JP3099338B2 - Sleep detection device and in-bed determination device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sleep determining apparatus for determining whether a sleeping person is in a sleep state and an in-bed determining apparatus for determining whether a human body is present in a bed. is there.

2. Description of the Related Art First, a conventional sleep detection device of this type detects a sleep asleep by detecting a brain wave or eye movement of a sleeping person and performing waveform processing of a detection signal to determine sleep asleep (Japanese Patent Application Laid-Open No. Sho 62-253034). Japanese Patent Application Laid-Open No. 63-150047) and a method of detecting a pulse wave of a sleeping person and performing a waveform process of a detection signal to determine falling asleep.
In either case, as shown in FIG.
Detecting means 1 for detecting a biological signal such as a pulse wave, and detecting means 1
A signal processing means 2 for processing a signal from the apparatus, and a determination means 3 for determining whether to fall asleep based on the output of the signal processing means 2. The detection means 1 is directly attached to the scalp or skin of a human body,
Signal processing of detected brain waves, eye movements, pulse waves, and the like was performed to determine falling asleep.

Next, this type of in-bed determination device is configured such that, for example, an infrared sensor or an ultrasonic sensor used in a security device is disposed on a bed or a wall surface around the bed, and infrared rays generated by the movement of a human body are used. The presence of the bed was determined by detecting the amount of change in the ultrasonic wave using a sensor. Others
There is also a configuration in which a pressure switch is arranged on the mattress surface,
The pressure switch was turned on based on the body weight to determine whether the person was in bed.

Problems to be Solved by the Invention However, in the configuration of the sleep onset determination device as described above,
There is a problem that the signal processing means 2 is expensive and impractical because signal processing for judging falling asleep from signals such as brain waves, eye movements, and pulse waves is complicated.

In addition, in the configuration of the above-described on-bed determination device, there is a problem in that when no body motion occurs due to falling asleep, the infrared or ultrasonic wave does not change, so that it is determined that the user is not on the floor and a malfunction occurs. In addition, in the configuration using the pressure switch, there is a problem that if heavy luggage or the like is left on the mattress, the switch is turned on and a malfunction occurs.

The present invention solves such a conventional problem, and provides a low-cost practical sleep detection device without performing complicated signal processing as described above. It is an object of the present invention to provide an in-bed determination device.

Means for Solving the Problems To solve the above problems, the sleep onset determination device of the present invention is
It consists of a flexible piezoelectric element and is placed on bedding such as futons, sheets, pillows or mattresses, or on a bed such as a bed frame. Motion detection means for detecting the heartbeat of the human body when the output signal from the body motion detection means is equal to or greater than a predetermined first set value and equal to or less than a predetermined second set value. The presence determination means for determining that the human body is in bed and in a resting state due to minute body movements due to breathing, etc., and the human body falls asleep when the output signal from the presence determination means continues for a predetermined time or more. A sleep onset judging means for judging a state.

In addition, the presence determination device of the present invention includes a mattress, a futon,
Body movement detecting means comprising a flexible piezoelectric element disposed on bedding such as sheets and detecting minute body movements such as heartbeat and respiration of the human body on the bed or body movements such as turning over; If the output signal from the motion detecting means is equal to or more than a predetermined first set value and equal to or less than a predetermined second set value, there is a minute body movement accompanying the heartbeat or respiration of the human body and the human body It is provided with arithmetic means for outputting as a resting state, and judging means for judging whether or not a human body is on the bed based on the output from the arithmetic means.

According to the above configuration, the sleep onset judging device of the present invention has a configuration in which the output signal from the body movement detecting means including the flexible piezoelectric element disposed on the bed is equal to or greater than the predetermined first set value, and If the value is equal to or smaller than the predetermined second set value, it is determined that the human body is in the occupied state, and if the resident state is continued for a certain period of time or more, it is determined that the human body is in the sleep state.

Further, according to the above-described configuration, the output of the body movement detection state including the flexible piezoelectric element disposed on the bedding such as the mattress, the futon, the sheet, or the like is set to the first setting. If the value is equal to or more than the value and equal to or less than the second predetermined set value, the output is performed by the calculating means. If the output from the calculating means continues for a certain period of time or more, it is determined that the human body is in the occupied state. You.

Embodiments First, a sleep onset determination device according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of the embodiment, and FIG. 2 is a block diagram. In FIG.
Is a body movement detecting means for detecting the body movement of the human body on the bed. Here, a polymer-filled material such as polyvinylidene fluoride (PVDF) is made into a thin film and a flexible electrode film is attached on both sides with a tape. It is a flexible piezoelectric element formed in a shape, and is fixed to the surface of the mattress 5 so as to be located immediately below the chest when the human body goes to sleep as shown in the figure. Reference numeral 6 denotes a low-pass filter 7, an amplifier 8, a rectifier 9, an integrator 10, and an on-board determination unit having a first comparator 11. Reference numeral 12 denotes a timer 13 and a second comparator 14.
This is a sleep onset judging means having:

The operation of the above configuration will be described below. When the piezoelectric element undergoes deformation due to body movement, a voltage is generated from the piezoelectric element.
3a and 3b show actual output results from the piezoelectric element.
FIG. 3b is an enlarged waveform diagram of FIG. 3a. Next, this output passes a component of 1 to 10 Hz through a low-pass filter 7, is amplified by an amplifier 8, is rectified by a rectifier 9, and is integrated in a unit time by an integrator 10. FIG. 4 shows the output from the integrator 10 when the person actually goes to bed. As shown in the figure, a large output is generated when rough body movement occurs, such as when entering the bed or turning over, but in other resting states, the output is low due to minute movements caused by heartbeat and respiration etc. of the human body Is obtained. That is,
If such a low level output is obtained, it is understood that the vehicle is in a resting state. Therefore, if the output signal from the integrator 10 is within the range of Va and Vb in the figure, the first comparator 11 performs output assuming that the human body is in the bed and in a resting state. Although there are some individual differences in minute body movements due to the heartbeat and respiration of the human body, Va and Vb can be obtained by subject experiments.

Next, the inventors conducted the following study on the relationship between the above-mentioned rough body movement and the sleep state. That is, based on the knowledge that the body motion disappears after falling asleep, the duration of the state in which the body motion does not occur in the sleep experiment (hereinafter referred to as the body motion stationary state) and the probability that the sleeper is in the sleep state in that state And sought a relationship. The results are shown in FIG. The abscissa of the figure indicates the duration of the rough movement stationary state, and the left ordinate indicates the probability of the subject falling asleep when the rough movement stationary state continues for T hours. In addition, in the falling asleep state, the rough movement stationary state continues, and the body shifts from the falling asleep state to the slow-wave sleep, which is a deeper sleep. At a certain point in time, the rough body movement occurs again and the slow-wave sleep ends. From this,
In the right vertical axis of FIG. 10, the probability of the occurrence of coarse movement and the end of slow wave sleep when the coarse movement stationary state continues for T hours is taken. From the figure, for example, if the static
85% probability of falling asleep and 10% probability of slow-wave sleep ending. Measuring duration of gross body motion quiescence to determine sleep adequacy at a level sufficient for practical use. Became possible. That is, the sleep onset judging means 12 performs the time counting operation of the timer 13 when there is an output from the first comparator 11 that the human body is in the bed and is in a resting state. Is stopped and reset. In the second comparator 14, the time t measured by the timer 13 is equal to a predetermined time.
When it becomes to or more, it is determined that the user is asleep. Here, about 15 minutes is appropriate as the value of to from the above experimental results.

Even when luggage is placed on a mattress, the piezoelectric element is deformed and generates voltage, but non-living objects such as luggage do not have minute movements associated with the heartbeat or respiration of the human body, so they malfunction. Does not occur. That is, the sleep state is determined only when the human body is in bed and in a resting state.

By the above operation, the body movement is detected by the piezoelectric element, and the state of falling asleep is determined from simple variables such as the size and the duration, so that the falling asleep is determined from signals such as brain waves, eye movements, and pulse waves as in the related art. It is not necessary to perform complicated and expensive signal processing as in the case, and it is possible to determine the state of sleep in a simpler and cheaper practical form, and to detect minute movements caused by heartbeat and respiration of the human body. Since the sleep state is determined based on the presence state based on the bed state, for example, when luggage or the like is placed on the mattress, it is determined that the user is absent and there is no malfunction.

Furthermore, the conventional sleep onset determination device directly attaches detection means for detecting biological signals such as brain waves, eye movements, and pulse waves directly to the scalp or skin of a human body. However, in this embodiment, since the piezoelectric element is arranged on the mattress to perform detection by indirect contact with the human body, sleep is disturbed by a sense of discomfort due to the mounting of the detection means as in the conventional case. There is an effect that the sleeping state can be determined in a normal sleeping state without falling.

In the above embodiment, the piezoelectric element is provided on the mattress. However, the piezoelectric element may be provided on bedding such as a futon, a sheet, a pillow or a bed such as a bedroom.

Next, an on-bed determination device according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 6 is a block diagram of the embodiment. In the figure, reference numeral 4 denotes a body movement detecting means for detecting a body movement of the human body on the bed, which is the same as the piezoelectric element used in the sleep onset determining device, and a chest part when the human body goes to sleep as shown in the figure. Is fixed to the surface of the mattress 5 so as to be located immediately below the mattress 5. 15 is a low-pass filter 7, an amplifier 8,
The arithmetic means having the rectifier 9, the integrator 10, and the first comparator 11, the judgment means 16 having the timer 13 and the third comparator 17 are shown.

The operation of the above configuration will be described below. When the piezoelectric element undergoes deformation due to body movement, a voltage is generated from the piezoelectric element.
3a and 3b show actual output results from the piezoelectric element.
FIG. 3b is an enlarged waveform diagram of FIG. 3a. Next, this output passes a component of 1 to 10 Hz through a low-pass filter 7, is amplified by an amplifier 8, is rectified by a rectifier 9, and is integrated in a unit time by an integrator 10. FIG. 4 shows the output from the integrator 10 when the person actually goes to bed. As shown in the figure, a large output is generated when rough body movement occurs, such as when entering the bed or turning over, but in other resting states, the output is low due to minute movements caused by heartbeat and respiration etc. of the human body Is obtained. That is,
As long as a human body is present in the bed at bedtime, the low output as described above can be obtained. Utilizing this, the first comparator 11 performs output assuming that the output signal from the integrator 10 is in a resting state if it is within the range of Va and Vb in the figure. Third
In the comparator 17, the output from the first comparator 11 is a timer
If there is at least one occurrence within the time t counted by 13, it is determined that the human body is on the floor, and the first
If the output from the comparator 11 does not occur once within the time t counted by the timer 13, it is determined that the user is absent. This determination operation is repeated again when the time t has elapsed, and is continuously performed. As the value of t, for example, 30 to 60
Use seconds. Here, although there are some individual differences in the minute body movements due to the heartbeat and respiration of the human body as described above, Va and Vb can be obtained by subject experiments.

By the above operation, a minute body movement accompanying the heartbeat or respiration of the human body is detected to determine the state of being in bed, so that it is found in the existing state of bed determination device using a configuration using an infrared sensor or an ultrasonic sensor. Such a malfunction does not occur, and there is an effect that the in-bed state can be reliably determined. When a luggage or the like is placed on a mattress, the piezoelectric element is deformed and generates a voltage.However, an inanimate object such as luggage does not have minute movements associated with the heartbeat or respiration of the human body. Is determined to be absent even if is placed, there is no occurrence of a malfunction as in a conventional occupancy determination device having a configuration using a pressure switch.

Next, a reference example (not shown) of the present invention will be described below. This embodiment is different from the above-described embodiment in that the calculating means includes a frequency analysis unit for frequency-analyzing the output signal from the piezoelectric element, and the output from the frequency analysis unit has power in a specific frequency region. In other words, a comparison output unit for outputting an output when the value is equal to or more than a predetermined value is provided.

FIG. 7 is a power spectrum obtained as a result of processing the output from the piezoelectric element by the frequency analysis unit when the human body at rest is in a resting state. FIG. 7 shows a distribution in which a peak is observed at 4 to 6 Hz, and it is considered that components due to minute body movements accompanying the heartbeat and respiration of the human body appear. If the power at 4 to 6 Hz is equal to or higher than P in FIG. Accordingly, if the person is in the bed and is in the resting state, there is an output from the comparison output unit, and the judgment unit performs the same processing as in the above embodiment to judge whether the person is in the bed.

By the above-described operation, the presence of the floor is determined based on the component of 4 to 6 Hz caused by minute body movements caused by the heartbeat and respiration of the human body, so that the effect of being able to determine the presence of the floor reliably without malfunction as in the related art is obtained. is there.

Another reference example (not shown) of the present invention is shown below. The point that this reference example is easier than the above-described embodiment is that a microcomputer that performs pattern recognition by an arithmetic unit preliminarily detects a waveform pattern generated by a minute body movement accompanying a heartbeat or respiration of the human body shown in FIG. 3B. In addition to storing, if the output from the piezoelectric element is similar to the waveform pattern, the output is performed.

This makes it possible to distinguish between minute body movements caused by heartbeat and breathing of the human body and coarse body movements such as turning over, and to distinguish it from vibrations caused by people walking around the bed or passing by bicycles etc. The malfunction prevention performance is improved. Also,
By storing the waveform pattern of a specific individual in the microcomputer, there is also an effect that individual identification becomes possible.

Effects of the Invention As described above, the following effects can be obtained by the sleep onset judging device of the present invention.

That is, since the body movement is detected and the sleep state is determined from simple variables such as the size and the duration, it is complicated as in the conventional case where the sleep state is determined from signals such as brain waves, eye movements, and pulse waves. There is no need to perform costly signal processing, and there is an effect that the sleep state can be determined in a simpler and less expensive practical form. In addition, since the sleeping state is determined after determining the state of bed based on minute movements caused by the heartbeat and breathing of the human body, for example, when luggage etc. are placed on a mattress, it is determined that there is no absence and there is no malfunction There is.

Further, according to the presence determination device of the present invention, the following effects can be obtained.

In other words, since the presence or absence of the body is determined by detecting minute body movements associated with the heartbeat or respiration of the human body, it can be seen in a conventional presence determination device using a configuration using an infrared sensor or an ultrasonic sensor. There is an effect that no erroneous operation occurs and the occupancy state can be reliably determined. In addition, even when luggage is placed on a mattress, inanimate objects do not have minute movements due to the heartbeat or breathing of the human body, and it is determined that there is no luggage even if luggage is placed. There is an effect that a malfunction such as that observed in the presence determination apparatus using a switch does not occur.

[Brief description of the drawings]

1 is a perspective view of a sleep onset judging device according to an embodiment of the present invention, FIG. 2 is a block diagram of the device, FIG. 3a is a waveform diagram showing an output from a piezoelectric element of the device, and FIG. FIG. 3a
FIG. 4 is a waveform diagram showing the output from the integrator of the apparatus, FIG. 5 is a characteristic diagram showing the relationship between the duration of the coarse motion stationary state and the probability of falling asleep, FIG. 6 is a block diagram of the occupancy determination device according to the embodiment of the present invention. FIG. 7 is a waveform diagram showing a power spectrum of an output from the body motion detecting means in the occupancy determination device of the reference example of the present invention. FIG. 2 is a block diagram of a conventional sleep onset determination device. 4 ... body movement detecting means, 5 ... mattress, 6 ... staying in bed determining means, 12 ... falling asleep determining means, 15 ... calculating means, 16 ... determining means.

Claims (2)

(57) [Claims] The present invention comprises a flexible piezoelectric element, which is disposed on a bed such as a bedding, a bed, a pillow or a mattress, or a bed such as a bed frame. A body movement detecting means for detecting body movement such as turning over, and an output signal from the body movement detecting means being equal to or more than a predetermined first set value and equal to or less than a predetermined second set value Is occupied by the occupancy determination means for determining that the human body is in bed and is in a resting state due to minute body movements associated with the heartbeat or respiration of the human body, and an output signal from the occupancy determination means continues for a predetermined time or more. In the case, a sleep determination device includes a sleep determination unit that determines that the human body is in a sleep state. 2. A body comprising a flexible piezoelectric element disposed on a bedding such as a mattress, a futon, a sheet, etc., for detecting a minute body movement and a body movement such as a turn over caused by a heartbeat or respiration of a human body on a bed. Body movement detecting means, and if the output signal from the body movement detecting means is equal to or greater than a predetermined first set value and equal to or less than a predetermined second set value, the heartbeat or respiration of the human body is affected. A calculating means for performing an output assuming that the human body is in a resting state due to the accompanying slight body movement, and a determining means for determining whether or not the human body is on the bed based on the output from the calculating means. Floor judgment device.