JP7688486B2 - Biometric information acquisition device - Google Patents

Description

The present invention relates to a biometric information acquisition device that acquires biometric information of a vehicle driver.

Currently, there is a known bioinformation measuring device that has a left electrode and a right electrode attached to the left and right grips of a vehicle steering wheel, so that the driver's electrocardiogram can be measured simply by gripping the steering wheel (see, for example, Patent Document 1). Such a bioinformation measuring device is equipped with a potential difference detection circuit that detects the potential difference between the left and right electrodes, and a data processing unit that detects the electrocardiogram, which shows the driver's electrocardiogram waveform, and the heart rate based on the potential difference.

JP 2017-217221 A

The above-mentioned vital information measuring device is mounted on a vehicle and is therefore subject to noise specific to the vehicle. However, as the vital information measuring device handles minute signals (called bioelectrical signals) from electrodes in contact with the skin of the human body, it is susceptible to the effects of noise.

It is therefore possible to use a filter to remove noise from the input signal containing the bioelectric signal. In order to reliably remove noise of various frequencies, it is desirable to use a bandpass filter with a narrow passband that targets a relatively wide frequency band for noise removal, taking into account a margin.

However, when a bandpass filter with a narrow passband is used in this way, the amount of information in the bioelectric signal output from the bandpass filter is reduced, making it difficult to accurately detect bioinformation such as electrocardiograms and electroencephalograms, which require precise signal waveforms. On the other hand, when a bandpass filter with a wide passband is used, noise may be superimposed on the bioelectric signal output from the bandpass filter. In this case, if the level of the noise is high, it becomes difficult to detect even bioinformation such as heart rate and respiratory rate, which do not require precise signal waveforms.

Therefore, one of the objectives of the present invention is to provide a biometric information acquisition device that can efficiently detect various types of biometric information even in a noisy environment.

The invention described in claim 1 is a biometric information acquisition device for acquiring biometric information of a vehicle driver, comprising: a signal acquisition unit for acquiring an input signal including a biometric signal generated in association with a biological phenomenon of the driver; a noise-related information acquisition unit for acquiring information related to noise contained in the input signal as noise-related information; a bandpass filter for extracting signal components of a specified band from the input signal and outputting an extraction signal representing the extracted signal components; a biometric information detection unit for acquiring biometric information of the driver based on the extraction signal; and a control unit for changing the specified band of the bandpass filter based on the noise-related information and setting the type of the biometric information detected by the biometric information detection unit.

FIG. 1 is a system configuration diagram showing a configuration of a biometric information acquisition system 100. 2 is a block diagram showing an internal configuration of a biological information detection unit 30. FIG. 10 is a flowchart showing the procedure of a biological information detection setting process executed by a control unit 400. 10 is a flowchart showing the procedure of another biological information detection setting process executed by the control unit 400. 10 is a flowchart showing the procedure of a notification process executed by a control unit 400.

A preferred embodiment of the present invention is described in detail below.

Figure 1 is a system configuration diagram showing the configuration of a biometric information acquisition system 100 installed in a vehicle.

The bioinformation acquisition system 100 includes sensor electrodes 20L and 20R, a bioinformation detection unit 30, a navigation device 40, a display unit 41, and a speaker 42.

Sensor electrode 20L is installed in an area of the ring portion of steering wheel 10 that is held by the driver's left hand, and sensor electrode 20R is installed in an area that is held by the driver's right hand. Sensor electrodes 20L and 20R are each connected to bioinformation detection unit 30 via wiring (not shown).

The biometric information detection unit 30 is installed, for example, on the spokes of the handlebars 10. The biometric information detection unit 30 is provided with a battery holder BP that holds a battery consisting of a primary battery or a secondary battery, and performs the following operations based on the power supplied from the battery.

The bioinformation detection unit 30 acquires bioinformation such as the driver's heart rate or electrocardiogram from the potential difference between the sensor electrodes 20R and 20L, that is, from electrical signals (hereinafter referred to as bioelectrical signals) emitted from within the body in association with the driver's biological phenomena, and generates a bioinformation signal representing the acquired bioinformation. The bioinformation detection unit 30 includes a bioinformation detection circuit that acquires such bioinformation, and a failure detection circuit that generates a failure detection signal indicating the occurrence of a failure in the bioinformation detection circuit or the sensor electrodes 20R, 20L.

The biometric information detection unit 30 also has a wireless communication function that establishes wireless communication with the navigation device 40 using Bluetooth (registered trademark) or the like.

The biometric information detection unit 30 wirelessly transmits to the navigation device 40 the biometric information signal generated as described above, the fault detection signal, and device information indicating the type of biometric information detection circuit and the type of vehicle in which the biometric information detection unit 30 is installed. The biometric information detection unit 30 also wirelessly transmits to the navigation device 40 various request signals, such as a road shape information request signal, a handle grip notification request signal, or a notification emphasis request signal.

Furthermore, when the biometric information detection unit 30 receives road topology information wirelessly transmitted from the navigation device 40, the operating state of the biometric information detection unit 30 is set so that it detects biometric information in a manner based on the road topology information.

The navigation device 40 includes a memory unit (not shown) that stores a road map and road configuration information that represents the configuration of the roads on the road map, and a position detection unit that detects the current position of the vehicle, and generates an image signal that shows the current position of the vehicle detected by the position detection unit on the road map.

Here, the road shape information is information that represents, for example, curved sections, straight sections, slope sections, intersection sections, unpaved sections, or tunnel sections on each road. A curved section represents, for example, a curve with a radius of curvature greater than a predetermined value or a road section in which such curves are continuous. A curved section may be defined as a road section having a radius of curvature such that the driver cannot continue driving for a predetermined period of time while holding the sensor electrodes 20L and 20R with both hands. A sloped section is a road section whose gradient exceeds a predetermined range, and an intersection section is a road section including a three-way intersection and a T-junction. An unpaved section is a road section whose road surface is not paved or whose pavement is deteriorated, and in which the vehicle vibrates relatively greatly when traveling. A straight section or a tunnel section is a road section in which lane changes are prohibited or there is one lane in each direction, the radius of curvature is less than a predetermined value, and the driving time required for detecting bioinformation when traveling at the legal speed is longer than the time required for detecting bioinformation. Additionally, a straight section may be defined as a road section where the driver can maintain driving at a legal speed for a predetermined period of time while holding the sensor electrodes 20L and 20R with both hands.

In addition, when the navigation device 40 receives a malfunction detection signal wirelessly transmitted from the bioinformation detection unit 30, it generates an audio signal that notifies the driver by voice that a malfunction has occurred in the bioinformation detection unit 30 or the sensor electrodes 20R, 20L, or an image signal that displays the occurrence of the malfunction in text. In addition, when the navigation device 40 receives a steering wheel gripping notification request signal transmitted from the bioinformation detection unit 30, it generates an audio signal that displays a steering wheel gripping notification in text, which prompts the driver to grip the steering wheel 10 of the vehicle with both hands, or an image signal that displays the steering wheel gripping notification in text. Here, when the navigation device 40 receives a notification emphasis request signal wirelessly transmitted from the bioinformation detection unit 30, it increases the volume of the audio signal that displays the steering wheel gripping notification in text, and it increases the size of the text or blinks the text of the image signal that displays the steering wheel gripping notification in text.

The navigation device 40 then supplies the image signal generated as described above to the display unit 41 to display an image based on the image signal, and supplies the audio signal generated as described above to the speaker 42 to acoustically output audio based on the audio signal.

When the navigation device 40 receives the bio-information signal wirelessly transmitted from the bio-information detection unit 30, it acquires weather information indicating the weather in the area including the vehicle's current location, for example, via a mobile phone line and the Internet NW. The navigation device 40 then transmits the above-mentioned weather information, device information, and current time information together with the received bio-information signal to a specific server SV, for example, via a mobile phone line and the Internet NW. The server SV provides registered users with images showing bio-information (heart rate, electrocardiogram, respiratory rate, electromyogram) based on the bio-information signal, or estimates of state values such as drowsiness, fatigue, and stress from the bio-information, and provides the numerical values or images expressing them via the Internet NW.

When the navigation device 40 receives a road topology information request signal wirelessly transmitted from the biometric information detection unit 30, it extracts the road topology of the road on which the vehicle is currently traveling or the road on which the vehicle is expected to travel from the above-mentioned road topology information. The navigation device 40 then wirelessly transmits the extracted road topology and road topology information indicating the current traveling speed of the vehicle to the biometric information detection unit 30.

The operation of the biometric information detection unit 30 and the navigation device 40 is described in detail below.

Figure 2 is a block diagram showing the internal configuration of the biometric information detection unit 30.

The biometric information detection unit 30 includes a power supply circuit 300, a variable bandpass filter 301, a biometric information detection circuit 302, a fault detection circuit 303, a two-hand contact detection circuit 304, a memory 305, a transmission/reception circuit 306, a noise-related information acquisition unit 307, and a control unit 400.

The power supply circuit 300 acquires power from a battery BT consisting of a primary or secondary battery held in a battery holder BP. The power supply circuit 300 supplies the acquired power to the variable band filter 301, the bioinformation detection circuit 302, the fault detection circuit 303, the both hand contact detection circuit 304, the memory 305, the transmission/reception circuit 306, the noise-related information acquisition unit 307, and the control unit 400, respectively, to operate each of these circuits. When the operation mode signal MOD supplied from the control unit 400 indicates the normal mode, the variable band filter 301 performs the following filtering process on the bioelectric signal based on the potential difference between the sensor electrodes 20L and 20R.

That is, the variable band filter 301 extracts signal components of a frequency band specified by a band specification signal FC supplied from the control unit 400 from the bioelectric signal. The variable band filter 301 then supplies an extraction signal BS representing the extracted signal components to the bioinformation detection circuit 302. Through this filtering process, the variable band filter 301 removes noise components from the bioelectric signal that interfere with the detection of bioinformation such as heart rate, electrocardiogram, respiratory rate, or electromyogram.

When the operation mode signal MOD indicates a power saving mode, the variable band-pass filter 301 is set to a state in which its operation (filtering process) is stopped, or to a low power consumption state in which the amount of current flowing through it is forcibly reduced.

When the operation mode signal MOD indicates the normal mode, the biometric information detection circuit 302 performs a biometric information detection operation to obtain the type of biometric information specified by the biometric information detection type designation signal ST supplied from the control unit 400 based on the extraction signal BS.

The types of biometric information specified by the biometric information detection type specification signal ST include a first type that requires a precise signal waveform, such as an electrocardiogram, and a second type that does not require precision in the signal waveform itself, such as heart rate or RRI (RR Interval).

When the bioinformation detection type designation signal ST indicates the first type, the bioinformation detection circuit 302 is set to a first detection mode in which an information signal representing an electrocardiogram is acquired as bioinformation from the extraction signal BS described above. On the other hand, when the bioinformation detection type designation signal ST indicates the second type, the bioinformation detection circuit 302 is set to a second detection mode in which an information signal representing a heart rate or RRI is acquired as bioinformation from the extraction signal BS. Then, the bioinformation detection circuit 302 supplies the acquired information signal as described above to the transmission/reception circuit 306 as a bioinformation signal BIS.

When the operation mode signal MOD indicates the power saving mode, the biometric information detection circuit 302 is set to a state in which its own biometric information detection operation is stopped, or to a low power consumption state in which the amount of current flowing through the circuit is forcibly reduced.

The fault detection circuit 303 determines whether or not a fault has occurred in the bioinformation detection circuit 302 or the sensor electrodes 20L, 20R, and if it determines that a fault has occurred, it supplies a fault detection signal FA indicating that a fault has been detected to the transmission/reception circuit 306. For example, the fault detection circuit 303 supplies a test signal for fault detection to the bioinformation detection circuit 302 at predetermined intervals, and determines that the bioinformation detection circuit 302 is faulty when the output result does not match the expected value. Alternatively, for example, even if it is found that the bioinformation detection circuit 302 is not faulty, it determines that the sensor electrodes 20L or 20R are faulty when the bioinformation detection circuit 302 cannot detect bioinformation for a predetermined long period of time. If the fault detection circuit 303 determines that a fault has occurred, it supplies the fault detection signal FA to the transmission/reception circuit 306.

The two-hand contact detection circuit 304 determines whether or not both hands of the driver of the vehicle are in contact with the sensor electrodes 20L and 20R based on the current flowing between the sensor electrodes 20L and 20R. The two-hand contact detection circuit 304 supplies the control unit 400 with a two-hand contact detection signal BH indicating the result of the determination, i.e., whether or not both hands of the driver are in contact with the sensor electrodes 20L and 20R.

The memory 305 is a non-volatile memory and has a storage area for storing the type of the biometric information detection circuit 302 (e.g., registered model number, detection method, etc.) and the type of vehicle in which the biometric information detection unit 300 is installed (e.g., vehicle model, model, vehicle name, etc.) as device information. The memory 305 supplies the device information DT stored in the storage area, which indicates the type of the biometric information detection circuit 302 and the type of the vehicle, to the transmission/reception circuit 306.

The transmission/reception circuit 306 wirelessly transmits the above-mentioned bio-information signal BIS and device information DT, or the above-mentioned failure detection signal FA, to the navigation device 40. Furthermore, when a travel road shape information request RQ1 is supplied from the control unit 400, the transmission/reception circuit 306 wirelessly transmits a travel road shape information request signal to the navigation device 40. Furthermore, when a handle gripping notification request RQ2 is supplied from the control unit 400, the transmission/reception circuit 306 wirelessly transmits a handle gripping notification request signal to the navigation device 40. Furthermore, when a notification emphasis request RQ3 is supplied from the control unit 400, the transmission/reception circuit 306 wirelessly transmits a notification emphasis request signal to the navigation device 40.

In addition, when the transmission/reception circuit 306 receives road configuration information wirelessly transmitted from the navigation device 40, it supplies this to the control unit 400 as road configuration information RD.

The noise-related information acquisition unit 307 acquires noise-related information that determines the level of noise superimposed on the bioelectrical signal based on the potential difference between the sensor electrodes 20L and 20R, and supplies the level indicated by the noise-related information to the control unit 400 as a noise level signal NS.

For example, when vibration occurs in the steering wheel 10, the contact between the driver's hands and the sensor electrodes 20L and 20R is interrupted at the vibration period, and this is superimposed on the bioelectric signal as noise. Therefore, a vibration sensor is provided in the noise-related information acquisition unit 307, and the vibration level of the steering wheel 10 detected by the vibration sensor is acquired as noise-related information. Also, for example, the higher the vehicle's traveling speed, the higher the level of noise emitted from the electric circuit related to the vehicle's drive system. Therefore, the noise-related information acquisition unit 307 acquires the vehicle's traveling speed indicated by the above-mentioned road configuration information RD as noise-related information. Also, from the bioelectric signal based on the potential difference between the sensor electrodes 20L and 20R, signal components in a band other than the frequency band required to acquire the bioinformation signal BIS may be extracted as a detected noise level, and this detected noise level may be acquired as noise-related information.

The noise-related information acquisition unit 307 supplies the control unit 400 with a noise level signal NS that represents one of the above-mentioned vibration level, driving speed, and detected noise level as a noise level.

The control unit 400 executes the biometric information detection setting process described below to set various operating modes of the variable band filter 301, the biometric information detection circuit 302, and the fault detection circuit 303.

Figure 3 is a flowchart showing the steps of the biometric information detection setting process.

In FIG. 3, first, the control unit 400 supplies an operation mode signal MOD indicating the normal mode to the variable band filter 301 and the biological information detection circuit 302 as the biological information detection unit (step S10). As a result, the variable band filter 301 and the biological information detection circuit 302 are set to the normal mode, and as described above, detection of the driver's biological information begins from both hands of the driver in contact with the sensor electrodes 20L and 20R.

Next, the control unit 400 acquires a noise level signal NS that indicates the noise level superimposed on the bioelectric signal (step S11). Next, the control unit 400 generates a band designation signal FC that designates a wider frequency band as the noise level signal NS becomes smaller, and supplies this to the variable band filter 301 (step S12). Next, the control unit 400 determines whether the noise level indicated by the noise level signal NS is less than a threshold value Th (step S13).

If it is determined in step S13 that the noise level is less than the threshold value Th, the control unit 400 supplies the bioinformation detection circuit 302 with a bioinformation detection type designation signal ST that designates the first type, which requires a precise signal waveform such as an electrocardiogram, as the type of bioinformation to be detected (step S14). This sets the bioinformation detection circuit 302 to a first detection mode in which a bioinformation signal BIS representing an electrocardiogram is acquired from the extraction signal BS described above. The bioinformation detection circuit 302 then wirelessly transmits the bioinformation signal BIS representing the driver's electrocardiogram acquired in the first detection mode to the navigation device 40 via the transmission/reception circuit 306.

On the other hand, if it is determined in step S13 that the noise level is equal to or greater than the threshold value Th, the control unit 400 supplies the bioinformation detection circuit 302 with a bioinformation detection type designation signal ST, which designates a second type of bioinformation to be detected that does not require precision in the signal waveform, such as heart rate or RRI (step S15). This sets the bioinformation detection circuit 302 to a second detection mode in which a bioinformation signal BIS representing the heart rate or RRI is acquired from the extraction signal BS. The bioinformation detection circuit 302 wirelessly transmits the bioinformation signal BIS representing the driver's heart rate or RRI acquired in the second detection mode to the navigation device 40 via the transmission/reception circuit 306.

After executing step S14 or S15 described above, the control unit 400 wirelessly transmits a travel road configuration information request RQ1 to the navigation device 40 via the transmission/reception circuit 306, and then retrieves the travel road configuration information RD wirelessly transmitted from the navigation device 40 in response to the travel road configuration information request signal (step S16).

Next, the control unit 400 determines whether the road currently being traveled corresponds to a curved section, a sloped section, an unpaved section, or an intersection section based on the traveled road configuration information RD (step S17).

If it is determined in step S17 that the road on which the vehicle is currently traveling is not a curved section, a hill section, an unpaved section, or an intersection section, the control unit 400 supplies an operation mode signal MOD indicating the normal mode to the variable band filter 301 and the biological information detection circuit 302 as the biological information detection unit (step S18). As a result, the variable band filter 301 and the biological information detection circuit 302 are set to the normal mode, and as described above, the biological information of the driver is detected from both hands of the driver that are in contact with the sensor electrodes 20L and 20R.

On the other hand, if it is determined in step S17 that the road currently being traveled is a curved section, a hill section, an unpaved section, or an intersection section, the control unit 400 supplies an operation mode signal MOD indicating the power saving mode instead of the normal mode described above to the variable band filter 301 and the biometric information detection circuit 302 as the biometric information detection unit (step S19). As a result, the variable band filter 301 and the biometric information detection circuit 302 are set to the power saving mode and the biometric information detection operation described above is stopped.

After executing step S18 or S19, the control unit 400 proceeds to execute step S11 and repeatedly executes the operations of steps S11 to S19 described above.

In the bioinformation detection setting process shown in FIG. 3, the bioinformation detection circuit 302 is set to normal mode, and is set to power saving mode when the vehicle is traveling on a road section such as a curved section, a sloped section, an unpaved section, or an intersection section, where it is difficult for the driver to hold the steering wheel 10 with both hands. In other words, when the vehicle is traveling on a road section such as a curved section, a sloped section, an unpaved section, or an intersection section, one of the driver's hands is removed from the sensor electrode 20L or 20R, making it difficult for the bioinformation detection circuit 302 to accurately detect bioinformation, particularly electrocardiograms and brain waves. Therefore, while the vehicle is traveling on a road section such as a curved section, a sloped section, an unpaved section, or an intersection section, it is not possible to accurately obtain bioinformation, so the operation of the bioinformation detection circuit 302 is stopped during this time to reduce consumption of the battery BT.

In the biometric information detection setting process shown in FIG. 3, the biometric information detection circuit 302 is set to the power saving mode only while the vehicle is traveling on road sections such as curved sections, slope sections, unpaved sections, or intersection sections. However, the power saving mode may be set at all times while the vehicle is traveling on roads other than straight sections where the driver can hold the steering wheel 10 with both hands, or tunnel sections where the driver will be holding the steering wheel 10 with both hands.

Figure 4 is a flowchart showing the steps of the biometric information detection setting process that has been implemented in consideration of the above points.

In addition, in the biometric information detection setting process shown in FIG. 4, step S20 is executed instead of step S10, and steps S21 to S24 are executed instead of steps S16 to S19. The other steps S11 to S15 are the same as those shown in FIG. 3.

The following describes the biometric information detection setting process shown in Figure 4, focusing on the operations in steps S20 to S24.

In FIG. 4, first, the control unit 400 supplies an operation mode signal MOD indicating the power saving mode to the variable band filter 301 and the biometric information detection circuit 302 as the biometric information detection unit (step S20). As a result, the variable band filter 301 and the biometric information detection circuit 302 are set to the power saving mode, and the above-mentioned biometric information detection operation is stopped.

After executing step S20, the control unit 400 executes steps S11 to S15 described above. Here, after executing step S14 or S15 shown in FIG. 4, the control unit 400 wirelessly transmits a travel road configuration information request RQ1 to the navigation device 40 via the transmission/reception circuit 306, and then retrieves the travel road configuration information RD wirelessly transmitted from the navigation device 40 in response to the travel road configuration information request signal (step S21).

Next, the control unit 400 determines whether the road currently being traveled corresponds to a straight section or a tunnel section based on the travel road configuration information RD (step S22).

If it is determined in step S22 that the road on which the vehicle is currently traveling is neither a straight section nor a tunnel section, the control unit 400 supplies an operation mode signal MOD indicating the power saving mode to the variable band filter 301 and the biometric information detection circuit 302, which serve as the biometric information detection unit (step S23). As a result, the variable band filter 301 and the biometric information detection circuit 302 are set to the power saving mode, and the above-mentioned biometric information detection operation is stopped.

On the other hand, if it is determined in step S22 that the road currently being traveled is a straight section or a tunnel section, the control unit 400 supplies an operation mode signal MOD indicating normal mode instead of the power saving mode described above to the variable band filter 301 and the biological information detection circuit 302 as the biological information detection unit (step S24). As a result, the variable band filter 301 and the biological information detection circuit 302 are set to the normal mode, and as described above, the biological information of the driver is obtained from both hands of the driver that are in contact with the sensor electrodes 20L and 20R.

After executing step S23 or S24, the control unit 400 proceeds to execute step S11 and repeatedly executes the series of operations consisting of steps S11 to S15 and S21 to S24 described above.

As described above in detail, in the bioinformation acquisition system 100 shown in FIG. 2, the sensor electrodes 20L and 20R serving as the signal acquisition unit acquire as an input signal a bioelectric signal generated in association with the driver's biological phenomenon when the driver touches the steering wheel 10 of the vehicle. At this time, various noises including noises specific to the vehicle may be superimposed on the bioelectric signal. In other words, the input signal may contain various noises. Therefore, in order to remove the noise superimposed on the bioelectric signal, the variable band filter 301 extracts signal components of a specified band specified by the band specification signal FC from the input signal, and outputs an extraction signal BS representing the extracted signal components. Then, the bioinformation detection circuit 302 acquires the driver's bioinformation (e.g., heart rate, electrocardiogram, etc.) based on the extraction signal BS.

Here, the noise-related information acquisition unit 307 acquires information related to the noise contained in the input signal described above as noise-related information (e.g., steering wheel vibration, driving speed, or noise components extracted from the input signal).

Then, the control unit 400 changes the width of the designated band of the variable band filter 301 based on the noise-related information, and sets the type of biometric information to be detected by the biometric information detection circuit 302 (for example, the first type: electrocardiogram, etc.).

As a result, when the level indicated by the noise-related information, that is, the level of the noise contained in the input signal, is low, the control unit 400 widens the width of the designated band of the variable band filter 301 compared to when it is high. This suppresses the reduction in the amount of information of the bioelectric signal due to the filtering process, so that the bioinformation detection circuit 302 can detect the first type of bioinformation that requires a precise signal waveform, such as an electrocardiogram. Therefore, at this time, the control unit 400 widens the width of the designated band of the variable band filter 301 and sets the bioinformation detection circuit 302 to the first detection mode so that the first type of bioinformation is the detection target. Note that, according to the operation of the control unit 400 described above, when the level (NS) indicated by the noise-related information is high, the width of the designated band of the variable band filter 301 is narrower compared to when it is low. Therefore, although the noise removal ability is high, the amount of information reduction of the bioelectric signal is correspondingly large, making it difficult to detect the first type of bioinformation, such as an electrocardiogram or an electroencephalogram. Therefore, at this time, the control unit 400 narrows the width of the specified band of the variable band filter 301 as described above, and sets the biological information detection circuit 302 to a second detection mode so as to detect a second type of biological information that does not require precision in the signal waveform itself, such as heart rate, respiratory rate, etc.

This makes it possible to obtain various types of biometric information, such as electrocardiograms and heart rate, with high accuracy even in noisy environments.

In the biometric information detection setting process shown in FIG. 3 (FIG. 4), steps S11 to S15 are executed first, followed by steps S16 to S19 (S21 to S24), but steps S16 to S19 (S21 to S24) may be executed first. Also, steps S16 to S19 (S21 to S24) may be omitted.

After executing step S18 or S24, the control unit 400 may cause the navigation device 40 to issue a notification urging the driver to hold the steering wheel 10 with both hands before proceeding to step S11. For example, while traveling on a straight section or a tunnel section, the driver can maintain the state of holding the steering wheel with both hands for a predetermined detection recommendation period. Therefore, for example, in step S22 shown in FIG. 4, if it is determined that the road currently being traveled is a straight section or a tunnel section based on the travel road configuration information RD, the control unit 40 executes a notification process to urge the driver to hold the steering wheel with both hands after executing step S24.

Figure 5 is a flowchart showing the steps of the notification process executed by the control unit 400.

In FIG. 5, first, the control unit 400 wirelessly transmits a handle gripping notification request signal to the navigation device 40 by supplying a handle gripping notification request R2 to the transmission/reception circuit 306 (step S31). Upon receiving the handle gripping notification request signal, the navigation device 40 outputs a voice urging the driver to grip the vehicle's handle 10 from the speaker 42, and displays an image on the display unit 41 showing text urging the driver to grip the vehicle's handle 10.

Next, the control unit 400 determines whether a predetermined time has elapsed since immediately after execution of step S31 (step S32), and if it determines that the predetermined time has elapsed, determines whether both hands of the driver are in contact with the sensor electrodes (20L, 20R) based on the both hands contact detection signal BH (step S33).

If it is determined in step S33 that both hands of the driver are not in contact with the sensor electrodes, the control unit 400 wirelessly transmits an emphasis notification request signal to the navigation device 40 by supplying an emphasis notification request R3 to the transmission/reception circuit 306 (step S34). Upon receiving the emphasis notification request signal, the navigation device 40 performs a voice emphasis process to increase the volume of the voice output from the speaker 42, and a display emphasis process to the text image displayed on the display unit 42, for example by enlarging the size of the text or blinking it.

After executing step S34, or if it is determined in step S33 that both hands of the driver are in contact with the sensor electrodes, the control unit 40 proceeds to execute step S11 shown in FIG. 3 or FIG. 4.

In this way, when the road currently being traveled is a straight section or a tunnel section, the biometric information acquisition system 100 considers that the driver can maintain a state in which both hands are gripping the steering wheel for a predetermined biometric information detection recommended period, and at this time issues a notification urging the driver to grip the steering wheel with both hands. This allows for accurate detection of the driver's biometric information.

If the acquired road configuration information does not include a straight section or a tunnel section for a specified recommended period for detecting biometric information, the navigation device 40 may display an image on the display unit 41 that guides the vehicle to a road that includes a straight section or a tunnel section. This makes it possible to prevent biometric information detected from the driver from being lost for a long period of time.

In the above-mentioned embodiment, the sensor electrodes arranged on the steering wheel are described as the signal acquisition unit that acquires the bioelectrical signals of the driver, but this is not limited to the above. For example, the sensor electrodes arranged on the backrest, seat, armrest, etc. of the vehicle seat may be used as the signal acquisition unit to acquire the bioelectrical signals of not only the driver but also the vehicle occupants, thereby acquiring the bioinformation of the occupants.

The configuration of the present invention is not limited to the above-described embodiment, and various omissions, substitutions, or modifications of the configuration are possible without departing from the spirit of the present invention.

10 Handle 20L, 20R Sensor electrode 30 Biological information detection unit 40 Navigation device 100 Biological information acquisition system 300 Power supply circuit 301 Variable band-pass filter 302 Biological information detection circuit 307 Noise-related information acquisition unit 400 Control unit

Claims (10)

A biometric information acquisition device that acquires biometric information of a vehicle occupant,
a signal acquiring unit that acquires an input signal including a biosignal generated in association with a biophenomenon of the occupant;
a noise-related information acquisition unit that acquires information related to noise included in the input signal as noise-related information;
a bandpass filter that extracts a signal component of a specified band from the input signal and outputs an extraction signal representing the extracted signal component;
a biometric information detection unit that acquires biometric information of the occupant based on the extraction signal;
a control unit that changes the designated band of the band filter based on the noise-related information and sets a type of the biometric information to be detected by the biometric information detection unit. The bioinformation acquisition device according to claim 1, characterized in that the noise-related information acquisition unit includes a vibration sensor that detects a level of vibration of the vehicle, and acquires the level of the vibration as the noise-related information. The biometric information acquisition device according to claim 1, characterized in that the noise-related information acquisition unit acquires the level of the vehicle's traveling speed as the noise-related information. The bioinformation acquisition device according to claim 1, characterized in that the noise-related information acquisition unit acquires the level of noise contained in the biosignal as the noise-related information. the noise-related information acquisition unit acquires, as the noise-related information, a vibration level of the vehicle, a traveling speed level of the vehicle, or a noise level included in the biological signal;
The control unit is
when any one of the vibration level , the running speed level , and the noise level included in the biological signal , which are indicated as the noise-related information, is smaller than a predetermined threshold value, the biological information detection unit is set to a first detection mode for acquiring a first type of biological information including an electrocardiogram;
The biometric information acquisition device according to claim 1, characterized in that, when the first level is equal to or higher than the predetermined threshold, the biometric information detection unit is set to a second detection mode in which a second type of biometric information not including the electrocardiogram is acquired. The control unit is
The biometric information acquiring device according to claim 5 , wherein when the biometric information detector is set to the first detection mode, the width of the designated band is made wider than when the biometric information detector is set to the second detection mode. The biometric information acquisition device according to any one of claims 2 to 6, characterized in that the control unit narrows the width of the specified band as the level indicated as the noise-related information increases. The biological information acquiring device according to claim 5 , wherein the first type of biological information indicates the electrocardiogram, and the second type of biological information indicates a heart rate or an RRI. The bioinformation acquisition device according to any one of claims 1 to 8, characterized in that the signal acquisition unit acquires the input signal from an electrode provided on a steering wheel of the vehicle. a memory for storing device information indicating a type of each of the vehicle and the biological information detection unit;
The biometric information acquisition device according to any one of claims 1 to 8, further comprising an information processing unit that, when the biometric information is detected by the biometric information detection unit, acquires information indicating the current position of the vehicle, the weather, and the time at the time of detection, and transmits the acquired information, the device information, and the biometric information to a specific server via the Internet.

Images