JPH04348741A - Sleeping state deciding device - Google Patents

Abstract

PURPOSE:To provide the sleeping state deciding device which detects bioinformation value, such as respiration, heart beats and bodily movements, without contact from a change in the electrostatic capacity between conductors installed near a living body to decide the change of the sleeping state with high accuracy. CONSTITUTION:This device has an electrostatic capacity measuring section 1 which is installed near the living body and measures the change in the electrostatic capacity of the living body without contact, a bioinformation detecting section 2 which detects at least one of the bioinformation values from the bodily movements, heart beats and respiration from the change in the electrostatic capacity and a sleeping state deciding section 3 which decides the sleeping state from the time series of the bioinformation values. The sleeping state in decided with high accuracy which lessering the invarion to the living body.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a sleep state determination device that detects changes in the sleep state of a living body based on relatively easily measurable living body activity information such as electrocardiogram, respiration, body movement, and skin temperature. It is something.

0002

BACKGROUND OF THE INVENTION It has been known that human sleep has cycles. In other words, the human sleep state is not uniform throughout the night, and cycles of non-REM sleep and REM sleep appear several times periodically, and the cycle lasts about 100 minutes (
80 to 120 minutes). In each cycle, the sleep state gradually shifts from a light sleep state to a deep sleep state during the non-REM sleep stage, and after the deep sleep state lasts for a while, it returns to a light sleep state, and then the REM sleep stage appears. Common.

[0003] To detect changes in sleep state, it is possible to use a polysomnography that includes electroencephalograms, eye movements, myoelectric waves, etc., but the equipment is large-scale and cannot be used in places equipped with measurement equipment such as laboratories and hospitals. Therefore, it is desired to detect sleep state with high accuracy by means instead of polysomnography. Therefore, it has been considered to focus on heart rate (pulse rate), breathing rate, and body movements during sleep, which are relatively easy to detect, and to detect sleep states from changes in these. That is, it is known that heart rate (pulse rate), breathing rate, and body movement decrease as a person falls asleep, and increase as the time of awakening approaches. In addition, during the non-REM sleep period, the heart rate, breathing rate, and body movements are stable, but during the REM sleep period, the activation state of the autonomic nervous system is disrupted, so the heart rate, breathing rate, and body movements fluctuate markedly. It is known that there is an increasing trend in cases of Furthermore, the interval between R waves of electrocardiogram (R
-R interval) spectrum analysis shows that 0.3H
The area around z indicates respiratory fluctuations, and the area around 0.1 Hz represents blood pressure fluctuations; the former reflects the activity state of the parasympathetic nerve in the autonomic nervous system, and the latter reflects the activity state of both the sympathetic and parasympathetic nerves. It is known that the activity state of each of the sympathetic and accessory nerves in the autonomic nervous system can be estimated.

[0004] Based on such knowledge, a conventional example of detecting the REM sleep period is disclosed in Japanese Patent Laid-Open No. 63-28.
As disclosed in Japanese Patent Application Laid-open No. 3623 and Japanese Patent Laid-Open No. 63-205592, there are methods that use increases and decreases in pulse rate as an index. Furthermore, a sleep state determination device that uses temporal fluctuations in pulse rate as an index has been proposed. Further, as a conventional example of detecting the timing of falling asleep, there is a method that uses the increase or decrease in pulse rate after going to bed as an index, as disclosed in Japanese Patent Application Laid-Open No. 182673/1983.

[0005]

[Problems to be Solved by the Invention] Conventional sleep state determination devices have a problem in that there are many individual differences in the rate of agreement with changes in actual sleep states, and the accuracy is considerably lower than that of polysomnography. In addition, there is a problem that the method is highly invasive to the living body and disturbs the living body's sleep.

[0006] The present invention has been made in view of the above points, and its purpose is to detect changes in the capacitance between conductive wires installed near a living body, such as breathing, electrocardiograms, body movements, etc. An object of the present invention is to provide a sleep state determination device that detects biological information values in a non-contact manner and determines changes in sleep state with high accuracy.

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the sleep state determination device of the present invention is installed near a living body to detect changes in the capacitance of the living body, as shown in FIG. A capacitance measurement unit 1 that measures the capacitance by contact; a bioinformation detection unit 2 that detects at least one biological information value among body movement, heartbeat, and respiration from changes in capacitance; and a biological information detection unit 2 that detects biological information values from a time series of biological information values. This device is characterized by having a sleep state determining section 3 that determines a sleep state.

As shown in FIG. 2, a skin temperature measuring section 4 for measuring the surface temperature of the skin is further provided, and the biological information detecting section 2 is a means for detecting the skin temperature as one of the biological information. is preferred.

Furthermore, as shown in FIG. 3, autonomic nerve activity detection detects the degree of activity of the autonomic nervous system from the time-series power spectrum of the interval between R waves of the electrocardiogram detected by the biological information detection unit 2. It is preferable that the sleep state determination unit 3 further includes a unit 5, and the sleep state determination unit 3 is a means for determining the sleep state from the time series of the biological information and the degree of activity of the autonomic nerve.

Furthermore, as shown in FIG. 4, it is even more preferable to use the skin temperature measuring section 4 and the autonomic nerve activity detecting section 5 together.

[0011]

[Function] As described above, in the present invention, by using the capacitance measurement unit 1 that is installed near the living body and measures changes in the capacitance of the living body in a non-contact manner, the burden caused by restraint on the living body is reduced. This makes it possible to perform measurements without disturbing the body's sleep. Furthermore, a biological information detection unit 2 is provided that detects at least one biological information value among body movement, heartbeat, and respiration from changes in the measured capacitance, and the sleeping state of the living body is determined based on this biological information value. By doing this, it is possible to determine the sleep state with high accuracy.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing the configuration of a sleep state determining apparatus according to claim 1. In the figure, 1 is a capacitance measuring section, which is installed near a living body and measures changes in capacitance of the living body in a non-contact manner. Reference numeral 2 denotes a biological information detection section, which detects at least one biological information value among body movement, heartbeat, and respiration from the change in capacitance measured by the capacitance measuring section 1. 3 is a sleep state determination section, and biological information detection section 2
The sleep state is determined from the time series of biometric information values detected.

FIG. 2 is a block diagram showing the configuration of the sleep state determining device according to the second aspect. In the figure, 4 is a skin temperature measuring section, which measures the temperature of the surface of the forehead and thighs of the living body. Although a contact type temperature sensor such as a thermistor may be used as this temperature measuring section, it is preferable to use a non-contact type temperature sensor such as a radiation thermometer if possible. Alternatively, the sleeping face of the sleeping person may be photographed using an infrared television camera, the location of the forehead area may be identified using image recognition technology, and the surface temperature may be measured. In this embodiment, skin temperature is included as one of the biological information values detected by the biological information detecting section 2, and the sleeping state determining section 3 determines the sleeping state by also considering information on the skin temperature. It is.

FIG. 3 is a block diagram showing the configuration of the sleep state determining device according to claim 3. In the figure, reference numeral 5 denotes an autonomic nerve activity detection unit, which detects the activity level of the autonomic nervous system from the time-series power spectrum of the interval between R waves of the electrocardiogram detected by the biological information detection unit 2. In this embodiment, the sleep state determination unit 3 determines the sleep state from the time series of the biological information and the degree of activity of the autonomic nerve.

FIG. 4 is a block diagram showing the configuration of the sleep state determining device according to claim 4. In the figure, 4 is a skin temperature measurement section, 5 is an autonomic nerve activity detection section, and their configuration is as follows.
This is the same as that described with reference to FIGS. 2 and 3. That is, this embodiment is a combination of the embodiments shown in FIGS. 2 and 3, and has the features of both embodiments.

FIG. 5 shows an example of how the capacitance measuring section 1 is installed. Two conductive wires 13 with open ends are installed under bedding such as the bed 11 and pillows 12, and the voltage between them is amplified by the capacitance measuring circuit 14, thereby measuring the capacitance of the living body. Changes can be detected and a mixed signal of body movement, breathing, and electrocardiogram can be obtained. From this signal, the frequency components of respiration and electrocardiogram can be detected using a bandpass filter or the like.

[0017] During the non-REM sleep period, the heart rate, breathing rate, and body movements are stable, but during the REM sleep period, the activation state of the autonomic nervous system is disrupted, so the heart rate, breathing rate, and body movements fluctuate significantly. Since there is an increasing trend in many cases,
It is possible to quantify fluctuations in breathing, heart rate, body movement variance, moving average, etc., and if a certain threshold is exceeded, it can be determined to be REM sleep. FIG. 6 shows, as an example, a case in which the REM sleep period is determined from fluctuations in pulse rate, and the determination results are in good agreement with the results determined from polysomnography.

FIG. 7 shows a time series of electrocardiogram R-R intervals,
A power spectrum obtained by frequency analysis of this is shown in FIG. RSA (respiratory fluctuation) around 0.3 Hz indicates the state of parasympathetic nerve activity, and MWSA (blood pressure fluctuation) around 0.1 Hz reflects the state of activity of both sympathetic and parasympathetic nerves. By analyzing the time series of the power spectrum values, when a certain threshold value is exceeded, it can be determined that the sleep is in REM sleep.

Next, FIG. 9 shows the results of a comparison between forehead temperature as skin temperature and sleep state determination using polysomnography. Forehead temperature changes with a delay of about 20 minutes relative to changes in sleep state, and as shown in FIG. 10, the correlation is particularly high in the first half of sleep. That is, changes in sleep state can be estimated based on changes in forehead temperature. In addition, when we compared thigh temperature with forehead temperature and sleep state determination using polysomnography, we found that thigh temperature was 35 to 36 degrees Celsius when the specified sleep depth was first reached. It can be used to determine when the target has been reached. Therefore, changes in skin temperature and body movements,
By integrating changes in breathing and electrocardiogram, sleep state can be determined with higher accuracy.

[0020]

Effects of the Invention In the sleep state determination device according to claim 1,
It is installed near a living body to non-contactly measure changes in the capacitance of the living body, detect at least one of body movement, heartbeat, and respiration from the changes in capacitance, and collect biological information. Since the sleep state is determined from the time series of values,
This has the effect of being able to determine the sleep state with high accuracy while minimizing the invasion of the living body.

[0021] Furthermore, as described in claims 2 to 4,
By using a skin temperature measurement section and an autonomic nerve activity detection section in combination, the sleeping state can be determined with even higher accuracy.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a first embodiment of the invention.

FIG. 2 is a block diagram of a second embodiment of the invention.

FIG. 3 is a block diagram of a third embodiment of the invention.

FIG. 4 is a block diagram of a fourth embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a capacitance measuring section used in the present invention.

FIG. 6 is a diagram showing measurement results of pulse rate changes and sleep state determination results according to the present invention.

FIG. 7 is a waveform chart showing a time series of electrocardiographic R-R intervals.

FIG. 8 is a diagram showing a frequency spectrum of an electrocardiogram R-R interval.

FIG. 9 is a waveform chart showing changes in forehead temperature and sleep depth of a living body.

FIG. 10 is a waveform chart showing the correlation coefficient between forehead temperature and sleep depth of a living body.

[Explanation of symbols]

1 Capacitance measurement section 2 Biological information detection unit 3 Sleep state determination section 4. Skin temperature measurement section 5 Autonomic nerve activity detection unit

Claims (4)

[Claims] 1. A capacitance measurement unit that is installed near a living body and measures changes in capacitance of the living body in a non-contact manner;
The device includes a biological information detection unit that detects at least one biological information value among body movement, heartbeat, and respiration from changes in capacitance, and a sleep state determination unit that determines a sleep state from a time series of biological information values. Features of sleep state determination device. 2. The skin temperature measuring device according to claim 1, further comprising a skin temperature measuring section that measures the surface temperature of the skin, and the biological information detecting section is a means for detecting the skin temperature as one of the biological information. Sleep state determination device. 3. The apparatus further comprises an autonomic nerve activity detection section that detects the degree of activity of the autonomic nervous system from the time-series power spectrum of the interval between R waves of the electrocardiogram detected by the biological information detection section, and sleep state determination. 2. The sleep state determination device according to claim 1, wherein the unit is a means for determining the sleep state from a time series of the biological information and the degree of activity of the autonomic nerve. 4. An autonomic nerve activity detection section that detects the activity level of the autonomic nervous system from the time-series power spectrum of the interval between R waves of the electrocardiogram detected by the biological information detection section, and a skin surface temperature detection section. It further includes a skin temperature measuring section for measuring the skin temperature, the biological information detecting section is a means for detecting the skin temperature as one of the biological information, and the sleep state determining section is a means for detecting the biological information and the time series of the autonomic nerve activity level. 2. The sleep state determination device according to claim 1, wherein the sleep state determining device is a means for determining a sleep state based on a person's sleep state.