JP2718303B2 - Sleep state determination device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sleep state judging device for detecting sleep.

[0002]

2. Description of the Related Art A conventional sleep state judging device of this type includes:
For example, one that detects a human body's brain wave or eye movement and performs waveform processing of a detection signal to determine falling asleep (Japanese Patent Laid-Open No. 62-25 / 1987)
No. 3034) and a method of detecting a pulse wave of a human body and performing waveform processing of a detection signal to determine falling asleep (Japanese Patent Application Laid-Open No.
No. 150047), all of which have a configuration in which a detecting means for detecting a biological signal such as an electroencephalogram, an eye movement, a pulse wave or the like is directly mounted on the scalp or skin of a human body. There was a problem that it was done. In view of these facts, the inventors detect body motion in a non-contact manner with the human body by using a piezoelectric element disposed on the bedding, and determine that the user has fallen asleep when the body motion quiescent time exceeds a certain set time. We first considered a sleep state determination device.

FIG. 12 is a block diagram of the conventional sleep state judging device. In the figure, the apparatus includes a piezoelectric element 1 disposed on a bedding, a filter 2 for filtering a specific frequency component of a signal of the piezoelectric element 1, an amplifying means 3, a smoothing means 4, absent, occupied, and body movement. First determining means 5 for determining
It comprises a timer 6 and a falling asleep judging means 7 and operates as follows. Here, the body motion of the human body when the human body is present on the bedding is defined separately in the following two. Minute body movements transmitted by the activity of the heart or respiration of the human body are referred to as fine body movements, and large body movements such as entering, waking up, and turning over are referred to as coarse body movements. When the piezoelectric element 1 disposed on the bedding is deformed by the fine body movement and the coarse body movement of the human body as described above, a voltage is generated from the piezoelectric element 1 according to the degree of the deformation. This output signal is filtered by the filter 2, amplified by the amplifier 3, and further smoothed by the smoother 4. FIG. 5 shows a waveform diagram of the output signal of the smoothing means 4. As shown in the figure, a high level output can be obtained in response to coarse body movements such as entering the bed, getting up and turning over, while a low level output can be obtained in response to fine body movements such as heartbeat and breathing if the person is in bed and at rest. Is obtained. Based on this fact,
The first determination unit 5 makes the following determination according to the signal level V of the smoothing unit 4. If V is less than a predetermined first set value Va, it is determined that "absence". If V is equal to or greater than Va and is less than a second predetermined value Vb, it is determined that the vehicle is "bed". If V is greater than or equal to Vb, it is determined that there has been a rough movement of the human body on the bedding, and a "body movement" is determined. Next, when there is the presence determination, the timer 6 starts the time counting operation. However, this timing operation is reset by the absence determination or the body movement determination. If the time measured by the timer 6 exceeds a predetermined set time To, the sleep determining means 7 determines that the human body has fallen asleep on the bedding.

[0004]

However, the above-mentioned conventional sleep state determination apparatus has a problem that it determines only sleep onset and cannot determine the depth of sleep. Further, if the awakening degree at the start of the body motion cessation is different, the transition of the sleep depth after that is different, so that even if the body motion quiescence continues for the same time, a different sleep depth may appear. For this reason, there is a problem that an error occurs in the sleep onset determination as described above.

A first object of the present invention is to solve the above-mentioned problem, and a first object of the present invention is to provide a sleep state judging device for estimating a sleep depth based on a body motion intensity at the start of body motion cessation and a subsequent body motion quiescence time. To provide.

A second object of the present invention is to provide a sleep state judging device for estimating a depth of sleep based on a frequency of occurrence of body motion at the start of body motion cessation and a subsequent body motion quiescence time.

A third object of the present invention is to provide a sleep state judging apparatus for estimating a sleep depth based on a body motion intensity and a body motion occurrence frequency at the start of body motion cessation and a subsequent body motion quiescence time.

[0008]

In order to achieve the first object, the present invention provides a piezoelectric element disposed on bedding, and a filter for filtering a specific frequency component of a signal of the piezoelectric element. Amplifying means for amplifying the signal of the filter, smoothing means for smoothing the signal of the amplifying means, and first judging means for judging absence, occupancy, and body movement based on the signal level of the smoothing means. A second determining means for determining the intensity of the signal level of the smoothing means when a body movement determining output of the first determining means is made; and a timer which operates based on an output signal of the first determining means. , The second determining means and estimating means for estimating a sleep state based on the output signal of the timer.

In order to attain the second object, the present invention provides a calculating means for calculating a frequency of occurrence of body movement based on a body movement determination output of a first determining means, a timer and an output signal of the calculating means. Estimating means for estimating a sleep state based on the sleep state.

Further, in order to achieve the third object, the present invention provides a calculating means for calculating a frequency of occurrence of a body movement based on a body movement determining output of a first determining means, a second determining means, a timer, Estimating means for estimating a sleep state based on an output signal of the calculating means.

[0011]

The present invention operates as follows by the above configuration. When the piezoelectric element disposed on the bedding undergoes deformation due to body movement, a voltage is generated from the piezoelectric element according to the degree of the deformation. This output signal is filtered by a filter, amplified by an amplifier, and smoothed by a smoother. In the smoothing means, a high-level output is obtained when the above-described coarse body motion occurs, and a low-level output is obtained by the above-described fine body motion when the body is at rest and in a resting state. Based on this fact, the first determination unit makes the following determination according to the signal level V of the smoothing unit. That is, when V is less than the first set value, the determination of “absence” is made. V is the first
If the value is equal to or more than the set value and is less than the second predetermined value, the determination of “occupied” is made. If V is greater than or equal to the second set value, a determination of "body movement" is made. Next, if there is a body movement determination, the second determination unit determines the strength of the body movement. After that, when there is an in-bed determination, a timer starts a timer operation. However,
This timing operation is reset by the absence determination or the body movement determination. The estimating means estimates the current sleep state based on the body motion intensity and the subsequent body motion stationary time up to the present time.

Further, according to the present invention, the frequency of occurrence of body motion is calculated for a period up to a predetermined time before the current time by the calculation means, the body motion stationary time at the current time is measured by the timer, and the body movement is estimated by the estimation means. The sleep state is estimated based on the occurrence frequency and the body motion quiescent time.

[0013] Further, the present invention provides a sleep based on the body motion intensity determined by the second determining means, the body motion stationary time up to the present time measured by the timer, and the body motion occurrence frequency calculated by the calculating means. The state is estimated.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view when the present embodiment is mounted on a bed, and FIG. 2 is a block diagram. 1 and 2, reference numeral 1 denotes a piezoelectric element made of polyvinylidene fluoride (PVD).
F) or the like, a thin film made of a high-molecular piezoelectric material, a flexible electrode film is adhered to both surfaces thereof, and formed into a tape shape, and is fixed to the surface of the mattress 8 as shown in FIG. Reference numeral 9 denotes a circuit unit, which includes a filter 2, an amplification unit 3, a smoothing unit 4, a first determination unit 5, a second determination unit 10, and an estimation unit 11 (not shown in FIG. 1). Piezoelectric element 1
And the circuit unit 9 are connected by a cider wire 12.

According to the structure of this embodiment, the present invention operates as follows. When a human body is present on the bedding and the piezoelectric element 1 is deformed by the fine body movement and the coarse body movement as described above, a voltage is generated from the piezoelectric element 1 according to the degree of the deformation. 3 and 4 show actual output signals output from the piezoelectric element 1. FIG. In the figure, a signal having a large level is a signal in the case of a rough movement such as entering a bed, turning over, or leaving a bed. FIG. 4 is an enlarged waveform diagram of FIG. 3, but when the human body is in bed and maintains a resting state, fine body movements, that is, minute body movements of the body propagated by the heart activity and respiratory activity of the human body. Are detected by the piezoelectric element 1 as shown in FIG.

The output signal of the piezoelectric element 1 is passed through a filter 2 at about 1 Hz to about 10 Hz, amplified by an amplifying means 3, and then smoothed by a smoothing means 4. FIG. 5 shows an output signal V output from the smoothing means 4 when a person actually goes to bed. As shown in the figure, V is large when a coarse body motion such as entering the bed, turning over, or leaving the bed, but in other resting states, a signal with a low level is obtained by the fine body motion. If no human body exists, V becomes zero. Based on this, the first determination means 5 makes the following determination according to V. That is, when V is less than a predetermined first set value (Va in FIG. 5), it is determined that no human body exists on the bed, that is, “absence”. When V is greater than or equal to the first set value Va and less than the second set value (Vb in FIG. 5), the human body is resting on the bed, that is, “being in bed”. Is determined. When V is greater than or equal to the second set value Vb, it is determined that the human body has caused a coarse movement on the bed, that is, “body movement”. Va and Vb can be obtained experimentally.

Next, when there is a body movement determination, the second determination means 10 determines the body movement intensity B1 (hereinafter the body movement intensity B1 is referred to as B1) as shown in the lower part of FIG. After the body motion determination, if there is a bed determination, the timer 6 starts a time measurement operation of the body motion stationary time T (hereinafter, the body motion stationary time T is referred to as T). However, this timing operation is reset by the absence determination or the body movement determination. The estimating means estimates the current sleep state based on B1 and T. The estimation process will be described below. As described above, when the arousal level W (hereinafter, arousal level W is referred to as W) at the start of the body motion rest is different, the subsequent sleep depth S (hereinafter, the sleep depth S is referred to as S) is different. Since there is a difference in the transition, different sleep depths may appear even when the body motion stillness continues for the same time. Therefore, first, the arousal level W at the time when the body motion occurs is obtained from the body motion intensity B1 at that time, and then S is estimated from W and T. Here, FIG. 6 shows the relationship between B1 and W, and FIG. 7 shows the relationship between W, T and S. As shown in FIG.
When W is high, S is shallow even if T is long. B from FIG.
W is obtained from 1 and then S is obtained from W and T from FIG.
6 and 7 can be obtained by a sleep experiment.

According to the above operation, the present embodiment has an effect that the sleep depth which could not be determined conventionally can be estimated based on the body motion intensity and the body motion rest time.

Next, a second embodiment of the present invention will be described below. This embodiment is different from the above-described embodiment in that, as shown in FIG. 8, the frequency of occurrence of body movement B2 (hereinafter, the frequency of occurrence of body movement B2 is B2 based on the body movement determination output of the first determination unit 5). (Hereinafter referred to as “calculation means”) and estimating means 11 for estimating the sleep state based on the output signals of the timer 6 and the calculation means 12.

According to the structure of this embodiment, the present invention operates as follows. That is, B2 is calculated for a period up to a predetermined time before the point in time when the body motion occurs, and then, when there is a bed determination, the timer 6 starts the timekeeping operation of the body motion stationary time T. However, this timing operation is reset by the absence determination or the body movement determination. The estimating means estimates the sleep state based on B2 and T. The process of the estimation will be described below. First, the arousal level W is calculated based on B2, and then S from W and T as in the first embodiment.
Is estimated. Here, FIG. 9 shows the relationship between B2 and W.
As shown in the figure, W is higher as B2 is higher. From FIG. 9, W is obtained from B2, and then S is obtained from W and T from FIG. 9 can be obtained by a sleep experiment.

According to the above operation, the sleep depth is estimated on the basis of the body motion occurrence frequency and the body motion stationary time which could not be determined conventionally in the present embodiment as in the first embodiment. There is an effect that it is possible to determine the sleep depth that could not be conventionally achieved.

Further, a third embodiment of the present invention will be described below. This embodiment is different from the above-described embodiment in that, as shown in FIG. 10, a calculating means 13 for calculating the frequency of occurrence of body movement based on the body movement determination output of the first determining means 5, The present invention is characterized by comprising a means 10, a timer 6, and an estimating means 11 for estimating a sleep state based on an output signal of the calculating means 13.

According to the configuration of this embodiment, the present invention operates as follows. That is, when there is a body movement determination, the second determination means 10 determines the strength B1 of the body movement, and the calculation means 13 performs the movement of the body movement for a certain period of time before the time when the body movement occurred. The occurrence frequency B2 is calculated, and thereafter, when there is a bed presence determination, the timer 6 starts the time counting operation of the body movement stationary time T. However, this timing operation is reset by the absence determination or the body movement determination. The estimating means estimates the current sleep state based on B1, B2, and T. The estimation process will be described below. First, the arousal level W at the time when the body motion occurs is obtained from B1 and B2, and then S is estimated from W and T. here,
FIG. 11 shows the relationship between B1, B2, and W. According to FIG.
W is higher as both B2 are higher. W is obtained from B1 and B2 from FIG. 11, and then S is obtained from W and T from FIG. FIG.
Can be obtained by a sleep experiment.

According to the above operation, the sleep depth is estimated based on the body motion intensity, the body motion occurrence frequency, and the body motion stationary time.
There is an effect that the sleep depth can be determined more accurately than in the first and second embodiments.

In the above description, the arousal level W is obtained from the strength and occurrence frequency of body movement.
The integrated value Ib of the signal level V of the smoothing means is calculated, and Tb
Or W may be obtained from Ib.

In the above embodiment, if the determination time To for detecting the falling asleep described in the conventional example is calculated so as to change the setting according to W as shown in FIG. 7, the accuracy of the falling asleep detection is improved. It has the effect of doing.

In the above embodiment, the body movement of the human body is detected by the piezoelectric element. However, the body movement may be detected by other detecting means, for example, a capacitance sensor, an infrared sensor, an ultrasonic sensor, or the like. .

[0028]

As described above, according to the sleep state judging device of the present invention, the following effects can be obtained.

The sleep depth that could not be determined conventionally can be estimated based on the body motion intensity and the body motion rest time.

In addition, the sleep depth that could not be determined conventionally can be estimated based on the body motion occurrence frequency and the body motion stationary time.

Further, since the sleep depth is estimated based on the body motion intensity, the body motion occurrence frequency, and the body motion rest time, the sleep depth can be accurately determined.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a sleep state determination device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of the apparatus.

FIG. 3 is a waveform chart showing an output from a piezoelectric element of the device.

FIG. 4 is an enlarged waveform diagram showing an output from a piezoelectric element of the device.

FIG. 5 is a waveform chart showing an output from a smoothing means of the apparatus.

FIG. 6 is a characteristic diagram showing a relationship between body motion intensity and arousal level.

FIG. 7 is a characteristic diagram showing a relationship between the arousal level, the body motion rest time, and the sleep depth.

FIG. 8 is a block diagram of a sleep state determination device according to a second embodiment of the present invention.

FIG. 9 is a characteristic diagram showing a relationship between a body motion occurrence frequency and a degree of arousal.

FIG. 10 is a block diagram of a sleep state determination device according to a third embodiment of the present invention.

FIG. 11 is a characteristic diagram showing a relationship between body movement intensity, body movement occurrence frequency, and arousal level.

FIG. 12 is a block diagram of a conventional sleep state determination device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric element 2 Filter 3 Amplifying means 4 Smoothing means 5 First judging means 6 Timer 7 Sleeping judging means 8 Mattress 9 Circuit unit 10 Second judging means 11 Estimating means 12 Shield wire 13 Arithmetic means

Claims (3)

(57) [Claims] A piezoelectric element disposed on the bedding, a filter for filtering a specific frequency component of a signal of the piezoelectric element, amplifying means for amplifying a signal of the filter, and a signal for the amplifying means. Smoothing means for smoothing, first determining means for determining absence, occupancy, and body movement based on a signal level of the smoothing means; and smoothing when a body movement determining output of the first determining means is made. Second determining means for determining the intensity of the signal level of the converting means, a timer which operates based on an output signal of the first determining means, and a sleep state based on the second determining means and an output signal of the timer. A sleep state determination device comprising: an estimation unit that estimates a sleep state. 2. The method according to claim 1, further comprising calculating means for calculating a frequency of occurrence of body movement based on the body movement determination output of the first determining means, and estimating means for estimating a sleep state based on an output signal of the timer and the calculating means. Item 7. The sleep state determination device according to Item 1. 3. A calculating means for calculating a frequency of occurrence of body movement based on a body movement determination output of the first determining means, a second determining means,
2. The sleep state determination device according to claim 1, further comprising: a timer and an estimation unit configured to estimate a sleep state based on an output signal of the calculation unit.