Probe for measuring deep temperature and deep thermometer

Abstract

In the present invention, a probe 1 for deep temperature measurement used to measure the temperature of the depth of a subject 9 comprises a plate-shaped substrate 10, a pair of first area temperature sensors 21, 22 mounted on a first area 11 of the substrate so as to face each other across the substrate 10, and a pair of second area temperature sensors 23, 24 mounted on a second area 12 of the substrate so as to face each other across the substrate 10. A through hole 15 penetrating between the observe surface 10a and the reverse surface 10b of the substrate 10 immediately below the first area temperature sensors 21, 22 is formed in the substrate 10, and the through hole 15 connects between the pair of first area temperature sensors 21, 22. The probe 1 for deep temperature measurement makes it possible to measure the temperature of the depth of a subject at a high accuracy, even if the thickness of the substrate constituting the probe is reduced.

Description

Technical Field

[0001] The present invention relates to a probe for deep body temperature measurement and a deep body thermometer, and mainly relates to a probe for deep body temperature measurement and a deep body thermometer for measuring the deep body temperature (core temperature) of a human body.

Background Art

[0002] Conventionally, a dual heat flow method for measuring the temperature of the deep part of the human body in a non-invasive manner has been studied. The dual heat flow method measures the heat flows passing through two different heat insulating materials and solves a system of equations related to the heat flows to obtain the deep body temperature TB without using the thermal resistance value of the living body skin, which is an unknown (see, for example, Non-Patent Document 1).

[0003] Non-Patent Document 1 and Patent Document 1 disclose a probe for deep body temperature measurement (hereinafter sometimes simply referred to as "probe") that measures the deep body temperature TB using the dual heat flow method. In order to configure a probe for the total heat flow method, it is important to provide a difference between the thermal resistance values of two heat flow paths (between the thermal resistance value of the first heat flow path and the thermal resistance value of the second heat flow path), and probes with such contrivances are also disclosed in these documents.

[0004] The probe for deep body temperature measurement described in Patent Document 1 is configured such that a difference occurs in the mutual thermal resistivity by making the occupancy rate and / or dispersion of the conductive pattern in the first region of the substrate different from the occupancy rate and / or dispersion of the conductive pattern in the second region. For example, in the example of FIG. 1, a conductive pattern is arranged between the layers of the substrate in the first heat flow path to lower the overall thermal resistance value R, while in the second heat flow path, such an interlayer conductive pattern is not arranged and the second heat flow path is constituted by the substrate material itself, so that a difference is created in the thermal resistance values of the heat flow paths between the two as a whole.

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Patent Document

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] By the way, these days, it often gets sweltering hot in summer. From the perspective of preventing heatstroke and the like, it is speculated that in the future, there will be an increasing number of efforts to monitor the deep body temperature TB (especially the deep body temperature of the human body) by attaching a probe for deep temperature measurement to a living body. As an attribute expected of a wearable probe, it is important to be "thin" in order to reduce the resistance during wearing and increase the wearing rate.

[0008] However, when the thickness of the substrate constituting the probe for deep temperature measurement is reduced, the dimensions in the thickness direction become smaller, so the thermal resistance value in the thickness direction decreases. At this time, based on the technology of the probe for deep temperature measurement described in Patent Document 1, even if a conductive pattern is inserted between layers to reduce the thermal resistance value of the first region, the thermal resistance value of the second region also becomes smaller due to the thinning of the substrate. Therefore, it is difficult to create a difference in thermal resistance values between the two regions. Therefore, even if a thin wearable probe for deep temperature measurement is configured using the technology described in Patent Document 1, it is difficult to maintain high accuracy in measuring and estimating the deep temperature (hereinafter simply referred to as "measurement").

[0009] Furthermore, in the probe for deep temperature measurement described in Patent Document 1, the smaller the size of the substrate is set, the more difficult it becomes to create many conductive patterns inside, and it lacks practicality and usability.

[0010] Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a probe for measuring deep body temperature capable of measuring the temperature deep in a subject with high accuracy even when the substrate constituting the probe is thinned. Another object of the present invention is to provide a deep thermometer equipped with such a probe for measuring deep body temperature.

Means for Solving the Problems

[0011] According to one aspect of the present invention, there is provided a probe for measuring deep body temperature used when measuring the temperature deep in a subject. Such a probe for measuring deep body temperature includes a plate-shaped substrate, a pair of "first region temperature sensors" which are a pair of temperature sensors mounted so as to face each other with the substrate interposed therebetween in a first region of the substrate, and a pair of "second region temperature sensors" which are a pair of temperature sensors mounted so as to face each other with the substrate interposed therebetween in a second region of the substrate. And a through hole penetrating between the front surface and the back surface of the substrate is formed directly below the first region temperature sensor on the substrate, and the space between the pair of first region temperature sensors is connected by the through hole.

[0012] According to another aspect of the present invention, there is provided a probe for measuring deep body temperature used when measuring the temperature deep in a subject in the same manner. Such a probe for measuring deep body temperature includes a plate-shaped substrate, a pair of "first region temperature sensors" which are a pair of temperature sensors mounted so as to face each other with the substrate interposed therebetween in a first region of the substrate, and a first heat flow path formed in the substrate of the first region, and a first heat flow measurement system for measuring the first heat flow flowing out from the subject. Also, a pair of "second region temperature sensors" which are a pair of temperature sensors mounted so as to face each other with the substrate interposed therebetween in a second region of the substrate, and a second heat flow path formed in the substrate of the second region, and a second heat flow measurement system for measuring the second heat flow flowing out from the subject. And a through hole penetrating between the front surface and the back surface of the substrate is formed directly below the first region temperature sensor on the substrate, and the first heat flow path is configured by an air layer disposed inside the through hole.

[0013] According to still another aspect of the present invention, there is provided a deep body temperature meter including the deep body temperature measurement probe described above and a deep body temperature estimation unit that estimates the deep body temperature using each temperature measured by a pair of first region temperature sensors and a pair of second region temperature sensors of the deep body temperature measurement probe.

Advantages of the Invention

[0014] According to the present invention, even if the substrate constituting the probe is thinned, it is possible to provide a deep body temperature measurement probe capable of measuring the temperature of the deep part of a subject with high accuracy. Further, it is possible to provide a deep body temperature meter including such a deep body temperature measurement probe.

Brief Description of the Drawings

[0015]

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Mode for Carrying Out the Invention

[0016] Hereinafter, the deep part temperature measurement probe and the deep part thermometer according to the present invention will be described with reference to the drawings. Regarding the reference numerals common to each drawing, since the content already described for the reference numerals can be applied also in the description of other drawings, the description in other drawings will be omitted.

[0017] [Embodiment 1] 1. Configuration of the deep thermometer probe 1 according to Embodiment 1 FIG. 1 is a diagram shown to explain the deep part temperature measurement probe 1 according to Embodiment 1. FIG. 1(a) is a cross-sectional view of the deep part temperature measurement probe 1 showing the B - B cross-section of FIG. 1(b). FIG. 1(b) is a plan view of the deep part temperature measurement probe 1 when viewed along the arrow A in FIG. 1(a). FIG. 2 is a diagram showing the components of the deep part temperature measurement probe 1 according to Embodiment 1.

[0018] (1) Outline of the deep part temperature measurement probe 1 As shown in FIG. 1, the deep part temperature measurement probe 1 is used when measuring the temperature of the deep part 9c of the subject 9, and measures the temperature (deep part temperature TB) of the deep part 9c of the subject by directly or indirectly contacting the back surface side with the subject surface 9a. In the figure, the symbol RS represents the thermal resistance value of the intermediate part 9b of the subject that cannot be directly measured. Typical subjects 9 include living bodies such as humans and animals. In this embodiment, the description will continue assuming a human. The deep part temperature measurement probe 1 includes a substrate 10 and temperature sensors 21, 22, 23, and 24. In this specification, the temperature sensor may sometimes be simply referred to as a "sensor".

[0019] (2) Substrate 10 FIG. 2(a) is a plan view showing the substrate 10, and shows a state when the surface of the bare substrate on which the temperature sensors 21, 22, 23, 24, and 25 are not mounted is viewed. As shown in FIG. 2(a), the substrate 10 is a printed circuit board on which a wiring pattern 13 is formed. As the substrate 10, for example, a glass epoxy substrate can be employed. The substrate 10 of the present embodiment is a so-called double-sided substrate having wiring patterns 13 on both the front surface 10a and the back surface 10b. The wiring pattern 13 (in a broad sense) includes a terminal 13c, a wiring pattern 13a in a narrow sense connecting between the terminals 13c, a land 13b in a narrow sense formed in a pad shape, and the like. In the figure, the description of the intermediate connection of the wiring pattern 13a in a narrow sense is omitted.

[0020] The substrate 10 has a front surface 10a and a back surface 10b, and has, for example, a plate-like shape. Here, the definitions of the front surface 10a and the back surface 10b are for convenience, and the surface facing the outside (atmosphere 8 side) is defined as the front surface 10a, and the surface on the side in contact with the object to be inspected 9 is defined as the back surface 10b. The substrate 10 has the function of a base portion on which the temperature sensors 21, 22, 23, and 24 are mounted, and also constitutes a heat flow path (thermal flow path) for heat flowing from the back surface 10b side to the front surface 10a side for a part (or all) thereof (see also FIG. 1).

[0021] (3) Temperature Sensors 21, 22, 23, 24 The temperature sensors 21, 22, 23, and 24 measure the temperature at the contacted portion (node) and output an output signal corresponding to the measured temperature. For example, they can be composed of discrete devices such as thermocouples, platinum resistance thermometers, thermistors, etc., or devices integrated into an IC (Integrated Circuit) and outputting an output signal digitally. The temperature sensors 21, 22, 23, and 24 of the present embodiment use those integrated into an IC, and may be realized, for example, in a so-called SON package (Small Outline Non-leaded package) as shown in the figure.

[0022] Fig. 2(b) is a bottom view showing the bottom surface of the package when the temperature sensors 21, 22, 23, 24, and 25 are realized in a SON package. The temperature sensors 21, 22, 23, 24, and 25 have semiconductor chips (not shown) inside that have the function of sensing temperature and converting it into an electrical signal, and external connection terminals 28 electrically connected to the semiconductor chips are exposed on the bottom surface. Also, the temperature sensors 21, 22, 23, 24, and 25 have thermal pads 29 on the bottom surface to improve the thermal coupling between the contact parts to be measured (specifically, the nodes of the heat flow path) and the internal semiconductor chips.

[0023] Returning to Fig. 1, the description of mounting the temperature sensors on the substrate will be continued. The temperature sensors 21 and 22 are mounted in a pair in the first region 11 of the substrate 10 so as to face each other with the substrate 10 interposed therebetween. The temperature sensor 21 is mounted on the back surface 10b of the substrate 10, and the temperature sensor 22 is mounted on the front surface 10a of the substrate 10. Similarly, the temperature sensors 23 and 24 are mounted in a pair in the second region 12 of the substrate 10 so as to face each other with the substrate 10 interposed therebetween. The temperature sensor 23 is mounted on the back surface 10b of the substrate 10, and the temperature sensor 24 is mounted on the front surface 10a of the substrate 10. What is indicated by reference numeral 60 in the figure is an external connector for making connections to the outside. Also, reference numeral 25 is a temperature sensor for measuring the outside air temperature. When experimentally determining the thermal resistance ratio K as described later, the outside air temperature T5 measured by the temperature sensor 25 is used to correct the thermal resistance ratio K. Note that the temperature sensor 25 is arranged adjacent to the regions constituting the first region 11 and the second region 12. It becomes possible to measure the outside air temperature with one module, and overall, the deep temperature gauge 500 can be realized in a small, light, and inexpensive manner.

[0024] In this specification, the pair of temperature sensors 21 and 22 may be referred to as "a pair of first region temperature sensors 21 and 22", and the pair of temperature sensors 23 and 24 may be referred to as "a pair of second region temperature sensors 23 and 24", respectively. The "first region 11" and the "second region 12" are regions where, in performing deep temperature measurement by the dual heat flow method, "first heat flow paths 115" and "second heat flow paths 125" are respectively provided so as to have a difference between their heat resistance values R1 and R2 (see Fig. 1(b), Fig. 2, etc.).

[0025] Each of the temperature sensors 21, 22, 23, 24 has its external connection terminal 28 connected to the terminal 13c of the substrate 10 via "solder 51", whereby both electrical connections are made and each sensor is fixed on the substrate 10.

[0026] The thermal pads 29 of the temperature sensors 23, 24 are connected to the lands 13b of the substrate 10 via "solder 51" over the entire overlapping region thereof, thereby improving the thermal coupling with the lands 13b of the substrate 10 (nodes as connection points of the second heat flow paths 125) and fixing the distance between the thermal pads 29 and the lands 13b with "solder 51" to suppress dynamic distance variations (assuming only a gap in the case where there is no solder 51). In soldering, the thickness of the "solder 51" is controlled to fall within a predetermined range of variations so that the distance between the thermal pads 29 and the lands 13b is made substantially constant. Thereby, the distance between the pair of second region temperature sensors 23, 24 can be kept substantially constant, and the heat resistance value R2 of the second heat flow paths 125 can be reproduced and managed to be substantially constant even during mass production.

[0027] Next, focusing on the second region 12 of the substrate 10, the second heat flow paths 125 are constituted by the substrate 10 itself and the "solder 51" inserted between the thermal pads 29 and the lands 13b. Since the second heat flow paths 125 are constituted while making use of the substrate 10 itself, the probe can be constituted with a simple configuration without any special processing and without particularly increasing the number of members, resulting in an economically advantageous probe. Through the second heat flow paths 125, the second heat flow 120a flows from the back side to the front side of the deep temperature measurement probe 1 (see the reference numeral 120a schematically shown by the thick arrow in Fig. 1(a)).

[0028] (4) Configuration of the First Heat Flow Path 115 On the other hand, focusing on the first region 11 of the substrate 10, a through hole 15 penetrating between the front surface 10a and the back surface 10b of the substrate 10 is formed in the substrate 10 directly below the temperature sensors 21 and 22 (first region temperature sensors 21 and 22). The space between the pair of first region temperature sensors 21 and 22 is connected by the through hole 15. Here, the term "connected" includes both the meaning of being spatially connected and the meaning of being connected from the perspective of a heat circuit.

[0029] In addition, in the deep temperature measurement probe 1 according to Embodiment 1, an air layer 30 is disposed inside the through hole 15. Reference numeral 15a indicates the inner wall of the through hole.

[0030] The first heat flow path 115 is constituted by the gap of the above-described through hole 15 (the air layer 30 in Embodiment 1). In other words, the air layer 30 disposed inside the through hole 15 formed in the substrate 10 realizes the heat resistor constituting the first heat flow path 115. Through such a first heat flow path 115, the first heat flow 110a flows from the back side to the front side of the deep temperature measurement probe 1 (refer to the symbol 110a schematically shown by the thick arrow in Fig. 1(a)).

[0031] Note that the first region temperature sensors 21 and 22 are configured as ICs made of semiconductors, and when viewed in plan, it is preferable that the through hole 15 overlaps with an area of 50% or more of the thermal pad 29 of the IC (or the back surface of the bare chip in Modification 3 described later) (refer to Fig. 1(b)). Furthermore, it is more preferable that the through hole 15 overlaps with the entire region of the thermal pad 29.

[0032] (5) The First Heat Flow Measurement System 110 and the Second Heat Flow Measurement System 120 The above-described first heat flow path 115 formed in the substrate of the first region 11 and the pair of first region temperature sensors 21 and 22 constitute the "first heat flow measurement system 110". Similarly, the second heat flow path 125 formed in the substrate of the second region 12 and the pair of second region temperature sensors 23 and 24 constitute the "second heat flow measurement system 120".

[0033] It can also be said that the deep temperature measurement probe 1 according to Embodiment 1 has the following configuration. That is, it has a pair of first region temperature sensors 21 and 22 mounted so as to face each other across the substrate 10 in the first region 11 of the substrate 10, and a first heat flow path 115 formed in the substrate of the first region 11, and includes a "first heat flow measurement system" for measuring the first heat flow 110a flowing out from the subject 9. And it has a pair of second region temperature sensors 23 and 24 mounted so as to face each other across the substrate 10 in the second region 12 of the substrate 10, and a second heat flow path 125 formed in the substrate of the second region 12, and includes a "second heat flow measurement system 120" for measuring the second heat flow 120a flowing out from the subject 9. And a through hole 15 penetrating between the front and back surfaces of the substrate 10 is formed directly below the first region temperature sensors 21 and 22 in the substrate 10, and the first heat flow path 115 is constituted by an air layer 30 disposed inside the through hole 15.

[0034] 2. Configuration of the deep thermometer 500 according to Embodiment 1 FIG. 3 is a block diagram showing an example of the hardware configuration of the deep thermometer 500 according to Embodiment 1. Reference numeral 200 indicates a temperature measurement unit.

[0035] The deep thermometer 500 according to Embodiment 1 can be configured to include the above-described deep temperature measurement probe 1 according to Embodiment 1 and a deep temperature estimation unit 210 that estimates the deep temperature TB using the respective temperatures measured by the pair of first region temperature sensors 21 and 22 and the pair of second region temperature sensors 23 and 24 of the deep temperature measurement probe 1. The deep temperature estimation unit 210 calculates and estimates the deep temperature TB by the dual heat flow method (for example, by the calculation of Equation (10) described later).

[0036] The deep temperature estimation unit 210 can be configured by either a dedicated circuit or a general-purpose circuit. As the general-purpose circuit, for example, it is realized by an information processing device (not labeled) as shown in FIG. 3. The information processing device constituting the deep temperature estimation unit 210 includes a processor 211, a memory 212, an input / output interface 214, and a communication interface 215. These are connected to a bus BS.

[0037] The processor 211 operates based on programs stored in a storage unit (the memory 212 and a storage not shown) to control each part. The storage unit (not labeled) also includes a non-volatile storage device (such as a ROM), and stores a boot program executed by the processor 211 when the information processing device is started up, programs dependent on the hardware of the information processing device, etc. The storage not shown is composed of auxiliary storage devices such as an SDD (Solid State Drive) and an HDD (Hard Disk Drive). The memory 212 appropriately stores data and the like necessary when the processor 211 executes various controls and processes. The processor 211 substitutes temperatures T1 to T4, etc. into the formula (10) described later to calculate the deep temperature TB as an estimated value. In this case, the deep temperature estimation unit 210 can also be said to have the function of a processor that calculates and estimates the deep temperature TB.

[0038] The input / output interface 214 performs input / output from / to input / output devices (specifically, temperature sensors 21, 22, 23, 24, 25 here). The communication interface 215 receives data from other electronic devices via a network or the like and sends it to the processor 211, and also sends data generated by the processor 211 via a network or the like to other electronic devices.

[0039] 3. Regarding the experimental system In the following formula (10) used for estimating the deep temperature TB, it is necessary to identify and prepare the value of the thermal resistance ratio K between the first heat flux measurement system 110 and the second heat flux measurement system 120. If the materials constituting the first heat flux path 115 and the second heat flux path 125 and their physical properties are known, it is also possible to theoretically obtain the thermal resistance ratio K. However, this time, the inventor has developed a method of experimentally obtaining the thermal resistance ratio K corresponding to the actual situation in a separate experimental system in advance and applying such a thermal resistance ratio K to formula (10), which will be described in detail below.

[0040] (1) Thermal equivalent circuit of the deep temperature measurement probe 1 FIG. 4 is a thermal equivalent circuit diagram of the deep temperature measurement probe 1 according to Embodiment 1. Ia shown in FIG. 4 is the heat flux (value) flowing through the first heat flux path 115, and Ib is the heat flux (value) flowing through the second heat flux path 125. Ic is the heat flux (value) flowing through the thermal resistance Rs (thermal resistance value) between the deep part 9c of the subject and the surface 9a (skin) of the subject in the first heat flux measurement system 110, and Id is the heat flux (value) flowing through the thermal resistance Rs (thermal resistance value) between the deep part 9c of the subject and the surface 9a (skin) of the subject in the second heat flux measurement system 120.

[0041] From the thermal equivalent circuit shown in FIG. 4, the following equation holds for the first heat flux measurement system 110. Ia = (T1 - T3) / R1 ··· (1) Ic = (TB - T1) / Rs ··· (2) Ia = Ic = (T1 - T3) / R1 = (TB - T1) / Rs ··· (3) From equation (3) TB = T1 + (T1 - T3)×(Rs / R1) ··· (4) Similarly, the following equation holds for the second heat flux measurement system 120. Ib = (T2 - T4) / R2 ··· (5) Id = (TB - T2) / Rs ··· (6) Ib = Id = (T2 - T4) / R2 = (TB - T2) / Rs ··· (7) From equation (7) TB = T2 + (T2 - T4)×(Rs / R2) ··· (8)

[0042] Here, there is a method of obtaining the deep temperature TB by removing Rs using Expression (4) and Expression (8). However, when the inventor conducted experiments, it was difficult to obtain the accurate deep body temperature.

[0043] Therefore, the inventor decided to obtain the deep temperature TB by another method. First, from the thermal equivalent circuit of FIG. 4, the thermal resistance ratio K between the first heat flow measurement system 110 and the second heat flow measurement system 120 is defined as follows. K = [(TB - T2)(T1 - T3)] / [(TB - T1)(T2 - T4)] ··· (9) Then, Expression (9) can be transformed into the following expression for obtaining the deep temperature TB. TB = T1 + (T1 - T2)(T1 - T3) / [K(T2 - T4) - (T1 - T3)] ··· (10) Based on this idea, the inventor conducted preliminary experiments and determined the thermal resistance ratio K using the relationship of Expression (9). Then, using the relationship of Expression (10), the deep temperature TB was calculated (estimated) based on the thermal resistance ratio K determined in the preliminary experiments and the temperatures (T1, T2, T3, T4) measured by the temperature sensors (15, 16, 17, 18). As a result of conducting experiments for verification, it has been confirmed that the accurate deep body temperature can be obtained.

[0044] That is, the deep temperature estimation unit 210 of Embodiment 1 is for the thermal resistance ratio K between the first heat flow path 115 between the pair of first region temperature sensors 21 and 22 and the second heat flow path 125 between the pair of second region temperature sensors 23 and 24, K = [(TB - T2)(T1 - T3)] / [(TB - T1)(T2 - T4)] the pre-determined thermal resistance ratio K using the relationship, and the temperatures T1, T2, T3, and T4 measured by probing the subject 9, TB = T1 + (T1 - T2)(T1 - T3) / [K(T2 - T4) - (T1 - T3)] It has been confirmed that it may be configured to estimate the deep temperature TB by applying to the relationship.

[0045] However, let the deep temperature be TB, and let the temperatures measured by sensor 21, which is arranged on the side of the subject 9 among the pair of first-region temperature sensors, sensor 22, which is arranged on the side of the subject 9 among the pair of second-region temperature sensors, sensor 23, which is arranged on the side opposite to the subject 9 among the pair of first-region temperature sensors, and sensor 24, which is arranged on the side opposite to the subject 9 among the pair of second-region temperature sensors, be T1, T2, T3, and T4, respectively.

[0046] Note that although Equation (2.6) in Non-Patent Document 1 is considered to correspond to Equation (10) in this specification, it should be noted that when the inventors verified Equation (2.6) in Non-Patent Document 1, there may be a misprint in Equation (2.6) of Non-Patent Document 1.

[0047] (2) Configuration of the experimental system FIG. 5 is a cross-sectional view schematically showing an "experimental system" for experimentally obtaining and determining the thermal resistance ratio K of the deep temperature measurement probe 1. As shown in FIG. 5, instead of the deep part 9c of the subject, a water bath 130 with a large heat capacity is used and placed in a thermostatic and humidity-controlled chamber (not shown). The temperature (ambient temperature) in the thermostatic and humidity-controlled chamber is set to a predetermined temperature between 10°C and 30°C. The water temperature (deep temperature TB) is made to be approximately constant (about 37°C). Note that reference numeral 109 indicates a substitute subject, and the surface 109a of the substitute subject is composed of a substitute skin imitating living skin made of a natural rubber sheet. Reference numeral 109b is a part corresponding to the middle part of the substitute subject, and reference numeral 109c is a part corresponding to the deep part of the substitute subject. Reference numeral 131a is a support rod that supports the temperature sensor 131 (such as a thermistor). The deep temperature measurement probe 1 is placed on the aluminum bucket 133, and the aluminum bucket 133 is floated in the water in the water bath 130.

[0048] By using such an experimental system and measuring the temperature with the temperature sensor 131, (i) the actual deep water temperature (deep temperature TBr) in the water bath 130 can be obtained. Further, the temperatures sensed by the temperature sensors 21 to 24 of the deep temperature measurement probe 1 are measured by the temperature measurement unit 200 and output to the deep temperature estimation unit 210. By performing calculations in the deep temperature estimation unit 210 based on such temperatures, (ii) the estimated deep water temperature (deep temperature TBp) can also be obtained.

[0049] (3) Determination of the thermal resistance ratio K While using Equation (9), an experiment (preliminary experiment) can be conducted as follows to determine the thermal resistance ratio K. (A) Conduct a preliminary experiment to measure the actual deep water temperature (deep temperature TBr), and measure the temperatures T1 to T4 with the temperature sensors 21 to 24. Apply the thermal resistance ratio K of the deep temperature measurement probe 1 (in a state of thermal equilibrium in the experimental system shown in FIG. 5) to the relationship of Equation (9) and calculate it. Repeat this process multiple times. (B) Obtain the average value of the thermal resistance ratio K for multiple times obtained from the multiple experiments conducted. (C) Compare the measured value of the water temperature (deep temperature TBr) with the estimated deep temperature TBp (water temperature) calculated by applying the average value of the thermal resistance ratio K and the temperatures T1 to T4 to the relationship of Equation (10), and check whether the difference (error) between the two becomes small. If the error is large, repeat the above operations (A) to (C) again to determine the thermal resistance ratio K that makes the error small.

[0050] (4) Estimation of the deep temperature TB Store the numerical value of the thermal resistance ratio K determined as described above in the memory 212 (see FIG. 3). By measuring the temperature using the temperature sensors 21 to 24 and the temperature measurement unit 200 and performing the calculation of Equation (10) in the deep temperature estimation unit 210, the deep temperature TB can be calculated (estimated).

[0051] (5) Incorporation of the prior application Note that the content of the prior application (Japanese Patent Application No. 2022-53593) in which the inventors of the present application and others have invented can be incorporated into this specification as it is (for example, FIGS. 4, paragraphs

[0038] to

[0046] , etc.), and can be used as a method for experimentally determining the thermal resistance ratio K of the present invention in advance. A detailed description in this specification regarding the experimental determination of the thermal resistance ratio K will be omitted hereinafter.

[0052] 4. Effects of the deep thermometer probe 1 and the deep thermometer 500 according to Embodiment 1 (1) In the substrate of the probe 1 for deep temperature measurement according to Embodiment 1, a through hole 15 penetrating between the front and back surfaces of the substrate 10 is formed directly below the first region temperature sensors 21 and 22, and the space between the pair of first region temperature sensors 21 and 22 is connected by the through hole 15. That is, in the probe 1 for deep temperature measurement, since the space between the pair of first region temperature sensors 21 and 22 is connected by the through hole 15 formed directly below the sensors, if no special treatment is applied, for example, in the case of a structure with only holes, the inside of the through hole 15 will only be an air layer 30, and the thermal resistance value R1 between the pair of first region temperature sensors 21 and 22 can be significantly increased. Thereby, even if the substrate 10 constituting the probe is thinned and the thermal resistance value in the thickness direction of the entire substrate 10 becomes small, it becomes easier to provide a difference between the thermal resistance value R1 of the first heat flow path 115 (between the pair of first region temperature sensors 21 and 22) and the thermal resistance value R2 of the second heat flow path 125 (between the pair of second region temperature sensors 23 and 24). Therefore, even if the substrate 10 constituting the probe is thinned, it becomes possible to measure the temperature (deep temperature TB) of the deep part 9c of the subject with high accuracy.

[0053] (2) While the thermal conductivity of air is 0.0241 [W / (mK)] (when at 0 °C), the thermal conductivity of the member constituting the substrate 10, for example, polyimide (PI), is 0.28 to 0.34 [W / (mK)]. In the deep temperature measurement probe 1 according to Embodiment 1, an air layer 30 is disposed inside the through hole 15. Therefore, from the viewpoint of thermal resistance, when looking at the deep temperature measurement probe 1, the air layer 30 can have a significantly larger thermal resistance value compared to the members constituting the substrate 10 and the like. Thus, since the thermal resistance value R1 of the first heat flow path 115 formed by the air layer 30 can be made significantly larger, a very simple structure can be realized as a structure for providing a difference between the thermal resistance value R1 of the first heat flow path 115 and the thermal resistance value R2 of the second heat flow path 125.

[0054] (3) The deep thermometer 500 according to Embodiment 1 includes the deep temperature measurement probe 1 according to Embodiment 1, and a deep temperature estimation unit 210 that estimates the deep temperature using the temperatures measured by the pair of first region temperature sensors 21 and 22 and the pair of second region temperature sensors 23 and 24 of the deep temperature measurement probe 1. Since the deep thermometer 500 includes the deep temperature measurement probe 1 that can measure the temperature (deep temperature TB) of the deep part 9c of the subject with high accuracy even with a thin substrate 10, it becomes a small and highly accurate deep thermometer.

[0055] (4) The deep thermometer 500 according to Embodiment 1 is configured to estimate the deep temperature TB by applying the thermal resistance ratio K determined in advance using the relationship represented by the above formula (9) for obtaining the thermal resistance ratio K, and the temperatures T1, T2, T3, and T4 measured by probing the subject 9, to the relationship represented by the above formula (10).

[0056] Actually, since it is considered to be affected by a diffusion-mode heat flux other than a linear heat flux, the theoretically obtained thermal resistance ratio K based on the known thermal conductivity of the material constituting each heat flow path may be different from the actual accurate thermal resistance ratio K. Therefore, by separately determining the thermal resistance ratio K in advance using the relationship represented by the above formula (9) in a separate experimental system, the deep temperature TB can be estimated based on a highly accurate thermal resistance ratio K close to the actual probe. For this reason, deep temperature measurement with higher accuracy becomes possible.

[0057] [Embodiment 2] FIG. 6 is a cross-sectional view showing the deep thermometer probe 2 according to Embodiment 2. The deep thermometer probe 2 according to Embodiment 2 basically has the same configuration as the deep thermometer probe 1 according to Embodiment 1, but is different from the deep thermometer probe 1 according to Embodiment 1 in the way of configuring the first heat flow path 115.

[0058] As shown in FIG. 6, in the deep thermometer probe 2 according to Embodiment 2, heat insulating paper 31 is further arranged inside the through hole 15. The heat insulating paper 31 is a paper having a heat conductivity approximately the same as that of air. For example, a sheet in which porous particles (so-called silica aerogel) made of silica gel containing foamed air are kneaded can be mentioned. When this heat insulating paper 31 is packed in the air layer 30 arranged in the through hole 15, the overall heat resistance value R1 of the internal space of the through hole 15 becomes approximately the same as the heat resistance value of air. The heat insulating paper 31 may be appropriately formed three-dimensionally, such as being alternately folded back into a wave shape, folded in a repeating valley and ridge shape, or randomly rolled, and then packed into the internal space of the through hole 15.

[0059] By arranging the heat insulating paper 31 inside the through hole 15 constituting the first heat flow path 115, the heat insulating paper 31 can prevent the movement of air inside the through hole 15, and the convection inside the through hole 15 can be suppressed. Thereby, the heat transfer by "convection" in the first heat flow path 115 is suppressed, and the direct heat transfer by "conduction" through the air layer 30 and the heat insulating paper 31 is mainly performed. Therefore, it becomes an even more ideal state in terms of the heat circuit, and it is possible to measure the deep temperature with higher accuracy.

[0060] The deep thermometer probe 2 according to Embodiment 2 basically has the same configuration as the deep thermometer probe 1 according to Embodiment 1 in the configuration other than the way of configuring the first heat flow path 115. Therefore, the deep thermometer probe 2 has the corresponding effects among the effects that the deep thermometer probe 1 has.

[0061] [Embodiment 3] FIG. 7 is a cross-sectional view showing the deep thermometer probe 3 according to Embodiment 3. The deep thermometer probe 3 according to Embodiment 3 basically has the same configuration as the deep thermometer probe 1 according to Embodiment 1, but is different from the deep thermometer probe 1 according to Embodiment 1 in the configuration of the substrate 10 and the configuration of the first heat flow path 115.

[0062] As shown in FIG. 7, in the deep thermometer probe 3 according to Embodiment 3, the substrate 10 is made of a glass substrate, and the inside of the through hole 15 is configured to be in a vacuum or a state 32 close to a vacuum.

[0063] By setting the inside of the through hole 15 that constitutes the first heat flow path 115 to a vacuum or a state 32 close to a vacuum, the thermal conductivity can be further reduced compared to the case of the air layer 30, that is, the thermal resistance value R1 between the pair of first region temperature sensors 21 and 22 can be further increased.

[0064] The deep thermometer probe 3 according to Embodiment 3 basically has the same configuration as the deep thermometer probe 1 according to Embodiment 1 in configurations other than the configuration of the substrate 10 and the configuration of the first heat flow path 115. Therefore, the deep thermometer probe 2 has the corresponding effects among the effects that the deep thermometer probe 1 has.

[0065] [Embodiment 4] FIG. 8 is a diagram shown to explain the deep thermometer probe 4 according to Embodiment 4. FIG. 8(a) is a cross-sectional view of the deep thermometer probe 4 showing the D-D cross section of FIG. 8(b). FIG. 8(b) is a plan view of the deep thermometer probe 4 when viewed along the arrow C in FIG. 8(a). The deep thermometer probe 4 according to Embodiment 4 basically has the same configuration as the deep thermometer probes 1, 2, and 3 according to Embodiments 1, 2, and 3, but is different from the deep thermometer probes 1, 2, and 3 according to Embodiments 1, 2, and 3 in that it has a configuration for suppressing thermal interference between the first heat flow path 115 and the second heat flow path 125.

[0066] As shown in FIG. 8, in the deep temperature measurement probe 4 according to Embodiment 4, an air layer 40 is disposed between the first region 11 and the second region 12 on the substrate 10. The air layer 40 may be formed, for example, as shown in FIG. 8, by forming a through hole that penetrates between the front surface 10a and the back surface 10b of the substrate 10, and may be composed of air disposed in such a through hole. The through hole may be configured as a long hole that penetrates most of the region beside the temperature sensor as shown in FIG. 8.

[0067] Since the deep temperature measurement probe 4 according to Embodiment 4 has such a configuration, the air layer 40, which can also be said to be a heat insulator, can block the heat conduction between the first region 11 where the first heat flow path 115 is disposed and the second region 12 where the second heat flow path 125 is disposed. Thereby, the thermal interference between the first heat flow path 115 and the second heat flow path 125 can be reduced, and the independence of both heat flow paths can be enhanced. Therefore, it becomes possible to measure the deep temperature with higher accuracy.

[0068] The deep temperature measurement probe 4 according to Embodiment 4 has basically the same configuration as the deep temperature measurement probes 1, 2, and 3 according to Embodiments 1, 2, and 3, except for the configuration that suppresses the thermal interference between the first heat flow path 115 and the second heat flow path 125. Therefore, the deep temperature measurement probe 4 has the corresponding effects among the effects that the deep temperature measurement probes 1, 2, and 3 have.

[0069] As described above, the present invention has been described based on the above embodiments, but the present invention is not limited to the above embodiments. It can be implemented in various modes without departing from the gist thereof. For example, the following modifications are also possible.

[0070] (1) In each embodiment, the second heat flow path 125 was configured by utilizing the substrate 10 itself. However, the present invention is not limited to this. For example, as shown in FIG. 9, in the substrate 10, another through hole 17 penetrating between the front surface 10a and the back surface 10b of the substrate 10 is formed directly below the second region temperature sensors 23 and 24, and a metal 37 is embedded in the another through hole 17, and it may be configured such that between the pair of second region temperature sensors 23 and 24 are connected via the metal 37 (Modification 1). Note that FIG. 9 is a cross-sectional view showing the deep temperature measurement probe 5 according to Modification 1.

[0071] For example, copper can be adopted as the metal 37. The thermal conductivity of copper is 403 [W / (mK)] (at 0 [°C]), which is significantly larger than that of the members constituting the substrate 10 or the like. From the viewpoint of thermal resistance, the metal 37 can have a thermal resistance value that is significantly smaller than that of the members constituting the substrate 10 or the like. Therefore, the thermal resistance value R2 of the second heat flow path 125 constituted by the metal 37 can be made significantly smaller, and the difference from the thermal resistance value R1 of the first heat flow path 115 can be easily ensured.

[0072] (2) In each embodiment, an example in which between the thermal pads 29 of the temperature sensors 23 and 24 and the land 13b of the wiring pattern 13 are connected by solder 51 was shown and described. However, the present invention is not limited to this. For example, a structure in which there is no electrical connection with only a gap (air layer) without inserting the "solder 51" between the thermal pad 29 and the land 13b of the wiring pattern 13 may be adopted (not shown). Even with such a structure, thermal coupling between the pair of second region temperature sensors 23 and 24 can be achieved.

[0073] (3) In each embodiment, the description was given by taking an example where the temperature sensors 21 to 24 were realized by ICs in a SON package. However, the present invention is not limited to this. For example, as shown in Fig. 10(a), the temperature sensors 21 to 24 can also be configured by ICs in a WL-CSP (Wafer level Chip Size Package) (Modification 2). Further, as shown in Fig. 10(b), the temperature sensors 21 to 24 can be configured in a form where bare chips are directly mounted on the substrate 10 (Modification 3). Also, although not shown, the temperature sensor may be configured by a temperature sensor other than an IC such as a thermocouple.

[0074] (4) In the probe 4 for deep temperature measurement according to Embodiment 4, for thermally separating between the first region 11 and the second region 12, the description was given by taking an example of forming a "slit-shaped (in plan view)" through hole penetrating between the front surface 10a and the back surface 10b of the substrate 10 (see Fig. 8). However, the present invention is not limited to this. For example, as shown in Figs. 11(a) and 11(b), a configuration can also be adopted in which a plurality of spot-like through holes penetrating the substrate 10 in a "circular (in plan view)" shape instead of a "slit" are arranged in parallel (Modification 4). Also, for example, as shown in Figs. 11(c) and 11(d), a cavity can be formed inside the substrate 10 in the thickness direction, and an air layer 40 can be configured by arranging air in such a cavity (Modification 5).

[0075] Also, as shown in Fig. 11, an air layer 41 may also be arranged between the regions constituting the first region 11 and the second region 12 and the temperature sensor 25. The air layer 41 may be configured by a slit penetrating most of the region beside the temperature sensor 25 as shown in the figure.

[0076] When viewed from the second region 12, in a plan view of the drawing, an air layer 40 is arranged on the left side, an air layer 41 is arranged on the right side, and the atmosphere 8 (air layer) is arranged on the upper and lower sides. Similarly, when viewed from the first region 11, in a plan view of the drawing, an air layer 40 is arranged on the right side, and the atmosphere 8 (air layer) is arranged on the left, upper, and lower sides. That is, an air layer is arranged around the first region 11 and / or the second region 12. If the above configuration is adopted, the heat flux between the pair of temperature sensors arranged on the front and back of the substrate 10 will be covered / surrounded by the air layer with low thermal conductivity. Therefore, the heat flow cannot go in the lateral direction in a plan view and becomes an ideal heat flux only in the vertical direction, and the accuracy of the deep temperature that can be measured is further improved. Furthermore, if a long hole is formed so as to cover / surround the region around the temperature sensor as much as possible (on four sides if possible), an even more ideal heat flux only in the vertical direction is obtained, and the accuracy of the deep temperature that can be measured is further improved. Also, heat insulating paper 31 with a thermal conductivity approximately equal to that of air may be arranged in each of the air layers 40, 41.

[0077] Note that FIG. 10 is a cross-sectional view of the main part showing the deep temperature measurement probes 6 and 7 according to Modification 2 and Modification 3. FIG. 11 is a diagram shown to explain the deep temperature measurement probes 4' and 4'' according to Modifications 4 and 5. FIG. 11(a) is a plan view of the deep temperature measurement probe 4', and FIG. 11(b) is a cross-sectional view of the deep temperature measurement probe 4' showing the E-E cross-section of FIG. 11(a). FIG. 11(c) is a plan view of the deep temperature measurement probe 4'', and FIG. 11(d) is a cross-sectional view of the deep temperature measurement probe 4'' showing the F-F cross-section of FIG. 11(c).

Explanation of Reference Numerals

[0078] 1, 2, 3, 4, 4', 4'', 5, 6, 7... probe for deep temperature measurement, 8... atmosphere, 9... subject, 9a... surface of the subject, 9b... middle part of the subject, 9c... deep part of the subject, 10... substrate, 10a... (surface of the) substrate, 10b... (back surface of the) substrate, 11... first region, 12... second region, 13... (wiring pattern in a broad sense), 13a... (wiring pattern in a narrow sense), 13b... land, 13c... terminal, 15... through-hole, 17... another through-hole, 21, 22... first region temperature sensor, 23, 24... second region temperature sensor, 25... temperature sensor, 28... external connection terminal, 29... thermal pad, 30... air layer, 31... heat insulation paper, 32... vacuum or a state close to vacuum, 37... metal, 40, 41... air layer, 51... solder, 109a... surface of the substitute subject, 110... first heat flow measurement system, 110a... first heat flow, 115... first heat flow path, 120... second heat flow measurement system, 120a... second heat flow, 125... second heat flow path, 130... water bath, 131... temperature sensor, 133... aluminum bucket, 200... temperature measurement unit, 210... deep temperature estimation unit, 211... processor, 212... memory, 214... input / output interface, 215... communication interface, 500... deep thermometer

Claims

1. A probe for deep body temperature measurement used when measuring the temperature of the deep part of a subject, a substrate, in a first region of the substrate, a pair of temperature sensors mounted so as to face each other with the substrate interposed therebetween, namely, "a pair of first region temperature sensors", in a second region of the substrate, a pair of temperature sensors mounted so as to face each other with the substrate interposed therebetween, namely, "a pair of second region temperature sensors", comprising: a through hole is formed in the substrate so as to penetrate between the front surface and the back surface of the substrate directly below the first region temperature sensor, and the space between the pair of first region temperature sensors is connected by the through hole, characterized in that it is a probe for deep body temperature measurement.

2. In the probe for deep body temperature measurement according to Claim 1, an air layer is disposed inside the through hole, characterized in that it is a probe for deep body temperature measurement.

3. In the probe for deep body temperature measurement according to Claim 2, further, heat insulating paper is disposed inside the through hole, characterized in that it is a probe for deep body temperature measurement.

4. In the probe for deep body temperature measurement according to Claim 1, the substrate is made of a glass substrate, the inside of the through hole is in a vacuum or a state close to a vacuum, characterized in that it is a probe for deep body temperature measurement.

5. In the probe for deep body temperature measurement according to Claim 1, another through hole is formed in the substrate so as to penetrate between the front surface and the back surface of the substrate directly below the second region temperature sensor, and metal is embedded in the another through hole, and the space between the pair of second region temperature sensors is connected via the metal, characterized in that it is a probe for deep body temperature measurement.

6. In the probe for deep body temperature measurement according to any one of Claims 1 to 5, an air layer is disposed in the substrate between the first region and the second region, characterized in that it is a probe for deep body temperature measurement.

7. In the probe for deep body temperature measurement according to any one of Claims 1 to 5, an air layer is disposed in the substrate around the first region and / or the second region, characterized in that it is a probe for deep body temperature measurement.

8. In the probe for deep body temperature measurement according to any one of Claims 1 to 5, a temperature sensor for measuring the outside air temperature is disposed in the substrate so as to be adjacent to the regions constituting the first region and the second region, characterized in that it is a probe for deep body temperature measurement.

9. A probe for deep body temperature measurement used when measuring the temperature of the deep part of a subject, a plate-shaped substrate, a pair of "first region temperature sensors" which are mounted so as to face each other with the substrate interposed therebetween in a first region of the substrate, and a first heat flow measurement system having a first heat flow path formed in the substrate of the first region and measuring a first heat flow flowing out from the subject, a pair of "second region temperature sensors" which are mounted so as to face each other with the substrate interposed therebetween in a second region of the substrate, and a second heat flow measurement system having a second heat flow path formed in the substrate of the second region and measuring a second heat flow flowing out from the subject, and a through hole is formed in the substrate so as to penetrate between the front surface and the back surface directly below the first region temperature sensor, and the first heat flow path is constituted by an air layer disposed inside the through hole, A probe for deep body temperature measurement, characterized in that.

10. In the probe for deep body temperature measurement according to claim 9, heat insulating paper is further disposed inside the through hole, A probe for deep body temperature measurement, characterized in that.

11. The probe for deep body temperature measurement according to any one of claims 1 to 5, and a deep body temperature estimation unit that estimates a deep body temperature using each temperature measured by the pair of first region temperature sensors and the pair of second region temperature sensors of the probe for deep body temperature measurement, A deep body thermometer characterized by comprising.

12. In the deep body thermometer according to claim 11, when the deep body temperature is TB, and the temperatures measured by the sensor disposed on the subject side among the pair of first region temperature sensors, the sensor disposed on the subject side among the pair of second region temperature sensors, the sensor disposed on the side opposite to the subject among the pair of first region temperature sensors, and the sensor disposed on the side opposite to the subject among the pair of second region temperature sensors are T1, T2, T3, and T4, respectively, the deep body temperature estimation unit for the heat resistance ratio K between the first heat flow path between the pair of first region temperature sensors and the second heat flow path between the pair of second region sensors, the heat resistance ratio K determined in advance using the relationship of K = [(TB - T2)(T1 - T3)] / [(TB - T1)(T2 - T4)], and the temperatures T1, T2, T3, and T4 measured by probing the subject, TB = T1 + (T1 - T2)(T1 - T3) / [K(T2 - T4) - (T1 - T3)] A deep body thermometer configured to estimate the deep body temperature TB by applying it to the relationship of

13. A deep body thermometer comprising a probe for deep body temperature measurement according to claim 9 or 10, and a deep body temperature estimation unit configured to estimate a deep body temperature using each temperature measured by the pair of first region temperature sensors and the pair of second region temperature sensors of the probe for deep body temperature measurement.

14. In the deep body thermometer according to claim 13, when the deep body temperature is TB, the temperatures measured by the sensor disposed on the subject side among the pair of first region temperature sensors, the sensor disposed on the subject side among the pair of second region temperature sensors, the sensor disposed on the side opposite to the subject among the pair of first region temperature sensors, and the sensor disposed on the side opposite to the subject among the pair of second region temperature sensors are T1, T2, T3, and T4, respectively, the deep body temperature estimation unit for the thermal resistance ratio K between the first heat flow path between the pair of first region temperature sensors and the second heat flow path between the pair of second region sensors, the thermal resistance ratio K determined in advance using the relationship K = [(TB - T2)(T1 - T3)] / [(TB - T1)(T2 - T4)], and the temperatures T1, T2, T3, and T4 measured by probing the subject, TB = T1 + (T1 - T2)(T1 - T3) / [K(T2 - T4) - (T1 - T3)] is configured to estimate the deep body temperature TB by applying it to the relationship of

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