WO2022013911A1

WO2022013911A1 - Temperature measurement device, method, and program

Info

Publication number: WO2022013911A1
Application number: PCT/JP2020/027224
Authority: WO
Inventors: 大地松永; 雄次郎田中
Original assignee: 日本電信電話株式会社
Priority date: 2020-07-13
Filing date: 2020-07-13
Publication date: 2022-01-20
Also published as: JP7464124B2; JPWO2022013911A1

Abstract

With a temperature measurement method according to the present invention, the temperature inside a living body is measured on the basis of the temperature detected by means of a sensor (31), wherein: an estimated temperature for the temperature inside the living body is calculated, in the sensor (31), by means of a first formula, which is based on a heat flux calculated on the basis of the difference between the temperature at a site in the vicinity of the living body and the temperature at another site or by means of a second formula, which corrects the estimated temperature calculated by means of the first formula; the difference between a first estimated temperature at a first time, which is before the time at which the time derivative of the heat flux exceeds a reference value, and a second estimated temperature calculated by means of the first formula at a second time, which is after the time at which the time derivative of the heat flux exceeds the reference value, and the difference between the first estimated temperature and a third estimated temperature calculated by means of the second formula at the second time are calculated; and the formula for calculating the estimated temperature is determined to be the first formula or the second formula on the basis of the two differences.　As a result, the temperature measurement method according to the present invention is capable of precisely measuring the temperature inside a living body in a non-invasive manner.

Description

Temperature measuring devices, methods and programs

The present invention relates to a temperature measuring device, method and program for non-invasively and accurately measuring the temperature inside a living body.

Conventionally, a technique for non-invasively measuring the body temperature inside a living body (including the deep part) is known. For example, Patent Document 1 (Japanese Unexamined Patent Publication No. 2020-003291) describes a living body, a temperature measuring sensor including a heat flux sensor including a plurality of thermometer elements (hereinafter referred to as “sensor”), and a pseudo in the outside air. It discloses a technique for estimating the core body temperature of a living body assuming a one-dimensional model.

FIG. 7 shows a schematic diagram of a pseudo one-dimensional model in the temperature measurement inside the living body 71. The temperature Tcore inside the object to be measured (living body) 71 is near the surface (the surface in contact with the object) of the sensor 72 when an object (sensor) having thermal resistance Rs is placed on the surface of the object to be measured (living body) 71. It can be estimated from the temperature Tskin of the above and the temperature Tt near the back surface (the surface on the side in contact with the outside air) of the sensor 72 using the following equation.

Tcore = Tskin + Rbody x Hskin

Here, Hskin is a heat flux and is represented by Hskin = (Tskin-Tt) / Rs. Further, Rbody is the thermal resistance of the living body, and Rs is the thermal resistance of the sensor.

Japanese Unexamined Patent Publication No. 2020-003291

However, in this estimation method, since the mode of heat transport to the outside air is assumed to be constant, an error occurs in the estimated temperature when the object is blown by a fan or when the object to be measured moves due to running or the like.

FIG. 8 shows a comparison between the true internal temperature 81 and the estimated temperature 82 when the wind is blown by a fan. The difference (error) between the true internal temperature 81 and the estimated temperature 82 is that when the wind exceeds a certain threshold, the heat transport mode changes from heat conduction to convection heat transfer, and the amount of heat transferred to the outside is Due to major changes.

In addition, since the heat flux Hskin also flows to the outside of the sensor due to the occurrence of convection, the Rbody at the time of convection changes, and an error occurs.

As described above, there is a problem that an error occurs in the estimated temperature in the measurement of the temperature inside the living body. Further, in the error of the estimated temperature, there are problems that the error continues for a long time and that the thermal resistance Rbody of the living body changes at the time of convection of heat which causes the error.

In order to solve the above-mentioned problems, the temperature measuring method according to the present invention is a temperature measuring method for measuring the temperature inside the living body based on the temperature detected by the sensor, and is a temperature measuring method inside the living body. The estimated temperature of the temperature is the first equation based on the heat flux calculated by the difference between the temperature of one place near the living body and the temperature of the other place in the sensor, and the estimated temperature by the first formula. Calculated by either of the second equations to be corrected, the first estimated temperature at the first time before the time when the time differential of the heat flux exceeds the reference value and the time differential of the heat flux are the reference. The difference between the second estimated temperature according to the first equation at the second time after the time exceeding the value, the first estimated temperature, and the second according to the second equation at the second time. It is characterized in that the difference from the estimated temperature of 3 is calculated, and the calculation formula of the estimated temperature is determined to be either the first formula or the second formula based on the two differences. ..

Further, the temperature measuring method according to the present invention is a temperature measuring method for measuring the temperature inside the living body based on the temperature detected by the sensor, and is the first method in the vicinity of the surface in contact with the living body in the sensor. The heat flux is calculated based on the step of measuring the temperature of the first temperature and measuring the second temperature at a position different from the position where the first temperature is measured, and the difference between the first temperature and the second temperature. Steps to detect the time when the time differential of the heat flux exceeds the reference value, the first equation for calculating the estimated temperature based on the heat flux, and the first equation for correcting the estimated temperature according to the first equation. The step of calculating the estimated temperature by any of the equations of 2, the first estimated temperature at the first time before the time when the time differential of the heat flux exceeds the reference value, and the time of the heat flux. Compare the second estimated temperature by the first equation at the second time after the time when the differentiation exceeds the reference value and the third estimated temperature by the second equation at the second time. Further, the step of determining the calculation formula of the estimated temperature is provided.

Further, the temperature measuring device according to the present invention is a temperature measuring method for measuring the temperature inside the living body based on the temperature detected by the sensor, and is the first method in the vicinity of the surface in contact with the living body in the sensor. The heat flux is calculated based on the step of measuring the temperature of the first temperature and measuring the second temperature at a position different from the position where the first temperature is measured, and the difference between the first temperature and the second temperature. A step of detecting a time when the time differentiation of the heat flux exceeds a reference value, a first equation for calculating an estimated temperature based on the heat flux, and a first equation for correcting the estimated temperature according to the first equation. The step of calculating the estimated temperature by any of the equations of 2 and the time differentiation of the first estimated temperature and the heat flux at the first time before the time when the time differentiation of the heat flux exceeds the reference value. According to the difference between the second estimated temperature according to the first equation at the second time after the time when the value exceeds the reference value, and the first estimated temperature and the second equation at the second time. A step of determining the calculation formula of the estimated temperature by comparing with the difference from the third estimated temperature is provided.

Further, the temperature measurement program according to the present invention measures the temperature inside the living body based on the temperature detected by the sensor, and obtains the estimated temperature of the temperature inside the living body in the sensor. Either the first equation based on the heat flux calculated by the difference between the temperature at one location near the living body and the temperature at another location, or the second equation that corrects the estimated temperature according to the first equation. The first estimated temperature at the first time before the time when the time differential of the heat flux exceeds the reference value, and the second time after the time when the time differential of the heat flux exceeds the reference value. The difference between the second estimated temperature according to the first equation, the first estimated temperature, and the third estimated temperature according to the second equation at the second time is calculated. The temperature measuring device is made to function by executing a process of determining the estimated temperature calculation formula as either the first formula or the second formula based on the difference between the two. ..

According to the present invention, it is possible to provide a temperature measuring device, a method and a program for non-invasively and accurately measuring the temperature inside a living body.

FIG. 1 is a schematic diagram of a change with time of temperature for explaining the temperature measuring method according to the first embodiment of the present invention. FIG. 2 is a diagram showing a change over time in the time derivative of the heat flux for explaining the temperature measuring method according to the first embodiment of the present invention. FIG. 3 is a block diagram showing a configuration of a temperature measuring device according to the first embodiment of the present invention. FIG. 4 is a flowchart of the temperature measuring method according to the first embodiment of the present invention. FIG. 5 is a diagram showing an example of the temperature measuring method according to the first embodiment of the present invention. FIG. 6 is a diagram showing a configuration example of a computer according to an embodiment of the present invention. FIG. 7 is a schematic diagram of a pseudo one-dimensional model in a conventional temperature measurement inside a living body. FIG. 8 is a diagram showing changes over time in the deep temperature measured by the conventional method.

FIG. 1 is a schematic diagram of a change over time in temperature for explaining the method according to the present embodiment. FIG. 1 is based on FIG. 8 described above, and shows a temperature change when a wind is applied. The solid line 11 shows the true internal temperature, and the dotted line 12 shows the estimated temperature Tcore calculated by the equation (1).

Tcore = Tskin + Rbody x Hskin (1)

Here, Hskin is a heat flux, is represented by Hskin = (Tskin-Tt) / Rs, and is calculated from the difference between Tskin and Tt. Further, Tskin is the temperature near the front surface (for example, the surface in contact with the living body) of the sensor, Tt is the temperature near the back surface (the surface in contact with the outside air) of the sensor, Rbody is the thermal resistance of the living body, and Rs is the heat of the sensor. It is resistance.

When the heat transport mode changes with the start of convection by applying wind, a positive peak (convex upward) appears at the estimated temperature 12. Further, when the wind is stopped and the heat transport mode (convection) changes with the end of convection, a negative peak (convex downward) appears at the estimated temperature 12.

As described above, since the estimated temperature 12 has an error as compared with the internal temperature 11, it is necessary to correct the estimated temperature 12 including this error in order to calculate an accurate estimated temperature.

In the correction of the estimated temperature, it is first necessary to detect when the correction is required, that is, when the heat transport mode (convection) changes. As shown in FIG. 1, the change in the estimated temperature 12 is gradual because it depends on the heat capacity of the living body and the sensor. Therefore, it is difficult to correct the estimated temperature 12 by detecting the heat transport mode by the change of the estimated temperature 12. Therefore, in the present embodiment, the change in the heat transport mode is detected by using the time derivative dHskin of the heat flux Hskin, and the error at the estimated temperature 12 is corrected.

FIG. 2 shows the time derivative dHskin of the heat flux Hskin with respect to the time course of the temperature shown in FIG. Unlike the change in the estimated temperature, the time derivative dHskin changes sharply when the heat transport mode changes and expresses steep peaks 21 and 22, so that it becomes easy to specify the time.

Further, the estimated temperature Tcore can be corrected and calculated by the following formula.

Tcore = Tskin + α x Rbody x Hskin (2)

Here, α is a correction coefficient, and it is desirable that it is 1.03 or more and 1.15 or less. In this embodiment, α = 1.05. As described above, the equation (2) corrects the estimated temperature according to the equation (1).

As described above, an error occurs in the estimated temperature due to the convection change, so the correction is performed when the convection change is detected. Specifically, when the time derivative dHskin of the heat flux Hskin exceeds the reference value (threshold value), it is determined that a convection change has occurred and correction is performed.

However, when the environmental temperature outside the sensor (hereinafter referred to as "external temperature") such as the outside air temperature and the room temperature changes, the time derivative dHskin of Hskin also exceeds the threshold value. As a result, even though the convection change has not occurred, it is erroneously recognized (detected) that the convection change has occurred. In this case, since the estimated temperature is calculated using the formula (2) instead of the formula (1) that should be originally used, an error occurs.

In order to eliminate this error, in the present embodiment, the estimated temperature is calculated by both the equations (1) and (2) and compared with the estimated temperature before the detection of the convection change, which is more accurate. Determine the formula for calculating the estimated temperature. The details will be described below.

<First Embodiment>
The first embodiment of the present invention will be described with reference to FIGS. 1 to 6.

<Configuration of temperature measuring device>
FIG. 3 shows a block diagram of the configuration of the temperature measuring device 30 according to the present embodiment. The temperature measuring device 30 includes a measuring unit (sensor) 31, a storage unit 32, a calculation unit 33, and an output unit 34.

The measuring unit (sensor) 31 is arranged near the surface of the object to be measured (for example, a living body) in contact with the surface, and measures the temperature Tskin (first temperature) near the surface of the measuring unit (sensor) 31. The thermometer element 1 and a second thermometer element for measuring the temperature Tt (second temperature) in the vicinity of the back surface of the measuring unit 31 (for example, the surface on the side in contact with the outside air) are provided.

Here, the place where the temperature Tt is measured is not limited to the back surface of the measuring unit 31, and may be a place different from the place where the temperature Tskin is measured, and is separated from the place where the temperature Tskin is measured, that is, the first thermometer element. It is desirable that the location is. The second thermometer element may be arranged at a position far enough away from the first temperature and the second temperature so that the heat flux can be accurately calculated.

Further, in the present embodiment, two thermometer elements are used, but the number is not limited to two and may be plural. It is possible to measure the heat flux more accurately by using a plurality of thermometer elements.

In the storage unit 32, the temperature storage unit 321 stores the measurement time and the measurement temperature measured by the measurement unit 31, and the time constant, the reference value (threshold), and the correction coefficient required for the temperature measurement according to the present embodiment. , Etc. are memorized. Further, the estimated temperature storage unit 322 stores the estimated temperature calculated by the equation (1) and the equation (2) by the calculation unit 331 of the calculation unit 33.

In the calculation unit 33, the calculation unit 331 calculates the estimated temperature by the equations (1) and (2). In addition, the difference in estimated temperature before and after the detection time of the change in heat flux is calculated. Further, the calculation unit 331 calculates and calculates numerical values necessary for temperature measurement according to the present embodiment, such as heat flux and its time derivative.

Further, the comparison unit 332 compares the time derivative dHskin of the heat flux calculated by the calculation unit 331 with the reference value. Further, regarding the difference in the estimated temperature calculated by the calculation unit 331, the difference based on the equation (1) and the difference based on the equation (2) are compared. In addition, the calculation formula of the estimated temperature is determined based on the result of the comparison.

The output unit 34 outputs (displays) the estimated temperature calculated by the equations (1) and (2). When the accurate temperature cannot be output, it is possible to output (display) a blank (state in which nothing is displayed) or the inability to measure the accurate temperature.

<Temperature measurement method>
An outline of the method according to the present embodiment will be described with reference to FIG. FIG. 4 shows a flowchart of the temperature measuring method according to the present embodiment.

First, by the sensor (measurement unit), the temperature near the front surface (surface in contact with the living body) of the sensor (first temperature) Tskin and the temperature near the back surface of the sensor (surface in contact with outside air) (second temperature). ) Tt is measured (step 401).

Next, the estimated temperature is calculated by the formula (1) (step 402).

Next, the time derivative dHskin of the heat flux Hskin is calculated (step 403). The dHskin is calculated as the difference between the heat flux Hskins at the adjacent sampling (measurement) times. Here, for example, the interval between adjacent sampling (measurement) times is about 1 second.

For example, when Tskin (ta) and Tt (ta) are measured at time ta, Hskin (ta) is calculated by Hskin (ta) = {Tskin (ta) -Tt (ta)} / Rs.

Similarly, when Tskin (tb) and Tt (tb) are measured at time tb following time ta, Hskin (tb) is Hskin (tb) = {Tskin (tb) -Tt (tb)} / Rs. It is calculated by.

At this time, dHskin is calculated by dHskin = Hskin (tb) -Hskin (ta).

Here, ta and tb do not have to be adjacent sampling (measurement) times, and may have a predetermined interval.

Next, the dHskin value is compared with the reference value (hereinafter referred to as “convection detection threshold”) dHskin_thres (step 404).

When dHskin is equal to or less than the convection detection threshold dHskin_thres (| dHskin | ≦ dHskin_thres), it is determined that the form of heat transfer has not changed due to convection. Determine the estimated temperature of and continue to measure at the next time.

On the other hand, when dHskin exceeds the convection detection threshold dHskin_thres (| dHskin |> dHskin_thres), that is, when a change in heat flux is detected, whether this change in dHskin is due to a change in convection, a change in external temperature, or the like. It is determined as follows whether it is due to the factor of. Here, the convection detection threshold dHskin_thres is set to, for example, 0.02 ° C./sec.

First, at the estimated temperature stored in the estimated temperature storage unit 322, estimation is performed at a time t0-τ1 (hereinafter referred to as “first time”) that is advanced by a predetermined time τ1 from the time t0 at which the change in heat flux is detected. Select (acquire) the temperature Tcore1 (hereinafter referred to as “first estimated temperature”) (step 405). Here, τ1 can be set from 60 seconds to 300 seconds.

Next, assuming that the change in dHskin is due to factors such as the change in external temperature, the estimated temperature is calculated based on the equation (1).

At the same time, assuming that the change in dHskin is due to factors such as changes in convection, the estimated temperature is calculated by correcting it with equation (2).

Next, the estimated temperature Tcore2 (hereinafter, referred to as “second time”) calculated by the equation (1) at the time t0 + τ2 (hereinafter referred to as “second time”) after a predetermined time τ2 from the time t0 when the change in heat flux is detected. The "second estimated temperature") and the estimated temperature Tcore3 calculated by the equation (2) (hereinafter referred to as "third estimated temperature") are acquired (step 406). Here, τ2 can be set to about 600 seconds. It is desirable that τ2 is 300 seconds to 1200 seconds.

Next, the difference between the first estimated temperature and the second estimated temperature (| Tcore1-Tcore2 |) is calculated. Further, the difference between the first estimated temperature and the third estimated temperature (| Tcore1-Tcore3 |) is calculated (step 407).

Next, the difference between the first estimated temperature and the second estimated temperature is compared with the difference between the first estimated temperature and the third estimated temperature (step 408).

As a result of comparing these differences, the formula for calculating the smaller difference between the second estimated temperature and the third estimated temperature, that is, the formula (1) or the formula (2) is estimated. It is used as a temperature calculation formula.

Continue measuring the temperature and calculating the estimated temperature using the adopted calculation formula (steps 409, 410).

<Example>
An example of the temperature measuring method according to the present embodiment will be described with reference to FIG.

FIG. 5 shows the time-dependent change 51 of the time derivative dHskin of the heat flux and the time-dependent change 52 of the estimated temperature in the temperature measuring method of the embodiment according to the present embodiment. The time-dependent change 52 of the estimated temperature indicates an estimated temperature 521 calculated by the formula (1) and an estimated temperature 522 calculated by the formula (2) in order to explain the temperature measuring method of the present embodiment.

Further, the time-dependent change 53 of the estimated temperature indicates the estimated temperature 531 by the temperature measuring method of the embodiment according to the present embodiment and the estimated temperature 532 by the temperature measuring method not considering the change of the external temperature as a comparative example. Further, the temperature measured by the eardrum is shown as the true internal temperature 530.

The case where the temperature measurement is started from the state where the convection change does not occur will be described as an example. First, the estimated temperature 52 is calculated by the equation (1) because no convection has occurred.

Next, when dHskin51 exceeds the reference value (threshold value) 511 at time t1, the estimated temperature Tcore1 (first estimated temperature) at time t1-τ1 is selected in the estimated temperature stored in the estimated temperature storage unit 322. (Acquired) (white circle in the figure).

Subsequently, the estimated temperature 521 according to the equation (1) and the estimated temperature 522 according to the equation (2) are calculated, and at time t1 + τ2, the second estimated temperature Tcore2 (black triangle in the figure) which is the estimated temperature 521 according to the equation (1). And the third estimated temperature Tcore3 (black circle in the figure), which is the estimated temperature 522 by the equation (2), is calculated.

Next, as a result of comparing the difference between the first estimated temperature Tcore1 and the second estimated temperature Tcore2 and the difference between the first estimated temperature Tcore1 and the third estimated temperature Tcore3, the first estimated temperature Tcore1 is obtained. Since the difference from the third estimated temperature Tcore3 is smaller, the formula (2) for calculating the third estimated temperature Tcore3 is adopted as the formula for calculating the estimated temperature to measure the temperature and calculate the estimated temperature. continue.

Next, when dHskin51 exceeds the reference value (threshold value) 511 at time t2, the estimated temperature (first estimated temperature) at time t2-τ1 is selected in the estimated temperature stored in the estimated temperature storage unit 322 (first estimated temperature). Acquired) (white circle in the figure).

In the estimated temperature 531 calculated by the temperature measuring method of the embodiment according to the present embodiment, the estimated temperature is calculated by the equation (2) including the correction by the convection change after the time t1, and is the same temperature as the internal temperature 530. Is shown. Further, at time t2, the change in dHskin51 is due to the change in the external temperature, and the convection state does not change, that is, the convection does not end. Therefore, the estimated temperature is calculated from the equation (2) as before t2. The temperature is equivalent to the internal temperature of 530.

On the other hand, in the estimated temperature 532 of the comparative example, after the time t1, the estimated temperature is calculated by the equation (2) including the correction by the convection change, and shows the same temperature as the internal temperature 530. However, at time t2, although the change in dHskin51 is due to the change in the external temperature, it is erroneously recognized as being due to the change in the convection state. As a result, it is considered that the convection has ended, and the estimated temperature is calculated from the equation (1), so that a difference (error) from the internal temperature 530 occurs.

As described above, according to the temperature measuring method according to the present embodiment, it is possible to measure the temperature inside the living body with high accuracy without erroneously recognizing the convection change when the temperature change occurs.

In the embodiment of the present invention, the generation of convection and the end of convection can be detected by measuring the change of the time derivative dHskin of the heat flux in positive and negative directions. For example, when the change in dHskin is 0 or more, the change in the morphology of heat conduction accompanying the start of convection is detected, and when the change in dHskin is less than 0, the change in the morphology of heat conduction accompanying the end of convection is detected. , The convection period can be detected.

In the embodiment of the present invention, when the change in the time derivative of the heat flux is not detected and the convection does not occur, the calculation unit 33 sequentially uses the temperature measured by the measurement unit (sensor) 31. The calculated estimated temperature is output to the output unit 34.

On the other hand, when the change in the time derivative of the heat flux is detected, the temperature data stored in the storage unit 32 after being measured by the measurement unit (sensor) 31 is read out (read) by the calculation unit 33. The calculation formula is determined, the estimated temperature is calculated, and it is output to the output unit 34. As a result, it takes, for example, about 20 minutes from the measurement to the output of the estimated temperature.

Alternatively, the temperature measured by the measuring unit (sensor) may be collectively stored in the storage unit, and then the temperature data may be read out (read) to calculate the estimated temperature.

The temperature measuring device according to the present embodiment may be attached to the user's body as an integral part of the wearable device.

Alternatively, in the temperature measuring device according to the embodiment of the present invention, the measuring unit (sensor) 31 is attached to the user's body as a wearable device, and the storage unit 32 and the calculation unit 33 are stored in a smartphone or server outside the wearable device. May be provided. In this case, the temperature measuring device is provided with a transmission / reception unit for each of the wearable device and an external server, etc., and the measured temperature measured by the wearable device is transmitted to the server or the like, and is stored and calculated by the server or the like. Finally, the estimated temperature and the like (including the display that the deep temperature is not measured) may be output to the server or the like, or may be transmitted to the wearable device or the like and output.

<Computer configuration example>
FIG. 6 shows a configuration example of the computer 60 in the temperature measuring device according to the embodiment of the present invention. The temperature measuring device can be realized by a computer 60 including a CPU (Central Processing Unit) 63, a storage device (storage unit) 62, and an interface device 61, and a program for controlling these hardware resources. Here, the measurement unit and the output unit are connected to the interface device. The CPU executes the process according to the embodiment of the present invention according to the temperature measurement program stored in the storage device. In this way, the temperature measuring program makes the temperature measuring device work.

In the temperature measuring device according to the embodiment of the present invention, a computer may be provided inside the device, or at least one part of the functions of the computer may be realized by using an external computer. Further, the storage unit may also use the storage medium 64 outside the apparatus, or may read out and execute the temperature measurement program stored in the storage medium 64. The storage medium 64 includes various magnetic recording media, optical magnetic recording media, CD-ROMs, CD-Rs, and various memories. Further, the temperature measurement program may be supplied to the computer via a communication line such as the Internet.

As described above, according to the temperature measuring device, method and program according to the present embodiment, the temperature inside the living body can be measured non-invasively and accurately.

In the embodiment of the present invention, an example of the structure, dimensions, materials, etc. of each component is shown in the configuration of the temperature measuring device, the temperature measuring method, and the like, but the present invention is not limited to this. Anything that exerts functions such as the configuration of the temperature measuring device and the temperature measuring method and exerts an effect may be used.

The present invention can be applied to a deep thermometer used for body temperature control of workers, athletes and the like.

30 Temperature measuring device 31 Measuring unit (sensor)
32 Storage unit 321 Temperature storage unit 322 Estimated temperature storage unit 33 Calculation unit 331 Calculation unit 332 Comparison unit 34 Output unit

Claims

It is a temperature measurement method that measures the temperature inside a living body based on the temperature detected by a sensor.
The first equation based on the heat flux calculated by the difference between the temperature of one place near the living body and the temperature of the other place in the sensor for the estimated temperature of the temperature inside the living body, and the first equation. Calculated by one of the second equations that correct the estimated temperature by the equation,
The first estimated temperature at the first time before the time when the time derivative of the heat flux exceeds the reference value, and the second time after the time when the time derivative of the heat flux exceeds the reference value. Calculate the difference between the second estimated temperature according to the equation 1 and the difference between the first estimated temperature and the third estimated temperature according to the second equation at the second time.
A temperature measuring method for determining the estimated temperature calculation formula as either the first formula or the second formula based on the difference between the two.
It is a temperature measurement method that measures the temperature inside a living body based on the temperature detected by a sensor.
In the sensor, a step of measuring a first temperature near a surface in contact with the living body and measuring a second temperature at a position different from the position where the first temperature is measured, and a step of measuring the second temperature.
The step of calculating the heat flux based on the difference between the first temperature and the second temperature, and
The step of detecting the time when the time derivative of the heat flux exceeds the reference value, and
A step of calculating the estimated temperature by either the first equation for calculating the estimated temperature based on the heat flux and the second equation for correcting the estimated temperature by the first equation.
The first estimated temperature at the first time before the time when the time differential of the heat flux exceeds the reference value and the first at the second time after the time when the time differential of the heat flux exceeds the reference value. The difference between the first estimated temperature and the third estimated temperature according to the second equation at the second time is compared with the difference from the second estimated temperature according to the above equation, and the estimated temperature is compared. A temperature measurement method with steps to determine the formula for.
The temperature measurement according to claim 2, further comprising a step of determining the formula for calculating the smaller difference between the first formula and the second formula as the calculation formula for the estimated temperature. Method.
The first equation is
Tcore = Tskin + Rbody × (Tskin-Tt) / Rs
The second equation is
Tcore = Tskin + α × Rbody × (Tskin-Tt) / Rs
Tskin is the first temperature, Tt is the second temperature, Rbody is the thermal resistance of the living body, Rs is the thermal resistance of the sensor, and α is the correction coefficient.
The temperature measuring method according to any one of claims 1 to 3.
The temperature measuring method according to claim 4, wherein the correction coefficient in the second equation is 1.03 or more and 1.15 or less.
When the time derivative of the heat flux is 0 or more, the change in the heat transport mode accompanying the start of convection is determined, and when the time derivative of the heat flux is smaller than 0, the change in the heat transport mode accompanying the end of the convection is determined. The temperature measuring method according to any one of claims 1 to 5, wherein the determination is made.
A temperature measuring device that measures the temperature inside a living body based on the temperature detected by a sensor.
A first thermometer element arranged near the surface in contact with the living body and measuring the first temperature, and a second thermometer element arranged at a position away from the first thermometer element and measuring the second temperature. The sensor having a thermometer element and
A first equation based on the heat flux calculated by the difference between the temperature at one location near the living body and the temperature at another location in the sensor, and a second equation for correcting the estimated temperature according to the first equation. And the calculation unit that calculates the estimated temperature by each,
An estimated temperature storage unit that stores the first estimated temperature at the first time before the time when the time derivative of the difference exceeds the reference value.
According to the first estimated temperature, the estimated temperature according to the first equation at the second time after the time when the time derivative of the difference exceeds the reference value, and the second equation at the second time. A temperature measuring device equipped with a comparison unit that compares with the estimated temperature.
For a temperature measuring device that measures the temperature inside a living body based on the temperature detected by a sensor.
The first equation based on the heat flux calculated by the difference between the temperature of one place near the living body and the temperature of the other place in the sensor for the estimated temperature of the temperature inside the living body, and the first equation. Calculated by one of the second equations that correct the estimated temperature by the equation,
The first estimated temperature at the first time before the time when the time derivative of the heat flux exceeds the reference value, and the second time after the time when the time derivative of the heat flux exceeds the reference value. Calculate the difference between the second estimated temperature according to the equation 1 and the difference between the first estimated temperature and the third estimated temperature according to the second equation at the second time.
To function a temperature measuring device, which comprises executing a process of determining the estimated temperature calculation formula as one of the first formula and the second formula based on the difference between the two. Temperature measurement program.