JP2007020759A - Endoscope distal end hood - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide detailed observation images in PDD or PDT and to quickly switch between the PDD and the PDT. <P>SOLUTION: An endoscope distal end hood 10 is provided with a main body 11 and a laser beam cut-off filter. A peripheral part 11a and a holding part 11b form the main body 11, and the holding part 11b holds the laser beam cut-off filter at a prescribed position. When the endoscope distal end hood 10 is mounted on an insertion tube, the laser beam cut-off filter covers an objective optical system. The PDD is performed by using an endoscope for fluorescent observation. When performing the PDT, it is mounted on the insertion tube of the endoscope for the fluorescent observation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an endoscope tip hood that can be attached to an insertion tube tip of an endoscope.

  In recent years, photochemical diagnosis (PDD) and photochemical treatment (PDT) of lesions such as cancer have been performed using laser light (Patent Document 1).

  PDD refers to the fact that a specific photosensitive drug accumulates in a lesion from a healthy part, and after administration of the photosensitive drug to the human body, irradiates a living tissue with light of a specific wavelength such as ultraviolet light as excitation light. By doing so, this is a diagnostic method for identifying a lesion based on the fluorescence emitted by the photosensitive drug. In addition, PDT means that a photosensitizing agent having affinity for cancer and the like and having a cell-killing action when excited by light is previously administered to the human body and accumulated in the lesion, and light is emitted to the lesion. It is a treatment method of irradiation.

  Usually, after specifying a lesion by performing PDD, PDT is performed on the identified lesion. In addition, PDD and PDT are performed while observing a lesion using an endoscope.

  By the way, in order to excite the cancer-affinity photosensitive drug in PDT, a strong laser beam is irradiated. Therefore, when performing PDT, the surroundings of the lesion are observed using a laser beam cut filter that cuts light of the wavelength of the laser beam.

  On the other hand, fluorescence having substantially the same wavelength as the wavelength of the laser light is emitted from the living tissue in the PDD. Therefore, if a laser light cut filter is used when performing PDD, fluorescence is absorbed, and thus a fluorescence image cannot be displayed.

  Conventionally, PDD and PDT have been performed using the PDT apparatus 40 shown in FIG. The PDT device 40 includes an add-on camera 41 and a fiber scope 42. The fiberscope 42 is inserted with an observation light guide (image guide, not shown) from the distal end of the insertion tube 22 ′ to the observation window 43.

  As shown in FIG. 8, the add-on camera 41 is provided with an image pickup device 29 'such as a CCD and a laser light cut filter 12'. The image sensor 29 'and the observation light guide are optically connected. The laser light cut filter 12 ′ is held so as to be freely inserted between the image pickup device 29 ′ and the fiber scope 42.

  When PDD is performed using the PDT device 40, the periphery of the lesion is observed without inserting the laser light cut filter 12 'between the imaging element 29' and the fiberscope 42. When performing PDT, a laser light cut filter 12 'is inserted, and an image obtained by cutting the laser light is observed.

  By the way, since the image obtained by the PDT device 40 is obtained by the mapping transmitted by the fiberscope 42, it is difficult to obtain a detailed image. In particular, the resolution was lower than that of an image obtained by an electronic endoscope provided with an image sensor at the distal end of the insertion tube.

  Therefore, in order to perform PDD and PDT with a detailed image, it is necessary to separately use a fluorescence observation electronic endoscope for PDD and an electronic endoscope with a laser light cut filter for PDT.

However, in general, the shorter the treatment time, the lighter the burden on the patient. Therefore, it is desirable to quickly switch between PDD and PDT. In addition, using a plurality of endoscopes is cumbersome for the user and has a great financial burden.
Japanese Patent No. 2596221

  Therefore, an object of the present invention is to obtain a detailed observation image at the time of PDD or PDT, and at the same time, to enable quick switching between PDD and PDT.

  The endoscope front end hood of the present invention includes a main body detachably attached to a distal end of an insertion tube provided with a light receiving unit for receiving light forming a subject image, and a laser that covers the light receiving unit when the main body is attached to the distal end of the insertion tube An optical cut filter is provided. With such a configuration, it is possible to switch between the PDD and the PDT without replacing the electronic endoscope by using the endoscope distal end hood when performing PDT.

  It is preferable that the main body includes a cylindrical body fitted to the distal end of the insertion tube and a holding body that holds the laser light cut filter at a first position in the cylindrical body.

  A first distance between a channel in which laser light irradiation means for irradiating laser light at the end face of the insertion tube tip is inserted, an objective optical system provided between the light receiving means and the laser light cut filter, and a laser The first position is determined according to the second distance determined based on the intensity of the laser light as the distance between the light irradiation means and the living tissue irradiated with the laser light, and the angle of view of the objective optical system. Is preferred. According to such a configuration, it is possible to easily position the laser light irradiation means with respect to the living tissue.

  The absorption wavelength peak of the laser light cut filter is preferably 620 to 680 nm.

  The light receiving means is preferably an image sensor.

  According to the present invention, PDD and PDT can be performed using a single endoscope for fluorescence observation, which is an electronic endoscope capable of fluorescence observation in addition to normal observation. Moreover, it becomes possible to determine in advance the insertion position of the laser beam irradiation means inserted into the living body via the endoscope during PDT.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, an electronic endoscope 20 to which an endoscope tip hood to which an embodiment of the present invention is applied will be described with reference to FIG. FIG. 1 is an external view of an electronic endoscope 20 to which an endoscope distal end hood to which an embodiment of the present invention is applied is mounted.

  The electronic endoscope 20 includes an operation unit 21, an insertion tube 22, and a connector unit 23. The operation unit 21 and the insertion tube 22 are connected. Further, the operation unit 21 and the connector unit 23 are connected. An endoscope distal end hood (not shown in FIG. 1) is attached to the distal end portion 24 of the insertion tube 22.

  An illumination light connector 23L provided in the connector portion 23 is optically connected to a light source device (not shown). A light guide (not shown in FIG. 1) is inserted from the illumination light connector 23L to the distal end portion 24 of the insertion tube 22. The light emitted from the light source device is emitted from the light guide emission end (not shown in FIG. 1) on the distal end portion 24 side.

  The distal end portion 24 is provided with an objective optical system (not shown in FIG. 1) and an image sensor (not shown in FIG. 1) such as a CCD. The objective optical system is provided on the end surface of the distal end portion 24. The objective optical system is optically connected to the image sensor. The insertion tube 22 is inserted into an observation site (not shown) in the living body.

  Light emitted from the exit end of the light guide is irradiated around the observation site. Light from the observation site is received by the imaging device as an optical image through an objective optical system (not shown in FIG. 1).

  A signal line (not shown) extends from the image sensor to the signal connector 23S of the connector unit 23, and a subject image captured by the image sensor is sent to the signal connector 23S as an image signal. The signal connector 23S is connected to an image signal processing device (not shown). The image signal output to the image signal processing device via the signal connector 23S is sent to a monitor (not shown) after being subjected to predetermined signal processing. The subject image is displayed on the monitor by the image signal subjected to the predetermined signal processing.

  The operation unit 21 is provided with an operation button (not shown) and an operation lever (not shown) for performing a predetermined operation of the electronic endoscope 20. The operation unit 21 is provided with a forceps port 25. A forceps channel (not shown in FIG. 1) connected to the forceps opening 25 is provided in the insertion tube 22. The forceps channel extends to the tip 24. A forceps (not shown), a laser probe (not shown in FIG. 1), and the like are inserted into the forceps channel from the forceps opening 25.

  Next, the configuration of the endoscope distal end hood 10 will be described with reference to FIGS. FIG. 2 is a perspective view of an endoscope tip hood to which an embodiment of the present invention is applied. FIG. 3 is a diagram illustrating a positional relationship when the endoscope front end hood is attached to the front end. FIG. 4 is a view of the endoscope front end hood as viewed from the direction opposite to the direction D1 in FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4 of the electronic endoscope 20 equipped with the endoscope front end hood. FIG. 6 is a diagram showing a display image displayed on the monitor.

  As shown in FIG. 2, the endoscope tip hood 10 includes a main body 11 and a laser beam cut filter 12. The main body 11 is formed by providing a disk-shaped holding portion 11b on the inner periphery of a cylindrical peripheral portion 11a. The holding part 11b is formed to be perpendicular to the cylindrical height direction D1 of the peripheral part 11a.

  As shown in FIG. 3, the endoscope front end hood 10 is attached to the insertion tube 22 from the attachment end 13 side which is one end along the cylindrical height direction D1 of the peripheral portion 11a. The inner periphery of the peripheral portion 11a on the mounting end 13 side is formed to have substantially the same shape as the outer periphery of the distal end portion 24 of the insertion tube 22. By fitting the distal end portion 24 and the mounting end 13 side of the peripheral portion 11a, the attachment of the endoscope distal end hood 10 to the insertion tube 22 is executed.

  As shown in FIG. 4, an observation hole 15, a forceps hole 16, and an irradiation hole 17 are formed in the holding portion 11b. The laser light cut filter 12 is fixed to the observation hole 15. As the laser light cut filter 12, for example, an optical filter having an absorption wavelength peak of 620 to 680 nm is used.

  In the state where the endoscope front end hood 10 is attached to the endoscope, the observation hole 15, the forceps hole 16, and the irradiation hole 17 are the objective optical system 26, the forceps channel 27, and the light at the distal end portion 24 of the insertion tube 22, respectively. The guide 28 is formed at a position overlapping the emission end 28a (see FIG. 3).

  The distance from the observation end 14, which is the end opposite to the mounting end 13, to the holding portion 11 b is set to a predetermined distance H as will be described later. Accordingly, the position of the laser light cut filter 12 held by the holding part 11b with respect to the peripheral part 11a is set to a predetermined position. The distance from the observation end 14 to the holding part 11b will be described with reference to FIG.

The predetermined distance H is a first distance h ₁ that is a distance between the center of the forceps channel 27 and the objective optical system 26 and a laser beam from the living tissue A that is determined with respect to the laser probe 31 that protrudes from the forceps hole 16. From the second distance h ₂ that is the distance to the emission end of the probe 31 and the angle of view (2 × θ) of the objective optical system 26, it is obtained by H = h ₂ + h ₁ × cot θ. Therefore, the predetermined distance H becomes longer as the first and second distances h ₁ and h ₂ become longer. Moreover, it becomes shorter as the angle of view (2 × θ) increases.

  The distance between the center of the forceps channel 27 and the objective optical system 26 is a distance connecting the point closest to the center of the forceps channel 27 from the periphery of the objective optical system 26 and the center of the forceps channel 27.

  A PDD and a PDT using the endoscope tip hood 10 having the above-described configuration will be described. First, when performing PDD, the insertion tube 22 is inserted into the living body without attaching the endoscope distal end hood 10.

  The electronic endoscope 20 when performing PDD is a fluorescence observation endoscope capable of normal observation and fluorescence observation, and an excitation light cut filter 30 is provided on the light receiving surface side of the image sensor 29 (FIG. 3, FIG. 3). (See FIG. 5). In addition, the light source device optically connected to the light guide 28 emits excitation light having a wavelength that causes fluorescence to be emitted to a photosensitive drug such as ultraviolet rays.

  Excitation light is applied to the observation site from the emission end 28 a of the light guide 28. The subject image of the observation site is captured by the image sensor 29 via the objective optical system 26 and the excitation light cut filter 30. The excitation light component is removed from the subject image by the excitation light cut filter 30. By removing the excitation light component, only the fluorescence component emitted from the biological tissue that is the subject when irradiated with the excitation light is imaged by the imaging element 29.

  A fluorescent image is displayed on a monitor (not shown) based on the fluorescent component of the subject imaged by the image sensor. PDD is performed by the user observing the fluorescent image.

  After confirming the position of the tumor or the like by PDD, the insertion tube 22 is once withdrawn from the living body. Next, the endoscope distal end hood 10 is attached to the distal end portion 24 of the insertion tube 22. Again, the insertion tube 22 is inserted into the living body.

  At this time, the subject is irradiated with white light from the emission end 28 a of the light guide 28. While observing the subject displayed on the monitor 32, a lesion such as cancer identified by the PDD is searched. After the lesion (see FIG. 6B) is found, the observation end 14 of the endoscope tip hood 10 is pressed against the living tissue A (see FIG. 5). Note that the observation end 14 is pressed so that the found lesion portion enters the inside of the surrounding portion 11a.

  The laser probe 31 is inserted into the space formed by the endoscope distal end hood 10 and the living tissue A through the forceps channel 27 and the forceps hole 16. As shown in FIG. 6, the laser probe 31 is inserted while the user observes the display image P displayed on the monitor 32.

  Prior to the insertion of the laser probe 31, the monitor 32 displays the lesion B and the inner wall of the peripheral part 11a. The laser probe 31 is inserted until the laser probe 31 appears at the end of the display image P. When the insertion of the laser probe 31 is completed, the lesion B is irradiated with laser light having a peak wavelength of 620 to 680 nm, and PDT is executed.

  After the PDT, the insertion tube 22 is once withdrawn from the living body. The endoscope distal end hood 10 attached to the distal end portion 24 is removed, and the insertion tube 22 is again inserted up to the peripheral region where PDT is performed in vivo.

  PDD is performed again in the peripheral area where PDT has been performed. That is, the peripheral region is irradiated with excitation light, and a fluorescence image is observed. By observing the fluorescence image after PDT, the therapeutic effect of PDT is confirmed. As described above, PDD and PDT are performed using the endoscope distal end hood 10 of the present embodiment.

  As described above, by using the endoscope tip hood 10 of the present embodiment, PDD and PDT can be performed by a single endoscope for fluorescence observation. Therefore, since there is no need to use a plurality of electronic endoscopes 20, switching of the electronic endoscope 20 is unnecessary, and the treatment time can be shortened. In addition, since the number of electronic endoscopes 20 prepared by the user is reduced, preparation and maintenance of the electronic endoscope are facilitated.

  Moreover, the positioning of the laser probe 31 is facilitated by using the endoscope distal end hood 10 of the present embodiment. As described above, the intensity of the laser beam used for PDT is high. Therefore, in order to ensure the safety of the patient, the distance from the living tissue is determined for each laser probe 31.

  As described above, when the laser probe 31 is displayed at the end of the display image P of the monitor 32 (see FIG. 6), the insertion is stopped, so that the distance between the laser probe 31 and the living tissue A can be determined. It is possible to adjust the distance to a predetermined distance for the laser probe 31.

  In addition, in this embodiment, although the cylindrical surrounding part 11a was used, what kind of shape may be sufficient. What is necessary is just to be able to fit with the front-end | tip part 24. In the present embodiment, the main body 11 is attached to the insertion tube 22 by fitting the peripheral portion 11a to the distal end portion 24. However, the main body 11 can be attached to the insertion tube 22 by any configuration. Good.

  Moreover, in this embodiment, although the holding part 11b was the disc in which the several holes 15-17 were formed, what kind of shape may be sufficient. When the endoscope front end hood 10 is attached to the insertion tube 22, the laser light cut filter 12 may be held at a position that covers the imaging element 29 and the objective optical system 26.

1 is an external view of an electronic endoscope to which an endoscope distal end hood to which an embodiment of the present invention is applied is mounted. It is a perspective view of the endoscope front end hood to which one embodiment of the present invention is applied. It is a figure which shows the positional relationship when attaching an endoscope front-end | tip hood to the front-end | tip part of an insertion tube. It is the figure which looked at the endoscope front end hood from the direction opposite to the direction D1 in FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4 of the electronic endoscope equipped with the endoscope front end hood. It is a figure which shows the display image displayed on a monitor. It is an external view of the conventional PDT apparatus. It is a figure which shows schematically the internal structure of an add-on camera.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 End endoscope hood 11 Main body 11a Peripheral part 11b Holding part 12 Laser light cut filter 13 Mounting end 14 Observation end 15 Observation hole 16 Forceps hole 17 Irradiation hole 20 Electronic endoscope 22 Insertion tube 24 Tip part 26 Objective optical system 27 Forceps channel 31 Laser probe 32 Monitor A Biological tissue B Foci P Display image

Claims (5)

A detachable main body at the distal end of the insertion tube provided with a light receiving means for receiving light forming the subject image
An endoscope distal end hood, comprising: a laser light cut filter that covers the light receiving means when the main body is attached to the distal end of the insertion tube.   2. The inner body according to claim 1, wherein the main body includes a cylindrical body that is fitted to a distal end of the insertion tube, and a holding body that holds the laser light cut filter at a first position in the cylindrical body. Endoscope hood. A first channel between a channel on the end face of the distal end of the insertion tube into which laser light irradiation means for irradiating laser light is inserted and an objective optical system provided between the light receiving means and the laser light cut filter. The distance of
A second distance determined on the basis of the intensity of the laser beam as a distance between the laser beam irradiation means and the biological tissue irradiated with the laser beam;
The endoscope front end hood according to claim 2, wherein the first position is determined according to an angle of view of the objective optical system.   The endoscope distal end hood according to any one of claims 1 to 3, wherein an absorption wavelength peak of the laser light cut filter is 620 to 680 nm. The endoscope front end hood according to any one of claims 1 to 4, wherein the light receiving means is an image sensor.

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