JPH07313478A - Method for displaying image of living body signal and device therefor - Google Patents

Abstract

PURPOSE:To enable the image display of the living body signal which can intuitively be grasped by finding two-dimensional coordinates for drawing amplitude values of living body signal data corresponding to the radii of circles, and writing the two-dimensional coordinate positions in specific locations of a bit map memory corresponding to respective display dots on a display screen. CONSTITUTION:A CPU 3 clears the storage contents of the bit map memory 7 to an initial state, places 0 at a starting point on a set circumference, and inputs the living body signal data from an A-D converter 1. The CPU 3 finds the angle of the amplitude of the living body signal data at the point 0, calculates the two-dimensional coordinates corresponding to the amplitude of the angle, and transfers the two-dimensional coordinate data to the bit map memory 7, thereby writing the data as an image at the positions corresponding to the respective display dots on the screen of a display device 8. Then the two-dimensional coordinate data are read out of the bit map memory 7 and sent out to the display device 8, which displays them on its screen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for displaying an image of a biological signal for displaying, for example, an electroencephalogram or an electrocardiogram signal waveform.

[0002]

2. Description of the Related Art Conventionally, when displaying a time-series biological signal such as an electroencephalogram or an electrocardiogram signal waveform on the screen of a display device such as a CRT, generally, the horizontal axis (X axis) is the time axis and the vertical axis ( (Y axis)
The waveform is displayed by using as the amplitude axis of the biological signal.

[0003]

However, in the conventional display using the time-amplitude coordinate, it is difficult to intuitively grasp the abnormality or the difference in detail unless the displayed waveform is observed well.

Therefore, in view of the above points, the present invention provides a method and apparatus for displaying an image of a biological signal that can be intuitively grasped by visualizing the characteristics of the biological signal such as an electroencephalogram or an electrocardiogram signal waveform. To aim.

[0005]

In the method and apparatus for displaying an image of a biomedical signal of the present invention, for example, as shown in FIG. 1, two-dimensional coordinates for drawing the amplitude value of the biomedical signal corresponding to the radius of a circle are displayed. The image processing program to be obtained is stored in advance, and the center coordinates to be displayed, the reference amplitude value of the biological signal, the radius from the center coordinates corresponding to the reference amplitude value, and a plurality of time points in one cycle of the circle drawn by the radius are set. , Based on the image processing program, calculate the angle for each time point in the amplitude value and calculate the two-dimensional coordinates of the amplitude value according to this angle, and then calculate the calculated two-dimensional coordinates at the position corresponding to each display dot on the display screen. The image-stored biomedical signal is sequentially displayed on the display screen.

[0006]

[Function] The two-dimensional coordinates to be drawn are obtained by correlating the amplitude value of the input biomedical signal data with the radius of the circle, and the two-dimensional coordinate position is determined at a predetermined position of the bitmap memory corresponding to each display dot on the display screen. Since the biological signals are written in and displayed as an image, it is possible to intuitively grasp the peak points and the maximum points that are the characteristics of each biological signal.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method and apparatus for displaying an image of a biological signal according to the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing the configuration of an apparatus according to the method of displaying an image of a biological signal of the present invention.

In FIG. 1, reference numeral 1 denotes an AD converter, which inputs an analog biological signal such as an electroencephalogram, an electrocardiogram signal or an electromyogram signal from an amplifier (not shown), and samples the clock signal output from a clock generator 2. Then, it is converted into digital biometric signal data (hereinafter, simply referred to as “biometric signal data”).

Reference numeral 3 denotes a control arithmetic unit (hereinafter, simply referred to as "CPU") including a CPU, which arbitrarily sets the amplitude value of the biological signal data based on an image processing program stored in a program memory described later. The two-dimensional coordinate position for drawing is calculated in correspondence with the radius of the circle designated by, and the entire apparatus is controlled.

Reference numeral 4 denotes an operation unit including, for example, a keyboard, which is used for various necessary data for image processing, that is, a center coordinate position to be displayed, a reference amplitude value of a biological signal, and a center coordinate position corresponding to the reference amplitude value. The radius and the time point of one cycle of the circle drawn by this radius (hereinafter referred to as "point") are set, and the data related to the biomedical signal is set, but these required data are set to arbitrary values. Can be set. At this time, the designation of whether to display dots or lines on the screen of the display device, which will be described later, is also performed.

Reference numeral 5 denotes a program memory including, for example, a ROM, in which an image processing program for calculating the two-dimensional coordinates to be drawn by correlating the amplitude value of each point of the biological signal with the radius of the circle is stored in advance. ing.

Reference numeral 6 denotes a memory including, for example, a RAM, which is used for the image processing and is set via the operation unit 4. The central coordinate position, the reference amplitude value of the biological signal, the radius R, the point data and the biological signal are stored. Other data related to processing is temporarily stored and held.

Reference numeral 7 is a bit map memory, for example, CP
The biological signal data corresponding to the radius of the circle with respect to the amplitude calculated by U3 is stored as an image of two-dimensional coordinates. Further, each coordinate position (address) of the bit map memory 7 corresponds to each display dot on the screen of the display device 8 as conventionally known. The display device 7 is composed of, for example, a CRT or the like, and displays an image of a biomedical signal or related data on a display screen.

With the above-mentioned configuration, a case will be described with reference to FIG. 3 in which the two-dimensional coordinate position for drawing the amplitude value of the biological signal data in correspondence with the radius of the circle is calculated. In FIG. 3, it is assumed that a waveform is displayed as an image on a circle having an arbitrary radius R corresponding to the reference amplitude value of the biological signal with an arbitrary coordinate position (Xc, Yc) on the screen of the display device 7 as the center. The rotation start angle of the signal is assumed to rotate clockwise with the positive Y-axis as a reference (0 degree). The center coordinate position to be displayed is (Xc, Yc), the radius serving as the display range from this center coordinate position is R, the reference amplitude value (AMPR) of the biological signal corresponding to this radius, and one rotation (2π) of the radius R. Number of points corresponding to the circle (N)
To set. At this time, the two-dimensional coordinate position of the amplitude value of the biological signal data at the point Pt at a certain time point is (X,
Y) and the angle θ, the angle θ is

[0015]

Mathematical Expression 1 can be expressed by θ = P / number of points (N) × 2π.

Therefore, the X and Y values of the two-dimensional coordinate position (X, Y) at the point Pt are respectively

[0017]

[Formula 2] X = Xc + A · CONVR · SINθ

[0018]

[Formula 3] Y = Yc + A · CONVR · COSθ

It becomes However, A is a signal value (amplitude value) at the point Pt, and CONVR (converted value) is “radius R /
The reference amplitude value (AMPR) of the biomedical signal "is represented respectively. Further, the amplitude value of the biological signal data changes depending on each point.

By performing the above calculation, it is possible to obtain a two-dimensional coordinate position in which the amplitude value of the biological signal corresponds to the radius of the circle. Such calculation is performed by the program memory 4 of FIG.
CP based on the image processing program stored and stored in
Performed by U3.

Next, referring to the flowchart of FIG.
The image processing operation of the embodiment shown in FIG. 1 will be described.

In FIG. 2, a power switch (not shown)
To put the device into operation. After the power is turned on, the center coordinate position (Xc, Yc) to be displayed which is necessary for image processing via the operation unit 4, the required radius R from this center coordinate position, the number of points of the circle drawn by this radius R, and the radius R The reference amplitude value corresponding to and the type of image display (dot display or line display) are set (step S1). Here, it is assumed that the line display is set.

Next, the CPU 3 uses the bit map memory 7
Clears the stored contents of the initial state (step S
2) Then, the first point of the set circumference is set to "0" (step 3), and the biomedical signal data is fetched from the AD converter 1 (step S4).

The CPU 3 obtains the angle of the amplitude value of the biological signal data at the point "0" by the above-mentioned equation 1,
The calculation of the two-dimensional coordinate position with respect to the amplitude value of this angle is performed by the above-described equations 2 and 3 (step S5), the calculated two-dimensional coordinate data is transferred to the bitmap memory 7, and each display on the screen of the display device 8 is performed. The image is written in the position (address) corresponding to the dot (step S6). When the biometric signal data is written in the bitmap memory 7, it is stored as a line connecting dots that are temporally continuous.

The two-dimensional coordinate data of the biological signal data stored in the bit map memory 7 is read out and displayed on the display device 8.
To display on the screen (step S7). In this case, the biometric signal data is written to the bitmap memory 7 and simultaneously output to the display device 8, so that the images are displayed in the order in which they were written.

Next, the CPU 3 increments the number of points by one (step S8), and determines whether or not the set number of points is equal to or greater than the predetermined number of points in one cycle of the radius R (step S9). If the number of points is less than or equal to the number of points in one cycle, the process returns to step S4 and the processes in and after step S4 are repeated until the number of points in one period is reached, and if the number of points is greater than or equal to the number of points in one cycle, step S2 Returning to step S2, the processing after step S2 is repeated to continue the image display.

FIG. 4 shows an example of an image display of, for example, an electroencephalogram displayed as described above. This display example is based on a line display that connects the temporally consecutive dots stored in the bitmap memory 7. When the dot display is designated through the operation unit 4, the image display becomes a dot shape.

FIG. 5 shows the image display of the electroencephalogram according to the present invention and the normal electroencephalogram display in association with each other. As apparent from FIG. 5, the peak point (P1) corresponding to the peak point (P1) and the maximum point (P2) of the conventional electroencephalogram display is displayed.
It can be seen that a) and the maximum point (P2a) are exaggeratedly displayed, and the peak point or the maximum point of the biological signal waveform having a large amplitude can be read at a glance.

Further, FIG. 6 shows four types of display examples in which specific waveform data having periodicity is input instead of the biomedical signal data in the embodiment of FIG. 6A is a sine wave, FIG. 6B is a sine wave containing a DC component (shown by a small waveform in the figure), FIG. 6C is a triangular wave, and FIG. 6D is a display when the angular velocity and the sine wave are not integral multiples. Therefore, even in the case of a biological signal, such a petal-like image is displayed for a signal having periodicity.

Next, a case where the image processing method of the present invention described above is applied to an image display device for an electrocardiogram signal will be described with reference to FIGS. Since the device configuration is the same as that of the device of FIG. 1, redundant description will be omitted with reference to this. FIG. 7 shows a display range when applied to image processing of an electrocardiogram signal. In FIG. 7, the maximum peak waveform (hereinafter,
It is simply called "R wave". ) Is detected and the interval of R waves, for example, the interval between R1 and R2 is determined as one cycle (T). R1 and R
For example, a period (hereinafter, referred to as a "preliminary display period") of two waves, for example, each one-quarter cycle before, is arbitrarily set, and (R1-T /
Calculate from the range from 4) to (R2-T / 4) as the display range. When the display range is calculated based on the preliminary display period and the detection of the R wave, the number of points in this range is automatically determined. The number of points of the display range according to the preliminary display period and the detection result of the R wave is stored in advance in the image processing program of the program memory 5, and is read according to the preliminary display period and the period of one cycle of the detected R wave. It is supposed to be. Then, the average value of the amplitude values of the electrocardiogram signal data corresponding to each point of the read display range is obtained, and this average value is set as the 0 level reference line.

Next, referring to the flowchart of FIG.
The operation of image processing of an electrocardiogram signal will be described. In FIG. 8, a power switch (not shown) is turned on, and a radius R to be displayed, a center coordinate position, a reference amplitude value corresponding to the radius R, and a display type (line display) are set via the operation unit 4. (Step S20).

After setting the required data, the CPU 3
Reads in the electrocardiogram signal data via the AD converter 1 (step S21), detects at least two consecutive R waves (maximum peak value) from the electrocardiogram signal data, and obtains the interval as one cycle ( Step S22). Next, the above-mentioned preliminary display period and reference amplitude value are set via the operation unit 4 (step S23). The CPU 3 calculates the display range based on the set preliminary display period and the calculated period of one cycle between R1 and R2 waves, and reads the number of points corresponding to this display range from the image processing program of the program memory 5, The average value of the sample values of the electrocardiogram signal data corresponding to the number of points in this display range is calculated and set as a reference line (reference line of 0 level) (step S24). Each data detected and calculated by the CPU 3 is temporarily stored and held in the memory 6.

Further, the CPU 3 uses the bit map memory 7
Is cleared (step S25), and the image processing is started from the electrocardiogram signal data of the first point "0" of the read points (step S26). C
The PU 3 calculates the angle of the point “0” by the above-mentioned formula 1, and calculates the coordinate position (X, Y) of the amplitude value of the electrocardiogram signal data at this point “0” based on the above-mentioned formulas 2 and 3. (Step S27).

When the calculation of the coordinate position (X, Y) of the amplitude value is completed, the data of this coordinate position is stored in the bit map memory 7.
And write it as a line at an address corresponding to a predetermined display dot on the screen of the display device 8 (step S2).
8). The coordinate position transferred to the bitmap memory 7 is immediately read and output to the display device 8 to display the corresponding dot on the screen (step S29). After the image processing and display of the point "0", the CPU 3 increments the point by 1 (step S30), performs the image processing of the next point "1", and determines whether or not the predetermined number of points is reached ( Step S31). In step 30, if the predetermined number of points is not reached, the process returns to step S26 and the above process is repeated until the predetermined number of points is reached. Continue displaying the image of ECG signal data.

FIG. 9 shows an image display example of one cycle (one rotation) of the electrocardiogram signal data thus obtained. As shown by the arrows in FIG. 9, it can be seen that, for example, R waves and T waves having large amplitude values are exaggeratedly displayed as R1 and T1 on the set circle.

FIG. 10 shows a display example of a half cycle of electrocardiogram signal data. In FIG. 10, the R wave and the T wave of the conventional display are respectively R on the circle of the image display.
It corresponds to 1 wave and T1 wave. As for the number of points in the half cycle, the number of points in one cycle of the display range is doubled to calculate the angle for each point, so that the image of the electrocardiogram signal data is contracted into a semicircle and displayed. This is to prevent the plus and minus portions of the waveform from overlapping and making it difficult to see when displaying an image in one cycle.

Further, FIG. 11 shows an example in which the image display of one cycle in FIG. 9 is overlapped in time series for three cycles. FIG. 12 shows an example in which the half-cycle images of FIG. 10 are overlapped for two half-cycles in time series. In this way, by superimposing the image displays, if there is no abnormality in the electrocardiogram signal, there is little disturbance or deviation in the superimposed waveforms, and if there is abnormality, the overlapping of waveforms is disturbed or the deviation becomes large, so Effective for discovery. Further, the superimposition of image displays can be performed by selecting the image data at any time.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0039]

As described above, according to the embodiments of the present invention, since the amplitude value of the biological signal is displayed as an image as two-dimensional coordinates corresponding to the radius of the circle, the large amplitude portion is exaggeratedly displayed. Therefore, the characteristics of the biological signal can be intuitively grasped.

Further, there is an advantage that the periodic element such as an electrocardiogram signal can be easily identified by changing the displayed period.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an apparatus to which a method for displaying an image of a biological signal of the present invention is applied.

FIG. 2 is a flowchart showing image processing of the embodiment shown in FIG.

FIG. 3 is a diagram for explaining calculation of a two-dimensional coordinate position in which the amplitude value of the biological signal in the embodiment of FIG. 1 is associated with the radius of a circle.

4 is a diagram showing an image display example of an electroencephalogram according to the embodiment of FIG.

FIG. 5 is a diagram illustrating a correspondence relationship between an image display of an electroencephalogram according to the embodiment of FIG. 1 and a conventional display.

6 is a diagram showing an image display example of four types of specific signal waveforms according to the embodiment of FIG.

FIG. 7 is a diagram illustrating a display range in which an image display method is applied to an electrocardiogram signal as another embodiment of the present invention.

FIG. 8 is a flowchart showing image processing of an electrocardiogram signal according to another embodiment of the present invention.

9 is a diagram in which the image display of one cycle of the electrocardiographic signal is made to correspond to the conventional electrocardiographic signal waveform by the image processing of FIG.

FIG. 10 is a diagram showing an image display example of the half cycle of FIG. 9;

FIG. 11 is a diagram showing an image display of one cycle by the process of FIG.
It is the figure which overlapped for a period.

FIG. 12 shows half-cycle image display by the process of FIG.
It is the figure which overlapped for half cycle.

[Explanation of symbols]

 3 control calculation unit 4 operation unit 5 program memory 7 bitmap memory 8 display device

Claims (3)

[Claims] 1. An image processing program for preliminarily storing a two-dimensional coordinate for drawing an amplitude value of a biomedical signal corresponding to a radius of a circle, a center coordinate to be displayed, a reference amplitude value of the biomedical signal, The radius from the center coordinate corresponding to the reference amplitude value and a plurality of time points in one cycle of a circle drawn by the radius are set, and an angle for each time point in the amplitude value is obtained based on the image processing program. Calculate the two-dimensional coordinates of the amplitude value according to the lever angle, store the calculated two-dimensional coordinates as an image at a position corresponding to each display dot on the display screen, the image-processed biological signal A method for displaying an image of a biological signal waveform, which is sequentially displayed on the display screen. 2. A storage unit that stores in advance an image processing program for obtaining a two-dimensional coordinate for drawing the amplitude value of the biomedical signal corresponding to the radius of the circle, the center coordinates to be displayed, and the reference amplitude of the biomedical signal. Value, the radius from the center coordinate corresponding to the reference amplitude value, and operating means for setting a plurality of time points in one cycle of a circle drawn by the radius, and the time at the amplitude value based on the image processing program. Control calculation means for obtaining an angle for each point and calculating the two-dimensional coordinates of the amplitude value corresponding to the angle, and storing the calculated two-dimensional coordinates as an image at a position corresponding to each display dot on the display screen. And a display means for sequentially displaying the image-processed biomedical signal on the display screen. 3. An image processing program for preliminarily storing an image processing program for obtaining a two-dimensional coordinate for drawing an amplitude value of an electrocardiogram signal corresponding to a radius of a circle, a center coordinate to be displayed, and a reference amplitude of the electrocardiogram signal. Value, the radius from the center coordinate corresponding to the reference amplitude value, and operating means for setting a preliminary display period for each R wave of the electrocardiogram signal; and based on the image processing program, the R wave is detected and adjacent. Calculate the display range from the preliminary display period and the period of one cycle,
A plurality of time points corresponding to the display range are read from the image processing program, an average value of the amplitude values for each time point is calculated, a reference line of the electrocardiogram signal is set, and each time point at the amplitude value is set. And a bit for storing the calculated two-dimensional coordinate as an image at a position corresponding to each display dot on the display screen. An image display device for an electrocardiogram signal, comprising a map memory and a display means for sequentially displaying the image-processed electrocardiogram signal on the display screen.