Heat risk warning device and program

Abstract

To reduce oversight of changes in the physical condition of a measurement subject, and to perform highly accurate management of the physical condition of the measurement subject.SOLUTION: A summer-heat risk warning device includes: a heart rate measuring unit 1 for measuring the heart rate of a measurement subject; a core body temperature measuring unit 2 for estimating or measuring the core body temperature of the measurement subject; a subjective information acquisition unit 3 for acquiring information on subjective symptoms of the measurement subject related to a thermal environment and exercise intensity; a determination unit 4 for determining the summer-heat risk level of the measurement subject on the basis of the measurement subject's heart rate, core body temperature, and subjective symptoms; and a notification unit 5 for notifying the work manager or the measurement subject of summer-heat risk notification information corresponding to the summer-heat risk level determined by the determination unit 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heat risk warning device that provides information useful for preventing heatstroke in subjects. Place and programs. [Background technology]

[0002] The number of deaths and injuries due to heatstroke in the workplace in 2019 was 790, the second highest number after 2018's 1,178 deaths and injuries when compared to the incidence over the past 10 years (2010-2019). By industry, there were 147 deaths and 172 deaths in the construction industry and manufacturing, indicating that the number of heatstroke cases is high in industries that are easily exposed to direct sunlight or hot and humid environments (see Non-Patent Document 1).

[0003] In such workplaces, there are cases where workers manage their own health, workers' time is managed by a work manager, and workers' health is managed by asking the work manager to collect subjective symptoms. However, work management that relies only on subjective information such as self-reporting may overlook changes in the worker's health caused by the stress that the worker receives from the hot environment.

[0004] In addition, as a method of managing health that does not rely on subjective information, there are cases where the work manager encourages workers to replenish fluids and salt and to take breaks based on the heat index WBGT (Wet Bulb Globe Temperature). However, WBGT is merely a value calculated based on outdoor observation points in a specific area, and is a reference value that does not reflect environmental changes that correspond to the individual behavior of workers. Therefore, it can be said that there is a risk that health management methods based on WBGT will overlook changes in workers' health, just like the subjective information mentioned above.

[0005] On the other hand, one method of managing physical condition that focuses on an individual's biological information is to monitor changes in the worker's core body temperature and heart rate. For example, the American Conference of Governmental Industrial Hygienists (AGCIH) has set the following indicators for monitoring the risk of developing heatstroke as the criteria for ceasing work in the heat: core body temperature is 38.5°C or higher for heat-acclimated individuals, and 38°C or higher for non-acclimated individuals, and the heart rate per minute exceeds (180 - age) for several consecutive minutes (see Non-Patent Document 2).

[0006] Of the above vital signs, deep body temperature is difficult to measure directly while a worker is active, so it is generally measured using non-invasive methods, but there is a variance of about ±0.2°C. For this reason, even when managing health using vital signs, there is a possibility that changes in the worker's health condition may be overlooked, just as with subjective information and WBGT. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] “2019 Status of Fatal and Injury Accidents Due to Heat Stroke in the Workplace”, Ministry of Health, Labor and Welfare, [Retrieved October 30, 2020],<https: / / www.mhlw.go.jp / content / 11303000 / 000612135.pdf> [Non-Patent Document 2] Shinichi Sawada, "Moral Thoughts on Heat Stroke Prevention in the Workplace (Part 2)", Industrial Safety and Health Research News, National Institute of Occupational Safety and Health, Japan Occupational Health and Safety Organization, 2013, [Retrieved October 30, 2020],<https: / / www.jniosh.johas.go.jp / publication / mail_mag / 2013 / 61-column.html> Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made to solve the above problems, and provides a heat risk warning device that reduces overlooking of changes in the physical condition of a person to be measured and enables highly accurate management of the physical condition of the person to be measured. Place The purpose of this website is to provide information and programs. [Means for solving the problem]

[0009] The heat risk warning device of the present invention is characterized by comprising a heart rate measuring unit configured to measure the heart rate of the subject, a deep body temperature measuring unit configured to estimate or measure the deep body temperature of the subject, a subjective information acquisition unit configured to acquire information on the subject's subjective symptoms related to the thermal environment and exercise intensity, a determination unit configured to determine the heat risk level of the subject based on the heart rate, deep body temperature, and subjective symptoms of the subject, and a notification unit configured to notify a work manager or the subject of the heat risk information corresponding to the heat risk level determined by the determination unit. In addition, in one configuration example of the heat risk warning device of the present invention, the subjective information acquisition unit is characterized in that it acquires information on thermal sensation, information on subjective intensity of exertion, and information on thermal comfort as information on the subject's subjective symptoms. In addition, in one configuration example of the heat risk warning device of the present invention, the determination unit is characterized in that it determines the heat risk level of the measurement subject for each of the heart rate, the deep body temperature, and the subjective symptoms. In addition, in one example configuration of the heat risk warning device of the present invention, the determination unit is characterized in that it determines a heat risk level for each of the heart rate, the deep body temperature, and the subjective symptoms based on whether or not each of the quantified values ​​of the heart rate, the deep body temperature, and the subjective symptoms exceeds a corresponding threshold value. In addition, in one configuration example of the heat risk warning device of the present invention, the determination unit determines a heat risk level related to the heart rate based on whether the duration during which the heart rate exceeds a corresponding threshold exceeds a predetermined heart rate observation time, and determines a heat risk level related to the deep body temperature based on whether the duration during which the deep body temperature exceeds a corresponding threshold exceeds a predetermined deep body temperature observation time.

[0010] In addition, the present invention program The method includes a first step of measuring the heart rate of the subject, a second step of estimating or measuring the deep body temperature of the subject, a third step of acquiring information on the subject's subjective symptoms related to the thermal environment and exercise intensity, a fourth step of determining a heat risk level of the subject based on the subject's heart rate, deep body temperature, and subjective symptoms, and a fifth step of notifying a work manager or the subject of heat risk notification information corresponding to the heat risk level determined in the fourth step. , have the computer run It is characterized by the above. Effect of the Invention

[0011] According to the present invention, by collecting both subjective information of the subject and objective information such as heart rate and deep body temperature, the heat risk of the subject can be comprehensively assessed, thereby reducing the risk of overlooking changes in the subject's physical condition and enabling the subject's physical condition to be managed with high accuracy. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a block diagram showing the configuration of a heat risk warning device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a flowchart illustrating the operation of the heat risk warning device according to the first embodiment of the present invention. [Diagram 3] FIG. 3 is a diagram showing an example of a thermal sensation. [Figure 4] FIG. 4 is a graph showing an example of the perceived exertion. [Diagram 5]FIG. 5 is a diagram showing an example of thermal comfort. [Figure 6] FIG. 6 is a flowchart illustrating the operation of classifying the heat risk state of a measurement subject by a notification unit according to the first embodiment of the present invention. [Figure 7] FIG. 7 is a diagram showing an example of a registration table of heat risk notification information according to the first embodiment of the present invention. [Figure 8] FIG. 8 is a block diagram showing the configuration of a deep body temperature measuring unit according to the second embodiment of the present invention. [Figure 9] FIG. 9 is a flowchart illustrating the operation of the deep body temperature measuring section according to the second embodiment of the present invention. [Figure 10] FIG. 10 is a block diagram showing the configuration of a deep body temperature measuring unit according to the third embodiment of the present invention. [Figure 11] FIG. 11 is a diagram showing a two-part, two-layer model of the subject's body and the amount of heat flowing in and out of each part and layer of the subject. [Figure 12] FIG. 12 is a flowchart illustrating the operation of the deep body temperature measuring section according to the third embodiment of the present invention. [Figure 13] FIG. 13 is a block diagram showing an example of the configuration of a computer that realizes the heat risk warning device according to the first to third embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [First Example] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a block diagram showing the configuration of a heat risk warning device according to a first embodiment of the present invention. The heat risk warning device includes a heart rate measuring unit 1, a deep body temperature measuring unit 2, a subjective information acquiring unit 3, a determining unit 4, and a notifying unit 5.

[0014] 2 is a flow chart explaining the operation of the heat risk warning device of this embodiment. The heart rate measurement unit 1 measures the heart rate of the measurement subject (FIG. 2, step S1). The heart rate measurement unit 1 is composed of, for example, a wearable or belt-type electrocardiograph that measures the cardiac potential of the measurement subject, and a calculation unit that calculates the heart rate from the cardiac potential measured by the electrocardiograph. In the present invention, the pulse rate of the subject may be measured as the heart rate. In this case, the heart rate measurement unit 1 is composed of a wristband-type or earphone-type pulse wave meter that measures the pulse wave of the subject, and a calculation unit that calculates the heart rate (pulse rate) from the pulse wave measured by the pulse wave meter.

[0015] The deep body temperature measuring unit 2 estimates or measures the deep body temperature of the subject (FIG. 2, step S2). The deep body temperature measuring unit 2 estimates the deep body temperature of the subject from data such as the subject's heart rate, the temperature and humidity in the vicinity of the subject (see, for example, JP 2020-65823 A). Note that another example of estimating the deep body temperature using these data will be described in the following examples.

[0016] The deep body temperature measuring unit 2 may estimate the deep body temperature of the subject using a method such as a heat flow compensation method or a dual heat flow method. For details on these methods, see, for example, the literature "Tokizawa Ken, "Toward the practical application of wearable deep body thermometers," Industrial Safety and Health Research News, National Institute of Occupational Safety and Health, Japan Occupational Health and Safety Organization, 2018,<https: / / www.jniosh.johas.go.jp / publication / mail_mag / 2018 / 119-column-1.html> " is disclosed.

[0017] The deep body temperature measuring unit 2 may directly measure the deep body temperature of the subject, for example, by using a swallowable thermometer. For swallowable thermometers, see, for example, the literature "CorTemp Sensor", HQ Inc.,<https: / / hqinc.net / home / cortemp / cortemp-products / cortemp-sensor / > " is disclosed. Further, the deep body temperature measuring section 2 may measure the eardrum temperature or ear canal temperature of the subject instead of the deep body temperature.

[0018] Next, the subjective information acquiring unit 3 acquires information on the subject's subjective symptoms related to the thermal environment and exercise intensity (FIG. 2, step S3). Examples of the acquired subjective symptom information include information on thermal sensation, information on subjective exercise intensity, and information on thermal comfort.

[0019] An example of thermal sensation is shown in Figure 3. In the example in Figure 3, thermal sensation is evaluated on a nine-point scale: very cold, cold, cool, slightly cool, neither, slightly warm, warm, hot, and very hot (see reference "Enomoto Hikaru et al., "Survey on the thermal environment in offices during the power saving period and comfort evaluation by workers," Humans and Living Environments, Vol. 23, No. 2, pp. 39-47, 2016").

[0020] Figure 4 shows an example of perceived exertion intensity. In the example in Figure 4, the perceived exertion intensity (Borg scale) is evaluated on a 10-point scale (reference: "B. Testing and Measurement Methods Necessary for Athletic Trainers," Examination, Measurement and Evaluation, Bunkodo, 2011, Japan Sports Association, Supervised by the Athletic Trainer Subcommittee of the Instructor Development Special Committee, "Japan Sports Association, Supervised by the Athletic Trainer Subcommittee of the Instructor Development Special Committee, "B. Testing and Measurement Methods Necessary for Athletic Trainers," Examination, Measurement and Evaluation, Bunkodo, 2011,<https: / / www.japan-sports.or.jp / Portals / 0 / data / ikusei / doc / AT / text%20kaitei / 2017AT5_p68.pdf> "reference).

[0021] An example of thermal comfort is shown in Figure 5. In the example in Figure 5, thermal comfort is evaluated on a four-level scale: uncomfortable, slightly uncomfortable, slightly comfortable, and comfortable (see reference "Tanaka Hideto et al., "Air conditioning usage in summer among elderly people and the effect of airflow on physiological responses and thermal comfort when using air conditioning," Journal of the Japanese Society of Biometeorology, Vol. 51, No. 4, pp. 141-150, 2015").

[0022] The subjective information acquisition unit 3 is configured, for example, by a smartphone carried by the subject. The smartphone executes processing according to an installed application program and functions as the subjective information acquisition unit 3. The subjective information acquisition unit 3 acquires subjective symptom information (numeric values ​​of thermal sensation, subjective exertion intensity, and thermal comfort) input by the subject.

[0023] Incidentally, the heart rate measuring section 1, the core body temperature measuring section 2 and the subjective information acquiring section 3 may be an integrated device or may be separate devices.

[0024] Next, the determination unit 4 determines the heat risk level of the subject based on the information obtained by the heart rate measurement unit 1, the deep body temperature measurement unit 2, and the subjective information acquisition unit 3 (FIG. 2, step S4). The determination unit 4 determines the heat risk level for each of the heart rate, deep body temperature, and subjective symptoms from two perspectives: whether the subject is in a state of excessive heat load, and whether the subject has recovered from the excessive heat load, as follows.

[0025] [Heat risk levels in relation to heart rate] The determination unit 4 sequentially calculates the average heart rate per minute from the heart rate of the subject obtained by the heart rate measurement unit 1. If the calculated average heart rate per minute does not exceed a predetermined heart rate threshold, the determination unit 4 determines that the subject is not exposed to excessive thermal load, and sets the heat risk level related to the heart rate to 0. In this embodiment, the heart rate threshold is (180-age) bpm, which is calculated from the age of the subject. The age of the subject is a known value, and a value corresponding to the actual situation may be set in advance.

[0026] If the calculated average heart rate per minute exceeds (180-age) bpm, the decision unit 4 determines that the subject is exposed to excessive heat load and sets the heat risk level related to the heart rate to 1.

[0027] If the subject's average heart rate per minute does not fall below (180-age) bpm even after a predetermined heart rate observation time has elapsed since the heat risk level related to heart rate was set to 1, the decision unit 4 determines that the subject is not showing any signs of recovery from excessive heat stress, and further increases the heat risk level related to heart rate by 1 to 2.

[0028] On the other hand, if the subject's average heart rate per minute falls below (180-age) bpm within the heart rate observation time from the time the heat risk level related to heart rate was set to 1, the decision unit 4 determines that the subject has recovered from excessive heat load and resets the heat risk level related to heart rate to 0.

[0029] The heart rate observation time can be determined in advance by experimentally measuring the time it takes for the subject's heart rate to transition from a state of sustained high heart rate caused by exercise stress such as work to a resting state.

[0030] [Heat risk level for core body temperature] When the deep body temperature of the measurement subject obtained by the deep body temperature measurement unit 2 is equal to or lower than a predetermined deep body temperature threshold, the determination unit 4 determines that the measurement subject is not exposed to excessive heat load, and sets the heat risk level related to the deep body temperature to 0. The determination unit 4 has two types of deep body temperature thresholds set: a deep body temperature threshold for a person who has not been acclimatized to heat and a deep body temperature threshold for a person who has been acclimatized to heat. The deep body temperature threshold for a person who has not been acclimatized to heat is 38°C, and the deep body temperature threshold for a person who has been acclimatized to heat is 38.5°C. The information on whether the measurement subject has been acclimatized to heat is known information, and may be set in advance according to the actual situation. The determination unit 4 may adopt a deep body temperature threshold corresponding to whether the measurement subject has been acclimatized to heat.

[0031] When the deep body temperature of the person to be measured exceeds the deep body temperature threshold, the decision unit 4 determines that the person to be measured is exposed to an excessive thermal load, and sets the heat risk level related to the deep body temperature to 1.

[0032] If the deep body temperature of the person being measured does not fall below the deep body temperature threshold even after a specified deep body temperature observation time has elapsed since the heat risk level for the deep body temperature was set to 1, the decision unit 4 determines that the person being measured is not showing any signs of recovery from the excessive heat load, and further increases the heat risk level for the deep body temperature by 1 to 2.

[0033] On the other hand, if the deep body temperature of the person being measured falls below the deep body temperature threshold within the deep body temperature observation time from the time when the heat risk level for the deep body temperature was set to 1, the decision unit 4 determines that the person being measured has recovered from excessive heat load and resets the heat risk level for the deep body temperature to 0.

[0034] As with the heart rate observation time, the above-mentioned deep body temperature observation time can be determined in advance by experimentally measuring the time it takes for the deep body temperature to transition from a state of continuous high deep body temperature caused by exercise stress such as work under normal circumstances to a resting state, or by experimentally measuring the time it takes for the deep body temperature to transition from a state of high deep body temperature caused by exercise stress such as work to a resting state, or by experimentally measuring the time it takes for the deep body temperature to transition from a state of high body temperature to a resting state after drinking water.

[0035] [Heat risk level related to subjective symptoms] The determination unit 4 sets a default value of the heat risk level related to subjective symptoms to 0. The determination unit 4 sets the heat risk level related to subjective symptoms to 1 when the thermal sensation, subjective intensity of exertion, and thermal comfort satisfy the conditions for determining that the subject has been exposed to an excessive thermal load.

[0036] Specifically, for thermal sensation, the thermal sensation threshold is 3 (hot), and a thermal sensation of 3 or higher is the condition for determining that the subject has been exposed to an excessive thermal load. For perceived exertion, the exercise intensity threshold is 7 (very hard), and a subjective exertion threshold of 7 or higher is the condition for determining that the subject has been exposed to an excessive thermal load. For thermal comfort, the comfort threshold is 1 (uncomfortable), and a thermal comfort threshold of 1 or lower is the condition for determining that the subject has been exposed to an excessive thermal load.

[0037] If at least one of the following conditions is satisfied: subjective intensity of exertion is 7 or more, thermal comfort is 1 or less, and thermal sensation is 3 or more, the decision unit 4 determines that the subject is exposed to excessive thermal load and sets the heat risk level related to subjective symptoms to 1.

[0038] Furthermore, if all of the thermal sensation, subjective intensity of exertion, and thermal comfort no longer satisfy the conditions for determining that the subject has been exposed to an excessive thermal load after the heat risk level related to the subjective symptoms is set to 1, the determination unit 4 determines that the subject is in a state where he or she has recovered from an excessive thermal load, and returns the heat risk level related to the subjective symptoms to 0. Specifically, if, after the heat risk level related to the subjective symptoms is set to 1, the subjective intensity of exertion is less than 7, the thermal comfort is 2 or more, and the thermal sensation is less than 3, the determination unit 4 returns the heat risk level related to the subjective symptoms to 0.

[0039] Next, the notification unit 5 classifies the state of the person being measured according to the heat risk level obtained by the determination unit 4, and notifies the work manager or the person being measured of heat risk notification information according to the classification (FIG. 2, step S5). For example, the notification unit 5 classifies the heat risk state of the person being measured into one of five categories, normal, caution, alert, high alert, and danger, according to the heat risk level related to the heart rate, deep body temperature, and subjective symptoms, and sets the wording of the heat risk notification information to be notified to the work manager or the person being measured.

[0040] Fig. 6 is a flowchart explaining the classification operation of the heat risk state of the measurement subject by the notification unit 5, and Fig. 7 is a diagram showing an example of a registration table set in the notification unit 5. As shown in Fig. 7, the registration table of heat risk notification information is a table in which the wording of heat risk notification information is registered in advance for each heat risk level related to the measurement subject's core body temperature, heart rate, and subjective symptoms.

[0041] If the heat risk levels related to the heart rate, deep body temperature, and subjective symptoms are all 0 (YES in steps S100 and S101 in FIG. 6), the notification unit 5 determines that the subject is not exposed to excessive heat load from the viewpoints of both biological information and subjective symptoms, and classifies the heat risk state of the subject as normal (step S102 in FIG. 6). The notification unit 5 obtains the text of the heat risk notification information for when the heat risk levels related to the heart rate, deep body temperature, and subjective symptoms are all 0, "Normal: Estimated internal body temperature and heart rate are normal," from the registration table shown in FIG. 7, and transmits the heat risk notification information to a smartphone carried by the work manager or a terminal such as a smartphone carried by the subject.

[0042] Furthermore, when the heat risk levels for both the heart rate and deep body temperature are 0 and the heat risk level for the subjective symptoms is 1 (NO in step S101 in FIG. 6), the notification unit 5 determines that the subject is not exposed to excessive heat load from the viewpoint of biological information, but is exposed to excessive heat load from the viewpoint of subjective symptoms, and classifies the subject's heat risk state as a caution state, which has a higher alert level than normal (step S103 in FIG. 6). The notification unit 5 retrieves and transmits the heat risk notification information text "Caution: If you find future work difficult, take a break" from the registration table when the heat risk levels for the heart rate and deep body temperature are 0 and the heat risk level for the subjective symptoms is 1.

[0043] In addition, if the heat risk levels for both heart rate and deep body temperature are not 0 and at least one of them is 1 or less, and the heat risk level for subjective symptoms is 0 or 1 (YES in step S104 of Figure 6), the notification unit 5 determines that the person being measured is exposed to excessive heat load from the perspective of at least one of the heart rate and deep body temperature, and classifies the heat risk state of the person being measured as an alert state, which is a higher alert level than caution (step S105 of Figure 6).

[0044] When the heat risk levels for the heart rate, deep body temperature, and subjective symptoms are all 1, the notification unit 5 obtains the corresponding heat risk notification information text "Alert: Estimated internal temperature and heart rate are high. We recommend taking a break if you find it difficult to work in the future" from the registration table and transmits it. When the heat risk levels for the heart rate and deep body temperature are both 1 and the heat risk level for the subjective symptoms is 0, the notification unit 5 obtains the corresponding heat risk notification information text "Alert: Estimated internal temperature and heart rate are high. Pay attention to your subjective symptoms and take a break if you find it difficult to work in the future" from the registration table and transmits it. When the heat risk levels for the deep body temperature and subjective symptoms are both 1 and the heat risk level for the heart rate is 0, the notification unit 5 obtains the corresponding heat risk notification information text "Alert: Estimated internal temperature is high. We recommend taking a break if you find it difficult to work in the future" from the registration table and transmits it.

[0045] When the heat risk level for the heart rate and the subjective symptoms is 1 and the heat risk level for the deep body temperature is 0, the notification unit 5 obtains the corresponding heat risk notification information text "Alert: Your heart rate is high. We recommend that you take a break if you feel uncomfortable working in the future" from the registration table and transmits it. When the heat risk level for the deep body temperature is 1 and the heat risk levels for the heart rate and the subjective symptoms are both 0, the notification unit 5 obtains the corresponding heat risk notification information text "Alert: Your estimated internal body temperature is high. Pay attention to your subjective symptoms and take a break if you feel uncomfortable" from the registration table and transmits it. When the heat risk level for the heart rate is 1 and the heat risk levels for the deep body temperature and the subjective symptoms are both 0, the notification unit 5 obtains the corresponding heat risk notification information text "Alert: Your heart rate is high. Pay attention to your subjective symptoms and take a break if you feel uncomfortable" from the registration table and transmits it.

[0046] In addition, if either the heat risk level related to the heart rate or the heat risk level related to the core body temperature is 2 and the heat risk level related to the subjective symptoms is 0 or 1 (YES in step S106 in Figure 6), the notification unit 5 determines that, from the perspective of either the heart rate or the core body temperature, the subject is not showing any signs of recovery from being exposed to excessive heat load, and classifies the heat risk state of the subject as a state of high alert, which is a higher alert level than alert (step S108 in Figure 6).

[0047] If the heat risk level for deep body temperature is 2, the heat risk level for heart rate is 0 or 1, and the heat risk level for subjective symptoms is 0, the notification unit 5 retrieves the corresponding heat risk notification information text "High alert: Estimated internal temperature is continuing to be high. Pay attention to subjective symptoms and consider taking a break" from the registration table and sends it. If the heat risk level for deep body temperature is 2, the heat risk level for heart rate is 0 or 1, and the heat risk level for subjective symptoms is 1, the notification unit 5 retrieves the corresponding heat risk notification information text "High alert: Estimated internal temperature is continuing to be high. Taking a break is recommended" from the registration table and sends it.

[0048] If the heat risk level for heart rate is 2, the heat risk level for deep body temperature is 0 or 1, and the heat risk level for subjective symptoms is 0, the notification unit 5 retrieves and transmits the corresponding heat risk notification information text "High alert: Heart rate is continuing to be high. Pay attention to subjective symptoms and consider taking a break" from the registration table. If the heat risk level for heart rate is 2, the heat risk level for deep body temperature is 0 or 1, and the heat risk level for subjective symptoms is 1, the notification unit 5 retrieves and transmits the corresponding heat risk notification information text "High alert: Heart rate is continuing to be high. Taking a break is recommended" from the registration table.

[0049] In addition, if the heat risk levels for both deep body temperature and heart rate are 2 and the heat risk level for subjective symptoms is 0 (YES in step S107 of Figure 6), the notification unit 5 determines that the subject is not showing any signs of recovery from being exposed to excessive heat load from the perspective of both heart rate and deep body temperature, but that the subject is not exposed to excessive heat load from the perspective of subjective symptoms, and classifies the subject's heat risk state as a high-alert state (step S108 of Figure 6).

[0050] If the heat risk levels for both core body temperature and heart rate are 2 and the heat risk level for subjective symptoms is 0, the notification unit 5 retrieves the corresponding heat risk notification information text, "High alert: Estimated body temperature and heart rate are continuing to be high. It is recommended that you pay attention to subjective symptoms and take a break," from the registration table and sends it.

[0051] In addition, if the heat risk levels for both the deep body temperature and heart rate are 2 and the heat risk level for the subjective symptoms is 1 (NO in step S107 of Figure 6), the notification unit 5 determines that, from the perspective of both the heart rate and deep body temperature, the subject is not showing any signs of recovery from being exposed to excessive heat load, and that the subject is also exposed to excessive heat load from the perspective of subjective symptoms, and classifies the subject's heat risk state as a dangerous state, which is a higher alert level than strict alert (step S109 of Figure 6).

[0052] If the heat risk levels for both core body temperature and heart rate are 2 and the heat risk level for subjective symptoms is 1, the notification unit 5 retrieves the corresponding heat risk notification information text "Danger: Estimated body temperature and heart rate are high and continuing. We recommend taking a break" from the registration table and sends it.

[0053] In addition to the above-mentioned wording, wording encouraging avoidance of heat risks, such as stopping work, taking shelter indoors, evacuating to a cooler place, drinking fluids, taking a break, etc., as well as preventing rising body temperature, lowering heart rate, and dehydration may be added as appropriate.

[0054] As described above, in this embodiment, by collecting both subjective information, such as the subject's own symptoms, and objective information, such as deep body temperature and heart rate, the heat risk of the subject can be comprehensively assessed, thereby reducing the risk of overlooking changes in the subject's physical condition and enabling the subject's physical condition to be managed with high accuracy.

[0055] [Second Example] Next, a second embodiment of the present invention will be described. This embodiment describes another example of the deep body temperature measuring unit 2 of the first embodiment. Fig. 8 is a block diagram showing the configuration of the deep body temperature measuring unit 2 of this embodiment. The deep body temperature measuring unit 2 of this embodiment is composed of a measuring unit 20, a measuring unit 21, a calculating unit 22, and a calculating unit 23.

[0056] The measurement unit 20 measures the temperature in the vicinity of the measurement subject. The measurement unit 20 can be configured, for example, from a thermometer. The measurement unit 21 measures the humidity in the vicinity of the measurement subject. The measurement unit 21 can be configured, for example, from a hygrometer. Furthermore, the measurement units 20 and 21 can also be configured from a thermometer and a hygrometer integrated with the heart rate measurement unit 1.

[0057] The calculation unit 22 calculates the amount of heat generated by the exercise of the person to be measured from the heart rate measured by the heart rate measurement unit 1.

[0058] The calculation unit 23 estimates the change in the deep body temperature of the subject from the amount of heat calculated by the calculation unit 22 at time t, the first amount of heat exchange between the atmosphere of the subject and the skin of the subject calculated from the temperature measured by the measurement unit 20 and the humidity measured by the measurement unit 21, the second amount of heat exchange between the skin and the deep part of the subject, and the amount of sweat evaporation calculated from the amount of sweat of the subject.

[0059] The calculation units 22 and 23 can be configured from a small computer device equipped with a microprocessor that operates according to a program, such as a mobile terminal device.

[0060] Next, the operation of the core body temperature measuring unit 2 according to this embodiment will be described with reference to Fig. 9. First, in step S200, the heart rate of the subject measured by the heart rate measuring unit 1 is acquired. Next, in step S201, the measuring unit 20 measures the temperature in the vicinity of the subject. Next, in step S202, the measuring unit 21 measures the humidity in the vicinity of the subject. Next, in step S203, the calculation unit 22 calculates the amount of heat generated by the exercise of the subject from the heart rate measured by the heart rate measuring unit 1 in step S200.

[0061] Next, in step S204, the calculation unit 23 estimates a change in the deep body temperature of the subject from the amount of heat, the first amount of heat exchange between the atmosphere of the subject and the skin of the subject, the second amount of heat exchange between the skin of the subject and the deep part, and the amount of evaporation of sweat of the subject. The amount of heat is calculated by the calculation unit 22 in step S203 at time t. The first amount of heat exchange is calculated from the temperature measured by the measurement unit 20 in step S201 and the humidity measured by the measurement unit 21 in step S202.

[0062] This will be explained in more detail below.

[0063] If we simplify the human body into an epidermis layer (skin) and a non-epidermis layer (deep layer), and assume that the deep layer body temperature is the same as that of the non-epidermis layer, the equations regarding the flow of heat in and out of the skin layer and deep layer at time t can be written as Equations (1) and (2), respectively.

[0064] The left side of equation (1) shows the amount of heat generated by the rise in skin temperature when the time transitions from t-Δt to t. The terms on the right side of equation (1) show the amount of heat flowing from deep areas to the skin due to the rise in skin and deep areas temperature when the time transitions from t-Δt to t, the amount of heat generated by skin metabolism, the amount of heat flowing out from the skin to the atmosphere, and the heat of evaporation generated by sweating on the skin surface.

[0065] The left side of equation (2) shows the amount of heat generated by the rise in deep temperature when the time changes from t-Δt to t. The terms on the right side of equation (2) show the amount of heat flowing from the skin to deep areas due to the rise in skin and deep area temperatures when the time changes from t-Δt to t, the amount of heat generated by deep area metabolism, and the amount of heat generated by the subject's movement.

[0066]

number

[0067] T skin,t [℃] is the skin temperature of the subject at time t, T body,t [℃] is the deep temperature of the subject at time t. T skin,t ,T body,t is used to calculate the temperature of each part and the amount of heat of each part when the time has passed Δt using the above two formulas. The amount of heat will be explained later.

[0068] W skin [kg] is the mass of the subject's skin, W body [kg] is the deep mass of the subject. skin [J / (kg·℃)] is the specific heat of the subject's skin, C body [J / (kg·℃)] is the specific heat of the deep part of the subject. M skin [W] is the metabolic rate of the subject's skin, M body [W] is the deep metabolic rate of the subject. The mass and specific heat of each part of the subject can be determined using anatomical human models such as "TARO" and "HANAKO" developed by the National Institute of Information and Communications Technology (NICT) or literature values. The metabolic rate of each part will be described later.

[0069] hx [W / ℃] is the heat exchange coefficient between the skin and the deep tissue. hx at time t is hx=hx0+hx1×2 A It is calculated as follows: A=2(T body,t-Δt -T body,0) / 1.2+{EX(t)-1) / 1.5. hx0 and hx1 are determined by experiment. For example, hx0=17.0[W / ℃] and hx1=23.5[W / ℃] can be used.

[0070] EX(t) [W] indicates the amount of heat generated by the exercise of the subject when the time transitions from t-Δt to t, and is calculated from the heart rate obtained by the calculation unit 22, and will be described in detail later.

[0071] SW(t) [W] is the heat of evaporation caused by sweating when the time transitions from t-Δt to t. SW(t) is calculated from the humidity(t) measured by the measurement unit 21 and the temperature of each part, and details will be described later.

[0072] T air [°C] indicates the ambient temperature, and the temperature measured by the measurement unit 20 is used. As shown in the third term on the right side of the formula (1), the heat transfer coefficient H [W / (m2·°C)] between the skin of the subject and the atmosphere (details will be described later) is used to calculate H·(T skin,t -T air ) over the total skin area. The skin area S can be calculated, for example, using the Duboi formula: S = height [cm] 0.725 ×Weight [kg] 0.425 x7.184x10 (-3) " can be used as an estimation formula.

[0073] The above formula can be transformed into the following formulas (3) and (4). The above constants and the subject's deep body temperature T at time t-Δt are body,t-Δt [℃], the initial value of the subject's skin temperature T skin,t-Δt [℃], the skin temperature and deep temperature at time t can be estimated using the heart rate, temperature, and humidity calculated from each measurement unit.

[0074] hx×(T body,m-1 -T skin,m-1 ),hx×(T skin,m-1 -T body,m-1 ) indicates the heat exchange between the skin and the deep tissue (the second heat exchange amount).S H×(T skin,m-1 -T air ) indicates heat exchange between the skin and the atmosphere (first heat exchange amount). The first heat exchange amount with the atmosphere and the amount of heat lost through evaporation of sweat are used to calculate the skin temperature. The amount of heat generated by exercise and the amount of heat generated by metabolism are used to calculate the deep body temperature. The second heat exchange amount between the skin and deep parts is used to calculate the skin temperature and deep part temperature, respectively. Note that in the integration of the term that calculates the outside air temperature and the amount of heat exchange (calculation by calculation unit 23), the skin can be divided into parts that are exposed to the outside air and parts that are not exposed, and the heat transfer coefficient (first heat exchange amount, amount of evaporation of sweat) for each can be changed.

[0075] Moreover, each constant is not limited to the values ​​described above or below, but may use a value that reflects reality, and may be set appropriately when performing calculations. The initial value of the temperature of each part may be actually measured. Similarly to the above, the initial value of the temperature of each part may use a value that reflects reality, and may be set appropriately when performing calculations.

[0076]

number

[0077] Next, each parameter used in the calculation by the calculation unit 23 will be described.

[0078] The amount of heat lost by evaporation of sweat SW(t) can be calculated from the sum E [W] of insensible and sensible transpiration. E = Q × (IP + swrate(t)). Here, IP [g / s] is insensible transpiration, Q [J / g] is the heat of evaporation of water, and swrate(t) is calculated using the constants α10, α11, α20, α21, β10, β11, β20, and β21, as follows: swrate(t) = [α11tanh{β11(T skin,t-Δt -T skin,0 )-β10}+α10]×(T skin,t-Δt -T skin,0 ) / minute+[α21tanh{β21(T body,t-Δt -T body,0 )-β20}+α20]×(T body,t-Δt -Tbody,0 ) / minute. mitute is minutes.

[0079] For example, the following values ​​can be set: α10=0.95, α11=0.55, α20=3.80, α21=3.20, β10=0.09, β11=0.59, β20=1.80, β21=2.70.

[0080] However, SW(t) is the maximum heat of vaporization E when the wetness ratio exceeds 1. max [W] cannot be exceeded. Wet=E / E max It can be calculated as follows: E max The calculation of air movement V air Convective heat transfer H depends on [m / s] c [W×m 2 / k], the saturated water vapor pressure of the skin P s [kPa], the saturated water vapor pressure of air P air It can be calculated from [kPa] using the following formula:

[0081] H c =3.0×√(10×V air ) ···(5)

[0082] P s =7.5×(10 D ) ···(6) In addition, D=7.23-((1750.3 / (273+T skin,t-Δt -38.1))).

[0083] P air =7.5×(10 G ) ···(7) Note that G=7.23-((1750.3 / (273+T air -38.1))).

[0084] E max =E max_coef ×H c ×(P s -humidity(t-Δt)×Pa)×{coverage+(1-coverage) / fpcl} ···(8)

[0085] In addition, E max_coef is a coefficient, coverage is the coverage rate of the subject's clothing, and fpcl is the moisture permeability coefficient.

[0086] The amount of heat Ex generated by exercise can be calculated using METs. For example, the number of METs is calculated using the formula: METs = (measured heart rate [bpm] - resting heart rate [bpm] of the person being measured) ÷ (maximum heart rate [bpm] of the person being measured - resting heart rate [bpm]) × maximum oxygen intake [ml] ÷ 3.5 [ml]. Using the calculated number of METs, the amount of heat is calculated using the formula: EX heat [W] = number of METs × 1.05 × body weight [kg] × 4184 ÷ 3600. The maximum oxygen intake can be calculated using an actual measured value. Also, the estimation formula (VO2 max =15HR max / HR rest ) can also be used to estimate maximum oxygen intake. rest is the measured resting heart rate. Also, HR max is the maximum heart rate measured or estimated using age: "Maximum heart rate = (208 - 0.7 x age) bpm."

[0087] The heat transfer coefficient H can be calculated from the heat transfer by convection Hc and the heat transfer by radiation Hr. H = (Hc + Hr) × fcl, where fcl is the coverage coefficient.

[0088] Basal metabolism is the skin metabolism of the subject. skin [W], the subject's deep metabolic rate M body [W] and M at time t skin and M. body is M skin =M skin,0 ×1.1 K , M body =M body、0 ×1.1 L It is calculated as follows. Note that K=(T skin,t-Δt -T skin,0 ), L=(T body,t-Δt -T body,0 ).

[0089] Here, M body,0 = (0.1238 + 0.0481 × weight × 0.92 + 0.0234 × height - 0.0138 × age - 0.5473 × sex_coef) × 1000000 / 24 / 3600 × activity_level. sex_coef is the coefficient for each gender, with 1 for men and 2 for women. activity_level is the physical activity level. Also, M skin,0 =M_ skin / ROU_ skin ×W_ skin Calculate with ROU_ skin is the density of the subject's skin [kg / m 3 ], M_ skin is the skin metabolism [W / m 3 ], W_ skin is calculated by multiplying body weight by 0.08. body,0 can be set according to the height, age, etc. of the person being measured in addition to the sex, physical activity level, and weight described above.

[0090] The calculation unit 22 calculates the amount of heat from the received heart rate data. Next, the calculation unit 23 calculates a first amount of heat exchange between the atmosphere of the subject and the skin of the subject from the received temperature and humidity data. The calculation unit 23 also calculates a second amount of heat exchange between the skin and the deep part of the subject. The calculation unit 23 also calculates the amount of sweat evaporation calculated from the amount of sweat produced by the subject. Using these amounts, the calculation unit 23 calculates (estimates) the change in the deep body temperature of the subject.

[0091] [Third Example] Next, a third embodiment of the present invention will be described. This embodiment describes yet another example of the deep body temperature measuring unit 2 of the first embodiment. FIG. 10 is a block diagram showing the configuration of the deep body temperature measuring unit 2 of this embodiment. The deep body temperature measuring unit 2 of this embodiment is composed of a measuring unit 24, a measuring unit 25, a heat generation amount calculation unit 26, a metabolic rate calculation unit 27, a heat transfer / heat radiation amount calculation unit 28 (first heat exchange amount calculation unit), a skin evaporation amount calculation unit 29, an exhaled evaporation amount setting unit 30 (fourth heat exchange amount setting unit), a heat exchange amount calculation unit 31 (second heat exchange amount calculation unit), a heat exchange amount calculation unit 32 (third heat exchange amount calculation unit), and a temperature calculation unit 33.

[0092] The heat generation amount calculation unit 26, the metabolic rate calculation unit 27, the heat transfer / heat radiation amount calculation unit 28, the skin evaporation rate calculation unit 29, the exhaled breath evaporation rate setting unit 30, the heat exchange rate calculation unit 31, and the heat exchange rate calculation unit 32 constitute a heat amount calculation unit 34.

[0093] The measurement unit 24 measures the temperature in the vicinity of the subject (the temperature of the atmosphere around the subject). The measurement unit 24 is, for example, a thermometer. Alternatively, the measurement unit 24 may acquire weather data in the vicinity of the subject from an external weather system.

[0094] The measurement unit 25 measures the humidity in the vicinity of the subject (humidity of the atmosphere around the subject). The measurement unit 25 is, for example, a hygrometer. Alternatively, the measurement unit 25 may acquire weather data in the vicinity of the subject from an external weather system, similar to the measurement unit 24.

[0095] The heart rate measurement unit 1, the measurement unit 24, and the measurement unit 25 may be an integrated measurement device, or may be separate measurement devices.

[0096] The heat calculation unit 34 calculates the amount of heat flowing into and out of the deep parts of the trunk (first region) and limbs (second region) and the skin of the subject based on the subject's heart rate, the temperature near the subject, and the humidity near the subject. The temperature calculation section 33 calculates the skin temperature and deep temperature of the measurement subject based on the amount of heat calculated by the amount of heat calculation section .

[0097] [Method of estimating deep body temperature: Method of calculating deep body temperature change at each time step] In this embodiment, as shown in Fig. 11, the body of the subject is considered to be composed of two parts, the trunk U and the limbs L, and each of the two parts, the trunk U and the limbs L, has two layers, the deep layer C and the skin layer S. That is, the body of the subject is composed of the trunk deep layer UC, the trunk skin layer US, the limb deep layer LC, and the limb skin layer LS. In this embodiment, the amount of heat that flows in and out of each part and layer of the subject and changes from moment to moment is calculated based on the acquired temperature, humidity, and heart rate information, and the temperature change of each part and layer of the subject is estimated from the change in the amount of heat.

[0098] In this embodiment, a method for calculating the change in deep body temperature for each time step in which sensor data is acquired will be described. As described above, this embodiment describes a calculation example in which the body of the subject is considered to be composed of two parts, the trunk and the limbs, but the trunk may be replaced with the upper body and the limbs with the lower body. In other words, the body of the subject may be considered to be composed of any two parts, the first part and the second part.

[0099] Equations (9) to (12) show examples of equations for estimating the temperature change of the trunk skin layer US, the trunk deep layer UC, the limb skin layer LS, and the limb deep layer LC of the subject, respectively. US [t] is the temperature of the trunk skin layer US at time t [℃], T UC [t] is the temperature of the deep layer UC of the trunk at time t [℃], T LS [t] is the temperature of the extremity skin layer LS at time t [℃], T LC [t] is the temperature [℃] of the deep layer LC of the limb at time t.

[0100]

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[0101]

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[0102]

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[0103]

number

[0104] Q 1,U is the amount of heat generated by the subject's trunk U during exercise [W], and Q 1,L is the amount of heat generated by the limb L due to exercise [W]. Q 2,US is the metabolic rate of the subject's trunk skin layer US [W], Q 2,UC is the metabolic rate of the deep trunk layer UC [W], Q 2,LS is the metabolic rate of the skin layer of the limbs LS [W], Q 2,LC Q is the metabolic rate of the deep layer LC of the limbs [W]. 3,U (1) Heat exchange quantity: Heat transfer and radiation quantity between the skin and the outside air at the trunk U of the subject [W], Q 3,L (First heat exchange amount) is the amount of heat transfer and radiation [W] between the skin in the limb L and the outside air.

[0105] Q 4,U is the skin evaporation rate at the subject's trunk U, and Q 4,L Q5 (fourth heat exchange volume) is the subject's exhaled breath evaporation volume [W]. Q 6,U (2nd heat exchange amount) is the heat exchange amount between the deep part and the skin in the trunk U of the subject [W], Q 6,L (The second heat exchange amount) is the heat exchange amount [W] between the deep part and the skin in the limb part L. Q7 (the third heat exchange amount) is the heat exchange amount [W] between the trunk and the limbs in the deep part of the subject.

[0106] W.C. US is the heat capacity of the subject's trunk skin layer US [J / ℃], WC UC is the heat capacity of the deep trunk layer UC [J / ℃], WC LS is the heat capacity of the skin layer LS of the limbs [J / ℃], WC LC is the heat capacity of the deep layer LC of the limb [J / ℃]. Δt is the calculation step time, for example, 1 [s] or less. In addition, the average skin temperature T at time t+Δtsk [t+Δt], and deep body temperature T[t+Δt] are expressed by equations (13) and (14).

[0107]

number

[0108]

number

[0109] sf_conf_US is the ratio [%] of the surface area of ​​the trunk U to the total body surface of the subject, and sf_conf_LS is the ratio [%] of the surface area of ​​the limbs L to the total body surface. Heat capacity WC US ,WC UC ,WC LS ,WC LC The ratios sf_conf_US and sf_conf_LS are known values, and may be set in advance to values ​​that correspond to the actual situation.

[0110] Fig. 12 is a flow chart explaining the operation of the core body temperature measuring unit 2 of this embodiment. The measuring unit 24 measures the temperature in the vicinity of the subject (air temperature of the subject's atmosphere) (Fig. 12, step S301). The measuring unit 25 measures the humidity in the vicinity of the subject (humidity of the subject's atmosphere) (Fig. 12, step S302).

[0111] [Calculation of heat generation Q1 due to exercise] Next, the heat generation amount calculation unit 26 calculates the heat generation amount Q in the deep layer of the trunk U due to the exercise of the subject based on the heart rate measured by the heart rate measurement unit 1. 1,U [W], the amount of heat generated in the deep layers of the limbs L by exercise Q 1,L [W] is calculated as in equations (15) and (16) (step S303 in FIG. 12).

[0112]

number

[0113]

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[0114] Equations (15) and (16) are based on the literature "2006 Exercise Guidelines for Health Promotion ~For Prevention of Lifestyle-Related Diseases~", Ministry of Health, Labor and Welfare, 2006,<https: / / www.mhlw.go.jp / shingi / 2006 / 07 / dl / s0719-3c.pdf> " where weight is the weight [kg] of the subject, ex_conf_U is the ratio [%] of muscle mass of the trunk U to the whole body of the subject, and ex_conf_L is the ratio [%] of muscle mass of the limbs L to the whole body. Weight and ratios ex_conf_U and ex_conf_L are all known values, and values ​​appropriate to the actual situation may be set in advance.

[0115] The calorific value calculation unit 26 calculates the heart rate HR[t][bpm] at time t acquired by the heart rate measurement unit 1, the resting heart rate HR rest , maximum heart rate HR max Then, METs[t] can be calculated using either equation (17) or equation (18).

[0116]

number

[0117]

number

[0118] Equation (18) is disclosed in the literature "J.R. Wicks, et al., "HR Index-A Simple Method for the Prediction of Oxygen Uptake", Medicine and Science in Sports and Exercise, 2011". Resting Heart Rate HR rest , maximum heart rate HRmax may be preset to values ​​that correspond to actual conditions as known values ​​obtained in past measurements. For METs[t] used in equations (15) and (16), not only instantaneous values ​​but also time average values ​​(for example, average values ​​over 6 minutes) may be used.

[0119] [Calculation of metabolic rate Q2] Next, the metabolic rate calculation unit 27 calculates the estimated average skin temperature T of the subject at time t calculated by the temperature calculation unit 33 Δt before. sk Based on [t][℃] and the estimated deep body temperature T[t][℃], the metabolic rate Q of the subject's trunk skin layer US is calculated. 2,US [W], metabolic rate Q of the deep trunk layer UC 2,UC [W], metabolic rate Q of the skin layer LS of the limbs 2,LS [W], metabolic rate of the deep layer LC of the limbs Q 2,LC [W] is calculated according to equations (19) to (22) (step S304 in FIG. 12).

[0120]

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[0121]

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[0122]

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[0123]

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[0124] Equations (19) to (22) are disclosed in the document "Ronald J Spiegel, "A Review of Numerical Models for Predicting the Energy Deposition and Resultant Thermal Response of Humans Exposed to Electromagnetic Fields", IEEE Transactions on Microwave Theory and Techniques, Volume 32, Issue 8, 1984". skin is a metabolic constant, and volume_US is the trunk skin layer US volume [m 3 ], volume_LS is the volume of the extremity skin layer LS [m 3 ], weight_U is the weight of the subject's trunk U [kg], and weight_L is the weight of the limb L [kg]. skin The volumes volume_US, volume_LS, and weights weight_U, weight_L are all known values, and may be set in advance to values ​​that correspond to the actual conditions.

[0125] T sk [0] is the average skin temperature T sk In this embodiment, the initial value T of the temperature of the trunk skin layer US is US [0], the initial temperature of the deep trunk layer UC, T UC [0], the initial temperature of the extremity skin layer LS, T LS [0], the initial temperature of the deep layer LC of the limbs T LC [0] is an actual value measured by another temperature measuring device or a known value at rest. Therefore, in the calculation of the initial metabolic rate Q2 at time t = 0, T sk [t]=T sk [0].

[0126] Similarly, the initial value T[0] of the deep body temperature T[t] is an actual value measured by another temperature measuring device or a known value at rest. Therefore, in the calculation of the initial metabolic rate Q2 at time t=0, T[t]=T[0]. Moreover, the metabolic rate calculation section 27 calculates M in the formulas (20) and (22) as shown in the formula (23).

[0127]

number

[0128] Equation (23) is disclosed in the literature "AA Ganpule, et al., "Interindividual variability in sleeping metabolic rate in Japanese subjects", European Journal of Clinical Nutrition, volume 61, 2007". weight_C is the deep body weight of the subject [kg], height is the height of the subject [cm], and age is the age of the subject. sexcoef is a constant that is 0.5473 when the subject is male and 0.5473 x 2 when the subject is female. activity_level is the physical activity level, A coef are parameters for metabolic adjustment. Weight weight_C, height height, age age, constants sexcoef, activity_level, parameter A coef are known values, and may be set in advance to values ​​that correspond to the actual situation.

[0129] As an example of setting activity_level, if the subject spends most of their time sitting and mainly doing static activities, it should be set to about 1.5. If the subject works mainly sitting but also moves around in the workplace, works while standing, or serves customers, or if their work includes commuting, shopping, housework, light sports, etc., activity_level should be set to about 1.75. If the subject works in a job that involves a lot of moving around and standing, or if they have active leisure time exercise habits such as sports, activity_level should be set to about 2.0. In this way, activity_level can be set appropriately according to the subject's exercise situation.

[0130] [Calculation of heat transfer and radiation Q3 between the skin and the outside air] Next, the heat transfer / heat radiation amount calculation unit 28 calculates the temperature T a [t][℃], and the estimated value T of the average skin temperature of the subject at time t calculated by the temperature calculation unit 33 Δt ago sk [t][℃] and the estimated temperature of the trunk skin layer US T US [t][℃] and the estimated temperature of the extremity skin layer LS T LS Based on [t][℃], the amount of heat transfer and radiation Q between the skin and the outside air in the trunk U of the subject is calculated. 3,U [W], Heat transfer and radiation between the skin and the air in the limbs L, Q 3,L [W] is calculated (step S305 in FIG. 12). a When measuring [t][℃], the amount of heat transfer and radiation Q 3,U ,Q 3,L is expressed as equations (24) and (25).

[0131]

number

[0132]

number

[0133] The proportions sf_conf_US and sf_conf_LS are as described above. fcl_US is a constant representing the heat transfer efficiency of clothing for the trunk U, fcl_LS is a constant representing the heat transfer efficiency of clothing for the limbs L, and coverage is the proportion [%] of the limbs L that are covered by clothing. The proportions sf_conf_US and sf_conf_LS, the constants fcl_US and fcl_LS, and the proportion coverage are all known values, and values ​​appropriate to the actual situation may be set in advance. The constants fcl_US and fcl_LS, and the proportion coverage may be set appropriately according to the clothing of the person being measured.

[0134] HS is the heat exchange coefficient between the measurement subject and the air [W / °C]. The heat transfer / heat radiation amount calculation unit 28 calculates the heat exchange coefficient HS [W / °C] using formula (26).

[0135]

number

[0136] sf is the subject's body surface area [m 2 The heat transfer and radiation amount calculation unit 28 calculates the body surface area sf [m 2 ] can be calculated from the subject's weight [kg] and height [m]. Body surface area sf [m 2 There are estimation formulas such as the DuBois formula and the Fujimoto formula to calculate [ ].

[0137] H cm is the convection heat transfer coefficient [W / ℃ / m 2 ], H r is the radiation heat transfer coefficient [W / ℃ / m 2 The heat transfer and heat radiation amount calculation unit 28 calculates the convection heat transfer coefficient H cm [W / ℃ / m 2 ], radiation heat transfer coefficient H r [W / ℃ / m 2 ] are calculated using equations (27) and (28), respectively.

[0138]

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[0139]

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[0140] Equations (27) and (28) are disclosed in the literature "D. Fiala, et al., "A computer model of human thermoregulation for a wide range of environmental conditions: the passive system", Journal of Applied Physiology, 1985". air is the wind speed [m / s]. The heat transfer and radiation amount calculation unit 28 calculates the wind speed V air The value [m / s] may be an actual measurement value obtained by an anemometer or the like, or a known value of the wind speed inside the clothing disclosed in literature or the like.

[0141] The heat transfer and heat radiation amount calculation unit 28 calculates the temperature T a When measuring [t][℃], the amount of heat transfer and radiation Q 3,U ,Q 3,L is calculated using equations (29) and (30).

[0142]

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[0143]

number

[0144] [Calculation of skin transpiration Q4] Next, the skin evaporation calculation unit 29 calculates the temperature T a[t][℃], the relative humidity humidity[t] in the vicinity of the subject measured by the measurement unit 25, and the estimated value T of the average skin temperature at time t calculated by the temperature calculation unit 33 Δt before sk Based on the estimated deep body temperature T[t][℃] and the measured body temperature, the amount of skin evaporation Q 4,U [W], skin evaporation amount Q in the limbs L 4,L [W] is calculated using equations (31) and (32), respectively (step S306 in FIG. 12).

[0145]

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[0146]

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[0147] sw_conf_US is the ratio [%] of the amount of sweating in the trunk U to the entire body surface of the subject, and sw_conf_LS is the ratio [%] of the amount of sweating in the limbs L to the entire body surface. The ratios sw_conf_US and sw_conf_LS are known values, and may be set in advance to values ​​that correspond to the actual conditions. sw is the amount of skin evaporation [W] of the entire body. The skin evaporation calculation unit 29 can calculate the amount of skin evaporation sw [W] by equation (33).

[0148]

number

[0149] min(E,E max ) is E and E max This means that the smaller of the two is adopted. E is the sum [W] of the insensible transpiration and the sensible transpiration in the skin of the subject. The skin transpiration calculation unit 29 can calculate the sum E [W] of the insensible transpiration and the sensible transpiration by the formula (34).

[0150]

number

[0151] PI is the insensible evaporation [W] in the subject's skin, Q ev is the heat of vaporization of water [J / g]. Insensible transpiration PI [W], heat of vaporization Q ev [J / g] are known values, and values ​​corresponding to the actual conditions may be set in advance. swrate is the sensible transpiration [g / min]. The skin transpiration calculation unit 29 can calculate the sensible transpiration swrate [g / min] by the formula (35).

[0152]

number

[0153] Equation (35) is disclosed in the document "D. Fiala, et al., "Computer prediction of human thermoregulatory and temperature responses to a wide range of environmental conditions", International Journal of Biometeorology, volume 45, 2001". aij,bij (i = 1, 2, j = 0, 1) are sweating coefficients. The sweating coefficients aij,bij are known values, and may be set in advance to values ​​that correspond to the subject's sweating tendency. Specifically, the sweating coefficients aij,bij may be set as shown in equation (36) according to three levels: low (hard to sweat), normal (normal), and high (easy to sweat).

[0154]

number

[0155] On the other hand, E max is the maximum heat of evaporation [W]. The skin evaporation calculation unit 29 calculates the temperature T a[t][℃] and the measurement unit 25 measures the relative humidity [t] outside the clothing of the person being measured, the maximum heat of evaporation E max [W] can be calculated using equation (37).

[0156]

number

[0157] In addition, the skin evaporation calculation unit 29 calculates the temperature T a [t][℃] and the measurement unit 25 measures the relative humidity [t] inside the clothing of the person being measured, the maximum heat of evaporation E max [W] can be calculated using equation (38).

[0158]

number

[0159] The ratios sw_conf_US, sw_conf_LS, and coverage are as described above. fpcl_US is a constant representing the heat transfer efficiency of clothing in the trunk U of the subject, fpcl_LS is a constant representing the heat transfer efficiency of clothing in the limbs L, and E max _ coef is a constant related to the maximum heat of vaporization. max _ coef are known values, and may be set in advance to values ​​that correspond to the actual situation.

[0160] H c is the heat transfer by convection depending on the air velocity [W m 2 / °C]. The skin evaporation calculation unit 29 calculates the heat transfer H c [W m 2 / °C] can be calculated using equation (39).

[0161]

number

[0162] Equations (37) to (39) are disclosed in the document "I. Laakso, et al., "Dominant factors affecting temperature rise in simulations of human thermoregulation during RF exposure", Physics in Medicine and Biology, Volume 56, 2011". s is the saturated water vapor pressure [kPa] in the skin layer of the subject. The skin evaporation calculation unit 29 calculates the saturated water vapor pressure P s [kPa] can be calculated using equation (40).

[0163]

number

[0164] P a is the saturated water vapor pressure [kPa] in the atmosphere where the humidity is being measured. The skin transpiration calculation unit 29 calculates the saturated water vapor pressure P a [kPa] can be calculated using equation (41).

[0165]

number

[0166] [Determination of expiratory transpiration rate Q5] Next, the breath evaporation rate setting unit 30 sets the breath evaporation rate Q5 [W] of the subject as shown in formula (42) (FIG. 12, step S307). The breath evaporation rate Q5 [W] corresponds to the amount of heat exchanged between the outside air and the deep part of the subject.

[0167]

number

[0168] [Calculation of heat exchange amount Q6 between deep tissue and skin] Next, the heat exchange amount calculation unit 31 calculates the heart rate HR [t] [bpm] measured by the heart rate measurement unit 1 and the estimated value T of the temperature of the trunk skin layer US at time t calculated by the temperature calculation unit 33 Δt before. US [t][℃] and the estimated temperature of the deep trunk layer UC T UC [t][℃] and the estimated temperature of the extremity skin layer LS T LS [t][℃] and the estimated temperature of the deep layer LC of the limbs T LC [t][℃] and the estimated mean skin temperature T sk Based on the estimated deep body temperature T[t][℃] and the measured body temperature, the amount of heat exchange Q between the deep body and the skin in the trunk U of the subject is calculated. 6,U [W], the amount of heat exchange between the deep tissue and the skin in the limbs L, Q 6,L [W] is calculated using equations (43) and (44), respectively (step S308 in FIG. 12).

[0169]

number

[0170]

number

[0171] The ratios sf_conf_US and sf_conf_LS are as described above. hx is the heat exchange coefficient between the skin and the deep part of the subject. The heat exchange amount calculation unit 31 can calculate the heat exchange coefficient hx by the formula (45).

[0172]

number

[0173] METs[t] is as described above. a, b, e, hx0, hx1, and hx_max are parameters related to the heat exchange coefficient. The parameters a, b, e, hx0, hx1, and hx_max are all known values, and values ​​appropriate to the actual situation may be used, and may be set appropriately through experiments.

[0174] [Calculation of heat exchange amount Q7 between the trunk and the limbs] Next, the heat exchange amount calculation unit 32 calculates the estimated value T of the temperature of the deep layer UC of the trunk at time t, which was calculated by the temperature calculation unit 33 Δt before. UC [t][℃] and temperature T of the deep layer LC of the limbs LC [t][℃] and the estimated mean skin temperature T sk Based on [t][℃] and the estimated deep body temperature T[t][℃], the amount of heat exchange Q7[W] between the trunk U and the limbs L in the deep part of the subject is calculated using equation (46) (Figure 12, step S309).

[0175]

number

[0176] Here, hcc is the heat exchange coefficient between the trunk U and the limbs L deep within the subject. The heat exchange amount calculation unit 32 can calculate the heat exchange coefficient hcc using equation (47).

[0177]

number

[0178] f and hcc0 are parameters related to the heat exchange coefficient. The parameters f and hcc0 are known values, and may be set appropriately through experiments based on actual values. hcc_T is the temperature contribution of the heat exchange coefficient hcc, and hcc_M is the METs contribution of the heat exchange coefficient hcc. The heat exchange amount calculation unit 32 can calculate the temperature contribution hcc_T of the heat exchange coefficient hcc using equation (48).

[0179]

number

[0180] hcc_Tmax is a prescribed upper limit value of hcc_T. Furthermore, the heat exchange amount calculation section 32 can calculate the METs contribution hcc_M of the heat exchange coefficient hcc by using the formula (49).

[0181]

number

[0182] hcc_Mmax is the prescribed upper limit of hcc_M. hcc1 is a parameter related to the heat exchange coefficient. The upper limits hcc_Tmax, hcc_Mmax, and parameter hcc1 are all known values, and values ​​appropriate to the actual situation may be used, and may be set appropriately through experiments. aveMETs[t] is the time average value of the number of METs (for example, the average value over 6 minutes). Parameters a and b are as described above.

[0183] In this way, the heat quantity calculation unit 26, the metabolic rate calculation unit 27, the heat transfer / heat radiation calculation unit 28, the skin evaporation rate calculation unit 29, the breath evaporation rate setting unit 30, the heat exchange rate calculation unit 31, and the heat exchange rate calculation unit 32 calculate the heat quantity Q 1,U ,Q 1,L ,Q 2,US ,Q 2,UC ,Q 2,LS ,Q 2,LC ,Q 3,U ,Q 3,L ,Q 4,U ,Q 4,L ,Q5,Q 6,U ,Q 6,L , Q7 can be calculated.

[0184] The temperature calculation unit 33 calculates an estimated value T US [t][℃] and metabolic rate Q of the trunk skin layer US 2,US [W] and the amount of heat transfer and radiation Q between the skin and the air in the trunk U 3,U [W] and the skin transpiration rate Q in the trunk U 4,U [W] and the amount of heat exchange between the deep tissue and the skin in the trunk U, Q 6,U [W] and the estimated trunk skin layer US temperature after Δt T US [t+Δt][° C.] is calculated using equation (9) (step S310 in FIG. 12).

[0185] The temperature calculation unit 33 calculates an estimated value T of the temperature of the deep layer UC of the trunk of the subject at time t. UC [t][℃] and the amount of heat generated in the deep layers of the trunk U, Q 1,U [W] and the metabolic rate Q of the deep trunk layer UC 2,UC [W], expiratory transpiration Q5[W], and heat exchange between the deep tissue and the skin in the trunk U, Q 6,U Based on the heat exchange amount Q7[W] between the trunk U and the limbs L in the deep part, the estimated temperature T of the trunk deep layer UC after Δt is UC [t+Δt][° C.] is calculated using equation (10) (step S311 in FIG. 12).

[0186] The temperature calculation unit 33 calculates an estimated value T LS [t][℃] and metabolic rate Q of the extremity skin layer LS 2,LS [W] and the amount of heat transfer and radiation Q between the skin and the air in the limb L 3,L [W] and the skin evaporation rate Q in the limbs L 4,L [W] and the amount of heat exchange between the deep tissue and the skin in the limbs L, Q 6,L [W] and the estimated temperature of the extremity skin layer LS after Δt T LS [t+Δt][° C.] is calculated using equation (11) (step S312 in FIG. 12).

[0187] The temperature calculation unit 33 calculates an estimated value T of the temperature of the deep layer LC of the extremity of the subject at time t. LC [t][℃] and the heat generation Q in the deep layer of the limb L 1,L [W] and metabolic rate Q of the deep layer LC of the limbs 2,LC [W] and the amount of heat exchange between the deep tissue and the skin in the limbs L, Q 6,L Based on the heat exchange amount Q7[W] between the trunk U and the extremities L in the deep part, the estimated temperature T of the extremities deep layer LC after Δt is LC [t+Δt][° C.] is calculated using equation (12) (step S313 in FIG. 12).

[0188] Thus, the temperature estimate T US [t+Δt],T UC [t+Δt],T LS[t+Δt],T LC [t+Δt] can be calculated sequentially. Then, the temperature calculation unit 33 calculates the estimated average skin temperature T sk [t+Δt][°C] is calculated using equation (13) (FIG. 12, step S314). Temperature calculation unit 33 also calculates the estimated deep body temperature T[t+Δt][°C] after Δt using equation (14) (FIG. 12, step S315).

[0189] The core body temperature measuring unit 2 performs the above steps S300 to S315 every cycle Δt. In the next calculation after Δt, the T calculated in the previous cycle is US [t+Δt],T UC [t+Δt],T LS [t+Δt],T LC [t+Δt],T sk [t+Δt], T[t+Δt] are respectively US [t],T UC [t],T LS [t],T LC [t],T sk [t], T[t], and then the processes of steps S300 to S315 may be performed.

[0190] In this embodiment, the case where the heart rate of the subject is used is described, but the pulse rate may be used instead of the heart rate.

[0191] The determination unit 4 and the notification unit 5 in the first to third embodiments can be realized by a computer equipped with a CPU (Central Processing Unit), a storage device, and an interface, and a program that controls these hardware resources. An example of the configuration of this computer is shown in FIG.

[0192] The computer includes a CPU 200, a storage device 201, and an interface device (I / F) 202. The I / F 202 is connected to the heart rate measurement unit 1, the measurement units 20, 21, 24, 25, and the hardware of the circuit unit of the notification unit 5. In such a computer, a heat risk warning program for realizing the heat risk warning methods of the first to third embodiments is stored in the storage device 201. The CPU 200 executes the processes described in the first to third embodiments in accordance with the program stored in the storage device 201.

[0193] The configuration of the heat risk warning device may be distributed among multiple computer devices. For example, the heat risk warning device may be configured with a first device such as a wearable sensor in which a heart rate measurement unit 1 and a deep body temperature measurement unit 2 are integrated, and a second device such as a smartphone in which a subjective information acquisition unit 3, a determination unit 4, and a notification unit 5 are integrated. In this case, the first device is worn on the body of the person to be measured, the person to be measured carries the second device, and data acquired by the first device is transmitted to the second device via a network, and the second device determines the heat risk level and issues a notification.

[0194] The heat risk warning device may also be composed of a first device such as a wearable sensor integrating a heart rate measurement unit 1 and a deep body temperature measurement unit 2, a second device such as a smartphone constituting a subjective information acquisition unit 3, and a third device such as a data server integrating a determination unit 4 and a notification unit 5. In this case, the first device is worn on the body of the person being measured, the person being measured carries the second device, and data acquired by the first and second devices is transmitted via a network to the third device, which determines the heat risk level and issues a notification. [Industrial Applicability]

[0195] The present invention can be applied to a technology for preventing heat stroke. [Explanation of symbols]

[0196] 1...heart rate measurement unit, 2...core body temperature measurement unit, 3...subjective information acquisition unit, 4...determination unit, 5...notification unit, 20, 21, 24, 25...measurement unit, 22, 23...calculation unit, 26...heat generation amount calculation unit, 27...metabolic rate calculation unit, 28...heat transfer / heat radiation amount calculation unit, 29...skin evaporation amount calculation unit, 30...exhaled evaporation amount setting unit, 31, 32...heat exchange amount calculation unit, 33...temperature calculation unit, 34...heat generation amount calculation unit.

Claims

1. A heart rate measurement unit configured to measure a heart rate of a subject; A deep body temperature measuring unit configured to estimate or measure the deep body temperature of the measurement subject; A subjective information acquisition unit configured to acquire information on subjective symptoms of the subject related to a thermal environment and exercise intensity; A determination unit configured to determine a heat risk level of the measurement subject based on the heart rate, deep body temperature, and subjective symptoms of the measurement subject; A heat risk warning device characterized by comprising a notification unit configured to notify a work manager or the measurement subject of heat risk notification information corresponding to the heat risk level determined by the determination unit.

2. The heat risk warning device according to claim 1, A heat risk warning device characterized in that the subjective information acquisition unit acquires information on the subject's subjective symptoms, such as information on thermal sensation, information on perceived intensity of exertion, and information on thermal comfort.

3. 3. The heat risk warning device according to claim 1, A heat risk warning device characterized in that the determination unit determines the heat risk level of the measurement subject for each of the heart rate, the deep body temperature, and the subjective symptoms.

4. 4. The heat risk warning device according to claim 3, A heat risk warning device characterized in that the determination unit determines a heat risk level for each of the heart rate, the deep body temperature, and the subjective symptoms based on whether or not the quantified values ​​of the heart rate, the deep body temperature, and the subjective symptoms exceed corresponding thresholds.

5. 5. The heat risk warning device according to claim 4, The heat risk warning device is characterized in that the determination unit determines a heat risk level related to the heart rate based on whether the duration during which the heart rate exceeds a corresponding threshold exceeds a predetermined heart rate observation time, and determines a heat risk level related to the deep body temperature based on whether the duration during which the deep body temperature exceeds a corresponding threshold exceeds a predetermined deep body temperature observation time.

6. A first step of measuring a heart rate of a subject; A second step of estimating or measuring the deep body temperature of the subject; A third step of acquiring information on the subject's subjective symptoms related to the thermal environment and exercise intensity; A fourth step of determining a heat risk level of the subject based on the subject's heart rate, core body temperature, and subjective symptoms; A program characterized by causing a computer to execute a fifth step of notifying a work manager or the measurement subject of heat risk notification information corresponding to the heat risk level determined in the fourth step.

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