WO2016088819A1

WO2016088819A1 - Fatigue detection device

Info

Publication number: WO2016088819A1
Application number: PCT/JP2015/083962
Authority: WO
Inventors: 亨志牟田
Original assignee: 株式会社村田製作所
Priority date: 2014-12-05
Filing date: 2015-12-03
Publication date: 2016-06-09
Also published as: JPWO2016088819A1; JP6226088B2

Abstract

A fatigue detection device (1) is provided with the following: a neckband (13) that can be worn along the circumferential direction of the neck of a user; a pair of biological-use electrodes (15, 15) that are attached to the neckband (13) and that acquire a biological signal which includes a myoelectric signal; a frequency analysis unit (331) that finds a frequency spectrum by performing frequency analysis on the acquired biological signal which includes the myoelectric signal; a myoelectric component acquisition unit (332) that acquires the ratio (myoelectric component ratio) of a power-value of a second frequency spectrum in a second frequency band, in which the proportion of myoelectric components to electrocardiographic components is higher than that in a first frequency band, to a power value of a first frequency spectrum in the first frequency band, in which the proportion of myoelectric components to electrocardiographic components is low; and a fatigue determination unit (333) which determines that a user is fatigued if the myoelectric component ratio is at least a reference value.

Description

Fatigue detection device

The present invention relates to a fatigue detection device.

Recently, a technique for detecting human fatigue has been proposed (see, for example, Patent Document 1). Here, Patent Document 1 establishes fatigue level determination reference value data for LF / HF values, and compares the subject's LF / HF value calculated from the pulse interval (or heart rate interval) with the fatigue level determination reference value data. Thus, a fatigue level determination processing system for determining the level of fatigue is disclosed.

In the fatigue level determination processing system described in Patent Document 1, for example, the aa interval of the acceleration pulse wave is expressed by a low frequency component (LF: about 0.04-0. 15 Hz) and high frequency components (HF: about 0.15-0.40 Hz), and the LF value is the working value of the subject's sympathetic nerve and the HF value is the working value of the subject's parasympathetic nerve. According to this fatigue level determination processing system, by using the LF / HF value, the enhancement of the sympathetic nerve function can be evaluated, and the fatigue level can be objectively evaluated.

JP 2010-201113 A

By the way, in the fatigue determination processing system using the LF / HF values described above, it is necessary to obtain data such as a pulse or a heart rate when the state of the autonomic nerve (that is, the sympathetic nerve and the parasympathetic nerve) is stable. The user is required to rest in a resting posture, for example, for about 5 minutes before measurement. Then, after taking a sufficient rest, it is necessary to continuously measure the photoelectric pulse wave or the electrocardiogram for 3 minutes or more (or 100 beats or more, for example) as it is.

Therefore, in the above-described fatigue level determination processing system, when sufficient rest cannot be taken before measurement, or when resting state cannot be maintained during measurement, the sympathetic nerve is dominant, and the correct fatigue state is evaluated. There was a risk that it could not be done. In addition, in this fatigue level determination processing system, the fatigue level determination accuracy is directly affected by whether or not the aa interval of the acceleration pulse wave can be accurately acquired. There was a problem that it was easy to decrease. Therefore, in the fatigue level determination processing system described in Patent Literature 1, it has been difficult to stably and accurately detect whether or not the user is fatigued.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a fatigue detection device capable of detecting whether or not the user is fatigued more stably and accurately. .

A fatigue detection device according to the present invention includes a mounting member that can be mounted along a circumferential direction of a user's neck, a plurality of biological electrodes that are attached to the mounting member and acquire a biological signal including a myoelectric signal, Frequency analysis means for obtaining a frequency spectrum by performing frequency analysis on biological signals obtained by a plurality of biological electrodes, myoelectric component acquisition means for obtaining an myoelectric component from the frequency spectrum obtained by the frequency analysis means, Fatigue determination means for determining fatigue when the myoelectric component acquired by the component acquisition means is greater than or equal to a reference value.

By the way, when the state where force is applied to the neck (that is, the state where the amount of myoelectric signal of the neck is large) continues, it can be assumed that the patient is in a state of tension or fatigue. Therefore, according to the fatigue detection device of the present invention, a biological signal including a myoelectric signal is acquired from the user's neck, subjected to frequency analysis, and a myoelectric component is acquired from the frequency analysis result (frequency spectrum). The Then, the myoelectric component and the reference value are compared to determine whether or not the user is fatigued. In this way, since the myoelectric signal acquired from the neck is used and it is determined whether or not the user is fatigued based on the frequency analysis result (frequency spectrum), it is determined whether or not the user is fatigued. It becomes possible to detect more stably and accurately.

In the fatigue detection device according to the present invention, the fatigue determination means determines that the user is fatigued when the ratio of the time during which the myoelectric component is equal to or higher than the reference value within a predetermined time is equal to or higher than the predetermined ratio. It is preferable to do.

In this case, it is determined that the user is tired when the time ratio in which the myoelectric component is equal to or higher than the reference value is equal to or higher than a predetermined ratio. Therefore, for example, when it is in a temporary tension state (when a force is temporarily applied to the neck), it can be prevented from being determined to be tired, and the accuracy of fatigue detection can be improved. It becomes possible to improve.

In the fatigue detection device according to the present invention, it is preferable that the fatigue determination means determine that the user is fatigued when a state where the myoelectric component is equal to or higher than a reference value continues for a predetermined time or longer.

In this case, when the state where the myoelectric component is equal to or higher than the reference value continues for a predetermined time or more, it is determined that the user is tired. Therefore, for example, when it is in a temporary tension state (when a force is temporarily applied to the neck), it can be prevented from being determined to be tired, and the accuracy of fatigue detection can be improved. It becomes possible to improve.

A fatigue detection device according to the present invention includes a mounting member that can be mounted along a circumferential direction of a user's neck, a plurality of biological electrodes that are attached to the mounting member and acquire a biological signal including a myoelectric signal, Frequency analysis means for obtaining a frequency spectrum by performing frequency analysis on biological signals acquired by a plurality of biological electrodes, and a power value of the first frequency spectrum in a first frequency band having a low myoelectric component ratio relative to an electrocardiographic component The myoelectric component acquisition means for acquiring the ratio of the power values of the second frequency spectrum in the second frequency band having a higher myoelectric component ratio than the first frequency band, and the myoelectric component acquisition means, Fatigue determination means for determining fatigue when the ratio of the power value of the second frequency spectrum to the power value of the first frequency spectrum is greater than or equal to a reference value. And wherein the Rukoto.

According to the fatigue detection device of the present invention, a biological signal including a myoelectric signal is acquired from the neck of the user, subjected to frequency analysis, and based on the frequency analysis result (frequency spectrum), the myoelectric for the electrocardiographic component is obtained. The ratio of the myoelectric component is higher than that of the first frequency band with respect to the power value of the first frequency spectrum in the first frequency band in which the ratio of the component is low (the electrocardiographic component is greater than the myoelectric component). The ratio of the power value of the second frequency spectrum in the second frequency band is obtained (the electrocardiogram component is less than the electrical component). Then, the ratio and the reference value are compared to determine whether or not the user is fatigued. Here, since the ratio increases as the myoelectric component increases, the myoelectric component can be obtained with high accuracy. As described above, since the myoelectric signal obtained from the neck is used and it is determined whether or not the user is tired based on the ratio obtained from the frequency analysis result (frequency spectrum), the noise It is possible to detect whether or not the vehicle is fatigued more stably and accurately.

In the fatigue detection device according to the present invention, the fatigue determination means determines that the tire is fatigued when the ratio of the time in which the ratio is equal to or higher than the reference value within a predetermined time is equal to or higher than the predetermined ratio. It is preferable.

In this case, it is determined that the user is tired when the time ratio in a state where the ratio is equal to or greater than the reference value is equal to or greater than a predetermined ratio. Therefore, for example, when it is in a temporary tension state (when a force is temporarily applied to the neck), it can be prevented from being determined to be tired, and the accuracy of fatigue detection can be improved. It becomes possible to improve.

In the fatigue detection device according to the present invention, it is preferable that the fatigue determination means determine that the tire is fatigued when the state where the ratio is equal to or higher than the reference value continues for a predetermined time or longer.

In this case, when the state where the ratio is equal to or higher than the reference value continues for a predetermined time or more, it is determined that the user is tired. Therefore, for example, when it is in a temporary tension state (when a force is temporarily applied to the neck), it can be prevented from being determined to be tired, and the accuracy of fatigue detection can be improved. It becomes possible to improve.

The fatigue detection device according to the present invention further includes an acceleration sensor that is attached to the mounting member and detects the acceleration of the neck of the subject, and when the acceleration detected by the acceleration sensor exceeds a predetermined threshold value The fatigue determination means preferably stops determining whether or not the user is fatigued.

In this way, for example, when the neck is moved (that is, when the myoelectric amount is temporarily increased due to the movement of the neck or the body motion noise is large), fatigue determination is stopped. Therefore, erroneous detection due to body movement can be prevented, and fatigue can be detected with higher accuracy.

In the fatigue detection device according to the present invention, it is preferable that the plurality of biomedical electrodes have one common electrode and one or more biomedical electrodes each paired with the common electrode.

For example, in the case of having three or more biological electrodes, a biological signal that is more suitable for processing is selected from a plurality of biological signals (myoelectric components) by using the biological electrodes in combination. It is possible to improve the detection accuracy of the myoelectric component. Further, the background noise can be removed by detecting the background noise using one of the biological electrode pairs. Therefore, the accuracy of fatigue determination can be further improved.

In the fatigue detection device according to the present invention, it is preferable that at least a pair of the living body electrodes among the plurality of living body electrodes is a living body electrode for measuring a living body signal including an electrocardiographic signal.

In this way, it is possible to simultaneously measure an electrocardiogram signal without providing a dedicated electrode for detecting the electrocardiogram signal. Therefore, together with the presence or absence of fatigue, for example, biological information such as heart rate and heart rate interval can be measured simultaneously.

In the fatigue detection device according to the present invention, the mounting member is preferably a neckband. In this way, it is possible to simply detect fatigue by simply attaching a neckband type fatigue detection device to the neck.

Further, in the fatigue detection device according to the present invention, the mounting member has a mounting body portion that is flexible and formed in a substantially band shape, and an adhesive portion that has adhesiveness attached to the mounting body portion. The adhesive part preferably has at least a part of conductivity and functions as the biological electrode.

In this case, since the adhesive portion having adhesiveness is attached to the flexible mounting body portion that is formed in a substantially strip shape, the mounting body portion (mounting member) is attached using the adhesiveness of the adhesive portion. Can be attached (attached) to the neck. In addition, since at least a part of the adhesive portion has conductivity and functions as a biological electrode, it is possible to easily detect fatigue by simply attaching (attaching) the attachment member to the neck portion.

It is preferable that the fatigue detection device according to the present invention further includes a presentation unit that presents the user with the fatigue state when it is determined that the fatigue state is present.

In this way, it is possible to inform the user that they are tired, and it is possible to prevent the user from becoming overly fatigued.

It is preferable that the fatigue detection apparatus according to the present invention further includes a heating means for heating the neck when it is determined that the fatigue state is present.

In this way, when the user is tired, the fatigue can be reduced or reduced by heating the neck.

In the fatigue detection device according to the present invention, it is preferable that the heating means warms the neck by raising the temperature of the living body electrode.

In this case, since the user's neck is heated via the living body electrode, there is no need to provide a separate heating portion. In addition, since the biomedical electrode is in contact with the user's neck, the neck can be reliably and efficiently heated.

According to the present invention, it is possible to detect whether or not the user is tired more stably and accurately.

It is a perspective view which shows the external appearance of the fatigue detection apparatus which concerns on 1st Embodiment. It is a perspective view which shows the structure (state which opened the frame) of the sensor part which comprises the fatigue detection apparatus which concerns on 1st Embodiment. It is a figure which shows the structure (state which closed the frame) of the sensor part which comprises the fatigue detection apparatus which concerns on 1st Embodiment. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is a block diagram which shows the function structure of the fatigue detection apparatus which concerns on 1st Embodiment. It is a figure which shows an example of the frequency spectrum of each biological signal when not including and including a myoelectric signal. It is a flowchart which shows the process sequence of the fatigue detection process by the fatigue detection apparatus which concerns on 1st Embodiment. It is a block diagram which shows the function structure of the fatigue detection apparatus which concerns on 2nd Embodiment. It is a perspective view which shows the external appearance of the fatigue detection apparatus which concerns on 3rd Embodiment. (A) is a top view which shows the external appearance of the fatigue detection apparatus which concerns on 3rd Embodiment. (B) is a bottom view which shows the external appearance of the fatigue detection apparatus which concerns on 3rd Embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Moreover, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

(First embodiment)
First, the configuration of the fatigue detection device 1 according to the first embodiment will be described with reference to FIGS. FIG. 1 is a perspective view illustrating an appearance of a fatigue detection device 1 according to the first embodiment. FIG. 2 is a perspective view showing the configuration of the sensor unit 12 (the state in which the frame body 12b is opened) constituting the fatigue detection device 1. FIG. 3 is a diagram illustrating a configuration of the sensor unit 12 (a state in which the frame body 12b is closed). 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a block diagram showing a functional configuration of the fatigue detection apparatus 1.

The fatigue detection device 1 detects fatigue by being mounted on the neck (neck muscle) (see FIG. 1), and is elastically mounted so as to sandwich the neck from the back side of the user's neck. A substantially U-shaped neckband (mounting member) 13 and a pair of

sensor parts

11 and 12 that are disposed at both ends of the neckband 13 and come into contact with both sides of the neck of the user are provided.

The neckband 13 can be worn along the circumferential direction of the user's neck. That is, as shown in FIG. 1, the neckband 13 is worn along the back of the user's neck from one side of the user's neck to the other side of the neck. More specifically, the neck band 13 includes, for example, a belt-shaped plate spring and a rubber tube that covers the plate spring. Therefore, the neckband 13 is biased so as to shrink inward, and when the user wears the neckband 13, the neckband 13 (sensor units 11 and 12) is in contact with the neck of the user. Retained.

In addition, it is preferable to use what has biocompatibility as a rubber tube. Moreover, it can replace with a rubber tube and can use the tube which consists of plastics, for example. In the rubber tube, a cable for electrically connecting both

sensor units

11 and 12 is also wired. Here, it is desirable that the cable be coaxial in order to reduce noise.

The sensor unit 12 (11) mainly sandwiches the periphery of the conductive cloth 15 between the conductive cloth 15 formed in a rectangular flat shape, the main body 12a on which the conductive cloth 15 is set, and the main body 12a. It has the frame 12b to hold down, and the input terminal 14 provided on the surface of the main body 12a facing the frame 12b. In this embodiment, the conductive cloth 15 is used as a biological electrode for detecting a biological signal including a myoelectric signal or an electrocardiographic signal. Moreover, one sensor part 12 has the photoelectric pulse wave sensor 20 in addition to the said structure. Instead of or in addition to the photoelectric pulse wave sensor 20, a piezoelectric pulse wave sensor, an oxygen saturation sensor, a sound sensor (microphone), a displacement sensor, a temperature sensor, a humidity sensor, or the like may be used.

Also, an acceleration sensor 22 that detects the acceleration of the subject's neck (that is, whether or not the neck is moving) is attached to the sensor unit 11 (or sensor unit 12) of the neckband 13. For example, a gyro sensor or the like may be used instead of the acceleration sensor.

As the conductive cloth 15 serving as the living body electrode, a woven fabric or a knitted fabric made of conductive yarn having conductivity is used. In this embodiment, the conductive cloth 15 is formed in a rectangular planar shape. Here, as the conductive yarn, for example, a resin yarn whose surface is plated with Ag, a carbon nanotube-coated one, or a conductive polymer such as PEDOT may be used. Moreover, you may use the conductive polymer thread | yarn which has electroconductivity. In order to prevent fraying and the like, the conductive cloth 15 is preferably subjected to end treatment such as folding four sides and sewing with a sewing machine, or cutting and welding treatment using laser or ultrasonic waves.

The main body 12a is formed of, for example, a resin so that it has a thin, approximately semi-cylindrical shape, that is, a surface in contact with the neck when drawing in a cross section along the short side. Thereby, a feeling of wearing is improved. Further, the main body portion 12a is formed such that a portion facing the frame body 12b (a region in which the frame body 12b fits) is recessed by the thickness of the frame body 12b (or deeper than the thickness).

The frame body 12b is formed in a rectangular shape. Further, the frame body 12 b is formed so that its dimension (outer edge) is slightly larger than that of the conductive cloth 15. The shape of the conductive cloth 15 and the shape of the frame body 12b are not limited to a rectangle.

A hinge portion is provided on one side surface of the main body portion 12a, and the frame body 12b can be opened and closed with the hinge portion as a fulcrum. On the other hand, two groove portions 12c are formed on the other side surface of the main body portion 12a. The frame 12b is fixed (locked) to the main body 12a by fitting a claw (not shown) formed in the frame 12b into the groove 12c. That is, as shown in FIG. 2, the frame 12b is opened, the conductive cloth 15 is set on the main body 12a, and then the frame 12b is closed and locked to easily set (or replace) the conductive cloth 15. )can do. The frame body 12b may be configured to be removable.

An input terminal 14 is disposed at a position facing the frame 12b of the main body 12a. When the conductive cloth 15 is sandwiched between the main body 12a and the frame body 12b, the conductive cloth 15 and the input terminal 14 are electrically connected. The conductive cloth (biological electrode) 15 is connected to a signal processing unit 31 described later via the input terminal 14.

As described above, the main body portion 12a is formed such that the portion facing the frame body 12b (the area in which the frame body 12b fits) is recessed by the thickness of the frame body 12b (or deeper than the thickness). Therefore, in a state where the conductive cloth 15 is set on the main body portion 12a, the surface of the frame body 12b is substantially the same as the surface of the central portion of the conductive cloth 15 as shown in FIG. It is fixed at a position that is recessed (lower) than the central portion of. Thereby, when it mounts | wears with a neck part, the conductive cloth 15 can be made to contact a neck part stably.

A photoelectric pulse wave sensor that has a light emitting element 201 and a light receiving element 202 in the vicinity of the conductive cloth (biological electrode) 15 on the inner surface (the surface in contact with the neck portion) of the main body 12a and detects a photoelectric pulse wave signal. 20 is arranged. The photoelectric pulse wave sensor 20 is a sensor that optically detects a photoelectric pulse wave signal using the light absorption characteristic of blood hemoglobin.

The light emitting element 201 emits light according to a pulsed drive signal output from a drive unit 350 of the signal processing unit 31 described later. As the light emitting element 201, for example, an LED, a VCSEL (Vertical Cavity Surface Emitting LASER), or a resonator type LED can be used. Note that the driving unit 350 generates and outputs a pulsed driving signal for driving the light emitting element 201.

The light receiving element 202 outputs a detection signal corresponding to the intensity of light irradiated from the light emitting element 201 and transmitted through the neck or reflected from the neck. As the light receiving element 202, for example, a photodiode or a phototransistor is preferably used. In the present embodiment, a photodiode is used as the light receiving element 202.

The light receiving element 202 is connected to the signal processing unit 31, and a detection signal (photoelectric pulse wave signal) obtained by the light receiving element 202 is output to the signal processing unit 31.

In addition, a battery (not shown) that supplies power to the photoelectric pulse wave sensor 20, the signal processing unit 31, the wireless communication module 60, and the like is accommodated in one sensor unit 11 (main body unit 11a). The other sensor unit 12 (main body unit 12a) includes a signal processing unit 31, fatigue information (fatigue determination result), a measured myoelectric signal, an electrocardiogram signal, a photoelectric pulse wave signal, and a pulse wave propagation time. A wireless communication module 60 that transmits biometric information such as such to an external device is housed.

The pair of biological electrodes (conductive cloth) 15 and 15 and the photoelectric pulse wave sensor 20 are each connected to a signal processing unit 31, and detected biological signals (myoelectric signals and electrocardiographic signals) and photoelectric pulses. A wave signal is input to the signal processing unit 31. The acceleration sensor 22 is also connected to the signal processing unit 31, and the detected acceleration signal is input to the signal processing unit 31.

The signal processing unit 31 mainly acquires a myoelectric component (or an index value indicating the magnitude of the myoelectric component) from a biological signal including the myoelectric signal and the electrocardiographic signal, and is in a fatigue state according to the myoelectric component. A determination is made (details will be described later). In addition, the signal processing unit 31 processes the input electrocardiogram signal to measure the heart rate and the heart rate interval, and also processes the input photoelectric pulse wave signal to measure the pulse rate and the pulse interval. To do. Further, the signal processing unit 31 measures the pulse wave propagation time from the time difference between the detected R wave peak of the electrocardiogram signal (electrocardiogram) and the peak of the first photoelectric pulse wave signal (pulse wave).

The signal processing unit 31 includes a biological signal amplification unit 311, a pulse wave signal amplification unit 321, a first signal processing unit 310, a second signal processing unit 320,

peak detection units

316 and 326,

peak correction units

318 and 328, and pulse wave propagation. It has a time measurement unit 330, a frequency analysis unit 331, a myoelectric component acquisition unit 332, and a fatigue determination unit 333. The first signal processing unit 310 includes an analog filter 312, an A / D converter 313, and a digital filter 314. On the other hand, the second signal processing unit 320 includes an analog filter 322, an A / D converter 323, a digital filter 324, and a second-order differentiation processing unit 325.

Here, among the above-described units, the

digital filter

314, 324, the second-order differentiation processing unit 325, the

peak detection unit

316, 326, the

peak correction unit

318, 328, the pulse wave propagation time measurement unit 330, the frequency analysis unit 331, the muscle The electric component acquisition unit 332 and the fatigue determination unit 333 temporarily store various data such as a CPU that performs arithmetic processing, a ROM that stores programs and data for causing the CPU to execute each processing, and arithmetic results. It is comprised by RAM etc. That is, the functions of the above-described units are realized by executing the program stored in the ROM by the CPU.

The biological signal amplifier 311 is configured by an amplifier using an operational amplifier, for example, and amplifies the biological signals (myoelectric signal and electrocardiographic signal) detected by the pair of biological electrodes (conductive cloth) 15 and 15. The biological signal (myoelectric signal and electrocardiographic signal) amplified by the biological signal amplification unit 311 is output to the first signal processing unit 310. Similarly, the pulse wave signal amplifying unit 321 is configured by an amplifier using, for example, an operational amplifier, and amplifies the photoelectric pulse wave signal detected by the photoelectric pulse wave sensor 20. The photoelectric pulse wave signal amplified by the pulse wave signal amplification unit 321 is output to the second signal processing unit 320.

As described above, the first signal processing unit 310 includes the analog filter 312, the A / D converter 313, and the digital filter 314, and the biological signal (myoelectric signal and electrocardiogram) amplified by the biological signal amplification unit 311. The pulsation component (including the myoelectric component) is extracted by performing a filtering process on No.).

Further, as described above, the second signal processing unit 320 includes the analog filter 322, the A / D converter 323, the digital filter 324, and the second-order differentiation processing unit 325, and is amplified by the pulse wave signal amplification unit 321. The pulsating component is extracted by subjecting the photoelectric pulse wave signal to filtering processing and second-order differentiation processing.

The analog filters 312, 322 and the

digital filters

314, 324 remove components (noise) other than the frequency characterizing the electrocardiogram signal (including myoelectric signal) and the photoelectric pulse wave signal, and improve the S / N. For filtering. More specifically, an ECG signal (including myoelectric signal) is generally dominated by a frequency component of 0.1 to 200 Hz, and a photoelectric pulse wave signal is dominated by a frequency component of 0.1 to several tens of Hz. Filtering is performed using

analog filters

312, 322 such as a low-pass filter and a band-pass filter, and

digital filters

314, 324, and the S / N is improved by selectively passing only signals in the frequency range.

In the case where only the extraction of pulsation components is intended, in order to improve noise resistance, components other than the pulsation component may be blocked by narrowing the pass frequency range. The analog filters 312, 322 and the

digital filters

314, 324 are not necessarily provided, and only one of the analog filters 312, 322 and the

digital filters

314, 324 may be provided. Note that the electrocardiogram signal subjected to the filtering process by the analog filter 312 and the digital filter 314 is output to the peak detection unit 316. Similarly, the photoelectric pulse wave signal subjected to the filtering process by the analog filter 322 and the digital filter 324 is output to the second-order differentiation processing unit 325.

The second-order differentiation processing unit 325 obtains a second-order differential pulse wave (acceleration pulse wave) signal by second-order differentiation of the photoelectric pulse wave signal. The acquired acceleration pulse wave signal is output to the peak detector 326. The peak (rising point) of the photoelectric pulse wave is not clearly changed and may be difficult to detect. Therefore, it is preferable to detect the peak by converting it to an acceleration pulse wave. However, a second-order differential processing unit 325 is provided. Is not essential and may be omitted.

The peak detection unit 316 detects the peak (R wave) of the electrocardiogram signal that has been subjected to signal processing by the first signal processing unit 310 (the pulsating component has been extracted). On the other hand, the peak detection unit 326 detects the peak of the photoelectric pulse wave signal (acceleration pulse wave) subjected to the filtering process by the second signal processing unit 320. Each of the peak detection unit 316 and the peak detection unit 326 performs peak detection within the normal range of the heartbeat interval and the pulse interval, and information on the peak time, peak amplitude, and the like for all detected peaks is stored in the RAM or the like. save.

The peak correction unit 318 obtains the delay time of the electrocardiogram signal in the first signal processing unit 310 (analog filter 312 and digital filter 314). The peak correction unit 318 corrects the peak of the electrocardiogram signal detected by the peak detection unit 316 based on the obtained delay time of the electrocardiogram signal. Similarly, the peak correction unit 328 obtains the delay time of the photoelectric pulse wave signal in the second signal processing unit 320 (analog filter 322, digital filter 324, second-order differentiation processing unit 325). The peak correction unit 328 corrects the peak of the photoelectric pulse wave signal (acceleration pulse wave signal) detected by the peak detection unit 326 based on the obtained delay time of the photoelectric pulse wave signal. The corrected peak of the electrocardiogram signal and the corrected peak of the photoelectric pulse wave signal (acceleration pulse wave) are output to the pulse wave propagation time measurement unit 330. Note that providing the peak correction unit 318 is not essential and may be omitted.

The pulse wave propagation time measurement unit 330 is configured to detect an interval (time difference) between the R wave peak of the electrocardiogram signal corrected by the peak correction unit 318 and the peak of the photoelectric pulse wave signal (acceleration pulse wave) corrected by the peak correction unit 328. ) To determine the pulse wave propagation time.

The pulse wave propagation time measurement unit 330 calculates, for example, a heart rate, a heartbeat interval, a heartbeat interval change rate, and the like from an electrocardiogram signal in addition to the pulse wave propagation time. Similarly, the pulse wave propagation time measurement unit 330 calculates a pulse rate, a pulse interval, a pulse interval change rate, and the like from the photoelectric pulse wave signal (acceleration pulse wave).

The frequency analysis unit 331 performs frequency analysis on a biological signal (including myoelectric signal and electrocardiographic signal) obtained by the pair of

biological electrodes

15 and 15 and filtered by the signal processing unit 310 to obtain a frequency spectrum. get. That is, the frequency analysis unit 331 functions as a frequency analysis unit described in the claims. Examples of the frequency analysis method include a fast Fourier transform method (FFT method), a maximum entropy method (MEM method), and a wavelet method.

Here, FIG. 6 shows an example of the frequency spectrum of each biological signal when the myoelectric signal is included and when it is not included. The horizontal axis in FIG. 6 is frequency (Hz), and the vertical axis is signal intensity. In FIG. 6, the frequency spectrum of a biological signal that does not include a myoelectric signal (that is, only the electrocardiographic signal) is indicated by a solid line, and the frequency spectrum of the biological signal that includes a myoelectric signal is indicated by a broken line.

As shown by the solid line in FIG. 6, the frequency component of the electrocardiogram is particularly large from 0.25 to 30 Hz. Since the frequency component of the electrocardiogram waveform has a frequency component corresponding to the heart rate, a peak in the range of 0.25 to 1.5 Hz corresponding to the heart rate (40 to 240 beats / min) and a peak of its harmonics are included. Have. There are also frequency components of the waveform itself, but there are many components below 30 Hz. Note that the frequency band where the frequency component of the photoelectric pulse wave is particularly large is the same as that of the electrocardiogram, but the frequency side is lower than that of the electrocardiogram. On the other hand, myoelectric signals have a wide frequency component, and there are many ratios of signals of 100 Hz or higher. In FIG. 6, the frequency spectrum of the biological signal including the myoelectric signal is gently attenuated at 40 Hz or more because of the influence of the LPF.

The frequency analysis unit 331 determines that the acceleration of the neck detected by the acceleration sensor 22 is equal to or greater than a predetermined threshold (that is, when the neck moves and body motion noise is expected to increase). The frequency analysis of the above-described biological signals (myoelectric signal and electrocardiographic signal) is stopped. In other words, when there is body movement, noise is likely to be applied, and the accuracy of the required myoelectric component may be reduced. When the body is moving, force is applied to the neck (neck) regardless of fatigue. Therefore, the acceleration sensor 22 determines a state in which the user has little movement, and performs a frequency analysis of the biological signal only when such a state continues for a predetermined time, and the frequency analysis result (frequency spectrum) ) To determine the fatigue state. The frequency analysis result (frequency spectrum) acquired by the frequency analysis unit 331 is output to the myoelectric component acquisition unit 332.

As described above, the myoelectric signal has a wide frequency component, whereas the electrocardiographic signal has many components of 30 Hz or less (see FIG. 6). Therefore, the myoelectric component acquisition unit 332 has the first frequency in the first frequency band (for example, 10 to 20 Hz) in which the ratio of the myoelectric component to the electrocardiographic component is low (the electrocardiographic component is large relative to the myoelectric component). The power value of the spectrum and the second frequency in the second frequency band (for example, 30 to 50 Hz) in which the ratio of the myoelectric component is higher than the first frequency band (the electrocardiographic component is smaller than the myoelectric component) Obtain the power value of the spectrum. Then, the myoelectric component acquisition unit 332 acquires the ratio of the power value of the second frequency spectrum to the power value of the first frequency spectrum (hereinafter also referred to as “myoelectric component ratio”). That is, the myoelectric component acquisition unit 332 functions as the myoelectric component acquisition unit described in the claims.

The myoelectric component acquisition unit 332 is used when the acceleration of the neck detected by the acceleration sensor 22 is equal to or higher than a predetermined threshold (that is, when the neck moves and body motion noise is expected to increase). Stops acquiring the above-described myoelectric component ratio. The myoelectric component ratio acquired by the myoelectric component acquisition unit 332 is output to the fatigue determination unit 333.

The fatigue determination unit 333 determines that the user is fatigued when the myoelectric component ratio acquired by the myoelectric component acquisition unit 332 is equal to or greater than a predetermined reference value (fatigue reference value). That is, the fatigue determination unit 333 functions as fatigue determination means described in the claims. At that time, the fatigue determination unit 333 determines that the ratio of the time during which the myoelectric component ratio is equal to or higher than the reference value within the predetermined time is equal to or higher than the predetermined ratio, or (and) the myoelectric component ratio is When the state above the reference value continues for a predetermined time (for example, several minutes) or more, it is determined that the user is tired. That is, primary force may be applied to the cervix even in a non-fatigue state. Therefore, if the measurement time is short (for example, several minutes), there may be no fatigue even if the myoelectric component ratio is high. Therefore, fatigue determination accuracy is improved by accumulating myoelectric component ratio data and determining fatigue. It should be noted that the fatigue determination unit 333 determines that the neck acceleration detected by the acceleration sensor 22 is equal to or greater than a predetermined threshold (that is, when the neck moves and body motion noise is expected to increase). Stop fatigue assessment.

When the fatigue determination unit 333 determines that the user is in a fatigued state, the fatigue detection device 1 informs the user that the user is in a fatigued state through a speaker (or buzzer) 70 (warning). To do). That is, the speaker (or buzzer) 70 functions as the presenting means described in the claims. In addition, when it is determined that the fatigue detection device 1 is in a fatigue state, the fatigue detection device 1 is connected to a PC (personal computer), a portable music player having a display, a smartphone, or the like via the wireless communication module 60. It has a function to transmit and display information (fatigue judgment result). Note that the acquired data such as fatigue information (fatigue judgment result) is stored and stored in, for example, the RAM described above, and output to a PC or the like for confirmation after the measurement is completed. Good. Furthermore, it can also be set as the structure which performs fatigue determination with PC, a smart phone, etc. which were connected by radio | wireless.

The neck heating unit 80 increases the temperature of the neck by heating the neck (around the neck) when the fatigue determination unit 333 determines that the user is tired. That is, the neck heating unit 80 functions as a heating unit described in the claims.

More specifically, the neck heating unit 80 warms the neck when it is determined that the user is tired. At that time, the neck heating unit 80 adjusts the output so that the temperature of the neck increases as the deviation between the myoelectric component ratio and the reference value increases. On the other hand, when it is determined that the user is not fatigued, the neck heating unit 80 maintains the state at that time or weakens the degree of heating.

Examples of the heating method by the neck heating unit 80 include a method using an electric heater or the like. More specifically, for example, it is preferable that the bioelectrode 15, the insulating layer, and the high resistance layer of the electric heater are sequentially stacked. In this case, the heat generated by the current flowing through the high resistance layer of the electric heater is transmitted to the user's neck through the insulating layer and the living body electrode 15. In addition, it is preferable to provide a temperature control by limiting the temperature adjustment or providing a temperature sensor so that the user does not feel uncomfortable.

Next, the operation of the fatigue detection device 1 will be described with reference to FIG. FIG. 7 is a flowchart showing a processing procedure of fatigue detection processing by the fatigue detection device 1. The processing shown in FIG. 7 is repeatedly executed mainly at a predetermined timing by the signal processing unit 31.

When the fatigue detection device 1 is attached to the neck and the sensor units 11 and 12 (the

biomedical electrodes

15 and 15 and the photoelectric pulse wave sensor 20) come into contact with the neck, the pair of

biomedical electrodes

15 and 15 are used in step S100. The detected biological signal (myoelectric signal, electrocardiographic signal) and the photoelectric pulse wave signal detected by the photoelectric pulse wave sensor 20 are read. In subsequent step S102, a filtering process is performed on the biological signal (myoelectric signal, electrocardiogram signal) and the photoelectric pulse wave signal read in step S100. Further, the acceleration pulse wave is obtained by second-order differentiation of the photoelectric pulse wave signal.

Subsequently, in step S104, for example, the wearing state of the fatigue detection device 1 is determined based on the amount of light received by the photoelectric pulse wave sensor 20 (amplitude of the photoelectric pulse wave signal). That is, the photoelectric pulse wave sensor 22 receives the light irradiated from the light emitting element 201, transmitted through the living body / reflected by the living body, and returned by the light receiving element 202, and detects the fluctuation of the light amount as a photoelectric pulse wave signal. Therefore, the amount of received signal light decreases when the device is not properly mounted. Therefore, in step S104, a determination is made as to whether the amplitude of the photoelectric pulse wave signal is greater than or equal to a predetermined value. If the amplitude of the photoelectric pulse wave signal is greater than or equal to a predetermined value, the process proceeds to step S108. On the other hand, when the amplitude of the photoelectric pulse wave signal is less than the predetermined value, it is determined as a mounting error, and mounting error information (warning information) is output in step S106. Thereafter, the process is temporarily exited. Instead of the method using the received light amount (amplitude of the photoelectric pulse wave signal) of the photoelectric pulse wave sensor 20 described above, for example, a method using the baseline stability of the electrocardiogram waveform or the noise frequency component ratio is adopted. You can also

In step S108, the peak of the electrocardiogram signal and photoelectric pulse wave signal (acceleration pulse wave signal) is detected. Then, the time difference (peak time difference) between the R wave peak of the detected electrocardiogram signal and the peak of the photoelectric pulse wave signal (acceleration pulse wave) is calculated.

Next, in step S110, the delay time (shift amount) of each of the R wave peak of the electrocardiogram signal and the peak of the photoelectric pulse wave signal (acceleration pulse wave) is obtained, and based on the obtained delay time, The time difference (peak time difference) between the R wave peak of the signal and the peak of the photoelectric pulse wave signal (acceleration pulse wave) is corrected.

Subsequently, in step S112, it is determined whether or not the peak time difference corrected in step S110 is a predetermined time (for example, 0.01 sec.) Or more. If the peak time difference is greater than or equal to the predetermined time, the process proceeds to step S116. On the other hand, when the peak time difference is less than the predetermined value, error information (noise determination) is output in step S114, and then the process is temporarily exited.

In step S116, the peak time difference calculated in step S108 is determined as the pulse wave propagation time, and the pulse wave interval is acquired.

Next, in step S118, whether or not the neck acceleration detected by the acceleration sensor 22 is equal to or greater than a predetermined threshold (that is, whether or not the neck moves and body motion noise increases). Judgment is made. If the neck acceleration is less than the predetermined threshold value, the process proceeds to step S122. On the other hand, when the cervical acceleration is equal to or greater than the predetermined threshold value, body motion error information is output in step S120, and then the process is temporarily exited.

In step S122, the biological signal including the myoelectric signal and the electrocardiographic signal is subjected to frequency analysis to obtain a frequency spectrum. Subsequently, in step S124, the first frequency spectrum in the first frequency band (for example, 10 Hz or more and 20 Hz or less) in which the ratio of the myoelectric component to the electrocardiographic component is low (the electrocardiographic component is large relative to the myoelectric component). Ratio of the power value of the second frequency spectrum in the second frequency band (for example, 30 Hz to 50 Hz) with a high myoelectric component ratio to the power value (the electrocardiographic component is less than the myoelectric component) (myoelectric component) Ratio) is acquired. In step S126, the myoelectric component ratio acquired in step S124 is stored in time series.

In step S128, whether or not the acquired myoelectric component ratio is greater than or equal to a reference value and the time ratio of the state is greater than or equal to a predetermined ratio, or (and) the myoelectric component ratio is greater than or equal to a reference value A determination is made as to whether or not has continued for a predetermined time or more. Here, when the said conditions are satisfied, it determines with having been fatigued and a process transfers to step S130. On the other hand, when the condition is not satisfied, it is determined that the user is not fatigued, and the process proceeds to step S132.

If it is determined that the user is tired, in step S130, the user is informed (warned) of the fatigue state by an alarm sound or voice. Further, the neck warming unit 80 is driven to warm the neck, thereby relieving and reducing user fatigue. Thereafter, the process is temporarily exited.

On the other hand, when it is determined that the user is not fatigued, in step S132, the operating state of the neck heating unit 80 is maintained without being changed (or the operating state is relaxed). Thereafter, the process is temporarily exited.

As described above in detail, according to the present embodiment, a biological signal including a myoelectric signal is acquired from the user's neck, subjected to frequency analysis, and from the frequency analysis result (frequency spectrum), The myoelectric component ratio is high with respect to the power value of the first frequency spectrum in the first frequency band (for example, 10 Hz or more and 20 Hz or less) in which the electric component ratio is low (the electrocardiographic component is greater than the myoelectric component). The ratio (myoelectric component ratio) of the power value of the second frequency spectrum in the second frequency band (for example, 30 Hz to 50 Hz) having a smaller electrocardiographic component than the component is acquired. Then, the myoelectric component ratio and the reference value are compared to determine whether or not the user is fatigued. Here, since the myoelectric component ratio increases as the myoelectric component increases, the myoelectric component can be accurately obtained. As described above, the use of the myoelectric signal obtained from the neck and the determination of whether or not the user is tired based on the myoelectric component ratio obtained from the frequency analysis result (frequency spectrum). In addition, it is possible to detect whether or not it is resistant to noise and fatigue more stably and accurately. In this case, it is possible to simply evaluate fatigue simply by attaching the neckband type fatigue detection device 1 to the neck.

Further, according to the present embodiment, when the time ratio when the myoelectric component ratio is equal to or higher than the reference value becomes equal to or higher than the predetermined ratio, or (and) when the myoelectric component ratio is equal to or higher than the reference value, the predetermined time If it continues for the above, it is determined that the user is tired. Therefore, for example, when it is in a temporary tension state (when a force is temporarily applied to the neck), it can be prevented from being determined to be tired, and the accuracy of fatigue detection can be improved. It becomes possible to improve.

According to the present embodiment, for example, when the neck is moved (that is, when the myoelectric amount temporarily increases due to the movement of the neck or the body motion noise is large), the fatigue determination is performed. Since it is stopped, erroneous detection due to body movement can be prevented, and fatigue can be detected more accurately.

According to the present embodiment, an electrocardiogram signal can be simultaneously measured without providing a dedicated electrode for detecting an electrocardiogram signal. Therefore, together with the presence or absence of fatigue, for example, biological information such as heart rate and heart rate interval can be measured simultaneously.

According to this embodiment, when it is determined that the user is in a fatigued state, the user is informed (warned) of the fatigued state by an alarm sound or voice. Therefore, it is possible to inform the user that the user is tired, and it is possible to prevent the user from being in an excessive fatigue state.

According to the present embodiment, when the user is fatigued, the neck (neck) is heated, so that fatigue can be reduced / reduced. At this time, according to the present embodiment, since the neck of the user is heated via the living body electrode 15, it is not necessary to provide a separate heating portion. In addition, since the biomedical electrode 15 is in contact with the neck of the user, the neck can be reliably and efficiently heated.

(Second Embodiment)
By the way, there are individual differences in the amplitude of the biological signal (electrocardiogram signal, myoelectric signal) measured at the neck. Here, the fatigue detection device 1 according to the first embodiment described above has two (a pair of) biological electrodes 15, but in order to further improve the determination accuracy, three (two pairs) or more. It is also preferable to have a configuration having the living body electrode 15.

Therefore, next, the fatigue detection device 2 according to the second embodiment will be described with reference to FIG. Here, the description of the same or similar configuration as in the first embodiment will be simplified or omitted, and different points will be mainly described. FIG. 8 is a block diagram illustrating a functional configuration of the fatigue detection device 2. In FIG. 8, the same or equivalent components as those in the first embodiment are denoted by the same reference numerals.

The fatigue detection device 2 includes three

biological electrodes

15A, 15B, and 15C, a biological signal amplification unit 311, and a signal processing unit 310, and a frequency analysis unit 331B instead of the frequency analysis unit 331. It differs from the fatigue detection apparatus 1 which concerns on 1st Embodiment mentioned above. Other configurations are the same as or similar to those of the fatigue detection device 1 described above, and thus detailed description thereof is omitted here.

The three

biological electrodes

15A, 15B and 15C are composed of one common electrode 15A and two

biological electrodes

15B and 15C which are paired with the common electrode 15A. Here, the biological electrode 15B is preferably disposed in the vicinity of the biological electrode 15C. A biological signal (myoelectric signal and electrocardiographic signal) is detected by the combination of the common electrode 15A and the biological electrode 15B and the combination of the common electrode 15A and the biological electrode 15C.

The frequency analysis unit 331B detects a biological signal (myoelectric signal and electrocardiographic signal) detected by a combination of the common electrode 15A and the living body electrode 15B and a living body detected by a combination of the common electrode 15A and the living body electrode 15C. Compare the signal (myoelectric signal and electrocardiographic signal) and select the biological signal (myoelectric signal and electrocardiographic signal) that is more suitable for fatigue determination (for example, the one with larger amplitude) and perform frequency analysis . Since the myoelectric component acquisition unit 332 and the fatigue determination unit 333 are the same as those described above, detailed description thereof is omitted here.

According to the present embodiment, since three

biological electrodes

15A, 15B, and 15C are provided, by using the

biological electrodes

15A, 15B, and 15C in combination, the two biological signals are more suitable for processing. A biological signal can be selected and used, and the myoelectric component detection accuracy can be improved. In addition, it is possible to detect background noise using one of the biological electrode pairs and remove the background noise. Therefore, the accuracy of fatigue determination can be further improved.

In the above-described embodiment, the substantially U-shaped neckband 13 that is mounted so as to sandwich the neck from the back side of the user's neck is used as the mounting member, but forms other than the neckband may be employed.

Therefore, next, the fatigue detection device 3 according to the third embodiment will be described with reference to FIGS. 9 and 10 together. Here, the description of the same or similar configuration as in the first embodiment will be simplified or omitted, and different points will be mainly described. FIG. 9 is a perspective view showing the appearance of the fatigue detection device 3. FIG. 10A is a top view showing the appearance of the fatigue detection device, and FIG. 10B is a bottom view showing the appearance of the fatigue detection device 3. 9 and 10, the same reference numerals are given to the same or equivalent components as those in the first embodiment.

The fatigue detection device 3 is a flexible mounting body part 16 having a substantially strip shape as a mounting member, and two adhesive parts attached to both ends on the back side of the mounting body part 16. It has

adhesive portions

17 and 17.

Each adhesive part 17 has conductivity in addition to adhesiveness, and also functions as the above-described biological electrode (hereinafter, the adhesive part 17 may also be referred to as “biological electrode 17”). As the adhesive part (bioelectrode) 17, for example, a biogel electrode is suitably used. Note that only a part of the adhesive portion 17 may be conductive.

The detection main body 18 in which the photoelectric pulse wave sensor 20, the signal processing unit 31, the wireless communication module 60, the battery, and the like are housed is attached to the central portion on the surface side of the mounting main body portion 16. Here, the pair of

biological electrodes

17 and 17 are electrically connected to the detection main body 18 (signal processing unit 31). Further, a hole is formed in the mounting main body 16 at a position corresponding to the photoelectric pulse wave sensor 20, and the photoelectric pulse wave sensor 20 is fitted into the hole. That is, when the mounting body 16 (fatigue detection device 3) is mounted on the neck, the photoelectric pulse wave sensor 20 (the light emitting element 201 and the light receiving element 202) is mounted so as to come into contact with the neck skin. Yes.

In this embodiment, the photoelectric pulse wave sensor 20 is disposed outside the region where the adhesive portion 17 is attached (see FIG. 10B), but the photoelectric pulse wave sensor 20 is attached to the adhesive portion 17. You may arrange | position in an area | region. In that case, a hole may be formed in the adhesive portion 17 so that the photoelectric pulse wave sensor 20 protrudes from the hole, or instead of forming a hole in the adhesive portion 17, A transparent adhesive material that transmits light may be used, and a photoelectric pulse wave signal may be acquired through the transparent adhesive material. The details of the photoelectric pulse wave sensor 20, the signal processing unit 31, the wireless communication module 60, and the like are as described above, and thus detailed description thereof is omitted here.

According to the present embodiment, since the adhesive portion 17 having adhesiveness is attached to the mounting body portion 16 having flexibility and formed in a substantially strip shape, the mounting body portion is utilized by using the adhesiveness of the adhesive portion 17. 16 can be affixed (attached) to the neck. Moreover, since the adhesion part 17 has electroconductivity and functions as a biological electrode, it is possible to easily detect fatigue simply by attaching (attaching) the attachment main body part 16 to the neck part.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, in the above-described embodiment, the fatigue detection devices 1 and 2 include the photoelectric pulse wave sensor 20, but may be configured not to include the photoelectric pulse wave sensor 20.

In the above embodiment, the pair of

sensor portions

11 and 12 are attached to both ends of the neckband 13, but the

sensor portions

11 and 12 are not necessarily attached to both ends of the neckband. Further, the neckband 13 may be configured such that its length can be adjusted by an adjusting mechanism or the like.

In the above embodiment, a conductive cloth is used as the living body electrode 15, but instead of the conductive cloth, for example, a metal (stainless steel, Au, etc.), silver-silver chloride, conductive rubber, etc. It may be used. In that case, it is preferable to design so that the area of the biomedical electrode in contact with the skin is increased.

In the above embodiment, the case where the number of the biological electrodes 15 is two or three has been described as an example, but the number of the biological electrodes 15 may be four or more.

In the above embodiment, the fatigue state is determined based on the myoelectric component ratio acquired from the biological signal, but the fatigue state may be determined based on the myoelectric component amount. More specifically, the myoelectric component acquisition unit 332 performs, for example, a frequency band of 30 Hz to 50 Hz with respect to the frequency analysis result (frequency spectrum) by the frequency analysis unit 331 (that is, the myoelectric component is low and has a small electrocardiographic component). A configuration in which the myoelectric component amount is obtained by integrating the frequency spectrum of a large frequency band) and the fatigue determination unit 333 determines that the user is tired when the obtained myoelectric component amount is equal to or greater than a reference value. Good. At that time, if the ratio of the time during which the myoelectric component amount is equal to or higher than the reference value within the predetermined time is equal to or higher than the predetermined ratio, or (and) the myoelectric component amount is equal to or higher than the reference value. It is preferable to determine that the state is fatigued when the state continues for a predetermined time or more. Thus, even if the fatigue state is determined based on the amount of myoelectric component obtained from the frequency analysis result (frequency spectrum), it is possible to more stably and accurately detect whether or not the user is fatigued. it can.

In the third embodiment, the fatigue detection device 3 is attached (attached) along the back of the user's neck from one side of the user's neck to the other side of the neck, For example, it is good also as a structure which arrange | positions a pair of

biological electrodes

17 and 17 closely, and affixes (attaches) it only to one side or back of a neck part.

In the above embodiment, when it is determined that the user is tired, the neck warming portion 80 is used to warm the neck (around the neck) and the fatigue is reduced / reduced. For example, a neck cooling means that cools the neck, or a neck that presses the neck (for example, a pressure is applied intermittently by inflating a built-in bag with a pump). It is good also as a structure which relieves / reduces fatigue using a part press means.

1, 2, 3

Fatigue detection device

11, 12 Sensor part 12a Body part 12b Frame 13 Neckband 14 Input terminal 15 Biological electrode (conductive cloth)
15A Biological electrode (common electrode)
15B, 15C Biological electrode 16 Mounting main body part 17 Adhesive part / biological electrode 18 Detection main body part 20 Photoelectric pulse wave sensor 201 Light emitting element 202 Light receiving element 22 Acceleration sensor 31, 31B Signal processing part 310 First signal processing part 320 Second Signal processing unit 311 ECG signal amplification unit 321 Pulse wave

signal amplification unit

312, 322 Analog filter 313, 323 A /

D converter

314, 324 Digital filter 325 Second-order

differentiation processing unit

316, 326

Peak detection unit

318, 328 Peak correction unit 330 Pulse wave transit time measurement unit 331, 331B Frequency analysis unit 332 Myoelectric component acquisition unit 333 Fatigue determination unit 350 Drive unit 60 Wireless communication module 70 Speaker 80 Neck heating unit

Claims

A mounting member that can be mounted along the circumferential direction of the user's neck;
A plurality of biological electrodes attached to the mounting member and acquiring biological signals including myoelectric signals;
Frequency analysis means for obtaining a frequency spectrum by performing frequency analysis on biological signals acquired by the plurality of biological electrodes;
Myoelectric component acquisition means for acquiring myoelectric components from the frequency spectrum obtained by the frequency analysis means;
A fatigue detection device comprising: fatigue determination means for determining fatigue when the myoelectric component acquired by the myoelectric component acquisition means is greater than or equal to a reference value.
The fatigue determination means determines that the user is fatigued when a ratio of a time during which the myoelectric component is equal to or higher than a reference value within a predetermined time is equal to or higher than a predetermined ratio. Item 2. The fatigue detection device according to Item 1.
The fatigue detection device according to claim 1 or 2, wherein the fatigue determination means determines that the user is fatigued when a state in which the myoelectric component is equal to or higher than a reference value continues for a predetermined time or longer.
A mounting member that can be mounted along the circumferential direction of the user's neck;
A plurality of biological electrodes attached to the mounting member and acquiring biological signals including myoelectric signals;
Frequency analysis means for obtaining a frequency spectrum by performing frequency analysis on biological signals acquired by the plurality of biological electrodes;
The second frequency in the second frequency band having a higher myoelectric component ratio than the first frequency band for the power value of the first frequency spectrum in the first frequency band having a low myoelectric component ratio relative to the electrocardiographic component Myoelectric component acquisition means for acquiring a ratio of spectrum power values;
Fatigue determination means for determining fatigue when the ratio of the power value of the second frequency spectrum to the power value of the first frequency spectrum acquired by the myoelectric component acquisition means is greater than or equal to a reference value; A fatigue detection apparatus comprising:
The fatigue determination means determines that the tire is fatigued when a ratio of a time in which the ratio is equal to or greater than a reference value within a predetermined time is equal to or greater than a predetermined ratio. The fatigue detection device described in 1.
The fatigue detection device according to claim 4 or 5, wherein the fatigue determination means determines that the tire is fatigued when a state where the ratio is equal to or higher than a reference value continues for a predetermined time or more.
An acceleration sensor attached to the mounting member for detecting the acceleration of the neck of the subject;
The fatigue determination means stops determination of whether or not the vehicle is fatigued when the acceleration detected by the acceleration sensor exceeds a predetermined threshold value. The fatigue detection apparatus according to item 1.
The plurality of biomedical electrodes include one common electrode and one or more biomedical electrodes paired with the common electrode, respectively. Fatigue detection device.
9. The biological electrode for measuring a biological signal including an electrocardiographic signal among at least a pair of the biological electrodes among the plurality of biological electrodes. The fatigue detection apparatus described.
The fatigue detecting device according to any one of claims 1 to 9, wherein the mounting member is a neckband.
The mounting member has flexibility, a mounting main body portion formed in a substantially band shape, and an adhesive portion having adhesiveness attached to the mounting main body portion,
The fatigue detection device according to any one of claims 1 to 9, wherein at least a part of the adhesive portion has conductivity, and functions as the biological electrode.
The fatigue detection apparatus according to any one of claims 1 to 11, further comprising a presentation unit that presents the user with a fatigue state when the fatigue state is determined.
The fatigue detection device according to any one of claims 1 to 12, further comprising a heating means for heating the neck when it is determined that the tire is in a fatigue state.
The fatigue detection apparatus according to claim 13, wherein the warming means warms the neck by raising the temperature of the living body electrode.