Fatigue level estimation system, fatigue level estimation method, and program

Abstract

A fatigue level estimation system (100) according to the present invention is for estimating the fatigue level of a user (99) and comprises: an acquisition unit (20) that acquires an expected future hours of sleep by the user (99); a fatigue level estimation unit (10) that estimates a change in the fatigue level of the user (99); and a presentation unit (60) that presents the estimated change in the fatigue level of the user (99), wherein the fatigue level estimation unit (10) has a recovery calculation unit (11) that calculates the fatigue level recovered according to the hours of sleep, and causes the recovery calculation unit (11) to calculate the fatigue level to be recovered by using the acquired expected future hours of sleep as the hours of sleep, and the change in the fatigue level of the user (99) includes a fatigue level to be recovered in the future, as calculated for the expected hours of sleep.

Description

Fatigue level estimation system, fatigue level estimation method, and program

[0001] The present disclosure relates to a fatigue level estimation system, a fatigue level estimation method, and a program.

[0002] There has been a need for estimating a person's fatigue level. For example, if a user working can know his or her own fatigue level, it can be useful information for dealing with the fatigue level, such as taking a rest at an appropriate time. Meanwhile, one concept of fatigue is fatigue that accumulates daily due to continuous work, etc. (also known as subacute fatigue or diurnal fatigue). Such fatigue is estimated based on the amount of fatigue accumulated daily and how well the user is getting sleep to recover from the fatigue. Patent Document 1 discloses, as an example of a fatigue monitoring and management system that handles such daily accumulated fatigue, a system that generates an assessment of a user's fatigue state in one or more processors, etc., based on data from one or more data sources, such as a non-intrusive sleep sensor, configured to generate an objective sleep measure for the user.

[0003] International Publication No. 2015 / 054134

[0004] However, conventional fatigue level estimation systems and the like may not present a fatigue level appropriately for a user to sleep appropriately while considering the balance between fatigue accumulation and recovery. Therefore, the present disclosure provides a fatigue level estimation system and the like that presents a more appropriate fatigue level.

[0005] In order to solve the above problem, a fatigue estimation system according to one embodiment of the present disclosure is a fatigue estimation system that estimates a user's fatigue level, and includes an acquisition unit that acquires the user's future planned sleep time, a fatigue estimation unit that estimates a change in the user's fatigue level, and a presentation unit that presents the estimated change in the user's fatigue level, wherein the fatigue estimation unit has a recovery calculation unit that calculates a fatigue level to be recovered according to sleep time, and causes the recovery calculation unit to calculate a fatigue level to be recovered using the acquired planned sleep time as the sleep time, and the change in the user's fatigue level includes a future fatigue level to be recovered calculated for the planned sleep time.

[0006] Furthermore, a fatigue level estimation method according to one aspect of the present disclosure is a fatigue level estimation method that is executed by a computer and estimates a user's fatigue level, and includes the steps of acquiring the user's future planned sleep time, estimating a change in the user's fatigue level, and presenting the estimated change in the user's fatigue level, wherein the estimating step calculates a fatigue level to be recovered based on sleep time, and calculates the fatigue level to be recovered using the acquired planned sleep time as the sleep time, and the change in the user's fatigue level includes a future fatigue level to be recovered calculated for the planned sleep time.

[0007] Furthermore, one aspect of the present disclosure can be realized as a program for causing a computer to execute the fatigue level estimation method, or as a computer-readable recording medium storing the program.

[0008] According to the present disclosure, a more appropriate fatigue level can be presented.

[0009] Fig. 1 is a block diagram showing the functional configuration of a fatigue level estimation system according to an embodiment. Fig. 2 is a diagram for explaining fatigue level estimation according to an embodiment. Fig. 3 is a diagram for explaining fatigue level estimation according to an embodiment. Fig. 4 is a diagram for explaining fatigue level estimation according to an embodiment. Fig. 5 is a flowchart showing a fatigue level estimation method according to an embodiment. Fig. 6 is a diagram for explaining an example of presentation of the results of fatigue level estimation according to an embodiment. Fig. 7 is a diagram for explaining another example of presentation of the results of fatigue level estimation according to an embodiment.

[0010] (Knowledge that led to the present disclosure) As described in Patent Document 1, there has been a need for estimating a person's fatigue level, particularly the fatigue level of fatigue accumulated over a medium period, also known as subacute fatigue or diurnal fatigue, and various technological developments have been underway. In such estimations, although the recovery from fatigue is particularly important, generally, only the recovery results are presented. From the user's perspective, many users want to know how to sleep to achieve a balance in fatigue levels (a balance between accumulation and recovery), but it may not be possible to estimate and present a fatigue level from the perspective of how to sleep in the future. Therefore, this disclosure describes a fatigue level estimation system and the like that can present how a user's fatigue level will change depending on their future sleep.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the embodiments described below all show comprehensive or specific examples of the present disclosure. Therefore, the numerical values, components, the arrangement and connection of the components, steps, and the order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, components that are not described in the independent claims of the present disclosure will be described as optional components.

[0012] Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, the scales and the like do not necessarily match in each figure. In each figure, the same reference numerals are used to denote substantially the same components, and redundant explanations will be omitted or simplified.

[0013] (Embodiment) [Configuration of Fatigue Level Estimation System] First, the functional configuration of a fatigue level estimation system 100 according to this embodiment will be described in detail with reference to Fig. 1. Fig. 1 is a block diagram showing the functional configuration of a fatigue level estimation system according to this embodiment.

[0014] 1 , the fatigue level estimation system 100 according to the present embodiment includes a fatigue level estimation unit 10, an acquisition unit 20, a reference acquisition unit 30, an information acquisition unit 40, a sleep time estimation unit 50, and a presentation unit 60. These components constituting the fatigue level estimation system 100 may be integrated into a single housing or the like, or may be realized as multiple individual devices connected to each other via a communication line. The fatigue level estimation system 100 is realized by a computer including a presentation device such as a smartphone, PC, or tablet terminal, and including a processor, a memory, and a program executed using these.

[0015] The fatigue level estimation unit 10 includes a recovery calculation unit 11, an accumulation calculation unit 12, and an output unit 13. The fatigue level estimation unit 10 is installed in the fatigue level estimation system 100 as one of its functions, for example.

[0016] The recovery calculation unit 11 is a function that calculates the degree of fatigue recovered according to the sleep duration (hereinafter also simply referred to as the recovery fatigue degree). The recovery calculation unit 11 calculates the degree of fatigue recovered according to, for example, the input sleep duration. If the user 99's planned future sleep duration is input to the recovery calculation unit 11, the degree of fatigue recovered by the user 99's future sleep can be calculated. The recovery calculation unit 11 has, for example, multiple data tables and calculates the degree of fatigue recovered by referring to the data tables. Figure 2 is a diagram for explaining fatigue degree estimation according to the embodiment. Figure 2 shows an example of multiple data tables.

[0017] As shown in FIG. 2 , the data table indicates the degree of fatigue recovery (fatigue recovery level) for each hour of sleep. The figure shows that a sleep duration longer than 5 hours but shorter than 6 hours results in a fatigue recovery of 60 (fatigue level minus 60). The data table may be prepared, for example, for each age group, or may be prepared for each attribute value of the other user 99 attributes. For example, even for the same sleep duration, the younger the age, the higher the fatigue recovery level, and the older the age, the lower the fatigue recovery level. Furthermore, even for the same sleep duration, the gender of the user 99 may be set to have a lower fatigue recovery level, and the gender of the user 99 may be set to have a higher fatigue recovery level. The attributes of the user 99, including age, will be described later. In this way, the recovery calculation unit 11 calculates the fatigue recovery level according to the sleep duration based on information other than the sleep duration. The recovery calculation unit 11 may use the data table as described above, or may perform inference using a trained model, or may calculate the fatigue recovery level from the input sleep duration using a predetermined arithmetic formula.

[0018] The accumulation calculation unit 12 is a function that calculates the fatigue level accumulated from a reference time point to a future sleep of the user 99 (hereinafter simply referred to as accumulated fatigue level). The accumulation calculation unit 12 calculates the fatigue level of the user 99 based on information including at least one of the attributes of the user 99, the physiological values ​​of the user 99, and the context information of the user 99. The calculation period calculated by the accumulation calculation unit 12 is from the reference time point to a time point when the accumulation of the user 99's fatigue level is expected to end (e.g., the end of work). The reference time point is, for example, the time when the user 99's sleep ends (e.g., a predetermined time in the morning). In this embodiment, the fatigue level estimation system 100 estimates the fatigue level for each reference time point each day by summing the yesterday's fatigue level remaining at the reference time point, the fatigue level accumulated until future sleep (until going to bed that day, i.e., the most recent sleep), and the fatigue level recovered by subsequent sleep. Therefore, the fatigue level at the reference point can be the total value obtained by adding up the fatigue level at the reference point yesterday (past), the fatigue level accumulated up until the user slept yesterday (past), and the fatigue level recovered by sleeping yesterday (past).

[0019] The fatigue level estimation system 100 is useful because it allows the user 99 to determine how to sleep in the future by receiving a presentation of changes in fatigue level at each reference time point. The accumulation calculation unit 12, for example, has multiple data tables and calculates the fatigue level to be recovered by referring to the data tables. FIG. 3 is a diagram for explaining fatigue level estimation according to an embodiment. FIG. 3 shows an example of multiple data tables. The data table in the figure shows a table in which the correlation between physiological amounts and context information is discretized. Specifically, FIG. 3 shows the correlation between the integrated value of LF / HF as a physiological amount and the step count as context information. It is known that the LF / HF value is low in a state of low stress (fatigue level is unlikely to increase) and high in a state of high stress (fatigue level is likely to increase). The figure shows that when the step count is more than 4,000 steps but less than 7,000 steps, if the integrated value of LF / HF is more than 30 but less than 40, a fatigue level of 50 is accumulated (fatigue level is increased by 50).

[0020] The data table may be prepared for each age group, or may be prepared for each attribute value for each of the other attributes of the user 99. For example, even if the sleep time is the same, the accumulated fatigue level may be lower for younger users and higher for older users. Furthermore, even if the sleep time is the same, the accumulated fatigue level may be higher for female users and lower for male users. The attributes of the user 99, including age, will be described later. In this manner, the accumulation calculation unit 12 calculates the accumulated fatigue level based on information (including attributes, physiological values, context information, etc.). The accumulation calculation unit 12 may use a data table as described above, or may perform inference using a trained model, or may calculate the accumulated fatigue level from input information (including attributes, physiological values, context information, etc.) using a predetermined arithmetic formula.

[0021] The output unit 13 has a function of calculating the sum of the calculated recovery fatigue level, the calculated accumulated fatigue level, and the fatigue level at the reference point, and outputting this as the change in fatigue level, which is the estimation result of the fatigue level estimation unit 10. The change in fatigue level output here means the change between the fatigue level at the reference point and the total fatigue level. In other words, the change in fatigue level indicates how the total fatigue level was reached from the fatigue level at the reference point through the accumulation and recovery of fatigue levels.

[0022] The acquisition unit 20 is a functional unit that acquires the planned sleep time of the user 99. The acquisition unit 20 may acquire the planned sleep time input by the user 99 to the fatigue level estimation system 100, may acquire the user 99's average planned sleep time, or may acquire multiple candidates for the planned sleep time to recommend to the user 99. For example, the acquisition unit 20 estimates the planned sleep time for the immediate future sleep from the average actual sleep time of the user 99 over a predetermined number of past days (e.g., 1 day, 2 days, 3 days, 5 days, 7 days, or 30 days). When estimating the planned sleep time, the predetermined number of past days may be changed taking into account attributes of the day, such as the day of the week or a public holiday, or days that fall within the predetermined number of past days may be set to be excluded. Note that the acquisition unit 20 may acquire the average sleep time of people of the same age as the planned sleep time.

[0023] Alternatively, the acquisition unit 20 may acquire, by calculation, a first time, a second time longer than the first time, and a third time longer than the second time as the expected sleep time. For example, the second time is a length of time in which the future fatigue level calculated for the second time offsets the fatigue level accumulated until the user's future sleep. Note that "fatigue levels are offset" means that the fatigue level subtracted by recovery matches the fatigue level added by accumulation. Therefore, in this case, the fatigue level at the reference point of the day (this morning) and the fatigue level at the reference point of tomorrow morning match.

[0024] For example, the third time period is a time period in which the calculated future recovery level for the third time period is offset by the sum of the fatigue level at the reference time point and the fatigue level accumulated until the user's future sleep. Therefore, in this case, the fatigue level at the reference time point tomorrow morning will be zero.

[0025] Furthermore, for example, the first time period is the length of time at which the fatigue level difference, calculated by subtracting the future fatigue level calculated for the first time period from the sum of the fatigue level at the reference time point and the fatigue level accumulated until the user's future sleep, reaches a predetermined threshold. This fatigue level difference corresponds to the fatigue level at the reference time point tomorrow morning. The predetermined threshold is set to a fatigue level that requires attention from the perspective of the user 99's health. The health level that requires attention is a level at which there is a high possibility of some kind of problem occurring if the accumulated fatigue continues and the user continues to perform activities the next day. One example of such a level is an accumulated level of fatigue that is accompanied by a weakened immune system that is likely to lead to the development of an opportunistic infection (such as a herpes virus infection).

[0026] The reference acquisition unit 40 is a functional unit that acquires the fatigue level at a reference time point. The reference acquisition unit 40 acquires the fatigue level at the reference time point by, for example, accessing a storage unit (not shown) that stores the fatigue levels at the reference time point for the past few days.

[0027] The information acquisition unit 40 is a functional unit that acquires information including attributes, physiological quantities, context information, etc. The information acquisition unit 40 is connected via a communication module to each module corresponding to the information, such as an input device and a memory unit for acquiring attributes, a sensor module and a calculation unit (processor, etc.) for acquiring physiological quantities, and a sensor module and a calculation unit (processor, etc.) for acquiring context information.

[0028] The physiological quantity is the result of sensing or the like and is an actual measurement value used to calculate the fatigue level. The physiological quantity includes, for example, an electrocardiogram, sweat rate, skin temperature, pupil diameter, etc. For example, when LF / HF is calculated from the RR interval of an electrocardiogram as the physiological quantity and an LF / HF integrated value is acquired by integrating this value, the information acquisition unit 40 is connected to an electrocardiograph and a calculation unit, calculates LF / HF from the RR interval, and acquires the LF / HF integrated value. Furthermore, the context information is information that provides a background interpretation for calculating the fatigue level to the results of sensing or the like and is an actual measurement value. The context information includes information on the user's exercise, activity, and surrounding environment, such as the number of steps, activity amount, season, date and time, and ambient temperature. For example, when a step count is acquired as context information, the information acquisition unit 40 is connected to an acceleration sensor, a GPS receiver, and a calculation unit, calculates the number of steps, and acquires the total step count for that day.

[0029] In addition, the information acquisition unit 40 may acquire, for example, the amount of sweating, skin temperature, pupil diameter, etc. The amount of sweating can be measured using a moisture sensor worn by the user 99. The amount of sweating increases when the user is under stress. Skin temperature can be measured using a thermal image sensor that captures an image of the user 99 to determine the nose skin temperature and forehead skin temperature, and the level of stress can be calculated from the difference between the nose skin temperature and the full body skin temperature. When the user is under stress, the nose skin temperature decreases relatively. Pupil diameter can be measured using a visible image sensor that captures an image of the user 99. It is known that pupil diameter constricts when the user is under stress. The information acquisition unit 40 may also acquire activity level, season, date and time, ambient temperature, etc. Similar to the number of steps, fatigue can be quantified from the amount of activity. Since people are less likely to get tired in a comfortable environment around 20°C and more likely to get tired at ambient temperatures above 30°C, using the season, date and time, ambient temperature, etc. allows for more accurate quantification.

[0030] The sleep time estimation unit 50 is a functional unit that acquires the charging time of a mobile device (e.g., a smartphone) owned by the user 99 and estimates the user's actual sleep time based on the acquired charging time. The sleep time estimation unit 50 estimates the user's actual sleep time based on the charging start and end times. FIG. 4 is a diagram for explaining fatigue level estimation according to an embodiment. FIG. 4 shows the transition of the charge amount of the mobile device of the user 99 over a portion of one day. As shown in FIG. 4, the charge amount of the mobile device starts to increase after 11:00 PM and reaches 100% within a few hours. The point at which this increase in charge amount begins, i.e., the start time of charging the mobile device, is close to the user's bedtime. The time at which the charge amount of the mobile device starts to increase can be determined as the sleep start time.

[0031] 4, the charge level of the mobile terminal begins to decrease at 6:00. The point at which this decrease in charge level begins, i.e., the time at which charging of the mobile terminal ends, is close to the wake-up time of the user 99. The time at which the charge level of the mobile terminal begins to decrease can be regarded as the wake-up time. By using the bedtime and wake-up time, it is possible to estimate the actual sleep time of the user 99. This allows for a simple and relatively accurate sleep time estimation without using a dedicated tracking device.

[0032] Note that since the user 99 may not have gone to bed yet even when the charge amount starts to increase, the actual sleep time may be obtained by subtracting the time difference (for example, 30 minutes) until the user actually goes to bed.

[0033] This time difference may be set based on attribute information such as age and gender. The attribute information may be information indicating, for example, the user 99's age, gender, place of residence, family structure, and occupation. The time difference until the user 99 actually goes to bed may be a long time difference, such as one hour, for a young user in their teens or twenties. The time difference until the user 99 actually goes to bed may also be changed depending on the time at which the charge amount starts to increase. For example, if the charge amount starts to increase before 8:00 PM, a longer time difference, such as 1.5 hours, may be set. The threshold time of 8:00 PM may also be set (changed) based on the sunset time in the user 99's place of residence. Furthermore, if the user 99 has the attribute of being a parent with children, the user 99 is likely to go to bed immediately after starting to charge the mobile device, and the time difference (time difference) until the user 99 actually goes to bed may be set to zero. Furthermore, if the user 99 has the attribute of being a parent with children, the user 99 is likely to go to bed immediately after starting to charge the mobile device, and the time difference (time difference) until the user 99 actually goes to bed may be set to zero.

[0034] The actual sleep time is used to ensure the fatigue level at a reference point. Specifically, by inputting the acquired actual sleep time into the recovery calculation unit 11, the fatigue level recovered during that actual sleep time can be calculated. This recovery fatigue level is accurate because it is based on the actual sleep time. In other words, instead of calculating the fatigue level at a reference point based on an uncertain sleep time such as a planned sleep time, the fatigue level at a past reference point is calculated using a recovery fatigue level based on the more accurate actual sleep time. Since the fatigue level can be presented as a change from the accurate reference point, the fatigue level estimation system 100 can present an accurate fatigue level. Note that the mobile device may be a computer in which the fatigue level estimation system 100 is installed.

[0035] The presentation unit 60 is a functional unit that presents the change in fatigue level as an estimation result to, for example, a mobile terminal (for example, a smartphone) owned by the user 99. A specific example of presentation by the presentation unit 60 will be described later.

[0036] [Operation of the Fatigue Level Estimation System] Next, the operation of the fatigue level estimation system 100 will be described with reference to FIGS. 5 to 7. FIG. 5 is a flowchart illustrating a fatigue level estimation method according to an embodiment. As shown in FIG. 5, when the operation of the fatigue level estimation system 100 is started, the reference acquisition unit 30 acquires the fatigue level at the most recent reference point in the past (step S101). Then, the accumulation calculation unit 12 calculates the fatigue level accumulated thereafter based on the acquired information (step S102). Meanwhile, the acquisition unit 20 acquires the planned sleep time (step S103). Then, the recovery calculation unit 11 calculates the future fatigue level to be recovered from the acquired planned sleep time (step S104). Then, the output unit 13 calculates and outputs the sum, thereby outputting the change in fatigue level as the estimation result of the fatigue level estimation unit 10. The presentation unit 60 presents the change in fatigue level of the user 99 (step S105). FIG. 6 is a diagram illustrating an example of the presentation of the fatigue level estimation result according to an embodiment.

[0037] FIG. 6 shows an example of the display provided by the display unit 60. As shown in FIG. 6 , the fatigue level estimation system 100 outputs and displays changes in fatigue level for three planned sleep times: Hour 1, Hour 2, and Hour 3 (Hour 1 < Hour 2 < Hour 3) (as indicated by dashed arrows in the figure). As described above, these three time periods include a sleep duration (Hour 2) long enough to maintain the fatigue level at the reference point this morning, a sleep duration (Hour 3) long enough to reduce the fatigue level to zero, including the fatigue level at the reference point this morning, and a sleep duration (Hour 1) long enough to achieve a level of fatigue requiring health care. These sleep durations are simultaneously displayed as shown in the figure, allowing the user 99 to appropriately balance the accumulation and recovery of fatigue levels while taking into account the amount of time they can devote to sleep. As shown in the figure, a face icon whose facial expression changes in conjunction with the fatigue level (the lower the fatigue level, the better the facial expression; the higher the fatigue level, the worse the facial expression) may also be displayed to make the level of fatigue easier to understand. The face icon for the first hour may indicate what health precautions are expected (such as a "Herpes Alert" in the figure), and may also indicate past changes in fatigue level (as indicated by solid arrows in the figure).

[0038] On the other hand, Fig. 7 is a diagram illustrating another example of presentation of the results of fatigue level estimation according to the embodiment. Fig. 6 shows another presentation example presented by the presentation unit 60. As shown in Fig. 6, the fatigue level estimation system 100 can also be set to acquire a single time period (such as an average sleep time) as the planned sleep time. In this case, the fatigue level estimation system 100 outputs and presents a single estimated change in fatigue level for that time period, as shown in Fig. 7.

[0039] [Effects, etc.] As described above, the fatigue level estimation system 100 according to the first embodiment of the present invention is a fatigue level estimation system 100 that estimates the fatigue level of a user 99, and includes an acquisition unit 20 that acquires the user 99's future planned sleep time, a fatigue level estimation unit 10 that estimates changes in the user 99's fatigue level, and a presentation unit 60 that presents the estimated changes in the user 99's fatigue level. The fatigue level estimation unit 10 has a recovery calculation unit 11 that calculates the fatigue level to be recovered according to the sleep time, and causes the recovery calculation unit 11 to calculate the fatigue level to be recovered using the acquired planned sleep time as the sleep time. The change in the user 99's fatigue level includes the fatigue level to be recovered in the future, calculated for the planned sleep time.

[0040] Such a fatigue level estimation system 100 can present changes in the estimated fatigue level of the user 99. The changes in fatigue level can include the fatigue level that would be recovered if the user 99 were to sleep for the planned sleep time, which is the sleep time of the sleep that the user plans to have in the future. As a result, the user 99 can recognize how their own fatigue level will change, including future sleep, and the user 99 can easily take sleep that corresponds to the level of fatigue they want to recover from, while considering the balance between fatigue accumulation and recovery. Therefore, a more appropriate fatigue level can be presented.

[0041] Furthermore, the fatigue level estimation system 100 according to the second aspect of this embodiment is the fatigue level estimation system 100 according to the first aspect, in which the acquisition unit 20 acquires a first time, a second time longer than the first time, and a third time longer than the second time as the planned sleep times, the fatigue level estimation unit 10 uses the acquired first time, second time, and third time as sleep times, respectively, and causes the recovery calculation unit 11 to calculate the degree of fatigue to be recovered, and the presentation unit 60 simultaneously presents changes in the fatigue level of the user 99, including the degree of fatigue to be recovered in the future calculated for the first time, the degree of fatigue to be recovered in the future calculated for the second time, and the degree of fatigue to be recovered in the future calculated for the third time.

[0042] This makes it possible to present changes in the user's 99 fatigue level, including the level of fatigue recovered when the user sleeps for each of the different lengths of first, second, and third hours. By selecting either the first, second, or third hours, or an intermediate length between any combination of these three lengths, the user 99 can easily sleep in a way that matches the level of fatigue they want to recover from while considering the balance between fatigue accumulation and recovery. This makes it possible to present a more appropriate level of fatigue.

[0043] Furthermore, the fatigue level estimation system 100 according to the third aspect of this embodiment is the fatigue level estimation system 100 according to the first or second aspect, and includes a reference acquisition unit 30 that acquires the fatigue level of the user 99 at a reference point in time, and the fatigue level estimation unit 10 further includes an accumulation calculation unit 12 that calculates the fatigue level accumulated from the reference point in time until the user 99's future sleep, and the change in the fatigue level of the user 99 includes the fatigue level of the user 99 at the reference point in time, the fatigue level accumulated until the user 99's future sleep, and the fatigue level of future recovery calculated for the planned sleep time.

[0044] This makes it possible to present changes in fatigue level including the fatigue level already accumulated in the user 99 at the reference time point, the fatigue level accumulated from the reference time point until the user 99 sleeps, and the fatigue level that is expected to be recovered by future sleep. The more accurate the fatigue level already accumulated at the reference time point and the fatigue level accumulated from the reference time point until the user sleeps, the more accurate the presented changes in fatigue level will be, and therefore a more appropriate fatigue level can be presented.

[0045] Furthermore, the fatigue level estimation system 100 according to the fourth aspect of the present embodiment is the fatigue level estimation system 100 according to the third aspect, and includes a sleep time estimation unit 50 that estimates the actual sleep time of the user 99 based on the charging time of the mobile device owned by the user 99, and the fatigue level estimation unit 10 causes the recovery calculation unit 11 to calculate the degree of fatigue to be recovered using the estimated actual sleep time as the sleep time, and the fatigue level at the reference point is the sum of the fatigue level at a past reference point, the fatigue level accumulated up to the time the user 99 slept in the past, and the recovered fatigue level calculated for the actual sleep time.

[0046] This makes it possible to estimate the actual sleep time, which is the actual value of the user's 99 past sleep time. By using the charging time of the mobile device owned by the user 99 to estimate the actual sleep time, the actual sleep time can be estimated by the daily action of charging the mobile device, without the user 99 having to install a tracking device (such as a wearable sensor) or a sleep evaluation app. The fatigue level that is considered to have actually recovered can be calculated based on this actual sleep time. In other words, the recovered fatigue level can be calculated more accurately. Calculating the fatigue level at the reference point using a more accurate value makes the subsequent estimated change in fatigue level more accurate, and therefore a more appropriate fatigue level can be presented.

[0047] Furthermore, the fatigue level estimation system 100 according to the fifth aspect of the present embodiment is the fatigue level estimation system 100 according to the third or fourth aspect, and includes an information acquisition unit 40 that acquires information including at least one of physiological values ​​and context information of the user 99, and the accumulation calculation unit 12 calculates the fatigue level accumulated according to the sleep time based on the acquired information as well.

[0048] According to this, the accumulation calculation unit 12 can calculate the accumulated fatigue level based on at least one of the physiological values ​​and context information of the user 99 included in the acquired information. The physiological values ​​are the results of sensing, etc., and are actual measured values ​​used to calculate the fatigue level. The context information is information that adds a background interpretation to the results of sensing, etc., for calculating the fatigue level, and is an actual measured value. By using such actual measured values ​​related to the accumulated fatigue level, the accumulated fatigue level can be calculated more accurately. If such actual measured values ​​are not used, it is necessary to calculate the accumulated fatigue level based on the elapsed time from the reference point and rules of thumb, which may lack reliability. However, using actual measured values ​​to obtain a more accurate accumulated fatigue level makes the subsequent estimated change in fatigue level more accurate, and therefore a more appropriate fatigue level can be presented.

[0049] Furthermore, the fatigue level estimation system 100 according to the sixth aspect of this embodiment is the fatigue level estimation system 100 according to the third aspect that references the second aspect, or the fourth or fifth aspect that references the second and third aspects, and the second time period is a length of time that offsets the future fatigue level calculated for the second time period and the fatigue level accumulated until the user 99 sleeps in the future.

[0050] This makes it possible to present changes in the user 99's fatigue level, including the level of fatigue that will be recovered if the user 99 sleeps for a length of time that offsets the future level of fatigue that will be recovered calculated for the second time period and the level of fatigue accumulated until the user 99's future sleep. Because the level of fatigue that will be recovered is offset by the accumulated level of fatigue, the user 99 can essentially understand how much sleep time is needed to maintain the user 99's fatigue level at the reference point in time. This makes it easier for the user 99 to sleep in a way that matches the level of fatigue that they want to recover from, while considering the balance between accumulated fatigue and recovery. Therefore, a more appropriate level of fatigue can be presented.

[0051] Furthermore, the fatigue level estimation system 100 according to the seventh aspect of this embodiment is a fatigue level estimation system 100 according to the third aspect that references the second aspect, or any one of the fourth to sixth aspects that reference the second and third aspects, in which the third time period is a length of time that offsets the future fatigue level calculated for the third time period with the sum of the fatigue level at the reference time point and the fatigue level accumulated until the user 99 sleeps in the future.

[0052] This makes it possible to present changes in the user 99's fatigue level, including the level of fatigue that will be recovered if the user sleeps for a length of time that offsets the future fatigue level calculated for the third hour with the sum of the fatigue level at the reference time and the accumulated fatigue level up until the user's future sleep. Because the recovered fatigue level is offset by the fatigue level at the reference time and the sum of the accumulated fatigue level, the user 99 can essentially understand how much sleep time is needed to reduce the user 99's fatigue level to zero. This makes it easier for the user 99 to sleep in a way that matches the level of fatigue they want to recover from, while considering the balance between accumulated fatigue and recovery. Therefore, a more appropriate level of fatigue can be presented.

[0053] Furthermore, the fatigue level estimation system 100 according to the eighth aspect of this embodiment is a fatigue level estimation system 100 according to the third aspect that references the second aspect, or any one of the fourth to seventh aspects that reference the second and third aspects, in which the first time period is the length of time required for the fatigue level difference, calculated by subtracting the future fatigue level calculated for the first time period from the sum of the fatigue level at the reference time point and the fatigue level accumulated until the user 99's future sleep, to reach a predetermined threshold value.

[0054] This allows the display of changes in the user's fatigue level, including the level of fatigue recovery that would occur if the user 99 were to sleep for a length of time such that the difference in fatigue level, calculated by subtracting the future fatigue level calculated for the first hour from the total of the user's fatigue level at the reference point and the accumulated fatigue level up until the user's future sleep, reaches a predetermined threshold. The user 99 can grasp the required length of sleep time before the difference in fatigue level between the reference point's fatigue level and the total accumulated fatigue level reaches the predetermined threshold, even when taking into account the fatigue level of recovery. This makes it easier for the user 99 to sleep in a way that matches the desired level of fatigue recovery while considering the balance between accumulated fatigue and recovery. This allows for a more appropriate display of fatigue levels.

[0055] Furthermore, the fatigue level estimation system 100 according to the ninth aspect of this embodiment is the fatigue level estimation system 100 described in the first aspect, and includes an information acquisition unit 40 that acquires information including at least one of physiological values ​​and context information of the user 99, and the recovery calculation unit 11 calculates the degree of fatigue recovery according to the sleep time based on the acquired information as well.

[0056] This allows the recovery calculation unit 11 to calculate the accumulated fatigue level based on at least one of the physiological values ​​and context information of the user 99 included in the acquired information. The physiological values ​​are the results of sensing, etc., and are actual measured values ​​used to calculate the fatigue level. The context information is information that adds a background interpretation to the results of sensing, etc., for calculating the fatigue level, and is an actual measured value. By using such actual measured values ​​related to the accumulated fatigue level, it is possible to more accurately calculate the fatigue level to be recovered. If such actual measured values ​​are not used, it is necessary to calculate the fatigue level to be recovered based on sleep time and empirical rules, etc., which may lack reliability. However, using actual measured values ​​to more accurately estimate the change in fatigue level, and therefore it is possible to present a more appropriate fatigue level.

[0057] In addition, the fatigue level estimation method according to the tenth aspect of the present embodiment is a fatigue level estimation method executed by a computer and estimating the fatigue level of a user 99, and includes a step of acquiring the user 99's future planned sleep time (step S103), a step of estimating a change in the user 99's fatigue level (steps S102 and S104), and a step of presenting the estimated change in the user's fatigue level (step S105). In the estimation step (steps S102 and S104), the fatigue level to be recovered is calculated based on the sleep time, and the acquired planned sleep time is used as the sleep time to calculate the fatigue level to be recovered (step S104). The change in the user's fatigue level includes the future fatigue level to be recovered calculated for the planned sleep time.

[0058] This can achieve the same effects as the fatigue level estimation system 100 described above.

[0059] A program according to an eleventh aspect of the present embodiment is a program for causing a computer to execute the fatigue level estimation method according to the tenth aspect.

[0060] This makes it possible to achieve the same effects as those of the fatigue level estimation system 100 described above using a computer.

[0061] (Other Embodiments) While the fatigue level estimation system, fatigue level estimation method, and program according to the present disclosure have been described above based on the above-mentioned embodiments, the present disclosure is not limited to the above-mentioned embodiments. For example, the present disclosure also includes forms obtained by applying various modifications to the embodiments that would occur to those skilled in the art, and forms realized by arbitrarily combining the components and functions of the embodiments within the scope of the present disclosure.

[0062] Furthermore, for example, the present disclosure can be realized not only as a fatigue level estimation system, but also as a program including, as steps, the processes performed by each component of the fatigue level estimation system, and as a computer-readable recording medium on which the program is recorded. The program may be pre-recorded on the recording medium, or may be supplied to the recording medium via a wide area communication network including the Internet.

[0063] In other words, the above-described comprehensive or specific aspects may be realized as a system, an apparatus, an integrated circuit, a computer program, or a computer-readable recording medium, or may be realized as any combination of a system, an apparatus, an integrated circuit, a computer program, and a recording medium.

[0064] REFERENCE SIGNS LIST 10 Fatigue level estimation unit 11 Recovery calculation unit 12 Accumulation calculation unit 13 Output unit 20 Acquisition unit 30 Reference acquisition unit 40 Information acquisition unit 50 Sleep time estimation unit 60 Presentation unit 99 User 100 Fatigue level estimation system

Claims

1. A fatigue estimation system for estimating a user's fatigue level, comprising: an acquisition unit for acquiring the user's future planned sleep time; a fatigue estimation unit for estimating a change in the user's fatigue level; and a presentation unit for presenting the estimated change in the user's fatigue level, wherein the fatigue estimation unit has a recovery calculation unit for calculating a fatigue level to be recovered according to sleep time, and causes the recovery calculation unit to calculate a fatigue level to be recovered using the acquired planned sleep time as the sleep time, and the change in the user's fatigue level includes a future fatigue level to be recovered calculated for the planned sleep time.

2. The fatigue level estimation system of claim 1, wherein the acquisition unit acquires a first time, a second time longer than the first time, and a third time longer than the second time as the planned sleep time, the fatigue level estimation unit causes the recovery calculation unit to calculate a fatigue level to be recovered using each of the acquired first time, second time, and third time as the sleep time, and the presentation unit simultaneously presents changes in the user's fatigue level including the future fatigue level to be recovered calculated for the first time, the future fatigue level to be recovered calculated for the second time, and the future fatigue level to be recovered calculated for the third time.

3. A fatigue estimation system as described in claim 1 or 2, comprising a reference acquisition unit that acquires the user's fatigue level at a reference time point, wherein the fatigue estimation unit further has an accumulation calculation unit that calculates the fatigue level accumulated from the reference time point until the user's future sleep, and the change in the user's fatigue level includes the user's fatigue level at the reference time point, the fatigue level accumulated until the user's future sleep, and the fatigue level to be recovered in the future calculated for the planned sleep time.

4. A fatigue estimation system as described in claim 3, further comprising a sleep time estimation unit which estimates the actual sleep time of the user based on the charging time of a mobile device owned by the user, wherein the fatigue estimation unit causes the recovery calculation unit to calculate a recovery fatigue level using the estimated actual sleep time as the sleep time, and the fatigue level at the reference point in time is the sum of the fatigue level at the reference point in the past, the fatigue level accumulated up to the time the user slept in the past, and the recovery fatigue level calculated for the actual sleep time.

5. A fatigue level estimation system as described in claim 3, further comprising an information acquisition unit that acquires information including at least one of physiological values ​​and context information of the user, and the accumulation calculation unit calculates the fatigue level accumulated according to the sleep time based on the acquired information.

6. A fatigue estimation system as described in claim 2, comprising a reference acquisition unit that acquires the user's fatigue level at a reference time point, wherein the fatigue estimation unit further has an accumulation calculation unit that calculates the fatigue level accumulated from the reference time point until the user's future sleep, wherein changes in the user's fatigue level include the user's fatigue level at the reference time point, the fatigue level accumulated until the user's future sleep, and the fatigue level of future recovery calculated for the planned sleep time, and wherein the second time period is a length of time such that the fatigue level of future recovery calculated for the second time period and the fatigue level accumulated until the user's future sleep period are offset.

7. A fatigue estimation system as described in claim 2, comprising a reference acquisition unit that acquires the user's fatigue level at a reference time point, wherein the fatigue estimation unit further has an accumulation calculation unit that calculates the fatigue level accumulated from the reference time point until the user's future sleep, wherein a change in the user's fatigue level includes the user's fatigue level at the reference time point, the fatigue level accumulated until the user's future sleep, and the fatigue level of future recovery calculated for the planned sleep time, and wherein the third time period is a length of time such that the fatigue level of future recovery calculated for the third time period is offset by the sum of the fatigue level at the reference time point and the fatigue level accumulated until the user's future sleep.

8. A fatigue estimation system as described in claim 2, comprising a reference acquisition unit that acquires the user's fatigue level at a reference time point, wherein the fatigue estimation unit further has an accumulation calculation unit that calculates the fatigue level accumulated from the reference time point until the user's future sleep, wherein a change in the user's fatigue level includes the user's fatigue level at the reference time point, the fatigue level accumulated until the user's future sleep, and the fatigue level of future recovery calculated for the planned sleep time, and wherein the first time period is a length of time at which a fatigue level difference obtained by subtracting the fatigue level of future recovery calculated for the first time period from the sum of the fatigue level at the reference time point and the fatigue level accumulated until the user's future sleep period reaches a predetermined threshold value.

9. A fatigue level estimation system as described in claim 1, further comprising an information acquisition unit that acquires information including at least one of physiological values ​​and context information of the user, and the recovery calculation unit calculates the degree of fatigue that will be recovered according to the sleep time based on the acquired information.

10. A fatigue estimation method executed by a computer for estimating a user's fatigue level, comprising the steps of: acquiring a future planned sleep time of the user; estimating a change in the user's fatigue level; and presenting the estimated change in the user's fatigue level, wherein in the estimating step, a fatigue level to be recovered from is calculated according to sleep time, and the acquired planned sleep time is used as the sleep time to calculate the fatigue level to be recovered from, and the change in the user's fatigue level includes a future fatigue level to be recovered from calculated for the planned sleep time.

11. A program for causing the computer to execute the fatigue level estimation method according to claim 10.

Images