JP2010142593A - Device and method for diagnosing automatic nerve function for vehicle - Google Patents

Abstract

To provide a vehicle autonomic nerve function diagnostic device and a vehicle autonomic nerve function diagnostic method that are superior in accelerating and maintaining the health of passengers by quantitatively measuring the autonomic nerve function of blood vessel control.
A vehicle autonomic nerve function diagnosis apparatus 100 for diagnosing an autonomic nerve function of an occupant of a vehicle and providing an adjustment action, the vasodynamic detection means 11-15 for detecting vasodynamics, and a first blood vessel A delay time detecting means 22 for detecting a delay time at which a cross-correlation function between the time series data of the kinetics and the time series data of the second vasodynamics is maximized; Adding a time, a regression line calculating means 23 for calculating a regression line of the time series data of the first or second vasodynamics, a blood vessel reflex system evaluating means 24 for quantifying blood pressure reflex sensitivity from the slope of the regression line, Stimulus providing means 25 for providing a stimulus for adjusting the autonomic nerve function according to the quantified blood pressure reflex sensitivity.
[Selection] Figure 1

Description

  The present invention relates to a vehicle autonomic nerve function diagnostic apparatus and a vehicle autonomic nerve function diagnostic method that can accurately and quantitatively diagnose a driver's autonomic nerve function while driving a vehicle.

  It is known that the occupant's autonomic nervous function affects the occupant while driving the vehicle. Conventionally, as an autonomic function diagnosis apparatus, a method of diagnosing autonomic function from heart rate variability by fluctuation measurement of an electrocardiogram RR interval using a Holter electrocardiogram or the like has been performed (for example, see Patent Document 1). Patent Document 1 discloses a method of performing periodic fluctuation analysis. However, since a nonlinear component that always exists in the human body is not analyzed, a holistic analysis is impossible. In addition, since information other than the heartbeat cannot be detected, it is difficult to comprehensively determine the autonomic nervous function.

  Moreover, the technique which determines the biological diagnosis system according to a driving condition from a driving condition is disclosed (for example, refer patent document 2). However, since the method described in Patent Document 2 is a method through a driver model, it is not sufficient for monitoring the autonomic nerve function.

  In addition, for example, for blood pressure reflex function via autonomic nerve function, pharmacologically vasoactive drugs such as vasopressor and antihypertensive drugs are intravenously injected to quantitatively analyze heart rate response when blood pressure fluctuates Thus, a method for estimating the blood pressure reflex function from the regression line calculated backward is proposed (see, for example, Non-Patent Document 1). However, it is difficult to spread an invasive technique to a human body that is injected into a patient and artificially induces a change in blood pressure.

  Further, there is a method for measuring the blood pressure reflex function by forcibly changing the position by a head-up tilt device with respect to the blood pressure reflex function via the nervous system, inserting a cannula into the radial artery, and continuously measuring the blood pressure. (For example, refer nonpatent literature 2). However, this method injects the burden on the patient and requires a large-scale measuring device. It is not widely used in general clinical hospitals, but is applied to research applications in some research facilities such as university hospitals. It has only been done.

  In addition, a method of indirectly estimating the autonomic nervous function by monitoring blood pressure by pulse wave measurement has been attempted (for example, see Non-Patent Document 3). In this method, blood pressure and heart rate are continuously measured, and a blood pressure reflex function is estimated from a regression line calculated backward by quantitatively analyzing the response of the heart rate when the blood pressure fluctuates. However, even if the autonomic nervous function of heart control can be diagnosed, the autonomic function of blood vessel control cannot be diagnosed.

  On the other hand, the activation action of the fragrance on the autonomic nerve has been traditionally known, for example, the sedative action by the rose-like fragrance and the excitement action by the lemon-like fragrance from the comparison of the heart rate between the two stimuli. (For example, refer nonpatent literature 4).

Further, a technique for releasing a scent to an occupant with a low arousal level to promote awakening is disclosed (see, for example, Patent Document 3). No technology has been proposed to provide it in an appropriate manner.
JP 10-57333 A JP 2007-272834 A JP 2004-149003 A McGarry K, Laher M, Fitzgerald D, Horgan J, O'Brien E, O'Malley K., “Baroreflex function in elderly hypertensives”, Hypertension. 1983 Sep-Oct; 5 (5): 763-6. London GM, Levenson JA, Safar ME, Simon AC, Guerin AP, Payen D, “Hemodynamic effects of head-down tilt in normal subjects and sustained hypertensive patients”, Am J Physiol. 1983 Aug; 245 (2): H194-202 . Bigger JT Jr, La Rovere MT, Steinman RC, Fleiss JL, Rottman JN, Rolnitzky LM, Schwartz PJ, “Comparison of baroreflex sensitivity and heart period variability after myocardial infarction”, J Am Coll Cardiol. 1989 Nov 15; 14 (6) : 1511-8. Kikuchi, A., Tanida, M., Uenoyama, S., Abe, T. and Yamaguchi, H. (1991). Effect of odors on cardiac response patterns in a reaction time task. In Y. “Queinnec & F. Daniellou (eds.) Designing for Everyone, vol1 ”, London: Taylor & Francis, 380-382. Tomoyuki Yamaya, Yoshifumi Saijo, Yasuyuki Shiraishi, Mitsuya Maruyama, Toshi Kaneno, Shinichi Nita, Saiyuki Yamaguchi, Hiroyuki Nakajima, Miaki Katahira, Soichi Shibata, Makoto Watanabe, Yoshiaki Mitsuki, Nao Sato, Nohisa Akino , Masahisa Honda, “Clinical Study on Accuracy of Rise Point Measurement of Pulse Waves”, Electronics Clinical 76; 23-34, 2007

  The conventional technique has a problem that a large-scale diagnosis system is necessary to quantitatively diagnose the autonomic nerve function while driving a vehicle. In addition, the autonomic nervous function measurement of the heart control is possible, but the autonomic nerve measurement of the blood vessel control is impossible. It is well known medically that the autonomic innervation of a living body has a local response and that only a part of the autonomic nerve diagnosis is insufficient. In addition, a vehicle device that diagnoses autonomic nerve function and provides appropriate fragrance release or massage to adjust the autonomic nerve, that is, a device that can manage health and improve driving ability when driving is reported. Has not been proposed.

  In view of the above problems, the present invention provides a vehicle autonomic nerve function diagnostic apparatus and a vehicle autonomic nerve function diagnostic method that quantitatively measure the autonomic nerve function of blood vessel control and that is superior in promoting and maintaining the health of passengers. For the purpose.

  In view of the above problems, the present invention provides a vehicle autonomic nerve function diagnostic apparatus for diagnosing an autonomic nerve function of a vehicle occupant and providing an adjustment action, a vasodynamic detection means for detecting vascular dynamics, and a first A delay time detecting means for detecting a delay time at which a cross-correlation function between the time-series data of vasodynamics and the second series of vasodynamics is maximized; and the delay in time-series data in the first or second vasodynamics A regression line calculating means for calculating a regression line of the time-series data of the first or second vasodynamics over time, a vascular reflex system evaluating means for quantifying blood pressure reflex sensitivity from the slope of the regression line, and quantification And a stimulus providing means for providing a stimulus for adjusting the autonomic nerve function according to the blood pressure reflex sensitivity.

  An autonomic nerve function diagnosing device for vehicles and an autonomic nerve function diagnosing method for vehicles that are superior in accelerating and maintaining occupant health can be provided by quantitatively measuring the autonomic nerve function of blood vessel control.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is an example of a diagram for explaining the outline of a vehicle autonomic nervous function diagnosis apparatus 100 according to this embodiment. The vehicle autonomic nervous function diagnostic device (hereinafter referred to as the diagnostic device 100) quantitatively diagnoses the autonomic nervous function of heart control and blood vessel control (circulatory system), for example, through measurement of vascular dynamics.

  The driver is equipped with a finger plethysmograph 11 as a pulse pressure meter, and the blood pressure value, heart rate, and stroke volume are monitored. These are preferably measured directly, but it is practical to process some data. In the diagnostic apparatus 100 according to the present embodiment, for example, PWTT (pulse wave propagation time: time from when the blood pulse wave is emitted to the fingertip after the blood pulse is emitted) is used. Although it is not impossible to calculate information corresponding to the R wave of the electrocardiogram from the pulse wave, in FIG. 1, two electrodes 12 and 13 for monitoring the electrocardiogram are provided on the steering wheel. From the pulse wave and the electrocardiogram, hemodynamic time series data including blood pressure value, PWTT, R wave signal, heart rate, stroke volume is obtained.

The diagnostic apparatus 100 quantifies blood pressure reflex sensitivity by two methods.
A) As is well known, the blood pressure reflex function of the autonomic nerve causes the heartbeat to slow down when the blood pressure rises, the blood vessels loosen, and the heart contraction (stroke volume) to decrease to lower the blood pressure. Works. Therefore, the function of the autonomic nerve can be measured if the heartbeat, the loosening of blood vessels, and the contraction of the heart can be measured. Therefore, it is evaluated by quantifying blood pressure reflex sensitivity whether or not the blood pressure reflex function is functioning appropriately.

  As an example, a cross-correlation function between blood pressure and PWTT is calculated, and a regression line between the two is obtained at a delay time at which the cross-correlation function is maximum. Because of the above blood pressure reflex sensitivity, PWTT should decrease if the blood pressure increases and PWTT should increase if the blood pressure decreases, so it is considered that the two have a positive correlation. Therefore, the degree of blood pressure reflex sensitivity can be evaluated from the slope of the regression line.

  The diagnostic device 100 provides scents, massages, and messages to passengers including the driver according to the evaluation of blood pressure reflex sensitivity.

  The same evaluation can be made from the relationship between blood pressure and heart rate, or blood pressure and heart contraction (stroke volume). The heart rate can be measured from either an electrocardiogram or a pulse wave (or from a heart sound diagram described later), and the heart contraction can be measured by an impedance method.

B) Also, quantification of the blood pressure reflex function is proposed using Mayer waves (fluctuations with a period of about 10 seconds included in time-series data of heart rate, time-series data of blood pressure, etc.). In this method, low frequency components of time series data of blood pressure and heart rate are extracted, and the maximum value (ρ _max ) of the cross-correlation coefficient between the low frequency components is used as an index of blood pressure reflex sensitivity. Since ρ _max decreases when the correlation between blood pressure and heart rate decreases, blood pressure reflex sensitivity can be evaluated from ρ _max .

  Since the method using the Mayer wave provides blood pressure reflex sensitivity in a shorter time than A), it becomes easy to provide a passenger with a scent or massage at an appropriate timing.

[Outline of Diagnostic Device 100]
FIG. 2 shows an example of a block diagram of the diagnostic apparatus 100 in A). The diagnostic device 100 is controlled by the control unit 20. The control unit 20 includes a finger plethysmograph 11, a pair of electrodes 12 and 13, a scent providing unit 16, a massage unit 17, and a display device 18. ) Or FlexRay or other in-vehicle LAN. The control unit 20 includes computers such as an electronic control unit for navigation, a body electronic control unit for controlling doors and room lighting, and a meter control unit for controlling lighting and display of a meter panel. Each block of the control unit 20 is implemented by a CPU that executes a program or a hardware circuit such as an ASIC (Application Specific Integrated Circuit).

  The blood pressure measurement unit 14, the electrocardiogram measurement unit 15, and the pulse wave transit time measurement unit 21 obtain blood vessel dynamics such as blood pressure, heart rate, and PWTT. From these, the delay time calculation unit 22 calculates the cross-correlation function between PWTT and blood pressure. The maximum delay time is obtained, the regression line calculation unit 23 calculates a regression line between the blood pressure and PWTT plus the maximum delay time, and the sensitivity evaluation unit 24 evaluates blood pressure reflex sensitivity from the slope of the regression line. . The occupant support unit 25 adjusts the occupant's autonomic function using the scent providing unit 16, the massage unit 17, and the display device 18 according to the evaluation result.

[A) Detection of blood pressure reflex sensitivity]
FIG. 3A is an example of a flowchart illustrating a procedure in which the diagnostic apparatus 100 evaluates blood pressure reflex sensitivity by the method of A). Hereinafter, a description will be given with reference to FIG.

<S10>
The finger plethysmograph 11 is disposed, for example, slightly inside the front side of the steering wheel, at a position where the driver's fingertip can be monitored, or at the fingertip side of the accelerator pedal. The finger plethysmograph 11 irradiates one or more fingertips of the driver with LED light of a predetermined wavelength, and measures the transmitted light (or reflected light) using a photodiode. Since the flow rate of hemoglobin is considered to be proportional to the blood flow, a pulse wave can be obtained from the reflected wave obtained by irradiating LED light having a wavelength reflected by hemoglobin.

  The blood pressure can be calculated from only the pulse wave, or the blood pressure can be calculated from PWTT. Several methods for calculating blood pressure from only a pulse wave have been proposed. For example, an acceleration pulse wave is used. The acceleration pulse wave is a positive wave (a wave) having the first local maximum point showing the maximum amplitude, a negative wave (b wave) following the a wave, and the following c wave, d wave, and e wave. There is a name after the value. For example, the blood pressure value can be obtained by adding the time interval between the a wave and the e wave to the calculation formula. The blood pressure may be measured by a tonometry method such as brachial artery or radial artery. Further, when PWTT is used, the blood pressure is calculated using a predetermined calculation formula using the fact that PWTT is shortened when the blood pressure is increased and becomes longer when the blood pressure is decreased. The heart rate is measured from the pulse wave.

  The pair of electrodes 12 and 13 are provided, for example, on the steering wheel, and are respectively disposed at portions that are gripped by the left and right palms in a neutral state. When the left and right palms of the driver touch the electrodes 12 and 13 independently, a potential difference is generated. The electrocardiogram measurement unit 15 can obtain an electrocardiogram by detecting, amplifying, and shaping the potential difference, and can detect, for example, an R wave, an RR interval, a heart rate, and the like from the electrocardiogram.

  In addition, although a pulse wave and an electrocardiogram are acquired in time series, an interval arises between measurement points. For this reason, it is preferable that the blood pressure measurement unit 14 and the electrocardiogram measurement unit 15 perform linear interpolation and spline interpolation on the time-series data, respectively, and convert the data into equally spaced data in time. Note that any interpolation method may be used.

  FIG. 4 shows an example of time series data of the heart rate (upper stage), pulse wave (interruption), and PWTT (lower stage) measured in this way. The pulse wave propagation time measurement unit 21 measures, for example, the difference between the R wave occurrence time in the electrocardiogram waveform and the rise time of the corresponding blood pressure waveform as PWTT. The rise time of the R wave and the rise time of the pulse wave are the time when the minimum value in the waveform corresponding to one beat is obtained, the time of the first derivative of the waveform, the time of the rise of the second derivative, the generation time of the high frequency component, etc. Can be obtained from

  Note that PWTT may be detected not from the rise of the R wave but from heart sounds. In this case, a microphone that collects heart sounds is provided instead of the electrodes 12 and 13. The time from the generation of the heart sound II to the generation of the pulse wave in the peripheral artery is PWTT.

  When stroke volume is used instead of PWTT, stroke volume is integrated by multiplying a pulse wave for one beat and multiplied by a predetermined coefficient, for example, ultrasonic cardiac tomography, ultrasonic Doppler blood flow measurement. It is possible to calculate by the method or the admittance method.

<S20, S30>
The delay time calculation unit 22 calculates a delay time at which the value of the cross-correlation function between blood pressure and PWTT is maximized. FIG. 5 shows an example of a cross-correlation function between blood pressure and PWTT. There are several ways to obtain the cross-correlation function, but it is calculated from the following equation, for example.
Cross-correlation function = Σ {a (t) × b (t + τ) / | a (t) || b (t + τ) |
a (t) is the blood pressure, b (t) is the PWTT, and τ is a delay time that changes while chopping up a predetermined increment while maximizing the period of one beat. Further, Σ means to add every measurement point. Here, the cross-correlation function was normalized (normalized cross-correlation function).

Each cross-correlation function is calculated while changing τ little by little. When the cross-correlation function is plotted against τ, as shown in FIG. 5, τ _{max at} which the cross-correlation function is largest is the “maximum delay time”. That is, the correlation between the two becomes the best by shifting either the PWTT or the blood pressure by the maximum delay time.

  As described above, when the autonomic nerve is functioning normally, there is a correlation between the blood pressure and the PWTT, and the correlation between the two at the most correlated delay time is an evaluation of blood pressure reflex sensitivity.

<S40>
Specifically, the regression line calculation unit 23 plots a PWTT obtained by adding the blood pressure and the maximum delay time τ _max on a scatter diagram, and calculates the regression line. FIG. 6 shows an example of a scatter diagram and a regression line. In FIG. 6, the blood pressure value is normalized (the average value is divided by 0 by the standard deviation). The regression line in FIG. 6 is as follows.
Regression line = 0.47 × x + 0.01
0.47 is the slope. The slope value itself varies from person to person. However, if the slope increases, the blood pressure reflex sensitivity increases, and if it decreases, the blood pressure reflex sensitivity decreases. Change can be detected. The inclination corresponds to the gain of the method B) described below.

  In addition, blood pressure reflex sensitivity is evaluated by the correlation coefficient R obtained by calculating the regression line (-1 to 1: -1 for complete inverse correlation, 0 for no correlation, 1 for complete correlation). May be. That is, in a state where the blood pressure reflex function is lowered, the correlation between the blood pressure and PWTT is lowered and the correlation coefficient is lowered. If the correlation coefficient R increases, the blood pressure reflex sensitivity increases. If the correlation coefficient R decreases, the blood pressure reflex sensitivity decreases. Therefore, if the change of the correlation coefficient R is monitored, a change in the blood pressure reflex sensitivity of the driver can be detected. The correlation coefficient corresponds to the coherence of the method B) described below.

<S50>
From the above consideration, the sensitivity evaluation unit 24 evaluates the driver's sensitivity from at least one of the slope of the regression line or the correlation coefficient R. For example, the slope of the past regression line of the same driver and the correlation coefficient R are recorded, and the blood pressure reflex sensitivity of the current driver is evaluated based on the past maximum and minimum values. The sensitivity evaluation unit 24 associates the blood pressure reflex sensitivity with any one of, for example, about 3 to 5 steps, and outputs the associated step to the occupant support unit 25 as an evaluation value. The larger the evaluation value, the better the blood pressure reflex sensitivity, and the smaller the evaluation value, the worse.

<S60>
The occupant support unit 25 supports the occupant by a predetermined method based on the evaluation value. For example, an appropriate scent is provided, an occupant is massaged, an evaluation result of blood pressure reflex sensitivity, a blood pressure, a heart rate, and the like are displayed on the display device 18 to alert attention to health management during driving. Details and effects of support will be described later.

[B) Detection of blood pressure reflex sensitivity]
The quantification of blood pressure reflex sensitivity by the method B) will be described. FIG. 7 is an example of a block diagram of the diagnostic apparatus 100 in B), and FIG. 3B is an example of a flowchart showing a procedure for evaluating blood pressure reflex sensitivity. In FIG. 7, the same parts as those in FIG. The diagnostic apparatus 100 in FIG. 7 includes a low-frequency component extraction unit 31 that extracts a low-frequency component of blood pressure and PWTT, and a cross-correlation function calculation unit 32 that calculates a cross-correlation function between the low-frequency components.

<S10, S120>
Step S10 is the same as FIG. When the time series data of blood pressure and heart rate is measured in S10, the low frequency component extraction unit 31 extracts both low frequency components in step S120.

  The time series data of blood pressure and the time series data of heart rate as shown in FIG. 2 include various frequency components. Of these, low frequency components (for example, 0.04 to 0.15 Hz) are derived from blood pressure fluctuations. It is known that the high frequency component (for example, 0.15 to 0.50 Hz) is derived from respiratory fluctuations. Therefore, if only the low frequency component is extracted, the component due to the function of the blood vessel reflection system can be extracted. FIG. 8 shows an example of the low frequency components (for example, 0.04 to 0.15 Hz) of heart rate, blood pressure, and PWTT.

  By the way, it is known that the blood vessel motion has a slow fluctuation component (Mayer wave) of about 10 seconds, and this fluctuation is also said to be a function of blood pressure reflex sensitivity. Therefore, it is conceivable to quantify the blood pressure reflex sensitivity from information of around 10 seconds.

<S130>
Specifically, the maximum value ρ _max of the cross-correlation function of the time-series data of blood pressure and the time-series data of heart rate is calculated. The cross-correlation function calculation unit 32 calculates the cross-correlation function ρ _xy (τ) from the following equation, for example. The time series data of blood pressure was x (t) and the time series data of heart rate was y (t). Then, the cross-correlation function ρ _xy (τ) is calculated for 60 seconds before and after a certain time (120 seconds in total).

相互相関関数ρ_xy(τ)はコヒーレンス（線形性）を示すもので０〜１の値を示すが、相互相関関数を算出するとゲインも得られる。ゲインは血圧と心拍数の振幅比であり、血圧反射感受性の強さに相当する。したがって、相互相関関数から相関の良否と血圧反射感受性の強さを定量化できることになる。相互相関関数の算出は非特許文献５に詳しい。

The cross-correlation function ρ _xy (τ) indicates coherence (linearity) and has a value of 0 to 1. A gain can also be obtained by calculating the cross-correlation function. The gain is an amplitude ratio between blood pressure and heart rate, and corresponds to the strength of blood pressure reflex sensitivity. Therefore, the quality of correlation and the strength of blood pressure reflex sensitivity can be quantified from the cross-correlation function. The calculation of the cross correlation function is detailed in Non-Patent Document 5.

<S140>
Then, the sensitivity evaluation unit 24 uses the maximum value (cross-correlation coefficient ρ _max ) of the cross-correlation function ρ _max (τ) as an index of blood pressure reflex sensitivity in a region where τ is positive. That is, the higher the cross correlation coefficient ρ _max , the higher the blood pressure reflex sensitivity.

上記の回帰直線の傾き又は相関係数Ｒと同様に、相互相関係数ρ_maxには個人差があるので、感受性評価部２４は過去の最大値と最小値を基準に、現在の運転者の血圧反射感受性を評価する。感受性評価部２４は、例えば３〜５段階程度の段階のうちいずれかの段階に血圧反射感受性を対応づけ、対応づけられた段階（数値が大きいほど血圧感受性が高い）を評価値として乗員支援部２５に出力する。乗員支援の態様は、Ａ）の方法と同様である。

Similar to the slope of the regression line or the correlation coefficient R, the cross-correlation coefficient ρ _max has individual differences. Therefore, the sensitivity evaluation unit 24 uses the past maximum value and the minimum value as a reference, and determines the current driver's Evaluate blood pressure reflex sensitivity. The sensitivity evaluation unit 24 associates the blood pressure reflex sensitivity with any one of, for example, about 3 to 5 steps, and uses the associated level (the larger the numerical value, the higher the blood pressure sensitivity) as an evaluation value. To 25. The mode of occupant support is the same as the method of A).

  Although the heart rate was used in the calculation of the cross-correlation function, the same evaluation (coherence, gain) can be performed by using time-series data of stroke volume and fluctuations in pulse pressure instead of the heart rate. .

[Modification of linearity ρ _max detection of blood pressure reflex function]
By the way, it is also possible to calculate the RR interval from only the pulse wave and detect the linearity ρ _max of the blood pressure reflex function. As a result, the electrodes 12, 13 and the electrocardiogram measurement unit 15 can be dispensed with. FIG. 9 is a diagram illustrating a verification example of ρ _max using the intra-beat integral value PWarea. The heart rate interval is calculated from the rising point of the pulse wave, and the blood flow volume and blood pressure are estimated from the pulse pressure. Further, the linearity of the blood pressure reflex function can be estimated from the time series data of the heartbeat and the time series data of the blood pressure.

[Crew support]
Explain crew support. The scent providing unit 16 is, for example, a scent tank installed in a duct of an air conditioner, an air cannon having a scent tank, or the like. A scent component such as lemon or rose is enclosed in the tank, and when the evaluation value of blood pressure reflex sensitivity is low, the scent component of lemon or rose is released.

  More specifically, when the evaluation value is 5 levels, the sympathetic nerve is dominant (evaluation value is 4 or more: correlation and sensitivity is high), so if the driving is disturbed, the sedative effect is When a certain scent component (rose, peppermint, jasmine, black pepper, etc.) is discharged and the parasympathetic nerve is dominant (evaluation value is 2 or less: correlation, sensitivity is low), it may interfere with driving. Discharges fragrant ingredients (lemon, orange, lavender, etc.) that have an awakening effect. As will be described later, these fragrances can control sympathetic / parasympathetic bunras, adjust blood pressure and heart rate, and improve autonomic balance. Since the diagnostic apparatus 100 of the present embodiment evaluates blood pressure reflex sensitivity numerically, the intensity of the scent component may be adjusted according to the numerical value.

  Moreover, the massage part 17 is the massage apparatus incorporated in the sheet | seat, for example. A massage ball or vibrator is built into the seat back or headrest to relax muscles, and massages such as wrapping while pressing the legs with an airbag are offered to passengers including the driver. The strong relationship between massage and blood pressure is known both experimentally and experimentally. By providing massage to the driver when the evaluation value is 1 or less, the blood pressure and heart rate are adjusted, and the autonomic nerve The balance can be improved.

  From the evaluation value of the blood pressure reflex function, sympathetic tonus (the nervous system that governs the smooth muscle of the arterial vessel wall, the blood pressure increases when the smooth muscle contraction by the sympathetic tonus increases, and decreases when it weakens) If you feel tired easily, you can get a sedative effect by providing a massage. That is, the activity of the autonomic nerve can be moderated by providing massage to the driver when the evaluation value is 5 or more, for example.

  Either the scent component or the massage may be provided, or both may be provided. In a state where the evaluation value of blood pressure reflex sensitivity is low, a synergistic effect can be expected by providing a massage with a fragrance. In addition, it is preferable that the massage is provided in a state where the vehicle is stopped and does not hinder driving, such as when the vehicle is waiting for a signal or parked.

  The display device 18 is, for example, a display for navigation, a liquid crystal display of a meter panel, and the like, and presents the physical condition of the driver diagnosed from the evaluation value of blood pressure reflex sensitivity as at least one of characters or icons. It may be provided by voice message. For example, if the sympathetic nerve is dominant, the message “Are you frustrated? Try to drive relaxed” is displayed, and if the parasympathetic nerve is dominant, “Have you been fatigued? Take a break. Is displayed. Drivers and passengers can see such indications and try to drive safely and manage their health. In addition, you may provide a fragrance and a massage with such a message, and you may make a driver | operator select whether to provide these.

[Relationship between aroma and hemodynamics]
Some experimental results on the relationship between aroma and hemodynamics are explained. FIG. 10 shows an example of a change in hemodynamics due to the release of a scent. In FIG. 10, from the top, heart rate (HR), stroke volume (SV), systolic blood pressure (BP), pulse wave propagation time (PWTT), and total peripheral vascular resistance (TPR). Providing a scent (for example, awakening lemon) at the timing of the arrow shown in the figure shows that stroke volume, systolic blood pressure, PWTT, and peripheral vascular resistance are affected. Therefore, providing a scent during driving will have a therapeutic effect on the hemodynamics and the autonomic nerves that govern them.

  FIG. 11 (a) is an example of a diagram showing the influence of the scent of lemon and rose on the heart rate. The increase and decrease in heart rate influenced by the scent of lemon and rose was shown immediately before giving each scent. Heart rate is increased by 1.8 due to lemon scent and decreased by 10.6 due to rose scent. Therefore, when the evaluation value of blood pressure reflex sensitivity is low, an awakening action is obtained by providing a lemon scent, and when the evaluation value of blood pressure reflex sensitivity is high, a sedative action is provided by providing a rose scent. Is obtained.

  FIG.11 (b) is an example of the figure which shows the influence which the scent of lemon and rose has on systolic blood pressure. The increase / decrease in systolic blood pressure influenced by the scent of lemon and rose was shown on the basis of immediately before giving each scent. The systolic blood pressure is decreased by 1.0 due to the lemon scent and increased by 2.0 due to the rose scent. When the blood pressure is lowered (increased), the autonomic nerve (raises) (lowers) the heart rate. Therefore, in both the lemon scent and the rose scent, results consistent with FIG. 11A are obtained.

  FIG.11 (c) is an example of the figure which shows the influence which the scent of lemon and rose has on the sensitivity of a blood-pressure reflex function. Since changes in the slope or gain of the regression line appear due to the scent of lemon and rose, the increase or decrease in the sensitivity of the blood pressure reflex function can be shown based on the time immediately before giving each scent. It can be confirmed that the sensitivity of the blood pressure reflex function can be reduced by the scent of lemon, and the sensitivity of the blood pressure reflex function can be increased by the scent of rose.

  Therefore, as described above, when irritated (sympathetic nerve is dominant), the scent of lemon can suppress irritability, and when sleepiness is strong (parasympathetic nerve is dominant), it is awakened with the scent of rose. The driver's autonomic nervous function can be adjusted and treated by providing an appropriate scent.

  As described above, the diagnostic apparatus 100 according to the present embodiment measures the driver's vascular dynamics while minimizing the restrictions on vehicle operation, and quantitatively diagnoses the autonomic nervous function of vascular control. Appropriate assistance to the driver becomes possible, and autonomic nerve function can be treated.

It is an example of the figure explaining the outline of the autonomic-nerve function diagnostic apparatus for vehicles. It is an example of the block diagram of a diagnostic apparatus. It is an example of the flowchart figure which shows the procedure which detects a blood pressure reflex sensitivity. It is an example of time-series data of a heart rate (upper stage), a pulse wave (interruption), and PWTT (lower stage). It is a figure which shows an example of the cross correlation function of pulse wave propagation time and blood pressure. It is an example of a regression line between the blood pressure and the pulse wave propagation time obtained by adding the _maximum delay time τ _max . It is an example of the block diagram of a diagnostic apparatus. It is an example of the low frequency component of heart rate, blood pressure, and PWTT. It is a figure which shows the verification example of (rho) _max using the integral value within a beat. It is an example of the hemodynamic change by discharge | release of fragrance. It is an example of the figure which shows the influence which the scent of lemon and rose has on heart rate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Finger plethysmograph 12, 13 Electrode 14 Blood pressure measurement part 15 Electrocardiogram measurement part 16 Fragrance provision part 17 Massage part 18 Display apparatus 100 Autonomic nerve function diagnostic apparatus for vehicles (diagnosis apparatus)

Claims (9)

An autonomic nerve function diagnostic device for a vehicle that diagnoses an autonomic nerve function of a vehicle occupant and provides a stimulus according to a diagnosis result,
Vasodynamic detection means for detecting vascular dynamics;
A delay time detecting means for detecting a delay time at which a cross-correlation function between the time series data of the first vasodynamics and the time series data of the second vasodynamics is maximized;
A regression line for calculating a regression line from a scatter diagram of the first vascular dynamic time series data and the second vascular dynamic time series data by adding the delay time to the first or second vascular dynamic time series data. A calculation means;
A blood vessel reflex system evaluation means for quantifying blood pressure reflex sensitivity from the slope of the regression line;
A stimulus providing means for providing a driver with a stimulus that adjusts the autonomic nerve function according to the quantified blood pressure reflex sensitivity;
An autonomic nerve function diagnostic apparatus for a vehicle characterized by comprising: Low-frequency component extraction means for extracting a low-frequency component from each of the time-series data of the first vasodynamics and the time-series data of the second vasodynamics;
Cross-correlation maximum value calculating means for obtaining a maximum value of a cross-correlation function between the low-frequency component of the first vasodynamics and the low-frequency component of the second vasodynamics,
The blood vessel reflex system evaluation means quantifies blood pressure reflex sensitivity from the maximum value in the previous period,
The vehicular autonomic nerve function diagnosis apparatus according to claim 1. The first vasodynamics are blood pressure values and the second vasokinetics is either pulse wave transit time, heart rate or stroke volume,
The vehicular autonomic nerve function diagnosis apparatus according to claim 1. The first vasodynamics is the blood pressure value, the second vasokinetics is the heart rate,
The vehicular autonomic nerve function diagnosis apparatus according to claim 2. Based on the quantified blood pressure reflex sensitivity, the stimulus providing means releases a sedative scent when the sympathetic nerve is dominant, and releases a scent with a wakefulness when the parasympathetic nerve is dominant.
The vehicle autonomic nervous function diagnosis apparatus according to any one of claims 1 to 4. The stimulus providing means provides the driver with a rose scent when the quantified evaluation value of blood pressure reflex sensitivity is equal to or higher than the first reference value, and provides a lemon scent when the evaluation value is lower than the second reference value. provide,
The vehicular autonomic nerve function diagnosis apparatus according to claim 1. The stimulus providing means massages the driver with a massage means built in the seat when the quantified evaluation value of blood pressure reflex sensitivity is equal to or greater than a third reference value.
The vehicular autonomic nerve function diagnosis apparatus according to claim 1. The stimulus providing means massages the driver with a massage means built in the seat when the quantified evaluation value of blood pressure reflex sensitivity is equal to or lower than a fourth reference value.
The vehicular autonomic nerve function diagnosis apparatus according to claim 1. A method for diagnosing an autonomic nerve function of a vehicle occupant and providing an adjustment action for the vehicle.
Detecting vasodynamics;
Detecting a delay time at which a cross-correlation function between the time series data of the first vasodynamics and the time series data of the second vasodynamics is maximized;
Adding a delay time to the time series data of the first or second vasodynamics and calculating a regression line from a scatter diagram of the time series data of the first vasodynamics and the time series data of the second vasodynamics; ,
Quantifying blood pressure reflex sensitivity from the slope of the regression line;
Providing a driver with a stimulus that adjusts autonomic function in response to the quantified blood pressure reflex sensitivity;
A method for diagnosing an autonomic nerve function for a vehicle, comprising:

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