JP6644899B2 - Measurement support device, endoscope system, and processor of endoscope system - Google Patents

Description

The present invention relates to a measurement support device, an endoscope system, and a processor of the endoscope system, and particularly to a measurement support device, an endoscope system, and an endoscope that measure the size of a subject using measurement auxiliary light. Regarding the processor of the system .

  In the field of measuring devices such as endoscopes, measuring a distance to a subject and calculating the length and size of the subject are performed. For example, in Patent Literature 1, a subject distance is measured by a stereo camera, and a mark size serving as a measure of the size of the subject is calculated based on the subject distance and the viewing angle of the endoscope. The display indicates that the size of the subject can be known from the mark.

  Patent Literature 2 discloses a technique for obtaining a subject distance using measurement auxiliary light. In Patent Literature 2, a laser beam is irradiated from an optical fiber to observe an irradiation surface. By using the fact that the irradiation point of the laser beam moves closer to or away from the center of the field of view depending on the distance from the optical fiber to the irradiation surface, it is possible to know the subject distance from the deviation amount by calibrating the deviation amount in advance. it can.

JP 2008-122770 A JP-A-8-285541

  However, in Patent Document 1 described above, two cameras are required to measure the distance with a stereo camera, and the endoscope end portion becomes large, so that the burden on the subject is large. Further, since the distance is measured and the size of the mark is calculated based on the result, the processing is complicated.

  Further, the technique described in Patent Document 2 is for performing distance measurement, the processing is complicated, and the length and size of the subject cannot be directly obtained. Further, since the laser beam is irradiated in parallel with the optical axis of the imaging optical system, when the observation distance is short (when the subject is close to the tip of the endoscope), the laser beam is applied to the visual field of the imaging optical system. And the measurement becomes impossible. Further, there is a problem that the sensitivity of the change of the position of the spot with respect to the change of the subject distance is low and the measurement accuracy is low.

  As described above, the conventional technology cannot easily and accurately measure the size (length) of a subject.

The present invention has been made in view of such circumstances, and has as its object to provide a measurement support device, an endoscope system, and a processor of an endoscope system that can easily and accurately measure the size of a subject. I do.

  In order to achieve the above-described object, a measurement support device according to a first aspect of the present invention includes a head that emits light emitted from a light source as measurement auxiliary light having a spread due to divergence, and a spot formed by the measurement auxiliary light. An imaging unit that acquires an image of a formed subject via an imaging optical system and an imaging device, and measures a position of an edge specific point that is a point on a spot edge in the imaging device based on the acquired image of the subject. A measurement unit, a storage unit that stores information indicating the relationship between the size of the subject on the image sensor and the actual size of the subject in association with the position of the edge specific point on the image sensor, and a storage unit that stores the measured position of the edge specific point. A marker generation unit that obtains information indicating the relationship from the storage unit based on the obtained information, and generates a marker indicating the actual size based on the obtained information; A display control unit for displaying the marker on the display device, the display control unit for displaying the marker near the edge specific point in the image of the subject, the head, at least a part of the edge of the imaging optical system A measurement auxiliary light which has a non-zero inclination angle with the optical axis and at least some of the edges cross the angle of view of the imaging optical system is emitted.

  In the first aspect, since the marker indicating the actual size of the subject is displayed together with the image of the subject, the user can easily measure the size of the subject by comparing the subject (measured object) with the marker. it can. In addition, since the position of the spot is measured, the information stored in the storage unit is acquired based on the measurement result, and the marker is generated and displayed, there is no need for distance measurement as in Patent Documents 1 and 2 described above. The device configuration is simple and measurement is easy.

  In addition, at least a part of the measurement auxiliary light forms an inclination angle other than 0 degree with the optical axis of the imaging optical system, and at least a part of the edge crosses the angle of view of the imaging optical system. By setting, even when the observation distance is short, the edge specific point of the spot formed by the measurement assistance can be set in the field of view of the imaging optical system, and measurement using a marker becomes possible. Furthermore, since the sensitivity of the change in the position of the spot to the change in the observation distance is high, the measurement accuracy is high. By generating and displaying the marker based on the position of the edge specific point in this manner, even when the measurement auxiliary light is emitted straight (when the optical axis of the measurement auxiliary light is parallel to the optical axis of the imaging optical system), the marker is generated obliquely. (The optical axis of the measurement auxiliary light is not parallel to the optical axis of the imaging optical system).

  In the first embodiment, any point on the edge can be set as an “edge specific point”. For example, a position near the center of the imaging optical system, a point near the center of the subject, a point with a high contrast on the edge, and the like can be set as the edge specific point.

  As described above, the measurement support apparatus according to the first aspect can easily and accurately measure the size of the subject. In the first embodiment, the specific value of the “actual size” can be set according to conditions such as the type of the subject and the purpose of measurement.

  In the first aspect, the “information indicating the relationship between the size of the subject on the image sensor and the actual size of the subject” is obtained by, for example, photographing a measurement figure in which a pattern corresponding to the actual size is regularly recorded. Can be obtained. In the first embodiment, the marker is displayed “near” the spot, but the center of the marker may be displayed in accordance with the center of the spot, or the marker may be displayed at a position distant from the spot. In the first embodiment, laser light, LED light, and the like can be used as measurement auxiliary light.

  In the measurement support device according to the second aspect, in the first aspect, at least a part of the edge of the measurement auxiliary light intersects the optical axis of the imaging optical system. Depending on the configuration of the imaging optical system, distortion increases. In this case, it is preferable to perform measurement at the center of the image rather than at the periphery of the image. However, according to the second aspect, the edge specific point is appropriately determined (for example, , At the point where the edge intersects the optical axis of the imaging optical system), measurement can be performed with high accuracy at a position near the center of the image.

  In the measurement support device according to the third aspect, in the first or second aspect, the edge specific point is a point closest to the optical axis of the imaging optical system among the edges of the spot on the imaging element. Depending on the configuration of the imaging optical system, distortion increases. In this case, it is preferable to perform measurement at the center of the image rather than at the periphery of the image. According to the third aspect, the above-described point is specified as an edge specifying point. This makes it possible to perform highly accurate measurement at a position near the center of the image.

  In the measurement support device according to the fourth aspect, in any one of the first to third aspects, the optical axis of the measurement auxiliary light is parallel to the optical axis of the imaging optical system. According to the fourth aspect, since the optical axis of the measurement auxiliary light is parallel to the optical axis of the imaging optical system, the head can be arranged straight (parallel to the optical axis of the imaging optical system), The portion can be made smaller (smaller diameter).

  In the measurement support device according to a fifth aspect, in any one of the first to fourth aspects, the head emits the measurement auxiliary light from a plurality of positions, and the marker generation unit outputs the measurement auxiliary light from the plurality of positions. A marker is generated for each of the lights. In the fifth aspect, since the markers are generated corresponding to the measurement auxiliary lights emitted from the plurality of positions, the size of the subject can be easily and accurately measured by the plurality of markers.

  In order to achieve the above object, an endoscope system according to a sixth aspect of the present invention includes the measurement support device according to any one of the first to fifth aspects. Since the endoscope system according to the sixth aspect includes the measurement support device according to any one of the first to fifth aspects, the size of the subject can be easily and accurately measured.

  An endoscope system according to a seventh aspect is the endoscope system according to the sixth aspect, wherein the insertion portion is inserted into the subject, and includes a distal end hard portion, a curved portion connected to a base end side of the distal end hard portion, An endoscope having an insertion portion having a flexible portion connected to the proximal end side of the bending portion and an operation portion connected to the proximal end side of the insertion portion, an emission portion for measurement auxiliary light, and a spot And an imaging lens for forming the optical image on the imaging element are provided on the distal end side end surface of the distal end hard portion. The seventh aspect defines one aspect of the configuration of the distal end hard portion of the endoscope.

  An endoscope system according to an eighth aspect is the endoscope system according to the sixth or seventh aspect, further comprising: an illumination light source that emits illumination light; and a control unit that controls the illuminance of the illumination light. In the measurement mode in which a spot image is acquired by the system, the illuminance of the illumination light is lower than in the normal observation mode in which the illumination light is applied to the subject to observe the subject. If the illuminance of the illuminating light at the time of imaging the spot is too high, the contrast between the spot and the other parts in the obtained image becomes small and the spot cannot be recognized, and as a result, it becomes difficult to detect the edge specific point. In some cases, the marker cannot be displayed. In the eighth mode, in the measurement mode in which the image of the spot is acquired by the imaging unit, the control unit performs the normal observation mode in which the object is observed by irradiating the object with illumination light. Since the illuminance of the illuminating light is lower than that, a clear image of the spot can be taken, and thereby highly accurate measurement can be performed. In the eighth aspect, how much the illuminance of the illumination light is reduced in the measurement mode may be set according to the type, size, brightness, and the like of the subject, and the illumination light may be turned off as necessary. .

  An endoscope system according to a ninth aspect is the endoscope system according to any one of the sixth to eighth aspects, wherein the imaging element is provided for a plurality of pixels including a plurality of light receiving elements arranged two-dimensionally and a plurality of pixels. A color filter of a plurality of filter colors provided, and a color filter of the filter color having the highest sensitivity to the wavelength of the measurement auxiliary light among the plurality of filter colors. The position of the edge specific point is measured based on the image generated by the image signal of the pixel. According to the ninth aspect, an edge specific point is determined based on an image generated by an image signal of a pixel provided with a color filter of a filter color having the highest sensitivity to the wavelength of the measurement auxiliary light among a plurality of filter colors. Since the position is measured, the position of the edge specific point can be measured with high accuracy by using a clear image of the spot, whereby the size of the subject can be measured with high accuracy.

  To achieve the above object, a processor according to a tenth aspect of the present invention is a processor of the endoscope system according to any one of the sixth to ninth aspects, wherein the light source drive drives a light source. Unit, a measurement unit, a storage unit, a marker generation unit, and a display control unit. According to the tenth aspect, similarly to the first aspect, the size of the subject can be easily and accurately measured. In the tenth aspect, the light source of the measurement auxiliary light is disposed in, for example, a scope (hand-operating unit of an endoscope) and mounted on an electric circuit board of the scope, and receives an electric signal from a processor (light source driving unit). Lighting, turning off, and light intensity are controlled accordingly.

  The processor according to an eleventh aspect is the processor according to the tenth aspect, wherein the measurement unit recognizes a spot shape on the image sensor, and measures an edge specific point based on the recognition result. According to the eleventh aspect, it is possible to accurately detect the edge specific point, thereby displaying a marker of an appropriate size and measuring the size of the subject with high accuracy.

  In the processor according to the twelfth aspect, in the tenth or eleventh aspect, the light source driving unit is a laser driving unit that drives a laser light source.

  In order to achieve the above-described object, a measurement support method according to a thirteenth aspect of the present invention includes a head that emits light emitted from a light source as measurement auxiliary light having a spread due to divergence, and a spot formed by the measurement auxiliary light. An imaging unit that acquires an image of the subject through the imaging optical system and the imaging device, and information indicating the relationship between the size of the subject on the imaging device and the actual size of the subject by using a point on the edge of a spot in the imaging device. And a storage unit for storing in association with the position of the edge specific point, wherein at least a part of the edge from the head is not 0 ° with respect to the optical axis of the imaging optical system. A measurement auxiliary light emitting step of emitting a measurement auxiliary light having an inclination angle and at least a part of the edges crossing the angle of view of the imaging optical system, and an object having a spot formed by the measurement auxiliary light. An imaging step of acquiring an image via an imaging unit, a measurement step of measuring a position of an edge specific point based on an image of a subject, and obtaining information indicating a relationship from a storage unit based on the measured position of the edge specific point A marker generating unit that generates a marker indicating the actual size based on the acquired information; and a display control step of displaying an image of the subject on which the spot is formed and the generated marker on a display device, A display control step of displaying a marker near the spot. According to the thirteenth aspect, similarly to the first aspect, the size of the subject can be easily and accurately measured.

As described above, according to the measurement support device, the endoscope system, and the processor of the endoscope system of the present invention, the size of the subject can be easily and accurately measured.

FIG. 1 is a diagram illustrating an entire configuration of an endoscope system according to a first embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of the endoscope system according to the first embodiment of the present invention. FIG. 3 is a diagram illustrating the configuration of the distal end surface of the distal end hard portion. FIG. 4 is a diagram showing another configuration of the distal end surface of the distal end hard portion. FIG. 5 is a cross-sectional view illustrating the configuration of the laser module. FIG. 6 is a cross-sectional view illustrating the configuration of the laser light source module. FIG. 7 is a diagram illustrating a relationship between the optical axis of the imaging optical system and the optical axis of the measurement auxiliary light. FIG. 8 is a diagram illustrating a state where the insertion section of the endoscope is inserted into the subject. FIG. 9 is a flowchart showing the processing of the measurement support method. FIG. 10 is a diagram showing how the position of the edge specific point changes according to the observation distance. FIG. 11 is a diagram illustrating the relationship between the wavelength and the sensitivity of the color filter. FIG. 12 is a diagram illustrating a state where a marker is displayed at an edge specific point closest to the optical axis of the imaging optical system. FIG. 13 is a diagram illustrating a state where a marker is displayed at an edge specific point far from a point closest to the optical axis of the imaging optical system. FIG. 14 is a diagram illustrating a state where a marker is displayed at a position distant from the edge specific point. FIG. 15 is a diagram illustrating a state where a marker deformed according to the distortion of the imaging optical system is displayed. FIG. 16 is a flowchart illustrating another example of the measurement support method. FIG. 17 is a diagram illustrating a state where the relationship between the position of the edge specific point and the size of the marker is measured. FIG. 18 is another diagram showing how the relationship between the position of the edge specific point and the size of the marker is measured. FIG. 19 is a diagram illustrating a relationship between the pixel position in the X direction of the spot and the number of pixels of the marker in the X axis direction. FIG. 20 is a diagram illustrating the relationship between the pixel position in the Y direction of the spot and the number of pixels in the X axis direction of the marker. FIG. 21 is a diagram illustrating a relationship between the pixel position in the X direction of the spot and the number of pixels in the Y axis direction of the marker. FIG. 22 is a diagram illustrating a relationship between the pixel position in the Y direction of the spot and the number of pixels in the Y axis direction of the marker. FIG. 23 is a block diagram illustrating a configuration of an endoscope system according to the second embodiment of the present invention. FIG. 24 is a diagram illustrating a relationship between the optical axis of the imaging optical system and the optical axis of the measurement auxiliary light. FIG. 25 is a diagram illustrating a display example of a marker according to the second embodiment. FIG. 26 is another diagram illustrating a display example of a marker according to the second embodiment.

  Hereinafter, embodiments of a measurement support device, an endoscope system, a processor of an endoscope system, and a measurement support method according to the present invention will be described in detail with reference to the accompanying drawings.

<First embodiment>
FIG. 1 is an external view showing an endoscope system 10 (a measurement support device, an endoscope system, and a processor of the endoscope system) according to the first embodiment, and FIG. It is a block diagram which shows a part structure. As shown in FIGS. 1 and 2, the endoscope system 10 includes an endoscope main body 110 (endoscope), an endoscope processor 200 (processor of the endoscope system), a light source device 300, and a monitor 400. Endoscope device 100 to be used.

<Configuration of the endoscope body>
The endoscope main body 110 includes a hand operation unit 102 (operation unit) and an insertion unit 104 (insertion unit) connected to the hand operation unit 102. The operator grasps and operates the operation unit 102 at hand, and inserts the insertion unit 104 into the body of the subject to perform observation. The insertion section 104 includes a flexible section 112 (flexible section), a curved section 114 (curved section), and a rigid distal section 116 (rigid distal section) in this order from the hand operation section 102 side. The distal end hard section 116 is provided with an imaging optical system 130 (imaging optical system, imaging section), an illumination section 123, a forceps port 126, a laser module 500, and the like (see FIGS. 1 to 3).

  At the time of observation or treatment, one or both of visible light and infrared light can be emitted from the illumination lenses 123A and 123B of the illumination unit 123 by operating the operation unit 208 (see FIG. 2). In addition, cleaning water is discharged from a water supply nozzle (not shown) by operating the operation unit 208, and the imaging lens 132 (imaging lens) of the imaging optical system 130 and the illumination lenses 123A and 123B can be cleaned. A conduit (not shown) communicates with the forceps port 126 opened at the distal end hard portion 116, and a treatment tool (not shown) for removing a tumor or the like is inserted into the conduit, and is appropriately advanced and retracted to the subject. Necessary measures can be taken.

  As shown in FIGS. 1 to 3, an imaging lens 132 is disposed on the distal end face 116 </ b> A of the distal end hard portion 116, and a CMOS (Complementary MOS) type imaging device 134 (imaging device) is provided behind the imaging lens 132. , A color imaging element, an imaging unit), a drive circuit 136, and an AFE 138 (AFE: Analog Front End), and output an image signal. The image sensor 134 is a color image sensor, and is arranged (two-dimensionally) in a specific pattern arrangement (Bayer arrangement, G stripe R / B complete checkerboard, X-Trans (registered trademark) arrangement, honeycomb arrangement, or the like) in a matrix. A plurality of pixels constituted by a plurality of light receiving elements, each pixel including a microlens, a red (R), green (G), or blue (B) color filter and a photoelectric conversion unit (such as a photodiode). In. The imaging optical system 130 can generate a color image from pixel signals of three colors of red, green, and blue, or generate an image from pixel signals of any one or two colors of red, green, and blue. You can also.

  In the first embodiment, the case where the image sensor 134 is a CMOS image sensor will be described. However, the image sensor 134 may be a CCD (Charge Coupled Device) type.

  An image of a subject (tumor or lesion) or an optical image of a spot (described later) is formed by an imaging lens 132 on a light receiving surface (imaging surface) of an image sensor 134 and is converted into an electric signal. And is output to the endoscope processor 200 via the. Thereby, an observation image or the like (see FIGS. 12 to 15) is displayed on the monitor 400 connected to the endoscope processor 200.

  Further, an illumination lens 123A (for visible light) and 123B (for infrared light) of the illumination unit 123 are provided on the distal end surface 116A of the distal end hard portion 116 adjacent to the imaging lens 132. An emission end of a light guide 170 to be described later is disposed behind the illumination lenses 123A and 123B. The light guide 170 is inserted into the insertion portion 104, the hand operation portion 102, and the universal cable 106, and The entrance end is arranged in the light guide connector 108.

  A laser head 506 (head, emission part of measurement auxiliary light) of the laser module 500 is further provided on the distal end surface 116A, and is irradiated with spot light (measurement auxiliary light). The configuration of the laser module 500 will be described later. In the first embodiment, the laser head 506 is provided separately from the forceps port 126 as shown in FIG. 3, but in the measurement support device and the endoscope system according to the present invention, as shown in FIG. Alternatively, the laser head 506 may be removably inserted into a conduit (not shown) communicating with the forceps port 126 opened by the distal end hard portion 116. In this case, there is no need to provide a dedicated conduit for the laser head 506, and the conduit communicating with the forceps port 126 can be shared with other treatment tools.

<Configuration of laser module>
As shown in FIGS. 2 and 5, the laser module 500 includes a laser light source module 502 (light source, laser light source), an optical fiber 504 (optical fiber), and a laser head 506 (head). The base end side (the laser light source module 502 side) of the optical fiber 504 is covered with a fiber sheath 501, and the front end side (the side from which laser light is emitted) is inserted into a ferrule 508 (ferrule) and adhered with an adhesive, and the end face is polished. Is done. The ferrule 508 is a member for holding and connecting the optical fiber 504, and a hole for inserting the optical fiber 504 is provided at the center in the axial direction (the left-right direction in FIG. 5). A reinforcing material 507 is provided outside the ferrule 508 and the fiber sheath 501 to protect the optical fiber 504 and the like. The ferrule 508 is housed in the housing 509 and forms a laser head 506 integrally with the reinforcing member 507 and the fiber sheath 501.

  In the laser head 506, a ferrule 508 having a diameter of, for example, 0.8 mm to 1.25 mm can be used. Note that a smaller diameter is more preferable for miniaturization. With the above configuration, the diameter of the entire laser head 506 can be set to 1.0 mm to 1.5 mm.

  The laser module 500 thus configured is mounted on the insertion section 104. Specifically, as shown in FIG. 2, the laser light source module 502 is arranged on the hand operation unit 102 (scope) and mounted on the electric circuit board unit. On the other hand, the laser head 506 is provided on the distal end hard portion 116, and the optical fiber 504 guides laser light from the laser light source module 502 to the laser head 506. Note that the laser light source module 502 may be provided in the light source device 300, and the laser light may be guided to the distal end hard portion 116 by the optical fiber 504.

  The laser light source module 502 includes a VLD (Visible Laser Diode) that receives power from a power supply (not shown) and emits laser light in a visible wavelength range, and a condenser lens 503 that collects laser light emitted from the VLD. This is a pigtail type module (TOSA; Transmitter Optical Sub Assembly) provided (see FIG. 6). The laser beam can be emitted as needed under the control of the endoscope processor 200 (CPU 210). The laser beam is emitted only when measurement is performed by irradiating spot light (measurement mode). (Normal mode). The laser light source module 502 is controlled to be turned on / off, and has a light intensity in accordance with an electric signal from the endoscope processor 200 (light source driving unit, laser driving unit).

  In the first embodiment, the laser light emitted from the VLD can be red laser light having a wavelength of 650 nm from a semiconductor laser. However, the wavelength of the laser beam in the present invention is not limited to this mode. The laser light focused by the focusing lens 503 is guided by the optical fiber 504. As the optical fiber 504, an optical fiber that transmits a laser beam in a single transverse mode may be used. If the spot size or sharpness does not pose a problem in measurement depending on the observation conditions such as the type and size of the subject, the laser beam may be used. May be used in multi-mode. A relay connector may be provided in the middle of the optical fiber 504. In addition, as the light source, an LED (Light-Emitting Diode) may be used instead of the semiconductor laser, and the semiconductor laser may be used in an LED emission state equal to or lower than the oscillation threshold. When it is necessary to control the spread of the measurement auxiliary light, a lens (or a lens group) such as a concave lens may be disposed in front of the emission end of the optical fiber 504 (left side in FIG. 5).

<Relationship between imaging optical system and measurement auxiliary light>
FIG. 7 is a conceptual diagram illustrating the relationship between the imaging optical system 130 and the measurement auxiliary light. In the first embodiment, as shown in FIG. 7, the imaging optical system 130 has a shooting angle of view θ, and the measurement auxiliary light has a beam spread angle δ due to divergence. The optical axis L1 of the measurement auxiliary light and the optical axis L2 of the imaging optical system 130 are parallel. Further, the edge E1 of the measurement auxiliary light (a part of the edge of the measurement auxiliary light) forms a non-zero inclination angle ε (= photographing field angle θ−beam spread angle δ) with the optical axis L2 of the imaging optical system 130. In the first embodiment, the edge E1 enters the angle of view at the observation distance D1 from the distal end surface 116A (point P4), and the edge E1 intersects the optical axis L2 of the imaging optical system 130 at the observation distance D2 (point P5). ). Therefore, if a point on the edge E1 in the spot formed by the measurement auxiliary light is defined as an “edge specific point”, the edge specific point is a point closest to the optical axis L2 of the imaging optical system. In addition, if the point P5 can be set as an edge specific point by adjusting the observation distance and the observation direction (by moving the insertion unit 104 forward and backward and / or bending), measurement can be performed with high accuracy at the center of the image with less aberration. In the first embodiment, the optical axis L1 of the measurement auxiliary light is parallel to the optical axis L2 of the imaging optical system. However, in the present invention, these optical axes are not limited to the parallel state. Alternatively, the measurement may be performed at the central portion where the aberration is small in the imaging angle of view θ.

  As an example of the beam divergence angle of the measurement auxiliary light, the emission angle in the air of light emitted from an optical fiber having a numerical aperture of 0.22 is 25.4 deg. In this case, the distance from the optical fiber end is At a position of 5.2 mm, the spot diameter becomes about 5 mm.

<Configuration of light source device>
As shown in FIG. 2, the light source device 300 includes a light source 310 (illumination light source) for illumination, a stop 330, a condenser lens 340, a light source control unit 350 (control unit), and the like. Light or infrared light) is incident on the light guide 170. The light source 310 includes a visible light source 310A (illumination light source) and an infrared light source 310B (illumination light source), and can emit one or both of visible light and infrared light. The illuminance of the illuminating light from the visible light source 310A and the infrared light source 310B is controlled by the light source control unit 350. As described later, the illuminance of the illuminating light is used as needed when the spot is imaged and measured (in the measurement mode). Or turn off the lights.

  By connecting the light guide connector 108 (see FIG. 1) to the light source device 300, the illumination light emitted from the light source device 300 is transmitted to the illumination lenses 123A and 123B via the light guide 170, and the illumination lenses 123A and 123B are connected. The observation area is irradiated from 123B.

<Configuration of endoscope processor>
Next, the configuration of the endoscope processor 200 (measurement unit, storage unit, marker generation unit, display control unit, light source driving unit, laser driving unit) will be described based on FIG. The endoscope processor 200 inputs an image signal output from the endoscope apparatus 100 via an image input controller 202, and performs image processing required by an image processing unit 204 (a measurement unit, a marker generation unit, and a display control unit). And outputs the result via the video output unit 206. As a result, the observation image is displayed on the monitor 400 (display device). These processes are performed under the control of a CPU 210 (Central Processing Unit; central processing unit) (measurement unit, marker generation unit, display control unit). In the image processing unit 204, in addition to image processing such as white balance adjustment, switching and superimposed display of an image displayed on the monitor 400, electronic zoom processing, display of an image according to an operation mode, and specific components (for example, luminance) from an image signal Signal). Further, the image processing unit 204 performs measurement of a spot position on the image plane of the image sensor 134, measurement of the position of an edge specific point, and calculation of a marker size (number of pixels) based on the measured position (described later). The memory 212 (storage unit) previously stores information necessary for the processing performed by the CPU 210 and the image processing unit 204, for example, the relationship between the position of the edge specific point on the imaging plane of the image sensor 134 and the size of the marker. . This relationship may be stored in a function format or a look-up table format.

  Further, the endoscope processor 200 includes an operation unit 208. The operation unit 208 includes an operation mode setting switch, a water supply instruction button, and the like (not shown), and can operate irradiation of visible light and / or infrared light.

<Observation by endoscope device>
FIG. 8 is a diagram illustrating a state in which the insertion unit 104 of the endoscope apparatus 100 is inserted into the subject, and illustrates a state where an observation image is acquired for the imaging range IA via the imaging optical system 130. FIG. 8 shows that the spot SP0 is formed in the vicinity of the tumor tm0 (the black raised portion). Note that the edge specific point is a point on the edge of the spot SP0, and a special mark or the like is not formed on the subject. Further, the marker is displayed on the screen, and is not formed on the subject.

<Flow of measurement processing>
Next, a method of supporting measurement of a subject using the endoscope system 10 will be described. FIG. 9 is a flowchart showing the processing of the measurement support method.

  First, the insertion section 104 of the endoscope apparatus 100 is inserted into the subject, and the endoscope system 10 is set to the normal observation mode (Step S10). The normal observation mode is a mode in which illumination light emitted from the light source device 300 is applied to a subject to acquire an image and observe the subject. The setting to the normal observation mode may be automatically performed by the endoscope processor 200 when the endoscope system 10 is activated, or may be performed according to an operation of the operation unit 208 by a user.

  When the endoscope system 10 is set to the normal observation mode, the object is imaged by irradiating the illumination light and displayed on the monitor 400 (step S12). The image of the subject may be a still image or a moving image. At the time of imaging, it is preferable to switch the type of illumination light (visible light or infrared light) according to the type of subject or the purpose of observation. The user moves the insertion unit 104 forward and backward and / or bends while looking at the image displayed on the monitor 400 so that the distal end hard part 116 is aimed at the observation target so that the subject to be measured can be imaged.

  Next, it is determined whether or not to shift from the normal observation mode to the measurement mode (step S14). This determination may be made based on the presence or absence of a user operation via the operation unit 208, or may be performed based on the presence or absence of a switching command from the endoscope processor 200. Further, the endoscope processor 200 may alternately set the normal observation mode and the measurement mode at a fixed frame interval (every 1 frame, every 2 frames, etc.). If the determination in step S14 is negative, the process returns to step S12 to continue imaging in the normal observation mode, and if the determination is positive, the process proceeds to step S16 to switch to the measurement mode.

  The measurement mode is for irradiating laser light (measurement auxiliary light) from the laser head 506 to form a spot on the subject, and for measuring the size (length) of the subject based on an image of the subject on which the spot is formed. This is a mode for generating and displaying a marker. In the first embodiment, red laser light is used as the measurement auxiliary light. However, in many endoscope images, the digestive tract is reddish, and depending on the measurement conditions, it may be difficult to recognize spots and edge specific points. Therefore, in the measurement mode, the illumination light is turned off when the image of the spot is acquired and the position of the edge specific point is measured, or the illuminance is reduced so as not to affect the recognition of the spot (step S18). Light is irradiated (Step S20: measurement auxiliary light emission step). Such control can be performed by the endoscope processor 200 and the light source control unit 350.

  In step S22, an image of the subject on which the spot has been formed by the measurement auxiliary light is captured (imaging step). When the observation distance is within the measurement range (in the example of FIG. 7, the observation distance D1 or more), a spot is formed within the imaging angle of view of the imaging optical system 130. As described in detail below, the position of the edge specific point (on the image sensor) in the image differs depending on the observation distance, and the size (number of pixels) of the marker to be displayed depends on the position of the edge specific point. Different.

<Position change of edge specific point according to observation distance>
FIG. 10 is a conceptual diagram illustrating a state in which the distal end hard portion 116 is viewed from the front (subject side). In accordance with the configurations in FIGS. 3 and 7, the position of the edge specific point in the image according to the observation distance. It shows how it changes. Note that FIG. 10 illustrates a case where the edge specific point is a point closest to the optical axis L2 of the imaging optical system 130 (point on the edge E1 in FIG. 7) among spot edges on the imaging element 134. In FIG. 10, at the observation distance D1, the imaging range is the range R2A and the edge specific point is the point P4 (see FIG. 7). At the observation distance D2, the imaging range is the range R2B and the edge specific point is the point P5. The observation distance D2 is a distance at which the edge E1 intersects the optical axis L2 of the imaging optical system 130. Note that the edge E1 forms a non-zero inclination angle ε with the optical axis L2 of the imaging optical system 130 (see FIG. 7).

  When the optical axis of the measurement auxiliary light is parallel to the optical axis of the imaging optical system (the inclination angle is 0 degree) as in Patent Document 2 described above, the optical axis of the measurement auxiliary light depends on the interval between the optical axes. The distance to the point crossing the angle of view of the system (corresponding to the observation distance D1 in FIG. 7) becomes long, and in that case, the spot cannot be photographed at a close distance, making measurement difficult. Such a situation can be a serious problem in an endoscope that often performs observation at a close distance. Further, when the optical axis of the measurement auxiliary light is parallel to the optical axis of the imaging optical system, the sensitivity of the change in the spot position with respect to the change in the observation distance becomes low, and sufficient measurement accuracy may not be obtained. Furthermore, Patent Document 2 considers “the position of the spot”, but does not consider “the position of the edge specific point with respect to the spot”. On the other hand, according to the configuration of the first embodiment, it is possible to measure over a wide range of observation distance from a close distance to a long distance, and it is possible to measure with high accuracy because the position change of the edge specific point with respect to the distance change is high. it can.

  As described above, the position of the edge specific point in the captured image (on the image sensor 134) is determined when the relationship of the edge specific point to the spot is specified (for example, the closest to the optical axis L2 of the imaging optical system 130 as described above). When the observation distance is short, the same actual size (for example, 5 mm) is shown, although it depends on the relationship between the optical axis L2 of the imaging optical system 130 and the optical axis L1 of the measurement auxiliary light and the observation distance. The number of pixels increases, and the number of pixels decreases as the viewing distance increases. Therefore, as will be described in detail later, information indicating the relationship between the position of the edge specific point and the size (number of pixels) of the marker corresponding to the actual size of the subject is stored in advance, and the information is stored in accordance with the position of the edge specific point. By obtaining the leverage information, the size of the marker can be calculated. It is not necessary to measure the observation distance itself at the time of calculation.

  Returning to the flowchart of FIG. 9, the recognition of the spot position on the imaging surface of the imaging element 134 and the measurement of the position of the edge specific point (step S24: measurement step) will be described. The position measurement of the edge specific point in step S24 is performed based on an image generated by a pixel signal of a pixel provided with a color filter of a red (R) filter color. Here, the relationship between the wavelength and the sensitivity in each color (red, green, blue) color filter provided in each pixel of the image sensor 134 is as shown in FIG. 11, and as described above, the laser head 506 is used. Is a red laser beam having a wavelength of 650 nm. That is, the measurement of the spot position and the measurement of the position of the edge specific point are performed on the pixel (R pixel) provided with the red color filter having the highest sensitivity to the wavelength of the laser beam among the (red, green, blue) color filters. This is performed based on an image generated by the image signal. At this time, a threshold value is provided to the signal intensity of the R pixel of the bitmap data of the pixel signal or the RAW (Raw image format) data to binarize, and the center of gravity of the white portion (the pixel whose signal intensity is higher than the threshold value) is calculated. In addition, the position of the spot can be recognized at high speed, and the position of the edge specific point can be measured based on this. When spots are recognized from an actual image (an image generated by pixel signals of all colors), a threshold value is set to pixel signals of pixels (G pixel and B pixel) provided with green and blue color filters. It is preferable to extract only pixels in which the values of the pixel signals of the G pixel and the B pixel having the bitmap data are equal to or less than the threshold value.

  The position measurement of the edge specific point based on the recognized spot is performed by recognizing the shape of the spot (extracting the edge), calculating the coordinates of the edge, and referring to the position of the optical axis L2 of the imaging optical system 130 (for example, extraction). Out of the points on the edge thus determined, the point closest to the optical axis L2 is set as the edge specific point). When there is a portion where the contour cannot be accurately extracted due to observation conditions such as the shape and brightness of the subject, the contour may be approximated by a figure such as a circle or an ellipse. Note that such a method is an example of a spot position measurement and edge specific point detection method, and another method may be employed.

  In the measurement mode, as described above, the illumination light is turned off or the illuminance is reduced to such an extent as not to affect spot recognition and edge specific point detection at the time of spot image acquisition (step S22) and position measurement (step S24). (Step S18), the measurement auxiliary light is emitted from the laser head 506 (Step S20). As a result, a clear image of the spot can be obtained, and the position of the edge specific point can be accurately measured to generate and display a marker having an appropriate size. Note that the illumination light does not necessarily need to be dimmed or turned off, and the illuminance may be kept as it is when there is no influence on spot recognition and edge specific point detection.

  In step S26, a marker indicating the actual size of the subject is generated (marker generation step). As described above, since the size of the marker differs depending on the position of the edge specific point in the image (that is, on the imaging surface of the image sensor), the size of the marker corresponding to the position of the edge specific point and the actual size of the subject is changed. The relationship with the size (the number of pixels) is measured in advance, and information indicating the relationship is stored in the memory 212, and the endoscope processor 200 reads the information from the memory 212 according to the position of the edge specific point measured in step S24. Information is obtained, and the size of the marker is obtained based on the obtained information. The procedure for obtaining the relationship between the position of the edge specific point and the size of the marker will be described later in detail.

  In step S28, the observation image and the marker are displayed on the monitor 400 (display control step). The display conditions (the type, number, actual size, color, etc. of the markers) can be set by a user operation via the operation unit 208. FIG. 12 shows a cross-shaped marker M1 indicating an actual size of 5 mm (horizontal direction and vertical direction of an observed image) with a spot SP1 formed in the vicinity of a subject (tumor tm1). It is a figure showing signs that it was displayed together. In FIG. 12, the point closest to the optical axis L2 of the imaging optical system 130 among the edges of the spot SP1 is defined as an edge specific point EP1, and the marker M1 is displayed at the center of the edge specific point EP1. In FIG. 12, a black circle is displayed at the position of the edge specific point EP1, but this is a symbol for clearly indicating the position of the edge specific point EP1, and such a display is performed on an actually displayed image. It is not necessary (same in the following figures). Further, the dotted line C1 is a virtual line connecting the center of the spot SP1 and the optical axis L2 of the imaging optical system 130, and is for explaining the position of the edge specific point. It is not necessary to do this (the same applies to the following figures).

  FIG. 13 illustrates a point other than the edge specific point EP1 (a point closest to the optical axis L2 of the imaging optical system 130 among the edges of the spot SP1) as the edge specific point EP2 in the example of FIG. In addition, the marker M2 is displayed. As such an edge specific point EP2, for example, a point having a high contrast inside and outside the spot on the edge or a point of a portion where the contour of the spot is an accurate arc (or ellipse) can be used. It is possible to accurately measure the position of a specific point and generate and display a marker of an appropriate size. In addition, the subject exists in the peripheral part of the image (a position distant from the optical axis L2 of the imaging optical system 130), and the "point closest to the optical axis L2 of the imaging optical system 130 among the edges of the spot SP1" is defined as an edge specific point. Then, when the object becomes far from the subject, a marker having an appropriate size can be generated and displayed by using the edge specific point EP2 other than the edge specific point EP1.

  In the examples of FIGS. 12 and 13 described above, the center of the marker is displayed together with the edge specific point. However, the display of the marker in the present invention is not limited to such a mode, and the marker may be displayed “near” the edge specific point. FIG. 14 is a diagram illustrating an example in which the marker M3 is displayed at a position distant from the edge specific point EP1 (the position of the optical axis L2 of the imaging optical system 130) in the state of FIG. In FIG. 14, the marker M3 is displayed at the position of the optical axis L2, but the marker may not be displayed at such a position. However, as described above, since the size of the marker is determined by the position of the edge specific point, it is necessary to move away from the edge specific point to generate and display a marker of an appropriate size and measure the size of the subject with high accuracy. It is preferable to display a marker at a position that is only too short.

  By generating and displaying the markers as exemplified in FIGS. 12 to 14, the user can easily and accurately measure the size of the subject without measuring the observation distance.

  Although the influence of distortion of the imaging optical system 130 is not considered in FIGS. 12 to 14 described above, an optical system used for an endoscope is generally wide-angle and has large distortion, which also affects the shape of a subject in a captured image. . Therefore, it is preferable to display the marker in a form in which the influence of the distortion is considered (corrected). In this case, since the distortion is small in the central part of the optical system and large in the peripheral part, the presence or absence of the correction may be determined according to the marker display position (spot position). FIG. 15 shows an example in which the marker is deformed in the peripheral portion of the image having a large distortion as a marker M4 and displayed on the edge specific point EP2 on the spot SP2 formed near the subject (tumor tm2). By displaying the marker in this manner, the size of the subject can be accurately measured in consideration of the influence of distortion of the imaging optical system. The distortion data may be set based on the design value of the imaging optical system 130 or may be separately measured and acquired.

  Instead of displaying the marker in a deformed form, the distortion in the captured image may be corrected, and the undeformed marker may be displayed in the corrected image.

  12 to 15 illustrate a case where a marker corresponding to the actual size of the subject of 5 mm is displayed, but the actual size of the subject may be any value (for example, 2 mm, 3 mm, 10 mm). Although a cross-shaped marker is displayed in FIGS. 12 to 15, a marker having a circular shape or another shape may be displayed. The number of markers may be one or more, and the color of the markers may be changed according to the actual size. Further, a number indicating the actual size (for example, “5” when the actual size is 5 mm) may be displayed near the marker. By displaying in this manner, the relationship between the subject and the marker can be visually identified, and the measurement of the subject can be performed easily and with high accuracy. Note that such a display mode may be selected by an operation via the operation unit 208.

  By comparing the marker as illustrated in FIGS. 12 to 15 with the subject, the user can easily measure the size of the subject without measuring the observation distance.

  In step S30, it is determined whether to end the measurement mode. This determination may be made based on a user operation via the operation unit 208 or may be made based on the presence or absence of a switching command from the endoscope processor 200. Also, as in the case of the transition to the measurement mode, the measurement mode may be automatically terminated after a certain number of frames has elapsed, and the mode may be returned to the normal observation mode. If the determination in step S30 is negative, the process returns to step S20, and the processing from step S20 to step S28 is repeated. If the determination in step S30 is affirmative, the process proceeds to step S32, in which the measurement auxiliary light is turned off. Then, in step S34, the illuminance of the illumination light is returned to the normal illuminance, and the process returns to the normal observation mode (return to step S10). If the observation in the normal observation mode is not hindered, the measurement auxiliary light need not be turned off.

  In the above-described method, when an image obtained in the measurement mode is dark and it is difficult to recognize a spot and measure the position of an edge specific point, measurement may be performed according to the procedure shown in the flowchart of FIG. In the flowchart of FIG. 16, after the measurement auxiliary light is turned on (Step S40), one frame is darkened for measurement (Step S42), an image is captured (Step S44), and spot recognition and edge identification are performed based on the captured image. Point position measurement (step S46) and marker generation (step S48) are performed. The next one frame is set to a normal illumination light amount (step S50) and an image is taken (step S52). In the diagnosis and observation using the measurement auxiliary light, the marker information is generated from the dark image (the image captured in step S44) (step S48), and the image of the normal illumination light amount (the image captured in step S52). (Step S54), the brightness of the observed image can be made the same as that in the case of normal illumination. In the flowchart of FIG. 16, the same steps as those in the flowchart of FIG. 9 are denoted by the same step numbers, and description thereof will be omitted.

  As described above, according to the endoscope system 10 (measurement support device, endoscope system, processor of the endoscope system) and the measurement support method using the same according to the first embodiment, the size of the subject Can be measured easily and with high accuracy.

<Measurement of relationship between position of edge specific point and size of marker>
In the first embodiment, the relationship between the position of the edge specific point on the imaging surface of the image sensor 134 and the size (the number of pixels) of the marker corresponding to the actual size of the subject is measured in advance, and the relationship is established with the position of the edge specific point. Then, the size of the marker is calculated by referring to this relationship according to the measured position of the edge specific point. Hereinafter, an example of a procedure for measuring the relationship between the position of the edge specific point and the size of the marker will be described. Here, the marker is described as having a cross shape, and the actual size in the horizontal and vertical directions is assumed to be 5 mm, but the marker in the present invention is not limited to such an embodiment.

  The relationship between the position of the edge specific point and the size of the marker can be obtained by imaging a chart in which patterns of the actual size are regularly formed. For example, a spot is formed by emitting the measurement auxiliary light, and the observation distance is changed to change the position of the spot while changing the position of the spot. And obtains the relationship between the position of the edge specific point (pixel coordinates on the imaging surface of the image sensor) and the number of pixels corresponding to the actual size (how many pixels represent the actual size of 5 mm). . When acquiring such a relationship, it is preferable that the relationship between the spot and the edge specific point is fixed (for example, the point closest to the optical axis L2 of the imaging optical system 130 is determined regardless of the observation distance). A specific point).

  Note that a plurality of edge specific points may be set for the same spot position, and information (the relationship with the marker size) corresponding to each of the plurality of edge specific points may be stored. For example, the relationship when the point closest to the optical axis L2 among the edges is set as the edge specific point and the relationship when the point farthest from the optical axis L2 is set as the edge specific point are measured and stored, You may use it properly according to the observation situation. When the observation distance is close to the closest end or when the imaging optical system 130 is directly facing the subject, the size of the marker does not change much even if any point on the edge is set as the edge specific point, but the observation distance is long. If the imaging optical system 130 is not directly facing the subject, the size of the marker may differ depending on which position on the edge is the edge specific point. In such a case, the edge specific point can be selected. In this case, a marker having an appropriate size can be displayed, and the size of the subject can be easily and accurately measured.

  FIG. 17 is a diagram showing a state in which a chart with a rule of 5 mm is photographed, and shows a state in which the distance between the rules is wide because the photographing distance is short. In FIG. 17, (x1, y1) are the X and Y directions of the edge specific point EP3 (the point on the edge of the spot SP3 and closest to the optical axis L2 of the imaging optical system 130) on the imaging surface of the imaging device 134. The pixel position (the upper left of FIG. 17 is the origin of the coordinate system). At the position (x1, y1) of the edge specific point EP3, the number of pixels in the X direction corresponding to the actual size of 5 mm is Lx1, and the number of pixels in the Y direction is Ly1. This number of pixels is “the number of pixels of the marker M5 when the position of the edge specific point EP3 is (x1, y1)”. Such measurement is repeated while changing the observation distance. FIG. 18 is a diagram showing a state in which the same 5 mm ruled chart as in FIG. 17 is photographed, but the photographing distance is closer to the far end than in the state in FIG. 17, and the ruled space is narrower. In the state shown in FIG. 18, the position (x2, y2) of the edge specific point EP4 (the point on the edge of the spot SP4 and closest to the optical axis L2 of the imaging optical system 130) on the imaging surface of the imaging element 134. The number of pixels in the X direction corresponding to the actual size of 5 mm is Lx2, and the number of pixels in the Y direction is Ly2. This number of pixels is “the number of pixels of the marker M6 when the position of the edge specific point EP4 is (x2, y2)”. The measurement as shown in FIGS. 17 and 18 is repeated while changing the observation distance, and the results are plotted. 17 and 18, for the sake of convenience, the image is displayed without considering the distortion of the imaging optical system 130.

  FIG. 19 is a diagram showing the relationship between the X coordinate of the position of the edge specific point and Lx (the number of pixels in the X direction of the marker), and FIG. 20 is a diagram showing the relationship between the Y coordinate of the position of the edge specific point and Lx. is there. Lx is expressed as Lx = g1 (x) as a function of the position in the X direction from the relationship of FIG. 19, and Lx = g2 (y) as a function of the position in the Y direction from the relationship of FIG. g1 and g2 can be obtained, for example, by the least square method from the above-mentioned plot results. As described above, two functions g1 and g2 representing Lx are obtained. However, the X coordinate and the Y coordinate of the position of the edge specific point have a one-to-one correspondence, and basically any of g1 and g2 can be used. Since the same result (the same number of pixels for the same edge specific point position) is obtained, either function may be used when calculating the marker size. A function having a higher sensitivity of a change in the number of pixels to a change in position may be selected from g1 and g2. If the values of g1 and g2 are significantly different, it may be determined that "the position of the spot and / or the edge specific point could not be recognized". In the first embodiment, information indicating the functions g1 and g2 obtained in this manner is stored in the memory 212 in advance in a function format, a lookup table format, or the like.

  FIG. 21 is a diagram showing the relationship between the X coordinate of the position of the edge specific point and Ly (the number of pixels in the Y direction), and FIG. 22 is a diagram showing the relationship between the Y coordinate of the position of the edge specific point and Ly. is there. From the relationship in FIG. 21, Ly is represented as Ly = h1 (x) as a function of the X direction position, and from the relationship in FIG. 22, Ly is represented as Ly = h2 (y) as a function of the Y direction position. As for Ly, any of the functions h1 and h2 may be used as in Lx.

<Second embodiment>
Next, a second embodiment of the measurement support device, the endoscope system, the processor of the endoscope system, and the measurement support method of the present invention will be described. In the above-described first embodiment, the case where one measurement auxiliary light is irradiated by the single laser head 506 has been described. However, in the second embodiment, the measurement auxiliary light is irradiated from a plurality of positions by a plurality of laser heads. The case where a plurality of markers are displayed by this will be described.

  FIG. 23 is a block diagram showing an endoscope system 10A according to the second embodiment. The endoscope system 10A is different from the endoscope system 10 according to the first embodiment in that a laser module 500A is provided in addition to the laser module 500. The laser module 500A includes a laser light source module 502A, an optical fiber 504A, and a laser head 506A (head). The configuration, operation, and effect of the laser module 500, the laser light source module 502, the optical fiber 504, and the laser according to the first embodiment are described. It is the same as the head 506, respectively. Also, since the configuration of the endoscope system 10A is the same as that of the endoscope system 10 except for the laser module 500A, in FIG. 23, the same components as those in FIG. 2 are denoted by the same reference numerals, and detailed description is omitted. .

  FIG. 24 is a diagram showing an arrangement of the imaging optical system 130, the laser head 506, and the laser head 506A in the distal end hard portion 116. The laser head 506A has a beam divergence angle δ due to divergence similarly to the laser head 506, and the optical axis L3 of the auxiliary measurement light by the laser head 506A is the optical axis L1 of the auxiliary measurement light by the laser head 506, and the light of the imaging optical system. It is parallel to the axis L2. The edge E2 of the measurement auxiliary light by the laser head 506A (a part of the edge of the measurement auxiliary light) is not equal to the optical axis L2 of the imaging optical system 130 and the non-zero tilt angle ε (= photographing field angle θ−beam spread angle δ). Make. Similarly to the measurement auxiliary light by the laser head 506, the edge E2 enters the angle of view at the observation distance D1 from the front end surface 116A (point P4A), and the edge E1 intersects the optical axis L2 of the imaging optical system 130 at the observation distance D2. (Point P5). Therefore, if a point on the edge E2 is defined as an “edge specific point”, the edge specific point is a point closest to the optical axis L2 of the imaging optical system 130.

  Note that the arrangement of the imaging optical system 130, the laser head 506, and the laser head 506A in the endoscope system 10A can be appropriately set within a range that satisfies the above-described conditions. For example, the laser head 506 and the laser The head 506A can be arranged symmetrically. The measurement processing in the endoscope system 10A can be performed in the same manner as in the endoscope system 10 (see the flowcharts in FIGS. 9 and 16 and corresponding descriptions).

  FIG. 25 is a diagram showing a state where a spot SP5A formed by the laser head 506 and a spot SP5B formed by the laser head 506A are formed near the subject (tumor tm1). In FIG. 25, a cross-shaped marker M7A indicating the actual size 5 mm (horizontal direction and vertical direction of the observation image; the same applies hereinafter) is displayed with the center aligned with the edge specific point EP5A, and the cross-shaped marker M7A also indicating the actual size 5 mm. It is a figure showing signs that marker M7B was displayed centering on edge specific point EP5B. In FIG. 25, a point closest to the optical axis L2 of the imaging optical system 130 among the edges of the spot SP5A is defined as an edge specific point EP5A, and a marker M7A is displayed at the center of the edge specific point EP5A. A point closest to the optical axis L2 of the imaging optical system 130 among the edges of the spot SP5B is defined as an edge specific point EP5B, and a marker M7B is displayed at the center of the edge specific point EP5B. The dotted lines C2A and C2B are virtual lines connecting the centers of the spots SP5A and SP5B and the optical axis L2 of the imaging optical system 130, similarly to the dotted line C1.

  FIG. 26 is a diagram showing a state in which a spot SP6A by the laser head 506 and a spot SP6B by the laser head 506A are formed near the subject (tumor tm1). In the example of FIG. 26, the spot SP6A and the spot SP6B overlap, and the intersections of the edges of these spots are designated as edge specific points EP6A and EP6B. The marker M8A is displayed around the edge specific point EP6A, and the marker M8B is displayed around the edge specific point EP6B.

<Modified example of measurement auxiliary light wavelength and measurement processing>
In the first and second embodiments described above, the case where the measurement auxiliary light is red laser light having a wavelength of 650 nm has been described. However, in the present invention, the wavelength of the measurement auxiliary light and the measurement processing based on these are limited to such an aspect. It is not something to be done. Other aspects of the wavelength of the measurement auxiliary light and the measurement process will be described below. In the following description, the same components as those in the first and second embodiments are denoted by the same reference numerals, and detailed description will be omitted.

<Modification 1>
The first modification is different from the first and second embodiments in that the wavelength of the measurement auxiliary light is a blue laser (semiconductor laser) having a wavelength of 445 nm. Note that an LED may be used instead of the semiconductor laser, and the semiconductor laser may be used in an LED emission state that is equal to or lower than the oscillation threshold. In the first modification of such a configuration, the processing of spot position measurement and marker generation is basically the same as in the first and second embodiments. Since a laser is used, a threshold value is set for the intensity of the B signal (pixel signal of a pixel provided with a blue color filter) of bitmap data or RAW data when measuring the position of a spot and the position of an edge specific point. The image is binarized, and the center of gravity of the white portion (pixel region where the signal intensity is higher than the threshold) is calculated. When measuring the spot position in an actual observation image, a threshold value is provided for the G signal and the R signal (pixel signals of pixels provided with green and red color filters, respectively), and the G signal and the G signal having bitmap data are provided. It is preferable to extract coordinates where the value of the R signal is equal to or less than the threshold value.

  In the endoscopic images, the digestive tract is often reddish, so that it may be difficult to recognize the spot with red light, and even in the case of using blue light as in Modification 1, recognition may be insufficient. In this case, in the frame (measurement mode) for measuring the position of the spot, it is preferable to turn off the white illumination light (the visible light source 310A) or to reduce the intensity so as not to affect the measurement of the spot. On the other hand, in a frame other than a frame in which spot recognition is performed (normal observation mode), an image is constructed by setting illumination light to a normal output. By controlling such illumination light, the success rate of spot recognition can be greatly improved.

<Modification 2>
Next, Modification 2 will be described. Modification 2 differs from the first and second embodiments and Modification 1 in that the wavelength of the measurement auxiliary light is a green laser (semiconductor laser) having a wavelength of 505 nm. Note that an LED (for example, a wavelength of 530 nm) or a solid-state laser (for example, a wavelength of 532 nm) may be used instead of the semiconductor laser, and the semiconductor laser may be used in an LED emission state equal to or lower than the oscillation threshold.

  In the modified example 2 of such a configuration, the measurement of the spot position and the generation of the marker are basically the same as those of the first and second embodiments, but as described above, in the modified example 2, the green laser is used as the measurement auxiliary light. Is used, when a spot position is measured and a position of an edge specific point is measured, a threshold value is set for the intensity of the G signal (pixel signal of the pixel provided with the green color filter) of the bitmap data or the RAW data, Is binarized, and the center of gravity of a white portion (a pixel region where the signal intensity is higher than a threshold value) is calculated. When measuring the spot position in an actual observation image, a threshold value is provided for the B signal and the R signal (pixel signals of pixels provided with blue and red color filters, respectively), and the B signal and the B signal having bitmap data are provided. It is preferable to extract coordinates where the value of the R signal is equal to or less than the threshold value.

  In the endoscopic images, the gastrointestinal tract is often reddish, so that it may be difficult to recognize a spot with red light, and even in the case of using green light as in Modification 2, recognition may be insufficient. In this case, in the frame (measurement mode) for measuring the position of the spot, it is preferable to turn off the white illumination light (the visible light source 310A) or to reduce the intensity so as not to affect the measurement of the spot. On the other hand, in a frame other than a frame in which spot recognition is performed (normal observation mode), an image is constructed by setting illumination light to a normal output. By controlling such illumination light, the success rate of spot recognition can be greatly improved.

<Modification of Lighting Light Source>
In the above-described embodiment and modified examples, the case where the light source device 300 (illumination light source) for illumination and observation includes the visible light source 310A (illumination light source) and the infrared light source 310B (illumination light source) is described. In the embodiment, the configuration of the light source is not limited to such an embodiment. For example, the light source may be constituted by a combination of a plurality of LEDs having different wavelengths such as (white), (blue, green, red) or (purple, blue, green, red). In this case, the LEDs of each color may emit light alone, or the LEDs of a plurality of colors may emit light simultaneously. Alternatively, white light may be emitted by simultaneously emitting LEDs of all colors.

  Further, the light source device may be composed of a laser light source for white light (broad band light) and a laser light source for narrow band light. In this case, the narrow band light can be selected from one or a plurality of wavelengths such as blue and purple.

  Further, the light source may be a xenon light source, and the light source device may include a light source for normal light (white light) and a light source for narrow band light. In this case, the narrow band light can be selected from one or a plurality of wavelengths such as blue and green. For example, a disk-shaped filter (rotary color) provided in front of the light source and provided with blue and green color filters is provided. The wavelength of the narrow band light to be irradiated may be switched by rotating the filter). The narrow band light may be infrared light having two or more different wavelengths.

  The type of light source, wavelength, presence or absence of a filter, and the like of the light source device are preferably configured according to the type of the subject, the purpose of observation, and the like. Are preferably combined and / or switched. For example, between the LED light of each color described above, between the white laser light and the first and second narrow band laser light (blue and purple), between the blue narrow band light and the green narrow band light, or It is preferable to appropriately combine and / or switch the wavelength of the illumination light between the first infrared light and the second infrared light.

<Modification of imaging device and imaging method>
In the above-described embodiments and modified examples, the case where the image sensor 134 is a color image sensor in which a color filter is provided for each pixel has been described. However, the present invention is not limited to this, and may be a monochrome imaging device (CCD type, CMOS type, etc.).

  In the case of using a monochrome image sensor, it is possible to sequentially switch the wavelength of the illumination light and perform image capturing in a frame sequential (color sequential) manner. For example, the wavelength of the emitted illumination light may be sequentially switched between (violet, blue, green, and red), or may be emitted by a broadband light (white light) and emitted by a rotary color filter (red, green, blue, etc.). The wavelength of the illumination light to be emitted may be switched. Alternatively, the wavelength of illumination light emitted by one or a plurality of narrowband lights (green, blue, etc.) and emitted by a rotary color filter (green, blue, etc.) may be switched. The narrow band light may be infrared light having two or more different wavelengths.

<Others>
INDUSTRIAL APPLICABILITY The measurement support apparatus, endoscope system, processor of the endoscope system, and measurement support method of the present invention are applicable not only to measurement of a living body but also to measurement of a non-living body such as a pipe. it can. Further, the measurement support device and the measurement support method of the present invention are not limited to endoscopes, and can be applied to the case of measuring the size and shape of industrial parts and products.

  Although an example of the present invention has been described above, the present invention is not limited to the above-described embodiments and modified examples, and various modifications can be made without departing from the spirit of the present invention.

Reference Signs List 10 Endoscope system 10A Endoscope system 100 Endoscope device 102 Hand operation unit 104 Insertion unit 106 Universal cable 108 Light guide connector 110 Endoscope main body 112 Flexible part 114 Curved part 116 Tip hard part 116A Tip end face 123 Lighting Unit 123A Illuminating lens 123B Illuminating lens 126 Forceps port 130 Imaging optical system 132 Imaging lens 134 Image sensor 136 Drive circuit 138 AFE
170 light guide 200 endoscope processor 202 image input controller 204 image processing unit 206 video output unit 208 operation unit 210 CPU
212 Memory 300 Light source device 310 Light source 310A Visible light source 310B Infrared light source 330 Aperture 340 Condensing lens 350 Light source control unit 400 Monitor 500 Laser module 500A Laser module 501 Fiber sheath 502 Laser light source module 502A Laser light source module 503 Condensing lens 504 Optical fiber 504A Optical fiber 506 Laser head 506A Laser head 507 Reinforcement 508 Ferrule 509 Housing C1 Dotted line C2A Dotted line C2B Dotted line D1 Observation distance D2 Observation distance E1 Edge E2 Edge EP1 Edge specific point EP2 Edge specific point EP3 Edge specific point EP4 Edge specific point EP5A Edge specific point EP5B Edge specific point EP6A Edge specific point EP6B Edge specific point IA Image pickup range L1 Optical axis L2 Optical axis L3 Optical axis 1 Marker M2 Marker M3 Marker M4 Marker M5 Marker M6 Marker M7A Marker M7B Marker M8A Marker M8B Marker R2A Range R2B Range S10-S54 Each step of the measurement support method SP0 Spot SP1 Spot SP2 Spot SP3 Spot SP4 Spot SP5A Spot SP5B Spot SPA Spot g1 function g2 function h1 function h2 function tm0 tumor tm1 tumor tm2 tumor δ beam spread angle ε inclination angle θ shooting angle of view

Claims (12)

A head that emits light emitted from the light source as measurement auxiliary light having a spread due to divergence,
An imaging unit that acquires an image of a subject on which a spot is formed by the measurement auxiliary light via an imaging optical system and an imaging element;
Based on the obtained image of the subject, a measurement unit that measures the position of an edge specific point that is a point on the edge of the spot in the image sensor,
A storage unit that stores information indicating the relationship between the size of the subject on the image sensor and the actual size of the subject, in association with the position of the edge specific point on the image sensor,
A marker generation unit that acquires information indicating the relationship from the storage unit based on the measured position of the edge specific point, and generates a marker indicating the actual size based on the acquired information.
A display control unit that displays an image of the subject on which the spot is formed and the generated marker on a display device, and a display control unit that displays the marker near the edge specific point in the image of the subject.
With
In the head, at least a part of the edge forms a non-zero inclination angle with the optical axis of the imaging optical system, and the at least one part of the head emits the measurement auxiliary light crossing an angle of view of the imaging optical system. Measurement support device.   The measurement support device according to claim 1, wherein the at least a part of the edge of the measurement auxiliary light intersects an optical axis of the imaging optical system.   The measurement support apparatus according to claim 1, wherein the edge specific point is a point closest to an optical axis of the imaging optical system among edges of the spot on the imaging element.   4. The measurement support device according to claim 1, wherein an optical axis of the measurement auxiliary light is parallel to an optical axis of the imaging optical system. 5. The head emits the measurement auxiliary light from a plurality of positions,
The measurement support device according to any one of claims 1 to 4, wherein the marker generation unit generates the marker corresponding to each of the measurement auxiliary lights emitted from the plurality of positions.   An endoscope system comprising the measurement support device according to any one of claims 1 to 5. An insertion portion to be inserted into the subject, the distal end having a rigid portion, a curved portion connected to the proximal end of the rigid distal portion, and a flexible portion connected to the proximal end of the curved portion. An endoscope having an insertion portion and an operation portion connected to a proximal end side of the insertion portion,
The endoscope system according to claim 6, wherein an emission part of the measurement auxiliary light and an imaging lens that forms an optical image of the spot on the imaging element are provided on a distal end surface of the distal end hard part. An illumination light source that emits illumination light, and a control unit that controls the illuminance of the illumination light,
The said control part lowers the illuminance of the said illumination light in the measurement mode which acquires the image of the said spot with the said imaging optical system, compared with the normal observation mode which irradiates the said illumination light to the said subject and observes the said subject. The endoscope system according to 6 or 7. The image sensor is a color image sensor including a plurality of pixels including a plurality of light receiving elements arranged two-dimensionally, and a color filter of a plurality of filter colors provided for the plurality of pixels,
The measurement unit is configured to detect the edge specific point based on an image generated by an image signal of a pixel provided with a color filter of a filter color having the highest sensitivity to the wavelength of the measurement auxiliary light among the plurality of filter colors. The endoscope system according to any one of claims 6 to 8, which measures a position.   The processor of the endoscope system according to any one of claims 6 to 9, wherein the light source driving unit that drives the light source, the measurement unit, the storage unit, the marker generation unit, A display control unit.   The processor according to claim 10, wherein the measurement unit recognizes a shape of the spot on the image sensor, and measures the edge specific point based on a result of the recognition.   The processor according to claim 10, wherein the light source driving unit is a laser driving unit that drives a laser light source.

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