Body temperature estimation device, body temperature estimation method, and body temperature estimation system

Abstract

The present invention provides a body temperature estimation device comprising: a measurement unit for measuring the temperature of an animal's eye; and a body temperature estimation unit for setting, in a body temperature estimation model, the temperature measured by the measurement unit and simulating heat conduction to estimate the core body temperature of the animal.

Description

[Technical field]

[0001] The present invention relates to a body temperature estimation device, a body temperature estimation method, and a body temperature estimation system. [Background technology]

[0002] A body temperature estimation model that estimates human core body temperature and other body temperatures using simulations is being used to evaluate outdoor environments and verify thermal management of the human body (e.g., Non-Patent Document 1). In addition, there is a demand for wearable devices that can prevent heatstroke and detect infection by determining changes in body temperature in real time (e.g., Non-Patent Document 2). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Shinichi Tanabe, Junta Nakano, Kozo Kobayashi: Study on 65-division thermoregulation model for thermal environment evaluation, Journal of Architecture and Planning (541), 9-16, 2001 [Non-Patent Document 2] FY2012 Heat Island Adaptation Measures and Post-Disaster Heat Island Countermeasures Study Project Reference Material 1-5 "Survey Results on Human Body Temperature Physiology Model" Summary of the Invention [Problem to be solved by the invention]

[0004] However, for example, the model described in Non-Patent Document 1 aims to express temperature changes in peripheral parts of the body such as fingertips and the feeling of a cold head and hot feet, so it is over-specified to obtain body temperature changes at rest and the amount of calculations can be large. In addition, multiple parameters are required for the simulation, and sensors need to be attached to the whole body, making it difficult to realize with a wearable device.

[0005] The present invention provides a body temperature estimation device that can more simply estimate body temperature. [Means for solving the problem]

[0006] One aspect of the present invention is a body temperature estimation device that includes a measurement unit that measures the temperature of an animal's eye, and a body temperature estimation unit that estimates the animal's deep body temperature by setting the temperature measured by the measurement unit in a body temperature estimation model and simulating heat conduction. Effect of the Invention

[0007] The body temperature estimation device of the present invention can more simply realize body temperature estimation. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a body temperature estimation device 1. [Diagram 2] 4 is a flowchart showing the operation of the body temperature estimation device 1. [Figure 3A] FIG. 2 is a front view of the body temperature estimation model. [Figure 3B] FIG. 2 is a side view of the body temperature estimation model. [Figure 4] FIG. 2 is a diagram showing a configuration of a body temperature estimation system 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] 1 is a diagram showing an example of the configuration of a body temperature estimation device 1. The body temperature estimation device 1 estimates body temperature by measuring the temperature of the caruncle. The body temperature estimation device 1 includes a temperature measurement unit 11, a body temperature estimation model storage unit 12, a body temperature estimation unit 13, and a presentation unit 14.

[0011] The temperature measuring unit 11 measures the temperature of the user's eye. The temperature measuring unit 11 may measure the temperature of the caruncle of the user's eye, for example. Arteries and veins run parallel to each other near the caruncle, and the temperature of the hypothalamus (core body temperature) is easily transmitted through heat transport in the blood vessels. In addition, since it can be considered that the heat transfer from the head to the body and the heat transfer from the body to the head are in equilibrium in the body temperature of a human being in a resting state, it can be assumed that the temperature of the hypothalamus is the same as the temperature of the body. The temperature measuring unit 11 estimates the temperature distribution of the entire face, for example, by a thermo camera, and sets the highest temperature as the temperature of the caruncle. The temperature measuring unit 11 estimates the temperature distribution of the entire face, for example, by a thermo camera, identifies the caruncle by face recognition, and estimates the temperature of the caruncle. The temperature measuring unit 11 may measure the temperature of the caruncle of the user's eye by contacting a thermocouple-type temperature sensor with the caruncle.

[0012] The body temperature estimation model storage unit 12 stores a body temperature estimation model. The body temperature estimation model is a model used for simulation by the body temperature estimation unit 13. The body temperature estimation model will be described in detail later.

[0013] The body temperature estimation unit 13 estimates the deep body temperature of the user by setting the temperature measured by the temperature measurement unit 11 in a body temperature estimation model stored in the body temperature estimation model storage unit 12 and performing a simulation.

[0014] The presentation unit 14 presents the deep body temperature of the user estimated by the body temperature estimation unit 13. The presentation unit 14 outputs the estimated deep body temperature of the user to the outside by displaying it on a display, for example.

[0015] FIG. 2 is a flowchart showing the operation of the body temperature estimation device 1. First, the temperature measuring unit 11 measures the temperature of the user's eye (step S1). The body temperature estimating unit 13 sets the temperature measured by the temperature measuring unit 11 in a body temperature estimation model and performs a simulation (step S2). The presenting unit 14 presents the deep body temperature of the user estimated by the body temperature estimating unit 13 (step S3).

[0016] The body temperature estimation model is created by dividing it into several nodes. The nodes are divided according to the parts of the actual human head, such as the brain and eyes. In general, the fewer the number of nodes, the less calculations are required for the simulation. The body temperature estimation model also includes a node for the blood vessels connecting the brain and eyes.

[0017] Figures 3A and 3B are examples of a body temperature estimation model. Figure 3A is a front view of the body temperature estimation model, and Figure 3B is a side view of the body temperature estimation model. In the body temperature estimation model shown in Figures 3A and 3B, there are seven nodes representing organs (hypothalamus, brain, cerebrospinal fluid, skull, skin, eyeball, and blood vessels). In addition, the method of heat transfer from the hypothalamus to the caruncle is assumed to be heat transfer by brain tissue and heat transport by blood vessels, but heat transport by blood vessels is considered to have a greater contribution. For this reason, a model of blood vessels is incorporated into the body temperature estimation model.

[0018] FIG. 3A shows a virtual sphere 20, a right eyeball 21-1, and a left eyeball 21-2. FIG. 3B shows the hypothalamus 22, the ophthalmic artery 23, the canthal artery 24, the internal carotid artery 25, and the external carotid artery 26. The body temperature estimation model is created by the following procedure. First, the hypothalamus 22 is placed in the center of the virtual sphere 20 as a heat source. Then, the brain, cerebrospinal fluid, skull, and skin are placed in that order around the outer periphery of the hypothalamus 22. Then, the eyeballs 21 are created symmetrically around the outer edge of the skin. At this time, the thermal conductivity, density, and specific heat of each part are set.

[0019] Thereafter, in order to simulate heat transport by blood from the hypothalamus 22 to the caruncle of the eye, the ophthalmic artery 23, the canthal artery 24, the internal carotid artery 25, and the external carotid artery 26 are arranged. The ophthalmic artery 23 is an artery that branches off from the internal carotid artery 25 and extends to the eyeball 21 along the optic nerve that connects the eyeball 21 and the hypothalamus 22. The canthal artery 24 is an artery that extends from the external carotid artery 26 along the skull to the eyeball 21. The internal carotid artery 25 extends from the bottom of the virtual sphere 20 through the brain to the vicinity of the hypothalamus 22. The external carotid artery 26 extends from the bottom of the virtual sphere 20, passes through the brain through a structure outside the skull, and extends to the vicinity of the hypothalamus 22. The internal carotid artery 25 anastomoses with the ophthalmic artery 23 near the hypothalamus 22, and the ophthalmic artery 23 anastomoses with the canthal artery 24 at the eyeball 21. In addition, the mass flow rate and specific heat of blood are set. In order to simulate the release of heat from the canthus oculi 24 to the outside of the body, the characteristics of the outside air (for example, the temperature of the outside air) are set. The internal carotid artery 25 and the external carotid artery 26 are connected to the torso, which is in thermal equilibrium with the head. In other words, in this model, the hypothalamus 22, the internal carotid artery 25, and the external carotid artery 26 are in thermal equilibrium, and are treated as having no change in thermodynamic state quantity. In other embodiments, the internal carotid artery 25 and the external carotid artery 26 may be treated as one model without distinction. Then, each node of the eyeball 21, the hypothalamus 22, the canthus oculi 23, the canthus oculi 24, the internal carotid artery 25, and the external carotid artery 26 is divided into a plurality of meshes, which are the minimum units of the simulation.

[0020] The body temperature estimation unit estimates the deep body temperature from the measured eye temperature by simulating the heat conduction to each organ by blood using the above body temperature estimation model. That is, the body temperature estimation unit 13 simulates the heat transport from the internal carotid artery 25, which is in thermal equilibrium with the hypothalamus 22, to the caruncle via the ophthalmic artery 23, and the heat transport from the external carotid artery 26, which is in thermal equilibrium with the hypothalamus 22, to the caruncle via the canthus oculi artery 24. The simulation method may be the finite element method. Then, the body temperature estimation unit obtains the temperature of the hypothalamus, which is the heat source, so that the temperature of the caruncle of the body temperature estimation model is the measured temperature. For example, the body temperature estimation unit sets the temperature of the hypothalamus of the body temperature estimation model to simulate the heat transport, and searches for the temperature of the hypothalamus of the body temperature estimation model based on the gradient method from the eye temperature obtained as a result of the simulation.

[0021] Thus, the body temperature estimation device 1 according to the embodiment includes a measurement unit that measures the temperature of the animal's eye, and a body temperature estimation unit that estimates the animal's deep body temperature by setting the temperature measured by the measurement unit in a body temperature estimation model and simulating heat conduction. This allows the body temperature estimation device 1 to measure the deep body temperature easily and accurately.

[0022] Examples of the above embodiment will now be described. In this embodiment, the simulation software used was COMSOL (registered trademark). The heat conduction in the body temperature estimation model was assumed to follow Pennes' biological heat conduction equation shown in formula (1).

[0023]

number

[0024] where k is the thermal conductivity of the tissue, T is the tissue temperature, and ρ t is the tissue density, c t is the specific heat of the tissue, W b is the mass flow rate of blood per unit volume of tissue, c b is the specific heat of blood, T a indicates the arterial temperature, respectively.

[0025] When the eye temperature was set in the body temperature estimation model and heat conduction was simulated using COMSOL according to Pennes's biological heat conduction equation, the temperature of each part was output, and the temperature of the hypothalamus 22 was used as an estimate of the deep body temperature. In this embodiment, the total number of meshes when COMSOL was used was 43,778. With this amount of data to be processed, it can be easily processed even on wearable devices such as smartphones.

[0026] <Variation 1> A body temperature estimation formula may be derived in advance using a body temperature estimation model. The body temperature estimation formula is a formula that indicates the relationship between the temperature of a human eye and deep body temperature. The body temperature estimation formula can be obtained, for example, by preparing several combinations of eye temperature and deep body temperature estimated when the eye temperature is set in the body temperature estimation model, and applying the least squares method to the combinations. An estimated value of deep body temperature can be calculated by substituting the eye temperature into the body temperature estimation formula. A body temperature estimation formula can be derived in the same way when measuring the temperature of the caruncle.

[0027] The body temperature estimation unit 13 may estimate the body temperature using a body temperature estimation formula instead of the body temperature estimation model. The body temperature estimation unit 13 calculates an estimated value of the hypothalamic temperature by substituting the temperature of the caruncle measured by the temperature measurement unit 11 into the body temperature estimation formula.

[0028] <Variation 2> The temperature measurement unit 11, the body temperature estimation unit 13, and the presentation unit 14 may be provided in separate devices. Fig. 3 is a diagram showing the configuration of a body temperature estimation system 3. The body temperature estimation system 3 is composed of a temperature measurement device 4, a body temperature estimation device 5, and a presentation device 6.

[0029] The temperature measuring device 4 includes a temperature measuring unit 41 and a first communication unit 42. The body temperature estimation device 5 includes a body temperature estimation unit 51, a second communication unit 52, and a body temperature estimation model storage unit 53. The presentation device 6 includes a presentation unit 61 and a third communication unit 62. The temperature measurement unit 41, the body temperature estimation unit 51, the body temperature estimation model storage unit 53, and the presentation unit 61 have functions equivalent to those of the temperature measurement unit 11, the body temperature estimation unit 13, the body temperature estimation model storage unit 12, and the presentation unit 14, respectively.

[0030] Information between the temperature measuring device 4, the body temperature estimation device 5, and the presentation device 6 is transmitted and received via a first communication unit 42, a second communication unit 52, and a third communication unit 62.

[0031] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs that do not deviate from the gist of the present invention are also included.

[0032] The subject of the body temperature estimation device 1 to estimate the body temperature is not limited to humans. For example, a body temperature estimation model may be created for animals other than humans (especially vertebrates) to estimate the body temperature of the animals. In this specification, "animals" includes humans. [Explanation of symbols]

[0033] 1 Body temperature estimation device, 11, 41 Temperature measurement unit, 12, 53 Body temperature estimation model memory unit, 13, 51 Body temperature estimation unit, 14, 61 Presentation unit, 20 Virtual sphere, 21 Eyeball, 22 Hypothalamus, 23 Ophthalmic artery, 24 Anterior canthal artery, 25 Internal carotid artery, 26 External carotid artery, 3 Body temperature estimation system, 4 Temperature measurement device, 5 Body temperature estimation device, 6 Presentation device, 42 First communication unit, 52 Second communication unit, 62 Third communication unit

Claims

1. A measurement unit for measuring the temperature of the animal's eye; a body temperature estimation unit that estimates the deep body temperature of the animal by setting the temperature measured by the measurement unit in a body temperature estimation model and simulating heat conduction; Equipped with The body temperature estimation unit estimates the animal's deep body temperature by simulating heat transport by blood passing through a blood vessel connected to the eye based on the temperature measured by the measurement unit. Body temperature estimation device.

2. The measuring unit measures the temperature of the lacrimal caruncle of the animal's eye. The body temperature estimation device according to claim 1 .

3. A measurement unit for measuring the temperature of an animal's eye; a body temperature estimation unit that estimates the deep body temperature of the animal by setting the temperature measured by the measurement unit in a body temperature estimation model and simulating heat conduction; Equipped with the body temperature estimation model includes a model of blood vessels connecting the eye and the brain and an organ covering the blood vessels; The body temperature estimation unit performs a simulation of heat transport by blood passing through the blood vessel. Body temperature estimation device.

4. A measurement unit for measuring the temperature of the animal's eye; a body temperature estimation unit that estimates the deep body temperature of the animal by setting the temperature measured by the measurement unit in a body temperature estimation model and simulating heat conduction; Equipped with The body temperature estimation model includes blood vessels connecting the eye and the brain, The body temperature estimation unit performs a simulation of heat transport by blood passing through the blood vessel. Body temperature estimation device.

5. A measuring step for measuring the temperature of the animal's eye; a body temperature estimation step of estimating a deep body temperature of the animal by setting the temperature measured in the measurement step in a body temperature estimation model and simulating heat conduction; having In the body temperature estimation step, a core body temperature of the animal is estimated by simulating heat transport by blood passing through a blood vessel connected to the eye based on the measured temperature. Body temperature estimation method.

6. a temperature measuring device for measuring the temperature of the animal's eye; a body temperature estimation device that estimates the deep body temperature of the animal by setting the temperature measured by the temperature measurement device in a body temperature estimation model and simulating heat conduction; Equipped with The body temperature estimation device estimates the animal's core body temperature by simulating heat transport by blood passing through a blood vessel connected to the eye based on the temperature measured by the temperature measurement device. Body temperature estimation system.

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