JP2015111049A - Electronic thermometer and control method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend a battery life without cost by exerting a more appropriate power control depending on a use state of an electronic thermometer.SOLUTION: A temperature change of an electronic thermometer is detected, and it is determined based on the temperature to be detected whether the electronic thermometer that is already turned on and that is in a state of a body temperature measurement mode is in a state in which the electronic thermometer is to measure a body temperature in the body temperature measurement mode. If a determination result indicates that the electronic thermometer is not in the state in which the electronic thermometer is to measure the body temperature in the body temperature measurement mode, the body temperature measurement mode transitions to a low current consumption mode in which the electronic thermometer is actuated at lower power than power consumption in the body temperature measurement mode.

Description

  The present invention relates to an electronic thermometer.

  Hospital thermometers may be sterilized by immersing them in chemical solutions to prevent infection. Therefore, the thermometer is sealed so that the chemical solution does not enter the thermometer. Then, using a magnet reed switch, the power is turned on and off by putting the thermometer in and out of the storage case. Here, since the thermometer is formed of a sealed casing, it has a specification that the battery cannot be replaced.

  However, if the thermometer is left in the state of being taken out of the storage case, the battery is consumed because it is always energized.

  In view of this, in this type of thermometer, the power is automatically turned off after a predetermined time has elapsed, or a switch is applied to the external housing portion of the thermometer, so that a transition to low current consumption is made.

  For example, Patent Document 1 discloses a configuration in which when the temperature is low, it is determined that there is time until the next temperature detection, and the current consumption is reduced by dropping the clock.

JP 2010-230579 A

  However, in the conventional configuration, if the auto power is turned off, the temperature measurement result is not known. On the other hand, it is also possible to store the temperature measurement result as the previous value, but if the specification is to display the previous value for a long time at the next measurement, there is a possibility of being confused with the next temperature measurement result, There are inconveniences such as being unable to display a display outside the measurement environment range. For this reason, at present, the specification is such that the display cannot be performed for a long time (the display is switched to the next display in a few seconds), and therefore the accurate temperature measurement result cannot be transferred or grasped. Furthermore, in order to attach a switch to the external casing portion of the thermometer, a mechanism for maintaining liquid tightness is required, which is a costly factor.

  Moreover, in the structure of patent document 1, the consumption current at the time of temperature detection is reduced by controlling the operation clock according to the temperature value at the time of temperature detection. Accordingly, no consideration is given to the reduction of current consumption when the start time until the temperature measurement is delayed for some reason, or when the temperature is not stored in the storage case after the temperature detection.

  Normally, thermometers for hospitals assume that the temperature measurement starts immediately after being taken out of the storage case, so immediately after being taken out of the storage case, the sampling state at the time of temperature measurement (measurement mode) It has become. That is, the hospital thermometer is not devised to reduce the current consumption during the time period until the thermometer is started or until the thermometer is stored in the storage case after the end of the temperature measurement.

  Further, from the viewpoint of maintaining and effectively utilizing the temperature measurement result, it is desirable that the thermometer is turned on with low power enough to maintain the temperature measurement result even after the time period until auto power off works. .

  The present invention has been made in view of the above problems, and by performing more appropriate power control according to the usage state of the electronic thermometer, an electronic thermometer that can improve the battery life without cost, and An object is to provide a control method thereof.

In order to achieve the above object, an electronic thermometer according to the present invention has the following configuration. That is,
An electronic thermometer,
Detecting means for detecting a temperature change of the electronic thermometer;
Determining whether or not the electronic thermometer in which the power is already turned on and in the body temperature measurement mode is in a state where body temperature measurement should be performed in the body temperature measurement mode based on the temperature change detected by the detection means Means,
As a result of the determination by the determination means, when it is determined that the electronic thermometer is not in a state where the body temperature measurement mode should not be measured, the body temperature measurement mode is operated at a power lower than the power consumption in the body temperature measurement mode. And a transition means for transitioning to the low current consumption mode.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic thermometer which can improve a battery life without cost, and its control method can be provided by performing more appropriate electric power control according to the use condition of an electronic thermometer.

It is a figure which shows the external appearance of the electronic thermometer of this embodiment, and its storage case. It is an internal block diagram which shows the function structure of the electronic thermometer of this embodiment. It is a flowchart which shows the body temperature measurement process in an electronic thermometer. It is a figure which shows the detailed structure of a temperature measurement part. It is a flowchart which shows the detail of a temperature measurement process. It is a figure which shows the time change of the voltage of the both ends of a capacitor | condenser, and the time change of the digital signal output from an A / D conversion part. It is a flowchart which shows the electric power control process of an electronic thermometer. It is a figure which shows the mode of the temperature change accompanying a series of usage condition (time passage) of an electronic thermometer. It is a figure which shows the example of a display of the display part at the time of low power consumption mode.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings as necessary. The embodiments described below are preferred specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these embodiments.

<1. External structure of electronic thermometer>
FIG. 1 is a diagram showing the external appearance of an electronic thermometer and its storage case according to this embodiment.

  As shown in FIG. 1A, the storage case 120 includes a storage portion 122 that is a container body and a lid portion 121 that serves as a cap member. The storage case 120 is made of plastic. The lid 121 is attached to the storage unit 122 via the rotation unit 15 and is rotated by the rotation unit 15 to allow the storage case 120 to be opened and closed. If the lid 121 is formed of, for example, a transparent member, it can be immediately recognized whether or not the electronic thermometer 100 (FIG. 1B) is stored in the storage case 120. A window 13 is provided on the top panel of the storage unit 122. The user can view the display unit 104 of the electronic thermometer 100 stored in the internal space of the storage case 120 from the outside. The user can know whether or not the electronic thermometer 100 is stored in the storage case 120 through the window 13. However, when the lid 121 is made transparent as described above, the window 13 can be omitted.

  As shown in FIG. 1B, when the lid 121 is rotated, the opening 14 for inserting and removing the electronic thermometer 100 into the internal space of the storage unit 122 is exposed. When the electronic thermometer 100 is stored in the storage case 120, the electronic thermometer 100 is inserted into the internal space of the storage unit 122 from the end cap 103 side. For example, the storage unit 122 is obtained by integrally molding an upper panel, a lower panel, and a side panel by injection molding. The storage portion 122 is formed of an impact-resistant thermoplastic resin, for example, a styrene resin such as a high impact styrene resin or an ABS resin.

  In FIG. 1B, the storage case 120 is configured to store one electronic thermometer 100, but is not limited thereto. For example, as shown in FIG. 1C, a storage case that can store a plurality of electronic thermometers 100 (units such as 2, 4, 6, 8, 10, etc.) may be used. In particular, FIG. 1C shows an example of a storage case that can store ten electronic thermometers 100 in a two-row configuration, with five in each row.

  Next, an external configuration of the electronic thermometer 100 according to the present embodiment will be described with reference to FIG. FIG. 1B shows an external perspective view of the electronic thermometer 100 according to the present embodiment, together with a conceptual diagram for inserting the electronic thermometer 100 into the storage portion 122.

  In FIG. 1B, reference numeral 101 denotes a main body housing (housing 101) of the electronic thermometer 100. The casing 101 is made of an impact-resistant thermoplastic resin, such as a high-impact styrene resin or ABS resin. Reference numeral 103 denotes an end cap. The end cap 103 is covered with a metal such as stainless steel so that the body temperature of the subject can be easily conducted to the built-in temperature measurement unit. A temperature measuring unit such as a thermistor for measuring temperature is housed in the end cap 103 and has liquid tightness. A display unit 104 displays data such as body temperature data as a body temperature measurement result, and is covered with a window member 104a formed of a transparent thermoplastic resin. The window member 104a is two-color molded with the housing 101 and has high liquid tightness.

<2. Functional structure of electronic thermometer>
FIG. 2 is an internal block diagram showing a functional configuration of the electronic thermometer 100 of the present embodiment.

  The electronic thermometer 100 according to the present embodiment has, as its operation mode, power consumption in a period when it is determined that the electronic thermometer 100 is left in addition to a normal body temperature measurement mode for measuring the body temperature of the subject. It has a low current consumption mode to reduce. This low current consumption mode is a mode in which operation is performed with lower power than that in the body temperature measurement mode.

  The electronic thermometer 100 calculates a body temperature of the subject by performing various processes based on the temperature measurement unit 210 that outputs an ON signal for a time corresponding to the temperature, and the ON signal output from the temperature measurement unit 210. And an arithmetic control unit 220 that controls the operation of the entire electronic thermometer 100. Further, the electronic thermometer 100 includes a display unit 104 that displays the calculated body temperature of the subject, an audio output unit 240 that outputs audio data, a power supply unit 250, and a sensor unit 260.

  The display unit 104 includes a liquid crystal display unit for displaying measurement information such as body temperature, for example. In addition to the measurement information, the display unit 104 can display status information of the electronic thermometer 100 (for example, a low current consumption mode, a body temperature measurement mode, etc.).

  The temperature measurement unit 210 includes a thermistor (measuring resistance element) and a reference resistance element, which are arranged inside the end cap 103 and connected in parallel to each other, and a single input integration type A / D conversion circuit. Then, the temperature measurement unit 210 outputs an ON signal corresponding to the temperature (a digital signal that changes the ON time corresponding to the temperature). The detailed configuration of the temperature measurement unit 210 and the details of the temperature measurement process will be described later. In this embodiment, the integration method is adopted as the temperature measurement method of the temperature measurement unit 210. However, the present invention is not limited to this, and other methods such as a CR oscillation method using a CR oscillation circuit are used. It may be used.

  The arithmetic control unit 220 includes a timer 222 that measures the ON time of the digital signal output from the temperature measurement unit 210. The timer 222 can also measure the time since the power supply unit 250 is turned on. As described above, the arithmetic control unit 220 can control ON / OFF and reset of the timer 222 according to a predetermined condition. Therefore, the arithmetic control unit 220 can switch between the body temperature measurement mode and the low current consumption mode based on the measurement time of the timer 222 as a predetermined condition.

  The arithmetic control unit 220 includes a ROM 224, an EEPROM 225, and a RAM 226. The ROM 224 stores a program for calculating temperature data based on the time measured by the timer 222 and predicting and calculating the body temperature of the subject based on the time change of the calculated temperature data. The RAM 226 stores the calculated temperature data in time series. The EEPROM 225 stores predetermined audio data, calibration values, sample numbers, error information, the number of measurements, and the like.

  In addition, the arithmetic control unit 220 performs arithmetic operations according to programs stored in the ROM 224 and outputs audio data, and a display for controlling the display unit 104 that displays arithmetic results in the arithmetic processing unit 223. A control unit 227 is provided. Furthermore, the calculation control unit 220 includes a control circuit 221 that controls the timer 222, the display control unit 227, the calculation processing unit 223, the temperature measurement unit 210, and the sensor unit 260.

  The sensor unit 260 is a sensor for detecting the state of the electronic thermometer 100. This sensor includes a temperature sensor that detects the environmental temperature of the electronic thermometer 100, an acceleration sensor that detects a physical external force (tilt and vibration) acting on the electronic thermometer 100, a tilt / vibration switch, and an object to the electronic thermometer 100. There are contact centers that detect contact. These sensors are used to detect the state of a thermometer that has transitioned to the low current consumption mode to return to the normal body temperature measurement mode, and the necessary sensors are mounted appropriately according to the specifications. Will do.

  Instead of mounting a temperature sensor on the sensor unit 260, the temperature measuring unit 210 can also detect the environmental temperature of the electronic thermometer 100.

  The electronic thermometer 100 is provided with a magnet reed switch (not shown). For this reason, when the electronic thermometer 100 is taken out of the storage case 120, the magnet reed switch is turned on, and power is continuously supplied from the power supply unit 250 to various components such as the arithmetic control unit 220, the temperature measurement unit 210, and the display unit 104. It will be. And if the electronic thermometer 100 is accommodated in the storage case 120 containing a permanent magnet, supply of a power supply will be interrupted | blocked and a power supply will be in an OFF state.

<3. Body temperature measurement processing with electronic thermometer>
First, the body temperature measurement process in the electronic thermometer executed in the body temperature measurement mode will be described. Here, although the temperature measurement process of the electronic thermometer 100 of the equilibrium temperature prediction type will be described, the present invention is not limited to this, and can be applied to an actual measurement type electronic thermometer and a prediction / measurement type electronic thermometer. .

  When the electronic thermometer 100 is attached to the measurement site of the subject, the electronic thermometer 100 starts temperature measurement at a predetermined cycle (sampling rate), and the subject is based on the time change of the acquired temperature data. The body temperature is predicted.

  FIG. 3 is a flowchart showing a body temperature measurement process in the electronic thermometer 100.

  When the power supply unit 250 of the electronic thermometer 100 is turned on, the electronic thermometer 100 is initialized in step S301, and temperature measurement by the thermistor is started. For example, the arithmetic processing unit 223 calculates temperature data as a sampling rate for measuring body temperature at a predetermined interval, for example, every 0.5 seconds.

  In step S302, it is determined whether a body temperature measurement start condition is satisfied. Specifically, whether or not the degree of increase from the value of the temperature data calculated by the previous temperature measurement (that is, the value of the temperature data 0.5 seconds before) has become a predetermined value (for example, 1 ° C.) or more. Determine whether.

  When it is determined that the degree of increase is equal to or greater than a predetermined value, it is determined that the body temperature measurement start condition is satisfied, and the timing at which the temperature data is measured is set as a reference point (t = 0) for predictive body temperature calculation. That is, 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).

  If it is determined in step S302 that the body temperature measurement start condition is satisfied (YES in step S302), the process proceeds to step S303, and temperature data acquisition is started. 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. On the other hand, if it is determined that the body temperature measurement start condition is not satisfied (NO in step S302), the process waits until it is determined that the body temperature measurement start condition is satisfied. Alternatively, when a predetermined time or more has elapsed, a low-consumption current mode described later may be entered as a measurement error.

  In step S304, the predicted body temperature is calculated by a predetermined prediction formula using the temperature data stored in the RAM 226 in step S303.

  In step S305, a predetermined value (for example, t = 25 to 30 seconds) calculated in step S304 is set in advance after a predetermined time (for example, 25 seconds) has elapsed from the reference point (t = 0). It is determined whether or not the predicted establishment condition is satisfied. Specifically, it is determined whether or not the predicted value is within a predetermined range (for example, 0.1 ° C.).

  If it is determined in step S305 that the prediction establishment condition is satisfied (YES in step S305), the process proceeds to step S306, and the temperature measurement is terminated. Next, in step S307, a sound indicating that the calculation of the predicted body temperature has been completed is output, and the calculated predicted body temperature is displayed on the display unit 104 as the body temperature of the measured value.

  On the other hand, if it is determined in step S305 that the prediction satisfaction condition is not satisfied (NO in step S305), the process proceeds to step S309. In step S309, it is determined whether a predetermined time (for example, 45 seconds) has elapsed from the reference point (t = 0). If it is determined that the time has elapsed, the temperature measurement is forcibly terminated. If the forced termination is performed, the predicted body temperature calculated at that time is displayed on the display unit 104 (step S307).

  When the electronic thermometer 100 is stored in the storage case 120 after step S307, that is, after predictive temperature detection is established, the magnet reed switch of the electronic thermometer 100 is turned off and the power supply from the power supply unit 250 is turned on. It is turned off.

<4. Detailed configuration of temperature measurement unit>
FIG. 4 is a diagram illustrating a detailed configuration of the temperature measurement unit 210.

  As shown in FIG. 4, in the temperature measurement unit 210, the thermistor 401 and the reference resistance element 402 are each connected to a capacitor 403. The capacitor 403 is charged to the voltage V from the voltage switching unit 410 via the thermistor 401 or the reference resistance element 402, but may be charged via a charging resistance element (not shown). Next, the electric charge charged in the capacitor 403 is caused by dropping the voltage switching unit 410 connected to the thermistor 401 to the GND level, or dropping the voltage switching unit 410 connected to the reference resistance element 402 to the GND level. , And are discharged through the thermistor 401 and the reference resistance element 402, respectively. In discharging, the output of the voltage switching unit 410 that is not used for discharging is switched to high impedance.

  Here, the reference resistance element 402 is a resistance element having a constant resistance value regardless of variations in ambient temperature. For this reason, when the voltage V is constant, the discharge time when discharged through the reference resistance element 402 is constant.

  On the other hand, the thermistor 401 is a resistance element whose resistance value varies according to variations in ambient temperature. For this reason, the discharge time when discharged via the thermistor 401 varies according to the ambient temperature.

  That is, when the voltage V is constant, the discharge time is always constant when the voltage V is discharged through the reference resistance element 402, and when the voltage V is discharged through the thermistor 401, the discharge time is It depends on the temperature.

  The amount of charge accumulated in the capacitor 403 is detected via the A / D conversion unit 420. The comparator 421 that constitutes the A / D conversion unit 420 is used while the capacitor 403 has a voltage equal to or higher than a voltage (here, 0.25 V) of a predetermined ratio of the voltage V applied via the voltage switching unit 410. , A predetermined signal is output. As a result, the A / D converter 420 outputs an ON signal as a digital signal.

  As described above, the capacitor 403 and the A / D conversion unit 420 form a single input integration type A / D conversion circuit.

  As a result of the discharge, the voltage across the capacitor 403 gradually decreases. When the voltage drops below a predetermined voltage (0.25 V), the digital signal output from the A / D converter 420 becomes an OFF signal.

  The timer 222 measures the ON time (discharge time) of the digital signal output from the A / D conversion unit 420.

  Here, as described above, when discharging is performed through the reference resistance element 402, the discharge time is constant. On the other hand, when discharged through the thermistor 401, the resistance value fluctuates according to the ambient temperature, so the discharge time also fluctuates.

  Therefore, the electronic thermometer 100 measures the discharge time when the charge accumulated in the capacitor 403 is discharged through the thermistor 401 in a state where the ambient temperature is known (reference temperature). In addition, the electronic thermometer 100 measures the discharge time when the charge accumulated in the capacitor 403 is discharged through the reference resistance element 402.

  As a result, only the discharge time when the charge accumulated in the capacitor 403 is discharged via the reference resistance element 402 is compared with the discharge time when the charge accumulated in the capacitor 403 is discharged via the thermistor 401. Thus, the fluctuation ratio with respect to the reference temperature can be calculated. Temperature data can also be calculated.

  Specifically, the normalized discharge time T at the measured temperature is calculated based on the following equation. In the memory, a table representing the correspondence relationship between the discharge time and the temperature is recorded, and the normalized discharge time T is converted into temperature by comparing with the table.

T = T37 × (Tth / Tref) × (Tref37 / Tth37)
In the above formula, the reference temperature is 37 ° C. Further, Tref37 indicates a discharge time measured when discharging is performed through the reference resistance element 402 at the reference temperature. Further, Tth37 indicates a discharge time measured when discharging is performed via the thermistor 401 at the reference temperature.

  Further, Tref indicates a discharge time measured when discharging is performed through the reference resistance element 402 in the temperature measurement process. Further, Tth indicates a discharge time measured when discharging is performed through the thermistor 401 in the temperature measurement process. T37 indicates a discharge time obtained when a resistance value serving as a reference for normalization is used at the reference temperature.

<5. Details of temperature measurement process>
FIG. 5 is a flowchart showing details of the temperature measurement process. FIG. 6 is a diagram showing the time change of the voltage across the capacitor 403 and the time change of the digital signal output from the A / D converter 420. A general temperature measurement process will be described with reference to FIGS. 5 and 6.

  In step S501, the capacitor 403 is charged. Reference numeral 601 in FIG. 6 indicates a period (charge period) in which charges are gradually accumulated in the capacitor 403.

  When the charging of the capacitor 403 is completed, the capacitor 403 is discharged in step S502 (discharge period 602). At this time, since the ON signal is output from the A / D conversion unit 420 (603), the timer 222 measures the time of the ON signal. As a result, the time (discharge time 604) Tref from when the discharge is started until the voltage of the capacitor 403 becomes equal to or lower than a predetermined voltage (here, 0.25 V) is measured (see 602 in FIG. 6).

  When the discharge of the capacitor 403 is completed, the capacitor 403 is charged again in step S503. Reference numeral 605 in FIG. 6 indicates a period (charge period) in which charges are gradually accumulated in the capacitor 403.

  When the charging of the capacitor 403 is completed, the capacitor 403 is discharged in step S504 (discharge period 606). At this time, since the ON signal is output from the A / D conversion unit 420 (607), the timer 222 measures the time of the ON signal. Thereby, the time (discharge time 608) Tth from the start of discharge until the voltage of the capacitor 403 becomes equal to or lower than a predetermined voltage (here, 0.25 V) is measured. Tth varies depending on the ambient temperature of the thermistor 401.

  When the discharge of the capacitor 403 is completed, in step S505, T = a × Tth / Tref (where a is a coefficient, where a = T37 × (Tref37 / Tth37)) is calculated to calculate the reference temperature. The fluctuation ratio is obtained and the standardized discharge time is calculated. In step S506, the normalized discharge time T is converted into a temperature measurement result.

  Thereby, one temperature measurement is completed. The temperature measurement process is repeatedly performed until the end of temperature measurement is instructed.

<6. Power control with low current consumption mode function>
Next, power control processing for reducing the power consumption of the electronic thermometer 100 by adaptively switching between the low current consumption mode (power saving mode) and the body temperature measurement mode, which is a characteristic configuration of the present embodiment. explain.

Normally, when the electronic thermometer 100 is taken out of the storage case 120, preparation for the body temperature measurement process of FIG. On the other hand, in this embodiment, assuming the following factors, the body temperature measurement mode is shifted to the low current consumption mode. Transition conditions for shifting to the low current consumption mode are as follows: 1. When the electronic thermometer 100 is left before the start or establishment of the temperature measurement. 2. When the temperature is soaked in the chemical solution or the electronic thermometer 100 is washed. It is assumed that the temperature has been measured at the rounds, but a certain period of time has passed (or left) before the health care workers (nurses, etc.) come to collect. Of course, it is possible to assume various factors other than the above and use them as the transition conditions. In other words, when the electronic thermometer 100 is not in a state where temperature measurement should not be performed in the body temperature measurement mode, the electronic thermometer 100 shifts to the low current consumption mode.

On the other hand, after shifting to the low current consumption mode, as a return condition for returning from the low current consumption mode to the body temperature measurement mode,
1. When a temperature change is detected,
2. If an interrupt to trigger a return is detected,
Assume a combination of 3.1 and 2.

  The “temperature change:” in the return condition 1 means a case where the temperature of the surrounding environment of the electronic thermometer 100 is increased or the fluctuation range of the temperature in a constant temperature state is collapsed by a certain amount. In addition to the detection by the temperature measurement unit 210, it can be realized by a dedicated temperature sensor separately mounted on the sensor unit 260.

  The “interrupt for triggering the return” in the return condition 2 is, for example, calculation control when an acceleration sensor, a tilt switch, or a vibration switch mounted on the sensor unit 260 detects the tilt or vibration of the electronic thermometer 100. This means interruption by a signal issued to the unit 220. Alternatively, it means an interruption by a signal issued to the arithmetic control unit 220 when a contact sensor mounted on the sensor unit 260 detects contact with the electronic thermometer 100. In any case, the transition to the body temperature measurement mode is made based on the presence or absence of an output from a sensor that can detect the situation to transition to the body temperature measurement mode.

  Based on the above premise, the power control process for realizing the low current consumption of the present embodiment will be described with reference to FIG.

  FIG. 7 is a flowchart showing power control processing of the electronic thermometer.

  In step S701, a magnet reed switch (not shown) of the electronic thermometer 100 is turned on, so that the power supply unit 250 of the electronic thermometer 100 is turned on. At this time, the electronic thermometer 100 shifts to the body temperature measurement mode. The power consumption at this time is, for example, about 60 μW.

  In step S702, it is determined whether or not the electronic thermometer 100 has been left for a first predetermined time (for example, 10 minutes). When it is determined that the electronic thermometer 100 has been left for the first predetermined time (YES in step S702), the process proceeds to step S712, and it is determined that the first condition is satisfied. Here, the first condition is a case where the temperature measurement unit 210 is left after the start of temperature measurement. For example, the determination of whether or not the temperature measurement is performed may be performed by, for example, temperature change of the temperature measurement unit 210 (steepness of temperature gradient or a constant temperature state). Judgment is made by monitoring (temperature rise / fall). Then, it progresses to step S709 and transfers to a low consumption current mode.

  Here, an example of a temperature change as a transition condition will be described with reference to FIG.

  FIG. 8 is a diagram illustrating a state of temperature change with a series of usage modes (elapsed time) of the electronic thermometer.

  In FIG. 8, after measuring the body temperature of the subject, the electronic thermometer 100 is wiped with alcohol absorbent cotton, then the body temperature of another subject is measured, washed with water, and the body temperature of another subject is further measured. It shows the temperature change when the electronic thermometer 100 is left after the measurement, after being put into the drug solution, and after measuring the body temperature of another subject.

  When the electronic thermometer 100 is taken out from the storage case 120 and measurement of the body temperature of the subject is started, the temperature gradient rises according to the body temperature to be measured, and when reaching the body temperature of the subject, the temperature enters a constant temperature state. To establish. Thereafter, when the electronic thermometer 100 is collected from the subject and wiped with alcohol absorbent cotton, the temperature gradient suddenly drops due to a rapid temperature drop due to heat of vaporization (A region in the figure).

  Thereafter, when the measurement of the body temperature of another subject is started, the temperature is measured through a similar temperature change, and the electronic thermometer 100 is recovered from the subject and washed with water. Is deprived, and the temperature gradient drops relatively rapidly (B region in the figure).

  Thereafter, when the measurement of the body temperature of another subject is started, the temperature is measured through the same temperature change, and when the electronic thermometer 100 is collected from the subject and immersed in the chemical solution, the temperature is close to the temperature of the chemical solution. The temperature of the electronic thermometer 100 becomes constant (C region in the figure).

  Thereafter, when the measurement of the body temperature of another subject is started, the temperature is measured through the same temperature change, and the electronic thermometer 100 is collected from the subject and left to stand. The temperature gradually decreases with the temperature gradient (D region in the figure).

  By detecting the state of the A region to the D region as described above by the temperature measurement unit 210, it is possible to determine the transition condition for shifting to the low current consumption mode. Specifically, a temperature change value indicating a temperature change within a certain time (for example, a steepness or inclination of a temperature gradient, a temperature difference), a threshold value corresponding to each situation (A region to D region), and temperature measurement. The determination is made using the temperature change value within a predetermined time obtained by the measurement of the unit 210. That is, when the temperature change value does not exceed the threshold value, it is determined that the electronic thermometer 100 is not in a state where temperature measurement should be performed in the body temperature measurement mode, and the mode is shifted to the low current consumption mode. On the other hand, when the temperature change value exceeds the threshold value, the electronic thermometer 100 determines that the body temperature measurement is to be performed in the body temperature measurement mode, and shifts to the body temperature measurement mode.

  Returning to the description of FIG.

  When it is determined that the electronic thermometer 100 has not been left for the first predetermined time (NO in step S702), the process proceeds to step S703, and it is determined whether or not temperature measurement is started. If it is determined that the temperature measurement is not started (NO in step S703), the process returns to step S702. On the other hand, when it is determined that the temperature detection is started (YES in step S703), the process proceeds to step S704, and it is determined whether or not the temperature detection is established. If it is determined that the temperature detection is not established (NO in step S704), the process returns to step S702. On the other hand, if it is determined that the temperature detection is established (YES in step S704), the process proceeds to step S705.

  The processes in steps S703 and S704 correspond to the body temperature measurement process (body temperature measurement mode) in FIG.

  Next, it is determined whether or not the electronic thermometer 100 has been charged (immersed) in the chemical solution. If it is determined that it is not put in the chemical (NO in step S705), it is determined in step S706 whether or not the electronic thermometer 100 has been left for a second predetermined time (for example, 3 minutes). If it is determined that the electronic thermometer 100 has not been left for the second predetermined time (NO in step S706), the process returns to step S705. On the other hand, when it is determined that the electronic thermometer 100 has been left for the second predetermined time (YES in step S706), the process proceeds to step S708, and it is determined that the second condition is satisfied. Here, the second condition is when the electronic thermometer 100 is left after the temperature measurement is established, that is, when the temperature measurement unit 210 detects the state of the D region in FIG. Then, it progresses to step S709 and transfers to a low consumption current mode.

  On the other hand, if it is determined that the chemical has been added (YES in step S705), the process proceeds to step S711, where it is determined that the third condition is satisfied. Here, the third condition is when the electronic thermometer 100 is immersed in the chemical solution, that is, when the temperature measurement unit 210 detects the state of the region C in FIG. Then, it progresses to step S709 and transfers to a low consumption current mode.

  Here, it is described that the determination that it has been introduced into the chemical solution is performed after the temperature detection is established (YES in step S704). However, even before the temperature measurement is established, the determination is made that the predetermined condition is satisfied. It is also possible to shift to the low current consumption mode.

  In the above embodiment, the transition to the low current consumption mode is performed using the temperature change detected by the temperature measurement unit 210, but the physical external force (inclination) acting on the electronic thermometer 100 detected by the sensor unit 260. It is also possible to shift to the low current consumption mode by determining whether or not to leave.

  As described above, the low current consumption mode is a mode in which power consumption of the power supply unit 250 is reduced to a power lower than the power consumption in the body temperature measurement mode. At this time, for example, power consumption is about 10 μW to 30 μW. Although a specific method for realizing low power consumption will be described later, power consumption varies depending on the method. Note that more power can be saved by performing a plurality of methods simultaneously.

  After shifting to the low current consumption mode, in step S710, it is determined whether or not the current state of the electronic thermometer 100 satisfies the return condition as described above. If it is determined that the return condition is not satisfied (NO in step S710), the process returns to step S709. On the other hand, when it is determined that the return condition is satisfied (YES in step S710), the low current consumption mode is returned to the body temperature measurement mode, and the process returns to step S702.

<7. Specific example of low current consumption mode>
Specific methods for realizing low current consumption include the following, for example.

    A. Increase the measurement interval (sampling rate). For example, the sampling rate is changed from 0.5 second in the body temperature measurement mode to 1 second, 2 seconds, 5 seconds, 10 seconds, and so on.

    B. Temperature measurement (sampling) is stopped, and the display on the display unit 104 is fixed at the temperature at the time of measurement. Fixing this display means displaying / blinking / inverting an indicator (specific image, mark, text string) indicating that the measurement is stopped, or changing the background color / brightness or blacking out. Etc.

    C. The temperature measurement (sampling) does not stop, but the display content on the display unit 104 blinks / extinguishes (reduction of current consumption necessary for display).

    D. The operating frequency of the electronic thermometer 100 is slowed (the slower the operating frequency, the smaller the current consumption).

    E. Reduce the resolution of temperature measurements.

        For example, when the measurement method shown in FIG. 4 is an integration method, the current consumption during charging can be reduced by reducing the capacitance of the capacitor 403 or by switching the capacitor 403 to be selected according to temperature by having a plurality of capacitors 403. . Alternatively, by increasing the threshold value of the comparator 421 (for example, from 0.25 Vcc to 0.5 Vcc), the discharge time is shortened, and as a result, current consumption can be reduced.

        In the case of the CR oscillation method, current consumption can be suppressed by shortening the gate length of the circuit element (transistor) constituting the CR oscillation circuit.

    F. Stop measuring the reference resistance element. At the timing when no strict temperature measurement is required, the measurement is stopped because the discharge time of the reference resistance element is substantially constant. Then, the value of the discharge time of the reference resistance element measured last time is used.

  The low current consumption is realized by combining the items A to F as described above alone or in combination. Of course, these items are only examples, and it is needless to say that the items are not limited to these items as long as low current consumption can be achieved. A configuration necessary for achieving low current consumption may be employed as appropriate in accordance with the application and purpose.

  However, as described above, even if the electronic thermometer 100 is left after the temperature measurement, it is desirable to store the temperature measurement result in the RAM 226 as the previous value so that the latest temperature measurement result can be confirmed immediately. By doing in this way, even in the low current consumption mode, the latest temperature measurement result (previous value) stored in the RAM 226 can be fixedly displayed on the display unit 104.

  Here, FIG. 9 shows a display example of the display unit 104 in the low power consumption mode in such a case.

  In FIG. 9, the display unit 104 displays an index 901 indicating the body temperature measurement mode, an index 902 indicating the low current consumption mode, and a temperature value 903 to be displayed in each mode. In FIG. 9, an underline image is displayed under the index 901 or the index 902 to indicate which mode is the current mode. FIG. 9 shows a case where the current state is the low current consumption mode.

  In the low current consumption mode, the temperature value 903 which is the latest temperature detection result (previous value) stored in the RAM 226 is displayed. On the other hand, in the body temperature measurement mode, the measured temperature may be displayed. Usually, the electronic thermometer 100 is attached to the subject's armpit, and the subject himself / herself displays the display unit 104. Since it is not easy to visually recognize the temperature, it is not always necessary to display the temperature during the temperature measurement. To the last, in the body temperature measurement mode, it is sufficient that the finally determined temperature value is displayed when the temperature measurement is established.

  As described above, according to the present embodiment, the state of the electronic thermometer (stand, immersion, etc.) is determined by monitoring the temperature change within a certain time, and the body temperature is measured according to the determination state. Transition from mode to low current consumption mode. Thereafter, when the state of the electronic thermometer is in a state where the temperature should be measured, the state quickly shifts to the body temperature measurement mode. Thereby, according to the use state of an electronic thermometer, mode switching can be performed adaptively, the power saving of an electronic thermometer, in other words, improvement of a battery life can be aimed at.

<Other embodiments>
In the above embodiment, the configuration for switching the mode between the body temperature measurement mode and the low current consumption mode has been described, but the present invention is not limited to this. Further, in addition to these modes, a conventional auto power-off may be made to function. For example, when the mode is left for a long time (for example, 3 hours or more) after shifting to the low current consumption mode, the auto power off function may be operated to further reduce power consumption.

  Further, in FIG. 9, the display unit 104 is configured to display an index indicating whether the body temperature measurement mode or the low current consumption mode and the temperature to be displayed in each mode are displayed. It is not limited to. For example, the voice output unit 240 may provide voice guidance of which mode is the current mode and the temperature to be output in each mode. However, in this case, a configuration for outputting sound is required. For example, by providing an acceleration sensor or a contact sensor in the sensor unit 260 to give vibration or contact to an object to the electronic thermometer 100, mode information indicating a mode at that time and a temperature to be output corresponding to the mode Information may be output by voice.

Claims (16)

An electronic thermometer,
Detecting means for detecting a temperature change of the electronic thermometer;
Determining whether or not the electronic thermometer in which the power is already turned on and in the body temperature measurement mode is in a state where body temperature measurement should be performed in the body temperature measurement mode based on the temperature change detected by the detection means Means,
As a result of the determination by the determination means, when it is determined that the electronic thermometer is not in a state where the body temperature measurement mode should not be measured, the body temperature measurement mode is operated at a power lower than the power consumption in the body temperature measurement mode. An electronic thermometer comprising: a transition means for transitioning to a low current consumption mode. The determination unit determines that the electronic thermometer is not in a state to perform body temperature measurement in the body temperature measurement mode when a temperature change value indicating a temperature change within a predetermined time detected by the detection unit does not exceed a threshold value. The electronic thermometer according to claim 1. As a state of the electronic thermometer, further comprising a detection means for detecting a physical external force acting on the electronic thermometer,
The determination means determines that the electronic thermometer is not in a state to perform body temperature measurement in the body temperature measurement mode when a change in the physical external force detected by the detection means does not exceed a threshold value within a predetermined time. The electronic thermometer according to claim 1. When the change in the physical external force detected by the detection means and the change in temperature detected by the detection means do not exceed a threshold value within a predetermined time, the determination means determines whether the electronic thermometer has a body temperature in the body temperature measurement mode. The electronic thermometer according to claim 3, wherein the electronic thermometer is determined not to be in a state to be measured. The electronic thermometer according to any one of claims 1 to 4, further comprising return means for returning from the low current consumption mode to the body temperature measurement mode based on a state of the electronic thermometer. The electronic thermometer according to claim 5, wherein the return means returns from the low current consumption mode to the body temperature measurement mode when a temperature change by the detection means is detected as a state of the electronic thermometer. The said return means returns to the said body temperature measurement mode from the said low consumption current mode, when the said physical external force by the said detection means is detected as a state of the said electronic thermometer. Electronic thermometer. The return means returns to the body temperature measurement mode from the low current consumption mode when the temperature change by the detection means and the physical external force by the detection means are detected as the state of the electronic thermometer. The electronic thermometer according to claim 5. The apparatus further comprises mode information indicating whether the current operation mode is the body temperature measurement mode or the low current consumption mode, and output means for outputting temperature information corresponding to the operation mode. Item 9. The electronic thermometer according to any one of Items 1 to 8. The output means is display means for displaying the mode information and the corresponding temperature information,
The electronic thermometer according to claim 9, wherein, in the low current consumption mode, a temperature measured in the latest body temperature measurement mode is displayed on the display unit as the temperature information. The electron according to any one of claims 1 to 10, wherein the transition means sets the measurement interval of the electronic thermometer to be longer than the measurement interval in the body temperature measurement mode as the low current consumption mode. Thermometer. The electron according to any one of claims 1 to 11, wherein the transition unit makes the measurement resolution of the electronic thermometer coarser than the measurement interval in the body temperature measurement mode as the low current consumption mode. Thermometer. The electronic thermometer according to any one of claims 1 to 12, wherein the transition unit omits measurement for temperature compensation of the electronic thermometer in the low current consumption mode. The electronic thermometer according to any one of claims 1 to 13, wherein the transition unit limits a display time of the electronic thermometer as the low current consumption mode. The transition means, as the low current consumption mode,
Making the measurement interval of the electronic thermometer longer than the measurement interval in the body temperature measurement mode,
Making the measurement resolution of the electronic thermometer coarser than the measurement interval in the body temperature measurement mode,
Omission of measurement for temperature compensation of the electronic thermometer,
The electronic thermometer according to any one of claims 1 to 7, wherein any two or more combinations of limiting the display time of the electronic thermometer are executed. A control method for an electronic thermometer,
A detection step of detecting a temperature change of the electronic thermometer;
Determining whether or not the electronic thermometer that is already turned on and in the body temperature measurement mode is in a state in which the body temperature measurement should be performed in the body temperature measurement mode based on the temperature change detected by the detection step Process,
As a result of the determination in the determination step, when it is determined that the electronic thermometer is not in a state where the body temperature measurement mode should not be measured, the body temperature measurement mode is operated with power lower than the power consumption in the body temperature measurement mode. And a transition step of transitioning to a low current consumption mode.