JPH09289976A - Waveform plotting device for patient monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To emphasize the specified part of a biological signal waveform by simple constitution. SOLUTION: This waveform plotting device 10 is provided with a data input means 12 for inputting two numerical data xn and xn+1 for indicating biological signals A and B at the two continuous times tn and tn+1 , a data difference calculation means 14 for calculating the difference |xn -xn+1 | of the numerical data xn and xn+1 inputted in the data input means 12 and a line width decision means 16 for deciding the line width Wn of the biological signal waveform corresponding to the difference |xn -xn+1 |calculated in the data difference calculation means 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveform drawing apparatus used in a patient monitoring system for monitoring a biological phenomenon of a patient, and for emphasizing a specific portion when drawing a biological signal waveform.

[0002]

2. Description of the Related Art Conventionally, in this type of waveform drawing apparatus, a biological signal waveform is drawn with a fixed line width. Further, when a specific portion of the biological signal waveform is emphasized, luminance modulation is used.

[0003]

However, the brightness modulation has a problem that the structure for changing the brightness becomes complicated. Also, for a user of the patient monitoring system, the brightness modulation is not easy to see because a bright part is generated.

[0004]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a waveform drawing apparatus for a patient monitoring system, which can emphasize a specific portion of a biological signal waveform with a simple structure and has excellent visibility.

[0005]

A waveform drawing apparatus according to the present invention is used in a patient monitoring system for monitoring a biological phenomenon of a patient, and draws a biological signal waveform. That is, data input means for inputting two numerical data representing biological signals at two consecutive times, data difference calculating means for calculating the difference between the two numerical data input by the data input means, and this data difference. And a line width determining unit that determines the line width of the biological signal waveform according to the difference between the numerical data calculated by the calculating unit. Further, the line width determination means may determine the line width to be large when the difference between the numerical data is small and to determine the line width to be small when the difference between the numerical data is large. Further, the line width determining means may determine the line width to be small when the difference between the numerical data is small and to determine the line width to be large when the difference between the numerical data is large.

[0006] After the two numerical data are output to the data input means, their difference is calculated by the data difference calculation means. The line width determining means determines the line width of the biological signal waveform according to the difference. For example, the line width of the portion where the difference in numerical data is small is increased, and the line width of the portion where the difference in numerical data is large is reduced. Then, the flat part of the biological signal waveform is emphasized thickly. Conversely, the line width of the portion where the difference between the numerical data is small is reduced, and the line width of the portion where the difference between the numerical data is large is increased. Then, the steep portion of the biological signal waveform is emphasized thickly.

[0007]

FIG. 1 is a functional block diagram showing an embodiment of a waveform drawing apparatus according to the present invention. Hereinafter, description will be given with reference to this drawing.

The waveform drawing device 10 comprises a data input means 12 for inputting two numerical data x _n , x _{n +1} representing biological signals A, B at two consecutive times t _n , t _{n +1} ;
Numerical data x _n , x input by the data input means 12
_{n + 1} of the difference | x _n -x n + ₁ | and data difference calculation means 14 for calculating a difference calculated by the data difference calculation means 14 | x _n -
and a line width determining means 16 for determining the line width W _n of the biological signal waveform according to x _{n + 1} |. Waveform drawing device 1
Each unit of 0 can be configured by, for example, a microcomputer and its computer program, but can also be configured by only hardware.

FIG. 2 is a functional block diagram showing a more specific example of the data difference calculating means 14 and the line width determining means 16 of the waveform drawing apparatus 10. FIG. 3 is a graph showing an example of the biological signal. Hereinafter, the operation of the waveform drawing apparatus 10 will be described with reference to FIGS.

Data difference calculating means 14 and line width determining means 1
6 is a counter 20, a comparator 22, and a counter control unit 2
4.

A biological signal A (t _n ,
x _n ) is output, and the biological signal B (t _{n + 1} , x _{n + 1} ) is output at the next sampling time Δt. The numerical data x _n and x _{n + 1} are compared in magnitude by the data input means 12, and the larger one is outputted to the terminal 30 and the smaller one is outputted to the terminal 32. For example, if x _n <x _{n + 1} , the numerical data x _n is output to the terminal 32 and the numerical data x _{n + 1} is output to the terminal 30. The numerical data _xn is transferred to the counter 20, and the comparator 24 compares the output signal _xn of the counter 20 with the numerical data _{xn + 1} . In this case, since x _n <x _{n + 1} , the comparator 24 outputs the comparison result to the counter control unit 26, and the counter control unit 26 increments the data x _n in the counter 20, that is, x _n ← x _n +1.

The counter control unit 26 repeats this operation until x _n = x _{n + 1,} and according to the final increment (x _{n + 1} −x _n ), the numerical data x _n in the counter 20 ₊₁ is further adjusted (incremented or decremented) to obtain numerical data _xne . The numerical data x _ne and the biological signal A (t _n , x _n ) are output to a waveform display device (not shown), and a line width W _n starting from x _n and ending at x _ne.
Is drawn on the display screen. On the other hand, the waveform drawing device 1
The biological signal C is set to 0 at the next sampling time Δt.
(T _{n + 2} , x _{n + 2} ) are output and the numerical data x
By continuing similar processing using _{n + 1} and _{xn + 2} , a line width Wn _{+ 1} is obtained.

[0013] Figure 4 is the difference between the numerical data in the line width determining unit 16 | is a graph showing an example of the relationship between the line width _{W n | x n -x n +} 1. FIG. 5 is a graph showing an example of a biological signal waveform drawn based on the relationship of FIG. Hereinafter, description will be made with reference to FIGS.

In this example, the difference | x _n -x _{n + 1} |
a thick line width W ₀ in x ₁ or less, the difference | is a narrow line width W ₁ at a constant value [Delta] x ₁ or | x _n -x _n + _1. As a result, as shown in FIG. 5, the base line of the biological signal waveform is displayed thick.

FIG. 6 is a graph showing another example of the biological signal waveform drawn by the waveform drawing device 10. Hereinafter, description will be given with reference to this drawing.

In this example, contrary to the relationship shown in FIG. 4, a thin line width is used when the difference between the numerical data is less than a certain value, and a thick line width when the difference between the numerical data is more than a certain value. As a result, the gradient angle of the biological signal waveform that is equal to or larger than a certain value can be displayed thick.

[0017]

According to the waveform drawing apparatus of the present invention, the line width of the biological signal waveform is determined according to the difference between the two numerical data representing the biological signal, so that the configuration is simple. It is possible to emphasize a specific part of the biological signal waveform. In addition, since there is no dazzling portion, visibility can be improved. Also,
It can also be applied to monochrome screens.

As described above, since the highlighting can be performed by changing the gradient, it can be suitably used, for example, for displaying when an arrhythmia occurs. In addition, it is possible to suitably use the display for each patient information by changing the line width for each patient.

According to the waveform drawing apparatus of the second aspect, the line width of the portion where the difference of the numerical data is small is made large, and the line width of the portion where the difference of the numerical data is large is made small so that the biological signal waveform is flat. The part can be emphasized thickly.

According to the waveform drawing apparatus of the third aspect, the line width of the portion where the difference of the numerical data is small is made small and the line width of the portion where the difference of the numerical data is large is made large. The part can be emphasized thickly.

[Brief description of drawings]

FIG. 1 is a functional block diagram illustrating an embodiment of a waveform drawing apparatus according to the present invention.

FIG. 2 is a functional block diagram showing an example in which a data difference calculation unit and a line width determination unit in the waveform drawing apparatus of FIG.

FIG. 3 is a graph showing an example of a biological signal.

FIG. 4 is a diagram illustrating a line width determining unit of the waveform drawing apparatus of FIG. 1;
9 is a graph illustrating an example of a relationship between a difference in numerical data and a line width.

FIG. 5 is a graph showing an example of a biological signal waveform drawn based on the relationship of FIG.

FIG. 6 is a graph showing another example of a biological signal waveform drawn by the waveform drawing device of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Waveform drawing apparatus 12 Data input means 14 Data difference calculation means 16 Line width determination means

Claims (3)

[Claims] 1. A waveform drawing device for use in a patient monitoring system for monitoring a biological phenomenon of a patient, for drawing a biological signal waveform, the data inputting two numerical data representing a biological signal at two consecutive times. The input means, the data difference calculating means for calculating the difference between the two numerical data input by the data input means, and the line width of the biological signal waveform according to the difference between the numerical data calculated by the data difference calculating means. A waveform drawing device for a patient monitoring system, comprising: a line width determining means for determining. 2. The line width determining means determines the line width to be large when the difference between the numerical data is small, and the line width to be small when the difference between the numerical data is large.
A waveform drawing device of the patient monitoring system described. 3. The line width determining means determines the line width small when the difference between the numerical data is small, and determines the line width large when the difference between the numerical data is large.
A waveform drawing device of the patient monitoring system described.