JP2012024283A - Endoscope diagnostic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope diagnostic apparatus for combining a polarization property image with at least either a fluorescent image or a narrow-band light image, displaying it, and improving diagnosis accuracy.SOLUTION: The endoscope diagnostic apparatus includes: a light source device for emitting many kinds of illumination light; an endoscope apparatus for guiding the illumination light to irradiate the subject with the light and picking up an image of the reflection light; a processor device for performing image processing of picked up image signals; and a display device for displaying images obtained by performing image processing. The processor device includes: a polarization image processing part for successively irradiating the subject with many kinds of polarized light different in polarization, performing image processing of the plurality of image signals obtained by successively picking up images of the reflection light, and generating polarization property images by prescribed polarization property; a fluorescent image processing part for irradiating the subject with excitation light for fluorescence observation, performing image processing to an image signal obtained by picking up an image of the reflection light, and generating a fluorescent image; and an image synthesized part for synthesizing the polarization property image with the fluorescent image to generate a synthesized image.

Description

  The present invention provides a plurality of types of illumination light, for example, excitation light for fluorescence observation, special light such as narrow-band light and polarized light, and light source device that emits white light, and fluorescence observation and narrow-band light observation. The present invention also relates to an endoscope diagnostic apparatus that performs special light observation such as polarized light observation, and further white light observation.

  Conventionally, an optical diagnostic system such as an endoscope or an optical microscope has been used for diagnosing whether there is a lesion in a living body and how much the lesion has progressed. In these diagnostic systems, a part of the living body is irradiated with light and the reflected light is imaged, and changes in the color, brightness, structure, etc. of the living body surface are observed. Is diagnosed. In such an optical system of a diagnostic system, not only natural light for normal observation but also polarized light can be used to capture changes in normal and diseased areas from the characteristics of biological anisotropy. A technique for increasing the accuracy has been proposed (see Patent Documents 1, 2, and 3).

  Patent Document 1 of the present applicant's application uses, as an example, polarized light, and the ratio of non-polarized light of the return light that returns from the digestive organ, particularly the mucosal layer having polarization anisotropy of the stomach wall, that is, It is disclosed that by calculating the thickness of the mucosal layer based on the degree of polarization of the return light, it is possible to diagnose the degree of cancer invasion by detecting the change in the thickness of the mucosal layer of the stomach wall. Yes.

  In addition, Patent Document 2 discloses an image of backscattered light when illumination light having parallel polarization is irradiated on a region of interest that is a local region where high-magnification observation is performed by using polarized light. Using the image of the backscattered light when irradiated with illumination light having vertically polarized light, an enlarged observation image is obtained while removing multiple scattered light from the deep layer at the site of interest. It is disclosed that a polarized image signal is obtained by differential processing, an enlarged observation image is obtained based on the obtained polarized image signal, and displayed on a monitor.

  Further, in Patent Document 3, it becomes noise when observing a blood vessel image in fat by using polarized light when recognizing the position of a blood vessel distributed in fat using near infrared light. It is disclosed that by cutting backscattered light on the fat surface, it is possible to prevent halation due to light reflected on the fat surface and to accurately recognize the position of blood vessels distributed in the fat.

JP 2009-240676 A JP 2006-325993 A JP 2007-282965 A

  However, as an important criterion in diagnosing intramucosal cancer (m cancer), whether the lesion is cancer or not, or whether it is intramucosal cancer or not, for example, submucosal invasive cancer It is important to distinguish whether it is (sm cancer). Therefore, it is determined whether or not there is a mucosal muscle plate, that is, it exists normally. However, the technique described in Patent Document 1 described above shows that there is a possibility of diagnosing the degree of cancer invasion by changing the thickness of the mucosal layer of the stomach wall. However, there is no criteria for distinguishing between intramucosal cancer and submucosal invasive cancer, and polarized images that enable such judgment are not shown. There was a problem that could not be obtained.

  Further, the methods disclosed in Patent Documents 2 and 3 can display a magnified observation image by using polarized light, and can accurately recognize the position of a blood vessel distributed in fat. Therefore, the accuracy of living body observation can be improved, but the purpose is to remove the multiple scattered light from the deep layer in the region of interest, and the purpose is to prevent halation due to surface reflected light. Because the purpose is not to detect the anisotropy of the tumor, it is necessary to measure polarized images that can determine whether the lesion is cancer or not, and whether it is intramucosal cancer or submucosal invasive cancer. There was a problem that could not.

  Further, it is known that an endoscope diagnostic apparatus improves diagnostic accuracy by performing special light observation such as narrow-band light observation and fluorescence observation in addition to white light observation. In such an endoscopic diagnosis apparatus, in addition to displaying only a white light image, only a narrow band light image, or only a fluorescence image, for example, a combination of a white light image and a narrow band light image, a white light image and a fluorescence image is combined. Can be displayed. However, for example, the polarization characteristic image and other special light images including the narrow band light image and the fluorescence image are displayed in combination, such as the polarization characteristic image and the narrow band light image, and the polarization characteristic image and the fluorescence image. An endoscopic diagnostic apparatus that can do this has not been realized.

  An object of the present invention is to solve the above-mentioned problems of the prior art and obtain a polarization characteristic image with a predetermined polarization characteristic in an endoscopic diagnostic apparatus capable of performing a plurality of types of special light observations. It is possible to display the exposed tissue in an identifiable manner, and to assist the doctor in identifying the exposed tissue from the lesion, etc., by observing this polarization characteristic image and diagnosing the degree of cancer invasion, etc. Another object of the present invention is to provide an endoscopic diagnostic apparatus that can improve the diagnostic accuracy by combining and displaying a polarization characteristic image and at least one of a fluorescence image and a narrowband light image.

In order to achieve the above object, the present invention provides a light source device that emits a plurality of types of illumination light, and
An endoscope apparatus that guides illumination light emitted from the light source device and irradiates the subject, images the reflected light, and outputs an image signal;
A processor device that performs image processing on an image signal obtained by the endoscope device and outputs an image corresponding to the illumination light;
A display device for displaying an image obtained by the processor device,
The processor device sequentially irradiates a subject with a plurality of polarized lights having different polarization states as the illumination light, performs image processing on a plurality of image signals obtained by sequentially imaging the reflected light, and performs predetermined processing. A polarization image processing unit that generates a polarization characteristic image according to polarization characteristics;
As the illumination light, a fluorescence image processing unit that irradiates a subject with excitation light for fluorescence observation, performs image processing on an image signal obtained by imaging the reflected light, and generates a fluorescence image; and the illumination As light, at least one of a narrowband light image processing unit that irradiates a subject with narrowband light and performs image processing on an image signal obtained by imaging the reflected light to generate a narrowband light image;
A composite image is formed by combining the polarization characteristic image obtained by the polarization image processing unit, the fluorescence image obtained by the fluorescence image processing unit, and at least one of the narrow band light image obtained by the narrow band light image processing unit. An image composition unit to generate,
The display device provides an endoscopic diagnosis device that displays a composite image obtained by the image composition unit.

  Here, it is preferable that the image synthesizing unit generates the synthesized image by arranging the polarization characteristic image and at least one of the fluorescent image and the narrowband light image.

  Moreover, it is preferable that the said image synthetic | combination part produces | generates the said synthesized image by superimposing the said polarization characteristic image, at least one of the said fluorescence image and the said narrow-band light image.

  Moreover, it is preferable that the said image synthetic | combination part produces | generates the said synthesized image by calculating-processing the said polarization characteristic image and at least one of the said fluorescence image and the said narrow-band light image.

The processor device further irradiates a subject with white light as the illumination light and performs image processing on an image signal obtained by imaging the reflected light to generate a white light image processing unit. With
The image composition unit generates a composite image by combining the polarization characteristic image, at least one of the fluorescence image and the narrowband light image, and a white light image obtained by the white light image processing unit. It is preferable that

  Here, it is preferable that the image composition unit is configured to arrange the polarization characteristic image, at least one of the fluorescence image and the narrowband light image, and further arrange the white light image to generate the composite image. .

  Further, it is preferable that the image composition unit is configured to superimpose the polarization characteristic image and at least one of the fluorescence image and the narrowband light image, and further generate the composite image by arranging the white light images. .

  Further, the image composition unit is configured to perform arithmetic processing on the polarization characteristic image and at least one of the fluorescence image and the narrowband light image, and further generate the composite image by arranging the white light images. preferable.

In addition, the polarization image processing unit performs polarization conversion processing on a plurality of pieces of light intensity image information by reflected light from a subject of the plurality of polarization lights having different polarization states as the image signal, thereby obtaining predetermined polarization characteristics. A polarization conversion processing unit that converts the polarization characteristic image information of
A display conversion processing unit that converts the polarization characteristic image information of the predetermined polarization characteristic obtained by the polarization conversion processing unit corresponding to the polarization characteristic image into display polarization characteristic image information for visualization and display. It is preferable.

  Here, the polarization conversion processing unit is any one of the polarization characteristics image information of the degree of depolarization, the degree of polarization of light, the phase difference, the direction of phase difference, the direction of absorption, and the polarization characteristic of optical rotation as the polarization characteristic image information. It is preferable to obtain

  According to the present invention, it is possible to obtain a polarization characteristic image having a predetermined polarization characteristic and display the exposed tissue from the lesioned part so as to be identifiable. It is possible to identify the exposed tissue and diagnose the invasion degree of intramucosal cancer.

In addition, according to the present invention, an endoscopic diagnosis apparatus and a laparoscopic navigation apparatus that can display an exposed tissue from a lesion or the like in an identifiable manner and can be used for endoscopic surgery, laparoscopic surgery, and the like. Applicable to.
Furthermore, according to the present invention, it is possible to easily and accurately perform endoscopy and diagnosis, and to provide a polarization image that helps to easily and accurately perform endoscopic surgery, laparoscopic surgery, and the like. Can do.

  In particular, according to the present invention, whether a lesion (lesion) at a predetermined site such as a digestive organ of a living body is cancerous or not, or whether it is intramucosal cancer or not, for example, submucosal invasion cancer Imaging and identifying "the presence or absence of collagen fibers appearing in the mucosal layer" corresponding to "the presence or absence of mucosal muscle plate" that is the judgment criterion of the discrimination by polarization measurement And a polarized image showing them can be obtained.

  Further, according to the present invention, “presence / absence of collagen fibers appearing in the mucosal layer”, which is a criterion for judging cancer, intramucosal cancer, submucosal invasive cancer, etc., is displayed on a display means such as a monitor in pseudo color. Can be displayed.

  Furthermore, according to the present invention, by displaying a combination of a polarization characteristic image and a special light image including a fluorescent image and a narrowband light image, the blood vessel, lymph vessel, collagen fiber, nerve Since fibers and the like can be observed at the same time, diagnostic accuracy by a doctor can be improved.

It is a block diagram which shows schematic structure of one Embodiment of the polarization image measurement display system which concerns on this invention. It is a schematic diagram of one Embodiment of the polarization imaging system of the polarization image measurement display system shown in FIG. It is a schematic block diagram of other embodiment of the polarization imaging system of the polarization image measurement display system shown in FIG. (A) is a schematic block diagram of other embodiment of the polarization imaging system of the polarization image measurement display system shown in FIG. 1, (b) is a patterning polarization / wave plate used for the polarization imaging system of (a). It is an expansion schematic diagram which expands and shows the element for 1 pixel of. (A) is a schematic block diagram of other embodiment of the polarization imaging system of the polarization image measurement display system shown in FIG. 1, (b) is a patterning polarization / wave plate used for the polarization imaging system of (a). It is an expansion schematic diagram which expands and shows the element for 1 pixel of. It is a schematic block diagram of other embodiment of the polarization imaging system of the polarization image measurement display system shown in FIG. It is explanatory drawing of the row Mueller measuring system for demonstrating the Mueller image conversion algorithm used for this invention. It is a schematic diagram of one Embodiment of the polarization conversion process part of the polarization image measurement display system shown in FIG. 1, and its polarization variable separation process part. (A) And (b) is a schematic block diagram of one Embodiment of the biological observation model at the time of carrying out variable separation by the polarization variable separation process part shown in FIG. 8, respectively. (A) is a schematic configuration schematic diagram of the vicinity of the surface layer of a normal living body, (b) is a schematic configuration schematic diagram of the vicinity of the surface layer of a living body in which intramucosal cancer has occurred, and (c) is a submucosal layer. It is a schematic structure schematic diagram near the surface layer of a living body that has progressed to invasive cancer. It is a flowchart which shows an example of the polarization image display method implemented with the polarization image measurement display system which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of 1st Embodiment showing the structure of the endoscope diagnostic apparatus which concerns on this invention. It is a block diagram showing the internal structure of the endoscope diagnostic apparatus shown in FIG. It is a conceptual diagram showing the mode of the front-end | tip part of the endoscope insertion part of the endoscope diagnostic apparatus shown in FIG. It is an expansion schematic diagram which expands and shows the element for 1 pixel of the patterning element used with the endoscope diagnostic apparatus shown in FIG. It is a conceptual diagram showing an example at the time of arrange | positioning a white light image, a polarization characteristic image, and a fluorescence image side by side as a synthesized image. It is an external view of 2nd Embodiment showing the structure of the endoscope diagnostic apparatus which concerns on this invention. It is a block diagram showing the internal structure of the endoscope diagnostic apparatus shown in FIG. It is a conceptual diagram showing the mode of the front-end | tip part of the endoscope insertion part of the endoscope diagnostic apparatus shown in FIG. (A) is a cross-sectional block diagram of light projection unit 162A, 162D, (b) is a cross-sectional block diagram of light projection unit 162B, 162C. It is the graph which shows the emission spectrum which wavelength-converted the blue laser beam from the laser light source LD2, and the blue laser beam by the fluorescent substance, and the emission wavelength of each laser beam from the laser light sources LD1, LD3, LD4, and LD5. It is an example of each irradiation pattern.

  Hereinafter, based on a preferred embodiment shown in the accompanying drawings, an endoscope diagnosis apparatus according to the present invention will be described in detail.

FIG. 1 is a schematic block diagram showing a schematic configuration of an embodiment of a polarization image measurement display system according to the present invention.
A polarized image measurement display system 10 of this embodiment shown in FIG. 1 inspects a predetermined part of a living body (subject), for example, a body cavity such as a digestive organ of a human body, an abdomen of a human body, etc. Applicable to endoscopes and laparoscopes used for observing, diagnosing, performing surgery and treatment, etc., and used for endoscope diagnostic devices, laparoscopic navigation devices, etc. Obtain a predetermined polarization characteristic, that is, a polarization characteristic image based on a polarization variable, to distinguish the exposed tissue that appears on the surface layer of the part from the surface layer tissue, and visualize the displayed tissue so that it can be distinguished from the surface tissue. To do.

The polarization image measurement and display system 10 in the illustrated example irradiates a predetermined part of a living body with irradiation light (polarized light) having a plurality of different polarization states, respectively, and a plurality of reflected light from a plurality of different polarization states from a surface layer of the predetermined part. A polarization imaging system 12 that captures a light intensity image and a polarization conversion process on a plurality of light intensity images in different polarization states to obtain polarization characteristic images (a plurality of polarization characteristic images each having a different polarization characteristic) with predetermined polarization characteristics A polarization conversion processing unit 14; a display conversion processing unit 16 that converts the polarization characteristic image into a display polarization characteristic image for visualizing and displaying the exposed tissue distinguishably from the surface tissue; and a display polarization characteristic image. Display unit 18 for displaying normal color imaging system 20 for acquiring a normal color image of a predetermined part, and a polarization characteristic image for display to be displayed on top of each other or side by side. Having an image combining unit 22 for combining the two images, the.
Note that the polarization imaging system 12 and the polarization conversion processing unit 14 constitute a polarization image measurement device according to the present invention.

  The polarization imaging system 12 can measure not only conventional P / S polarized light but also a high-order polarization parameter (Mueller matrix) including a plurality of deflection characteristics (polarization variables), that is, photographing. It constitutes a Mueller imaging system that can measure the Mueller of the object, and a polarized light irradiation unit 24 that irradiates a predetermined part of a living body with irradiation light of a plurality of different polarization states from its surface layer, and polarized light with different polarization states is irradiated with polarized light Each time the living body is irradiated from the unit 24, the reflected light of the plurality of polarization states is sequentially received from the surface layer of the predetermined portion irradiated by the irradiation light of the plurality of polarization states, and a plurality of light intensity images of the surface layer of the predetermined portion And an image pickup unit 26 for picking up images.

  In the present invention, the polarization imaging system 12 may be any imaging system as long as it can constitute such a Mueller imaging system. Various types can be used.

In FIG. 2, the schematic diagram of one Embodiment of the polarization imaging system of this invention is shown.
The polarization imaging system 12a shown in the figure is used as the polarization imaging system 12 shown in FIG. 1 and forms an optical system of an Azzam type double phaser type Mueller matrix polarimeter. Imaging is performed by receiving, as detection light, a polarized light irradiation unit 24a that irradiates a human body abdomen A, which is a predetermined part of a target living body, with irradiation light in a predetermined polarization state, and reflected light in a predetermined polarization state reflected from the human body abdomen A as detection light. An imaging unit 26a.

  The polarized light irradiation unit 24a is disposed on the light source 34, the polarizing plate 36a that is the first polarizer of the present invention fixedly disposed on the human body abdomen A side from the light source 34, and the human body abdomen A side, and is rotated every predetermined angle. An irradiation-side first polarizing filter section 40a that includes a rotation phase difference plate 38a that is a first phase difference providing unit of the present invention and that sequentially transmits only irradiation light in one polarization state among a plurality of polarization states. Have

  The imaging unit 26a is arranged on the CCD camera 42, the polarizing plate 36b, which is the second polarizer of the present invention fixedly arranged on the human body abdomen A side from the camera 42, and the human body abdomen A side. Only the reflected light in one polarization state corresponding to one polarization state of the irradiation light transmitted through the first polarizing filter section 40a. And a second polarizing filter section 40b on the reflection side that sequentially transmits the light.

  The light source 34 used for the polarized light irradiation unit 24a is not particularly limited as long as it can emit light of a predetermined wavelength that can illuminate the human abdomen A so that it can be imaged. For example, a laser or LED that emits a laser beam of a predetermined narrow band wavelength Etc., white lamps such as xenon lamps, fluorescent lamps, mercury lamps, etc., white LEDs or white lasers composed of LEDs or lasers of three primary colors such as RGB, pseudo-white composed of lasers and phosphors of a predetermined wavelength A laser or the like can be used. In the case of using a white light or a white LED, it is necessary to use a color filter that transmits a predetermined narrow band wavelength or a so-called band pass filter.

  Here, the predetermined narrow-band wavelength of the irradiation light is not particularly limited, but may be a visible region such as 400 nm to 700 nm or an infrared region of 700 nm to 1300 nm. The band is, for example, 5 nm to 50 nm, preferably 10 nm to 20 nm.

  The camera 42 acquires light intensity image information by polarized light of the human abdomen A as digital image information, and for example, a high pixel density camera including an image sensor such as a CCD or a CMOS can be used. The number of pixels is not particularly limited, but in order to obtain a high-definition polarized image, it is preferably 200,000 pixels or more, more preferably 1 million pixels or more. The upper limit of the number of pixels is not particularly limited, but may be determined according to the number of pixels of a CCD of a camera of the imaging unit 26a described later or a CCD 56 described later.

  The polarizing plates 36a and 36b of the first and second polarizing filter sections 40a and 40b are used as a polarizer and an analyzer, respectively. The same polarizing plate is used, and the optical axis of the light emitted from the light source 34 is used. It is fixed to the vertical. For example, the light emitted from the light source 34 is linearly polarized by the polarizing plate 36a. The reflected light that has passed through the rotational retardation plate 38b is linearly polarized by the polarizing plate 36b.

  In addition, the rotating phase difference plates 38a and 38b of the first and second polarizing filter sections 40a and 40b are, for example, rotating disk-shaped λ / 4 wavelength plates, that is, λ / 4 wavelength plates are used as optical axes. It can be configured by rotating at predetermined angles around the optical axis in a vertical plane. For example, light that has passed through the rotational phase difference plate 38a becomes linearly polarized light or circular (elliptical) polarized light, and light reflected by the human abdomen A also becomes linearly polarized light or circular (elliptical) polarized light. Note that the two λ / 4 wave plates serving as the rotational phase difference plates 38a and 38b are rotated by a predetermined angle in a state shifted by a predetermined angle around the optical axis so as to have a predetermined phase difference perpendicular to the optical axis. The

  The mechanism for rotationally driving the rotational phase difference plates 38a and 38b is not particularly limited, and a known rotational driving mechanism that rotates while holding the outer periphery of the disk constituting the rotational phase difference plates 38a and 38b. Can be used.

  Since the first polarization filter unit 40a of the polarization irradiation unit 24a of the polarization imaging system 12a and the second polarization filter unit 40b of the imaging unit 26a need to be accurately maintained in their respective predetermined polarization states, both Must be accurately aligned.

  Since the polarization imaging system 12a needs to rotationally drive the rotation phase difference plates 38a and 38b, and the apparatus becomes large, the polarized light irradiation unit 24a and the imaging unit 26a need to be installed outside the abdomen A of the human body. However, the polarization characteristic (polarization variable) is perfect, and can be preferably applied to a laparoscope, and can be preferably used for a laparoscopic navigation apparatus. The rotational retardation plates 38a and 38b are not limited to λ / 4 plates, and λ / 2 plates or other retardation plates may be used.

  Here, for example, the polarization imaging system 12a according to the illustrated embodiment constitutes a Mueller imaging system, and obtains a light intensity polarization image for obtaining a 4 rows × 4 columns Mueller matrix of the imaging target (sample) M. It is.

  Therefore, in the present embodiment, in order to obtain all the polarization characteristics included in the Mueller matrix, that is, all 16 (= 4 × 4) polarization variables, details will be described later, but at least 16 sheets having different polarization states from each other. It is necessary to obtain a light intensity polarization image of the. That is, at least four types of polarization states of incident light emitted from the first polarizing filter unit 40a and incident on the abdomen A of the human body are different from each other, reflected from the abdomen A of the human body, and emitted from the second polarizing filter unit 40b. It is necessary to rotate the rotational phase difference plates 38a and 38b so that the detection light has at least four different polarization states, and the combination has at least 16 different polarization states.

For example, in the polarization imaging system 12a, the λ / 4 wavelength plate of the rotational phase difference plate 38a of the first polarizing filter unit 40a is set to the polarization state of light to be described later so that the polarization state of incident light is at least four different from each other. Is rotated so that the Stokes parameters S ₀ , S ₁ , S ₂ and S _{3 of the} incident light representing each other are different from each other, and the λ / 4 wavelength plate of the rotational retardation plate 38b of the second polarizing filter unit 40b is for each of the Stokes parameters _{S 0,} S 1, _{S 2} and _{S 3,} so that the polarization state of the emitted light is at least four mutually different, for example, the Stokes parameters of the emitted light _{S 0,} S 1, _{S 2} and while rotating the S ₃ to be different from each other, the imaging unit 26 captures more than 16 times, 16 frames (pictures) or more optical intensity polarized image, i.e. more than 16 frames Light intensity polarization image information needs to be acquired. In this case, resist processing is preferably performed.

The Stokes parameters S ₀ , S ₁ , S ₂ , and S ₃ are the polarizations of the entire intensity of polarization (sum of vertical and horizontal polarization vectors) and vertical and horizontal (horizontal and vertical directions), respectively. It can be said that the vector difference, the polarization vector difference between 45 and 135 degrees, and the difference between right circular polarization and left circular polarization.

In the present invention, Stokes parameters S ₀ , S ₁ , S ₂ , and S ₃ of incident light and outgoing light are obtained from light intensity polarization images of 16 frames (sheets) or more having different polarization states. The matrix may be obtained. However, if the calculation method is set in advance so as to directly obtain the Mueller matrix from the light intensity polarization images of 16 frames (sheets) or more having different polarization states, the Stokes of the incident light and the emitted light is set. The parameters S ₀ , S ₁ , S ₂ , and S ₃ are not necessarily obtained.

  In the present embodiment, when the polarization angle (rotation angle) of the λ / 4 wavelength plate that is the rotation phase difference plate 38a is θ, the polarization angle (rotation) of the λ / 4 wavelength plate that is the rotation phase difference plate 38b. The angle is preferably 5θ or more and an odd multiple of θ, preferably 5θ.

  For example, the rotation angle θ of the λ / 4 wavelength plate of the rotational retardation plate 38a of the first polarizing filter section 40a is changed by a predetermined angle from 0 ° to 180 °, for example, every 11.25 °, and the first While changing the rotation angle of the λ / 4 wavelength plate of the rotational retardation plate 38b of the two-polarization filter unit 40b by 5 times or more, that is, for each angle of 5θ or more, the imaging unit 26 is 16 (= 180 / 11.25). ) It is possible to obtain 16-frame light intensity polarization images.

  Although details will be described later, in the present invention, in the polarization imaging system 12a, the imaging unit 26 changes the polarization angle θ of the λ / 4 wavelength plate from 0 degrees to 180 degrees, for example, every 7.2 degrees. It is more preferable to take 25 (= 180 / 7.2) times and obtain 25 frames (sheets) of light intensity polarization image, that is, 25 frames of light intensity polarization image information.

  Note that the rotation method of the rotation phase difference plates 38a and 38b is not limited to this, and even one of the 16 polarization variables (elements) of the 4 × 4 Mueller matrix may be missing and cannot be obtained. Basically, any rotation method may be used as long as the polarization state of the incident light and the outgoing light can be changed into different polarization states including a circularly polarized light component and a linearly polarized light component and having a change in azimuth. However, all polarization variables are evenly modulated (for example, linearly polarized light ← → elliptically polarized light ← → circularly polarized light, the optical axis direction is 0 ° ← → 180 ° (= the entire surface of the Poincare sphere)), and the same condition is not overlapped. It is preferable to do. For example, if the rotation angle of the rotating phase plate 38a is 0 °, 90 °, 180 °, and 270 °, the circularly polarized components of 45 ° and 135 ° do not occur, and all polarization variables of 4 rows by 4 columns of the Mueller matrix. It is necessary to rotate the angle in between. Also, the optical axis has only two directions of 0 ° and 90 °, and if there is no 45 ° or 135 ° component between the azimuths, it is impossible to obtain all polarization variables of the Mueller matrix. It will be complete.

  If it is not necessary to obtain all the polarization characteristics (polarization variables) included in the Mueller matrix and only specific polarization characteristics (polarization variables) are required, the light intensity polarization image of at least 16 frames such as 25 frames. It is not necessary to acquire the light intensity polarization image of the required number of frames according to the required polarization characteristic (polarization variable). For example, when only the polarization state related to linear polarization becomes a problem, a light intensity polarization image of less than 16 frames, for example, only 12 frames may be acquired.

  The polarization imaging system 12a of the embodiment shown in FIG. 2 uses a rotating phase difference plate 38a as the first phase difference providing means of the present invention of the polarized light irradiation unit 24a, and the second phase difference of the present invention of the imaging unit 26a. Although the rotation phase difference plate 38b is used as the applying unit, the present invention is not limited to this, and for example, a phase difference sheet or two phase modulation elements may be used as the first phase difference applying unit. And as a 2nd phase difference provision means, you may use the patterning element affixed on two phase modulation elements, a polarizer sticking patterning element, or a polarizer and a phaser.

FIG. 3 shows an embodiment of a polarization imaging system using two phase modulation elements as the first and second phase difference providing units.
The polarization imaging system 12b shown in FIG. 3 uses the optical imaging system 12a shown in FIG. 2 except that two phase modulation elements 44a, 45a and 44b, 45b are used instead of the rotational phase difference plates 38a and 38b, respectively. Therefore, detailed description thereof is omitted.
The polarization imaging system 12b includes a polarization irradiation unit 24b and an imaging unit 26b. The polarization irradiation unit 24b includes a light source 34, a polarizing plate 36a, a first phase modulation element 44a, and a second phase modulation element 45a. The imaging unit 26b includes a first polarizing filter unit 46b including first and second phase modulation elements 44b and 45b and a polarizing plate 36b, and a camera 42.

The first and second phase modulation elements 44a and 45a used in the first polarization filter unit 46a of the polarized light irradiation unit 24b are the first and second phase modulation elements 44b used in the second polarization filter unit 46b of the imaging unit 26b. It has the same configuration as 45b. These phase modulation elements 44a, 44b, 45a and 45b have directionality in refractive index and cannot be changed with respect to the direction, but the height of the refractive index can be changed by being electrically driven. For example, when linearly polarized light enters, it is possible to pass only linearly polarized light by changing the refractive index height, or elliptically polarized light or circularly polarized light depending on the height of the vertical and horizontal refractive indexes. It is an element that can also pass (λ / 4). Examples of such phase modulation elements 44a, 44b, 45a, and 45b include a phase modulation element using a liquid crystal element and a commercially available phase modulation element (for example, manufactured by Meadowlark). it can.
By installing the second phase modulation elements 45a and 45b at 45 degrees with respect to the first phase modulation elements 44a and 44b (for example, arranged at 0 degree) (for example, arranged at 45 degrees), Circularly polarized light can be linearly polarized light, ellipticity of elliptically polarized light can be changed, and elliptically polarized light of various angles can be obtained. For example, when linearly polarized light in the direction of 45 ° is incident on the first phase modulation element 44a installed at 0 °, the phase difference (birefringence) of the phase modulation element 44a is 0 (= 0 °) In this case, the linearly polarized light is transmitted as it is without being changed. On the other hand, when the phase difference of the phase modulation element 44a is λ / 4 (= 90 ° = π / 2), the linearly polarized light has no influence. In response, it will come out as circularly polarized light.

For this reason, in the polarization imaging system 12b, the first phase modulation elements 44a and 44b and the second phase modulation elements 45a and 45b are combined and electrically modulated to drive the rotational phase difference plate 38a that rotates mechanically. The function similar to 38b can be exhibited. That is, the incident light realized by rotating the rotation phase difference plates 38a and 38b in the polarization imaging system 12a shown in FIG. 2 by combining the first phase modulation elements 44a and 44b with the second phase modulation elements 45a and 45b, respectively. The polarization state of the incident light, the polarization state of the incident light, and the polarization state of the same detection light can be achieved. Even in the incident light from the polarization irradiation unit 24b, in the detection light of the imaging unit 26b , The Stokes parameters S ₀ , S ₁ , S ₂ and S ₃ can be determined and set.

That is, the first phase modulation element 44a of the first polarizing filter unit 46a of the polarized light irradiation unit 24b is, for example, a slow axis of 0 degree with respect to the slow axis of the polarizing plate 36a, that is, an axis (a direction with a high refractive index) ) Is set to be 0 ° so that the amount of polarization (vector) of the linearly polarized light is vertical and horizontal, that is, the phase difference is Δ1 and Δ2, and the first phase modulation element 44b is set to be delayed. The phase axis is set to 45 degrees with respect to the slow axis of the polarizing plate 36a, that is, the angle of the axis (the direction in which the refractive index is high) is set to 45 °. By setting the phase difference to Δ1 and Δ2, Stokes parameters S ₀ , S ₁ , S ₂ and S ₃ representing the polarization state of light to be described later are made different from each other in the incident light from the polarized light irradiation unit 24b. be able to.

On the other hand, for the second phase modulation elements 45a and 45b of the second polarizing filter section 46a of the imaging unit 26b, the angle of the axis (the direction in which the refractive index is high) of the second phase modulation element 45b is 0 °. Is set so that the phase difference is Δ1, Δ2, and the second phase modulation element 44a is set so that the angle of the axis (the direction in which the refractive index is high) is 45 °, and the phase difference is Δ1, By making Δ2, the Stokes parameters S ₀ , S ₁ , S ₂ and S ₃ can be made different from each other even in the detection light of the imaging unit 26b.

  Therefore, the polarization imaging system 12b of the present embodiment also constitutes a Mueller imaging system, and can obtain at least 16 light intensity images with polarized lights having different polarization states, and all 16 polarization variables included in the Mueller matrix. Can be obtained.

  Since this polarization imaging system 12b drives the phase modulation elements 44a, 44b, 45a and 45b, the polarization characteristic (polarization variable) is perfect, and the polarization shown in FIG. 1 which rotationally drives the rotation phase plates 38a and 38b. Since the apparatus can be downsized as compared with the imaging system 12a, the apparatus can be more suitably applied to a laparoscope and can be preferably incorporated into a laparoscopic navigation apparatus.

  In the example shown in FIGS. 2 and 3, the same polarizing filter unit is used for the polarized light irradiation unit 24 and the imaging unit 26. However, the present invention is not limited to this, and different polarizing filter units are used. Alternatively, different phase difference providing means may be used. For example, the polarization imaging unit may be configured by using the polarization irradiation unit 24a illustrated in FIG. 2 and the imaging unit 26b illustrated in FIG. 3, or conversely, the polarization irradiation unit 24b illustrated in FIG. A polarization imaging system may be configured using the imaging unit 26a.

  In the example shown in FIGS. 2 and 3, the polarized light irradiation unit 24 and the imaging unit 26 are disposed outside the living body, and are applied to a laparoscope or the like. An example applicable to the inside of a living body is shown.

FIG. 4A is a schematic diagram of one embodiment of a polarization imaging system applied to an endoscope, and FIG. 4B is a pattern polarization / wave plate for one pixel used in the polarization imaging system. It is an expansion schematic diagram which expands and shows this element.
The polarization imaging system 12c shown in FIG. 4A includes a polarization irradiation unit 24c and an imaging unit 26c. The polarization irradiation unit 24c includes a light source 34, a polarizing plate 36a, and first and second phase modulation elements 44a and 45a. A first polarizing filter unit 46 a and an optical probe 50 including an optical fiber 48, and the imaging unit 26 c is a second polarizing filter unit including a patterning polarization / wave plate 52 disposed in the optical probe 50. 54 and a CCD 56.
Here, since the light source 34 and the first polarizing filter unit 46a of the polarized light irradiation unit 24c have the same configuration as the polarization imaging system 12b shown in FIG. 3, detailed description thereof will be omitted.

  The optical fiber 48 functions as an optical transmission unit of the endoscope, guides irradiation light in a predetermined polarization state that has passed through the second polarizing filter unit 54 to the tip of the optical probe 50, and passes a predetermined part from the tip. Is irradiated to the surface layer of the digestive organ B such as the stomach, which is a predetermined part in the body cavity of the living body.

  The CCD 56 is a high pixel density image sensor that acquires light intensity image information by polarized light on the surface layer of the body cavity B as digital image information, but other image sensors such as a CMOS may be used.

  As shown in FIG. 4B, the patterned polarization / wavelength plate 52 disposed in the optical probe 50 includes a rectangular polarizing plate 55a composed of an array of four polarizers having different polarization states, and one of them. A plurality of rectangular polarizers and phase shifter patterning elements 53 each including a phase plate (wave plate) 55b attached to one polarizer are arranged in an array by the number of pixels of a polarization image to be acquired, for example. Is. That is, the patterning polarization / wave plate 52 alone constitutes the second polarization filter section 54 and has the same function as the second polarization filter sections 40b and 46b shown in FIGS.

  As the polarizer and phaser patterning element 53, as shown in an enlarged view in FIG. 4B, the lower left polarization angle (axis (refractive index of the refractive index) of the four polarizers of the rectangular polarizing plate 55a. Polarization angle 45 ° to the polarizer 53a of 0 °, the polarizer 53b having an upper left polarization angle of 90 °, the polarizer 53c having an upper right polarization angle of 45 °, and the polarizer having an upper right polarization angle of 90 °. A phaser-attached polarizer 53d to which the above-described phaser (wavelength plate) is attached is arranged in a 2 × 2 array to form one pixel of a polarization image.

As described above, the polarizers 53b and 53a of the polarizer and phaser patterning element 53 have longitudinal (90 °) and lateral (0 °) polarization components, and the polarizer 53c has an oblique (45 °) polarization component. Ellipsoidal polarization component (circular polarization component: 90 °, 45 °) (axis (high refractive index direction) angle: 90 °, phase difference: Δ1 = 0, axis angle: 90 °, phase difference) : Δ2 = λ / 4) can be obtained. Therefore, similarly to the second polarizing filter units 40b and 46b of the imaging units 26a and 26b shown in FIGS. Total intensity (sum of vertical and horizontal polarization vectors), vertical and horizontal (horizontal and vertical) polarization vector differences, polarization vector difference between 45 and 135 degrees, and right circular polarization Stokes para corresponding to the difference between left and right circularly polarized light It chromatography data _{S 0,} S 1, _{S 2} and can be different ones _{S 3,} also can be obtained, it can be set.

  Therefore, the polarization imaging system 12c of this embodiment also constitutes a Mueller imaging system, and can obtain at least 16 light intensity images with polarized lights having different polarization states, and all 16 polarization variables included in the Mueller matrix. Can be obtained.

  When it is not necessary to obtain all 16 polarization variables included in the Mueller matrix, the second polarization filter unit 54 of the polarization imaging system 12c shown in FIG. Instead of the patterning polarization / wave plate 52 comprising an array, a polarizer patterning element comprising an array of three polarizers having different polarization states, that is, the right side of the polarizer and phaser patterning element 53 shown in FIG. A patterning polarizing plate in which polarizer patterning elements composed of only three polarizers 53a, 53b, and 53c, which do not have a phaser-attached polarizer 53d corresponding to an elliptically polarized light component, are arranged in an array may be used. In this case, among all 16 polarization variables included in the Mueller matrix, 12 polarization variables corresponding to linearly polarized light that do not correspond to elliptically polarized light components can be obtained.

  In the case of using the patterning polarization / wave plate 52 and the patterning polarizing plate, one pixel of the CCD 56 is provided for each of the polarizers and phaser patterning elements 53 and the polarizers 53a to 53d arranged in an array of the polarizer patterning elements. Need to be detected accurately and only the polarized light from each of the polarizers 53a to 53d needs to be detected. However, it is difficult to assemble and manufacture each of the polarizers 53a to 53d and the respective pixels of the CCD 56 completely. It is preferable to perform correction processing as a signal or data.

  As described above, since the array of four polarizers of the polarizer and phaser patterning element 53 and the array of three polarizers of the polarizer patterning element become one pixel of the polarization image, the number of pixels of the CCD 56 is polarized light. Four or three times the number of pixels of the light intensity image by light is required. Therefore, if the number of pixels of the light intensity image is 200,000 pixels, for example, the number of pixels of the CCD 56 is 800,000 pixels or 600,000 pixels. If the number of pixels of the light intensity image is 1 million pixels, for example, the CCD 56 The number of pixels is 4 million pixels or 3 million pixels.

  Here, the polarization imaging system applied to the endoscope is not limited to the polarization imaging system 12c shown in FIG. 4A, but like the polarization imaging system 12d shown in FIG. In place of the first and second phase modulation elements 44a and 45a of the first polarizing filter unit 46a of the polarized light irradiation unit 24c shown in a), a first polarizing filter unit 40a using a rotational phase difference plate 38a shown in FIG. 2 is provided. The polarized light irradiation unit 24d may be used.

  Note that the polarization imaging systems 12c and 12d have a patterning polarization / wavelength plate 52 in which the polarizers and the phaser patterning elements 53 shown in FIGS. 4B and 5B are arranged in an array at the tip of the optical probe 50. Since the CCD 56 is incorporated, the polarization characteristics (polarization variable) are perfect despite the fact that the apparatus can be miniaturized, so that it can be more suitably applied to an endoscope, and is preferably incorporated into an endoscope diagnostic apparatus. be able to.

  Further, like the polarization imaging system 12e shown in FIG. 6, in the polarization imaging system 12c shown in FIG. 4A, instead of the patterning polarization / wave plate 52 and the CCD 56 arranged in the optical probe 50 of the imaging unit 26c. The reflected light in a predetermined polarization state from the digestive organ B is transmitted through the optical fiber 48 of the optical probe 50 and emitted from the other end, and the second polarizing filter unit 46b shown in FIG. The polarized reflected light emitted from the other end of the optical fiber 48 is transmitted through the image fiber 58, is incident on the second polarizing filter unit 46b, and is imaged by the CCD 56 disposed behind the polarizing filter unit 46b. The part 26d may be used.

  In this polarization imaging system 12e, since the polarized reflected light from the digestive organ B is guided by the optical fiber 48 and the image fiber 58, the resolution may be lowered, but the change in the polarization state is small and the polarization state is maintained. Therefore, since it is not necessary to incorporate the imaging unit 26d in the optical probe 50, it is not necessary to downsize the apparatus, and the degree of freedom of the apparatus configuration can be increased.

  Also in the polarization imaging system 12e of the present embodiment, the polarization characteristics (polarization variables) are perfect, as in the polarization imaging systems 12c and 12d, and can be more easily applied to the endoscope, and can be easily performed by the endoscope diagnostic apparatus. Can be incorporated.

The polarization imaging system applied to the endoscope is not limited to the polarization imaging systems 12c, 12d, and 12e, and various polarization filter units that are different or the same are used for the polarization irradiation unit 24 and the imaging unit 26. Alternatively, different or the same various phase difference providing means may be used.
The polarization imaging system 12 is basically configured as described above.

  Next, as shown in FIG. 1, the polarization conversion processing unit 14 includes image information of a plurality of light intensity images by polarized light (reflected light in a plurality of polarization states) imaged by the polarization imaging system 12, for example, 25 The light intensity image information of the frame is received from the imaging unit 26, Mueller image conversion is performed on the received plurality of light intensity image information, and a plurality of Mueller images (for example, 16 frames) with respect to a plurality of (for example, 16) polarization variables. Mueller image conversion unit 28 for obtaining (Muller image information), and a plurality of obtained Mueller images (multiple frames of Mueller image information) are subjected to polarization variable separation processing and expressed on the surface of a predetermined part of a living body A polarization variable separation processing unit 30 for converting the tissue into a polarization characteristic image (polarization characteristic image information) based on a predetermined polarization variable (polarization characteristic) for distinguishing the tissue from the surface layer; Polarizers (36a, 36b), rotational phase plates (38a, 38b), phase modulation elements (44a, 44b, 45a, 45b), patterning polarization / wave plates (52), etc. used for Mueller image conversion in the conversion unit 28 A polarizing element characteristic correction processing unit 32 that corrects polarizing element characteristics such as a polarization angle of the phase difference providing means.

  Here, the Mueller image conversion unit 28 is a part that performs a conversion process for obtaining a higher-order polarization parameter (Mueller matrix).

  By the way, when the sample M has polarization characteristics given by each element of the Mueller matrix M and the polarization characteristics represent the characteristics of the sample M, it is necessary to obtain the Mueller matrix M, that is, its elements. Here, the Mueller matrix M is a matrix of 4 rows and 4 columns and is given by the following formula (1) and has 16 elements, so that 16 Mueller images of samples by each element are obtained.

Here, although it is difficult to strictly correspond to each of the 16 elements m _{00 to} m ₃₃ of the Mueller matrix M and the physical properties of the polarized light, as a rough relation, the element m ₀₀ represents the luminance, 16 elements m _{00 to} m ₃₃ represent the degree of polarization, elements m ₀₁ , m ₀₂ , m ₁₀ and m ₂₀ represent dichroism (linear double absorption), and elements m ₀₃ and m ₃₀ represent Represents chromaticity (circular double absorption), elements m ₁₁ , m ₁₂ , m ₂₁ and m ₂₂ represent optical rotation (circular birefringence), and elements m _{11 to} m ₁₃ , m _{21 to} m ₂₃ and m ₃₁ to m ₃₃ is representative of the birefringence (linear birefringence).
When measuring all 16 elements m _{00 to} m ₃₃ of the Mueller matrix M, it is necessary to configure a Mueller measuring system in which the sample M is represented by the Mueller matrix as shown in FIG. Therefore, it is necessary to obtain light intensity images using light of 25 different polarization states. Note that this Mueller measurement system is composed of the same polarized light irradiation unit 24a and imaging unit 26a as the polarization imaging system 12a shown in FIG.

Here, a Mueller matrix conversion algorithm in the Mueller image conversion unit 28 will be described.
Sixteen polarization elements of the sample M are represented by the Mueller matrix M. In the Mueller measurement system shown in FIG. 7, the polarization state of the incident light on the sample M is expressed by the Stokes parameters S ₀ , S ₁ , S ₂ and represented by S _3, the polarization state of the detection light reflected from the sample M is represented by the Stokes parameter _{S '0, S' 1,} S '2 and S' _3, the Mueller matrix of the polarizing plate 36a and 36b Is P ₁ and P ₂ and the Mueller matrices of the quarter λ plates (λ / 4 wavelength plates) 38a and 38b at the angle θ are represented by R ₁ (θ) and R ₂ (5θ), the following formula (2) Satisfied.

Here, since the Stokes parameter S ′ ₀ is I (θ) (S ′ ₀ = I (θ)), the light intensity at the angle θ of the ¼λ plate (λ / 4 wavelength plate) 38a is Fourier-transformed. When converted, it is represented by the following formula (3).
Here, when the measured value of the light intensity is Φ (θ), 25 Fourier coefficients (amplitudes) a ₀ to 25 so that the error between Φ (θ) and I (θ) is minimized by the least square method. We will be seeking a ₁₂ and _b 1 _{~b 12,} since 25 pieces of the above formula for different theta (3) is needed, in the above formula (3), and the I (θ) = Φ (θ ) 25 simultaneous equations will be solved.

As a result, each element m _{00 to} m ₃₃ of the Mueller matrix M can be expressed using Fourier coefficients a _{0 to} a ₁₂ and b _{1 to} b ₁₂ as shown in the following formula (4). Each element m _{00 to} m ₃₃ of M can be obtained.
m ₀₀ = a ₀ −a ₂ + a ₈ −a ₁₀ + a ₁₂
m ₀₁ = 2 (a ₂ -a ₈ -a ₁₂ )
_{m 02 = 2 (b 2 +} b 8 -b 12)
_{m 03 = b 1 -2b 11 =} b 1 + 2b 9 = b 1 + b 9 -b 11
_{m 10 = 2 (-a 8 +} a 10 -a 12)
m ₁₁ = 4 (a ₈ + a ₁₂ )
m ₁₂ = 4 (−b ₈ + b ₁₂ )
_{m 13 = -4b 9 = 4b 11} = 2 (-b 9 + b 11)
m ₂₀ = 2 (−b ₈ + b ₁₀ −b ₁₂ )
m ₂₁ = 4 (b ₈ + b ₁₂ )
m ₂₂ = 4 (a ₈ −a ₁₂ )
_{m 23 = 4a 9 = -4a 11} = 2 (a 9 -a 11)
_{m 30 = 2b 3 -b 5 =} -b 5 + 2b 7 = b 3 -b 5 + b 7
_{m 31 = -4b 3 = -4b 7} = -2 (b 3 + b 7)
_{m 32 = -4a 3 = 4a 7} = 2 (-a 3 + a 7)
_{m 33 = -2a 4 = 2a 6} = -a 4 + a 6) ...... (4)

Note that it is difficult to make λ / 4 (90 °) strictly λ / 4 plate installed in the polarization imaging system 12a configured by the Mueller matrix polarimeter shown in FIG. 7 depending on the wavelength characteristics of the material and the manufacturing technology. Therefore, when the λ / 4 plates 38a and 38b and the polarizing plates 36a and 36b have principal axis directions and birefringence phase differences, the elements m _{00 to} m ₃₃ of the Mueller matrix include errors. Therefore, this error needs to be calibrated to improve the accuracy of polarization measurement.
These error calibration methods are omitted here, but a calibration method proposed by Chipman or Goldstein may be applied.

From the above, in order to obtain 16 Mueller images for all 16 elements of the Mueller matrix M, 25 light intensity images having different polarization states are required.
Thus, the Mueller image conversion unit 28 uses 25 light intensity images (information) with different light states obtained by imaging the angle θ every 7.2 degrees (180/25) by the conversion processing algorithm. A Mueller matrix can be obtained, and 16 Mueller images (information) based on all 16 elements can be obtained.

As can be seen from the above equation (4), some of the Fourier coefficients a _{0 to} a ₁₂ and b _{1 to} b ₁₂ are not linearly independent. Therefore, as described above, all 16 elements (Mueller parameters) of the Mueller matrix M can be obtained without using all 25 light intensity images. That is, in the present invention, when Fourier transform is performed, it is preferable to acquire 25 light intensity images, but at least 16 light intensity images may be acquired.

On the other hand, as can be seen from the above equation (1), since the Mueller matrix M has 16 elements m _{00 to} m ₃₃ , in order to obtain all of these elements (Mueller parameters), at least 16 kinds of elements are required. It can be seen that light intensity images (polarized images) having different polarization states are necessary.

Therefore, as apparent from the above equation (2), there are four types of Stokes parameters representing the polarization state of the incident light on the sample M, S ′ ₀ , S ′ ₁ , S ′ ₂ and S ′ ₃ , and Since the Stokes parameters representing the polarization state of the detection light of S are S ₀ , S ₁ , S ₂ and S ₃ , the polarization state of the incident light to the sample M and the polarization state of the detection light from the sample M are different from each other. For example, as described above, the vertical (90 °: vertical) linear polarization component, the horizontal (0 °: horizontal) linear polarization component, the oblique (45 °) linear polarization component, and the ellipticity are By setting so as to have different (90 ° / 45 °) elliptical (circular) polarization components, four Stokes parameters S ′ ₀ , S ′ ₁ , S ′ ₂ and 4 S _'3 and _{S 0, S} 1, S And for obtaining the S _3, it is possible to obtain 16 kinds of light intensity image of the sample M of the polarization state. As a result, all 16 Mueller parameters can be obtained.

  Next, the polarization variable separation processing unit 30 performs a process for separating the polarization characteristics (polarization variables) mixed in the Mueller matrix by performing a decomposition process on the Mueller matrix obtained by the Mueller image conversion unit 28. In other words, a polarization variable separation process is performed on a plurality of obtained Mueller images (multiple frames of Mueller image information), and the exposed tissue exposed on the surface layer of a predetermined part of the living body is surface layer. This is a part that is converted into a polarization characteristic image (polarization characteristic image information) based on a predetermined polarization variable (polarization characteristic) for discriminating it from the tissue. In addition, it can be said that the polarization characteristic image (polarization characteristic image information) represents the degree of expression of the exposed tissue such as collagen fibers that are exposed on the surface layer of the predetermined part.

  In the polarization variable separation processing unit 30, the Mueller matrix M is mainly divided into three types of retardance characteristics (birefringence and optical rotation), absorption characteristics (dichroism and circular dichroism), and depolarization characteristics. To be separated. From these separated polarization characteristics, the degree of depolarization, phase difference, azimuth (phase difference), azimuth (absorption) and optical rotation of a predetermined part (sample) of a living body, and further, the degree of polarization of light and the direction of polarization of light, etc. The polarization characteristics can be obtained.

  Here, the phase difference is the difference between the vertical and horizontal refractive indices of a material in a plane perpendicular to the light traveling direction, and the degree of depolarization is the degree of polarization of the light that enters the material and is emitted. This is a value indicating how much the polarization state (state indicating whether it is polarized or not (polarized)) is affected, and the direction of the phase difference indicates the direction in which the refractive index is maximum as an angle. The azimuth of absorption is the same as the dichroic azimuth, and the direction of highest absorption is expressed as an angle, and the optical rotation is the rotation characteristic with respect to linearly polarized light as an angle, and has no azimuth. This is different from the phase difference.

Meanwhile, when the Mueller matrices is M, a matrix representing the degree of depolarization and M _delta, a matrix representing the retardance (phase difference) and M _R, the matrix representing the two-color and M _D, the following formula (5 ). These matrices are 4 × 4 matrices.
_{M = M Δ M R M D} ... (5)

Thus, based on the equation (1), by degrading the Mueller matrix M, the matrix M _delta, seeking _{M R,} and _{M D,} degree of depolarization of the matrix M _delta, the phase difference from the matrix _{M R,} and matrix it can be determined dichroism from M _D.

  As for the method of decomposing the Mueller matrix and the relationship between each characteristic and the elements of the Mueller matrix, methods and relational expressions proposed by Azzam, Chipman, Goldstein, etc. Here, the detailed results are omitted, and the results are described here (“Polarized light”, Dennis Goldstein, 2th ed., Marcel Dekker, NY (2003), Chapter 9 “Mathematics of the Mueller Matrix “9.5“ The Lu-Chipman Decomposition ”P175-P186 and SPIE Vol. 3120“ Decomposition of Mueller Matrix ”P385-P396).

That is, the decomposed matrix _{M R,} given by the following equation (6) using element _m 00 _{~m 33} of the Mueller matrix M, the phase difference R is seen to be given by the following equation (7). Here, the coefficients a and b are given by the following equations (8) and (9), respectively.

The decomposed matrix M _D is also given by the following formula (10) using the elements m _{00 to} m ₃₃ of the Mueller matrix M, and the dichroism D is given by the following formula (11). Again, the coefficients a and b are given by the above equations (8) and (9), respectively.

Further, it is understood that the matrix M _Δ is given by the following formula (12) by _modifying the above formula (5), and the depolarization degree m _Δ is given by the following formula (13). Here, m ′, κ1, κ2, and κ3 are given by the above equations (14), (15), (16), (17), and (18), respectively. Incidentally, .lambda.1, .lambda.2, and λ3 can be derived from the eigenvalues of m _delta.
M _Δ = MM _D ⁻¹ M _R ⁻¹ (12)

  The present inventors have found that, among the polarization characteristics obtained in this way, there is a property of distinguishing an exposed tissue in which a specific polarization characteristic appears on the surface layer of a predetermined site from the surface layer structure.

Such polarization characteristics include phase difference, depolarization degree, azimuth (phase difference), azimuth (absorption), optical rotation, light polarization degree, light polarization azimuth, dichroism, dichroism azimuth, and p-polarized light. In addition, polarization characteristics such as s-polarized light are preferable for distinguishing an exposed structure that appears on the surface layer of a predetermined portion from a surface layer structure. As a result, polarization characteristics images based on these polarization characteristics, that is, phase difference image, depolarization degree image, orientation image (phase difference), orientation image (absorption), optical rotation image, polarization degree image of light, polarization direction of light In the image, the dichroic image, the dichroic orientation image, the p-polarized light, and the s-polarized image, the exposed tissue and the surface tissue can be distinguished and displayed, for example, in a quasi-colored manner.

  The exposed tissue that can be identified by such polarization characteristics is preferably a fibrous tissue, and the fibrous tissue is preferably collagen fibers, nerve fibers, or muscle fibers.

FIG. 8 is a schematic diagram of an embodiment of the polarization conversion processing unit and the polarization variable separation processing unit of the polarization image measurement and display system shown in FIG. 1, and in particular, an explanatory diagram illustrating the polarization variable separation processing unit in detail. .
As shown in FIG. 8, the polarization variable separation processing unit 30 includes a separation unit 82 that performs a decomposition process on the Mueller matrix obtained by the Mueller image conversion unit 28, and a polarization characteristic image separated by the separation unit 82. And a post-separation image forming unit 84 for forming an enhanced polarization characteristic image that has been subjected to enhancement processing for distinguishing the exposed tissue that appears on the surface layer of the region from the surface tissue, and the polarization conversion of the polarization image measurement display system 10 As described above, the processing unit 14 further performs variable separation from the Mueller image conversion unit 28 by the polarization variable separation processing unit 30 in addition to the Mueller image conversion unit 28, the polarization variable separation processing unit 30, and the polarization element characteristic correction processing unit 32. For post-separation image formation for setting the region of the polarization characteristic of the emphasized polarization characteristic image formed by the biological observation model setting unit 86 for setting the living body observation model at the time and the post-separation image forming unit 84 And a parameter setting section 88.

  The separation unit 82 uses the biological observation model set by the biological observation model setting unit 86 to separate polarization characteristics mixed in the measured Mueller matrix, that is, from each of the plurality of elements of the Mueller matrix. By performing a polarization variable separation process on a plurality of Mueller images, a predetermined polarization variable (polarization characteristic) suitable for distinguishing the exposed tissue exposed on the surface of a predetermined part of the living body from the surface tissue. This is a part for outputting a polarization characteristic image (polarization characteristic image information). For example, if the polarization characteristic is a phase difference, the output signal of the separation unit 82 is image information of 0 to 360 °.

  The post-separation image forming unit 84 identifies the exposed tissue exposed on the surface layer of a predetermined part of the living body from the surface layer tissue with respect to the polarization characteristic image based on the predetermined polarization property separated by the separation unit 82. This is a part for forming an emphasized polarization characteristic image obtained by performing enhancement processing on an emphasis region (region of interest) having a predetermined polarization characteristic set by the post-separation image forming parameter setting unit 88, and is also called an emphasized polarization property image forming unit. it can.

  FIGS. 9A and 9B are schematic configuration diagrams of an embodiment of a living body observation model when variables are separated by the polarization variable separation processing unit shown in FIG. 8, respectively, and polarization variable separation is performed from the Mueller image conversion unit, respectively. It is explanatory drawing explaining the biological observation model at the time of carrying out variable separation by a process part.

  As a living body observation model that can be used in the present invention, first, a “transmission model” 90a that transmits through a living body in which irradiation light in a plurality of polarization states is observed can be exemplified as shown in FIG. Here, the separation unit 82 performs variable separation by the polarization variable separation processing unit 30 on the assumption of the transmission model 90a. The transmission model 90a is a model in which a plurality of layers of “dichroism”, “phase difference × optical rotation”, and “degree of depolarization” are stacked as shown in FIG. 9A. The transmission model 90a is an effective model for acquiring the polarization characteristics of the biological sample.

  On the other hand, in an actual system, irradiation light is obliquely applied to an observed living body, and the reflected light is imaged. Therefore, it is conceivable that the “reflection model” 90b shown in FIG. 9B is used as the living body observation model as the living body observation model of the present invention. As a living body observation model in this case, for example, as shown in FIG. 9B, a plurality of “scattering (depolarization degree)”, “phase difference”, “optical rotation”, and “dichroic” layers are stacked. There are other models. Further, since the reflection model is used, reflected light is generated in each layer. For example, reflected light in which scattering + phase difference is mixed is observed. In such a reflection model, since these can be assumed, the polarization variable separation processing unit 30 can improve the variable separation accuracy, and expect to improve the accuracy of the retardance characteristic, the absorption characteristic, and the depolarization property.

  The biological observation model setting unit 86 shown in FIG. 8 is for setting the biological observation model such as the transmission model 90a and the reflection model 90b described above as the biological observation model when the variable separation is performed by the polarization variable separation processing unit. Is. In this way, by allowing the living body observation model setting unit 86 to select the living body observation model in accordance with the actual observation system, the polarization variable separation processing unit 30 increases the variable separation accuracy, the retardance characteristics, Expected to improve accuracy of absorption characteristics and depolarization.

  The post-separation image forming parameter setting unit 88 is an enhanced polarization characteristic image formed by the post-separation image forming unit 84 in order to distinguish an exposed tissue in which a specific polarization characteristic appears on the surface layer of a predetermined site from a surface layer tissue. This is intended to set the region of the polarization characteristics of each of the regions, and for each tissue to be observed, a region to be emphasized in a specific polarization property such as a phase difference can be set.

The present inventors have provided such a post-separation image forming parameter setting unit 88 in order to distinguish an exposed tissue in which a specific polarization characteristic appears on the surface layer of a predetermined site from the surface layer tissue. This is because it has been found that it is necessary to be able to set a phase difference region to be enhanced if the polarization property region to be enhanced, for example, if the polarization property is a phase difference, for each observation tissue.
In the present invention, at the time of observing the polarization characteristic image, by selecting an appropriate parameter for each observed tissue from the post-separation image forming parameter setting unit 88, the exposed tissue exposed on the surface layer is clearly distinguished from the surface tissue. can do.

  For example, if the polarization characteristic is a phase difference, the output signal from the separation unit 82 is image information of 0 to 360 °. Therefore, when the observation tissue is collagen fibers, the phase difference region to be emphasized is separated. The post-image forming parameter setting unit 88 can set an area of 140 ° ± 10 °.

  In addition, although the example of setting the area | region of the polarization characteristic which should be emphasized here for every observation tissue (a nerve, a lymph node, a blood vessel) was shown, each observation part (upper digestive organ, lower digestive organ, respiratory organs) was shown. You may make it set.

In particular, the degree of expression of collagen fibers is effective in diagnosing the degree of progression of cancer.
The relationship between the degree of progression of cancer and the degree of expression of collagen fibers can be considered as follows.

FIG. 10A is a schematic configuration schematic diagram in the vicinity of the surface layer of a normal living body, and FIG. 10B is a schematic configuration schematic diagram in the vicinity of the surface layer of the living body in which intramucosal cancer has occurred. c) is a schematic structural schematic diagram of the vicinity of the surface layer of a living body that has progressed to submucosal invasive cancer.
As shown in FIG. 10 (a), a tissue 60a near the surface layer of a normal living body has a mucosal layer 62 from the surface side, a mucosal muscle plate 64 below it, and a submucosal layer 66 below it. It exists in the submucosal layer 66 below the mucosal muscle plate 64.

  Next, in the tissue 60b in the vicinity of the surface layer of the living body in which the intramucosal cancer has occurred as shown in FIG. 10B, the intramucosal cancer (m cancer) 70 has occurred in the mucosal layer 62. The lower mucosal muscle plate 64 is not torn, and the collagen fibers 68 present in the lower mucosal layer 66 below the mucosal muscle plate 64 are not exposed to the mucosal layer 62. For this reason, in the tissue 60b near the surface of the living body in which intramucosal cancer has occurred, even if the polarization measurement according to the present invention is performed, the tissue 60b appears in the mucosal layer 62 as in the case of the tissue 60a near the surface of a normal living body. It is not possible to detect the collagen fibers 68.

  In contrast, in the tissue 60c in the vicinity of the surface layer of the living body where the cancer 72 shown in FIG. 10C has progressed, that is, the submucosal invasive cancer (sm cancer) 72 exists, the submucosal invasive cancer 72 is present. The mucosal muscle plate 64 of the portion that has progressed to the right is torn, the collagen fibers 68 of the submucosa 66 move from the torn portion 65 to the mucosa layer 62, and grow between the cancer cells 72 of the surface mucosa layer 62 The collagen fibers 68 are exposed to the surface mucosa layer 62. For this reason, in the tissue 60c in the vicinity of the surface layer of the living body where the submucosal invasive cancer 72 exists, the polarization measurement according to the present invention can be performed to detect the collagen fibers 68 exposed in the mucosal layer 62, and other tissues. Can be identified. As a result, the collagen fibers 68 appearing on the mucosal layer 62 can be colored, the expression of the collagen fibers 68 to the mucosal layer 62 can be known, and the submucosal invasive cancer 72 can be detected. .

  That is, as shown in FIG. 10 (c), when the mucosal muscle plate 64 is broken as the submucosal invasive cancer 72 progresses, fibroblasts generate collagen fibers 68 from the submucosal layer 66 below the mucosal muscle plate 64. The cells enter, and the collagen fibers 68 in the submucosal layer 66 move to the mucosal layer 62 from the tearing, and many collagen fibers 68 are generated in the upper mucosal layer 62. That is, it is possible to distinguish between the intramucosal cancer 70 shown in FIG. 10B and the submucosal invasive cancer 72 shown in FIG.

Since the collagen fibers 68 are made of a polymer and have optical anisotropy, the collagen fibers 68 can be distinguished from the mucosal layer 62 by the polarization characteristics, and can be displayed in an identifiable manner. Therefore, the collagen fibers 68 can be visualized as a pseudo color image so as to be distinguishable from the mucosal layer 62.
Therefore, if such an image shows that collagen fibers have grown between cancer cells on the surface of a given site and the interstitial change (the expression of collagen fibers to the mucosa) can be confirmed, it is diagnosed that metastasis is highly likely. It is possible to diagnose whether it is cancer or not, and whether it is intramucosal cancer or submucosal invasive cancer.

  Next, the display conversion processing unit 16 performs display conversion processing, that is, display color brightness image conversion processing, on the polarization characteristic image (information) having a predetermined polarization characteristic obtained by the polarization variable separation processing unit 30 of the polarization conversion processing unit 14. And performing the polarization characteristic image (information) visualization so that the exposed tissue can be discriminated from the surface tissue, and for example, colored into a pseudo color and converted into display polarization characteristic image information for pseudo color display It is.

  Here, the display conversion processing by the display conversion processing unit 16 is based on the polarization characteristic image information, and the colors to be colored on the exposed tissue and the surface tissue according to the value of the predetermined polarization variable (intensity of the polarization characteristic). It is preferable to generate and display polarization characteristic image information for visualizing and displaying the expression distribution of the exposed tissue by determining and color-mapping the exposed tissue and the color to be colored on the surface tissue. .

The display unit 18 is configured to visualize the display tissue on the display screen based on the display polarization characteristic image information obtained by the display conversion processing unit 16 so as to be distinguishable from the surface layer tissue, that is, to perform pseudo color display. A known monitor or display can be used for the display unit 18.
Note that the display of the polarization characteristic image by the display unit 18 preferably displays the distribution of the exposed tissue colored to the color to be colored based on the display polarization characteristic image information.

  The normal color imaging system 20 obtains a light intensity image (information) obtained by irradiating a predetermined site with illumination light for normal observation and imaging the reflected light. An image capturing system can be used.

  In addition, the image composition unit 22 generates a display polarization characteristic image and a display polarization characteristic image based on the display polarization characteristic image information obtained by the display conversion processing unit 16 and the normal color light intensity image information obtained by the normal color imaging system 20. In combination with a normal color light intensity image, for example, the combined image information for display is generated by superimposing or arranging them together, or processing both. As a result, the display unit 18 can display a composite image based on the composite image information.

  The polarized image measurement display system according to the present invention is basically configured as described above.

Hereinafter, the operation of the polarization image measurement display system according to the present invention, and the polarization image measurement method and polarization image display method implemented in these systems will be described.
FIG. 11 is a flowchart showing an example of a polarization image display method according to the polarization image measurement method implemented in the polarization image measurement display system according to the present invention, that is, a polarization image measurement and display method.

  First, in the present invention, in step S100, the polarization image measurement display system 10 shown in FIG. 1 is prepared to measure the surface layer of a predetermined part of the living body, and the number of light intensity images in different polarization states to be captured, Various initial values and conditions used in the polarization image measurement display system 10 are set.

  Next, in step S102, the polarized light irradiation unit 24 of the polarization imaging system 12 of the polarization image measurement display system 10 irradiates a predetermined part of the living body with irradiation light in a predetermined polarization state from its surface layer.

  Subsequently, in step S104, reflected light of a predetermined polarization state from the surface layer of a predetermined portion by irradiation light of a predetermined polarization state irradiated by the polarization irradiation unit 24 is imaged by the imaging unit 26, and one polarization modulation is performed. The light intensity image (data) of the surface layer of the predetermined part of the living body is measured and acquired.

  Next, in step S106, it is determined whether the obtained light intensity image (data) has reached a predetermined number, preferably at least 16, for example, 25, and if it has not reached the predetermined number ( NO), returning to step S102, the polarized light irradiation unit 24 changes the polarization state and changes the irradiation light irradiation step S102 for irradiating a predetermined part of the living body and the next step S104 according to the polarization state of the irradiation light. The imaging step S104 in which the reflected light in the polarized state is imaged by the imaging unit 26 to acquire one light intensity image (data) is repeated until the predetermined number is reached. The process moves to step S108.

  Next, in step S108, the polarization conversion processing unit 14 performs polarization conversion processing on at least 16 light intensity images (data) acquired by the imaging unit 26. That is, in sub-step S110, the polarization conversion processing unit 14 16 Mueller images (data) are obtained by the Mueller image conversion process of the Mueller image conversion unit 28, and further, in the sub-step S112, the exposed tissue that is displayed on the surface layer of the predetermined part by the polarization variable separation processing unit 30 Is a polarization variable (data) with clear physical meaning (phase difference, phase difference azimuth, depolarization degree, polarization degree of light, dichroism, dichroic azimuth, optical rotation, A polarization characteristic image (data) based on a predetermined polarization variable (polarization characteristic) is acquired by separating and converting into light polarization direction and P / S polarization.

  Subsequently, in step S114, the display tissue of the polarization characteristic image (data) obtained by the polarization conversion processing unit 14 can be distinguished from the surface tissue by the display conversion processing unit 16. In order to visualize and display, the image is converted into a display image (data) colored in a pseudo color.

  In step S108, after obtaining the polarization characteristic image (data) by the polarization variable separation processing unit 30, the post-separation image forming unit 84 performs enhancement processing on the region of interest in the polarization characteristic image, and enhances it. A processed polarization characteristic image (data) is formed, and in step S114, the display conversion processing unit 16 performs display conversion processing on the enhanced polarization characteristic image (data) formed by the post-separation image forming unit 84. It may be converted into a display image (data) colored in a pseudo color.

  In step S114, the display conversion processing unit 16 obtains the display image (data), and then the image composition unit 22 captures the image in advance based on the display image (data) obtained by the display conversion processing unit 16. Display of a combination of two or more of the depolarization degree image, the polarization degree image of the light, the phase difference image, the phase difference azimuth image, the absorption azimuth image, and the optical rotation image, for example, two or more It is also possible to generate composite image information for displaying the polarization characteristic images superimposed or side by side, and display the composite image based on the composite image information (data) on the display unit 18.

Next, in step S116, based on the display image (data) obtained by the display conversion processing unit 16, the exposed tissue that appears on the surface layer of the predetermined part is visualized and displayed so as to be distinguishable from the surface tissue. Therefore, a display image colored in a pseudo color as a display color that can be easily determined by a doctor is displayed on the monitor screen of the display unit 18.
Thus, the polarization image display method according to the present invention is completed.

  The present inventors use the polarized image measurement display system 10 to perform the polarization image display method described above, measure the surface of the cancerous part of the stomach with the polarization imaging system 12, and display the display unit 18. As shown on the monitor screen, it was confirmed on the monitor screen that there was a clear difference that was not seen in the normal part of the stomach.

  In the polarized image display method according to the present invention, in another step, the normal color imaging system 20 irradiates a predetermined part with illumination light for normal observation and images the reflected light to obtain normal color light intensity image information. (Data) is acquired, and in the next step, the image combining unit 22 displays the display polarization characteristic image information (data) obtained by the display conversion processing unit 16 and the normal color image pickup system 20 obtained by the normal color imaging system 20. Based on the color light intensity image information (data), a composite image information (data) for displaying the display polarization characteristic image and the normal color light intensity image in an overlapped manner or side by side is generated, and in the next step, A composite image based on the composite image information (data) may be displayed on the display unit 18.

In the present invention, the polarization imaging system (light source, polarization camera) 12 shown in FIG. 1 measures four polarization-modulated light intensity images of a living body, converts them into phase difference images and phase difference azimuth images, and provides a doctor. Can be displayed on the monitor screen of the display unit 18 as a display color that can be easily determined.
When the surface of the cancerous part of the stomach was measured with this optical system, it was confirmed that there was a clear phase difference that was not found in the normal part of the stomach.

  Furthermore, in the present invention, the polarization imaging system 12 of the polarization image measurement and display system 10 shown in FIG. 1 measures the light intensity images of the surface layer of a predetermined part of the living body subjected to polarization modulation of four and three, and in each case The polarization conversion processing unit 14 performs polarization conversion processing, converts it into a phase difference image and a phase difference azimuth image, converts it into display image information colored in a pseudo color in the display conversion processing unit 16, and the doctor determines It is displayed on the monitor screen of the display unit 18 as an easy display color.

  In addition, when the present inventors measured the surface of the cancerous part of the stomach with the polarization imaging system 12 using this optical image measurement display system 10, in the case of four light intensity images, In the case of the light intensity image, it was confirmed on the monitor screen that there was a clear difference that was not seen in the normal part of the stomach.

  Next, a first embodiment of the endoscope diagnosis apparatus of the present invention will be described.

  FIG. 12 is an external view of the first embodiment showing the configuration of the endoscope diagnosis apparatus according to the present invention, and FIG. 13 is a block diagram showing its internal configuration. As shown in these drawings, the endoscope diagnosis apparatus 101 has a light source device 105 that generates a plurality of types of illumination light, and guides the illumination light emitted from the light source device 105 to irradiate an observation area of the subject. An endoscope apparatus 103 that captures the reflected light and outputs an image signal; and a processor that performs image processing on the image captured by the endoscope apparatus 103 and outputs an endoscopic image corresponding to the illumination light. The apparatus 107 includes a display device 108 that displays an endoscopic image obtained by image processing by the processor device 107, and an input device 110 that receives an input operation.

  Here, the endoscope diagnostic apparatus 101 irradiates a subject with white light, irradiates the subject with white light, images the reflected light and displays (observes) the white light image, and irradiates the subject with polarized light. , A polarized light observation mode that images the reflected light and displays a polarization characteristic image, and a self-emitted light emitted from the drug irradiated with the excitation light by irradiating the fluorescent light excitation light to the subject injected with the fluorescent drug A fluorescence observation mode in which fluorescence is imaged and a fluorescence image is displayed. Each observation mode is appropriately switched based on an instruction input from the changeover switch 158 of the endoscope apparatus 103 or the input device 110.

  The light source device 105 includes a white light source 111, a narrow band filter 115, a polarizing filter 117, an optical system such as a lens 119, a coupler 120 that is a duplexer, and a rotation control unit 113.

  The white light source 111 is always turned on to emit white light when the light source device 105 is powered on. The white light source 111 is not limited as long as it emits white light. For example, a white light such as a xenon lamp, a fluorescent lamp, or a mercury lamp is used.

  The narrow band filter 115 is a band pass filter that transmits only a narrow band light of a predetermined narrow band from the white light emitted from the white light source 111. The narrow band filter 115 has a disk shape, a light passage part that allows white light to pass through as it is, a first light transmission part that allows passage of only the first narrow band light of 750 to 790 nm, and a second narrow band of 405 ± 10 nm. A second light transmitting portion that transmits only light. The narrow band filter 115 is disposed perpendicular to the optical path between the white light source 111 and the lens 119 and is appropriately rotated by a motor (not shown) under the control of the rotation control unit 113. In the white light observation mode, the light passage portion is inserted into the optical path, and the white light passes as it is. In the fluorescence observation mode, the first light transmission part is inserted into the optical path and only the first narrowband light is transmitted. In the polarized light observation mode, the second light transmission part is inserted into the optical path. Thus, only the second narrowband light is transmitted.

  In this embodiment, ICG (Indocyanine Green) is used as a fluorescent agent when capturing a fluorescent image. The first narrowband light is excitation light for fluorescence observation for causing fluorescence from ICG introduced into the body of the subject, and its wavelength and band should be determined as appropriate according to the type of fluorescent agent to be used. Kimono. The second narrowband light is irradiation light for generating polarized light for obtaining a polarization characteristic image. The wavelength and band of the second narrowband light are not limited at all, and the above is an example.

  The polarizing filter 117 changes the illumination light (second narrowband light) incident through the narrowband filter 115 according to the rotation angle, for example, one for each frame, into a total of four types of polarization states. Sequentially converted into different polarized light. The polarizing filter 117 has a disk shape, and includes a light passing portion that allows the illumination light to pass as it is, and a light polarization portion that converts the illumination light into polarized light. The polarizing filter 117 is arranged perpendicular to the optical path and is appropriately rotated by a motor (not shown) under the control of the rotation control unit 113. In the white light observation mode and the fluorescence observation mode, the light passage part is inserted into the optical path, and the illumination light (white light and first narrowband light) passes through as it is. In the polarized light observation mode, the light polarization unit is inserted into the optical path, and the rotation is controlled by the rotation control unit 113. The illumination light (second narrowband light) is, for example, one frame according to the rotation angle. Each is converted to polarized light having a total of four different polarization states, one for each.

  The rotation control unit 113 controls the rotation of the narrowband filter 115 and the polarization filter 117 as described above under the control of the control unit 152 of the processor device 107. The white light emitted from the white light source 111 is collected by the lens 119 through the narrow band filter 115 and the polarization filter 117 under the control of the rotation control unit 113 and is incident on the coupler 120. In the white light observation mode, the light passage part of the narrow band filter 115 and the light passage part of the polarization filter 117 are inserted into the optical path, and white light is incident on the coupler 120. In the fluorescence observation mode, the first light transmission part of the narrow band filter 115 and the light passage part of the polarization filter 117 are inserted into the optical path, and the first narrow band light is incident on the coupler 120. In the polarized light observation mode, the second light transmission part of the narrowband filter 115 and the light polarization part of the polarization filter 117 are inserted into the optical path, and the polarized light of the second narrowband light is incident on the coupler 120.

  The coupler 120 distributes the illumination light collected by the lens 119 to two identical illumination lights. The two distributed illumination lights are incident on the incident ends of the two optical fibers 142A and 142B of the endoscope apparatus 103, respectively.

  Subsequently, the endoscope apparatus 103 images an illumination optical system that emits two systems (two lamps) of illumination light from the distal end of the endoscope insertion unit 122 that is inserted into the subject, and an image of the observation region 2. An electronic endoscope having a system (two eyes) imaging optical system. The endoscope apparatus 103 includes an endoscope insertion section 122, an operation section 124 that performs an operation for bending and observing the distal end of the endoscope insertion section 122, and the endoscope apparatus 103 as a light source device 105 and a processor. Connector portions 126A and 126B that are detachably connected to the device 107 are provided.

  The endoscope insertion portion 122 includes a flexible soft portion 128, a bending portion 130, and a distal end portion (hereinafter also referred to as an endoscope distal end portion) 132.

  The bending portion 130 is provided between the flexible portion 128 and the distal end portion 132 and is configured to be bent by a turning operation of an angle knob 134 disposed in the operation portion 124. The bending portion 130 can be bent in an arbitrary direction and an arbitrary angle according to a part of a subject in which the endoscope apparatus 103 is used, and the irradiation ports 136A and 136B and the imaging element of the endoscope distal end portion 132. The observation directions of 138A and 138B can be directed to a desired observation site.

  As shown in FIG. 13, the endoscope distal end portion 132 has two systems of irradiation ports 136A and 136B for irradiating light to the observation area, and two systems for imaging reflected light or fluorescence from the observation area. Windows 140A and 140B are arranged.

  Optical fibers 142A and 142B as light guides are housed in the back of the irradiation ports 136A and 136B, respectively. The optical fibers 142A and 142B are multimode fibers. For example, a thin fiber cable having a core diameter of 105 μm, a clad diameter of 125 μm, and a diameter including a protective layer as an outer shell of φ0.3 to 0.5 mm can be used. . The optical fibers 142A and 142B are laid from the light source device 105 to the endoscope distal end portion 132 via the connector portion 126A, emitted from the light source device 105, and guided to the endoscope distal end portion 132 by the optical fibers 142A and 142B. The illuminated illumination light is irradiated to the observation region of the subject from the irradiation ports 136A and 136B.

  Here, in the endoscope distal end portion 132, the irradiation ports 136A and 136B are arranged on both sides of the observation window 140A as shown in FIG. In this case, the optical fibers 142A and 142B are arranged on both sides of the observation window 140A so that the line connecting them crosses the observation window 140A. Therefore, by irradiating the same illumination light (white light, excitation light for fluorescence observation, polarized light) from the optical fibers 142A and 142B arranged on both sides, it is possible to prevent illumination unevenness of the illumination light. it can.

  An optical system such as an objective lens unit 144A for capturing image light of the observation region of the subject is attached to the back of the observation window 140A, and further, image information of the observation region is stored behind the objective lens unit 144A. An imaging device 138A such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor to be acquired is attached. On the light receiving surface of the image sensor 138A, an excitation light cut filter 146A that cuts (shields) light of a wavelength in a predetermined band including the first narrowband light (excitation light for fluorescence observation) among the received light is mounted. Has been. Similarly, an optical system such as an objective lens unit 144B is attached to the back of the observation window 140B, and an image sensor 138B is attached to the back of the objective lens unit 144B. On the light receiving surface of the image sensor 138B, a patterning element 146B for simultaneously converting the light received by the light receiving surface into polarized light of four different polarization states is mounted. The image sensor 138B is for observation of polarized light, and the image sensor 138A is for other observations (for white light observation and fluorescence observation).

  The patterning element 146B is not limited as long as it performs the same function. For example, as shown in FIG. 15, in addition to the patterning element 146B shown in FIG. ) Angle) A rectangular polarizer of 0 °, a rectangular polarizer with a lower right polarization angle of 90 °, a rectangular polarizer with an upper right polarization angle of 45 °, and a rectangular shape with a lower left polarization angle of 135 ° Can be used that are arranged in a 2 × 2 array to form one pixel of a light intensity polarization image. Moreover, you may use the patterning element converted into the polarized light of three types of different polarization states.

  Here, in the white light observation mode, white light emitted from the light source device 105 is guided by the optical fibers 142A and 142B, and irradiated from the endoscope distal end portion 132 toward the observation region of the subject. Then, the reflected light from the observation region of the subject irradiated with white light is collected by the objective lens unit 144A, and the light of the predetermined band including the excitation light is cut by the excitation light cut filter 146A. A white light image is captured by the image sensor 138A.

  Similarly, in the fluorescence observation mode, excitation light emitted from the light source device 105 is guided by the optical fibers 142A and 142B, and is directed from the endoscope distal end portion 132 toward the observation region of the subject injected with ICG. Irradiated. Then, the autofluorescence emitted from the fluorescent agent in the observation region of the subject irradiated with the excitation light is collected by the objective lens unit 144A, and the light of a predetermined band including the excitation light is cut by the excitation light cut filter 146A. After that, a fluorescence image is captured by the image sensor 138A.

  In the polarized light observation mode, four types of polarized light emitted from the light source device 105 and having different polarization states are sequentially guided by the optical fibers 142A and 142B, and directed from the endoscope distal end 132 toward the observation region of the subject. Is irradiated. Then, every time the polarized light with different polarization state is irradiated, the reflected light from the observation region of the object irradiated with the polarized light is condensed by the objective lens unit 144B, and four kinds of different polarized light are collected by the patterning element 146B. After the polarized light in the state is obtained, a light intensity polarization image is captured by the image sensor 138B. That is, light intensity polarization images of polarized light having 16 different polarization states in total are taken.

  An imaging signal (analog signal) of each image (white light image, fluorescent image) output from the imaging element 138A is input to the A / D converter 150A through the scope cable 148A. Further, an image signal (analog signal) of an image (light intensity polarization image) output from the image sensor 138B is input to the A / D converter 150B through the scope cable 148B. The A / D converters 150A and 150B convert imaging signals (analog signals) from the imaging elements 138A and 138B into image signals (digital signals), respectively. The converted image signal is input to the image processing unit 154 of the processor device 107 via the connector unit 126B.

  Although not shown in the figure, various channels such as a forceps channel for inserting a tissue collection treatment instrument and the like, a channel for air supply / water supply, and the like are provided inside the operation unit 124 and the endoscope insertion unit 122. Is provided.

  Subsequently, the processor device 107 includes a control unit 152, an image processing unit 154, and a storage unit 156. The display unit 108 and the input device 110 are connected to the control unit 152. The processor device 107 controls the rotation control unit 113 of the light source device 105 based on an instruction input from the changeover switch 158 or the input device 110 of the endoscope device 103 and also receives an image signal input from the endoscope device 103. Are processed, a display image is generated and output to the display device 108.

  The control unit 152 is based on an instruction from the changeover switch 158 of the endoscope device 103 or the input device 110, for example, an instruction such as an observation mode or an image display mode, and the rotation control unit 113 of the light source device 105. To control the operation. The image display mode displays a combination of two or more images (white light image, fluorescent image, polarization characteristic image) that display either a white light image, a fluorescent image, or a polarization characteristic image with a predetermined polarization characteristic. This is an instruction for designating the display form of an image, such as displaying two or more images in a superimposed manner, displaying them side-by-side, or displaying them after arithmetic processing.

  Based on the observation mode, the image processing unit 154 controls the image signal input from the endoscope apparatus 103 according to the image type of the white light image, the fluorescence image, and the polarization characteristic image based on the observation mode. Predetermined image processing. The image signal processed by the image processing unit 154 is sent to the control unit 152, converted into an endoscopic observation image together with various information by the control unit 152, and displayed on the display device 108. If necessary, a memory or storage The data is stored in a storage unit 156 that is a device.

  The image processing unit 154 includes a white light image processing unit 154A, a fluorescence image processing unit 154B, a polarization image processing unit 154D, and an image composition unit 154E. In the white light observation mode and the fluorescence observation mode, the image signal converted into a digital signal by the A / D converter 150A is supplied to the white light image processing unit 154A and the fluorescence image processing unit 154B. In the polarized light observation mode, the image signal converted into a digital signal by the A / D converter 150B is supplied to the polarization image processing unit 154D.

  In the white light observation mode, the white light image processing unit 154A performs predetermined image processing suitable for the white light image on the image signal of the white light image, and outputs a white light image signal (white light image). (Generate). Examples of image processing include white balance correction, gamma correction, contour enhancement, color correction, and the like. The white light image processing unit 154A corresponds to an image processing unit included in the normal color imaging system shown in FIG.

  In the fluorescence observation mode, the fluorescence image processing unit 154B performs predetermined image processing suitable for the fluorescence image on the image signal of the fluorescence image, and outputs a fluorescence image signal (fluorescence image). In addition to the above, the image processing includes high sensitivity processing such as digital gain, frame addition, and digital binning. Digital gain is a process of amplifying digital image data at a predetermined amplification factor. The frame addition is a process of adding image data of a plurality of continuous frames imaged by the image sensor 138A. Digital binning is a process of increasing the sensitivity of the image sensor 138A by increasing the light receiving area by combining a plurality of image capture pixels (pixels) adjacent to the image sensor 138A.

  In the polarized light observation mode, the polarization image processing unit 154D performs predetermined image processing suitable for the light intensity polarization image on the image signal of the light intensity polarization image, and generates a polarization image signal (polarization light) having a predetermined polarization characteristic. (Characteristic image) is output. In addition to the above, the image processing includes polarization conversion processing and display conversion processing. Further, the polarization image processing unit 154D generates a polarization characteristic image having a predetermined polarization characteristic according to the image display mode. The polarization image processing unit 154D corresponds to the polarization conversion processing unit 14 and the display conversion processing unit 16 illustrated in FIG.

  The white light image signal, the fluorescence image signal, and the polarization image signal are stored in the storage unit 156 in units of, for example, one image (one frame).

  The image composition unit 154E combines two or more images from the white light image, the fluorescence image, and the polarization characteristic image based on the white light image signal, the fluorescence image signal, and the polarization image signal stored in the storage device according to the image display mode. A composite image is generated and a composite image signal is output. The image composition unit 154E generates, as a composite image, a composite image in which two or more images (a white light image, a fluorescence image, and a polarization characteristic image) are overlaid, arranged, or processed. The image composition unit 154E corresponds to the image composition unit 22 shown in FIG.

  From the image processing unit 154, a white light image signal, a fluorescence image signal, a polarization image signal, and a composite image signal are output and input to the control unit 152. Based on the white light image signal, the fluorescence image signal, the polarization image signal, and the composite image signal, the control unit 152 causes the display device 108 to display one of the white light image, the fluorescence image, the polarization characteristic image, and the composite image. Is displayed.

Next, the operation of the endoscope diagnosis apparatus 101 will be described.
First, the operation in the white light observation mode will be described.

  Instructions such as an observation mode and an image display mode are input to the control unit 152 of the processor device 107 from the changeover switch 158 of the endoscope device 103 or the input device 110. Then, the control unit 152 controls the image processing unit 154 and the rotation control unit 113 of the light source device 105 according to the observation mode. In the light source device 105, the rotation control unit 113 controls the rotation of the narrow band filter 115 and the polarization filter 117 according to the observation mode.

  In the white light observation mode, in the light source device 105, the light passage part of the narrow band filter 115 and the light passage part of the polarization filter 117 are inserted in the optical path, and the white light emitted from the white light source 111 is directly applied to the lens 119. After being collected, the coupler 120 distributes the illumination light into two systems (white light).

  In the endoscope apparatus 103, two systems of white light emitted from the light source apparatus 105 are guided by the respective optical fibers 142A and 142B, and are irradiated onto the observation region of the subject from the irradiation ports 136A and 136B. Then, the reflected light (white light) from the observation region is collected by the objective lens unit 144A, and the light of a predetermined band including the excitation light is cut by the excitation light cut filter 146A, and then the image sensor 138A performs photoelectric conversion. It is converted and an imaging signal (analog signal) of a white light image is output.

  The imaging signal of the white light image is converted into an image signal (digital signal) by the A / D converter 150A, and predetermined image processing suitable for the white light image is performed by the white light image processing unit 154A according to the observation mode. A white light image signal is output.

  According to the image display mode, a white light image signal is output to the display device 108 and a white light image is displayed on the display device 108.

  When the observation is completed, the endoscope insertion portion 122 is taken out from the body cavity of the subject, and the power of each device is turned off.

  Next, the operation in the fluorescence observation mode will be described.

  In the fluorescence observation mode, ICG is intravenously injected into the subject as a fluorescent agent before the observation is started.

  In the light source device 105, the first light transmission part of the narrow band filter 115 and the light passage part of the polarization filter 117 are inserted into the optical path, and the first narrow band light of the white light emitted from the white light source 111 is a lens. After being condensed at 119, it is distributed by the coupler 120 into two systems of illumination light (excitation light for fluorescence observation).

  In the endoscope apparatus 103, two systems of excitation light emitted from the light source apparatus 105 are similarly applied to the observation area of the subject. Then, the fluorescence emitted from the ICG in the observation region of the subject irradiated with the excitation light is collected by the objective lens unit 144A, and the light of a predetermined band including the excitation light is cut by the excitation light cut filter 146A. Thereafter, photoelectric conversion is performed by the image sensor 138A, and an imaging signal (analog signal) of a fluorescent image is output.

  The imaging signal of the fluorescent image is converted into an image signal (digital signal) by the A / D converter 150A, and predetermined image processing suitable for the fluorescent image is performed by the fluorescent image processing unit 154B according to the observation mode. Is output.

  According to the image display mode, the fluorescence image signal is output to the display device 108 and the fluorescence image is displayed on the display device 108. In the fluorescence observation mode, it is possible to obtain a fluorescence image in which blood vessels and lymph vessels of a predetermined depth are emphasized from the surface of the observation region according to the wavelength of the excitation light. When the wavelength of the excitation light is near infrared light of 750 to 790 nm as in this embodiment, a deep blood vessel of 2 to 3 mm can be observed from the surface of the observation region. Generally, as the wavelength of the excitation light becomes shorter, the middle layer to the surface layer blood vessel or the like of the observation region can be observed.

  When the observation is completed, the endoscope insertion portion 122 is taken out from the body cavity of the subject, and the power of each device is turned off.

  Next, the operation in the polarized light observation mode will be described.

  In the polarized light observation mode, in the light source device 105, the first light transmission part of the narrow band filter 115 and the light polarization part of the polarization filter 117 are inserted in the optical path, and the white light emitted from the white light source 111 is out of the white light. The second narrowband light is converted into polarized light and collected by the lens 119, and then distributed to two systems of illumination light (polarized light) by the coupler 120.

  Here, as described above, in the polarized light observation mode, according to the rotation angle of the polarization filter 117, illumination light (second narrowband light) is, for example, one per frame, for a total of four. Sequentially converted into polarized light of different polarization states.

  In the endoscope apparatus 103, two systems of polarized light emitted from the light source apparatus 105 are similarly applied to the observation area of the subject. Then, the reflected light (polarized light) from the observation region is condensed by the objective lens unit 144B, converted into polarized light of four different polarization states by the patterning element 146B, and then photoelectrically converted by the imaging element 138B. An imaging signal (analog signal) of a light intensity polarization image is output.

  As described above, in the polarized light observation mode, a total of four types of polarized light having different polarization states are sequentially irradiated to the observation region of the subject, one for each frame, and the polarized light is irradiated. Each time, the patterning element 146B simultaneously converts the light into four types of polarized light having different polarization states. That is, in the case of this embodiment, the imaging device 138B sequentially outputs imaging signals of four types of irradiation × four types of conversion = 16 types of light intensity polarization images every four frames.

  The imaging signals of 16 types of light intensity polarization images are converted into image signals (digital signals) by the A / D converter 150B, and predetermined image processing suitable for the light intensity polarization images is performed by the polarization image processing unit 154D according to the observation mode. And a polarized image signal is output. In the polarized light observation mode, polarization conversion processing and display conversion processing are performed on image signals of 16 types of light intensity polarization images, and polarization image signals of polarization characteristic images having predetermined polarization characteristics are generated according to the image display mode. Is done.

  According to the image display mode, a polarization image signal is output to the display device 108 and a predetermined polarization characteristic image is displayed on the display device 108. In the polarized light observation mode, a polarization characteristic image in which collagen fibers and nerve fibers are emphasized can be obtained.

  When the observation is completed, the endoscope insertion portion 122 is taken out from the body cavity of the subject, and the power of each device is turned off.

  Subsequently, the composite image will be described.

  As described above, the endoscope diagnostic apparatus 101 captures a white light image, a fluorescence image, and a polarization characteristic image according to the observation mode, and combines the two or more images according to the image display mode ( (Overlapping display, parallel display, calculation processing display) can be displayed. The image composition unit 154E captures two or more images of a white light image, a fluorescence image, and a polarization characteristic image of the same observation region (observation site), and then, according to the image display mode, the white light image, the fluorescence image Two or more images of the image and the polarization characteristic image are overlapped, arranged side by side, or a composite image that has been subjected to arithmetic processing is generated.

  FIG. 16 is a conceptual diagram illustrating an example when a white light image, a polarization characteristic image, and a fluorescence image are arranged in a horizontal row as a composite image. As shown in the figure, even in a white light image, even if it is difficult to identify a lesioned part or the like, as a composite image, for example, by displaying a fluorescence image and a polarization characteristic image side by side, blood vessels and lymph vessels are displayed in the fluorescence image. It can be highlighted and collagen fibers and nerve fibers can be highlighted in the polarization characteristic image. In this way, by displaying the fluorescence image and the polarization characteristic image side by side, blood vessels, lymph vessels, collagen fibers, nerve fibers, etc. can be observed simultaneously with a single composite image, thereby improving the diagnostic accuracy by the doctor. be able to.

  Note that it is not essential to display the white light image side by side next to the fluorescent image and the polarization characteristic image. However, by displaying the white light images side by side, there is an advantage that it is easy to visually recognize each part of the observation region of the subject in the fluorescence image and the polarization characteristic image. As described above, the polarization characteristic image (polarization characteristic image information) includes various polarizations including the degree of depolarization, the degree of polarization of light, the phase difference, the direction of phase difference, the direction of absorption, and the polarization characteristic of optical rotation. A characteristic image can be exemplified.

  Next, a second embodiment of the endoscope diagnosis apparatus of the present invention will be described.

  FIG. 17 is an external view of the second embodiment showing the configuration of the endoscope diagnosis apparatus according to the present invention, and FIG. 18 is a block diagram showing the internal configuration thereof. Since the difference between the endoscope diagnosis apparatus 101 of the first embodiment and the endoscope diagnosis apparatus 100 of the second embodiment is only a part of the light source device 104, the endoscope device 102, and the processor device 106, the following In the description, the same reference numerals are given to the common components between the two, and the detailed description thereof will be omitted.

  That is, as shown in FIGS. 17 and 18, the endoscope diagnosis apparatus 100 includes a light source device 104, an endoscope device 102, a processor device 106, a display device 108, and an input device 110. Yes.

  Here, in addition to the white light observation mode, the polarized light observation mode, and the fluorescence observation mode, the endoscope diagnosis apparatus 100 further irradiates the subject with narrowband light and images the reflected light to narrowband light. It has a narrow-band light observation mode for displaying (observing) an image.

  The light source device 104 includes a light source control unit 112, a plurality of laser light sources LD1 to LD5 that emit laser beams having different central emission wavelengths, an optical distributor 114, a polarization modulator 116, a combiner 118, and a coupler 120. It is configured.

  In the present embodiment, the laser light sources LD1 to LD5 emit narrowband light of a predetermined narrowband having center emission wavelengths of 405 nm, 445 nm, 530 nm, 665 nm, and 785 nm, respectively. LD1 is a light source for observing narrow band light that emits violet laser light and light source for observing polarized light, and LD3 is a light source for observing narrow band light that is suitable for observing thick blood vessels in a deep tissue layer. The LD 2 is a light source for white light observation for emitting white light from a phosphor 160 described later by irradiating blue laser light as excitation light. The LD 4 is a light source for performing photodynamic therapy (PDT) in which a surface of a living tissue is irradiated with a laser beam having a specific wavelength with a relatively strong output to treat a tumor such as cancer. The LD 5 is a light source that emits excitation light for fluorescence observation of ICG injected into a blood vessel.

  In the present embodiment, the laser light source LD1 is commonly used as a light source for narrowband light observation using illumination light (narrowband light) of the same wavelength and a light source for polarized light observation. Polarized light is not narrowband light, and for example, a light source that emits broadband light such as white light can be used. However, use of a light source that emits narrowband light is more suitable for conversion to polarized light and is suitable. (RMA AZZAM and NM BASHARA, "ELLIPSOMETRY AND POLARIZED LIGHT", North-Holland Pub. Co., April 1, 1987, p. 398). Therefore, by sharing the light source for observing narrow band light and the light source for observing polarized light, one light source can be used as two types of light sources for special light observation, and the number of necessary light sources can be reduced. And has the advantage that it can be easily converted into polarized light.

  The LD 1 is also used as illumination light for performing photodynamic diagnosis (PDD). PDD has a tumor affinity in advance, and after a photosensitive substance that is sensitive to specific excitation light is administered to a living body (subject), the surface of the living tissue is a relatively weak output of laser light serving as excitation light. Is a method for observing fluorescence from a site where the concentration of a photosensitive substance is high in the lesion of a tumor such as cancer. PDT treatment is performed on the lesion identified by PDD.

  The laser light sources LD1 to LD5 are individually dimmed and controlled by the light source control unit 112 controlled by the control unit 152 of the processor device 106, and the light emission timings and the light quantity ratios of the laser light sources LD1 to LD5 are changed. It is free.

  As the laser light sources LD1 to LD5, a broad area type InGaN laser diode can be used, and an InGaNAs laser diode, a GaNAs laser diode, or the like can also be used. In addition, a light-emitting body such as a light-emitting diode may be used as the light source. The LD 2 may be a xenon lamp that emits white light, a white lamp such as a fluorescent lamp or a mercury lamp, or the like. In addition, when a white lamp or the like that emits white light is used as a light source for white light observation, the phosphor 160 described later is unnecessary.

  Moreover, the center light emission wavelength of laser light source LD1-LD5 is not limited to the said example, It can change suitably as needed.

  The laser light emitted from the laser light source LD1 is input to the light distributor 114. The light distributor 114 distributes the laser light emitted from the laser light source LD1 into two laser lights having the same wavelength. The light distributor 114 can be configured by, for example, a beam splitter (half mirror) that distributes laser light into transmitted light and reflected light, a reflective mirror that reflects reflected light from the beam splitter, and the like.

  The polarization modulator 116 sequentially converts one laser light output from the light distributor 114 into a plurality of polarized lights having different polarization states for observing the polarized light, in this embodiment, four types of polarized lights having different polarization states. Modulate and output. The specific configuration of the polarization modulator 116 is not limited at all. For example, a configuration similar to that of the first polarizing filter unit 40a shown in FIG. 2 or the first polarizing filter unit 46a shown in FIG. 3 is used. be able to.

  The other laser light (LD1) output from the light distributor 114, the polarized light output from the polarization modulator 116, and the laser light emitted from each of the laser light sources LD2 to LD5 are a condensing lens (not shown). Are respectively input to the corresponding optical fibers and transmitted to the connector unit 126A via the combiner 118 which is a multiplexer and the coupler 120 which is a duplexer. Not limited to this, without using the combiner 118 and the coupler 120, laser light output from the optical distributor 114, polarized light output from the polarization modulator 116, and laser light from each of the light sources LD2 to LD5. May be sent directly to the connector portion 126A.

  The illumination light to be emitted can be switched at an arbitrary timing or programmed by the operation of the changeover switch 158 of the endoscope apparatus 102, the operation from the input device 110, or the light source device 104 shown in FIG. Can be done at the timing.

  Subsequently, the endoscope apparatus 102 includes an illumination optical system that emits four systems (four lights) of illumination light from the distal end of the endoscope insertion unit 122, and two systems (two eyes) that image an observation region. An electronic endoscope having an optical system. The difference between the endoscope apparatus 103 of the first embodiment and the endoscope apparatus 102 of the second embodiment is only that the illumination optical system is four systems (four lights). Only the differences will be described.

  That is, the endoscope apparatus 102 includes an endoscope insertion part 122, an operation part 124, and connector parts 126A and 126B. The endoscope insertion portion 122 includes a flexible portion 128, a bending portion 130, and a distal end portion (endoscope distal end portion) 132. The endoscope distal end portion 132 is provided with two irradiation ports 136A and 136B and two observation windows 140A and 140B.

  Two systems of optical fibers 142A and 142C are stored in the back of the irradiation port 136A, and two systems of optical fibers 142B and 142D are stored in the back of the irradiation port 136B. The optical fibers 142A to 142D are laid from the light source device 104 to the endoscope distal end portion 132 via the connector portion 126A. The four systems of illumination light emitted from the light source device 104 correspond to the corresponding optical fibers 142A to 142A, respectively. 142D leads to the irradiation ports 136A and 136B.

  Here, in the endoscope distal end portion 132, the irradiation ports 136A and 136B are arranged on both sides of the observation window 140A as shown in FIG. In this case, the optical fibers 142A and 142D are arranged on both sides of the observation window 140A so that the line connecting them crosses the observation window 140A, and the optical fibers 142B and 142C are the optical fibers 142A and 142D. Are arranged on both sides of the observation window 140A so that the lines connecting the optical fibers 142B and 142C intersect on the observation window 140A. Then, the same illumination light (white light) is emitted from the optical fibers 142A and 142D arranged on both sides, and the same illumination light (excitation light for fluorescence observation, narrowband light, polarized light) is also emitted from the optical fibers 142B and 142C. ) Can prevent the illumination unevenness of the illumination light from occurring.

  The illumination light guided from the light source device 104 by the optical fibers 142A to 142D is irradiated from the endoscope distal end portion 132 toward the observation region of the subject. Then, the state of the observation region irradiated with the illumination light is imaged on the light receiving surfaces of the image sensors 138A and 138B by the objective lens units 144A and 144B, and photoelectrically converted by the image sensors 138A and 138B to be imaged. From the imaging elements 138A and 138B, imaging signals (analog signals) of the observed region of the imaged subject are output.

  Here, in the white light observation mode, the excitation light of the white light emitted from the light source device 104 is guided by the optical fibers 142A and 142D to irradiate the phosphor 160, and the white light emitted from the phosphor 160 is irradiated. The observation area of the subject is irradiated from the mouths 136A and 136B. Then, the reflected light from the observation region of the subject irradiated with white light is condensed by the objective lens unit 144A, and the light of a predetermined band including the excitation light for fluorescence observation is cut by the excitation light cut filter 146A. After that, a white light image is captured by the image sensor 138A.

  In the fluorescence observation mode and the polarized light observation mode, the same as in the first embodiment, except that the excitation light and polarized light for fluorescence observation emitted from the light source device 104 are guided by the optical fibers 142B and 142C. It is.

  In the narrow-band light observation mode, narrow-band light (LD1, LD3) emitted from the light source device 104 is guided by the optical fibers 142B and 142C, and irradiated from the endoscope distal end 132 toward the observation region of the subject. Is done. Then, the reflected light from the observation region of the subject irradiated with the narrow band light is collected by the objective lens unit 144A, and the light of a predetermined band including the excitation light for fluorescence observation is emitted by the excitation light cut filter 146A. After being cut, a narrowband light image is captured by the image sensor 138A.

  An imaging signal (analog signal) of each image (white light image, fluorescent image, narrowband light image) output from the imaging device 138A and an imaging signal (light intensity polarization image) output from the imaging device 138B ( Analog signals) are input to A / D converters 150A and 150B through scope cables 148A and 148B, respectively, and converted into image signals (digital signals). The converted image signal is input to the image processing unit 154 of the processor device 106 via the connector unit 126B.

  Subsequently, the processor device 106 includes a control unit 152, an image processing unit 154, and a storage unit 156. The display unit 108 and the input device 110 are connected to the control unit 152. The processor device 106 controls the light source control unit 112 of the light source device 104 based on an instruction input from the changeover switch 158 or the input device 110 of the endoscope device 102, and an image signal input from the endoscope device 102. Are processed, a display image is generated and output to the display device 108.

  The control unit 152 is based on an instruction from the changeover switch 158 of the endoscope apparatus 102 or the input device 110, for example, an instruction such as an observation mode or an image display mode, and the light source control unit 112 of the light source device 104. To control the operation.

  Based on the observation mode, the image processing unit 154 is input from the endoscope apparatus 102 according to the image type such as a white light image, a fluorescence image, a narrowband light image, and a polarization characteristic image based on the observation mode. Predetermined image processing is performed on the image signal to be processed. The image signal processed by the image processing unit 154 is sent to the control unit 152, converted into an endoscopic observation image together with various information by the control unit 152, and displayed on the display device 108. If necessary, a memory or storage The data is stored in a storage unit 156 that is a device.

  The image processing unit 154 includes a white light image processing unit 154A, a fluorescence image processing unit 154B, a narrowband light image processing unit 154C, a polarization image processing unit 154D, and an image composition unit 154E. In the white light observation mode, the fluorescence observation mode, and the narrow band light observation mode, the image signal converted into the digital signal by the A / D converter 150A is converted into the white light image processing unit 154A, the fluorescence image processing unit 154B, It is supplied to the band light image processing unit 154C. In the polarized light observation mode, the image signal converted into a digital signal by the A / D converter 150B is supplied to the polarization image processing unit 154D.

  The white light image processing unit 154A, the fluorescence image processing unit 154B, and the polarization image processing unit 154D are the same as those in the first embodiment. In the narrow-band light observation mode, the narrow-band light image processing unit 154C performs predetermined image processing suitable for the narrow-band light image on the image signal of the narrow-band light image, and outputs the narrow-band light image signal To do.

  The white light image signal, the fluorescence image signal, the narrow band light image, and the polarization image signal are stored in the storage unit 156, for example, in units of one image (one frame).

  The image composition unit 154E, based on the white light image signal, the fluorescence image signal, the narrowband light image signal, and the polarization image signal stored in the storage unit 156, in accordance with the image display mode, the white light image, the fluorescence image, and the narrowband light image. A composite image is generated by combining two or more images from the polarization characteristic image, and a composite image signal is output. The image composition unit 154E generates, as a composite image, a composite image obtained by superimposing or arranging two or more images (a white light image, a fluorescence image, a narrowband light image, and a polarization characteristic image) or arranging them. The image composition unit 154E corresponds to the image composition unit 22 shown in FIG.

  From the image processing unit 154, a white light image signal, a fluorescence image signal, a narrowband light image, a polarization image signal, and a composite image signal are output and input to the control unit 152. The control unit 152 displays one of the white light image, the fluorescence image, the polarization characteristic image, and the composite image on the display device 108 according to the image display mode.

  Next, the configuration of the endoscope distal end portion 132 will be described in detail.

  The optical fiber 142A constitutes a part of the light projecting unit 162A, and the optical fiber 142B constitutes a part of the light projecting unit 162B. The optical fiber 142C constitutes a part of the light projecting unit 162C, and the optical fiber 142D constitutes a part of the light projecting unit 162D. A pair of the light projecting units 162A and 162C and a pair of the light projecting units 162B and 162D are arranged on both sides of the endoscope tip portion 132 with the image pickup device 138A and the objective lens unit 144A sandwiched therebetween (see FIG. 19). .

  Here, FIG. 20A illustrates a cross-sectional configuration diagram of the light projecting units 162A and 162D, and FIG. 20B illustrates a cross-sectional configuration diagram of the light projecting units 162B and 162C. The light projecting unit 162A and the light projecting unit 162D have the same configuration. The phosphor 160, a cylindrical sleeve member 164 that covers the outer periphery of the phosphor 160, and a protective glass (illumination window) that seals one end of the sleeve member 164 ) And a ferrule 168 inserted into the sleeve member 164 and holding the optical fiber 142A (142D) on the central axis. In addition, a flexible sleeve 170 covering the outer skin of the optical fiber 142A (142D) extended from the rear end side of the ferrule 168 is inserted between the sleeve member 164 and the optical fiber 142A (142D).

  On the other hand, the light projecting unit 162B and the light projecting unit 162C have the same configuration, and the light projecting units 162A and 162D are not provided with the phosphor 160, and are the light projecting units except that they are guided by the optical fibers 142B and 142C. The configuration is the same as 162A and 162D.

The phosphors 160 of the light projecting units 162A and 162D absorb a part of the blue laser light from the laser light source LD2 and emit a plurality of kinds of phosphor materials (for example, YAG-based phosphors or BAM ( And a phosphor such as BaMgAl ₁₀ O ₁₇ ). Thereby, the green to yellow excitation light emitted from the blue laser light as the excitation light and the blue laser light transmitted without being absorbed by the phosphor 160 are combined to generate white (pseudo white) illumination light.

  FIG. 21 is a graph showing an emission spectrum obtained by converting the wavelength of the blue laser light and the blue laser light from the laser light source LD2 by the phosphor 160, and the emission wavelength of each laser light from the laser light sources LD1, LD3, LD4, and LD5. is there. The blue laser light is represented by a bright line having a center wavelength of 445 nm, and the excitation light emitted from the phosphor 160 by the blue laser light has a spectral intensity distribution in which the emission intensity increases in a wavelength band of approximately 450 nm to 700 nm. The white light described above is formed by the profile of the excitation light and the blue laser light. If a semiconductor light-emitting element is used as an excitation light source as in this configuration example, high-intensity white light can be obtained with high luminous efficiency, the intensity of white light can be easily adjusted, and the color temperature and chromaticity of white light can be adjusted. Can be kept small.

  Here, the white light referred to in the present specification is not limited to the one that strictly includes all wavelength components of visible light, and examples thereof include R (red), G (green), and B (blue) that are reference colors. As long as it includes light in a specific wavelength band, for example, light including a wavelength component from green to red, light including a wavelength component from blue to green, and the like are broadly included.

  The phosphor 160 described above can prevent the occurrence of noise superposition, which is an obstacle to imaging, or flickering when performing moving image display, due to speckle caused by the coherence of laser light. In addition, the phosphor 160 considers the refractive index difference between the phosphor constituting the phosphor and the fixing / solidifying resin serving as a filler, and changes the particle size of the phosphor itself and the filler to light in the infrared region. In contrast, it is preferable to use a material that has low absorption and high scattering. This enhances the scattering effect without reducing the light intensity for red or infrared light, and reduces the optical loss.

Next, the operation of the endoscope diagnosis apparatus 100 will be described.
First, the operation in the white light observation mode will be described.

  An instruction such as an observation mode or an image display mode is input to the control unit 152 of the processor device 106 from the changeover switch 158 of the endoscope device 102 or the input device 110. Then, the control unit 152 controls the image processing unit 154 and the light source control unit 112 of the light source device 104 according to the observation mode. In the light source device 104, the light source control unit 112 performs dimming control of the laser light sources LD1 to LD5 individually according to the observation mode.

  In the white light observation mode, the light source device 104 emits white light excitation light (blue laser light) from the laser light source LD2, passes through the combiner 118, and is coupled to two systems of illumination light (white light excitation light). Distributed to.

  In the endoscope apparatus 102, the two systems of illumination light emitted from the light source device 105 are guided by the respective optical fibers 142A and 142D to irradiate the phosphor 160, and the white light emitted from the phosphor 160 is The region to be observed of the subject is irradiated from the irradiation ports 136A and 136B. The subsequent operation is the same as that in the first embodiment.

  Next, the operation in the fluorescence observation mode will be described.

  In the fluorescence observation mode, ICG is intravenously injected into the subject as a fluorescent agent before the observation is started.

  In the light source device 104, excitation light for fluorescence observation is emitted from the semiconductor laser LD5, and is distributed to two systems of illumination light (excitation light for fluorescence observation) by the coupler 120 via the combiner 118.

  In the endoscope apparatus 102, two systems of excitation light emitted from the light source device 104 are guided by the respective optical fibers 142B and 142C, and are irradiated onto the observation region of the subject from the irradiation ports 136A and 136B. The subsequent operation is the same as that in the first embodiment.

  Next, the operation in the narrow band light observation mode will be described.

  In the narrow-band light observation mode, the light source device 104 emits violet laser light from the semiconductor laser LD1, and is distributed to two systems of illumination light (narrow-band light) by the coupler 120 via the light distributor 114 and the combiner 118. The

  In the endoscope apparatus 102, two narrow-band light beams emitted from the light source device 104 are guided by the optical fibers 142B and 142C, and are irradiated onto the observation region of the subject from the irradiation ports 136A and 136B. . Then, the reflected light (narrow band light) from the observation region is collected by the objective lens unit 144A, and the light of a predetermined band including the excitation light for fluorescence observation is cut by the excitation light cut filter 146A. It is photoelectrically converted by the image sensor 138A, and an imaging signal (analog signal) of a narrowband light image is output.

  The imaging signal of the narrowband light image is converted into an image signal (digital signal) by the A / D converter 150A, and predetermined image processing suitable for the narrowband light image is performed by the narrowband light image processing unit 154E according to the observation mode. The narrow-band optical image signal is output.

  According to the image display mode, a narrowband light image signal is output to the display device 108 and a narrowband light image is displayed on the display device 108.

  When the observation is completed, the endoscope insertion portion 122 is taken out from the body cavity of the subject, and the power of each device is turned off.

  Next, the operation in the polarized light observation mode will be described.

  In the polarized light observation mode, the light source device 104 emits a violet laser beam from the semiconductor laser LD1, passes through the light distributor 114, and is sequentially modulated by the polarization modulator 116 into four types of polarized light having different polarization states. Through the combiner 118, the coupler 120 distributes the illumination light (polarized light) into two systems.

  In the endoscope apparatus 102, two systems of polarized light emitted from the light source device 104 are guided by the optical fibers 142B and 142C, and are irradiated onto the observation region of the subject from the irradiation ports 136A and 136B. The subsequent operation is the same as that in the first embodiment.

  Subsequently, the composite image will be described.

  The endoscope diagnosis apparatus 100 captures a white light image, a fluorescence image, a narrowband light image, and a polarization characteristic image according to the observation mode, and combines two or more images (superposition) according to the image display mode. Display, parallel display, arithmetic processing display). The image composition unit 154E captures two or more of the white light image, the fluorescence image, the narrow band light image, and the polarization characteristic image, and then, according to the image display mode, the white light image, the fluorescence image, and the narrow band light image. In addition, two or more of the polarization characteristic images are overlapped, arranged side by side, or a composite image that has undergone arithmetic processing is generated.

  In the endoscopic diagnosis apparatus 100 of the second embodiment, as in the case of the endoscopic diagnosis apparatus 101 of the first embodiment, by combining and displaying a fluorescence image and a polarization characteristic image by a composite image, for example, Since blood vessels, lymphatic vessels, collagen fibers, nerve fibers, etc. can be observed simultaneously, the diagnostic accuracy by the doctor can be improved. In addition, since blood vessels and the like can be highlighted with a narrow band light image, the same effect can be obtained by displaying the narrow band light image and the polarization characteristic image in combination. That is, the diagnostic accuracy can be similarly improved by combining the polarization characteristic image and the special light image including at least one of the fluorescence image and the narrowband image.

  Next, laser light (LD1) output from the light distributor, polarized light output from the polarization modulator, and each laser light from the laser light sources LD2 to LD5 are appropriately output by the light projecting units 162A to 162D. Each illumination pattern that emits in combination and generates various illumination lights will be described.

  FIG. 22 shows an example of each irradiation pattern. As in the illustrated example, A, B, C, and D on both sides of the objective lens unit 144A represent the light projecting units 162A, 162B, 162C, and 162D, respectively.

<First irradiation pattern>
Laser light having a central wavelength of 445 nm from LD2 is introduced into the light projecting units 162A and 162D, and white light is irradiated from each. In addition, laser light (LD1) having a central wavelength of 405 nm from the light distributor is introduced into the light projecting units 162B and 162C, and purple narrow band light is irradiated from each. As for the irradiation timing, illumination with white light and illumination with narrow band light may be performed separately, or illumination with white light and narrow band light may be performed simultaneously.

  According to this illumination pattern, by irradiating white light from the light projecting units 162A and 162D, normal observation can be performed with minimal illumination unevenness even when a raised portion exists in the observation site. Moreover, by irradiating purple narrow-band light from the light projecting units 162B and 162C, it is possible to emphasize and observe the capillaries on the surface layer of the mucosal tissue. Furthermore, by simultaneously irradiating light from each of the light projecting units 162A to 162D, an observation image in which capillaries are emphasized in the normal observation image is obtained. In this case, the distribution in the depth direction of the superficial blood vessel can be observed by arbitrarily adjusting the ratio of the emitted light quantity of LD1 and LD2.

  Further, the violet narrow-band light from the light projecting units 162B and 162C is that the laser light (LD1) from the light distributor is emitted as it is through the optical fibers 142B and 142C, and does not pass through the phosphor. For this reason, the light emitting component of the phosphor does not appear as noise in the observation image, and the emitted light intensity does not decrease due to light absorption or light diffusion of the phosphor. Furthermore, since the same narrow band light is emitted from the plurality of light projecting units 162B and 162C, the light intensity of the narrow band light can be improved.

<Second irradiation pattern>
For the light projecting units 162A and 162D, laser light having a central wavelength of 445 nm from the LD 2 is introduced, and white light is irradiated from each. In addition, a laser beam (LD1) having a center wavelength of 405 nm from the light distributor is introduced into the light projecting unit 162C to irradiate purple narrowband light. Then, a laser beam having a center wavelength of 530 nm from the LD 3 is introduced into the light projecting unit 162B. As for the irradiation timing, illumination with white light and illumination with each narrow band light may be performed separately, or each narrow band light or illumination with white light and narrow band light may be performed simultaneously.

  According to this illumination pattern, white light is emitted from the light projecting units 162A and 162D, purple narrow band light is emitted from the light projecting unit 162C, and green narrow band light is emitted from the light projecting unit 162B. . As a result, in addition to normal observation, it is possible to selectively observe capillary blood vessels in the mucosal tissue surface layer using purple narrow-band light and observation of thick blood vessels deep in the tissue using green narrow-band light. In this case, the distribution of blood vessels from the mucosal tissue surface layer to the deep layer can also be observed by arbitrarily adjusting the ratio of the emitted light quantity of LD1 and LD3. It is preferable to irradiate light with a wavelength of 390 to 445 nm for capillary blood vessel observation on the surface layer of the mucosal tissue, and 530 to 550 nm for deep blood vessel observation.

<Third irradiation pattern>
For the light projecting units 162A and 162D, laser light having a central wavelength of 445 nm from the LD 2 is introduced, and white light is irradiated from each. Further, a laser beam (LD1) having a center wavelength of 405 nm from the light distributor or a laser beam having a center wavelength of 530 nm from the LD3 is introduced into the light projecting unit 162B, and irradiated with purple or green narrow band light. . Also, the light projecting unit 162C selectively introduces the laser beams from the LD1 and LD3 in the same manner as the light projecting unit 162B.

  According to this illumination pattern, the light emitted from the light projecting units 162B and 162C can be arbitrarily selected as either LD1 or LD3, and can be appropriately switched according to the observation scene. Therefore, necessary information according to the observation scene can be freely extracted, and an observation image suitable for the observation purpose can be obtained. Further, when the laser beams from LD1 and LD3 are emitted at the same time, the laser beams from LD1 and LD3 can be emitted from the same light projecting units 162B and 162C. Lighting conditions can be matched with high accuracy. As a result, it is possible to accurately extract changes in the observation image due to differences in illumination light.

<Fourth irradiation pattern>
For the light projecting units 162A and 162D, in addition to introducing laser light having a central wavelength of 445 nm from LD2, laser light having a central wavelength of 530nm from LD3 and laser light having a central wavelength of 785nm from LD5 are selectively used. To introduce. Further, for the light projecting units 162B and 162C, at least one of laser light (LD1) having a central wavelength of 405 nm from the optical distributor, laser light having a central wavelength of 530 nm from LD3, and laser light having a central wavelength of 785 nm from LD5 is used. Selectively introduce.

  According to this illumination pattern, in addition to white light, various narrow-band lights can be freely emitted from each of the light projecting units 162A to 162D. For this reason, when applying the light projecting unit to an endoscope navigation system for obtaining position information of blood vessels around the bronchi, for example, it becomes possible to irradiate the light from a plurality of light projecting units with high intensity light. The treatment can be performed with high accuracy. Specifically, in this blood vessel navigation, laser light having a central wavelength of 785 nm from the LD 5 is irradiated toward indocyanine green (ICG) injected into the blood vessel. Then, in the portion where blood and ICG react, fluorescence having a broad spectral characteristic with a peak wavelength of 830 nm is generated, and navigation is performed using this fluorescence as a mark.

  The laser light of LD3 and LD5 has a characteristic that the phosphor 160 (see FIG. 20A) has a low absorptance in the wavelength band around 500 nm. Since the light emission is slight, the observation image is not affected by the color mixture of white light.

<Fifth irradiation pattern>
For the light projecting units 162A and 162D, laser light having a central wavelength of 445 nm from the LD 2 is introduced, and white light is irradiated from each. Further, at least one of laser light (LD1) having a central wavelength of 405 nm from the optical distributor and laser light having a central wavelength of 665 nm from the LD4 is selectively introduced into the light projecting units 162B and 162C.

  According to this illumination pattern, in addition to the white light, the PDD light beam (LD1) from the light distributor and the PDT light beam from the LD4 can be emitted. That is, after moving the endoscope to the vicinity of the lesion by normal observation with white light, the position of the lesion is identified by irradiating the PDD light beam. And the light spot for PDT is irradiated toward the specified lesion part, and a lesion part is treated. The PDT beam may be applied to a lesion by inserting a probe for emitting PDT beam from the forceps hole of the endoscope and projecting the probe from the distal end of the endoscope.

<Sixth irradiation pattern>
Laser light having a central wavelength of 445 nm from LD2 is introduced into the light projecting units 162A and 162D, and white light is irradiated from each. Further, polarized light having a central wavelength of 405 nm from the polarization modulator is introduced into the light projecting units 162B and 162C, and four types of polarized light having different polarization states are sequentially irradiated from the respective light projecting units 162B and 162C. For the irradiation timing, illumination with white light and illumination with polarized light are individually performed.

  According to this illumination pattern, by irradiating white light from the light projecting units 162A and 162D, normal observation can be performed with minimal illumination unevenness even when a raised portion exists in the observation site. In addition, each time four types of polarized light having different polarization states are sequentially emitted from the light projecting units 162C and 162D, and the polarized light having different polarization states is irradiated, the reflected light is reflected from the observation region of the subject. The light is converted into polarized light of four different polarization states by the patterning element, and this is imaged by the imaging element, and a total of 16 light intensity images of polarized light having different polarization states are captured. Can be observed.

  Further, the polarized light emitted from the light projecting units 162B and 162C is that the polarized light output from the light distributor is emitted as it is through the optical fiber and does not pass through the phosphor. For this reason, the light emitting component of the phosphor does not appear as noise in the observation image, and the emitted light intensity does not decrease due to light absorption or light diffusion of the phosphor. Furthermore, since the polarized light having the same polarization state is emitted from the plurality of light projecting units 162B and 162C, the light intensity of the polarized light can be improved.

  The outgoing light is switched at an arbitrary timing or a programmed specified timing by the operation of the selector switch 158 of the endoscope apparatus 102 shown in FIG. 17, the operation from the input device 110, or the light source device 104. be able to.

  As described above, by combining a plurality of light projecting units and irradiating white light and narrow band light, both normal observation with white light and special light observation with narrow band light can be performed in a good illumination environment. Can be done below. Further, since the narrowband light is not passed through the phosphor for generating white light, the narrowband light can be irradiated with high intensity without accompanying unnecessary light components.

The endoscope apparatus 100 having this configuration is not limited to the above-described embodiment, but can be changed and applied by those skilled in the art based on the description and well-known techniques. Yes, included in the scope of protection.
Note that the above-described light projecting units 162A to 162D are not limited to being applied to an endoscope apparatus, but can also be applied to other types of medical devices such as rigid endoscopes, forceps, and scope endoscopes.

The present invention is basically as described above.
Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and it is needless to say that various improvements and modifications may be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 Polarization image measurement display system 12, 12a, 12b, 12c, 12d, 12e Polarization imaging system 14 Polarization conversion process part 16 Display conversion process part 18 Display part 20 Normal color imaging system 22 Image composition part 24, 24a, 24b, 24c Polarization Irradiation unit 26, 26a, 26b, 26c, 26d Imaging unit 28 Mueller image conversion unit 30 Polarization variable separation processing unit 32 Polarization element characteristic correction processing unit 34 Light source 36a, 36b Polarizing plate 38a, 38b Rotating phase difference plate 40a, 40b, 46a , 46b, 54 Polarization filter section 42 Camera 44a, 44b, 45a, 45b Phase modulation element 48 Optical fiber 50 Optical probe 52 Patterning polarization / wave plate 53 Polarizer and phaser patterning element 56 CCD
82 Separating unit 84 Image forming unit after separation 86 Living body observation model setting unit 88 Image forming parameter setting unit after separation 100, 101 Endoscopic diagnosis device 102, 103 Endoscopic device 104, 105 Light source device 106, 107 Processor unit 108 Display Device 110 Input device 111 White light source 112 Light source control unit 113 Rotation control unit 114 Optical distributor 115 Narrow band filter 116 Polarization modulator 117 Polarization filter 118 Combiner 119 Lens 120 Coupler 122 Endoscope insertion unit 124 Operation unit 126A, 126B Connector Part 128 Soft part 130 Bending part 132 Tip part 134 Angle knob 136A, 136B Irradiation port 138A, 138B Imaging element 140A, 140B Observation window 142A-142D Optical fiber 144A, 140B Objective lens unit 146A Excitation light cut filter 146B Patterning element 148A, 148B Scope cable 150A, 150B A / D converter 152 Control unit 154 Image processing unit 154A White light image processing unit 154B Fluorescence image processing unit 154C Narrow band light image processing unit 154D Polarized image processing Unit 154E Image composition unit 156 Storage unit 158 Changeover switch 160 Phosphor 162A to 162D Projection unit 164 Sleeve member 166 Protective glass (illumination window)
168 Ferrule 170 Flexible sleeve LD1-LD5 Laser light source

Claims (10)

A light source device that emits multiple types of illumination light;
An endoscope apparatus that guides illumination light emitted from the light source device and irradiates the subject, images the reflected light, and outputs an image signal;
A processor device that performs image processing on an image signal obtained by the endoscope device and outputs an image corresponding to the illumination light;
A display device for displaying an image obtained by the processor device,
The processor device sequentially irradiates a subject with a plurality of polarized lights having different polarization states as the illumination light, performs image processing on a plurality of image signals obtained by sequentially imaging the reflected light, and performs predetermined processing. A polarization image processing unit that generates a polarization characteristic image according to polarization characteristics;
As the illumination light, a fluorescence image processing unit that irradiates a subject with excitation light for fluorescence observation, performs image processing on an image signal obtained by imaging the reflected light, and generates a fluorescence image; and the illumination As light, at least one of a narrowband light image processing unit that irradiates a subject with narrowband light and performs image processing on an image signal obtained by imaging the reflected light to generate a narrowband light image;
A composite image is formed by combining the polarization characteristic image obtained by the polarization image processing unit, the fluorescence image obtained by the fluorescence image processing unit, and at least one of the narrow band light image obtained by the narrow band light image processing unit. An image composition unit to generate,
The endoscope diagnosis apparatus, wherein the display device displays a composite image obtained by the image composition unit.   The endoscope diagnosis apparatus according to claim 1, wherein the image composition unit generates the composite image by arranging the polarization characteristic image and at least one of the fluorescence image and the narrowband light image.   The endoscope diagnosis apparatus according to claim 1, wherein the image composition unit generates the composite image by superimposing the polarization characteristic image and at least one of the fluorescence image and the narrowband light image.   The endoscope diagnosis apparatus according to claim 1, wherein the image synthesis unit generates the synthesized image by performing arithmetic processing on the polarization characteristic image and at least one of the fluorescence image and the narrowband light image. The processor device further irradiates a subject with white light as the illumination light and performs image processing on an image signal obtained by imaging the reflected light to generate a white light image processing unit. With
The image composition unit generates a composite image by combining the polarization characteristic image, at least one of the fluorescence image and the narrowband light image, and a white light image obtained by the white light image processing unit. The endoscope diagnosis apparatus according to claim 1.   The said image synthetic | combination part arrange | positions the said polarization characteristic image, at least one of the said fluorescence image and the said narrow-band light image, and also arrange | positions the said white light image, and produces | generates the said synthesized image. Endoscopic diagnostic device.   The said image composition part superimposes the said polarization characteristic image, at least one of the said fluorescence image and the said narrow-band light image, Furthermore, it arrange | positions the said white light image and produces | generates the said synthesized image. Endoscope diagnostic device.   The image synthesizing unit is configured to perform arithmetic processing on the polarization characteristic image and at least one of the fluorescence image and the narrowband light image, and further generate the synthesized image by arranging the white light images. The endoscope diagnosis apparatus described. The polarization image processing unit performs polarization conversion processing on a plurality of pieces of light intensity image information by reflected light from a subject of the plurality of polarization lights having different polarization states as the image signal, and polarization having predetermined polarization characteristics A polarization conversion processing unit for converting into characteristic image information;
A display conversion processing unit that converts the polarization characteristic image information of the predetermined polarization characteristic obtained by the polarization conversion processing unit corresponding to the polarization characteristic image into display polarization characteristic image information for visualization and display. The endoscope diagnostic apparatus according to any one of claims 1 to 8.   The polarization conversion processing unit obtains, as the polarization characteristic image information, any one of polarization characteristic image information of depolarization degree, light polarization degree, phase difference, phase difference azimuth, absorption azimuth, and optical rotation polarization characteristic. The endoscope diagnosis apparatus according to claim 9.