JP2006346110A - Biological information detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a detection accuracy of biological information using a sweating action, which relates to a biological information detecting device for detecting living body information using a sweating action of a human being who is a living body.
SOLUTION: In a biological information detecting device for detecting a sweating action of a palm of a driver as biological information, an air passage 24 is formed in a steering portion 22 held by the driver, and the air passage 24 and the steering portion 22 are provided. A steering wheel 14 formed with a communication hole 25 communicating with the surface, an air conditioner 11 that supplies dry air to the air passage 24, and a first humidity that detects the humidity of air sent from the air conditioner 11 to the air passage 24. A detection unit 13, a second detection unit 16 that detects the humidity of the air discharged from the air passage 24, and a computer (PCSECU 17) that detects biological information based on the humidity of the air detected by each of the detection units 13 and 16. ).
[Selection] Figure 1

Description

  The present invention relates to a biological information detection apparatus, and more particularly to a biological information detection apparatus that detects biological information by utilizing the sweating action of a human being who is a living body.

  In recent years, attempts have been made to realize safer and better driver viability by detecting biological information and using the detection result for operation control. In order to perform this control accurately and reliably, it is necessary to accurately detect the biological state of the driver. In addition, there are various types of biometric information, and one of them is detecting a driver's sweating action as biometric information.

  In particular, the human palm is less affected by thermal sweating and is a suitable part for detecting mental sweating. Further, since the driver is in constant contact with the steering wheel during driving, it is a suitable part for measuring the amount of sweating. For this reason, there has been proposed a biological information detection device configured to measure a driver's biological state by incorporating a sensor that detects the driver's sweat into the steering wheel (see, for example, Patent Document 1).

Conventionally, in this type of biological information detection device, as a sensor for detecting the sweat of the palm of the driver, a plurality of electrodes are exposed so as to form a loop over the entire circumference of the steering wheel, and a constant current 3 The method of measuring the skin impedance of the palm by the electrode method has been adopted.
Japanese Patent Laid-Open No. 10-080405

  However, the conventional biological information detection device that detects the sweating action of the driver as biological information is configured to measure the amount of sweating by measuring the skin impedance of the palm using the electrodes disposed on the steering wheel as described above. Therefore, it is conceivable that sweat remains on the steering wheel. In this case, there is a problem that an accurate amount of perspiration cannot be measured.

  In addition to sweating due to mental causes (referred to as mental sweating), the driver is also known to perform sweating due to high temperature (referred to as thermal sweating). The palm is a portion where thermal sweating is difficult to occur as described above, but thermal sweating also occurs in the palm when the temperature inside the vehicle rises greatly in summer or the like.

  The driver's biological information (sweat) that can be used for driving control is mental sweating, and thermal sweating is an error factor. However, the conventional biological information detection apparatus has a problem that this thermal sweating cannot be effectively excluded from the biological information detection.

  The present invention has been made in view of the above points, and provides a biological information detection apparatus capable of detecting biological information using sweating action with high accuracy by preventing sweat from remaining on the steering wheel. The purpose is to do.

  In order to solve the above-described problems, the present invention is characterized by the following measures.

The invention according to claim 1
In the biological information detection device that detects the sweating action of the palm of the driver as biological information,
A steering wheel in which an air passage is formed in the steering portion gripped by the driver and a communication hole is formed to communicate the air passage and the surface of the steering portion;
Dry air supply means for supplying dry air to the air passage formed in the steering wheel;
First detection means for detecting the humidity of air sent from the dry air supply means to the air passage;
Second detection means for detecting the humidity of the air discharged from the air passage;
The apparatus has a humidity of air detected by the first detection means and a biological information detection means for detecting biological information based on the humidity of air detected by the second detection means. .

  According to the invention, dry air is sent from the dry air supply means to the air passage formed in the steering wheel, and a part of the dry air passes through the communication hole and is gripped by the driver on the surface of the steering unit. Sent. For this reason, sweat does not remain in the steering part gripped by the driver, and the accuracy of biometric information detection can be improved.

  Further, since dry air is constantly applied to the palm of the driver, the amount of thermal sweating generated can be reduced even if the temperature inside the vehicle rises. As described above, since the amount of thermal sweating that becomes an error factor of biological information detection can be reduced, the accuracy of biological information detection can also be increased.

The invention according to claim 2
The biological information detection apparatus according to claim 1,
An air conditioner is used as the dry air supply means.

  According to the above-described invention, dry air can be generated using an air conditioner that is normally mounted on the vehicle, so that a biological information detection device can be realized with a simple configuration.

The invention according to claim 3
The biological information detection apparatus according to claim 1 or 2,
The biological information detection means detects biological information based on a humidity difference obtained by subtracting the air humidity detected by the first detection means from the air humidity detected by the second detection means. To do.

  According to the above invention, the biological information is detected in the dry air by detecting the biological information based on the humidity difference obtained by subtracting the humidity of the air detected by the first detecting means from the humidity of the air detected by the second detecting means. Even if an error factor is included in the detection, this error factor is calculated when the air humidity detected by the first detection means is subtracted from the air humidity detected by the second detection means in order to obtain the humidity difference. Since it cancels out, the detection accuracy of biological information can be improved.

  As described above, according to the present invention, it is possible to prevent residual sweat, and thus it is possible to improve the detection accuracy of biological information.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a block configuration diagram of a biological information detection apparatus 10 according to an embodiment of the present invention, and FIGS. 2 and 3 are diagrams for explaining a steering wheel 14 constituting the biological information detection apparatus 10.

  As shown in FIG. 1, the biological information detection apparatus 10 includes an air conditioner 11 (hereinafter abbreviated as “air conditioner”), a first detection unit 13, a steering wheel 14, a second detection unit 16, and a PCSECU 17. It is configured. In FIG. 1, an arrow indicated by a solid line indicates an air flow, and an arrow indicated by a broken line indicates a signal flow.

  A general air conditioner 11 can be used, but at least a dehumidifying function is required. The air conditioner 11 used in the present embodiment is configured to be able to perform dehumidification while performing indoor cooling and heating.

  Dehumidified air generated by the air conditioner 11 (hereinafter referred to as dry air) is blown into the room from the air conditioner outlet 12 and is sent to the first detector 13.

The first detection unit 13 has a hygrometer and a flow meter. The hygrometer detects the humidity of dry air, and for example, a sensor using moisture-sensitive ceramics such as MgCr ₂ O ₄ —TiO ₂ porous ceramics can be used. The flow meter measures the flow rate of dry air, and for example, a Karman vortex flow meter can be used. The first humidity signal corresponding to the humidity detected by the first detection unit 13 and the first flow velocity signal corresponding to the flow velocity are transmitted to the PCSECU 17.

  Dry air generated by the air conditioner 11 and measured for humidity and flow velocity by the first detection unit 13 is sent to the steering wheel 14. The steering wheel 14 includes a steering unit 22 that is gripped and operated by a driver, and a plurality of (three in this embodiment) spokes 23A to 23C that connect a steering shaft (not shown) and the steering unit 22. It is set as having.

  As shown in FIGS. 2 and 3, the steering wheel 14 has an air passage 24 formed in the steering portion 22. The air passage 24 is disposed in the upper half of the steering wheel 14 in this embodiment. Specifically, the ejection part 26 formed at the center part of the steering wheel 14, the spoke 23 </ b> A, the upper half part of the steering part 22, the spoke 23 </ b> B, and the suction part 27 formed at the center part of the steering wheel 14 are communicated. It is formed as follows.

  The ejection unit 26 is connected to the first detection unit 13 described above, and thus dry air generated by the air conditioner 11 is supplied to the steering wheel 14 via the first detection unit 13. The dry air blown out from the ejection portion 26 passes through the air passage 24 formed in the spoke 23A, the air passage 24 formed in the upper half of the steering portion 22, and the air passage 24 formed in the spoke 23B. The suction part 27 is configured to be sucked.

  In the region where the air passage 24 is formed, a large number of communication holes 25 are formed between the surface of the steering wheel 14 and the air passage 24. The communication hole 25 is formed in the steering wheel 14 by selecting a region that the driver may grip for a long time. 2B and 3, the diameter of the communication hole 25 is shown larger than the actual diameter in order to facilitate the illustration and understanding, but the actual diameter of the communication hole 25 is as small as 1 mm or less. It is the hole diameter.

  The communication hole 25 communicates the surface of the steering wheel 14 and the air passage 24, so that dry air is supplied to the surface of the steering wheel 14. In addition, the formation position of the communication hole 25 is selected particularly in an area where the driver may grip for a long time. Therefore, in the region where the driver is holding the steering wheel 14 (see FIG. 3), the dry air flowing through the air passage 24 comes into contact with the palm of the driver via the communication hole 25.

  Therefore, when the driver is sweating, the sweat increases the humidity of the dry air. The increase in the humidity of the dry air is proportional to the amount of sweating, and the mental sweating of the driver changes according to the degree of tension of the driver. It becomes possible to detect the tension state (biological information).

  In addition, part of the dry air sent from the air conditioner 11 as described above flows into the vehicle compartment through the communication hole 25 in the process of drawing through the air passage 24. However, the dry air generated by the air conditioner 11 is originally generated because the air is blown into the vehicle interior via the air conditioner outlet 12, and therefore there is a particular problem even if it is blown out from the steering wheel 14 into the vehicle interior. Does not occur.

  Further, since dry air is constantly applied to the palm of the driver through the communication hole 25, sweat does not remain on the steering portion 22 gripped by the driver. In addition, the amount of thermal sweating generated can be reduced even when the vehicle interior temperature rises. Thereby, since the generation amount of thermal sweating which becomes an error factor of biological information detection can be reduced, the accuracy of biological information detection can be increased.

  The steering wheel 14 is provided with a steering angle sensor 15, and the steering angle detected by the steering angle sensor 15 is transmitted to the PCSECU 17 as a steering angle signal.

  As described above, the dry air having the humidity corresponding to the mental sweat which is the biological information of the driver by flowing in the steering wheel 14 is secondly detected after being sucked from the suction unit 27. Supplied to the unit 16.

  The second detection unit 16 has the same configuration as the first detection unit 13 described above, and thus includes a hygrometer using moisture-sensitive ceramics and a flow meter such as a Karman vortex flow meter, for example. It is said that. The second humidity signal corresponding to the humidity detected by the second detection unit 16 and the second flow velocity signal corresponding to the flow velocity are transmitted to the PCSECU 17.

  The PCSECU 17 is composed of a microcomputer, and performs a biopsy of the driver based on various information transmitted from the first detection unit 13 and the steering wheel 14 and the like. The PCSECU 17 detects the biological state of the driver based on the first humidity signal transmitted from the first detection unit 13 and the second humidity signal transmitted from the second detection unit 16.

  Specifically, the PCSECU 17 first determines the humidity of the dry air detected by the second detection unit 16 (in other words, the humidity of the dry air having a humidity corresponding to mental sweating, which is the driver's biological information). The amount of perspiration indicating the driver's biological state is subtracted from the humidity of the dry air detected by the first detector 13 (in other words, the humidity of the dry air not including the driver's biological information). W is detected.

  FIG. 4 shows an example of the sweating amount calculated in the PCSECU 17 as described above. In the figure, the horizontal axis indicates time, and the vertical axis indicates the sweating amount W. The amount of perspiration and the driver's biological state have a relationship. When the amount of perspiration increases, the living body is in a tension state, and conversely, when the amount of perspiration is small, it indicates a relaxed state.

  In this example, an experiment was conducted in which a tension state and a relaxed state were experimentally created for a large number of people, and the amount of perspiration at this time was determined. Based on the data obtained by this experiment, the average sweating amount W1 (hereinafter referred to as the maximum sweating amount W1) in an average human normal state (a state that is neither a tension state nor a relaxed state) and a normal state The minimum sweating amount was determined as W1 (hereinafter referred to as the minimum sweating amount W2).

  The maximum sweating amount W1 and the minimum sweating amount W2 are stored in the PCSECU 17 in advance. Then, with the maximum sweating amount W1 and the minimum sweating amount W2 as threshold values, when the sweating amount W exceeds the maximum sweating amount W1, the driver determines that the driver is in a tension state, and the sweating amount W is the minimum sweating amount. If it is less than W2, it is determined that the person is in a relaxed state (see FIG. 4). This makes it possible to detect biological information with certainty and accuracy.

  The driver's biometric information detected in this way is transmitted from the PCSECU 17 to various computers (meter ECU 18, brake ECU 19, EPSECU 20, PSBECU 21, etc.) mounted on the vehicle, and is reflected in each control. This makes it possible to perform various highly accurate controls corresponding to the driver's current biological state.

  Further, as described above, in the present embodiment, since the configuration is such that the dry air is supplied to the palm of the driver using the air conditioner 11 that is normally mounted on the vehicle, it is simpler than the configuration in which the dry air generation means is separately provided. A living body information detecting device can be realized with a simple configuration.

  Furthermore, in this embodiment, since the first and second detectors 13 and 16 are provided with flow meters for detecting the flow rate of the dry air flowing in the air passage 24, the gripping state of the driver's steering is detected. It is also possible. This will be described below.

  As described above, a number of communication holes 25 are formed in the steering wheel 14, but if the driver has released his hand from the steering wheel 14, all the communication holes 25 should be open. It becomes. For this reason, the outflow amount that the dry air flows out of the air passage 24 from the communication hole 25 increases, and the second detection unit is compared with the flow rate H1 of the dry air measured by the flow meter of the first detection unit 13. The flow rate H2a of dry air measured by the 16 flow meters is greatly reduced.

  On the other hand, if the driver is holding the steering wheel 14 with both hands, the number of communication holes 25 that are blocked by the palm of the driver is the largest. For this reason, the outflow amount of the dry air flowing out of the air passage 24 from the communication hole 25 is smaller than that when all the communication holes 25 are opened as described above, and the flow rate of the first detection unit 13 is reduced. The flow rate H2b of the dry air measured by the flow meter of the second detector 16 is greater than the flow rate H2a of the flow rate H1 of the dry air measured by the meter.

  Furthermore, if the driver is holding the steering wheel 14 with one hand, the number of communication holes 25 that are blocked by the driver's palm is approximately the intermediate number of the above two examples. For this reason, the outflow amount of the dry air flowing out of the air passage 24 from the communication hole 25 is smaller than that in the case where all the communication holes 25 are opened, and the communication hole 25 is gripped with both hands. More than if open. Accordingly, the flow rate H2c of the dry air measured by the flow meter of the second detection unit 16 with respect to the flow rate H1 of the dry air measured by the flow meter of the first detection unit 13 is the flow rate H2a and H2b. (H2a <H2c <H2b).

  Therefore, by comparing the flow rate of the dry air detected by the flow meter of the first detection unit 13 and the flow rate of the dry air detected by the flow meter of the second detection unit 16, the steering of the driver It is possible to detect the gripping state.

FIG. 1 is a block diagram of a biological information detection apparatus according to an embodiment of the present invention. FIG. 2 is a view for explaining a steering wheel constituting a biological information detecting apparatus according to an embodiment of the present invention. FIG. 3 is a diagram for explaining the reason why human body sweating, which is a living body, is detected by the biological information detecting apparatus according to an embodiment of the present invention. FIG. 4 is a diagram showing sweating information detected by the biological information detection apparatus according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Biological information detection apparatus 11 Air conditioner 12 Air-conditioner outlet 13 1st detection part 14 Steering wheel 16 2nd detection part 22 Steering part 24 Air passage 25 Communication hole 26 Ejection part 27 Suction part

Claims (3)

In the biological information detection device that detects the sweating action of the palm of the driver as biological information,
A steering wheel in which an air passage is formed in the steering portion gripped by the driver and a communication hole is formed to communicate the air passage and the surface of the steering portion;
Dry air supply means for supplying dry air to the air passage formed in the steering wheel;
First detection means for detecting the humidity of air sent from the dry air supply means to the air passage;
Second detection means for detecting the humidity of the air discharged from the air passage;
Biological information detection comprising: air humidity detected by the first detection means; and biological information detection means for detecting biological information based on the humidity of air detected by the second detection means. apparatus. The biological information detection apparatus according to claim 1,
An air conditioner is used as the dry air supply means. The biological information detection apparatus according to claim 1 or 2,
The biological information detection means detects biological information based on a humidity difference obtained by subtracting the air humidity detected by the first detection means from the air humidity detected by the second detection means. Biological information detecting device.

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