JPH08299443A - Doze preventing device - Google Patents

Abstract

PURPOSE: To provide a portable doze preventing device analyzing the awakening level of a human body from the behavior of brain waves to detect the doze of a driver to emit a warning. CONSTITUTION: An operation part 8 detects the push-down of the button provided to a wristwatch to send out data to a CPU 1. Whereupon, the CPU 1 starts the doze monitoring operation to a driver wearing this device. The pulse wave signal measured from the radial artery part of the driver is detected by a pulse wave detection part 4 to be converted to a digital signal by an A/D converter 5. The CPU successively stores the converted signal in a data memory and calculates the peak of the waveform of a pulse wave in parallel thereto to calculate RR 50. When the calculated RR 50 becomes larger than a predetermined reference value, a buzzer 9 is started to emit a warning to awake the driver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention detects the dozing state of a living body by analyzing the pulse wave obtained from the living body,
The present invention relates to a portable drowsiness prevention device that warns a driver or the like.

[0002]

2. Description of the Related Art In recent years, there have been many traffic accidents caused by drowsiness while driving a car or the like. Therefore, various drowsiness prevention devices have been devised conventionally for the purpose of preventing the occurrence of such a traffic accident. An example is a doze prevention device attached to the handle. In such a device, conductors are attached to the left and right sides of the steering wheel, and both hands of the driver are constantly in contact with the conductors to measure the resistance of the human body (driver). Therefore, when the driver falls asleep and releases his hand from the steering wheel, the resistance value between the conductors changes. Therefore, by catching this phenomenon as a snooze and issuing a warning sound to the driver, an accident can be prevented. Further, as other examples, one using a heart rate variability obtained from measurement of an electrocardiogram of the driver, one utilizing a variability of the driver's breath, and the like are considered.

[0003]

By the way, in the method of attaching the conductor to the steering wheel as described above, it is accurate when the driver is driving with one hand or when the driver is wearing gloves. I can't monitor naiveness. In addition, a system that captures heart rate variability, respiratory variability, and the like requires a large-scale device and is not suitable for a driver to carry on a daily basis. The present invention has been made in view of the above points, the object is to measure the pulse wave of the human body, by analyzing the awakening level of the human body from the behavior of the pulse wave, to detect a drowsy state and drive (EN) It is an object to provide a portable drowsiness prevention device that warns a hand.

[0004]

In order to solve the above problems, an invention according to claim 1 is a drowsiness prevention device provided in a portable device, wherein a pulse wave is detected from a user of the portable device. Detecting means, storage means for storing the waveform of the pulse wave, and analysis for extracting the state of the living body of the user by reading out and analyzing the waveform of the pulse wave for a predetermined time in the past from the storage means. Means, comparing the state of the living body and a predetermined reference value to determine the user's dozing state, control means for issuing a warning instruction when a dozing state is detected, and based on the warning instruction , Warning means for warning the user.

According to a second aspect of the invention, in the first aspect of the invention, the analyzing means calculates the time intervals of adjacent pulse waves, and the fluctuation amount of the continuous time intervals exceeds a predetermined time. The number is output as the state of the living body, and the control means issues the warning instruction when the state of the living body exceeds the reference value. In the invention according to claim 3, in the invention according to claim 1, the analyzing means calculates a time interval between adjacent pulse waves, performs a spectrum analysis with respect to a variation in the time interval, and performs the analysis. Output the amplitude value of the low-frequency component of the obtained spectral components as the state of the living body, the control means,
The warning instruction is issued when the state of the living body falls below the reference value.

According to a fourth aspect of the present invention, in the first aspect of the invention, the analyzing means calculates a time interval between adjacent pulse waves, and performs a spectrum analysis on fluctuations in the time interval. The amplitude value of the high-frequency component of the spectral components obtained by the analysis is output as the state of the living body, and the control unit issues the warning instruction when the state of the living body exceeds the reference value. Is characterized by.

According to a fifth aspect of the present invention, in the first aspect of the invention, the analyzing means calculates a time interval between adjacent pulse waves, and performs spectrum analysis on fluctuations in the time interval. When the ratio of the amplitude of the low-frequency spectrum component and the amplitude of the high-frequency spectrum component obtained by the analysis is obtained and output as the state of the living body, the control means, when the state of the living body exceeds the reference value. Is issued to the warning instruction. The invention according to claim 6 is characterized in that, in the invention according to any one of claims 1 to 5, the detecting means detects the pulse wave by measuring a pulse pressure.

According to a seventh aspect of the present invention, in the invention according to any one of the first to fifth aspects, the detecting means irradiates a blood vessel under the skin with light and is reflected by the blood vessel. It is characterized in that the pulse wave is detected by receiving the reflected light. The invention according to claim 8 is the invention according to any one of claims 1 to 5, wherein the portable device is a wristwatch, and the detecting means is
It is characterized in that it is slidably attached to the wristwatch band, and that the storage means, the analysis means, the control means and the warning means are built in the body of the wristwatch.

According to a ninth aspect of the present invention, in the invention according to any one of the first to fifth aspects, the portable device is a necklace, and the portable device further includes the storage means and the analysis means. A case in which the control means and the warning means are built in, the case being attached to the chain of the necklace, and the detecting means being attached to the chain of the necklace, the case being attached to a blood vessel under the skin. The photoelectric pulse wave sensor includes a light emitting element that emits light and an optical sensor that receives reflected light reflected by the blood vessel under the skin. According to a tenth aspect of the invention, in the invention according to any one of the first to fifth aspects, the mobile device is eyeglasses, and the mobile device further includes the storage unit, the analysis unit, and the control unit. Means and the warning means are built in, the case is attached to the vine of the frame of the spectacles, the detection means is a light emitting element for irradiating light to blood vessels under the skin, and the light The photoelectric pulse wave sensor includes an optical sensor that receives the reflected light reflected by the blood vessel under the skin.

[0010]

According to the invention described in claim 1, the drowsiness prevention device is provided in the portable device, the detecting means detects the pulse wave from the user of the portable device, and the analyzing means analyzes the waveform of the pulse wave. As a result, the state of the user's living body is extracted, the control unit compares the state of the living body with a reference value to determine the dozing state, and when the dozing is detected, the warning unit gives a warning. As a result, it becomes possible to detect the dozing of the user by a relatively simple method of detecting the pulse wave. In addition, it is possible to provide a drowsiness prevention device that is always portable for the user.

According to the second aspect of the present invention, the analyzing means calculates the time interval between the adjacent pulse waves, and sets the number of consecutive fluctuations of the time interval exceeding the predetermined time as the state of the living body. Then, the control means determines that the user is dozing when the state of the living body exceeds the reference value. As a result, the obtained state of the living body becomes one index indicating the state of the autonomic nerve, and it becomes possible to control the prevention of drowsiness based on the index.

According to the third aspect of the invention, the analyzing means calculates the time interval between the adjacent pulse waves and performs spectrum analysis on the fluctuation of the time interval to obtain a low frequency side. With the amplitude value of the spectral component as the state of the living body,
The control means determines that the user is dozing when the state of the living body falls below a reference value. As a result, the obtained state of the living body represents the degree of sympathetic nerve tension, and it becomes possible to control the prevention of drowsiness based on the degree of tension.

According to the invention described in claim 4, the analyzing means calculates the time interval between the adjacent pulse waves, and the spectrum on the high frequency side obtained as a result of the spectrum analysis with respect to the fluctuation of the time interval. With the amplitude value of the component as the state of the living body,
The control means determines that the user is dozing when the state of the living body exceeds the reference value. As a result, the obtained state of the living body represents the degree of parasympathetic nerve tension, and it becomes possible to control the prevention of drowsiness based on the degree of tension.

According to the fifth aspect of the invention, the analyzing means calculates the time intervals of the adjacent pulse waves, and the low frequency and the high frequency obtained as a result of the spectrum analysis with respect to the fluctuation of the time intervals. The control means determines that the user is dozing when the state of the living body exceeds the reference value, with the amplitude ratio of the spectrum component of <1> as the living body state. As a result, the obtained state of the living body represents the degree of tension in which variations due to individual differences are eliminated, and it becomes possible to detect a dozing state without bias due to differences in users.

According to the invention described in claim 7, light is emitted from the light emitting element to a blood vessel under the skin, and light reflected from the blood vessel is received by an optical sensor. As a result, the pulse wave can be easily measured for any part of the human body, and the range of selection of the measurement part can be widened. In addition, according to the invention described in claims 8 to 10, the drowsiness prevention device is incorporated into a wristwatch, a necklace or glasses. This allows
The drowsiness prevention device does not interfere with driving of a car and the like, and the drowsiness prevention can be performed without requiring a large-scale device.

[0016]

An embodiment of the present invention will be described below with reference to the drawings. [Outline of Examples] It is well known that the human state repeats a cycle of excitement and sedation according to a regular rhythm with a cycle of one day. The pulse wave is one of the means for grasping this rhythm from outside the body. It is known that there is a correlation described below in detail between the information included in this pulse wave and the arousal level of the human body.
The present embodiment detects the dozing state of the human body based on such a correlation.

The pulse wave of the human body is measured by an invasive or non-invasive method. As a method of non-invasively obtaining a pulse wave, there are a method of obtaining a change in lateral pressure of a blood vessel due to ejection of blood from the heart, a method of obtaining a change in blood volume in the blood vessel, and the like. Further, as a concrete means for detecting the pulse wave, in addition to commonly used pressure sensors, visible light, near-infrared light, light, audible sound, ultrasonic sound, electromagnetic waves, etc. can be considered. ing.

In the present embodiment, a pulse wave is measured by pressing a pressure sensor mounted on a wrist watch against the radial artery, and several measured quantities obtained from this pulse wave are used to determine the awake state of the human body. It is used as the indicator above. Specific examples of these measured amounts include LF, HF, and RR50 as information regarding “fluctuation” of pulse waves. Hereinafter, these pieces of information will be described.

A. In the LF and HF electrocardiograms, the time interval between the R wave of one heartbeat and the R wave of the next heartbeat is called the RR interval. This RR interval is a numerical value that is an index of autonomic nerve function in the human body. Figure 2
FIG. 4 is a diagram showing heartbeats on an electrocardiogram and RR intervals obtained from the waveforms of these heartbeats. As can be seen from the figure, it is known from the analysis of the measurement results of the electrocardiogram that the RR interval changes with the passage of time.

On the other hand, the fluctuations in blood pressure measured in the radial artery and the like are defined as the fluctuations of the systolic blood pressure and the diastolic blood pressure for each beat, and correspond to the fluctuations of the RR interval in the electrocardiogram. FIG. 3 shows the relationship between the electrocardiogram and blood pressure. As can be seen from this figure, the systolic and diastolic blood pressure for each beat is the maximum value of the arterial pressure in each RR interval,
And as the local minimum seen just before the maximum.

Further, when spectrum analysis of heartbeat fluctuation or blood pressure fluctuation is performed, it is found that these fluctuations are composed of waves of a plurality of frequencies. The waves of these plural frequencies are classified into the following three types of fluctuation components.・ HF (High Frequency) component that is a fluctuation that matches breathing ・ LF (Low Frequency) that fluctuates in a cycle of about 10 seconds
Components ・ Trends that fluctuate at frequencies lower than the measurement limit (Tren
d)

For each of the measured pulse waves, the RR interval between adjacent pulse waves is obtained, and the discrete value of the obtained RR interval is calculated by an appropriate method (for example, cubic spline interpolation).
Interpolation is performed (see FIG. 3). Then, by performing FFT (Fast Fourier Transform) processing on the interpolated curve and performing spectrum analysis, it becomes possible to extract the above-mentioned fluctuation component as a peak on the frequency axis. Figure 4 (a)
Shows the fluctuation waveform of the RR interval of the measured pulse wave and the waveform of each fluctuation component when the fluctuation waveform is decomposed into the above three frequency components. Further, FIG. 4B is a result of spectrum analysis on the fluctuation waveform of the RR interval shown in FIG.

As can be seen from this figure (b), 0.07
Peaks are seen at two frequencies around Hz and around 0.25 Hz. The former is the LF component and the latter is the HF component. Since the trend component is below the measurement limit, its frequency cannot be read from the figure. LF
The component represents the degree of sympathetic tone, and the greater the amplitude of this component, the greater the tone. On the other hand, H
The F component represents the degree of parasympathetic tone, and the greater the amplitude of this component, the more relaxed it is.

Here, since the amplitude values of the LF component and the HF component have individual differences, as an index taking this into consideration, the amplitude ratio of the LF component and the HF component is "LF / HF".
Is useful for estimating the degree of tension in the human body that does not depend on the individual. From the characteristics of the LF and HF components described above, "LF /
The higher the value of "HF", the higher the degree of tension, and
The smaller the value of “HF”, the lower the degree of tension, and the subject is relaxed.

B. RR50 RR50 is defined as the number of times that the absolute value of the RR interval of two consecutive heartbeats varies by 50 milliseconds or more in the measurement of the pulse wave for a predetermined time. It has been clarified that the larger the value of RR50, the more sedated the subject is, while the smaller the value of RR50, the more excited. In addition, as the subject sleeps deeper, the state of the living body shifts to a sedative state.
Therefore, when the subject falls asleep, for example, RR50
It is known that the value of increases gradually.

[Arrangement of Embodiment] FIG. 1 is a block diagram showing the arrangement of a doze prevention device according to this embodiment. A user of this device (for example, a driver of a car or a train) wears the wristwatch 20 shown in FIG. 5, and the device shown in FIG. 1 is incorporated inside the wristwatch 20.

In FIG. 1, a CPU (central processing unit) 1
Is a central part that controls each circuit in the drowsiness prevention device, and its function will be described later in the description of the operation.
In addition, the ROM (Read Only Memory) 2 has a CPU
The control program, the control data, etc. which 1 runs are stored. The temporary storage memory 3 is a type of RAM (random access memory) and is used as a work area when the CPU 1 performs a calculation.

The pulse wave detector 4 constantly measures the pulse wave in the radial artery of the user and outputs the measurement result as an analog signal. A / D (analog / digital) converter 5
Quantizes this analog signal, converts it into a digital signal, and outputs it. The data memory 6 is a non-volatile memory composed of a battery backed up RAM or the like, and is based on the pulse wave waveform data and the like acquired by the CPU 1 from the A / D converter 5 and the pulse wave data. Calculated L
The values of F, HF, “LF / HF”, RR50, etc. are stored.

The clock circuit 7 generates time and is used as the time for displaying on the wristwatch 20, and the CPU 1 may read the time from the clock circuit 7 for the purpose of knowing the present time. Further, various buttons (details will be described later) provided on the wristwatch 20 are connected to the operation unit 8, and when the buttons are pressed, the types of the buttons are output. Further, the buzzer 9 emits a warning sound to the user based on the ringing start / ring stop instruction from the CPU 1. The buzzer 9 is, for example, an alarm mechanism attached to a commercially available digital wristwatch.

On the other hand, the wristwatch 20 shown in FIG. 5 has two modes: a "normal use mode" used as an ordinary wristwatch and a "monitoring mode" for detecting the dozing state of the user and issuing a warning to the user. It is a timepiece having a mode. Further, reference numeral 21 is a main body of a wristwatch, and like a general wristwatch, a time display portion 22 for displaying the current time and date is provided on the upper surface portion. Further, a time setting button 24 (so-called crown) for adjusting the time and a mode switching button 25 are attached to the right side surface of the wristwatch 20. The mode switching button 25 is a button for switching between the normal use mode and the monitoring mode, and the normal use mode and the monitoring mode are alternately switched each time the button is pressed. When the power is turned on, the normal use mode is initialized.

Next, 27 is a pressure sensor, 28 is an attachment, and the pulse wave detecting section 4 of FIG. 1 described above is actually composed of these two members. As shown in FIG. 5, the pressure sensor 27 is mounted on the surface of the fitting 28, and the fitting 28 is slidably mounted on the watch band 29. By mounting the wristwatch 20 on the user's wrist, the pressure sensor 27 can be pressed against the radial artery part with an appropriate pressure. Here, the pressure sensor 27 is composed of a strain gauge or the like, and a pulse wave signal representing a radial artery waveform is obtained in an analog amount from terminals (not shown) provided at both ends of the pressure sensor 27. This pulse wave signal is sent to the A / D converter 5 in FIG. 1 through a signal line (not shown) embedded in the watch band 29.

[Operation of the Embodiment] Next, the operation of the drowsiness prevention device having the above-described configuration will be described. In the examples below, R
A case will be described in which the doze detection is performed based on the calculated value of R50. A) Transition to monitoring mode The user of this device presses the mode switching button 25 of the wristwatch 20 when driving a car, for example. The operation unit 8 that has detected the pressing of the button sends the fact that the switching button 25 has been pressed to the CPU 1. This allows the CPU
Reference numeral 1 switches the wristwatch 20 from the current normal use mode to the monitoring mode to enable the drowsiness monitoring function during driving.

B) Capturing of Waveform of Pulse Wave The pulse wave detecting section 4 uses the pressure sensor 27 of the wristwatch 20.
The pulse wave of the radial artery of the user is constantly measured. The measurement result is converted into digital data by the A / D converter 5 and output to the common bus. When the CPU 1 enters the monitoring mode by pressing the above-mentioned button, the CPU 1 reads this digital data at a predetermined time interval and stores it in the data memory 6 together with the current time read from the clock circuit 7.

C) Analysis of Waveform of Pulse Wave Next, the CPU 1 calculates the RR50 by analyzing the waveform of the pulse wave for the past predetermined time accumulated in the data memory 6.
Therefore, first, the RR interval is calculated. a. Calculation of RR Interval CPU 1 extracts the maximum point from the waveform of the pulse wave. For that purpose, the CPU 1 first takes the time derivative of the waveform of the pulse wave. Next, by obtaining the time when the time differential value is zero, all the times when the waveform has a pole point are obtained. Next, whether the pole at each time point is the maximum or the minimum is determined from the slope (that is, the time differential value) of the waveform near the pole. For example, for a certain pole, a moving average is calculated for the slope of the waveform from a certain time before the time of the pole to the time. It can be seen that if this moving average is positive, the extreme point is maximum, and if it is negative, it is minimal.

Next, the CPU 1 obtains, for each of the extracted maximum points, the minimum point existing immediately before the maximum point. Then, the amplitudes of the pulse waves at these maximum and minimum points are read from the data memory 6 and the amplitude difference between the two is obtained. If this difference is greater than or equal to a predetermined value, the time of the maximum point is set as the peak of the pulse wave. Then, the peak detection processing is performed on all the waveforms of the pulse waves for the predetermined time. After that, based on the times of the two adjacent peaks, the time interval between them (RR
Corresponding to the interval).

B. Calculation of RR50 Next, the CPU 1 sequentially finds the time difference between the adjacent RR intervals based on the RR interval obtained above, and checks whether or not the time difference exceeds 50 milliseconds for each time difference. Then, the number of corresponding time differences is counted, and this number is set as RR50. c. Storing in the data memory 6 Then, the current time read from the clock circuit 7 is stored in the RR5.
It is stored in the data memory 6 together with 0.

D) Discrimination of Awakening State and Control of Warning Sound Next, the CPU 1 determines whether or not the user is in a dozing state based on the calculated RR50. That is, the magnitude relation between the calculated value of RR50 and a predetermined reference value is obtained, and if the calculated value of RR50 is larger than the reference value, it is considered that the user is asleep. So C
The PU 1 sends a ringing instruction to the buzzer 9, whereby the buzzer 9 emits a warning sound and awakens the user.

After that, when the user wakes up, the CPU 1
The RR50 calculated by is gradually decreased, and finally falls below the reference value. Upon detecting this, the CPU 1 sends a ringing stop instruction to the buzzer 9, which stops the warning sound from the buzzer 9. Alternatively, when the user who wakes up presses the mode switching button 25, the user is notified by the operation unit 8 that the button has been pressed, and the CPU
Reference numeral 1 switches the wristwatch 20 from the monitoring mode to the normal use mode, and at the same time, sends a ringing stop instruction to the buzzer 9 to stop the generation of the warning sound.

[Application 1] In the above embodiment, the awake state of the user is determined based on the value of RR50. However, instead of RR50, the above-mentioned LF, H
It is also possible to use F or "LF / HF". These various quantities can be obtained by the following procedure.

A) in C) above. The value of the RR interval obtained in (1) is discrete on the time axis. Therefore, similarly to the interpolation of the waveform of the pulse wave, the adjacent RR intervals are interpolated by an appropriate interpolation method to obtain a curve as shown in FIG. next,
When FFT processing is performed on the interpolated curve, FIG.
A spectrum as shown in is obtained. Therefore, the maximum determination processing similar to that performed on the waveform of the pulse wave is applied to this spectrum waveform to obtain the maximum value in the spectrum and the frequency corresponding to the maximum value. Then, the maximum value obtained in the low frequency region is the LF component and the maximum value obtained in the high frequency is the HF component, and the amplitude of each component is obtained to calculate the amplitude ratio “LF / HF” of both.

Here, as described above, the state of the living body is in a sedative state "as the amplitude of the LF component is smaller", "as the amplitude of the HF component is larger", or "as the value of LF / HF is smaller". Can be said. Therefore, in determining the awake state of the user in the above D),
If the amplitude of F is below the reference value, the value of HF is above the reference value, or the value of “LF / HF” is below the reference value, it is determined that the user is asleep. good.
The operation other than the above is the same as the case of the RR 50 described above, and the description thereof is omitted here.

[Application 2] In the above-mentioned embodiment, the warning sound is emitted to the driver when the dozing state is detected.
However, instead of warning the driver, a drowsiness prevention device and the car are wirelessly connected wirelessly, and when the driver's drowsiness is detected, a command is automatically issued to the braking device of the car. It is also possible to apply the brakes. FIG. 6 shows the configuration of a drowsiness prevention device according to such an application example. In the figure, components having the same functions as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted here.

The transmitter 10 provided in the wristwatch 20 is C
The electric signal sent from PU1 is amplified so that it may fit into the transmitting antenna 11. The transmitting antenna 11 converts this electric signal into a radio wave and sends it out. Reference numeral 30 denotes a car on which the driver is riding. Further, the receiving antenna 31 receives the radio wave transmitted from the transmitting antenna 11 and converts it into an electric signal. The receiver 32 amplifies this electric signal and outputs it to the controller 33 at the next stage. The control unit 33 includes the receiving unit 3
2. Controls various devices (not shown) inside the brake device 34 and the vehicle 30. The braking device 34 controls the braking operation of the automobile 30 according to an instruction from the control unit 33.

Next, the operation of the doze prevention device having the above configuration will be outlined. The CPU 1 measures and analyzes the waveform of the driver's pulse wave in the monitoring mode and detects the driver's dozing state by the same procedure as in the above-described embodiment. Then
The CPU 1 sends a braking instruction signal for the brake to the transmitter 10. This braking instruction is converted into a radio wave by the transmission antenna 11 via the transmission unit 10 and radiated to the outside of the wristwatch 20.

Then, this radio wave is received by the receiving antenna 31 provided on the side of the automobile 30 and converted into an electric signal. This electric signal is amplified by the receiving unit 32 and sent to the control unit 33. The control unit 33 receives the electric signal from the receiving unit 32 and analyzes the instruction. When recognizing that the instruction is a brake braking instruction, the control unit 33 sends the braking instruction to the brake device 34. As a result, the braking device 34 brakes and stops the automobile 30. Note that the driver may be warned by the above-described buzzer 9 together with the brake being applied to stop the vehicle.

[Application Example 3] In this application example, a case where the drowsiness prevention device is combined with an accessory (accessory) will be described. Here, as an example of accessories, FIG.
The necklace shown in is taken up, but there is no problem with other accessories. In the figure, reference numeral 41 denotes a sensor pad, which is made of, for example, a sponge-like cushioning material. In the sensor pad 41, a photoelectric pulse wave sensor 42 corresponding to the pulse wave detector 4 in FIG. 1 is attached so as to contact the skin surface. As a result, when this necklace is worn around the neck, the photoelectric pulse wave sensor 42 can contact the skin on the back side of the neck and measure the pulse wave.

The main body 43 is shown in FIG.
Each unit (CPU 1 and the like) is incorporated. The main body 43 has a brooch-like shape, and the front surface thereof is shown in FIG.
The same mode switching button 25 as shown in is provided. Further, the photoelectric pulse wave sensor 42 and the main body 43 are attached to a chain 44, respectively, and are electrically connected via a lead wire (not shown) embedded in the chain 44. Incidentally, in practice, the mode switching button 25 may be attached anywhere on the main body 43. In addition, since the doze prevention device according to the present application does not need the time display or the like, the time display unit 22, the time setting button 24 and the like shown in FIG. 5 are not provided.

Next, the structure of the photoelectric pulse wave sensor 42 is shown in FIG. In this figure, 45 is a wavelength of 940 nm
A light emitting element composed of an infrared light emitting diode,
Reference numeral 46 is an optical sensor including a phototransistor and the like. The light emitted from the infrared light emitting diode 45 is reflected by the blood vessel passing directly under the skin with which the photoelectric pulse wave sensor 42 is in contact. The reflected light is received by the optical sensor 46, and the pulse wave detection signal M is obtained as a result of photoelectric conversion. This pulse wave detection signal M is sent to the A / D converter 5 in FIG. In this application example, the pulse wave is the pressure sensor 2 of FIG.
The difference is that the pulse wave is captured by the photoelectric pulse wave sensor 42 instead of 7, and the pulse wave of the neck portion is measured instead of the radial artery pulse wave. Therefore, the operation of the doze prevention device according to the present embodiment is the same as that of the above-mentioned embodiment, and the description thereof will be omitted here.

[Application Example 4] In this application example, a case where the drowsiness prevention device is combined with eyeglasses will be described. FIG. 9 is an enlarged view of the vine part of the spectacles. According to the example in this figure,
A snooze prevention device is attached to the vine 51 of the eyeglass frame. The main body 52 of the doze prevention device incorporates each unit (CPU 1 and the like) of FIG. 1 excluding the pulse wave detection unit 4. Further, the main body 52 is provided with the same mode switching button 25 as in FIG. The above application example 3
Similarly to the above, the mode switching button 25 may be attached anywhere on the main body 52, and the time display section 22 and the time setting button 24 in FIG.

The configuration of the pulse wave detecting section 4 of FIG. 1 is the same as that of the application example 3 and is shown in FIG. Here, the infrared light emitting diode 45 and the optical sensor 46 are respectively built in the pads 55 and 56 shown in FIG. 9, and the earlobe is sandwiched between the pads 55 and 56 to be fixed to the ear. The pads 55 and 56 are connected to the lead wire 5 drawn from the main body 52.
It is electrically connected by 7, 57 as shown in FIG. In this embodiment, the pulse wave is captured by the photoelectric pulse wave sensor 42 of FIG. 8 instead of the pressure sensor 27 of FIG. 5, and the pulse wave of the ear lobe is measured instead of the radial artery pulse wave. is there. Therefore, the operation of the drowsiness prevention device according to the present embodiment is the same as that of the above-mentioned embodiment, and the description thereof is omitted here.

[Modification] In the above-mentioned embodiment, the warning to the driver is given by the sounding of the buzzer, but various warning methods can be considered. For example,
According to the method of giving an electrical stimulus, a method is possible in which electrodes are attached to the back surface of the wristwatch and a weak voltage is generated between the electrodes when a drowsiness is detected to give a shock. There is also a method of giving a mechanical stimulus to the driver by providing a structure in which a protrusion (for example, a needle that is not very sharp) can be put in and out from the back of the wristwatch.

In the above embodiment, the RR50 at the present time is
A warning should be issued when the value exceeds the "fixed" standard value. However, the value of RR50 is always collected and stored in the data memory 6, and when determining the dozing, the moving average of the past RR50 is calculated and the RR5 at the present time is calculated.
A warning may be issued when the value of 0 exceeds the moving average value.

It is also conceivable that the warning sound does not always have the same volume, but the strength is set according to the difference between the calculated RR50 and the reference value. Further, as in the above embodiment, the RR50, the amplitude of the LF component, the amplitude of the HF component,
Instead of using the individual values of “F / HF” alone, all (or some) of these values may be taken into consideration before deciding whether to issue the warning.

Further, although the wristwatch, necklace, and glasses are presented as the portable form of the drowsiness prevention device, the present invention is not limited to this, and it may be incorporated in other everyday items. Further, the part for detecting the pulse wave is not limited to the radial artery part or the neck, and the measurement may be performed at other parts of the living body as long as the same pulse wave characteristics as those in the above-described embodiment can be obtained. . Further, the pulse wave detection method is not limited to the method shown in the above embodiment, an optical method,
Various methods such as sound, electromagnetic waves, etc. can be considered.

[0055]

As described above, according to the invention described in claim 1, the state of the living body obtained by providing the drowsiness prevention device on the portable device and analyzing the pulse wave detected by the user of the portable device. Based on the above, by comparing the state of the living body with a reference value and determining the dozing state to issue a warning, it is possible to detect the dozing of the user by a relatively simple method of detecting the pulse wave. This also makes it possible to provide an effect that the user can provide a drowsiness prevention device that is always portable.

According to the second aspect of the present invention, the number of adjacent pulse waves whose time interval variation exceeds the predetermined time is set as the state of the living body. Therefore, the obtained state of the living body is the state of the autonomic nerve. Is obtained, and the effect of enabling control of drowsiness prevention based on the index is obtained. According to the invention of claim 3, the amplitude value of the spectrum component on the low frequency side obtained as a result of the spectrum analysis of the fluctuation of the time intervals of the adjacent pulse waves is set as the state of the living body. Represents the degree of sympathetic tone, and the effect of enabling control of drowsiness prevention based on the degree of tone is obtained.

Further, according to the invention of claim 4, the amplitude value of the spectrum component on the high frequency side obtained as a result of the spectrum analysis of the fluctuation of the time intervals of the adjacent pulse waves is set to the state of the living body, and thus the obtained living body This state represents the degree of parasympathetic nerve tension, and the effect of enabling control of drowsiness prevention based on the degree of tension can be obtained. In addition, claim 5
According to the invention described above, the amplitude ratio of the low-frequency and high-frequency spectral components obtained as a result of the spectrum analysis of the fluctuation of the time intervals of the adjacent pulse waves is set to the state of the living body. Since the degree of tension without variations is represented, it is possible to obtain an effect that it is possible to detect a dozing state that is not biased by the difference between users.

According to the invention of claim 7, the pulse wave is optically measured. Therefore, the pulse wave can be easily measured on any part of the human body, and The effect is that the range of selection can be expanded. In addition, according to the invention of claims 8 to 10, since the drowsiness prevention device is incorporated in a wrist watch, a necklace or glasses, the drowsiness prevention device does not interfere with driving of a car or the like, and a large-scale device is provided. It is possible to obtain the effect that the prevention of drowsiness can be implemented without the need.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a drowsiness prevention device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between an electrocardiogram and an RR interval.

FIG. 3 is a diagram showing a relationship between an electrocardiogram and a pulse wave.

FIG. 4A is a diagram showing the relationship between the RR interval fluctuation and the frequency components constituting the fluctuation. Further, (b) is a diagram showing a result of a spectrum analysis of RR interval fluctuation.

FIG. 5 is a perspective view of a wrist watch 20 incorporating the same device.

FIG. 6 is a block diagram showing a configuration of a drowsiness prevention device according to an application example 2 of the present invention.

FIG. 7 is a diagram showing a configuration of a drowsiness prevention device according to an application example 3 of the present invention.

FIG. 8 is a circuit diagram of a photoelectric pulse wave sensor 42 according to Application Examples 3 to 4 of the present invention.

FIG. 9 is a diagram showing a configuration of a drowsiness prevention device according to an application example 4 of the present invention.

[Explanation of symbols]

1 ... CPU, 2 ... ROM, 3 ... Temporary storage memory, 4 ... Pulse wave detection unit, 5 ... A / D converter, 6 ... Data memory, 7 ...
Clock circuit, 8 ... Operation unit, 9 ... Buzzer, 10 ... Transmission unit, 1
DESCRIPTION OF SYMBOLS 1 ... Transmission antenna, 20 ... Wristwatch, 21 ... Wristwatch body, 22 ... Time display part, 24 ... Time setting button, 25
... mode switching button, 27 ... pressure sensor, 28 ... attachment, 29 ... watch band, 30 ... automobile, 31 ... reception antenna, 32 ... reception section, 33 ... control section, 34 ... brake device, 41 ... sensor pad, 42 … Optical pulse wave sensor,
43 ... Main body, 44 ... Chain, 45 ... Infrared light emitting diode,
46 ... Optical sensor, 51 ... Vine, 52 ... Main body, 55, 56 ...
Pad, 57 ... Lead wire

Claims (10)

[Claims] 1. A drowsiness prevention device provided in a mobile device, comprising: detecting means for detecting a pulse wave from a user of the mobile device; storage means for storing the waveform of the pulse wave; and a predetermined time in the past. By analyzing the waveform of the minute pulse wave from the storage means and analyzing it, the analysis means for extracting the state of the living body of the user, and the use by comparing the state of the living body with a predetermined reference value A doze prevention device comprising: a control unit that determines a person's dozing state and issues a warning instruction when the dozing state is detected; and a warning unit that issues a warning to the user based on the warning instruction. 2. The analyzing means calculates time intervals between adjacent pulse waves, and outputs the number of continuous fluctuations in the time intervals exceeding a predetermined time as the state of the living body, the control means comprising: The warning instruction is issued when the state of the living body exceeds the reference value.
The drowsiness prevention device described. 3. The analyzing means calculates a time interval between adjacent pulse waves, performs a spectrum analysis with respect to a variation in the time interval, and selects a low-frequency side component of the spectrum components obtained by the analysis. 2. The amplitude value is output as the state of the living body, and the control means issues the warning instruction when the state of the living body falls below the reference value.
The drowsiness prevention device described. 4. The analysis means calculates time intervals between adjacent pulse waves, performs spectrum analysis on fluctuations in the time intervals, and analyzes the amplitude of the high-frequency-side component of the spectrum components obtained by the analysis. A value is output as the state of the living body, and the control unit issues the warning instruction when the state of the living body exceeds the reference value.
The drowsiness prevention device described. 5. The analysis means calculates time intervals between adjacent pulse waves, performs spectrum analysis on fluctuations in the time intervals, and analyzes the amplitude and the high frequency of the low-frequency spectrum component obtained by the analysis. 2. The ratio of amplitudes of spectrum components is obtained and output as the state of the living body, and the control means issues the warning instruction when the state of the living body exceeds the reference value.
The drowsiness prevention device described. 6. The doze prevention device according to claim 1, wherein the detection means detects the pulse wave by measuring a pulse pressure. 7. The detecting means detects the pulse wave by irradiating a blood vessel under the skin with light and receiving the reflected light reflected by the blood vessel. The dozing prevention device according to any one of 5 above. 8. The portable device is a wristwatch, the detection means is slidably attached to a band of the wristwatch, and the storage means, the analysis means, the control means and the warning means are the wristwatch. The doze prevention device according to any one of claims 1 to 5, wherein the device is incorporated in the body of the device. 9. The mobile device is a necklace, and the mobile device further has a case containing the storage means, the analysis means, the control means and the warning means, the case being a chain of the necklace. Attached to the chain of the necklace, the detection means, a light emitting element for irradiating light to blood vessels under the skin, and the light reflected light reflected by the blood vessels under the skin. The drowsiness prevention device according to any one of claims 1 to 5, which is a photoelectric pulse wave sensor including an optical sensor for receiving light. 10. The portable device is eyeglasses, and the portable device further has a case in which the storage means, the analysis means, the control means and the warning means are built in, and the case is the eyeglasses. Attached to the vine of the frame, the detection means is a photoelectric device comprising a light emitting element for irradiating light to blood vessels under the skin, and an optical sensor for receiving reflected light reflected by the blood vessels under the skin. 6. A doze prevention device according to claim 1, wherein the device is a pulse wave sensor.