JP2012132842A - Electronic clinical thermometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic clinical thermometer that has a heater for preheating a probe part, is capable of performing body temperature measurement involving execution of preheating at any time and reduces consumption of a built-in battery.SOLUTION: An electronic clinical thermometer has: a probe part including a tip cap and a temperature detection element attached inside the tip cap; a casing part connected to the tip cap; and a heater for heating the tip cap from the inside. When the electronic clinical thermometer is started by turning-on of a power supply, it starts heating of the tip cap by the heater and controls the heating by the heater in such a manner that the temperature of the tip cap is within a temperature range between a first temperature value and a second temperature value which is higher than the first temperature value. After a prescribed time elapses since the start of the electronic clinical thermometer, the heating by the heater is stopped.

Description

  The present invention relates to an electronic thermometer and a control method thereof.

  Generally, in an electronic thermometer, a temperature measurement value is obtained by measuring a resistance change accompanying a temperature change of a thermistor provided inside a metal cap in a probe portion. The probe part (metal cap) of the electronic thermometer immediately before use becomes the temperature (for example, room temperature) where the electronic thermometer has been left until then. Therefore, if an electronic thermometer left in a cold place is sandwiched between the armpits for body temperature measurement, there is a cool feeling and the user may feel uncomfortable. In addition, if the difference between the temperature of the metal cap at the start of body temperature measurement and the body temperature of the user is large, it takes time to measure the body temperature.

  From the above situation, it has been proposed to preheat the probe portion of the electronic thermometer. Patent Document 1 describes that in a female thermometer, a preheat unit separate from the electronic thermometer is used to preheat the probe unit in order to shorten the measurement time. According to Patent Document 1, the preheating unit automatically starts preheating of the mounted electronic thermometer at the time set by the timer, and controls the probe unit to have a constant temperature.

JP-A-10-274666

  However, in the electronic thermometer described in Patent Document 1, since the preheating part and the main body of the electronic thermometer are separate, after the electronic thermometer is heated and taken out from the preheating part, until the actual temperature measurement is started Heat is generated at the probe section. Therefore, the effect of preheating may be reduced. In addition, a user operation for preheating such as setting a timer to start preheating by the preheating unit occurs. Moreover, since preheating is started by the timer setting, the timing for measuring the body temperature is defined by the device (by the timer setting state).

  On the other hand, it is conceivable to incorporate a heater for preheating in the electronic thermometer. However, since power for driving the heater is provided by the built-in battery, power consumption of the built-in battery is accelerated. In particular, if an electronic thermometer in a state where the probe portion is heated is left unattended, useless power is consumed and the battery life is shortened.

  The present invention has been made in view of the above problems, and in an electronic thermometer with a built-in heater for preheating the probe unit, it is possible to perform body temperature measurement accompanying the execution of preheating at any time and consume the built-in battery. It aims at reducing.

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 tip cap and a probe portion including a temperature detection element mounted inside the tip cap, and a housing portion connected to the tip cap,
A heater for heating the tip cap from the inside;
When the electronic thermometer is activated by turning on the power, heating by the heater is started, and the tip cap is between a first temperature value and a second temperature value higher than the first temperature value. Heating control means for controlling the driving of the heater so as to fall within a temperature range;
And a prohibiting unit that prohibits driving of the heater after a predetermined period has elapsed since the electronic thermometer was activated.

  According to the present invention, in an electronic thermometer incorporating a heater for preheating the probe unit, body temperature measurement accompanying execution of preheating can be performed at any time, and consumption of the internal battery is reduced.

It is a figure which shows the external appearance structure of the electronic thermometer concerning embodiment. It is an internal block diagram which shows the function structure of the electronic thermometer concerning embodiment. It is a figure which shows the internal structural example of the probe part of the electronic thermometer concerning embodiment. It is a flowchart explaining operation | movement of the electronic thermometer concerning embodiment. It is a figure explaining heater control by an embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
1. Appearance Configuration FIG. 1 of the electronic thermometer is a diagram showing an external configuration of the electronic clinical thermometer 100 according to an embodiment of the present invention, FIG. 1 (a) is a plan view, FIG. 1 (b) shows a side view respectively ing. Reference numeral 101 denotes a casing made of a thermoplastic resin having impact resistance and chemical resistance, and stores an electronic circuit such as an arithmetic control unit 220 described later with reference to FIG.

  Reference numeral 102 denotes a tip cap constituting the probe portion (215 in FIG. 2). The tip cap 102 is preferably a metal cap made of stainless steel or the like from the viewpoint of thermal conductivity. Inside the tip cap 102, a thermistor (details will be described later) for measuring temperature is stored in a liquid-tight manner. The tip cap 102 and the casing 101 are connected to each other and provide an outer shape as shown in the figure of the electronic thermometer 100. Reference numeral 103 denotes a power ON / OFF switch. When pressed once, the power unit 250 (FIG. 2) is turned ON, and when pressed again, the power unit 250 is turned OFF. In an electronic thermometer for hospitals and the like, a magnet reed switch 251 (FIG. 2) is provided without providing a manual ON / OFF switch such as the power ON / OFF switch 103 in order to provide liquid tightness. Yes. The magnet reed switch 251 is maintained in an OFF state (open state) by a permanent magnet provided in a storage case (not shown), and is in an ON state (closed state) when the permanent magnet is deactivated. Therefore, when the electronic thermometer 100 is taken out of the storage case, the magnet reed switch 251 is turned on, and power is supplied from the power supply unit 250 to the arithmetic control unit 220, the temperature measurement unit 210, the display unit 104, and the like as will be described later with reference to FIG. Is done. The supply of power is maintained until the electronic thermometer 100 is stored in a storage case containing a permanent magnet, and the electronic thermometer 100 is maintained in a power-on state so that measurement of body temperature and the like can be performed. The electronic thermometer 100 may include both the power ON / OFF switch 103 and the magnet reed switch 251.

  Reference numeral 104 denotes a display unit composed of, for example, a liquid crystal display or the like, and displays the body temperature of the subject. Reference numeral 105 denotes a buzzer unit that notifies the user of the end of body temperature measurement, for example. In addition, it is good also as a speaker which outputs an audio | voice based on the process in the calculation control part 220 instead of a buzzer. Further, the display unit 104 is not limited to the liquid crystal. Further, the display unit 104 has impact resistance and chemical resistance, and is covered with a window member formed of a transparent thermoplastic resin. This window member is molded in two colors with the casing unit 101 and has liquid-tightness. Have.

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.

  In the electronic thermometer 100, the probe unit 215 includes a tip cap 102, a thermistor 211 as a temperature detection element provided inside the tip cap 102, and a heater 212 for heating (described later with reference to FIG. 3). The temperature measurement unit 210 outputs an ON signal for a time corresponding to the resistance value of the thermistor 211. The operation control unit 220 obtains the temperature value detected by the probe unit 215 by measuring the output period (ON time) of the ON signal output from the temperature measurement unit 210. The calculation control unit 220 calculates the body temperature of the subject based on the temperature value thus obtained and controls the overall operation of the electronic thermometer 100. For example, the calculation control unit 220 displays the subject's calculated body temperature on the display unit 104 or sounds the buzzer unit 105 to notify the end of body temperature measurement. The power supply unit 250 includes a battery built in the housing unit 101, and the electric power is supplied to each unit of the electronic thermometer 100 such as the arithmetic control unit 220 via the magnet reed switch 251.

  The temperature measurement unit 210 includes a thermistor 211 (measuring resistance element) and a reference resistance element (not shown) connected in parallel to each other, and a single input integration type A / D conversion circuit, and it corresponds to the time corresponding to the temperature. The ON signal is output.

  The arithmetic control unit 220 includes a counter 222 that measures the ON time of the digital signal output from the temperature measurement unit 210. The counter 222 counts the clock generated by a clock generation unit (not shown) in the control circuit 221 and measures the ON time based on the obtained count value and the frequency of the clock. The arithmetic processing unit 223 acquires the temperature value detected by the thermistor 211 from this ON time.

  Further, the arithmetic processing unit 223 in the arithmetic control unit 220 calculates a temperature value based on the time measured by the counter 222 by executing a program stored in the ROM 224. Then, the arithmetic control unit 220 stores the calculated temperature value in the RAM 226 in time series as temperature data, and predicts and calculates the body temperature of the subject based on the temporal change of the temperature data. The timer 225 is used to control the heating of the heater 212.

  The display control unit 227 controls the display unit 104 that displays the calculation result in the calculation processing unit 223. The measurement switch 213 controls power supply to the temperature measurement unit 210. The heater switch 214 controls driving (ON / OFF) of the heater 212. In addition, the control circuit 221 controls the counter 222, the display control unit 227, the calculation processing unit 223, the temperature measurement unit 210, the measurement switch 213, and the heater switch 214 in accordance with instructions from the calculation processing unit 223.

  The configuration of the probe unit 215 of the electronic thermometer 100 according to the present embodiment will be described with reference to FIG. As shown in FIG. 3A, a thermistor 211 and a heater 212 are provided inside the tip cap 102 of the probe portion 215. The heater 212 is controlled to heat the tip cap 102 from the inside and maintain it between the temperature T1 and a temperature T2 lower than T1. Thus, heating the tip cap 102 speeds up the body temperature measurement, and prevents discomfort caused by the cold tip cap touching the subject. The temperature T1 is a temperature that does not hinder body temperature measurement, that is, a temperature lower than the normal body temperature (for example, about 34 degrees). Further, the temperature T2 is preferably a temperature that does not give a tight feeling when the subject touches the tip cap, for example, about 30 to 32 degrees.

3. Process Flow in Electronic Thermometer Next, the process at the time of body temperature measurement in the electronic thermometer 100, particularly the control of the heater 212 will be described in detail. It should be noted that the body temperature measurement can be applied to an electronic thermometer of any system such as an equilibrium temperature prediction formula, an actual measurement formula, or a type that uses prediction / measurement together.

  FIG. 4 is a flowchart for explaining the operation of the electronic thermometer 100 of the present embodiment. When the electronic thermometer 100 is removed from the storage case and the magnet reed switch 251 is turned on, power is supplied to the arithmetic control unit 220, and the process shown in FIG. 4 is started. If the power ON / OFF switch 103 as described with reference to FIG. 1 is provided instead of the magnet reed switch 251, power is supplied to the arithmetic control unit 220 when the power ON / OFF switch 103 is turned ON. The process shown in FIG. In any case, when the power source 250 is turned on, the processing shown in FIG. 4 is started. Note that the processing illustrated in FIG. 4 is realized by the arithmetic processing unit 223 executing a program stored in the ROM 224.

  In step S <b> 401, the arithmetic processing unit 223 turns on the measurement switch 213 via the control circuit 221 to supply power from the power supply unit 250 to the temperature measurement unit 210, and starts temperature measurement by the temperature measurement unit 210. In step S402, the arithmetic processing unit 223 activates the timer 225. The timer 225 outputs a time-up after measuring a predetermined time. In the following steps S403 to S406, the heating value of the heater 212 is controlled by using the temperature value acquired using the thermistor 211 that is a temperature detection element.

  In step S403, the arithmetic processing unit 223 determines whether or not the temperature value t measured by the temperature measurement unit 210 is equal to or less than T2. When the temperature value t measured using the thermistor 211 is T2 or less, the process proceeds to step S404, and the arithmetic processing unit 223 turns on the heater switch 214 via the control circuit 221 to drive the heater 212, Start heating. Thereafter, the process proceeds to S407.

  On the other hand, if the measured temperature value t is higher than T2 in step S403, the process proceeds to step S405. In step S405, the arithmetic processing unit 223 determines whether the measured temperature value t is equal to or greater than T1. When the measured temperature value t is equal to or greater than T1, the process proceeds to step S406, where the arithmetic processing unit 223 turns off the heater switch 214 via the control circuit 221 and stops heating by the heater 212. Then, the process proceeds to step S407.

  In step S407, the arithmetic processing unit 223 confirms whether or not the timer 225 has expired. If the timer 225 has expired, the process proceeds to step S408, and the arithmetic processing unit 223 turns off the heater switch 214 and the measurement switch 213. Thereafter, the arithmetic processing unit rings the buzzer unit 105 to notify the user that the time-up has occurred (determined that the thermometer has been left) (step S416), and the control circuit 221 and the display control unit A warning is displayed on the display unit 104 via 227 (step S417), and this process is terminated. Thus, in the case where the body temperature measurement is not started before the predetermined period elapses after the activation of the electronic thermometer 100 (by the time the timer 225 times out), the electronic thermometer 100 is assumed to be left as it is. 100 is put into a dormant state, and wasteful consumption of the power supply unit 250 is prevented. In addition, since the user can know from the buzzer sound and display that the electronic thermometer 100 has been in the dormant state due to the time-up of the timer 225, the electronic thermometer 100 in the dormant state is used for the body temperature measurement. Such a situation can be avoided. From the viewpoint of driving the heater 212, the driving of the heater 212 is prohibited after a predetermined period has elapsed since the electronic thermometer 100 was activated. In such a state, the user activates the process of FIG. 4 from the beginning by putting the electronic thermometer 100 in and out of the storage case or re-operating the power source by the power ON / OFF switch 103. The electronic thermometer 100 can be used. The predetermined period is, for example, about 20 seconds to 30 seconds. If the predetermined period is too short, the user will finish preheating even though the user intends to measure the body temperature. If the predetermined period is too long, the preheating is performed wastefully and the built-in battery is wasted. Will be exhausted.

  If the timer 225 has not expired in step S407, the process proceeds to step S409. In step S409, the arithmetic control unit 223 determines whether or not the heater 212 is being driven, that is, whether or not the heater switch 214 is ON. If the heater is being driven, the procedure returns to step S403, and the above processing is repeated. On the other hand, if it is determined that the heater 212 is not being driven, the process proceeds to step S410. In step S410, the arithmetic processing unit 223 determines whether or not body temperature measurement has been started from the temperature value measured by the temperature measurement unit 210. For example, the arithmetic processing unit 223 determines that the body temperature measurement is started when the measured temperature value exceeds T1. That is, the arithmetic processing unit 223 determines that the body temperature measurement is started when the temperature value exceeds T1 in a state where the heater is OFF. If it is determined that body temperature measurement has not been started, the process returns to step S403, and the above-described process is repeated. If it is determined that the body temperature measurement has been started, the process proceeds to step S411. Therefore, it is ensured that the heater 212 is OFF when it is determined that the body temperature measurement is started.

  FIG. 5 shows changes in the temperature of the tip cap 102 (temperature value detected by the thermistor 211) due to the heating control in steps S403 to S410. A time point when the magnet reed switch 251 is turned on (a time point when the power ON / OFF switch 103 is turned on) is set to time zero. Since the temperature of the tip cap 102 is equal to or lower than T2 at time 0, the heater 212 is immediately turned on and heating by the heater 212 is started (S403, S404). Thereafter, the tip cap 102 is heated by the heating of the heater 212, and when the temperature reaches T1, the heater 212 is turned off (S405, S406). When the heater 212 is turned off, the tip cap 102 is cooled by heat dissipation, and when the temperature falls below T2, the heater 212 is turned on again and heating of the tip cap 102 is started (S403, S404). Thereafter, the temperature of the tip cap 102 is maintained between T2 and T1 by controlling ON / OFF of the heater 212 by the processing of S403 to S406.

  On the other hand, the timer 225 activated with the activation of the electronic thermometer 100 is timed up at the time tup from the activation, and if the body temperature measurement has not been started by the time up, the measurement switch 213 and the heater switch 214 are turned off, The thermometer 100 is put into a resting state. For example, tup is preferably about 30 seconds. When the temperature value changes as shown by a dashed line 501 before the timer 225 expires, that is, when the temperature value rises above T1 while the heater 212 is off, body temperature measurement is started. The process proceeds to step S411 and subsequent steps in FIG. Although the timer 225 is activated when the electronic thermometer 100 is activated, the timer 225 may be activated when the heater 212 is first driven. Since the first drive of the heater 212 is performed immediately after the electronic thermometer 100 is started, the start timings of these timers 225 are equivalent.

  Returning to FIG. 4, in step S <b> 411, the arithmetic processing unit 223 executes body temperature measurement processing. Body temperature measurement is performed by a known process such as an equilibrium temperature prediction formula or an actual measurement formula. When the body temperature measurement is completed and the body temperature measurement value is confirmed, the process proceeds from step S412 to step S413. In step S413, the arithmetic processing unit 223 turns off the measurement switch 213 and ends the temperature measurement by the electronic thermometer 100. Although there is a method of switching to the actual value display after a predetermined time after the predicted body temperature measurement is confirmed, in this embodiment, the temperature measurement is terminated in step S413 to reduce battery consumption. Thereafter, in step S414, the arithmetic processing unit 223 sounds the buzzer unit 105 to notify the user of completion of the body temperature measurement. In step S415, the arithmetic processing unit 223 causes the display unit 104 to display the result of temperature measurement (temperature value) via the control circuit 221 and the display control unit 227. When the electronic thermometer 100 is stored in the storage case, the magnet reed switch 251 is turned off, and the power supply to the electronic thermometer 100 is turned off.

  In the above embodiment, the electronic thermometer 100 is detected to be left as the predetermined time is elapsed by the timer 225. However, the present invention is not limited to this. For example, you may make it determine progress of a predetermined period based on the frequency | count of ON / OFF of the heater 212 performed in order to maintain the heater 212 in the temperature range of T2-T1. For example, the electronic thermometer 100 is counted by counting the number of times the heater 212 is turned on or off in order to maintain the temperature range from T2 to T1, and determining whether the predetermined period has elapsed or not depending on whether or not the count value exceeds a predetermined number. It may be possible to detect whether or not the user has left the computer.

In the above embodiment, the temperature of the tip cap 102 is maintained at T2 to T1 by controlling the ON / OFF of the heater switch 214 based on the temperature value measured using the thermistor 211. However, the present invention is limited to this. is not. For example, as shown in FIG. 3B, for example, a bimetallic temperature switch 301 is connected in series with the heater switch 214, and the temperature of the tip cap 102 is maintained at T2 to T1 by the temperature switch 301. It may be. In this case, the heater switch 214 is turned on until the timer 225 expires after the electronic thermometer 100 is activated, and the temperature switch 301 is independently turned on and off in S403 to S406. Therefore, the processing by the arithmetic processing unit 223 is obtained by modifying the processing shown in FIG. 4 as follows.
In step S401, both the measurement switch 213 and the heater switch 214 are turned on.
In step S415, both the measurement switch 213 and the heater switch 214 are turned off.
-The process of S403-S406 is abbreviate | omitted.
According to such a configuration, power consumption can be reduced by the amount of processing of the arithmetic control unit 220 related to the heater switch 214 being reduced.

  Moreover, you may make it notify a user that the temperature measurement value reached T2 by the heating started at the time 0 of FIG. Such notification is convenient because the user can recognize that the tip cap 102 of the electronic thermometer 100 is appropriately heated. In addition, various forms can be considered for the notification method, including the forms exemplified below. For example, when the measured temperature value becomes equal to or higher than T2, a display (for example, an OK mark) indicating that fact can be performed on the display unit 104. Or you may make it light up LED provided separately. Moreover, you may make it perform the display which shows that it is preheating, while the measured temperature value is less than T2. For example, when two red and green LEDs are provided, red may be displayed while the temperature value is less than T2, and green may be displayed when the temperature value reaches T2 to indicate completion of preheating during preheating. Alternatively, the remaining period until the preheating is completed may be displayed on the display unit 104 by counting down. The countdown display estimates and displays the time required from the measured current temperature value to the completion of preheating (the time required to heat the temperature difference between [temperature T2]-[current temperature value t]). You may do it.

  As described above, according to the electronic thermometer 100 of the present embodiment, when the electronic thermometer 100 is activated by removing it from the storage case (or by operating the power ON / OFF switch 103), the tip of the heater 212 is immediately used. Heating of the cap 102 is started. For this reason, since the thermistor 211 can always maintain a temperature within a certain range, the time for heat conduction for the temperature of the thermistor 211 to rise to the body temperature can be greatly shortened. Therefore, the measurement time (whether it is a prediction formula or an actual measurement formula) can be shortened. In addition, there is no need to perform any special operation regarding the preheating of the tip cap 102 or the thermistor 211 (no need to use a separate device for preheating), and body temperature measurement through preheating can be performed at any time. It is. Further, since the tip cap 102 is preheated, the user can measure the body temperature without feeling uncomfortable (a chilly feeling) when the electronic thermometer 100 is worn. The heater 212 mainly preheats the tip cap 102, but the heating range may extend to the housing portion 101. Further, the housing portion 101 and the tip cap 102 may be integrally formed.

DESCRIPTION OF SYMBOLS 100: Electronic thermometer 101: Housing part 102: Tip cap 103: Power supply ON / OFF switch 104: Display part 210: Temperature measurement part 211: Thermistor 212: Heater 213: Measurement switch 214: Heater Switch 215: probe unit 220: calculation control unit 250: power supply unit 251 magnet reed switch

Claims (11)

An electronic thermometer having a tip cap and a probe portion including a temperature detection element mounted inside the tip cap, and a housing portion connected to the tip cap,
A heater for heating the tip cap from the inside;
When the electronic thermometer is activated by turning on the power, heating by the heater is started, and the tip cap is between a first temperature value and a second temperature value higher than the first temperature value. Heating control means for controlling the driving of the heater so as to fall within a temperature range;
An electronic thermometer comprising: prohibiting means for prohibiting driving of the heater after a predetermined period has elapsed since the electronic thermometer was activated.   The electronic thermometer according to claim 1, wherein the heating control unit controls heating so that the tip cap is within the temperature range by repeating ON and OFF of the heater. A timer for starting timing with the activation of the electronic thermometer;
The electronic thermometer according to claim 1, wherein the prohibiting unit prohibits driving of the heater after the timer detects that a predetermined time has elapsed.   3. The electronic thermometer according to claim 2, wherein the prohibiting unit prohibits the driving of the heater after the number of repetitions of ON and OFF of the heater by the heating control unit exceeds a predetermined number.   The electronic thermometer according to claim 1, wherein the heating control unit controls driving of the heater using a temperature value acquired from the temperature detection element.   The electronic thermometer according to any one of claims 1 to 4, wherein the heating control means is formed by a bimetal temperature switch.   The electronic thermometer according to any one of claims 1 to 6, further comprising a magnet reed switch for turning on power from a power supply unit.   The apparatus further comprises display means for performing a predetermined display when the temperature value obtained by the temperature detection element exceeds the first temperature value after the heating control means starts heating. Item 8. The electronic thermometer according to any one of Items 1 to 7. Estimating means for estimating the time until the temperature value of the tip cap reaches the first temperature value by heating by the heater from the current temperature value of the tip cap detected by the temperature detection element;
The electronic thermometer according to claim 1, further comprising display means for displaying the time estimated by the estimating means.   The electronic thermometer according to claim 1, wherein the heater further heats the housing portion. A control method for an electronic thermometer comprising a tip cap and a probe portion including a temperature detection element mounted inside the tip cap, a housing portion connected to the tip cap, and a heater for heating the tip cap from the inside. There,
When the electronic thermometer is activated by turning on the power, heating by the heater is started, and the tip cap is between a first temperature value and a second temperature value higher than the first temperature value. A heating control step for controlling heating of the heater so as to fall within a temperature range;
An electronic thermometer control method comprising: a prohibiting step of prohibiting driving of the heater after a predetermined period has elapsed since the electronic thermometer was started.

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