JPH08114512A - Prediction type electronic clinical thermometer - Google Patents

Abstract

PURPOSE: To shorten the necessary temperature measuring time, and enhance predicted value measuring accuracy by considering influence exerted by an outside air temperature, by correcting an predicted value of a balanced temperature predicting means based on output of a bodily temperature sensor by output of an outside air temperature sensor. CONSTITUTION: When a human being 1 closes the armpit, a blood vessel of the armpit is warmed by blood flowing from a core part 11, and an armpit center part 12 is put at the same temperature with the core part 11. When the whole of a clinical thermometer 2 exists in outside air 3, heat flows to a heat sensitive part 21 and a main body 22 from the outside air 3 by heat transmission, and the heat transmission is performed between the heat sensitive part 21 and the main body 22. When the heat sensitive part 21 is put in the armpit, the armpit center part 12 is warmed by the core part 11, and the armpit center part 12 warms the heat sensitive part 21 by heat transmission. Heat of the heat sensitive part 21 is transmitted to the main body 22, and heat of the main body 22 is transmitted to the outside air 3. Therefore, a highly accurate predicted value is obtained by correcting a bodily temperature predicted value predicted from output of the heat sensitive part 21 by output of an outside air temperature sensor arranged on the inverse side of the clinical thermometer 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a predictive electronic thermometer which greatly reduces the time required for temperature measurement by predicting the thermal equilibrium temperature.

[0002]

2. Description of the Related Art A conventional thermometer is disclosed in Japanese Examined Patent Publication Sho 53-3679.
It has been known to use another temperature sensor other than the body temperature sensor to improve the measurement accuracy, as disclosed in Japanese Patent Laid-Open No. 8 and JP-A-4-240531. However, these are not for predictive calculation of the final temperature, and therefore it takes a long time to reach the thermal equilibrium temperature, so that the time required for temperature measurement cannot be significantly shortened, and it is not convenient yet.

On the other hand, the Japanese Patent Publication No. 38895/1990 discloses a predictive calculation of the final temperature, and is technically superior to the above-mentioned ones. However, since the predictive electronic thermometer disclosed in the publication does not include an outside air temperature sensor, the influence of the outside air temperature cannot be taken into consideration and there is still a problem in accuracy.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve such problems and drawbacks, and its purpose is to significantly reduce the time required for temperature measurement, and the influence of the outside temperature. It is to provide a predictive electronic thermometer that is highly accurate in consideration of the above.

[0005]

In order to achieve the above object, in the predictive electronic thermometer according to the present invention, a thermistor for detecting the body temperature is provided at the tip of the thermometer, while an outside air temperature sensor is provided on the opposite side of the thermometer. The predicted value detected on the body temperature sensor side is corrected by this outside air temperature sensor. A body temperature sensor for detecting the body temperature, an outside air temperature sensor for detecting the outside air temperature, and an equilibrium temperature prediction based on the output of the body temperature sensor. Means and correction means for correcting the predicted value of the equilibrium temperature prediction means by the output of the outside air temperature sensor.

The principle to which the present invention is applied will be described below. FIG. 1 is a block diagram showing the flow of heat between the armpit of a human 1 and a thermometer under the armpit and the outside air. In the figure, the core 11 is the temperature of the heart or brain of the human 1 and is almost constant (However, to be exact, there is a slight temperature change within one day, and there is a sine wave of about 1 degree per day. It changes in shape ...) It is stable on average. From this almost constant temperature, heat is mainly caused by blood, axillary 12
However, since the surface of the armpit 12 is in contact with the outside air 3, a value deviating from the temperature of the core portion 11 appears.
Normally, if the armpit 12 is closed, the heat flow is transmitted only from the armpit 12 to the temperature sensing portion 21, and the temperature of the core becomes almost the same as the temperature of the armpit. When the armpit 12 is opened, it contacts the outside air 3 and A →
It goes out to the outside in the loop of 3. Then, put the thermometer 2 on the armpit
When it is inserted and closed, the heat escapes from the core part 11 to the armpit 12, the heat flows to the sensor 21 of the thermometer 2, and the heat is further transferred to the thermometer main body 22.

The following four cases can be summarized systematically by the above heat flow. (1) When the human 1 closes the axilla At this time, the blood flowing from the core 11 warms the blood vessels of the axilla 12 and the central part of the axilla is heated by heat conduction. In the model of FIG. 1, if a human has closed the armpit for a long time, the armpit central portion 12 has the same temperature as the core portion 11. (2) When the whole thermometer 2 is in the outside air 3 At this time, heat is supplied from the outside air 3 to the temperature sensing unit 21 and the main body 22 by heat transfer. Further, heat conduction is performed between the temperature sensing portion 21 and the main body 22. In FIG. 1, if the thermometer 2 is exposed to the outside air for a long time, the temperature sensing unit and the main body have the same temperature as the outside air. (3) When the human 1 opens the armpit 12, the human 1 inserts the temperature sensing portion 21 of the thermometer 2 into the armpit 12
When is opened, heat is released from the state of (1) to the outside air 3. That is, heat is transferred from the armpit 12 to the outside air 3, and the temperature of the armpit 12 decreases. If the armpit 12 is opened for a long time, the temperature of the armpit central portion 12 will be increased by the thermal resistance.
The temperature is balanced between the temperature (i.e., the core temperature) and the temperature of the outside air 3 (outside air temperature). (4) When the temperature sensing part 21 is put under the armpit 12 (the temperature sensing part 21
Touches under the armpit 12, omitting the time when the armpit 12 is open. ) When the temperature sensing part 21 of the thermometer 2 is inserted and the armpit 12 is closed, the armpit central part 12 is warmed by the core part 11. Then, the armpit center portion 12 heats the temperature sensing portion 21 by heat conduction. The heat of the temperature sensing portion 21 is conducted to the main body 22, and the heat of the main body 22 is transferred to the outside air 3. Eventually, the core temperature and the outside air temperature are balanced, and the temperature of the temperature sensing unit 21 is displayed as the body temperature.

Therefore, the four cases of the above heat flow will be considered in the equivalent circuit of FIG. Here, assuming that the temperature distribution in the body is uniform, the model of the equivalent circuit is created by applying the concentrated heat capacity method of heat transfer engineering. FIG. 2 is an equivalent circuit showing a thermal connection between a human, a thermometer, and the outside air. The analysis by the concentrated heat capacity method is effective when [h × (V / A)] / when the volume V, the surface area A, the heat transfer coefficient h, and the heat transfer coefficient k are set for each substance.
This is the case where k <0.1 is satisfied.

(1) When a human is closing his armpit In FIG. 2, the outside air is indicated by the heat source E∞, and the outside air temperature T∞ is generated at the positive electrode of this heat source E∞. And
The switch SW2 connected to the positive electrode of the heat source E∞ is off because the armpit is not in contact with the outside air because the armpit is closed. Furthermore, the switch SW3 is off because the temperature-sensing part of the thermometer is not in contact with the armpit.
Next, the human core is indicated by the heat source E0, and the core temperature T0 is generated at the positive electrode of the heat source E0. The thermal resistance R2 having one end connected to the heat source E0 is a resistance related to heat conduction between the armpit and the core. And thermal resistance R2
The heat capacity C2 connected to the other end of the armpit is the armpit capacity, and the armpit lower temperature T2 is generated at the connecting portion between the heat capacity C2 and the heat resistance R2. Next, R7 connected between the heat capacity C2 and the switch SW3 is a heat resistance related to heat conduction in the armpit on the temperature sensing side of the thermometer. Further, R5 connected between the heat capacity C2 and the switch SW2 is a thermal resistance related to heat transfer in the armpit and the outside air. In the above connection state,
If humans keep their armpits closed for a long time, the armpit temperature T2 is the heat source E0.
Becomes equal to the core temperature T0.

(2) When the entire thermometer is in the open air In FIG. 2, the switch SW3 is off because the temperature sensing portion of the thermometer is not in contact with the armpit. And
The switch SW4 connected to the positive electrode of the heat source E∞ is turned on because the temperature sensing part is in contact with the outside air. R11 connected to the other end of the switch SW4 is a thermal resistance relating to heat transfer between the outside air and the temperature sensing unit. Further, R8 connected to the other end of the switch SW3 is a thermal resistance relating to heat conduction in the temperature sensing part on the human armpit. Cs connected to the connecting portion of the thermal resistance R8 and the thermal resistance R11 is the heat capacity of the temperature sensing portion. The temperature sensing part temperature Ts required for the heat capacity Cs is generated. On the other hand, R10, one end of which is connected to the heat source E∞, is a thermal resistance related to heat transfer between the body of the thermometer and the outside air. C3 connected to the other end of the thermal resistance R10 is the heat capacity of the main body. A body temperature T3 is generated at the connecting portion between the heat capacity C3 and the heat resistance R10. In addition, R9 connected between the heat capacity Cs and the heat capacity C3 is a heat resistance related to heat conduction between the temperature sensing part of the thermometer and the main body. In the above connected state, if the thermometer is exposed to the outside air for a long time, the temperature sensing part temperature Ts and the body temperature T3 become equal to the outside air temperature T∞ of the heat source E∞.

(3) When a human opens his armpit In FIG. 2, the switch S connected to the positive electrode of the heat source E∞
W2 is turned on because the armpit is in contact with the outside air because the armpit is open. However, the switch SW3 is off because the temperature-sensing portion of the thermometer is not in contact with the armpit. At first, assuming the state of (1) above, the armpit temperature T2 is the same as the core temperature T0. Usually core temperature T0
Is higher than the outside air temperature T∞, the heat stored in the heat capacity C2 flows to the heat source E∞ through the heat resistance R5. Therefore, the armpit temperature T2 gradually decreases. Eventually, the armpit temperature T2 is balanced by the temperature obtained by adding the outside air temperature T∞ to a value obtained by dividing the temperature difference obtained by subtracting the outside air temperature T∞ from the core temperature T0 by the thermal resistances R2 and R5.

(4) When the temperature sensing part is put under the armpit (the temperature sensing part contacts the bottom of the armpit and omits the time when the armpit is open) In FIG. 2, the switch SW2 has the armpit closed, and therefore the armpit is closed. And because the outside air does not come into contact, it is turned off. The switch SW4 is off because the temperature sensing part of the thermometer is not in contact with the outside air. And the switch SW
3 is turned on because the temperature sensing part of the thermometer is in contact with the armpit. First, assuming that the above states (2) and (3) are satisfied, the temperature sensing unit temperature Ts and the body temperature T3 are the outside air temperature T.
The temperature is the same as ∞. The armpit temperature T2 is a temperature between the core temperature T0 and the outside air temperature T∞. Therefore, since the armpit temperature T2 is higher than the temperature sensing part temperature Ts and the main body temperature T3, the heat stored in the heat capacity C2 is the thermal resistance R7.
Through the switch SW3 side. This heat flow (that is, the heat flow) flows through the heat resistance R8 to the heat capacity Cs, then through the heat resistance R9 to the heat capacity C3, and further to the heat source E∞ through the heat resistance R10. That is, heat propagates to the heat source E∞ side. At the same time, the heat flow from the heat source E0 causes the heat capacity C2 to accumulate heat, and as a result, the temperatures T2, T3, Ts of the respective parts are increased.
Is balanced by a temperature obtained by adding the outside air temperature T∞ to a value obtained by dividing the temperature difference obtained by subtracting the outside air temperature T∞ from the core temperature T0 by the thermal resistances R2 and R7 to R10.

Here, the thermal resistance and the thermal capacity described in the equivalent circuit of FIG. 2 will be described. (1) Heat resistance R2 = heat conduction between the armpit and the core. Meat thermal conductivity k1, length L1, cross-sectional area S1
Then, the thermal resistance R2 is represented by R2 = L1 / (k1 * S1). However, this R2 is difficult to set, so
Treat as unknown. The thermal conductivity k at the temperature T
Is the thermal conductivity k0 at the reference temperature (usually 0 ° C),
Assuming a constant u, k = k0 × (1 + uT). (2) Heat resistance R5 = heat transfer between the armpit and the outside air. Assuming the surface area A4 of the armpit and the heat transfer coefficient h4, the thermal resistance R
5 is represented by R5 = 1 / (h4 × A4). However, this R5 is also an unknown number because it is difficult to set it. (3) Thermal resistance R7 = heat conduction in the armpit on the temperature sensing side of the thermometer. Axillary thermal conductivity k6, length L6,
If the cross-sectional area is S6, the thermal resistance R7 is represented by R7 = L6 / (k6 × S6). This R7 is also unknown. (4) Thermal resistance R8 = heat conduction in the temperature sensing part on the axilla side of a human. Thermal conductivity of temperature sensing part k8, length L
8, and the cross-sectional area S8, the thermal resistance R8 is R8 = L8 /
It is represented by (k8 × S8). (5) Thermal resistance R9 = heat conduction between the temperature-sensitive part of the thermometer and the main body. The R9 is represented by the sum of the thermal resistance R'8 of the temperature sensing unit on the main body side and the thermal resistance R'10 of the main body on the temperature sensing unit side. The area S9 of the joint surface between the temperature sensing portion and the body, the length L8 'between the sensor in the temperature sensing portion and the joint surface, and the length 1/2 between the joint surface and the body end within the range of L10' and L8 '. Equivalent thermal conductivity k8 ', equivalent thermal conductivity k1 in the range of L10'
If it is 0 ', the thermal resistance R9 is represented by R9 = R8' + R10 '= [L8' / (k8 '* S9)] + [L10' / (k10 '* S9)]. The equivalent thermal conductivity is experimentally determined. (6) Thermal resistance R10 = related to heat transfer between the body of the thermometer and the outside air. If the surface area of the main body is A10 and the heat transfer coefficient is h10, the thermal resistance R10 is represented by R10 = 1 / (h10 × A10). (7) Thermal resistance R11 = relative to heat transfer between the temperature sensing part of the thermometer and the outside air. If the surface area A11 of the temperature sensing portion and the heat transfer coefficient h11 are taken, the thermal resistance R11 is expressed by R11 = 1 / (h11 × A11). (8) Heat capacity C2 = heat capacity of armpit, specific heat H of armpit
If the density is 1, the density ρ1 and the volume V1, the heat capacity C2 is represented by C2 = H1 × ρ1 × V1. However, this C2 is difficult to set, so
Treat as unknown. (9) Heat capacity Cs = heat capacity of the temperature sensing part, and specific heat H
Assuming s, density ρs, and volume Vs, the heat capacity Cs is expressed by Cs = Hs × ρs × Vs. (10) Heat capacity C3 = heat capacity of the body of the thermometer,
If the specific heat H3, the density ρ3, and the volume V3, the heat capacity C3
Is represented by C3 = H3 × ρ3 × V3.

In the above description, T0 ≧ T2> Ts (T
3) Although the description is made in consideration of ≧ T∞, this setting is not always the case. For example, when measuring temperature continuously,
Since the outside air temperature is higher than the body temperature, the temperature sensing part may be cooled with water to measure the temperature.

The above heat equivalent circuit of FIG. 2 can be replaced with an electric circuit as it is. Since the temperature T0 of the core is kept constant, the direct current voltage E0 is applied as a heat source.
There is a thermal resistance R2 that flows from there to the armpit, and there is a heat capacity C2 of the armpit. It is not accurate to say that the heat source is the outside air that is connected from the armpits to the outside air, but since the air capacity is large, it is considered as a direct current voltage E∞. If the armpit is closed, the temperature of the core part accumulates in the armpit due to the heat flow in this state. Next, when the armpit is opened, heat flows from the core to the armpit, and escapes to the outside air through the thermal resistance from the armpit to the outside air. Then, when the thermometer is inserted and the armpit is closed, the switch SW2 is turned off, while the switch SW3 is turned on so that heat flows from the thermometer sensor unit → the thermometer main body → the main body to the outside air. In this way, the transient phenomenon when the switch is turned on determines how the temperature change of each part will rise. This is represented by the third-order differential equation, which cannot be easily solved by a general formula, but can be solved under certain conditions. That is, in the design, the values on the side of the thermometer are obtained by experiments in advance for the respective constants, and since the temperature of the outside air is known by the outside air temperature sensor, it is only the human side's numerical value that is unknown. That is, as human unknowns, there are four unknowns: the temperature T0 of the core, the thermal resistance R2 between the core and the armpit, the heat capacity C2 of the armpit, and the thermal resistance R7 flowing from the armpit to the thermometer. Therefore, since the heat capacity and the heat resistance of the thermometer are known and the outside air temperature is also known, the transient phenomenon of the temperature T _s after inserting the temperature sensing portion of the thermometer into the armpit is 4 if at least 4 points are taken with respect to time. Each of these four unknowns can be obtained by one simultaneous equation. What is noteworthy here is that the core temperature T0, which has been impossible until now, is obtained as a by-product in the process of calculating the equilibrium temperature of the sensor temperature T _s . Therefore, if the heat resistance, heat capacity, and core temperature for these human beings are obtained, the equilibrium temperature (the temperature finally reached) of the temperature T _s of the temperature sensing portion will be calculated, and
By correcting this with the output T∞ of the outside air temperature sensor at that time, the saturation value of the temperature T _s at the sensor, that is, the equilibrium temperature can be calculated. The above is the principle adopted by the predictive electronic thermometer of the present invention.

[0016]

[Advantages] With the above configuration, 1) the final predicted value displayed on the thermometer is calculated with higher accuracy by calculating from the heat resistance and heat capacity of each part of the human body based on the temperatures of the body temperature sensor and the outside air temperature sensor. And it will be possible to calculate quickly, and 2) it will be possible to measure even the core temperature, which is the temperature of the core that was not possible until now.

[0017]

[Examples] From this, the case of measuring the body temperature using the above-mentioned thermometer will be analyzed below. Before that, first,
The thermometer implemented in the present invention will be described. The configuration of the electronic thermometer used in the present invention is composed of the following four elements, as shown in the block diagram of FIG.

(1) Main body (FIG. 8) A body temperature display portion, a buzzer portion, a power switch, a button battery, an outside air temperature sensor and a calculation portion are provided, and the shell material is made of chemical resistant ABS (manufactured by Denki Kagaku Kogyo). It is a waterproof structure, and the main body is shaped like a "tsu" as shown in Fig. 8. The upper head has a liquid crystal display unit and an outside air temperature sensor unit as shown in FIG. 9, and the legs have a temperature sensing unit (body temperature sensor unit).
Is provided. Use the thermometer for thumb, index finger and middle finger 3
A slight curve conforming to the shape of the finger is formed on the upper three side surfaces so that it can be easily held by the fingers of the book. In other words, the outside air temperature sensor unit, which should not be touched by a human finger, is provided on the upper head so that the finger does not touch it. Outputs from the outside air temperature sensor unit and the body temperature sensor unit are given to the multimeters 1 and 2 via the lead wires in FIG.
The output is given to the personal computer (the multimeters 1 and 2 and the personal computer are substitutes for the above-mentioned arithmetic unit, etc.), and two data are arithmetically processed by the personal computer to measure the temperature. Body temperature display (Fig. 9) It consists of a liquid crystal and displays a digit (digital) 3 digit, ° C, a battery consumption warning mark, a predicted value display mark (Fig. 9-A) and an error display mark (Fig. B). The height of the numbers is
4.5 mm. The setting circuit (on the circuit board) of the arithmetic unit can switch the display between the three-digit number display and the four-digit number display. Similarly, the display can be switched between ° C and ° F so that it can be used both overseas and domestically. This is because if two bits are prepared, four types of discrimination can be made.
By changing the input to 2 bits by 2 bits, the flowchart shown in FIG. 5 is selected. Buzzer This is a piezoelectric element, which gives an electronic sound when the power switch is pressed, when the body temperature ends and when an error occurs. Power switch Consists of conductive rubber and substrate contacts, and is pressed at the start and end of temperature measurement. Button battery A 1.5V DC button battery or a 3V DC button battery (Maxell lithium battery CR1220) is incorporated.
The diameter of CR1220 is about 12 mmφ. Outside temperature sensor An important component of the present invention is a thermistor (about 5 mmφ) which is a temperature sensitive element, and a metal part (aluminum: about 7 mmφ) in which this thermistor is mounted. Operation unit The main circuit is a one-chip microcomputer (4 bits or 8 bits) or a custom IC. Note that FIG.
As shown in -1, the setting (2 bits) on the circuit board is read by the initialization process, and the display switching between the three-digit numerical display and the four-digit numerical display and the display switching between "° C" and "° F" can be performed. it can.

(2) Temperature Sensing Section A thermistor which is a temperature sensing element, a metal section (aluminum) in which the thermistor is mounted, and a probe made of a chemical resistant ABS which is mounted at the tip of the metal section ( Made of a material that has sufficient mechanical strength to withstand normal use and does not cause human skin irritation.) The adhesive is an epoxy adhesive (Nippon Pernox Co., Ltd. ME
-105, XH-1716-1) is used as a main component. It is an immersion type and has a structure that can be wiped with a cloth soaked in a neutral detergent or alcohol cotton.

(3) Protective case The thermometer is stored in this case. As mentioned above, the thermometer has a peculiar shape, and it is easy for the tip to be broken or cracked, so we will put it in the case. There are two types of cases as shown in FIGS. 10 and 11. FIG. 10 shows a slide type, and FIG. 11 shows a hinge type storage case. The slide type of FIG. 10 is one in which a slit is formed inside a hard case having a “tsu” shape (FIG. 10-A, article on the left side), and the slit has a leg of a thermometer (FIG. 10-A, article on the right side). The portion (temperature sensitive portion) is guided in the direction of the arrow and stored. FIG. 10-B is a front view of the state in which the thermometer is housed in the sliding "T" shaped hard case. On the other hand, FIG. 11 shows a hinge type storage case.
The upper and lower cases are hinged to each other by the curved portion of the V-shaped hard case. Therefore, as shown in FIG. 11-A, with the upper case opened, the thermometer is inserted from above with the legs of the thermometer, and after the whole is stored, the upper case may be closed. FIG. 11-B is a front view of the case where the thermometer is stored in the case.

5 to 7 are operation flowcharts of the thermometer, and the method of using the thermometer according to the present invention will be described with reference to these flowcharts. As shown in FIG.
By switching the display between the digit display and the 4-digit display and the display between "° C" and "° F",
The thermometer is used as a prediction formula (case A) or as an actual measurement formula (case B).

A. When the calculation unit is set to "3 digit number display" and "° C" (Fig. 6) (1) Wipe the axillary sweat well before measuring the temperature, and close the axilla in advance (at least 30 seconds before). deep. (2) Press the power switch. At this time, the buzzer sounds once (beep ♪). The body temperature indicator lights for about 2 seconds during initialization. (All liquid crystal displays light up) Next, the display of "L" blinks. Further, “° C.” and the predicted value display mark “|” blink. At this time, the temperature of the temperature sensing portion is stored (memorized value M _o ). Now you are ready. When the temperature difference between the outside air temperature and the temperature sensing portion exceeds the predetermined range, the error display mark "Er" is lit for a predetermined time. At the same time, a buzzer (♪♪♪) sounds. Then, after the buzzer ends, the power is automatically turned off and the temperature measurement ends. That is, this flowchart is a prediction formula that considers errors, and if the temperature of the temperature sensing part is hot from the beginning, for example, if the temperature of the body temperature sensor is around 40 degrees, the curve may change. An error check is put in, including a judgment as to whether or not prediction calculation is possible. (3) Start temperature measurement. Press the temperature sensing part against the temperature sensing part. Insert the thermometer's temperature-sensing part under the armpit that was previously closed, and close the armpit. For infants, it is advisable to support them by gently pressing their arms. The measurement starts. The internal timer is started when the measured temperature value changes by 0.1 ° C. with respect to the stored value M _o . And the temperature measurement value is 34.
When the temperature exceeds 5 ° C, the display of the actual value is switched to the lighting display, and the temperature gradually rises as the temperature of the temperature sensing unit rises. "℃" during measurement
Flashes. A buzzer sounds to indicate the end of temperature measurement. i) First buzzer-at the end of normal temperature measurement. (Prediction formula) When the prediction calculation is completed (approx. 3 from internal timer start)
After 0 seconds, the buzzer sounds intermittently for 5 seconds (the tone changes ♪♪♪ ・ ♪♪♪ ・ ♪♪♪ ─). The predictive value is calculated by measuring at least 5 points. At the same time, “° C” on the body temperature display section is switched to lighting, and the predicted value is displayed. Further, the mark "|" indicating the predicted value display is turned on. If the calculation result of the predicted value is not confirmed even after the internal timer has passed for 30 seconds, the error display mark "Er" is displayed instead of the above.
Lights up and the buzzer sounds at the same time. Then, the temperature measurement value is stored at a time point 1 minute after the buzzer sounds (memorized value M
₆ ). Further, when the measured temperature value changes by 0.1 ° C or more with respect to the stored value M ₆ , “° C” is switched to blinking again,
Shift to the measurement formula. At this time, the mark "|"
Lights up. ii) Second buzzer-At the end of precise temperature measurement (actual measurement type, but not peak hold type). Two and a half minutes after the display of i), the buzzer sounds continuously for 5 seconds (♪♪♪), and at the same time, “° C” on the body temperature display switches to lighting. The actual measurement value at this time is held and displayed for about 1 minute. It should be noted that, after the display of the actual measurement value has passed for about one minute, the actual measurement formula is returned to and the actual measurement display is repeated every minute. In this case, the buzzer does not sound. Further, in each sampling of the temperature measurement, three consecutive data are compared, and when the central data is the maximum value or the minimum value, the temperature difference between the central data and the third data is within a predetermined range (range of temperature fluctuation due to pulse). ) Is exceeded, the error display mark "Er" is lit and the buzzer sounds at the same time because it is determined that the temperature sensing portion is displaced or slipped out. In other words, it includes error handling for misalignment and dropout such that the tip of the thermometer is displaced from the baby's armpit or moved outside. Then, after the buzzer ends, the power is automatically turned off and the temperature measurement ends. Read the temperature value. Take out the temperature sensing part (both main body) that was pressed against the temperature measurement site. The body temperature display section displays “3 digit number display” and “° C.”. However, when the body temperature value is lower than 34.5 ° C, “34.5 ° C” blinks. When the temperature exceeds 42.5 ° C, “42.5 ° C” blinks. (4) End temperature measurement. Press the power switch again to turn off the power. At this time, the buzzer sounds once (beep ♪). Even if you forget to press the power switch,
About 12 minutes after the internal timer starts, the power is automatically turned off. (5) Put the thermometer in the storage case.

B. When the setting of the calculation unit is “4 digit display” and “° C.” (FIG. 7) In this case, the display unit is 0.01 ° C. Further, only the actual measurement type (the temperature measuring time is about 5 minutes) is used, and the maximum temperature is displayed (peak hold type). (1) Press the power switch. At this time, the buzzer sounds once (beep ♪). The body temperature indicator lights for about 2 seconds during initialization. (All liquid crystal displays light up) Next, the display of "L" blinks. Also, "° C" blinks. At this time, the temperature of the temperature sensing portion is stored (memorized value M _o ). Now you are ready. (2) Start temperature measurement. Press the temperature sensing part against the temperature sensing part. The measurement starts. The internal timer starts when the measured temperature rises by 0.10 ° C. with respect to the stored value M _o . And the measured temperature is 3
When the temperature exceeds 4.50 ° C, the actual display of the lighting indicator "|"
, And gradually rises as the temperature of the temperature sensing part rises. “℃” flashes during measurement. A buzzer sounds to indicate the end of temperature measurement. About 5 minutes after the internal timer starts, the buzzer sounds continuously for 5 seconds. At the same time, "℃" on the body temperature display switches to lighting. In each sampling of temperature measurement, three consecutive data are compared, and when the central data is the maximum value, the temperature difference between the central data and the third data exceeds a predetermined range (range of temperature fluctuation due to pulse). In this case, it is determined that the temperature sensing portion is displaced or slipped out, and the error display mark "Er" lights up, and the buzzer sounds at the same time. And
After the buzzer ends, the power automatically turns off and the temperature measurement ends. Read the temperature value. Take out the temperature sensing part (both main body) that was pressed against the temperature measurement site. When the body temperature value is less than 34.50 ° C, "34.
"50 ° C" blinks. When the temperature exceeds 42.50 ° C, “42.50 ° C” blinks. It should be noted that, after the display of the actual measurement value has passed for about one minute, the actual measurement formula is returned to and the actual measurement display is repeated every minute. In this case, the buzzer does not sound. (3) End temperature measurement. Press the power switch again to turn off the power. At this time, the buzzer sounds once (beep ♪). Even if you forget to press the power switch, the power will automatically turn off in about 12 minutes from the start of the internal timer.

C. When the setting of the calculation unit is "3 digit number display" and "° F" In this case, it is similar to the case of A, but the liquid crystal display shows "°".
The display is switched from "C" to "° F", and the number is changed from Celsius to Fahrenheit. That is, t _F = 1.8 × t _C +32 t _C : Measured Celsius temperature (° C) t _F : Calculated Fahrenheit display (° F) to switch the numeric display.

D. Invalid when the setting of the calculation unit is "4 digit number display" and "° F". In this case, it is similar to the case of A, but the outside air temperature is not detected (the outside air temperature sensor 25 ° C regardless of temperature
Error) related to the outside temperature is not displayed.

The product specifications of the electronic thermometer used here are as follows. (1) Rated power supply voltage DC1.5V or DC3V
(Lithium battery CR1220) It can be used up to 1.0V or less at DC1.5V battery or 2.0V or less atDC3V battery. (Number of temperature measurements: 5,000 times) (2) Rated power consumption about 0.1 mW (3) Battery life about 5 years (use for about 9 minutes a day) (4) Display temperature range 34.50 to 42.50 ° C (However, the temperature measurement range is 10.00 to 42.50 ° C.) Display unit 0.1 ° C (can be switched to 0.01 ° C.) Digital display (5) Temperature measurement accuracy ± 0. 1 ° C (measured value) However, at 34.50 to 38.50 ° C, ± 0.05
° C (measured value). Estimated error of predicted value: ± 0.2 ° C with respect to the value actually measured for 10 minutes or more with the same thermometer. (6) Temperature measurement display Number 3 digits (switchable to 4 digits), Number character height: 4.5 mm ℃ (switchable to ° F) Measured value display mark: "|" Predicted value display mark: " ｜ ”Error display mark:“ Er ”Battery consumption warning mark:“ Convex ”(7) Temperature sensor Thermistor (B constant tolerance
(Within ± 1%) (For temperature sensing part / outside temperature sensor) (8) Operation part Uses a 1-chip microcomputer (4 bits or 8 bits) or a custom IC. (9) Temperature measurement time Armpit approximately 3 minutes (measurement formula) approximately 30 seconds (prediction formula) (10) Time accuracy within ± 0.1% (measurement formula) Use a quartz crystal for a watch. (11) Measurement interval 30 seconds or more (pause time during repeated measurement)

Now, a specific case in which the body temperature is measured using the thermometer as described above will be analyzed below. Looking at how the thermometer is normally used, the thermometer is kept at the outside temperature for a long time and immediately inserted into the armpit. Therefore, considering only after the switch SW2 and the switch SW4 are turned off and the switch SW4 is inserted, the equivalent circuit of FIG. 2 is simplified as shown in FIG.

Therefore, in this embodiment, the equivalent circuit of FIG. 3 will be analyzed below. In the equivalent circuit of FIG. 3, the unsteady heat conduction (transient phenomenon) when the switch SW ₃ is turned on at time t = 0 is analyzed, and the temperature T of the temperature sensing part is analyzed.
_Clarify changes in _S. In addition, E is a heat source, R is a thermal resistance, C is a heat capacity, i is a heat flow, and Q is a heat quantity. In the above equivalent circuit, the heat flows i _{1 to} i ₇ are

[0029]

[Equation 1]

It becomes Therefore, for example, when the heat flow i ₆ is calculated,

[0031]

[Equation 2]

Here, the auxiliary equation of the above equation (22) is determined. For this purpose, the following settings are made.

[0033]

(Equation 3)

The heat transfer engineering equivalent circuit is basically a single energy circuit, and no vibration occurs. In other words, it is considered that the root of equation (23) does not become an imaginary root but always becomes a real root (including equipotential roots). In addition, it is not preferable to set the root to be a singular point, since an equivalent circuit including human body data loses versatility.

[0035]

[Equation 4]

Therefore, by inserting the thermometer constant into the above variables, the general solution of i ₆ can be obtained first, and the expression of T _s is obtained by substituting the expression of i ₆ into i _4. be able to.

As can be seen from the above analysis, according to the present invention, in the course of solving the equations of the heat flows i _{1 to} i ₇ ,
First, i ₆ is obtained at the first stage. Then, by solving the simultaneous equations from the equation of T _s , four unknowns can be known, and thereby the equilibrium temperature can be measured. Furthermore, according to this method, the core temperature can also be measured. In other words, if the constant is obtained, the core temperature will be obtained on the way.

[0038]

As described above, according to the present invention, the body temperature sensor for detecting the body temperature, the outside air temperature sensor for detecting the outside air temperature,
By equipping the equilibrium temperature predicting means based on the output of the body temperature sensor and the correcting means for correcting the predicted value of the equilibrium temperature predicting means by the output of the outside air temperature sensor, the time required for temperature measurement is significantly shortened. It is possible to provide a predictive electronic thermometer that is capable of achieving excellent accuracy.

[0039]

[Brief description of drawings]

FIG. 1 is a block diagram showing a heat flow between a human armpit, an underarm thermometer, and outside air.

FIG. 2 is an equivalent circuit diagram showing a thermal connection between a human, a thermometer, and the outside air.

FIG. 3 is an equivalent circuit diagram in the case of being simplified.

FIG. 4 is a block diagram showing a configuration of an electronic thermometer used in the present invention.

FIG. 5 is a flowchart showing a selection stage operation of the thermometer.

FIG. 6 is a flowchart of a prediction formula.

FIG. 7 is a flow chart of a measurement type.

FIG. 8 is an external view of a thermometer.

FIG. 9 is a diagram showing a display example of a display unit.

FIG. 10 is an external view of a slide type storage case of the thermometer.

FIG. 11 is a hinged storage case.

[Explanation of Codes] 1 ... Human 11 ... Core 12 ... Armpit 2 ... Thermometer 21 ... Temperature Sensor (Sensor) 22 ... Main Body 3 ... Outside Air

Claims (1)

[Claims] 1. A body temperature sensor for detecting a body temperature, an outside air temperature sensor for detecting an outside air temperature, an equilibrium temperature predicting means based on an output of the body temperature sensor, and a predicted value of the equilibrium temperature predicting means for the outside air temperature sensor. A predictive electronic thermometer, comprising: a correction unit that corrects the output.