JP2011067269A - Endoscope apparatus - Google Patents

Abstract

An endoscope apparatus capable of always stably obtaining an appropriate color observation image in real time for any of PDD, PDT, and normal observation is provided.
Receiving therapeutic light LB3 through a wavelength cut filter 21 for limiting the wavelength component of therapeutic light (PDT laser light) LB3 by a plurality of image sensors 23R, 23G, and 23B, and acquiring the acquired R, G The output signal from the image sensor 23B that detects the blue component B is superimposed on the output signal from the specific image sensor 23R that detects the red component R with respect to the B wavelength component, and the superimposed output signal is used as the specific image sensor. A composite image is generated as an output signal from 23R and displayed on the monitor 60.
[Selection] Figure 1

Description

  The present invention relates to an endoscope apparatus, and more particularly, to an endoscope apparatus that performs photodynamic diagnosis (PDD) and photodynamic therapy (PDT).

  In an endoscopic device that observes and examines a body cavity, a photosensitive substance that has a tumor affinity and is sensitive to specific excitation light is administered to a living body in advance, and then the laser light that is the excitation light is relatively weak Photodynamic Diagnosis (hereinafter referred to as Photodynamic Diagnosis), which is used to diagnose tumors by irradiating the surface of living tissue with output and observing fluorescence from a site where the concentration of photosensitive substances is high in the lesion of the tumor such as cancer There is a device capable of performing abbreviated as PDD. There has also been proposed an apparatus capable of performing photodynamic therapy (hereinafter abbreviated as PDT) for treating a tumor such as cancer by irradiating the surface of a living tissue with a laser beam with a relatively strong output (see Patent Document). 1).

  At the time of PDT, it is desired to display and monitor the state of the affected area on a TV monitor so that the irradiation position of the PDT laser beam does not deviate from the irradiation target site. However, the intensity of the laser light used differs greatly between PDD and PDT, and in PDT, when imaging is performed under normal imaging conditions, reflected light of high-energy PDT laser light enters the imaging element through the objective lens, and imaging is performed. A good observation image may not be obtained because the luminance level of the image is saturated and halation occurs in the video on the monitor.

  In order to solve this problem, for example, a wavelength cut filter that blocks only light in the wavelength band of the same wavelength as the PDT laser light is interposed between the objective lens and the image sensor. However, if a long wavelength (wavelength band including red region) wavelength cut filter is always provided in the endoscope, information in the red region is lost by the wavelength cut filter, so that an observation image whose luminance level is not saturated during PDT can be obtained. However, the color reproducibility of the observation image at the time of PDD or normal observation deteriorates.

The endoscope for PDT described in Patent Document 1 includes a main objective lens and a sub objective lens in which a wavelength cut filter for limiting PDT laser light is provided on the optical path. With this configuration, an image obtained from the main objective lens is displayed on the monitor in the normal observation mode in which white light is irradiated and in the PDD mode in which white light and PDD laser light are irradiated. On the other hand, in the PDT mode, a laser irradiation probe is inserted from the forceps hole and irradiated with the laser light for PDT and simultaneously with the white light, and the image obtained from the sub objective lens in which the PDT laser light is cut by the wavelength cut filter is monitored. It is displayed above.
However, an image obtained at the time of PDT does not include information on the wavelength band of the same wavelength as the laser light for PDT, in other words, an image that does not include important blood vessel information, and in order to perform more precise treatment, An appropriate color observation image equivalent to an image obtained by white light illumination has been desired.

JP 2008-86680 A

  Accordingly, an object of the present invention is to provide an endoscope apparatus that can always stably obtain an appropriate color observation image in real time for any of PDD, PDT, and normal observation.

The present invention has the following configuration.
An endoscope apparatus for imaging an inside of a body cavity by inserting an endoscope insertion portion into the body cavity,
An observation light source that generates illumination light for observation;
A therapeutic light source for generating therapeutic light for use in photodynamic therapy;
Light transmission means for guiding light from the observation light source and the treatment light source to the distal end of the endoscope insertion portion and irradiating the tissue in the body cavity;
An optical path splitting optical element for decomposing light from the body cavity tissue irradiated with the illumination light and treatment light into a plurality of light fluxes for each wavelength;
A wavelength cut filter that is disposed on the front side of the optical path of the optical path splitting optical element and limits at least a wavelength component of the treatment light;
A plurality of image sensors for individually receiving each light beam divided by the optical path dividing optical element;
Out of the plurality of image sensors, the output signal from the specific image sensor having the highest light receiving sensitivity to the wavelength component of the treatment light is separately processed from the output signals from other image sensors to synthesize the output signals. A control device for generating a composite image,
An endoscopic apparatus comprising:

  According to the endoscope apparatus of the present invention, an appropriate color observation image can always be stably obtained in real time for any of PDD, PDT, and normal observation.

1 is an overall configuration diagram of an endoscope apparatus for explaining an embodiment of the present invention. 5 is a graph showing PDD laser light (purple laser light) from an excitation light source for PDD, and an emission spectrum obtained by converting the wavelength of blue laser light and blue laser light from a blue laser light source with a phosphor. It is a graph which shows the spectral characteristic of a PDT laser beam, and the spectral absorption characteristic of a wavelength cut filter. It is a schematic diagram which shows the state by which the wavelength of R component was cut by the wavelength cut filter. Is a graph showing the hemoglobin Hb, the spectral absorption coefficient of the oxygenated hemoglobin HbO ₂ in blood. It is explanatory drawing which shows typically the synthesis | combination method of each image signal of R, G, B at the time of PDT light irradiation. It is explanatory drawing which showed typically the method to synthesize | combine each image signal of R, G, and B at the time of PDD light and white light irradiation. It is a flowchart which shows an example of the procedure of PDD diagnosis and PDT treatment. It is principle explanatory drawing which shows the relationship between excitation light, autofluorescence, and chemical | medical agent fluorescence.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an overall configuration diagram of an endoscope apparatus for explaining an embodiment of the present invention. As shown in FIG. 1, an endoscope apparatus 100 includes an endoscope 10, an imaging unit 20 connected to the endoscope 10, and a control device 30 to which the endoscope 10 and the imaging unit 20 are connected. Have

  The endoscope 10 includes an endoscope insertion portion 11 that is a straight rigid tube shape that is inserted into a subject, and an operation portion 27 that performs an operation for observation. The operation unit 27 includes an operation switch 12 (described later) and a connector unit 13 </ b> A that detachably connects the endoscope 10 to the light source device 40. The distal end portion 11 a of the endoscope insertion portion 11 has irradiation ports 14 A and 14 B that irradiate light to the observation region 19 and an observation window 15 that acquires image information of the observation region 19. Information about the observed region 19 is sent to the imaging unit 20 through the relay lens 16.

  The imaging unit 20 includes a wavelength cut filter 21 that limits the wavelength component of the PDT laser beam LB3, a dichroic prism 22 that is an optical path dividing optical element that separates incident light into R, G, and B color components, and R, G , B are provided with a three-plate image pickup device having an R image pickup device 23R, a G image pickup device 23G, and a B image pickup device 23B that receive light separated into the respective color components. As each of the image sensors 23R, 23G, and 23B, a CCD (Charge Coupled Device) image sensor, a CMOS (Complementary Metal-Oxide Semiconductor) image sensor, or the like can be used. The dichroic prism 22 exemplifies a Philips type dichroic prism 22 having a configuration in which three triangular prisms 22R, 22G, and 22B are joined. However, other optical elements such as a Kester type may be used.

  The control device 30 includes a light source device 40 that generates illumination light to be supplied to the irradiation ports 14A and 14B provided at the distal end portion 11a of the endoscope insertion unit 11, and a processor 50 that performs image processing on an image signal from the imaging unit 20. The light source device 40 and the processor 50 are connected to the endoscope 10 and the imaging unit 20 via connector units 13A and 13B, respectively.

  The processor 50 includes an image signal processing unit 51 and a control unit 59. The image signal processing unit 51 performs image processing on the imaging signal transmitted from the imaging unit 20 based on an instruction from the operation switch 12 provided in the endoscope 10, and generates a display image signal. (TV monitor) 60 to supply and display the observation image on the display unit 60. The control unit 59 performs various controls of the light source device 40 and the image signal processing unit 51 based on instructions from the operation switch 12.

  The light source device 40 includes a PDD excitation light source 41 that generates PDD laser light (PDD excitation light) LB1 having a center wavelength of 405 nm, and a blue laser that generates blue laser light (white illumination laser light) LB2 having a center wavelength of 445 nm. A light source 42 and a PDT treatment light source 43 that generates PDT laser light (PDT treatment light) LB3 having a center wavelength of 664 nm. The amount of light emitted from each of the light sources 41, 42, 43 can be changed by individually controlling each semiconductor light emitting element (not shown) built in each light source 41, 42, 43 by the light source control unit 44.

  As the PDD excitation light source 41 and the blue laser light source 42, a broad area type InGaN laser diode can be used, and an InGaNAs laser diode or a GaNAs laser diode can also be used. In addition, it is good also as a structure using light-emitting bodies, such as a light emitting diode, as these light sources. In addition, as the PDT laser light (PDT treatment light) LB3 generated from the PDT treatment light source 43, laser light having a center wavelength of 664 nm is used when the photosensitizer used for PDD and PDT is rezaphyrin (Npe6). Is used. In addition to this, when the photosensitizer used is photofrin (Polfimer sodium: PHE), an excimer dye laser having a center wavelength of 630 nm, a YAG-OPO laser, or the like can be used.

  Laser light (PDD laser light LB1, blue laser light LB2, and PDT laser light LB3) emitted from each of the light sources 41, 42, and 43 is input to an optical fiber by a condenser lens (not shown). The signal is transmitted to the distal end portion 11a of the endoscope insertion portion 11 of the endoscope 10 through a combiner 45 that is a multiplexer and a coupler 46 that is a duplexer. However, the present invention is not limited to this, and a configuration in which the laser beams LB1, LB2, and LB3 from the light sources 41, 42, and 43 are combined by a dichroic mirror without using the combiner 45 and the coupler 46, or the endoscope is directly inserted. The structure which transmits to the front-end | tip part 11a of the part 11 may be sufficient.

  The laser beam obtained by combining the blue laser beam LB2, the PDD laser beam LB1, and the PDT laser beam LB3 propagates to the distal end portion 11a of the endoscope insertion portion 11 of the endoscope 10 through the optical fibers 17A and 17B. Is done. Then, the blue laser light LB2 excites the phosphor 18 that is a wavelength conversion member disposed at the light emitting ends of the optical fibers 17A and 17B of the endoscope insertion portion 11 to emit fluorescence. Further, part of the blue laser light LB2 passes through the phosphor 18 as it is. The PDD laser beam LB1 and the PDT laser beam LB3 are transmitted without exciting the phosphor 18.

  The optical fibers 17A and 17B are multimode fibers. As an example, a thin fiber cable having a core diameter of 105 μm, a cladding diameter of 125 μm, and a diameter of φ0.3 to 0.5 mm including a protective layer serving as an outer shell can be used. .

The phosphor 18 includes a plurality of types of phosphors (for example, YAG phosphors or phosphors such as BAM (BaMgAl ₁₀ O ₁₇ )) that absorb a part of the blue laser beam LB2 and emit light in green to yellow. Consists of. Thereby, the green to yellow excitation light using the blue laser light LB2 as excitation light and the blue laser light LB2 transmitted without being absorbed by the phosphor 18 are combined to form white (pseudo white) illumination 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.

  The phosphor 18 described above can prevent noise superimposition that causes an obstacle in imaging and flickering when performing moving image display due to speckles caused by the coherence of laser light. Further, the phosphor 18 considers the refractive index difference between the phosphor constituting the phosphor 18 and the fixing / solidifying resin serving as the filler, and sets the particle size relative to the phosphor itself and the filler in the infrared region. It is preferable to use a material that absorbs light little and scatters a lot. This enhances the scattering effect without reducing the light intensity for red or infrared light, and reduces the optical loss.

  FIG. 2 is a graph showing the PDD laser light LB1 from the PDD excitation light source 41 and the emission spectrum obtained by wavelength-converting the blue laser light LB2 and the blue laser light LB2 from the blue laser light source 42 by the phosphor 18. . The PDD laser beam LB1 is represented by an emission line (profile A) having a center wavelength of 405 nm. The blue laser beam LB2 is represented by a bright line having a center wavelength of 445 nm, and the excitation light emitted from the phosphor 18 by the blue laser beam LB2 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 B of the excitation light and the blue laser light LB2.

  If the light emission intensities of the profile A and the profile B are relatively increased and decreased by the light source control unit 44, illumination light having an arbitrary luminance balance can be generated.

  Here, the white light referred to in this specification is not limited to one that strictly includes all wavelength components of visible light, and may be any light that includes light in a specific wavelength band such as R, G, and B, for example. For example, light including a wavelength component from green to red, light including a wavelength component from blue to green, and the like are included in a broad sense.

  Returning to FIG. 1 again, the image signal processing unit 51 converts the output signal of each color component from each of the image pickup devices 23R, 23G, and 23B of the image pickup unit 20 into a digital signal by the A / D conversion unit 52, and then outputs the pre-stage signal. The processing unit 53 performs pre-stage processing such as gamma correction and edge enhancement to separate the color components into R, G, and B colors. The separated color components are sent to the R calculation unit 54, the G calculation unit 55, and the B calculation unit 56, and are processed by the calculation units 54, 55, and 56 for each color. Then, the signals of the respective colors that have been subjected to the arithmetic processing are synthesized by the image synthesis unit 57 under desired conditions, and are sent to the subsequent signal processing unit 58. The post-stage signal processing unit 58 converts the image signal obtained from the image synthesis unit 57 into a video signal such as a video composite signal, a Y / C separation signal, and the like, performs D / A conversion, and outputs it to the display unit 60 as needed. . The video signal is displayed on the display unit 60 together with various information.

  FIG. 3 is a graph showing the spectral characteristics of the PDT laser beam LB3 and the spectral absorption characteristics of the wavelength cut filter 21. As shown in FIG. 3, the emission wavelength component of the PDT laser beam LB3 having a center wavelength of 664 nm is absorbed by the wavelength cut filter 21 that limits the wavelength component of approximately 600 nm or more, so that the component reaches the dichroic prism 22. Therefore, the intensity of the received light signal of the image sensor 23R is greatly reduced.

  FIG. 4 is a schematic diagram showing a state in which the wavelength of the R component is cut by the wavelength cut filter 21. As shown in FIG. 4, the laser light incident on the dichroic prism 22 has a wavelength component of approximately 600 nm or more limited by the wavelength cut filter 21, so that the amount of received R component (red component) detected by the image sensor 23 </ b> R is small. Has been reduced. However, the R component image information includes blood vessel information in addition to redness information on the mucosal surface. When detection of this R component is restricted, the image of the mucosal surface is displayed from the image displayed on the display unit 60. Not only is the R component decreased, but also blood vessel information, which is particularly important information, is lost.

Therefore, in this endoscope apparatus, this lost blood vessel information can be reproduced in a pseudo manner and displayed. A specific reproduction method will be described below.
FIG. 5 is a graph showing spectral absorption coefficients of hemoglobin Hb and oxygenated hemoglobin HbO _{2 in} blood. As shown in FIG. 5, hemoglobin is absorbed to such an extent that it appears in the captured image even in the wavelength band of 600 to 700 nm, but the absorption increases in the shorter wavelength band of 400 to 500 nm. Therefore, the blood vessel information in the band of the wavelength of 600 to 700 nm lost by the wavelength cut filter 21 is supplemented from the blood vessel information of the band near the wavelength of 400 to 500 nm, thereby adding the blood vessel information to the R component image information. it can. That is, the image signal from the image sensor 23B that detects blue (B) is superimposed on the image signal from the image sensor 23R that detects red (R), and this is handled as a red (R) image signal. Blood vessel information will be displayed more naturally.

  Here, FIG. 6 shows an explanatory diagram of a method for synthesizing R, G, and B image signals when the PDT laser beam LB3 is irradiated. As shown in FIG. 6, the B and G image signals output from the image sensors 23B and 23G are used as image information of the observation image as usual, and the wavelength cut filter 21 cuts a wavelength component having a wavelength of approximately 600 nm or more. For the R image signal output from the image pickup device 23R, the B image signal is superimposed on the received R image signal to obtain red R pseudo image information Ra.

  As a method of superimposing the B image signal on the R image signal, the corresponding pixels are added and averaged to obtain a new pixel value (Ra = (R + B) / 2), and the B image signal is multiplied by a coefficient. Thus, an appropriate method such as a method of adding a new pixel value by adding to the R image signal (Ra = R + kB) may be used. The obtained R image signal is a pseudo R color image signal in which blood vessel information that was originally B image information is captured as R image information, and is combined with the B and G image signals to form an observation image. .

  As a result, blood vessel information that is particularly important as observation information is superimposed on the R image information that is lost by the wavelength cut filter 21. Therefore, even when the PDT laser light LB3 is irradiated, the irradiation region of the PDT laser light LB3 In addition, it is possible to clearly observe the state of the tissue in the surrounding area as a color image close to nature.

Next, display of an observation image during PDD and white light irradiation will be described.
FIG. 7 is an explanatory view schematically showing a method of synthesizing R, G, and B image signals when the PDD laser beam LB1 and white light are irradiated. As shown in FIG. 7, even when the PDD laser beam LB1 and white light are irradiated, the wavelength cut filter 21 restricts the amount of R component received by the image sensor 23R. Therefore, the image displayed on the display unit 60 is R The image signal has a reduced luminance level.

Therefore, the reduction of the luminance level of the R image signal is corrected by amplifying the _R image signal with a larger gain (α _R > α _B , α _G ) than the B and G image signals. . As a result, it is possible to prevent color balance from being lost during white light illumination, and it is possible to obtain observation information matched with a real image. Note that, as indicated by a broken line in FIG. 7, a B image signal may be further superimposed on the amplified R image signal.

  Next, PDD diagnosis and PDT treatment procedures will be described with reference to FIG. As shown in FIG. 8, the surgeon administers a photosensitizer such as resaphyrin (Npe6) to the subject in advance and accumulates it in the tumor part of the subject. Then, after inserting the endoscope insertion portion 11 of the endoscope 10 into the subject, the operation switch 12 or the like is operated to irradiate the blue laser light LB2 having the central wavelength of 445 nm from the blue laser light source 42, and this blue White light is emitted by the laser light LB2 and the excitation light emitted from the phosphor 18 (step S1). Then, normal observation of the affected area is performed with the image displayed on the display unit 60 based on the output signals of the respective color components sent from the respective image sensors 23R, 23G, and 23B (step S2).

  At this time, the image signal obtained by the imaging unit 20 is a signal in which the R component is limited by the wavelength cut filter 21, but as already described in FIG. 7, the R image signal is the B, G image signal. Amplification processing is performed with a larger gain to correct a decrease in luminance level. Therefore, the image displayed on the display unit 60 is a color image excellent in color reproducibility that is close to a real image, and the affected part can be easily and finely observed.

  The endoscope 10 is operated while viewing the color image of the display unit 60 so that the distal end portion 11a of the endoscope insertion unit 11 is opposed to the portion considered to be a tumor part, and then the operation switch 12 or the like is operated, A PDD laser beam LB1 having a center wavelength of 405 nm is irradiated from the PDD excitation light source 41 (step S3), and a fluorescence image displayed on the display unit 60 is observed to find a lesion portion (step S4). At this time, the image displayed on the display unit 60 lacks R image information due to the wavelength cut filter 21, but originally the PDD laser beam LB1 has a small R wavelength component, and the R wavelength at the time of PDD is also small. Since the importance of image information is low, it does not hinder the detection of a lesion.

  FIG. 9 is an explanatory diagram showing the relationship between excitation light, autofluorescence and drug fluorescence. When the PDD laser beam LB1 is irradiated, the intensity of the autofluorescence L1 in the normal part is higher than that of the autofluorescence L3 in the lesion part. In addition, the intensity of the drug fluorescence L4 in the lesioned part is higher than that of the drug fluorescence L2 in the normal part. By observing the difference in fluorescence intensity between the normal part and the lesion part, the location, size, shape, etc. of the lesion part can be easily determined. Note that the detection of light with respect to the drug fluorescence L2 and L4 is restricted by the wavelength cut filter 21, but observation is possible by processing such as setting the gain of the image signal R to be larger than G and B.

  Returning to FIG. 8, the distal end portion 11a of the endoscope insertion portion 11 is aimed at the lesion portion confirmed by the PDD diagnosis (step S5), and the operation switch 12 or the like is operated to operate the light source for PDT treatment. 43 generates PDT laser light (PDT treatment light) LB3 having a center wavelength of 664 nm (step S6), and irradiates the lesion portion until a predetermined time elapses (step S7).

  As already described with reference to FIG. 6, the display image of the display unit 60 at the time of irradiation with the PDT laser beam LB3 is B with respect to the R image signal among the image signals output from the imaging elements 23R, 23B, and 23G. Since the image signal is superimposed and displayed as pseudo image information Ra, only an image lacking important blood vessel information was seen. However, according to the endoscope apparatus 100 of this configuration, the irradiation region of the PDT laser beam LB3 In addition, it is possible to clearly observe the state of the tissue in the surrounding area as a natural color image including blood vessel information, and irradiate the lesion portion while confirming the irradiation position of the PDT laser beam LB3 reliably and easily. be able to.

  Then, when the PDT laser beam LB3 is irradiated for a predetermined time, the operation switch 12 or the like is operated to stop the irradiation of the PDT laser beam LB3 (step S8), and the PDD laser beam LB1 is irradiated again to thereby detect the lesion portion. Observe (step S9) and confirm whether the lesion part is gone (step S10). When a lesion portion remains in the diagnosis by the PDD laser beam LB1, the remaining lesion portion is found again after step S4, and the same processing is performed.

  As described above, according to the endoscope apparatus 100 of this configuration, after irradiating the PDD laser beam LB1 and specifying the location of the lesioned part, the probe for PDT irradiation is inserted from the forceps hole and the PDT laser beam LB3 is inserted. Compared with the endoscope apparatus that irradiates the patient, diagnosis (PDD) and treatment (PDT) can be performed continuously without using a probe for PDT irradiation, and the load on the patient can be reduced. Further, by switching or simultaneously irradiating the PDD laser beam LB1 and the PDT laser beam LB3, it is possible to confirm the progress of the treatment of the lesioned part in real time, and it is possible to perform a more reliable treatment. Furthermore, even during treatment with irradiation with the PDT laser beam LB3, the state of the tissue including blood vessel information can be observed as a color image close to nature, and more reliable treatment is possible.

  In addition, as the white light used for the endoscope apparatus 100 of this configuration, in addition to the configuration generated by the combination of the laser light and the phosphor, the light from the xenon lamp or the halogen lamp is transmitted to the endoscope distal end by the fiber bundle. It is good also as a structure which guides light.

  The present invention is not limited to the above-described embodiments, and those skilled in the art can change or apply the present invention based on the description of the specification and well-known techniques. included.

As described above, the following items are disclosed in this specification.
(1) An endoscope apparatus that inserts an endoscope insertion portion into a body cavity and images the inside of the body cavity,
An observation light source that generates illumination light for observation;
A therapeutic light source for generating therapeutic light for use in photodynamic therapy;
Light transmission means for guiding light from the observation light source and the treatment light source to the distal end of the endoscope insertion portion and irradiating the tissue in the body cavity;
An optical path splitting optical element for decomposing light from the body cavity tissue irradiated with the illumination light and treatment light into a plurality of light fluxes for each wavelength;
A wavelength cut filter that is disposed on the front side of the optical path of the optical path splitting optical element and limits at least a wavelength component of the treatment light;
A plurality of image sensors for individually receiving each light beam divided by the optical path dividing optical element;
Out of the plurality of image sensors, the output signal from the specific image sensor having the highest light receiving sensitivity to the wavelength component of the treatment light is separately processed from the output signals from other image sensors to synthesize the output signals. A control device for generating a composite image,
An endoscopic apparatus comprising:
According to this endoscope apparatus, since the wavelength component of the treatment light is limited by the wavelength cut filter, no halation occurs due to saturation of the luminance level of the captured image, and an observation image with an appropriate luminance level is displayed on the display device. Can be displayed. In addition, the output signal from the specific image sensor with the highest light sensitivity to the wavelength component of the treatment light is individually processed and combined with the output signal from the other image sensor to generate a composite image. Although the wavelength component of the treatment light is limited by the cut filter, an appropriate color observation image including information on the limited wavelength component can be displayed on the display device.

(2) The endoscope apparatus according to (1),
When the control apparatus irradiates the tissue in the body cavity with the treatment light, an output signal from another image sensor is superimposed on an output signal obtained from the specific image sensor, and the superimposed output signal is the specific image An endoscope apparatus that generates the composite image as an output signal from an element.
According to this endoscope apparatus, since the output signal from the other image sensor is superimposed on the output signal of the specific image sensor that detects the wavelength limited by the wavelength cut filter, the composite image is generated. An appropriate color observation image can be displayed on the display device without saturation of the output signal of the specific image sensor.

(3) The endoscope apparatus according to (2),
The treatment light is red band light,
An endoscope apparatus in which the control device superimposes an output signal from the image sensor that detects a blue component on an output signal from the specific image sensor that detects a red component.
According to this endoscope apparatus, the absorption wavelength band of hemoglobin is in the red band, and blood vessel information is not reflected in the image sensor for red detection, but there is also an absorption wavelength in the blue band. By superimposing the detection signal of the image sensor on the red detection signal, a natural color image including blood vessel information can be displayed on the display device.

(4) The endoscope apparatus according to any one of (1) to (3),
When the control device irradiates the tissue in the body cavity with the illumination light, the output image obtained from the specific imaging device is higher in amplification factor than the output signals from other imaging devices and generates the composite image Mirror device.
According to this endoscope apparatus, blood vessel information is not reflected in the image sensor for red detection by the wavelength cut filter even during white light illumination, but the amplification factor of the output signal obtained from the image sensor for red detection is increased. By generating a composite image, a natural color image including blood vessel information can be displayed on the display device.

(5) The endoscope apparatus according to any one of (1) to (4),
An endoscope apparatus in which the endoscope insertion portion has a straight rigid tube shape.
According to this endoscope apparatus, since the endoscope insertion portion has a straight rigid tube shape, the optical path dividing optical element and the three-plate imaging element can be arranged outside the endoscope, and the resolution is high. An image is obtained.

(6) The endoscope apparatus according to any one of (1) to (5),
The optical path splitting optical element is a prism that decomposes into R, G, and B color components,
An endoscope apparatus in which the image sensor is a three-plate image sensor having an R image sensor, a G image sensor, and a B image sensor.
According to this endoscope apparatus, since each color component separated into R, G, and B by the prism is received by the dedicated image sensor, signal processing is performed for each of the R, G, and B color components. In any of PDD, PDT, and normal observation, the state of the tissue can be clearly observed as a color image close to nature.

(7) The endoscope apparatus according to any one of (1) to (6),
An endoscope apparatus including a monitor that displays information of a composite image generated by the control device.
According to this endoscope apparatus, an observation image can always be displayed in real time regardless of PDD, PDT, and normal observation.

DESCRIPTION OF SYMBOLS 10 Endoscope 11 Endoscope insertion part 17A Optical fiber (optical transmission means)
17B optical fiber (optical transmission means)
19 Observation area (tissue in body cavity)
21 wavelength cut filter 22 dichroic prism (optical path splitting optical element)
23B image sensor for B (image sensor for detecting blue component)
23G G image sensor 23R R image sensor (specific image sensor for detecting red component)
30 Controller 41 Excitation light source for PDD (light source for observation)
42 Blue laser light source (light source for observation)
43 Light source for PDT treatment (light source for treatment)
60 Display (Monitor)
100 Endoscopic device LB1 Laser light for PDD (diagnostic light)
LB2 Blue laser light (illumination light)
LB3 PDT laser light (treatment light)
α _R gain (amplification factor)
α _B gain (amplification factor)
α _G gain (amplification factor)

Claims (7)

An endoscope apparatus for imaging an inside of a body cavity by inserting an endoscope insertion portion into the body cavity,
An observation light source that generates illumination light for observation;
A therapeutic light source for generating therapeutic light for use in photodynamic therapy;
Light transmission means for guiding light from the observation light source and the treatment light source to the distal end of the endoscope insertion portion and irradiating the tissue in the body cavity;
An optical path splitting optical element for decomposing light from the body cavity tissue irradiated with the illumination light and treatment light into a plurality of light fluxes for each wavelength;
A wavelength cut filter that is disposed on the front side of the optical path of the optical path splitting optical element and limits at least a wavelength component of the treatment light;
A plurality of image sensors for individually receiving each light beam divided by the optical path dividing optical element;
Out of the plurality of image sensors, the output signal from the specific image sensor having the highest light receiving sensitivity to the wavelength component of the treatment light is separately processed from the output signals from other image sensors to synthesize the output signals. A control device for generating a composite image,
An endoscopic apparatus comprising: The endoscope apparatus according to claim 1,
When the control apparatus irradiates the tissue in the body cavity with the treatment light, an output signal from another image sensor is superimposed on an output signal obtained from the specific image sensor, and the superimposed output signal is the specific image An endoscope apparatus that generates the composite image as an output signal from an element. The endoscope apparatus according to claim 2, wherein
The treatment light is red band light,
An endoscope apparatus in which the control device superimposes an output signal from the image sensor that detects a blue component on an output signal from the specific image sensor that detects a red component. The endoscope apparatus according to any one of claims 1 to 3,
When the control device irradiates the tissue in the body cavity with the illumination light, the output image obtained from the specific imaging device is higher in amplification factor than the output signals from other imaging devices and generates the composite image Mirror device. The endoscope apparatus according to any one of claims 1 to 4,
An endoscope apparatus in which the endoscope insertion portion has a straight rigid tube shape. The endoscope apparatus according to any one of claims 1 to 5,
The optical path splitting optical element is a prism that decomposes into R, G, and B color components,
An endoscope apparatus in which the image sensor is a three-plate image sensor having an R image sensor, a G image sensor, and a B image sensor. The endoscope apparatus according to any one of claims 1 to 6,
An endoscope apparatus including a monitor that displays information of a composite image generated by the control device.

Images