JPH09154835A - Doze detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect a doze without being influenced by a posture, an air temperature and an individual difference by providing an awakening degree judging means to output a signal corresponding to an awakening degree to an external part, a skin temperature detecting means and a detection control means to control an action of the awakening degree judging means. SOLUTION: An air temperature detecting means 15 is composed of an air temperature sensor 3, and detects an air temperature by receiving a trigger signal from a detection control means 11, and outputs it to a temperature data holding means 4 of a data holding means 16. A temperature processing means 5 reads nasal bone upper skin temperature data, masticatory muscle upper skin temperature data and air temperature data from the temperature data holding means 4, and performs, for example, moving average processing for past 300 seconds on the temperature data, and outputs its operation result to an operation result holding means 6. An awakening degree judging means 7 detects a skin temperature change generated according to reduction in an awakening degree from a moving average temperature registered in the operation result holding means 6, and outputs a symptom of a doze and a signal corresponding to the doze to an external part on the basis of the skin temperature change.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a doze detecting device for detecting awakening degree and dozing of a human.

[0002]

2. Description of the Related Art As a conventional wakefulness / drowsiness detecting device, as disclosed in, for example, Japanese Patent Application Laid-Open No. 6-197888, a vehicle-mounted type is used to estimate the wakefulness of a driver from a heart rate and a steering cycle of a steering wheel. What is known is.

In addition, as disclosed in Japanese Unexamined Patent Publication No. 05-212003, there is known one that detects a sleep / wake state based on the intensity of fluctuation of infrared rays radiated from a human body due to body movement. Has been.

[0004]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Laid-Open No. 6-1
It is generally known that the heart rate taken up in the vehicle-mounted drowsiness detection device disclosed in Japanese Patent No. 97888 fluctuates due to various factors, and the steering cycle of the steering wheel is also determined by the awakening degree of the driver. Rather, it has a problem that it reflects road conditions and driver's operation.

Further, the above-mentioned Japanese Patent Laid-Open No. 05-212003.
In the conventional doze detection device disclosed in Japanese Patent Publication No.
Since it is determined that there is almost no body motion as sleeping, it is erroneously determined as sleeping even when the operation is stopped due to tension.
In addition, when body movement occurs due to the attenuation of muscle tonus during the dozing of a sitting posture, there is a possibility that it may be erroneously determined to be awake.

The present invention solves the above-mentioned problems of the prior art, and an object of the present invention is to provide a drowsiness detection device having high drowsiness detection accuracy regardless of the heart rate, the steering period, and the body movement.

[0007]

In order to achieve this object, a dozing detection device of the present invention comprises a skin temperature detecting means for detecting the skin temperature of a human body, an air temperature detecting means for detecting an air temperature, and the skin temperature detecting means. Data holding means for registering the skin temperature data detected by the means and the air temperature data measured by the air temperature detecting means, a temperature processing means for performing time series arithmetic processing on the temperature data registered in the data holding means, and the temperature Awakening degree determining means for determining the awakening degree of the user from the calculation result output from the processing means and outputting a signal corresponding to the awakening degree to the outside, and controlling the operations of the skin temperature detecting means and the awakening degree determining means It is characterized in that it is provided with a configuration comprising a detection control means for doing so.

Further, the present invention is characterized in that the skin temperature detecting means is provided with a skin temperature detecting means for extracting the skin temperature on the nasal bone and the skin temperature on the masseter muscle from the skin temperature of the human face. .

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, by detecting not the absolute value of the skin temperature but the relative change, the posture, temperature,
Drowsiness can be detected accurately without being affected by individual differences.

Further, the present invention detects the increase in the skin temperature of the human body which occurs when the person falls asleep, based on the human body skin temperature which is closely related to the skin blood flow controlled by the sympathetic nervous system. Awakening and dozing can be discriminated with high accuracy.

According to the doze detection device of the present invention,
It is possible to detect the skin temperature above the masseter muscle in which a significant rise in skin temperature corresponding to dozing occurs, and the skin temperature above the nasal bone that reacts sensitively to the activity of the sympathetic nervous system. From the change, it is possible to discriminate between the three states of awakening, signs of dozing, and dozing.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a doze detection device according to an embodiment of the present invention.

This apparatus comprises awakening degree determining means 7, detection control means 11, data holding means 16, skin temperature detecting means 14, temperature detecting means 15, temperature processing means 5, and awakening degree determining means 7.

The detection control means 11 outputs a trigger signal for instructing temperature detection to the skin temperature detection means 14 and the air temperature detection means 15 in accordance with a predetermined time interval, and the skin temperature detection means 14 and the air temperature detection means 15 detect the temperature. Defines the time interval of. Further, the time interval is output to the temperature processing means 5.

The data holding means 16 comprises a temperature data holding means 4 and a calculation result holding means 6, and the skin temperature detecting means 1
4. The temperature data output from the air temperature detecting means 15 is held and output to the temperature processing means 5, and the calculation result output from the temperature processing means 5 is held and output to the awakening degree determining means 7.

The skin temperature detecting means 14 comprises a nasal bone skin temperature sensor 1 and a masseter muscle skin temperature sensor 2 which are thermocouples.
The nasal bone temperature sensor 1 is installed so as to contact the skin surface on the user's nasal bone, and the masseter muscle temperature sensor 2 is installed so as to contact the skin surface on the user's masseter muscle. Upon receiving the trigger signal, the skin temperature is detected and output to the temperature data holding means 4 provided in the data holding means 16.

The air temperature detecting means 15 comprises an air temperature sensor 3 which is a thermistor, receives a trigger signal from the detection control means 11 to detect the air temperature, and outputs it to the temperature data holding means 4 provided in the data holding means 16. .

The temperature processing means 5 is a temperature data holding means 4
The nasal bone skin temperature data, the masseter muscle skin temperature data, and the air temperature data are read from the above, and the moving average processing for the past 300 seconds is performed on the temperature data, and the calculation result is output to the calculation result holding unit 6.

The awakening degree determining means 7 detects a change in skin temperature caused by a decrease in the awakening degree from the moving average temperature registered in the calculation result holding means, and based on the change in skin temperature,
It outputs to the outside a sign of dozing and a signal corresponding to dozing.

It is generally known that in monotonous mental work such as monitoring work, the arousal level is likely to decrease. In the process of decreasing wakefulness, a transient rise in skin temperature is generally observed before and after falling asleep. This is a phenomenon that occurs because the sympathetic nerve that governs the contraction of skin blood vessels is relaxed due to a decrease in alertness, and the skin blood flow increases. A graph showing changes in skin temperature corresponding to such falling asleep is shown in FIG. The solid line shows the skin temperature above the masseter muscle, and the thin line shows the skin temperature above the nasal bone. That is, the area (a) changes the skin temperature in the state of continuing awakening, the area (b) decreases the arousal level and changes in the skin temperature until falling asleep, and the area (c) falls asleep. Change in skin temperature when awakened from
Similar to (a), it shows changes in skin temperature in the state of continuing awakening. As seen in the area (b), during sleep, a phenomenon occurs in which the skin temperature above the nasal bone and the skin temperature above the masseter muscle rise in synchronization for a relatively long time.

The temperature processing means 5 in the configuration of this embodiment for capturing the change in the skin temperature corresponding to the fall asleep.
The operation of the awakening degree determination means 7 will be described below.

First, the processing of the temperature data in the temperature processing means 5 will be described with reference to the flowchart shown in FIG. In FIG. 3, first, the temperature data reading counter TN is reset to 0 (step 41), and the temperature data detection time interval TS output from the detection control means 11 is detected.
I is read (step 42). Then, the nasal skin temperature nst (n), the masseter muscle skin temperature cst (n), and the air temperature at
Each time (n) is read (step 43), the read counter TN is incremented by +1 (step 44). The temperature data is read until the number of read data TN exceeds the number of data TN0 required for moving average temperature calculation (step 45), and then the moving average temperature of the TN point is calculated (step 46), and the data holding means (Step 47) returns to Step 43, and the moving average temperature is continuously calculated and registered.

Next, the outline of the doze determination method based on the moving average temperature in the awakening degree determination means 7 will be described with reference to FIG. First, the monotonous increase in the nasal bone temperature within a predetermined time is detected (step 51), and then when the nasal bone temperature is monotonically increased, it is confirmed whether the air temperature is also monotonically increasing (step 52). If it is not increased, the monotonous increase in the skin temperature on the masseter muscle within the predetermined time is detected, and the dozing state is determined (step 53). Here, if both the skin temperature on the nasal bone and the skin temperature on the masseter muscle monotonically increase within a predetermined time, it is determined that the person has fallen asleep (step 5).
4) If only the skin temperature above the nasal bone monotonically increases, it is determined that it is a sign of dozing (step 55).

Further, details of the processing of steps 51, 52 and 53 will be described with reference to the flow charts shown in FIGS. 5, 6 and 7. The flowchart of FIG. 5 is for detecting the monotonous increase of the skin temperature on the nasal bone in step 51 of FIG. First, the doze detection sensitivity AST is read (step 61). The drowsiness detection sensitivity AST is
It is possible to input according to the user beforehand. This is input in seconds and is the time for detecting a monotonous increase in temperature data. The doze detection sensitivity AST
If the value of is small, a signal corresponding to dozing will be output at an early stage when the skin temperature rises. Next, a counter M that counts the number of data items on the nasal bone temperature when the nasal skin temperature is monotonically increasing is set (step 6
2) Two consecutive moving averages of the nasal skin temperature are read from the data holding means (step 63), and the magnitude comparison with the immediately preceding value is performed (step 64). At this time, if the moving average value of the skin temperature above the nasal bone is not monotonically increasing, the flow returns to step 63 to read the temperature data, but if the moving average value of the skin temperature above the nasal bone is monotonically increasing, the counter M is incremented by +1. (Step 65) Then, it is confirmed whether or not the monotonous increase continues for the time set by the drowsiness detection sensitivity AST (step 66), and if so, the drowsiness flag Fatt is set (step 67). If it does not continue, the doze sign flag Fatt is reset (step 68), and the nasal bone upper skin temperature is continuously read.

In step 67 of FIG. 5, when the doze symptom flag Fatt is set, the process shifts to a process of confirming a monotonous increase in temperature (step 52 in FIG. 4). The processing performed there will be described below with reference to the flowchart of FIG. First, a counter L that counts the number of temperature data when the temperature is monotonically increasing is set (step 7
1), the moving average value of the temperature is read from the data holding means (step 72), and the magnitude comparison with the immediately preceding value is performed (step 73). At this time, if the moving average value of the temperature is not monotonically increasing, the process returns to step 72 to read the temperature data continuously, but if it is monotonically increasing, the counter L is incremented by +1 (step 74), and the monotonous increase is the drowsiness detection sensitivity AST. It is confirmed whether or not it has been maintained for the set time (step 75), and if it is maintained, the temperature condition flag Fat is reset (step 76), and the nasal bone upper skin temperature is continuously read. If not, the room temperature state flag Fat is set (step 77).

If the room temperature state flag Fatt cannot be set in step 77 of FIG. 6, the process shifts to a process of confirming a monotonous increase in the skin temperature on the masseter muscle and determining a drowsiness (step 53 in FIG. 4). The processing performed there will be described below with reference to the flowchart of FIG. First, a counter N that counts the number of data items of the masseter muscle skin temperature when the masseter muscle skin temperature monotonously increases is set (step 81), and the moving average value of the masseter muscle skin temperature is read from the data holding means (step 81). 82), and compares the magnitude with the immediately preceding value (step 83). At this time, if the moving average value of the air temperature is not monotonically increasing, the process returns to step 82 and the data of the skin temperature on the masseter muscle is continuously read.
It is incremented (step 84), and it is confirmed whether or not the monotonous increase continues for the time set by the drowsiness detection sensitivity AST (step 85), and if so, the doze state flag Fsl is set (step 86), If it does not continue, the dozing state flag Fsl is not set (step 87), and the dozing state flag is output to the outside (step 88).

At step 88, the tension state flag F
The att is always 0, and there are two combinations of the tension state flag Fatt and the doze state flag Fsl. (Fat
When the combination of (t, Fsl) is (0, 0), the nasal epidermis skin temperature monotonically increased within a predetermined time, but the masseter muscle skin temperature did not monotonically increase within a predetermined time. . This corresponds to the sympathetic nerve, which controls skin blood flow, but not so much that the temperature of the skin above the masseter muscle decreased, that is, a sign of dozing. In addition, (Fatt,
When the combination of (Fsl) is (0,1), it shows that the skin temperature above the nasal bone and the skin temperature above the masseter muscle monotonically increased within a predetermined time period, and this change in skin temperature means relaxation of the sympathetic nervous system. And respond to the start of dozing.

The skin temperature detecting means of the present invention does not necessarily have to be a contact type sensor such as a thermocouple as in the above-mentioned embodiment, and all the body temperature sensors including non-contact type sensors are used for the face part. The skin temperature above the nasal bone and the skin temperature above the masseter muscle can be detected.

[0029]

As is apparent from the above description, according to the doze detection device of the present invention, the influence of posture, temperature and individual difference is detected by detecting not the absolute value of the skin temperature but the relative change. The snooze is detected accurately without being affected.

According to the doze detection device of the present invention,
It is possible to detect the skin temperature above the masseter muscle in which a significant rise in skin temperature corresponding to dozing occurs, and the skin temperature above the nasal bone that reacts sensitively to the activity of the sympathetic nervous system. From the change, it is possible to discriminate between the three states of awakening, signs of dozing, and dozing.

[Brief description of the drawings]

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

[Fig.2] Time series graph of "snooping" of skin temperature above masseter muscle and skin temperature above nasal bone

FIG. 3 is a flowchart showing a process in a temperature processing means of the doze detection device shown in FIG.

4 is a flowchart showing an outline of a wakefulness determination method in a wakefulness determination means of the doze detection device shown in FIG.

5 is a flowchart showing a process of skin temperature above the nasal bone in the awakening degree determination means of the doze detection device shown in FIG.

FIG. 6 is a flowchart showing temperature processing in the awakening degree determination means of the doze detection device shown in FIG.

FIG. 7 is a flowchart showing the processing of the skin temperature above the nasal bone in the awakening degree determination means of the doze detection device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nasal skin temperature sensor 2 Masseter muscle skin temperature sensor 3 Air temperature sensor 4 Temperature data holding means 5 Temperature processing means 6 Calculation result holding means 7 Arousal level determination means 11 Detection control means

Front page continued (72) Inventor Tomoko Kitamura 1006 Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A skin temperature detecting means for detecting a skin temperature of a human body, an air temperature detecting means for detecting an air temperature, skin temperature data detected by the skin temperature detecting means, and air temperature data measured by the air temperature detecting means. A data holding means for registering, a temperature processing means for time-series arithmetic processing of temperature data registered in the data holding means, and a calculation result output from the temperature processing means, to determine the awakening degree of the user, A drowsiness detecting device comprising: an awakening degree determining means for outputting a signal corresponding to the awakening degree to the outside; and a detection control means for controlling the operations of the skin temperature detecting means and the awakening degree determining means. 2. The drowsiness detecting apparatus according to claim 1, further comprising a skin temperature detecting means for extracting the skin temperature on the nasal bone and the skin temperature on the masseter muscle from the skin temperature of the face portion of the human body.