JP2010172541A - Vigilance maintaining system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vigilance maintaining system for effectively enabling a target person to keep a vigilance state by adding appropriate vigilance stimulation to the target person who feels sleepy. <P>SOLUTION: When a driver D being the target person feels sleepy, an air bag 3 is inflated to add the vigilance stimulation being a pressure sensation stimulation to the erector muscle of spine of the driver D. A physiological measuring instrument 8 measures muscle potential as a parameter indicating the active state of the erector muscle of spine. A vigilance maintaining ECU 11 performs control to allow the intensity of the pressure sensation vigilance stimulation to be added to the erector muscle of spine by the air bag 3 to be the intensity appropriate to activate the activity of brain cells of the driver D, on the basis of the measured muscle potential. Additionally, a vibration body 7 adds a vibration stimulation to the erector muscle of spine. As a result, the driver D who feels sleepy is effectively kept in the vigilance state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wakefulness maintenance device that maintains a subject in a wakeful state by giving a wakeful stimulus to the subject who is drowsy.

  2. Description of the Related Art Conventionally, devices that give arousal stimulation to a person who has drowsiness are generally known (see, for example, Patent Documents 1 and 2). Here, Patent Document 1 describes a device that tilts the seat back of a driver's seat and generates a shift force that stimulates the driver to feel pressure to return the driver to an awake state. Further, Patent Document 2 describes a device that provides an alarm sound having a volume corresponding to the depth of sleepiness as an arousal stimulus corresponding to the degree of driver's consciousness decrease.

JP 2004-344613 A JP-A-8-147484

  By the way, since the device described in Patent Document 1 stimulates the driver's pressure sensation by tilting the seat back of the driver's seat, it is difficult to give the driver a wakeful stimulus having an appropriate intensity. On the other hand, since the device described in Patent Document 2 uses alarm sound as a wakeful stimulus, there is a difficulty in effectively maintaining the driver's wakefulness.

  Then, this invention makes it a subject to provide the wakefulness maintenance apparatus which can maintain a subject person in a wakeful state effectively by adding an appropriate wakeful stimulus to the subject who sleeps.

  A wakefulness maintaining apparatus according to the present invention is a wakefulness maintaining apparatus that adds a wakeful stimulus to a skeletal muscle of a subject who is drowsy to maintain the subject in a wakeful state, and adds a wakeful stimulus to the skeletal muscle of the subject. Awakening stimulus adding means, a parameter acquiring means for acquiring a parameter indicating an activity state of the skeletal muscle of the subject to which the awakening stimulus is added by the awakening stimulus adding means, and a stimulus adding means based on the parameters acquired by the parameter acquiring means And a stimulus intensity control means for controlling the intensity of the arousal stimulus added to the skeletal muscle of the subject to a predetermined intensity.

  In the wakefulness maintenance device according to the present invention, when the subject is drowsy, the wakefulness stimulus adding means adds the wakefulness stimulus to the subject's skeletal muscle, and the parameter acquiring means sets a parameter indicating the activity state of the subject's skeletal muscle. Based on the acquired parameters, the stimulus intensity control means controls the intensity of the arousal stimulus added to the skeletal muscle of the subject to a predetermined intensity. And the intensity | strength of this arousal stimulus is controlled by the appropriate intensity | strength which activates the activity of a subject's brain cell, and a subject is effectively maintained in an arousal state.

  Here, the wakefulness maintaining apparatus according to the present invention includes a vibration stimulus adding unit that adds a vibration stimulus to the skeletal muscle of the subject in addition to the wakefulness stimulus controlled to a predetermined intensity by the stimulus intensity control unit. be able to. In this case, a vibration stimulus is added to the skeletal muscle of the subject in addition to the arousal stimulus controlled to a predetermined intensity, so that a decrease in the amount of neural activity due to the habituation to the subject's arousal stimulus is suppressed, and the arousal stimulus Increases the duration of the effect.

  In the wakefulness maintenance device according to the present invention, when the subject is drowsy, the wakefulness stimulus adding means adds the wakefulness stimulus to the subject's skeletal muscle, and the parameter acquiring means sets a parameter indicating the activity state of the subject's skeletal muscle. Based on the acquired parameters, the stimulus intensity control means controls the intensity of the arousal stimulus added to the skeletal muscle of the subject to a predetermined intensity. Therefore, according to the present invention, the subject can be effectively maintained in the arousal state by controlling the strength of the arousal stimulus to an appropriate strength that activates the activity of the brain cells of the subject.

1 is a side view of the vicinity of a driver's seat schematically showing a configuration of a wakefulness maintaining device according to an embodiment of the present invention together with a driver of a vehicle as a target person. It is a functional block diagram which shows the structure of the same awakening maintenance apparatus. It is a schematic diagram which shows the correlation of the myoelectric potential of skeletal muscle, and thickness. It is a flowchart which shows an example of the procedure of the process which the awakening maintenance ECU shown in FIG. 2 performs. It is a graph which shows correlation with the muscular strength of a skeletal muscle, and the nerve electrical pulse density. It is a graph which shows the time change of the nerve electrical pulse density demonstrated by comparing the case where a muscle spindle received only a pressure stimulus and the case where a vibration stimulus was received in addition to the pressure stimulus. It is a side view corresponding to FIG. 1 which shows the modification of an arousal stimulus addition means. It is a side view corresponding to FIG. 1 which shows the modification of a vibration stimulus addition means. It is a side view corresponding to FIG. 1 which shows the modification of a parameter acquisition means. It is a side view corresponding to FIG. 1 which shows the other modification of an awakening stimulus addition means. It is a side view corresponding to FIG. 10 which shows the modification of the awakening stimulus addition means shown in FIG. It is a side view corresponding to FIG. 10 which shows the modification of the parameter acquisition means shown in FIG.

  Hereinafter, embodiments of the wakefulness maintaining device according to the present invention will be described with reference to the drawings. The wakefulness maintaining apparatus according to an embodiment adds a wakeful stimulus to the skeletal muscle of the driver D who is drowsy, for example, with the driver D of the vehicle seated on the driver seat 1 shown in FIG. It is a device that maintains D in the awake state. This wakefulness maintenance device includes driver fixing means, wakefulness stimulus adding means, vibration stimulus adding means, parameter acquisition means, and stimulus intensity control means, which will be described below. Specifically, as shown in FIGS. It has a simple configuration.

  The driver fixing means presses and fixes the upper body of the driver D seated on the driver's seat 1 against the seat back 1A. The shoulder belt 2A of the seat belt device 2 attached to the driver's seat 1 and this A winding motor 2B that winds up the shoulder belt 2A is provided. The hoisting motor 1 is driven to be hoisted when necessary to tighten the shoulder belt 2 </ b> A, thereby pressing the upper body of the driver D against the seat back 1 </ b> A of the driver seat 1.

  The arousal stimulus adding means is a means for adding a pressure arousal stimulus (hereinafter also referred to as a pressure awake stimulus) to the spine standing muscle that is the skeletal muscle of the driver's D waist. This awakening stimulus adding means includes an airbag 3 embedded in a lower portion of the seat back 1A so as to press the waist of the driver D, and an electromagnetic that opens and closes the air flow path 5 between the airbag 3 and the compressor 4. And a valve 6. The awakening stimulus adding means can be configured by changing the airbag 3 to a water bag, the compressor 4 to a water pump, and the air flow path 5 to a liquid flow path.

  The vibration stimulation adding means is means for applying vibration stimulation to the spine standing muscle of the lumbar region of the driver D, and includes a vibrating body 7 fixed to the front portion of the airbag 2, for example. The vibrating body 7 is configured to be subjected to excitation control at a frequency of, for example, 60 to 100 Hz by energization.

  The parameter acquisition unit acquires a parameter indicating the activity state of the skeletal muscle of the driver D to which the awakening stimulus is added by the awakening stimulus adding unit, and acquires a parameter indicating the maximum muscle strength of the skeletal muscle of the driver D. The parameter acquisition means includes a physiological measuring device 8 for acquiring a parameter indicating the activity state of the skeletal muscle of the driver D, and a skeletal muscle ratio measurement for acquiring a parameter indicating the maximum muscle strength of the skeletal muscle of the driver D. The apparatus 9 is provided.

  The physiological measurement device 8 measures the myoelectric potential of the skeletal muscle as a parameter indicating the activity state of the skeletal muscle of the driver D. The physiological measurement device 8 includes a physiological measurement electrode 8A that is adsorbed to the body surface of the driver D, and measures the myoelectric potential of the skeletal muscle of the driver D through the physiological measurement electrode 8A. The physiological measurement device 8 may be a simple myoelectric meter, or may be constituted by a medical telemeter or a portable multipurpose biological amplifier.

  Here, among human skeletal muscles, the lumbar spine standing muscles have many red muscles, and the red muscles contain many muscle spindles. This muscle spindle is a tension receptor that emits neuroelectric pulses from the spine to the brain when stimulated, and brain cells can be efficiently used by adding awakening stimulus to the spinal column standing muscle that contains many muscle spindles. And the driver D can be effectively maintained in the awake state.

  Therefore, in one embodiment, on the premise that the airbag 3 constituting the above-described arousal stimulus adding means presses the waist of the driver D and applies the awake stimulus of the pressure sense stimulus to the spinal column standing muscle, The 8 physiological measurement electrodes 8A are adsorbed on the body surface of the waist of the driver D so as to measure the myoelectric potential of the standing muscle of the driver D.

  The skeletal muscle rate measuring device 9 measures the skeletal muscle rate of the driver D as a parameter indicating the maximum strength of the skeletal muscle of the driver D. This skeletal muscle ratio measuring device 9 has a pair of measurement electrodes 9A that are embedded and disposed in the left and right portions of the steering wheel 10 so that the driver D can hold with both hands.

  Such a skeletal muscle rate measuring device 9 measures an electrical resistance value when a weak current is passed through the body of the driver D via a pair of measurement electrodes 9A, and the measured electrical resistance value is a driver-specific basis. The skeletal muscle rate of the driver D is measured by analyzing with a predetermined algorithm in combination with the data. In the skeletal muscle rate measuring device 9, data such as height, weight, age, and sex is registered in advance as basic data unique to the driver.

  The stimulus intensity control means determines the intensity of the pressure wakefulness stimulus applied to the spine standing muscle of the driver D by the airbag 3 constituting the wakefulness stimulus adding means based on the parameter obtained by the parameter obtaining means, that is, a predetermined strength, A means for controlling the driver D to a predetermined intensity that can effectively maintain the driver D in the wakefulness state. Specifically, the driver D is configured by a wakeup maintenance ECU (Electronic Control Unit) 11.

  The wakefulness maintenance ECU 11 includes an input / output interface I / O, an A / D converter, a ROM (Read Only Memory) that stores programs and data, a RAM (Random Access Memory) that temporarily stores input data and the like, and a CPU ( A central processing unit) or the like is configured as a hardware, and a stimulus intensity setting unit is configured using the hardware and software.

  In order to estimate the muscular strength corresponding to the activity state of the spine standing muscle of the driver D, the awake maintenance ECU 11 receives the measurement data of the myoelectric potential of the spine standing muscle of the driver D measured by the physiological measuring device 8. . The arousal maintenance ECU 11 to which the measurement data of the myoelectric potential is input estimates the thickness of the standing spine muscle of the driver D based on the correlation between the myoelectric potential and the thickness of the skeletal muscle, and the estimated thickness of the standing spine muscle. Based on the correlation between the muscle strength and the muscle strength, the muscle strength of the spinal column standing muscle is estimated in real time.

  Here, the correlation between the myoelectric potential and the thickness of the skeletal muscle is such that the skeletal muscle M becomes thin when the myoelectric potential is low, as shown in FIG. 3A, and the muscle as shown in FIG. The relationship is that the skeletal muscle M becomes thicker when the potential is high, and the principle that muscle contraction occurs when the muscle is electrically stimulated (Glerup, H., Eriksen, ER; Chapter 102 Muscles and Falls. Vitamin D second edition. Elsevier Academic Press. Burlington, MA, USA: 1805-1820, 2005).

  On the other hand, the principle of estimating the muscular strength from the thickness of the spine standing muscle is the principle that the muscular strength can be estimated from the muscle thickness (Hiroshi Nakazawa, Daily Life Activity and Muscle Strength, Physical Therapy Science, 18 (1), 7-13 , 2003 reference).

  In addition, measurement data of the skeletal muscle rate of the driver D measured by the skeletal muscle rate measuring device 9 is input to the awakening maintenance ECU 11 in order to estimate the maximum strength of the standing muscle of the spine of the driver D. The wakefulness maintenance ECU 11 to which the measurement data of the skeletal muscle rate is input estimates the maximum thickness of the erection column from the skeletal muscle rate of the driver D, and the maximum of the erection column muscle from the estimated maximum thickness of the erection column. Muscle strength is estimated based on the principle described above.

  Here, in order to enable the wakefulness maintenance ECU 11 to determine a state in which the driver D is awakened (increase in sleepiness), the camera unit 12 that images the face of the driver D is, for example, a column in front of the steering wheel 10. It is installed on the upper surface of the cover 13. Then, the image data of the face of the driver D photographed by the camera unit 12 is input to the awakening maintenance ECU 11.

  The awakening maintenance ECU 11 to which the image data of the face of the driver D is input from the camera unit 12 detects the shape of the eyelid of both eyes of the driver D by, for example, predetermined edge processing, and performs predetermined matching from the detected shape of the eyelid. The closed eye rate of both eyes of the driver D is acquired by the processing. Then, the awakening maintenance ECU 11 is configured such that when the acquired closed eye rate is greater than a predetermined threshold value indicating a decrease in the arousal level of the driver D (an increase in the drowsiness level), the driver D exhibits drowsiness and the awakening level is decreased. judge.

  The awakening maintenance ECU 11 controls the operations of the hoisting motor 2B constituting the driver fixing means, the electromagnetic valve 6 and the compressor 4 constituting the awakening stimulus adding means, and the vibrating body 7 constituting the vibration stimulation adding means, respectively. 14 is configured to be controlled via. That is, the awakening maintenance ECU 11 outputs a predetermined control signal to the controller 14 to drive the hoist motor 1 to wind up when necessary, to open and close the electromagnetic valve 6 when necessary, and to turn on / off the operation of the compressor 4 when necessary. The vibrating body 7 is configured to vibrate and vibrate when necessary.

  Next, an example of the procedure of the process executed by the wakefulness maintenance ECU 11 will be described sequentially along the flowchart shown in FIG. This wakefulness maintenance ECU 11 adds the wakefulness stimulus of the pressure sensation to the spine standing muscle of the driver D who is drowsy after the engine is started by turning on the ignition switch of the vehicle (not shown). A series of processes for effectively maintaining the driver D in the awake state by controlling the intensity to a predetermined intensity is executed.

  First, in step S <b> 1, the awakening maintenance ECU 11 outputs a measurement start signal to the skeletal muscle rate measuring device 9 to measure the skeletal muscle rate of the driver D. In the next step S2, the shape of the eyelid of both eyes of the driver D is detected by predetermined edge processing based on the image data of the face of the driver D input from the camera unit 12, and the predetermined shape is determined from the detected shape of the eyelid. The eye closure rate of both eyes of the driver D is acquired as sleepiness information by the matching process.

  In a subsequent step S3, it is determined whether or not the awakening level of the driver D has decreased. That is, it is determined whether or not the closed eye rate of the driver D acquired as sleepiness information is larger than a threshold value indicating a decrease in the arousal state.

  If the determination result in step S3 is NO and the eye closure rate is smaller than the threshold value, it is assumed that the driver D is in an awake state, and the process returns to step S2, but the determination result is YES and the eye closure rate is When it is larger than the threshold value, it is considered that the driver D is drowsy and the arousal level is lowered, and the process proceeds to the next step S4 for the corresponding processing.

  In step S4, the awakening maintenance ECU 11 outputs a predetermined drive signal to the hoisting motor 2B via the controller 14, thereby hoisting the shoulder belt 2A of the seatbelt device 2 by a predetermined amount by the hoisting motor 2B and driving the upper body of the driver D. Is fixed to the seat back 1A.

  In the subsequent step S5, a predetermined control signal is output to the controller 14, thereby opening the electromagnetic valve 6 and starting the compressor 4. Thereby, compressed air is supplied to the airbag 3 from the compressor 4 via the air flow path 5, and the airbag 3 expand | swells. As a result, a pressure sensation according to the amount of inflation of the airbag 3 is added as a wakeful stimulus to the lumbar region (vertical column standing muscle) of the driver D.

  In the next step S6, measurement data of the skeletal muscle rate of the driver D is acquired from the skeletal muscle rate measuring device 9, and the maximum thickness of the spine standing muscle of the driver D is estimated from the measurement data of the skeletal muscle rate. Then, the arousal maintenance ECU 11 estimates the maximum muscle strength Tmax of the erected spine based on the above-described principle.

  In the subsequent step S7, the measurement data of the myoelectric potential of the spine standing muscle of the driver D is acquired from the physiological measurement device 8, and the thickness of the spine standing muscle is calculated based on the correlation between the myoelectric potential and the thickness of the spine standing muscle. presume. Then, the awakening maintenance ECU 11 estimates the muscular strength T of the spine standing muscle in real time based on the estimated thickness of the spine standing muscle based on the principle described above.

  In the next step S8, the wakefulness maintenance ECU 11 determines whether or not the muscular strength T of the spine standing muscle estimated in step S7 has reached X% of the maximum muscular strength Tmax of the spine standing muscle estimated in step S6. Here, X% is a value at which the density of the neuroelectric pulse emitted by the muscle spindle contained in the erected spine muscle that has received pressure wakefulness stimulation is maximized, for example, the muscular strength of the skeletal muscle and the nerve electrical pulse density. In the graph of FIG. 5, which is generally known as a graph showing the correlation, the value is around 30% at which the neuroelectric pulse density becomes maximum.

  If the decision result in the step S8 is NO, the process returns to the process in the step S7. However, when the muscular strength T of the erected column muscle reaches X% of the maximum muscular strength Tmax and the decision result is YES, in the subsequent step S9, the wakefulness maintenance ECU 11 By outputting a predetermined control signal to the controller 14, the solenoid valve 6 is closed and the operation of the compressor 4 is stopped.

  As a result, the air flow path 5 is blocked and the airbag 3 is held at a predetermined expansion amount, and the intensity of the pressure wakefulness stimulation to the spine standing muscle of the driver D by the airbag 3 is kept constant. As a result, the muscle strength of the spine standing muscle of the driver D is held at X% (for example, around 30%) of the maximum muscle strength Tmax, and the muscle spindle included in the spine standing muscle is fired from the spine toward the brain. The density of the neuroelectric pulse is kept at the maximum density. For this reason, a brain cell is activated efficiently and the driver | operator D is effectively maintained in an arousal state.

  Here, when the muscle spindle receives only the pressure sense stimulus, the density of the neuroelectric pulse emitted by the muscle spindle exhibits a time change as shown by the dotted line graph in FIG. 6, and the muscle spindle adds to the pressure sense stimulus. It has been experimentally confirmed that when a vibration stimulus is received, a time change as shown in the solid line graph of FIG. 6 is exhibited.

  That is, it is confirmed that when the muscle spindle receives vibration stimulation in addition to pressure stimulation, the state of high nerve electrical pulse density persists and the duration of stimulation effect becomes longer than when only pressure stimulation is received Has been. Incidentally, it has been experimentally confirmed that a stimulus effect duration of about 30 seconds can be obtained by adding a vibration stimulus of about 20 seconds.

  Therefore, the awakening maintenance ECU 11 outputs a predetermined control signal to the controller 14 to vibrate the vibrating body 7 in step S10 following step S9, and vibrates the vibrating body 7 at a frequency of, for example, 60 to 100 Hz for 20 seconds. .

  As a result, a vibration stimulus by the vibrating body 7 is added to the spine standing muscle of the driver D in addition to the pressure sense stimulus by the airbag 2, and the nerve electrical pulse density from the muscle spindle is attenuated by accustoming to the pressure sense stimulus. That is, a decrease in the amount of neural activity of the driver D is suppressed. As a result, a stimulation effect duration of, for example, about 30 seconds can be obtained as the stimulation effect duration in a state where the nerve electrical pulse density is high.

  When the vibrating body 7 vibrates for 20 seconds by the process of step S10, the stimulus effect is maintained for about 30 seconds without the addition of the pressure sensation. Therefore, in step S11, the wakefulness maintenance ECU 9 sends a predetermined value to the controller 14. By outputting a control signal to open the solenoid valve 6, the air in the airbag 3 is released to the air flow path 5 to contract the airbag 3, and then waits for 30 seconds while the stimulation effect continues (S12). ).

  After waiting for 30 seconds while the stimulus effect is sustained, the wakefulness maintenance ECU 9 determines whether or not the wakefulness level of the driver D has increased. In step S13, the wakefulness maintenance ECU 9 performs image processing similar to that in step S2 to perform the driver's D. The closed eye rate of both eyes is acquired as sleepiness information. In subsequent step S14, it is determined whether or not the awakening level of the driver D has increased. That is, it is determined whether or not the closed eye rate acquired as sleepiness information is smaller than a threshold value indicating a decrease in the arousal state.

  If the determination result in step S14 is YES and the eye closing rate is smaller than the threshold value, it is considered that the driver D has returned to the awake state, and the process proceeds to return, but the determination result is NO and the eye closing rate is When it is larger than the threshold value, it is assumed that the driver's D awakening level is still lowered, and the process returns to step S5 for the corresponding process.

  As described above, in the wakefulness maintaining device of one embodiment, when the driver D is drowsy, the airbag 3 is inflated by the process of step S5 of the flowchart shown in FIG. Awakening stimulus of pressure stimulus is added to (vertebral column standing muscle). Then, the intensity of the pressure sensation stimulus is controlled to an appropriate intensity by which the muscle spindle of the erected spine that has received the pressure sensation stimulus emits a maximum density neuroelectric pulse by the processes of steps S8 and S9. For this reason, a brain cell is activated efficiently and the driver | operator D is effectively maintained in an arousal state.

  In addition, by the processing in step S10, the driver D's spinal column muscles are added with the vibration stimulus by the vibration of the vibrating body 7 in addition to the pressure stimulus by the airbag 2, so that the muscle spindle from accustoming to the pressure stimulus can be used. Attenuation of the neuroelectric pulse density is suppressed. As a result, as the duration of the effect of maintaining arousal for the driver D, for example, a stimulation effect duration of about 30 seconds is obtained.

  Therefore, according to the wakefulness maintenance device of one embodiment, the driver D who has drowsiness can be effectively maintained in the wakefulness state, and the vibrator 7 is vibrated as the duration of the wakefulness maintenance. A stimulus effect duration of about 50 seconds in total of 20 seconds and 30 seconds thereafter can be obtained.

  The awakening maintenance device according to the present invention is not limited to the above-described embodiment. For example, the drowsiness information acquired in step S2 of the flowchart shown in FIG. 4 is a heart rate that is a physiological index of the driver D, and the determination of the arousal level decrease performed in step S2 indicates that the heart rate indicates a decrease in the arousal state. You may make it determine whether it is less than a threshold value. In this case, the heart rate of the driver D may be measured using the physiological measurement device 8 shown in FIG.

  Further, the awakening stimulus adding means including the compressor 4, the air flow path 5, the electromagnetic valve 6 and the airbag 3 shown in FIG. 1 may be changed to a configuration provided with the hydraulic cylinder device 20 shown in FIG. . The hydraulic cylinder device 20 presses the waist of the driver D by being embedded in the lower part of the seat back 1 </ b> A of the driver seat 1. In this case, the hydraulic cylinder device 20 is preferably controlled by a hydraulic control circuit (not shown) so that a vibration stimulus is applied after a pressure stimulus is applied to the spine standing muscle of the driver D. The hydraulic cylinder device 20 can be changed to an air cylinder device.

  Furthermore, the vibration stimulus adding means including the vibrating body 7 illustrated in FIG. 1 may be changed to a configuration including the eccentric motor 30 illustrated in FIG. The eccentric motor 30 is embedded in the lower part of the seat back 1A of the driver seat 1 to give vibration stimulation to the waist of the driver D. In this case, it is preferable that the eccentric motor 30 is controlled so that the frequency of the vibration stimulation added to the standing muscle of the driver D can be changed.

  Further, the parameter acquisition means including the physiological measurement device 8 illustrated in FIG. 1 may be changed to a configuration including a torque sensor 40 coaxially connected to the hoisting motor 2B of the seat belt device 2 as illustrated in FIG. . When the airbag 3 shown in FIG. 1 is inflated, the torque sensor 40 presses the upper body of the driver D forward of the seat back 1A, the shoulder belt 2A is tensioned, and the tension acts on the winding motor 2B. The torque of the motor 2B is measured as the tension of the shoulder belt 2A. In this modification, the wakefulness maintenance ECU 11 estimates the muscular strength of the spine standing muscle of the driver D based on the tension of the shoulder belt 2A measured by the torque sensor 40.

  Here, the soleus muscle of the leg of the driver D contains many muscle spindles like the erection of the spine. When the soleus is extended, the muscle spindle emits a neuroelectric pulse by the pressure stimulus. Thus, brain cells are activated efficiently. Therefore, as shown in FIG. 10 and FIG. 11, the driver is provided with an awakening stimulus adding means including an airbag 3 for adding a pressure and awakening stimulus to the spine standing muscle of the lumbar region of the driver D shown in FIG. It can comprise so that a pressure sensation stimulus may be added to the soleus of the leg of D.

  The awakening stimulus adding means of the modification shown in FIG. 10 includes a footrest 50 whose front end is supported so as to be able to swing up and down, and a belt 51 for fixing the ankle of the driver D whose sole is supported on the footrest 50. And a motor 52 that transmits a swinging torque to the rear end of the footrest 50 to swing the front end of the footrest 50 up and down. In this modified example, the front end portion of the footrest 50 is swung upward by the motor 52, so that the soleus muscle of the leg of the driver D is stretched and pressure sense arousal stimulation is added to the soleus muscle. In this modification, the physiological measurement electrode 8A of the physiological measurement device 8 is adsorbed to the calf portion of the leg of the driver D so as to measure the myoelectric potential of the soleus of the driver D.

  11 is provided with a hydraulic cylinder device 53 that swings the front end portion of the footrest 50 up and down instead of the motor 52 shown in FIG. The configuration is the same as the modification shown in FIG. In this modified example, the front end portion of the footrest 50 is swung upward by the hydraulic cylinder device 53 so that the soleus of the leg of the driver D is stretched and pressure sense arousal stimulation is added to the soleus.

  Here, the parameter acquisition means including the physiological measurement device 8 illustrated in FIG. 10 is changed to a configuration including a thickness detection band 60 wound around the calf portion of the driver D as in the modification illustrated in FIG. May be. The thickness detection band 60 measures the change in the thickness of the soleus by expanding and contracting according to the thickness of the calf portion of the driver D. In this modification, the wakefulness maintenance ECU 11 estimates the muscle strength of the soleus muscle of the driver D based on the thickness of the soleus muscle measured by the thickness detection band 60.

  In addition, although illustration is abbreviate | omitted, the skeletal muscle rate measuring apparatus 9 shown in FIG. 1 can be changed into the abdominal echo apparatus which can image | photograph the cross-sectional image ranging from the abdominal part of the driver | operator D to a back. In this case, the wakefulness maintenance ECU 11 estimates the thickness of the spine standing muscle of the driver D based on the cross-sectional image captured by the abdominal echo device.

  DESCRIPTION OF SYMBOLS 1 ... Driver's seat 1A ... Seat back 2 ... Seat belt device 2A ... Shoulder belt 2B ... Winding motor 3 ... Air bag 4 ... Compressor 5 ... Air flow path 6 ... Solenoid valve 7 ... Vibration Body, 8 ... Physiological measurement device, 8A ... Physiological measurement electrode, 9 ... Skeletal muscle rate measurement device, 9A ... Measurement electrode, 10 ... Steering wheel, 11 ... Awakening maintenance ECU, 12 ... Camera unit, 13 ... Column cover, 14 ... controller.

Claims (2)

A wakefulness maintaining device for maintaining a subject in a wakeful state by adding a wakeful stimulus to the skeletal muscle of the subject who is drowsy,
Awakening stimulus adding means for adding awakening stimulus to the subject's skeletal muscle, a parameter obtaining means for obtaining a parameter indicating an activity state of the subject's skeletal muscle to which the awakening stimulus has been added by the awakening stimulus adding means, and a parameter obtaining means And a stimulus intensity control means for controlling the intensity of the arousal stimulus added to the skeletal muscle of the subject by the arousal stimulus addition means to a predetermined intensity based on the parameters acquired by Awakening maintenance device. The wakefulness according to claim 1, further comprising vibration stimulus adding means for adding a vibration stimulus to the skeletal muscle of the subject in addition to the wakefulness stimulus controlled to a predetermined intensity by the stimulus intensity control means. Maintenance device.

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