JP4577644B2 - Biological information detection device for vehicle - Google Patents

Description

  The present invention relates to a veterinary information detecting device for a vehicle that detects a driver's breathing or pulse in order to recognize the situation of the driver who drives the vehicle, and in particular, a driver's body pressure detected from a driver's seat in contact with the driver. The present invention relates to a biological information detecting device for a vehicle that detects a respiratory rate and a heart rate from the above.

  As a method to assist the driver who drives the vehicle, it detects or recognizes the driver's state (individual difference, health / mental state, etc.) and provides information to the driver or controls driving by the driver's operation. There is a way to change it.

In this case, as an example of detecting or recognizing the state of the driver, it is conceivable to perform based on the detection of the driver's breath or pulse (respiration rate or heart rate). For example, taking the respiratory rate as an example, an increase in the respiratory rate is seen due to fatigue and stress, while the respiratory rate decreases if there is a sudden event. It is possible to recognize the physical / mental state of the driver from the relationship between the breathing or pulse and the state of the driver, and to provide information and reflect it on the driving control based on the recognition result. As an example of detecting the respiration rate from the pressure on the seat, Patent Document 1 detects the pressure by the human body at the lower part of the seat or the upper part of the seat, detects the respiration rate from the pressure change and vibration waveform, and the body of the seated person An example of recognizing mental and mental states is shown.
Japanese Patent Laid-Open No. 5-312966

  However, if an attempt is made to detect respiration by the occupant body pressure applied to the seat cushion (lower seat), for example, the occupant's load is too large to detect the respiration accurately. That is, if the load is too large, it is necessary to provide a strong sensor that can withstand the load. However, since the accuracy and the load resistance are generally contradictory, the accuracy deteriorates. In addition, when trying to detect breathing by the occupant body pressure on the upper part of the seat back, it is sufficient if it rests against the seat, but the load is greatly reduced due to a change in the posture of the occupant (for example, a stoop posture) In some cases, it may be zero, and it becomes impossible to detect respiration or a pulse such as a heartbeat or a heartbeat.

In view of the above-described conventional problems, the present invention provides a veterinary biometric information detection device capable of detecting a respiration or a pulse of a driver with high accuracy regardless of a change in posture on a driver's seat. I will provide a.

In order to solve such a problem, a biological information detecting device for a vehicle according to the present invention is a biological information detecting device for a vehicle that detects a change in a driver's breathing or pulse, and is a body pressure measurement provided on a vehicle seat. Body pressure measuring means for measuring body pressure applied by a seated driver having a sensor, and period change detecting means for detecting a driver's breathing or pulse period change based on the measured body pressure measurement result The body pressure measurement sensor is provided at a position corresponding to the waist of the driver in the lower part of the seat back and at a height of 10 to 25 cm from the seat cushion in the lower part of the seat back. And

Here, before Symbol body pressure measuring sensor is provided with a plurality on the left and right of the seat back lower part. Further, the body pressure measuring means has a displacement means for displacing the position of the body pressure measuring sensor in the front-rear direction in a seat back so that the body pressure measured by the body pressure measuring sensor is within a predetermined range. . Further, the apparatus further comprises vibration detection means for detecting vehicle vibration, and the displacement means displaces the body pressure measurement sensor backward in the seat back in response to the vehicle vibration detected by the vibration detection means. . The body pressure measuring means includes body pressure drop detecting means for detecting a case where the driver's body pressure suddenly decreases, and the displacement means is configured such that the body pressure drop detecting means When a sudden drop is detected, the body pressure measurement sensor is displaced backward in the seat back. Further, the apparatus further includes door opening / closing detection means for detecting opening / closing of a vehicle door, and the displacement means detects the body pressure measurement sensor when the door opening / closing detection means detects that the door near the driver's seat is open. Is moved backward in the seat back.

ADVANTAGE OF THE INVENTION According to this invention, regardless of the posture change on the driver | operator's seat which drives a vehicle, this driver | operator 's respiration or a pulse can be detected with high precision. In particular, the position of the body pressure measurement sensor that measures the driver's body pressure in the seat in order to detect the driver's breathing or pulse with high accuracy could be specified.

According to the second aspect of the present invention, since the plurality of body pressure measurement sensors are provided, the seating position of the occupant on the seat is shifted to the left or right, or the occupant is directed leftward or rightward with respect to the front of the seat. Detects the breathing or pulse of the occupant with high accuracy without being affected by the posture of the occupant when seated or when the vehicle is accelerated in the left or right direction when driving on a curve. be able to.

According to the third aspect of the present invention, the sensor is displaced in the forward direction of the vehicle when there is a sudden drop in body pressure. Therefore, there is a possibility that the sensor may be damaged when the body pressure is suddenly increased such as re-sitting. Although it increases, body pressure can always be measured stably with an appropriate strength, and occupant breathing or pulse can be detected with high accuracy.

According to the invention which concerns on Claim 4 , destruction of the body pressure measurement sensor by vehicle vibration can be prevented.

According to the fifth aspect of the present invention, it is possible to prevent the body pressure measurement sensor from being destroyed due to a sudden increase in body pressure due to the occupant re-sitting.

According to the invention which concerns on Claim 6 , destruction of the body pressure measurement sensor by the sudden increase in body pressure when a passenger | crew gets on can be prevented.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the relative arrangement of components, the display screen, and the like described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. In the present embodiment, the respiration rate is described as respiration or pulse. However, the sensor sensitivity needs to be increased in the heart rate as well, but the tendency is the same and is included in the present invention.

<Outline of Respiration or Pulse Detection of this Embodiment>
FIG. 1 is a diagram showing an outline of respiration or pulse detection in the vehicular biological information detection apparatus of this embodiment.

  When breathing is detected by the occupant body pressure applied to the seat, if the seat cushion 1 (lower seat) is to be detected, the occupant's load is too large to detect the breath with high accuracy. That is, if the load is too large, it is necessary to provide a strong sensor that can withstand the load. However, since the accuracy and the load resistance are generally contradictory, the accuracy deteriorates. In addition, when trying to detect the upper part of the seat back 2, it is sufficient if it is resting against the seat, but the load is greatly reduced due to a change in the posture of the occupant (for example, a stooped posture), and in some cases it becomes zero. In other words, it is impossible to detect respiration or a pulse such as a heartbeat or a pulse.

  Position 3 corresponding to the occupant's waist was selected from among the parts of the human body in contact with the seat back as a position where stable and strong pressure could be detected. Selection was based on the following criteria: A seat back can detect a body pressure fluctuation that is larger than the passenger's load. The part that receives strong body pressure in the seat back is the position 2a corresponding to the shoulder of the upper part 2 of the seat back, the position 3 corresponding to the waist of the driver in the seat back, and the position corresponding to the hips of the driver in the seat back. 4 parts. A portion where the change in contact with the seat back is small due to the change in the posture of the occupant is the position 3 corresponding to the waist of the driver in the seat back. The part where the periodic fluctuation of the body pressure due to the double breathing appears strongly is also the position 3 corresponding to the driver's waist in the seat back.

  From the above selection results, a plurality of sensors were attached to the position 3 corresponding to the driver's waist in the seat back, and the body pressure was measured to confirm the change in body pressure due to respiration. As a result, in the sensor provided at a height of 10 to 25 cm from the seat cushion in the lower part of the seat back, which corresponds to the waist of the occupant, it was possible to detect a stable and large pressure fluctuation regardless of the posture change of the occupant. .

  The present embodiment is for a vehicle in which a body pressure sensor is provided at a specific position in the seat back, that is, a height of a range 3a of 10 to 25 cm from the seat cushion in the lower portion of the seat back based on the above selection and measurement results. A biological information detection device is proposed.

<Configuration Example of the Vehicle Biological Information Detection Device of the Present Embodiment>
(Respiration or pulse detection unit)
FIG. 2 is a diagram showing an outline of a respiration or pulse detection unit in the vehicular biological information detection apparatus of the present embodiment.

  The breathing or pulse detecting unit is located at a height of 20 cm from the most suitable seat cushion in the position corresponding to the waist of the occupant having a height of 10 to 25 cm from the seat cushion in the lower part of the seat back shown in FIG. The left and right pressure sensors 21 provided, the lumbar support 22 that holds the pressure sensor 21, and the lumbar support 22 according to the body pressure of the occupant so that the pressure sensor 21 can measure a stable pressure. And a movable mechanism 23 for controlling the front-rear position so that the body pressure applied to the sensor 21 is substantially constant.

  In FIG. 2, two pressure-sensitive sensors 21 are provided on the left and right sides at a height of 20 cm from the seat cushion. However, the height from the seat cushion may be in the range of 10 cm to 25 cm, and a plurality of sensors may be arranged vertically. May be provided, and the number thereof may be three or more. Although the detection of respiration or pulse is more stable when many sensors are provided, it is expensive, so it is most cost-effective, and two left and right components are provided at a height of 20 cm from a seat cushion that can stably detect body pressure. Is selected. When a plurality of pressure-sensitive sensors 21 are provided, an average value of these detection signals is taken, or a higher detection signal is selected to detect a change in the period of breathing or pulse. Detection is possible.

(First example of movable mechanism)
FIG. 3 is a diagram illustrating an example of the movable mechanism 23 in FIG. 2. The reaction force (the lumbar board 22 moves rearward when the body pressure applied to the sensor increases, but the lumbar board engages when the body pressure applied to the sensor decreases. It is the structure by the hard mechanism which has the reaction force generation | occurrence | production spring 31 which produces | generates the force which moves 22 forward.

  In this example, the reaction force generation spring 31 is hung on a spring holding pin 33 fixed to the guide plate 32 and a roller 34 combined to move the lumbar support 22 back and forth. The roller 34 is rotated in the X direction by the reaction force, and the lumbar support 22 connected so that the roller 34 can rotate is moved forward. That is, when the reaction force of the reaction force generation spring 31 is larger than the body pressure and the roller 34 rotates in the X direction, the shaft 35 that connects the roller 34 and the lumbar support 22 and rotates as the rotation axis of the roller 34 rotates. Since the gear 35 a and the gear 36 a on the groove lower surface 36 of the guide plate 32 are fitted, the roller 34 and the lumbar support 22 move forward with respect to the guide plate 32. On the other hand, if the body pressure is greater than the reaction force of the reaction force generation spring 31, the roller 34 rotates in the anti-X direction, and the roller 34 and the lumbar support 22 move backward with respect to the guide plate 32. Accordingly, the position of the lumbar support 22, that is, the position of the pressure sensor 21 is controlled at a position where the reaction force of the reaction force generation spring 31 and the body pressure are balanced.

  According to this movable mechanism 23, body pressure can be controlled without burden on the control system. Note that the spring holding pin 33 and the lumbar board 22 may be directly connected by the reaction force generating spring 31 without using the roller 34. Further, it is desirable that the reaction force generating spring 31 has a long spring length so that a substantially constant body pressure can be measured in the moving range of the lumbar board 22.

(Second example of movable mechanism)
FIG. 4 is a diagram showing another example of the movable mechanism 23 that controls the movement of the lumbar board 22 back and forth by a motor in addition to the reaction force generation spring 31 of FIG.

  The relationship and operation of the reaction force generation spring 31, the roller 34, and the shaft 35 of the lumbar support 22 via the gear 35a and the gear 36a of the groove lower surface 36 of the guide plate 32 are the same as in the first example. In this example, the shaft (or shaft 35) of the roller 34 is configured to be rotatable by the motor 41. In FIG. 4, the rotational force is transmitted by the belt and the chain 41a.

  In this example, the front and rear movement of the lumbar board 22 is controlled by the motor 41 in accordance with the body pressure information from the pressure sensor 21. In particular, in this example, when the body pressure exceeds a predetermined set value, the lumbar board 22 is moved back to a position where the body pressure does not reach the pressure sensor 21 by the motor 41, and the reaction force generated by the reaction force generation spring 31 is used. Control for returning the lumbar board 22 to a position where the pressure-sensitive sensor 21 detects body pressure is preferable.

  According to this movable mechanism 23, although the burden on the control system increases, it is possible to perform later-described control such as protecting the sensor 21 by retreating the lumbar support 22 in anticipation of a sudden increase in body pressure.

  According to this example, it is possible to suppress an increase in the burden on the control system and to prevent the occurrence of delay in the case of return due to the return reaction force of the reaction force generation spring 31. It is possible to control the position of the lumbar board 22 only by the motor 41 without the reaction force generating spring 31.

(Third example of movable mechanism)
FIG. 5 is an example of still another movable mechanism 23 that further sends air to the lumbar board 22 by the air pump 51 to stabilize the body pressure at the pressure-sensitive sensor 21.

  In this example, by controlling the air pump 51 that sends air to the balloon 53 in front of the lumbar board 22 and the release valve 52 that discharges the air from the balloon 53 in response to body pressure information from the pressure sensor 21, Absorbs subtle fluctuations in body pressure applied to the pressure sensor 21.

  In FIG. 5, the pressure signal from the pressure sensor 21 is sent to the respiration / heart rate measurement unit 60 together with the pressure control by the reaction force generation spring 31, and from the determination based on the signal, the respiration / heart rate measurement unit 60 sends the motor 41. In addition, the air pump 51 and the release valve 52 are controlled by sending control signals, but the air control and the reaction force generation spring 31 in this example without the motor 41 may be used. The structure of only the air control and the motor 41 of this example without the reaction force generation spring 31 may be used. Further, if a device is devised so that a large body pressure is not directly applied to the pressure-sensitive sensor 21, body pressure control only by air control without the reaction force generation spring 31 and the motor 41 is possible.

(Respiratory or pulse detection control unit)
In FIG. 6, the respiratory rate and heart rate are measured by the body pressure from the detection unit including the movable mechanism 23. In the second and third examples of the movable mechanism 23, the motor 41, the air pump 51, and the release valve are used. Reference numeral 52 denotes a control system including a respiration / heart rate measurement unit 60 which is a respiration or pulse detection control unit for controlling the displacement amount of the lumbar board 22. The respiration rate and / or heart rate measured by the respiration / heart rate measurement unit 60 is notified to the occupant state detection / driving support system 69 for driving support.

  In the present embodiment, the control of the respiration / heart rate measurement unit 60 such as extraction of the respiration signal based on the body pressure detection signal from the pressure sensor 21 and calculation of the respiration rate from the respiration signal is included in the present invention. Although it is an indispensable configuration, it is not the main configuration for problem solving, so it will not be described in detail. A signal that is not a breathing signal is filtered from the body pressure detection signal, for example, the vibration of the vehicle, body pressure change during brake / accelerator operation of the occupant, and other noises are removed, or only the breathing signal is amplified to extract the breathing signal Is done. Furthermore, it is also possible to learn the occupant's respiration rate and select it by gate pulses. If the respiration signal can be extracted, the respiration rate can be obtained by counting the respiration signal. The heart rate is basically the same except for the frequency. In FIG. 6, the breathing / heart rate measurement unit 60 and the occupant state detection / driving support system 69 are illustrated separately. However, they may be integrated into a unit controlled by the same CPU, engine control, etc. You may implement | achieve integrally with other control.

  In FIG. 6, a respiration / heart rate measuring unit 60 includes a CPU 60a for calculation control for performing program control, a ROM 60b for storing fixed parameters and programs executed by the CPU, and parameters including input / output information and information during calculation control. Is included. Information input to the respiration / heart rate measurement unit 60 includes pressure information from the pressure sensors 21a and 21b (the number of pressure sensors is not limited to two), a throttle opening 61, a brake switch 62, and a steering angle sensor 63. The information output from the door opening / closing sensor 64 and the vibration sensor 65 and output from the respiration / heart rate measuring unit 60 based on the following control is displacement correction information for controlling the motor 41 and / or the air pump 51. This is feedback control for controlling the motor 41 to retract the lumbar board 22 and preventing the pressure sensor 21 from being destroyed.

<Operation example of the biological information detecting device for a vehicle according to the present embodiment>
An example of the control procedure of the respiration / heart rate measurement unit 60 will be described using the above configuration example. As described above, the detailed procedure for detecting the respiratory rate from the body pressure information is not described here.

(Position correction example)
FIG. 7 is a flowchart of a control procedure example of the respiration / heart rate measurement unit 60 in the second example or the third example of the movable mechanism. This flowchart is repeatedly executed at predetermined intervals. The “avoidance position” in the following description represents the backward position of the rearmost end of the pressure sensor 21 where the body pressure does not reach the pressure sensor 21 even if the occupant leans strongly against the seat. Represents a predetermined position ahead of the rearmost position at which the pressure-sensitive sensor 21 can sense body pressure when the occupant sits on the seat.

  First, in step S71, information from various sensors shown in FIG. 6 is acquired. Here, only the vehicle vibration from the vibration sensor 65 will be described, but it may be controlled by information on other vehicle steering conditions, brake / accelerator operation, and switch operation.

  In step S72, it is determined whether or not there is vehicle vibration, or whether or not there is vibration of a predetermined value or more. If there is vibration, the process proceeds to step S78, and the lumbar board 22 is moved to the avoidance position to protect the pressure sensitive sensor 21. In step S79, the passenger is notified of avoidance. In this example, the occupant is notified and returned to the sensing position (not shown) according to the occupant's instruction (not shown). However, control may be performed so that the occupant returns to the sensing position after a predetermined time.

  If there is no vehicle vibration or no more vibration than the predetermined value, it is determined in step S73 whether or not the body pressure displacement acquired from the pressure sensor 21 exceeds a set value. If it exceeds the set value, the process proceeds to step S78, and in order to protect the pressure sensor 21, it is moved back to the avoidance position in the same manner as described above.

  If it does not exceed the set value, it is determined in step S74 whether or not the body pressure sensor value is in a range that requires position correction. If it is determined that position correction is necessary, position correction is performed by the motor 41 or air valve 51 in step S75. I do. That is, if the body pressure sensor value is smaller than the first predetermined value in step S74, the lumbar board 22 is moved forward so that the body pressure is more strongly applied to the pressure sensitive sensor 21 in step S75. On the other hand, if the body pressure sensor value is larger than the second predetermined value that is larger than the first predetermined value in step S74, the lumbar board 22 is moved backward so as to make the body pressure applied to the pressure sensor 21 weaker in step S75. . If position correction is not necessary, step S75 is skipped. In addition, you may always correct | amend without determination of step S74.

  In step S76, body pressure is detected, the waveform of respiration and / or heartbeat is detected from the variation in body pressure detected so far, and the respiration rate and / or heart rate is calculated in step S77. The calculated respiration rate / heart rate is output when the occupant state detection / driving support system 69 is separately provided as shown in FIG. 6, and is used as it is inside the control unit if it is controlled by a common control unit. .

  As for body pressure sensing for respiration / heartbeat detection or retreat to the avoidance position, the preferred one is selected from the plurality of pressure-sensitive sensors 21 in the case of respiration / heartbeat detection, or a plurality of sensors. Information from 21 can also be combined. In the body pressure sensing for retreating to the avoidance position, the pressure sensor that senses a stronger body pressure is selected.

(Other avoidance control)
FIG. 7 shows avoidance of the lumbar board 22 for protecting the pressure sensitive sensor 21 in the case of vehicle vibration. However, according to the flowchart of FIG. The avoidance control of the lumbar board 22 for the case where the vehicle is present or when there is no passenger is described. The processing of FIG. 8 is also repeatedly executed at predetermined intervals. The following “avoidance position” and “sense position” also represent the position of the pressure-sensitive sensor 21 similar to the above.

  First, in step S81, it is determined whether or not the engine is stopped. If the engine is stopped, the process proceeds to step S85, and the lumbar board 22 is moved back to the avoidance position. Next, step S82 checks whether the door is opened or closed. If the door is open, it is avoided in step S85. Next, in step S83, it is checked whether there is a passenger. If no occupant is present, it is avoided in step S85.

  When the engine is operating, the door is closed, and an occupant is detected, the lumbar board 22 is moved to the body pressure sensing position in step S84.

  With this process, it is possible to protect the pressure sensor 21 (control in step S83) when it is not necessary to sense body pressure or when the occupant predicts that body pressure will be applied at once.

It is a figure which shows the outline of the respiration or pulse detection in the biometric information detection apparatus for vehicles of this embodiment. It is a figure which shows the biometric information detection part in the biometric information detection apparatus for vehicles of this embodiment. It is a figure which shows the 1st example of the movable mechanism of the biometric information detection part which concerns on this embodiment. It is a figure which shows the 2nd example of the movable mechanism of the biometric information detection part which concerns on this embodiment. It is a figure which shows the 3rd example of the movable mechanism of the biometric information detection part which concerns on this embodiment. It is a block diagram which shows the control system containing the respiration / heart rate measurement unit figure which concerns on this embodiment. It is a flowchart which shows the example of control of the lumbar board 22 which concerns on this embodiment. It is a flowchart which shows the avoidance control example of the lumbar board 22 for another sensor 21 protection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seat cushion 2 Seat back upper part 2a The position corresponding to a driver | operator's shoulder in a seat back 3 The position corresponding to a driver | operator's waist | hip | lumbar part in a seat back 4 The position corresponding to a driver | operator's buttocks in a seat back 21 Pressure sensitivity Sensor 22 Lumber support 23 Movable mechanism 31 Reaction force generating spring 32 Guide plate 33 Spring holding pin 34 Roller 41 Motor 51 Air pump 52 Release valve 53 Balloon

Claims (6)

A biological information detection device for a vehicle that detects a change in a driver's breathing or pulse cycle,
A body pressure measuring means for measuring a body pressure applied by a seated driver, having a body pressure measuring sensor provided in a vehicle seat;
Based on the measurement result of the measured body pressure, comprising a period change detecting means for detecting a period change of the driver's breathing or pulse,
The body pressure measuring sensor is located at a position corresponding to the waist of the driver in the lower part of the seat back, and is provided at a height of 10 to 25 cm from the seat cushion in the lower part of the seat back . Biological information detection device. A plurality of the body pressure measurement sensors are provided on the left and right in the lower part of the seat back,
2. The vehicle according to claim 1, wherein the cycle change detecting means detects a cycle change of respiration or pulse based on an average value or a higher value of the body pressure measured by the plurality of body pressure measuring sensors. Biological information detection device.   The body pressure measuring means has displacement means for displacing the position of the body pressure measuring sensor in the front-rear direction within a seat back so that the body pressure measured by the body pressure measuring sensor is within a predetermined range. The biological information detecting device for a vehicle according to claim 1, wherein A vibration detecting means for detecting the vibration of the vehicle;
Said displacement means, when the vibration of the vehicle detected by said vibration detecting means is a predetermined value or more, for a vehicle according to claim 3, wherein the displacing rearward the body pressure measuring sensor in the seat back Biological information detection device. The body pressure measuring means includes body pressure drop detecting means for detecting a case where the driver's body pressure is suddenly reduced,
Said displacement means according to claim 3, wherein the body pressure lowering detection means when detecting a rapid decrease of the driver's body pressure, and wherein the displacing rearward the body pressure measuring sensor in the seat back The biological information detection apparatus for vehicles as described. A door opening / closing detecting means for detecting opening / closing of the vehicle door;
Said displacement means, when the door opening and closing detection unit detects that the open door near the driver's seat, according to claim 3, wherein the displacing rearward the body pressure measuring sensor in the seat back Biological information detection apparatus for vehicles.

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