JP2010185782A - Optical structure observing device and structure data processing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly extract a plurality of the specific structure elements of a measuring target having a layered structure while detecting a region at every specific structure element. <P>SOLUTION: The structure data processing part 22 of this optical structure observing device is equipped with an optical stereoscopic structure image forming part 220, a shape memory part 221, a threshold value memory part 222, a cross-sectional image extracting part 223, a specific element extracting part 224, a specific element distribution calculating part 225, a distribution boundary line extracting part 226, a depleted region extracting part 227, a depleted region specifying element extracting part 228, a depleted region specifying element distribution calculating part 229, a depleted region distribution boundary line extracting part 230, a synthetic image forming part 231, a display control part 236, and an I/F part 237. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical structure observation apparatus and a structure information processing method thereof, and more particularly to an optical structure observation apparatus and a structure information processing method thereof characterized by extraction of a specific element to be measured having a layer structure.

  Conventionally, when acquiring an optical tomographic image of a living tissue, an optical tomographic image acquisition apparatus using OCT (Optical Coherence Tomography) may be used. This optical tomographic image acquisition apparatus divides low-coherent light emitted from a light source into measurement light and reference light, and then reflects or backscatters light from the measurement object when the measurement light is applied to the measurement object. The light and the reference light are combined, and an optical tomographic image is acquired based on the intensity of the interference light between the reflected light and the reference light.

  The OCT measurement is roughly divided into two types: TD-OCT (Time domain OCT) measurement and FD-OCT (Fourier Domain OCT) measurement.

  In the TD-OCT measurement, the reflected light intensity distribution corresponding to the position in the depth direction of the measurement target (hereinafter referred to as the depth position) is acquired by measuring the interference light intensity while changing the optical path length of the reference light. Is the method.

  On the other hand, in the FD-OCT measurement, the interference light intensity is measured for each spectral component of the light without changing the optical path lengths of the reference light and the signal light, and the spectral interference intensity signal obtained here is Fourier transformed by a computer. This is a method of obtaining a reflected light intensity distribution corresponding to a depth position by performing a representative frequency analysis. In recent years, it has attracted attention as a technique that enables high-speed measurement by eliminating the need for mechanical scanning existing in TD-OCT.

  Typical examples of the apparatus configuration for performing FD-OCT measurement include an SD-OCT (Spectral Domain OCT) apparatus and an SS-OCT (Swept Source OCT).

  By the way, OCT measurement is a method for acquiring an optical tomographic image of a specific region as described above. Under an endoscope, for example, a cancer lesion is observed by observation with a normal illumination endoscope or a special optical endoscope. By finding and performing OCT measurement of the region, it is possible to determine how far the cancerous lesion has infiltrated. Further, by scanning the optical axis of the measurement light two-dimensionally, three-dimensional information can be acquired together with depth information obtained by OCT measurement.

  The fusion of OCT measurement and 3D computer graphic technology makes it possible to display a 3D structural model with a resolution on the order of micrometers. Alternatively, it is called optical three-dimensional structure information.

  OCT measurement has an advantage that the resolution is about 10 μm higher than that of ultrasonic measurement, and a detailed tomographic image inside the living body can be obtained. A three-dimensional tomographic image can be obtained by acquiring a plurality of images while shifting the position in a direction perpendicular to the tomographic image.

  For example, for a measurement object having a layer structure, in OCT measurement, a differential filter is applied to structure information to detect a desired boundary layer. In this case, a boundary layer missing portion due to the influence of noise or the like may occur. For this missing portion, for example, a technique for setting an estimated edge point by user input and interpolating the boundary layer with an interpolation curve is disclosed. (Patent Document 1).

JP 2008-206684 A

  However, in the technique of Patent Document 1 and the like, since the missing portion of the boundary layer is simply subjected to curve interpolation by setting the estimated edge point by user input, the interpolation is performed without eliminating the influence of noise or the like in the missing portion. There is a problem that the boundary layer of the missing part cannot be optimally interpolated.

  Moreover, it is known that the shape of the tissue structure is transformed depending on the degree of progression of a lesion such as cancer in a measurement object having a layer structure, particularly a biological tissue. For example, the boundary layer is optimized as described above. Another reason is that the shape of the tissue structure cannot be extracted and the lesion area corresponding to the degree of progression based on the shape of the tissue structure cannot be detected because interpolation cannot be performed.

  The present invention has been made in view of such circumstances, and an optical structure capable of appropriately extracting a plurality of specific structural elements to be measured having a layer structure and detecting a region for each specific structural element An object is to provide an observation apparatus and a structure information processing method thereof.

  In order to achieve the object, the optical structure observation apparatus according to claim 1 is orthogonal to the first direction which is a depth direction of a measurement target having a layer structure using low interference light and the first direction. To obtain a plurality of optical structure information of the measurement object obtained by scanning a scan plane consisting of a second direction while shifting the position along a third direction which is a direction substantially orthogonal to the scan plane, In an optical structure observation apparatus that constructs an optical three-dimensional structure image based on a plurality of the obtained optical structure information, threshold storage means storing a plurality of predetermined threshold values, and the first direction of the optical three-dimensional structure image An element extraction unit that extracts a specific element having a specific shape by a first element extraction threshold value from the threshold value storage unit on a cross-sectional image having a distribution, and a distribution calculation that calculates a distribution of the specific element on the cross-sectional image Means and the threshold memory Boundary line extracting means by the first line extraction threshold to extract a boundary line of the distribution of the specific elements from, configured with a.

  The optical structure observation apparatus according to claim 1, wherein the element extraction unit has a specific shape based on a first element extraction threshold from the threshold storage unit on a cross-sectional image having the first direction of the optical three-dimensional structure image. The distribution calculation means calculates the distribution of the specific elements on the cross-sectional image, and the boundary line extraction means uses the first line extraction threshold value from the threshold value storage means as the specific element. By extracting the boundary line of the distribution, it is possible to appropriately extract a plurality of specific structural elements to be measured having a layer structure and to detect a region for each specific structural element.

  The optical structure observation apparatus according to claim 1, as in the optical structure observation apparatus according to claim 2, wherein a missing area extraction unit that extracts a missing area where the boundary line is missing, and the missing area In the missing area element extracting means for extracting a specific element having a specific shape by the second element extraction threshold value from the threshold value storage means having a value smaller than the first element extraction threshold value, and the specific element in the missing area A boundary line of the distribution of the specific element in the missing area is calculated by a distribution calculating means in the missing area for calculating the distribution and a second line extraction threshold value from the threshold value storage means having a value smaller than the first line extraction threshold value. It is preferable to further include a missing area boundary line extracting means for extracting.

  The optical structure observation apparatus according to claim 1, as in the optical structure observation apparatus according to claim 3, wherein a missing area extraction unit that extracts a missing area where the boundary line is missing, and the missing area A specific element having a specific shape is extracted by a search area setting means for setting a predetermined search area in the search area and a second element extraction threshold value from the threshold value storage means having a value smaller than the first element extraction threshold value in the search area. Search area element extraction means; search area distribution calculation means for calculating the distribution of the specific element in the search area; and second line from the threshold storage means having a value smaller than the first line extraction threshold value. It is preferable to further include a search area boundary line extraction unit that extracts a boundary line of the distribution of the specific element in the search area based on an extraction threshold.

  The optical structure observation apparatus according to claim 3, wherein the search area boundary line extraction unit is calculated by the search area distribution calculation unit, as in the optical structure observation apparatus according to claim 4. Based on a specific element, a boundary candidate line extraction unit that extracts a plurality of boundary candidate lines of the distribution of the specific element in the search region based on the second line extraction threshold, and a calculation within the search region distribution calculation unit A accuracy determination means for determining at least one of the accuracy of the specific element and the accuracy of the plurality of boundary candidate lines extracted by the boundary candidate line extraction means by a predetermined parameter, the accuracy determination means; Based on at least one of the specific element and boundary candidate line having the determined accuracy, the boundary line of the distribution of the specific element in the search region is extracted. It is preferred.

  The optical structure observation apparatus according to claim 4, wherein the cross-sectional image having the boundary line having the maximum accuracy determined by the accuracy determination unit is provided as the optical structure observation apparatus according to claim 5. In the reference cross-sectional image extracting means for extracting as a reference cross-sectional image, and in the adjacent cross-sectional image adjacent to the reference cross-sectional image, when it is determined that the missing region exists, the boundary line of the reference cross-sectional image on the adjacent cross-sectional image It is preferable to further comprise boundary line correction means for setting a new search area based on the above and correcting at least one of the specific element and the boundary line.

  The optical structure observation device according to any one of claims 1 to 5, wherein the optical structure observation device according to claim 6 generates an image of the specific element and an image of the boundary line, It is preferable that the image processing apparatus further includes image combining means for combining with the cross-sectional image.

  The optical structure observation device according to any one of claims 1 to 6, wherein the optical structure observation device according to claim 7 stores in advance a plurality of types of shape information of the specific shape, It is preferable that the apparatus further includes shape information storage means for outputting shape information to the element extraction means, and the element extraction means extracts the specific element based on the shape information.

  The optical structure observation apparatus according to claim 7, wherein the measurement target is a biological tissue, and the specific element is a tissue structure element of the biological tissue. Preferably, the shape information storage means outputs a plurality of specific shapes corresponding to a plurality of lesion progress degrees of the living tissue to the element extraction means.

  The optical structure observation apparatus according to claim 8, wherein the shape information storage unit corresponds to a low degree of lesion progression from the plurality of specific shapes. It is preferable that the specific shape corresponding to the high degree of lesion progression from the specific shape is sequentially output to the element extraction unit.

  The optical structure observation apparatus according to claim 7, wherein the optical structure observation apparatus according to claim 7 includes a cross-sectional angle setting unit that sets a cross-sectional angle of the cross-sectional image of the optical three-dimensional structure image. The shape information storage means outputs the specific shape related to the cross-sectional angle to the element extraction means, and the element extraction means outputs the first shape on the cross-sectional image of the cross-sectional angle of the optical three-dimensional structure image. It is preferable to extract the specific element having the specific shape by an element extraction threshold.

  The optical structure observation device according to any one of claims 1 to 10, as in the optical structure observation device according to claim 11, wherein the specific element and the boundary line are from the threshold storage unit. It is preferably extracted by a predetermined edge detection process based on a threshold value.

  The optical structure observation device according to any one of claims 4 to 10, wherein the boundary candidate line is based on a threshold value from the threshold value storage unit. It is preferable to extract by a predetermined edge detection process.

  The structure information processing method of the optical structure observation apparatus according to claim 13 is a second direction orthogonal to the first direction that is a depth direction of a measurement target having a layer structure using low interference light and the first direction. A plurality of acquired optical structure information of the measurement target obtained by scanning a scan plane consisting of a plurality of directions while shifting a position along a third direction that is a direction substantially orthogonal to the scan plane. In the structure information processing method of an optical structure observation apparatus that constructs an optical three-dimensional structure image based on the optical structure information, a plurality of predetermined threshold values on a cross-sectional image having the first direction of the optical three-dimensional structure image An element extraction step of extracting a specific element having a specific shape by a first element extraction threshold from the threshold storage means storing the distribution, a distribution calculation step of calculating a distribution of the specific element on the cross-sectional image, The threshold memory Constructed and a boundary line extracting a boundary line of the distribution of the specific element by the first line extraction threshold value from stage.

  The structure information processing method of the optical structure observation apparatus according to claim 13, wherein the element extraction step includes a first element from the threshold storage step on a cross-sectional image having the first direction of the light three-dimensional structure image. A specific element having a specific shape is extracted by an extraction threshold, the distribution calculating step calculates a distribution of the specific element on the cross-sectional image, and the boundary line extracting step is a first line extraction from the threshold storing step. By extracting a boundary line of the distribution of the specific element by using a threshold value, it is possible to appropriately extract a plurality of specific structural elements to be measured having a layer structure and to detect a region for each specific structural element. .

  As described above, according to the present invention, it is possible to appropriately extract a plurality of specific structural elements to be measured having a layer structure and to detect a region for each specific structural element.

1 is an external view showing an image diagnostic apparatus according to a first embodiment of the present invention. The block diagram which shows the internal structure of the OCT processor of FIG. Sectional view of the OCT probe of FIG. The figure which shows a mode that optical structure information is obtained using the OCT probe derived | led-out from the forceps opening | mouth of the endoscope of FIG. The block diagram which shows the structure of the process part of FIG. The figure which shows an example of the shape model stored in the shape storage part of FIG. The flowchart which shows the flow of an effect | action of the process part of the OCT processor of FIG. The figure explaining extraction of the cross-sectional image of the depth direction by the cross-sectional image extraction part of FIG. The figure which shows the differential filter classified by direction used in step S4 of FIG. The figure which shows the edge direction of the specific element extracted by the differentiation filter classified by direction of FIG. The figure which shows an example of the specific element extracted by the differential filter according to direction of FIG. FIG. 7 is a first diagram for explaining the calculation of the distribution of specific elements in the process of step S5 in FIG. 2nd figure for demonstrating calculation of distribution of the specific element in the process of step S5 of FIG. The figure which shows an example of the boundary line of distribution of the specific element extracted by step S6 of FIG. The figure which shows an example of the specific element extracted by step S9 of FIG. The figure which shows an example of the boundary line in the missing area | region of distribution of the specific element extracted by step S10 of FIG. The figure which shows the example of a display on the monitor apparatus by the display control part of the synthesized image produced | generated by step S11 of FIG. The figure which shows an example of the cross-sectional image parallel to the biological tissue surface at the time of applying the process of FIG. 7 to all the cross sections of an optical three-dimensional structure image. The figure which shows the modification of extraction of the cross-sectional image of the optical three-dimensional structure image of the cross-sectional image extraction part of FIG. The 1st figure explaining the modification of 1st Embodiment The 2nd figure explaining the modification of 1st Embodiment The block diagram which shows the structure of the process part which concerns on the 2nd Embodiment of this invention. The flowchart which shows the flow of an effect | action of the process part of FIG. Is a diagram showing a search area set by the search area specifying element extraction unit of FIG. The figure which shows the specific element of the search area | region extracted by the search area | region specific element extraction part of FIG. The figure which shows the some boundary candidate line extracted by the distribution boundary candidate line extraction part of FIG. The figure which shows the boundary line determined by the distribution boundary line determination part of FIG. FIG. 22 is a diagram illustrating a plurality of cross-sectional images for the reference cross-sectional image extraction unit of FIG. 22 to extract a reference cross-sectional image. The figure which shows the reference | standard cross-sectional image extracted in FIG. The figure which shows the cross-sectional image which has a missing area adjacent to the reference | standard cross-section image of FIG.

  Hereinafter, an optical structure observation apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

First embodiment:
<Appearance of diagnostic imaging equipment>
FIG. 1 is an external view showing an image diagnostic apparatus according to a first embodiment of the present invention.

  As shown in FIG. 1, in this embodiment, the diagnostic imaging apparatus 10 mainly includes an endoscope 100, an endoscope processor 200, a light source device 300, an OCT processor 400 as an optical structure observation device, and a monitor device 500. It is configured. Note that the endoscope processor 200 may be configured to incorporate the light source device 300, and constitutes an endoscope device together with the endoscope 100.

  The endoscope 100 includes a hand operation unit 112 and an insertion unit 114 that is connected to the hand operation unit 112. The surgeon grasps and operates the hand operation unit 112 and performs observation by inserting the insertion unit 114 into the body of the subject.

  The hand operation part 112 is provided with a forceps insertion part 138, and the forceps insertion part 138 communicates with the forceps port 156 of the distal end part 144. In the diagnostic imaging apparatus 10 according to the present invention, the OCT probe 600 is led out from the forceps port 156 by inserting the OCT probe 600 from the forceps insertion portion 138. The OCT probe 600 is inserted from the forceps insertion part 138 and inserted from the forceps port 156, an operation part 604 for the operator to operate the OCT probe 600, and the OCT processor 400 via the connector 410. It consists of a cable 606 to be connected.

<Configuration of endoscope, endoscope processor, and light source device>
[Endoscope]
At the distal end portion 144 of the endoscope 100, an observation optical system 150, an illumination optical system 152, and a CCD (not shown) are disposed.

  The observation optical system 150 forms an image of a subject on a light receiving surface (not shown) of the CCD, and the CCD converts the subject image formed on the light receiving surface into an electric signal by each light receiving element. The CCD of this embodiment is a color CCD in which three primary color red (R), green (G), and blue (B) color filters are arranged for each pixel in a predetermined arrangement (Bayer arrangement, honeycomb arrangement). It is.

[Light source device]
The light source device 300 causes visible light to enter a light guide (not shown). One end of the light guide is connected to the light source device 300 via the LG connector 120, and the other end of the light guide faces the illumination optical system 152. The light emitted from the light source device 300 is emitted from the illumination optical system 152 via the light guide, and illuminates the visual field range of the observation optical system 150.

[Endoscope processor]
An image signal output from the CCD is input to the endoscope processor 200 via the electrical connector 110. The analog image signal is converted into a digital image signal in the endoscope processor 200, and necessary processing for displaying on the screen of the monitor device 500 is performed.

  In this manner, observation image data obtained by the endoscope 100 is output to the endoscope processor 200, and an image is displayed on the monitor device 500 connected to the endoscope processor 200.

<Internal configuration of OCT processor and OCT probe>
FIG. 2 is a block diagram showing an internal configuration of the OCT processor of FIG.

[OCT processor]
An OCT processor 400 and an OCT probe 600 shown in FIG. 2 are for acquiring an optical tomographic image of the measuring object S by an optical coherence tomography (OCT) measurement method, and emit light La for measurement. The first light source (first light source unit) 12 and the light La emitted from the first light source 12 are branched into measurement light (first light flux) L1 and reference light L2, and a measurement target which is a subject. An optical fiber coupler (branching / combining unit) 14 that combines the return light L3 from S and the reference light L2 to generate interference light L4, and the measurement light L1 branched by the optical fiber coupler 14 is guided to the measurement target In addition, the OCT probe 600 including the rotation-side optical fiber FB1 that guides the return light L3 from the measurement object S, and the measurement light L1 to the rotation-side optical fiber FB To the fixed side optical fiber FB2 that guides the return light L3 guided by the rotation side optical fiber FB1, and the rotation side optical fiber FB1 so as to be rotatable with respect to the fixed side optical fiber FB2. The optical connector 18 that transmits the light L1 and the return light L3, the interference light detection unit 20 that detects the interference light L4 generated by the optical fiber coupler 14 as an interference signal, and the interference signal detected by the interference light detection unit 20 And processing unit 22 for acquiring optical structure information. In addition, an image generated based on the light structure information acquired by the processing unit 22 is displayed on the monitor device 500.

  In the present embodiment, for example, the large intestine mucosal tissue is the measurement target S, and the endoscope apparatus such as the endoscope 100 and the endoscope processor 200 uses the endoscopic image of the pit pattern on the mucosal surface of the large intestine. Further, the OCT processor 400 and the OCT probe 600 obtain a pit pattern image having a predetermined depth in the mucosa of the large intestine.

  The OCT processor 400 also includes a second light source (second light source unit) 13 that emits aiming light (second light flux) Le for indicating a mark of measurement, and an optical path that adjusts the optical path length of the reference light L2. A length adjusting unit 26, an optical fiber coupler 28 that splits the light La emitted from the first light source 12, and detectors 30a and 30b that detect return lights L4 and L5 combined by the optical fiber coupler 14, And an operation control unit 32 for inputting various conditions to the processing unit 22 and changing settings.

  In the OCT processor 400 shown in FIG. 2, various lights including the above-described emission light La, aiming light Le, measurement light L1, reference light L2, return light L3, and the like are guided between components such as optical devices. Various optical fibers FB (FB3, FB4, FB5, FB6, FB7, FB8, etc.) including the rotation-side optical fiber FB1 and the fixed-side optical fiber FB2 are used as light paths for wave transmission.

  The first light source 12 emits light for OCT measurement (for example, laser light having a wavelength of 1.3 μm or low coherence light), and the first light source 12 sweeps the frequency at a constant period. It is a light source that emits a laser beam La centered at a wavelength of 1.3 μm, for example, in the infrared region. The first light source 12 includes a light source 12a that emits laser light or low-coherence light La, and a lens 12b that condenses the light La emitted from the light source 12a. As will be described in detail later, the light La emitted from the first light source 12 is divided into the measurement light L1 and the reference light L2 by the optical fiber coupler 14 through the optical fibers FB4 and FB3, and the measurement light L1 is the light. Input to the connector 18.

  Further, the second light source 13 emits visible light so as to make it easy to confirm the measurement site as the aiming light Le. For example, red semiconductor laser light with a wavelength of 0.66 μm, He—Ne laser light with a wavelength of 0.63 μm, blue semiconductor laser light with a wavelength of 0.405 μm, or the like can be used. Therefore, the second light source 13 includes, for example, a semiconductor laser 13a that emits red, blue, or green laser light and a lens 13b that collects the aiming light Le emitted from the semiconductor laser 13a. The aiming light Le emitted from the second light source 13 is input to the optical connector 18 through the optical fiber FB8.

  In the optical connector 18, the measurement light L 1 and the aiming light Le are combined and guided to the rotation side optical fiber FB 1 in the OCT probe 600.

  The optical fiber coupler (branching / combining unit) 14 is composed of, for example, a 2 × 2 optical fiber coupler, and is optically connected to the fixed-side optical fiber FB2, the optical fiber FB3, the optical fiber FB5, and the optical fiber FB7, respectively. ing.

  The optical fiber coupler 14 splits the light La incident from the first light source 12 through the optical fibers FB4 and FB3 into measurement light (first light flux) L1 and reference light L2, and the measurement light L1 is fixed side light. The light is incident on the fiber FB2, and the reference light L2 is incident on the optical fiber FB5.

  Furthermore, the optical fiber coupler 14 is incident on the optical fiber FB5, is subjected to frequency shift and optical path length change by the optical path length adjusting unit 26 described later, and is returned by the optical fiber FB5 and acquired by the OCT probe 600 described later. Then, the light L3 guided from the fixed side optical fiber FB2 is multiplexed and emitted to the optical fiber FB3 (FB6) and the optical fiber FB7.

  The OCT probe 600 is connected to the fixed optical fiber FB2 via the optical connector 18, and the measurement light L1 combined with the aiming light Le is rotated from the fixed optical fiber FB2 via the optical connector 18. The light enters the side optical fiber FB1. The measurement light L1 combined with the incident aiming light Le is transmitted by the rotation side optical fiber FB1, and is irradiated to the measurement object S. Then, the return light L3 from the measuring object S is acquired, the acquired return light L3 is transmitted by the rotation side optical fiber FB1, and is emitted to the fixed side optical fiber FB2 via the optical connector 18.

  The optical connector 18 combines the measurement light (first light beam) L1 and the aiming light (second light beam) Le.

  The interference light detection unit 20 is connected to the optical fibers FB6 and FB7, and uses the interference lights L4 and L5 generated by combining the reference light L2 and the return light L3 by the optical fiber coupler 14 as interference signals. It is to detect.

  Here, the OCT processor 400 is provided on the optical fiber FB6 branched from the optical fiber coupler 28. The detector 30a detects the light intensity of the interference light L4, and the light of the interference light L5 on the optical path of the optical fiber FB7. And a detector 30b for detecting the intensity.

  The interference light detection unit 20 performs Fourier transform on the interference light L4 detected from the optical fiber FB6 and the interference light L5 detected from the optical fiber FB7 based on the detection results of the detectors 30a and 30b, thereby measuring the measurement target S. The intensity of the reflected light (or backscattered light) at each depth position is detected.

  From the interference signal extracted by the interference light detection unit 20, the processing unit 22 is a region where the OCT probe 600 and the measurement target S are in contact at the measurement position, more precisely, a probe outer cylinder (described later) of the OCT probe 600. A region where the surface and the surface of the measuring object S can be considered to be in contact with each other is detected, optical structure information is acquired from the interference signal detected by the interference light detection unit 20, and optical solids are obtained based on the acquired optical structure information. A structure image is generated, and an image obtained by performing various processes on the optical three-dimensional structure image is output to the monitor device 500. The detailed configuration of the processing unit 22 will be described later.

  The optical path length adjustment unit 26 is disposed on the emission side of the reference light L2 of the optical fiber FB5 (that is, the end of the optical fiber FB5 opposite to the optical fiber coupler 14).

  The optical path length adjustment unit 26 includes a first optical lens 80 that converts the light emitted from the optical fiber FB5 into parallel light, a second optical lens 82 that condenses the light converted into parallel light by the first optical lens 80, and The reflection mirror 84 that reflects the light collected by the second optical lens 82, the base 86 that supports the second optical lens 82 and the reflection mirror 84, and the base 86 are moved in a direction parallel to the optical axis direction. The optical path length of the reference light L2 is adjusted by changing the distance between the first optical lens 80 and the second optical lens 82.

  The first optical lens 80 converts the reference light L2 emitted from the core of the optical fiber FB5 into parallel light, and condenses the reference light L2 reflected by the reflection mirror 84 on the core of the optical fiber FB5.

  The second optical lens 82 condenses the reference light L2 converted into parallel light by the first optical lens 80 on the reflection mirror 84 and makes the reference light L2 reflected by the reflection mirror 84 parallel light. Thus, the first optical lens 80 and the second optical lens 82 form a confocal optical system.

  Further, the reflection mirror 84 is disposed at the focal point of the light collected by the second optical lens 82 and reflects the reference light L2 collected by the second optical lens 82.

  As a result, the reference light L2 emitted from the optical fiber FB5 becomes parallel light by the first optical lens 80 and is condensed on the reflection mirror 84 by the second optical lens 82. Thereafter, the reference light L2 reflected by the reflection mirror 84 becomes parallel light by the second optical lens 82 and is condensed by the first optical lens 80 on the core of the optical fiber FB5.

  The base 86 fixes the second optical lens 82 and the reflecting mirror 84, and the mirror moving mechanism 88 moves the base 86 in the optical axis direction of the first optical lens 80 (the direction of arrow A in FIG. 2). .

  By moving the base 86 in the direction of arrow A with the mirror moving mechanism 88, the distance between the first optical lens 80 and the second optical lens 82 can be changed, and the optical path length of the reference light L2 can be adjusted. Can do.

  The operation control unit 32 as an extraction region setting unit and a two-dimensional region designation unit includes an input unit such as a keyboard and a mouse, and a control unit that manages various conditions based on the input information. It is connected. The operation control unit 32 inputs, sets, and changes various processing conditions and the like in the processing unit 22 based on an operator instruction input from the input unit.

  Note that the operation control unit 32 may display the operation screen on the monitor device 500, or may provide a separate display unit to display the operation screen. Further, the operation control unit 32 controls the operation of the first light source 12, the second light source 13, the optical connector 18, the interference light detection unit 20, the optical path length, the detectors 30a and 30b, and sets various conditions. May be.

[OCT probe]
FIG. 3 is a cross-sectional view of the OCT probe of FIG.

  As shown in FIG. 3, the distal end portion of the insertion portion 602 has a probe outer cylinder 620, a cap 622, a rotation side optical fiber FB 1, a spring 624, a fixing member 626, and an optical lens 628. .

  The probe outer cylinder (sheath) 620 is a flexible cylindrical member and is made of a material through which the measurement light L1 combined with the aiming light Le and the return light L3 are transmitted in the optical connector 18. The probe outer cylinder 620 is a tip through which the measurement light L1 (aiming light Le) and the return light L3 pass (the tip of the rotation side optical fiber FB1 opposite to the optical connector 18, hereinafter referred to as the tip of the probe outer cylinder 620). It is only necessary that a part of the side is made of a material that transmits light over the entire circumference (transparent material), and parts other than the tip may be made of a material that does not transmit light.

  The cap 622 is provided at the distal end of the probe outer cylinder 620 and closes the distal end of the probe outer cylinder 620.

  The rotation side optical fiber FB1 is a linear member, is accommodated in the probe outer cylinder 620 along the probe outer cylinder 620, is emitted from the fixed side optical fiber FB2, and is emitted from the optical fiber FB8 by the optical connector 18. The measurement light L1 combined with the aiming light Le is guided to the optical lens 628, and the measurement object L is irradiated with the measurement light L1 (aiming light Le) to return from the measurement object S acquired by the optical lens 628. The light L3 is guided to the optical connector 18 and enters the fixed optical fiber FB2.

  Here, the rotation-side optical fiber FB1 and the fixed-side optical fiber FB2 are connected by the optical connector 18, and are optically connected in a state where the rotation of the rotation-side optical fiber FB1 is not transmitted to the fixed-side optical fiber FB2. ing. The rotation-side optical fiber FB1 is disposed so as to be rotatable with respect to the probe outer cylinder 620 and movable in the axial direction of the probe outer cylinder 620.

  The spring 624 is fixed to the outer periphery of the rotation side optical fiber FB1. The rotation side optical fiber FB1 and the spring 624 are connected to the optical connector 18.

  The optical lens 628 is disposed at the measurement-side tip of the rotation-side optical fiber FB1 (tip of the rotation-side optical fiber FB1 opposite to the optical connector 18), and the tip is measured from the rotation-side optical fiber FB1. In order to collect the light L1 (aiming light Le) with respect to the measuring object S, it is formed in a substantially spherical shape.

  The optical lens 628 irradiates the measurement target S with the measurement light L1 (aiming light Le) emitted from the rotation side optical fiber FB1, collects the return light L3 from the measurement target S, and enters the rotation side optical fiber FB1. .

  The fixing member 626 is disposed on the outer periphery of the connection portion between the rotation side optical fiber FB1 and the optical lens 628, and fixes the optical lens 628 to the end portion of the rotation side optical fiber FB1. Here, the fixing method of the rotation side optical fiber FB1 and the optical lens 628 by the fixing member 626 is not particularly limited, and the fixing member 626, the rotation side optical fiber FB1 and the optical lens 628 are bonded and fixed by an adhesive. Alternatively, it may be fixed with a mechanical structure using a bolt or the like. The fixing member 626 may be any member as long as it is used for fixing, holding or protecting the optical fiber such as a zirconia ferrule or a metal ferrule.

  The rotation side optical fiber FB1 and the spring 624 are connected to a rotation cylinder 656, which will be described later. By rotating the rotation side optical fiber FB1 and the spring 624 by the rotation cylinder 656, the optical lens 628 is moved to the probe outer cylinder 620. On the other hand, it is rotated in the direction of arrow R2. The optical connector 18 includes a rotary encoder, and detects the irradiation position of the measurement light L1 from the position information (angle information) of the optical lens 628 based on a signal from the rotary encoder. That is, the measurement position is detected by detecting the angle of the rotating optical lens 628 with respect to the reference position in the rotation direction.

  Further, the rotation side optical fiber FB1, the spring 624, the fixing member 626, and the optical lens 628 are moved through the probe outer cylinder 620 in the arrow S1 direction (forceps opening direction) and the S2 direction (probe outer cylinder 620) by a driving unit described later. It is configured to be movable in the direction of the tip.

  Further, the left side of FIG. 3 is a diagram showing an outline of a drive unit such as the rotation side optical fiber FB1 in the operation unit 604 of the OCT probe 600.

  The probe outer cylinder 620 is fixed to a fixing member 670. On the other hand, the rotation side optical fiber FB1 and the spring 624 are connected to a rotating cylinder 656, and the rotating cylinder 656 is configured to rotate via a gear 654 in accordance with the rotation of the motor 652. The rotary cylinder 656 is connected to the optical connector 18, and the measurement light L1 and the return light L3 are transmitted between the rotation side optical fiber FB1 and the fixed side optical fiber FB2 via the optical connector 18.

  Further, the frame 650 containing these includes a support member 662, and the support member 662 has a screw hole (not shown). A forward and backward movement ball screw 664 is engaged with the screw hole, and a motor 660 is connected to the forward and backward movement ball screw 664. Therefore, the frame 650 can be moved forward and backward by rotationally driving the motor 660, whereby the rotation side optical fiber FB1, the spring 624, the fixing member 626, and the optical lens 628 can be moved in the S1 and S2 directions in FIG. It has become.

  The OCT probe 600 is configured as described above, and the measurement side light L1 emitted from the optical lens 628 is obtained by rotating the rotation-side optical fiber FB1 and the spring 624 in the direction of the arrow R2 in FIG. (Aiming light Le) is irradiated to the measuring object S while scanning in the arrow R2 direction (circumferential direction of the probe outer cylinder 620), and the return light L3 is acquired. The aiming light Le is irradiated to the measuring object S as, for example, blue, red, or green spot light, and the reflected light of the aiming light Le is also displayed as a bright spot on the observation image displayed on the monitor device 500.

  Thereby, the desired site | part of the measuring object S can be caught correctly in the perimeter of the circumference direction of the probe outer cylinder 620, and the return light L3 which reflected the measuring object S can be acquired.

  Further, when acquiring a plurality of optical structure information for generating an optical three-dimensional structure image, the optical lens 628 is moved to the end of the movable range in the arrow S1 direction by the driving unit, and the optical structure information including the tomographic image is obtained. While acquiring, it moves in the S2 direction by a predetermined amount, or moves to the end of the movable range while alternately repeating the acquisition of optical structure information and the predetermined amount of movement in the S2 direction.

  In this manner, a plurality of pieces of optical structure information in a desired range can be obtained for the measurement object S, and an optical three-dimensional structure image can be obtained based on the obtained plurality of pieces of optical structure information.

  That is, the optical structure information in the depth direction (first direction) of the measurement target S is acquired from the interference signal, and the measurement target S is scanned in the direction of arrow R2 in FIG. 3 (circumferential direction of the probe outer cylinder 620). Thus, it is possible to acquire the optical structure information on the scan plane composed of the first direction and the second direction orthogonal to the first direction, and further, the third direction orthogonal to the scan plane. A plurality of pieces of optical structure information for generating an optical three-dimensional structure image can be acquired by moving the scan plane along the line.

  FIG. 4 is a diagram showing how optical structure information is obtained using an OCT probe derived from the forceps opening of the endoscope of FIG. As shown in FIG. 4, the optical structure information is obtained by bringing the distal end portion of the insertion portion 602 of the OCT probe close to a desired portion of the measurement target S. When acquiring a plurality of pieces of optical structure information in a desired range, it is not necessary to move the OCT probe 600 main body, and the optical lens 628 may be moved within the probe outer cylinder 620 by the driving unit described above.

[Processing part]
FIG. 5 is a block diagram showing a configuration of the processing unit of FIG. As shown in FIG. 5, the processing unit 22 includes an optical three-dimensional structure image generation unit 220, a shape storage unit 221 as a shape information storage unit, a threshold storage unit 222 as a threshold storage unit, a cross-sectional image extraction unit 223, and an element extraction unit. A specific element extraction unit 224 as a distribution element, a specific element distribution calculation unit 225 as a distribution calculation unit, a distribution boundary line extraction unit 226 as a boundary line extraction unit, a missing region extraction unit 227 as a missing region extraction unit, and an element extraction in a missing region Missing region specifying element extraction unit 228 as means, missing region specifying element distribution calculation unit 229 as missing region distribution calculating unit, missing region distribution boundary line extraction unit 230 as missing region boundary line extracting unit, and image composition unit , A composite image generation unit 231, a display control unit 236, and an I / F unit 237 serving as a cross-sectional angle setting unit.

  The optical three-dimensional structure image generation unit 220 calculates optical structure information from the interference signal detected by the interference light detection unit 20 and generates an optical three-dimensional structure image of the measurement target S. The shape storage unit 221 is a storage unit that stores a plurality of shape models of the tissue structure of the measurement target S in advance. FIG. 6 is a diagram illustrating an example of a shape model stored in the shape storage unit of FIG. In the present embodiment, as shown in FIG. 6, the shape storage unit 221 stores in advance, for example, a U shape, a J shape, a circular shape, an elliptical shape, a spiral shape, a V shape, etc. as a shape model. .

  The threshold storage unit 222 is a storage unit that stores a plurality of types of thresholds used in the processing unit 22 in advance.

  The cross-sectional image extraction unit 223 extracts, for example, a cross-sectional image of a cross section in the depth direction of the optical three-dimensional structure image.

  The specific element extraction unit 224 measures the shape corresponding to the shape model from the shape storage unit 221 based on the first element extraction threshold value from the threshold value storage unit 222 on the cross-sectional image extracted by the cross-sectional image extraction unit 223. A specific structural element (hereinafter referred to as a specific element) having a specific shape of the target S is extracted. In the present embodiment, when the specific element is the large intestine, it is a gland duct structure element of the mucosal layer.

  The specific element distribution calculation unit 225 quantifies the degree of occupancy on the cross-sectional image of the specific element extracted by the specific element extraction unit 224 and calculates it as a point distribution of the specific element. Details of the calculation method of the distribution of the specific element will be described later.

  The distribution boundary line extraction unit 226 extracts the boundary line of the point distribution of the specific element calculated by the specific element distribution calculation unit 225 based on the first line extraction threshold value from the threshold value storage unit 222.

  The missing area extraction unit 227 determines whether or not the boundary line extracted by the distribution boundary line extraction unit 226 is missing, and if there is a missing area, extracts the missing area.

  The missing region specifying element extraction unit 228 uses the second element extraction threshold value from the threshold storage unit 222 having a value smaller than the first element extraction threshold value in the missing region extracted by the missing region extraction unit 227 on the cross-sectional image. Thus, a specific element having a specific shape of the measuring object S that is a shape corresponding to the shape model from the shape storage unit 221 is extracted.

  The missing area specific element distribution calculation unit 229 quantifies the degree of occupation of the specific element extracted by the missing area specific element extraction unit 228 in the missing area and calculates it as a point distribution of the specific element.

  The missing region distribution boundary line extraction unit 230 uses the second line extraction threshold value from the threshold value storage unit 222 having a value smaller than the first line extraction threshold value, to determine the specific element calculated by the missing region specific element distribution calculation unit 229. The boundary line of the point distribution is extracted.

  The composite image generation unit 231 includes the specific element calculated by the missing region specific element distribution calculation unit 229, the boundary line extracted by the distribution boundary line extraction unit 226, the specific element calculated by the specific element distribution calculation unit 225, and the missing region distribution boundary line. Each of the boundary lines extracted by the extraction unit 230 is imaged to generate a combined image.

  The display control unit 236 selectively outputs the cross-sectional image extracted by the cross-sectional image extraction unit 223 and the composite image generated by the composite image generation unit 231 to the monitor device.

  The I / F unit 237 is a communication interface unit that transmits a setting signal and a designation signal from the operation control unit 32 to each unit.

  The operation of this embodiment configured as described above will be described with reference to the flowchart of FIG. FIG. 7 is a flowchart showing the flow of operation of the processing unit of the OCT processor of FIG. The surgeon turns on the power to each part of the endoscope 100, the endoscope processor 200, the light source device 300, the OCT processor 400, and the monitor device 500, and the OCT probe 600 led out from the forceps opening of the endoscope 100. For example, the distal end portion of the insertion portion 602 is brought close to the mucous membrane (measurement target S) of the large intestine, and optical scanning is started by the OCT probe 600.

  Then, as shown in FIG. 7, the OCT processor 400 uses a low interference light by the OCT probe 600 and a first direction that is a depth direction of the measurement target having a layer structure and a first direction orthogonal to the first direction. The optical structure information of the measurement object S obtained by scanning the scan plane composed of two directions is transferred to the interference light detection unit 20 while shifting the position along the third direction which is a direction substantially orthogonal to the scan plane. A plurality of interference signals are acquired (step S1).

  Subsequently, the processing unit 22 of the OCT processor 400 generates an optical stereoscopic structure image of the measurement target S from the interference signal detected by the interference light detection unit 20 in the optical stereoscopic structure image generation unit 220 (step S2).

  FIG. 8 is a diagram for explaining extraction of a cross-sectional image in the depth direction by the cross-sectional image extracting unit of FIG. As illustrated in FIG. 8, the processing unit 22 extracts, for example, a cross-sectional image of a cross section in the depth direction of the optical three-dimensional structure image 900 using the cross-sectional image extraction unit 223 (step S3).

  Then, the processing unit 22 uses the first element extraction threshold value from the threshold value storage unit 222 on the cross-sectional image extracted by the cross-sectional image extraction unit 223 in the specific element extraction unit 224, and the shape model from the shape storage unit 221. The specific element which has the specific shape of the measuring object S which is a shape corresponding to is extracted (step S4).

  The extraction of the specific element is performed by edge detection by a known method such as Japanese Patent Application Laid-Open No. 2008-004123, that is, by using threshold processing (first element extraction threshold) for the magnitude of the image signal edge intensity. The edge is detected by the edge tracking method with the curve angle restriction by the differential filter.

  9 is a diagram showing the direction-specific differential filter used in step S4 of FIG. 7, FIG. 10 is a diagram showing the edge direction of the specific element extracted by the direction-specific differential filter of FIG. 9, and FIG. It is a figure which shows an example of the specific element extracted by the differential filter classified by direction. As illustrated in FIG. 9, the processing unit 22 applies a direction-specific differential filter indicated by F1 to F4 filters to the central specific element (0, 0) as illustrated in FIG. Based on the first element extraction threshold value from 222, as shown in FIG. 10, the edge strength and the edge direction, which are specific elements of the center coordinates (0, 0), are extracted. As shown in FIG. 11, the specific element extraction unit 224 performs, for example, a U-shaped specific element 920 on the cross-sectional image 910 by the process of step S <b> 4 by the direction-specific differential filter to which the first element extraction threshold is applied. Extract.

  Next, in the specific element distribution calculation unit 225, the processing unit 22 quantifies the degree of occupancy of the specific element extracted by the specific element extraction unit 224 on the cross-sectional image, and calculates the point distribution of the specific element (step) S5).

  12 and 13 are diagrams for explaining the calculation of the point distribution of the specific element in the process of step S5 of FIG. In step S5, the specific element distribution calculation unit 225 sets a block area 930 having a predetermined size on the cross-sectional image 910 as illustrated in FIG. 12, and covers the entire cross-sectional image 910 in pixel units. The block area 930 is moved at. Then, as illustrated in FIG. 13, the specific element distribution calculation unit 225 quantifies, for example, the occupation ratio of the specific element 920 in the block area 930 and sets it as a point of the central pixel 931 in the block area 930.

  Specifically, the specific element distribution calculation unit 225 does not include the specific element 920 in the block areas 930B-a and 930B-d in FIG. Since the point = 0, and the specific element 920 exists in the block areas 930B-b, 930B-c, and 930B-e, the point = 5, the block of the central pixel 931 in the block area 930B-b, according to the occupation ratio The point distribution of the center pixel 931 in the area 930 </ b> B-c = 3 and the point = 4 in the center pixel 931 of the block area 930 </ b> B-e are digitized to calculate the distribution of the points as the distribution of the specific element.

  The calculation of the point distribution of the specific element is not limited to the above, and for example, the point distribution may be calculated as the distribution of the specific element by quantifying based on the number of specific elements existing in the block region 930. Good.

  Subsequently, in the distribution boundary line extraction unit 226, the processing unit 22 extracts the boundary line of the point distribution of the specific element calculated by the specific element distribution calculation unit 225 using the first line extraction threshold value from the threshold value storage unit 222. (Step S6).

  Specifically, the distribution boundary line extraction unit 226 applies the first line extraction threshold to the point distribution that is the distribution of the specific element calculated by the specific element distribution calculation unit 225, and in step S4. The point distribution, that is, the edge strength and the edge direction of the distribution of the specific element are extracted using the direction-specific differential filter (see FIG. 9).

  FIG. 14 is a diagram showing an example of the boundary line of the point distribution of the specific element extracted in step S6 of FIG. As illustrated in FIG. 14, the distribution boundary line extraction unit 226 extracts the boundary line 950 that is the boundary of the point distribution of the specific element 920 on the cross-sectional image 910 by the process of step S <b> 6 in FIG. 7.

  As shown in FIG. 14, the boundary line 950 is not a continuous curve, and a missing region may exist. In this missing region, the first element extraction threshold and the first line extraction threshold (see steps S4 and S6) when extracting the specific element 920 used to avoid the influence of noise on the cross-sectional image 910 are too large. It occurs because of

  Therefore, the processing unit 22 determines whether or not the boundary line 950 extracted by the distribution boundary line extraction unit 226 is missing in the missing region extraction unit 227, and extracts the missing region if there is a lack (step) S7). If the boundary line 950 is not missing, the processing unit 22 moves the process to step S11.

  Then, when the missing area is extracted by the missing area extracting unit 227, the processing unit 22 first extracts the missing area extracted by the missing area extracting unit 227 on the cross-sectional image by the missing area specifying element extracting unit 228. The specific element having the specific shape of the measuring object S that is the shape corresponding to the shape model from the shape storage unit 221 is extracted by the second element extraction threshold value from the threshold value storage unit 222 having a value smaller than the element extraction threshold value ( Step S8).

  FIG. 15 is a diagram illustrating an example of the specific element extracted in step S8 of FIG. As illustrated in FIG. 15, the specific element extraction unit 224 causes the missing region of the boundary line 950 on the cross-sectional image 910 by the process of step S <b> 9 by the direction-specific differential filter (see FIG. 9) to which the second element extraction threshold is applied. Then, for example, a J-shaped specific element 921 is extracted.

  Next, in the missing region specific element distribution calculation unit 229, the processing unit 22 quantifies the degree of occupation of the specific element extracted by the missing region specific element extraction unit 228 and calculates it as a point distribution of the specific element (step S9). ).

  Since the process in step S9 is the same as that in step S5 described above, description thereof is omitted (see FIGS. 12 and 13).

  Then, in the missing region distribution boundary line extraction unit 230, the processing unit 22 causes the missing region specifying element distribution calculation unit 229 to use the second line extraction threshold value from the threshold storage unit 222 having a value smaller than the first line extraction threshold value. The boundary line of the point distribution of the specific element calculated in this way is extracted (step S10).

  Specifically, the missing region distribution boundary line extraction unit 230 applies the second line extraction threshold to the point distribution that is the distribution of the specific element calculated by the missing region specific element distribution calculation unit 229. The point distribution, that is, the edge strength and the edge direction of the distribution of the specific element are extracted using the direction-specific differential filter (see FIG. 9) described in step S4.

  FIG. 16 is a diagram illustrating an example of a boundary line in the missing region of the distribution of the specific element extracted in step S10 of FIG. As shown in FIG. 16, the missing region distribution boundary line extraction unit 230 extracts a boundary line 951 that is a boundary of the specific element 921 in the missing region on the cross-sectional image 910 by the process of step S <b> 10 in FIG. 7. Become.

  Next, in the composite image generation unit 231, the processing unit 22 calculates the specific element calculated by the specific element distribution calculation unit 225, the boundary line extracted by the distribution boundary line extraction unit 226, and the missing region specific element distribution calculation unit 229. A specific image and the boundary line extracted by the missing region distribution boundary line extraction unit 230 are imaged and combined to generate a combined image, which is output to the display control unit 236 (step S11).

  FIG. 17 is a diagram showing a display example on the monitor device by the display controller of the composite image generated in step S11 of FIG. As shown in FIG. 17, the display control unit 236 extracts the specific element 920 generated by the specific element distribution calculation unit 225 and the distribution boundary line extraction unit 226 generated by the composite image generation unit 231 on the cross-sectional image 910. The boundary line 950, the specific element 921 calculated by the missing region specific element distribution calculating unit 229, and the boundary line 951 extracted by the missing region distribution boundary line extracting unit 230 are selectively superimposed and displayed on the monitor device 500.

  As described above, in this embodiment, a specific element is extracted using the first element extraction threshold, the specific element is quantified to obtain the point distribution, and the boundary line of the specific element is calculated using the first line extraction threshold. And the detected specific element and the boundary line can be displayed on the monitor device 500 or the like, so that the specific element of the measurement target S having a layer structure is appropriately extracted and each specific structural element is Can be detected, and the structural information of the measurement object S can be appropriately determined and diagnosed.

  Furthermore, in this embodiment, when a missing region occurs in the boundary line of a specific element using the first line extraction threshold, the second element extraction threshold having a value smaller than the first element extraction threshold is used. The specific element in the missing area is extracted, the specific element in the missing area is quantified to obtain the point distribution, and the second line extraction threshold having a value smaller than the first line extraction threshold is used. Since it is possible to extract the boundary line of the specific element, it is possible to appropriately extract the specific element of the measurement target S having the layer structure and to detect the area for each specific structural element.

  In the present embodiment, the processing unit 22 performs the processing described with reference to FIG. 7 on the cross-sectional image extraction unit 223 for all cross-sections of the optical three-dimensional structure image, thereby specifying the optical three-dimensional structure image. Since elements and boundary lines can be extracted, as shown in FIG. 18, specific elements and boundary lines can be synthesized and displayed on the monitor device 500 in a cross-sectional image parallel to the surface of the living tissue.

  In the present embodiment, as illustrated in FIG. 19, the processing unit 22 is based on a setting signal (see a broken line in FIG. 5) from the operation control unit 32 by the I / F unit 237, and the optical stereoscopic structure image 900. The angle θ of the slice plane can also be set. That is, the cross-sectional image extraction unit 223 extracts a plurality of cross sections corresponding to the angle θ of the slice plane by using this setting signal (see the broken line in FIG. 5), and extracts specific elements for each cross section. In this case, the shape storage unit 221 is based on the designation signal (see the broken line in FIG. 5) from the operation control unit 32 by the I / F unit 237 according to the angle of the slice plane with respect to the biological surface of the cross section. Switch the shape of a specific element to be extracted.

(Modification)
In the present embodiment, when the measurement target S is a living tissue, the shape storage unit 221 may register the position and shape of the specific element as a database according to the advancement degree of the lesioned portion assumed in advance. .

  In this case, the processing unit 22 first detects a specific element V0 (for example, a specific element 920 whose shape is U-shaped) assuming a normal part over the entire tomographic image, and proceeds in a missing portion of the specific element V0. A specific element Vi (for example, a specific element 921 having a J-shape) is detected assuming a lesion having a small degree, and further, progress is made in a missing part (see FIG. 20) of the specific element Vi (specific element 921). The process proceeds to search for a specific element Vj (for example, a specific element 922 having a V-shape) assuming a lesion having a high degree (see FIG. 21). At this time, an extraction process with a large calculation amount is applied to search for a serious lesion. By executing such processing, it is possible to narrow down specific elements step by step and improve the efficiency of calculation time and the extraction accuracy.

  When the processing unit 22 points the ratio of the specific element, the processing unit 22 sets the point distribution density of the specific element Vi (specific element 921) for the progress degree I as positive, and the specific element for the adjacent progress degree J The point distribution density of Vj (specific element 922) may be negative, the total value thereof may be obtained, and the boundary line may be obtained by differentiating the points of the total value.

Second embodiment:
Since the second embodiment is almost the same as the first embodiment, only different points will be described, and the same components will be denoted by the same reference numerals, and description thereof will be omitted.

  FIG. 22 is a block diagram illustrating a configuration of a processing unit according to the second embodiment. As illustrated in FIG. 22, the processing unit 22 of the present embodiment includes an optical three-dimensional structure image generation unit 220, a shape storage unit 221, a threshold storage unit 222, a cross-sectional image extraction unit 223, a specific element extraction unit 224, and a specific element distribution calculation. Unit 225, distribution boundary line extraction unit 226, missing region extraction unit 227, search region specification element extraction unit 240 as search region setting means and search region element extraction means, and search region specification element distribution as search region distribution calculation means Calculation unit 241, accuracy calculation unit 242 as accuracy determination unit, distribution boundary candidate line extraction unit 243 as search area boundary line extraction unit and boundary candidate line extraction unit, boundary line determination unit 244, reference cross-section image extraction unit Reference cross-sectional image extraction unit 245, line correction unit 246 as boundary line correction means, composite image generation unit 231, display control unit 236 It constructed an I / F section 237. The boundary candidate line extraction unit includes a boundary line determination unit 244. Other configurations are the same as those of the first embodiment.

  The search area specifying element extraction unit 240 sets a predetermined search area in the missing area extracted by the missing area extraction unit 227, and the second value from the threshold storage unit 222 having a value smaller than the first element extraction threshold in the search area. With this element extraction threshold, a specific element having a specific shape of the measuring object S that is a shape corresponding to the shape model from the shape storage unit 221 is extracted.

  The search area specific element distribution calculation unit 241 quantifies the degree of occupancy in the search area of the specific element extracted by the search area specific element extraction unit 240 and calculates it as a point distribution of the specific element.

  The distribution boundary candidate line extraction unit 243 uses the second line extraction threshold value from the threshold value storage unit 222 having a value smaller than the first line extraction threshold value to determine the specific element point calculated by the search region specific element distribution calculation unit 241. A plurality of boundary candidate lines of the distribution are extracted.

  The accuracy calculation unit 242 calculates the accuracy of the specific element and the plurality of boundary candidate lines extracted by the search region specific element extraction unit 240 and the distribution boundary candidate line extraction unit 243 using predetermined parameters.

  The boundary line determination unit 244 determines a boundary line from a plurality of boundary candidate lines based on the specific element calculated by the accuracy calculation unit 242 and the accuracy of the boundary candidate line.

  The reference cross-sectional image extraction unit 245 reads the accuracy of the specific element and the boundary line calculated by the accuracy calculation unit 242 and the cross-sectional image associated with the accuracy, and has the boundary line including the specific element having the maximum accuracy. A cross-sectional image is extracted as a reference cross-sectional image.

  When it is determined that there is a missing region in the adjacent cross-sectional image adjacent to the reference cross-sectional image, the line correction unit 246 corrects the boundary line of the adjacent cross-sectional image from the boundary line of the reference cross-sectional image, and the corrected adjacent cross-sectional image The boundary line is output to the image composition unit 232.

  The operation of the present embodiment configured as described above will be described with reference to the flowchart of FIG. FIG. 23 is a flowchart showing a flow of operation of the processing unit of FIG. As illustrated in FIG. 23, the processing unit 22 of the present embodiment performs the processing of steps S1 to S6 described in the first embodiment (step S31), and then the distribution boundary line extraction is performed in the missing region extraction unit 227. It is determined whether the boundary line 950 extracted by the unit 226 is missing, and if there is a missing, the missing area is extracted (step S7). When there is no omission in the boundary line 950, the processing unit 22 proceeds to step S38.

  When determining that the boundary line 950 is missing, the processing unit 22 sets a predetermined search area in the missing area extracted by the missing area extraction unit 227 in the search area specifying element extraction unit 240 (step S32). Further, the shape corresponding to the shape model from the shape storage unit 221 is determined by the search region specifying element extraction unit 240 based on the second element extraction threshold value from the threshold value storage unit 222 having a value smaller than the first element extraction threshold value in the search region. A specific element having a specific shape of the measuring object S is extracted (step S33).

  24 is a diagram showing search areas set by the search area specifying element extraction unit in FIG. 22, and FIG. 25 is a diagram showing specific elements in the search area extracted by the search area specifying element extraction unit in FIG. . Specifically, in step S32, as shown in FIG. 24, the search area specifying element extraction unit 240 has a predetermined size in the missing area of the boundary line 950 of the U-shaped specific element 920 on the cross-sectional image 910, for example. The search area 970 is set. Further, in step S33, the search area specifying element extraction unit 240 specifies, for example, a J-shape in the search area 970 by using the second element extraction threshold value from the threshold storage unit 222 having a value smaller than the first element extraction threshold value. Element 921 is extracted.

  Next, the processing unit 22 causes the search region specific element distribution calculation unit 241 to digitize the degree of occupation of the specific element extracted by the search region specific element extraction unit 240 in the search region. Then, the point distribution of the specific element is calculated (step S34).

  In the first embodiment, when calculating the distribution of the specific element, a block area 930 having a predetermined size is set, and the block area 930 is set in units of pixels of the cross-sectional image 910 over the entire cross-sectional image 910. Although it has been moved (see FIG. 12), in this embodiment, the distribution of specific elements is calculated by moving the block area 930 of a predetermined size only within the search area, so that the calculation efficiency is higher than that of the first embodiment. Can be dramatically improved.

  FIG. 26 is a diagram showing a plurality of boundary candidate lines extracted by the distribution boundary candidate line extraction unit of FIG.

  The processing unit 22 uses the second line extraction threshold value from the threshold value storage unit 222 having a value smaller than the first line extraction threshold value in the distribution boundary candidate line extraction unit 243, as shown in FIG. A plurality of boundary candidate lines 980a and 980b of the distribution of the specific element calculated by the distribution calculation unit 241 are extracted (step S35).

Subsequently, in the accuracy calculation unit 242, the processing unit 22 calculates the accuracy of the specific element and the plurality of boundary candidate lines extracted by the search region specific element extraction unit 240 and the distribution boundary candidate line extraction unit 243 using predetermined parameters. (Step S36). An example of a parameter is
(1) Parameter for accuracy of specific element: edge strength / number / density of contour of specific element (2) Parameter for accuracy of boundary line: strength accumulation of differential filter output of point distribution score.

  The accuracy is corrected with another evaluation standard parameter for the boundary line. For example, using features such as curvature distribution / fractal dimension / frequency distribution, boundary lines based on evaluation standard parameters corresponding to deviations from characteristics of normal parts (lines of strong signal parts in the target sample / samples in the database) Correct the accuracy.

    FIG. 27 is a diagram showing boundary lines determined by the boundary line determination unit in FIG.

  Then, the processing unit 22 uses a plurality of boundary candidate lines 980a and 980b based on the specific elements calculated by the accuracy calculation unit 242 and the accuracy of the boundary candidate lines in the boundary line determination unit 244, as shown in FIG. For example, the boundary candidate line 980a is determined as the boundary line 980 (step S37).

  Next, the processing unit 22 determines whether to extract a reference tomographic image based on an instruction signal from the operation control unit 32 via the I / F unit 237 (step S38). The processing unit 22 moves the process to step S39 when extracting the reference tomographic image, and moves the process to step S11 when extracting the reference tomographic image.

  FIG. 28 is a diagram showing a plurality of cross-sectional images for the reference cross-sectional image extraction unit of FIG. 22 to extract the reference cross-sectional images. 29 is a diagram showing the reference cross-sectional image extracted in FIG. 28, and FIG. 30 is a diagram showing a cross-sectional image having a missing region adjacent to the reference cross-sectional image of FIG.

  In step S39, the processing unit 22 identifies the accuracy calculated by the accuracy calculation unit 242 in the reference cross-sectional image extraction unit 234 and the accuracy that is the maximum from the plurality of cross-sectional images illustrated in FIG. A cross-sectional image 920 (I) shown in FIG. 29 having elements and boundary candidate lines is extracted as a reference cross-sectional image.

  Further, in step S39, when the cross-sectional image 920 (I + 1) adjacent to the cross-sectional image 920 (I) has a missing area of the specific boundary layer as shown in FIG. At 246, a search range is set in the cross-sectional image 920 (I + 1) based on the extracted boundary line in the reference cross-section 920 (I), and the boundary line of the cross-sectional image 920 (I + 1) is corrected. Similarly, for the next adjacent cross-sectional image 920 (I + 2), the reference cross-sectional image is replaced with the cross-sectional image 950 (I + 1), the search range is set in the extracted boundary line in the reference cross-sectional image, and the cross-sectional image 920 (I + 2) is set. ) Boundary line correction processing is performed. Note that the search area 970 set in step S39 is smaller than the search area 970 (see FIG. 24) set in step S32.

  Thereafter, the processing unit 22 executes the process of step S11 described in the first embodiment.

  As described above, in this embodiment, in addition to the effects of the first embodiment, when there is a missing area, a search area 970 having a predetermined size is set, and the specific element and the boundary line are set only in this search area. Therefore, the calculation speed can be improved.

  Although the optical structure observation apparatus of the present invention has been described in detail above, the present invention is not limited to the above examples, and various improvements and modifications may be made without departing from the scope of the present invention. Of course.

DESCRIPTION OF SYMBOLS 10 ... Image diagnostic apparatus, 22 ... Processing part, 100 ... Endoscope, 200 ... Endoscope processor, 220 ... Optical three-dimensional structure image generation part, 221 ... Shape storage part, 222 ... Threshold storage part, 223 ... Cross-sectional image extraction , 224 ... specific element extraction unit, 225 ... specific element distribution calculation unit, 226 ... distribution boundary line extraction unit, 227 ... missing region extraction unit, 228 ... missing region specific element extraction unit, 229 ... missing region specific element distribution calculation unit , 230 ... Missing region distribution boundary line extraction unit, 231 ... Composite image generation unit, 236 ... Display control unit, 237 ... I / F unit

Claims (13)

The light of the measurement object obtained by scanning a scan plane composed of a first direction which is a depth direction of the measurement object having a layer structure and a second direction orthogonal to the first direction using low interference light. An optical structure that obtains a plurality of structure information while shifting the position along a third direction that is a direction substantially orthogonal to the scan plane, and constructs an optical three-dimensional structure image based on the obtained plurality of the optical structure information In the observation device,
Threshold storage means for storing a plurality of predetermined thresholds;
Element extraction means for extracting a specific element having a specific shape by a first element extraction threshold value from the threshold value storage means on a cross-sectional image having the first direction of the optical three-dimensional structure image;
A distribution calculating means for calculating a distribution of the specific element on the cross-sectional image;
Boundary line extraction means for extracting a boundary line of the distribution of the specific element according to a first line extraction threshold from the threshold storage means;
An optical structure observation apparatus comprising: A missing area extracting means for extracting a missing area where the boundary line is missing;
A missing area element extracting means for extracting a specific element having a specific shape by a second element extraction threshold value from the threshold value storage means having a value smaller than a first element extraction threshold value in the missing area;
A distribution calculation means for calculating the distribution of the specific element in the missing area;
A missing area boundary line extracting means for extracting a boundary line of the distribution of the specific element in the missing area by a second line extraction threshold from the threshold storage means having a value smaller than the first line extraction threshold;
The optical structure observation apparatus according to claim 1, further comprising: A missing area extracting means for extracting a missing area where the boundary line is missing;
Search area setting means for setting a predetermined search area in the missing area;
A search area element extraction means for extracting a specific element having a specific shape by a second element extraction threshold value from the threshold value storage means having a value smaller than a first element extraction threshold value in the search area;
A search area distribution calculating means for calculating a distribution of the specific element in the search area;
Search area boundary line extraction means for extracting a boundary line of the distribution of the specific element in the search area by a second line extraction threshold value from the threshold value storage means having a value smaller than the first line extraction threshold value;
The optical structure observation apparatus according to claim 1, further comprising: The search area boundary line extraction means comprises:
Boundary candidate line extraction means for extracting a plurality of boundary candidate lines of the distribution of the specific element in the search area by the second line extraction threshold based on the specific element calculated by the search area distribution calculation means; ,
Accuracy determination means for determining the accuracy of at least one of the accuracy of the specific element calculated by the intra-search area distribution calculation means and the accuracy of the plurality of boundary candidate lines extracted by the boundary candidate line extraction means by a predetermined parameter; Further comprising
The boundary line of the distribution of the specific element in the search region is extracted based on at least one of the specific element and the boundary candidate line having the maximum accuracy determined by the accuracy determination means. The optical structure observation apparatus according to 1. Reference cross-sectional image extraction means for extracting the cross-sectional image having the boundary line with the maximum accuracy determined by the accuracy determination means as a reference cross-sectional image;
In the adjacent cross-sectional image adjacent to the reference cross-sectional image, when it is determined that there is the missing region, a new search region based on the boundary line of the reference cross-sectional image is set on the adjacent cross-sectional image, and the specific element And boundary line correction means for correcting at least one of the boundary lines;
The optical structure observation apparatus according to claim 4, further comprising: The optical structure observation apparatus according to claim 1, further comprising: an image synthesis unit that generates an image of the specific element and an image of the boundary line and synthesizes the image with the cross-sectional image. . Preliminarily storing a plurality of types of shape information of the specific shape, further comprising a shape information storage means for outputting the shape information to the element extraction means,
The optical structure observation apparatus according to any one of claims 1 to 6, wherein the element extraction unit extracts the specific element based on the shape information. The measurement object is a living tissue, and the specific element is a tissue structure element of the living tissue,
The optical structure observation apparatus according to claim 7, wherein the shape information storage unit outputs a plurality of specific shapes corresponding to a plurality of lesion progress degrees of the biological tissue to the element extraction unit. The shape information storage means sequentially outputs the specific shape corresponding to the high lesion progression degree from the specific shape corresponding to the low lesion progression degree to the element extraction means sequentially from the plurality of specific shapes. 9. The optical structure observation apparatus according to claim 8, wherein A cross-sectional angle setting means for setting a cross-sectional angle of the cross-sectional image of the optical three-dimensional structure image;
The shape information storage means outputs the specific shape related to the cross-sectional angle to the element extraction means,
The said element extraction means extracts the said specific element which has the said specific shape by the said 1st element extraction threshold value on the cross-sectional image of the said cross-sectional angle of the said optical three-dimensional structure image. Optical structure observation device. The optical structure observation apparatus according to claim 1, wherein the specific element and the boundary line are extracted by a predetermined edge detection process based on a threshold value from the threshold value storage unit. The optical structure observation apparatus according to claim 4, wherein the boundary candidate line is extracted by a predetermined edge detection process based on a threshold value from the threshold value storage unit. The light of the measurement object obtained by scanning a scan plane composed of a first direction which is a depth direction of the measurement object having a layer structure and a second direction orthogonal to the first direction using low interference light. An optical structure that obtains a plurality of structure information while shifting the position along a third direction that is a direction substantially orthogonal to the scan plane, and constructs an optical three-dimensional structure image based on the obtained plurality of the optical structure information In the structure information processing method of the observation device,
A specific element having a specific shape is extracted by a first element extraction threshold value from a threshold value storage unit that stores a plurality of predetermined threshold values on a cross-sectional image having the first direction of the optical three-dimensional structure image. An element extraction step;
A distribution calculating step of calculating a distribution of the specific element on the cross-sectional image;
A boundary line extraction step of extracting a boundary line of the distribution of the specific element by a first line extraction threshold from the threshold storage means;
A structure information processing method for an optical structure observation apparatus.