JP7388266B2 - ear thermometer - Google Patents

Description

The present invention relates to an ear thermometer that is inserted into the external auditory canal of a person to measure body temperature without contact.

In recent years, ear thermometers have been known that measure a person's body temperature by inserting a probe into the person's ear canal and measuring the temperature of the eardrum using an infrared temperature sensor in a non-contact manner (for example, see Patent Document 1). . It is said that eardrum temperature is a good reflection of core body temperature.

However, although it is possible to accurately measure eardrum temperature by inserting an infrared temperature sensor deep into the ear canal, there are safety issues and there are individual differences in the shape and size of the ear canal, so it is difficult to manufacture a general-purpose product. is difficult. For this reason, it has been proposed to provide an infrared temperature sensor near the entrance of the ear canal. As such an ear thermometer, for example, an ear thermometer 200 as shown in FIGS. 9 and 10 has been proposed. That is, the ear thermometer 200 includes a casing 210 that houses a battery and a control circuit, an engaging part 220 that engages with the entrance of the external auditory canal, an insertion part 230 provided at the back of this engaging part 220, and a housing 210 that houses a battery and a control circuit. An infrared temperature sensor 240 provided inside the section 230 is provided. The field of view of the infrared temperature sensor 240 is a narrow angular range in FIG. 9, and a wide angular range in FIG. In these figures, G indicates the external auditory canal, K indicates the eardrum, H indicates the human head, and L indicates the outside of the external ear.

However, as shown in FIG. 9, when using an infrared temperature sensor 240 with a narrow field of view, depending on the direction of the infrared temperature sensor 240, the field of view may be within the range indicated by the two-dot chain line P1, that is, when measuring the outside of the outer ear (outer ear wall). , the visual field range is the range indicated by the two-dot chain line P2, that is, the case where the eardrum K is measured. The temperature outside the outer ear tends to fluctuate depending on the outside air, and a lower temperature may be detected than when only the temperature of the eardrum K is measured. Further, when the outside temperature fluctuates, the measured body temperature fluctuates along with the fluctuations in the outside temperature, making it impossible to accurately measure the body temperature that is originally intended to be measured.

On the other hand, if an infrared temperature sensor 240 with a wide viewing range is used as shown in FIG. 10, the viewing range will include the range indicated by the two-dot chain line Q, that is, the temperature outside the outer ear will be measured, and the body temperature that is originally desired to be measured will also be measured. Cannot measure accurately.

In order to eliminate the influence of such outside temperature, it is conceivable to attach a temperature sensor that measures the outside temperature to the housing 210 or the like. However, the casing 210 is small, and if the temperature sensor is provided in the casing 210 that houses the battery and the control board, it is susceptible to the heat generated by them, and accurate temperature calibration cannot be performed. Further, since the temperature outside the outer ear and the outside air temperature do not necessarily have a constant relationship, it is not possible to derive the temperature outside the outer ear even if the outside air temperature is measured.

Japanese Patent Application Publication No. 2002-340681

An object of the present invention is to accurately measure the external auditory canal temperature, which fluctuates under the influence of the external temperature, to correct measurement errors caused by the external external temperature and the external auditory canal temperature, and to measure body temperature with high precision.

One aspect of the present invention includes a non-contact infrared temperature sensor that is inserted into the ear canal toward the inner side of the ear canal and measures the temperature of the object to be measured, and a non-contact infrared temperature sensor that measures the temperature near the entrance of the ear canal to compensate for the influence of outside temperature. The outside temperature influence is corrected based on the correction temperature sensor to be measured, the temperature of the temperature measurement target obtained by the infrared temperature sensor, and the temperature near the entrance of the external auditory canal obtained by the correction temperature sensor. a control unit that derives the temperature of the temperature measurement target;
a casing that houses the control unit;
The correction temperature sensor is provided outside the casing and is spaced apart from the casing.

According to the present invention, body temperature can be measured with high accuracy by eliminating the influence of body temperature fluctuations due to outside temperature.

FIG. 1 is a schematic diagram showing a state in which the ear thermometer according to the first embodiment of the present invention is attached to an external auditory canal. FIG. 2 is a front view showing the ear thermometer. FIG. 7 is a front view showing an example of the mounting position of the correction temperature sensor when the ear thermometer is worn. An explanatory diagram showing temperature changes outside the outer ear measured by the ear thermometer. FIG. 3 is an explanatory diagram showing temperature changes in infrared light reception temperature measured by the ear thermometer. Explanatory diagram showing temperature changes in eardrum temperature linked temperature derived by the ear thermometer. FIG. 7 is a top view showing an ear thermometer according to a second embodiment of the present invention. FIG. 7 is an explanatory diagram showing a biosensor provided with an ear thermometer according to a third embodiment of the present invention. The schematic diagram which shows an example of the visual field range of an ear type thermometer. The schematic diagram which shows another example of the visual field range of an ear thermometer.

FIG. 1 is a schematic diagram showing the ear thermometer 10 according to the first embodiment of the present invention being attached to the external auditory canal, FIG. 2 is a front view showing the ear thermometer 10, and FIG. 3 is the ear thermometer 10 being attached. It is a front view which shows an example of the mounting position of the correction|amendment temperature sensor at the time of doing. In these figures, G indicates the external auditory canal, K indicates the eardrum, H indicates the human head, M indicates the auricle, R indicates the tragus of the ear, S indicates the concha cavity, and L indicates the outside of the external ear.

The ear thermometer 10 includes a housing 20 that engages with the entrance of the external auditory canal, an ear insertion part 30 that is attached to the side wall of the housing 20, and is inserted into the external auditory canal G and fixed therein, and controls for the housing 20 that will be described later. The correction temperature sensors 50 and 60 are connected to the section 22 (calculation section). The housing 20 includes a case 21 made of a silicone resin material, and a control section 22 (not shown) including a battery, a memory, a control circuit, a wireless communication section, etc. is housed in the case 21. Silicone resin material has little effect on the human body, is a flexible material, and has low thermal conductivity.

The control unit 22 performs calculations based on the outer ear external temperature T1 and the infrared light receiving temperature T2 as described later.

The ear insertion part 30 includes a cylindrical case 31 made of silicone resin. It is desirable that the case 31 be made of a softer material than the case 21 from the viewpoint of reducing the burden upon insertion into the ear. An opening 32 is provided on the side of the eardrum K of the case 31, and an infrared temperature sensor 40 is accommodated therein. The infrared temperature sensor 40 has a wide viewing angle. The infrared temperature sensor 40 is composed of, for example, a thermopile, a bolometer, etc., and outputs a detection signal, from which an infrared reception temperature T2 is derived in processing by the control unit 22.

The correction temperature sensor 50 includes a temperature measuring element, such as a thermistor (temperature sensor) 51, and a cable (lead wire) 52 that connects the thermistor 51 and the control unit 22. Like the correction temperature sensor 50, the correction temperature sensor 60 also includes a thermistor (temperature sensor) 61 and a cable (lead wire) 62 that connects the thermistor 61 and the control section 22. Note that the lengths of the cables 52 and 62 are approximately several centimeters.

Detection signals are output from each of the correction temperature sensors 50 and 60, and the average value is taken by the control unit 22 to derive the outer ear external temperature T1.

The ear thermometer 10 configured as described above measures body temperature in the following manner. That is, the ear thermometer 10 is brought close to the entrance of the external auditory canal G, and the thermistors 51 and 61 of the correction temperature sensors 50 and 60 are adhered to the vicinity of the entrance of the external auditory canal G, for example, the back of the tragus R and the concha cavity S. For adhesion, use adhesive tape or adhesive that is safe for the skin. Then, the ear insertion part 30 is inserted toward the external auditory canal G, and the thermistors 51 and 61 are sandwiched between the case 21, the back of the tragus R, and the concha cavity S.

When the ear thermometer 10 is powered on in such a state, the control section 22 is activated, and the infrared temperature sensor 40 and correction temperature sensors 50 and 60 connected to the control section 22 start measurement. The infrared temperature sensor 40 measures the intensity of infrared rays input from the tip side. The measured infrared intensity is output as a detection signal, and the controller 22 performs processing such as amplification and A/D conversion to derive the infrared reception temperature T2.

The correction temperature sensors 50 and 60 measure the temperature of the parts that are in contact with the thermistors 51 and 61, and input the measured temperature to the control unit 22 as a detection signal. The detection signal is subjected to processing such as amplification, averaging, and A/D conversion in the control unit 22 to derive the outer ear external temperature T1.

The control unit 22 derives the eardrum temperature-linked temperature T3 as follows. In addition, FIG. 4 is an explanatory diagram showing a temperature change in the outer ear external temperature T1 measured by the ear thermometer 10, FIG. 5 is an explanatory diagram showing a temperature change in the infrared reception temperature T2 measured by the ear thermometer 10, and FIG. 1 is an explanatory diagram showing a temperature change in the eardrum temperature-linked temperature T3 derived by the ear thermometer 10. FIG.

As shown in FIG. 1, the thermistors 51 and 61 that measure temperature changes in the outer ear external temperature T1 are placed in areas that are separated from the housing 20 and are in contact with the outside air, so they are easily influenced by the outside air and are subject to fluctuations. Although a large detection signal can be obtained, it is not easily affected by the heat generated by the battery, memory, control circuit, wireless communication unit, etc. included in the control unit 22 housed in the housing 20, and the measured temperature is within the external auditory canal G. The temperature is close to that of Note that the case 21 included in the case 20 is made of a material with low thermal conductivity, and the influence from the external ear L side, which has a large heat capacity, is large, so the error due to heat conduction from the case 20 is reduced. Occurrences are kept to a minimum. Note that if the housing 20 is in a state where it generates heat or absorbs heat that affects the thermistors 51 and 61, this will also affect the temperature outside the outer ear L, so the effects will be canceled out. become.

Next, the infrared temperature sensor 40 that measures the infrared reception temperature T2 maintains the temperature of the eardrum K, which is approximately at the body temperature level, but also includes the external ear L, which is affected by the outside temperature, within its field of view, so the external ear temperature is increased to some extent. It fluctuates in conjunction with T1.

Here, let k be the variation ratio coefficient between outer ear external temperature T1 and infrared light reception temperature T2, and let Tref be the reference value of outer ear external temperature T1 (for example, the average value of outer ear external temperature T1), and calculate the corrected temperature T at each measurement point. It is calculated using the following equation (1).

T=T2-k(T1-Tref)...(1)
After adjusting the variation in the outer ear external temperature T1 to the variation ratio of the infrared light receiving temperature T2, the variation in the outer ear external temperature T1 is removed from the infrared light receiving temperature T2 by subtracting it if it is greater than Tref and adding it if it is less than Tref.

It can be said that the corrected temperature T derived in this way is a tympanic membrane temperature-linked temperature T3 that indicates the movement of the tympanic membrane temperature. The eardrum temperature-linked temperature T3 is body temperature data derived by the control unit 22. Body temperature data is stored in memory or outputted to the outside via wireless or the like.

As described above, according to the ear thermometer 10, by removing the influence of the outside temperature on the temperature fluctuations of the eardrum K, which are small at the level of 1°C to 2°C, the fluctuations in the eardrum temperature are not buried in the fluctuations of the outside temperature. , it is possible to measure eardrum temperature with high accuracy. Incidentally, eardrum temperature fluctuations, that is, body temperature changes, are said to indicate circadian rhythms and brain activity, and are useful as important vital signs.

On the other hand, by installing the thermistors 51 and 61 outside the casing 20, the influence of heat generated by the control unit 22 can be removed compared to when the thermistors 51 and 61 are installed inside the casing 20. Therefore, it is not necessary to install a heat shielding wall inside the housing 20, and the configuration of the housing can be simplified and the size and weight can be reduced.

Note that the cables 52 and 62 may be set a little longer and adhered to positions spaced apart from the housing 20 using adhesive tape or adhesive. For the thermistors 51 and 61, if the diameter of the ear canal G is large and there is a margin between the ear insertion part 30 and the outside of the outer ear, a temperature sensor may be attached near the side of the ear insertion part.

FIG. 7 is a top view showing an ear thermometer 10A according to the second embodiment of the present invention. In FIG. 7, the same reference numerals are given to the same functional parts as in FIG. 2, and detailed explanation thereof will be omitted.

The ear thermometer 10A includes correction temperature sensors 50A and 60A instead of the correction temperature sensors 50 and 60. The correction temperature sensors 50A and 60A are both attached to the outer surface of the housing 20 and connected to the control unit 22. The correction temperature sensors 50A and 60A measure the outer ear external temperature T1 in the same manner as the correction temperature sensors 50 and 60, and the control unit 22 measures the outer ear external temperature T1 and the infrared temperature sensor 40 as described above. The eardrum temperature linked temperature T3 is derived based on the infrared light receiving temperature T2. Therefore, the same effects as those of the ear thermometer 10 described above can be obtained.

FIG. 8 is an explanatory diagram showing a biosensor 100 provided with an ear thermometer 140 according to a third embodiment of the present invention.

The biosensor 100 includes a housing 110 that houses a battery, a circuit board, etc., and is formed sufficiently larger than the entrance of the external auditory canal G. The housing 110 is provided with a hook 120 for hooking onto the auricle M, a pulse detection sensor 130 provided on the side wall surface of the housing 110, and an ear thermometer 140 inserted into the external auditory canal G. The housing 110 is formed to be sufficiently larger than the external auditory canal G, and has a shape that allows it to be attached to the entrance of the external auditory canal G due to its positional relationship with the ear thermometer 140 inserted into the external auditory canal G. The ear thermometer 140 has a housing 141 made of silicone resin.

A control unit 142 (not shown) including a battery, a memory, a control circuit, a wireless communication unit, and the like is housed within the casing 141 . Furthermore, an infrared temperature sensor 150 is held. Correction temperature sensors 160 and 170 are connected to the control unit 142 . The correction temperature sensors 160 and 170 are equipped with temperature measuring elements such as thermistors 161 and 171, for example. The correction temperature sensors 160 and 170 are attached to other components separate from the ear thermometer 140, that is, the pulse detection sensor 130 and the hook 120.

Since both the pulse detection sensor 130 and the hook 120 are in contact with the human head H in a manner that blocks outside temperature, it is possible to measure the body temperature influenced by the outside temperature. Therefore, the outer ear external temperature T1 is measured in the same manner as the correction temperature sensors 50 and 60 described above, and the control unit 142 adjusts the outer ear external temperature T1 and the infrared reception temperature T2 measured by the infrared temperature sensor 150, as described above. Based on this, the eardrum temperature linked temperature T3 is derived. Therefore, the same effects as those of the ear thermometer 10 described above can be obtained.

Note that the present invention is not limited to the embodiments described above. For example, in the above example, the correction temperature sensor is connected to the casing via a string-like connection part, but other structures may be used as long as the influence of heat generated by the casing can be suppressed. Furthermore, although silicone resin is used as the material for the casing of the ear thermometer, other resin materials may be used as long as they have no adverse effects on the human body and have low thermal conductivity. Although there are two temperature sensors for correction, one or three or more may be provided. When a plurality of correction temperature sensors are used, the representative value may be an average value or a lower value may be used as appropriate. In addition, when multiple correction temperature sensors are used, even if one of the correction temperature sensors adhered to the human body detaches from the human body, the outer ear external temperature T1 is measured by the other correction temperature sensor. This increases the reliability of deriving the eardrum temperature-linked temperature T3. It goes without saying that various other modifications can be made without departing from the gist of the present invention.

Although some embodiments of the present invention have been described, the present invention is included in the scope of the invention described in the claims and its equivalents. Below, the invention described in the original claims of the present application will be added.
[Additional note 1]
A non-contact infrared temperature sensor that is inserted into the ear canal toward the inner side of the ear canal and measures the temperature of the object to be measured;
a correction temperature sensor that measures the temperature near the entrance of the ear canal to correct for the influence of outside temperature;
The temperature of the temperature measurement target with the outside temperature influence corrected based on the temperature of the temperature measurement target obtained by the infrared temperature sensor and the temperature near the entrance of the external auditory canal obtained by the correction temperature sensor. a control unit that derives
a casing that houses the control unit;
Equipped with
The correction temperature sensor is an ear thermometer provided outside the housing and spaced apart from the housing.
[Additional note 2]
The ear thermometer according to [Appendix 1], wherein the correction temperature sensor is disposed to be sandwiched between the external auditory canal entrance side and the casing.
[Additional note 3]
The ear thermometer according to [Appendix 1] or [Appendix 2], wherein the correction temperature sensor includes a lead wire connected to the control section and a temperature sensor attached to the tip of the lead wire.
[Additional note 4]
The correction temperature sensor is attached to a separate member separated from the housing [Additional Note 1]
The ear thermometer described in .
[Additional note 5]
The ear thermometer according to any one of [Appendix 1] to [Appendix 4], wherein a plurality of correction temperature sensors are provided.

DESCRIPTION OF SYMBOLS 10... Ear thermometer, 10A... Ear thermometer, 20... Housing, 21... Case, 22... Control part (calculation part), 30... Ear insertion part, 31... Case, 32... Opening part, 40... Infrared temperature sensor , 50...Temperature sensor for correction, 50A...Temperature sensor for correction, 51...Thermistor (temperature sensor), 52...Cable (lead wire), 60...Temperature sensor for correction, 60A...Temperature sensor for correction, 61...Thermistor (temperature) sensor), 62... Cable (lead wire), 100... Biosensor, 110... Housing, 120... Hook, 130... Pulse detection sensor, 140... Ear thermometer, 141... Housing, 142... Control unit (calculating unit) ), 150... infrared temperature sensor, 160... temperature sensor for correction, 161... thermistor, 170... temperature sensor for correction, 171... thermistor, 200... ear type thermometer, 210... housing, 220... engaging portion, 230... insertion Part, 240...Infrared temperature sensor, G...Earth canal, H...Human head, K...Eardrum, L...Outer ear, M...Auricle, S...Concha cavity, T...Temperature after correction, T1...Outer ear Temperature, T2...Infrared light reception temperature, T3...Temperature linked to eardrum temperature.

Claims (5)

A non-contact infrared temperature sensor that is inserted into the ear canal toward the inner side of the ear canal and measures the temperature of the object to be measured;
a correction temperature sensor that measures the temperature near the entrance of the ear canal to correct for the influence of outside temperature;
The temperature of the temperature measurement target with the outside temperature influence corrected based on the temperature of the temperature measurement target obtained by the infrared temperature sensor and the temperature near the entrance of the external auditory canal obtained by the correction temperature sensor. a control unit that derives
a casing that houses the control unit;
Equipped with
The correction temperature sensor is an ear thermometer provided outside the housing and spaced apart from the housing. The ear thermometer according to claim 1, wherein the correction temperature sensor is disposed to be sandwiched between the external auditory canal entrance side and the casing. The ear thermometer according to claim 1 or 2, wherein the correction temperature sensor includes a lead wire connected to the control section and a temperature sensor attached to the tip of the lead wire. The ear thermometer according to claim 1, wherein the correction temperature sensor is attached to a separate member spaced apart from the housing. The ear thermometer according to any one of claims 1 to 4, wherein a plurality of correction temperature sensors are provided.