Patent Publication Number: US-2021169311-A1

Title: Fiberscope having excellent insertability

Description:
TECHNICAL FIELD 
     The invention relates to a fiberscope. 
     BACKGROUND ART 
     A laser therapy to irradiate laser light to an affected part is carried out in a cancer therapy using a fiberscope as an endoscope, for example. In this laser therapy, the tip of the endoscope is moved to a target site via a plurality of branch locations of a lumen in the body to irradiate the laser light. For example, in Patent Document 1, a hand operating portion provided on the proximal side of the endoscope is operated to carry out the curving operation of the endoscope at a branch location to make it easy to move the endoscope to the target site. 
     PRIOR ART DOCUMENT 
     Patent Document 
     
         
         Patent Document 1: JP 2015-062532 A 
       
    
     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
     However, in a case of an endoscope having a hand operating portion as in Patent document 1, a path for an operating member such as a wire needs to be provided from the hand operating portion (the proximal side of the endoscope) to the tip of the endoscope. In that case, the diameter of the endoscope increases in an amount corresponding to the space to provide the path for the operating member. Moreover, in a case of a structure in which an endoscope is guided along a guide wire, a channel for inserting the guide wire therethrough needs to be provided in the endoscope, increasing the diameter of the endoscope. 
     In a case that the tip of the endoscope cannot be operated with the hand operating portion or the guide wire, a procedure by a practitioner, such as rotating the endoscope in the circumferential direction of the axis thereof or pushing it in the axial direction thereof, causes the tip of the endoscope to be moved toward a target site. In this case, an insertion portion of the endoscope, such as the tip of the endoscope, which insertion portion thereof is inserted into a lumen, being flexible makes it easy for the endoscope to follow the shape of a route to the target site, the route being three-dimensionally winding. However, when the insertion portion of the endoscope is flexible, adjusting position of the tip of the endoscope at a branch location to the target site becomes difficult. 
     Thus, in view of such problems, an object of the invention is to provide an endoscope that makes it possible to select a target branched lumen at a branch of a lumen while maintaining the shape without increasing the diameter of the endoscope and adjust position of the tip portion and that makes it possible to curve along a route of the target branched lumen. 
     Means to Solve the Problem 
     An endoscope comprises a flexible elongated member having a tip portion and a proximal portion, the flexible elongated member comprising an elongated outer tube to be inserted into a lumen to be observed and an optical element unit provided inside the outer tube, wherein the flexible elongated member has a grip portion provided between the tip portion and the proximal portion, the flexible elongated member has an intermediate portion provided between the tip portion and the grip portion, when a rotating force in a circumferential direction of an axis of the flexible elongated member and a pushing force are applied to the grip portion, the rotating force and the pushing force are transmitted to the tip portion via the intermediate portion to position the tip portion in a predetermined direction, wherein the outer tube has an outer layer mainly containing a resin having flexibility and a reinforcement layer provided inside the outer layer, the optical element unit comprises an image transmission portion for image transmission, a laser transmission portion, and a fiber bundle for illumination, and the flexible elongated member has rigidity capable of selecting a target branched lumen from a branch of the lumen while maintaining the shape and position the tip portion, and flexibility capable of curving along a route to the target branched lumen. 
     Effects of the Invention 
     The endoscope according to the invention makes it possible to select a target branched lumen at a branch of a lumen while maintaining the shape without increasing the diameter of the endoscope and adjust position of the tip portion and makes it possible to curve along a route of the target branched lumen. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows one example of an endoscope system including an endoscope according to one embodiment of the invention. 
         FIG. 2  shows a cross section along X-X in  FIG. 1 . 
         FIG. 3  shows an enlarged view of an area E in  FIG. 1 , showing the internal structure of an outer tube in  FIG. 1 . 
         FIG. 4  schematically shows the tip of the endoscope according to one embodiment of the invention being introduced into a bronchiole of the lung. 
         FIG. 5  schematically shows a view of the tip of the endoscope according to one embodiment of the invention reaching the position of a tumor cell. 
         FIG. 6  schematically shows another view of the tip of the endoscope according to one embodiment of the invention reaching the position of the tumor cell. 
     
    
    
     EMBODIMENT FOR CARRYING OUT THE INVENTION 
     Below, with reference to the drawings, an endoscope according to one embodiment of the invention is described. The embodiments shown below are merely exemplary, so that the endoscope according to the invention is not limited to the embodiments below. 
       FIG. 1  shows one example of an endoscope system S comprising an endoscope according to one embodiment of the invention. The endoscope system S is used when carrying out examination and/or therapy for a patient using the endoscope, and, as shown in  FIG. 1 , comprises an endoscope and a system main body B. 
     A flexible elongated member  1  to be used as an endoscope is inserted into a lumen of the patient and the like, and examination and/or therapy with respect to a target site of the patient is carried out by making a tip portion T of the flexible elongated member  1  reach a target site being a site to be observed such as an affected part or a site to be examined. As shown in  FIGS. 1 and 2 , the flexible elongated member  1  comprises a tip portion T, a proximal portion P, and an elongated member main body H to be inserted into the lumen. The flexible elongated member  1  comprises an outer tube  2  being elongated, and an optical element unit  3  provided inside the outer tube  2 . The optical element unit  3  comprises an image transmission portion for image transmission  31 , a laser transmission portion  32 , and a fiber bundle for illumination  33 . While details are described below, after the flexible elongated member  1  is inserted into a lumen, a target site to be examined is illuminated by light from the fiber bundle for illumination  33 , an image of the lumen is transmitted by the image transmission portion  31  to make it possible to check the state of the target site. Laser therapy is carried out by laser light irradiated from the laser transmission portion  32 . The laser therapy using the endoscope includes ablation therapy and photodynamic therapy (PDT), for example. In the endoscope in the specification, the outer tube  2  mainly contains a deformable resin having flexibility and comprises a reinforcement layer  22 . The tip portion T of the outer tube  2  is deformed according to a curved shape of the lumen and a hand operation for deforming the tip portion T of the outer tube  2  is not performed. While the use of the flexible elongated member  1  is not particularly limited, in the embodiment, the endoscope is an endoscope for examination and/or therapy of the lung to be inserted into a lung peripheral part (a bronchiole, a respiratory bronchiole). Moreover, in another embodiment being different from the invention, the optical element unit  3  may be configured by the image transmission portion  31  and the fiber bundle for illumination  33  without using the laser transmission portion  32 , for example. In a case that the laser transmission portion  32  is provided to the endoscope, laser therapy may be carried out. 
     The overall shape of the flexible elongated member  1  is not particularly limited as long as the flexible elongated member  1  has an effect described below. In the embodiment, the flexible elongated member  1  is inserted into the lumen as shown in  FIG. 1 . The flexible elongated member  1  comprises the elongated member main body H, three tubes being first to third tubes  12   a ,  12   b ,  12   c  branching from a junction  6  connecting to the elongated member main body H, proximal portions Pa, Pb, Pc of the flexible elongated member  1  provided at the end of the three tubes being the first to third tubes  12   a ,  12   b ,  12   c , and first to third connectors  13   a ,  13   b ,  13   c  provided at the proximal portions Pa, Pb, Pc, respectively, and connected to the system main body B. The proximal portions Pa, Pb, Pc are collectively called the proximal portion P. For the first to third tubes  12   a ,  12   b ,  12   c  and the first to third connectors  13   a ,  13   b ,  13   c , an integrated-type connector in which the first to third connectors  13   a ,  13   b ,  13   c  are integrated may be used, or one tube may be used, without dividing into the first to third tubes  12   a ,  12   b ,  12   c , to provide a singular integrated-type connector at the end of the one tube. The elongated member main body H comprises the outer tube  2  and the optical element unit  3 . The optical element unit  3  is separated into members configuring the optical element unit  3  to extend to the proximal portions Pa, Pb, Pc through the first to third tubes  12   a ,  12   b ,  12   c . The first tube  12   a  and the first connector  13   a  connect the image transmission portion  31  to the system main body B. The second tube  12   b  and the second connector  13   b  connect the laser transmission portion  32  to the system main body B. The third tube  12   c  and the third connector  13   c  connect the fiber bundle for illumination  33  to the system main body B. While the flexible elongated member  1  may be introduced into the lumen without using other members, a bronchoscope may be used as an introduction assisting tool U when the elongated member  1  is introduced into the lumen. In the embodiment, the endoscope does not have a hand operating portion to subject the tip portion T of the flexible elongated member  1  to a curving action on the proximal portion P side of the flexible elongated member  1  and also does not have a physical channel through which a different member such as a guide wire is inserted. The flexible elongated member  1  also does not have an operating wire for operation to connect the hand operating portion and the tip portion T. Details of the endoscope will be described below. 
     The system main body B is a device to which the flexible elongated member  1  is connected and is to be an illumination light source and a laser light source of the endoscope. The system main body B processes an image imaged by the endoscope. In the embodiment, as shown in  FIG. 1 , the system main body B has a display device D, an imaging device IM, and a light source device LS. Moreover, the system main body B has a control device C and carries out various controls needed for illumination, imaging, and laser therapy by the flexible elongated member  1  as the endoscope. 
     The elongated member main body H is connected to the imaging device IM via the first connector  13   a . Light transmitted to the imaging device IM from the tip portion T via the image transmission portion  31  of the flexible elongated member  1  is processed by the imaging device IM. An image processed by the imaging device IM is displayed on the display device D. A known display device may be used for the display device D. 
     According to the embodiment, the light source device LS has an illumination light source LS 1  and a laser light source LS 2 . The elongated member main body H is connected to the illumination light source LS 1  via the third connector  13   c . Light irradiated from the illumination light source LS 1  such as an LED is transmitted to the tip portion T via the fiber bundle for illumination  33 . Light transmitted to the fiber bundle for illumination  33  is irradiated from the tip of the fiber bundle for illumination  33 , making it possible to illuminate the target site or the lumen to be observed. 
     The elongated member main body H is connected to the laser light source LS 2  via the second connector  13   b . Laser light output from the laser light source LS 2  is transmitted to the tip portion T via the laser transmission portion  32 . In this way, laser light for therapy is irradiated from the tip of the laser transmission portion  32 , making it possible to subject the affected part to laser therapy. The output and the wavelength of the laser light to be output from the laser light source LS 2  may be changed as needed in accordance with the therapy objective or the therapy method. For example, in a case of the photodynamic therapy (PDT), the output of the laser light may generally be set to approximately between 100 and 500 mW, or between 100 and 1000 mW, while the wavelength of the laser light may be set to a wavelength that makes it possible to excite a photosensitive drug, the wavelength being in the ultraviolet ray region (between 400 and 450 nm or in the neighborhood thereof) or in the infrared ray region (between 600 and 850 nm). A ruby laser, an alexandrite laser, a YAG laser, a dye laser, a diode laser, an excimer laser, or a fiber laser such as Yb (Ytterbium), for example, may be used as a laser to be output from the laser light source. 
     The image transmission portion  31  transmits light entering from the tip of the image transmission portion  31  to the imaging device IM. According to the embodiment, the image transmission portion  31  is an optical fiber extending from the proximal portion Pa (the first connector  13   a  side) of the flexible elongated member  1  to the tip portion T of the flexible elongated member  1 . The image transmission portion  31  is configured by approximately 9,000 optical fibers to set the curvature radius to less than or equal to 10 mm, and, more preferably, to between 6 and 7 mm. The image transmission portion  31  transmits light irradiated from the tip of the fiber bundle for illumination  33  and reflected from an observation object to the imaging device IM. This makes it possible to cause an image of the lumen to be displayed on the display device D. The first tube  12   a  is covered with a resin, so that the optical fibers are not bare. 
     The laser transmission portion  32  transmits laser light output from the laser light source LS 2  and irradiates the laser light from the tip of the laser transmission portion  32 . According to the embodiment, the laser transmission portion  32  is an optical fiber extending from the proximal portion Pb (the second connector  13   b  side) of the flexible elongated member  1  to the tip portion T of the flexible elongated member  1 . The laser transmission portion  32  may be configured by one or a plurality of optical fibers. The laser transmission portion  32  has the diameter of approximately 200 μm and preferably less than or equal to 150 μm. When the tip portion T of the flexible elongated member  1  reaches the target site, the laser light is irradiated from the laser transmission portion  32 . The laser light from the laser transmission portion  32  causes a photosensitive substance accumulated in an affected part such as a tumor cell to produce a photochemical reaction to subject the affected part to therapy in a case of PDT and causes the affected part such as the tumor cell to undergo ablation in a case of ablation therapy. The second tube  12   b  is covered with a resin, so that the optical fibers are not bare. 
     The fiber bundle for illumination  33  irradiates light from the tip of the fiber bundle for illumination  33 , the light being irradiated from the illumination light source LS 1 . According to the embodiment, the fiber bundle for illumination  33  is configured by a plurality of optical fibers extending from the proximal portion Pc side (the third connector  13   c ) of the flexible elongated member  1  to the tip portion T of the flexible elongated member  1 . The fiber bundle for illumination is configured by approximately between 150 and 300, or approximately less than 400 of optical fibers having the diameter of approximately between 30 and 50 μm. The light irradiated from the illumination light source LS 1  is irradiated via the fiber bundle for illumination  33  and illuminates the target site for examination or therapy, or the lumen at the branch location to the target site to cause the target site or the lumen to be visually recognizable. The third tube  12   c  is covered with a resin, so that the plurality of optical fibers are not bare. 
     As shown in  FIG. 2 , the fiber bundle for illumination  33  is provided so as to fill the space between an inner surface  21   a  of the inner layer  21  of the below-described outer tube  2 , an outer surface  31   a  of the image transmission portion  31 , and an outer surface  32   a  of the laser transmission portion  32 . Therefore, the image transmission portion  31 , the laser transmission portion  32 , and the fiber bundle for illumination  33  are filled inside the outer tube  2 . In other words, the flexible elongated member  1  being the endoscope does not have a hand operating portion capable of changing the curving state of the tip portion T by a hand operation (on the proximal portion P side) and the curving direction of the tip portion T of the flexible elongated member  1  is changed by rotational operation in the circumferential direction of the axis of the flexible elongated member  1  by a hand operation. Therefore, an operating member such as a wire that extends to the tip portion T from the proximal portion P side of the flexible elongated member  1  to change the curving state of the tip portion T is not provided. Moreover, a physical channel through which a different member such as a guide wire is to be inserted is also not provided. The tip portion T of the flexible elongated member  1  is curved beforehand and the advancing direction of the flexible elongated member  1  is changed when the extending direction of the tip T is changed by rotating the flexible elongated member  1  in the circumferential direction of the axis thereof. 
     The outer tube  2  is a tubular part being provided along the outer periphery of the optical element unit  3  and being positioned outer side of the flexible elongated member  1 . According to the embodiment, as shown in  FIG. 3 , the outer tube  2  has an outer layer  23  mainly containing a resin having flexibility, the reinforcement layer  22  provided inside the outer layer  23 , and the inner layer  21  configured by a resin having flexibility, the inner layer  21  covering the inside of the reinforcement layer  22 . While the outer tube  2  is configured by the inner layer  21 , the reinforcement layer  22 , and the outer layer  23 , it is not limited to the three-layer structure, so that the outer tube  2  may be configured by only the reinforcement layer  22  and the outer layer  23 . For example, the outer layer  23  may be subjected to coating treatment, or the reinforcement layer  22  may be directly wound to the optical element unit  3  without providing the inner layer  21 . 
     The inner layer  21  is a tubular layer configured by a resin having flexibility. The resin configuring the inner layer  21  includes Pebax, a polyamide-based elastomer, urethane, and nylon, for example. The inner layer  21  does not have to be formed. The optical element unit  3  is provided inside the inner surface  21   a  of the inner layer  21 . The reinforcement layer  22  is formed by a reinforcement body such as a wire made of a metal being wound outside the inner layer  21  in a mesh shape. The reinforcement layer  22  being formed in a mesh shape allows the flexible elongated member  1  to have a predetermined rigidity. The reinforcement layer  22  may be a metal braid layer configuring a metal wire in a net shape, or a coil layer, for example, however, the reinforcement layer  22  is not limited to such examples. The outer layer  23  is a tubular covering layer to cover the reinforcement layer  22 , and the outer layer  23  is configured by a resin having flexibility. The resin configuring the outer layer  23  includes Pebax, a polyamide-based elastomer, urethane, and nylon, for example. The outer layer  23  may be subjected to hydrophilic coating treatment. 
     The outer diameter of the outer tube  2  may be changed as needed in accordance with the use of the flexible elongated member  1 . In a case that the endoscope is an endoscope for lung examination and/or therapy to be inserted toward a lung peripheral part (a bronchiole, a respiratory bronchiole), for example, the outer diameter of the outer tube  2  may be set to be preferably between 0.5 and 2.5 mm and more preferably between 0.8 and 1.5 mm. 
     According to the embodiment, in the flexible elongated member  1 , when a rotating force in the circumferential direction of the axis of the flexible elongated member  1  is applied to a grip portion  4  provided between the tip portion T and the proximal portion P, the rotating force is transmitted to the tip portion T of the flexible elongated member  1  via an intermediate portion  5 . Therefore, the tip portion T of the flexible elongated member  1  is positioned in a predetermined direction. For example, in a case that, at a location in a lumen up to a target site (such as an affected part to be observed), the orientation of the tip portion T of the flexible elongated member  1  is not directed in the direction toward a route up to the target site, a rotating force is applied such that a twist is applied by a hand operation to the grip portion  4  of the flexible elongated member  1  in the circumferential direction of the axis thereof. In this way, a rotating force applied to the grip portion  4  of the flexible elongated member  1  is transmitted to the tip portion T of the flexible elongated member  1  via the intermediate portion  5  and the tip portion T of the flexible elongated member  1  rotates in the circumferential direction of the axis thereof. When the tip portion T is oriented in the direction of the route up to the target site, the grip portion  4  of the flexible elongated member  1  is pushed manually to advance the tip portion T of the flexible elongated member  1  in the lumen. Moreover, when the flexible elongated member  1  is introduced into the lumen, a bronchoscope may be used as the introduction assisting tool U. At that time, the bronchoscope is inserted up to the main bronchus of the lung and the flexible elongated member  1  is inserted into the sheath of the bronchoscope. After the tip portion T of the flexible elongated member  1  reaches the tip of the bronchoscope inserted into the lumen, by further advancing the flexible elongated member  1  so as to extend from the bronchoscope, the tip portion T can reach a target position TS beyond a lobar bronchus. 
     According to the embodiment, the reinforcement layer  22  and the optical element unit  3  have a predetermined rigidity capable of transmitting a rotating force of the flexible elongated member  1  in the circumferential direction of the axis thereof and a pushing force in the axial direction of the flexible elongated member  1 . Because of a predetermined rigidity of the reinforcement layer  22  provided inside the outer tube  2  and the optical element unit  3  provided along the axial direction of the outer tube  2  inside the reinforcement layer  22 , the rotating force applied at the grip portion  4  of the flexible elongated member  1  may be transmitted to the tip portion T of the flexible elongated member  1  via the intermediate portion  5 , so that the tip portion T of the flexible elongated member  1  easily rotates in the circumferential direction of the axis of the outer tube  2 . Therefore, it is easy to operate the tip portion T of the flexible elongated member  1  in a desired direction and it is easy to advance the flexible elongated member  1  toward the target site at the branch location of the lumen. Moreover, the reinforcement layer  22  and the optical element unit  3  having a predetermined rigidity makes it possible to transmit a pushing force being applied to the grip portion  4  of the flexible elongated member  1  to the tip portion T of the elongated member  1  so that the tip portion T of the flexible elongated member  1  easily advances. 
     Moreover, according to the embodiment, the reinforcement layer  22  and the optical element unit  3  have flexibility capable of curving along a route of a branch of a lumen while holding the shape of the tip portion T of the flexible elongated member  1 . The reinforcement layer  22  and the optical element unit  3  have a predetermined rigidity as described in the above, so that a predetermined shape may be held in a case that an external force is not applied to the tip portion T of the flexible elongated member  1 , and the shape of the tip portion T stabilizes to allow the tip portion T of the flexible elongated member  1  to be easily adjusted in the direction toward the target site at the branch location of the lumen. Furthermore, the reinforcement layer  22  and the optical element unit  3  have a predetermined flexibility, so that a portion from the tip portion T of the flexible elongated member  1  to the proximal portion P thereof can curve along the route of the branch of the lumen to be deformed. In the body, the body cavity is normally branched, so that, if rigidity of the flexible elongated member  1  is too high, the flexible elongated member  1  may press the wall portion of the lumen at a portion ahead of the branch and at a portion behind the branch at the time of advancing of the flexible elongated member  1 . However, since the flexible elongated member  1  has flexibility capable of deforming according to a curvature along the route of the branch of the lumen, pressing of the wall portion of the lumen may be prevented. Therefore, slidability in the lumen is improved. Therefore, even in a case of a large curvature of the lumen, insertion of the flexible elongated member  1  thereinto is possible, also reducing the burden on the lumen. For example, according to the embodiment, when the reinforcement layer  22  and the optical element unit  3  are inserted toward a lung peripheral part from a branch location in a bronchus of the lung, they have flexibility capable of curving along the curvature of the branch location. In this way, in a case that the flexible elongated member  1  is an endoscope for lung examination and/or therapy, the flexible elongated member  1  may be advanced along a route branching in a complex manner in the lung peripheral part from the lung bronchus, making it possible to carry out examination and/or therapy in the lung peripheral part. Moreover, in a case that the endoscope is inserted into a bronchoscope, flexibility of the flexible elongated member  1  does not impede the curving operation of the bronchoscope in a case that the tip of the bronchoscope is subjected to a curving operation, for example. 
     The flexible elongated member  1  is capable of curving along a complex branch of the lung, for example, the flexible elongated member  1  may curve with 90 degrees or greater, such as 180 degrees, while maintaining a bend radius of less than or equal to 10 mm, for example, between 6 and 7 mm. The bend radius of the flexible elongated member  1  may be decreased such that the flexible elongated member  1  may advance to a desired branched lumen at a branch of a lumen. The flexible elongated member  1  has flexibility capable of curving along the shape of a bronchus and rigidity capable of selecting a target branched lumen while holding the curvature shape and adjusting position of the tip portion T. To move to a target branched lumen to reach the target site, the flexible elongated member  1  positions the tip portion T thereof at a branch to an opening of the target branched lumen to advance the tip portion T thereof to the target branched lumen. In a case that rigidity of the flexible elongated member  1  is low, the tip portion T is hard to be positioned with respect to the opening of the target branched lumen at a branch due to the flexibility. However, as the flexible elongated member  1  has rigidity in addition to flexibility, it can position the tip portion T thereof to the opening of the target branched lumen at a branch and can advance the tip portion T thereof to the target branched lumen. 
     Moreover, the space between the inner surface  21   a  of the inner layer  21  of the flexible elongated member  1 , the outer surface  31   a  of the image transmission portion  31 , and the outer surface  32   a  of the laser transmission portion  32  are filled by the fiber bundle for illumination  33 . Furthermore, as described in the above, the flexible elongated member  1  is not provided with a physical channel to insert therethrough a different member such as a guide wire, or an operating member such as a wire, the operating member extending to the tip portion T from the proximal portion P of the flexible elongated member  1  to operate the tip portion T of the flexible elongated member  1  by a hand operation with a hand operating portion. Therefore, the outer diameter of the endoscope does not increase, making it possible to decrease the diameter of the endoscope. Thus, the endoscope may be easily inserted into a lumen having a narrow portion into which insertion of the endoscope is difficult, such as a lung peripheral part (a bronchiole, a respiratory bronchiole). 
     Next, an operation method of the endoscope according to the embodiment is described with a therapy method (PDT) of lung cancer being generated in a bronchiole or a respiratory bronchiole as an example. 
     First, a photosensitive substance such as a substance having oncotropicity and photosensitivity, for example, laserphyrin (registered trademark) or photofrin (registered trademark) is administered to a lung cancer patient. After the photosensitive substance accumulates in a tumor cell of lung cancer, a flexible elongated member  1  being an endoscope is moved to a bronchiole BR 2  via a bronchus BR 1  as shown in  FIG. 4 . At a branch location of the bronchiole BR 2  of the lung, a practitioner moves a tip portion T of the flexible elongated member  1  toward a target site TS while checking an image being transmitted from an image transmission portion  31  and being displayed on a display device D (see  FIG. 1 ). The tip portion T of the flexible elongated member  1  may be shaped such that the tip portion T curves slightly before being inserted into a lumen of the patient. As described in the above, the endoscope has a predetermined rigidity caused by a reinforcement layer  22  and a light element unit  3 , making it easy to adjust position of the tip portion T of the flexible elongated member  1  of the endoscope at the branch location of the bronchiole BR 2  of the lung and making it possible to cause the flexible elongated member  1  to reach the target site TS as shown in  FIG. 5 . 
     Laser light having a predetermined wavelength being irradiated from a laser transmission portion  32  of the endoscope, in a case that a site being irradiated is a tumor cell, causes the photosensitive substance being accumulated in the tumor cell to emit fluorescence. This completes specifying the site of the tumor cell by photodynamic diagnosis (PDD). After the tumor cell is specified, the wavelength of the laser light is changed by a light source device LS and the laser light is irradiated to the tumor cell emitting fluorescence. Therefore, a photodynamic reaction is produced to bring about the necrosis of the tumor cell due to a strong oxidation action. This makes it possible to carry out therapy of a tumor generated in the bronchiole BR 2  of the lung, or a respiratory bronchiole being further branched from the bronchiole BR 2  thereof. 
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
         
           
               1  FLEXIBLE ELONGATED MEMBER 
               12   a  FIRST TUBE 
               12   b  SECOND TUBE 
               12   c  THIRD TUBE 
               13   a  FIRST CONNECTOR 
               13   b  SECOND CONNECTOR 
               13   c  THIRD CONNECTOR 
               2  OUTER TUBE 
               21  INNER LAYER 
               21   a  INNER SURFACE OF INNER LAYER 
               22  REINFORCEMENT LAYER 
               23  OUTER LAYER 
               3  OPTICAL ELEMENT UNIT 
               31  IMAGE TRANSMISSION PORTION 
               31   a  OUTER SURFACE OF IMAGE TRANSMISSION PORTION 
               32  LASER TRANSMISSION PORTION 
               32   a  OUTER SURFACE OF LASER TRANSMISSION PORTION 
               33  FIBER BUNDLE FOR ILLUMINATION 
               4  GRIP PORTION 
               5  INTERMEDIATE PORTION 
               6  JUNCTION 
             B SYSTEM MAIN BODY 
             BR 1  BRONCHUS 
             BR 2  BRONCHIOLE 
             C CONTROL DEVICE 
             D DISPLAY DEVICE 
             H ELONGATED MEMBER MAIN BODY 
             IM IMAGING DEVICE 
             LS LIGHT SOURCE DEVICE 
             LS 1  ILLUMINATION LIGHT SOURCE 
             LS 2  LASER LIGHT SOURCE 
             P PROXIMAL PORTION OF FLEXIBLE ELONGATED MEMBER 
             Pa PROXIMAL PORTION OF FLEXIBLE ELONGATED MEMBER ON FIRST TUBE SIDE 
             Pb PROXIMAL PORTION OF FLEXIBLE ELONGATED MEMBER ON SECOND TUBE SIDE 
             Pc PROXIMAL PORTION OF FLEXIBLE ELONGATED MEMBER ON THIRD TUBE SIDE 
             S ENDOSCOPE SYSTEM 
             T TIP PORTION OF FLEXIBLE ELONGATED MEMBER 
             TS TARGET SITE 
             U INTRODUCTION ASSISTING TOOL