JP2008080071A - Evaluation device for quality of sleep - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an evaluation device for quality of sleep, comprising a living body signal detection means disposed under an examinee on bed, capable of extracting heartbeat signals out of detected living body signals to compute the intensity of the heartbeat signals, and taking irregularity of the obtained heartbeat intensity signals for a sleep evaluation index. <P>SOLUTION: The evaluation device for quality of sleep is provided with a heartbeat signal detection means to detect the heartbeat signals from the examinee, a heartbeat intensity determination means to determine the heartbeat intensity signals based on the detected heartbeat signals, a heartbeat intensity dispersion value determination means to determine the dispersion value of data within prescribed time for the heartbeat intensity signals determined, and a sleep evaluation means to evaluate the quality of sleep based on the average value of the heartbeat intensity dispersion value and the dispersion value. The sleep evaluation means takes the square sum of the average value of the heartbeat intensity dispersion value and the dispersion value, or square-root of the sum of squares for the index for evaluation of sleep. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sleep quality evaluation apparatus that analyzes sleep, which is an important requirement in health management, and evaluates the sleep quality.

  As society becomes more complex and sophisticated, insomnia has increased dramatically due to the stress caused by trying to cope with the situation. At present, it is said that about 20-30% of the people are prone to insomnia and insomnia, and they are susceptible to stress such as shift work due to changes in social structure and intensifying competition in economic activities. Work posture will increase, and physical and mental disorders caused by sleep will increase more and more.

  Sleep is said to be a barometer of health, and if you can wake up comfortably with a good sleep, you will feel refreshed when you wake up. On the other hand, if you have insomnia or insomnia, or if you are forced to sleep with a reversed night / day life due to late-night work, the mood after waking up is often poor. That is, regardless of whether they are conscious or unconscious, the state of sleep affects the mood and behavior at the time of subsequent awakening, which in turn determines the quality of activity after awakening.

  Sleep is an important factor in our physical and mental activities, and it can be said that if we can get good sleep, we can guarantee daily activities that are physically and mentally healthy. If you can have a comfortable sleep, you will be mentally stable, and if you are mentally stable, you can have a comfortable sleep. That is, if it is possible to know the quality of sleep from the biological signal information at the time of sleep of the subject, it becomes possible to grasp whether the sleep is comfortable, that is, the feeling of sleep, and the mental health level In other words, it is thought that mental health can be grasped.

  As a conventional method of grasping the quality of sleep, a method of grasping the transition of sleep stages such as REM sleep and non-REM sleep and determining the quality of sleep from the transition and appearance is common. For example, the transition of the sleep stage is recorded by the PSG method, and the ratio of the deep sleep stages (the third and fourth stages of non-REM sleep) among the sleep stages is calculated from the result, and whether or not sufficient sleep is taken Judgment.

  In the case of young and middle-aged subjects, the quality of sleep can be evaluated within the practically acceptable range according to the above evaluation criteria. On the other hand, depending on the subject such as the elderly, even if the deep sleep stage (the third and fourth stages of non-REM sleep) may not appear in the sleep stage, the person's impression after sleep is a comfortable sleep. There are also cases where it cannot be determined from the ratio of the deep sleep stages (the third and fourth stages of non-REM sleep) among the sleep stages as described above. Thus, when it is going to determine the quality of sleep using a sleep step, there exists a problem that it is inconsistent with a test subject's experience in many cases.

  In addition, when determining the quality of sleep from the transition and appearance of sleep stages during sleep, there is a problem that complicated processing is required to grasp the sleep stages. In particular, in the method of obtaining the sleep feeling of the subject by the PSG method, it is necessary to collect measurement data by attaching an electrode to the subject's head and is difficult to use on a daily basis. Since the equipment is expensive, it is not practical for the subject to use it regularly in hospital life or at home.

  As described above, there is a problem that the method of grasping the quality of sleep by measuring the transition and appearance of the sleep stage often does not match the subject's experience. Moreover, in order to grasp | ascertain a sleep stage, a complicated process is required, and it is difficult to use constantly at home, and it is not practical.

  In view of the above problems, the present invention makes it possible to easily grasp the quality of sleep during sleep without detecting the sleep stage, and without subjecting the subject physically and mentally. An object of the present invention is to provide a device for evaluating the quality of practical sleep that can be used in a practical manner.

  In order to achieve the above object, a sleep quality evaluation apparatus according to a first solving means of the present invention includes a heartbeat signal detecting means for detecting a heartbeat signal from a subject, and a heartbeat for calculating a heartbeat intensity signal from the detected heartbeat signal. The quality of sleep from the intensity calculating means, the heart rate intensity dispersion value calculating means for calculating the variance value of the calculated heart rate intensity signal within a certain time, and the average value and the variance value of the above heart rate intensity variance values during sleep And a sleep evaluation means for evaluating the above.

  According to the first solving means described above, the sleep quality evaluation device of the present invention comprises a heartbeat signal detection means, a heartbeat intensity calculation means, a heartbeat intensity variance value calculation means, and a sleep evaluation means, Sleep quality can be evaluated from the average value of heart rate intensity variance and its variance, so it is easy to understand and evaluate sleep quality without the need for complicated processing steps such as detecting the sleep stage. can do.

  The second solving means is the sleep quality evaluating apparatus of the first solving means, wherein the sleep evaluating means uses the sum of the average value of the heart rate intensity dispersion values and the dispersion value as an index of sleep evaluation. It is characterized by that.

  A third solving means is the sleep quality evaluating apparatus of the first solving means, wherein the sleep evaluating means calculates an average value of the heartbeat intensity variance values and a square sum of the variance values or a square root of the square sum. It is used as an index for sleep evaluation.

  A fourth solving means is the sleep quality evaluation apparatus of the first solving means, wherein the heartbeat signal detecting means detects a biological signal by means of a biological signal detecting means arranged under the body of the subject. A heartbeat signal is extracted from the obtained biological signal.

  The fifth solving means is the sleep quality evaluation apparatus according to the fourth solving means, wherein the biological signal detecting means is composed of a slight differential pressure sensor and a biological signal detecting unit, and is housed inside the biological signal detecting unit. A biological signal is detected by detecting a change in the pressure of the air that is detected by a fine differential pressure sensor.

  A sixth solving means is the sleep quality evaluation apparatus according to the first solving means, wherein the heartbeat signal detecting means is a sphygmograph or a sphygmomanometer worn on the wrist or upper arm.

  As described above, the sleep quality evaluation apparatus of the present invention calculates the heart rate intensity of the heart rate signal by the heart rate intensity calculating means, calculates the variance value of the heart rate intensity signal within a predetermined time, and averages the variance values during sleeping. The sleep quality is evaluated with the value and the dispersion value, and it is possible to easily evaluate the sleep quality without requiring complicated processing steps such as detecting the sleep stage.

  In addition, if the biological signal detection means that does not restrain the subject is used as the heartbeat signal detection means, it becomes possible to grasp the activity of the exchange nervous system without placing a physical and mental burden on the subject. It is possible to grasp and evaluate the quality of sleep while living a normal life.

  The method and apparatus of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by a present Example.

  FIG. 1 is a block diagram showing the configuration and steps of an embodiment of the sleep quality evaluation apparatus of the present invention, and FIG. 1B is a partial cross-sectional view seen from the direction of the arrow. The biological signal detection means 1 shown in FIG. 1 is a detection means for detecting a minute biological signal of the subject without restraining the subject, and the biological amplification is performed so that the signal can be processed in a later processing step by the signal amplification shaping means 2. The signal detected by the detection means 1 is amplified, and unnecessary signals such as respiration are removed by a band pass filter or the like.

  The biological signal detection means 1 includes a pressure sensor 1a and a pressure detection tube 1b, and constitutes a biological signal detection means that does not restrain the subject. The pressure sensor 1a is a sensor that detects minute fluctuations in pressure. In this embodiment, a low-frequency condenser microphone type is used. However, the pressure sensor 1a is not limited to this, and has an appropriate resolution and dynamic range. If it is.

  The low-frequency condenser microphone used in this example is replaced with a general acoustic microphone that does not consider the low-frequency area. This is a significant improvement and is suitable for detecting minute pressure fluctuations in the pressure detection tube 1b. In addition, it is excellent for measuring minute differential pressure, has a resolution of 0.2 Pa and a dynamic range of about 50 Pa, and is several times the performance of a fine differential pressure sensor using a ceramic that is normally used. It is suitable for detecting a minute pressure applied to the pressure detection tube 1b through a biological signal through the body surface. The frequency characteristic shows an almost flat output value between 0.1 Hz and 20 Hz, and is suitable for detecting minute biological signals such as heartbeat and respiration rate.

  As the pressure detection tube 1b, a tube having an appropriate elasticity so that the internal pressure fluctuates corresponding to the pressure fluctuation range of the biological signal is used. Further, in order to transmit the pressure change to the fine differential pressure sensor 1a at an appropriate response speed, it is necessary to appropriately select the volume of the hollow portion of the pressure detection tube 1b. When the pressure detection tube 1b cannot satisfy the appropriate elasticity and the volume of the hollow portion at the same time, the hollow portion of the pressure detection tube 1b is loaded with a core wire having an appropriate thickness over the entire length of the tube, and the volume of the hollow portion is appropriately set. Can take.

  The pressure detection tube 1b is disposed on a hard sheet 8 laid on the bed 7, and an elastic cushion sheet 9 is laid thereon, on which a subject lies down. Note that the pressure detection tube 1b may have a structure in which the position of the pressure detection tube 1b is stabilized by being incorporated in the cushion sheet 9 or the like. Note that the bedding such as a futon is not shown here.

  In this embodiment, two sets of biological signal detection means 1 are provided, one of which detects a biological signal of the chest part of the subject and the other of the subject's buttocks part of the subject, Although it is configured to stably detect the biological signal regardless of the posture, the pressure detection tube 1a may be disposed only in one of the chest region and the buttocks region.

  The biological signal detected by the biological signal detection means 1 is a signal in which various vibrations emitted from a human body are mixed, and includes a heartbeat signal, a respiratory signal, a wake-up signal, and the like. The biological signal detected by the biological signal detecting means 1 is amplified by the signal amplification and shaping means 2, and an appropriate signal shaping process is performed, for example, by removing a signal having an apparently abnormal level.

  The output signal of the signal amplification shaping means 2 includes various signals generated by the living body such as heartbeat, respiration, and body movement, and the heartbeat signal detection means 3 detects the heartbeat signal using a bandpass filter.

  The heart rate intensity signal detection means 4 is composed of an automatic gain control means 41 and a signal intensity calculation means 42. The automatic gain control means 41 is a so-called AGC circuit that automatically performs gain control so that the output of the heartbeat signal detection means 3 falls within a predetermined signal level range. The gain value (coefficient) at this time is used as the signal intensity. It outputs to the calculating means 42. For gain control, for example, the gain is set so that the amplitude of the output signal decreases when the peak value of the signal exceeds the upper threshold, and the gain is increased when the peak value falls below the lower threshold. is doing.

  The signal strength calculation means 42 calculates the signal strength from the gain control coefficient applied to the biological signal in the automatic gain control means 41. It is preferable to set a function indicating the signal strength so that the gain value obtained from the AGC circuit is set to be small when the signal size is large and to be large when the signal size is small.

  The sleep index value evaluation unit 5 includes a heart rate intensity variance calculation unit 51 and a sleep index value calculation unit 52, and is a unit that calculates an index value for evaluating the quality of sleep from the value of the heart rate intensity variance value. The heart rate intensity variance calculating unit 51 calculates the variance value (standard deviation) of the 60-second data of the heart rate obtained by the heart rate intensity signal detecting unit 4. The heart rate intensity data is measured every second, and the data for 60 seconds, that is, the variance value of 60 heart rate intensity data, is determined from that point. As a result, time-series data at intervals of 1 second of variation (dispersion value) in heart rate intensity is obtained. Here, the variance value indicates a so-called statistical variance, and a standard deviation may be used instead of the variance.

  Subsequently, in the sleep index value calculating means 52, the average value and the variance value are obtained for all the sleeping data of the variance value of the data obtained by the heart rate intensity variance calculating means 51, and the average value and the variance value of the heart rate intensity variance values are obtained. Are used to calculate an index value indicating the quality of sleep and evaluate the quality of sleep. The result is output to the data storage / output means 6 to be displayed on a monitor device (not shown) or printed on a printing device.

  In the above-described embodiment, an example in which a hollow tube is used as the biological signal detection means has been described. However, the air mat shown in FIG. 2 can also be used as the detection means. Here, the biological signal detection means 10a is an air mat in which air is enclosed, and an air tube 10b is connected to one end of the biological signal detection means 10a and is connected to the fine differential pressure sensor 10c. As the fine differential pressure sensor 10c, the same sensor as that described in the case of the biological signal detection means using the hollow tube shown in FIG. 1, that is, the fine differential pressure sensor 1a can be used.

  Next, the procedure for evaluating the quality of sleep will be described with reference to FIGS. The signal amplification and shaping means 2 amplifies and shapes the signal from the biological signal detected by the biological detection means 1, and then the heartbeat signal detection means 3 removes unnecessary signals such as respiration by a bandpass filter or the like. Is detected. As shown in FIG. 3, a peak value of the detected heartbeat signal is controlled by controlling the gain of the heartbeat signal by the automatic gain control means (AGC) 41 in the heartbeat intensity signal detection means 4. The heart rate signal intensity is calculated using this peak value. By using the automatic gain control means (AGC) 41, the abnormal value of the heart rate intensity signal is eliminated, thereby improving the reliability of data processing.

  The heart rate intensity variance value calculating unit 51 of the sleep index value evaluating unit 5 traces back the heart rate intensity signal calculated by the heart rate intensity signal detecting unit 4 from each time point for 60 seconds as shown in the flowchart of FIG. Calculate the variance (standard deviation) of the intensity data. FIG. 4 shows continuously the dispersion value (standard deviation) of the heart rate intensity of the subject who is sleeping. FIG. 4 shows time-series data of the standard deviation of the heart rate intensity, and the unit of the standard deviation of the heart rate intensity in FIG. 4 is a percentage based on the standard deviation of the maximum possible heart rate intensity.

  The present inventors have confirmed through experiments that the fluctuation tendency of the variance value (standard deviation) of the heart rate intensity is highly correlated with the transition of the sympathetic nervous system of the autonomic nervous system. Since the transition of the autonomic nervous system activity reflects the transition of the sleep state while sleeping, the transition of the dispersion value of the heart rate intensity can reflect the transition of the sleep state. Therefore, if the value of the variance value (standard deviation) of the heart rate intensity is low and the fluctuation range is small, it is judged that the sleep is relaxed, and the level of the variance value of the heart rate intensity and the fluctuation are judged for the sleep quality. It is an indicator.

  In the sleep index value calculation means 52, an average value and a variance value of all the data during sleeping shown in FIG. 4 are obtained. Using these two parameters, an index value indicating sleep quality and a sleep index value are calculated. The smaller this value, the better the quality of sleep.

An index value P indicating the quality of sleep is obtained by the following equation.
Here, P is an index value indicating the quality of sleep, A ₀ is an average value of the heart rate intensity variance value during the whole sleeping period, and S is a standard deviation (variance value) of the heart rate intensity variance value during the whole sleeping period. The smaller the index value P indicating the quality of sleep, the better the sleep. Condition index value P indicating the quality of sleep is small is a condition that the standard deviation S of the entire sleeping dispersion value of the average value A ₀ and heart strength of the entire sleeping dispersion value of the pulse strength is reduced is there.

  If the index value P indicating the quality of sleep is a small value, the dispersion value of the heart rate intensity, that is, the fluctuation of the heart rate intensity is small in the whole time during sleeping, or the fluctuation of the fluctuation of the heart rate intensity is the circle time during sleeping However, it is possible that the case is small or both are small. From this, when the variation in heart rate is stable and small, the index value P indicating the quality of sleep is small, and it can be determined that the sleep is stable, in other words, comfortable sleep.

The index value P indicating the quality of sleep is not limited to the above formula, and any index value P may be used as long as it indicates that the variation in heart rate intensity is small and stable. Incidentally, the following equation may be used to obtain the index value P indicating the quality of sleep.
Here, P is an index value indicating the quality of sleep, A ₀ is an average value of the heart rate intensity variance value during the whole sleeping period, and S is a standard deviation (variance value) of the heart rate intensity variance value during the whole sleeping period.

  In the description of the present embodiment, as a method for detecting a heartbeat signal, a method for extracting a heartbeat signal from a biological signal obtained by a biological signal detection means placed under the body of the subject has been shown. The above-described biological signal detection means constituting the present embodiment does not require a wearing object that restrains the body of the subject and a signal cord connected to these wearing objects, and does not disturb the sleeping of the subject. Also, by providing the device with a function such as a timer, an operation such as turning on the power is unnecessary, and the subject's biological signal can be acquired without any operation by the subject.

  However, the method for detecting a heartbeat signal is not limited to the configuration described in the present embodiment, and any detection means that can continuously obtain a heartbeat signal or a signal equivalent to a heartbeat signal can be used. For example, it can be used as the biological signal detecting means of the present invention as long as it is a heart rate meter, a pulse meter or a pulse meter of the type worn on the body and can continuously record data.

  The sleep quality evaluation apparatus of the present invention is a method for obtaining the heartbeat signal intensity of a subject and obtaining an index value of sleep quality from the variation (dispersion) of the intensity. Since it is unnecessary, a highly accurate device is realized with a simple configuration for grasping and evaluating the quality of sleep.

  In addition, since it is a device that makes it possible to grasp the quality of sleep without restraining the subject or with a relatively light burden, it can be used without difficulty in daily life. It is feasible to understand and evaluate the quality of sleep that was used only in general fields or medical fields, and is expected to be useful for comprehensive health management. There is a big thing.

It is a block diagram which shows the process of calculating | requiring the index value of sleep quality in the sleep quality evaluation apparatus of this invention. It is a top view which shows another biological signal detection means. It is a flowchart which shows the procedure which calculates the index value which evaluates the quality of sleep. It is a graph which shows the time series data of the dispersion | distribution value of the heart rate strength by the sleep quality evaluation apparatus of this invention.

Explanation of symbols

1 Biological signal detection means (pressure detection means)
DESCRIPTION OF SYMBOLS 1a Differential pressure sensor 1b Pressure detection tube 2 Signal amplification shaping means 3 Heart rate signal detection means 4 Heart rate intensity signal detection means 5 Sleep index value evaluation means 6 Data storage / output means 7 Bed 8 Hard sheet 9 Cushion seat 10 Living body detection means ( Pressure detection means)
10a Pressure detection means (air mat)
10b Air tube 10c Differential pressure sensor 41 Automatic gain control (AGC) means 42 Signal intensity calculating means 51 Heart rate intensity dispersion calculating means 52 Sleep index value calculating means

Claims (6)

A heartbeat signal detecting means for detecting a heartbeat signal from a subject;
Heart rate intensity calculating means for calculating a heart rate intensity signal from the detected heart rate signal;
Heart rate intensity variance value calculating means for calculating a variance value of data within a predetermined time of the calculated heart rate intensity signal;
A sleep quality evaluation apparatus comprising sleep evaluation means for evaluating sleep quality based on an average value of the above heart rate intensity variance values during sleep and the variance values thereof.   The sleep quality evaluation apparatus according to claim 1, wherein the sleep evaluation means uses the sum of the average value of the heart rate intensity variance values and the variance value as an index for sleep evaluation.   The sleep quality evaluation apparatus according to claim 1, wherein the sleep evaluation means uses an average value of the heartbeat intensity dispersion values and a square sum of the dispersion values or a square root of the sum of squares as an index of sleep evaluation.   2. The sleep signal according to claim 1, wherein the heartbeat signal detecting means detects a biological signal by a biological signal detecting means disposed under the body of the subject, and extracts a heartbeat signal from the detected biological signal. Quality evaluation device.   The biological signal detection means includes a fine differential pressure sensor and a biological signal detection unit, and detects a biological signal by detecting a change in pressure of air stored in the biological signal detection unit with the fine differential pressure sensor. The sleep quality evaluation apparatus according to claim 4, wherein:   The sleep quality evaluation apparatus according to claim 1, wherein the heartbeat signal detecting means is a pulse meter or a blood pressure monitor worn on a wrist or an upper arm.