Wearable terminal and physical condition estimation method

Abstract

To more accurately evaluate heat stress experienced by a user.SOLUTION: The wearable terminal includes a sensor that detects a pulse rate of a user, and a controller. The controller estimates an intensity of exercise by the user from the number of pulses detected by the sensor, and determines that the user is experiencing heat stress when a degree of decrease in the number of pulses is smaller than a predetermined reference value in a period in which the estimated intensity of the exercise has decreased. Iga.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] An embodiment of the present disclosure relates to a wearable device for estimating a user's physical condition and a physical condition estimation method. [Background technology]

[0002] Technologies are being developed to assess the heat stress a user is experiencing based on current environmental information, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-179094 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem that the present disclosure aims to solve is to more accurately assess the heat stress that a user is experiencing. [Means for solving the problem]

[0005] In one aspect of the present disclosure, a wearable device includes a sensor that detects a user's pulse rate and a control unit that estimates the intensity of the user's exercise based on the pulse rate detected by the sensor, and determines that the user is experiencing heat stress if the degree of decrease in the pulse rate during a period in which the estimated intensity of the exercise decreases is less than a predetermined reference value. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic diagram showing an example of how a wearable terminal according to an embodiment is used. [Figure 2] FIG. 2 is a block diagram showing the functional configuration of the wearable terminal. [Figure 3]FIG. 3 is a schematic diagram for explaining an experiment regarding exercise intensity and pulse rate. [Figure 4] FIG. 4 is a data diagram showing an example of the reference value database. [Figure 5] FIG. 5 is a flowchart showing the flow of processing by the wearable terminal. [Figure 6] FIG. 6 is a block diagram showing the hardware configuration of the information processing device. DETAILED DESCRIPTION OF THE INVENTION

[0007] <1. Embodiment> Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. In the present specification and each drawing, elements similar to those already described are designated by the same reference numerals, and detailed description will not be repeated. In this embodiment, "heartbeat" means the beating of the heart, and "pulse" means the contraction of the artery based on the beating of the heart. "Heart rate" means the number of heartbeats per unit time, and "pulse rate" means the number of pulse beats per unit time. Note that the heart rate and pulse rate are the same except in abnormal states such as arrhythmia.

[0008] (1.1. Wearable Device 1) 1, the wearable device 1 is a device that can be worn by a user. In this embodiment, the wearable device 1 has a wristwatch-type or wristband-type shape that can be worn on the wrist or arm of the user.

[0009] The wearable device 1 includes, for example, a main body 10 and a belt 15. The belt 15 can be worn on the user's body. For example, the belt 15 is flexible and can be fastened to the user's arm. The main body 10 includes a fastening portion 15a to which the belt 15 is fastened.

[0010] The belt 15 may be detachable from the main body 10. The belt 15 may not be included in the wearable terminal 1. In this case, the main body 10 is referred to as the wearable terminal 1. Alternatively, the belt 15 may be formed integrally with the main body 10. The shape of the wearable terminal 1 shown in FIG. 1 is an example, and the wearable terminal 1 may have other shapes (for example, a ring shape, a glasses shape, a clothing shape, etc.) as long as it can be worn on the user's body.

[0011] The main body 10 of the wearable terminal 1 is an information processing device including a display 11, an operation unit 12, etc. The hardware configuration of the information processing device will be described later. The wearable terminal 1 may also include wireless communication means such as Bluetooth (registered trademark). The functions of the wearable terminal 1 will be described later in detail.

[0012] (1.2. Functional configuration of wearable device 1) The functional configuration of the wearable terminal 1 will be described with reference to Fig. 2. As shown in Fig. 2, the wearable terminal 1 includes a display 11, an operation unit 12, a pulse sensor 13, a control unit 20, and a storage unit 30.

[0013] The display 11 is a liquid crystal display, an organic electro-luminescence (OEL) display, or the like, and displays various types of information under the control of the control unit 20.

[0014] The operation unit 12 is a button, a touch panel, or the like that can accept operations by the user. If the operation unit 12 is a touch panel, the wearable terminal 1 may be provided with a touch screen that includes the display 11 and the operation unit 12. If the wearable terminal 1 has a voice recognition function, the operation unit 12 may be a microphone that can input commands by voice from the user.

[0015] Pulse sensor 13 measures the user's pulse wave and pulse rate. Pulse sensor 13 is, for example, a photoplethysmogram (PPG) sensor that detects pulse waves accompanying the heartbeat by measuring changes in the blood volume in the arteries and capillaries that correspond to changes in the user's heart rate. However, the method for measuring pulse waves and pulse rate is not limited to this.

[0016] The control unit 20 includes an acquisition module 21, an estimation module 22, and a determination module 23. The acquisition module 21 acquires the pulse rate of the user detected by the pulse sensor 13. The estimation module 22 estimates the intensity of the exercise performed by the user from the pulse rate acquired by the acquisition module 21.

[0017] The determination module 23 determines that the user is experiencing heat stress if the degree of decrease in pulse rate during the period when the estimated exercise intensity decreased is smaller than a predetermined standard. Generally, in experiments in which a subject alternates between resting and exercising and the pulse rate is measured during this period, it is known that a significant difference appears in the degree of decrease in pulse rate immediately after the exercise intensity decreases when the pulse rates measured when the subject is normal and when the subject is experiencing heat stress are compared.

[0018] For example, in the experimental example shown in FIG. 3, a subject was asked to rest, exercise, and rest in sequence, while their pulse rate was measured at predetermined intervals. In this case, a significant difference between a normal subject and a heat-stressed subject was observed immediately after exercise and after the post-exercise rest. Specifically, when a subject is heat-stressed, the degree of decrease in pulse rate from measurement 2 to measurement 3 (or measurement 4 to measurement 5) is smaller than that in a normal state. In other words, when a subject is heat-stressed, it takes longer for the pulse rate to decrease after the exercise intensity decreases. Using this physiological phenomenon, the determination module 23 determines that the user is heat-stressed if the degree of decrease in pulse rate during the period when the exercise intensity decreases is smaller than a predetermined standard.

[0019] The storage unit 30 includes a reference value database (DB) 31. The reference value database 31 stores information relating to the pulse rate of the user in a normal state that has been measured in advance. Details of the reference value database 31 will be described later.

[0020] (1.3. Reference Value Database 31) The data structure of the reference value database 31 will be described with reference to Fig. 4. Note that the data structure shown in Fig. 4 is an example and is not limited to this form. The reference value database 31 holds data on the relationship between the intensity of exercise performed by the user (hereinafter also referred to as exercise intensity) and the pulse rate. Specifically, the reference value database 31 includes an item "exercise intensity" and an item "reference pulse value."

[0021] The item "exercise intensity" is data on the exercise intensity of the user using the wearable device 1. The item "reference pulse value" is data on the user's pulse rate at the corresponding exercise intensity. These data are measured in advance when the user is in a normal state where they are not under heat stress, and are stored in the reference value database 31.

[0022] It is preferable that the reference value database 31 holds data for each user who uses the wearable device 1. For example, if multiple users use the wearable device 1, the reference value database 31 may hold items for identifying each user. Alternatively, a different reference value database 31 may be stored in the storage unit 30 for each of the multiple users.

[0023] (1.4. Processing flow) The flow of processing in the wearable device 1 will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the flow of processing by the wearable device 1 to evaluate heat stress.

[0024] In step S100, the acquisition module 21 of the control unit 20 starts acquiring the pulse rate of the user detected by the pulse sensor 13. Thereafter, the acquisition module 21 continues acquiring the pulse rate until the evaluation process ends.

[0025] In step S200, the estimation module 22 of the control unit 20 estimates the exercise intensity of the user. As an example, the estimation module 22 estimates the exercise intensity of the user using the Karvonen method from the pulse rate acquired from the pulse sensor 13. In the Karvonen method, the exercise intensity is estimated using the following calculation formula: Exercise intensity (%) = (exercise heart rate - resting heart rate) / (maximum heart rate - resting heart rate) x 100 Here, the heart rate during exercise corresponds to the pulse rate obtained from the pulse sensor 13. The resting heart rate and maximum heart rate may be measured in advance and stored in the storage unit 30.

[0026] In step S300, the determination module 23 of the control unit 20 determines whether the estimated exercise intensity satisfies a predetermined condition. The predetermined condition may include a condition on the value of the exercise intensity and a condition on the period during which the condition on the value is satisfied.

[0027] As an example, the determination module 23 determines heat stress using the determination period as the period after the estimated exercise intensity value (hereinafter also referred to as the estimated value) exceeds a first threshold (e.g., 65) and then falls below a second threshold (e.g., 45). Preferably, the determination period may be the period after the estimated value exceeds the first threshold, remains at or above the second threshold for a first hour (e.g., 5 minutes), and then falls below the second threshold. This makes it possible to exclude cases such as a sudden increase in exercise intensity from the determination target, thereby improving the accuracy of the heat stress assessment.

[0028] More preferably, the determination period may be a period after a second time (e.g., two minutes) has elapsed since the estimated value fell below the second threshold. This allows the heat stress experienced by the user to be evaluated after the exercise intensity has decreased and the pulse rate has stabilized, thereby improving the accuracy of the heat stress evaluation.

[0029] The specific values ​​of the first threshold, the second threshold, the first time, and the second time can be changed as appropriate. Alternatively, the first time and the second time may not be set, and the determination period may be the period from when the value exceeds the first threshold to when it falls below the second threshold. Alternatively, only one of the first threshold and the second threshold may be set.

[0030] In step S400, the judgment module 23 of the control unit 20 refers to the item "Pulse Reference Value" in the reference value database 31 stored in the memory unit 30, and obtains the pulse rate of the user in a normal state, which has been measured in advance, as the reference value.

[0031] In step S500, the determination module 23 of the control unit 20 determines whether the user is experiencing heat stress based on the acquired reference value. As an example, the determination module 23 compares the user's pulse value at the exercise intensity during the determination period with the reference value acquired from the reference value database 31. If the user's pulse value exceeds the reference ratio for the item "pulse reference value," the determination module 23 determines that the user is experiencing heat stress.

[0032] Specifically, for example, assume that the exercise intensity during the assessment period is 40, and the "Pulse Reference Value" item in the reference value database 31 for that exercise intensity is 100 beats per minute. The reference ratio is also 8 percent. In this case, if the user's pulse value exceeds 108 beats per minute, the assessment module 23 determines that the degree of decrease in pulse rate is smaller than the predetermined standard and determines that the user is experiencing heat stress. In this case, the wearable device 1 may be configured to issue an alert.

[0033] The specific value of the above-mentioned reference ratio may be set as appropriate. Furthermore, the determination module 23 may set the predetermined reference in a manner different from the reference ratio. For example, a threshold value may be set as the predetermined reference for the degree of decrease in pulse rate for each exercise intensity after the decrease. Furthermore, the predetermined reference may be changed depending on the length of the period during which the exercise intensity is high. For example, the threshold value may be set as the predetermined reference for a longer period during which the exercise intensity is high.

[0034] (1.4. Hardware configuration of information processing device) The hardware configuration of the information processing device will be described with reference to Fig. 6. The wearable terminal 1 as the information processing device is realized, for example, by a computer 90 shown in Fig. 6. The computer 90 includes a CPU 91, a ROM 92, a RAM 93, a storage 94, an input interface 95, an output interface 96, and a communication interface 97.

[0035] The CPU 91 functions as a processor that executes the processing of the control unit 20. Specifically, the CPU 91 uses the RAM 93 as a work memory and executes a program stored in at least one of the ROM 92 and the storage 94. During the execution of the program, the CPU 91 controls each component via a system bus 98 and executes various processes.

[0036] The ROM 92 serves as the storage unit 30 and stores a program for controlling the operation of the computer 90. The ROM 92 stores programs necessary for the computer 90 to perform each of the above-described processes. The RAM 93 functions as a storage area in which the programs stored in the ROM 92 are expanded.

[0037] The storage 94 serves as the memory unit 30 and stores data necessary for executing the programs and data obtained by executing the programs. The storage 94 includes one or more selected from a hard disk drive (HDD) and a solid state drive (SSD). The storage 94 may also be implemented as an external storage medium such as an SD card or a universal serial bus (USB) memory.

[0038] The input interface (I / F) 95 can connect the computer 90 to an input device 95a. The input interface 95 is, for example, a serial bus interface such as USB. The CPU 91 can read various data from the input device 95a via the input interface 95.

[0039] The output interface (I / F) 96 can connect the computer 90 and an output device 96a. The output interface 96 is, for example, a video output interface such as DVI (Digital Visual Interface) or HDMI (High-Definition Multimedia Interface / registered trademark). The CPU 91 can transmit data to the output device 96a via the output interface 96 and cause the output device 96a to output the data.

[0040] The input device 95a is an example of an input means and includes the operation unit 12. The input device 95a may also include one or more selected from a microphone (audio input) and a touchpad. The output device 96a is an example of an output means and includes the display 11. The output device 96a may also include a speaker (audio output). A device having the functions of both the input device 95a and the output device 96a, such as a touch panel, may also be used.

[0041] The communication interface (I / F) 97 can connect the computer 90 to an external server 97a located outside the computer 90. The communication interface 97 is, for example, a network card such as a LAN card. The CPU 91 can read various data from the external server 97a via the communication interface 97.

[0042] Each process executed by the wearable device 1 may be realized by one computer 90 or by multiple computers 90 working together.

[0043] The various data processing operations described above may be recorded as a computer-executable program on a magnetic disk (such as a flexible disk or hard disk), an optical disk (such as a CD-ROM, CD-R, CD-RW, DVD-ROM, DVD±R, or DVD±RW), a semiconductor memory, or other non-transitory computer-readable storage medium.

[0044] For example, information recorded on a recording medium can be read by a computer (or an embedded system). The recording medium may have any recording format (storage format). For example, the computer reads a program from the recording medium and causes a processor to execute instructions written in the program based on the program. The computer may acquire (or read) the program via a network.

[0045] (1.5.Summary) As described above, the wearable device 1 according to this embodiment includes a pulse sensor 13 that detects the user's pulse rate and a control unit 20. The control unit 20 estimates the intensity of the user's exercise from the pulse rate detected by the sensor, and determines that the user is experiencing heat stress if the degree of decrease in the pulse rate during a period in which the estimated exercise intensity decreases is smaller than a predetermined standard. This configuration allows for a more accurate assessment of the user's heat stress, regardless of the user's exercise habits, physical strength, etc.

[0046] The wearable device 1 may further include a storage unit 30. The storage unit 30 may store information about the user's pulse rate measured in advance when the user is in a normal state. This configuration allows for rapid evaluation of heat stress based on a comparison with the user's normal state.

[0047] Furthermore, the estimation module 22 of the control unit 20 estimates the exercise intensity of the user from the pulse rate detected by the sensor using the Karvonen method. By adopting such specifications, it is possible to calculate a highly reliable estimate of exercise intensity from the pulse rate detected by the sensor.

[0048] Furthermore, the determination module 23 of the control unit 20 determines whether or not the user is experiencing heat stress by determining the period after the estimated exercise intensity exceeds the first threshold and falls below the second threshold as the determination period. This specification allows the exercise intensity that triggers the determination of heat stress to be specifically determined.

[0049] The assessment period may also be the period after the first threshold is exceeded, the first hour has passed at a value equal to or greater than the second threshold, and the second hour has passed after the value has fallen below the second threshold. This specification makes it possible to exclude cases such as a sudden increase in exercise intensity from assessment, thereby improving the accuracy of heat stress assessment.

[0050] The determination period may also be the period after the second time has elapsed since the pulse rate fell below the second threshold. This specification allows the heat stress experienced by the user to be evaluated after the exercise intensity has decreased and the pulse rate has stabilized, thereby improving the accuracy of the heat stress evaluation.

[0051] <2. Other embodiments> Although the wearable device 1 according to the present embodiment has been described above, application of the technical concept of the present disclosure is not limited to the above embodiment. For example, in the above embodiment, the estimation module 22 of the control unit 20 estimates the exercise intensity of the user using the Karvonen method from the pulse rate detected by the sensor, but the present disclosure is not limited to this aspect. In other words, the estimation module 22 may estimate the exercise intensity of the user using a method other than the Karvonen method.

[0052] Specifically, for example, instead of the pulse sensor 13 of the wearable device 1, an acceleration sensor may be attached to a part of the user's body (for example, a wrist, ankle, finger, chest, etc.), and the estimation module 22 may estimate the exercise intensity of the user based on the amount of body movement detected by the acceleration sensor. Alternatively, the wearable device 1 may be equipped with an acceleration sensor.

[0053] In the above embodiment, the storage unit 30 of the wearable device 1 stores information about the user's pulse rate in a normal state, but this is not limited to this. For example, the wearable device 1 may be configured to receive information about the user's pulse rate in a normal state from another information processing device or the like.

[0054] Furthermore, in the above embodiment, a wristwatch-type wearable device 1 equipped with a pulse sensor 13 for detecting a pulse rate is employed, but the present invention is not limited to this. For example, the technical idea of ​​the present disclosure may be applied by acquiring a user's heart rate using an electrocardiogram or the like. In this case, the information regarding the acquired heart rate may be directly input by an operator to an information processing device including a control unit 20 and a storage unit 30. Furthermore, the technical idea of ​​the present disclosure may be realized by acquiring other physiological indices, such as a respiratory rate or ventilation volume, instead of a pulse rate (or heart rate).

[0055] The disclosure may include the following features. (Appendix 1) a sensor for detecting a user's pulse rate; a control unit, The control unit Estimating the intensity of the exercise performed by the user from the pulse rate detected by the sensor; The wearable terminal determines that the user is experiencing heat stress if the degree of decrease in the pulse rate during the period in which the estimated exercise intensity has decreased is smaller than a predetermined standard. (Appendix 2) Further comprising a storage unit, 2. The wearable terminal according to claim 1, wherein the memory unit stores information relating to the user's pulse rate in a normal state that has been measured in advance. (Appendix 3) 3. The wearable terminal according to claim 1, wherein the control unit estimates the intensity of the exercise performed by the user using the Karvonen method from the pulse rate detected by the sensor. (Appendix 4) The wearable device of any one of Appendices 1 to 3, wherein the control unit determines the heat stress using the period after the estimated exercise intensity exceeds a first threshold and falls below a second threshold as the determination period. (Appendix 5) The wearable terminal of claim 4, wherein the determination period is a period after the first threshold is exceeded, a first time has elapsed with a value equal to or greater than the second threshold, and after the value falls below the second threshold. (Appendix 6) The wearable terminal according to claim 5, wherein the determination period is a period after a second time has elapsed since the power supply voltage fell below the second threshold. (Appendix 7) obtaining a user's heart rate; estimating the intensity of exercise performed by the user from the acquired heart rate; and determining that the user is experiencing heat stress if the degree of decrease in the heart rate during the period in which the estimated exercise intensity has decreased is less than a predetermined standard.

[0056] Although several embodiments of the present disclosure have been illustrated above, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims. Furthermore, the above-described embodiments can be implemented in combination with each other. [Explanation of symbols]

[0057] 1: Wearable terminal, 10: Main body, 11: Display, 12: Operation unit, 13: Pulse sensor, 15: Belt, 15a: Fixing unit, 20: Control unit, 21: Acquisition module, 22: Estimation module, 23: Judgment module, 30: Memory unit, 31: Reference value database, 90: Computer, 91: CPU, 92: ROM, 93: RAM, 94: Storage, 95: Input interface, 95a: Input device, 96: Output interface, 96a: Output device, 97: Communication interface, 97a: External server, 98: System bus

Claims

1. a sensor for detecting a user's pulse rate; A control unit; Equipped with The control unit Estimating the intensity of the exercise performed by the user from the pulse rate detected by the sensor; The wearable terminal determines that the user is experiencing heat stress if the degree of decrease in the pulse rate during the period in which the estimated exercise intensity has decreased is smaller than a predetermined standard.

2. Further comprising a storage unit, The wearable terminal according to claim 1 , wherein the storage unit stores information relating to a pulse rate of the user in a normal state that is measured in advance.

3. The wearable terminal according to claim 1 , wherein the control unit estimates the intensity of the exercise performed by the user from the pulse rate detected by the sensor using a Karvonen method.

4. The wearable terminal according to claim 1 , wherein the control unit determines the heat stress using a period after the estimated exercise intensity exceeds a first threshold and falls below a second threshold as a determination period.

5. The wearable terminal according to claim 4 , wherein the determination period is a period from when the power exceeds the first threshold, when a first time has elapsed with a value equal to or greater than the second threshold, and when the power falls below the second threshold.

6. The wearable terminal according to claim 5 , wherein the determination period is a period after a second time has elapsed since the power supply voltage fell below the second threshold.

7. obtaining a user's heart rate; estimating the intensity of exercise performed by the user from the acquired heart rate; determining that the user is experiencing heat stress when the degree of decrease in the heart rate during the period in which the estimated exercise intensity is decreased is smaller than a predetermined standard; A physical condition estimation method comprising:

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