JP2006061222A - Motion detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motion detector capable of accurately recognizing the motion of an object without letting sensitivity depend on the position of the object. <P>SOLUTION: Since the motion detector is provided with a projection device 11 for projecting a plurality of luminescent points in an object area, an image pickup device 12 for picking up the image of the object area where the plurality of luminescent points are projected, a measurement means 14 for measuring the motion of the object present in the object area on the basis of the movement of the plurality of luminescent points on the picked-up image and correction means 24 and 24a for correcting the motion of the object corresponding to the position at which the image of the luminescent point or the area including the luminescent point is picked up in the case that the respective intervals of the adjacent ones of the plurality of luminescent points are not equal on a plane inside the object area, the motion detector capable of accurately recognizing the motion of the object without letting the sensitivity depend on the position of the object is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motion detection device, and more particularly to a motion detection device capable of accurately grasping the motion of an object without depending on the sensitivity of the position of the object.

2. Description of the Related Art Conventionally, a motion detection sensor has been proposed as a motion detection device that detects a motion of an object in a space, for example, a bathroom or a toilet, for example, a person. A typical example is a motion detection device that monitors a sleeper's breathing by calculating a pattern movement amount from an image obtained by projecting a pattern onto a sleeper on a bed and continuously capturing the projected pattern. was there. In this apparatus, for example, not only the presence / absence of respiration can be detected, but also the increase / decrease and the amount of respiration movement can be measured / monitored (see, for example, Patent Document 1).
JP 2002-175582 A (page 5-9, FIG. 1-13)

  However, according to the conventional apparatus as described above, for example, when the measurement points on the pattern cannot be obtained at a constant density over the entire screen of the target area, the density of motion detection depends on the position of the target object. There was a possibility. For example, when many spots are projected in a lattice pattern using a two-dimensional diffraction grating, the spot density (spot spacing) can be regarded as almost constant in the region close to the center, but the spot spacing increases as the distance from the center increases. It becomes wider and the error when it is considered constant increases. Furthermore, for example, when the pattern projector is installed off the center of the object to increase the baseline length, the pattern is projected obliquely, and the spot density (spot spacing) on the object For example, if the object is a breathing object, the dependence of the sensitivity of the breathing signal on the position of the object cannot be ignored, and it may be difficult to accurately grasp the movement of the object. It was.

  Therefore, an object of the present invention is to provide a motion detection device that can accurately grasp the motion of an object without depending on the position of the object.

  In order to achieve the above object, a motion detection apparatus according to a first aspect of the present invention includes, for example, a projection device 11 that projects a plurality of bright spots on a target area, as shown in FIGS. An imaging device 12 that images the target area on which the image is projected; measurement means 14 that measures the movement of the target existing in the target area based on the movement of a plurality of bright spots on the captured image; When the intervals between adjacent bright spots of a plurality of bright spots on the plane are not equal, the correction means 24 corrects the movement of the object according to the imaged position of the bright spot or the area including the bright spot. , 24a.

  When configured in this way, the correcting means determines that the movement of the object is the bright spot or the area including the bright spot when the intervals between adjacent bright spots of the plurality of bright spots are not equal on the plane in the target area. Therefore, it is possible to provide a motion detection device that can accurately grasp the motion of the object without depending on the sensitivity of the position of the object.

  Further, as described in claim 2, in the motion detection device according to claim 1, the correction is performed by using the ratio of the interval between the bright spot to be corrected and the adjacent bright spot to the reference interval. You may comprise as follows.

  With this configuration, the correction unit can calculate the density of the bright spot according to the position of the target region from the ratio of the distance between the bright spot to be corrected and the adjacent bright spot to the reference interval. And the movement of the object can be corrected using the density of bright spots.

  Further, as described in claim 3, in the motion detection device according to claim 1 or 2, the correction is performed by calculating an amount related to the movement of the object to be corrected on a surface in the target area. You may comprise by dividing | segmenting by the number of the bright spots per unit area in the partial area | region containing the bright spot which correct | amends.

  If comprised in this way, the correction | amendment means can calculate the density of the bright spot according to the position of an object area | region by measuring the number of the bright spots per unit area in a partial area, and reduces calculation amount be able to. Further, it is possible to reduce the influence of unexpected disappearance of bright spots due to unevenness of the target area.

  According to a fourth aspect of the present invention, the motion detection device according to any one of the first to third aspects includes a variation information generation unit 22 that generates variation information of a motion based on a measurement result. You may comprise as follows.

  If comprised in this way, the fluctuation | variation information of the motion of the target object after correction | amendment can be referred to diagnosis, such as a doctor.

  Further, as described in claim 5, in the motion detection device according to any one of claims 1 to 4, the object breathes; the breathing of the object based on the fluctuation information You may comprise so that the respiration determination means 23 which determines the state may be provided.

  If comprised in this way, the state of breathing of a subject can be grasped easily. For example, information can be used for diagnosis of sleep apnea syndrome (SAS) and other respiratory diseases.

  As described above, according to the present invention, a projection apparatus that projects a plurality of bright spots on a target area, an imaging apparatus that captures a target area on which a plurality of bright spots are projected, and a plurality of bright spots on the captured image. When the distance between adjacent bright spots of a plurality of bright spots on a plane in the target area is not equal to the measuring means that measures the movement of the target existing in the target area based on the movement of the points, the target Correction means for correcting the movement of the object according to the imaged position of the bright spot or the area including the bright spot, so that the sensitivity does not depend on the position of the target object, and the movement of the target object is accurately grasped. It is possible to provide a motion detection device that can

  Embodiments of the present invention will be described below with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the mutually same or equivalent member, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a schematic external view of a respiratory monitor 1 as a motion detection apparatus according to the first embodiment of the present invention. The respiratory monitor 1 is configured to monitor a target area. The respiratory monitor 1 is a three-dimensional sensor that measures the movement in the height direction of an object existing in the target region at a plurality of measurement points. In this embodiment, the FG sensor 10 and an arithmetic device 20 that controls the FG sensor 10 are used. It is comprised including.

  In the present embodiment, the object typically breathes. That is, the object is, for example, a person or an animal. In the present embodiment, the object is described as a person 2. The movement of the object in the height direction is a movement caused by breathing. That is, the movement in the height direction is a movement caused by the breathing of the person 2. In the present embodiment, the target area is on the bed 3. Furthermore, the target area is an area captured on the bed 3 by an imaging device 12 (see FIG. 2) described later. The FG sensor 10 can also measure the height at each measurement point in the target area.

  In addition, the person 2 lies on the bed 3 in the figure. In addition, a bedding 4 is hung on the person 2 and covers a part of the person 2 and a part of the bed 3. In this case, the FG sensor 10 measures the movement of the upper surface of the bedding 4 in the height direction. When the bedding 4 is not used, the FG sensor 10 measures the movement of the person 2 in the height direction.

  An FG sensor 10 is disposed above the bed 3 in the vertical direction. The FG sensor 10 will be described in detail later. In the figure, the FG sensor 10 and the arithmetic unit 20 are illustrated as separate bodies, but may be configured integrally. In this way, the respiratory monitor 1 can be reduced in size. The computing device 20 is typically a computer such as a personal computer.

  FIG. 2 is a schematic external view for explaining the FG sensor 10 of the respiratory monitor 1 according to the first embodiment of the present invention. The FG sensor 10 is typically configured to measure the movement of the person 2 in the height direction using a triangulation method. The FG sensor 10 includes a projection device 11 that projects pattern light onto the bed 3 serving as a target region, an imaging device 12 that captures the bed 3 on which the pattern light is projected, and a pattern on the image captured by the imaging device 12. And a measuring device 14 as measuring means for measuring movement. Furthermore, the measuring device 14 is configured to measure the movement of the person 2 in the height direction at a plurality of points based on the measured movement of the pattern. The projection device 11 and the imaging device 12 are electrically connected to the measurement device 14 and controlled by the measurement device 14. In the present embodiment, the measurement device 14 is configured integrally with the arithmetic device 20.

  The pattern light projected by the projection device 11 is typically an array of bright spots, and is a plurality of bright spots. That is, in other words, the projection device 11 projects a plurality of bright spots on the bed 3 as the target region, and the imaging device 12 is configured to capture the bed 3 on which the plurality of bright spots are projected.

Here, the pattern light to be projected is a pattern 11a formed by a plurality of bright spots 11b arranged in a substantially square lattice as will be described later with reference to FIG. In the drawing, the projection device 11 projects a pattern 11 a onto the bed 3. The plurality of bright spots projected on the bed 3 correspond to the plurality of measurement points on the bed 3, respectively. That is, the position of each bright spot is the position of the measurement point. Furthermore, the plurality of measurement points correspond to the bright spots existing within the angle of view of the image captured by the imaging device 12 among the bright spots projected on the person 2. The measurement point is a point at which the movement of the person 2 in the height direction can be measured as will be described later. Here, the movement in the height direction is a change in the height of the object from the time of the previous measurement (an image acquired immediately before, that is, an N-1 frame described later). Further, the movement in the height direction of the person 2 measured at a plurality of points corresponds to the movement of the bright spot described later with reference to FIG. 6 (note that the amount of movement corresponds to the movement amount of the bright spot).
Each configuration will be described below.

  First, installation of the FG sensor 10 will be described. The projection device 11 and the imaging device 12 are disposed above the bed 3 in the vertical direction. In the figure, the imaging device 12 is disposed approximately above the center of the bed 3, and the projection device 11 is disposed approximately above the head of the person 2. Here, the angle of view of the imaging device 12 is set so that the upper body of the person 2 can be imaged at approximately the center of the bed 3. The distance between the projection device 11 and the imaging device 12 is referred to as a baseline length d (see FIG. 5). The baseline length d (see FIG. 5) is the distance between the projection device 11 and the imaging device 12 in the baseline direction of triangulation.

  The FG sensor 10 is installed so that the direction of the straight line connecting the projection device 11 and the imaging device 12, that is, the baseline direction of the triangulation method, is parallel to the center line in the longitudinal direction of the bed 3. Furthermore, in the FG sensor 10, the base line direction of the FG sensor 10 and the center line in the longitudinal direction of the bed 3 are parallel, and the base line connecting the projection device 11 and the imaging device 12 is the center line in the longitudinal direction of the bed 3. It is arrange | positioned so that it may be located in the vertical upper direction. Here, the base line direction is described as being parallel to the longitudinal center line of the bed 3, but may be, for example, a direction orthogonal to the longitudinal center line of the bed 3. Even in this case, there is no problem in measuring the movement of the person 2.

  Here, the baseline length d (see FIG. 5) will be described. Here, the FG sensor 10 measures the movement of a bright spot forming a pattern, as will be described later with reference to FIG. At this time, for example, the greater the movement of the object (here, the person 2) in the height or height direction, the greater the movement amount of the bright spot. For this reason, according to the concept described later with reference to FIG. 5, if the amount of movement of the bright spot is large, a phenomenon may occur in which the bright spot adjacent to the bright spot to be compared is skipped. In this case, it is determined that the light has moved from the adjacent bright spot, and the amount of movement of the bright spot to be measured may be small. That is, the movement amount of the bright spot cannot be measured accurately. When the base line length is short, the amount of movement of the bright spot is small and the above jump is unlikely to occur, but it is difficult to distinguish it from noise for minute movements. In addition, when the base line length d (see FIG. 5) is long, even a slight movement of the object is greatly reflected in the amount of movement of the bright spot, for example, a minute movement in the height or height direction. However, jumping may occur when there is a large movement, for example.

  In the present embodiment, as described above, the imaging device 12 is disposed approximately above the central portion of the bed 3 and the projection device 11 is disposed approximately above the head of the person 2, and the projection device 11 and the imaging device 12 have a certain degree. Installed at a distance. That is, the projection device 11 is arranged at a position shifted from the center of the person 2 (a position outside the bed 3 with respect to the horizontal direction).

  As shown in the figure, the projection device 11 has its optical axis (in this embodiment, the projection direction of the laser beam L1 shown in FIG. 3) inclined with respect to the vertical direction of the upper surface of the bed 3. Install in. With this configuration, it is possible to easily install the imaging device 12 and the projection device 11 apart from each other, and it is possible to easily increase the baseline length d (see FIG. 5). In other words, it is easy to take a long baseline length for triangulation, and the baseline length d (see FIG. 5) becomes long, so that changes can be detected sensitively.

  Here, the imaging device 12 is installed with its optical axis approximately parallel to the vertical direction of the upper surface of the bed 3. That is, the optical axis of the projection device 11 is installed with an inclination with respect to the optical axis of the imaging device 12.

  FIG. 3 is a schematic perspective view for explaining the projection device 11 of the respiratory monitor 1 according to the first embodiment of the present invention. With reference to this figure, the projection apparatus 11 suitable for the respiration monitor 1 is demonstrated. Here, for the sake of explanation, a case will be described where the target region is the plane 102 and a laser beam L1 described later is projected perpendicularly to the plane 102. The projection apparatus 11 includes a light beam generation unit 105 serving as a light beam generation unit that generates a coherent light beam, and a fiber grating 120 (hereinafter simply referred to as a grating 120). The coherent light beam projected by the light beam generation unit 105 is typically an infrared laser. The light beam generation unit 105 is configured to generate a parallel light beam. The light flux generation unit 105 is typically a semiconductor laser device including a collimator lens (not shown), and the generated parallel light flux is a laser light flux L1. The laser light beam L1 is a light beam having a substantially circular or elliptical cross section. Here, the parallel light flux only needs to be substantially parallel, and includes a nearly parallel light flux.

  Further, here, the grating 120 is disposed in parallel to the plane 102 (perpendicular to the Z axis). Laser light L1 is incident on the grating 120 in the Z-axis direction. Then, the laser beam L1 is condensed in a plane having the lens effect by each optical fiber 121, and then spreads as a diverging wave, interferes, and interferes with a plurality of bright spot arrays on the plane 102 which is a projection plane. A pattern 11a is projected. Note that the arrangement of the grating 120 in parallel with the plane 102 means, for example, that the plane including the axis of each optical fiber 121 of the FG element 122 constituting the grating 120 and the plane 102 are parallel.

  The grating 120 includes two FG elements 122. In the present embodiment, the planes of the FG elements 122 are parallel to each other. Hereinafter, the plane of each FG element 122 is referred to as an element plane. In the present embodiment, the axes of the optical fibers 121 of the two FG elements 122 are substantially orthogonal to each other.

  The FG element 122 is configured by arranging, for example, several tens to several hundreds of optical fibers 121 having a diameter of several tens of microns and a length of about 10 mm in parallel in a sheet shape. Further, the two FG elements 122 may be arranged in contact with each other, or may be arranged at a distance from each other in the normal direction of the element plane. In this case, the distance between the two FG elements 122 is set so as not to interfere with the projection of the pattern 11a. The laser beam L1 is typically incident perpendicular to the element plane of the grating 122. Here, the grating 120 using the FG element 122 will be described. However, the present invention is not limited to this. For example, another type of diffraction element or microlens array may be used instead of the grating 120.

  As described above, since the projection device 11 generates a large amount of light by the grating 120 configured to include the two FG elements 122, the optical housing can be miniaturized without requiring a complicated optical system. Furthermore, by using the grating 120, the projection device 11 can project a plurality of bright spots 11b onto the target region as a pattern 11a with a simple configuration, and unlike a projection by image formation, a distance at which clear bright spots can be obtained. Wide range. The pattern 11a is typically a plurality of bright spots 11b arranged in a square lattice pattern. The shape of the bright spot 11b is a substantially circular shape including an ellipse.

  Returning to FIG. The imaging device 12 includes an imaging optical system 12a (see FIG. 5) and an imaging element 15 (see FIG. 5). The image sensor 15 is typically a CCD image sensor. In addition to the CCD, an element having a CMOS structure has recently been actively announced as the image pickup element 15, and these can naturally be used. In particular, some of the elements themselves have inter-frame difference calculation and binarization functions, and it is preferable to use these elements.

  The imaging device 12 may include a filter 12b (see FIG. 5) that attenuates light having a wavelength other than the peripheral portion of the wavelength of the laser beam L1 generated by the above-described light beam generation unit 105 (see FIG. 3). The filter 12b is typically an optical filter such as an interference filter, and may be disposed on the optical axis of the imaging optical system 12a. In this way, the imaging device 12 can reduce the influence of disturbance light because the light intensity of the pattern 11a projected from the projection device 11 out of the light received by the imaging device 15 is relatively increased. The laser beam L1 generated by the beam generator 105 is typically an infrared laser beam. Further, the laser beam L1 may be irradiated continuously or intermittently. When irradiating intermittently, imaging by the imaging device 12 is performed in synchronization with the timing of irradiation.

  FIG. 4 is a block diagram showing a configuration example of the respiratory monitor 1 according to the first embodiment of the present invention. With reference to this figure, the structural example of the respiration monitor 1 is demonstrated. As described above, the arithmetic device 20 is configured integrally with the measuring device 14. Furthermore, the measuring device 14 is configured integrally with a control unit 21 described later. The projection device 11 and the imaging device 12 are electrically connected to the measurement device 14 and controlled as described above. In the present embodiment, the arithmetic device 20 is remotely arranged with respect to the projection device 11 and the imaging device 12. Specifically, for example, it is installed in the side of the bed 3 or in a room different from the room in which the bed 3 is installed, such as a nurse station.

  First, the measuring device 14 will be described. As described above, the measuring device 14 measures the movement of the pattern on the image picked up by the image pickup device 12, and further determines the movement of the person 2 in the height direction based on the measured movement of the pattern. Measure at multiple points. The measuring device 14 is configured to acquire an image captured by the imaging device 12. Further, the measuring device 14 is configured to measure the movement of each bright spot on the image picked up by the image pickup device 12. Here, the projected bright spot and the image of the bright spot on the captured image are simply referred to as bright spot for convenience. Here, measuring the movement of the bright spot means measuring the amount of movement of the bright spot (hereinafter referred to as the movement amount). Further, the measured moving amount of the bright spot is a concept including the moving direction of the bright spot. That is, it is assumed that the moving amount of the bright spot to be measured includes information on the moving direction.

  Here, the measurement of the movement of the bright spot by the measuring device 14 will be described in detail. The measuring device 14 is configured to measure the movement of the bright spot based on two different time points acquired from the imaging device 12.

  Here, the measurement of the movement of the bright spot based on the images at two different time points will be described. The images at two different time points may be an arbitrary time point and a slightly previous time point. “Slightly before” only needs to be a time interval sufficient to detect the movement of the person 2. In this case, when a slight movement of the person 2 is desired to be detected, the time is short, for example, the movement of the person 2 does not become too large, and the time can be regarded as substantially no movement, for example, about 0.1 seconds. . Or it is good to set it as the 1-10 period (1 / 30-1 / 3) of a television period. Further, when it is desired to detect a rough movement of the person 2, it may be long, for example, about 10 seconds. However, in the case of detecting the respiration of the person 2 as in the present embodiment, if it is too long, accurate detection of respiration cannot be performed. Hereinafter, an image acquired at an arbitrary time (current) is described as an acquired image, and an image acquired slightly before (past) the acquired image is described as a reference image. The reference image is stored in the storage unit 31.

  Further, in the present embodiment, the images at two different time points are an acquired image (N frame) and an image acquired immediately before the acquired image (N-1 frame). That is, the reference image is an image acquired immediately before the acquired image. The image acquisition interval may be appropriately determined depending on, for example, the processing speed of the apparatus and the content of the motion to be detected as described above. For example, the interval is 0.1 to 3 seconds, preferably about 0.1 to 0.5 seconds. It is good to do. In addition, it is effective to acquire images at shorter time intervals and perform averaging or filtering to reduce the influence of random noise, for example.

  It should be noted that a waveform obtained by measuring the movement of a bright spot (for example, the sum of bright spot movement amounts) based on an image at an arbitrary time point and two time points slightly different from the previous time point is a differential waveform of distance, It becomes a waveform showing the transition of the height change. For example, when it is desired to obtain a waveform representing the height transition, if the waveform is integrated, a distance waveform, that is, a waveform indicating the height transition is obtained.

  Here, the acquired image and the reference image are images picked up by the image pickup device 12, for example, and are concepts including the position information of the bright spot on each image. That is, the acquired image and the reference image are images of the pattern 11a formed by the projection of the projection device 11 at each time point. In the present embodiment, the reference image is stored in the storage unit 31 in the form of position information such as coordinates regarding the position of each bright spot, for example, not as a so-called image. Note that the coordinates here are set, for example, in an image captured by the imaging device 12. In this way, when measuring the movement amount of the bright spot, which will be described later, for example, it is only necessary to compare the coordinates and direction of the bright spot, so the processing becomes simple. Further, here, the position of the bright spot is the barycentric position of the bright spot. By doing in this way, the movement of a slight bright spot can also be measured.

  Further, as described above, the moving amount of the bright spot is obtained by comparing the position information of each bright spot on the reference image stored in the storage unit 31 with the position information of each bright spot on the acquired image. Measure the amount of bright spot movement. Each amount of movement can be obtained, for example, by counting the number of pixels to which the position of the bright spot has moved (how many pixels have moved). The measured moving amount of the bright spot is a concept including the moving direction of the bright spot. That is, information on the moving direction is also included in the measured moving amount of the bright spot. In this way, as will be described later, it is not necessary to generate a difference image, so that the processing can be simplified.

  In the above description, the position information of the bright spots is compared. However, a difference image between the reference image and the acquired image may be created. In this case, the movement amount of the bright spot is measured based on the position of the corresponding bright spot from the difference image. In this way, since only the moved bright spot remains on the difference image, the processing amount can be reduced.

  Furthermore, the moving amount of the bright spot measured by the measuring device 14 may be a moving average value or a period average value of the moving amount of the bright spot that has been measured a certain number of times in the past or measured within the past fixed period. By doing so, it is possible to reduce random noise and sudden noise caused by sunlight flickering through a window, and the reliability of the measured moving amount of bright spots is improved.

  The measuring device 14 is configured to measure the movement of the bright spot as described above for each bright spot forming the pattern 11a. That is, the positions of a plurality of bright spots become a plurality of measurement points. The measuring device 14 outputs the bright spot movement measured for each bright spot forming the pattern 11a, that is, the measured bright spot movement amount to the control unit 21 as a measurement result. That is, the measurement result is the moving amount of the bright spot measured based on images at two different time points. As will be described later with reference to FIG. 5, this measurement result corresponds to the movement of the object at each bright spot (measurement point), in this case, the person 2 in the height direction. Hereinafter, this measurement result is referred to as motion information. The measuring device 14 outputs the measurement result at each measurement point as motion information. Note that the movement of the person 2 in the height direction is, for example, movement accompanying the breathing of the person 2.

  FIG. 5 is a conceptual perspective view for explaining the concept of bright spot movement of the respiratory monitor 1 according to the first embodiment of the present invention. Here, the concept of bright spot movement will be described with reference to FIG. Here, it is easy to understand, and the target area will be described as the plane 102 and the target object as the object 103. Further, here, for description, the reference image is an image of the pattern 11a when the object 103 is not present on the plane 102, and the acquired image is described as the pattern 11a when the object 103 is present on the plane 102. To do.

  In the figure, an object 103 is placed on the plane 102. Further, the orthogonal coordinate system XYZ is taken so that the XY axis is placed in the plane 102, and the object 103 is placed in the first quadrant of the XY coordinate system. On the other hand, a projection device 11 and an imaging device 12 are arranged above the plane 102 on the Z axis in the drawing. The imaging device 12 images the plane 102 on which the pattern 11 a is projected by the projection device 11. That is, the object 103 placed on the plane 102 is imaged.

  Here, the imaging lens 12a as the imaging optical system of the imaging device 12 is disposed so that its optical axis coincides with the Z-axis. The imaging lens 12 a forms an image of the pattern 11 a on the plane 102 or the object 103 on the image receiving surface 15 ′ (image plane) of the imaging device 15 of the imaging device 12. The image receiving surface 15 ′ is typically a surface orthogonal to the Z axis. Further, an xy orthogonal coordinate system is taken in the image receiving surface 15 ′ so that the Z axis passes through the origin of the xy coordinate system. The projection device 11 is arranged at a distance equal to the imaging lens 12a from the plane 102 and a distance d (baseline length d) from the imaging lens 12a in the negative direction of the Y axis. A pattern 11 a formed by a plurality of bright spots 11 b is projected onto the object 103 and the plane 102 by the projection device 11. The y-axis direction is also the baseline direction of the triangulation method.

  The pattern 11 a projected onto the plane 102 by the projection device 11 is blocked by the object 103 and does not reach the plane 102 in a portion where the object 103 exists. Here, if the object 103 exists, the bright spot 11 b to be projected onto the point 102 a on the plane 102 is projected onto the point 103 a on the object 103. Since the bright spot 11b has moved from the point 102a to the point 103a and the imaging lens 12a and the projection device 11 are separated by a distance d (base line length d), the point 102a ′ on the image receiving surface 15 ′. An image to be imaged at (x, y) is imaged at a point 103a ′ (x, y + δ). In other words, the image of the bright spot 11b moves by a distance δ in the y-axis direction between the time when the object 103 does not exist and the time when the object 103 exists.

  For example, as shown in FIG. 6, the bright spot formed on the image receiving surface 15 ′ of the image sensor 15 moves in the y-axis direction by δ by the object 103 having a height.

  Thus, by measuring the movement amount δ of the bright spot, the position of the point 103a on the object 103 can be specified three-dimensionally. That is, for example, the height of the point 103a is known. In this way, by measuring the difference between the point that should be imaged on the image receiving surface 15 ′ if the object 103 is not present and the actual image forming position on the image receiving surface 15 ′, the object 103 is obtained. It is possible to measure the height distribution, in other words, the three-dimensional shape. Alternatively, the three-dimensional coordinates of the object 103 can be measured. Further, if the pitch of the pattern 11a, that is, the pitch of the bright spot 11b is made fine enough that the correspondence relationship of the bright spot 11b is not unknown, the height distribution of the object 103 can be measured in detail.

  Based on the above concept, the measuring device 14 can measure the height of the object by measuring the moving amount of the bright spot. However, here, since the movement in the height direction is measured based on the acquired image and the image acquired immediately before the acquired image, that is, the reference image, the amount of change in height is determined by the amount of movement of the bright spot. Become. For this reason, for example, the absolute height of the person 2 cannot be measured, but a change in the height direction of the person 2 can be measured, which is suitable for measuring the movement of the person 2 in the height direction. 7, the actual height (absolute height) of the person 2 does not have to be calculated, so that the calculation amount in the measuring device 14 can be reduced.

  Note that, as will be described below, the measurement device 14 can also calculate the actual height change amount of the person 2 based on the measured movement amount of the bright spot.

  FIG. 7 is a diagram for explaining the calculation of the height of the object by the measuring device 14 of the respiratory monitor 1 according to the first embodiment of the present invention. Here, as in FIG. 5, it is assumed that the target area is the plane 102 and the target object is the object 103 for easy understanding. Furthermore, for the sake of explanation, the reference image is an image of the pattern 11a (see FIG. 5) when the object 103 is not present on the plane 102, and the acquired image is a pattern when the object 103 is present on the plane 102. This will be described as 11a (see FIG. 5). Here, calculating the change in height is also referred to as calculating the height for convenience.

  This figure is a side view of the relationship between the imaging device 12, the projection device 11, the object 103, and the plane 102 in the X-axis direction (see FIG. 5). Here, the case where the height of the object 103 is Z1 will be described. The center of the projection device 11 (the center of the pattern light source) and the center of the imaging lens 12a are arranged parallel to the plane 102 and separated by a distance d, and the image receiving surface 15 ′ (imaging device 15) is separated from the imaging lens 12a. The distance from the imaging lens 12a to the plane 102 is h, and the height of the point 103a of the object 103 from the plane 102 is Z1. As a result of placing the object 103 on the plane 102, it is assumed that the point 102a 'on the image receiving surface 15' has moved to a point 103a 'separated by δ.

If the point where the line connecting the center of the imaging lens 12a and the point 103a intersects the plane 102 in the figure is 102a ″, the distance D between the point 102a and the point 102a ″ is the triangle 103a′-102a′-12a. If attention is paid to the triangle 102a ″ −102a−12a, D = δ · h / l. (H-Z1). When Z1 is obtained from both equations, the following equation is obtained.

Z1 = (h ² · δ) / (d · l + h · δ) (1)

  As described above, the measurement apparatus 14 can calculate the height of the object 103, and if the plane 102 is considered to be the previous height (N-1 frame) and the object 103 is assumed to be the current height (N frame). The actual height change amount between these two time points can be calculated. In this case, the measuring device 14 outputs the height change amount of the object at each measurement point to the control unit 21 as a measurement result. This measurement result is called height information.

  In the following description of the present embodiment, unless otherwise specified, as described above with reference to FIGS. 5 and 6, the measuring device 14 measures the movement amount of the bright spot (change amount of the bright spot movement). The first correction unit 24, which will be described below in the case where the movement of the person 2 in the height direction is measured, and which will be described later, is a movement amount of a bright spot or a movement amount of a bright spot in a partial area described later. It is assumed that the movement of the object is corrected by correcting the sum of the two. In order to obtain the height change amount strictly, the equation (1) is used. However, since the value of h · δ in the equation (1) is actually sufficiently smaller than the value of d · l, Z1 is set to δ. It can be treated as being proportional. Therefore, δ can be used as a height change amount instead of Z1. Further, the position of the measurement point in the object plane slightly changes with the height change, but does not particularly affect the main point of the motion detection of the present invention.

  Note that the respiration monitor 1 can be configured such that a measurement point at which the amount of movement measured by the FG sensor 10 is less than or equal to a threshold value is not used for calculation by the calculation device 20. In the present embodiment, it is configured not to output data of a measurement point whose amount of movement measured by the measurement device 14 is equal to or less than a threshold value to the arithmetic device 20. The threshold is typically set smaller than the breathing movement of the person 2. Specifically, the movement is set to be smaller than the respiration of the person 2, more specifically, the movement amount of the bright spot corresponding to the small movement. This makes it possible to ignore measurement points at which movement smaller than respiration is measured. By doing in this way, the influence by noise can be effectively excluded, for example. The movement smaller than the movement of breathing means movement smaller than the range of movement in the height direction by breathing. As described above, since the movement amount of the bright spot indicates the change amount of the bright spot movement, in other words, the movement speed, the movement smaller than respiration is, for example, the movement speed in the height direction due to respiration. When the range is about 2 to 40 mm / s, it means a movement at a speed of 2 mm / s or less. That is, in this case, the threshold value is preferably set to 2 mm / s. In other words, the moving amount of the bright spot corresponding to the movement speed of 2 mm / s is set. For example, when image acquisition is performed four times per second, the threshold of the bright spot movement amount is set to the bright spot movement amount corresponding to the movement amount of the person 2 of 0.5 mm (2 mm / s ÷ 4). To do.

  Further, the respiration monitor 1 may be configured such that a measurement point at which the frequency of movement measured by the FG sensor 10 is equal to or greater than a threshold value is not used for calculation by the calculation means. In the present embodiment, it is configured not to output data of a measurement point whose frequency of motion measured by the measurement device 14 is equal to or greater than a threshold value to the arithmetic device 20. The frequency threshold value may be set to a frequency higher than the breathing frequency of the person, for example, about 60 cycles per minute. By the way, although the respiration rate of an adult is in the range of about 5 to 30 cycles per minute, in the case of an infant, the respiration rate tends to increase further. . As a result, the measurement point at which the movement of the frequency higher than the respiration frequency is measured can be ignored. By doing so, it is possible to effectively eliminate the influence of movements that are not related to the movement of breathing, such as noise.

  Returning to FIG. 4, the arithmetic unit 20 will be described. The computing device 20 includes a control unit 21 that controls the respiratory monitor 1. Furthermore, a storage unit 31 is connected to the control unit 21. The storage unit 31 may store the images acquired from the imaging device 12 in time series. The storage unit 31 can store data such as calculated information.

  For example, a display 40 as information output means for outputting information indicating the state of the person 2 is connected to the control unit 21. The display 40 is typically an LCD. The display 40 outputs, for example, by displaying a waveform pattern of breathing of the person 2 generated by the fluctuation information generation unit 22 described later. The display 40 typically displays a respiration waveform pattern in real time. Real-time display means, for example, that the waveform pattern of breathing of the person 2 that is immediately output by the fluctuation information generation unit 22 described later is displayed immediately. If there is no need to output information on the spot, it is not particularly necessary to provide the display 40.

  The control unit 21 is connected to an input device 35 for inputting information for operating the respiratory monitor 1. The input device 35 is, for example, a touch panel, a keyboard, or a mouse. Although the input device 35 is illustrated as being externally attached to the arithmetic device 20 in this figure, it may be incorporated. In the present embodiment, the case where the input device 35 is provided will be described.

  Furthermore, in the control unit 21, fluctuation information generation for generating fluctuation information on the movement of the person 2 (see FIG. 2) in the height direction, that is, movement of breathing, based on the measurement result of the measurement device 14, that is, movement information. When the intervals between the adjacent bright spots of the plurality of bright spots 11a (see FIG. 2) on the plane in the bed 3 (see FIG. 2) as the target area and the bed 3 (see FIG. 2) as the target area are not equal, A first correction unit 24 is provided as correction means for correcting the movement of the person 2 in accordance with the imaged position of the bright spot or the area including the bright spot. In other words, the arithmetic device 20 includes a fluctuation information generation unit 22 and a first correction unit 24. The computing device 20 may further include a breath determination unit 23 as a breath determination unit that determines the breathing state of the person 2 based on the variation information generated by the variation information generation unit 22. In the present embodiment, the case where the breath determination unit 23 is provided will be described.

The fluctuation information generation unit 22 calculates the sum of the movements of the bright spots of the measurement points measured by the measurement device 14, and calculates the respiration waveform pattern of the person 2 as fluctuation information formed by arranging the sums in the time direction. Is to be generated. The fluctuation information generation unit 22 is typically configured to output the waveform data of the breathing of the person 2 as fluctuation information indicating the state of the person 2 in real time. To output in real time means to immediately output, for example, the total sum of movements of bright spots calculated for each image captured by the imaging device 12. Furthermore, in this case, by outputting the sum in real time, the fluctuation information generation unit 22 generates a respiration waveform pattern of the person 2 formed side by side in the time direction. Further, the fluctuation information generation unit 22 is configured to output the generated respiration waveform pattern of the person 2 to the display 40. The display 40 displays the respiration waveform pattern of the person 2 as described above. Thereby, the waveform pattern of the respiration of the person 2 can be used as a reference for diagnosis by a doctor, for example.
FIG. 8 is a diagram showing an example of a respiratory waveform pattern.

  Note that the fluctuation information generation unit 22 is also configured to calculate the volume fluctuation amount of the person 2 when the measuring device 14 calculates the height change amount. The volume fluctuation amount can be calculated from height information as a measurement result by the measuring device 14, that is, a height change amount. In this case, for example, the sum of the height change amounts may be used as the volume fluctuation amount. Thus, by calculating the volume fluctuation amount, for example, the actual inhalation amount when the person 2 breathes can be known. The calculated volume fluctuation amount may be displayed on the display 40 or stored in an electronic medium or the like (for example, the storage unit 31 here).

  The respiration determination unit 23 is configured to determine the respiration state of the person 2 based on the respiration waveform pattern of the person 2 generated by the variation information generation unit 22. That is, the breath determination unit 23 determines the breathing state of the person 2 based on the motion information measured at the plurality of measurement points by the measuring device 14, that is, the motion of the person 2 in the height direction. Further, the breath determination unit 23 is configured to determine the type of movement of the person 2 based on the measurement result measured by the measurement device 14.

  The types of movement of the person 2 determined by the breath determination unit 23 are typically breathing, body movement, no movement (immobility), and respiratory movement reduction. The body movement is a movement of the body of the person 2 and is a concept including a wide range of movements such as standing and sitting, as well as movements of limbs and turning over.

  Further, the respiration determining unit 23 sets a predetermined upper and lower limit threshold for both or either of the amplitude and the period (frequency) of the periodic change of the respiration waveform pattern generated by the variation information generating unit 22. You may make it determine whether it is respiration compared with a threshold value, and may detect respiration. The upper and lower limit threshold values of the cycle may be set in a range including a person's breathing cycle, for example, a lower limit of 5 cycles per minute and an upper limit of 60 cycles per minute. By the way, although the respiratory rate of an adult exists in the range of about 5-30 times per minute, in the case of an infant, there exists a tendency for the respiratory rate to increase further. The range of the upper and lower limits of the amplitude corresponds to a range including the movement amount of the bright spot corresponding to the breathing amplitude of the person 2, for example, the height change amount of the person 2 having an upper limit of about 20 mm and a lower limit of about 1 mm. The amount of movement of the bright spot is good. In addition, a change in the state of the person 2 can be detected and determined from a change in amplitude or period.

  Furthermore, the respiration determining unit 23 may detect the respiration rate. The respiration rate can be detected, for example, by performing a data process such as Fourier transform on the temporal change in the total amount of movement of the bright spots in the region where the movement is determined to be respiration.

  The respiration determining unit 23 is configured to determine the respiration state of the person 2 based on the respiration waveform pattern of the person 2 generated by the variation information generating unit 22 when detecting respiration. The breath determination unit 23 is typically configured to determine whether the breathing state of the person 2 is a normal breathing state or an abnormal breathing state.

  The determination criterion of the breathing state of the person 2 by the breath determination unit 23 may be set in consideration of the following. For example, when breathing is detected, if the cycle of the breathing pattern is disturbed in a short time, or if the cycle of the breathing pattern changes abruptly, for example, lung diseases such as spontaneous pneumothorax and bronchial asthma Since it can be estimated that the disease is a heart disease such as congestive heart failure or a cerebral vascular disease such as cerebral hemorrhage, it is set so as to be determined as an abnormal respiratory state. Further, when the disappearance of the breathing pattern continues, it can be estimated that the breathing of the person 2 has stopped, so that it is determined to determine that the person is in an abnormal breathing state. If the movement of the person 2 occurs frequently instead of the breathing pattern in a short time, it can be estimated that the person 2 is suffering and violent for some reason. It is good to set.

  FIG. 9 is a schematic diagram showing an example of a waveform pattern of normal and abnormal breathing. The normal breathing pattern is a periodic pattern as shown in FIG. However, in the case of adults, the normal range for the respiratory rate per minute is about 10 to 20 times. Abnormal breathing patterns occur, for example, when there is a physiological disorder in the body, such as Cheyne-Stokes breathing, central hyperventilation, ataxic breathing, or Kussmul's breathing. It is a breathing pattern that is considered. FIG. 9B shows a respiratory pattern of Cheyne-Stokes respiration, FIG. 9C shows a respiratory pattern of central hyperventilation, and FIG. 9D shows a respiratory pattern of ataxic respiration. Furthermore, FIG. 10 is a diagram showing a table of disease names or disease locations corresponding to abnormal respiratory waveform patterns, and shows the disease names or disease locations when the above-described abnormal breath patterns occur.

  The respiration determining unit 23 determines whether the respiration pattern of the person 2 belongs to the respiration pattern of the person 2 by using the difference in the respiration frequency, appearance frequency, and depth of each respiration pattern. It is preferable to determine whether there is, that is, the person 2 is in a dangerous state. The breathing pattern as described above may be stored in the storage unit 31. By doing so, it is possible to easily determine whether or not the breathing of the person 2 is normal by comparing with these patterns.

  The determination result by the breath determination unit 23 as described above is configured to be displayed on the display 40. The breath determination unit 23 outputs the determination result to the fluctuation information generation unit 22. In this case, the variation information generation unit 22 outputs the determination result to the display 40 together with the respiration waveform pattern of the person 2. By displaying the determination result by the breath determination unit 23 on the display 40, for example, a measurer (doctor or the like) can easily recognize the abnormality of the person 2.

  By the way, according to (1) described above, in the FG sensor 10, if the baseline length d (see FIG. 11) and the distance h (see FIG. 11) to the surface on which the object is present are constant, the height direction of the person 2 The motion detection sensitivity is constant.

  FIG. 11 is a diagram for explaining the detection sensitivity of the motion in the height direction of the respiratory monitor 1 according to the first embodiment of the present invention. Here, for easy understanding, the position of the reference object (the position of the surface of the object) is the plane 102, and the position of the object after the movement (position of the surface of the object) is changed. This will be described as the plane 104. The reference position of the target object is, for example, the position of the target object in the N-1 frame, and the position of the target object after being changed by movement is, for example, the position of the target object in the N frame. Furthermore, for the sake of explanation, the reference image is an image of the pattern 11a (see FIG. 5) when the position of the surface of the object exists on the plane 102, and the acquired image has the position of the surface of the object at the plane 104. Will be described as a pattern 11a (see FIG. 5).

  In the triangulation method, the distance between AB and CD on the plane 104 is equal to the movement of the object in the height direction. That is, the movement amount of the bright spot is constant in the base line length d (see FIG. 11) and the distance h (see FIG. 11) to the plane 102, and the amount of movement of the object in the height direction, that is, the plane 102 and the plane 104. If the height change amount Z1 which is the distance to the constant is constant, it is constant regardless of which position on the plane 102 the position of the bright spot is. Therefore, the respiration signal obtained by the total movement amount of each bright spot, that is, the waveform pattern of respiration, has constant sensitivity to the movement in the height direction at any position on the plane 102 if the density of the bright spots on the plane 102 is constant. It is.

  However, in order to make the base line length d as long as possible, the projection device 11 may be arranged at a position shifted from the center of the object as in the present embodiment.

  FIG. 12 is a diagram illustrating a case where the projection device 11 of the respiratory monitor 1 according to the first embodiment of the present invention is installed such that the optical axis thereof is inclined with respect to the vertical direction of the plane 102. (A) is a diagram, and (b) is a schematic diagram of a bright spot on the plane 102. Here, as in FIG. 5, the target region will be described as the plane 102 because it is easy to understand.

  As shown to (a), the projection apparatus 11 projects each light ray by equiangular (alpha) space | interval. For this reason, the distance between the bright spots on the plane 102 increases as the distance from the projection device 11 increases. That is, the distance between the bright spots increases in the y-axis direction (baseline direction) and the x-axis direction (direction perpendicular to the baseline direction) as the distance from the projection device 11 increases, and the bright spot density decreases. An example of the bright spot pattern obtained as a result is shown in FIG. Even when the projection device 11 is not installed so that the optical axis thereof is inclined with respect to the vertical direction of the plane 102 (that is, when the optical apparatus is installed so that the optical axis is perpendicular to the plane 102). Since each light beam is projected at equiangular α intervals, the bright spot density actually decreases as the distance from the projection device 11 increases. However, in this case, since the difference in the bright spot interval depending on the position is extremely small, there is no problem even if it is ignored. Even in such a case, when it is desired to accurately measure the movement of the object at a position away from the projection device 11, correction may be performed in the same manner as described below. For example, one projection device 11 is arranged in a plurality of target areas, for example, in the center of four beds 3 so as to face downward in the vertical direction, and the four imaging devices 12 are arranged directly above each bed 3. It can be applied in any case.

  As shown in (b), if the intervals between the bright spots are not uniform, the amount of movement of the object (person 2) in the height direction as described above (ie, the above-described amount) (ie, the above-mentioned) If the height change amount is the same, the bright spot density on the image receiving surface 15 ′ is constant, but the bright spot density varies depending on the position on the plane 102. For this reason, even if the amount of movement in the height direction is the same, the respiratory movement obtained by calculating the sum of the amount of bright spot movement in the region where the movement of the object (person 2) is present in the height direction exists. The waveform pattern varies depending on the position of the region on the plane 102. Therefore, the sensitivity of the respiration waveform pattern depends on the position on the plane 102.

  That is, for example, even if the amount of movement in the height direction is the same and the range of the region on the plane 102 where the movement in the height direction exists is the same, the range is substantially vertical of the projection device 11. Since the bright spot density on the plane 102 is different between the case where it exists below and the case where it exists away from the projection device 11, the number of bright spots which are present in the region and take the sum total. And the sensitivity of the respiration waveform pattern is different.

  Therefore, as described above, the arithmetic device 20 of the respiratory monitor 1 according to the first embodiment of the present invention has a plurality of bright spots 11a (see FIG. 2) on the plane in the bed 3 (see FIG. 2) as the target region. 1), the first correction as correction means for correcting the movement of the person 2 in accordance with the imaged position of the bright spot or the area including the bright spot when the intervals between adjacent bright spots are not equal. It has part 24 (refer to Drawing 4).

  In the present embodiment, the first correction unit 24 specifically corrects the movement in the height direction by correcting the movement amount of the bright spot. That is, as described above, in the present embodiment, it is considered that the amount of movement of the bright spot and the amount of change in height are proportional, so by correcting the amount of movement of the bright spot, as a result, the movement in the height direction is also increased. This is because it can be regarded as corrected. Of course, the height may be obtained by using the equation (1). However, in this case, if the unevenness of the object is unknown, it is necessary to substitute the value of h by using an average value of h.

  In this correction, typically, the bright spot movement amount is corrected using the bright spot density (the number of bright spots per unit area). In the present embodiment, as will be described below, this is performed using the ratio of the interval between a bright spot for correcting the movement amount relative to the reference bright spot interval and the adjacent bright spot.

The correction performed by the first correction unit 24 will be described with reference to FIG. Here, as described above, it is assumed that the projection device 11 projects each light beam at an equal angle α interval. First, on the basis of the bright spot projected on the plane 102 substantially downward in the vertical direction of the projector 11, the interval between the bright spot and the bright spot first adjacent in the y-axis direction (baseline direction) is Δy ₁ , When the distance between the bright points adjacent the spacing between the bright points adjacent bright points and second adjacent to the first to the bright spot and the n-th adjacent to [Delta] y _{2, n-1} th and [Delta] y _n, [Delta] y _n Can be obtained by the following equation (2).

Δy _n = h (tann · α−tan (n−1) · α) (2)

The distance between the reference bright spot and the bright spot first adjacent in the y-axis direction (baseline direction) is Δy _{1 that} is the lower part of the projection device 11 in the vertical direction. Axial elongation is the smallest. Therefore, Δy ₁ is set as a reference interval.

The elongation rate in the y-axis direction of the interval Δy _n between the (n−1) -th adjacent luminescent spot and the n-th adjacent luminescent spot can be obtained by the following equation (3) using the interval Δy ₁ as a reference.

Elongation rate in the y-axis direction = Δy _n / Δy ₁
= (Tann · α-tan (n-1) · α) / tan α (3)

Similarly, with the bright spot projected on the plane 102 substantially below the projection device 11 as a reference, the bright spot and the bright spot first adjacent in the x-axis direction (the direction perpendicular to the baseline direction) are the same. The interval is Δx ₁ , the interval between the first adjacent luminescent spot and the second adjacent luminescent spot is Δx ₂ , and the interval between the n′−1th adjacent luminescent spot and the n′th adjacent luminescent spot is Assuming Δx _{n ′} , Δx _{n ′} can be obtained by the following equation (4), and the elongation in the x-axis direction can be obtained by the following equation (5) with the interval Δx ₁ as a reference.

Δx _{n ′} = h (tann ′ · α−tan (n′−1) · α) (4)

Elongation rate in the x-axis direction = Δx _{n ′} / Δx ₁
= (Tann '· α-tan (n'-1) · α) / tanα (5)

As shown in the following equation (6), the inverse of the product of the elongation rate in the y-axis direction and the elongation rate in the x-axis direction calculated by the equations (4) and (5) (that is, the area increase rate) is taken. Thus, the bright spot density at the bright spot position adjacent to the reference bright spot nth in the y-axis direction and n′th in the x-axis direction is calculated.

Bright spot density = 1 / (elongation rate in x-axis direction x elongation rate in y-axis direction) (6)

Based on the bright spot density obtained for each bright spot as described above, the first correction unit 24 corrects the bright spot moving amount and corrects the bright spot as shown in the following equation (7). The amount of movement is calculated.

Bright spot movement after correction = Bright spot movement / Bright spot density
= Bright spot movement x x-axis direction elongation x y-axis direction elongation (7)

By correcting the moving amount of the bright spot measured by the measuring device 14 by the first correcting unit 24, the movement in the height direction measured by the measuring device 14 is also corrected as a result. Note that the calculations from formula (2) to formula (6) are calculated in advance from the settings of the optical system if the respiratory monitor 1 is not moved much after the respiratory monitor 1 is installed. It is also possible to store the bright spot density of each bright spot obtained in this manner in the storage unit 31 and read out the bright spot density when the first correction unit 24 performs the calculation of equation (7). good. For example, for the bright spot density, a table corresponding to the bright spot position may be created in advance and stored in the storage unit 31. Thereby, the calculation amount by the 1st correction | amendment part 24 can be reduced. Also, the target area is divided into a plurality of partial areas, and an average correction value, that is, a bright spot density is obtained for each partial area, and the total of the movement amount of bright spots within the partial area is averaged for each partial area It is also possible to divide by the average bright spot density and add the values over the whole area to obtain the whole respiration waveform.

  The variation information generation unit 22 (see FIG. 4) described above calculates the measurement results corrected by the first correction unit 24, that is, the sum of the corrected bright spot movement amounts, and forms the sum in the time direction. A waveform pattern of breathing of the person 2 is generated as fluctuation information.

  According to the respiratory monitor 1 according to the first embodiment of the present invention described above, the projection device 11 is installed off the center of the object in order to increase the baseline length, and the interval between the bright spots is one. Even if this is not the case, the first correction unit 24 corrects the movement amount of the bright spot measured by the measuring device 14, and consequently the movement in the height direction measured by the measuring device 14 is also corrected. Therefore, the sensitivity of the waveform pattern of the respiration of the person 2 can be accurately grasped without depending on the position of the object. That is, it is possible to obtain accurate measurement results and respiratory waveform patterns with constant sensitivity regardless of the position on the target region.

  In addition, the target region is divided, for example, in the base line direction, and the movement of the person 2 in each region of the chest and abdomen of the person 2 is distinguished to determine obstructive apnea or central apnea, or chronic obstructive lung Even in the case of evaluating each part of the respiratory movement due to a disease or the like, the sensitivity of the respiration waveform pattern of the person 2 does not differ for each divided area or for each area corresponding to each part of the person 2. The state of the person 2 can be accurately grasped.

  In addition, for example, an FG sensor having a low sensitivity, that is, a short baseline length d is further provided, and the height distribution is obtained by the low sensitivity FG sensor, thereby accurately obtaining the movement in the height direction, and the object of the bright spot. Compared to the case where the position in the region is accurately obtained and the position dependency is corrected, the sensitivity of the respiration waveform pattern of the person 2 does not depend on the position of the object, and the position of the object is reduced. It can be set as the respiratory monitor which can grasp | ascertain a motion correctly.

  The respiratory monitor 1 according to the first embodiment of the present invention described above is not limited to the above-described embodiment, and various modifications can be made within the scope described in the claims.

  In the above description, the respiration waveform pattern has been described as being obtained by calculating the sum of the movement amounts of the bright spots. However, the measurement device 14 is the actual amount of movement in the height direction of the person 2, that is, When calculating the height change amount described in FIG. 7, the sum of the height change amounts (that is, the volume change amount) may be calculated. Furthermore, the first correction unit 24 corrects the moving amount of the bright spot measured by the measuring device 14 by dividing it by the bright spot density, and as a result, moves in the height direction measured by the measuring device 14. However, when the measuring device 14 calculates the amount of change in height, the amount of change in height may be divided by the bright spot density for correction. Furthermore, by calculating the volume variation based on the height variation corrected in this way, the volume variation of the person 2 can be measured more accurately. This is extremely effective in measuring the amount of minute movements such as breathing.

  Furthermore, FIG. 13 is a block diagram showing a configuration example of a respiration monitor 1a as a motion detection device according to the second embodiment of the present invention. The configuration is basically the same as that of the respiratory monitor 1 described in the first embodiment, except that a second correction unit 24 a is provided instead of the first correction unit 24. In the following description, overlapping description of the components common to the first embodiment, such as the FG sensor 10 and the arithmetic unit 20, will be omitted as much as possible.

  The first correction unit 24 (see FIG. 4) of the respiratory monitor 1 described in the first embodiment obtains the bright spot density of each bright spot from the bright spot position theoretically predicted from the setting of the optical system. On the other hand, the second correction unit 24a of the respiratory monitor 1a according to the second embodiment of the present invention calculates the amount related to the movement of the object to be corrected on the plane in the target area. The number of bright spots per fixed area in the partial area including the bright spot to be corrected is measured and divided by the number of bright spots in the partial area, that is, the bright spot density in the partial area. By doing so, it is configured to perform correction.

  Specifically, the second correction unit 24a sets, for each luminescent spot, a partial region in a range appropriately set based on the number of pixels of the entire plane 102, the luminescent spot interval, and the like around each luminescent spot, for example, 20 A partial region in a range of about × 20 pixels is set, and a bright spot is searched in the partial region. The second correction unit 24a calculates the number of bright spots in the partial area, that is, the bright spot density in the partial area. The second correction unit 24a calculates the corrected bright spot movement amount by correcting the bright spot movement amount by the above-described equation (7) based on the bright spot density for each bright spot. By comprising in this way, since the calculation from Formula (2) to Formula (6) mentioned above can be abbreviate | omitted, the calculation amount by the calculating device 20 can be reduced. In addition, it is also possible to reduce the influence of an unexpected disappearance of a bright spot due to the unevenness of the target area, for example, due to wrinkles of the futon. Further, for example, even when the bright spot projections are not equiangular intervals and the bright spot intervals are randomly different, the sensitivity of the respiration waveform pattern of the person 2 does not depend on the position of the target object, and the movement of the target object is determined. Accurately grasp. That is, it is possible to obtain accurate measurement results and respiratory waveform patterns with constant sensitivity regardless of the position on the target region.

  Note that the second correction unit 24a does not divide the partial area for each bright spot, but the entire flat surface 102 as the target area is substantially evenly, for example, a partial area of about 20 × 20 pixels or about 40 × 40 pixels. In addition, the partial areas may be divided so as not to overlap with each other, and a bright spot may be searched in the partial areas. In this case, the bright spot density may be a common bright spot density for each bright spot in the partial region. If comprised in this way, since the number of the partial area | region which the 2nd correction | amendment part 24a divides becomes small, the calculation amount by the 2nd correction | amendment part 24a can be reduced. Once the respiratory monitor 1 is installed, if the respiratory monitor 1 is not moved much, the bright spot density is measured in advance by visual observation or the like, and the bright spot density of each bright spot obtained by the actual measurement is calculated. You may comprise so that it may store in the memory | storage part 31 and the said bright spot density may be read when the 2nd correction | amendment part 24a performs the calculation of Formula (7). Thereby, the calculation amount by the 2nd correction | amendment part 24a can be reduced.

It is a typical external view of the respiratory monitor which concerns on the 1st Embodiment of this invention. It is a typical external view for demonstrating the FG sensor of the respiration monitor which concerns on the 1st Embodiment of this invention. It is a typical perspective view explaining the projection apparatus of the respiration monitor which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the structural example of the respiration monitor which concerns on the 1st Embodiment of this invention. It is a conceptual perspective view explaining the concept of the movement of the bright spot of the respiratory monitor according to the first embodiment of the present invention. FIG. 6 is a schematic diagram illustrating a bright spot formed on an image receiving surface in the case of FIG. 5. It is a diagram explaining the calculation of the height of the target object by the measuring apparatus of the respiratory monitor which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows an example of the respiration waveform pattern of the respiration monitor which concerns on the 1st Embodiment of this invention. It is the schematic shown about an example of the waveform pattern of normal and abnormal respiration. It is the figure which showed the table | surface of the disease name or disease location corresponding to the waveform pattern of an abnormal respiration. It is a diagram explaining the detection sensitivity of the motion of the height direction of the respiratory monitor which concerns on the 1st Embodiment of this invention. It is a diagram explaining the case where the projection apparatus of the respiration monitor which concerns on the 1st Embodiment of this invention is installed so that the optical axis may incline with respect to the perpendicular direction of a plane. It is a block diagram which shows the structural example of the respiration monitor which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a Respiration monitor 2 Person 3 Bed 10 FG sensor 11 Projection apparatus 11a Pattern 11b Bright spot 12 Imaging apparatus 14 Measuring apparatus 20 Calculation apparatus 21 Control part 22 Fluctuation information generation part 23 Respiration determination part 24 1st correction | amendment part 24a 2nd Correction unit 40 display 102 plane 103 object 105 light beam generation unit 120 grating 121 optical fiber 122 FG element

Claims (5)

A projection device that projects a plurality of bright spots on a target area;
An imaging device for imaging a target area on which the plurality of bright spots are projected;
Measuring means for measuring movement of an object existing in the target area based on movement of the plurality of bright spots on the imaged image;
When the intervals between adjacent bright spots of the plurality of bright spots on the plane in the target area are not equal, the movement of the target is determined according to the imaged position of the bright spot or the area including the bright spot. Correction means for correcting
Motion detection device. The correction is performed using a ratio of the interval between the bright spot to be corrected and the adjacent bright spot to the reference interval;
The motion detection device according to claim 1. The correction is performed by dividing the amount related to the movement of the object to be corrected by the number of bright spots per unit area in a partial area on the surface in the target area and including the bright spot to be corrected. To do;
The motion detection apparatus according to claim 1 or 2. Fluctuation information generating means for generating fluctuation information of the movement based on the measurement result;
The motion detection device according to any one of claims 1 to 3. The object is breathing;
Respiration determining means for determining a respiration state of the object based on the variation information;
The motion detection device according to any one of claims 1 to 4.

Images