be expressed, and the electrocardiogram waveform is reproduced using information with a very small dynamic range, and it is used to transmit electrocardiogram data using telephone lines and record it in electronic recording means. will be executed efficiently. Specifically, the centralized management of diagnosis using electrocardiograms can be easily carried out, and its effects are remarkable. Furthermore, if the electrocardiogram data that has been compressed using differential data is compressed using a known method such as 5APA, the transmission efficiency of electrocardiogram data using telephone lines etc. can be made more effective. will be able to improve.

[Brief explanation of drawings]

FIG. 1 is a block diagram illustrating an electrocardiogram processing device according to an embodiment of the present invention, FIG. 2 is a diagram showing the state of an electrocardiogram to be measured, and FIGS. 3 to 7 are respectively operations of the above embodiment. FIG. 8 is a flowchart illustrating the state and is a diagram illustrating one example of the data compression means. 11... Electrocardiogram measuring device, 12... A/D converter,
13... QRSR8 waveform detection circuit 4... Active period determination circuit, 17... Active period compression circuit, 18... Rest period determination circuit, 19... Rest period compression circuit. Applicant's agent Patent attorney Takehiko Suzue Figure 1 M3U! ! 1 Figure 4, Display of the case Patent application No. 60-54869, name of the invention Electrocardiogram data processing device, person making the amendment Relationship to the case Patent applicant Corporal Matsumoto (and one other person), agent, Tokyo Port 17th Mori Building, 1-26-5 Toranomon
105 Telephone 03 (502) 3181 (main representative)
7. Contents of amendment (1) In the 6th line of page 5 of the specification attached to the application, "...Court...J" is corrected to "...Code...". (2) Similarly, on page 6, line 10 of the specification, “Measurement measurement
``...'' should be corrected to ``Measure...''. (3) Similarly, in the 13th line of page 6 of the specification, “...I
Correct the phrase "heartbeat..." to "...one heartbeat...". (4) Similarly, in the first line of page 10 of the specification, the phrase "...go forward..." is corrected to "...go forward...". (5) Similarly, on page 10, line 17 of the specification, “data
. . ." is corrected to "compared with the addition value to the number of data (300 ms).". (6) Similarly, in the third line of page 111 of the specification, “xl...
” should be corrected to r
1...xiJ means "×(1n,×(2),
...X(i) Correct it as J. (8) Similarly, in the 1st line of page 12, the text ``r(i-n)J'' is corrected to ``(i+n)J.'' (9) Similarly, in the 13th line of page 12 of the specification, ``ro, 06
``...'' is corrected to ``60...''. (10) In the same way, on page 12, line 14 of the specification, "r(NJ" is corrected as r(j)J.) (11) Similarly, on page 12, line 17 of the specification, "...
Correct 0.08J to "...80". (13) Same (r・” on page 12, line 18 of the specification)
0, 06 m5ecJ and r...60m5e
Correct it to cJ. (14) Similarly, on page 14, line 18 of the specification, “...
・LAEGC..." is replaced with "...-LAECG--
・” I corrected it. (15) Similarly, in the 6th line of page 17 of the specification, the words "...address..." are corrected to "...store...". (16) Similarly, in the 8th line of page 17 of the specification, the phrase "...sample, interval..." was replaced with "...sample point...
・” I corrected it. (17) Figures 3 to N5 of the drawings attached to the application shall be corrected as shown in the attached sheets. Figure 3

Claims (1)

[Scope of Claims] Means for converting continuous electrocardiogram data into digital data and storing and setting; means for detecting a QRS complex from the digital data stored and setting; and the QRS complex corresponds to one heartbeat with respect to time. means for extracting and separating electrocardiographic waveform data from resting phase data; storage means for storing and setting at least one of the electrocardiographic waveform data; and storage means for storing the separated and extracted electrocardiographic waveform data in the storage means. means for comparing the digital data for one heartbeat and the position of the QRS complex on a time basis and calculating digital waveform data corresponding to the difference; and means for encoding and data compressing the difference waveform and the rest waveform. An electrocardiogram data processing device comprising: a means for outputting the data-compressed digital signal; and a means for updating and storing the electrocardiogram waveform data stored in the storage means.