JP2003032672A - Monitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monitor which not only senses surely the state of a person while asleep, but also is small-sized and simple. SOLUTION: The monitor 1 has a photographing means 11 for photographing continuously a monitoring object 2 illuminated by a constant quantity of light; a difference-image generating means 14 for generating the difference-image between the images of two frames obtained by the imaging means 11 which are generated at a predetermined time-interval; an operating means 32 for obtaining from the difference-image the varying output associated with the variation generated between the two frames; and a sensing means 33 for sensing the movement of the monitoring object 2 based on the temporal variation of the varying output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device and a monitoring method for monitoring an object to be monitored, and more particularly to a monitoring device and a monitoring method for monitoring changes such as respiration of a sleeping person.

[0002]

2. Description of the Related Art As a monitoring device for monitoring changes in the breathing of a sleeping person, a device for monitoring the changes in the breathing of the sleeping person has been conventionally proposed based on the time transition of the pressure distribution detected by a load sensor or a pressure sensor. ing.

[0003]

However, according to the conventional device as described above, the monitoring device has high performance in order to acquire and detect a stable signal because the measured signal is very small. It required a complicated signal amplifier and some kind of signal processing, which made the system complicated and large-scale.

Therefore, an object of the present invention is to provide a monitoring device which is not only capable of reliably detecting the state of a sleeping person but is also small and simple.

[0005]

In order to achieve the above object, a monitoring device according to the invention according to claim 1 is a monitoring device which is illuminated with a constant amount of light as shown in FIGS. 1, 2 and 3, for example. An image pickup means 11 for continuously picking up an image of the object 2; a difference image generation means 14 for generating a difference image of images of two frames obtained by the image pickup means 11 at a predetermined time interval; and between the two difference frames from the difference image. And a detecting means 33 for detecting the movement of the monitored object 2 from the time change of the change output.

With this configuration, the image pickup means 11 and
Difference image generation means 14, calculation means 32, and detection means 3
3 is included, a difference image of two frame images at a predetermined time interval obtained by the image pickup means 11 is generated, and the movement of the monitoring target object 2 is determined from the time change of the change output regarding the change between the two frames from the difference image. By detecting, not only can the state of the sleeping person 2 be reliably detected, but also a small and simple monitoring device 1 can be provided. Illumination with a constant amount of light is not limited to illumination with an artificial light source, and may be illumination with natural light. The movement of the monitored object 2 is typically a periodic movement.

Further, as described in claim 2, the monitoring device 1 according to claim 1 is provided with an illumination pattern projecting means 12 for illuminating the monitored object 2 with a predetermined pattern illumination light 13a. It is preferable that the illumination light 13a has an illumination distribution in a direction parallel to the direction connecting the illumination pattern projecting unit 12 and the imaging unit 11.

Further, as described in claim 3, in the monitoring device 1 according to claim 1 or 2, the image pickup means 10 is provided.
Has an image sensor in which a plurality of pixels are arranged.

Further, as described in claim 4, in the monitoring device 1 according to any one of claims 1 to 3, the difference image generation means 14 performs a binarization process on the difference image. It is characterized by

Further, as described in claim 5, in the monitoring device 1 according to any one of claims 1 to 4, the calculating means 32 is an accumulating means for accumulating each pixel value of the difference image. 32a may be provided.

Further, as described in claim 6, in the monitoring device 1 according to any one of claims 1 to 4, the calculating means 32 uses the pattern on the difference image as the change output. The feature is that the pattern movement amount of each moving portion is calculated. Further, the calculation means 32 may calculate the accumulation of the pattern movement amount.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In each drawing, the same or corresponding members are designated by the same reference numerals or similar reference numerals, and redundant description will be omitted.

FIG. 1 is a schematic perspective view of a monitoring device 1 according to an embodiment of the present invention. A person 2 (hereinafter referred to as a sleeping person 2) as a monitoring target lies on a bed 6 in the figure. Moreover, the bedclothes 3 are further laid on the sleeping person 2 to cover a part of the sleeping person 2 and a part of the bed 6.

On the other hand, immediately above the abdomen of the sleeping person 2, an image pickup section 11 is installed as an image pickup means for continuously picking up the image of the sleeping person 2 illuminated with a constant amount of light. It is sufficient that the constant amount of light does not change significantly during the exposure of the image pickup unit 11 and is substantially constant. More specifically, it suffices that there is no large change, for example, a change in light amount of 10% or more, during a time interval for obtaining two frames for generating a difference image described later. That is, on the difference image, most of the bright points that have not moved are removed together with the background (the smaller the change in the light amount, the higher the removal degree), and the light amount does not have to change to the extent that the moved bright points can be extracted. Further, the illumination may not be performed outside the exposure time.

Further, a light projecting section as an illumination pattern projecting means for illuminating the sleeping person 2 with a predetermined pattern of illumination light is provided above the sleeping person 2 approximately above the foot or head (in the case where the sleeping person is above the foot). 12 is installed, and the bedding 3 is approximately on the abdomen of the sleeping person 2.
Lighting is centered around. The illuminated range may be set to a range that covers the abdomen, chest, back, and shoulders of the sleeping person 2 that can be taken during sleep. Similarly, the imaging unit 1
The range of the imaging region by 1 may be set to a range that covers the positions where the abdomen, chest, back, and shoulders of the sleeping person 2 can take while sleeping. In the present embodiment, the imaging unit 11 is directly above the abdomen of the sleeping person 2, and the light projecting unit 12 is the sleeping person 2.
Although it is assumed that it is installed approximately above the foot or the head, it is not limited to this, and it may be set at a position where it is easy to detect the periodic movement of the sleeping person 2. Alternatively, it may be set at a position where it can be easily installed, and may be installed, for example, avoiding above the sleeping person 2. Here, the periodic movement is typically the breathing of the sleeping person 2.

Further, the image pickup section 11 and the light projecting section 12 are installed so that the axis connecting the image pickup section 11 and the light projecting section 12 is substantially parallel to the center line of the bed 6. The image pickup unit 11 and the light projecting unit 12 may be installed on a ceiling, for example. However, when a wall is present in the vicinity, it may be a wall or may be attached to a stand. That is, the installation location may be appropriately determined according to the purpose and specifications of the monitoring device. By installing in this way, small periodic movements of the sleeping person 2, for example, respiration, can be detected sensitively. The image pickup unit 11 has an image pickup device in which a plurality of pixels are arranged, and is typically a CCD.
It is a camera.

The light projecting section 12 is typically a light projecting means using a diffractive element having a periodic structure. The diffractive element is typically a fiber grating (FG) element, but may be any element as long as it spatially discretizes and projects light, such as a diffraction grating. It may be an image formed by a lens array, a light source array or an aperture array, collimated light emitted from the light source array or the aperture array, and the like. Further, the patterned illumination light has an illumination distribution in a direction parallel to the direction connecting the light projecting unit 12 and the imaging unit 11. The illumination distribution means that the illumination light has a distribution of intensity changes. That is, the patterned illumination light is
For example, linear illumination light as shown in FIG. 16 may be used. The intensity of the linear illumination light is constant in the direction orthogonal to the parallel direction, but there is a distribution of intensity changes in the parallel direction. The light projecting section 12 is
The sleeping person 2 is illuminated with a grating pattern 13a in which bright points are arranged in a square lattice. The FG element 13 will be described later with reference to FIG.

Referring to the block diagram of FIG. 2, the monitoring device 1
An example of the configuration will be described. The monitoring device 1 is configured to include an imaging device 10 including an imaging unit 11 and a light projecting unit 12, an arithmetic device 30, and a reporting device 40. The arithmetic unit 30 is typically a personal computer or a microcomputer. The arithmetic unit 30 includes a control unit 31 and controls the monitoring device 1. An interface 35 is connected to the control unit 31, and the imaging device 10 and the notification device 40 are connected.
Are connected to and controlled by the control unit 31 via the interface 35.

Now referring to the conceptual perspective view of FIG.
The imaging device 10 will be described. Here, the sleeping person 2 will be described as the object 20 having a rectangular parallelepiped shape and the surface illuminated by the FG element will be described as the flat surface 21. For easier understanding, the change (movement) of the object 20 will be described when the object 20 exists and when it does not exist.

In the figure, an object 20 is placed on a flat surface 21. Cartesian coordinate system X so that the XY axes are placed in the plane 21.
YZ is taken, and the object 20 is placed in the first quadrant of the XY coordinate system.

On the other hand, the image pickup section 11 is arranged above the plane 21 on the Z axis in the figure. Imaging lens 1 of imaging unit 11
1a is arranged such that its optical axis coincides with the Z axis. An image forming surface 15 '(image plane) of the image sensor 15 on which the image forming lens 11a forms an image of the plane 21 or the object 20 is a surface orthogonal to the Z axis. 15 'in the image plane
The xy Cartesian coordinate system is taken to be such that the Z axis passes through the origin of the xy coordinate system.

The FG element 13 is arranged at the same distance from the plane 21 as the imaging lens 11a and at a distance d from the imaging lens 11a in the negative direction of the Y-axis. Figure 3
As will be described later with reference to, the laser light L1 is continuously incident on the FG element 13 in the Z-axis direction, and the plane 21 is continuously irradiated with a pattern in which dots are arranged in a square lattice. To be done. That is, the object 20 and the plane 21 are illuminated with the patterned illumination light. The image processing unit 14 is electrically connected to the image capturing unit 11 as a differential image generating unit that generates a differential image of two frame images obtained by the image capturing unit 11 at predetermined time intervals. The image processing unit 14 includes an image sensor 15
The difference image is generated by taking the difference for each pixel of.
The predetermined time interval is an interval sufficient for monitoring the fine periodic movement of the object 20, that is, the breathing of the sleeping person 2, and is, for example, about 2 to 3 frames / sec. Further, although the image pickup device 15 and the image processing unit 14 are shown as separate bodies in the drawing, they may be integrally configured.

When a light source such as a laser having a substantially single wavelength light source is used for the light projecting section 12 as in the present embodiment,
The image pickup unit 11 may include a filter 11b that attenuates light having a wavelength other than the peripheral portion having the substantially single wavelength. Filter 1
1b is typically an optical filter, and the imaging lens 1b
It may be arranged on the optical axis of 1a. By doing so, the intensity of the light emitted from the light projecting unit 12 among the light received by the image sensor 15 is relatively increased, so that the image capturing unit 11 can reduce the influence of ambient light.

The FG element will be described with reference to FIG. F
The G element is formed by arranging about 100 optical fibers each having a diameter of several tens of microns and a length of about 10 mm in a sheet shape and stacking the two fibers so that the two fibers are orthogonal to each other. In the FG element 13, the above-mentioned sheet is arranged parallel to the plane 21 (perpendicular to the Z axis). The laser light L1 is incident on the FG element 13 in the Z-axis direction. Then, the laser light L1 is condensed at the focal points of the individual optical fibers and then becomes a diffracted beam array, which is a plane 21 which is a projection surface.
Pattern 13a, which is a bright spot matrix in a square lattice
Is projected.

Although the image pickup apparatus 10 has been described above using the FG element 13 as the diffractive element, a two-dimensional microlens array may be used as the diffractive element.

The two-dimensional microlens array 16 (hereinafter simply referred to as the lens array 16) will be described with reference to the schematic diagram of FIG. (A) is a perspective view and (b) is a partial cross-sectional view showing a cross section in the left half of the front view. The lens array 16 is formed by forming a plurality of lenses 17 on one surface of a plate at a period of several tens of microns, for example.
Here, as the lens array 16, a surface on which the plurality of lenses 17 of the lens array 16 is formed (hereinafter simply referred to as a lens surface 18) is used in which the high reflection processing is performed. High-reflection treatment is typically aluminum coating 18
a. By doing so, the lens 17 has the same structure as the concave mirror, so that the lens array 16 can be easily made to have a short focal point.

The lens array 16 has a lens surface 18
Instead of applying aluminum coating on the lens surface 18
A plane mirror may be provided immediately after. In this case, light is incident on the lens 17 twice, so that the lens array 16 can be easily made to have a short focal length.

In this case, as shown in the schematic view of FIG. 6, the lens array 16 includes a beam splitter 19 which reflects or transmits light depending on the incident angle of the incident light. The laser light L1 is applied to the lens array 16 by Z
It is incident in the direction perpendicular to the axis. Then, the laser light L1 is
It is reflected by the beam splitter 19 and enters the lens array 16. The incident laser light L1 is transmitted to each lens 17
After being reflected by the lens surface 18 of No. 1 and condensed at the focal point of the lens 17, the light is transmitted through the beam splitter 19 and spreads as a spherical wave, which causes interference and causes a plane 21 which is a projection surface.
The pattern 16a, which is a bright spot matrix, is projected in a square lattice shape.

Further, as shown in FIG. 7, the lens array 16
Alternatively, two identical lens arrays 16 may be installed with their lens surfaces 18 arranged close to each other. In this case, the lens surface 18 is used without the aluminum coating 18a. This 2
A lens array 16 'in which the lens arrays 16 are arranged close to each other
Then, the laser light L1 is made incident on the Z-axis direction. Then, the laser light L1 is condensed at the combined focal point of the respective two lenses 17, and then spreads as a spherical wave to spread and interfere with each other, causing a bright spot matrix in a square lattice on the plane 21 which is the projection surface. Pattern 16a ′ is projected.

In the lens array 16, it is desirable that the gap between the adjacent lenses 17 is as small as possible. Therefore, if the lenses 17 are arranged in a rectangular lattice shape, it is better to make the opening shape rectangular rather than circular.

The image pickup apparatus 10 can further use a low output laser by using the lens array 16 having high wavefront accuracy as described above for the light projecting section 12. Below, F
The case where the G element 13 is used will be described.

Returning to FIG. 3, the image pickup apparatus 10 will be further described. In the pattern 13a projected on the plane 21 by the FG element 13, the part where the object 20 exists is the object 2
It is blocked by 0 and does not reach the plane 21. Here, if the object 20 does not exist, the bright spot to be projected on the point 21a on the plane 21 is projected on the point 20a on the object 20. Since the bright point has moved from the point 21a to the point 20a, and the imaging lens 11a and the FG element 13 are separated by the distance d, the point 21a '(x,
The portion to be imaged on y) is imaged on the point 20a ′ (x, y + δ). That is, when the object 20 does not exist and when the object 20
Means that the bright spot moves by a distance δ in the y-axis direction.

The image processing section 14 determines the image formation plane 1 at these two time points.
By generating the two-frame difference image received (imaged) at 5 ′, the difference image in which the bright spot has moved can be generated.
In addition, by taking the difference between the images of the two frames, this difference image removes the bright spots that have not moved together with the background,
The image is an image in which the bright spots that have moved are extracted. The two frames here may be the latest imaged frame and a frame at a time point in the past from this frame, and are, for example, two frames shifted by one frame.

As described above, since the image pickup apparatus 10 produces the difference image, the influence of ambient light can be eliminated. For example, even if a shadow caused by an object other than the sleeping person 2 is applied to the sleeping person 2 due to sunlight, or the illumination intensity due to ambient light varies among the sleeping person 2 in a partial portion, such a shadow or Since the influence of variation can be eliminated, it is easy to perform the binarization processing described later. The difference image can be obtained by A / D converting the image signal, storing it in the frame memory, and computing the corresponding image data. In particular, this feature is remarkable when a moving body detection element is used as the image pickup element 15.
The moving object detection element has a function of storing the pixel value of a frame in each pixel of the image pickup element 15 and performing a threshold process on the difference between the pixel value of the latest frame shifted by one frame or the difference and outputting the value. With the element, the difference image can be generated without being affected by noise in the signal transmission process.

Further, the image processing section 14 carries out a binarization process on this difference image. For example, when the above-described moving body detection element is used, the binarization processing is performed by using 2 pixels for each pixel of an image of 2 frames.
The output value of each frame is peak-held including the bias, and a comparator (not shown) outputs 1 when the absolute value of the difference between the pixels is greater than or equal to a threshold value, and outputs 0 when the absolute value is less than the threshold value. Such threshold processing is performed. By doing so, the SN of the image sensor can be fully used to perform the subtraction. Therefore, it is possible to perform detection with a wider dynamic range than in normal image processing (for example, pixel data is quantized into 8 bits). Thereby, the imaging device 10
Can detect slight changes in the pattern without using a high-power laser or performing a short exposure (imaging) by synchronizing the shutter with light emission. Accordingly, the laser light L1 may be a low-power laser, and it is not necessary to synchronize the laser emission and the exposure, and the laser light L1 can be continuously emitted.

The laser light L1 is pulsed light which is emitted intermittently, and the image pickup section 11 is provided with a shutter (not shown) so as to intermittently pick up an image on the image forming surface 15 '. May be. In this case, the light projecting unit 12 may use a pulsed light source in which the light source emits light for a predetermined light emission time, or may have a structure in which light is repeatedly shielded and irradiated in a pulsed manner by a shutter. Further, although it is preferable to use an electronic shutter as the shutter, a mechanical shutter may be used.

The relationship between the intermittent irradiation of the light L1, that is, the illumination of the plane 21 and the intermittent imaging will be described with reference to the chart of FIG. In each of (a), (b), and (c), the horizontal axis is the time t axis. The vertical axis of (a) shows the illumination intensity of the patterned illumination light that has passed through the FG element 13, the vertical axis of (b) shows the illumination intensity of ambient light, and the vertical axis of (c) shows the combined illumination intensity of the two.

The illumination light shown in (a) has a pulse duration t.
It is a pulsed light that lasts only 1. On the other hand, as shown in (c), the image capturing unit 11 captures an image by opening the shutter for the exposure time t2. In this figure, the exposure time t2
Indicates the case where the pulse duration is slightly longer than t1. The exposure time may also be the illustrated exposure time t2 'which is shorter than the pulse duration t1. For example, the exposure time t
2'is 0.01 ms and the pulse duration t1 is 0.05
There may be a case like ms. However, they are preferably substantially the same.

The duration (pulse width) t1 of the pulsed light is
The range is about 1 / 100,000 to 0.1 seconds, but it is preferable to set the video rate to 0.03 seconds or less.

The timing of illumination with pulsed light and the timing of imaging are synchronized. That is, in FIG. 8, the irradiation start time of pulsed light (starting point of time t1) and the exposure start time (starting point of time t2) are set to be the same. Thus, the synchronization is preferably synchronized so that the irradiation start and the exposure start occur at the same time, but they may be slightly deviated.
An image is formed on the image plane 15 'during this time t2 or t2'.

As a result, the image pickup device 10 can relatively weaken the intensity of the ambient light, so that the influence of the ambient light can be suppressed, and since the pulsed light is used, the absolute amount of light can be suppressed to a low level. . Therefore, even when the imaging target is a person (sleeping person 2), the adverse effect on the eyes can be minimized. In other words, since the exposure amount energy of the ambient light with respect to the exposure amount energy of the illumination light is relatively reduced, bright illumination can be performed and the influence of the ambient light can be reduced. In addition, a large illuminating means, which has a problem of heat generation and large energy consumption, becomes unnecessary. In addition, the threshold value processing described above becomes easy, and at the same time, it becomes very easy to evaluate the amount of movement of the bright spot that has moved.

Returning to FIG. 2, the monitoring device 1 will be further described. A storage unit 34 is connected to the control unit 31, and can store data such as a difference image input from the imaging device 10 and calculated information. The arithmetic device 30 calculates the difference image input from the imaging device 10 via the interface 35,
The storage unit 34 is configured to store in time series.
Further, the storage unit 34 is provided with a breathing pattern storage unit 36 that stores a normal breathing pattern and an abnormal breathing pattern of the sleeping person 2. The breathing pattern will be described later with reference to FIG.

Further, the control unit 31 is connected with an input device 37 for inputting information for operating the monitoring device 1 and an output device 38 for outputting a result processed by the monitoring device 1. The input device 37 is, for example, a touch panel, a keyboard or a mouse, and the output device 38 is, for example, a display, a printer or an alarm device. Although the input device 37 and the output device 38 are illustrated as being externally attached to the arithmetic device 30 in the present drawing, they may be incorporated therein.

Further, the control section 31 is provided with a calculation section 32 as a calculation means for obtaining a change output regarding a change between two frames from a difference image input from the image pickup apparatus 10. The arithmetic unit 32 further includes an accumulating unit 32a as an accumulating unit that accumulates each pixel value of the difference image. The change output is typically the cumulative value of the pixel values. That is, the change output is for extracting and representing the shape change in the monitoring target area obtained from the difference image. This is, for example, a sleeping person 2
It is to extract movements such as breathing. Thereby, the extracted motion of the sleeping person 2 forms a waveform pattern.

The calculating section 32 obtains a change output by accumulating the pixel values of the difference image by the accumulating section 32a. In this way, when the sum of the pixel output values of the difference image is simply taken, the sum total becomes the smallest at the transition timing of exhalation and inspiration, and the sum total becomes the largest during exhalation and during inhalation. Conceivable. Since the difference image is input as a binarized image, as described above, when the output of a pixel whose absolute value of the difference is equal to or greater than the threshold value is 1, the cumulative value can be calculated by counting the number. I want it. By arranging these accumulated values in time series, the change output can be obtained. Figure 9
The waveform pattern of the change output obtained from the cumulative value of each pixel value is shown in FIG.

Further, the calculation unit 32 may be configured to calculate the pattern movement amount of each moving portion of the pattern on the difference image as the change output. At this time, the pattern movement amount is calculated by distinguishing between positive and negative depending on the moving direction of the pattern. Thus, the respiratory rate can be detected by measuring the number of “zero crosses” (intersections where the signs are inverted) that appear between the inspiration pattern and the expiration pattern in the detection of the respiratory rate by the detection unit 33 described later. Also, the pattern movement amount is
It is preferable to calculate the pattern movement amount in the axial direction connecting the light projecting unit 12 and the imaging unit 11 on the difference image.

Here, the pattern movement amount will be described with reference to the schematic view of FIG. The x'y 'axes in the figure correspond to the xy axes in FIG. That is, the y′-axis direction on the difference image is parallel to the axial direction connecting the light projecting unit 12 and the imaging unit 11. As shown in the figure, the input difference image becomes an image in which the bright points that have not moved are removed together with the background, and the bright points that have moved are extracted. Here, it is assumed that the moved bright point A has moved by a distance δ in the y′-axis direction.

The monitoring device 1 can detect the movement of the sleeping person 2 by the detection unit 33, which will be described later, by following the change of δ. Further, if the pitch of the pattern 13a, that is, the pitch of the bright spots is made fine so that the correspondence between the bright spots is not unclear, the movement of the sleeping person 2 can be detected in more detail.

At this time, the calculation unit 32 may calculate the distance δ as the pattern movement amount. This is because when the imaging device 10 is installed as in the present embodiment, the vertical movement due to the breathing of the sleeping person 2 appears in the movement of the pattern in the y′-axis direction. Further, by doing so, the calculation unit 32 does not have to calculate the pattern movement amounts in both the x′-axis direction and the y′-axis direction, and thus the calculation amount can be significantly reduced.

Further, regarding the pattern movement amount, if the image pickup device 10 picks up images in the order of no light emission, light emission, and light emission and generates a difference image for each, the position of the original bright spot can be obtained in the first difference image, and Only the bright spots that have moved in the difference image can be taken. Therefore, the position of the bright spot can be used to know where the bright spot has moved from. That is, the moving direction of the bright spot (pattern) can be known.

When calculating the pattern movement amount, the calculation unit 3
2 obtains a change output by accumulating the pattern movement amount of each moving portion calculated above. A change output can be obtained by arranging the movement amount cumulative values in time series.
In addition, the arithmetic unit 32 distinguishes positive and negative from each other and accumulates them, so that it is possible to distinguish between exhalation and inspiration by detecting respiration by the detection unit 33 described later. FIG. 11 shows a waveform pattern of the change output of the movement amount cumulative value.

Further, the arithmetic unit 32 may obtain the change output by accumulating the absolute values of the pattern movement amounts of the respective moving portions calculated above. This way,
By setting the cumulative value of the movement amount to an absolute value, it is impossible to discriminate between exhalation and inspiration by the detection of breath by the detection unit 33 described later, but it is possible to prevent the plus and minus from canceling each other and lowering the sensitivity to movement. it can.

Further, the arithmetic unit 32 may obtain a change output by accumulating the pattern movement amount of the positive or negative movement portion, which is larger among the pattern movement amounts of the respective movement portions calculated above. Good. By doing so, it is possible to prevent the plus and minus from canceling each other and lowering the sensitivity to movement, while knowing whether the pattern movement amount is positive or negative.

Further, of the pattern movement amounts of the respective moving portions calculated above, the arithmetic unit 32 signs the accumulation of the pattern movement amount of the one having the larger positive or negative movement portion to the accumulation of the smaller pattern movement amount. The change output may be obtained by calculating the value subtracted with. By doing so, the positive / negative and plus / minus of the pattern movement amount are not cancelled, and the sensitivity to the movement can be increased.

Further, the arithmetic unit 32 compares the respective phases of the pattern movement amounts of the respective moving portions calculated above with each other,
By this comparison, each of those with similar phases is grouped,
The sum of the pattern movement amount of each group is calculated. And
You may make it calculate the sum total of each group between the groups which are in antiphase. By doing this, groups of pattern movement amounts that are close to each other are grouped,
Since the sum total is obtained, for example, the breathing of the sleeping person 2 can be extracted as a group and amplified. Furthermore, since the sum of each group is subtracted between groups close to the opposite phase, and the movement of the sleeping person 2 is detected based on the value obtained by the subtraction, for example, a portion that rises due to the breathing of the sleeping person 2 Even if there is a falling portion, the difference can be amplified to amplify the breathing pattern amplitude, and breathing can be reliably detected.

Further, the calculation unit 32 may be configured to integrate the pattern movement amount for each pixel with respect to time. By doing so, the value obtained by time integration becomes a value similar to the absolute height. By doing so, a value similar to the absolute value of the height of the sleeping person 2 can be obtained as the change output. In this case, the calculation unit 32 can obtain a change output by time-integrating the pattern movement amount of each moving portion calculated above for each pixel. Further, the calculation unit 32 may obtain the change output by accumulating the time integral value of each pixel calculated in this way. A change output can be obtained by arranging the cumulative values of the accumulated amount of movement in time series. Figure 1
2 shows the waveform pattern of the change output of the movement amount time integrated value.

As described above, the calculating section 32 can obtain the waveform pattern of the change output using any of the above-mentioned configurations. Further, the configuration of the arithmetic unit 32 described above may be appropriately selected depending on the installation state, the use state of the device, the purpose, and the like. Further, the calculation unit 32 only needs to be able to obtain a change output waveform pattern that reflects the motion of the sleeping person 2,
The configuration is not limited to the one described above.

Further, the control section 21 is provided with a detection section 33 as a detection means for detecting the movement of the sleeping person 2 from the time change of the change output. The detection unit 33 is configured to detect the respiration of the sleeping person 2 and the respiration rate thereof when the change output is cyclically changing. Further, the detection unit 33 is configured to consider that there is a motion other than breathing when the change output is not a periodic fluctuation. Further, the detection unit 33 may be configured to consider a motion other than breathing when the absolute value of the change output exceeds a certain value.

Further, when the change output is the above-mentioned cumulative value (see FIG. 9), the detecting unit 33 determines the respiration rate with the two cycles as one breath when the change output is cyclically changing. To detect. When the change output is the above-described movement amount cumulative value or movement amount cumulative time integrated value (see FIGS. 11 and 12), the detection unit 33 causes the change output to be Respiratory rate is detected with one cycle as one breath.

The detecting unit 33 detects the movement of the sleeping person 2 such as breathing as described above. The breathing pattern of the breath detected by the detection unit 33 is, for example, when the cycle of the breathing pattern is disturbed in a short time, or when the cycle of the breathing pattern is rapidly changed, for example, spontaneous pneumothorax and bronchial asthma. Lung diseases such as, heart diseases such as congestive heart failure,
Alternatively, it can be inferred that it is a cerebrovascular disease such as cerebral hemorrhage.
If the breathing pattern continues to disappear, the sleeping person 2
Can be inferred to have stopped breathing. And if the movement of the sleeping person 2 frequently occurs in a short time instead of the breathing pattern,
It can be inferred that the sleeping person 2 is suffering for some reason and is rampaging.

Further, the detection unit 33 detects the detected sleeping person 2
Is configured to determine the state of the sleeping person 2. Accordingly, the detection unit 33 can determine that the sleeping person 2 is in a dangerous state in the above case.

Further, the detection of movements of the sleeping person 2 other than the respiration is greater than that in the case where the waveform pattern detects only the respiration.
It can be detected easily because it fluctuates much more. In this case, the detection unit 33 can further detect from the change output whether the sleeping person 2 is moving on the spot, such as turning over, or moving, such as getting up from the bed. Further, even when the sleeping person 2 makes periodic small movements such as convulsions, the abnormality can be determined from the waveform pattern. Furthermore, by storing the waveform pattern of the convulsive state in the storage unit 34, it is possible to determine that the sleeping person 2 is in the convulsive state.

Further, the detection unit 33 determines that the sleeping person 2 on the bed 6
It may be possible to determine that the area where the area exists is extremely close to one of the ends of the bed 6. Accordingly, the monitoring device 1 can determine the situation where the sleeping person 2 is in a dangerous position such as falling from the bed 6.

Here, examples of normal and abnormal breathing patterns will be described with reference to FIG. The normal breathing pattern stored in the breathing pattern storage unit 36 in the storage unit 34 is a periodic pattern as shown in FIG. The abnormal breathing pattern stored in the breathing pattern storage unit 36 is, for example, Chain-Stokes (C
Heyne-Stokes) breathing, central hyperventilation, ataxic breathing, Kusmul breathing, etc.
It is a breathing pattern that is considered to occur when there is a physiological disorder in the body.

In FIG. 13B, Cheyne-Stock is shown.
The breathing pattern of es breathing, the breathing pattern of central hyperventilation are shown in FIG. 13 (c), and the breathing pattern of ataxic breathing is shown in FIG. 13 (d). Further, FIG. 14 shows a disease name or a diseased part when the above-mentioned abnormal breathing pattern occurs.

The detection unit 33 determines which breathing pattern the sleeping person 2 belongs to by utilizing the fact that the breathing frequency, the number of appearances, and the depth of each breathing pattern are different. Determine the state of.

Further, the detection unit 33 detects that the sleeping person 2 is breathing
When it is determined that it belongs to a breathing pattern that is thought to occur in a physiologically impaired Yuto,
It is determined that the sleeping person 2 is breathing abnormally and is in a dangerous state. The state of the sleeping person 2 determined in this way is output from the output device 38 by the control unit 31. Further, the output contents include the determined respiratory rate and movement frequency of the sleeping person 2, the name of the abnormal breathing pattern, the disease name that is considered to cause the breathing, the diseased organ, the diseased part, and the like.

Here, the reporting device 40 for reporting the determination result of the state of the sleeping person 2 by the detection unit 33 to the outside will be described. The reporting device 40 reports the determination result of the state of the sleeping person 2 by the detection unit 33 to the outside. The notification device 40 informs the nurse station, the living room, the dining room, another bedroom, etc. of the state of the sleeping person 2 determined by the detection unit 33, the information of the sound acquired from the microphone (not shown) provided in the bed 6, and the like. Wireless communication device using wireless communication for delivering to another place of
It is configured to include a wired communication device using a power line or a dedicated line. The information sent by these communication devices can be used to send an emergency message, make an alarm sound, or give a light sign.
Further, these information and messages can be sent to a person or device at a remote place through a fixed telephone line, a data communication line, a CATV line, a mobile telephone line, or the like.

Further, the monitoring device 1 may be provided with a pressure sensitive switch in the bedding placed below the sleeping person as an auxiliary means for accurately detecting whether or not the sleeping person 2 is present. By turning this switch on / off, it is possible to easily determine the presence / absence of a sleeping person.

In the above, the case where the monitoring device 1 detects the movement of the sleeping person 2 on the bed 6 has been described, but the present invention is not limited to this and is applied to a monitoring area such as a toilet or a bathroom. When it is limited, it works particularly effectively. For example, as shown in FIG.
When is installed on the ceiling of the bathroom, it is possible to reliably detect the breathing and movement of a person taking a bath. Further, although the case where the light projecting unit 12 is provided has been described in the present embodiment, the same configuration can be implemented without the light projecting unit 12.

According to the present embodiment as described above, the monitoring device 1 reliably detects the sleep of the sleeping person by the simple image processing without being affected by the posture of the sleeping person 2 or the ambient light. can do. As a result, the monitoring device 1 can realize prompt emergency response when an elderly person or a sick person falls into a critical situation.

[0072]

As described above, according to the present invention, an image pickup means for continuously picking up an image of a monitored object illuminated with a constant amount of light, and two frame images at predetermined time intervals obtained by the image pickup means. Difference image generating means for generating a difference image of
The state of the sleeping person is surely detected, since the calculating means for obtaining the change output regarding the change between the two frames from the difference image and the detecting means for detecting the movement of the monitored object from the time change of the change output are provided. In addition, it is possible to provide a monitoring device that is small and simple.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an outline of a monitoring device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of a monitoring device used in the embodiment of the present invention.

FIG. 3 is a conceptual perspective view showing a configuration example of an imaging device used in the embodiment of the present invention.

FIG. 4 is a conceptual perspective view illustrating an FG element used in the embodiment of the present invention.

5A and 5B are (a) a schematic perspective view and (b) a schematic partial sectional view illustrating a two-dimensional microlens array used in an embodiment of the present invention.

FIG. 6 is a conceptual perspective view illustrating a case where the two-dimensional microlens array in FIG. 5 is subjected to high reflection processing.

FIG. 7 is a conceptual perspective view illustrating a case of using two two-dimensional microlens arrays in the case of FIG.

FIG. 8 is a chart illustrating the relationship between intermittent irradiation of illumination light and intermittent exposure.

FIG. 9 is a schematic diagram showing a waveform pattern of a change output obtained from the cumulative value of each pixel value of a difference image.

FIG. 10 is a schematic diagram illustrating a case where a pattern movement amount is calculated from a difference image.

FIG. 11 is a schematic diagram showing a change output waveform pattern obtained from the movement amount cumulative value of the pattern movement amount.

FIG. 12 is a schematic diagram showing a change output waveform pattern obtained from a movement amount cumulative time integrated value of a pattern movement amount.

FIG. 13 is a schematic diagram showing waveform patterns of normal and abnormal breathing.

FIG. 14 is a diagram showing a table of disease names or disease locations corresponding to abnormal respiratory waveform patterns.

FIG. 15 is a schematic perspective view showing an outline when the monitoring device according to the embodiment of the present invention is installed in a bathroom.

FIG. 16 is a schematic diagram illustrating an example of an illumination pattern.

[Explanation of symbols]

1 Monitoring device 2 sleepers 3 bedding 6 beds 10 Imaging device 11 Imaging unit 11b filter 12 Projector 13 FG element 13a Grating pattern 14 Image processing unit 15 Image sensor 16 Two-dimensional microlens array 30 arithmetic unit 31 Control unit 32 arithmetic unit 33 Detector 34 Storage 35 Interface 36 Breathing pattern storage 37 Input device 38 Output device 40 reporting device

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G08B 25/04 G08B 25/08 A 25/08 A61B 5/10 310A (72) Inventor Toshiharu Takei 2 Sarue, Koto-ku, Tokyo −16−5 Sumise Fukagawa Building Sumitomo Osaka Cement Co., Ltd. F-term (reference) 4C038 VA16 VB31 VC05 5C054 CA06 CH01 FC01 FC13 FC15 FF06 HA12 5C086 AA22 BA04 CA28 CB36 DA08 DA14 DA33 EA40 EA41 EA45 5C087 AA02 AA07 BB31 DD49 EE01 EE08 FF01 FF04 FF19 FF23 FF30 GG02 GG20

Claims (6)

[Claims] 1. An image pickup means for continuously picking up an image of a monitored object illuminated with a constant amount of light; A monitoring device, which comprises: calculating means for obtaining a change output related to the change between the two frames from the difference image; and detecting means for detecting a movement of the monitored object from a time change of the change output. 2. An illumination pattern projecting means for illuminating the monitored object with a predetermined patterned illumination light, wherein the patterned illumination light is parallel to a direction connecting the illumination pattern projecting means and the imaging means. The monitoring device according to claim 1, wherein the monitoring device has an illumination distribution in various directions. 3. The monitoring device according to claim 1, wherein the image pickup unit has an image pickup element in which a plurality of pixels are arranged. 4. The monitoring device according to claim 1, wherein the difference image generating means performs a binarization process on the difference image. 5. The calculating means comprises an accumulating means for accumulating each pixel value of the difference image.
The monitoring device according to any one of 1. 6. The calculation means, as the change output,
The pattern moving amount of each moving portion of the pattern on the difference image is calculated;
The monitoring device according to any one of 1.