JP2006158813A - Graphical representation of medical digital data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that when fine pulsing analog potential signals sampled by a specific frequency are represented in a digital graph, the graph has a high probability to become a stepwise incomplete waveform so that it is difficult to observe initial motion of a fine suggestive wave, or a sign of the ventricular fibrillation based on digital bioinformation data of a conventional portable Holter monitor. <P>SOLUTION: An intersection between a straight line connecting a first base point data point of time-series data points obtained by digital-converting cardiac potential analog data to a data point right before it and a straight line connecting a second base point data point to data point right after it is found, and a waveform becoming incomplete in the digital conversion is graphically displayed as novel amplified data point to provide the initial observation graphical representation for finding the suggestive wave of the ventricular fibrillation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an approximate amplification graph display of a high-speed fine potential wave that is difficult to obtain as a complete waveform at a sampling frequency when a cardiac potential wave, which is biometric information analog data obtained by medical practice, is converted to digital data.

Conventionally, medical analog data obtained from a Holter electrocardiograph is converted into digital data at a 12-bit or 16-bit quantization conversion, a conversion speed of 2 microseconds, and a sample frequency of 100 to 250 Hz. Whether or not a high-speed fine potential of an abnormal P wave R wave that causes atrial fibrillation and ventricular fibrillation has occurred is determined by the behavior change of normal P wave and QRS wave (R) and heart rate variability. You can know as an anomaly. At this time, it must be said that the disease has already progressed as a heart disease. See Non-Patent Document 1.
When converting electrocardiographic waves, which are medical analog data, into digital data, potential values that belong to the middle between sampling points that are converted as potential values divided by the quantization level are not converted. When the digital data is displayed again as a graph, the diagram is stepped. Therefore, the display of the high-speed fine potential is unclear. See Non-Patent Document 2.
Generally, there are cases where patient electrocardiogram is measured using a portable Holter electrocardiograph for the occurrence of subjective symptoms or already illness, but in early signs of atrial fibrillation and ventricular fibrillation leading to heart disease If it is suspicious that high-speed micropotentials are difficult to measure, or if there is psychological anxiety of the patient, intracardiac electrocardiogram measurement is performed by hospitalization at a sampling frequency of 1 to several kilohertz, and analog data of fibrillation potential is obtained. Obtain and diagnose. See US Pat.
Recognizing the initial minute signal of abnormal cardiac potential is important for early diagnosis of heart disease prevention. Before diagnosing with a precise system and equipment, the initial observation is based on the data of a conventional portable Holter electrocardiograph. There is a need to encourage.

Prior art illustrations

As shown in FIG. 1, diagnosis of tachycardia and after-pulses is performed by observing waveforms with abnormal P-wave, QRS-wave (R), T-wave, and U-wave potentials and generation periods with respect to a normal ECG. Is going. In particular, the RR interval is determined as an important factor. However, this is a result of cardiac activity, and the measurement of high-speed fine potential due to abnormal power generation near the myocardium of the atrium or ventricle that causes it is difficult to display with a portable Holter electrocardiograph and does not show a means.

As shown in FIGS. 4 and 5, when the graph is displayed again based on the digital data, the shape between the data is stepped.

As shown in FIG. 4, the same applies to the case where the medical analog data is converted into digital data, further compressed, and then decompressed and displayed again. After acquiring the result factor of cardiac activity, it is difficult to confirm the initial motion observation data even if the fine potential is confirmed.

As described above, it is difficult to acquire digital data that facilitates initial observation of fine electrocardiographic data, which is medical analog data, within the patient's daily life. It is a necessary and important issue.
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"Research Introduction Medical Network and ECG Data Compression of Digital Holter Electrocardiograph", Tokyo Denki University Department of Electronics, Signal Processing Laboratory, Takashi Komine “Non-insulated analog I / O board AD12-8 (PM) instruction manual”, Contec Co., Ltd., 2004, p. 46 JP 2002-219109 A

When digital conversion of medical analog data sampled at a frequency of 100 Hz to 250 Hz, such as the portable Holter electrocardiograph described above, it is difficult to convert a high-speed electric potential signal faster than 250 Hz, so it is difficult to observe the initial movement in abnormal cardiac activity. .
The speed of the potential signal for sinus node generation is 1 m / sec to 1 cm / sec. However, when the stimulation conduction distance is very short, potential stimulation due to abnormal power generation in the atria and ventricles is generated at the same time as the sign of instantaneous contraction movement. To. Abnormal power generation without initial subjective symptoms is fine and does not lead to the detection of a manifested f-wave, making initial observation difficult.

  In the present invention, analog data sampled at a frequency of 250 Hz or less is a conventional digital conversion technique, and amplifying and reproducing an unacquired potential signal point generated between the converted data and the abnormal heart activity. The purpose of this is to realize early preventive treatment for the occurrence of heart disease.

  In order to achieve the above object, according to the present invention, when medical analog data is converted into digital data and then displayed as a graph of orthogonal coordinates with the X axis as the time axis and the Y axis as the potential amount, the arbitrary data is the first reference point data. Then, the first base point data point is connected to the immediately preceding data point, and the angle between the plus direction and the extended straight line in the negative direction and the X axis is obtained to determine the angle component of the first base point data.

Further, the second problem solving means is that when the data point immediately after the first base point data is a point excluding the inflection point of the apex and valley, and when it is not on the extended straight line of the first base point data, Is connected to the next data point as the second base data point, and the extension line is obtained, the intersection of the extension line of the first base data and the extension line of the second base data is obtained, and the graph is plotted as the new data point Let it be a point. This data point is the result of amplifying the graph display.

Further, as a third problem solving means, the first and second series of processing of the solving means are repeated in time series for each data one after another with the passage of time of the X-axis, so that the number of samples at the time of digital conversion is obtained. It is configured to obtain a lot of data and display the amplified graph at the same time.

The operation of the first problem solving means is as follows. An inclination is obtained with respect to the X axis of the time axis by adding an angle component to the digital data giving the magnitude of the potential. Originally, by giving an angle component to digital data which is a scalar value, the directionality to the next data with the passage of time can be obtained.
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  The action by the second problem solving means can determine whether or not the extension line of the first base point data and the extension line of the second base point intersect, and if so, a new data point can be obtained. This data point exhibits an effect of estimating data existing between sampling digital data that could not be obtained with a sampling frequency of 250 Hz or less.

The action of the third problem solving means is that new potential data between sampled digital data is displayed in graph form by continuously obtaining data between digital data that could not be displayed as sampled digital data during digital conversion. It can be estimated as a point and at the same time exhibits the effect of amplification display of fine signals.
By displaying the graph display obtained in the present invention and the graph display based on the original data in an overlapping manner, the effect of prompting confirmation of the change of each electrocardiographic waveform is exhibited.

  As described above, it is possible to display a graph of approximate data points by acquiring data between the sampling digital data of the present invention, and it is possible to provide a graph display in which a minute signal suggesting an abnormal cardiac potential is amplified.

In addition, as a method for determining whether or not the behavior of newly obtained data indicates an abnormality of electrocardiogram, two types of graphs are displayed by overlaying and displaying original digital data graphs that do not implement the present invention. This makes it possible to compare the graphs, and demonstrates the effect of enhancing the judgment of the presence or absence of suspicious electrocardiographic abnormality by initial observation.
Furthermore, in order to reliably obtain medical judgment as to whether or not the suspicious cardiac potential abnormality is a fibrillation potential, the need for more accurate intracardiac cardiac potential measurement is promoted, and an effect leading to early detection of cardiac abnormalities can be expected.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  The embodiment will be described with reference to the schematic diagram of the standard electrocardiogram pattern of FIG. Situation of U wave 6 and P wave 1 for confirming an atrial fibrillation predictor of a waveform pattern composed of P wave 1, Q point 2, R point 3, S point 4 and T wave 5, U wave 6 The sign wave 7 that is difficult to visually recognize is shown in the situation between the Q point 2R point 3 of the QRS wave for confirming the sign of ventricular fibrillation.

FIG. 2 illustrates an embodiment in which the predictive wave 7 that is difficult to view is enlarged and the graph display is amplified.
The X axis is the time axis 10, the Y axis is the potential axis 9, and the X-axis / Y-axis dividing line 13 is drawn for each data point based on the sampling frequency when the cardiac potential waveform of analog data is converted into digital data. Data near the precursory wave 7 is defined as a first base point data point 14 and is connected to the immediately preceding data point 15 by a straight line A16 to obtain an extension line A17. When the data point immediately after the first base point data point 14 is not on the extension line A17, the data point immediately after the first base point data point 14 is set as the second base point data point 18. A data point 19 immediately after the second base data point 18 is connected to the straight line B20 to obtain an extension line B21. The intersection of the extension line 17 and the extension line 21 is obtained as a new data point 22 and is set as a graph display point between the first base point data point 14 and the second base point data point 18.
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This process is repeated for each data point in one cycle from the start point 11 of the P wave of the electrocardiogram waveform to the end point 12 of the U wave shown in FIG. Thereafter, the same processing is repeated for each generation cycle.

The new graph display point group is configured to obtain a new data point 22 as an amplified display point from the start point 11 of the P wave to the end point 12 of the U wave in addition to the original data group.

  The operation of the above configuration will be described below. The amplification point of the new data point 22 is displayed in time series with the original data group in FIG. 1 with respect to the X-axis time axis, and is simply on the Y-axis potential axis in portions other than the predictive wave 7 that are difficult to observe. The shape of the graph swells. Also, the intersection cannot be obtained. On the other hand, the data in the vicinity of the precursory wave 7 can be observed as a result of amplifying the shape of the precursory wave 7.

Further, by displaying the graph of the original data group in FIG. 1 and the start point 11 of the graph of the amplification point of the new data point 22 in the same manner, the two graphs can be compared, and the vicinity of the P wave 1U wave 6 This makes it possible to promote observation of a portion where the display tendency in is significantly different. In addition, the effect of obtaining an opportunity to observe the difference between QRs of QRS waves can be obtained.

The present invention amplifies and displays a minute waveform that cannot be clearly observed in the cardiac potential waveform obtained in the portable Holter cardiac potential measurement, thereby realizing initial motion observation at the examination site and medical judgment leading to early detection treatment of heart disease The example which enables is possible.
In addition, it is intended for the construction of a system in which the patient himself / herself voluntarily presents the initial motion observation data to the doctor by linking with software that automatically extracts the atrial / ventricular fibrillation waveform obtained by amplification display. can give.

  At present, heart diseases are considered to be three major diseases and are increasing. However, due to the variety of heart diseases and the limitation of attachment / detachment of the electrocardiographic electrode in daily life of patients, it is considered difficult to obtain an appropriate diagnosis of early malfunctions by observing the initial motion of heart activity by constant measurement. However, in order to reduce heart disease, we must expect to improve the lifestyle and eating habits of patients through early detection and treatment. For that purpose, it is indispensable to give improvement treatment and guidance at the stage when the arrhythmia tendency appears in the patient, not at the stage where the disease has progressed, and to have early treatment recognition. By using the present invention to enable initial observation of a minute portion of a cardiac potential waveform, the diagnosis by a portable Holter electrocardiograph becomes careful and easy, and at the same time an opportunity to develop a more precise examination of heart disease is obtained. Medical care by enhancing medical knowledge of patients and appropriate health management by eliminating patient anxiety, contributing to preventive medical care for heart disease, and managing patient's own medical information under the ownership of patients. It can be expected to contribute to cost reduction.

Electrocardiographic waveform diagram with occurrence of predictive wave Illustration of predictive wave amplification Flowchart system diagram showing conditions for magnification amplification Digitized graph of conventional ECG data Characteristic diagram of digitized data 5

Explanation of symbols

1 P wave 2 Q point 3 R point 4 S point 5 T wave 6 U wave
7 Predictive waves 8 1 period (1 to 1.5 Hz)
9 Potential axis 10 Time axis 11 Start point 12 End point 13 Dividing line 14 First base point data point 15 Previous data point 16 Line 17 Extension line 18 Second base point data point 19 Immediate data point 20 Line 21 Extension line 22 New data Point (amplification point)
23 Normal wave part 24 Fine wave generation part 25 Potential decrease part

Claims (3)

When medical analog data is digitally converted and graph display of Cartesian coordinates with the X axis as the time axis and the Y axis as the electric potential is displayed, each arbitrary data to be displayed is the first base point data, and the first base point data and immediately before Each data point is connected, the plus direction and the angle between the extended straight line in the minus direction and the X axis are determined, and the direction component of each data is determined. If the data immediately after the first base point data is not on the extended straight line 1 obtained in claim 1, the next straight point data is used as the second base point data to connect each point with the next data to obtain the extended straight line 2; The intersection of the extended straight line 1 and the extended straight line 2 is used as new data and is used as a data point in the graph display.   Along with the progress of the time axis of the X axis, a graph display of data points obtained by amplifying the potential amount is performed by repeating the processing of claims 1 and 2 in time series for each data at the time of digital conversion.

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