JP2007212407A - Non-heated deep body thermometer and deep body temperature measuring device using the same - Google Patents

Abstract

An object of the present invention is to measure a body temperature of a deep part of a body with high accuracy non-invasively and without using a heater.
A first temperature sensor and a second temperature sensor are provided in order from a measurement surface 1a side in contact with a body surface, and a heat insulating material is provided between the first temperature sensor and the second temperature sensor. 4, a set of the first temperature sensor 2-1 and the second temperature sensor 3-1, the first temperature sensor 2-2, and the second temperature sensor 3-1. A pair of temperature sensors 3-2 and at least two sets of temperature sensors, and the first temperature sensor and the second temperature sensor for each set of the first temperature sensor and the second temperature sensor; The heat resistance value K of the heat insulating material 4 between is different from that of the non-heating type deep thermometer.
[Selection] Figure 3

Description

  The present invention relates to a non-heating type depth thermometer that measures a body temperature in a deep part of a body without using a heater that compensates for heat flow, and a depth body temperature measuring apparatus using the same.

  As a conventional apparatus for measuring the body temperature in the deep part of the body, a deep body temperature measuring apparatus developed by Fox and Solman in 1971 is known. This deep body temperature measurement device applies a heat flow compensation method to make the heat dissipation from the body surface apparently zero, thereby eliminating the heat flow from the body surface to the body surface, and achieving thermal equilibrium between the body surface and the body depth part. In this state, the body surface temperature is measured to measure the same temperature as the deep body, and the deep body temperature is indirectly measured from the body surface.

  Specifically, the conventional deep body temperature measuring device includes a first temperature sensor, a second temperature sensor, and a heater in order from the measurement surface side that contacts the body surface, and the first temperature sensor, A heating-type deep thermometer having a heat insulating material between the second temperature sensor and the measurement surface is brought into close contact with the body surface to measure the body surface temperature with the first temperature sensor. The heater temperature is measured by the above, and the heat flow is compensated by controlling the heater temperature so that the temperature difference between the first and second temperature sensors approaches zero, so that the heat flow in the thermometer becomes zero. To do. This deep body temperature measuring device is less affected by the outside air temperature, and can measure the deep body temperature non-invasively without using a puncture needle (see, for example, Patent Document 1).

  The technology of deep body temperature management using the above-mentioned conventional deep body temperature measuring device has been improved by the group such as Togawa and Nemoto and Terumo, and in particular, the management of deep body temperature from the forehead has been widely used in Japan today. Used in the area. Deep body temperature management is also used in intensive care units and circulatory failure.

  On the other hand, as a conventional apparatus for measuring the body temperature in the deep part of the body, an apparatus using a non-heating type simple depth thermometer is also known. When a heat insulating material having the same thermal conductivity as that of the subcutaneous tissue is brought into close contact with the body surface, the body heat carried in the bloodstream is conducted through the subcutaneous tissue and the heat insulating material due to its thermal resistance value and temperature difference. Since heat is dissipated in the outside air, the heat characteristics of the subcutaneous tissue are almost constant if the temperature of the body surface contact surface and the outside air contact surface of this heat insulating material is measured using a heat insulating material with a known thermal resistance value. Therefore, the deep body temperature can be measured non-invasively. This conventional apparatus uses such a principle.

Tb is the temperature in the deep part of the body, Ta is the temperature of the surface of the insulation that is in contact with the outside air, Tt is the temperature of the surface of the insulation that is in contact with the body surface, Rt is the thermal resistance value of the subcutaneous tissue, and the thermal resistance of the insulation When the value is Ra, the following relational expression (1) is established according to the electric circuit similarity method.

Here, the thermal resistance value Rt of the subcutaneous tissue is determined by the depth Lt up to the depth at which the temperature is measured and the thermal conductivity kt, the depth Lt = 2 cm, and the thermal conductivity kt = 1 × 10 ⁻³ cal / cm.・ Assuming sec · ° C. (assuming that the subcutaneous tissue is muscle tissue), the thermal resistance value Rt is 2 × 10 ³ cm · sec · ° C./cal.

  Therefore, specifically, the deep body temperature measuring device includes the first temperature sensor and the second temperature sensor in order from the measurement surface side in contact with the body surface, and the first temperature sensor and the second temperature sensor. The surface of the heat insulating material in contact with the outside air using a non-heated deep thermometer comprising a heat insulating material whose thermal resistance value Ra is determined in advance between the temperature sensor 2 and the thickness La and the thermal conductivity Ka. The temperature Tb of the body and the temperature Tt of the surface of the heat insulating material in contact with the body surface are measured and substituted into the above equation (1) to obtain the temperature Tb of the deep body (see, for example, Patent Document 2) .

  As a conventional deep body temperature measuring apparatus using a non-heating type simple deep body thermometer, an apparatus using thermal equilibrium is also known as in the previous heating type. Covering the body surface with a heat insulating material with a known thermal resistance value, the heat flow from the deep part of the living body to the surface of the body is made almost zero, the body surface temperature distribution is made substantially the same as the body temperature of the deep body part, and the body surface contact surface of the heat insulating material And the outside air contact surface can be measured noninvasively to measure the deep body temperature. This conventional apparatus uses such a principle.

ここで、断熱材の熱抵抗値Ra を皮下組織の熱抵抗値Rtより充分大きくしておく（Ra≫Rt）と、Ra／（Rt + Ra）≒１となり、Tt≒Ta となるので、深部体温を体表面温度として測定することができる。 Tb is the temperature in the deep part of the body, Ta is the temperature of the surface of the insulation that is in contact with the atmosphere, Tt is the temperature of the surface of the insulation that is in contact with the body surface, Rt is the thermal resistance value of the subcutaneous tissue, and the thermal resistance of the insulation When the value is Ra, the following relational expression (2) is established according to the electric circuit similarity method.

Here, if the thermal resistance value Ra of the heat insulating material is sufficiently larger than the thermal resistance value Rt of the subcutaneous tissue (Ra >> Rt), Ra / (Rt + Ra) ≈1 and Tt≈Ta. Body temperature can be measured as body surface temperature.

Therefore, specifically, the conventional deep body temperature measuring device includes the first temperature sensor, the heat insulating material, and the second temperature sensor in the order closer to the body surface, and the thickness La of the heat insulating material in advance. Using a non-heating type deep thermometer that appropriately determines the thermal resistance value Ra of the heat insulating material based on the thermal conductivity Ka, the temperature Ta of the surface of the heat insulating material in contact with the atmosphere and the heat insulating material in contact with the skin By measuring the surface temperature Tt and substituting them into the above equation (2), the temperature Tb of the deep part of the body is obtained (see, for example, Patent Document 3).
JP 2002-202205 JP JP 61-120026 JP Japanese Patent Laid-Open No. 61-120027

  However, the former heating-type deep thermometer requires a power source for heating with a heater and requires a high-precision control circuit for controlling the heater, and a measuring device using the same is large and expensive. There is a problem that it will be. Furthermore, since the power of the heater is required, there is a problem that measurement cannot be performed for a long time by battery drive and cannot be applied to a portable deep thermometer.

  On the other hand, in the first of the latter non-heating type thermometers, it is assumed that the thermal resistance value Rt of the skin and subcutaneous tissue is a constant value. However, the thermal resistance value Rt is actually different among individuals. At the same time, since it varies depending on the head, abdomen, limbs, etc., there is a problem that the measurement error of the deep body temperature is large.

  The second of the latter non-heated deep thermometers assumes that the heat flow reaching the body surface is almost zero, but it is difficult to make the heat flow zero by simply covering with a heat insulating material. There is a problem that the measurement error of deep body temperature is large.

  This invention aims at solving the said subject advantageously, and the non-heating type depth thermometer of this invention is based on the following knowledge of this inventor.

  When an area on the body surface is covered with a heat insulating material, heat dissipation from the body surface is reduced in that portion, so that the temperature of the body surface becomes higher than the portion exposed to the outside air. Assuming that the heat flow is constant in the heat insulating material and the subcutaneous tissue immediately below and is vertically upward with respect to the body surface, the heat flow is obtained from the heat resistance value of the heat insulating material and the temperature difference. Similarly, since the heat flow is also obtained from the deep temperature in the subcutaneous tissue of the part covered with the heat insulating material, the temperature difference of the body surface, and the thermal resistance value of the subcutaneous tissue, the deep temperature is the thermal resistance value of the subcutaneous tissue. It is calculated | required from the temperature and heat resistance value of a heat insulating material as an unknown.

Therefore, assuming that the thermal resistance value of the subcutaneous tissue is constant, when the body surface is covered with at least two types of thermal resistance insulation materials, the depth temperature is determined for each thermal insulation material with the subcutaneous tissue thermal resistance value as an unknown. By obtaining the temperature difference of the heat insulating material and the thermal resistance value, and by eliminating the thermal resistance value of the subcutaneous tissue by simultaneous expression of these deep temperature equations, the deep body temperature can be obtained.
1 (a) is, consider the case of covering the body surface with a heat insulating material of the thermal resistance R _1. When the heat flow in the thermal insulation and the tissue immediately below it is constant upward, and the thermal resistance in the tissue is R, according to the electric circuit similarity method, the potential difference, current, resistance in the temperature difference, heat flow rate, and thermal conductivity, respectively. An equivalent circuit corresponding to can be considered as FIG.

Considering an equivalent circuit, the heat flow I is obtained by the following equation (3).

When the deep temperature TB is obtained by deformation

  Here, TC and TA are the temperatures on the measurement surface side and the outside air side in contact with the body surface of the heat insulating material, and R and R1 are the thermal resistance values of the subcutaneous tissue and the heat insulating material. However, since the thermal resistance value of the subcutaneous tissue varies among individuals and varies depending on the site such as the head and abdomen, it is difficult to set a constant value. Therefore, in order to calculate without using the thermal resistance value of the subcutaneous tissue, considering the case where the skin surface is covered with two kinds of heat insulating materials as shown in FIG. 2 (a), the equivalent circuit is shown in FIG. 2 (b). It becomes a circuit. It is assumed that the heat flow is constant upward and there is no heat transfer between the two heat insulating materials. In this equivalent circuit, it is assumed that the two types of thermal resistance values are R1 and R2, and the outside air temperatures T3 and T4 are isothermal.

When TB is obtained between ab and cd in FIG. 2B, respectively,

よって、上記式（７）より、二種の熱抵抗値R1，R2の比Kは、次式（８）で与えられる。

なお、熱抵抗値比Kの値は、本願発明者の実験の結果、外気温の影響を受けることが判明しているが、あらかじめ外気温の変化に応じて求めておくか、後述のように体温計をさらに断熱材で覆うことで、外気温の影響を排除することができる。 Here, when R1 = KR2 and R is removed from the above equations (5) and (6), the deep body temperature TB is

Therefore, from the above equation (7), the ratio K of the two types of thermal resistance values R1 and R2 is given by the following equation (8).

The value of the thermal resistance value ratio K has been found to be affected by the outside air temperature as a result of the experiment by the present inventor, but is determined in advance according to a change in the outside air temperature, or as described later. By further covering the thermometer with a heat insulating material, the influence of the outside air temperature can be eliminated.

  The present invention is based on the above-described measurement principle, and the non-heating type depth thermometer of the present invention includes a first temperature sensor and a second temperature sensor in order from the measurement surface side in contact with the body surface. In the non-heating type depth thermometer including a heat insulating material between the first temperature sensor and the second temperature sensor, the first temperature sensor and the second temperature sensor include at least two sets, The thermal resistance value of the heat insulating material between the first temperature sensor and the second temperature sensor is different for each set of the first temperature sensor and the second temperature sensor. It is.

  Further, the deep body temperature measuring device of the present invention using the non-heating type deep body thermometer of the present invention includes a difference in temperature measured by the first temperature sensor and the second temperature sensor, and the first temperature sensor. The deep body temperature is obtained from the ratio of the thermal resistance values between at least two sets of the first temperature sensor and the second temperature sensor.

  According to the non-heating type depth thermometer of the present invention, at least two sets of the first temperature sensor and the second temperature sensor are provided, and for each set of the first temperature sensor and the second temperature sensor, they are provided. Since the heat resistance value of the heat insulating material between the first temperature sensor and the second temperature sensor is different, the temperature measured by the first temperature sensor (for example, T1 and T2 above) and the first temperature sensor as described above. From the temperature measured by the two temperature sensors (for example, T3 and T4) and the ratio of the thermal resistance values between the at least two sets of the first temperature sensor and the second temperature sensor (for example, K). Since the deep body temperature can be obtained, the body temperature of the deep body can be measured with high accuracy non-invasively and without using a heater.

  In addition, according to the non-heating type deep body temperature measuring device of the present invention, the temperature measured by the first temperature sensor of the non-heating type deep body thermometer of the present invention (for example, T1 and T2 above) and the second temperature sensor measured. From the temperature (for example, T3 and T4) and the ratio of the thermal resistance value between each of at least two sets of the first temperature sensor and the second temperature sensor (for example, K), as described above, Since the body temperature can be obtained, the body temperature in the deep part of the body can be measured with high accuracy by a small and inexpensive device.

  In the non-heated deep thermometer of the present invention, the heat insulating material is centered on the thickness between the measurement surface side surface located on the measurement surface side of one type of heat insulating material and the outside air surface facing it. By changing concentrically according to the distance from the surface, the thermal resistance value between the measurement surface side surface and the outside air side surface differs according to the distance from the center, and the first temperature sensor The second temperature sensor is arranged on the measurement surface side surface and the outside air side surface of the heat insulating material so that the distance from the center of the heat insulating material is different for each set of the temperature sensors. May be. If it does in this way, a non-heating type deep body thermometer can be comprised easily and cheaply with one type of heat insulating material.

  Moreover, in the non-heating type deep thermometer of this invention, the said heat insulating material is good also as a closed-cell type foaming sponge rubber. In this way, since bubbles are independent, water such as sweat does not penetrate into the heat insulating material, and air does not enter or leave the heat insulating material, so that the thermal resistance value is kept constant. Can do.

  Furthermore, in the non-heating type depth thermometer according to the present invention, the heat insulating material is stepwise in a concentric manner in which the thickness between the measurement surface side surface and the outside air side surface increases with an increase in the distance from the center. By decreasing, the thermal resistance value between the measurement surface side surface and the outside air side surface may decrease stepwise as the distance from the center increases. If it does in this way, the thickness of an outer peripheral part can be made thin and a non-heating type deep body thermometer can be comprised compactly.

  Furthermore, in the non-heating type depth thermometer of this invention, the measurement surface side surface of the heat insulating material belongs to the same set of at least two sets of the first temperature sensor and the second temperature sensor. A measuring surface side heat transfer member that connects the plurality of first temperature sensors is provided, and all of the first temperature sensor and the second temperature sensor are provided on the outside air side surface of the heat insulating material. An outside air side heat transfer member that connects the second temperature sensors of the set may be provided. In this way, when any one of the temperature sensors has a plurality of the first temperature sensors, the temperatures of the first temperature sensors can be made uniform by the heat conduction of the measurement surface side heat transfer member, and Since the temperature of the second temperature sensors of all sets of temperature sensors can be made uniform by the heat conduction of the outside air side heat transfer member, the partial temperature variation of the body surface is averaged, and the deep body temperature can be more accurately obtained. Can be measured.

  And in the non-heating type deep body thermometer of this invention, the outside air side surface of the heat insulating material includes at least the outside air side surface of the heat insulating material, the first temperature sensor, and the second temperature sensor. A cover made of heat insulating material may be provided to cover the second temperature sensor of the set. If such a cover is provided, the change in the thermal resistance value ratio of the heat insulating material due to the outside air temperature can be suppressed as described above, so that a constant thermal resistance value ratio can be used regardless of the outside air temperature, Calculation can be made easy.

  The deep body temperature measuring device of the present invention can be configured by using a computer such as a personal computer or a microcomputer or an analog arithmetic circuit, for example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 3 is a cross-sectional view showing an embodiment of the non-heating type deep thermometer of the present invention, and FIGS. 4A and 4B are a plan view and a bottom view showing the non-heating type deep thermometer of the embodiment. It is a figure, the non-heating type depth thermometer 1 of this example is the 1st temperature sensors 2-1 and 2-2 in order from the measurement surface 1a side which touches the body surface which is a downward surface in the figure, The second temperature sensors 3-1 and 3-2 are provided, and a heat insulating material is provided between the first temperature sensors 2-1 and 2-2 and the second temperature sensors 3-1 and 3-2. 4, where the first temperature sensor 2-1 and the second temperature sensor 3-1 form one set (first set) and the first temperature sensor 2-2. The second temperature sensor 3-2 forms another set (second set). As these temperature sensors 2-1, 2-2, 3-1, 3-2, for example, an IC temperature sensor AD590 manufactured by Analog Devices, Inc. can be used.

  Further, here, the heat insulating material 4 is made of a closed-cell foamed sponge rubber, and the thickness between the lower measurement surface side surface 4a in the figure and the upper outside air side surface 4b in the figure is a distance from the center. In the example shown in the figure, it is formed in a disk shape consisting of a central portion 4c having a thickness of 13 mm and a peripheral portion 4d having a thickness of 7 mm so as to gradually decrease concentrically with the increase. 4, the thermal resistance value between the measurement surface side surface 4a and the outside air side surface 4b decreases stepwise in the peripheral portion 4d with respect to the central portion 4c.

  Furthermore, the non-heating type deep thermometer 1 of this embodiment is made of copper having an outer diameter of 8 mm and a thickness of 1 mm in the illustrated example attached to the central portion of the measurement surface side surface 4a of the central portion 4c of the heat insulating material 4. In the illustrated example, the outer diameter is 36 mm, the width is 3 mm, and the thickness is 1 mm. The disk 5 and the measurement surface side surface 4 a of the peripheral portion 4 d of the heat insulating material 4 are attached concentrically with the heat insulating material 4. In the illustrated example, the outer diameter of the peripheral portion is 44 mm and the outer diameter of the central portion is attached to the ring 6 and the outer air side surface 4b of the heat insulating material 4 so as to cover the central portion 4c and the peripheral portion 4d of the heat insulating material 4. A copper cap 7 having a hat-shaped cross section of 26 mm, a height of 8 mm, and a thickness of 2 mm is provided.

  And in the non-heating type depth thermometer 1 of this Example, the 1st temperature sensor 2-1 which is one side of the said 1st temperature sensor is the center part of the measurement surface side surface 4a of the center part 4c of the said heat insulating material 4. And the first temperature sensor 2-2, which is the other of the first temperature sensors, is interposed between the measurement surface side surface 4a of the peripheral portion 4d of the heat insulating material 4 and the above-described one. Four (only two are shown in the figure) are interposed between the copper ring 6 at regular intervals in the circumferential direction, and the second temperature sensor 3 is one of the second temperature sensors. -1 is interposed between the center portion of the outside air side surface 4b of the central portion 4c of the heat insulating material 4 and the copper cap 7, and the second temperature sensor 3 which is the other of the second temperature sensors. -2 is four between the outside air side surface 4a of the peripheral portion 4d of the heat insulating material 4 and the copper cap 7. Four so that each first temperature sensor 2-2 aligned in the thickness direction of the heat insulating material 4 (shown only two in the figure) is interposed.

  According to the non-heating type depth thermometer 1 of this embodiment, the heat flow flowing inside the heat insulating material 4 measured by the first and second temperature sensors 2-1, 2-2, 3-1, 3-2, and From the thermal resistance value ratio K between the central portion 4c and the peripheral portion 4d of the heat insulating material 4, the deep body temperature TB is calculated by the above equation (7).

  FIG. 5 shows the output voltages of the first and second temperature sensors 2-1, 2-2, 3-1 and 3-2 respectively amplified and compared with the reference voltage, and the first and second temperatures. The analog circuit that outputs the temperature measured by the sensors 2-1, 2-2, 3-1, 3-2 at a voltage of 1 ° C. = 1 V is illustrated, and the output voltage of the analog circuit is not shown in the normal A / D converter converts it into a digital signal, and inputs the ratio K of the thermal resistance value between the central portion 4c and the peripheral portion 4d of the heat insulating material 4 obtained in advance to an ordinary personal computer (not shown) From the temperatures T1, T2 measured by the first temperature sensors 2-1, 2-2 and the temperatures T3, T4 measured by the second temperature sensors 3-1, 3-2 and the ratio K of the thermal resistance value, By letting the personal computer calculate the equation (7), It is possible to calculate the temperature TB. Therefore, the non-heating type deep thermometer 1, the analog circuit of FIG. 5, the A / D converter, and the personal computer of this embodiment constitute one embodiment of the deep body temperature measuring apparatus of the present invention.

  6A and 6B show the cover 8 made of a heat insulating material used for the non-heated deep thermometer 1 of the above embodiment as viewed obliquely from below with respect to the cover alone and the state where the non-heated deep thermometer 1 is covered. It is a perspective view shown in the state. The cover 8 in the illustrated example is made of sponge and has an outer diameter of 50 mm and a thickness of 40 mm.

FIG. 7 is an explanatory diagram showing a simulation experiment method for measuring deep body temperature. In this experiment, a copper box was floated on a constant water surface of 37 ° C. in a constant temperature water bath, and the thermal conductivity was 1.7 × 10 ⁻² J / cm ° C. and a thickness of 1 to 10 mm at the bottom of the box. Ten rubber plates were aligned and fixed every 1 mm in thickness. The environment (outside air) temperature was kept constant at room temperature of 20 ° C., 25 ° C., and 30 ° C. And the non-heating type deep thermometer 1 of this embodiment, the analog circuit, the A / D converter, and the normal personal computer constitute the deep body temperature measuring device of the above embodiment, and the non-heating type deep thermometer of this embodiment Measurement temperatures T1, T2, T3, and T4 of each temperature sensor 1 were recorded on a personal computer at intervals of 30 seconds via the analog circuit and the A / D converter.

  From the result of the simulation experiment, the value K of the thermal resistance ratio of the heat insulating material 4 is obtained from the relationship between the measured temperatures T1, T2, T3, T4 of each temperature sensor of the non-heating type thermometer 1 of this embodiment and the water temperature 37 ° C. Was calculated. The value K of the thermal resistance ratio was determined so that the error between the detected temperature and the water temperature with a rubber plate thickness of 1 to 10 mm was minimized.

  FIGS. 8A, 8B, and 8C are relationship diagrams respectively showing errors when an optimum thermal resistance ratio is obtained in a simulation experiment at room temperature of 20 ° C., 25 ° C., and 30 ° C. FIG. At room temperature of 20 ° C., K was 2.5, and could be detected within ± 0.1 ° C. At room temperature of 25 ° C., K was 2.8, and could be detected within ± 0.1 ° C. When the room temperature was 30 ° C., K was 3.0 and could be detected within ± 0.1 ° C. From the above results, it was shown that the value K of the thermal resistance ratio of the non-heating type deep thermometer 1 of this example was affected by the room temperature, and K had temperature characteristics in the range of 2.5 to 3.0.

  FIG. 9 shows the value K of the thermal resistance ratio at the time of a simulation experiment at a room temperature of 25 ° C. and the detection error up to a rubber plate thickness of 1 to 10 mm when the unheated deep thermometer 1 of this example is covered with the cover 8. In this experiment, the optimum value K of the thermal resistance ratio at room temperature of 25 ° C. was 4.0. In addition, using the optimum value, the error when detecting a water temperature of 37 ° C. with a rubber plate of 1 to 10 mm in a simulation experiment was within ± 0.1 ° C.

  10 (a), 10 (b), and 10 (c) show the heat flow-compensated deep thermometer and the cover 8 covered with the heat flow compensation type thermometer for each part of the human body, that is, the temporal region, chest region, and abdomen at room temperature of 20 ° C. FIG. 10D is a relationship diagram showing the comparison result of the detected temperature with the non-heating type deep thermometer 1 of the example. FIG. 10D is a heat flow compensation type deep thermometer of the human chest at room temperature 30 ° C. and the cover 8. It is a relationship line figure which shows the comparison result of the detected temperature by the non-heating type depth thermometer 1 of this Example covered with.

  The relationship diagrams of FIGS. 10 (a), (b), and (c) show that the detected temperature value in the measuring device using both thermometers was within ± 0.1 ° C. at each room temperature. Yes. The temperature equilibration time was about 25 minutes for the temporal region, about 30 minutes for the chest region, and about 40 minutes for the abdominal region. The relationship diagram of FIG. 10D shows that when the room temperature reaches 30 ° C., the temperature equilibration time is shortened, and the detection results of the deep body temperature measuring device using both thermometers are almost the same.

  FIG. 11 shows detection of a heat flow compensated deep thermometer and a non-heated deep thermometer 1 of this embodiment covered with a cover 8 on the left and right sides of 10 test subjects when they are measured simultaneously. It is a relationship diagram which shows the result of having performed the comparison of temperature. The average detected temperature of the heat flow compensated deep thermometer was 36.87 ° C., whereas the average detected temperature of the non-heated deep thermometer 1 of this example is 36.85 ° C., and both thermometers are almost the same. The value is shown.

  Summarizing the above results, in the non-heating type depth thermometer 1 of this example and the deep body temperature measuring device of this example using the same, at room temperature 20 ° C., 25 ° C., 30 ° C. from a simulation experiment using a rubber plate. The thermal resistance ratio values K of the heat insulating material 4 with the smallest detection error at a rubber plate thickness of 1 to 10 mm at each room temperature were 2.5, 2.8, and 3.0. The influence of temperature was recognized on the value K of the thermal resistance ratio.

  By covering the non-heating type depth thermometer 1 of this example with a cover 8 (50 mmφ × 40 mm), the thermal resistance ratio K at which the detection error is minimized showed 4.0. By attaching the cover 8, the influence of room temperature was almost negligible, and a water temperature of 37 ° C. could be detected within ± 0.1 ° C. with a thickness of 1 to 10 mm.

  As a result of comparing the non-heating type thermometer 1 of this example covered with the cover 8 and the heat flow compensation type thermometer, the difference in the detection accuracy of the subcutaneous body temperature of each part of the human body was within ± 0.1 ° C. . The response time was almost the same value. And in the experiment using 10 test subjects, the comparison of the temporal deep body temperature detection results showed that the non-heated deep thermometer 1 and the heat flow compensated deep thermometer of this embodiment covered with the cover 8 showed substantially the same temperature. .

  Therefore, according to the non-heating type deep body thermometer 1 of this embodiment, the body temperature of the deep part of the body can be measured with high accuracy non-invasively and without using a heater. According to the deep body temperature measuring device of this embodiment, the body temperature of the deep body can be measured with high accuracy with a small and inexpensive device.

  Although the present invention has been described based on the illustrated examples, the present invention is not limited to the above examples, and can be appropriately changed within the scope of the claims, for example, the first temperature sensor and the second temperature sensor. Three or more temperature sensor pairs may be provided, and the body temperature measured in two pairs of them may be averaged, and the top surface of the heat insulating material may be a truncated cone or a partial spherical shape. The thermal resistance value may change continuously in the radial direction. Further, a plurality of types of heat insulating materials may be used, such as different materials of the heat insulating material between the first set and the second set of the first temperature sensor and the second temperature sensor. As an example, urethane foam may be used. Furthermore, the material of the heat transfer member is not limited to copper in the above embodiment, and for example, silicon or the like may be used.

  Furthermore, the analog amplifier, the A / D converter, and the microcomputer may be incorporated in the non-heated deep thermometer of the present invention to constitute a deep body temperature measuring device that integrally includes the non-heated deep thermometer.

  Thus, according to the non-heating type deep body thermometer of the present invention, the body temperature of the deep part of the body can be measured with high accuracy non-invasively and without using a heater. According to the deep body temperature measuring device of the present invention, the body temperature at the deep part of the body can be measured with high accuracy by a small and inexpensive device.

(A) is explanatory drawing which shows the relationship between temperature, heat flow, and thermal conductivity when the body surface is covered with a heat insulating material, and (b) is an equivalent using the electrical potential difference, current, resistance, etc. It is a circuit diagram shown with a circuit. │ (A) is explanatory drawing which shows the relationship between temperature, heat flow, and thermal conductivity when a body surface is covered with two types of heat insulating materials having different thermal resistance values, and (b) is an electrical diagram showing the relationship described above. FIG. 6 is a circuit diagram showing an equivalent circuit using a potential difference, current, resistance, and the like. │ It is sectional drawing which shows one Example of the non-heating type depth thermometer of this invention. (A), (b) is the top view and bottom view which show the non-heating-type deep thermometer of the said Example. It is a circuit diagram which illustrates the analog circuit which comprises one Example of the deep body temperature measuring apparatus of this invention. (A), (b) is a perspective view showing a cover made of a heat insulating material used for the non-heated deep thermometer of the above embodiment as viewed obliquely from below with respect to each of the cover alone and the state where the non-heated deep thermometer is covered. FIG. It is explanatory drawing which shows the method of the simulation experiment of the deep body temperature measurement which detects the water temperature under the rubber plate from the surface of the rubber plate of thickness 1-10 mm. (A), (b), (c) is a relationship diagram which respectively shows the error at the time of calculating | requiring the optimal thermal resistance ratio at the time of the simulation experiment in room temperature 20 degreeC, 25 degreeC, and 30 degreeC. Relationship line indicating relationship between thermal resistance ratio value K and detection error of rubber plate thickness of 1 to 10 mm at the time of simulation experiment at room temperature of 25 ° C. when the non-heated deep thermometer of this example is covered with a cover FIG. (A), (b), (c) are temperatures detected at the room temperature of 20 ° C. by the heat flow-compensated deep thermometer and the non-heated deep thermometer of each part of the human body including the temporal region, chest and abdomen. (D) is a relationship diagram showing a comparison result of detected temperatures of a human chest at a room temperature of 30 ° C. using a heat flow compensation type thermometer and a non-heating type thermometer. is there. A heat flow compensation type thermometer and a non-heating type thermometer of this embodiment covered with a cover were fixed to the left and right sides of 10 subjects' heads, and comparison was made between the detected temperatures when measured simultaneously. It is a relationship diagram which shows a result.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Non-heating type depth thermometer 1a Measurement surface 2-1, 2-2 1st temperature sensor 3-1, 3-2 2nd temperature sensor 4 Heat insulating material 4a Measurement surface side surface 4b Outside air side surface 4c Center part 4d Around Part 5 Disc 6 Ring 7 Cap 8 Cover

Claims (7)

The first temperature sensor and the second temperature sensor are provided in order from the measurement surface side in contact with the body surface, and a non-heated material is provided with a heat insulating material between the first temperature sensor and the second temperature sensor. In the type of thermometer,
Comprising at least two sets of the first temperature sensor and the second temperature sensor;
The thermal resistance value of the heat insulating material between the first temperature sensor and the second temperature sensor is different for each set of the first temperature sensor and the second temperature sensor, Non-heated deep thermometer.   The non-heating type deep thermometer according to claim 1, wherein the heat insulating material is a closed-cell foaming sponge rubber. The heat insulating material is such that the thickness between the measurement surface side surface located on the measurement surface side of one type of heat insulating material and the outside air surface facing it changes concentrically according to the distance from the center. The thermal resistance value between the measurement surface side surface and the outside air side surface is different depending on the distance from the center,
The measurement surface side surface of the heat insulating material is arranged such that the first temperature sensor and the second temperature sensor are located at different distances from the center of the heat insulating material for each set of the temperature sensors. The non-heating type deep thermometer according to claim 1, wherein the non-heating type deep body thermometer is arranged on the outside air side surface.   The heat insulating material is formed such that the thickness between the measurement surface side surface and the outside air side surface decreases stepwise in a concentric manner as the distance from the center increases, so that the measurement surface side surface and the outside air side The non-heating type depth thermometer according to claim 3, wherein the thermal resistance value between the surface and the surface decreases stepwise as the distance from the center increases. A measurement surface connecting the plurality of first temperature sensors belonging to the same set of at least two sets of the first temperature sensor and the second temperature sensor on the measurement surface side surface of the heat insulating material. A side heat transfer member is provided,
An outside air side heat transfer member that connects all the second temperature sensors of the first temperature sensor and the second temperature sensor is provided on the outside air surface of the heat insulating material. The non-heating type depth thermometer according to any one of claims 1 to 4, wherein   On the outside air side surface of the heat insulating material, at least the outside air side surface of the heat insulating material and the heat insulating material covering all the second temperature sensors of the first temperature sensor and the second temperature sensor. The non-heating type depth thermometer according to any one of claims 1 to 5, further comprising a cover made of metal. Using the non-heating type depth thermometer according to any one of claims 1 to 6,
The temperature measured by the first temperature sensor and the second temperature sensor, respectively, and the thermal resistance value of the pre-insulation material between at least two sets of the first temperature sensor and the second temperature sensor, respectively. A deep body temperature measuring device, wherein the deep body temperature is obtained from the ratio of the above.

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