Deep body temperature measurement system

Abstract

To provide a wearable living body core temperature measurement system having a simple configuration with high accuracy and capable of providing power for self and communication functions.SOLUTION: A living body core temperature measurement system is equipped with a printed circuit board 2, a thermoelectric conversion module 4 mounted on the printed circuit board 2 in which a plurality of p-type thermoelectric element chips 53 and n-type thermoelectric element chips 54 are alternately connected in series, and a temperature sensor 6 mounted on the printed circuit board. In the system, a printed circuit board is placed in contact with a living body surface, and the core body temperature of the living body is measured by measuring the electromotive force in the thermoelectric conversion module and the surface temperature of the living body measured by a temperature sensor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system for measuring core body temperature of a living body. [Background technology]

[0002] In recent years, the importance of measuring not only normal body temperature (temperature just below the skin) but also deep body temperature has been pointed out from the perspective of preventing heatstroke. Furthermore, it is also important to transmit the measured data to medical institutions. Therefore, not only the measurement and communication functions but also the power source that drives them must be made wearable.

[0003] Small batteries have traditionally been considered as a power source for wearable devices, but the cost of replacing batteries has become a major issue, and there is a strong demand for the development of independent power sources using energy harvesting technology that utilizes heat generated by living organisms.

[0004] Patent Document 1 discloses a core body thermometer equipped with two heat flow detection systems. FIG. 6 is a cross-sectional view showing the configuration of the core body thermometer disclosed in Patent Document 1. As shown in FIG. 6, the core body thermometer 100 includes a heat input terminal 101 through which heat from a subject is input and which splits and outputs a first heat flow and a second heat flow. The first heat flow is measured using a first input temperature sensor 102 and a first output temperature sensor 103, and the second heat flow is measured using a second input temperature sensor 105 and a second output temperature sensor 106. A first thermal resistor 108 is provided between the heat input terminal 101 and the first input temperature sensor 102, and a second thermal resistor 109 is provided between the heat input terminal 101 and the second input temperature sensor 105. The core body temperature is measured based on the first and second heat flows flowing out of the subject. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2016-185905 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the core body thermometer disclosed in Patent Document 1 requires four temperature sensors embedded in a laminate, making the configuration complex, and the power source that drives the core body thermometer and communication means is a rechargeable battery, which poses major challenges as a wearable device.

[0007] The present invention has been made in consideration of the above-mentioned problems, and its main purpose is to provide a wearable deep body temperature measurement system for a living body that is highly accurate, has a simple configuration, and can supply power for itself and for communication functions. [Means for solving the problem]

[0008] The deep body temperature measurement system of the present invention comprises a printed circuit board, a thermoelectric conversion module mounted on the printed circuit board and having a plurality of p-type thermoelectric element chips and n-type thermoelectric element chips connected alternately in series, and a temperature sensor mounted on the printed circuit board, and is characterized in that the printed circuit board is placed in contact with the surface of the living body, and the deep body temperature of the living body is measured by measuring the electromotive force in the thermoelectric conversion module and the surface temperature of the living body measured by the temperature sensor.

[0009] Another system for measuring the deep body temperature of a living organism according to the present invention comprises a printed circuit board, two thermoelectric conversion modules mounted on the printed circuit board and having a plurality of p-type thermoelectric element chips and n-type thermoelectric element chips connected alternately in series, and two temperature sensors mounted on the printed circuit board and positioned near each thermoelectric conversion module, and is characterized in that the printed circuit board is placed in contact with the surface of the living organism, and the deep body temperature of the living organism is measured by measuring the surface temperature of the living organism measured by each temperature sensor, the temperature on the atmospheric side, and the thermal resistance between the surface of each thermoelectric conversion module that contacts the living organism and the surface on the atmospheric side. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a wearable deep body temperature measurement system for a living body that is highly accurate, has a simple configuration, and can supply power for itself and for communication functions. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a principle diagram showing a schematic configuration of a deep body temperature measuring system according to an embodiment of the present invention; [Figure 2] 1 is a configuration diagram of a thermoelectric conversion module according to an embodiment of the present invention. [Figure 3] FIG. 4 is another configuration diagram of a thermoelectric conversion module according to an embodiment of the present invention. [Figure 4] FIG. 10 is a principle diagram schematically illustrating the configuration of a deep body temperature measuring system according to another embodiment of the present invention. [Figure 5] 1 is a diagram showing an example of a block configuration of a deep body temperature measuring system according to the present invention; [Figure 6] FIG. 10 is a cross-sectional view showing the configuration of a conventional core body thermometer. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the following embodiment. Furthermore, appropriate modifications can be made within the scope of the effects of the present invention.

[0013] Fig. 1 is a principle diagram showing a schematic configuration of a living body core body temperature measurement system according to one embodiment of the present invention. As shown in Fig. 1, a thermoelectric conversion module 4 mounted on a printed circuit board 2 is placed in contact with a living body surface 1. A portion of the thermoelectric conversion module 4 is used as a temperature sensor 6. A low-radiation heat insulating material 11 is provided around the thermoelectric conversion module 4.

[0014] FIG. 2 is a diagram showing an example of the configuration of the thermoelectric conversion module 4. As shown in FIG.

[0015] 2, in the thermoelectric conversion module 4, p-type thermoelectric element chips 53 and n-type thermoelectric element chips 54 are mounted on wiring lands 52 on a printed circuit board 51(2), and are alternately connected in series by upper connection wiring 56 formed on an upper wiring board 55. The thermoelectric conversion module 4 can generate electricity using the temperature difference between the temperature of the bottom surface of the printed circuit board 51 that contacts the surface of the living body and the environmental temperature (Ta) outside the upper wiring board 55, and the generated power can be extracted from power extraction electrodes 57a and 57b.

[0016] The thermoelectric conversion module 4 uses the top row in the figure as the temperature sensor 6. That is, the temperature of the bottom surface of the printed circuit board 51, i.e., the temperature of the skin in contact with the bottom surface of the printed circuit board 51, can be measured from the electromotive force between the power supply extraction electrode 57a and the temperature sensor extraction electrode 57c, or the temperature dependence of the resistance, preferably the AC resistance.

[0017] Here, a part of the thermoelectric conversion module 4 is used to measure the skin temperature, but a normal thermistor, thermocouple, platinum resistance temperature sensor, etc. may also be used. In this case, relatively accurate measurement of the skin temperature is possible by using a thin sheet-like thermocouple or the like and inserting it between the skin and the thermoelectric conversion module 4. It is preferable to ensure good contact between the skin and the thermoelectric conversion module 4 to prevent changes in heat flow and large measurement errors.

[0018] 3, a thermistor chip 59 may be mounted on a printed circuit board 51 as the temperature sensor 6. This simplifies the manufacturing process and makes it easier to attach to a living body.

[0019] Furthermore, it is preferable that the printed circuit board 51 is made of a material with high thermal conductivity and is thin. This reduces thermal resistance, allowing for more accurate measurement of skin temperature. It is also preferable that the printed circuit board 51 is flexible. This allows it to be attached more closely to curved, easily deformed surfaces such as the surface of a living body.

[0020] In the deep body temperature measurement system shown in Figure 1, low-radiation heat insulating material 11 is provided around the thermoelectric conversion module 4, so that heat flow Q from the deep part of the living body (temperature: Tx) is released to the outside through the thermoelectric conversion module 4. Therefore, [deep temperature (Tx) - surface (skin) temperature (T1)] is proportional to the heat flow Q. In addition, the thermoelectromotive force of the thermoelectric conversion module 4 is proportional to the heat flow Q. Therefore, [deep temperature (Tx) - surface (skin) temperature (T1)] is proportional to the thermoelectromotive force (V) of the thermoelectric conversion module 4, and the following equation (1) holds:

[0021] Tx-T1=a×V+b (1) Here, the constants a and b can be experimentally determined using actual measurements made with a deep body thermometer. The surface (skin) temperature (T1) can be measured by a temperature sensor 6.

[0022] Based on the above formula (1), the deep temperature (Tx) of the living body can be determined by measuring the thermoelectromotive force (V) of the thermoelectric conversion module 4 and the surface (skin) temperature (T1).

[0023] (Other embodiments) Fig. 4 is a principle diagram that shows a schematic configuration of a system for measuring deep body temperature of a living body in another embodiment. As shown in Fig. 4, two thermoelectric conversion modules 4 and 5 are mounted on a printed circuit board 2. A low-radiation heat insulating material 11 is provided around the thermoelectric conversion modules 4 and 5, so that heat flows Q1 and Q2 from the deep part of the living body (temperature Tx) are discharged to the outside through the thermoelectric conversion modules 4 and 5, respectively. For the heat flows Q1 and Q2, the thermal resistances within the living body are R1 and R2, and the thermal resistance of the thermoelectric conversion modules 4 and 5 is R M1 , R M2 Then, the following equations (2) and (3) hold: M1 , R M2 is the thermal resistance between the surfaces of the thermoelectric conversion modules 4 and 5 that come into contact with the living body and the surfaces that face the atmosphere.

[0024] Q1=(T1-Ta) / R M1 =(Tx-T1) / R1 (2) Q2=(T2-Ta) / R M2 =(Tx-T2) / R2 (3) Here, Ta is the ambient temperature outside the thermoelectric conversion modules 4 and 5, T1 is the surface (skin) temperature near the thermoelectric conversion module 4, and T2 is the surface (skin) temperature near the thermoelectric conversion module 5. The surface (skin) temperatures T1 and T2 are measured by temperature sensors 6 and 7 arranged near the thermoelectric conversion modules 4 and 5, respectively.

[0025] If the thermoelectric conversion modules 4 and 5 have the same configuration and area, R1≒R2 is considered, and therefore the above equations (2) and (3) become simultaneous equations consisting of two unknowns (Tx, R1 (≒R2)). Therefore, based on equations (2) and (3), the surface (skin) temperature (T1, T2), the temperature on the air side Ta, and the thermal resistance of the thermoelectric conversion modules 4 and 5 can be calculated as R M1 , R M2 By measuring each of these, the deep body temperature (Tx) of the living body can be determined.

[0026] The thermal resistance R of the thermoelectric conversion modules 4 and 5 M1 , R M2 When these two equations are the same, T1=T2, and the above two equations (2) and (3) are the same, so R M1 , R M2 The thermal resistance R of the thermoelectric conversion modules 4 and 5 must be different. M1 , R M2 Since the thermoelectric element chips 53 and 54 occupy a large area, the thermal resistance R M1 , R M2 To make the values ​​different, it is easy to change the height (H) (see FIG. 2) of the thermoelectric element chips 53 and 54. Alternatively, a plurality of thermoelectric conversion modules may be stacked to change the thermal resistance.

[0027] In this embodiment, the two thermoelectric conversion modules 4 and 5 are preferably mounted on a common printed circuit board 51. This simplifies the manufacturing process and simplifies attachment to a living body.

[0028] Fig. 5 is a block diagram of the core body temperature measuring system. As shown in Fig. 5, the core body temperature measuring system includes a processing device 31 that receives signals from the temperature sensors 6, 7 and the environmental temperature sensor 8 and calculates the core body temperature, and a wireless communication device 32 that transmits the calculated data. The system also includes a DC-DC converter 33 that supplies the power generation output of the thermoelectric conversion modules 4, 5 as power for the processing device 31 and the wireless communication device 32.

[0029] When parts of the thermoelectric conversion modules 4, 5 are used as the temperature sensors 6, 7, it is preferable to provide voltage amplifiers 34, 35 when converting electromotive force into temperature because the electromotive force is small. Note that when using a converted value from an AC resistance value, the voltage amplifiers 34, 35 are not necessary, and the processing device 31 can have that function.

[0030] Although two thermoelectric conversion modules 4, 5 are shown in FIG. 5, it goes without saying that the number of thermoelectric conversion modules 4 may be one, as shown in FIG. [Explanation of symbols]

[0031] 1. Biological surface 2 Printed circuit board 4, 5 Thermoelectric conversion module 6, 7 Temperature sensor 8 Environmental Temperature Sensor 11 Low-emissivity insulation 31 Processing equipment 32 Wireless communication equipment 33 DC-DC converter 34, 35 Voltage amplifier 51 Printed Circuit Board 52 Wiring land 53 p-type thermoelectric element chip 54 n-type thermoelectric element chip 55 Upper wiring board 56 Upper connection wiring 57a, 57b, 57c electrodes 59 Thermistor Chip

Claims

1. A printed circuit board; a thermoelectric conversion module mounted on the printed circuit board and including a plurality of p-type thermoelectric element chips and n-type thermoelectric element chips alternately connected in series; a temperature sensor mounted on the printed circuit board; a heat insulating material surrounding the thermoelectric conversion module; Equipped with A system for measuring the deep body temperature of a living organism, in which the printed circuit board equipped with the thermoelectric conversion module is placed in contact with the surface of the living organism, and the deep body temperature of the living organism is measured based on the thermoelectric power in the thermoelectric conversion module generated by the temperature difference between the temperature of the bottom surface of the printed circuit board in contact with the surface of the living organism and the environmental temperature outside the printed circuit board, which is caused by the heat flow released from deep within the living organism through the thermoelectric conversion module to the outside, and the surface temperature of the living organism measured by the temperature sensor.

2. A deep body temperature measurement system as described in claim 1, wherein when the thermoelectric power generated by the thermoelectric conversion module is V and the surface temperature of the living body measured by the temperature sensor is T1, the deep body temperature Tx of the living body is measured based on the following equation (1): Tx-T1=a×V+b...(1) Here, the constants a and b are values ​​experimentally determined using actual measurements taken with a deep body thermometer.

3. A deep body temperature measurement system as described in claim 1, wherein the insulating material is made of low-emissivity insulating material.

4. 4. The deep body temperature measuring system of claim 1, wherein the thermoelectric conversion module generates electricity using a temperature difference between body temperature and ambient temperature.

5. The deep body temperature measurement system of any one of claims 1 to 4, wherein the electricity generated by the thermoelectric conversion module is used as a power source for a deep body temperature measurement system including a communication function.

6. A printed circuit board; a thermoelectric conversion module mounted on the printed circuit board and including a plurality of p-type thermoelectric element chips and n-type thermoelectric element chips alternately connected in series; a temperature sensor mounted on the printed circuit board; Equipped with A part of the thermoelectric conversion module is used as a temperature sensor converted from an AC resistance value, A system for measuring the deep body temperature of a living organism, in which the printed circuit board is placed in contact with the surface of the living organism and the deep body temperature of the living organism is measured by measuring the electromotive force in the thermoelectric conversion module and the surface temperature of the living organism measured by the temperature sensor.

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