JPH0910312A - Awakening judgement device, awakening judging method, and sleeping judging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To judge sleeping precisely corresponding to individuals, by judging awakening from a variation pattern of skin impedance level calculated from voltage signal of a living body and the variation pattern of nictation calculated from voltage signal according to nictation. SOLUTION: Signals which are obtained from a skin impedance measuring part 41 by which variation pattern of skin impedance level is calculated from voltage signal of a living body and a nictation measuring part 42 by which variation pattern of nictation is calculated from voltage signal according to nictation, are for example wireless-transmitted to a driving computer 43 which is carried in a motor vehicle, in an awakening judging part. Awakening is judged from both of variation pattern of the received skin impedance level and the variation pattern of nictation by means of an awakening judging part 44, and an on-board safety system 45 carried on the motor vehicle is constituted to be worked when awakening is judged to be reduced. The driver is noticed warning by means of sound or vibration of this on-board safety system 45, and his sleepiness is shaken off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wakefulness determination device and a wakefulness determination method for determining a wakefulness from a change pattern of skin impedance level and a change pattern of blink occurrence.
In addition, the present invention relates to a doze determination method for determining doze.

[0002]

2. Description of the Related Art Conventionally, as a method for determining arousal level and dozing by physiological measurement, there is a method using α power of electroencephalogram and level of electrodermal activity. These methods make use of the fact that when the arousal level decreases, the frequency of appearance of α-waves in the electroencephalogram increases, the wave becomes slower, and the skin impedance level increases (or the skin potential level decreases).

[0003]

However, in the conventional methods for determining arousal level and drowsiness as described above, the arousal level is determined when the increase in the α wave amount of the EEG or the impedance level becomes relatively clear. Since, for example, when driving an automobile or the like, the determination is too late, and there is a problem that the risk of causing an accident due to a drowsy driving increases.

[0004] Further, the degree of awakening and the doze vary greatly among individuals,
For example, even if it is determined to be awake or dozing state for one person, it may not be the case for another person, and it is desirable to determine according to each person, but in the conventional determination method,
There is nothing that corresponds to individual differences in physiological responses. Therefore,
The present invention has been made in view of such conventional problems, and an object thereof is to provide a wakefulness determination device and a wakefulness determination method capable of accurately and quickly determining the wakefulness. .

It is another object of the present invention to provide a doze judging method capable of accurately and quickly judging drowsiness for each individual.

[0006]

In order to achieve the above-mentioned object, a wakefulness determination device of the present invention (claim 1) is a skin impedance measuring means for calculating a change pattern of skin impedance level from a potential signal of a living body. And a blink measuring means for calculating a change pattern of blink occurrence from a potential signal accompanying the blink, and an awakening degree determining means for determining awakening degree from the calculated change pattern of skin impedance level and the change pattern of blink occurrence And is provided.

[0007] The awakening level determination method of the present invention (claim 3)
Detects the skin impedance level from the potential signal of the living body, calculates the change pattern of the level, detects the potential signal accompanying the blink, and calculates and calculates the change pattern of blink occurrence from the potential signal. It is characterized in that the arousal level is determined from the change pattern of the skin impedance level and the change pattern of the blink occurrence.

Since both the arousal level determination device and the arousal level determination method of the present invention determine the arousal level from the change pattern of the skin impedance level and the change pattern of the blink occurrence, a clear decrease in the arousal level is shown. It becomes possible to determine the state of decreased arousal at a stage before the start of the operation, and the decrease of arousal can be determined earlier and accurately. Thus, for example, in the case of driving an automobile or the like, it is possible to prevent the determination of the awakening degree from being delayed, and it is possible to prevent an accident due to a dozing driving or the like.

The dozing determination method of the present invention (claim 4) detects the skin impedance level from the potential signal of the living body, calculates the change pattern of the level, and detects the potential signal associated with the blink. A change pattern of blink occurrence is calculated from the potential signal, and dozing is determined from the calculated change pattern of the skin impedance level and the change pattern of blink occurrence.

According to this drowsiness determination method, the drowsiness is determined from the change pattern of the skin impedance level and the change pattern of the blink occurrence, that is, the skin impedance and the blink drowsiness of the blink obtained by the experimental data are different from each other. As for the reaction result, since the variation patterns are combined and complement each other, the dozing state can be determined in a wide range, and the determination can be performed accurately and quickly.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. FIG. 1 shows a state in which the subject M is equipped with the wakefulness determination device according to one embodiment. This arousal level determination device calculates a change pattern of skin impedance level (skin impedance measuring means) 1 for calculating a change pattern of skin impedance level from a potential signal of a living body, and a change pattern of blink occurrence from a potential signal accompanying a blink. A blink measuring section (blink measuring means) 2 is provided. In this embodiment, the skin impedance measuring unit 1 is of a wristwatch type and has a skin impedance sensor 11 for detecting the skin impedance.
And a main body 12 that also functions as a receiver for receiving a signal wirelessly transmitted from the blink measuring unit 2. The main body unit 12 determines the awakening degree from the change pattern calculated from the skin impedance level obtained by the sensor 11 and the change pattern of the blink occurrence that is transmitted from the blink measuring unit 2 (wakefulness determination unit (wakefulness). Degree determination means) is built in.

The blink measuring section 2 includes a band (band-shaped member) 21 wound around the head, an electrode (not shown) for detecting a potential signal provided near the forehead contact portion of the band 21,
An electrode 22 for detecting a potential signal that is attached to the earlobe, and a main body 23 that also serves as a transmitter for calculating a change pattern of blink occurrence from the detected potential signal and transmitting the change pattern to the skin impedance measuring unit 1. Equipped with.

The apparatus shown in FIG. 1 is an example in which the skin impedance measuring section 1 and the nictation measuring section 2 are separated, but an example in which they are integrated is shown in FIG. The wakefulness determination device of FIG. 2 is one in which the skin impedance measurement unit 1 is integrated with the blink measurement unit 2 shown in FIG. In other words, this device
1, a main body 32 attached to the band 31, an electrode (not shown) for blinking measurement arranged on the forehead contact portion of the band 31, and an electrode 33 for blinking measurement attached to the earlobe. , And an electrode 34 for measuring skin impedance, which is arranged at a forehead contact portion of the band 31. The main body 32 has a built-in awakening degree determination unit that determines the awakening degree from the change pattern of the skin impedance level and the change pattern of the blink occurrence.

The skin impedance measuring unit and the nictation measuring unit may be various combinations such as the above-mentioned separated type and integrated type, and examples of the combinations are shown in FIGS. 3 and 4. In FIG. 3, the skin impedance measuring unit 41 and the nictation measuring unit 42 are separated, and the signals obtained by the respective measuring units 41, 42 are wirelessly transmitted to the driving computer 43 mounted in, for example, an automobile, and the received skin is received. Based on the change pattern of the impedance level and the change pattern of the blink occurrence, the awakening degree determination unit 4
4 determines the arousal level, and the in-vehicle safety system 45 mounted on the vehicle is activated when the awakening level is determined to decrease. The in-vehicle safety system 45 notifies the driver of a decrease in arousal level and slows down the speed of the vehicle.
For example, the sound or vibration is used to warn the driver of a caution and make him drowsy.

FIG. 4 is equivalent to the device of FIG. 1, in which the skin impedance measuring section 41, the awakening degree determining section 44 and the output / warning section 46 are integrated, and the signal of the blink measuring section 42 is transmitted to the skin impedance measuring section 41. It will be sent. Here, the output / warning unit 46 calls the driver's attention. Next, FIG. 5 shows a configuration example of the skin impedance measuring unit 41 shown in FIG. The skin impedance measuring unit 41 includes a sensor unit (electrode) 51 attached to the skin, a skin impedance calculating unit 52, and an awakening degree determining unit 53 that determines the awakening degree from a change pattern of the calculated skin impedance level.
And an output / warning unit 54 that outputs / warns when a decrease in arousal level is determined, and an energization control unit 55 that controls energization to the sensor unit 51. The signal transmitted from the measurement unit 41 is received by the driving computer 43 on the automobile side, and the in-vehicle safety system 45 operates according to the determination result of the awakening degree determination unit 44. Here, the skin impedance measuring unit 41 itself also has the awakening degree determining unit 53.

On the other hand, FIG. 6 shows an example of the configuration of the blink measuring section 42 shown in FIG. The nictation measuring unit 42 includes a sensor unit (electrode) 61 attached to the skin, an EOG (electro-oculograph) detection amplifier 62, and a nictation detecting unit 63 that detects nictation from the obtained signal. An awakening degree determination unit 64 that determines the awakening degree from the detected change pattern of the blink occurrence, and an output / warning unit 65 that outputs / warns when the decrease in the awakening degree is determined. The signal transmitted from the measuring unit 42 is
Similarly to the above, the vehicle-mounted safety system 4 is received by the driving computer 43 according to the result of the awakening degree determination unit 44.
5 is activated.

Further, the algorithms for determining the awakening levels in the skin impedance measuring section and the blink measuring section will be described. First, the algorithm of the skin impedance measuring unit will be described. FIG. 10 shows changes in the skin impedance level during driving operation of a car. As a result of observing this operation state, it is considered that the fluctuation is in a normal state until about 15 minutes. However, from the time of over 17 minutes, 2
The level increased significantly over the course of 5 minutes, and the arousal level has decreased considerably at this point. After that, the levels gradually declined and continued to decline for 34 minutes (this may be a state of fighting drowsiness). However, the sharp drop around 34 minutes was due to speech. When moving in such a direction that the level decreases, the arousal level tends to increase, although there are differences in degree. The arousal level decreased again from 34 minutes to 42 minutes and then recovered.

From the above, in order to judge the arousal level,
When looking at the change pattern of skin impedance level,
Exclude the part where the level is lowered. Then, it is necessary to distinguish between a natural fluctuation or a decrease in arousal level regarding the rising part of the level. Therefore, in order to determine the awakening degree in real time, the determination is performed as follows. The impedance level is observed every 15 seconds, and the time when the increase in the value compared with the previous value continues for 90 seconds or more is targeted. Further, the average value and variance of the level for the immediately preceding 60 seconds are obtained, the value of the average + α variance is sequentially tracked on the time series, and if it deviates from the range, it is determined that the awakening level has decreased. However,
If it falls within the range, it is a natural fluctuation. Even if the increase of the previous value and the comparison value is within 90 seconds (ie,
If the level immediately rises and then continues to rise further and exceeds the average + α variance value, it is determined that the arousal level is low. However, α is a different coefficient depending on the individual difference in the magnitude of the reaction.

On the other hand, the algorithm in the blink measuring section will be described. The change pattern of nictation occurrence is intended for the nictation rate within a certain period of time, the clustered nictation rate, the average value or variance of the intervals between nictation, and the like. FIG. 11 shows 1 as an example.
It shows the blink rate for each minute. In this example, the blink rate increases almost continuously from around 16 minutes to around 25 minutes, but this section shows a decrease in arousal level from observation.
The same applies from 34 minutes to 40 minutes. As the blink rate increases, the average value of the blink intervals inevitably decreases.
It is also expected that cluster blinks will usually increase in the normal case.
These indicators are closely related to each other, and all of them can observe the change pattern of blink occurrence.

From the above, an example of determining the arousal level will be shown below. The blink rate is calculated every 30 seconds or 60 seconds. The target is the time when the increase in the blink rate compared to the previous value continues for 3 minutes or more. Further, the average and variance of the blink rate for the immediately preceding 3 minutes are calculated, and when the value of the average + α variance is exceeded (that is, when the blink rate is significantly increased), it is determined that the awakening degree has decreased. . Even if the comparison value with the previous value rises within 3 minutes (ie,
If the blink rate immediately starts to rise, and continues to rise further and exceeds the average + α variance, it is determined that the awakening degree has decreased.

It should be noted that the fact that the blink rate is constantly high is considered to represent a tension state, and in short, it is to judge the point of time when the blink rate rapidly increases. On the contrary, the blink rate suddenly decreases (or 0 times / hour with eyes closed)
This is a case where the arousal decline is extremely advanced and is a phenomenon that has been often used in the past, but it is not an early detection of the awakening decline.

FIG. 7 shows a specific example of a flow chart for determining a decrease in arousal level from the change pattern of the skin impedance level. First, in step (hereinafter abbreviated as ST) 11, the skin impedance level is calculated every 15 seconds, and the calculated value is compared with the previous value (ST12). If the calculated value is smaller than the previous value, it is determined that the arousal level is high. (ST13), otherwise proceed to ST14. In ST14, it is determined whether or not the increase in the value compared with the previous value has continued for 90 seconds or more, and if NO, S
Return to T12, and if YES, proceed to ST15. Here, since the skin impedance level is calculated every 15 seconds, when the process proceeds to ST15, the level calculation is the sixth time.

In ST15, the average value and the variance of the skin impedance level for the immediately preceding 60 seconds are obtained, and the value of the average + α variance is followed sequentially in the time series (comparing the average + α variance with the calculated value this time). When it deviates from the range (when the calculated value this time exceeds the average + α variance), it is determined that the awakening degree has decreased (ST16). If it is within the range, it is determined that the fluctuation is natural (ST17). However, as described above, even if the increase in the value compared with the previous value is within 90 seconds, that is, even if the skin impedance level temporarily decreases, the level immediately starts to increase and continues to increase further. If the average + α variance value is exceeded, it is determined that the arousal level has decreased.

FIG. 8 shows a specific example of a flow chart for determining a decrease in arousal level from a change pattern of blink occurrence. First, ST2
In step 1, the blink rate is calculated every 30 seconds or 60 seconds, the calculated value is compared with the previous value (ST22), and if the calculated value is smaller than the previous value, it is determined that the arousal level is high (ST23), otherwise. If so, proceed to ST24. In ST24, it is determined whether or not the increase in the value compared with the previous value has continued for 3 minutes or more. If NO, S
Return to T22, and if YES, proceed to ST25. Since the blink rate is calculated here every 30 seconds or 60 seconds,
When the process proceeds to ST25, the blink rate calculation is the sixth or third time.

In ST25, the average and variance of the blink rate for the immediately preceding 3 minutes are calculated, and when the value of the average + α variance exceeds the previous value in the sequential time series (that is, the blink rate significantly increases). Is detected), it is determined that the arousal level has decreased (ST2
6). If it does not exceed, it is determined to be a natural fluctuation (ST27). As described above, the decrease in arousal level can be determined from the change pattern of the skin impedance level and the change pattern of the blink occurrence. However, in order not to make a mistake in the determination due to factors such as mental tension, the awakening degree can be determined more reliably and accurately by observing these two change patterns.

An algorithm for blink detection and calculation of the blink interval is shown in FIG. In ST31, the potential signal (EOG waveform) obtained from the living body (forehead) is differentiated (ST3
2) The waveform is sliced (ST33) and the blink interval is calculated (ST34). Next, a doze determination method will be described. Even with this drowsiness determination method, the skin impedance and the blink are measured.
This is the same as in the case of the awakening level determination method and device. or,
The skin impedance has a direct current component (SIL) and an alternating current component (SIR), but the SIL value calculated from the skin impedance, the SIR frequency value, the blink rate calculated from the blink, and the IBLI standard deviation value are also calculated. , As described above.

Incidentally, SIL and SIR can be obtained as follows. The skin impedance Z is Z = | Z
| Ε ^ (-jθ) [where ^ (-jθ) represents a power index]. A sine wave of √2 A · sin ωt is generated in OSC, and converted into a constant current of √2 I _O · sin ωt by the current driver. This constant current is applied to the skin by two electrodes. The other electrode is used as a potential electrode, and the measurement potential V _S detected by the differential amplifier is V _S = √2 | Z | I _O · sin (ωt−θ). When this output signal and the oscillation signal from the OSC are mixed by a multiplier (Mixer), the output is as follows. _{V S · √2 A · sinωt =} √2 | Z | I O · sin (ωt-θ) · √2 A · sinωt = 2 | Z | AI O · sinωt · sin (ωt-θ) = 2 | Z | _{AI O · sinωt · (sinωt ·} cosθ-cosωt · sinθ) = 2 | Z | AI O (sinωt 2 · cosθ-sinωt · cosωt · sinθ) = 2 | Z | AI O {cosθ · 1/2 · (1- cos2ωt) −1 / 2 · sin2ωt · sinθ｝ = | Z | AI _O ｛cosθ · (1−cos2ωt) −sin2ωt · sinθ｝ = | Z | AI _O ｛cosθ− (cosθ · cos2ωt + sin2ωt · sinθ) ＝ = | Z │AI _O ｛cosθ-cos (2ωt-θ)｝ Therefore, cos (2ωt-
Removal of the high-frequency component of the theta), the DC component of skin impedance variations which is the output (SIL) is, SIL = AI _O | was cosθ, and the energization current I _O and the oscillation signal amplitude A from the OSC coefficient | Z The real number (pure resistance) of the skin impedance Z is determined. Further, a high-pass filter (HPF) is used to change the fluctuation component (SI
R), SIR = ΔAI _O | Z | cos θ

FIG. 12 is a table showing the characteristics of the change pattern of the skin impedance and the method of determining whether or not to warn against falling asleep on the basis of the characteristics. FIG.
As shown in FIG. 2, the skin impedance change pattern is classified into four types, for example, A1 type, A2 type, A3 type, and A4 type. There are two types of alert judgment methods, # 1 type and # 2 type. is there. However, the # 1 type follows the flow chart of the alert determination process shown in FIG. 15, and the # 2 type follows the flow diagram of the alert determination process shown in FIG.

FIG. 13 is a table showing the characteristics of the blink pattern and the method of determining whether or not to warn against falling asleep on the basis of the characteristics. As shown in FIG. 13, the blink change pattern is, for example, 2 of B1 type and B2 type.
Classified as follows. Further, FIG. 14 is a table showing the determination of drowsiness level. Here, the drowsiness level is 0 to 3 depending on the degree of drowsiness of the subject based on the video inspection and the comment of the subject.
It was judged by characterizing it in four stages.

The process of warning judgment (# 1 type and # 2 type) is as follows.
The flow charts are shown in FIGS. 15 and 16, respectively. However, in FIG. 15 and FIG. 16, the analysis item is S
It represents one of the IL value, the SIR frequency value, the blink rate, and the IBLI standard deviation value. The set time is variable, and the accuracy of determination can be adjusted. In the flowchart of FIG. 15, first, analysis items are set (ST41), and set time is set (ST4).
2) Obtain the analysis item value Xi every 15 seconds (ST4
3). Subsequently, the addition cumulative average value Xm of the analysis item values Xi is calculated by the formula as shown (ST44), and it is compared whether the analysis item value Xi is larger than the addition cumulative average value Xm (S).
T45). If this is Yes, it is further determined whether or not it has exceeded the set time (ST46), and if this is also Yes, it is determined that it is necessary to be alert because it is in the dozing state (ST46).
47), and outputs a warning alarm (ST48). In the case of No in ST45 or ST46, it is determined that it is safe rather than a dozing state (ST49). In ST50, it is asked whether to end the analysis. If Yes, the warning determination process is ended,
If No, the process returns to ST43.

The flow chart of FIG. 16 is basically the same as the flow chart of FIG. 15, except for ST45 '. ST45 '
Then, it is compared whether the analysis item value Xi is smaller than the addition cumulative average value Xm. FIGS. 17 to 24 show changes in skin impedance patterns (A1, A2, A3, A4).
Type), drowsiness level, and a graph of warning results, and FIG.
FIG. 28 shows a graph of blink pattern (B1 type, B2 type), drowsiness level, and warning result. In FIGS. 17 to 28, the measured signal value of the skin impedance and the blink and the added average value thereof are shown on the vertical axis value on the left side, the drowsiness level and the warning alert are shown on the vertical axis value on the right side, and the horizontal axis value is the time. Is shown. According to the flow chart of FIG. 15 for the warning determination, the flow chart of FIG. 15 is used for the warning determination, and 0 is output for the safety determination and 1 is output for the warning determination according to the flow chart of FIG.

[0032]

As described above, according to the first aspect of the present invention,
The arousal level determination device described above and the arousal level determination method according to claim 3 both determine the arousal level from the change pattern of the skin impedance level and the change pattern of the blink occurrence, so the following effect (1) To (4). (1) Since it is possible to detect the previous stage of the decrease in the awakening level, the determination of the awakening level does not occur too late, and for example, an accident due to a dozing driving of a car can be prevented. (2) There are some fluctuations in the skin impedance level even in the awake state including the increase in the level, and the fluctuation in the blink occurrence may also show the same fluctuation as the decrease in the arousal level due to the tension state pattern. By combining the fluctuation patterns of the physiological index, it is possible to accurately and surely determine the decrease in arousal level. (3) There are individual differences in physiological response, and there is a difference in sensitivity depending on the state even in the state of decreased arousal level in the previous stage, but by combining two fluctuation patterns, it is possible to determine the decreased arousal level in a wider range. it can. (4) The skin impedance measuring means and the nictation measuring means are integrated with a band-shaped member wound around the head (claim 2
The change pattern of blink occurrence can be measured from the potential change of the forehead and the change pattern of the skin impedance level can also be measured from the forehead, and the subject only has to wrap the band-shaped member around the forehead. The feeling of restraint when judging the degree is extremely low.

Further, according to the method of judging dozing of claim 4 of the present invention, since the dozing is judged from the change pattern of the skin impedance level and the change pattern of the blink occurrence, the following effects (5) to (7) are obtained. ) Has. (5) By combining two fluctuation patterns of physiological responses with individual differences, it is possible to accurately and quickly determine dozing in a wider range. (6) Real-time processing can be performed. (7) Since the skin impedance and the blink are the same determination method, there is versatility.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state in which a device according to an embodiment is attached to a subject.

FIG. 2 is a diagram showing a state in which a device according to another embodiment is attached to a subject.

FIG. 3 is a block diagram showing a configuration of an apparatus according to an embodiment.

FIG. 4 is a block diagram showing a configuration of an apparatus according to another embodiment.

5 is a block diagram showing a configuration example of a skin impedance measuring section in the device shown in FIG.

6 is a block diagram showing a configuration example of a blink measuring section in the device shown in FIG.

FIG. 7 is a flow chart showing an example of an algorithm for determining an arousal level from a change pattern of skin impedance level.

FIG. 8 is a flowchart showing an example of an algorithm for determining the arousal level from a change pattern of blink occurrence.

FIG. 9 is a flowchart showing an algorithm for blink detection and blink interval calculation.

FIG. 10 is a diagram showing a change pattern of skin impedance level.

FIG. 11 is a diagram showing a change pattern (blink rate) of blink occurrence.

FIG. 12 is a diagram showing characteristics of a change pattern of skin impedance and a warning determination method.

FIG. 13 is a diagram showing characteristics of a blinking change pattern and a warning determination method.

FIG. 14 is a diagram showing the degree of drowsiness.

15 is a diagram showing a warning determination method in FIGS. 12 and 13;
It is a flow figure showing type 1 processing.

FIG. 16 is a flow chart of the warning determination method in FIG. 12 and FIG.
It is a flow figure showing type 2 processing.

FIG. 17 is a graph showing changes in skin impedance, drowsiness, and warning results.

FIG. 18 is a graph showing changes in skin impedance, drowsiness, and warning results.

FIG. 19 is a graph showing changes in skin impedance, drowsiness, and warning results.

FIG. 20 is a graph showing changes in skin impedance, drowsiness, and warning results.

FIG. 21 is a graph showing changes in skin impedance, drowsiness, and warning results.

FIG. 22 is a graph showing changes in skin impedance, drowsiness, and warning results.

FIG. 23 is a graph showing changes in skin impedance, drowsiness, and warning results.

FIG. 24 is a graph showing changes in skin impedance, drowsiness, and warning results.

FIG. 25 is a graph showing a blink pattern, drowsiness, and a warning result.

FIG. 26 is a graph showing blink pattern, drowsiness level, and warning result.

FIG. 27 is a graph showing a blink pattern, drowsiness level, and warning result.

FIG. 28 is a graph showing blink pattern, drowsiness level, and warning result.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Skin impedance measurement unit 2 Blink measurement unit 21, 31 Band (band-shaped member) 41 Skin impedance measurement unit 42 Blink measurement unit 44 Awakening degree determination unit

Front Page Continuation (72) Inventor Masayuki Suzuki 24 Yamanouchi Yamanoshitamachi, Ukyo-ku, Kyoto City Omron Life Science Research Institute Co., Ltd.

Claims (4)

[Claims] 1. A skin impedance measuring means for calculating a change pattern of a skin impedance level from a potential signal of a living body, and a blink measuring means for calculating a change pattern of blink occurrence from a potential signal associated with a blink. An arousal level determination device, comprising: an arousal level determination means for determining an arousal level from a skin impedance level change pattern and a blink occurrence change pattern. 2. The blink measuring means comprises a band-shaped member wound around a head, an electrode for detecting a potential signal provided near the forehead contact portion of the band-shaped member, and a potential signal to be worn on the earlobe. The awakening degree determination device according to claim 1, further comprising a detection electrode. 3. A skin impedance level is detected from a potential signal of a living body, a change pattern of the level is calculated, a potential signal associated with a blink is detected, and a change pattern of blink occurrence is calculated from the potential signal. A method for determining arousal level, which comprises determining the arousal level from the calculated change pattern of the skin impedance level and the change pattern of the blink occurrence. 4. A skin impedance level is detected from a potential signal of a living body, a change pattern of the level is calculated, a potential signal associated with a blink is detected, and a change pattern of blink occurrence is calculated from the potential signal. A doze determination method, which comprises determining doze from the calculated change pattern of the skin impedance level and the change pattern of the blink occurrence.