JP2005334254A - Eardrum thermometer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eardrum thermometer capable of accurately measuring the eardrum temperature without being offset by the environmental temperature. <P>SOLUTION: The eardrum thermometer 20 comprises a case 32 part of which is inserted into an external auditory meatus 10 of a subject at the time of measurement, a thermo-pile 22 stored in the case 32 for detecting infrared rays radiated from an eardrum 23 of the subject, an internal temperature sensor 25 for measuring the internal temperature in the case and the cold junction temperature of the thermo-pile 22, and a calculation means 26a for calculating the eardrum temperature of the subject by using the output values from the thermo-pile 22 and the internal temperature sensor 25. The eardrum thermometer 20 also has an external temperature sensor 30 for detecting the external temperature of the case facing the outside of the external auditory meatus at the time of measurement, and a temperature adjusting means 28 for heating or cooling the case based on the external temperature and the internal temperature. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an eardrum thermometer, and more particularly to an eardrum thermometer that detects temperature by detecting infrared rays emitted from the eardrum in a non-contact manner.

  Underarm thermometers and sublingual thermometers are widely known as thermometers. In recent years, a technique for measuring body temperature from the temperature of the eardrum has been proposed and put into practical use. As an eardrum thermometer for that purpose, Patent Document 1 proposes, for example.

  FIG. 9 is an enlarged view of a main part of FIG. The tympanic thermometer 100 includes a support 103 having a length that reaches the first bend 102 of the ear canal from the ear canal entrance 101, a lead wire 105 that is movably inserted into an insertion hole 104 formed in the support 103, A package 106 attached to the tip of the lead wire 105, a holder 107 fitted in the insertion hole 104, a stopper 108 for defining the insertion amount of the lead wire 105, and a connection extending from the rear end of the lead wire 105 to the thermometer body 109 Line 110.

  The package 106 includes a thermopile and a thermistor (not shown). The thermopile detects the infrared radiation of the eardrum 111 in the field of view θ indicated by two straight lines. A signal obtained by adding the detection signal of the package 106 itself that measures the temperature with the thermistor to the detection signal is sent to the thermometer main body 109 through the lead wire 105 and the connection wire 110. The thermometer main body 109 processes the signal and then displays the temperature (tympanic temperature) on the thermometer main body 109. The lead wire 105 is rigid and also serves as a support member that holds the package 106 in the position shown in the figure.

  In the visual field θ shown by two straight lines, not only the eardrum 111 but also the inner ear portion 113 of the ear canal facing the eardrum 111 from the second bent portion 112 can face. As a result, the temperature obtained by averaging the inner ear canal portion 113 and the eardrum 111 is displayed on the thermometer main body 109. That is, the inner ear canal 113 is lower in temperature than the eardrum 111, and the display temperature of the thermometer body 109 is lower than the actual temperature of the eardrum 111.

  There is a method of detecting only the eardrum 111 by narrowing the visual field θ so as not to face the inner ear canal 113. However, when the directivity is increased in this way, there is a risk that even if the lead wire 105 is slightly bent, the lead wire 105 is detached from the eardrum 111 and the inner ear canal 113 is detected. Therefore, a technique that can reliably detect the radiant infrared rays of the eardrum 111 with a thermopile is desired.

  In order to meet the above demand, the eardrum thermometer in Patent Document 2 is a thermopile as a non-contact type temperature sensor that detects infrared rays emitted from the eardrum, and a thermistor that measures the temperature of the thermopile itself for temperature compensation, It consists of a preamplifier circuit that amplifies the outputs of these thermopiles and thermistors, and a case that collectively stores these thermopiles, thermistors, and preamplifier circuits. When the case is referred to as a first curve or a second curve from the entrance to the eardrum, the case includes a first bent portion along the first curve and a second bent portion along the second curve. The part reached between the second curve and the eardrum, and a thermopile was installed at the tip.

  The principle of temperature measurement by the above tympanic thermometer will be described. Assuming that the temperature of the eardrum is T1, the ambient temperature of the thermopile is T2, and the temperature difference between the two temperatures T1 and T2 is ΔT, the temperature T1 of the eardrum is expressed as T1 = T2 + ΔT. Therefore, in order to obtain the eardrum temperature T1 from the ambient temperature T2 detected by the thermopile, it is necessary to obtain the temperature difference ΔT. Here, if the temperature difference ΔT is sufficiently smaller than both temperatures T1 and T2, the infrared energy q received by the thermopile from the eardrum can be approximated as q = k1ΔT (where k1 is a constant). In the thermopile, since the output voltage V is proportional to the incident energy, V = k2q = k1k2ΔT can be obtained if the proportionality constant is k2. Here, if 1 / k1 and k2 = k, the temperature difference ΔT can be obtained by ΔT = kV.

  Therefore, if the proportionality constant k is experimentally obtained using a black body furnace, the temperature difference ΔT can be obtained based on the thermopile output voltage V, and by detecting the ambient temperature T2 of the thermopile with the thermistor, The eardrum temperature T1 can be obtained.

  By the way, the measurement accuracy of the eardrum thermometer as described above depends on the accuracy of the proportional constant k. Since the proportional constant k includes the constant k1, it depends on the shape of the ear canal, the shape of the eardrum, the position of the sensor unit, and the like. Change. In particular, since the shape of the ear canal and the eardrum vary among individuals, it is impossible to measure body temperature with high accuracy if the same proportional constant k is used for each person.

  Therefore, in Patent Document 1, the proportional constant necessary for obtaining the temperature difference between the temperature of the eardrum and the ambient temperature of the thermopile (cold junction) can be obtained for each measured person from the output of the thermopile. An eardrum thermometer is disclosed in which the measurement error due to individual differences is reduced by using a proportional constant, and thus the temperature of the eardrum can be made with high accuracy.

  The eardrum thermometer detects infrared rays from the eardrum and generates an output voltage proportional to the temperature difference between the ambient temperature and the temperature of the eardrum, and a temperature-compensating thermistor that is arranged near the thermopile and detects the ambient temperature. And a probe having a sensor unit housed in a package inserted into the ear canal, and calculating the sum of the output voltage of the thermopile by a predetermined proportional constant and the temperature detected by the thermistor as the temperature of the eardrum In the eardrum thermometer equipped with the thermopile, the arithmetic processing unit is operable to output the thermopile output voltage and the temperature detected by the thermistor at a plurality of times within a period from when the probe is inserted into the ear canal until the output of the thermopile and the thermistor reaches an equilibrium state. And calculating the proportional constant based on the change in the output voltage and the detected temperature over time. Because, determine the temperature of the tympanic membrane by using the above proportional constant output is determined to reach to the output voltage and the detected temperature equilibrium after reaching equilibrium with the thermopile and the thermistor.

When measuring the eardrum using the above-described eardrum thermometer, if the environmental temperature is higher than the body temperature, the temperature of the cold junction of the thermopile that is more susceptible to the terminal temperature than the thermistor becomes higher. Therefore, there is a problem that the temperature difference from the light receiving portion is reduced, the output of the thermopile is reduced, and the reading is lower than the true temperature of the object.
Japanese Patent No. 2671946 JP 2002-340681 A

  An object of the present invention is to solve the problem that the reading is offset by the environmental temperature in an eardrum thermometer using a thermopile.

  In view of the above problems, an object of the present invention is to provide an eardrum thermometer capable of performing an accurate measurement in which the reading is not offset by the environmental temperature.

  The eardrum thermometer according to the present invention is configured as follows in order to achieve the above object.

  A first eardrum thermometer (corresponding to claim 1) includes a case in which a part of the eardrum thermometer is inserted inside the ear canal of the temperature-measured person and a case that is housed in the case and radiates from the eardrum of the temperature-measured person A thermopile that detects the infrared rays that are detected, and an internal temperature sensor that measures the internal temperature of the case and the cold junction temperature of the thermopile, and calculates the eardrum temperature of the person to be measured using the output values of the thermopile and the internal temperature sensor An eardrum thermometer with a calculation means is provided with an external temperature sensor that detects the external temperature of the case facing the outside of the ear canal during temperature measurement, and temperature adjustment that heats or cools the case based on the external temperature and internal temperature Characterized by the provision of means.

  In the second eardrum thermometer (corresponding to claim 2), preferably, the temperature adjusting means is controlled so that the output temperature by the internal temperature sensor and the output temperature by the external temperature sensor are the same. It is characterized by that.

  A third eardrum thermometer (corresponding to claim 3) includes a case where a part of the eardrum thermometer is inserted into the ear canal of the temperature-measured person and a case that is housed in the case and radiates from the eardrum of the temperature-measured person. A thermopile that detects the infrared rays that are detected, and an internal temperature sensor that measures the internal temperature of the case and the cold junction temperature of the thermopile, and calculates the eardrum temperature of the person to be measured using the output values of the thermopile and the internal temperature sensor The eardrum thermometer provided with a calculating means is provided with an external temperature sensor for detecting the external temperature of the case facing the outside of the ear canal during temperature measurement, and the calculating means further calculates the eardrum temperature based on the external temperature. It is characterized by.

  Since temperature adjusting means for heating or cooling the outside of the case is provided and the output temperature of the thermistor is corrected based on the external temperature, the thermistor is not affected by the temperature outside the ear canal and can accurately measure the eardrum temperature. Further, since the external temperature is measured by the external temperature sensor and the internal temperature measured by the thermistor is corrected, the eardrum temperature can be accurately measured.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.

  The configurations, shapes, sizes, and arrangement relationships described in the embodiments are merely schematically shown to the extent that the present invention can be understood and implemented, and the numerical values and compositions (materials) of the respective configurations are illustrated. Only. Therefore, the present invention is not limited to the embodiments described below, and can be modified in various forms without departing from the scope of the technical idea shown in the claims.

  FIG. 1 is a cross-sectional view of an ear equipped with an eardrum thermometer according to a first embodiment of the present invention. An operational state is shown in which an eardrum thermometer 20 is inserted deeply into the ear canal 10 and infrared rays emitted from the eardrum 23 are detected by a thermopile 22 provided at the distal end portion 21 thereof. Reference numeral 24 denotes an output line for extracting a signal to the outside.

  FIG. 2 is a front sectional view of the eardrum thermometer 20 according to the first embodiment of the present invention. FIG. 3 is a block diagram of the eardrum thermometer 20. The eardrum thermometer 20 includes a thermopile 22 as a non-contact temperature sensor that detects infrared rays emitted from the eardrum, a thermistor 25 that measures the temperature of the thermopile 22 itself for temperature compensation, and the thermopile 22 and thermistor 25. The control unit 26 for detecting the output, the power source 27, the Peltier element 28, the heat sink 29, the temperature sensor 30 for the Peltier element, the harness 31 for electrically connecting them, the thermopile 22, the thermistor 25, the control unit 26, and the power source 27 are collectively stored. And a case 32. Moreover, the heat transfer member 35 which supports the thermistor 25 and the thermopile 22, and the package 34 which has the infrared rays transmission window 33 which covers them are provided.

  The thermopile 22 uses a hot junction side of a thermocouple row in which a plurality of thermocouples are connected in series as a light receiving portion. When infrared rays are incident on the light receiving unit, a temperature difference is generated between the hot junction and the cold junction according to the amount of incident infrared rays, and a thermoelectromotive force is generated according to the difference. In order to know the temperature here, it is necessary to measure the temperature on the cold junction side and perform correction based on this temperature. Therefore, in order to obtain the temperature of the cold junction, the temperature of the thermopile itself is measured by the thermistor 25.

  The thermistor 25 is connected to the heat transfer member 35 and measures the temperature of the cold junction of the thermopile 22 via the heat transfer member 35, and an internal temperature sensor that measures the ambient temperature inside the case. Function as.

  The Peltier element 28 is for heating or cooling the case 32 based on the external temperature T3 measured by the temperature sensor 30 and the internal temperature T2 measured by the thermistor 25, and is used as a temperature adjusting unit. When this element is energized, it generates heat and absorbs heat. A heat sink 29 is attached to the Peltier element 28.

  The external temperature sensor 30 measures the external temperature T3 of the case 32, and is provided at a portion facing the outside of the ear canal of the temperature-measured person at the time of temperature measurement.

  The control unit 26 includes a calculation unit 26a, has an eardrum temperature calculation program, and has a heating program for Peltier element operation.

  Next, the operation of the eardrum thermometer 20 will be described with reference to FIGS.

  In the measurement using the eardrum thermometer 20 of the present invention, first, the person to be measured inserts the eardrum thermometer 20 of the present invention into the ear as shown in FIG. First, the heating program of the control unit 26 is activated. FIG. 4 is a flowchart of the heating / cooling process. The internal temperature T2 of the case 32 is detected by the thermistor 25 and stored in the storage unit 26b (step S11). Next, the external temperature T3 is detected by the external temperature sensor 30 and stored in the storage unit 26b (step S12). Then, the stored internal temperature T2 and external temperature T3 are compared (step S13). If the internal temperature T2 and the external temperature T3 are different, the temperature adjusting unit (Peltier element) 28 is energized (step S14). If the internal temperature T2 and the external temperature T3 are equal, the temperature adjustment is terminated. Next, signals from the thermistor 25 and the thermopile 22 are input to the control unit 26. The calculating unit 26a adds the value ΔT obtained by converting the internal temperature T2 and the value from the thermopile 22 into a temperature difference, and outputs the eardrum temperature (Ti = T2 + ΔT). Then, the eardrum temperature T1 is displayed on a display (not shown).

  In this way, the Peltier element is installed between the back surface of the case 32 and the outer surface of the case 32, and the terminal temperature is not affected by the environmental temperature because it is controlled to the same temperature or a constant temperature difference as the thermistor temperature. Temperature can be measured.

  Next, an eardrum thermometer according to the second embodiment of the present invention will be described.

  FIG. 5 is a front sectional view of an eardrum thermometer 40 according to the second embodiment of the present invention. FIG. 6 is a block diagram of the eardrum thermometer 40. The eardrum thermometer 40 includes a thermopile 22 as a non-contact type temperature sensor that detects infrared rays radiated from the eardrum, a thermistor 25 that measures the temperature of the thermopile 22 itself for temperature compensation, and the thermopile 22 and the thermistor 25. A control unit 41 that detects output, an environmental temperature sensor 42, a harness 43 that electrically connects them, and a case 44 that collectively stores the thermopile 22, the thermistor 25, and the control unit 41.

  In this embodiment, the difference from the first embodiment is that there is no temperature adjusting means and 42 environmental temperature sensors are used. The environmental temperature sensor 42 is a sensor that detects the temperature outside the case 44. Since the other components are the same as those in the first embodiment, the reference numerals are the same and the description thereof is omitted.

  Next, the operation of the eardrum thermometer 40 will be described with reference to FIGS. 5 and 6.

  In the measurement using the eardrum thermometer 40 of the present invention, first, the person to be measured inserts the eardrum thermometer 40 of the present invention into the ear. The internal temperature T2 of the case 44 is detected by the thermistor 25 and stored in the storage unit 41a. Next, the external temperature T3 is detected by the environmental temperature sensor 42 and stored in the storage unit 41a. Next, signals from the thermistor 25 and the thermopile 22 are input. Then, the calculation unit 41b adds the value ΔT obtained by converting the internal temperature T2 and the value from the thermopile 22 into a temperature difference to obtain the eardrum temperature (T1 = T2 + ΔT). And when internal temperature T2 and external temperature T3 are equal, T1 is output as it is. Then, the eardrum temperature T1 is displayed on a display (not shown). Further, when the internal temperature T2 and the external temperature T3 are different, a value obtained by multiplying a difference (T3−T2) between the external temperature T3 and the internal temperature T2 by a predetermined correction coefficient k (k · (T3−T3)). T2)) is added, and the eardrum temperature (T1 = T2 + k · (T3−T2) + ΔT) is output.

  In this manner, the environmental temperature T3 on the back surface of the case 44 is measured, corrected, and output, so that the temperature of the eardrum can be accurately measured without being affected by the environmental temperature.

  Next, an eardrum thermometer according to a third embodiment of the present invention will be described. FIG. 7 is a front sectional view of the eardrum thermometer 50 according to the present embodiment. FIG. 8 is a diagram showing measurement using the eardrum thermometer 50. The eardrum thermometer 50 includes a thermopile 22 as a non-contact temperature sensor that detects infrared rays emitted from the eardrum, a thermistor 25 that measures the temperature of the thermopile 22 itself for temperature compensation, and the thermopile 22 and thermistor 25. It comprises a control unit 51 that detects output, a harness 52 that electrically connects them, and a case 52 that collectively stores the thermopile 22, the thermistor 25, and the control unit 51. The control unit 51 includes a wireless transmission device 51b that transmits a signal related to the eardrum temperature T1. The exposed surface of the case 52 is covered with a heat insulating material 53. And the signal transmitted from the wireless transmitter 51b by the external receiver 54 is received, and the eardrum temperature T1 is displayed. Inside the eardrum thermometer 50, the description of the same components as those in the first embodiment is omitted except that the wireless transmission device 51b is provided.

    Next, the operation of the eardrum thermometer 50 will be described with reference to FIGS.

  In the measurement using the eardrum thermometer 50 of the present invention, first, the person to be measured inserts the eardrum thermometer 50 of the present invention into the ear. Signals from the thermistor 25 and the thermopile 22 are input to the control unit 51. Then, the calculation unit 51a adds the value ΔT obtained by converting the internal temperature T2 and the value from the thermopile 22 into a temperature difference to obtain the eardrum temperature (T1 = T2 + ΔT). And the signal which concerns on the eardrum temperature T1 is transmitted with the wireless transmitter 51b. The receiver 54 receives the signal and displays the eardrum temperature T1.

  In this way, the case 52 is covered with the heat insulating material 53, and a signal related to the measured eardrum temperature T1 is wirelessly output and received by the receiver to display the eardrum temperature. Temperature can be measured.

  The present invention is used as an eardrum thermometer that is inserted into the ear canal and measures the temperature of the eardrum.

1 is a cross-sectional view of an ear equipped with an eardrum thermometer according to a first embodiment of the present invention. It is front sectional drawing of the eardrum thermometer 20 which concerns on the 1st Embodiment of this invention. It is a block diagram of a tympanic thermometer. It is a processing flowchart of heating and cooling. It is front sectional drawing of the eardrum thermometer which concerns on the 2nd Embodiment of this invention. It is a block diagram of a tympanic thermometer. It is front sectional drawing of the eardrum thermometer which concerns on the 3rd Embodiment of this invention. It is a figure which shows the measurement using an eardrum thermometer. FIG. 3 is an enlarged view of a main part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 External auditory canal 20 Tympanic thermometer 21 Tip part 22 Thermopile 23 Tympanic membrane 24 Output line 25 Thermistor 26 Control part 26a Calculation part 26b Storage part 27 Power supply 28 Peltier element 29 Heat sink 30 Temperature sensor 31 Harness 32 Case 33 Infrared transmission window 34 Package 35 Heat transfer Element

Claims (3)

When measuring the temperature, a part of it is inserted inside the ear canal of the patient,
A thermopile that is housed in the case and detects infrared rays emitted from the eardrum of the temperature-measured person,
An internal temperature sensor for measuring the internal temperature of the case and the cold junction temperature of the thermopile, and
In the eardrum thermometer provided with calculation means for calculating the eardrum temperature of the temperature-measured person using output values of the thermopile and the internal temperature sensor,
At the time of temperature measurement, an external temperature sensor for detecting the external temperature of the case facing the outside of the ear canal is provided,
An eardrum thermometer comprising temperature adjusting means for heating or cooling the case based on the external temperature and the internal temperature.   The eardrum thermometer according to claim 1, wherein the temperature adjusting means is controlled so that the output temperature by the internal temperature sensor and the output temperature by the external temperature sensor are the same. When measuring the temperature, a part of it is inserted inside the ear canal of the patient,
A thermopile that is housed in the case and detects infrared rays emitted from the eardrum of the temperature-measured person,
An internal temperature sensor for measuring the internal temperature of the case and the cold junction temperature of the thermopile, and
In the eardrum thermometer provided with calculation means for calculating the eardrum temperature of the temperature-measured person using output values of the thermopile and the internal temperature sensor,
At the time of temperature measurement, an external temperature sensor for detecting the external temperature of the case facing the outside of the ear canal is provided,
The tympanic thermometer characterized in that the calculating means further calculates the tympanic temperature based on the external temperature.

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