JP5596323B2 - Electronic thermometer and control method of electronic thermometer - Google Patents

Description

  The present invention relates to an electronic thermometer that measures the body temperature of a subject.

  2. Description of the Related Art Conventionally, an electronic thermometer that measures a body temperature of a subject, predicts an equilibrium temperature from the obtained temperature value, and displays a predicted value is widely used (Patent Document 1). In this type of electronic thermometer, since the equilibrium temperature is predicted based on the change over time of the actual measured value of the temperature at the non-measurement site detected by the thermometer, the measurement result of the body temperature of the subject can be presented quickly.

JP 2007-024531

  In the electronic thermometer, the prediction algorithm is adjusted so that the equilibrium temperature can be predicted quickly and accurately at normal body temperature or fever. Therefore, for example, when the actually measured value does not exceed the predetermined temperature, the process ends as an error. Therefore, for example, if you try to measure the body temperature of a subject with hypothermia using an electronic thermometer with an equilibrium temperature prediction formula, a measurement error will occur, and the body temperature of the subject with hypothermia will be measured. Such an electronic thermometer could not be used for such applications. In addition, hypothermia here is a pathological condition in which the body temperature is lowered to 35 ° C. or lower for some reason, 33 to 30 ° C. (moderate), 30 to 25 ° C. (severe), 25 to 20 ° C. (serious: Coma, asphyxia), 20 ° C or less (very serious: almost dead).

  The present invention has been made in view of the above problems, and when measuring the body temperature of a subject having normal body temperature, the body temperature measurement value is presented by predicting the equilibrium temperature, and for hypothermia subjects. It is an object of the present invention to provide an electronic thermometer that can perform quick and accurate body temperature measurement.

In order to achieve the above object, an electronic thermometer according to an aspect of the present invention has the following arrangement. That is,
An electronic thermometer having a predicting means for predicting an equilibrium temperature based on a change with time of an actual measurement value of a temperature at a measurement site detected by a temperature measuring element,
A prediction execution means for starting prediction by the prediction means when it is detected that an actual measurement value detected by the temperature sensing element satisfies a prediction start condition;
Display means for displaying the actual measurement value until the actual measurement value exceeds the first temperature value, and displaying the predicted value obtained from the prediction means when the actual measurement value exceeds the first temperature value. When,
After detecting that the change over time of the actual measurement value satisfies a predetermined condition, when detecting that the change over time of the actual measurement value does not exceed the first temperature value and is stable, An informing means for informing that the measurement has been completed ,
Said display unit, when the notification means makes a notification of completion of body temperature measurement, you peak hold display of the measured value.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic thermometer which can measure the body temperature of the test subject in the state of hypothermia can be provided, maintaining the function as a prediction type thermometer.

The figure which shows the external appearance structure of the electronic thermometer by embodiment. The internal block diagram which shows the function structure of the electronic thermometer by embodiment. The flowchart which shows the flow of the whole body temperature measurement process in an electronic thermometer. The flowchart which shows the hypothermia measurement process in an electronic thermometer. The flowchart which shows the prediction process of the equilibrium temperature in an electronic thermometer. The figure explaining switching of the temperature display in an electronic thermometer.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, but the scope of the present invention is not limited thereto, and can be appropriately changed.

1. FIG. 1 is a diagram showing an external configuration of an electronic thermometer 100 according to an embodiment of the present invention. FIG. 1 (a) is a plan view and FIG. 1 (b) is a side view. ing. Reference numeral 101 denotes a main body case in which an electronic circuit such as an arithmetic control unit 220 described later with reference to FIG.

  Reference numeral 102 denotes a stainless steel metal cap, in which a thermistor (details will be described later) for measuring temperature is housed, and has a liquid tightness. A power ON / OFF switch 103 is turned on when the power supply unit 250 is pressed once, and turned off when pressed again. In an electronic thermometer for hospitals or the like, a magnet reed switch is provided without providing a manual ON / OFF switch such as the power ON / OFF switch 103 in order to provide liquid tightness. For this reason, when the electronic thermometer 100 is taken out of a storage case (not shown) containing a permanent magnet, the magnet reed switch is turned on. Then, until the electronic thermometer 100 is stored in the storage case, power is continuously supplied from the power supply unit 250 of FIG. 2 to the electronic circuit such as the calculation control unit 220, the temperature measurement unit 210, the display unit 230, and the like. The power is turned on. Reference numeral 104 denotes a display unit, and the display window is formed of a transparent thermoplastic resin, and the internal LCD displays the body temperature of the subject. Reference numeral 105 denotes an audio output unit that outputs audio based on processing in the arithmetic control unit 220. In order to have liquid-tightness, the display window and the body case 101 are preferably formed by two-color molding. The main body case 101 is formed of a styrene resin (high impact polystyrene, ABS resin), a polyolefin resin (polypropylene, polyethylene), or the like, which is a thermoplastic material having impact resistance and chemical resistance. Moreover, in order to give an antibacterial property, you may shape | mold so that a silver phosphate silver compound may be contained about 1 to 2.5 weight%.

2. Functional Configuration of Electronic Thermometer FIG. 2 is an internal block diagram showing the functional configuration of the electronic thermometer 100 according to the present embodiment.

  The electronic thermometer 100 outputs a signal corresponding to the temperature, performs various processes based on the signal output from the temperature measurement unit 210, calculates the body temperature of the subject, and also controls the entire electronic thermometer 100. A calculation control unit 220 that controls the operation, a display unit 230 that displays the calculated body temperature of the subject, a voice output unit 240 that outputs voice data, and a power supply unit 250 are provided. A buzzer may be provided in addition to or instead of the audio output unit 240.

  The temperature measuring unit 210 includes a thermistor (measuring resistance element) 213, a reference resistance element 215, a capacitor 214, and a single-input integration type A / D conversion circuit 211. Correspondingly, a digital signal whose ON time changes) is output. Note that the configuration of the temperature measurement unit 210 is not limited to that using such a single-input integration type A / D conversion circuit. For example, a configuration may be used in which a CR oscillation circuit is formed using the thermistor 213 and the capacitor 214 to acquire a signal corresponding to the temperature.

  The arithmetic control unit 220 includes a counter 222 that measures the ON time of the signal output from the temperature measurement unit 210. The counter 222 counts the clock generated by the clock generation unit 228 in the control circuit 221 and measures the ON time based on the obtained count value and the frequency of the clock.

  The arithmetic control unit 220 includes an arithmetic processing unit 223. The arithmetic processing unit 223 calculates a temperature data based on the time measured by the counter 222 by executing a program stored in the ROM 224, and stores the calculated temperature data in the RAM 226 in time series. The body temperature of the subject is predicted based on the temporal change of the temperature data, and the hypothermia measurement process described later is performed. The EEPROM 225 stores predetermined audio data, and the arithmetic processing unit 223 outputs audio data from the audio output unit 105 using the audio data. In addition, the calculation control unit 220 includes a display control unit 227 for controlling the display unit 230 that displays the calculation result in the calculation processing unit 223. The arithmetic control unit 220 further includes a control circuit 221 that controls the counter 222, the display control unit 227, the arithmetic processing unit 223, and the temperature measurement unit 210.

3. Flow of Body Temperature Measurement Processing in Electronic Thermometer 3.1 Overall Flow of Body Temperature Measurement Processing in Electronic Thermometer Next, the flow of body temperature measurement processing in electronic thermometer 100 of the present embodiment having the above-described configuration will be described.

  FIG. 3 is a flowchart showing the flow of the body temperature measurement process in the electronic thermometer 100. Hereinafter, the flow of the body temperature measurement process in the electronic thermometer 100 will be described with reference to FIG. Note that the processing illustrated in FIG. 3 is executed by the arithmetic processing unit 223, for example.

  When the power source 250 of the electronic thermometer 100 is turned on by manual operation of the power ON / OFF switch 103 or a magnet reed switch (not shown) being turned on, in step S301, the electronic thermometer 100 is initialized. Then, temperature measurement by the thermistor 213 which is a temperature measuring element is started. For example, the arithmetic processing unit 223 calculates temperature data at a predetermined time interval, for example, every 0.5 seconds. Next, in step S302, the arithmetic processing unit 223 starts the hypothermia measurement process so that the body temperature of the hypothermic subject can be measured. In the hypothermia measurement process, hypothermia measurement is started based on the temporal change of the actual measurement value detected by the thermistor 213, and the temporal change of the actual measurement value is stable after the hypothermia measurement is started (the rate of change is predetermined). Measurement is complete when it falls within the range. The hypothermia measurement process will be described in detail with reference to FIG. Thereafter, the process of FIG. 3 and the hypothermia measurement process shown in FIG. 4 are executed in parallel. Hereinafter, a value acquired based on a signal from the temperature measurement unit 210 is referred to as an actual measurement value, and a value obtained by predicting an equilibrium temperature based on a change over time of the actual measurement value is referred to as a predicted value.

  In step S303, when the actual measurement value by the thermistor 213 exceeds a predetermined temperature value T0 (for example, 20 ° C.), the process proceeds to step S304, and the arithmetic processing unit 223 causes the display control unit 227 to display the actual measurement value on the display unit 230. . If the measured value does not exceed the predetermined temperature value T0, the process proceeds to step S305. In step S303, it is assumed that the YES branch is made only when the actually measured value first exceeds the temperature value T0, and in other cases, the branch is NO.

  In step S305, the arithmetic processing unit 223 determines whether or not the actual measurement value satisfies the prediction start condition. When it is determined that the actual measurement value satisfies the prediction start condition, the equilibrium temperature prediction process is started in step S306. In step S305, the process is branched to YES only when the prediction condition is satisfied first. Therefore, once the prediction process is activated, the process branches to NO in step S305 regardless of whether or not the actual value prediction condition is satisfied.

  As the prediction start condition, for example, it is determined that the prediction start condition is satisfied when the rate of change of the actual measurement value with time exceeds a predetermined value. More specifically, the degree of increase from the temperature data value calculated by the previous temperature measurement (that is, the temperature data value 0.5 seconds before) is a predetermined value (for example, 1 ° C.) or more. When this happens, the equilibrium temperature prediction process is started. Alternatively, as the prediction start condition, it may be determined whether or not the actually measured value exceeds a predetermined value. For example, when the actual measurement value exceeds a predetermined temperature value T1 (for example, 32 ° C.), the prediction of the equilibrium temperature is started. Furthermore, an AND or OR condition of a plurality of prediction start conditions as described above may be employed. When the prediction process is started in step S306, this prediction process is executed in parallel in addition to the hypothermia measurement process started in step S302.

  Next, in step S307, the arithmetic processing unit 223 determines whether or not the actually measured value has reached a predetermined temperature value T2 (for example, 34 ° C.), and if so, measures the predicted value by the prediction process. Processing proceeds to step S308 for use as a result. In step S308, the arithmetic processing unit 223 stops the hypothermia measurement process started in step S302. In step S309, the arithmetic processing unit 223 switches the display on the display unit 230 by the display control unit 227 to display the predicted value obtained by the prediction process. That is, in S307 to S309, when the measured value exceeds the predetermined temperature value T2, the arithmetic processing unit 223 stops the hypothermia measurement process and switches the display to the predicted value obtained from the prediction process. To finish this processing. As a result, only the body temperature measurement by the prediction process is performed, and the operation is the same as the body temperature measurement by a general equilibrium temperature prediction type electronic thermometer.

  In step S310, the arithmetic processing unit 223 determines whether or not the measurement by the hypothermia measurement process is completed. The case where the measurement by the hypothermia measurement process is completed is a state in which a measurement result by the hypothermia measurement process is obtained (or a state considered to be obtained). Therefore, when it is determined that the measurement by the hypothermia measurement process is completed, the process proceeds to step S311. If the prediction process is activated in step S306, the process is stopped and the process is terminated. As a result, only the hypothermia measurement process shown in FIG. 4 is continued.

3.2 Flow of the hypothermia measurement process in the electronic thermometer Next, the hypothermia measurement process according to the present embodiment will be described with reference to the flowchart of FIG. 4.

  In step S <b> 401, the arithmetic processing unit 223 starts timing by the timer 1. In step S402, it is determined whether or not a predetermined measurement end time (preferably 120 to 240 seconds, in this example, 240 seconds: in order to measure hypothermia as an actual measurement value with higher accuracy) has elapsed by the timer 2 in step S402. To do. Here, when the passage of the measurement end time is detected, the process proceeds to step S410 to forcibly complete the measurement (time up). The processing after step S410 will be described later.

  If the measurement end time has not elapsed, in step S403, the arithmetic processing unit 223 determines whether or not the hypothermia measurement condition is satisfied based on the temporal change of the actual measurement value. For example, when the rate of change of the actual measurement value with time exceeds a positive predetermined value, it is determined that the hypothermia measurement is started. Note that it is preferable that the rate of change used in the hypothermic temperature measurement start condition is smaller than the rate of change used in the above-described prediction start condition (S305). This is because when the subject has hypothermia, the rate of increase in the temperature value is assumed to be smaller than when a normal subject is measured. If the hypothermia measurement start condition is not satisfied, the process returns to step S402.

When the arithmetic processing unit 223 determines that the hypothermia measurement start condition is satisfied, the process proceeds to step S404, and the arithmetic processing unit 223 starts the time measurement by the timer 2. And the arithmetic processing part 223 is after a predetermined time (preferably 40 to 60 seconds, 40 seconds in this example: in order to measure the hypothermia more accurately and accurately as an actual measurement value) has elapsed by the timer 2, It is determined that the hypothermia measurement is completed when the change over time of the actual measurement value falls within a predetermined range (steps S405 and S406). In step S406, for example, when the change in the actual measurement value is 0.02 ° C./8 seconds or less, it is detected that the actual measurement value has been stabilized, that is, it is determined that the hypothermia measurement has been completed. When the stability of the actual measurement value is detected in step S406, the arithmetic processing unit 223 notifies the user of that by the sound output unit 240 or by sounding the buzzer (step S410), and the actual value display is peak-held. (Step S411). By these steps S410 and S411, the hypothermia measurement process is completed, and in the above-described step S310, this state of the hypothermia measurement process is detected.

  On the other hand, when waiting for the timer 2 time-up in step S405 and the temperature stabilization in step S406 to be detected by the timer 1 started in step S401, the arithmetic processing unit 223 advances the process to step S410, Forced to complete measurement. As described above, even when step S410 is executed because the timer 1 has exceeded 240 seconds (YES in S402 and S407), it is determined in step S310 that the hypothermia measurement process has ended. .

  In step S408, the arithmetic processing unit 223 determines whether or not the hypothermia measurement needs to be performed again. In the present embodiment, when the time change of the actual measurement value changes in the negative direction and the rate of decrease exceeds a predetermined value, it is determined that the measurement needs to be repeated. If it is not determined that redo is necessary, the process returns to step S405, and the above-described process is repeated. On the other hand, if it is determined that redo is necessary, the process proceeds to step S409. In step S409, the arithmetic processing unit 223 resets the timer 2 and returns the process to step S402. By such determination of re-execution, even when the user tries to measure the body temperature of the subject and touches the metal cap 102 to increase the actual measurement value, the re-measurement can be performed.

  In addition, when the hypothermia measurement process is started in steps S402 and S407, but the actual measurement value remains at the outside air temperature, or the actual measurement value decreases for some reason, or the hypothermia measurement Since the hypothermia measurement process is forcibly completed when the start condition is satisfied but the temperature is not stable forever, it is possible to avoid a situation where the measurement is not completed indefinitely depending on the measurement condition (environment).

3.3 Flow of Prediction Processing in Electronic Thermometer FIG. 5 is a flowchart for explaining prediction processing by the electronic thermometer 100 of the present embodiment. If it is determined in step S305 that the prediction process start condition is satisfied, the prediction process described below is started. The prediction process is not limited to the following, and a well-known prediction process can be applied.

  In step S501, the timing at which the actually measured value is measured when it is determined that the prediction process start condition is satisfied is set as the reference point (t = 0) for the predicted body temperature calculation. That is, in the prediction process in the electronic thermometer 100, when a rapid temperature rise is measured, it is considered that the subject wears the electronic thermometer 100 at a predetermined measurement site (for example, armpit). Subsequently, in step S502, the acquisition of temperature data is started. More specifically, the output temperature data and the timing at which the temperature data is measured are stored in the RAM 226 as time series data.

  Next, in step S503, the arithmetic processing unit 223 calculates a predicted body temperature using a predetermined prediction formula using the temperature data stored in step S502. That is, the temperature (thermal equilibrium temperature) in a thermal equilibrium state with the external temperature of the thermistor 213 is estimated from the measured temperature data. This estimation process uses the establishment of the body temperature measurement start condition as a reference point (t = 0), and a predetermined period (for example, t = 25 seconds to 45 seconds) after a predetermined time (for example, 25 seconds) has elapsed from the reference point. For 20 seconds). When the display is switched to the predicted value in step S309, the predicted value calculated as the estimated value in the calculation of the predicted body temperature is displayed.

  In step S504, the arithmetic processing unit 223 sets in advance the predicted value over the predetermined interval (for example, 5 seconds) calculated in step S304 in the predetermined period (t = 25 to 45 seconds in this example). It is determined whether or not a prediction establishment condition is satisfied. Specifically, it is determined whether or not the estimated value of the thermal equilibrium temperature in a certain section is within a predetermined range (for example, 0.1 ° C.).

  If it is determined in step S504 that the prediction establishment condition is satisfied, the process immediately proceeds to step S505 to end the temperature measurement and to step S506 to output a sound to the effect that the calculation of the predicted body temperature has been completed. The calculated predicted body temperature is displayed on the unit 230. On the other hand, if it is determined in step S504 that the predetermined period has passed without satisfying the prediction establishment condition, the process proceeds to step S508. In step S508, it is determined that an estimated value has not been obtained even after a predetermined time (t = 45 seconds in this example) has elapsed, and temperature measurement is forcibly terminated. In addition, when it forcibly terminates, the predicted body temperature calculated at that time is displayed on the display unit 230 (step S506). At this time, you may make it alert | report that the body temperature measurement was forcibly terminated using the display part 230 or the audio | voice output part 240 (buzzer).

  In step S507, it is determined whether a body temperature measurement end instruction has been accepted. If it is determined in step S507 that a body temperature measurement end instruction has not been received, the process returns to step S502.

  On the other hand, if it is determined in step S507 that a body temperature measurement end instruction has been received, the power supply unit is turned off. The body temperature measurement end instruction is given by the user, for example, by the power ON / OFF switch 103. Alternatively, it may be determined that the end of the body temperature measurement is instructed when the new body temperature measurement is not performed for a predetermined time. Alternatively, the electronic thermometer 100 is housed in a housing case (not shown) containing a permanent magnet, whereby the magnet reed switch is turned off and the power supply from the power supply unit 250 is turned off.

  FIG. 6 is a view for explaining temperature display by the electronic thermometer 100 of the present embodiment described above. When the body temperature of the subject is measured, the measured value is displayed while the measured value is between the predetermined temperature value T0 (20 ° C.) and the predetermined temperature value T2 (34 ° C.). When the prediction start is determined based on the prediction start condition (in FIG. 6, it is a condition that the actual measurement value exceeds T1), the prediction calculation is started. At this time, the display of the actual measurement value is continued. Thereafter, when the actual measurement value exceeds the predetermined temperature value T2 (34 ° C.), the display on the display unit 230 is switched to the predicted value by the prediction calculation. When the predetermined temperature value does not exceed T2 (34 ° C.) as in the actual measurement value 601, the hypothermia measurement process is continued and the actual measurement value display is continued. If the start of measurement and the stability of the actual measurement value are detected by the hypothermia measurement process, the actual measurement value is notified to the user as the body temperature measurement result (measurement value at the time of hypothermia).

In summary, in the electronic thermometer 100 of the present embodiment,
When the body temperature is equal to or higher than the temperature value T2 (34 ° C. in this example), the operation is the same as that of an electronic thermometer having a normal equilibrium temperature prediction function.
-If the body temperature is higher than the outside air temperature but does not exceed the temperature value T2 (34 ° C in this example), voice output is made when the stability of the measured value is detected (for example, 0.02 ° C / 8 seconds or less) The fact is notified by the sound of the unit 240 or the buzzer, and the actual measurement value at that time is displayed as a measurement result by the hypothermia measurement process.
When the body temperature is the same as the outside air temperature, the state where the hypothermia start condition is not satisfied continues for a predetermined time (in this embodiment, the time by the timer 1), and a voice output is issued to notify the end of the measurement by the hypothermia measurement process. The sound output by the unit 240 or a buzzer is made.
When the body temperature is lower than the outside air temperature, a state that does not satisfy the hypothermia start condition continues for a predetermined time (in this embodiment, the time by the timer 1), and a voice output is issued to notify the end of the measurement by the hypothermia measurement process. The sound output by the unit 240 or a buzzer is made.

  In addition, when a predetermined time (for example, 4 minutes 30 seconds) has elapsed since the prediction start (t = 0), the prediction display may be further switched to the actual measurement display. Furthermore, when a predetermined time (for example, 10 minutes) has elapsed from the start of prediction (t = 0), the measurement value may be held as a 10-minute value.

  As described above, according to the present embodiment, an electronic thermometer capable of measuring the body temperature of a subject in a hypothermic condition while maintaining the function as a predictive thermometer is provided.

Claims (6)

An electronic thermometer having a predicting means for predicting an equilibrium temperature based on a change with time of an actual measurement value of a temperature at a measurement site detected by a temperature measuring element,
A prediction execution means for starting prediction by the prediction means when it is detected that an actual measurement value detected by the temperature sensing element satisfies a prediction start condition;
Display means for displaying the actual measurement value until the actual measurement value exceeds the first temperature value, and displaying the predicted value obtained from the prediction means when the actual measurement value exceeds the first temperature value. When,
After detecting that the change over time of the actual measurement value satisfies a predetermined condition, when detecting that the change over time of the actual measurement value does not exceed the first temperature value and is stable, An informing means for informing that the measurement has been completed ,
Said display unit, when the notification means makes a notification of completion of body temperature measurement, electronic thermometer characterized that you peak hold display of the measured value.   The prediction start condition is that a rate of change with time of an actual measurement value exceeds a predetermined value and / or an actual measurement value exceeds a second temperature value of 32 ° C. Item 2. The electronic thermometer according to Item 1.   3. The electronic thermometer according to claim 1, wherein the notification unit stops its function when an actual measurement value exceeds 34 ° C. which is the first temperature value. 4.   When the notification means detects that the change in measured value with time satisfies the predetermined condition, and after a predetermined time has elapsed from the detection, the rate of change in the measured value with time falls within a predetermined range The electronic thermometer according to any one of claims 1 to 3, wherein the completion of the body temperature measurement is notified to the user.   The informing means detects a change rate of the actual measurement value over time in a negative direction before the body temperature measurement is completed after detecting that the actual change of the actual measurement value satisfies the predetermined condition. 5. The electronic thermometer according to claim 4, wherein if it exceeds, the operation from the process of detecting that the change with time of the actual measurement value satisfies the predetermined condition is redone. A method of controlling an electronic thermometer having a prediction function for predicting an equilibrium temperature based on a change over time of an actual measurement value of a temperature at a measurement site detected by a temperature measuring element,
A prediction execution step of starting prediction by the prediction function when it is detected that the actual measurement value detected by the temperature detecting element satisfies a prediction start condition;
The actual measurement value is displayed until the actual measurement value exceeds the first temperature value. When the actual measurement value exceeds the first temperature value, the actual measurement value is obtained from the prediction function started in the prediction execution step. A display process for displaying the predicted value,
When it is detected that the change over time of the actual measurement value satisfies a predetermined condition, it is detected that the change over time of the actual measurement value is stable without exceeding the first temperature value. A notification step for notifying that the measurement has been completed ,
Wherein in the display step, the notification when the notification of completion of body temperature measurement is performed in step, the electronic clinical thermometer control method characterized by peak hold to Rukoto display of the measured value.

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