JP5785791B2 - Sleep state determination device - Google Patents

Description

  The present invention relates to a sleep state determination device that detects a biological signal of a subject without wearing and unconstrained and determines a sleep state in real time.

  As a conventional determination apparatus for determining a sleep state, various instruments such as an electroencephalograph that detects an electroencephalogram, an electrocardiograph that detects an electrocardiogram, or an electromyograph that detects the movement of an eyeball are used. What determines a sleep state based on the biological signal detected by this is known.

  However, in the above-described determination device, since various instruments are used that detect a change in the potential of a living body by directly attaching an electrode to the skin, the movement of the subject is restrained and a large stress is applied to the subject during the measurement. In other words, it is not suitable for continuous measurement, and it requires a skill in electrode mounting work and handling. In addition, when the subject moves, the position of the instrument shifts and the biological signal may not be detected with high accuracy. Furthermore, when the sleep state is determined, the biological signal data at the time of sleep detected by various instruments is temporarily stored, and then data analysis is performed using a computer or the like. .

  Therefore, in recent years, a determination device has been proposed in which a biological signal of a subject is detected without wearing and unconstrained, and a sleep state is determined in real time. For example, Patent Document 1 discloses an apparatus for determining a sleep state based on a heartbeat signal detected without being worn and unconstrained with respect to a subject, and Patent Document 2 is unworn and unconstrained with respect to a subject. An apparatus for determining a sleep state based on a detected body motion signal is disclosed. However, the current state of the art is that a sleep state determination device that can instantaneously determine the sleep timing that requires real-time characteristics has not been realized yet.

JP 2005-152310 A JP 2006-181263 A

  The present invention was devised in view of the current situation, and the purpose of the present invention is to detect a subject's biological signal in real time without attachment and without restraint, and to make it possible to instantaneously determine the sleep timing. The object is to provide a state determination device.

The sleep state determining apparatus according to the present invention includes a biological signal detection unit (1) that detects a body motion signal and a heartbeat signal of the subject without wearing and unconstrained with respect to the subject, and presence / absence of body motion from the body motion signal Body motion presence / absence detecting means (12) for detecting heart rate, heart rate detecting means (10) for obtaining a heart rate from the heartbeat signal, frequency analysis of the time series data of the heartbeat signal, and sympathy occupying the heartbeat fluctuation component Based on the frequency analysis means (11) for determining the ratio of the LF component that is a nerve component and the ratio of the HF component that is a parasympathetic nerve component, the presence or absence of body movement, the heart rate, the ratio of the LF component, and the ratio of the HF component, A sleep onset determining means (13) for determining a sleep onset timing, wherein the sleep onset determining means (13) is continuously inactive for 2 minutes or more, and the heart rate continuously decreases for the same time. And said L After an antagonistic state in which the ratio of the F component and the ratio of the HF component have become equal, the ratio of the LF component is lower than the ratio of the HF component, the ratio of the LF component tends to decrease, and the HF It is characterized in that the point in time when the ratio of the components is increasing and the difference between the ratio of the LF component and the ratio of the HF component is 60% or more is determined as a sleep timing .

  Specifically, the sleep onset determination means 13 is an antagonistic state in which there is no body movement continuously for a certain time, the heart rate tends to decrease, and the ratio of the LF component and the ratio of the HF component are equal. The ratio of the LF component is lower than the ratio of the HF component, the ratio of the LF component is decreasing, and the ratio of the HF component is increasing. The point in time when the difference from the ratio of the HF component is equal to or greater than a predetermined value is determined as the sleep timing.

  Further, the sleep onset judging means 13 has passed an antagonistic state in which there is no body movement continuously for a certain time, the heart rate tends to decrease, and the ratio of the LF component is equal to the ratio of the HF component. Then, immediately before the ratio of the LF component is lower than the ratio of the HF component, the ratio of the LF component switches from a decreasing trend to an increasing trend, and the ratio of the HF component shifts from an increasing trend to a decreasing trend. The time immediately before switching is determined as the sleep timing.

  Further, the biosignal detecting means 1 is provided with a foaming resin material and air sealed therein, and a sensor pad 3... Installed on the bed 2 on which the subject lies, and the air pressure in the sensor pad 3. And a piezoelectric sensor 4 for detecting the change of.

  Furthermore, the apparatus control means 14 which controls the drive of the housing equipment 15 such as a lighting apparatus and an air conditioner based on the determination result of the sleep onset determination means 13 is provided.

  Here, the above-mentioned “heartbeat fluctuation” specifically means a fluctuation of the heartbeat period (fluctuation of the RR interval of the heartbeat signal), and reflects the activity of the autonomic nerve. The autonomic nerve is composed of two nervous systems: a sympathetic nerve that increases in a tension state and a parasympathetic nerve that increases in a relaxed state.

  By performing frequency analysis (fast Fourier transform) on this “beat fluctuation” and deriving, for example, the power spectral density, the activity (intensity) of the sympathetic nerve component (LF component) having a peak at around 0.1 Hz and 0 It is a known technique to quantify the activity (intensity) of the parasympathetic nerve component (HF component) having a peak at around 3 Hz. Hereinafter, the activity (intensity) of the quantified sympathetic nerve component (LF component) is referred to as “value of LF component”, and the activity (intensity) of the quantified parasympathetic nerve component (HF component) is expressed as “ This is referred to as “the value of the HF component”.

  The above-mentioned “ratio of the LF component that is a sympathetic nerve component in the heartbeat fluctuation component” is specifically the ratio of the value of the LF component to the total value of the value of the LF component and the value of the HF component, that is, “ LF / (HF + LF) ”, and the above-mentioned“ ratio of the HF component that is a parasympathetic nerve component in the heartbeat fluctuation component ”is specifically the sum of the value of the LF component and the value of the HF component. The ratio of the value of the HF component to the value, that is, “HF / (HF + LF)” is meant. The ratio of the heartbeat fluctuation component as a whole is the sum of the ratio of the LF component and the ratio of the HF component and is 100%. For example, when the ratio of the LF component is 20%, the ratio of the HF component is 80%. It is in a relationship such as Therefore, the above-mentioned “antagonized state in which the ratio of the LF component and the ratio of the HF component are equal” means that the ratio of the LF component and the HF component is both 50%, that is, the sympathetic nerve and the parasympathetic nerve are balanced. It means that there is.

  According to the sleep state determining apparatus of the present invention, a biological signal of a subject can be detected in real time without wearing, and the sleep timing can be instantaneously and accurately determined without applying stress to the subject. In addition, by using this sleep determination, the housing equipment can be controlled in real time according to the sleep timing, and can be applied to energy saving measures and safety / safety measures.

It is explanatory drawing which shows schematic structure of the sleep state determination apparatus which concerns on one Embodiment of this invention. It is explanatory drawing which shows schematic structure of a biosignal detection means. It is explanatory drawing which shows the determination step of a sleep determination means. It is explanatory drawing which shows schematic distribution of the LF component of a heartbeat period frequency analysis, and an HF component. It is the figure which displayed the experimental result of the sleep determination using the sleep state determination apparatus with the experimental result by sleep state grasping | ascertainment measurement.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the sleep state determining apparatus according to an embodiment of the present invention includes a biological signal detection unit 1 that detects a biological signal of a subject without wearing and unconstrained with respect to the subject. Based on the biological signal detected by the detection means 1, the sleep timing of the subject is determined in real time.

  As shown in FIG. 2, the biological signal detection means 1 includes a plurality of sensor pads 3... Installed on a bed 2 on which a subject lies on a substantially parallel basis at appropriate intervals so as to cross the subject. Each sensor pad 3 is an elastic bag formed by enclosing a foamed resin material and air inside, and accompanying a change in sound or / and pressure on the body surface caused by the biological activity of the subject on the bed 2. The internal air pressure is changed.

  A piezoelectric sensor (pick-up) 4 for detecting a change in air pressure in the sensor pads 3 is connected to the sensor pads 3. The output signal from the piezoelectric sensor (pick-up) 4 is amplified and filtered by a signal processing circuit 5, and the amplified and filtered signal is separated into a heartbeat signal, a respiratory signal, and a body motion signal by a signal separation circuit 6. The heartbeat signal, the respiratory signal, and the body motion signal are A / D converted by the A / D conversion circuit 7, the period is calculated by the period calculation circuit 8 using the data after the A / D conversion, and the period data ( (Time series data) is output. Further, the subject's landing state and leaving state are discriminated from these periodic data, and the landing signal and the leaving signal are also output together.

  Note that the piezoelectric sensor (pick-up) 4, signal processing circuit 5, signal separation circuit 6, A / D conversion circuit 7, and period calculation circuit 8 in the biological signal detection means 1 are arranged together in the sensor unit 9. ing.

  Further, as shown in FIG. 1, the sleep state determination device includes body movement presence / absence detection means 12 for detecting the presence / absence of body movement from periodic data of body movement signals output from the biological signal detection means 1, and biological signal detection means. The heart rate detection means 10 for obtaining the heart rate from the period data of the heartbeat signal output from 1 and the period data (heartbeat fluctuation) of the heartbeat signal output from the biological signal detection means 1 are subjected to fast Fourier transform (FFT). 4, the values of the sympathetic nerve component (LF component) around 0.1 Hz and the parasympathetic nerve component (HF component) around 0.3 Hz are respectively calculated, and the sympathetic nerve component (LF) occupying the heartbeat fluctuation component is calculated. Component) ratio “LF / (HF + LF)” and the parasympathetic nerve component (HF component) ratio “HF / (HF + LF)” in the heartbeat fluctuation component, and frequency analysis means 11 for determining the presence of these body movements. None, heart rate, LF component ratio, and HF component ratio based on sleep onset determination means 13 for determining sleep onset timing, and on the basis of the determination result of the sleep onset determination means 13, the driving of the housing equipment 15 is controlled. Device control means (control output circuit) 14.

  Note that the heart rate fluctuation, the ratio of the sympathetic nerve component (LF component) to the heart rate fluctuation component “LF / (HF + LF)”, and the ratio of the parasympathetic nerve component (HF component) to the heart rate fluctuation component “HF / (HF + LF)” The meaning of "" is as described above, and the description thereof is omitted to avoid duplication.

  FIG. 3 shows a sleep determination step performed by the sleep detection means 13. First, based on the presence / absence of body motion detected by the body motion presence / absence detecting means 12, it is determined whether or not the body motion is in a continuous state for a certain time (for example, 2 minutes or more) (S1). At the same time, based on the heart rate obtained by the heart rate detection means 10, an average value of the heart rate every predetermined time (for example, every minute) is calculated (S2), and whether or not the heart rate is in a downward trend. Is discriminated (S3). Further, based on the ratio of the LF component and the ratio of the HF component obtained by the frequency analyzing means 11, an average value of the ratio of the LF component and the HF component is calculated every predetermined time (for example, every 1 minute) (S4). It is determined whether or not the first antagonistic state in which the ratio of the component and the ratio of the HF component are equal (the state in which the ratios of the LF component and the HF component are both 50%) has passed (S5). If the first antagonistic state has elapsed, it is determined whether or not the ratio of the LF component is lower than the ratio of the HF component (S6). If the ratio is low, the ratio of the LF component tends to decrease. It is determined whether or not it is immediately before switching to an increasing trend (near the boundary) and immediately before the ratio of the HF component switches from increasing trend to a decreasing trend (near the boundary) (S7).

  And, a first determination element based on the fact that the body movement is continuous for a certain period of time (for example, 2 minutes or more), a second determination element based on the tendency that the heart rate tends to decrease, and the ratio of the LF component Immediately after the first antagonistic state in which the ratio of the HF component becomes equal, the ratio of the LF component is lower than the ratio of the HF component and immediately before the ratio of the LF component switches from a decreasing trend to an increasing trend (near the boundary) In addition, the time point when all the third determination elements based on the fact that the ratio of the HF component is immediately before the change from the increasing tendency to the decreasing tendency (near the boundary) is satisfied is determined as the sleep timing (S8). .

  Among these first to third determination elements, as the third determination element, the ratio of the LF component is lower than the ratio of the HF component regardless of the presence or absence of the antagonistic state, and the ratio of the LF component tends to decrease, and Only the ratio of the HF component tends to increase may be used as a reference.

  Further, as a third determination factor, after the first antagonistic state in which the ratio of the LF component and the ratio of the HF component are equal, the ratio of the LF component is lower than the ratio of the HF component, and the ratio of the LF component is It may be based on a decreasing tendency and an increase in the ratio of the HF component, and the difference between the ratio of the LF component and the ratio of the HF component is a predetermined value (for example, 60%) or more.

  In this sleep state determination device, the determination result of the sleep sleep determination means 13, that is, the sleep time determined as described above (the sleep state before sleep and the sleep / wakefulness antagonistic state assumed from the sleep time) Etc.), the device control means 14 controls the driving of the housing equipment 15 such as lighting equipment, air conditioning equipment, and other various home appliances to provide a comfortable living space for the sleep of the subject. ing.

  In order to confirm the sleep detection accuracy by the sleep state determination device, the following experiment was performed. That is, for the test subject lying on the bed, the sleep state was grasped by measuring the electroencephalogram, eye movement, electromyogram and the like at the same time while performing the sleep determination by the sleep state determination device.

  FIG. 5 shows the experimental results. In FIG. 5, the first graph A from the top is the time series change of the body movement amount, the second graph B from the top is the time series change of the heart rate, and the third graph C from the top is the ratio of the LF component and the HF component. The time series change of the ratio, and the fourth graph D from the top respectively show the determination results from the sleep state grasping measurement. Moreover, the vertical line which passes through each graph of FIG. 5 has shown the time when the sleep timing was determined in the sleep state determination apparatus.

  As is apparent from the experimental results, the time point when the sleep state determination device determines that it is the sleep time is the time point 10 minutes after the start of the experiment. The first antagonistic state where the body is in a state of continuous inactivity for more than a minute, the heart rate tends to decrease as shown in graph B, and the ratio of the LF component and the ratio of HF component are both 50% as shown in graph C (Near one minute later), immediately before the ratio of the LF component is lower than the ratio of the HF component and the ratio of the LF component is changed from a decreasing tendency to an increasing tendency (near the boundary), and The time is immediately before the ratio of the HF component switches from an increasing tendency to a decreasing tendency (near the boundary).

  Further, at the time point 10 minutes after the start of the experiment, as shown in graph C, the ratio of the LF component is lower than the ratio of the HF component, the ratio of the LF component tends to decrease, and the ratio of the HF component tends to increase. It can be said that it is a certain point. Further, as shown in graph C, after the first antagonistic state (near 1 minute later) in which both the ratio of the LF component and the ratio of the HF component are 50%, the ratio of the LF component is the HF component. The ratio of the LF component is decreasing and the ratio of the HF component is increasing, and the difference between the ratio of the LF component and the ratio of the HF component is 60% or more. It can be said that.

  The time point 10 minutes after the start of the experiment is the time point when it is determined that the state has shifted from awake to stage 1 (Stage 1) in the sleep state grasp measurement. Therefore, the sleep timing determined by the sleep state determination device and the sleep timing determined by the sleep state grasp measurement are almost the same, and the sleep detection accuracy by the sleep state determination device is good and practical. It can be said that it has reached a level where there is no problem.

  The present invention is not limited to the above embodiment, and it is needless to say that many modifications and changes can be made to the above embodiment within the scope of the present invention.

  1 ·· Biological signal detection means 2 ·· Bed bed 3 ·· Sensor pad 4 ·· Piezoelectric sensor 10 ·· Heart rate detection means 11 ·· Frequency analysis means 12 ·· Body motion presence / absence detection means 13 ..Sleep determination means, 14 ... Equipment control means, 15 ... Housing equipment

Claims (4)

Biological signal detection means (1) for detecting the body movement signal and heartbeat signal of the subject without wearing and unconstrained with respect to the subject, and body movement presence / absence detection means for detecting the presence or absence of body movement from the body movement signal ( 12), a heart rate detection means (10) for obtaining a heart rate from the heartbeat signal, frequency analysis of the time series data of the heartbeat signal, and a ratio of an LF component which is a sympathetic nerve component in a heartbeat fluctuation component, and Frequency analysis means (11) for determining the proportion of the HF component which is a parasympathetic nerve component, and sleep onset determination means for determining the sleep onset timing based on the presence or absence of body movement, the heart rate, the ratio of the LF component and the ratio of the HF component ( 13), and the sleep determination means (13) is inactive continuously for 2 minutes or more, the heart rate is continuously decreasing for the same time, and the ratio of the LF component and the HF component discount After passing the antagonistic state in which the ratio is equal, the ratio of the LF component is lower than the ratio of the HF component, the ratio of the LF component is decreasing, and the ratio of the HF component is increasing A sleep state determination apparatus characterized in that a time point when the difference between the ratio of the LF component and the ratio of the HF component is 60% or more is determined as a sleep timing . Biological signal detection means (1) for detecting the body movement signal and heartbeat signal of the subject without wearing and unconstrained with respect to the subject, and body movement presence / absence detection means for detecting the presence or absence of body movement from the body movement signal ( 12), a heart rate detection means (10) for obtaining a heart rate from the heartbeat signal, frequency analysis of the time series data of the heartbeat signal, Frequency analysis means (11) for determining the proportion of the HF component which is a parasympathetic nerve component, and sleep onset determination means for determining the sleep onset timing based on the presence or absence of body movement, the heart rate, the ratio of the LF component and the ratio of the HF component ( 13), and the sleep determination means (13) is inactive continuously for 2 minutes or more, the heart rate is continuously decreasing for the same time, and the ratio of the LF component and the HF component discount After the antagonizing state in which the ratio is equal, the ratio of the LF component is lower than the ratio of the HF component, and immediately before the ratio of the LF component switches from a decreasing trend to an increasing trend, and the HF component A sleep state determination apparatus , characterized in that a time point immediately before the percentage of the change from an increase trend to a decrease trend is determined as a sleep timing . The biological signal detection means (1) includes a foamed resin material and air sealed therein, a sensor pad (3...) Installed on a bed (2) on which the subject lies, and the sensor pad (3 A sleep state determination device according to any one of claims 1 to 2 , further comprising a piezoelectric sensor (4) for detecting a change in air pressure in the inside. The apparatus control means (14) according to any one of claims 1 to 3 , further comprising a device control means (14) for controlling the driving of a housing equipment (15) such as a lighting device or an air conditioner based on a determination result of the sleep detection means (13). The sleep state determination device described.