Wakefulness state control system, wearable device, and wakefulness state control method

Abstract

To provide a technology that suppresses a decrease in efficiency of controlling a user's wakefulness state.SOLUTION: A wakefulness state control system includes a sensor that acquires biometric information of a user, and a stimulus imparting device that imparts stimuli to the user to control the wakefulness state based on vital values obtained from the biometric information that serve as indicators of the user's wakefulness state. The stimuli imparted by the stimulus imparting device include a relaxing stimulus that leads the user's vital value change rate in a negative direction, an awakening stimulus that leads the vital value change rate in a positive direction, and a super-awakening stimulus that is greater than the awakening stimulus and leads the vital value change rate in a positive direction. The vital value change rate is a rate of change in the vital value when the stimulus is applied, relative to a predetermined standard vital value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wakefulness control system, a wearable device, and a wakefulness control method. [Background technology]

[0002] The autonomic nervous system regulates autonomic functions such as breathing, digestion, circulation, and maintaining body temperature, and is maintained by a balance between the sympathetic and parasympathetic nervous systems. The sympathetic nervous system is active during arousal, while the parasympathetic nervous system is active during relaxation. A high level of arousal increases concentration, but if the arousal level is too high, excessive stress can lead to a decline in performance. This relationship between arousal state and performance is known as the Yerkes-Dodson law.

[0003] A stress reduction system has been proposed that measures biological information such as a user's body temperature and heart rate, and generates soothing effects such as images, music, and tactile stimulation (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] However, the system described in Patent Document 1 leaves room for improvement in that no measures are taken to address the decrease in efficiency in controlling the user's wakefulness state.

[0005] The present invention aims to provide a technique for suppressing a decrease in efficiency in controlling a user's wakefulness state. [Means for solving the problem]

[0006] An alertness control system according to one aspect of the present invention comprises a sensor that acquires biometric information of a user, and a stimulus-giving device that applies stimuli to the user to control the alertness state based on vital values ​​obtained from the biometric information and serving as indicators of the user's alertness state, the stimuli applied by the stimulus-giving device including a relaxing stimulus that leads the user's rate of change in vital value in a negative direction, an awakening stimulus that leads the rate of change in vital value in a positive direction, and a super-awakening stimulus that leads the rate of change in vital value in a positive direction greater than the awakening stimulus, and the rate of change in vital value is the ratio of change in the vital value when the stimulus is applied to a predetermined standard vital value. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a technique for suppressing a decrease in the efficiency of controlling the wakefulness state of a user. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of an alertness state control system according to an embodiment; [Figure 2] FIG. 1 is a schematic diagram showing a first example of a wearable device in a worn state. [Figure 3A] FIG. 1 is a diagram illustrating a first example of a wearable device. [Figure 3B] FIG. 10 is a diagram illustrating a second example of a wearable device. [Figure 3C] FIG. 10 is a diagram illustrating a third example of a wearable device. [Figure 4] FIG. 2 is a hardware configuration diagram of an information processing device. [Figure 5] FIG. 2 is a functional block diagram of a stimulation control unit. [Figure 6] 4 is a flowchart of a process performed by the wakefulness state control system according to the embodiment. [Figure 7] FIG. 10 is a diagram illustrating a second example of a wearable device. [Figure 8] FIG. 8 is a diagram showing an example of the configuration of the side of the wearable device in FIG. 7 that comes into contact with the skin. [Figure 9] FIG. 10 is a diagram illustrating a third example of a wearable device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are examples for embodying the technical ideas of the invention, and the present invention is not limited to the following configurations and methods. In the drawings, the same components are given the same reference numerals, and redundant description may be omitted. The size and positional relationship of components shown in the drawings may be exaggerated to make the invention easier to understand.

[0010] <Configuration example of wakefulness control system and wearable device> FIG. 1 is a schematic diagram of an alertness state control system 1 according to an embodiment.

[0011] The alertness state control system 1 includes a sensor 115 that acquires biometric information of a user, and a stimulus imparting device 12 that imparts a stimulus to the user to control the alertness state based on a vital value obtained from the biometric information and serving as an index of the user's alertness state. The alertness state control system 1 shown in FIG. 1 also includes a stimulus control unit 210 that determines a stimulus to control the alertness state based on the vital value. The stimulus imparting device 12 imparts the stimulus determined by the stimulus control unit 210 to the user. The stimulus control unit 210 is implemented by an information processing device 200. The stimulus imparting device 12 is implemented in the form of a wearable device 10.

[0012] The wearable device 10, the sensor 115, and the information processing device 200 may be separate devices, or at least one of the sensor 115 and the stimulus control unit 210 may be incorporated into the wearable device 10. The connection between the wearable device 10, the sensor 115, and the information processing device 200 may be a cable connection or a wireless connection. As the information processing device 200, a microprocessor may be incorporated inside the wearable device 10, or the wearable device 10 may be a separate personal computer, smartphone, tablet terminal, or the like. The sensor 115 may be connected to the wearable device 10 or the information processing device 200 by wire or wirelessly.

[0013] By wearing the wearable device 10 while working, a user using the alertness control system 1 can receive stimuli to achieve a desired alertness state while working. However, if the user is in a hyperalert state due to excessive stress or drowsiness, or if the user has become accustomed to the stimuli, the stimuli may not achieve the desired alertness state. For example, even if a soothing stimulus is provided to the user, the user may not be able to transition to the desired relaxed state due to the user's hyperalert state. In such cases, in order to transition to the desired alertness state, it may be necessary to provide the stimuli for a long period of time or to ensure a long break without work. As a result, the efficiency of controlling the user's alertness state may decrease, and the user's intellectual productivity may also decrease.

[0014] In the wakefulness state control system 1, the stimuli applied by the stimulus application device 12 include relaxing stimuli, awakening stimuli, and super-awakening stimuli. The awakening stimuli are stimuli that increase the wakefulness level or concentration. The relaxing stimuli are stimuli that decrease the wakefulness level (stimuli that alleviate the wakefulness state). The awakening stimuli have a greater rate of change in vital values ​​than the relaxing stimuli. The super-awakening stimuli have a greater rate of change in vital values ​​than the awakening stimuli.

[0015] The arousal level (sometimes referred to as the arousal state) refers to the subject's level of arousal (sometimes referred to as tension) or relaxation. The arousal level is evaluated such that a subject is more tense than the reference arousal level, and a subject is more relaxed, and the arousal level is expressed as a low arousal level. In an embodiment of the present invention, the arousal level is expressed as a vital value. A target vital value is used as an example of a desired arousal level.

[0016] For example, if the low frequency (LF) component of the heart rate fluctuation frequency is LF and the high frequency (HF) component of the heart rate fluctuation frequency is HF, the vital sign value is expressed as LF / HF. More specifically, LF is the low frequency component included in the power spectrum of the heart rate fluctuation obtained by analyzing the heart rate. HF is the high frequency component included in the power spectrum of the heart rate fluctuation obtained by analyzing the heart rate.

[0017] The vital value change rate refers to the rate of change in the vital value when a stimulus is applied relative to a predetermined standard vital value. For example, if the vital value change rate is A, the user's vital value when a stimulus is applied is B, and the standard vital value is C, the vital value change rate A is calculated using the following formula. Note that the standard vital value C is, for example, the vital value calculated immediately before the stimulus is applied. A = (BC) / C × 100

[0018] For example, a relaxation stimulus is a vital value change rate less than 0, an awakening stimulus is a vital value change rate greater than 0 and less than 200, and a super awakening stimulus is a vital value change rate greater than 200.

[0019] By providing a user with a super-arousal stimulus, which has a stronger arousal effect than a relaxing stimulus and an arousal stimulus, the user quickly transitions to a target arousal state due to the sense of relief provided by the super-arousal stimulus. This eliminates the need to provide the stimulus for a long period of time or to ensure a long break without work. As a result, this embodiment provides a technology that suppresses a decrease in efficiency in controlling the user's arousal state. Furthermore, by suppressing a decrease in efficiency in controlling the user's arousal state, the user's intellectual productivity is improved.

[0020] FIG. 2 is a schematic diagram showing a first example of how the wearable device 10 is worn. The wearable device 10 is worn at a body location that can efficiently provide stimulation to the user 5. The wearable device 10 shown in FIG. 2 is designed to be worn around the neck 51 of the user 5. The wearable device 10 shown in FIG. 2 is U-shaped, surrounding a portion of the neck 51 of the user 5, but may also be C-shaped or O-shaped, surrounding the entire neck 51 of the user 5. The shape and configuration can be changed to allow the device to be worn on the shoulder, waist, upper arm, lower arm, or other appropriate location on the body. The stimulation device 12 provides the user with a relaxing stimulation, an awakening stimulation, and a super-awakening stimulation.

[0021] For example, the stimulation device 12 applies an awakening stimulation, a relaxing stimulation, or a super-awakening stimulation to an appropriate location on the neck 51. The stimulation device 12 may use a temperature stimulation and an electrical stimulation as stimulations for adjusting vital values, and may apply these stimulations simultaneously or alternately. Note that the number of types of stimulations applied simultaneously or separately may be three or more. Furthermore, instead of applying different types of stimulation separately, the same type of stimulation may be applied with different intensities.

[0022] When the sensor 115 is incorporated into the wearable device 10, the sensor 115 may be incorporated inside the wearable device 10 at a position that contacts the carotid artery below the ear 52 of the user 5, or may be configured to be worn on the user's earlobe 52 or wrist.

[0023] 3A, 3B, and 3C show configuration examples of the wearable device 10. In FIG. 3A, the wearable device 10A has a main body 110 and stimulating devices 12a, 12b, and 12c (collectively referred to as "stimulating devices 12" as appropriate) provided on the main body 110. The configuration of FIG. 3A is a configuration in which the sensor 115 and the information processing device 200 in the wakefulness state control system 1 of FIG. 1 are separate from the wearable device 10. A communicator 117 is provided on the main body 110 of the wearable device 10A. The communicator 117 receives a control signal indicating an analysis result of biological information from the external information processing device 200. Some or all of the stimulating devices 12a, 12b, and 12c are driven in accordance with the received control signal. Any information processing device 200 may be used as long as it has the function of analyzing the biological information acquired from the sensor 115 and transmitting the analysis result to the wearable device 10. As described above, the information processing device 200 may be a personal computer, a smartphone, a tablet terminal, or the like.

[0024] The stimulation devices 12a, 12b, and 12c each generate a different stimulation. As an example, the stimulation device 12a has a first electrode 121 and a first electrode 122 provided on the inside of the curved portion 101 of the U-shaped main body 110. The first electrode 121 and the first electrode 122 are provided so as to come into contact with the back of the neck 51 or the nape of the user 5 when the wearable device 10A is worn on the neck 51 of the user 5. The stimulation device 12a provides a thermal stimulation or a low-frequency electrical stimulation to the nape of the user 5 via the first electrode 121 and the first electrode 122. The number of first electrodes is not limited to two, and three or more first electrodes may be provided along the inner surface of the curved portion 101 of the main body 110.

[0025] When the stimulation device 12a generates heat, a heater provided inside the stimulation device 12a is heated in accordance with a control signal received by the communication device 117, and the heat is provided from the first electrodes 121 and 122. When the stimulation device 12a provides low-frequency stimulation, an oscillation circuit provided inside the stimulation device 12a is turned on, and low-frequency vibrations are provided via the first electrodes 121 and 122. The low-frequency vibrations provide electrical muscle stimulation (EMS). The heat and low-frequency vibrations provided to the nape of the neck generally act as relaxing stimuli that relieve muscle tension, but may also act as awakening stimuli depending on individual differences and the intensity of the stimulation.

[0026] The stimulation device 12b is attached to an arm 130 extending on both sides of the curved portion 101 of the main body 110, and has second electrodes 123 and 124 protruding from the arm 130 in the width (or height) direction of the main body 110. The second electrodes 123 and 124 come into contact with the skin surface around the carotid artery below the ear 52 or gill of the user 5 when the wearable device 10A is worn on the neck 51 of the user 5. The stimulation device 12b applies high-frequency electrical stimulation to the carotid artery of the user 5 via the second electrodes 123 and 124. An oscillator circuit provided inside the stimulation device 12b is turned on, and high-frequency vibrations are applied via the second electrodes 123 and 124. High-frequency vibrations generally act as a relaxing stimulation that improves blood flow, but may also act as an awakening stimulation depending on individual differences and the intensity of the stimulation.

[0027] The stimulation device 12c is provided inside an arm 130 extending on both sides of the curved portion 101 of the main body 110 and has a third electrode 125 and a third electrode 126 facing each other. The third electrode 125 and the third electrode 126 are provided so as to contact the skin surface around the carotid artery along the nape of the user 5 when the wearable device 10A is worn on the neck 51 of the user 5. The stimulation device 12c applies a cooling stimulus or a heat stimulus to the carotid artery of the user 5 via the third electrode 125 and the third electrode 126. When the stimulation device 12c applies a cooling or heat stimulus, the cooling or heat stimulus is generated by controlling the on / off of a voltage that drives a Peltier element provided inside the stimulation device 12c and the polarity of the applied voltage. Appropriate cooling and heating of the carotid artery generally works to increase vital signs, but if the blood vessels are excessively dilated, the cooling stimulus may cause the user to transition to a relaxed state.

[0028] FIG. 3B is a schematic diagram of a wearable device 10B. In addition to the configuration of FIG. 3A, the wearable device 10B has a sensor 115 connected to a communication device 117. The configuration of FIG. 3B is a configuration in which the sensor 115 is provided as a set with the wearable device 10 and the information processing device 200 is separate from the wearable device 10 in the wakefulness state control system 1 of FIG. 1. In the example of FIG. 3B, the sensor 115 is connected to the main body 110 via a cable 116 and electrically connected to the communication device 117. However, the sensor 115 may be wirelessly connected to the communication device 117. If the sensor 115 is configured to be able to communicate directly with the external information processing device 200 without using the communication device 117, the configuration is as shown in FIG. 3A. The sensor 115 is a biosensor such as a heart rate sensor, pulse sensor, temperature sensor, or sweat sensor. The heart rate sensor or pulse sensor may be attached to the user's earlobe or fingertip, or may be attached to the chest.

[0029] The communicator 117 transmits the biological information acquired by the sensor 115 to the external information processing device 200. The information processing device 200 analyzes the acquired biological information, determines a stimulus to be given to the user, and transmits the determined stimulus as a control signal to the wearable device 10B. The wearable device 10B drives some or all of the stimulus imparting devices 12a, 12b, and 12c based on the control signal received by the communicator 117. The configurations and functions of the stimulus imparting devices 12a, 12b, and 12c provided in the main body 110 are as described with reference to FIG. 3A.

[0030] FIG. 3C is a schematic diagram of a wearable device 10C. The wearable device 10C has a microprocessor 120 provided in the main body 110 and a sensor 115 connected to the microprocessor 120. The configuration of FIG. 3C is a configuration in which the sensor 115 and the information processing device 200 are integrated with the wearable device 10 in the wakefulness state control system 1 of FIG. 1. The information processing device 200 is realized as the microprocessor 120, but may also be realized as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). In FIG. 3C, the sensor 115 is connected to the main body 110 and the microprocessor 120 by a cable, but may also be wirelessly connected to the microprocessor 120 with built-in communication capabilities.

[0031] The microprocessor 120 analyzes the biological information acquired from the sensor 115 and drives some or all of the stimulating devices 12a, 12b, and 12c provided in the main body 110. The configurations and functions of the stimulating devices 12a, 12b, and 12c are as described with reference to FIG. 3A. In addition to the configuration examples shown in FIGS. 3A, 3B, and 3C, the main body 110 may be configured to include only the microprocessor 120 with wireless communication capabilities. In this case, in the wakefulness state control system 1 of FIG. 1, the wearable device 10 and the information processing device 200 are integrated, and the sensor 115 is separate. The wakefulness state control system 1 and the wearable device 10 may be configured in any manner as long as they can acquire biological information and generate one or more types of stimuli based on the biological information to control the user's wakefulness state.

[0032] 4 is a hardware configuration diagram of an information processing device 200. The information processing device 200 has a processor 201, a main memory 202, an auxiliary memory 203, an input / output interface (denoted as "I / F" in the figure) 204, and a communication interface 205. These are connected to each other via a system bus 206.

[0033] The processor 201 executes control processing including various types of calculation processing, and realizes the functions of the stimulation control unit 210. The control processing executed by the processor 201 includes acquiring biometric information, analyzing the biometric information, determining stimulation, and acquiring the target vital value and subjective evaluation set by the user. Determining stimulation includes determining the type, combination, stimulation application time, stimulation intensity, etc., and correcting or changing these. As will be described later, the type of stimulation to be applied, application time, target vital value corresponding to the task, etc. can be corrected based on changes in the difference between the target vital value and the vital value calculated from the biometric information, and the subjective evaluation of performance.

[0034] Main memory 202 includes read-only memory (ROM) that stores programs used in the operation of processor 201, and random access memory (RAM) that is used as a work area for processor 201. Auxiliary memory 203 includes storage devices such as a hard disk drive (HDD) or solid-state drive (SSD), and stores various programs and parameter information required for program startup, as well as information and parameters required for wakefulness state control.

[0035] The input / output interface 204 connects input / output devices such as a display device, a touch panel, a speaker, earphones, a microphone, and a keyboard to the information processing device 200. The communication interface 205 enables communication between the information processing device 200 and an external device via a public communication network, a LAN, a short-range communication standard, etc. Communication between the information processing device 200 and the sensor 115 or the wearable device 10 may be performed using a short-range wireless communication standard.

[0036] <Functional configuration of the stimulation control unit> 5 is a functional block diagram of the stimulation control unit 210. The stimulation control unit 210 is realized by the processor 201. The stimulation control unit 210 has a biological information acquisition unit 211, a target level setting unit 212, a data analysis unit 213, a stimulation determination unit 214, and an evaluation acquisition unit 215.

[0037] The biometric information acquisition unit 211 acquires biometric information of the user wearing the wearable device 10. The biometric information may be acquired directly from the sensor 115 worn by the user as described above, or may be acquired from the wearable device 10.

[0038] The target level setting unit 212 acquires a target vital value setting from a user input. The target vital value indicates the level of alertness or tension that the user aims to achieve when working, and can use values ​​such as the respiratory rate, sweat level, heart rate, and blink frequency.

[0039] The LF component is a frequency band of 0.004 to 0.150 Hz in the power spectrum of heart rate variability, and is said to reflect the activity of both the sympathetic and parasympathetic nervous systems. The HF component is a frequency band of 0.150 to 0.400 Hz in the power spectrum of heart rate variability, and is said to reflect the activity of the parasympathetic nervous system. The vital value indicates which of the sympathetic and parasympathetic nervous systems is dominant and to what extent. When the user is awake or tense, the sympathetic nervous system is dominant over the parasympathetic nervous system, and the vital value increases. When the user is relaxed, the parasympathetic nervous system is dominant over the sympathetic nervous system, and the vital value decreases.

[0040] The data analysis unit 213 (sometimes referred to as the wakefulness state acquisition unit) analyzes biological information to determine the user's vital values. The data analysis unit 213 extracts LF and HF components from the fluctuation spectrum of the acquired heart rate data to calculate the vital values. The data analysis unit 213 also refers to the target vital value set by the user and identifies the difference between the calculated vital value and the target vital value. When the magnitude of the difference between the current vital value and the target vital value exceeds the allowable range, it detects that the user is in an excessively relaxed state or an excessively tense state. The data analysis unit 213 monitors the direction of change in the difference.

[0041] The stimulus determination unit 214 determines a stimulus to be applied to the user based on the analysis result of the data analysis unit 213. When the stimulus determination unit 214 determines that the user is in an excessively relaxed state based on the difference between the calculated vital value and the target vital value, the stimulus determination unit 214 determines an awakening stimulus that raises the vital value as the stimulus to be applied to the user. On the other hand, when the user is determined to be in an excessively tense state, the stimulus determination unit 214 determines a relaxing stimulus that alleviates the vital value as the stimulus to be applied to the user. Since what kind of stimulus is effective in raising and alleviating the vital value differs from user to user, the user's tendencies may be measured in advance and an awakening stimulus that is effective for the user may be determined by the stimulus determination unit 214.

[0042] For users who can transition from a tense state to a relaxed state by cooling the carotid artery, a cooling stimulation is selected when the user is in a strong tense state. For users who transition to an alert state by low-frequency electrical stimulation, a low-frequency electrical stimulation is selected when the user is excessively relaxed. Conversely, for users who transition from a relaxed state to an alert state by cooling the carotid artery, a cooling stimulation is selected when the user is excessively relaxed, and for users who relax by low-frequency electrical stimulation, a low-frequency electrical stimulation is selected when the user is excessively tense.

[0043] As the initial stimulus, a stimulus that is generally considered to be effective for awakening or relaxation may be selected by default, or a stimulus may be randomly selected from the stimulus-providing devices 12 mounted on the wearable device 10.

[0044] The stimulus determination unit 214 also determines whether the absolute value of the difference between the calculated vital value and the target vital value is greater than a predetermined threshold. If the absolute value of the difference between the calculated vital value and the target vital value is greater than ΔL, the stimulus determination unit 214 determines that the target vital value cannot be quickly reached under the current conditions and determines whether to apply an ultra-awakening stimulus. The determination of whether to apply an ultra-awakening stimulus is made, for example, based on the length of time elapsed since the application of the awakening stimulus or the relaxation stimulus began. Specifically, if the absolute value of the difference between the acquired vital value and the target vital value is greater than a threshold after the awakening stimulus or the relaxation stimulus has been applied for a maximum of 30 minutes, preferably 15 minutes, the stimulus determination unit 214 determines to apply an ultra-awakening stimulus. The stimulus determination unit 214 determines the ultra-awakening stimulus as the stimulus to be applied to the user. On the other hand, if the absolute value of the difference between the vital value and the target vital value is equal to or less than the threshold, the stimulus determination unit 214 determines not to apply an ultra-awakening stimulus and determines the awakening stimulus or the relaxation stimulus as the stimulus to be applied to the user.

[0045] The evaluation acquisition unit 215 acquires an evaluation of whether performance has improved as a result of wearing the wearable device 10. The evaluation may be a subjective evaluation that the user inputs into the information processing device 200 after completing a task, or an evaluation that is automatically determined by the data analysis unit 213 based on the degree of convergence to the target vital value and the convergence time.

[0046] By determining different types of stimulation based on the user's biological information, the user's state of alertness can be appropriately controlled. By detecting whether the target level of alertness has been reached and correcting or changing the type of stimulation, stimulation duration, stimulation intensity, etc., it is possible to guide the user to an appropriate vital value. By providing feedback on the performance evaluation results, the target vital value can be revised for each user.

[0047] <Processing by the wakefulness state control system 1> Fig. 6 is a flowchart showing the processing by the wakefulness state control system 1. For example, the wakefulness state control system 1 starts the processing in Fig. 6 when the user wears the wearable device 10 and starts a predetermined application on the information processing device 200, causing the sensor 115 to start acquiring biological information.

[0048] First, in step S1, the wakefulness state control system 1 acquires, via the stimulus control unit 210, user information including the type of work to be performed by the user, the start time of the work, the user's physical and mental state, and the like.

[0049] Next, in step S2, the alertness state control system 1 acquires a target vital value according to the type of work to be performed by the user. The work type and the target vital value are input by the user to the information processing device 200. The work type indicates the degree of intellectual work involving the user's thinking, and is expressed as simple, normal, complex, etc. A planned work time may also be input together with the work type. The target vital value indicates the alertness state required or desired for the planned work.

[0050] The target vital value may be a value acquired when the user previously used the same task type. Alternatively, the target vital value may be acquired by associating the task type entered by the user with task type data stored in advance in the information processing device 200 and target vital value data for each task type that is generally considered valid.

[0051] In the process shown in FIG. 6, a target vital value or its range is input by the user. When a vital value is used, the target vital value can be appropriately set within a range of 1.5 to 5.0 depending on the type of work. For simple work, the target vital value may be set slightly higher so as not to induce drowsiness. For complex intellectual work, the target vital value may be set slightly lower so as not to cause excessive stress. The order of steps S1 and S2 does not matter, and they may be taken into the stimulation control unit 210 in parallel.

[0052] Next, in step S3, the wakefulness state control system 1 acquires the user's current vital values ​​by analyzing the biological information acquired from the sensor 115 using the stimulation control unit 210. For example, the stimulation control unit 210 analyzes the user's heart rate data acquired as biological information at predetermined time intervals, extracts the LF component and the HF component contained in the heart rate fluctuations, and calculates the vital values. The stimulation control unit 210 analyzes the heart rate data for five minutes to calculate the vital values, and updates the process every minute. However, this is not a limitation. The accumulation time and update interval of the heart rate data can be set as appropriate. The time interval for data analysis and the calculated vital values ​​are, for example, as follows:

[0053] Time interval Vital values 10:00 - 10:05 2.0 10:01 - 10:06 1.4 10:02 - 10:07 1.8 10:03 - 10:08 1.2 From then on, the 5-minute analysis interval shifts by one minute, and vital values ​​are calculated.

[0054] Next, in step S4, the wakefulness state control system 1 determines whether the difference between the current vital value and the target vital value calculated in each analysis interval is positive or negative by the stimulus control unit 210. This determination is made to determine whether the stimulus to be applied to the user is an awakening stimulus or a relaxing stimulus.

[0055] If it is determined in step S4 that the absolute value of the difference between the calculated vital value and the target vital value is not positive (step S4, NO), the wakefulness state control system 1 determines in step S5 whether the difference between the current vital value and the target vital value is less than 0.

[0056] If it is determined in step S5 that the value is not less than 0 (step S5, NO), the arousal state control system 1 proceeds to step S15. On the other hand, if it is determined in step S5 that the value is less than 0 (step S5, YES), the arousal state control system 1 applies an arousal stimulus to the user by the stimulus applying device 12 in step S6.

[0057] Subsequently, in step S7, the wakefulness state control system 1 causes the stimulation control unit 210 to analyze the biological information acquired from the sensor 115, thereby acquiring the current vital values ​​of the user.

[0058] Next, in step S8, the arousal state control system 1 determines whether the absolute value of the difference between the calculated vital value and the target vital value is greater than a first threshold ΔL1 using the stimulus control unit 210. The first threshold ΔL1 used in this determination is used to determine whether to prepare to switch the stimulus applied to the user from an awakening stimulus to a super-awakening stimulus. The value of the first threshold ΔL1 can be changed as appropriate depending on the mental and physical state of the user performing the work, the type of work, etc.

[0059] If it is determined in step S8 that the absolute value of the difference between the vital value and the target vital value is not greater than the first threshold ΔL1 (step S8, NO), the arousal state control system 1 determines that preparation for applying an ultra-arousal stimulus is unnecessary and proceeds to step S15. On the other hand, if it is determined in step S8 that the absolute value is greater than the first threshold ΔL1 (step S8, YES), the arousal state control system 1 determines in step S9 whether or not to apply an ultra-arousal stimulus to the user using stimulus control unit 210 in preparation for applying an ultra-arousal stimulus.

[0060] For example, if the absolute value of the difference between the vital value and the target vital value is greater than the first threshold ΔL1 after a first time has elapsed since the start of application of the awakening stimulus (step S9, YES), the stimulus control unit 210 determines that the target vital value cannot be reached quickly under these conditions and decides to apply a super-awakening stimulus. The awakening state control system 1 then proceeds to step S14. The first time is, for example, a maximum of 30 minutes, preferably 15 minutes. However, the first time can be set appropriately depending on the mental and physical state of the user performing the work, the type of work, and the like. On the other hand, if the absolute value of the difference between the vital value and the target vital value is not greater than the first threshold ΔL1 after the first time has elapsed since the start of application of the awakening stimulus (step S9, NO), the stimulus control unit 210 decides not to apply a super-awakening stimulus. The awakening state control system 1 then proceeds to step S15.

[0061] Also, in step S4, if it is determined that the difference between the calculated current vital value and the target vital value is positive (step S4, YES), the wakefulness state control system 1 in step S10 applies a relaxing stimulus to the user using the stimulus applying device 12.

[0062] Subsequently, in step S11, the wakefulness state control system 1 causes the stimulation control unit 210 to analyze the biological information acquired from the sensor 115, thereby acquiring the current vital values ​​of the user.

[0063] Next, in step S12, the arousal state control system 1 determines whether the absolute value of the difference between the calculated vital value and the target vital value is greater than a second threshold ΔL2 using the stimulus control unit 210. The second threshold ΔL2 used in this determination is used to determine whether to prepare to switch the stimulus applied to the user from a relaxing stimulus to a super-arousing stimulus. The value of the second threshold ΔL2 can be changed as appropriate depending on the mental and physical state of the user performing the work, the type of work, etc.

[0064] If it is determined in step S12 that the absolute value of the difference between the vital value and the target vital value is not greater than the second threshold ΔL2 (step S12, NO), the arousal state control system 1 determines that preparation for applying an ultra-arousal stimulus is unnecessary and proceeds to step S15. On the other hand, if it is determined in step S12 that the absolute value is greater than the second threshold ΔL2 (step S12, YES), the arousal state control system 1 determines in step S13 whether or not to apply an ultra-arousal stimulus to the user using stimulus control unit 210 in preparation for applying the ultra-arousal stimulus.

[0065] For example, if the absolute value of the difference between the vital value and the target vital value is greater than the second threshold ΔL2 after a second time has elapsed since the start of application of the relaxation stimulus (YES in step S13), the stimulus control unit 210 determines that the target vital value cannot be reached quickly under these conditions and determines to apply a super-arousal stimulus. The wakefulness state control system 1 then proceeds to step S14. The second time is, for example, a maximum of 30 minutes, preferably 15 minutes. However, the second time can be set appropriately depending on the mental and physical state of the user performing the work, the type of work, and the like. On the other hand, if the absolute value of the difference between the vital value and the target vital value is not greater than the second threshold ΔL2 after the second time has elapsed since the start of application of the relaxation stimulus (NO in step S13), the stimulus control unit 210 determines not to apply a super-arousal stimulus. The wakefulness state control system 1 then proceeds to step S15.

[0066] In step S14, the wakefulness state control system 1 applies a super-awakening stimulus to the user using the stimulus application device 12. Because the super-awakening stimulus has a strong awakening effect, it is preferable that it be applied for a maximum of 15 minutes or less, preferably 5 minutes or less. When the vital value does not change even when either the awakening stimulus or the relaxing stimulus is applied, the wakefulness state control system 1 applies the super-awakening stimulus, which has a strong awakening effect and can change the vital value. As a result, the wakefulness state control system 1 can bring the user out of a hyper-awakened state and quickly bring the user's vital value to the target vital value.

[0067] The application of super-arousal stimuli is particularly effective in situations where a relaxing stimulus does not lower vital signs. After the strong awakening effect of the super-arousal stimulus, the release of the stimulus reverses the effect and produces a strong relaxing effect. As a result, the wakefulness control system 1 can bring the user out of a hyperarousal state where a relaxing stimulus is ineffective.

[0068] Subsequently, in step S15, the wakefulness state control system 1 determines whether or not to end the process by the stimulus control unit 210. For example, the wakefulness state control system 1 determines to end the process when it detects that the user has finished the task.

[0069] If it is determined in step S15 that the process should not be terminated (step S15, NO), the wakefulness state control system 1 repeats the process from step S3 onwards until it is determined in step S15 that the process should be terminated. On the other hand, if it is determined in step S15 that the process should be terminated (step S15, YES), the wakefulness state control system 1 turns off the power of the sensor 115 in step S16 and then terminates the process.

[0070] The processing from step S5 to step S13 corresponds to a first mode in which a relaxing stimulus and an awakening stimulus are applied alternately or in parallel. Meanwhile, the processing in step S14 corresponds to a second mode in which an ultra-awakening stimulus is applied. If it is determined in step S15 that the processing is not to be terminated, the wakefulness state control system 1 performs the first mode again from step S3 onward. From another perspective, if the target vital value is not reached even after applying an awakening stimulus or a relaxing stimulus in the first mode, the stimulus application device 12 performs the second mode, applies an ultra-awakening stimulus in the second mode, and then performs the first mode. When the first mode is performed after performing the second mode, the application of the ultra-awakening stimulus in the second mode has brought the user out of the hyper-awakening state. Therefore, the wakefulness state control system 1 can quickly guide the user's vital value to the target vital value by subsequently applying an awakening stimulus or a relaxing stimulus in the first mode.

[0071] Although the above describes alertness control based on a specific embodiment, various modifications are possible within the scope of the technical concept of the present invention. If the wearable device 10 incorporates a sensor 115, a communicator 117, or a microprocessor 120, they do not necessarily need to be connected or installed to the curved portion 101 of the main body 110, but may be connected or installed at an appropriate location on the arm 130. The biological information acquired by the sensor 115 is not limited to heart rate data. Other biological data that can determine the user's state of tension or relaxation, such as respiratory rate, sweating level, or blink rate, may also be detected. In addition to thermal and electrical stimuli, aroma or light stimuli may also be applied. Wearable device 10 worn around the neck, as shown in FIG. 2, does not necessarily have to be configured to be worn around the neck. It may also be worn on other parts of the body, such as the wrist, earlobe, fingertip, forearm, thigh, shoulder, or back, as long as it can measure biological information such as pulse rate, body temperature, and sweating level and apply stimuli.

[0072] <Other aspects of wearable devices> FIG. 7 is a diagram showing a second example of a wearable device. FIG. 8 is a diagram showing an example of the configuration of the skin-contacting surface side of the wearable device 1000 of FIG. 7. The wearable device 1000 is configured to be worn on the wrist. The wearable device 1000 includes a main body 1001 and a mounting unit 1002. As shown in FIG. 8, the main body 1001 includes an operation unit 1003, a stimulus imparting device 1004, and a sensor 1005. The stimulus imparting device 1004 is arranged so as to contact the inside of the wrist, for example. The sensor 1005 is arranged in a position where biometric information can be easily acquired, for example, on the inside of the wrist or in a position that contacts an artery. An operation unit 1003 may be provided on the side of the main body 1001. The operation unit 1003 allows the user to turn the power on / off, adjust the intensity of the stimulus, etc. The main body 1001 has a built-in communication device 117 (see FIGS. 3A and 3B) or a microprocessor 120 (see FIG. 3C), and the acquired biological information is transmitted to a remote processor or analyzed within the wearable device 1000. Note that while FIG. 8 shows a case where there is only one stimulus imparting device 1004, this is not limiting. For example, another stimulus imparting device may be provided on the same surface of the main body 1001, so that multiple types of stimuli, such as thermal stimuli and electrical stimuli, can be imparted.

[0073] FIG. 9 is a diagram showing a third example of a wearable device. The wearable device 2000 is configured to be wearable on the ear. The wearable device 2000 includes a main body 2001, a mounting unit 2002, a stimulus imparting device 2003, and a sensor 2004. The main body 2001 incorporates the communication device 117 or the microprocessor 120. The wearable device 2000 may incorporate a speaker as the stimulus imparting device 2003. The speaker can impart sound stimuli to the user. Furthermore, when the stimulus imparting device 2003 that imparts, for example, a temperature stimulus is provided, it is preferably disposed on the contact surface of the mounting unit 2002 with the earlobe so as to easily contact the ear. Similarly, the sensor 2004 is preferably disposed in a position on the mounting unit 2002 that easily contacts the ear (earlobe).

[0074] Wearable devices 1000 and 2000 can also apply different types or intensities of stimulation to the user's wearing area based on the user's biological information.

[0075] The above embodiment may take the following forms. <1> The device has a sensor that acquires biometric information of a user, and a stimulus imparting device that imparts stimuli to the user to control the user's state of alertness based on vital values ​​obtained from the biometric information and serving as indicators of the user's state of alertness, wherein the stimuli imparted by the stimulus imparting device include a relaxing stimulus that leads the user's rate of change in vital value in a negative direction, an alerting stimulus that leads the rate of change in vital value in a positive direction, and a super-alerting stimulus that leads the rate of change in vital value in a positive direction to a greater extent than the alerting stimulus, and the rate of change in vital value is the ratio of change in the vital value when the stimulus is imparted to a predetermined standard vital value. <2> When the low frequency component of the heart rate fluctuation frequency is LF and the high frequency component of the heart rate fluctuation frequency is HF, the vital value is expressed as LF / HF. <1> 2 is a wakefulness control system according to the present invention. <3> When the vital value change rate is A, the vital value when the stimulus is applied is B, and the standard vital value is C, the vital value change rate is calculated by the following formula: A=(BC) / C×100 The aforementioned <1> or the above <2> 2 is a wakefulness control system according to the present invention. <4> The relaxation stimulus is a vital value change rate that is less than 0, the awakening stimulus is a vital value change rate that is equal to or greater than 0 and equal to or less than 200, and the super-awakening stimulus is a vital value change rate that is greater than 200. <1> From the above <3> The wakefulness control system according to any one of the above items. <5> The modes in which the stimulus imparting device imparts the stimulus include a first mode in which the relaxing stimulus and the awakening stimulus are imparted alternately or in parallel, and a second mode in which the super-awakening stimulus is imparted. <1> From the above <4> The wakefulness control system according to any one of the above items. <6> the stimulus imparting device performs the second mode when the target vital value is not reached even after imparting the awakening stimulus or the relaxing stimulus in the first mode, and performs the first mode after imparting the super-awakening stimulus in the second mode; <5> 2 is a wakefulness control system according to the present invention. <7> The wearable device has a main body and a stimulus imparting device that imparts stimuli to a user wearing the main body to control the user's state of alertness based on vital values ​​obtained from the user's biometric information and serving as an indicator of the user's state of alertness, wherein the stimuli imparted by the stimulus imparting device include a relaxation stimulus, an alert stimulus whose rate of change in vital values ​​is greater than that of the relaxation stimulus, and a super-alert stimulus whose rate of change in vital values ​​is greater than that of the alert stimulus, and the rate of change in vital values ​​is the ratio of change in the vital value when the stimulus is imparted to a predetermined standard vital value. <8> a sensor for acquiring the biological information; and a communication device for transmitting the biological information to an information processing device and receiving a control signal for driving the stimulus applying device from the information processing device. <7> The wearable device is described in <9> a processor that acquires and analyzes the biological information from the sensor, and the stimulus applying device is driven based on the analysis result of the biological information by the processor; <7> or the above <8> The wearable device is described in <10> a processor that analyzes the biological information; and a biological sensor connected to the processor, wherein the processor analyzes the biological information based on an output of the biological sensor, and the stimulus applying device is driven based on an analysis result of the biological information by the processor; <7> From the above <9> The wearable device is described in any one of the above. <11> An alertness control method using an alertness control system, wherein the alertness control system acquires biometric information of a user using a sensor, and provides stimuli to the user using a stimulus-providing device to control the alertness based on vital values ​​obtained from the biometric information and serving as indicators of the user's alertness, the stimuli provided by the stimulus-providing device including a relaxing stimulus that leads the rate of change of the user's vital value in a negative direction, an alerting stimulus that leads the rate of change of the vital value in a positive direction, and a super-alert stimulus that leads the rate of change of the vital value in a positive direction greater than the alerting stimulus, and the rate of change of the vital value is the ratio of change in the vital value when the stimulus is provided to a predetermined target vital value. <12> The mode in which the stimulus-giving device provides the stimulus includes a first mode in which the stimulus-giving device provides the awakening stimulus and the relaxing stimulus alternately or in parallel, and a second mode in which the stimulus-giving device provides the super-awakening stimulus. <11> 2. The wakefulness control method according to claim 1, wherein [Explanation of symbols]

[0076] 1. Arousal control system 10, 10A, 10B, 10C, 1000, 2000 Wearable Devices 12, 12a, 12b, 12c, 1004, 2003 Stimulation device 101 Curved section 110, 1001, 2001 main unit 115, 1005, 2004 sensors 116 Cable 117 Communication Device 120 microprocessors 121, 122 1st electrode 123, 124 2nd electrode 125,126 3rd electrode 130 Arm 200 Information processing device 201 processor 202 Main Memory 203 Auxiliary Memory 204 Input / Output Interface 205 Communication Interface 210 Stimulation control unit 211 Biometric information acquisition unit 212 Target level setting section 213 Data Analysis Department 214 Stimulus determining section 215 Evaluation Department 1002, 2002 mounting part 1003 Operation section ΔL1 First threshold ΔL2 Second threshold [Prior art documents] [Patent documents]

[0077] [Patent Document 1] Japanese Patent Application Publication No. 2020-2029716

Claims

1. a sensor for acquiring biometric information of a user; a stimulus imparting device that imparts a stimulus to the user to control the wakefulness state based on a vital value that is obtained from the biological information and serves as an index indicating the wakefulness state of the user, the stimuli applied by the stimulus applying device include a relaxing stimulus that causes the rate of change in the vital value of the user to be negative, an awakening stimulus that causes the rate of change in the vital value to be positive, and a super-awakening stimulus that is greater than the awakening stimulus and causes the rate of change in the vital value to be positive, An alertness state control system, wherein the vital value change rate is a ratio of change in the vital value when the stimulus is applied to a predetermined standard vital value.

2. If the low frequency component of the heart rate fluctuation frequency is LF and the high frequency component of the heart rate fluctuation frequency is HF, then The wakefulness control system according to claim 1 , wherein the vital values ​​are expressed as LF / HF.

3. When the vital value change rate is A, the vital value when the stimulus is applied is B, and the standard vital value is C, the vital value change rate is calculated by the following formula: A=(B-C) / C×100 3. The wakefulness control system according to claim 1 or 2.

4. The relaxation stimulus is a stimulus in which the rate of change in vital value is less than 0, the awakening stimulus is a vital value change rate of 0 or more and 200 or less, 3. The wakefulness state control system according to claim 1, wherein the super-awakening stimulus is a vital value change rate greater than 200.

5. 3. The alertness state control system of claim 1, wherein the modes in which the stimulus delivery device delivers the stimulus include a first mode in which the relaxing stimulus and the awakening stimulus are delivered alternately or in parallel, and a second mode in which the ultra-awakening stimulus is delivered.

6. 6. The alertness state control system of claim 5, wherein the stimulus-giving device performs the second mode when the target vital value is not reached even after the awakening stimulus or the relaxing stimulus is given in the first mode, and performs the first mode after giving the ultra-awakening stimulus in the second mode.

7. The main body and a stimulus imparting device that imparts a stimulus to the user to control the wakefulness state based on a vital value that is obtained from biological information of the user wearing the main body and that is an index indicating the wakefulness state of the user, the stimuli applied by the stimulus applying device include a relaxing stimulus, an awakening stimulus having a greater rate of change in vital value than the relaxing stimulus, and a super-awakening stimulus having a greater rate of change in vital value than the awakening stimulus; A wearable device, wherein the vital value change rate is a ratio of change in the vital value when the stimulus is applied to a predetermined standard vital value.

8. a sensor for acquiring the biological information; The wearable device according to claim 7 , further comprising: a communication device that transmits the biological information to an information processing device and receives a control signal for driving the stimulating device from the information processing device.

9. a processor that acquires and analyzes the biological information from the sensor; The wearable device according to claim 7 or 8, wherein the stimulus applying device is driven based on a result of analysis of the biological information by the processor.

10. a processor that analyzes the biological information; a biosensor connected to the processor; The processor analyzes the biological information based on the output of the biological sensor; The wearable device according to claim 7 or 8, wherein the stimulus applying device is driven based on a result of analysis of the biological information by the processor.

11. 1. A method for controlling an alertness state by an alertness state control system, comprising: The sensor acquires the user's biometric information, a stimulus applying device applies a stimulus to the user to control the wakefulness state based on a vital value obtained from the biological information and serving as an index indicating the wakefulness state of the user; the stimuli applied by the stimulus applying device include a relaxing stimulus that causes the rate of change in the vital value of the user to be negative, an awakening stimulus that causes the rate of change in the vital value to be positive, and a super-awakening stimulus that is greater than the awakening stimulus and causes the rate of change in the vital value to be positive, The vital value change rate is a rate of change in the vital value when the stimulus is applied, relative to a predetermined target vital value.

12. The wakefulness state control method of claim 11, wherein the modes in which the stimulus-giving device delivers the stimulus include a first mode in which the stimulus-giving device delivers the awakening stimulus and the relaxing stimulus alternately or in parallel, and a second mode in which the stimulus-giving device delivers the super-awakening stimulus.

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