JP2022029421A - Method of determining operator's mental and physical condition, and system for the same - Google Patents

Abstract

To provide a method and system for determining an operator's mental and physical condition from both of heart rate data and aspiration data of an operator to be measured.SOLUTION: The method and system determine an operator's mental and physical condition by using time variation of a heart rate and aspiration measured for an operator during operation of a railroad vehicle and calculating an RSA value as a respiratory sinus arrhythmia (RSA) component of the heart rate on the basis of this association. The system measures the time variation in a simulation operation interval including a tension task and determines each reference value concerning physiological indexes, in advance. While measuring time variation in a real operation interval, in a case where the RSA value is lower than a reference RSA value at a specific position for determining an operator's mental and physical condition, the system determines a tension state of the operator on the basis of a variation width from a reference value of each physiological index. Furthermore, the system comprises: a measurement unit including a sensor for measuring time variation; and a control unit for calculating the physiological index.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method and a system for determining a driver's mental and physical condition while driving a railroad vehicle, and in particular, a method for determining the driver's mental and physical condition from both measured driver's heart rate and respiration data and the system thereof. Regarding the system.

The human autonomic nerve is composed of a sympathetic nervous system and a parasympathetic nervous system, and balances these to maintain the mind and body in a normal state and corresponds to various daily lives. Here, heart rate variability (HRV) includes both components that reflect the activity of the sympathetic nervous system that reflects the state of mental and physical tension and the activity of the parasympathetic nervous system that leads this function to a sedative state. There is. Therefore, there has been proposed a system that determines the activity state of the autonomic nerve of the driver from the change in the heartbeat of the driver while driving the vehicle, reflects it in the driving control of the vehicle, or gives an alarm.

For example, Patent Document 1 discloses a method of detecting a change in the heartbeat of a driver and determining the activity state of the autonomic nerve of the driver. Here, the driver's heartbeat is measured by the electrodes provided on the steering wheel of the vehicle, the gripping state of the steering wheel provided with a plurality of electrodes is detected, and the driver is imaged to detect the posture to detect the heartbeat. From the state of the driver, it is possible to determine the active state of the autonomic nerves, that is, the state requiring attention when driving the vehicle, such as tension, drowsiness, impatience, fatigue, and vagueness (distraction).

In addition, breathing has a relationship with the autonomic nerves as well as heartbeat, but since breathing can be changed by human will, the activity state of the driver's autonomic nerves can be determined from the measured biological cycle information of breathing only. It is very difficult to judge.

For example, Patent Document 2 discloses a method of determining the degree of psychological agitation of a driver by measuring a change in a driving state in accordance with a change in breathing. The breathing signal is extracted from the body pressure signal from the pressure sensor provided on the back of the seat and the running state amount of the accelerator and the brake, and the body pressure signal includes the body pressure fluctuation based on the operation of the accelerator and the brake. Therefore, it is said that an accurate breathing signal is obtained by removing the body pressure fluctuation from the body pressure signal according to the running state amount.

Further, in Patent Document 3, the interbeat time (RRI) in which the appearance of respiratory fluctuation is expected for the measured heartbeat is numerically filtered, and the fluctuation state of RRI is the one in the normal operation state or abrupt. It discloses an arousal degree determination method for determining an arousal degree which is an index of an autonomic nerve activity state such as "sleeping" by detecting whether it is a simple increase or a simple decrease corresponding to a change in mental load. Here, the reference line f (n) corresponding to the fluctuation of RRI is changed between the normal state and the simple increase or decrease, and the variance RRVn of RRI with respect to this reference line f (n) is calculated. Then, the degree of arousal is detected based on the dispersed RRVn.

International Publication No. 2007/11223 Japanese Unexamined Patent Publication No. 2006-042903 Japanese Unexamined Patent Publication No. 2007-04145

It has been proposed to extract components corresponding to respiratory sinus arrhythmia (RSA) from the measured heart rate variability HRV and determine the activity state of the autonomic nerves. Here, it is difficult to determine the activity state of the driver's autonomic nerve from the measured respiratory-only or heartbeat-only biological cycle information, but the respiratory variability is measured at the same time as the heartbeat and a predetermined filter process is performed to eliminate noise. By removing it, it is expected that both heart rate and respiration data will be analyzed together and an evaluation of the response to various situations while driving the vehicle will be obtained.

The present invention has been made in view of the above situations, and an object thereof is a method for determining a driver's mental and physical condition from both measured driver's heart rate and respiration data. It is to provide the system.

The method for determining the mental and physical condition of a driver while driving a vehicle according to the present invention uses the time variation of the heartbeat and breathing measured by the driver while driving a railroad vehicle, and from this correspondence, the respiratory sinus arrhythmia (RSA) component of the heartbeat. This is a method of calculating the RSA value as an RSA value to determine the mental and physical condition, in which the time variation is measured in a simulated operation section including a tension task, and the operation is performed with respect to a physiological index including the respiratory length and / or the respiratory amplitude and the RSA value. Each reference value including the reference breathing length and / or the reference breathing amplitude is determined together with the reference RSA value as the reference for each person, and the time variation is measured in the actual operation section to specify the mental and physical condition. When the RSA value is lower than the reference RSA value at the position, the tension state of the driver is determined from the fluctuation range of the physiological index from each reference value.

According to such a feature, the mental and physical condition of the driver can be more clearly determined from both the measured heart rate and respiration data of the driver.

In the above-described invention, the reference heart rate is determined according to the reference breathing length and / or the reference breathing amplitude together with the reference RSA value, and the fluctuation of the heart rate from the reference heart rate is determined in the determination of the tension state. It may be characterized in that the width and / or the fluctuation range of the RSA value from the reference RSA value is further combined and determined.

In the above invention, the reference value may be determined as an arithmetic mean of the corresponding physiological index through the simulated driving section.

The invention described above may be characterized in that the determination of the tension state includes the determination of the magnitude of the fluctuation range with respect to the standard deviation of the physiological index through the simulated driving section.

In the above-described invention, the RSA value may be calculated from the heartbeat corresponding to one breath of the breath.

In the above-mentioned invention, one or more is selected for each driver together with the breathing length from the physiological index further including the heart rate, the heart rate change rate, and the respiratory length change rate, and used as the specific physiological index. The feature is that each reference value is determined from the measurement in the simulated operation section for the physiological index, and the determination is made based on the fluctuation range with respect to the corresponding reference value for the specific physiological index in the determination of the tension state. May be good.

In the above-described invention, the simulated driving section includes a non-tension task, and one or more is selected for each driver together with the breath length from the physiological index corresponding to the non-tension task, and a second specific physiological index is selected. Then, each reference value is determined from the measurement in the simulated driving section for the second specific physiological index, and when the RSA value is higher than the reference RSA value, the response to the second specific physiological index is taken. It may be characterized in that the determination is made based on the fluctuation range with respect to the reference value.

In the above-described invention, the fluctuation range from the reference RSA value is multiplied by a correction coefficient determined by comparing one breathing waveform and one breathing heart rate variability waveform corresponding to one breath of the respiratory waveform and the heart rate variability waveform, respectively. It may be characterized by correcting.

In the above-mentioned invention, the simulated driving section may be characterized by being given by a driving simulator. According to such a feature, the time variation of the heartbeat and the respiration in the simulated driving section can be easily measured, and the mental and physical condition of the driver can be easily determined.

In the above-mentioned invention, the time variation of the respiration may be obtained by measuring the chest circumference or the abdominal circumference of the driver. According to such a feature, the respiratory data can be easily acquired, and the mental and physical condition of the driver can be easily determined.

Further, the mental and physical condition determination system of the driver while driving the vehicle according to the present invention uses the time variation of the heartbeat and the breath measured by the driver while driving the railroad vehicle, and from this correspondence, the respiratory sinus arrhythmia (RSA) of the heartbeat is used. ) A system that calculates the RSA value as a component and determines the mental and physical condition, from the measurement unit including the sensor that measures the time fluctuation and the time fluctuation measured by the measurement unit, the breath length and / or the breath. The control unit includes a control unit for calculating a physiological index including an amplitude and an RSA value, and the control unit is operated with respect to the physiological index from the time variation measured by the measuring unit in a simulated operation section including a tension task. Along with the reference RSA value, which is the reference for each person, each reference value of the reference breath length and / or the reference breath amplitude is determined, and the time variation is measured in the actual operation section by the measurement unit to determine the mental and physical condition. When the RSA value is lower than the reference RSA value at a specific position, the tension state of the driver is determined from the fluctuation range of the physiological index from each reference value.

According to such a feature, the mental and physical condition of the driver can be more clearly determined from both the measured heart rate and respiration data of the driver.

In the above-described invention, the reference heart rate is determined according to the reference breathing length and / or the reference breathing amplitude together with the reference RSA value, and in the determination of the tension state, the heart rate is based on the reference heart rate. It may be characterized in that the fluctuation range and / or the fluctuation range of the RSA value from the reference RSA value is further combined and determined.

In the above-described invention, the control unit selects one or more for each driver from the physiological index further including the heart rate, the heart rate change rate, and the respiratory length change rate, and stores them as a specific physiological index. For the specific physiological index, each reference value is determined from the measurement in the simulated operation section, and in the determination of the tension state, the determination is made based on the fluctuation range from the corresponding reference value for the specific physiological index. It may be a feature.

In the above invention, the control unit is based on the time variation measured by the measuring unit in the simulated operation section including the non-tension task, from the physiological index corresponding to the non-tension task, together with the respiratory length. One or more is selected for each driver and stored as a second specific physiological index, each reference value for the second specific physiological index is determined, and an RSA is used at a specific position for determining the physical and mental condition. When the value is higher than the reference RSA value, the determination may be made based on the fluctuation range from the corresponding reference value for the second specific physiological index.

It is a block diagram of the system by a typical example of this invention. It is the waveform data of the driver's heartbeat and respiration. It is a graph of the appearance rate for each score of RSA during the stop operation and the station stop in the simulated operation. It is a graph of the appearance rate for each score of (a) heart rate, (b) respiratory length, and (c) respiratory amplitude during stop operation and station stop in simulated driving. It is a graph of the appearance rate for each score of the comprehensive judgment during the stop operation and the station stop in the simulated driving. It is a graph of (a) the appearance rate of the non-tension tendency and the tension tendency in each physiological index, and (b) the appearance rate when comprehensively judged by combining the physiological indexes for a plurality of tension tasks and non-tension tasks in simulated driving. ..

Hereinafter, a method for determining the mental and physical condition of a driver while driving a vehicle according to a typical example of the present invention and a specific embodiment of the system will be described with reference to FIGS. 1 to 5.

As shown in FIG. 1, the determination system 1 of the mental and physical condition of the driver while driving the vehicle is from a waveform measuring unit 10 and a waveform measuring unit 10 that measure time fluctuations between the driver's heartbeat and breathing as waveforms, respectively. It includes a control unit 20 including a function of receiving and analyzing time-varying waveform data.

The waveform measuring unit 10 is, for example, a belt-shaped wearing device having elasticity that can be worn on the chest or abdomen of a driver, and includes a heartbeat measuring sensor 11 for measuring heartbeat, a breathing measuring sensor 12 for measuring a breathing state, and a breathing measuring sensor 12. including. Here, the heart rate measurement sensor 11 can acquire the time variation of the heart rate, that is, the heart rate variation waveform HRV by a plurality of electrocardiogram electrodes or the like. Further, the breathing measurement sensor 12 can acquire a breathing waveform which is a time variation of breathing by a displacement sensor or the like that detects a change in the chest circumference or abdominal circumference of the driver, that is, the circumference of the chest or abdomen. As a result, the waveform measuring unit 10 can be used as a wearable sensor, for example, and can measure the time fluctuations of the heartbeat and the respiration at the same time and in the vicinity without limiting the movement of the driver.

The control unit 20 controls the operation of the entire determination system 1 and includes the control device 21, the determination device 22, and the storage device 23. The control device 21 can instruct the waveform measuring unit 10 to measure the time variation between heartbeat and respiration and receive the waveform data. The determination device 22 can analyze the waveform data transferred from the control device 21 to determine the physical and mental state of the driver. The storage device 23 can store the program executed by the determination device 22 and the waveform data received from the waveform measurement unit 10. The control unit 20 may further include an output device (not shown) such as a monitor.

The determination device 22 measures the heartbeat and the time variation of respiration in the waveform data measured by, for example, the waveform measurement unit 10 by a predetermined determination program, and together with the RSA value as an RSA (respiratory sinus arrhythmia) component, the heartbeat. The number (heart rate interval), heart rate amplitude, breathing length and breathing amplitude are obtained as physiological indexes, and the mental and physical condition of the driver, especially the tensioned state or the non-tensioned state, is comprehensively determined by using these time fluctuations. Can be done. The heart rate interval is obtained as the reciprocal of the heart rate. In addition, among these physiological indicators, the heartbeat amplitude and the respiratory amplitude are standardized including the measurement method and the method of quantifying the amplitude. For example, one value may be obtained for each of these amplitudes per breath, and the amplitude when the driver is in the mental and physical state closest to the normal state may be set to 1, and each amplitude may be expressed as a relative value to the amplitude.

Here, the relative magnitude and change of the RSA value are said to indicate the active state of the parasympathetic nervous system, and the RSA value tends to be relatively lowered when the tension state is increased. Therefore, it is also possible to determine a reference RSA value which is a reference value of the RSA value, and determine that the state of tension is reached when the RSA value measured from the reference RSA value decreases. However, it is difficult to determine the tension state with high accuracy by the determination using only the RSA value as an index.

Therefore, in this embodiment, the tension state is determined as follows. As mentioned above, the RSA value tends to decrease in a tense state. Therefore, when the RSA value is lower than the reference RSA value, it is highly probable that the driver's mental and physical condition is in a tense state. Therefore, when the RSA value is lowered from the reference RSA value, the relative strength of the tension state is determined by the respiratory length and / or the respiratory amplitude, which are respiratory components. When the tension is increased, both the respiratory length and the respiratory amplitude tend to decrease. Therefore, when the breathing length and the breathing amplitude are smaller than the predetermined reference breathing length and the reference breathing amplitude, the tension state is stronger than the reference tension state (tension state that should correspond to the reference RSA value). It is highly probable that the strength of the tension state is determined based on the reference breath length and the fluctuation range from the reference breath amplitude. That is, the determination is made based on the breathing length and the breathing amplitude, which are the values related to respiration, triggered by the RSA value, which is the value related to heartbeat.

Here, the reference RSA value, the reference respiration length, and the reference respiration amplitude are all determined for each driver by measuring the time variation of the heartbeat and respiration in the simulated driving section including the task of giving tension. In other words, fluctuations in heartbeat and respiration with respect to tension differ depending on the driver, and the accuracy of determining the tension state is ensured by setting a reference value for each driver.

Further, in the determination of the tension state, the heart rate, the heart rate amplitude, and the RSA value may be added in addition to the breathing length and the breathing amplitude. For example, the reference heart rate is also determined for the heart rate, and the fluctuation range of the heart rate from the reference heart rate is determined and combined with the determination. Further, the fluctuation range of the heartbeat amplitude from the reference heartbeat amplitude and the fluctuation range of the RSA value from the reference RSA value may be similarly combined with the determination. With these, improvement of judgment accuracy can be expected.

The method of determining the reference value (reference RSA value, reference breath length, reference breath amplitude, reference heart rate, reference heart rate amplitude) differs depending on what kind of tension state is desired to be determined. For example, if it is desired to determine only a relatively strong tension state, the reference value may be set small (large for the heart rate). Further, by using the value corresponding to a specific task in the simulated driving section as a reference value, it is possible to determine the strength of the tension state relatively compared with the tension state for the specific task.

Further, it is confirmed that the correlation with the combination of the RSA value, the respiratory length, the respiratory amplitude, the heart rate, and the heart rate amplitude in the tense state or the non-tension state tends to be different for each driver. This tendency can be derived from the results in the simulated driving section described above, and the physiological index is selected and the combination is determined based on the strong correlation, that is, the tendency to reproduce the change, whereby the vehicle is being driven. The physical and mental condition of the driver may be determined. According to this, since it is possible to determine the state more clearly, it is possible to perform the determination not only in the tense state but also in the non-tensioned state.

Next, an example in which the mental and physical condition of the driver is actually determined using the determination system 1 will be described.

Here, the mental and physical condition of the driver while driving the railroad vehicle, particularly the tension state, was determined. Therefore, using the determination system 1 described above, the heartbeat and respiration of the driver who is driving the vehicle in the simulated driving section including the task of giving tension (tension task) are measured, and the time variation thereof is obtained.

In the simulated driving section, simulated driving using a driving simulator was carried out in order to measure the heartbeat and respiration of the driver during the driving work. Specifically, a simple railroad operation simulator composed of a large TV monitor and a one-handle type controller was used. In the simulated driving, the driver repeatedly performed the driving task a predetermined number of times with a break. As a driving task, we set a driving section between stations with a required time of about 4/10. The driving task included a task of giving tension such as a driving motion of stopping a running vehicle at a predetermined position. In addition, in order to concentrate on simulated driving, the driver was instructed to drive at the specified speed limit according to the timetable. Here, the measurement results of the simulated driving repeatedly performed by one driver will be described.

As shown in FIG. 2, first, for the measured waveform data, the heart rate variability waveform HRV and the respiratory waveform BW were arranged on the same time axis. The heart rate variability waveform HRV was cut out for each time range corresponding to the respiratory section T separated by the respiratory start point S in the respiratory waveform BW. At this time, there was synchronization between the heart rate variability waveform HRV and the respiratory section T. Then, the amplitude of the heart rate variability waveform HRV in each breathing section T was used as the RSA value. That is, the RSA value was obtained from the heartbeat corresponding to one breath. For the RSA value, line segment data connecting points on the heart rate variability waveform HRV corresponding to each breathing start point S in time is defined, and this line segment data is subjected to conversion processing by subtracting it from the heart rate variability waveform HRV. It is preferable to obtain at. By such a conversion process, components of the blood pressure fluctuation system affected by both the sympathetic nerve and the parasympathetic nerve can be removed.

For example, here, the arithmetic mean of the RSA value, heart rate, respiratory length, and respiratory amplitude obtained through the simulated driving section described above is used as the respective reference value, and the standard deviation from the average value is used for each other than the respiratory amplitude. I asked. The reference values were referred to as a reference RSA value, a reference heart rate, a reference breathing length, and a reference breathing amplitude, respectively. In addition, from the simulated driving section, the RSA value, heart rate, breathing length, and breathing amplitude corresponding to the position during the stop operation (the point 20 seconds immediately before the stop at the station) and the position during the stop at the station where tension is less likely to occur. Was extracted, and these were compared with the standard values as shown below to determine the score.

That is, as shown in FIG. 3, +1 point when the RSA value is larger than the standard deviation with respect to the standard RSA value, +2 points when the RSA value is more than twice the standard deviation, and -1 point when the RSA value is smaller than the standard deviation. , The score was set as -2 points when it was more than twice the standard deviation, and the results other than 0 points were shown by the appearance rate for each of the stop operation and the station stop. That is, with respect to the fluctuation range from the reference RSA value, the magnitude of the RSA value with respect to the standard deviation or twice the standard deviation was discriminated and a score was given. As a result, it was found that the RSA value tends to decrease during the stop operation, which tends to cause tension. However, it was found that it is difficult to judge the tension state only by the RSA value because the RSA value is often small even when the train is stopped at the station where it is difficult to get nervous.

Further, as shown in FIG. 4A, +1 point when the heart rate is larger than the standard deviation with respect to the standard heart rate, +2 points when the heart rate is more than twice the standard deviation, and when it is smaller than the standard deviation. A score was set as -1 point and -2 points when it was more than twice the standard deviation, and the results other than 0 points were shown by the appearance rate for each of the stop operation and the station stop. The heart rate tended to increase during the stop operation, which tends to be tense.

As shown in FIG. 4 (b), +1 point when the breathing length is larger than the standard deviation with respect to the standard breathing length, +2 points when the breathing length is more than twice the standard deviation, and -1 when the breathing length is smaller than the standard deviation. A score was set as -2 points when the points and standard deviations were twice or more smaller than the standard deviation, and the results other than 0 points were shown by the appearance rate for each of the stop operation and the station stop. Breathing length tended to decrease during the stop operation, which tends to be tense.

As shown in FIG. 4 (c), a score is set as +1 point when the respiratory amplitude is more than twice the reference respiratory amplitude and -1 point when the respiratory amplitude is less than half of the reference value, and 0. The results other than the points are shown by the appearance rate for each of the stop operation and the station stop. The respiratory amplitude tended to decrease during the stop operation, which tends to be tense.

However, it was found that it is more difficult to determine the tension state alone in terms of heart rate, respiratory length, and respiratory amplitude than the above-mentioned determination by the RSA value.

Therefore, the code of the score is changed so that the score of RSA, heart rate, respiratory length, and respiratory amplitude is positive so that the one that tends to occur in a tense state is positive, that is, the score of RSA value, respiratory length, and respiratory amplitude is converted to-. Multiply by 1 and add up the scores to make a comprehensive judgment.

As shown in FIG. 5, in the comprehensive judgment, in the judgment of the score "3", the stop operation was almost in progress, and it was considered that the mental and physical condition of the driver was a relatively strong tense state. On the other hand, in the judgment that the score is negative, there is almost no one during the stop operation, and it is considered that there is a very high possibility that the tension is relatively weak.

As described above, it is possible to determine the relative strength of the tension state of the driver's mental and physical condition from both the measured driver's heartbeat and respiration data. In particular, since the determination is made based on the difference between the reference value and the predetermined value, such as using the reference RSA value and the standard deviation, the determination can be made only by the relative numerical change in the heart rate variability waveform and the respiratory waveform. That is, the accuracy of the measured value as an absolute value is not required. Therefore, the detailed calculation method of the RSA value is not particularly limited, and one may be defined from the simulated driving to the determination of the physical and mental condition of the driver. In addition, it is meaningful to judge the physical and mental condition of the driver from both heartbeat and respiration data, and even if the judgment based on the RSA value is combined with the judgment of one of the respiratory length and the respiratory amplitude, at least the RSA value is used. It is possible to judge the mental and physical condition more accurately than the judgment by. Further, it is preferable to make a determination in which both the respiratory length and the respiratory amplitude are combined, and further, the determination can be made by combining the heart rate, the RSA value, and the heartbeat amplitude as described above.

Further, as described above, since the measured value does not require accuracy as an absolute value, the acquisition of the respiratory waveform can be a simple measurement method that only detects the change in the chest circumference or abdominal circumference of the driver. A wearable sensor could be used for measurement.

Further, in the above example, the RSA value, heart rate, heart rate amplitude, respiratory length, and respiratory amplitude during the stop operation and the station stop were extracted from the simulated driving section and determined, but the determination was made in the simulated driving section. By using the reference value and standard deviation, it is possible to determine the physical and mental condition of the driver by measuring the time variation of the driver's heartbeat and breathing in the actual operation section as well. That is, the reference RSA value, the reference breathing length, the reference breathing amplitude and their respective standard deviations, and the reference heart rate and the reference heartbeat amplitude are calculated in the simulated operation and stored in the storage device 23. In other driving sections such as the operating section, the mental and physical condition of the driver can be determined in real time at a specific position. The specific position is a position for determining the mental and physical condition of the driver, which is a position on the time axis in which the time fluctuation of heartbeat and respiration is measured, but the position in the space in the driving section corresponds to the time axis. It can also be set as a position in space. In particular, in the case of railways, the travel schedule of vehicles on the operating section is set, and for example, the mental and physical condition of the driver can be determined even immediately before a specific section such as a station or railroad crossing, and an alarm may be issued in some cases. It is also possible to emit. As described above, since these reference values and standard deviations include individual differences of the driver, they are determined and used for each driver.

In the above example, the reference RSA value, the reference heart rate, the reference heart rate amplitude, the reference breathing length, and the reference breathing amplitude are determined as the arithmetic mean through the simulated driving section, but may be determined by others. For example, if the reference RSA value is determined to be the maximum value of the value acquired in the simulated driving section, the reference RSA value can be assumed to be in an almost completely relaxed state. Then, the tension state is gradually scored according to the fluctuation range in which the RSA value is lowered from the reference RSA value, and this is combined with the discrimination of the fluctuation range from the reference value such as the respiratory length in the same manner as described above. It is possible to judge the mental and physical condition.

Further, there is also a method of correcting such a fluctuation range in the case of determining the mental and physical condition by combining the fluctuation range of the RSA value from the reference RSA value. First, the breathing waveform and the heart rate variability waveform corresponding to one breath are defined as one breathing breathing waveform and one breathing heart rate variability waveform, respectively. At this time, the one-breathing breathing waveform and the one-breathing heart rate variability waveform are compared, and a correction coefficient is determined in which the higher the correlation is, the closer it is to 1, and the lower the correlation is, the closer it is to 0. Such a correction coefficient can be calculated using, for example, a correlation coefficient or a phase difference between the one-breathing breathing waveform and the one-breathing heart rate variability waveform. When the correlation coefficient is used, the absolute value of the correlation coefficient can be used as the correction coefficient. When phase difference is used, the absolute value of (π-phase difference) / π can be used as the correction coefficient. These two integrated values may be used as a correction coefficient. Then, the correction is performed by multiplying the correction coefficient related to the fluctuation range from the reference RSA value, and the determination is made in the same manner as above. The higher the correlation between the 1-breathing breathing waveform and the 1-breathing heart rate variability waveform, the higher the reliability as the RSA value tends to be. Therefore, by making such a correction, the reliability of the RSA value is reflected and the accuracy is increased. It is possible to judge the physical and mental condition of the driver well.

Further, in the above-described embodiment, the tension state at a certain time point is determined by the time variation of the heartbeat and the respiration at the time point, but the mental and physical state can also be determined based on the temporal context. For example, from a state where the RSA value is very high (for example, 4 times or more the reference RSA value), the fluctuation range (distance) from the reference RSA value is much less than the standard deviation in the next breathing interval T (see FIG. 2). In that case, it can be determined that the patient is in an extremely tense state or is psychologically upset. In addition, when breathing regularly, there is a high possibility that the patient is in a moderately tense state, which is preferable for performing a driving operation, or is in a state of decreased arousal. Therefore, if the distance from the reference breathing length of the breathing length is 10% or less in any of the four consecutive breathing sections T, it is regarded as regular breathing, and the heart rate is larger than the reference heart rate. If it is constant or increased, it is judged to be moderate tension, and if it is constant or decreased at a value smaller than the reference heart rate, it is considered to be a weaker tension state (or arousal decrease state). It can be judged. In addition, when a large breath is taken, such as when the breathing amplitude exceeds twice the standard breathing amplitude or when the breathing length is more than twice the standard deviation of the standard breathing length, the mental and physical states are switched before and after that time. It can also be determined that there was.

Here, in the five physiological indexes obtained by adding the respiratory length change rate and the heart rate change rate to the three physiological indexes of the RSA value, the respiratory length, and the heart rate, the change for the tension task for each individual driver to be measured is changed. While there was a difference in the reproduction tendency, it was found that the change in the respiratory length for the tension task was constant regardless of the individual driver. Therefore, by determining the tension state using the breathing length and other physiological indexes combined with it, which have a high tendency to reproduce changes to the tension task that differs for each driver, a more accurate determination is made. Is possible.

That is, the determination system 1 reproduces the changes in the respiratory length change rate, the heart rate (heart rate interval), and the heart rate change rate (heart rate interval change rate) RSA values corresponding to the tension task for each driver in the control unit 20. A tendency, that is, one or more of the physiological indexes showing the same change repeatedly, is selected and stored as a specific physiological index together with the respiratory length. For such selection, the change width may be set in advance and filtering may be performed automatically, or other known methods may be used. Then, along with the reference RSA value and the reference respiration length as the reference for each driver, each reference value for the specific physiological index is determined in the same manner as described above. Then, in the determination of the tension state, the fluctuation range from the corresponding reference value for the specific physiological index including the respiratory length is combined and determined in the same manner as described above.

FIG. 6A shows an example of the appearance rate of the non-tension tendency and the tension tendency in each physiological index for the tension task in the simulated driving including a plurality of tension tasks and the non-tension tasks. The left side of the bar graph of each physiological index is judged to be a tendency of non-tension state, that is, the appearance rate showing an error of being judged to be non-tension state despite being a tension task, and the right side of the bar graph is the tendency of tension state. It is the appearance rate that is judged, that is, the correct answer is shown.

The heart rate interval change rate and the respiratory length change rate were calculated and evaluated as follows. In detail, the heartbeat interval calculated in advance when the driver is estimated to be in the mental and physical state closest to the normal state is defined as "1". Then, among the heartbeat intervals calculated four times in succession for each breath, the difference from the previous time of the second to fourth heartbeat intervals excluding the first one (in the case of the second time, the difference from the first time) is all "0". When it is 0.25 ”or less, it is evaluated that the heartbeat interval is stable and regular, and this is used to judge the mental and physical condition. That is, the reference heart rate interval change rate is set to "0.25" or less, and the change rate per breath of the four consecutive heart rate intervals is evaluated. The rate of change in respiratory length can be calculated and evaluated in the same manner as the rate of change in heart rate interval.

According to this, it tends to show the correct answer in the heart rate interval as well as the breathing length. Therefore, as described above, it is compared with the comprehensive judgment B (see FIG. 6 (b)) in which the fluctuation range of the respiratory length with respect to the reference respiratory length and the fluctuation range of the respiratory length change rate with respect to the standard respiratory length change rate are combined. Therefore, the comprehensive judgment A (see FIG. 6B), which combines the fluctuation range of the breathing length with respect to the reference breathing length and the fluctuation range of the heartbeat interval with respect to the reference heartbeat interval, more correctly shows the tendency of the tension state. ..

Although it was difficult to determine the non-tension state, as in the above, the breathing length was also obtained for the second specific physiological index, which has a high tendency to reproduce changes to the non-tension task (for example, while the train is stopped) that differs for each driver. Can be used to determine the tension state.

Although the typical examples according to the present invention have been described above, the present invention is not necessarily limited to this, and can be appropriately modified by those skilled in the art. That is, a person skilled in the art will be able to find various alternative examples and modifications without departing from the attached claims.

1 Judgment system 10 Waveform measurement unit 11 Heart rate measurement sensor 12 Respiration measurement sensor 20 Control unit 21 Control device 22 Judgment device 23 Storage device

Claims (14)

It is a method to determine the mental and physical condition by calculating the RSA value as a respiratory sinus arrhythmia (RSA) component of the heartbeat from this correspondence using the heartbeat and the time variation of breathing measured by the driver while driving a railroad vehicle. ,
The time variation is measured in the simulated driving section including the tension task, and the reference respiratory length and / or the reference respiratory length and / or the physiological index including the respiratory length and / or the respiratory amplitude and the RSA value are measured together with the reference RSA value which is the reference for each driver. Determine each reference value including the reference breathing amplitude,
While measuring the time variation in the actual operation section, when the RSA value is lower than the reference RSA value at a specific position for determining the mental and physical condition, the operation is performed from the fluctuation range of the physiological index from each reference value. A method for determining a driver's mental and physical condition while driving a vehicle, which comprises determining a person's tension state. Along with the reference RSA value, the reference heart rate is determined according to the reference breathing length and / or the reference breathing amplitude.
The vehicle driving according to claim 1, wherein in the determination of the tension state, the fluctuation range of the heart rate from the reference heart rate and / or the fluctuation range of the RSA value from the reference RSA value is further combined and determined. How to determine the physical and mental condition of the driver. The method for determining the mental and physical condition of a driver while driving a vehicle according to claim 1 or 2, wherein the reference value is determined as an arithmetic mean of the corresponding physiological index through the simulated driving section. The method for determining the mental and physical condition of a driver during vehicle driving according to claim 3, wherein the determination of the tension state includes determination of the magnitude of the fluctuation range with respect to the standard deviation of the physiological index through the simulated driving section. .. The method for determining a mental and physical condition of a driver while driving a vehicle according to one of claims 1 to 4, wherein the RSA value is calculated from the heartbeat corresponding to one breath of the breath. From the physiological index further including the heart rate, the rate of change in heart rate, and the rate of change in respiratory length, one or more is selected for each driver together with the respiratory length as a specific physiological index, and the simulated physiological index is used as the specific physiological index. Determine each reference value from the measurement in the driving section,
The method for determining a mental and physical condition of a driver while driving a vehicle according to claim 1, wherein the determination of the tension state is performed based on the fluctuation range with respect to the corresponding reference value for the specific physiological index. The simulated driving section includes a non-tension task, and one or more is selected for each driver together with the breathing length from the physiological index corresponding to the non-tension task to be used as a second specific physiological index. For the specific physiological index of, each reference value is determined from the measurement in the simulated driving section.
The vehicle is being operated according to claim 6, wherein when the RSA value is higher than the reference RSA value, the determination is made based on the fluctuation range with respect to the corresponding reference value for the second specific physiological index. How to determine the physical and mental condition of the driver. It is possible to correct the fluctuation range from the reference RSA value by multiplying the correction coefficient determined by comparing the 1-respiratory breathing waveform and the 1-respiratory heart rate variability waveform corresponding to 1 breath of the respiratory waveform and the heart rate variability waveform, respectively. The method for determining the physical and mental condition of a driver while driving a vehicle according to claim 2. The method for determining a mental and physical condition of a driver while driving a vehicle according to one of claims 1 to 8, wherein the simulated driving section is given by a driving simulator. The method for determining a physical and mental condition of a driver while driving a vehicle according to any one of claims 1 to 9, wherein the time variation of breathing is obtained by measuring the chest circumference or abdominal circumference of the driver. It is a system that calculates the RSA value as a respiratory sinus arrhythmia (RSA) component of the heartbeat from this correspondence using the heartbeat and the time fluctuation of breathing measured by the driver while driving a railroad vehicle, and judges the mental and physical condition. ,
A measurement unit including a sensor for measuring the time fluctuation, and a measurement unit.
It includes a control unit that calculates a physiological index including a respiratory length and / or a respiratory amplitude and an RSA value from the time variation measured by the measuring unit.
The control unit is
From the time variation measured by the measuring unit in the simulated driving section including the tension task, the physiological index includes the reference breathing length and / or the reference breathing amplitude together with the reference RSA value which is the reference for each driver. While determining each reference value,
While measuring the time variation in the actual operation section by the measuring unit, when the RSA value is lower than the reference RSA value at a specific position for determining the mental and physical condition, the variation of the physiological index from each reference value. A driver's mental and physical condition determination system during vehicle driving, wherein the driver's tension state is determined from the width. Along with the reference RSA value, the reference heart rate is determined according to the reference breathing length and / or the reference breathing amplitude.
The vehicle operation according to claim 11, wherein in the determination of the tension state, the fluctuation range of the heart rate from the reference heart rate and / or the fluctuation range of the RSA value from the reference RSA value is further combined and determined. A system for determining the physical and mental condition of the driver inside. The control unit is
From the physiological index further including the heart rate, the rate of change in heart rate, and the rate of change in respiratory length, one or more is selected for each driver and stored as a specific physiological index, and the simulated driving section is used for the specific physiological index. While determining each reference value from the measurement in
The mental and physical condition determination system for a driver while driving a vehicle according to claim 11, wherein in the determination of the tension state, the determination is made based on the fluctuation range from the corresponding reference value for the specific physiological index. The control unit is
Based on the time variation measured by the measuring unit in the simulated driving section further including the non-tension task, one or more is selected for each driver together with the breath length from the physiological index corresponding to the non-tension task. Then, it is stored as a second specific physiological index, and each reference value for the second specific physiological index is determined, and at the same time.
When the RSA value is higher than the reference RSA value at a specific position for determining the mental and physical condition, the determination is made based on the fluctuation range from the corresponding reference value for the second specific physiological index. The mental and physical condition determination system of a driver while driving a vehicle according to claim 13.

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