The present disclosure relates to a heat-stress effect estimating device, a heat-stress effect estimating method, and a computer program.
If a person is exposed to a heat stress for a long time or frequently and the amount of accumulated heat stress increases, a probability of occurrence of heatstroke, hypothermia, insomnia resulting from a sweltering night or the like, summer fatigue, fatigue due to a temperature difference, or the like increases.
In the related art, there has been proposed a system that estimates an amount of accumulated heat stress resulting from a heat environment, a work intensity, a work pattern, and the like by using a heat index (WBGT (Wet Bulb Globe Temperature)) as an index representing the heat stress and manages the heat stress (Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2009-518106).
In a first aspect of the present disclosure, a heat-stress effect estimating device is configured to estimate an effect of a heat stress imposed on a subject by an ambient temperature of the subject. The heat-stress effect estimating device includes a storage unit and a calculation unit. The storage unit is configured to store a correlation of at least an ambient temperature of a person and an outdoor air temperature with at least one index indicating an effect of a heat stress on a person. The calculation unit is configured to estimate a state of the subject in terms of the at least one index, based on the correlation stored in the storage unit, an ambient temperature of the subject at a predetermined time point, and a history of an outdoor air temperature up to the predetermined time point.
An embodiment of the present disclosure will be described below with reference to the drawings. Note that the embodiment below is a preferable example in essence and does not intend to limit the scope of the present invention and of the applications or uses thereof.
As a result of tests performed on subjects under various temperature-humidity environment conditions in winter and summer, the inventors of this application have found a temperature (hereinafter, may also be referred to as a boundary temperature of sleepiness) that serves as a boundary at which the subjects start feeling sleepiness and also have found that the boundary temperature of sleepiness varies with the season.
The heat stress reaction model illustrated in
Note that when the heat stress reaction model illustrated in
In addition, since the boundary temperature of sleepiness varies between individuals, a subject to which the heat stress reaction model illustrated in
In addition, the heat stress reaction model illustrated in
A model similar to the heat stress reaction model illustrated in
As illustrated in
The heat-stress effect estimating device (10) may include a room temperature measurement unit (13) that measures an ambient temperature of a subject, for example, a room temperature in a room where the subject is present. The heat-stress effect estimating device (10) may further include, in addition to the room temperature measurement unit (13), a function of measuring or inputting a humidity, a radiant heat, an air flow, or the like around the subject, or a metabolic rate, an amount of clothing, or the like of the subject. The heat-stress effect estimating device (10) may also include an outdoor air temperature measurement unit (14) that measures an outdoor air temperature. The heat-stress effect estimating device (10) may also include an environment information storage unit (15) that stores the room temperature measured by the room temperature measurement unit (13) and the outdoor air temperature measured by the outdoor air temperature measurement unit (14). The heat-stress effect estimating device (10) may also include a state estimation target period determination unit (16) that determines a target period (such as one month or one season, for example) in which the effect of the heat stress is to be estimated. When determining the target period, the state estimation target period determination unit (16) may set, as the target, only a specific time period (for example, a period of business hours) among 24 hours of the day.
The configuration described above enables the calculation unit (12) to use the room temperature and the outdoor air temperature stored in the environment information storage unit (15) to estimate a state of the subject in terms of the index in the predetermined period determined by the state estimation target period determination unit (16). In this case, the calculation unit (12) may calculate an average room temperature and an average outdoor air temperature of each day by using the room temperatures and the outdoor air temperatures stored in the environment information storage unit (15) and may store the calculation results in the environment information storage unit (15). The calculation unit (12) may use an operation history (a history of the set temperature) of an air conditioner, instead of the room temperatures stored in the environment information storage unit (15). The calculation unit (12) may use outdoor air temperature information acquired from Internet such as from the AMeDAS, instead of the outdoor air temperatures stored in the environment information storage unit (15).
The calculation unit (12) may estimate the state of the subject in terms of the index over the predetermined period and may calculate a cumulative frequency of the estimated state.
The calculation unit (12) may classify the estimated state in accordance with at least one of a degree of the state, a duration of the state, and an occurrence time of the state, and may calculate a cumulative frequency for each classification or create a histogram.
The calculation unit (12) may compare the estimated state with a state of a person prepared in advance in terms of the index on a per-health-condition basis and may estimate a health condition of the subject.
The heat-stress effect estimating device (10) may include a display unit (17) that displays the state of the subject estimated in terms of the index by the calculation unit (12) and/or secondary information obtained based on the state (for example, frequencies of various states (an awake state, a sleepy state, and so on) of the subject).
In a heat-stress effect estimating method using the heat-stress effect estimating device (10), a heat stress reaction model (“an effect of an ambient environment on a person”=F (an ambient temperature, an outdoor air temperature)) is created in advance in which the effect of the ambient (room) environment on the person is associated with ambient temperature information indicating a state of the ambient environment and with outdoor air temperature information for use in correction of an error caused by temperature adaptation characteristics of the person. In addition, ambient temperature (room temperature) data and outdoor air temperature data corresponding to the ambient temperature data are collected. By using these pieces of data and the heat stress reaction model (for example, a sleepiness model), ambient temperature information (room temperature information) is converted into the effect of the heat stress on the subject. Further, the effect, that is, frequencies of the various states (the awake state, the sleepy state, and so on) of the subject are visualized. That is, a temperature history experienced by the subject is converted into the effect of the heat stress on the subject, and the effect is visualized.
In the heat-stress effect estimating device (10), the room temperature measurement unit (13) may be a temperature sensor carried by the subject or temperature sensors installed at a plurality of places (such as a room, a public facility, and outdoors). In the latter case, the ambient temperature of the subject is calculated based on temperature history data measured by the temperature sensors installed at the plurality of places and movement history data of the subject. The movement history data of the subject may be stored in advance or may be set and input by the subject appropriately or in accordance with a schedule of that day. Alternatively, the movement history data of the subject may be obtained, for example, by sensing, with an occupancy sensor installed in each room, the presence state of the subject in the room and accumulating presence information of the subject. Methods for sensing the presence state include a method for recognizing/determining the subject through image recognition, an automatic detection method using a location detection technique of a mobile phone or the like, and so on. The movement history data of the subject is associated with the accumulated temperature history data for the plurality of places. This enables the ambient temperature of the subject at the predetermined time point to be known.
Note that the heat-stress effect estimating device (10) includes a computer such as a microcomputer. The computer executes a program, so that each of the functions such as the calculation unit (12), that is, the heat-stress effect estimating method according to the present embodiment is carried out. The computer includes, as a main hardware component, a processor that operates in accordance with the program. The processor may be any kind of processor that can implement the functions by executing the program. For example, the processor may be constituted by, for example, one or a plurality of electronic circuits including a semiconductor integrated circuit (IC) or an LSI (large scale integration). The plurality of electronic circuits may be integrated into one chip, or may be disposed on or in a plurality of chips. The plurality of chips may be put together in one device or may be included in a plurality of devices. The program is recorded on a non-transitory recording medium such as a computer-readable ROM, optical disc, or hard disk drive. The program may be stored on the recording medium in advance, or may be supplied to the recording medium via a wide area communication network including Internet or the like.
As the heat stress reaction model storage unit (11) and the environment information storage unit (15), a computer-readable-writable recording medium, for example, a RAM or the like may be used. The heat stress reaction model storage unit (11) and the environment information storage unit (15) may be constituted by the same recording medium. As the state estimation target period determination unit (16), for example, a keyboard, a mouse, a touchpad, or the like may be used. As the display unit (17), for example, a monitor capable of displaying an image, such as a CRT display or a liquid crystal display may be used.
A manner in which the heat-stress effect estimating device (10) is implemented is not limited but the heat-stress effect estimating device (10) may be implemented in a remote control of an air conditioner, for example. In this case, the heat stress reaction model storage unit (11), the calculation unit (12), the display unit (17), and the like may be constituted by a microcomputer, a memory, a touch panel, and so on of the remote control.
Each of
The states of the subject in terms of the indices used in the histograms illustrated in
Note that the manner of classification according to the “degrees”, the “durations”, or “the occurrence times” is not limited. As for the “degrees”, the classification may be performed by strength-weakness-indicating levels from 1 to 10, for example. As for the “durations”, the classification may be performed by 10 minutes, 30 minutes, 1 hour, 5 hours, and so on, for example. As for the “occurrence times”, the classification may be performed by morning, afternoon, and evening or may be by time periods such as 7:00-9:00, for example.
That is, an association between “frequency patterns of states of a person estimated in terms of various indices” and “a health condition of the person” is converted in advance into data such as a histogram of a healthy person (see
Histograms are not necessarily used in the above-described comparison of the state estimated in terms of the indices. That is, by comparing the history of each state of the subject in terms of the appropriately selected index with the histories of each state of the healthy person and the person in a presymptomatic state, the health condition of the subject can be determined.
As described above, if health information related to a thermal environment can be acquired, the diagnosis accuracy of an environment-related presymptomatic state such as, for example, a cold sensitivity can be increased by adding the health information to a conventional medical examination report.
If health information related to the thermal environment can be acquired, the health information can be used as basis data in a consulting service or the like for giving advice on the good way of use of the air conditioner.
A heat-stress effect estimating device (10) according to the present embodiment includes a storage unit (11) configured to store a correlation of at least an ambient temperature of a person and an outdoor air temperature with at least one index indicating an effect of a heat stress on a person, and a calculation unit (12) configured to estimate a state of a subject in terms of the at least one index, based on the correlation stored in the storage unit (11), an ambient temperature of the subject at a predetermined time point, and a history of an outdoor air temperature up to the predetermined time point. Thus, a correlation of an ambient temperature of a person and an outdoor air temperature with an index indicating an effect of a heat stress on a person is determined in advance. Based on the correlation, an ambient temperature of a subject, and a history of an outdoor air temperature, the state of the subject can be estimated in terms of the index. Thus, the effect of the heat stress can be easily estimated not only for a reaction caused in a person by the heat stress such as a likelihood of heatstroke but also for various reactions caused in the person by the heat stress such as wakefulness and fatigue through selectin of the index. Consequently, since it becomes easier to grasp the effect of the accumulated heat stress on health, for example, the effect of the accumulated heat stress can be made use of in prevention of the occurrence of a disease.
However, simply determining or visualizing frequencies of the ambient temperature of the subject, for example, the room temperature is not enough to use the frequencies in evaluation of an effect on health or the like because even at the same room temperature, the state of the subject or a suitable situation (scene) changes in accordance with the outdoor air temperature.
In contrast, the heat-stress effect estimating device (10) according to the present embodiment estimates various states (such as an awake state and a sleepy state, for example) of the subject from room temperature data measured by a room temperature sensor and outdoor air temperature data at that time by using a relational model formula (for example, a relational model formula of a boundary temperature of sleepiness) that represents an effect of a room environment on a person based on, for example, room temperature information that represents a state of the room environment and average air temperature information for use in correction of an error caused by temperature adaptation characteristics of the person. The heat-stress effect estimating device (10) according to the present embodiment visualizes the cumulative times or the like of the respective states in a predetermined period. For example, the relational model formula of the boundary temperature of sleepiness is obtained by converting, into a numerical formula, a relation between a room temperature serving as the boundary of sleepiness and an outdoor air temperature, based on a database acquired by performing tests on subjects under various temperature-humidity environment conditions.
If, for example, a graph that visualizes cumulative times of the respective states of the subject is created by using the heat-stress effect estimating device (10) according to the present embodiment, the health condition of the subject can be estimated by comparing the graph with a graph of a person having each health condition (such as a graph of a healthy person or a graph of a person in a presymptomatic state) created in advance based on the database. That is, whether the subject has been exposed to an unbalanced thermal environment, for example, whether the subject has been in an environment in which the sympathetic nerve is always dominant and the time when the subject gets sleepy is short or in an environment in which the time when the sympathetic nerve is dominant and the time when the parasympathetic nerve is dominant are well balanced can be easily checked.
If the heat-stress effect estimating device (10) according to the present embodiment is used, an environment-related health condition is known from, for example, room temperature information for a room environment where the subject is present or a history of a set temperature of an air conditioner. Thus, the room environment can be improved for the health of the subject. Whether the room environment is suitable for the purpose, for example, whether the room environment is a thermal environment for awaking and improving the workability in the daytime or whether the room environment is a thermal environment in which the parasympathetic nerve is dominant and sleepiness is slightly induced in the nighttime can be easily checked.
Note that the heat-stress effect estimating device (10) according to the present embodiment can more accurately estimate the effect of the heat stress if a converted temperature determined by taking into account at least one of an ambient humidity, an ambient radiant heat, an ambient air flow, a metabolic rate, and an amount of clothing of the subject is used as the ambient temperature of the subject.
The heat-stress effect estimating device (10) according to the present embodiment can also estimate the effect of the heat stress in terms of a degree of wakefulness or a degree of fatigue if the degree of wakefulness or the degree of fatigue is used as the index indicating the effect of the heat stress on the person.
The heat-stress effect estimating device (10) according to the present embodiment can also evaluate an amount of heat stress accumulated over a predetermined period if the state of the subject is estimated in terms of the index over the predetermined period and a cumulative frequency of the estimated state is calculated with the calculation unit (12).
The heat-stress effect estimating device (10) according to the present embodiment can also evaluate the effect of the heat stress from multiple perspectives if the estimated state is classified in accordance with at least one of the degree of the state, the duration of the state, and the occurrence time of the state and the cumulative frequency is calculated for each classification with the calculation unit (12).
The heat-stress effect estimating device (10) according to the present embodiment can easily measure the ambient temperature of the subject also when the subject moves if the ambient temperature of the subject is measured by a temperature sensor carried by the subject.
The heat-stress effect estimating device (10) according to the present embodiment can measure the ambient temperature of the subject also when the subject moves without carrying a temperature sensor if the ambient temperature of the subject is calculated based on temperature information measured by temperature sensors installed at a plurality of places and a movement history of the subject.
The heat-stress effect estimating device (10) according to the present embodiment can evaluate the effect of the heat stress in an easy-to-understand manner if the heat-stress effect estimating device (10) according to the present embodiment further includes a display unit (17) that displays the estimated state and/or secondary information obtained based on the state.
It becomes easier for the heat-stress effect estimating device (10) according to the present embodiment to accurately grasp the effect of the heat stress on health if the health condition of the subject is estimated by comparing the estimated state with a state of a person prepared in advance in terms of the index on a per-health-condition basis with the calculation unit (12). Thus, the estimated state can be made use of in prevention of the occurrence of a disease.
Differences of a heat-stress effect estimating device (10A) according to the present modification from the heat-stress effect estimating device (10) according to the embodiment illustrated in
The correction input unit (21) is used by a subject to whom the heat stress reaction model is applied to input a setting for correcting the model in accordance with their preference. The subject can correct, for example, the boundary temperature through the correction input unit (21).
The subject attribute information input unit (22) is used by the subject to whom the heat stress reaction model is applied to input their attribute information. The subject can input, for example, their gender, age, metabolic rate, body fat percentage, blood pressure, or the like through the subject attribute information input unit (22).
As the correction input unit (21) and the subject attribute information input unit (22), for example, a keyboard, a mouse, a touchpad, or the like may be used.
The heat stress reaction model correction unit (23) corrects the heat stress reaction model stored in the heat stress reaction model storage unit (11), based on content input to the correction input unit (21) or the subject attribute information input unit (22). When the subject attribute information input unit (22) is used, a plurality of heat stress reaction models may be prepared for different pieces of attribute information and may be stored in the heat stress reaction model storage unit (11) in advance, and from among the plurality of heat stress reaction models, the heat stress reaction model correction unit (23) may select one model in accordance with the content input to the subject attribute information input unit (22). Note that the heat stress reaction model correction unit (23) may be configured to be integral with the calculation unit (12).
The heat-stress effect estimating device (10A) according to the present modification can correct the heat stress reaction model (correlation) stored in the storage unit (11), based on a setting input by the subject or the attribute information of the subject by using the correction input unit (21), the subject attribute information input unit (22), and the heat stress reaction model correction unit (23). Thus, the effect of the heat stress can be estimated by taking into account a difference between individuals.
In the embodiment (including the modification) described above, the state of the subject is estimated in terms of the index using the heat stress reaction model, based on the ambient temperature of the subject and the history of the outdoor air temperature. To remove a factor not related to a thermal environment such as a psychological factor from history information of the estimated state, the subject may be caused to carry a sensor for measuring sweating, pulse waves, an electrocardiogram, or the like to acquire physiological information.
In the embodiment (including the modification) described above, the heat stress reaction model is created by using sleepiness (a degree of wakefulness) or fatigue (a degree of fatigue) as the effect of the heat stress caused by the ambient temperature on a person. However, the effect of the heat stress caused by the ambient temperature on a person is not limited, and the heat stress reaction model may be created by using, for example, a degree of enthusiasm (motivation), a degree of irritation, a degree of relaxing, or the like in addition to the degree of wakefulness and the degree of fatigue.
While the embodiment and modification have been described above, it should be understood that various modifications can be made on the configurations and details without departing from the gist and the scope of the claims. The embodiment, the modification, and the other embodiments described above may be combined or replaced as appropriate as long as the functionality of the target of the present disclosure is not reduced.
The present disclosure is useful for a heat-stress effect estimating device and a heat-stress effect estimating method.
Number | Date | Country | Kind |
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2019-093363 | May 2019 | JP | national |
This is a continuation of International Application No. PCT/JP2020/019558 filed on May 15, 2020, which claims priority to Japanese Patent Application No. 2019-093363, filed on May 17, 2019. The entire disclosures of these applications are incorporated by reference herein.
Number | Date | Country | |
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Parent | PCT/JP2020/019558 | May 2020 | US |
Child | 17527988 | US |