JP6754110B2 - Driver monitoring device - Google Patents

Description

The present invention relates to a driver monitoring device.

The electrical impedance tomography (hereinafter, simply referred to as EIT) measuring device allows a weak current to flow from a pair of electrodes attached on the body surface, and also from the potential difference generated on the body surface, the conductivity distribution or conductivity in the living body. It is a technique for imaging the distribution of changes. EIT (Electrical Impedance Tomography) can acquire tomographic images just by passing a weak current, so compared to X-ray CT (Computed tomography), there is no problem of radiation exposure, and miniaturization, long-term measurement, and real-time measurement are possible. It has the advantage of being easy.

In the EIT measurement, for example, a plurality of electrodes are used. These electrodes are brought into contact with the periphery of the measurement target site, and signal cables individually connected to the electrodes are routed and connected to the measurement circuit.

As a related technique, Patent Document 1 discloses an EIT measuring device that combines an EIT technique and a technique for estimating the contour and shape of a body.

International Publication No. 2015/002210

By the way , further technological development is desired for the purpose of grasping the condition of the human body and the like.

Therefore, an object of the present invention is to provide a driver monitoring device capable of solving the above-mentioned problems.

According to the first aspect of the present invention, the driver monitoring device is electrically connected to the curvature sensor of the seat belt provided with a plurality of curvature sensors, and the curvature data acquired through the curvature sensor is obtained. Based on this, it includes a shape estimation unit that estimates the shape of the seatbelt, and a state determination unit that determines the state of the driver based on the shape of the seatbelt.

In the driver monitoring device described above, the state determination unit estimates the range in which the seatbelt contacts the driver and drives the curvature sensor located in the contact range.

In the above-mentioned driver monitoring device, the state determination unit determines whether the driver's condition is normal or abnormal by using any one or more of the shape of the seat belt, the heart rate, and the ventilation state.

In the driver monitoring device described above, the seatbelt is electrically connected to the electrodes of the seatbelt provided with a plurality of electrodes, and the state determination unit energizes the plurality of electrodes and the electrodes. Based on the voltage signal generated between the above, a tomographic image of the driver in the range where the seatbelt contacts the driver is generated, and the state of the driver is determined based on the tomographic image.

In the driver monitoring device described above, the state determination unit detects the driver's heart rate based on energization of the plurality of electrodes and voltage signals generated between the electrodes.

In the driver monitoring device described above, the state determination unit detects the ventilation state of the driver based on energization of the plurality of electrodes and voltage signals generated between the electrodes.

The driver monitoring device described above includes a recording unit that records any one or more of the tomographic image, the heart rate, the ventilation state, and the driver's state.

The above-mentioned driver monitoring device includes a display processing unit that displays one or more information of the tomographic image, the heart rate, the ventilation state, and the driver's state on a monitor.

In the above-mentioned driver monitoring device, the state determination unit operates a warning sensor when it determines that the driver's condition is abnormal.

The driver monitoring device described above includes a correction unit that corrects the output information of the curvature sensor based on the shape of the seatbelt when the seatbelt is in a predetermined state where it is not used.

Further, according to the second aspect of the present invention, the driver monitoring device is electrically connected to the electrodes of the seat belt provided with the plurality of electrodes, and the plurality of electrodes are energized and the electrodes are energized. It is provided with a state determination unit that generates a tomographic image of the driver in the range where the seatbelt contacts the driver based on the voltage signal generated between them and determines the state of the driver based on the tomographic image. ..

Further, according to the third aspect of the present invention, the monitoring device is connected to a body contact member provided with a plurality of electrodes, and a tomographic image and a heartbeat of the person to be measured are based on an electric signal obtained from the electrodes. It is provided with a state determination unit that calculates one or more state information of any one or more of the number and the ventilation state and determines the normality or abnormality of the state of the person to be measured by using the state information.

Further, according to the fourth aspect of the present invention, the monitoring device is connected to a body contact member provided with a plurality of curvature sensors, and the body movement of the person to be measured is based on the signal obtained from the curvature sensors. It is provided with a state determination unit that calculates one or more state information of the heart rate and the ventilation state and determines the state of the person to be measured by using the state information.

Further, according to the fifth aspect of the present invention, in the monitoring method, a monitoring device connected to a body contact member provided with a plurality of electrodes is used for a person to be measured based on an electric signal obtained from the electrodes. One or more state information of any one or more of the tomographic image, the heart rate, and the ventilation state is calculated, and the normal or abnormal state of the person to be measured is determined using the state information.

Further, according to the sixth aspect of the present invention, in the monitoring method, a monitoring device connected to a body contact member provided with a plurality of curvature sensors is a person to be measured based on a signal obtained from the curvature sensor. One or more state information of any one or more of the body movement, the heart rate, and the ventilation state is calculated, and the state of the person to be measured is determined using the state information.

Further, according to a seventh aspect of the present invention, the program measures a computer of a monitoring device connected to a body contact member provided with a plurality of electrodes based on an electric signal obtained from the electrodes. One or more state information of any one or more of the tomographic image, the heart rate, and the ventilation state of the above is calculated, and the state information is used to function as a state determination means for determining the normality or abnormality of the state of the subject.

Further, according to an eighth aspect of the present invention, the program measures a computer of a monitoring device connected to a body contact member provided with a plurality of curvature sensors based on a signal obtained from the curvature sensors. One or more of the state information of the person's body movement, heart rate, and ventilation state is calculated, and the state information is used to function as a state determination means for determining the state of the person to be measured.

Further, according to the ninth aspect of the present invention, the seat belt includes a plurality of electrodes that are periodically arranged, and a plurality of curvature sensors that are periodically arranged in parallel with the plurality of electrodes.

Further, in the present invention, the above-mentioned seat belt includes an output unit that detects the use of the seat belt and outputs a use detection signal to the driver monitoring device.

According to the present invention, the state of the body of the person to be measured can be easily grasped by the belt.

It is a figure which shows the driver monitoring device and a seat belt by 1st Embodiment. It is a 1st figure which shows the internal structure of the seat belt which concerns on 1st Embodiment. It is a figure which shows the functional structure of the driver monitoring apparatus which concerns on 1st Embodiment. It is a figure explaining the structure of the seat belt and the driver monitoring apparatus which concerns on 1st Embodiment. It is a figure which shows the example of the tomographic image generated by the state determination part by 1st Embodiment. It is a figure which shows the structure of the curvature sensor by 1st Embodiment. It is a figure which shows the arrangement example of the strain gauge by 1st Embodiment. It is a figure which shows the comparison of the thickness of the signal line connected to the strain gauge by 1st Embodiment, and the signal line in a strain gauge. It is a figure which shows the connection example which connected the bridge and the signal conversion module in many-to-one according to 1st Embodiment. It is a figure which shows the example of the shape of a part of the seat belt by 1st Embodiment. It is the first figure which shows the partial shape estimation process of the shape estimation part by 1st Embodiment. It is a 2nd figure which shows the partial shape estimation process of the shape estimation part by 1st Embodiment. It is a 2nd figure which shows the internal structure of the seat belt by 1st Embodiment. It is a figure which shows the outline of the process which specifies the contact range X by 1st Embodiment. It is the first figure which shows the processing flow of the driver monitoring apparatus by 1st Embodiment. It is a 2nd figure which shows the processing flow of the driver monitoring apparatus by 1st Embodiment. FIG. 3 is a third diagram showing a processing flow of the driver monitoring device according to the first embodiment. FIG. 4 is a fourth diagram showing a processing flow of the driver monitoring device according to the first embodiment. FIG. 2 is a second diagram showing a functional configuration of a driver monitoring device according to the first embodiment. It is a figure which shows the monitoring device and the restraint belt by 2nd Embodiment.

<First Embodiment>
Hereinafter, the driver monitoring device, the driver monitoring method, and the program according to the first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a driver monitoring device and a seat belt according to the first embodiment.
As shown in FIG. 1, the driver monitoring device 2 is connected to an electric circuit configured on a flexible substrate built in the seat belt 1 via a communication cable 3.
As an example, the seatbelt 1 has an electric circuit including at least a plurality of electrodes periodically arranged and a plurality of curvature sensors periodically arranged in parallel with the plurality of electrodes.
Further, the driver monitoring device 2 estimates the shape of the seatbelt 1 based on the curvature data acquired via the curvature sensor built in the seatbelt 1. The driver monitoring device 2 determines the state of the driver based on the shape of the seat belt 1.
The driver's condition may be the driver's consciousness, tomographic image, heart rate, ventilation condition, body movement, and the like. The driver monitoring device 2 uses any one or more of these driver states to determine whether the driver's state is normal or abnormal.

A flexible substrate 14 is provided inside the seat belt 1. Specifically, the flexible substrate 14 is sandwiched between two overlapping bands on the front and back surfaces forming the seat belt 1.
FIG. 2 is a first diagram showing the internal configuration of the seat belt according to the first embodiment.
As shown in FIG. 2, the seat belt 1 has a configuration in which a plurality of electrode pads 12A to 12H are arranged side by side (periodic arrangement) at equal intervals P on a strip-shaped flexible substrate 14. Further, on the flexible substrate 14, a plurality of curvature sensors 150A to 150H are periodically arranged in parallel with the electrode pads 12A to 12H at equidistant distances P. The plurality of electrode pads 12A to 12H are collectively referred to as electrode pads 12. Further, the plurality of curvature sensors 150A to 150H are collectively referred to as a curvature sensor 150. Although eight electrode pads 12 and eight curvature sensors 150 are shown in FIG. 2, a larger number of electrode pads 12 and curvature sensors 150 may be provided.

The electrode pads 12A to 12H and the curvature sensor 150 are provided inside the seatbelt 1 so as to be located in the measurement target range such as the chest and abdomen when the seatbelt 1 is wrapped around the driver's body. There is.
The seat belt 1 may have strain gauges for the curvature sensors 150A to 150H, respectively. The curvature sensor 150 has two strain gauges, and by using a two-active gauge method in which a pair of strain gauges for each measurement point are connected to one bridge circuit, the temperature correction of the curvature sensors 150A to 150H is automated and the sensitivity is increased. , High accuracy can be realized.
Alternatively, the seat belt 1 may have a temperature sensor at the same position on the back surface of each of the curvature sensors 150A to 150H. Then, the driver monitoring device 2 may perform temperature correction of the curvature data based on the curvature data acquired by the curvature sensors 150A to 150H based on the temperature data acquired by the temperature sensor. By doing so, it is possible to realize high sensitivity and high accuracy of the curvature sensors 150A to 150H.

Further, the measurement circuit 11 is an electric circuit that mediates the exchange of electric signals between the driver monitoring device 2, the electrode pads 12A to 12H, and the curvature sensors 150A to 150H. For example, the measurement circuit 11 is provided with a circuit for amplifying an electric signal output by the curvature sensors 150A to 150H and performing A / D (Analog / Digital) conversion.

FIG. 3 is a first diagram showing a functional configuration of the driver monitoring device according to the first embodiment.
The driver monitoring device 2 according to the first embodiment is composed of a computer. The driver monitoring device 2 may be incorporated in the car navigation system.

As shown in FIG. 3, the driver monitoring device 2 includes a CPU (Central Processing Unit) 200 that controls the overall operation and a work area of the CPU 200 when executing a measurement program or the like used for EIT measurement. A RAM (Random Access Memory) 210 and an HDD (Hard Disk Drive) 211 as a storage means for storing various programs and tomographic images acquired by the state determination unit 201 are provided.
Further, the operation input unit 212 is composed of, for example, an operation button, a touch panel, or the like, and receives input of various operations by an operator such as a driver. The image display unit 213 is a liquid crystal display or the like, and displays information necessary for EIT measurement, an acquired tomographic image, or the like.
The external interface 214 is a communication interface for communicating with an external device. In particular, in the present embodiment, the external interface 214 is connected to the seat belt 1 via a dedicated communication cable 3 and acquires various signals from the seat belt 1. It is a functional part to be used.
The CPU 200, RAM 210, HDD 211, operation input unit 212, image display unit 213, and external interface 214 are electrically connected to each other via the system bus 215.

As shown in FIG. 3, the CPU 200 executes a predetermined measurement program in a state where the seatbelt 1 is used, and at the time of execution, functions as a state determination unit 201 and a shape estimation unit 202.
The state determination unit 201 acquires a tomographic image of the measurement target unit X while energizing the plurality of electrode pads 12A to 12H and acquiring voltage signals generated between the electrode pads 12A to 12H.
Further, the shape estimation unit 202 estimates the shape of the seat belt 1 based on the curvature data acquired via the curvature sensors 150A to 150H.

FIG. 4 is a diagram illustrating a configuration of a seat belt and a driver monitoring device according to the present embodiment.
Hereinafter, the function of the state determination unit 201 will be described with reference to FIGS. 4 and 5. As shown in FIG. 4, a current source I and a voltmeter V are connected between the electrode pads 12A to 12H, respectively. The state determination unit 201 has a function of controlling the current source I and the voltmeter V.

The state determination unit 201 controls to flow a predetermined weak current between the pair of electrode pads (for example, between the electrode pads 12A and the electrode pads 12B) among the electrode pads 12A to 12H via the current source I. .. The state determination unit 201 measures the potential difference generated between each of the other electrode pads (electrode pads 12C to 12H) via the voltmeter V while passing a weak current through the pair of electrode pads. By sequentially changing the electrode pads through which the current flows to 12B and 12C, 12C and 12D, ..., And repeatedly measuring the potential difference, the resistivity distribution in the fault of the measurement target portion X can be obtained.

The state determination unit 201 generates a tomographic image using, for example, a general back projection method based on the resistivity distribution on the tomographic surface as the measurement target acquired as described above. The state determination unit 201 causes the driver, the ambulance crew, and the like to visually recognize the tomographic image by displaying the generated tomographic image on the image display unit 213. A known technique may be used as a method for generating a tomographic image using EIT in the state determination unit 201.
FIG. 4 shows a situation in which the current source I and the voltmeter V are provided between different electrode pads 12, but the current source I and the voltmeter V may be provided between the electrode pads 12. The 4-electrode method may be used or the 2-electrode method may be used for measuring the current value and the voltage value between the electrode pads 12. Further, the electrode pad 12 having any structure may be applied to the electrode pad 12.

FIG. 5 is a diagram showing an example of a tomographic image generated by the state determination unit.
FIG. 5 is a tomographic image of the chest of the measurement subject acquired by the state determination unit 201, and is shown in a darker shade in a region having a higher electrical impedance. According to FIG. 5, it can be seen that the lung fields, whose electrical impedance is measured to be high due to the presence of air, exist on the left and right.
As a method for the state determination unit 201 to generate a tomographic image, a method using a finite element method (FEM) in addition to the above-mentioned back projection method, or a method combining a finite element method and a back projection method can be considered. Be done. When the back projection method is used, the state determination unit 201 can image only relative changes based on a certain state, but by using the finite element method, the absolute electrical resistance at the tomographic surface A tomographic image based on the resistivity [Ωm] can be formed.

FIG. 6 is a diagram showing the configuration of the curvature sensor.
The curvature sensor 150 measures the curvature of the seat belt 1 at the position where the curvature sensor 150 is arranged. As shown in FIG. 6, the curvature sensor 150 includes a bridge (Wheatstone bridge) 151 in which resistors 152-1 and 152-2 are combined with strain gauges 153-1 and 153-2, and an amplifier 156. Will be done. The bridge 151 receives a DC voltage from the power supply unit 111 when measuring the curvature. The current from the power supply unit 111 flows to the ground (zero potential point) through the bridge 151.

The output of the curvature sensor 150 is transmitted to the driver monitoring device 2 via the A / D converter (analog-digital converter) 157 and the serial communication circuit 114.
Hereinafter, the resistors 152-1 and 152-2 are collectively referred to as the resistor 152. Further, the strain gauges 153-1 and 153-2 are collectively referred to as a strain gauge 153.
The functions of the circuits shown in FIG. 6 may be printed on the flexible substrate 14.

FIG. 7 is a diagram showing an arrangement example of strain gauges.
The figure shows an example of a cross section of the seat belt 1 viewed from the side, and the arrow B11 indicates the longitudinal direction of the seat belt 1.
All of the strain gauges 153 are arranged so that the direction in which the strain (strain) is detected coincides with the longitudinal direction of the seat belt 1. Further, as shown in FIG. 7, the strain gauges 153-1 and 152-2 are arranged so as to sandwich the flexible substrate 14. For example, the strain gauge 153-1 is arranged on the front surface band 41 side of the seat belt 1 when viewed from the flexible substrate 14, and the strain gauge 153-2 is arranged on the back surface band 42 side of the seat belt 1 when viewed from the flexible substrate 14. There is.

Due to this arrangement, when the flexible substrate 14 is bent, there is a difference between the impedance of the strain gauge 153-1 and the impedance of the strain gauge 153-2. When the driver wears the seatbelt 1 and the flexible substrate 14 bends convexly toward the front surface side of the seatbelt 1 and concavely toward the back surface side, the strain gauge 153-1 arranged on the front surface side of the seatbelt 1 extends. The impedance becomes large. On the other hand, the strain gauge 153-2 arranged on the back surface side of the seat belt 1 shrinks to reduce the impedance.

Due to this impedance difference, a voltage (potential difference) is generated between the points P11 and P12 in FIG. The magnitude of the voltage between the points P11 and P12 indicates the magnitude of bending of the seatbelt 1 at the arrangement position of the strain gauge 153 on the seatbelt 1 (the arrangement position of the curvature sensor 150).
The amplifier 156 converts the voltage between the points P11 and P12 into the curvature of the seatbelt 1 at the installation position of the strain gauge 153. Specifically, a calibration curve showing the relationship between the voltage between the points P11 and P12 and the curvature of the seatbelt 1 is obtained in advance, and the amplifier 156 sets the voltage between the points P11 and P12. It is set to amplify according to this calibration curve.

The bridge 151 may be provided with only one strain gauge 153. Specifically, the bridge 151 may be provided with a resistor instead of any one of the strain gauges 153-1 and 153-2. As the resistance in this case, a resistance value that is the same as the resistance value when the strain gauge 153 is not bent is used.
On the other hand, when the bridge 151 is provided with one strain gauge 153 as shown in FIG. 6, the voltage difference between the points P11 and P12 is larger than that when the bridge 151 is provided with only one strain gauge 153, and the curvature is increased. The accuracy of the sensor 150 is improved. Further, since the bridge 151 is provided with one strain gauge 153, it is less susceptible to temperature changes than when the bridge 151 is provided with only one strain gauge 153.

The wiring inside the strain gauge 153 is thinned, and the wiring connected to the strain gauge 153 is thickened. Thereby, the accuracy of the curvature sensor 150 can be improved. This point will be described with reference to FIG.
FIG. 8 is a diagram showing a comparison of the thickness of the signal line connected to the strain gauge and the signal line in the strain gauge.
In the figure, the wiring W11 in the strain gauge 153 and the wiring W12 connected to the strain gauge 153 are shown.

When the strain gauge 153 is bent, the length and / or width of the wiring W11 changes, so that the impedance of the strain gauge 153 changes. The strain gauge 153 indicates the magnitude of bending by this change in impedance.
The width of the wiring W11 is narrowed (the wiring W11 is narrowed) so that the impedance of the strain gauge 153 can be easily changed. As a result, when the strain gauge 153 is bent and the width of the wiring W11 changes, the rate of change from the original width increases.

On the other hand, in order to measure the impedance of the strain gauge 153 with high accuracy, it is preferable that the resistance between the strain gauge 153 and the circuit for detecting the impedance (amplifier 156 in the example of FIG. 6) is small. Therefore, the width of the wiring W12 is widened (the wiring W12 is thickened).
In this way, the accuracy of the curvature sensor 150 can be improved by thinning the wiring in the strain gauge 153 and thickening the wiring connected to the strain gauge 153.

The A / D converter 157 converts an analog signal (for example, a voltage value proportional to the curvature) output by the amplifier 156 into a digital signal.
The serial communication circuit 114 transmits the digital signal output by the A / D converter 157 to the driver monitoring device 2 by serial communication. As a result, the serial communication circuit 114 transmits the digital signal output by the A / D converter 157 to the driver monitoring device 2. The serial communication circuit 114 is provided for each curvature sensor 150, for example, and the first serial communication unit 110 includes these serial communication circuits 114.

As the communication method of the serial communication circuit 114, various serial communication methods such as SPI (Serial Peripheral Interface) or I2C (Inter-Integrated Circuit) (I2C is a registered trademark) can be used.
When the serial communication circuit 114 performs serial communication, the sensor value by the curvature sensor 150 can be communicated with a small number of wires of about 3 to 5. Since a large number of wires are not required, it is possible to avoid an increase in the size of the seat belt 1 such that the band constituting the seat belt becomes wider or thicker.

Hereinafter, the combination of the amplifier 156, the A / D converter 157, and the serial communication circuit 114 is referred to as a signal conversion module 181. The signal conversion module 181 converts the analog signal (voltage between the points P11 and P12) formed by the bridge 151 into a digital signal showing the curvature, and further converts the analog signal into a digital signal according to the serial communication standard.
Here, the signal conversion module 181 is configured as one IC chip, or the signal conversion module 181 is configured as one substrate, and the signal conversion module 181 is integrated into one. As a result, it is not necessary to design the signal conversion module 181 for each curvature sensor 150 (bridge 151 of the curvature sensor 150). In this respect, the signal conversion module 181 can be arranged relatively easily when designing the seat belt 1.

Note that one signal conversion module 181 may transmit the curvatures of the plurality of bridges 151.
FIG. 9 is a diagram showing a connection example in which the bridge and the signal conversion module are connected in a many-to-one manner.
In the example of the figure, the four bridges 151 are connected to the signal conversion module via a multiplexer 182.

The multiplexer 182 switches the bridge 151 connected to the signal conversion module 181 in a time division manner. The signal conversion module 181 converts the voltage of the bridge 151 (voltage between the points P11 and P12 in FIG. 6) connected via the multiplexer 182 into a digital signal showing curvature and transmits it by serial communication. To do. As a result, the curvature can be transmitted by a relatively small number of signal conversion modules.

On the other hand, when the bridge 151 and the signal conversion module are arranged one-to-one, the signal conversion module 181 is arranged near the bridge 151. As a result, it is possible to prevent a decrease in the S / N ratio (Signal To Noise Ratio) of the signal (voltage at the bridge 151) acquired by the signal conversion module 181. At this point, the curvature sensor 150 can measure the curvature with high accuracy.

Further, when the bridge 151 and the signal conversion module 181 are arranged one-to-one, the length of the wiring between the bridge 151 and the signal conversion module 181 is the same regardless of the combination of the bridge 151 and the signal conversion module 181. Align. As a result, it is possible to reduce variations in the measurement accuracy of the curvature for each combination of the bridge 151 and the signal conversion module 181. The signal conversion module 181 may be built in the measurement circuit 11.

The shape estimation unit 202 detects the contact (proximity) range X of the measurement target (chest or abdomen) on the seatbelt 1 by using the measurement result of the curvature sensor 150 or the like, and estimates the seatbelt shape.
The shape estimation unit 202 communicates with the measurement circuit 11 by serial communication. In particular, the shape estimation unit 202 receives various data transmitted by the measurement circuit 11 such as a measured value of curvature.
The shape estimation unit 202 determines whether or not to start detecting the contact range X and estimating the seatbelt shape. Specifically, the shape estimation unit 202 determines whether or not the conditions for starting the processing of detecting the contact range X of the seatbelt with respect to the measurement target and estimating the seatbelt shape are satisfied. The driver monitoring device 2 determines that the start condition is satisfied when, for example, the switch provided on the buckle that engages the seatbelt 1 is ON, and determines that the start condition is satisfied, and the state determination unit 201 and the shape estimation unit 202. Notify to. The switch provided on the buckle may have a structure that turns ON when the metal fitting plate provided on the seat belt and the buckle are engaged when the seat belt is used. When it is determined that the start condition is satisfied, the state determination unit 201 and the shape estimation unit 202 start the process.

When the shape estimation unit 202 determines that the start condition is satisfied, the shape estimation unit 202 estimates the seatbelt shape of the seatbelt contact range X with respect to the measurement target based on the sensor value of the curvature sensor 150 (curvature detected by the curvature sensor 150).
The shape estimation process performed by the shape estimation unit 202 will be described with reference to FIGS. 10 to 12.

FIG. 10 is a diagram showing an example of the shape of a part of the seat belt.
The figure shows a state in which the flexible substrate 14 and the plurality of curvature sensors 150 provided on the flexible substrate 14 are bent. The partial shape of the flexible substrate 14 can be regarded as the partial shape of the seat belt 1 (partial shape of the band portion). Here, the curvature sensor 150 is referred to as a curvature sensor 150-1, a curvature sensor 150-2, a curvature sensor 150-3, and so on.

In the example of FIG. 10, the curvature sensors 150 are arranged at equal intervals (distance d intervals). Ranges of distance d are assumed centered on each of the curvature sensors 150, and the ends of these ranges are indicated by points P0, P1, P2, P3, .... The partial shape estimation unit 241 approximates each of these ranges with an arc of curvature indicated by the curvature sensor 150 to obtain the partial shape.
Further, it is assumed that the curvature of the curvature sensor 150-1 is C1, the curvature of the curvature sensor 150-2 is C2, and the curvature of the curvature sensor 150-3 is C3.

FIG. 11 is a first diagram showing a partial shape estimation process of the shape estimation unit.
11 in the coordinate system relative to the origin O, a curvature sensor 150-1, one end of the range of the distance d around the curvature sensor 150-1 (point P0), the other end (point _P 1) Is shown. The value of the distance d is a known value, shape estimation unit 202 obtains a curvature C _1, which curvature sensor 150a measures. Shape estimation unit 202 calculates the radius of curvature _{R 1} than the curvature _{C 1} based on equation (1).

Equation (1) is a general equation. In equation (1), C indicates a curvature and R indicates a radius of curvature.
Based on the radius of curvature R ₁ and the curvature C ₁ , the shape estimation unit 202 uses the central angle of an arc that approximates the range of the distance d centered on the curvature sensor 150-1 (the central angle of the fan shape having this arc). ) Θ ₁ is calculated by Eq. (2).

Equation (2) is a general equation. In equation (2), θ indicates the central angle and C indicates the curvature. Further, the distance d indicates the length of the arc. The center point of the fan shape is referred to as O _1. The shape estimation unit 202 uses the coordinates of the center point O ₁ of the fan shape, the coordinates of the point P ₀ , and the center angle θ ₁ to obtain a range of the distance d centered on the curvature sensor 150-1 according to the equation (3). It calculates a point P ₀ with a different direction of coordinate point P ₁ at the end of.

Here, P ₀ , P ₁ , and O ₁ are column vectors indicating the coordinates of the point P ₀ , the point P ₁ , and the center point O ₁ , respectively.
The coordinates of the center point O ₁ of the fan shape can be calculated from the origin O and the point P ₀ of the coordinate system and the value of the radius of curvature R ₁ . Further, the center point of an arc (the center point of the fan shape having this arc) that approximates the range of the distance d centered on the curvature sensor 150- (i + 1) adjacent to the curvature sensor 150-i (i is an integer of i ≧ 0). ) The coordinates of O _{i + 1} can be calculated by the equation (4).

In the equation (4), O _{i + 1} , P _i , and O _i are column vectors indicating the coordinates of the center point O _{i + 1} , the point P _i , and the center point O _i , respectively. Further, R _i and R _{i + 1} are radii of curvature obtained from the curvatures C _i and C _{i + 1} , respectively, by the equation (1).
If the point of the arc of the end to approximate the range of the distance d around the curvature sensor 0.99-i was P _i-1, P _i point of the arc of the other end can be calculated by the equation (5) ..

In equation (5), P _i-1 is a matrix vector indicating the coordinates of the point P _i-1 . Further, θ _i indicates the central angle of an arc (the central angle of the fan shape having this arc) that approximates the range of the distance d centered on the curvature sensor 150-i.

FIG. 12 is a second diagram showing a partial shape estimation process of the shape estimation unit.
FIG. 12 shows an example when the process shown in FIG. 11 is repeated. As described above, the shape estimation unit 202, based on the curvature the curvature sensor 0.99-i was measured C _i and the distance d (the length of the arc), calculates the coordinates of the point P _i from the point P _i-1 of the coordinates can do. In the first process of partial shape estimation, the point P ₀ may be a coordinate arbitrarily set in the coordinate system.
The shape estimation unit 202 calculates the coordinates of the points P ₁ , P ₂ , P ₃ , ... In order. As a result, the shape estimation unit 202 approximates the shape of the portion of the seat belt 1 in which the curvature sensor 150 is arranged (including the portion between the curvature sensor 150 and the curvature sensor 150) with a continuous arc to estimate. Can be done.

The shape estimation unit 202 estimates by approximating the shape of the portion where the curvature sensor 150 is arranged as described above with a continuous arc based on information such as curvature obtained from a plurality of curvature sensors 150 provided on the seat belt 1. As a result, the three-dimensional shape of the seatbelt contact range X with respect to the entire seatbelt 1 or the measurement target is calculated. The driver monitoring device 2 stores in advance 3D modeling data of a plurality of three-dimensional shapes of seat belts in the chest and abdomen according to different human body shapes in a storage unit such as HDD 211. In this case, the shape estimation unit 202 compares the calculated overall three-dimensional shape of the seatbelt 1 with the three-dimensional modeling data of the plurality of three-dimensional shapes and the plurality of three-dimensional shapes of the seatbelt according to the human body shape. The shape estimation unit 202 identifies 3D modeling data similar to the three-dimensional shape of the current driver. The shape estimation unit 202 specifies the contact range X in the seat belt 1 recorded in the storage unit in association with the specified 3D modeling data. The information on the range X of the seatbelt 1 differs depending on the body shape of the person, and indicates the contact range X of the seatbelt with respect to the measurement target when the seatbelt 1 is worn according to the body shape of the person. Since the range of the seatbelt 1 in contact with the chest and abdomen of the body differs depending on the body shape, the driver monitoring device 2 stores information on the contact range X of the seatbelt when worn according to the human body shape. The driver monitoring device 2 may store information on the set position of the seat (seat) 4 and the contact range X of the seat belt when worn according to the combination of the human body shape. Then, the shape estimation unit 202 detects the current set position of the seat 4 from the position detection device provided on the seat 4 or the like, and the seat belt is recorded in the storage unit in association with the information on the installation position of the seat. 3D modeling data of a plurality of three-dimensional shapes of 1 may be acquired, and the data may be compared with the calculated three-dimensional shape of the current seatbelt 1.

The shape estimation unit 202 outputs information on the contact range X of the specified seatbelt 1 to the state determination unit 201. The state determination unit 201 identifies the electrode pad 12 included in the contact range X based on the information of the contact range X. The state determination unit 201 determines the identified electrode pad 12 as the operating electrode pad 12. The state determination unit 201 generates a tomographic image of the measurement target unit X while energizing the specified plurality of electrode pads 12 and acquiring a voltage signal generated between two of the electrode pads 12. May be good. Since the driver monitoring device 2 identifies the electrode pads 12 based on the human body shape and the set position of the seat 4, it is not necessary to energize all the electrode pads 12 provided on the seat belt. The driver monitoring device 2 has a large number of set positions such as the angle of the back of the seat 4 and the front-rear position of the seat surface of the seat 4, and a plurality of three-dimensional bodies of the seat belt 1 according to these set positions. The 3D modeling data of the shape may be stored.

Even if the state determination unit 201 identifies the curvature sensor 150 included in the contact range X based on the information of the contact range X acquired from the shape estimation unit 202 and determines that the curvature sensor 150 operates only the curvature sensor 150. Good. According to this process, the state determination unit 201 estimates the range in which the seat belt 1 contacts the driver, and drives the electrode pad 12 or the curvature sensor 150 located in the contact range.

The state determination unit 201 may estimate the range in which the seat belt 1 contacts the driver based on the voltage signal generated between the electrode pads 12. For example, the driver monitoring device 2 passes a high frequency current between two adjacent electrode pads 12. Then, an electric field E is generated between the electrode pads 12. Then, for example, when a body enters this electric field region, the electric field fluctuates, and the voltage value measured by the voltmeter V changes. The driver monitoring device 2 constantly monitors the impedance change due to the influence of the measurement target such as the body in the electric field region from the fluctuation of the voltage value by the voltmeter V connected in parallel with the current source I. The impedance value is obtained by dividing the voltage value by the current value. Then, when the impedance change becomes lower than a predetermined value, the driver monitoring device 2 can determine that the range of the seat belt 1 in the vicinity of the electrode pad 12 is in contact with the body.
The electrode pad 12 shown in FIG. 2 may be an electrode pad 12 used only for generating a tomographic image by EIT. In this case, on the substrate of the seat belt 1, a plurality of dedicated electrode pads for detecting the contact range X may be periodically arranged at short intervals.

FIG. 13 is a second view showing the internal configuration of the seat belt.
In FIG. 13, the notation of the electrode pads 12A to 12H and the strain gauges 13A to 13H is omitted in order to avoid complicating the drawings, but in reality, the flexible substrate 14 is the same as in the first embodiment. Above they are in a periodic array.
As shown in FIG. 13, the seatbelts 1 according to the present embodiment are periodically arranged along the longitudinal direction thereof (in parallel with the electrode pads 12A to 12H and the like) at intervals α shorter than the interval P. Electrode pads 301, 302, ..., 30f for measuring the contact range may be provided.

The state determination unit 201 may specify the heart range and the lung range in the contact range X. For example, the state determination unit 201 stores the heart range and lung range of the contact range X based on the information of the contact range X acquired from the shape estimation unit 202, and the heart range and lung range with respect to the contact range X stored in advance. It may be specified based on the information of the position of.

FIG. 14 is a diagram showing an outline of a process for specifying the contact range X.
FIG. 14A shows how the seat belt 1 is in contact with the measurement target.
As shown in FIG. 14A, a case where the seatbelt 1 is in contact with a person to be measured from position A1 to position A2 will be described. The seatbelt 1 is close to the human body M in the contact range X from the position A1 to the position A2, and is separated from the human body M in other regions.
FIG. 14B shows in detail the vicinity of the position A1 of the seatbelt 1 in the state shown in FIG. 14A. For example, it is assumed that the electrode pads 301, 302, 303, 304, 305, and 306 are arranged in the vicinity of the position A1 as shown in FIG. 14 (b). In this case, the shape estimation unit 202 changes each electrode pad pair in order, for example, between the electrode pads 301-302, between the electrode pads 303-302, between the electrode pads 303-304, and so on. Acquire the electrical impedance between the pairs. The electrical impedance acquired by the shape estimation unit 202 is a value depending on the electric fields E0, E1, ..., E4 (FIG. 14B) generated between each electrode pad pair.

Here, attention is paid to the path of the electric fields E0 to E4 generated between each pair of electrode pads. As shown in FIG. 14B, the electrode pads 301a and 302 are not in close proximity to the human body M, and the electric field E0 generated between them is generated in the atmosphere. On the other hand, since the electrode pads 305 and 306 are close to the human body at the position A1, the electric field E4 generated between them passes through the human body M (in the living body). Therefore, the electrical impedance between the electrode pads 305 and 306 is measured lower than the electrical impedance between the electrode pads 301 and 302.
That is, since the electrode pads 301, 302, ... Gradually approach the human body M toward the position A1, the electric fields E0, E1, E2, E3, E4 gradually pass through the human body M in the path. As the region increases, the electrical impedance corresponding to each electric field E0 to E4 gradually decreases.

As described above, in the region where the seatbelt 1 is close to the human body M, the electrical impedance between the pair of electrode pads belonging to the region is measured low, and in the region where the seatbelt 1 is not close (contact) with the human body M, The electrical impedance between the pair of electrode pads belonging to that region is measured high. Therefore, the shape estimation unit 202 compares the electric impedance with the preset threshold value, and identifies the electrode pads constituting between the electrode pads that could acquire the electric impedance lower than the threshold value as the electrode pads located in the contact range X.

After the start of the process, the shape estimation unit 202 repeatedly detects the seatbelt shape information at predetermined time intervals. The shape estimation unit 202 detects the movement of the body such as the distance and the period of movement of the body based on the shape of the contact range X in the seatbelt when the seatbelt is fastened. The shape estimation unit 202 outputs the moving distance and period of the body to the state determination unit 201.

The state determination unit 201 may estimate the heart rate and the ventilation volume in addition to generating a tomographic image and estimating the shape of the seat belt 1.
The state determination unit 201 generates a tomographic image of the human body corresponding to the position of the contact range X at short intervals. The state determination unit 201 detects the movement of the shape of the lungs and chest in the tomographic image by image processing, identifies the cycle of reduction and expansion of the size, and calculates the heart rate per unit time based on the cycle. You may. Further, the state determination unit 201 detects the movement of the shape of the lung or chest by image processing, identifies the change in shape when the shape of the lung or chest is reduced or enlarged, and based on the change, the ventilation volume per unit time. May be calculated.

The driver monitoring device 2 may calculate the heartbeat and the ventilation volume based on the high frequency current flowing through the electrode pad 12. The state determination unit 201 passes a high frequency current through the electrode pad 12. As a result, the state determination unit 201 can detect the impedance change caused by the inflow and outflow of air into the lungs due to respiration based on the input signal from the voltmeter V. More specifically, since the impedance of air is high, when the amount of air flowing into the lungs decreases (corresponding to the amount of ventilation exhaled), the impedance value of the lungs decreases accordingly. Therefore, when the lungs are dilated, the amount of air increases (corresponding to the amount of inhaled ventilation), and the state determination unit 201 detects that the impedance value has increased. On the other hand, when the lung contracts and air flows out of the lung, the state determination unit 201 detects that the impedance has changed in the lower direction. In this way, the ventilation volume of the lungs can be measured by the driver monitoring device 2.

In addition, the blood volume in the heart changes depending on the heartbeat. The state determination unit 201 passes a high frequency current through the electrode pad 12. As a result, the state determination unit 201 can detect the impedance change caused by the increase or decrease in the blood volume in the heart accompanying the beating of the heart, based on the input signal from the voltmeter V. More specifically, since the impedance of blood is low, the impedance of the heart increases as the blood volume of the heart decreases. Therefore, when the heart contracts, the state determination unit 201 detects that the impedance has changed in the higher direction. On the other hand, when the heart expands and blood flows into the heart, the state determination unit 201 detects that the impedance has changed in the lower direction. In this way, the heartbeat information of the heart can be measured by the driver monitoring device 2.

Further, since the driver monitoring device 2 directly detects the increase or decrease of the blood volume in the heart by the impedance change, it is possible to detect the heartbeat information with higher accuracy than before. The state determination unit 201 detects, for example, the heart rate per unit time based on the number of peak values per unit time based on the impedance change.

In the above-mentioned measurement of ventilation volume, the voltmeter V measures the voltage and outputs it to the state determination unit 201. The state determination unit 201 calculates the impedance value based on the result of the voltage measurement of the voltmeter V. Then, the state determination unit 201 determines a change from the impedance value in the stable state. The state determination unit 201 converts the amount of change in impedance into a ventilation amount based on the amount of change in impedance and a correction formula, a correction table, or the like. The state determination unit 201 repeatedly calculates the ventilation volume at short-time intervals (for example, at intervals of several milliseconds). Then, the state determination unit 201 records the ventilation volume at each time in the memory according to the passage of time.

In the above-mentioned heart rate measurement, the voltmeter V measures the voltage and outputs it to the state determination unit 201. Then, the state determination unit 201 calculates the impedance value based on the result of the voltage measurement of the voltmeter V. The state determination unit 201 repeatedly calculates the impedance value at short-time intervals (for example, at intervals of several milliseconds). The state determination unit 201 records the amount of change in impedance at each time in the memory according to the passage of time. The state determination unit 201 calculates the heart rate per unit time based on the number of peak values per unit time based on the impedance change and records it in the memory. By the above processing, heartbeat information at each time according to the passage of time is accumulated in the memory.
The state determination unit 201 controls to switch between the process of acquiring the ventilation volume and the process of acquiring the heart rate. Alternatively, when the state determination unit 201 can specify the heart range and the lung range with respect to the contact range X, the state determination unit 201 acquires the ventilation volume from the signal of the electrode pad 12 located in the lung range, and the electrode pad 12 located in the heart range. The heart rate may be obtained from the signal of.

The state determination unit 201 determines whether the driver's condition is normal or abnormal by using any one or more of the shape of the seat belt 1, the tomographic image, the heart rate, and the ventilation volume. The shape of the seatbelt 1 used by the state determination unit 201 for the driver's state may be the shape of the contact range X. Alternatively, when the state determination unit 201 is used for the driver's state, the driver's body movement, heart rate, and ventilation volume are measured by using only the curvature data from the curvature sensor 150 provided on the seat belt 1. Any one or more may be used to determine the normality or abnormality of the driver's condition. The movement of the body is, for example, the movement of the driver's body facing the steering wheel, which repeatedly moves toward and away from the steering wheel. The state determination unit 201 determines the movement of the body by using the conversion of the value of the curvature data at each predetermined interval of the curvature sensor 150. The state determination unit 201 also gives an electric signal to the chest of the driver who holds the pacemaker of the heartbeat in the body by estimating the movement of the body, the heart rate, and the ventilation volume only by the change in the shape of the seatbelt 1. The state of the driver can be determined without any need.

The state determination unit 201 may determine whether the driver feels drowsy based on the body movement distance, cycle, or body movement pattern determined based on the shape of the seat belt.
Further, the state determination unit 201 may detect the respiratory interval and the ventilation volume based on the change in the lung region obtained by the image processing of the tomographic image. The state determination unit 201 determines whether the breathing interval or ventilation volume has increased or decreased more than the breathing interval or ventilation volume detected in the initial period during driving, or the driver's drowsiness or drowsiness based on the repeated pattern of increase and decrease. Other physical conditions may be determined.
Further, the state determination unit 201 detects the heart rate per unit time obtained by image processing of the tomographic image. The state determination unit 201 determines whether the heart rate has increased or decreased from the heart rate detected in the initial period during driving, or the driver's drowsiness or other physical condition based on the pattern of repeated increase and decrease. The state may be determined.
In addition, the state determination unit 201 may determine the driver's drowsiness and other physical conditions by combining the breathing interval and the pattern of increase or decrease in the heart rate.
The state determination unit 201 may use a known technique in determining the driver's condition using the heart rate, the ventilation volume, the body movement, and the breathing interval.

FIG. 15 is a first diagram showing a processing flow of the driver monitoring device.
The shape estimation unit 202 of the driver monitoring device 2 acquires curvature data from the curvature sensor 150 (step S101). The shape estimation unit 202 determines the shape of the seat belt from the curvature data (step S102). The shape estimation unit 202 outputs information indicating the shape of the seat belt to the state determination unit 201. The information indicating the shape of the seat belt 1 may be 3D modeling data of the shape, or may be the curvature value itself obtained from each curvature sensor 150. The state determination unit 201 calculates state information such as body movement, respiration interval, and ventilation volume from the information indicating the shape of the seat belt 1 (step S103). The state determination unit 201 determines whether the driver's condition is bad by using one or more of the condition information (step S104). The state determination unit 201 outputs warning information when it is determined that the driver's condition is bad (step S105). The warning information is a signal that sounds an alarm, which is a warning sensor. The state determination unit 201 may vibrate a vibrating device, which is a warning sensor provided on the seat and the steering wheel, to issue a warning.
When the driver monitoring device 2 performs the process shown in FIG. 15, the seatbelt 1 may be provided with a plurality of curvature sensors 150 even if the electrode pads 12 are not provided.

FIG. 16 is a second diagram showing a processing flow of the driver monitoring device.
The shape estimation unit 202 of the driver monitoring device 2 acquires an electric signal from the electrode pad 12 (step S201). The state determination unit 201 generates a tomographic image using the above-mentioned EIT technique (step S202). The state determination unit 201 uses the tomographic image to calculate state information such as the breathing interval, the ventilation volume, and the heartbeat based on the change in the image with the passage of time (step S203). The state determination unit 201 determines whether the driver's condition is bad by using one or more of the condition information (step S204). The state determination unit 201 outputs warning information when it is determined that the driver's condition is bad (step S205). The warning information may be an alarm sound. The state determination unit 201 may vibrate the vibrating device provided on the seat and the steering wheel to issue a warning. Further, the warning information may be a control signal for a control device such as an automatic brake. By outputting the warning information to the device that controls the vehicle in this way, more active danger avoidance control may be performed in combination with automatic steering (automatic driving) technology or the like.
When the driver monitoring device 2 performs the process shown in FIG. 16, the seatbelt 1 may be provided with a plurality of electrode pads 12 even if the curvature sensor 150 is not provided.

FIG. 17 is a third diagram showing a processing flow of the driver monitoring device.
The shape estimation unit 202 of the driver monitoring device 2 acquires curvature data from the curvature sensor 150 (step S301). The shape estimation unit 202 determines the shape of the seat belt 1 from the curvature data (step S302). The shape estimation unit 202 outputs information indicating the shape of the seat belt 1 to the state determination unit 201. The information indicating the shape of the seat belt 1 may be 3D modeling data of the shape, or may be the curvature value itself obtained from each curvature sensor 150. The state determination unit 201 calculates state information based on the shape of the seatbelt 1, such as body movement, respiration interval, and ventilation volume, from the information indicating the shape of the seatbelt 1 (step S303).

The shape estimation unit 202 of the driver monitoring device 2 acquires an electric signal from the electrode pad 12 (step S304). The state determination unit 201 generates a tomographic image using the above-mentioned EIT technique (step S305). The state determination unit 201 uses the tomographic image to calculate state information such as the breathing interval, the ventilation volume, and the heartbeat based on the change in the image with the passage of time (step S306). The state determination unit 201 determines whether the driver's condition is bad by using the state information calculated in step S303 and one or more of the state information calculated in step S306 (step S307). Subsequent processing is the same as the processing shown in FIGS. 15 and 16. The state determination unit 201 outputs warning information when it is determined that the driver's condition is bad (step S308).

FIG. 18 is a fourth diagram showing a processing flow of the driver monitoring device.
The shape estimation unit 202 of the driver monitoring device 2 acquires curvature data from the curvature sensor 150 (step S401). The shape estimation unit 202 determines the shape of the seat belt 1 from the curvature data (step S402). The shape estimation unit 202 outputs information indicating the shape of the seat belt to the state determination unit 201. The information indicating the shape of the seat belt 1 may be 3D modeling data of the shape, or may be the curvature value itself obtained from each curvature sensor 150. The shape estimation unit 202 identifies the contact range X based on the shape of the seat belt (step S403), and outputs information on that range to the state determination unit 201. Based on the contact range X, the state determination unit 201 determines that the electrode pad 12 and the curvature sensor 150 located in that range are to be operated, and determines that the current is applied (step S404). After that, the state determination unit 201 and the shape estimation unit 202 receive signals from the electrode pads 12 and the curvature sensor 150 that are determined to be energized.

The shape estimation unit 202 determines the shape of the seatbelt based on the curvature data acquired from the operating curvature sensor 150 (step S405). The state determination unit 201 determines the body movement and breathing interval from the information indicating the shape of the seatbelt 1. , Calculate state information such as ventilation volume (step S406). The shape estimation unit 202 acquires an electric signal from the electrode pad 12 (step S407). The state determination unit 201 generates a tomographic image using the above-mentioned EIT technique (step S408). The state determination unit 201 uses the tomographic image to calculate state information such as the breathing interval, the ventilation volume, and the heartbeat based on the change in the image with the passage of time (step S409). The state determination unit 201 determines whether the driver's condition is bad by using the state information calculated in step S406 and one or more of the state information calculated in step S409 (step S410). The state determination unit 201 outputs warning information when it is determined that the driver's condition is bad (step S411).
Although the processing flow shown in FIGS. 15 to 17 does not include the process of specifying the contact range X, it may include the process of specifying the contact range X. Further, in the processing flow shown in FIGS. 15 to 18, each processing described in paragraphs 0083 to 807 may be included.
According to the above-mentioned processing of the driver monitoring device, it is possible to detect the state of the driver's body and issue a warning to the driver, or to use the control for assisting the driving operation. The control that assists the driving operation may be brake control such as automatic deceleration.
Further, according to the above-mentioned driver monitoring device, it is possible to easily determine an abnormality in the health condition of a driver during driving without using a special device.

FIG. 19 is a second diagram showing a functional configuration of the driver monitoring device according to the first embodiment.
The driver monitoring device 2 may further have the functions of the recording unit 203, the display processing unit 204, and the correction unit 205 by executing the program.
The recording unit 203 records any one or more of the tomographic image, the heart rate, the ventilation state, and other driver's states in the HDD 211. By the processing of the recording unit, it is possible to grasp the state of the driver's body and consciousness during the past driving.
The display processing unit 204 displays one or more of the tomographic image, the heart rate, the ventilation state, and other driver's states on a monitor such as the image display unit 123.
The correction unit 205 corrects the value output by the curvature sensor based on the shape of the seatbelt 1 when the seatbelt 1 is in a predetermined state where it is not used. For example, the situation where the seat belt 1 is not used is detected by some detection function. When the seatbelt 1 is not used, for example, the output of the curvature sensor 150 on the seatbelt 1 is a predetermined value. When the value of the curvature sensor 150 is not a predetermined value when the seat belt 1 is not used, the difference between the predetermined value and the currently acquired value is used as the correction value.

The above-mentioned seat belt 1 may have a mechanism that can be removed from the vehicle body of the car. When an accident occurs, an ambulance crew or the like removes the seatbelt 1 from the vehicle body and winds it around the passenger to operate the seatbelt 1 and the driver monitoring device 2. Then, by the process of the first embodiment, the state of the passenger of the vehicle in which the accident has occurred may be monitored. In this case, the seat belt 1 and the driver monitoring device 2 may have a function of being able to communicate and connect via wireless communication. Further, the seat belt 1 has a function of wirelessly communicating with the mobile terminal, and the mobile terminal may have a function of a driver monitoring device. In this case, each signal received from the seat belt 1 is processed, and the mobile terminal performs the above-mentioned processing equivalent to that of the driver monitoring device. As a result, the state of the passengers in the car can be monitored by the mobile terminal.
Since the internal structure of the seatbelt 1 is composed of the flexible substrate 14 on which the circuit pattern is printed, the seatbelt can be wrapped around the human body to monitor the condition of the person to be measured as described above.
The above-mentioned seat belt 1 and driver monitoring device 2 may be mounted on a moving body on which various subjects such as a car and an aircraft are boarded.

<Second embodiment>
FIG. 20 is a diagram showing a monitoring device and a restraining belt according to the second embodiment.
In the above description, the driver monitoring device 2 that detects the state of the driver by using the seat belt 1 is described. However, the restraint belt 7 having the same function as the seat belt 1 described in the first embodiment and the monitoring device 6 having the same function as the driver monitoring device 2 described in the first embodiment. May be used by the monitoring device 6 to monitor the condition of the person to be measured. For example, the restraint belt 7 is attached to the bed 5. FIG. 20 shows the connection relationship between the top view of the bed 5 and the monitoring device 6. The patient lying on the bed 5 may be fixed by the restraint belt 7, and the monitoring device 6 may acquire the patient's body movement, respiratory interval, ventilation volume, heartbeat, tomographic image, etc. while lying down.
The operation of the monitoring device 6 is the same as the operation according to the processing flow shown in FIGS. 15 to 18.
According to the above-mentioned monitoring device, the state of the person to be measured can be easily measured by the belt.

An electrode pad 12 and a curvature sensor 150 equivalent to the suppression belt 7 are periodically arranged on the sheets of the bed 5 shown in FIG. 20, and the state of the person to be measured is described from the signals of the electrode pad 12 and the curvature sensor 150. It may be monitored by the same method as.
In this case, the sheets and mats of the bed 5 include a plurality of electrode pads 12 and a plurality of curvature sensors 150. The monitoring device is electrically connected to the electrode pads 12 and the curvature sensor 150 provided on the sheets and mats. Then, the monitoring device estimates the deformation of the sheets and the mat based on the curvature data acquired via the curvature sensor 150. For example, the change in the shape of the sheets or mat may be a change in the shape of the surface of the sheets or mat due to a change in the force applied to the sheets or mat when the subject moves his / her body. Alternatively, the change in the shape of the sheets or mat may be a minute change in the shape of the surface of the sheets or mat based on the breathing or beating of the subject. Then, the monitoring device determines the state of the person to be measured based on the deformed shape of the sheets or mat. Further, the monitoring device calculates one or more state information of the tomographic image, the heart rate, and the ventilation state of the person to be measured based on the electric signal obtained from the electrode pad 12 provided on the sheets or the mat. The normal or abnormal state of the subject is judged using the state information.

<Third embodiment>
In the third embodiment, the electrode pads 12 and the curvature sensor 150 are periodically arranged on the sheet 4 shown in FIG. 4, and the state of the person to be measured is described from the signals of the electrode pads 12 and the curvature sensor 150. It may be monitored by the same method as.
In this case, the sheet 4 includes a plurality of electrode pads 12 and a plurality of curvature sensors 150. The monitoring device is electrically connected to the electrode pad 12 and the curvature sensor 150 provided on the sheet 4. Then, the monitoring device estimates the deformation of the sheet 4 based on the curvature data acquired via the curvature sensor 150. For example, the change in the shape of the seat 4 may be a change in the shape of the surface of the backrest due to a change in the force with which the driver leans against the backrest. Alternatively, the change in the shape of the seat 4 may be a change in the shape of the surface of the backrest due to the driver's action of bringing the body into close contact with or separated from the backrest. Alternatively, the change in the shape of the seat 4 may be a minute change in the shape of the backrest surface based on the driver's breathing or beating. Then, the monitoring device determines the state of the person to be measured based on the deformed shape of the sheet 4. Further, the monitoring device calculates one or more state information of the tomographic image, the heart rate, and the ventilation state of the person to be measured based on the electric signal obtained from the electrode pad 12 provided on the sheet 4, and the state is concerned. The information is used to determine whether the subject's condition is normal or abnormal.

The seat belt 1, seat 4, bed 5, sheets, mat, and the like described in each of the above-described embodiments are examples of body contact members.

The driver monitoring device 2 and the monitoring device 6 described above have a computer system inside. The process of each process described above is stored in a computer-readable recording medium in the form of a program, and the above process is performed by the computer reading and executing the program. Here, the computer-readable recording medium refers to a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Further, this computer program may be distributed to a computer via a communication line, and the computer receiving the distribution may execute the program.

Further, the program may be a program for realizing a part of the functions described above. Further, a so-called difference file (difference program) may be used, which can realize the above-mentioned functions in combination with a program already recorded in the computer system.

1 ... Seat belt 2 ... Driver monitoring device 3 ... Communication cable 4 ... Seat 5 ... Bed 6 ... Monitoring device 7 ... Suppression belt 11 ... Measuring circuit 12 ... Electrode pad 114 ... Serial communication circuit 150 ... Curvature sensor 156 ... Amplifier 157 ... A / D converter 181 ... Signal conversion module

Claims (10)

It is electrically connected to the curvature sensor, which is a plurality of curvature sensors and converts the potential difference generated by the impedance difference of the strain gauges constituting the bridge circuit into the curvature of the seatbelt at the installation position of the strain gauge and outputs it.
A shape estimation unit that estimates the shape of the seatbelt based on the curvature data acquired through the curvature sensor, and
A state determination unit that determines the driver's condition based on the shape of the seat belt,
A driver monitoring device characterized by being equipped with. The driver monitoring device according to claim 1, wherein the state determination unit estimates a range in which the seat belt contacts the driver and drives the curvature sensor located in the contact range. The state determination unit
The driver according to claim 1 or 2, wherein the normality or abnormality of the driver's condition is determined by using any one or more of the shape of the seatbelt, the heart rate, and the ventilation state. Monitoring device. The seatbelt is electrically connected to the electrodes of the seatbelt provided with a plurality of electrodes.
The state determination unit
Based on the energization of the plurality of electrodes and the voltage signal generated between the electrodes, a tomographic image of the driver in the range where the seatbelt contacts the driver is generated, and based on the tomographic image. The driver monitoring device according to claim 3, wherein the state of the driver is determined. The state determination unit
The driver monitoring device according to claim 4, wherein the driver's heart rate is detected based on energization of the plurality of electrodes and a voltage signal generated between the electrodes. The state determination unit
The invention according to any one of claims 4 to 5, wherein the ventilation state of the driver is detected based on the energization of the plurality of electrodes and the voltage signal generated between the electrodes. The driver monitoring device described. A recording unit that records any one or more of the tomographic image, the heart rate, the ventilation state, and the driver's state.
The driver monitoring device according to any one of claims 4 to 6, wherein the driver monitoring device is provided. A display processing unit that displays one or more information on the tomographic image, the heart rate, the ventilation state, and the driver's state on the monitor.
The driver monitoring device according to any one of claims 4 to 7, wherein the driver monitoring device is provided. The driver monitoring device according to any one of claims 1 to 8, wherein the state determination unit operates a warning sensor when it determines that the driver's condition is abnormal. A correction unit that corrects the output information of the curvature sensor based on the shape of the seatbelt when the seatbelt is in a predetermined state where it is not used.
The driver monitoring device according to any one of claims 1 to 9, wherein the driver monitoring device is provided.