JP6738458B2 - Sleep state determination device and sleep state determination method - Google Patents

Description

The present invention relates to a sleep state determination device and the like.

BACKGROUND ART Conventionally, there is known a technique for determining a sleep state by a sleep polysomnograph (PSG) from heartbeat/respiration information. In recent years, there has been a need to determine REM sleep and non-REM sleep among sleep states by a method other than PSG.

For example, an invention is disclosed in which REM sleep and non-REM sleep are determined using the standard deviation of the heart rate for each minute (for example, refer to Patent Document 1).

There is also known a sleep state estimation device that estimates a sleep state from a coefficient of variance of variance of peak intervals of a respiratory waveform and a coefficient of variance of variance of peak values (for example, see Patent Document 2).

There is also known a device that determines a sleep state stepwise by using a respiratory rate, a heartbeat, and the like (see, for example, Patent Documents 3 and 4).

Japanese Patent No. 3733133 Japanese Patent No. 4551148 Japanese Patent No. 4582642 Japanese Patent No. 4356680

The conventional technology uses the respiratory cycle/breathing interval and the respiratory peak value for evaluation, but there is a problem that it is difficult to accurately detect the sleep state from the respiratory waveform because it is input together with various noises. ..

In addition, the respiratory waveform changes in addition to the original factors of the human body due to the wearing position of the wearable sensor and the relative positional relationship between the sensor such as the sleeping position and the human body of the non-wearing sensor. When a large amount of measurement information is used, the accuracy of the final evaluation result may improve if all measurement items can be measured with high accuracy, but if there are measurement items with low accuracy, However, there was a problem that the accuracy of the final evaluation result was lowered.

For example, in Patent Document 1, Patent Document 2 and Patent Document 3, there is a problem that the influence of individual differences and judgment errors are likely to occur because they are based on the respiratory waveform. In Patent Document 4, a section in which the standard deviation of the night is 20% or more is determined as REM sleep from the largest order, but the REM appearance rate is not necessarily 20%, and a large error occurs.

Further, in Patent Document 1, although light sleep and deep sleep are discriminated, it is not possible to discriminate between non-REM sleep and REM sleep.

In view of the above-mentioned problems, the object of the present invention is, as biological information within a predetermined time of the measurement subject, for example, by using a respiratory rate within a fixed time, etc., simple and accurate, and non-REM sleep and It is an object of the present invention to provide a sleep state determination device or the like that can determine REM sleep.

In order to solve the above problems, the sleep state determination device of the present invention,
Detection means for detecting respiration or heartbeat as the biological information of the person to be measured,
Calculating means for calculating, from the detected biological information, first information indicating a deviation from the average of the respiration rate or the heart rate per unit time included in the first calculation section from getting up to getting up;
Sleep state determining means for determining, from the first information, whether the sleep state of the measurement subject is REM sleep or non-REM sleep;
It is characterized by including.

The sleep state determination method of the present invention,
A detection step of detecting breathing or heartbeat as the biological information of the measured person,
From the detected biological information, a calculation step of calculating first information indicating a deviation from an average of the respiratory rate or heart rate per unit time included in the first calculation section from getting up to getting up,
A sleep state determining step of determining from the first information whether the sleep state of the measurement subject is REM sleep or non-REM sleep;
It is characterized by including.

According to the sleep state determination device of the present invention, the breath of the subject is detected, and the respiratory rate included in the respiratory rate calculation time is output from the detected respiratory. Further, the respiratory rate variation coefficient is calculated from the average value and the standard deviation of the respiratory rate included in the variation coefficient calculation section. By comparing this respiratory rate variation coefficient with the average respiratory rate variation coefficient, which is the average value of the respiratory rate variation coefficients from getting up to getting up, the sleep state of the measurement subject can be determined.

As a result, the sleep state can be determined using the respiratory rate as the biological information of the measurement subject. This makes it possible to appropriately determine the sleep state by using a simple device that calculates the respiratory rate.

It is a figure for explaining the whole in a 1st embodiment. It is a figure for explaining the functional composition in a 1st embodiment. It is a figure showing an example of data composition of a breathing rate table in a 1st embodiment. It is a figure which shows an example of the data structure of the variable table in 1st Embodiment. It is a figure which shows the data flow of the area respiratory rate output process in 1st Embodiment. It is a figure which shows the data flow of sleep state determination processing in 1st Embodiment. It is a figure for demonstrating the agreement of determination in 1st Embodiment. It is the figure which showed the respiration rate in 1st Embodiment, the coefficient of variation, and the plot of the determination result. It is a figure for demonstrating the agreement of determination in 1st Embodiment. It is a figure for demonstrating the agreement of determination in 2nd Embodiment. It is the figure which showed the respiration rate in 2nd Embodiment, the coefficient of variation, and the plot of the determination result. It is a figure for demonstrating the agreement of determination in 2nd Embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. It should be noted that the present embodiment describes an example of the invention and does not limit the content of the invention.

[1. First Embodiment]
[1.1 System appearance]
First, the first embodiment will be described. FIG. 1 is a diagram for explaining how to use the sleep determination system. As shown in FIG. 1, the sleep determination system 1 includes a detection device 3 placed between the floor of the bed 10 and the mattress 20, and a processing device 5 for processing a value output from the detection device 3. It is equipped with. The detection device 3 and the processing device 5 constitute a sleep state determination device.

When the person to be measured P is present on the mattress 20, the detection device 3 detects the body movement (vibration) of the person to be measured P via the mattress 20. Then, based on the vibration detected as the biometric information, the respiration of the subject P (the respiration rate within a predetermined time) is detected (output). In the present embodiment, the detected respiration (number) is wirelessly transmitted to the processing device 5 (for example, a computer or the like), but is integrally formed by providing the detection device 3 with a display unit or the like. Good. Moreover, since the processing device 5 may be a general-purpose device, the processing device 5 is not limited to an information processing device such as a computer, and may be configured by a device such as a tabread or a smartphone.

Here, the detection device 3 is formed in a sheet shape so as to have a small thickness. As a result, even if it is placed between the bed 10 and the mattress 20, it can be used without causing the person P to be measured to feel uncomfortable.

It should be noted that the detection device 3 only needs to be able to detect the breathing of the measurement subject P as biological information. In the present embodiment, the respiration is detected based on the body movement. However, for example, the breathing sound is detected by using the voice sensor, the body movement of the person to be measured P is detected by the infrared sensor, or the distortion is detected. An actuator with a gauge may be used.

[1.2 Functional configuration]
Next, the mechanical configuration of the sleep determination system 1 will be described with reference to FIG. The sleep determination system 1 in the present embodiment is configured to include the detection device 3 and the processing device 5, and each functional unit (processing) may be realized by any one other than the breath detection unit 200.

In the sleep determination system 1, the respiration detection unit 200, the storage unit 300, the input unit 400, and the display unit 500 are connected to the control unit 100 via a bus.

The control unit 100 is a functional unit for controlling the operation of the sleep determination system 1, and includes a control circuit such as a CPU necessary for the sleep determination system 1. The control unit 100 realizes various processes by reading and executing various programs stored in the storage unit 300. Although the control unit 100 operates as a whole in the present embodiment, it is provided in each of the detection device 3 and the processing device 5.

The breath detection unit 200 is a functional unit for detecting the breath of the measurement subject. In this embodiment, it is a sensor unit for detecting vibration. The breathing of the measurement subject is detected from the vibration (body movement) detected by the sensor unit. Further, by using the sensor unit, it is possible to detect body movements other than respiration of the person to be measured P, such as turning over and heartbeat.

The respiration detection unit 200 in the present embodiment detects, for example, the vibration (body motion) of the measurement subject by the pressure sensor and detects the respiration from the vibration, but the position of the center of gravity (body motion) of the measurement subject is measured by the load sensor. Respiration may be detected based on the change of, or by providing a microphone, the respiration may be detected based on the sound picked up by the microphone. That is, any of the conventional sensors may be used to detect the respiratory rate of the measurement subject.

The storage unit 300 is a functional unit that stores various data and programs for operating the sleep determination system 1. The control unit 100 realizes various functions by reading and executing the program stored in the storage unit 300. Here, the storage unit 300 is composed of, for example, a semiconductor memory, a magnetic disk device, or the like.

The storage unit 300 also stores a breathing rate table 302 and a variable table 304. In addition, a respiratory rate output program 310 and a sleep state determination program 312 are stored as programs.

The breathing rate table 302 is a table that calculates and stores the breathing rate per unit time from the breaths detected by the breathing detection unit 200. Here, as the unit time, the time of the section for calculating the respiratory rate is set, such as “20” seconds, “30” seconds, and “1” minutes. In the present embodiment, as shown in FIG. 3, the respiratory rate every 60 seconds is detected and stored.

The variable table 304 is an area in which various thresholds and variables are stored. For example, the threshold value α (for example, “1.2”) and the average respiratory rate variation coefficient C (for example, “0.06”) stored in FIG. 4 are stored. In addition to this, temporarily used variables are also stored.

The average respiratory rate variation coefficient C stores an average respiratory rate variation coefficient for one night (one sleep). The coefficient C is calculated from the respiratory rate in one night, but may be constantly calculated and updated based on the acquired value, for example.

The input unit 400 is a functional unit for the measurer to give instructions and operations to the sleep determination system 1. For example, it is composed of operation buttons, a touch panel, a voice input device, and the like.

The display unit 500 is a functional unit that displays a sleep state and an evaluation, and displays the operation of the sleep determination system 1. For example, it is configured by a display device such as a liquid crystal display.

[1.3 Process flow]
Next, the flow of processing of the sleep determination system 1 according to this embodiment will be described.

[1.3.1 Breathing rate output processing]
First, the breathing rate output process of outputting the breathing rate of the measurement subject will be described with reference to FIG. The breathing rate output process is a process that is implemented by reading the breathing rate output program 310 in FIG. 2 and executing it by the control unit 100.

Respiration is detected by the respiration detection unit 200 (step S102). Then, it is determined whether or not the respiratory rate calculation time has elapsed (step S104). Here, when the respiratory rate calculation time has elapsed (step S104; Yes), the number of breaths detected during the respiratory rate calculation time is output to the respiratory rate table 302 as the respiratory rate (step S106). This process is repeatedly executed until the breathing rate output process is completed (step S108; No→step S102).

[1.3.2 Sleep State Determination Processing]
Next, the sleep state determination process will be described with reference to FIG. The sleep state determination process is a process implemented by the sleep state determination program 312 in FIG. 2 being read and executed by the control unit 100.

First, the respiratory rate An is calculated by executing the respiratory rate calculation process described above (step S202). Here, the calculated respiration rate is the respiration rate per unit time.

Then, the respiratory rate variation coefficient Bn is calculated from the calculated respiratory rate (step S204). In the method of calculating the respiratory rate variation coefficient Bn, first, the respiratory rate average value and the standard deviation of each section of the respiratory rate variation coefficient calculation section are calculated. That is, based on a plurality of sections before and after a certain time n, the respiratory rate average value and the respiratory rate standard deviation at the time n are calculated, and the number obtained by dividing the standard deviation by the average value is calculated as the respiratory rate variation coefficient Bn.

For example, a method of calculating including seven sections before and after each (7 minutes before and after) will be described. First, the respiratory rate average value Xn in the respiratory rate variation coefficient calculation section is calculated from the respiratory rate An in each section.
Next, the standard deviation Yn is calculated from the respiratory rate An.
Although the denominator calculates the standard deviation by using n-1, the standard deviation may be calculated by using n.
As a result, the respiratory rate variation coefficient Bn is calculated. The time for calculating the coefficient of variation is usually 3 minutes to 25 minutes.

At this time, if one section is for 20 seconds, Bn is calculated from the respiratory rate in a little over 2 minutes before and after. Further, if one section is 1 minute, Bn is calculated from the respiratory rate in 7 minutes before and after. Note that the number of sections for calculating Bn may be any number of sections. That is, it is only necessary that the respiratory rate variation coefficient Bn can be calculated based on the respiratory rate before and after the sleep state determination time.

Next, the average respiratory rate variation coefficient C is calculated (step S206). Here, as the average respiratory rate variation coefficient C, the average value of the overnight respiratory rate variation coefficient Bn is calculated. That is, for the respiratory rate variation coefficient Bn calculated in step S204, an average value for one night is calculated and updated.

Next, the calculated respiratory rate variation coefficient Bn is compared with the average respiratory rate variation coefficient C (step S208). Here, for adjustment, a value obtained by multiplying the average respiratory rate variation coefficient C by a threshold value α is compared with the respiratory rate variation coefficient Bn.

At this time, when Bn is C×α or more, the sleep state is determined as REM sleep (step S208; Yes→step S210), and in other cases, it is determined as non-REM sleep (step S212).

Here, as the threshold value, a value of "1" to "1.5" is usually used. In the case of "1", a large amount of REM sleep will be detected, and in the case of "1.5", a small amount of REM sleep will be detected. It is preferable to set an appropriate threshold according to the condition of the person to be measured.

For example, when the person to be measured has a sleep disorder such as an apnea disorder, breathing disorder occurs when the apnea occurs (as an example, an increase in respiratory rate due to return to breathing or the like). In this case, the determination of REM sleep increases. By setting a high threshold for such a person to be measured, it becomes possible to more appropriately determine the sleep state.

The sleep state determination may not be performed in the awake state. That is, when the person to be measured is determined to be awake, the sleep state may be determined to be awake. Here, whether or not the person to be measured is awake can be determined based on the breathing rate, or the awake state can be separately determined by the body movement detection sensor.

[1.4 Example]
Subsequently, an example using the sleep determination system 1 according to the present embodiment will be described. In the present embodiment, as shown in FIG. 1, a device using a sheet-type body vibrometer (SBV) for detecting respiration is placed under the person to be measured and breathing is performed from the body movement of the person to be measured. Detected and executed.

FIG. 7 is a diagram for explaining a situation in which a sleep state is determined by using the present embodiment (SBV) and a case in which an expert determines a sleep state by using a sleep polysomnograph (PSG). ..

This data is obtained from the data of 6 subjects for 2 nights. The basic characteristics of the test subjects are 2 males, 4 females, the age of 30-40s, the height of 155-170cm, and the weight of 49-62kg.

FIG. 7 shows how the awakening (Wake), REM sleep (REM), and non-REM sleep (NREM) of each of the data of 12 nights (6 persons×2 nights) were determined. Here, when the determination result using the method of the present embodiment and the determination result of the sleep state when using PSG are matched, the Wake138+REM898+NREM2873=3909 sections match among the 5227 sections, and the matching rate is It shows a high agreement rate of 74.8%.

This is an average value, and the matching rate can be further increased by adjusting the threshold value α for each individual, for example.

FIG. 8A is a diagram in which the number of breaths per unit time in one subject is plotted, and the unit time is 1 minute here. FIG. 8(b) is a diagram showing the relationship between the respiratory rate variation coefficient per unit time and the average respiratory rate variation coefficient, and FIG. 8(c) shows that the sleep state is determined from the respiratory rate variation coefficient. It is a figure. Here, in FIG. 8C, the thin line indicates the determination of the sleep state by the PSG, and the circles (○) indicate the three-stage determination of the sleep state according to the present embodiment: “wake (Wake), REM sleep ( REM), non-REM sleep (NREM)”. Further, the thin lines indicate awakening (Wake), REM sleep (REM), and non-REM sleep (Stage 1 to Stage 4) when PSG is used. Further, FIG. 9 is a table showing the agreement of the sleep states determined by the PSG and the SBV of the example shown in FIG.

Among all 484 sections, the determination by PSG and SBV coincided with each other in the Wake13+REM146+NREM237=396 section, showing an extremely high coincidence rate of 81.8%. As described above, according to the present embodiment, it is possible to appropriately determine the sleep state of the measurement subject, such as REM sleep and non-REM sleep, even though the device is a simple device.

[2. Second Embodiment]
Next, the second embodiment will be described. The second embodiment has the same functional configuration and processing as the first embodiment, but a case will be described in which the standard deviation is used as the determination value instead of the variation coefficient.

That is, the determination is made based on the comparison between the standard deviation Yn calculated in the first embodiment and the average standard deviation which is an average of overnight. Specifically, the standard deviation Yn is calculated in step S204 of FIG. 6, and the overnight average standard deviation Cy is calculated in step S206.

Then, in step S208, it is determined whether the standard deviation Yn is greater than or equal to the average standard deviation Cy, and it is determined whether the sleep state is REM sleep or non-REM sleep. Here, similarly to FIG. 6, the average standard deviation Cy may be multiplied by a predetermined threshold value.

An example when the determination is made in the second embodiment will be described with reference to the drawings. FIG. 10 is a diagram for explaining a situation in which a sleep state is determined by using the present embodiment (SBV) and a case in which an expert determines a sleep state by using a sleep polysomnograph (PSG). ..

This data is obtained from the data of 6 subjects for 2 nights. The basic characteristics of the test subjects are 2 males, 4 females, the age of 30-40s, the height of 155-170cm, and the weight of 49-62kg.

FIG. 10 shows how the data of 12 nights (6 persons×2 nights) were determined for each of awakening (Wake), REM sleep (REM), and non-REM sleep (NREM). Here, when the determination result using the method of the present embodiment and the determination result of the sleep state when using PSG are matched, the Wake138+REM904+NREM2893=3935 section is matched among all 5227 sections, and the concordance rate is high. It shows a high agreement rate of 75.3%.

FIG. 11A is a diagram in which the number of breaths per unit time in one subject is plotted, where the unit time is 1 minute. FIG. 11B is a diagram showing the relationship between the standard deviation per unit time and the average standard deviation, and FIG. 11C is a diagram showing that the sleep state is determined from the standard deviation. Here, in FIG. 11C, the thin line indicates the determination of the sleep state by the PSG, and the circles (○) indicate the three-stage determination of the sleep state according to the present embodiment: “wake (Wake), REM sleep ( REM), non-REM sleep (NREM)”. Further, the thin lines indicate awakening (Wake), REM sleep (REM), and non-REM sleep (Stage 1 to Stage 4) when PSG is used. Further, FIG. 12 is a table showing the agreement of the sleep states determined by the PSG and the SBV of the example shown in FIG. 11.

Of the total 484 sections, the determination by PSG and SBV coincided in the Wake13+REM153+NREM240=406 section, and the coincidence rate was 83.9%, which is an extremely high coincidence rate. As described above, according to the present embodiment, by using the standard deviation, it is possible to appropriately determine the sleep state such as REM sleep and non-REM sleep of the measurement subject, although the device is simple. ..

[3. Modification]
Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and a design etc. within the scope not departing from the gist of the present invention are also claimed. include.

In the above-described embodiment, the respiratory rate is used as an example of the biometric information, but the heart rate may be used as the biometric information of the person to be evaluated in the same manner. That is, the same sleep determination can be performed by using the detected respiration as the heart rate and the respiration rate as the heart rate.

By using the heart rate (number) instead of the respiration (number) as the biometric information, it is possible to appropriately evaluate sleep by using a conventional device that detects a heart rate, such as an electrocardiograph. There is.

1 Sleep Determination System 3 Detection Device 5 Processing Device 10 Bed 20 Mattress 100 Control Unit 200 Breath Detection Unit 300 Storage Unit 302 Respiration Rate Table 304 Variable Table 310 Respiration Rate Output Program 312 Sleep State Determination Program 400 Input Unit 500 Display Unit

Claims (4)

A detection means for detecting a heartbeat as the biological information of the person to be measured,
From the detected biometric information, a standard deviation or a coefficient of variation showing the deviation from the average of the heart rate per unit time included in the first calculation section from the time of getting up to getting up is calculated, and Calculating means for calculating an average standard deviation or an average coefficient of variation, which is an average value of the standard deviation or the coefficient of variation ;
By comparing the standard deviation and a value obtained by multiplying the average standard deviation by a coefficient in the range of 1 to 1.5, or by changing the coefficient of variation and the average coefficient of variation in the range of 1 to 1.5. by comparing the value obtained by multiplying a certain coefficient, and sleep state determining means for determine a constant or REM sleep or Roh Nremu sleeping as sleeping state of the subject,
A sleep state determination device comprising: A detection unit that detects respiration as biological information of the measurement subject,
From the detected biological information, a standard deviation indicating the deviation from the average of the respiration rate per unit time included in the first calculation section from wake up to wake up is calculated, and the standard deviation from wake up to wake up Calculating means for calculating the average standard deviation, which is the average value of
By comparing the standard deviation and a value obtained by multiplying the average standard deviation by a coefficient in the range of 1 to 1.5, sleep state determination for determining whether the sleep state of the measurement subject is REM sleep or non-REM sleep Means and
A sleep state determination device comprising: A detection step of detecting a heartbeat as the biological information of the measurement subject,
From the detected biometric information, a standard deviation or a coefficient of variation showing the deviation from the average of the heart rate per unit time included in the first calculation section from the time of getting up to getting up is calculated, and A calculation step of calculating an average standard deviation or an average coefficient of variation that is an average value of the standard deviation or the coefficient of variation ;
By comparing the standard deviation and a value obtained by multiplying the average standard deviation by a coefficient in the range of 1 to 1.5, or by changing the coefficient of variation and the average coefficient of variation in the range of 1 to 1.5. by comparing the value obtained by multiplying a certain coefficient, and sleep state determining step of determine a constant or REM sleep or Roh Nremu sleeping as sleeping state of the subject,
A sleep state determination method comprising: A detection step of detecting respiration as biological information of the measurement subject,
From the detected biometric information, a standard deviation indicating the deviation from the average of the respiration rate per unit time included in the first calculation section from wake up to wake up is calculated, and the standard deviation from wake up to wake up A calculation step for calculating the average standard deviation, which is the average value of
By comparing the standard deviation and a value obtained by multiplying the average standard deviation by a coefficient in the range of 1 to 1.5, sleep state determination for determining whether the sleep state of the subject is REM sleep or non-REM sleep Steps,
A sleep state determination method comprising: