阅读说明：本技术 使用非接触传感器的睡相判定装置、睡相判定方法及保存有用来判定睡相的程序的记录介质 (Device and method for determining sleep phase using non-contact sensor, and recording medium storing program for determining sleep phase ) 是由 井上谦一 于 2019-05-08 设计创作，主要内容包括：有关本发明的一形态的睡相判定装置具备：接收器,接收通过使用非接触传感器测定对象者而得到的测定结果；提取电路,从上述测定结果提取上述对象者的呼吸信号；存储器,保持有与呼吸信号的电平有关的基准信息；以及判定电路,基于上述对象者的上述呼吸信号的电平与上述基准信息的比较,判定上述对象者的睡相。(A sleep phase determination device according to an aspect of the present invention includes: a receiver that receives a measurement result obtained by measuring a subject using a non-contact sensor; an extraction circuit that extracts a respiratory signal of the subject from the measurement result; a memory that holds reference information relating to the level of the respiration signal; and a determination circuit configured to determine a sleep phase of the subject person based on a comparison between a level of the breathing signal of the subject person and the reference information.)

1. A sleep phase determination device is provided with:

a receiver that receives, from at least 1 non-contact sensor, a measurement result obtained by measuring a subject person using the at least 1 non-contact sensor;

an extraction circuit that extracts a respiratory signal of the subject from the measurement result;

a memory for storing 1 st reference information related to the level of the respiration signal; and

and a determination circuit for determining a sleep phase of the subject person based on a 1 st comparison between the level of the breathing signal of the subject person and the 1 st reference information, and outputting a determination result of the sleep phase.

2. The sleep phase determination apparatus according to claim 1,

the extraction circuit extracts the periodic physical activity of the subject person indicated by the measurement result as the respiration signal.

3. The sleep phase determination apparatus according to claim 1 or 2,

the 1 st reference information is a threshold value of a level of the respiration signal;

the determination circuit determines that the sleep phase of the subject person is supine when the level of the breathing signal of the subject person is equal to or higher than the threshold value,

the determination circuit determines that the sleep phase of the subject person is a sleep phase other than the supine sleep phase when the level of the breathing signal of the subject person is smaller than the threshold value.

4. The sleep phase determination apparatus according to claim 3,

the sleep phase of the subject person is determined to be supine, and the apparatus further includes an update circuit for generating new 1 st reference information using the breathing signal of the subject person extracted when the sleep phase of the subject person is determined to be supine, and updating the 1 st reference information held in the memory with the new 1 st reference information.

5. The sleep phase determination apparatus according to any one of claims 1 to 3,

a rotation detector for detecting a rotation of the subject person based on the measurement result;

the determination circuit determines the sleep phase of the subject person based on the 1 st comparison and the detection result of the rotation operation.

6. The sleep phase determination apparatus according to any one of claims 1 to 5,

the at least 1 non-contact sensor includes a plurality of non-contact sensors disposed in different directions with respect to the subject person;

the receiver receives the measurement results from the plurality of non-contact sensors, respectively;

the extraction circuit extracts a breathing signal of the subject person for each of the plurality of non-contact sensors from the measurement result;

the memory further holds reference 2 information on a relationship between levels of the respiration signals and the plurality of non-contact sensors;

the determination circuit determines the sleep phase of the subject person based on a 2 nd comparison between the level of the breathing signal of the subject person between the plurality of non-contact sensors and the 2 nd reference information.

7. The sleep phase determination apparatus according to claim 6,

the 2 nd reference information indicates a relationship between levels of the breathing signal in the plurality of non-contact sensors, in association with each of a plurality of sleep phases including a supine position, a lateral position, and a prone position;

the determination circuit determines which of the plurality of sleep phases the sleep phase of the subject person is based on the 2 nd comparison.

8. The sleep phase determination apparatus according to any one of claims 1 to 7,

and a notification device for notifying a user of the determination result when it is determined that the sleep phase of the subject person is a sleep phase other than the supine sleep phase.

9. The sleep phase determination apparatus according to any one of claims 1 to 8,

the at least 1 non-contact sensor is a doppler radar.

10. A sleep phase determination method includes the following processes:

receiving, from at least 1 non-contact sensor, a measurement result obtained by measuring the subject person using the at least 1 non-contact sensor;

extracting a respiratory signal of the subject from the measurement result; and

the sleep phase of the subject person is determined based on a comparison between the level of the breathing signal of the subject person and the reference information with reference to the reference information on the level of the breathing signal, and the determination result of the sleep phase is output.

11. A computer-readable recording medium storing a program for determining a sleep phase, wherein,

when the program is executed by the computer, the following processing is executed:

receiving, from at least 1 non-contact sensor, a measurement result obtained by measuring the subject person using the at least 1 non-contact sensor;

extracting a respiratory signal of the subject from the measurement result; and

the sleep phase of the subject person is determined based on a comparison between the level of the breathing signal of the subject person and the reference information with reference to the reference information on the level of the breathing signal, and the determination result of the sleep phase is output.

Technical Field

The present invention relates to a sleep phase determination device and a sleep phase determination method using a non-contact sensor, and a recording medium storing a program for determining a sleep phase.

Background

There is a disease called SIDS (Sudden Death Syndrome) in which infants and young children suddenly die during sleep. In order to reduce the risk of SIDS onset, it is known to be effective not to allow infants to sleep prone. For example, in a nursing home, the risk of SIDS is reduced by regularly monitoring the infant by the nursing staff while the infant is asleep.

As an example of a technique for mechanically determining the sleep phase of a subject person, patent document 1 discloses a biological monitoring system for determining a breathing signal, a sleeping posture, and a weight of a sleeper based on a plurality of load signals output from pressure-sensitive elements disposed below, inside, or on the surface of bedding in a predetermined distribution.

Disclosure of Invention

Problems to be solved by the invention

The invention provides a sleep phase determination device, a sleep phase determination method and a recording medium storing a program for determining a sleep phase, which are easy and convenient to handle.

Means for solving the problems

A sleep phase determination device according to an aspect of the present invention includes: a receiver that receives, from at least 1 non-contact sensor, a measurement result obtained by measuring a subject person using the at least 1 non-contact sensor; an extraction circuit that extracts a respiratory signal of the subject from the measurement result; a memory for storing 1 st reference information related to the level of the respiration signal; and a determination circuit for determining a sleep phase of the subject person based on a 1 st comparison between a level of the breathing signal of the subject person and the 1 st reference information, and outputting a determination result of the sleep phase.

The overall and specific aspects of the present invention may be realized by a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or may be realized by any combination of a system, a method, an integrated circuit, a computer program, and a recording medium.

Effects of the invention

According to the sleep phase determination device of the present invention, the sleep phase of the subject person can be determined based on the comparison between the level of the breathing signal and the reference information, using the characteristic that the level of the breathing signal differs depending on the sleep phase of the subject person.

Drawings

Fig. 1 is a block diagram showing an example of a functional configuration of a sleep phase determination device according to embodiment 1.

Fig. 2 is a diagram showing an example of measurement results of the non-contact sensor according to embodiment 1.

Fig. 3 is a conceptual diagram illustrating an example of the measurement situation according to embodiment 1.

Fig. 4 is a flowchart showing an example of the operation of the sleep phase determination device according to embodiment 1.

Fig. 5 is a graph showing an example of the measurement results according to embodiment 1.

Fig. 6A is a conceptual diagram illustrating an example of a sleep phase according to embodiment 1.

Fig. 6B is a conceptual diagram illustrating an example of the sleep phase according to embodiment 1.

Fig. 7 is a graph showing an example of the breathing signal corresponding to sleep according to embodiment 1.

Fig. 8 is a block diagram showing an example of a functional configuration of the sleep phase determination device according to embodiment 2.

Fig. 9 is a flowchart showing an example of the operation of the sleep phase determination device according to embodiment 2.

Fig. 10 is a block diagram showing an example of a functional configuration of the sleep phase determination device according to embodiment 3.

Fig. 11 is a flowchart showing an example of the operation of the sleep phase determination device according to embodiment 3.

Fig. 12A is a conceptual diagram illustrating an example of the idea of rotation detection according to embodiment 3.

Fig. 12B is a conceptual diagram illustrating an example of the idea of rotation detection according to embodiment 3.

Fig. 13 is a block diagram showing an example of a functional configuration of the sleep phase determination device according to embodiment 4.

Fig. 14 is a flowchart showing an example of the operation of the sleep phase determination device according to embodiment 4.

Fig. 15A is a conceptual diagram illustrating an example of the relationship between the levels of the breathing signal corresponding to sleep and the plurality of non-contact sensors according to embodiment 4.

Fig. 15B is a conceptual diagram illustrating an example of the relationship between the levels of the breathing signal corresponding to sleep and the plurality of non-contact sensors according to embodiment 4.

Fig. 15C is a conceptual diagram illustrating an example of the relationship between the levels of the breathing signal corresponding to sleep and the plurality of non-contact sensors according to embodiment 4.

Fig. 15D is a conceptual diagram illustrating an example of the relationship between the levels of the breathing signal corresponding to sleep and the plurality of non-contact sensors according to embodiment 4.

Detailed Description

(knowledge as a basis of the present invention)

In the living body monitoring system of patent document 1, since the pressure-sensitive elements are disposed in a predetermined distribution under, in, or on the surface of the bedding, the pressure-sensitive elements are in contact with the subject person directly or via the bedding. Therefore, when the living body monitoring system of patent document 1 is used for monitoring the sleep phase of an infant in a nursing home, there is a possibility that the comfort of the subject person is impaired, and the burden on the nursing staff and the nursing staff is increased by replacement due to consumption of the pressure-sensitive element, daily disinfection, and the like.

The position and motion of a subject person can be measured in a non-contact manner if a non-contact sensor such as a radio wave radar or an ultrasonic sonar is used, but an effective technique for determining the sleep phase of the subject person from the measurement result of such a non-contact sensor has not been known in the past.

The present inventors have found that the level of the respiration signal extracted from the measurement result of the non-contact sensor differs depending on the sleep phase of the subject person. The present inventors have proposed a sleep phase determination device, a sleep phase determination method, a recording medium, and a program for determining a sleep phase of a subject person based on a measurement result obtained by measuring the subject person with a non-contact sensor based on the recognition.

A sleep phase determination device according to an aspect of the present invention includes: a receiver that receives, from at least 1 non-contact sensor, a measurement result obtained by measuring a subject person using the at least 1 non-contact sensor; an extraction circuit that extracts a respiratory signal of the subject from the measurement result; a memory for storing 1 st reference information related to the level of the respiration signal; and a determination circuit for determining a sleep phase of the subject person based on a 1 st comparison between a level of the breathing signal of the subject person and the 1 st reference information, and outputting a determination result of the sleep phase.

According to such a configuration, the sleep phase of the subject person can be determined based on the comparison between the level of the extracted breathing signal and the 1 st reference information, using the characteristic that the level of the breathing signal differs depending on the sleep phase of the subject person. Since the respiration signal is extracted from the measurement result of the subject person obtained by the non-contact sensor, the comfort of the subject person is not impaired as compared with the case of using the contact sensor, and the burden on the user due to replacement of the pressure-sensitive element and daily sterilization can be reduced. As a result, a sleep phase determination device with excellent ease of treatment can be obtained.

The extraction circuit may extract, as the respiration signal, a periodic physical activity of the subject indicated by the measurement result.

With this configuration, the breathing signal of the subject person can be easily extracted using a specific method such as a low-pass filter or a trend elimination filter from the time series of the measurement results.

Further, the 1 st reference information may be a threshold value of a level of the respiration signal; the determination circuit determines that the sleep phase of the subject person is supine when the level of the breathing signal of the subject person is equal to or higher than the threshold value, and determines that the sleep phase of the subject person is not supine when the level of the breathing signal of the subject person is lower than the threshold value.

According to such a configuration, the sleep phase of the subject person can be determined by comparing the extracted breathing signal with a threshold value, using the characteristic that the level of the breathing signal when the subject person sleeps supine is greater than the level of the breathing signal when the subject person sleeps in a sleep phase other than supine.

Further, the sleep phase of the subject person may be determined to be supine, and the sleep phase of the subject person may be extracted by using the respiration signal of the subject person to generate new 1 st reference information, and the 1 st reference information held in the memory may be updated by using the new 1 st reference information.

According to such a configuration, since the 1 st reference information is updated in accordance with the level of the breathing signal specific to the subject person and the temporal variation in the level of the breathing signal, the sleep phase of the subject person can be determined more accurately and stably.

Further, the apparatus may further include a rotation detector for detecting a rotation of the subject person based on the measurement result; the determination circuit determines the sleep phase of the subject person based on the 1 st comparison and the detection result of the rotational operation.

With this configuration, it is possible to detect whether or not the subject person has a change in the sleep phase such as turning over by detecting the rotational movement, and more accurately determine the sleep phase of the subject person. Thus, for example, even when the level of the breathing signal does not decrease with the rotation operation, a suspected abnormality such as a respiratory arrest of the subject can be detected separately from the change in the sleep phase.

Further, the at least 1 non-contact sensor may include a plurality of non-contact sensors provided in different directions with respect to the subject person; the receiver receives the measurement results from the plurality of non-contact sensors, respectively; the extraction circuit extracts a breathing signal of the subject person for each of the plurality of non-contact sensors from the measurement result; the memory further holds reference 2 information on a relationship between levels of the respiration signals and the plurality of non-contact sensors; the determination circuit determines the sleep phase of the subject person based on a 2 nd comparison between the level of the breathing signal of the subject person between the plurality of non-contact sensors and the 2 nd reference information.

According to such a configuration, the sleep phase of the subject person can be more accurately determined based on the comparison between the relationship between the levels of the extracted breathing signal and the 2 nd reference information, using the characteristic that the relationship between the levels of the breathing signal among the plurality of non-contact sensors differs according to the sleep phase of the subject person.

Further, the 2 nd reference information may indicate a relationship between the levels of the respiration signals in the plurality of non-contact sensors in correspondence with a plurality of couches including a supine position, a lateral position, and a prone position, respectively; the determination circuit determines which of the plurality of sleep phases the sleep phase of the subject person is based on the 2 nd comparison.

In such a configuration, for example, the levels of the breathing signals extracted from the measurement results of the non-contact sensors located directly above and obliquely above the subject person exhibit a magnitude relationship unique to each of a plurality of sleep phases including the supine, lateral, and prone positions of the subject person. By using this characteristic, the sleep phase of the subject person can be determined from the magnitude relation established for the level of the extracted respiratory signal.

Further, the sleep management system may further include a notification device that notifies the user of the determination result when the sleep phase of the subject person is determined to be a sleep phase other than the supine sleep phase.

With this configuration, by notifying the user of the sleep phase of the subject person, appropriate measures corresponding to the sleep phase can be urged. For example, in the case of a nursing home, by notifying the nursing officer that the infant is in a sleeping phase other than the supine sleeping phase, the infant can be encouraged to return to the supine sleeping phase with a lower risk of SIDS.

Further, the at least 1 non-contact sensor may be a doppler radar.

According to such a configuration, since the target person can be stably measured by using the doppler radar, the sleep phase determination device having excellent sleep phase determination performance can be obtained.

A sleep phase determination method according to an aspect of the present invention includes: receiving, from at least 1 non-contact sensor, a measurement result obtained by measuring the subject person using the at least 1 non-contact sensor; extracting a respiratory signal of the subject from the measurement result; and determining a sleep phase of the subject person based on a comparison between the level of the breathing signal of the subject person and the reference information with reference to the reference information on the level of the breathing signal, and outputting a determination result of the sleep phase.

According to such a method, the sleep phase of the subject person can be determined based on the comparison between the level of the extracted breathing signal and the reference information, using the characteristic that the level of the breathing signal differs depending on the sleep phase of the subject person. Since the respiration signal is extracted from the measurement result of the subject person obtained by the non-contact sensor, the comfort of the subject person is not impaired as compared with the case of using the contact sensor, and the burden on the user due to replacement of the pressure-sensitive element and daily sterilization can be reduced. As a result, a method for determining a sleep phase with excellent ease of operation can be obtained.

A computer-readable recording medium according to an aspect of the present invention is a computer-readable recording medium storing a program for determining a sleep phase, and when the program is executed by the computer, executes: receiving, from at least 1 non-contact sensor, a measurement result obtained by measuring the subject person using the at least 1 non-contact sensor; extracting a respiratory signal of the subject from the measurement result; and determining a sleep phase of the subject person based on a comparison between the level of the breathing signal of the subject person and the reference information with reference to the reference information on the level of the breathing signal, and outputting a determination result of the sleep phase.

A program according to an aspect of the present invention is a computer-executable program for determining a sleep phase, causing a computer to execute: receiving, from at least 1 non-contact sensor, a measurement result obtained by measuring the subject person using the at least 1 non-contact sensor; extracting a respiratory signal of the subject from the measurement result; and determining a sleep phase of the subject person based on a comparison between the level of the breathing signal of the subject person and the reference information with reference to the reference information on the level of the breathing signal, and outputting a determination result of the sleep phase.

With this configuration, the sleep phase determination method having the same effect as described above can be executed by the computer.

In the present invention, all or a part of a circuit, a unit, a device, a part, or a portion of a block diagram, or all or a part of a functional block may be executed by one or more electronic circuits including a semiconductor device, a semiconductor Integrated Circuit (IC), or an lsi (large scale integration). The LSI or IC may be integrated into one chip, or may be configured by combining a plurality of chips. For example, functional blocks other than the memory element may be integrated into one chip. Here, the term LSI or IC is used, but the term LSI varies depending on the degree of integration, and may be referred to as system LSI, VLSI (very large scale integration), or ulsi (ultra large scale integration). A Field Programmable Gate Array (FPGA) that can be programmed after the manufacture of the LSI, or a reconfigurable logic device that can perform the reconfiguration of the bonding relationship inside the LSI or the setting of circuit partitions inside the LSI may be used for the same purpose.

Further, the functions or operations of all or a part of the circuits, units, devices, components or parts may be performed by software processing. In this case, the software is recorded in one or more non-transitory recording media such as a ROM, an optical disk, and a hard disk drive, and when the software is executed by the processing device (processor), the function specified by the software is executed by the processing device (processor) and the peripheral device. The system or apparatus may also include one or more non-transitory recording media on which software is recorded, a processing device (processor), and a required hardware device, such as an interface.

Hereinafter, a sleep phase determination device according to an aspect of the present invention will be specifically described with reference to the drawings.

The embodiments described below are specific examples of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, steps, order of the steps, and the like shown in the following embodiments are examples, and do not limit the present invention. Further, among the components of the following embodiments, components that are not recited in the independent claims representing the uppermost concept will be described as arbitrary components.

(embodiment mode 1)

Fig. 1 is a block diagram showing an example of the functional configuration of the sleep phase determination device 10. In fig. 1, a non-contact sensor 70 is shown together with the sleep phase determination device 10. The non-contact sensor 70 may be included in the sleep phase determination apparatus 10.

First, the non-contact sensor 70 will be explained. The non-contact sensor 70 measures the distance to the subject person in the detection area and the movement of the subject person in a non-contact manner. The non-contact sensor 70 is constituted by, for example, a doppler radar. The doppler radar transmits an ultrasonic wave or an electromagnetic wave as a probe wave to a detection area and receives a reflected wave from a target person, thereby measuring a distance to the target person and a motion of the target person in a non-contact manner.

Fig. 2 is a diagram showing an example of the measurement result of the non-contact sensor 70. As shown in fig. 2, the measurement result 110 of the non-contact sensor 70 is composed of the reflection intensity 112 and the phase rotation amount 113 of each range bin (range bin) 111.

The distance library 111 represents the measurement result of the dispersion of the distance from the non-contact sensor 70 to the subject person, and corresponds to the one-way time from the transmission of the probe wave to the reception of the reflected wave. For example, when the probe wave is a radio wave of a microwave band having a pulse width of 0.5 ns, the resolution of the width of the range bank 111, that is, the range is 7.5 cm. The reflection intensity 112 is the intensity of the reflected wave, and indicates the probability that the target person exists in the corresponding distance library. The phase rotation amount 113 is a change amount of the phase of the reflected wave with respect to the probe wave, and its time change corresponds to the relative velocity of the subject person (for example, physical activity by breathing of the subject person). Here, the relative velocity of the subject person refers to a velocity component in the line-of-sight direction of the subject person viewed from the non-contact sensor 70.

Referring to fig. 1, the sleep phase determination device 10 includes a receiver 11, an extraction circuit 12, a memory 13, a determination circuit 14, and a notification device 15.

The receiver 11 receives a measurement result obtained by measuring the object person in the detection area by the non-contact sensor 70. The measurement result may also indicate the distance to the subject person and the movement of the subject person. The extraction circuit 12 extracts a respiration signal from the received measurement result. The memory 13 holds reference information on the level of the respiration signal. The determination circuit 14 determines the sleep phase of the subject person based on a comparison between the level of the extracted breathing signal and the reference information, and outputs a determination result. The notifier 15 notifies the user of the determination result when the sleep phase of the subject is determined to be a sleep phase other than the supine sleep phase. Here, the user refers to, for example, a nurse, or the like that monitors the health status of the subject person.

The sleep phase determination device 10 is constituted by a computer system having a processor, a memory, a communication circuit, and the like, for example. The components of the sleep phase determination device 10 shown in fig. 1 may be software functions that function by a processor executing a program recorded in a memory, for example.

Next, the operation of the sleep phase determination device 10 configured as described above will be described based on a specific example of the measurement situation.

Fig. 3 is a conceptual diagram illustrating an example of a measurement situation. Fig. 3 schematically shows a state in which the non-contact sensor 70 is disposed on the ceiling E and the subject S is on the floor F. In fig. 3, the area between adjacent concentric circles represents a distance library, and numbers provided in the radial direction of the concentric circles represent the numbers of the distance library. The range bin is a concentric spherical shell-shaped region that extends three-dimensionally and omnidirectionally. In fig. 3, the non-contact sensor 70 is illustrated directly above the subject S for simplicity, but the non-contact sensor 70 may be disposed diagonally above the subject S.

Fig. 4 is a flowchart showing an example of the operation of the sleep phase determination device 10.

The sleep phase determination device 10 operates as follows according to the flowchart of fig. 4 in the measurement situation of fig. 3.

The receiver 11 receives the measurement result from the non-contact sensor 70 (S121).

Fig. 5 is a graph showing an example of the measurement result corresponding to the measurement state of fig. 4. In the example of fig. 5, the reflection intensity of the reflected wave from the subject S and the amount of phase rotation derived from the physical movement due to the breathing of the subject S are detected in the 7 th range bin.

The extraction circuit 12 extracts a respiration signal from the received measurement result (S122 in fig. 4). The respiration signal is a frequency component of about ten or more Hz derived from the respiration of the subject person included in the time series of the measurement results. The extraction circuit 12 may also extract the breathing signal using a low-pass filter or a trend elimination filter, for example, from a time series of phase rotation amounts at a distance (7 th distance bin in the example of fig. 5) where the subject person exists.

Further, if the resolution of the distance of the non-contact sensor 70 is sufficiently high, it is also possible to grasp the displacement of the body surface of the subject person from the variation of the distance library having the peak of the reflection intensity. In this case, the extraction circuit 12 may extract, as the breathing signal, a frequency component of about ten or more Hz included in the time series of the displacement of the body surface of the subject person, that is, the variation of the distance library having the peak of the reflection intensity. The level of the extracted respiratory signal varies according to the sleep phase of the subject person.

Fig. 6A and 6B are conceptual views illustrating an example of the sleep phase of the subject, with fig. 6A showing the sleep phase lying on the back and fig. 6B showing the sleep phase lying on the stomach. As indicated by the long radial arrows in fig. 6A, in the supine sleep phase, the subject S moves radially in the chest and abdomen, and as indicated by the short parallel arrows in fig. 6B, in the prone sleep phase, the subject S moves relatively little vertically in parallel over the entire back.

Fig. 7 is a graph showing an example of a respiration signal corresponding to sleep. Fig. 7 shows the breathing signals extracted from the measurement results obtained by the non-contact sensor 70 provided directly above or obliquely above the subject S, in the case where the subject is lying supine (solid line) and in the case where the subject is lying prone (dotted line).

Based on the difference in the movement of the subject person corresponding to sleep, a respiratory signal having a higher level is extracted when lying on the back than when lying on the stomach. Here, the level of the respiration signal refers to an appropriate value indicating the magnitude of the respiration signal, and for example, a root mean square of the amplitude of the respiration signal in a predetermined time (for example, several seconds) is used.

In fig. 7, the levels of the breathing signals in the supine and prone positions are denoted as L1 and L2, respectively. In the supine sleep phase, the chest and abdomen portions of the body part of the subject, which are most moved due to breathing, are opened upward, and therefore, a respiratory signal of a level L1 higher than that in any other sleep phase such as prone position and not-shown lateral position is extracted.

Therefore, by setting a threshold TH smaller than the level of the breathing signal when the subject person is asleep and comparing the current level of the breathing signal with the threshold TH, it is possible to determine whether the subject person is asleep or not supine.

The threshold TH is not particularly limited, and may be set, for example, based on the measurement result before the sleep phase start determination. For example, the level of the breathing signal when the subject is asleep in the supine position may be obtained in advance, and a value obtained by multiplying the obtained level by a coefficient smaller than 1 may be used as the threshold TH. Alternatively, the level of the breathing signal in the supine position and the level of the breathing signal in the sleep phase other than the supine position may be obtained in advance, and the intermediate value between the obtained levels may be used as the threshold TH.

The set threshold TH is held in the memory 13 as reference information on the level of the respiration signal.

The determination circuit 14 determines whether the current sleep phase of the subject is a supine or other sleep phase by comparing the level of the breathing signal extracted from the most recent measurement result with the threshold TH from the memory 13 with reference to the threshold TH (S123 in fig. 4). The determination circuit 14 determines that the sleep phase of the subject person is supine when the level of the breathing signal is equal to or higher than a threshold TH, for example, and determines that the sleep phase of the subject person is not supine when the level of the extracted breathing signal is lower than the threshold, and outputs the determination result.

When the sleep phase of the subject person is determined to be supine (yes in S124), the sleep phase determination device 10 continues the determination of the sleep phase without notifying the user of the sleep phase. Further, the determined sleep phase may be stored as a record even if the user is not notified.

If the sleep phase of the subject is determined to be a sleep phase other than the supine sleep phase (no in S124), the notifier 15 notifies the user of the sleep phase (S180). For example, in the nursing home, the notifying device 15 may notify the nursing staff of the fact that the infant is in a sleeping phase other than the supine position in an appropriate form such as sound, vibration, light, or the like via a portable terminal or a display provided in the nursing home. This can prompt the nursing staff to return the infant to a supine sleep phase with a lower risk of SIDS. Note that the notification by the notifier 15 is not limited to the nursing home, and may be notified to nurses, managers, and the like in the same manner as described above, for example, facilities such as hospitals and old people's homes.

In this way, according to the sleep phase determination device 10, the sleep phase of the subject person can be determined based on the comparison between the level of the breathing signal and the reference information, using the characteristic that the level of the breathing signal differs depending on the sleep phase of the subject person. Since the respiration signal is extracted from the measurement result of the subject person obtained by the non-contact sensor, the comfort of the subject person is not impaired as compared with the case of using the contact sensor, and the burden on the user due to replacement of the pressure-sensitive element by consumption, daily sterilization, or the like can be reduced. As a result, a sleep phase determination device with excellent ease of treatment can be obtained.

(embodiment mode 2)

In embodiment 2, a sleep phase determination device that updates reference information using a breathing signal determined to be supine will be described. The same components and steps as those described in the above embodiment are referred to by the same reference numerals, and overlapping description thereof is appropriately omitted.

Fig. 8 is a block diagram showing an example of a functional configuration of the sleep phase determination device according to embodiment 2. The sleep phase determination device 20 of fig. 8 is added with a refresh circuit 26 compared to the sleep phase determination device 10 of fig. 1.

The update circuit 26 generates new reference information using the breathing signal extracted when the sleep phase of the subject person is determined to be supine, and updates the reference information held in the memory 13 with the new reference information.

Fig. 9 is a flowchart showing an example of the operation of the sleep phase determination device 20. In the operation of the sleep phase determination device 20 shown in fig. 9, step S190 is added to the operation of the sleep phase determination device 10 shown in fig. 4.

In the sleep phase determination device 20, similarly to the sleep phase determination device 10, the sleep phase of the subject person is determined based on the comparison between the level of the breathing signal and the reference information, and if the sleep phase is a sleep phase other than the supine position, the user is notified (S121 to S124, S180). The contents of steps S110 to S124, and S180 and the applied measurement state are as described in embodiment 1.

In the sleep phase determination device 20, when the sleep phase of the subject person is determined to be supine (yes in S124), the level of the breathing signal is collected by the update circuit 26. The update circuit 26 generates a new threshold by multiplying an average value of levels of a predetermined number of respiration signals collected most recently by a coefficient smaller than 1, for example, and updates the threshold held in the memory 13 with the new threshold.

In this way, according to the sleep phase determination device 20, the reference information is sequentially updated using the breathing signal determined to be in the supine position in the process of performing the sleep phase determination. Thus, the reference information is updated in accordance with the level of the breathing signal specific to the subject person and the temporal variation in the level, and therefore, the sleep phase of the subject person can be determined more accurately and stably from the personal difference and the variation in the physical condition of the subject person.

(embodiment mode 3)

In the determination of the sleep phase, a turning motion of the subject person, typically turning over, may be considered.

In embodiment 3, a description will be given of a sleep phase determination device that determines a sleep phase of a subject person by detecting a rotational motion of the subject person. The same components and steps as those described in the above embodiment are referred to by the same reference numerals, and overlapping description thereof is appropriately omitted.

Fig. 10 is a block diagram showing an example of a functional configuration of the sleep phase determination device according to embodiment 3. In the sleep phase determination device 30 of fig. 10, a determination circuit 34 is provided instead of the determination circuit 14 and a rotation detector 37 is added as compared with the sleep phase determination device 10 of fig. 1. The rotation detector 37 detects a rotation operation of the subject person based on the measurement result.

Fig. 11 is a flowchart showing an example of the operation of the sleep phase determination device 30. In the operation of the sleep phase determination device 30 shown in fig. 11, step S131 is added to the operation of the sleep phase determination device 10 shown in fig. 4, and steps S133 and S134 are provided instead of steps S123 and S124.

The sleep phase determination device 30 receives the measurement result (S121) and extracts a respiratory signal from the measurement result (S122), as in the sleep phase determination device 10. In the sleep phase determination device 30, the rotation detector 37 also detects the rotation of the subject person (S131).

Fig. 12A and 12B are conceptual diagrams illustrating an example of the idea of rotation detection. When the subject S turns as a turning operation, a part of the side of the forearm etc. is turned as a fulcrum P.

Fig. 12A schematically shows a turning operation from a state of lying on the back or the stomach to a state of lying on the side by a clockwise white arrow. In this operation, almost all the parts of the body of the subject S move in a direction close to the non-contact sensor 70 (the speed of the movement in this direction is a positive relative speed), and the relative speed also differs for each part as indicated by the upward black arrow. As a result, the distribution of the relative velocity biased to the positive side (hereinafter, referred to as a doppler spectrum) as shown in the right box was measured.

Fig. 12B schematically shows the movement from the side-lying state to the prone position or the supine position by a counterclockwise white arrow. In this operation, many parts of the body of the subject S move in a direction away from the non-contact sensor 70 (the speed of the movement in this direction is set to a negative relative speed), and the relative speed also differs for each part as indicated by a downward black arrow. As a result, a negatively biased doppler spectrum as shown in the right box was measured.

The doppler spectrum changes every moment in accordance with the state of turning over. For example, when the subject S changes the sleeping phase from the supine position to the prone position (or vice versa) through the lateral position, the pattern is such that a positive distribution in which the relative velocity is dominant is first presented and then a negative distribution in which the relative velocity is dominant is presented, if observed in time series.

Therefore, the rotation detector 37 detects the rotation of the subject person based on the measurement result of the doppler spectrum.

The determination circuit 34 determines the sleep phase of the subject person using the detection result of the rotation operation in addition to the comparison between the level of the breathing signal and the reference information (S133 in fig. 11). The determination circuit 34 may determine that the sleep phase of the subject person is a sleep phase other than the supine position even if the level of the breathing signal is equal to or higher than the threshold value when the rotation operation is detected in a state where the sleep phase of the subject person is determined to be the supine position, for example. Further, it is also possible to detect an abnormal state such as a respiratory arrest of the subject person, such as a decrease in the level of the respiratory signal without the rotation operation, separately from the change in the sleep phase.

The notifier 15 notifies the user of a suspected abnormality of the subject in addition to the notification of the sleep phase other than the supine position of the subject (S180).

In this way, according to the sleep phase determination device 30, the sleep phase of the subject person is determined using the detection result of the rotational operation in addition to the comparison between the level of the breathing signal and the reference information, and therefore the sleep phase of the subject person can be determined more accurately. As a result, it is possible to appropriately detect a change in sleep phase and an abnormal situation that cannot be detected only by comparing the level of the breathing signal with the reference information, and to notify the user of the change.

(embodiment mode 4)

The number of the non-contact sensors used for determining the sleep phase of the subject is not limited to 1. A plurality of non-contact sensors may be used for determination of the sleep phase.

In embodiment 4, a description will be given of a sleep phase determination device that determines a sleep phase of a subject person using measurement results obtained by measuring the subject person using a plurality of non-contact sensors. The same components and steps as those described in the above embodiment are referred to by the same reference numerals, and overlapping description thereof is appropriately omitted.

Fig. 13 is a block diagram showing an example of a functional configuration of the sleep phase determination device according to embodiment 4. In the sleep phase determination device 40 of fig. 13, a memory 43 and a determination circuit 44 are provided instead of the memory 13 and the determination circuit 14, respectively, as compared with the sleep phase determination device 10 of fig. 1. Further, a plurality of non-contact sensors 70a, 70b, 70c provided in different directions (for example, directly above and obliquely above) from the subject person are used. The plurality of non-contact sensors 70a, 70b, 70c may be included in the sleep phase determination device 40. The number of the plurality of non-contact sensors may be 2 or 4 or more.

The memory 43 holds reference information on the relationship between the levels of the respiration signals in the plurality of non-contact sensors 70a, 70b, and 70 c. The determination circuit 44 determines the sleep phase of the subject person based on a comparison between the relationship between the levels of the extracted respiratory signal among the plurality of non-contact sensors 70a, 70b, 70c and the reference information held in the memory 43.

Fig. 14 is a flowchart showing an example of the operation of the sleep phase determination device 40. In the operation of the sleep phase determination device 40 shown in fig. 14, steps S111 and S141 are added to the operation of the sleep phase determination device 10 shown in fig. 4, and steps S143 and S144 are provided instead of steps S123 and S124.

In the sleep phase determination device 40, the process of selecting 1 of the plurality of non-contact sensors (S111) and extracting the respiratory signal from the measurement result of the selected non-contact sensor (S121, S122) is repeated until all the non-contact sensors are selected (S141).

If the breathing signal is extracted for all the non-contact sensors (yes in S141), the determination circuit 44 determines the sleep phase of the subject person based on a comparison between the relationship between the levels of the extracted breathing signal among the plurality of non-contact sensors and the reference information.

The relationship between the levels of the extracted respiratory signals among the plurality of non-contact sensors differs depending on the sleep phase of the subject person.

Fig. 15A to 15D are conceptual diagrams illustrating an example of the relationship between the levels of a plurality of respiratory signals corresponding to sleep. Fig. 15A to 15D show the relationship between the levels La, Lb, and Lc of the breathing signals extracted from the measurement results of the non-contact sensors 70a, 70b, and 70c, in the case where the sleeping phase of the subject S is lying on the back, lying on the stomach, lying on the right side, and lying on the left side. The non-contact sensors 70a, 70b, and 70c are disposed right above, diagonally above left, and diagonally above right of the subject S, respectively.

As can be seen in fig. 15A, in the supine sleep phase, a movement of expanding and contracting radially occurs in the chest and abdomen of the subject S by breathing. Since the radial movement of the thoracic and abdominal parts is isotropic as viewed from any of the non-contact sensors 70a, 70b, 70c, the levels La, Lb, Lc of the breathing signals are substantially the same. That is, the levels La, Lb, Lc of the respiration signals are in a relationship of Lb ≈ La ≈ Lc.

As can be seen from fig. 15B, in the prone sleeping phase, the breathing causes parallel movements in the vertical direction on the entire back of the subject S. If viewed obliquely from the non-contact sensors 70b, 70c, the movement of the back appears smaller than if viewed directly from above by the non-contact sensor 70a, so the levels Lb, Lc of the respiration signal are smaller than the level La of the respiration signal. That is, the levels La, Lb, and Lc of the breathing signal have a relationship Lb < La > Lc.

As can be seen from fig. 15C and 15D, in the sleep phases of the right-side lying and the left-side lying, the breathing generates the radial expansion and contraction motion in the chest and abdomen of the subject S, and the horizontal motion occurs in the entire back. The movement of the back of the subject S is smaller than the movement of the chest and abdomen, and the movement of the body side is smaller than the movement of the back.

In the example of fig. 15C, the non-contact sensors 70a, 70b, and 70C measure the body side, the back, and the chest and abdomen of the subject S, respectively. Therefore, the level Lc of the respiration signal in the non-contact sensor 70c is maximum, then the level Lb of the respiration signal in the non-contact sensor 70b is large, and the level La of the respiration signal in the non-contact sensor 70a is minimum. That is, the levels La, Lb, Lc of the breathing signals have a relationship of Lb > La < < Lc.

In the example of fig. 15D, the non-contact sensors 70a, 70b, and 70c measure the body side, the chest and abdomen, and the back of the subject S, respectively. Therefore, the level Lb of the respiration signal in the non-contact sensor 70b is maximum, then the level Lc of the respiration signal in the non-contact sensor 70c is large, and the level La of the respiration signal in the non-contact sensor 70a is minimum. That is, the levels La, Lb, and Lc of the breathing signal have a relationship of Lb > > La < Lc.

The relationship between the levels La, Lb, and Lc of the breathing signal illustrated in fig. 15A to 15D is an example of the relationship between the levels of the breathing signal and the non-contact sensors.

The memory 43 stores the relationship between the levels La, Lb, Lc of the breathing signals in association with the sleep phase, for example, by the relational expression described above (not shown).

The determination circuit 44 determines the sleep phase of the subject person based on a comparison between the relationship between the levels La, Lb, Lc of the current breathing signal and the reference information held in the memory 43. Specifically, the determination circuit 44 determines the sleep phase held in the memory 43 in accordance with the relational expression established for the levels La, Lb, and Lc of the current breathing signal as the sleep phase of the subject person.

In this way, according to the sleep phase determination device 40, the sleep phase of the subject person can be determined based on the comparison between the relationship between the levels of the extracted breathing signal and the reference information, using the characteristic that the relationship between the levels of the breathing signal among the plurality of non-contact sensors differs according to the sleep phase of the subject person. This enables more accurate determination of a wider variety of sleep phases than simple threshold comparison.

In the embodiments of the present invention, the non-contact sensor is provided directly above or obliquely above the subject person, but the present invention is not limited to this. The signal correction and the like may be performed as necessary, and the apparatus may be provided at a position other than directly above and obliquely above the subject person.

Although the sleep phase determination device, the sleep phase determination method, and the program according to the embodiments of the present invention have been described above, the present invention is not limited to the embodiments. The present invention may be embodied in various forms, such as a modified form, and a form constructed by combining constituent elements of different embodiments, which are assumed by those skilled in the art, without departing from the spirit of the present invention.

Industrial applicability

The sleep phase determination device, the sleep phase determination method, and the recording medium according to the present invention can be widely used for applications of determining a sleep phase, such as a nursing system for infants in a nursing home.

Description of the reference symbols

10. 20, 30, 40 sleep phase determination device

11 receiver

12 extraction circuit

13. 43 memory

14. 34, 44 decision circuit

15 informing device

26 updating circuit

37 rotation detector

70. 70a, 70b, 70c non-contact sensor

110 measurement results

111 distance library

112 intensity of reflection

113 amount of phase rotation