JP4754893B2 - Electronic thermometer - Google Patents

Description

  The present invention relates to an electronic thermometer, and more particularly to an electronic thermometer that reads data necessary for temperature detection from a memory when the temperature is measured.

  In the electronic thermometer, when the power is turned on, data necessary for temperature measurement such as a temperature measurement parameter is read from a nonvolatile memory such as an EEPROM. Conventionally, this data is read out immediately after the power is turned on.

When the electronic thermometer is turned on and the user tries to put the thermometer under the heel and the metal cap on the tip of the thermometer touches the charged clothes, the data required for the above temperature measurement due to the influence of static electricity Reading may fail. Thus, when data reading from the EEPROM fails, the conventional thermometer notifies the user of an error and prompts the user to perform temperature measurement again (Patent Document 1).
JP 59-114424 A

  Certainly, when data reading fails due to the influence of static electricity like a conventional electronic thermometer, if the user is informed of the error, the user will be aware of the error and can turn on the power again and restart the temperature measurement. .

  However, a thermometer that generates an error in the first place is not necessarily easy to use because it forces the user to operate again.

  For this reason, in order to suppress the influence of static electricity, it is conceivable to shield the metal cap part at the tip of the thermometer with an insulator, but if the metal cap is shielded, the sensitivity of the temperature sensor is affected, and conversely the temperature measurement time is There is also a problem that it takes a long time or the number of parts increases, leading to an increase in cost.

  The present invention has been made in view of such problems, and provides an electronic thermometer that does not generate a data read error even in an environment with static electricity and does not require the addition of a structure or parts. is there.

To achieve the above object, an electronic clinical thermometer according to the present invention is an electronic clinical thermometer for calculating and displaying the body temperature on the basis of the change over time to detect the temperature of the measurement site, after power ON, the measurement at predetermined time intervals A temperature detecting means for detecting the temperature of the part, a storage means for storing data necessary for deriving the body temperature, and a temperature detected in advance for each of the temperatures detected by the temperature detecting means at the predetermined time interval A temperature calculation unit that calculates a temperature gradient based on the difference, and a temperature gradient that is equal to or greater than a predetermined temperature gradient value continuously M times (M is an integer of 2 or more) by the gradient calculation unit; Control means for controlling to read out the data necessary for derivation from the storage means .

  The electronic thermometer is a prediction equation (equilibrium temperature prediction equation) electronic thermometer that predicts an equilibrium temperature based on a change in temperature of the measurement site over time.

  Further, the storage means is a nonvolatile memory, particularly an EEPROM.

  Other features of the present invention will become apparent from the following description of the best mode for carrying out the invention and the accompanying drawings.

  According to the electronic thermometer of the present invention, it is not necessary to add a new structure or parts, and no data read error occurs even in an environment with static electricity. it can.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings.

<Appearance of electronic thermometer>
1A and 1B are views showing the appearance of an electronic thermometer 100 according to the present embodiment. FIG. 1A is a plan view, FIG. 1B is a side view, and FIG. 1C is a rear view. Reference numeral 2 denotes a main body case in which an electronic circuit such as an arithmetic control unit 20 described later, a buzzer 31, a battery (power source unit) 40, and the like are stored.

Reference numeral 3 denotes a stainless steel metal cap, which stores a temperature measurement unit including a thermistor 13 (see FIG. 2) necessary for body temperature measurement, fixed with an adhesive. The main body case 2 and the metal cap 3 are joined and fixed in a liquid-tight manner via an adhesive. Thus, the metal cap 3 transfers the body temperature (temperature) to the thermistor 13 and protects the thermistor 13 from external impacts and the like. The metal cap 3 has an outer diameter of about 3 mm, a thickness of about 0.2 mm, a total length of about 8 mm, and a weight of 240 to 250 mg. The length of the joint at the front end of the main body case 2 is about 3.5 mm to 5 mm. Yes .

  The heat sensitive part including the metal cap 3 incorporating the thermistor 13 has a heat capacity reduced to about 0.1 J / ° C. The main body case 2 is formed of a styrene resin (high impact polystyrene, ABS resin), a polyolefin resin (polypropylene, polyethylene), or the like containing approximately 1 to 2.5% by weight of the silver phosphate silver compound, and the display unit 30. The transparent window portion 2d that covers is preferably formed by two-color molding.

  The window 2d is made of transparent resin such as polystyrene and butadiene / styrene copolymer; polyolefin resin such as poly-2-methylpentene and polypropylene; acrylic resin such as polymethyl methacrylate; cellulose acetate and the like. Cellulose ester; formed from polyester such as polyethylene terephthalate. A power ON / OFF switch 4 is provided on the side opposite to the metal cap 3 of the main body case 2.

  In addition, a concave portion 2a is provided on the back surface of the main body case 2 so that the electronic thermometer after temperature measurement can be easily grasped and taken out easily. Reference numerals 2b and 2c denote slip-off portions which prevent the electronic thermometer from shifting during temperature measurement. Reference numeral 2d denotes a battery lid cover for replacing the battery. The broken line indicates the storage position of the battery (power supply unit) 40, and the center of gravity is positioned in front of the longitudinal direction in the state where the battery 40 is stored.

  30a is a prediction mode display unit that displays a prediction mode, and 30b is a mute mode display unit that displays a so-called mute mode that does not generate a buzzer sound.

  The electronic thermometer 100 has a width of about 28 mm, a thickness of about 10 mm, and a weight of about 20 gw. The position of the center of gravity, width, weight, and slip-sliding part makes it stable when an electronic thermometer is attached to the temperature measuring part.

<Circuit configuration of electronic thermometer>
FIG. 2 is a block diagram showing a circuit configuration for performing body temperature measurement in the electronic thermometer 100 of the present embodiment.

  The electronic thermometer 100 measures the temperature and outputs it as a digital value, calculates the predicted temperature from the measured temperature, and displays the measurement result and the calculation control unit 20 that controls the electronic thermometer. The display unit 30 includes a backlight (LED) 30c.

  The temperature measurement unit 10 includes a thermistor 13 and a capacitor 14 installed in a temperature sensing unit connected in parallel, and a CR oscillation circuit 11 for temperature measurement. The count amount of the counter 16 corresponds to the temperature of the thermistor 13. By changing, the temperature is output as a digital quantity.

  The arithmetic control unit 20 includes an EEPROM 22a storing parameters necessary for body temperature measurement, a RAM 23 for storing measured temperatures in time series, a ROM 22 storing programs such as prediction formulas, and a display control unit for controlling the display unit 30. 30d, a counter 16 that counts the oscillation signal of the temperature measuring CR oscillation circuit 11, an arithmetic processing unit 21, a counter 16, an arithmetic processing unit 21, and a display control unit 30a that perform calculation under the conditions written in the EEPROM 22a according to the program of the ROM 22. And a control circuit 50 for controlling.

  Note that the configuration of the main body thermometer is an example, and is not limited to this. In the present embodiment, the block configuration of the predictive electronic thermometer is particularly shown, but it should be noted that the present invention can be applied without being limited to the presence or absence of the prediction calculation.

  In the present embodiment, data necessary for the temperature measurement stored in the EEPROM 22a, for example, conditions for terminating the temperature measurement, coefficients of the prediction formula, and the like are read from the EEPROM 22a at the timing determined as appropriate instead of when the power is turned on. Are stored in the RAM 23. As a result, it is possible to prevent a read error due to the influence of static electricity.

<Regarding the reading control of data necessary for temperature measurement>
Data readout control necessary for temperature measurement will be described with reference to FIGS.

  FIG. 3 is a flowchart for explaining the operation of controlling the timing for reading data necessary for temperature measurement. FIG. 4 is a diagram showing a correspondence between an example of the temperature rise curve and each operation of FIG. Note that the operation control of each step in FIG. 3 is executed by an arithmetic processing unit (CPU) 21 in FIG.

  In FIG. 3, when power ON is detected in step S101, a program corresponding to the flowchart of FIG. 3 is read from the ROM 24, and is expanded in the RAM 23 to prepare for operation start. Then, as shown in FIG. 4, sampling of temperature data is started at a predetermined interval, for example, 500 msec.

  In step S102, the counter value Ct of the temperature rise detection counter 25 is reset (Ct = 0). For example, the temperature rise detection counter 25 counts the number of times the temperature gradient is 0.03 ° C./500 msec or more. In step S103, a calculation for acquiring a temperature gradient for each point from the temperature data obtained by sampling is executed.

  In step S104, it is determined whether or not the temperature gradient calculated in step S103 is a predetermined value (for example, 0.03 ° C./500 msec) or more. If the temperature gradient is equal to or greater than a predetermined value (for example, 0.03 ° C./500 msec), the process proceeds to step S105. Otherwise, the process returns to step S102 and the counter value Ct is reset.

  In step S105, the counter value Ct is counted up. In step S106, it is determined whether or not the counter value Ct is a predetermined value (eg, 3). If Ct is a predetermined value (for example, 3), the process proceeds to step S107. Otherwise, the process returns to step S103, and the temperature gradient calculation and the like (steps S103 to S105) are subsequently executed.

  If the counter value Ct reaches a predetermined value (for example, 3), it is recognized that the temperature has risen sufficiently. Therefore, it is determined that the thermometer is attached to the measurement site (such as the armpit or the mouth). And if it is already mounted, data reading will not fail due to the influence of static electricity. That is, even if static electricity is generated during wearing, the generated static electricity travels through the surface layer of the main body case 2 made of resin and escapes toward the human body having a lower impedance than the metal cap 3. It is because there is no influence on the. Therefore, in step S107, data necessary for temperature measurement is read from the EEPROM 22a and stored in the RAM 23.

  In step S108, the temperature detection operation is executed using the data read from the EEPROM 22a. In step S109, it is determined whether or not the temperature rise is less than 0.1 ° C. at a predetermined value (for example, 4 seconds). If the temperature rise is equal to or higher than the predetermined value (0.1 ° C.), the temperature detection operation is continued in step S108. . If it is less than the predetermined value (0.1 ° C.), it is determined that the temperature measurement has been completed, a temperature measurement end buzzer is issued, and the user is notified of the completion of the temperature measurement.

  The above operation will be described with reference to the temperature curve of FIG. In FIG. 4, since the temperature curve is flat between point A and point B, the thermometer is not yet attached to the measurement site. Then, since a temperature rise of 0.03 ° C./500 msec or more was detected three times in succession from point B → C → D → E, it is determined that the attachment was made at B. That is, the internal temperature measurement start time is point B.

  In the algorithm of the present embodiment, when a temperature equal to or higher than a predetermined value (for example, 0.03 ° C.) is continuously detected a predetermined number of times (three times), it is determined that it is surely attached to the measurement site at that time. At that timing, data necessary for temperature detection is read from the EEPROM 22a, and the temperature detection operation is started.

Further, in this embodiment, the temperature rise is monitored even during the temperature detection operation, and the temperature measurement is terminated if the temperature rises less than a predetermined value (for example, 0.1 ° C.) within a predetermined second (4 seconds). In the temperature curve of FIG. 4, since the temperature increase from the point F to the point G is determined to be less than 0.1 ° C., it is determined that the temperature measurement is finished.

It is a figure which shows the external appearance of the electronic thermometer which can apply this embodiment. It is a block diagram which shows the structure of the electronic thermometer of this embodiment. It is a flowchart for demonstrating the operation | movement of the data read timing control of this embodiment. It is a figure which shows a response | compatibility with each process of a temperature measurement curve and the flowchart of FIG.

Claims (4)

An electronic thermometer that detects the temperature of the measurement site and calculates and displays the body temperature based on changes over time,
A temperature measuring means for detecting the temperature of the part to be measured at predetermined time intervals after turning on the power;
Storage means for storing data necessary for derivation of body temperature;
Gradient calculation means for calculating a temperature gradient based on a difference from a temperature detected in advance for each of the temperatures detected at the predetermined time intervals by the temperature detection means;
Control is performed to read out the data necessary for deriving the body temperature from the storage means when a temperature gradient equal to or greater than a predetermined temperature gradient value is calculated M times (M is an integer equal to or greater than 2) by the gradient calculating means. Control means to
Electronic thermometer characterized in that it comprises a.   The data necessary for deriving the body temperature includes a condition for ending the temperature detection by the temperature detecting means,
  The condition is that the temperature rise detected by the calculation means in a predetermined period is less than a predetermined temperature.
The electronic thermometer according to claim 1.   The electronic thermometer is a predictive electronic thermometer that predicts an equilibrium temperature based on a change over time in the temperature of the measurement site,
  The data required for derivation of body temperature is a coefficient of a prediction formula used for the prediction of equilibrium temperature.
The electronic thermometer according to claim 1 or 2, characterized in that.   The control means further uses the preceding temperature gradient used for calculating the first consecutive M temperature gradients when a temperature gradient equal to or greater than a predetermined temperature gradient value is calculated M times consecutively by the calculation means. 4. The electronic thermometer according to claim 1, wherein one or more temperatures detected by the temperature detector after the detected temperature are used for calculating the body temperature. 5.

Images