JPH05264365A - Electronic clinical thermometer - Google Patents

Abstract

PURPOSE:To provide bodily temperature information when a calculating expression for prediction is inappropriate or a predicted or detected temperature is unstable by deciding the reliability of a displayed temperature based on the change of the predicted and/or detected temperature with time and informing of insufficient reliability when the reliability is decided as insufficient. CONSTITUTION:A temperature measuring section 10 outputs the temperature of a thermister 13 as a digital amount when the count value of a counter 16 changes in corresponding to the temperature. An arithmetic and control section 20 is composed of a CPU21 for controlling calculation, a ROM22 having a predicting expression storing section 22a for storing control programs and predicting expression, a parameter storing section 22b for storing parameters, and deciding condition storing section 22c for storing conditions for deciding unstableness of predicted values or detected temperatures, and a RAM23 for flags FKP and FKM, a flickering indicating flag 23a, auxiliary storage, and storing measured temperatures and controls operations, such as initial decision, grouping, predicting calculation, unstableness decision, decision of established conditions, etc. When a predicted temperature is not reliable, it is informed by displaying the predicted temperature is a flickering state and, in case the predicted and/or detected temperature is unstable when predicting calculation is completed, it is decided that the temperature is not reliable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic clinical thermometer, and more particularly to an electronic clinical thermometer that performs a predictive calculation by selecting a predictive calculation formula based on a change in detected temperature over time and displays the predicted calculated value as a measured temperature value. is there.

[0002]

2. Description of the Related Art In a conventional predictive electronic thermometer, when a detected temperature is a predetermined value or more and a temperature increase rate is a predetermined value or more, the prediction calculation is started, and the fluctuation of the prediction calculation value is within a predetermined value. When that happens, the prediction is achieved. In general, the prediction formula is such that when the predicted value is Y, the detected temperature is T, and the multiplication amount is U,
Given by Y = T + U.

Various calculation methods are known as the additional amount U in this case. For example, if t is the elapsed time from the predicted starting point, then U = a ₁ × dT / dt + b ₁ or U = (a ₂ × t + b ₂ ) × dT + (c ₂ × t + d ₂ ).

In order to keep the accuracy of the additional amount U constant regardless of the subject and the temperature measuring element, the parameters a ₁ , b ₁ , a ₂ , b ₂ , c ₂ , d of the optimum calculation formula are kept. A device to select ₂ is also made. Further, it is also possible to divide the temperature rise predictions into groups based on the characteristics of the subject and the characteristics of the temperature measuring element, and assign the parameter groups of the calculation formula. Further, in order to maintain continuity of display values, it is considered to weight U. For example, the display value is H, and the weighting function M = (t
/ 50) ² , H = T + U × M. In this case, the display value H is displayed on the display, and t is 50
From the second, the display value H is equal to the predicted value Y.

[0005]

However, in the conventional predictive electronic thermometer, when the detected temperature is unstable or the predictive calculation formula is inappropriate, the temperature display is stopped and an error occurs. In this case, the temperature must be measured again or another temperature measurement method should be tried, and no information can be obtained after measuring the body temperature.

The present invention eliminates the above-mentioned conventional drawbacks, and provides an electronic thermometer which gives body temperature information even when the prediction calculation formula is inappropriate or when the predicted temperature and the detected temperature are unstable.

[0007]

In order to solve this problem, the electronic thermometer of the present invention is an electronic thermometer that detects the temperature of a measurement site and predicts the equilibrium temperature based on the change over time. Reliability determination means for determining the reliability of the display temperature based on the change in the temperature and / or the detected temperature with time,
And a notification unit that notifies that the reliability of the predicted temperature is not sufficient when the reliability determination unit determines that the reliability is not sufficient.

Here, the notification means comprises a temperature display means, and blinks and displays the predicted temperature to notify that the reliability of the predicted temperature is not sufficient. The reliability determining means determines that the reliability is not sufficient when the predicted temperature and / or the detected temperature at the end of the prediction calculation are unstable. Further, the reliability determination means determines that the reliability is not sufficient when the predicted temperature and / or the detected temperature from the start of prediction to the end of the prediction calculation are unstable.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In this embodiment, an electronic thermometer that selects a prediction formula based on grouping will be described as an example of temperature prediction, but the technical idea of the present invention is applied to other prediction thermometers.

<Example of Temperature Prediction of Electronic Thermometer> FIGS. 1 and 2 are views for explaining the prediction principle of the electronic thermometer for selecting a prediction formula based on grouping.

The predictive electronic thermometer sequentially predicts a body temperature of 600 seconds. The prediction calculation is started when the detected temperature is 30 ° C. or higher and the temperature rise rate is 0.25 ° C./4 seconds or higher.

The predicted value Y is given by the following equation, where T is the detected temperature and t is the time elapsed from the predicted starting point.

U = (a × t + b) × dT (c × t + d) ... Override amount Y = T + U where a to d are constants, dT is a temperature rise for the past 20 seconds.

Grouping is performed at the time point t = 40 seconds from the predicted starting point. The measured data is divided into 1 to 5 groups using the temperature rise value for 30 to 40 seconds (vertical axis in FIG. 1) and the temperature for 30 seconds (horizontal axis in FIG. 1). Note that the 6th group in FIG. 1 is not predictable, and the 7th group is not a human body and is not predicted, and the actual measurement value is displayed. Here, the first group is the group having the fastest thermal response, the initial temperature is high, but the rise is stopped immediately, and the additional amount required for prediction is small. On the contrary, the fifth group is the group having the slowest thermal response, and the initial temperature is low, but the temperature rise continues until late, and the required additional amount is large (see FIG. 2). These relationships were obtained from a large number of measurement samples.

After 40 seconds, a to a corresponding to each group
A prediction calculation is performed using the coefficient of d. As an example, 40-
List a to d of each group for 60 seconds.

First group a = 0.03859: b = -0.56178: c = -0.00642
: D = 0.78483 2 groups a = 0.03363: b = -0.15209: c = -0.00623:
d = 0.7967 3 groups a = 0.03363: b = -0.15209: c = -0.00389:
d = 0.7977 4th group a = 0.03363: b = -0.15209: c = -0.00674:
d = 1.0937 5 groups a = 0.06137: b = -0.85641: c = -0.00701:
d = 0.95034 or less, a to d are switched to a predetermined value every 40 seconds from 40 seconds to 120 seconds.

Further, U is weighted in order to maintain continuity of displayed values. Assuming that the display value is H, up to 50 seconds, H = T + U × M ₁ , M ₁ = (t / 50) ² ... Weighting function The display value H is displayed on the LCD. When t is 50 seconds, the display value H becomes equal to the predicted value Y.

From 50 seconds to 120 seconds, H = T + U × M
₂ , M ₂ = 1 and there is no weight. The buzzer sounds when the prediction is established within 50 to 120 seconds. The conditions for this prediction to be met are two points: the temperature rise of the measured value is below a certain value determined by the group and the coefficient interval The predicted value is stable (the slope of the regression line of the estimated value is below a certain value) Is established.

As an example, the temperature rise as the condition for the prediction to be satisfied is as follows: 1 group ≤0.19 ° C / 20 seconds 2 group ≤0.23 ° C / 20 seconds 3 group ≤0.20 ° C / 20 for 40 to 60 seconds Second group ≦ 0.15 ° C./20 seconds 5 group ≦ 0.17 ° C./20 seconds

On the other hand, the slope KA of the regression line of the predicted value is t
SY = Y (t) + Y (t-2) + Y (t-4) + Y (t-6) + Y (t-8) + Y (t- 10) STY = 2 * Y (t-2) + 4 * Y (t-4) + 6 * Y (t-6) + 8 * Y (t-8) + 10 * Y (t-1
0) Calculate with KA = 20 * (SY / 14 + STY / 70). When the KA is 0.04 ° C./20 seconds or less, it is determined that the predicted value is stable.

When the prediction is not established by 120 seconds, 1
Forced to establish in 20 seconds.

After 120 seconds, the additional amount U at 120 seconds
_{Using 120} , H = T + U ₁₂₀ × M ₃ M ₃ = A × t + B. Here, A and B are constants and are switched in 270 seconds, and M ₃ is a polygonal line of 0 in 120 seconds and 1600 seconds. Thus, after 600 seconds, the detected temperature T becomes the display temperature H as it is.

The outline of the prediction method of the latest predictive electronic thermometer has been described above.

<Improvement of Temperature Prediction> In this embodiment, the predicted value and the actually measured value are observed at the time of grouping 40 seconds after the start of prediction and after the grouping, and when the grouping is not suitable or the actually measured value is obtained. When there is a change, the predicted value blinks at the time of forced establishment: 120 seconds and is displayed.

(Judgment of Instability of Predicted Value) As a first method of judging instability of the predicted value, as shown in FIG.
The difference between the maximum and minimum predicted values for 120 seconds is 0.9
There is a method of determining that the predicted value is unstable when the temperature is 1 ° C. or higher.

As a second method for judging the instability of the predicted value, as shown in FIG. 4, there is a method of judging that the grouping (or the prediction calculation formula, the coefficient, etc.) is inappropriate. If the grouping is inappropriate, the prediction value shows a monotonous increase or monotonic decrease in the prediction calculation after the grouping.

After grouping 40 seconds after the start of prediction, the predicted value is observed as follows. The slope of the regression line of the predicted value is 0.0
If it is 2 ° C./20 seconds or more, the flag FKP = 1 is set.
On the contrary, if the inclination is −0.02 ° C./20 seconds or less,
The flag FKM = 1. Both flags FKP and FKM
If it becomes 1, it will not return to 0 until 120 seconds, 4 after the start of prediction
The regression line of the predicted value is obtained from 0 seconds to 120 seconds, and the flags FKP and FKM are updated.

At the time of forced establishment (120 seconds), (FKP, F
When the set of (KM) is (0,0), the prediction is established as the predicted value is sufficiently stable. When (1, 0), the predicted value is monotonically increasing, so that it is determined that the grouping was inappropriate and the predicted value is displayed in blinking. When (0, 1), it is assumed that the predicted value monotonically decreases.

As a third method for determining the instability of the predicted value, if the predicted value changes greatly during forced establishment, displaying the predicted value as it is may cause a large error. Blinks. That is, if the slope of the regression line of the predicted value at the time of forced establishment (120 seconds) is a certain value or more (± 0.31 ° C / 20 seconds or more), the predicted value is unstable and blinks. Next, a method for determining the instability or abnormality of the detected temperature will be shown.

As a method for judging the instability or abnormality of the detected temperature, there is a method of making the case where it is judged that there are 6 groups in FIG. 1 at the time of grouping for 40 seconds. <Example of Configuration of Electronic Thermometer> FIG. 5 is a block diagram showing the configuration of the electronic thermometer of this embodiment.

The electronic thermometer measures a temperature and outputs a temperature as a digital value, a temperature measuring section 10, an arithmetic control section 20 for calculating a predicted temperature from the measured temperature and controlling the electronic thermometer, and a measurement result. And a display unit 30 for displaying.

The temperature measuring unit 10 includes a thermistor 13 and a capacitor 14 installed in a temperature sensing unit connected in parallel,
According to the time constant of the thermistor 13 and the capacitor 14, a one-shot multi 15 for hitting the one-shot,
A clock generator 11 for generating a reference clock, a frequency divider 12 for dividing the reference clock, and a one-shot multi 1
5 is composed of a counter 16 for counting the number of clocks from the clock generator 11 while the output is High, and the temperature is output as a digital amount by changing the count amount of the counter 16 according to the temperature of the thermistor 13. To do.
The configuration of the main temperature measurement unit 10 is an example, and the present invention is not limited to this.

The arithmetic control unit 20 includes a CPU 2 for arithmetic control.
1, a prediction formula storage unit 22a that stores a control program and stores a prediction formula used in the electronic thermometer, and a parameter storage unit 22 that stores parameters a, b, c, and d.
RO having b and a judgment condition storage unit 22c that stores a condition for judging the instability of the predicted value or the detected temperature.
M22, flags FKP and FKM, and blinking display flag 23
a) A RAM 23 for auxiliary storage and for storing measured temperature in time series, and the operation of the electronic thermometer such as initial judgment, grouping, prediction calculation, instability judgment, and judgment of establishment conditions according to a program. Take control.

FIG. 6 shows an external view of the main body of the electronic thermometer. The main body is a liquid crystal display (LCD) 1, which corresponds to the display unit 30.
The case 2 is composed of a tip metal cap 3 that conducts body temperature to the thermistor 13 shown in FIG.

FIG. 7 shows an overall flow chart showing the operation procedure of the electronic thermometer. Here, the buzzer is used when, for example, a condition for obtaining sufficient prediction accuracy is satisfied.

First, when the power is turned on by a predetermined start switch, such as a reed switch, initialization is performed in step S1. In step S2, the data from the temperature measuring unit 10 is stored according to the passage of time. Step S
In 3, prediction calculation is performed based on the prediction formula after grouping. In step S4, it is determined whether or not it is time to determine the instability of the predicted value and the detected temperature. If it is determined, in step S5, the instability of the predicted value and the detected temperature is determined according to the above conditions.

It is checked whether or not the prediction satisfaction condition selected in step S6 is satisfied. If the prediction satisfaction condition is not satisfied, the process proceeds to step S8. If the prediction is established, the procedure proceeds from step S6 to step S7, the buzzer for notifying is sounded, and the procedure proceeds to step S8.

In step S8, it is determined whether the display is blinking or not. If it is not the blinking display, the LCD is displayed in step S10, and the process returns from step S12 to step S2. On the other hand, in the case of blinking display, in step S9, it is determined whether even seconds or odd seconds have elapsed from the start of prediction, and if even seconds have elapsed, step S10
In step S11, the LCD display of the predicted value is displayed, and if the odd number of seconds has elapsed, the LCD display is turned off and a blinking display is realized.

The measurement is repeated until the termination condition is satisfied, and the measurement is terminated when the termination condition, for example, the thermometer is removed from the measurement site.

In this embodiment, an electronic thermometer which selects a prediction formula based on grouping has been described as an example of temperature prediction, but it is obvious that the technical idea of the present invention is applied to other prediction thermometers. Is.

[0041]

According to the present invention, it is possible to provide an electronic thermometer that gives body temperature information even when the prediction calculation formula is inappropriate or the predicted temperature and the detected temperature are unstable.

[Brief description of drawings]

FIG. 1 is a diagram illustrating grouping of electronic thermometers according to an embodiment.

FIG. 2 is a diagram showing an example of a temperature rise curve of the electronic thermometer of the present embodiment.

FIG. 3 is a diagram illustrating an example of unstable temperature measurement of the electronic thermometer of the present embodiment.

FIG. 4 is a diagram illustrating another example of correction when the electronic thermometer according to the present embodiment is forcibly established.

FIG. 5 is a block diagram showing a configuration example of an electronic clinical thermometer of the present embodiment.

FIG. 6 is an external perspective view of the electronic thermometer according to the present embodiment.

FIG. 7 is a flow chart showing an operation example of the electronic thermometer of the present embodiment.

Claims (1)

[Claims] 1. An electronic thermometer for detecting the temperature of a measurement site and predicting an equilibrium temperature based on a change with time, wherein reliability of a display temperature is calculated based on a predicted temperature and / or a change with time of a detected temperature. An electronic clinical thermometer comprising: a reliability determining means for determining; and an informing means for informing that the reliability of the predicted temperature is not sufficient when the reliability determining means determines that the reliability is not sufficient. ..