Heat stroke determination device, heat stroke determination method, and program

Abstract

To improve heat stroke determination accuracy.SOLUTION: A heat stroke determination device 1 includes: a heart rate specification unit 153 for specifying an actually measured heart rate of a subject U; a temperature specification unit 154 for specifying a depth temperature of the subject U; a calculation unit 155 for calculating an estimated heart rate on the basis of the depth temperature; and a determination unit 156 that outputs alert information indicating that heat stroke is suspected when the relationships between the actually measured heart rate and the estimated heart rate satisfy a first condition, and does not output alert information when the relationships between the actually measured heart rate and the estimated heart rate do not satisfy a first condition.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a heatstroke diagnosis device, a heatstroke diagnosis method, and a program. [Background technology]

[0002] Conventionally, there is known a technique for determining whether or not a person has heat stroke based on deep body temperature (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-134137 A Summary of the Invention [Problem to be solved by the invention]

[0004] Even if the core body temperature rises, the risk of heat stroke is small if the autonomic nervous system is functioning normally. However, with conventional technology, there was a problem in that a heat stroke warning would be issued if the core body temperature was above a threshold, even if the risk of heat stroke was low.

[0005] Therefore, the present invention has been made in consideration of these points, and aims to improve the accuracy of heat stroke determination. [Means for solving the problem]

[0006] A heatstroke determination device according to a first aspect of the present invention comprises a heart rate determination unit that determines an actual heart rate of a subject, a temperature determination unit that determines a deep body temperature of the subject, a calculation unit that calculates an estimated heart rate based on the deep body temperature, and a determination unit that outputs alert information indicating a suspicion of heatstroke if a relationship between the actual heart rate and the estimated heart rate satisfies a first condition, and does not output the alert information if the relationship between the actual heart rate and the estimated heart rate does not satisfy the first condition.

[0007] The temperature determination unit may determine the deep body temperature based on a conversion equation whose variables are the subject's body surface temperature measured by a body temperature sensor and the temperature of the space measured by a temperature sensor installed in the space in which the subject is located.

[0008] The calculation unit may calculate the estimated heart rate by multiplying the core body temperature by a predetermined coefficient.

[0009] The calculation unit may calculate the estimated heart rate by multiplying the core body temperature by the predetermined coefficient stored in a memory unit in association with the subject.

[0010] The calculation unit may calculate a minimum value of the estimated heart rate and a maximum value of the estimated heart rate, and the determination unit may output the alert information when the first condition is satisfied, that is, the actual measured heart rate is not included between the minimum value of the estimated heart rate and the maximum value of the estimated heart rate.

[0011] The heatstroke determination device may further include a spectrum identification unit that identifies a frequency spectrum of heart rate fluctuation, which is the fluctuation of the actual heart rate, based on a plurality of the actual heart rates measured at different times, and the determination unit may output the alert information when a second condition is satisfied that a ratio of a first component of the heart rate fluctuation included in a first frequency band to a second component of the heart rate fluctuation included in a second frequency band lower than the first frequency band is equal to or greater than a threshold value.

[0012] A second aspect of the heatstroke diagnosis method of the present invention includes the steps of: determining an actual heart rate of a subject, determining a deep body temperature of the subject, calculating an estimated heart rate based on the deep body temperature, and outputting alert information indicating a suspicion of heatstroke if a relationship between the actual heart rate and the estimated heart rate satisfies a predetermined condition, executed by a computer.

[0013] A third aspect of the program of the present invention is a program for causing a computer to execute the steps of identifying an actual heart rate of a subject, identifying a deep body temperature of the subject, calculating an estimated heart rate based on the deep body temperature, and outputting alert information indicating a suspicion of heat stroke if the relationship between the actual heart rate and the estimated heart rate satisfies a predetermined condition. Effect of the Invention

[0014] The present invention has the effect of improving the accuracy of determining heat stroke. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram for explaining an overview of a heatstroke determination device 1. [Diagram 2] FIG. 1 is a diagram showing a configuration of a heatstroke determination device 1. [Diagram 3] 4 is a flowchart showing a process flow in the heatstroke determination device 1. [Figure 4] FIG. 13 is a diagram showing a configuration of a heatstroke determination device 1A according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] [Overview of heat stroke detection device 1] 1 is a diagram for explaining an overview of a heatstroke determination device 1. The heatstroke determination device 1 is a device that determines whether or not a subject U has heatstroke. The heatstroke determination device 1 may be any device having a processor capable of executing arithmetic processing, such as a computer, a smartphone, or a dedicated device.

[0017] The heatstroke determination device 1 transmits and receives data to and from the information terminal 2 via an intranet or short-distance wireless communication. For example, the heatstroke determination device 1 transmits a determination result as to whether or not there is heatstroke to the information terminal 2, and the information terminal 2 displays the determination result. The heatstroke determination device 1 may display the determination result on a display provided in the heatstroke determination device 1.

[0018] The heatstroke determination device 1 determines whether the subject U has heatstroke or not, depending on whether the relationship between the heart rate estimated based on the subject U's deep body temperature and the actually measured heart rate matches the relationship when the probability of heatstroke is high. By operating in this way, the heatstroke determination device 1 can determine that the body temperature rise is not due to heatstroke but is due to exercise, for example, when the subject U's body temperature and heart rate increase due to exercise. On the other hand, when the subject U's heart rate does not increase but the deep body temperature increases, the heatstroke determination device 1 can determine that the probability of the body temperature rise due to heatstroke is high, and output alert information.

[0019] Although details will be described later, the heatstroke determination device 1 transmits a transmission wave TX, which is a high-frequency radio wave (e.g., millimeter wave radar), toward the subject U, and receives a reflected wave RX reflected by the subject U. The heatstroke determination device 1 measures the heart rate by analyzing the received reflected wave RX and identifying the period in which the subject U's heart beats. The high-frequency radio wave contains, for example, a chirp signal whose frequency changes over time. The heatstroke determination device 1 converts the reflected signal into the frequency domain by Fourier transforming it, and identifies the frequency contained in the reflected signal, thereby measuring the propagation time from when the signal of that frequency is transmitted to when it is received, and measuring the heart rate based on the period of variation in the propagation time. The configuration and operation of the heatstroke determination device 1 will be described in detail below.

[0020] [Configuration of heat stroke detection device 1] 2 is a diagram showing the configuration of the heatstroke determination device 1. The heatstroke determination device 1 has a transmission unit 11, a reception unit 12, a communication unit 13, a storage unit 14, and a control unit 15. The control unit 15 has an instruction acceptance unit 151, a radio wave control unit 152, a heart rate identification unit 153, a temperature identification unit 154, a calculation unit 155, and a determination unit 156.

[0021] The transmitter 11 transmits a transmission signal in a frequency band equal to or greater than the millimeter wave band at a predetermined time interval under the control of the radio wave control unit 152. The transmitter 11 transmits a chirp signal at a period of, for example, 12.5 milliseconds. The transmitter 11 has a signal generating circuit that generates a chirp signal, and an antenna for transmitting the transmission signal as radio waves. As an example, the heatstroke determination device 1 may have multiple transmitters 11 that transmit transmission signals to different ranges at different times. In this case, the heatstroke determination device 1 can simultaneously determine whether or not each of multiple subjects U has heatstroke.

[0022] The transmitting unit 11 transmits a transmission signal at a time interval less than half the minimum value of the period in which a preset biological condition changes. For example, if the maximum value of the heart rate is assumed to be 150 beats / minute, the minimum value of the period of the heart rate fluctuation is 0.4 seconds. Therefore, the transmitting unit 11 transmits a transmission signal at a time interval less than 0.2 seconds. By transmitting a transmission signal at such a time interval, the heat stroke determination device 1 can identify the change state of a part of the body of the subject U based on the reflected signal received by the receiving unit 12 at that time interval. The length of the transmission signal transmitted by the transmitting unit 11 is arbitrary, but it is desirable that it is sufficiently shorter than the time interval at which the transmission signal is transmitted, for example, within 2 milliseconds.

[0023] The receiving unit 12 receives a reflected signal generated when the transmitted signal is reflected by the subject U. As an example, the receiving unit 12 may have a plurality of receiving units 12 each receiving a reflected signal arriving from a different range. The receiving unit 12 inputs the received reflected signal to the heart rate identification unit 153.

[0024] The communication unit 13 has a communication interface for transmitting and receiving various data to and from the information terminal 2. The communication unit 13 has, for example, a Bluetooth (registered trademark) communication interface. The communication unit 13 receives data indicating the user's operation content inputted at the information terminal 2. The communication unit 13 also transmits the determination result outputted by the spectrum specification unit 157 to the information terminal 2.

[0025] The communication unit 13 may receive data indicating temperature from a measurement device that measures the body surface temperature of the subject U and the temperature of the space in which the subject U is located. The communication unit 13 inputs the received temperature data to the calculation unit 155.

[0026] The storage unit 14 has a storage medium such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The storage unit 14 stores a program executed by the control unit 15. The storage unit 14 also stores the reflected signal received by the receiving unit 12 and the heart rate calculated by the control unit 15 analyzing the reflected signal.

[0027] The control unit 15 has, for example, a CPU (Central Processing Unit). The control unit 15 executes the programs stored in the storage unit 14 to function as an instruction receiving unit 151, a radio wave control unit 152, a heart rate identification unit 153, a temperature identification unit 154, a calculation unit 155, a determination unit 156, and a spectrum identification unit 157.

[0028] The instruction receiving unit 151 receives instruction data input from the information terminal 2 via the communication unit 13. The instruction receiving unit 151 receives, for example, an instruction to start checking whether or not the subject has heat stroke. The instruction receiving unit 151 may receive an instruction to set attributes of the subject U, such as age, sex, weight, etc.

[0029] The radio wave control unit 152 controls the transmitting unit 11 and the receiving unit 12. The radio wave control unit 152 controls, for example, the timing at which the transmitting unit 11 transmits a transmission signal. The radio wave control unit 152 also controls the range in which the transmitting unit 11 transmits a transmission signal and the range in which the receiving unit 12 receives a reflected signal.

[0030] The heart rate determination unit 153 determines the actual heart rate of the subject U. Specifically, the heart rate determination unit 153 determines the period of variation in the distance between the heat stroke determination device 1 and the part where the signal transmitted by the transmission unit 11 is reflected, based on the reflected wave received by the reception unit 12, thereby determining the heart rate of the subject U.

[0031] For example, the heart rate determination unit 153 converts the reflected signal received by the receiving unit 12 into a frequency domain signal by performing a Fourier transform. In the frequency domain, the heart rate determination unit 153 identifies a frequency component contained in a chirp signal constituting the reflected signal, and determines, as the propagation time, the difference between the time when the transmitting unit 11 transmits the frequency component and the time when the receiving unit 12 receives the frequency component contained in the reflected signal.

[0032] The heatstroke determination device 1 identifies the distance to the part where the radio wave was reflected based on the propagation time. When the heatstroke determination device 1 determines that the change in distance over time is due to the beating of the heart, it calculates the heart rate based on the period of the change. When the period of the change in distance is within a range expected as the period of the heartbeat and the amplitude of the change in distance is a magnitude corresponding to the amount of fluctuation of the surface of the heart, the heatstroke determination device 1 calculates the heart rate based on the period of the change in distance. The heart rate determination unit 153 notifies the temperature determination unit 154 of the calculated heart rate in association with the time.

[0033] The temperature specifying unit 154 specifies the deep body temperature of the subject U based on the body surface temperature of the subject U and the temperature of the space in which the subject U is present. The temperature specifying unit 154 specifies the deep body temperature based on a conversion equation having as variables the body surface temperature of the subject U measured by a body temperature sensor and the temperature of the space in which the subject U is present measured by a temperature sensor provided in the space.

[0034] The temperature specifying unit 154 acquires body surface temperature data indicating the distribution of the body surface temperature of the subject U measured by, for example, a thermograph, and space temperature data indicating the space temperature measured by a thermometer. The temperature specifying unit 154 determines the highest temperature among the body surface temperatures at multiple positions included in the body surface temperature data as the body surface temperature of the subject U.

[0035] The body surface temperature measured by a temperature measuring device such as a thermograph generates an error due to the temperature around the temperature measuring device. Therefore, the temperature determining unit 154 corrects the body surface temperature based on the space temperature data. Specifically, when the body surface temperature is Ts, the space temperature is Ta, and the corrected body surface temperature is Tsh, the temperature determining unit 154 corrects the body surface temperature, for example, by the following formula. Tsh = Ts + a1 × Ta 2 +b1×Ta-c1 Here, a1, b1, and c1 are coefficients.

[0036] Next, the temperature specifying unit 154 specifies the deep body temperature Td based on the corrected body surface temperature Tsh using, for example, the following formula: The temperature specifying unit 154 inputs the specified deep body temperature to the calculation unit 155. Td = a2 × Tsh 3 -b2×Tsh 2 +c2×Tsh-d Here, a2, b2, c2, and d are coefficients.

[0037] The calculation unit 155 calculates the estimated heart rate based on the deep body temperature of the subject U identified by the temperature identification unit 154. It is known that there is a correlation between the deep body temperature and the heart rate, and the calculation unit 155 calculates the estimated heart rate by multiplying the deep body temperature by a predetermined coefficient corresponding to the correlation. The calculation unit 155 may calculate the estimated heart rate by multiplying the deep body temperature by a predetermined coefficient associated with the subject U or the attributes of the subject U and stored in the storage unit 14. The calculation unit 155 calculates the minimum and maximum values ​​of the estimated heart rate using the following formula, for example, based on the assumption that the heart rate increases by 10 when the deep body temperature increases by 0.55°C.

[0038] BT-Th=ΔBT ΔHR = (ΔBT ÷ 0.55) × 10 HRE min =HR min +ΔHR HRE max =HR max +ΔHR Here, BT is the core body temperature, Th is the standard core body temperature (e.g., 36.5°C), ΔBT is the difference between the core body temperature and the standard core body temperature, ΔHR is the estimated difference from the standard heart rate, and HR min is the minimum standard heart rate, HR max is the maximum standard heart rate, HRE min is the minimum estimated heart rate, HRE max is the maximum estimated heart rate.

[0039] HR min and HR max are the minimum and maximum heart rates measured, for example, when subject U is in a healthy, resting state. HR min and HR max may be stored in advance in the storage unit 14 or may be set by the information terminal 2. The storage unit 14 stores a plurality of HRs in association with the attributes of people. min and HR max The calculation unit 155 stores HR min and HR max may also be used.

[0040] The determination unit 156 determines whether or not the subject U is highly likely to have heat stroke based on the relationship between the actual heart rate and the estimated heart rate. When the relationship between the actual heart rate and the estimated heart rate satisfies a first condition, the determination unit 156 outputs alert information indicating that heat stroke is suspected, and does not output the alert information when the relationship between the actual heart rate and the estimated heart rate does not satisfy the first condition. The first condition is, for example, a condition that the actual heart rate is not included between the minimum and maximum values ​​of the estimated heart rate.

[0041] For example, HR min is 60 and HR max When the relationship between the fever state and the heart rate of the subject U is 85, the determination unit 156 determines that the relationship between the fever state and the heart rate of the subject U is abnormal and the probability of heat stroke is high in the following cases: Actual heart rate < 60 + ΔHR or 85 + ΔHR < Actual heart rate On the other hand, in the following cases, the determination unit 156 determines that the relationship between the fever state and the heart rate of the subject U is normal and the probability of heat stroke is low. 60+ΔHR≦actual heart rate≦85+ΔHR

[0042] In this way, the judgment unit 156 judges whether or not the subject U is highly likely to have heat stroke based on the relationship between the actual measured heart rate and the estimated heart rate based on the deep body temperature, thereby reducing the probability that a heat stroke warning will be issued when the deep body temperature is above a threshold value even if the likelihood of heat stroke is low.

[0043] In the above description, it is assumed that the body surface temperature is measured correctly, but in reality, there are cases where the body surface temperature is not measured correctly. In such a case, if the subject U is determined to have a high probability of having heat stroke based on the relationship between the actual measured heart rate and the estimated heart rate based on the deep body temperature, an erroneous determination may be made. Therefore, the determination unit 156 may determine whether the reliability of the measured body surface temperature is high, and may determine that the probability of heat stroke is high when the reliability of the measured body surface temperature is equal to or higher than a threshold value and the relationship with the estimated heart rate based on the deep body temperature satisfies the first condition.

[0044] The determining unit 156 determines that the reliability of the body surface temperature is less than the threshold value in any of the following cases, for example. (1) When the maximum temperature indicated by the data obtained from the thermography is outside the rated range (2) When the area of ​​the highest temperature region in the temperature image obtained from the thermography is less than the threshold value. (3) When the measured body surface temperature is above a threshold value (e.g. 30°C) (4) When the heart rate determination unit 153 does not detect a heart rate (when a person is not detected)

[0045] [Processing flow in heat stroke determination device 1] Fig. 3 is a flowchart showing the flow of processing in the heatstroke determination device 1. The flowchart shown in Fig. 3 starts from the point in time when the heatstroke determination device 1 starts transmitting radio waves for measuring the heart rate to the subject U. When the heatstroke determination device 1 determines whether or not each of the multiple subjects U has heatstroke, the heatstroke determination device 1 executes the processing shown in Fig. 3 in parallel.

[0046] The heart rate identification unit 153 identifies the actually measured heart rate based on the reflected wave received via the receiving unit 12 (S11). The temperature identification unit 154 identifies the body surface temperature of the subject U based on the data acquired from the thermograph (S12). The temperature identification unit 154 determines whether the reliability of the identified body surface temperature is equal to or higher than a threshold (S13). If the temperature identification unit 154 determines that the reliability is less than the threshold (NO in S13), the determination unit 156 displays that there is a problem with the measurement of the body surface temperature, and then the control unit 15 returns the process to S11.

[0047] When the temperature determination unit 154 determines that the reliability is equal to or higher than the threshold (YES in S13), the temperature determination unit 154 converts the body surface temperature into a deep body temperature after correcting the body surface temperature based on the space temperature (S14). The calculation unit 155 calculates an estimated heart rate by multiplying the deep body temperature by a predetermined coefficient (S15). The determination unit 156 compares the actual heart rate with the estimated heart rate (S16), and when the relationship between the actual heart rate and the estimated heart rate satisfies a first condition (YES in S17), determines that the probability of heat stroke is high and outputs alert information (S18). When the determination unit 156 determines that the relationship between the actual heart rate and the estimated heart rate does not satisfy the first condition (NO in S17), for example, the control unit 15 returns the process to S11 and continues measuring, but the control unit 15 may end the measurement without continuing the measurement.

[0048] [Variations] Fig. 4 is a diagram showing the configuration of a heatstroke determination device 1A according to a modified example. The heatstroke determination device 1A shown in Fig. 4 differs from the heatstroke determination device 1 shown in Fig. 2 in that it further includes a spectrum determination unit 157, but is the same in other respects. The heatstroke determination device 1A does not need to include the temperature determination unit 154 and the calculation unit 155.

[0049] When the sympathetic nervous system is activated and the parasympathetic nervous system is deactivated, the heart rate fluctuation (RR interval fluctuation) is small. When the sympathetic nervous system is activated and dominant over the parasympathetic nervous system, there is a high probability that the subject U is stressed. If the subject U is stressed, the body temperature regulation function in a hot environment is reduced, increasing the probability of heat stroke. Therefore, the heat stroke determination device 1A determines whether or not the subject U is likely to have heat stroke, based on the frequency components of the heart rate fluctuation, which is correlated with the state of the autonomic nervous system.

[0050] In order to enable the determination unit 156 to determine whether or not the probability of heat stroke is high based on the frequency components of the heart rate variability, the spectrum determination unit 157 determines the frequency spectrum of the heart rate variability, which is the variability of the actual heart rate, based on a plurality of actual heart rates measured at different times (e.g., at intervals of 100 milliseconds). The spectrum determination unit 157 determines the frequency spectrum of the heart rate variability, for example, by Fourier transforming waveform data indicating the heart rate variability constituted by data on the plurality of actual heart rates. The determination unit 156 outputs alert information when a second condition is satisfied, that is, a ratio of a second component of the heart rate variability included in a second frequency band lower than the first frequency band to a first component of the heart rate variability included in a first frequency band is equal to or greater than a threshold value.

[0051] In order to determine whether the heart rate fluctuation satisfies the second condition, the judgment unit 156 first judges whether there is a high probability of heat stroke depending on which of the following three frequency ranges the frequency spectrum of the identified heart rate fluctuation falls within: VLF: Low frequency region (0Hz-0.05Hz) LF: Intermediate frequency range (0.05Hz-0.20Hz) HF: High frequency region (0.20Hz-0.35Hz)

[0052] The low frequency region is likely to be influenced mainly by sympathetic nerve activity. The mid frequency region is likely to be influenced by sympathetic nerve activity and parasympathetic nerve activity. The high frequency region is likely to be influenced by parasympathetic nerve activity caused by breathing. Using these properties, the determination unit 156 estimates the balance between sympathetic nerve activity and parasympathetic nerve activity depending on which frequency region the frequency spectrum identified by the spectrum identification unit 157 is included in.

[0053] Specifically, when the frequency spectrum has the largest proportion included in the high frequency region (corresponding to the first frequency band), the judgment unit 156 judges that the parasympathetic nerves are activated and the subject U is in a relaxed state. On the other hand, when the frequency spectrum has the largest proportion included in the low frequency region (corresponding to the second frequency band), the judgment unit 156 judges that the sympathetic nerves are activated and the subject U is in a stressed state. That is, when the judgment unit 156 satisfies a second condition that the ratio of low frequency components to high frequency components in the frequency spectrum of the heart rate fluctuation is equal to or greater than a threshold, the judgment unit 156 judges that the subject U is in a stressed state, and when the ratio of low frequency components to high frequency components is less than the threshold, the judgment unit 156 judges that the subject U is in a relaxed state.

[0054] When the determination unit 156 determines that the subject U is in a stressed state, it determines that the probability of heat stroke is high and outputs alert information. When the determination unit 156 determines that the subject U is in a relaxed state, it determines that the probability of heat stroke is low and does not output alert information.

[0055] In this way, the judgment unit 156 judges whether or not there is a high probability of heatstroke based on the ratio of low frequency components to high frequency components in the frequency spectrum of heart rate fluctuation, thereby reducing the probability that a heatstroke warning will be issued when the core body temperature is above a threshold value even though the risk of heatstroke is low.

[0056] The determination unit 156 may determine the probability of heat stroke based on both the relationship between the actual heart rate and the estimated heart rate based on the deep body temperature, and the ratio of low frequency components to high frequency components in the frequency spectrum of the heart rate fluctuation. For example, the determination unit 156 calculates a first score indicating the probability of heat stroke based on the relationship between the actual heart rate and the estimated heart rate based on the deep body temperature, and calculates a second score indicating the probability of heat stroke based on the ratio of low frequency components to high frequency components. The determination unit 156 determines whether the probability of heat stroke is high or not based on whether the result of adding or multiplying the first score and the second score is equal to or greater than a threshold value. In this way, the determination accuracy is further improved by the determination unit 156 determining the probability of heat stroke based on both the relationship with the estimated heart rate based on the deep body temperature and the ratio of low frequency components to high frequency components in the frequency spectrum of the heart rate fluctuation.

[0057] [Effects of heat stroke detection device 1] As described above, the heatstroke determination device 1 outputs alert information indicating a suspicion of heatstroke when the relationship between the actual measured heart rate and the estimated heart rate satisfies the first condition, and does not output alert information when the relationship between the actual measured heart rate and the estimated heart rate does not satisfy the first condition. In this way, the heatstroke determination device 1 determines the likelihood of heatstroke based on the relationship between the actual measured heart rate and the estimated heart rate, thereby preventing a heatstroke warning from being issued when the core body temperature is equal to or higher than a threshold value, even if the risk of heatstroke is low.

[0058] In addition, the heat stroke judgment device 1 judges the likelihood of heat stroke based on whether the frequency components of the heart rate fluctuations are more prevalent in the high frequency region or the low frequency region, based on the frequency spectrum of the heart rate fluctuations, which is the fluctuation of the measured heart rate. This also prevents a heat stroke warning from being issued when the core body temperature is above a threshold value, even though the risk of heat stroke is low.

[0059] In the above description, the heatstroke determination device 1 transmits millimeter wave radio waves to the subject U, and the heart rate determination unit 153 determines the actual heart rate of the subject U. However, the method by which the heart rate determination unit 153 determines the actual heart rate is not limited to this, and any method is possible. For example, the heart rate determination unit 153 may determine the actual heart rate based on data transmitted from a heart rate monitor worn by the subject U. In addition, the method by which the temperature determination unit 154 determines the deep body temperature is also arbitrary, and the deep body temperature of the subject U may be determined based on data transmitted from a thermometer capable of measuring deep body temperature.

[0060] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by distributing or integrating functionally or physically in any unit. In addition, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effect of the new embodiment resulting from the combination combines the effect of the original embodiment. [Explanation of symbols]

[0061] 1. Heat stroke detection device 2. Information terminal 11 Transmitter 12 Receiving section 13. Communications Department 14 Storage section 15 Control section 151 Instruction Reception Department 152 Radio Control Unit 153 Heart rate identification unit 154 Temperature identification section 155 Calculation Section 156 Judgment section 157 Spectral Identification Unit

Claims

1. A heart rate determination unit that identifies the actual heart rate of the subject, A temperature determination unit that identifies the core body temperature of the subject, A calculation unit that calculates an estimated heart rate based on the aforementioned core body temperature, A determination unit that determines whether or not there is a suspicion of heatstroke based on the relationship between the measured heart rate and the estimated heart rate, A heatstroke detection device having the following features.

2. The temperature determination unit determines the core body temperature based on a conversion formula that uses the surface body temperature of the subject measured by a body temperature sensor and the temperature of the space where the subject is located measured by a temperature sensor installed in the space as variables. The heatstroke detection device according to claim 1.

3. The temperature determination unit uses the highest body surface temperature among the body surface temperatures of multiple locations of the subject measured by the body temperature sensor as the variable in the conversion formula. The heatstroke detection device according to claim 2.

4. The temperature determination unit determines the core body temperature based on the following formula: Td=a2×Tsh 3 -b2×Tsh 2 +c2×Tsh−d Here, Td is the core body temperature, Tsh is the subject's surface temperature, and a2, b2, c2, and d are constants. The heatstroke detection device according to claim 1.

5. The calculation unit calculates the estimated heart rate by multiplying the core body temperature by a predetermined coefficient. The heatstroke detection device according to claim 1.

6. The calculation unit calculates the estimated heart rate by multiplying the core body temperature by a predetermined coefficient stored in the memory unit in association with the subject. The heatstroke detection device according to claim 5.

7. The calculation unit calculates the minimum value and the maximum value of the estimated heart rate. The determination unit determines that there is a suspicion of heatstroke if the measured heart rate does not fall between the minimum and maximum estimated heart rates. The heatstroke detection device according to claim 1.

8. The system further includes a spectrum identification unit that identifies the frequency spectrum of the heart rate variability, which is the amount of variation in the measured heart rate, based on a plurality of measured heart rates taken at different times. The determination unit determines that there is a suspicion of heatstroke if the second condition is met, which is that the ratio of the second component of the heart rate variability included in a second frequency band lower than the first frequency band to the first component of the heart rate variability included in the first frequency band is greater than or equal to a threshold. The heatstroke detection device according to claim 1.

9. A computer executes Steps to identify the subject's actual heart rate, The steps include identifying the core body temperature of the subject, A step of calculating an estimated heart rate based on the aforementioned core body temperature, A step of determining whether or not there is a suspicion of heatstroke based on the relationship between the measured heart rate and the estimated heart rate, A method for determining heatstroke.

10. On the computer, Steps to identify the subject's actual heart rate, The steps include identifying the core body temperature of the subject, A step of calculating an estimated heart rate based on the aforementioned core body temperature, A step of determining whether or not there is a suspicion of heatstroke based on the relationship between the measured heart rate and the estimated heart rate, A program to execute.

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