Optical fiber and tube for endoscope

Abstract

The present invention addresses the problem of obtaining an optical fiber that makes it possible to easily expand the field of view and an irradiation range without being constrained by the material used while avoiding an increase in size, and that is capable of maintaining insertability into a bent portion of a lumen of a digestive system organ, a respiratory system organ, or the like or a bent portion of a pipe of mechanical equipment. An optical fiber (100) according to the present invention has a body part (110) and a tip-end part (120). The tip-end part (120) is bent in advance with respect to the body part (110). For example, a bend angle (K1) obtained in advance is set such that a region along the axis (Ax1) of the body part (110) is included in a light reception or irradiation range (Vr) centered around the axis (Ax2) of the tip-end part (120).

Description

Fiber optic and endoscope tubing

[0001] The present invention relates to an optical fiber and an endoscope tube, and more particularly to a structure in which the tip portion is bent relative to the main body portion.

[0002] In recent years, optical fibers have been developed that enable image observation by bundling optical fiber strands. For example, Patent Document 1 (paragraph 0009) discloses a multi-optical fiber that constitutes an image transmission body as such an optical fiber. Optical fibers for irradiating a laser to treat an affected area are also known.

[0003] Japanese Patent Application Publication No. 9-146014

[0004] However, with optical fibers capable of transmitting such images, the resolution decreases when the field of view is expanded, so in order to expand the field of view while maintaining image quality, it is necessary to increase the number of optical fiber strands and make the bundle thicker.

[0005] However, this contradicts the need to reduce the diameter of optical fibers to improve their insertability into curved parts of lumens such as digestive organs such as the stomach and intestines, or respiratory organs such as the trachea and lungs, as well as curved parts of piping in mechanical equipment.

[0006] Furthermore, in optical fibers that transmit images or light (laser light or illumination light), the refractive index is limited by the material used, and therefore the incident and exit angles of the optical fiber (the incident and exit angles of light relative to the optical fiber) have an upper limit depending on the material used. Therefore, the expansion of the field of view or range of illumination by increasing the incident and exit angles is restricted by the material used.

[0007] The present invention aims to provide an optical fiber capable of transmitting images and light, which can easily expand the field of view and irradiation range without being restricted by the materials used while avoiding an increase in size of the optical fiber, and which can maintain insertability into curved parts of lumens such as those of the digestive system or respiratory system, or curved parts of piping in mechanical equipment. Another object of the present invention is to improve insertability into curved parts of lumens such as those of the intestines or lungs.

[0008] The present invention provides the following items.

[0009] (Item 1) An optical fiber having a body portion and a tip portion, the tip portion being pre-bent relative to the body portion.

[0010] (Item 2) The optical fiber according to Item 1, wherein the pre-bent bending angle is set so that a light receiving or irradiating range centered on the axis of the tip portion includes a region along the axis of the main body portion.

[0011] (Item 3) The optical fiber according to item 1, wherein the optical fiber has a structure in which a plurality of optical fiber bodies each consisting of a core portion as a core material and a cladding portion on the outside thereof are bundled together.

[0012] (Item 4) The optical fiber according to Item 1, wherein the optical fiber includes an image guide section that transmits an image or a laser irradiation section that irradiates laser light, the image guide section or the laser irradiation section is provided on one side of the axis of the main body section, and the tip section is bent in advance toward the side where the image guide section and / or the laser irradiation section is located with respect to the axis of the main body section.

[0013] (Item 5) The optical fiber according to item 1, wherein the bending angle formed by the axis of the tip portion relative to the axis of the main body portion is configured to be set according to the numerical aperture of the optical fiber.

[0014] (Item 6) The optical fiber according to Item 5, wherein the bending angle K is set based on the following formula:

[0015] K<arcsin NA (NA=numerical aperture) (Item 7) The optical fiber according to Item 5, wherein the bending angle K is set based on the following formula: K<arcsin NA (NA=numerical aperture) (Item 7)

[0016] K<(arcsin NA) / 3 (NA=numerical aperture) (Item 8) The optical fiber according to Item 6, wherein the angle formed by the axis of the tip portion with respect to the axis of the main body portion is set to be about 17 degrees to about 64 degrees or about 6 degrees to about 21 degrees when the numerical aperture of the optical fiber is about 0.3 to about 0.9, or about 13 degrees or about 4 degrees when the numerical aperture of the optical fiber is about 0.22.

[0017] (Item 9) A flexible tube for use in an endoscope, comprising the optical fiber according to item 1.

[0018] (Item 10) A tube according to Item 9, comprising a plurality of optical fibers, one of which comprises an image guide section for transmitting an image, and another of which comprises a light guide section for transmitting illumination light or a laser irradiation section for irradiating laser light, wherein the tip of at least one of the optical fibers is bent with respect to the main body section on the side where the image guide section is located with respect to the axis of the main body section.

[0019] (Item 11) A flexible tube for use in an endoscope, the tube having a main body and a tip, the tip having a camera provided on one side of its axis, and the tip being bent toward the side where the camera is located.

[0020] (Item 12) The tube according to item 11, further comprising a hollow tube therein into which a biopsy forceps, a therapeutic fiber, a thermocouple and / or a biopsy needle can be inserted.

[0021] According to the present invention, an optical fiber can be obtained that can easily expand the field of view and irradiation range without being restricted by the materials used, while avoiding the need for larger optical fibers, and that can maintain ease of insertion into curved parts of lumens such as digestive and respiratory organs, or curved parts of piping in mechanical equipment.

[0022] FIG. 2 is a diagram showing the appearance of an optical fiber 100 according to a first embodiment of the present invention. FIG. 3 is a diagram showing the specific structure of the optical fiber 100 shown in FIG. 1. FIG. 4 is a diagram explaining a mechanism for expanding the field of view or irradiation range of the optical fiber 100 shown in FIG. 1. FIG. 5 is a diagram showing a jig for rotating the optical fiber 100 shown in FIG. 1. FIG. 6 is a diagram showing an endoscope system 1000 including the optical fiber 100 shown in FIG. 7 is a diagram showing the structure of an endoscopic tube 200 according to a second embodiment of the present invention.

[0023] The present invention will be described below.Unless otherwise specified, it should be understood that the terms used in this specification are used in the meanings generally used in the relevant field.Therefore, unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the art to which this invention belongs.In the event of any discrepancy, this specification (including definitions) shall prevail.

[0024] In this specification, the term "about" refers to a range of ±10% of the following number.

[0025] The present invention aims to provide an optical fiber capable of transmitting images and light, which can easily expand the field of view or irradiation range without being restricted by the materials used while avoiding an increase in size, and which can be inserted easily into curved parts of lumens such as digestive organs and respiratory organs, or curved parts of piping in mechanical equipment.The above-mentioned problem has been solved by providing an optical fiber having a main body and a tip, and the tip is pre-bent relative to the main body.

[0026] In the optical fiber of the present invention having such a configuration, the tip portion is bent in advance relative to the main body portion, so that the end face of the tip portion (i.e., the light entrance face or light exit face of the optical fiber) faces in a direction inclined relative to the axis of the main body portion. Therefore, by rotating the main body portion about its axis, the end face of the tip portion faces in a direction inclined relative to the axis of the main body portion. As a result, in this optical fiber, the light entrance face or light exit face can be oriented in a direction inclined relative to the axis of the main body portion within a 360° range around the axis of the main body portion.

[0027] As a result, an optical fiber can be realized that can expand the field of view and irradiation range without being restricted by the material used and without increasing the diameter of the optical fiber.

[0028] As described above, the optical fiber of the present invention is not particularly limited in other configurations as long as the tip portion is bent in advance relative to the main body portion.

[0029] For example, in the optical fiber of the present invention, the bending angle is preferably set so that the field of view and irradiation range centered on the axis of the tip include the area along the axis of the main body. This is because, in this case, the area along the axis of the main body (also called the frontal area) can be included in the field of view and irradiation range without losing the area along the axis of the main body from the field of view and irradiation range, and the positional relationship between the expanded field of view and irradiation range and the frontal area (i.e., the area forward as the optical fiber is advanced) can be easily recognized. This makes it easier to analyze image information transmitted from the optical fiber and enables accurate application of illumination light, or even laser light for treatment or excitation, to the target object, preventing damage to the digestive organs, etc.

[0030] However, depending on the usage conditions of the optical fiber, if it is desired to include an area significantly deviated from the front area in the field of view or irradiation range, the bending angle of the optical fiber may not be set so that the field of view or irradiation range centered on the axis of the tip includes an area along the axis of the main body.

[0031] Here, the optical fiber preferably has a structure in which a plurality of optical fiber bodies (i.e., optical fiber strands) each consisting of a core portion as a core material and an outer cladding portion are bundled together. In this case, by increasing the number of optical fiber strands, the field of view or the illumination range can be expanded as an image guide portion for transmitting an image or a light guide portion for transmitting illumination light.

[0032] Furthermore, the optical fiber of the present invention includes an image guide section for transmitting an image. When the image guide section is located on one side of the axis of the main body section, the tip section is preferably bent in advance toward the side where the image guide section is located with respect to the axis of the main body section. This is because, by bending the tip section toward the image guide section that acquires an image, the optical fiber can include an image of an area along a direction more inclined relative to the axis of the main body section, compared to when the tip section is bent toward the opposite side of the image guide section, thereby further expanding the field of view of the image guide section. Note that a laser irradiation section that irradiates laser light may be provided instead of the image guide section. This laser irradiation section is a laser guide section that transmits laser light and is generally composed of an optical fiber strand (single strand). However, if the structure is composed of multiple optical fiber strands, the irradiation range of the laser light can be expanded by increasing the number of optical fiber strands. Furthermore, the laser guide section may be, for example, a therapeutic laser irradiation section that cauterizes an affected area, or an excitation laser irradiation section that excites a fluorescent agent.

[0033] Furthermore, a light guide section may be provided instead of the laser guide section. In this case, the light guide section transmits the illumination light, so that it is possible to expand the irradiation range of the illumination light.

[0034] In the optical fiber of the present invention, the bending angle formed by the axis of the tip portion relative to the axis of the main body portion is preferably set in accordance with the numerical aperture of the optical fiber.

[0035] Numerical aperture (NA) is generally an index used to determine the brightness, resolution, and focal depth of a lens. The numerical aperture of an optical fiber is an index that indicates the range of light that can be taken in by the optical fiber, or the range of illumination light from a laser light or an LED, a xenon lamp, or the like that can be irradiated from the optical fiber, or, simply put, the extent to which light from a direction inclined relative to the axis of the optical fiber can be taken in or irradiated. In light of this, the inventors of the present application have discovered a relationship between the numerical aperture of an optical fiber and the bending angle.

[0036] For example, if the numerical aperture of the optical fiber is large, it can also take in light from a direction more inclined with respect to the axis of the main body, and therefore by setting the bending angle according to the numerical aperture of the optical fiber, it is possible to set the bending angle of the tip with respect to the main body just enough so that the front region does not fall outside the field of view, thereby efficiently expanding the field of view. Alternatively, it is possible to irradiate light in a direction more inclined with respect to the axis of the main body, and therefore by setting the bending angle according to the numerical aperture of the optical fiber, it is possible to set the bending angle of the tip with respect to the main body just enough so that the front region does not fall outside the irradiation range, thereby efficiently expanding the irradiation range.

[0037] The relationship between the bending angle (K) and the numerical aperture (NA) of the optical fiber is expressed by the following formula (1).

[0038] K<arcsin NA (1) In particular, it is preferable to satisfy the following formula (2):

[0039] K<(arcsin NA) / 3 ...Equation (2) This is because, considering that the intensity of light emitted from a light source such as a light-emitting element (LED) or a laser element (LD) decreases according to a roughly Gaussian distribution as it moves away from the center of the optical axis toward the periphery, and that the performance of the lens also decreases in a similar manner, as long as the range satisfying equation (2) is met, the light intensity and optical performance practically required in the axial direction of the optical fiber can be obtained.

[0040] In practical use, the angle (bending angle) between the axis of the tip portion and the axis of the main body portion is set to, for example, about 17 degrees to about 64 degrees (preferably about 6 degrees to about 21 degrees) when the numerical aperture of the optical fiber is about 0.3 to about 0.9, or about 13 degrees (preferably about 4 degrees) when the numerical aperture of the optical fiber is about 0.22. Note that if the bending angle is too small, the selectivity for the shape of the digestive organ into which the optical fiber is inserted decreases, making it more likely to strike tissue. On the other hand, if the bending angle is too large, the front (direction of travel) becomes invisible, and the field of view and laser light irradiation range do not hit the front, making operation difficult. Therefore, the optical fiber of the present invention is characterized by setting the bending angle so that the field of view or irradiation range centered on the axis of the tip portion includes the area along the axis of the main body portion. Furthermore, in one embodiment, the optical fiber of the present invention is used in an endoscopic tube.

[0041] In this case, a flexible endoscopic tube for use in an endoscope includes the optical fiber described above.

[0042] Furthermore, in this case, the endoscope tube may include one optical fiber or a plurality of optical fibers.

[0043] When the endoscopic tube includes a plurality of optical fibers, one of the plurality of optical fibers may include an image guide portion for transmitting an image, and another of the plurality of optical fibers may include a laser irradiation portion for irradiating laser light (a laser guide portion for transmitting laser light). In this case, it is preferable that at least one of the optical fibers including the image guide portion has its tip bent relative to the axis of the main body portion toward the side where the image guide portion is located. The reason for this is that the range (observation field) for acquiring image information can be further widened, as described above.

[0044] The endoscopic tube may also include a plurality of optical fibers, one of which includes an image guide for transmitting an image, and another of which includes a light guide for transmitting illumination light. In this case, it is preferable that the tip of at least one optical fiber bends toward the side of the main body where the image guide is located with respect to the axis of the main body. This is because, as described above, the range (field of view) for acquiring image information can be further widened. It is also preferable that the tip of the endoscopic tube itself, in which the optical fiber is provided, bends toward the side of the main body where the image guide is located.

[0045] Furthermore, the optical fiber structure of the present invention (structure in which the tip portion is bent relative to the main body portion) can also be applied to an endoscopic tube that has flexibility for use in an endoscope and does not have an optical fiber.

[0046] In this case, the tube has a main body and a tip, and the tip is equipped with a camera provided on one side of its axis, and the tip is bent toward the side where the camera is located, so other configurations are not limited.

[0047] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0048] In this specification, the terms optical fiber strand, fiber bundle, image guide, light guide, laser guide, and fiberscope are defined as follows, and optical fiber is a general term for these, and refers to a fiber-like optical transmission body through which light propagates.

[0049] Optical fiber wire: A single wire consisting of a core portion as the core material and an outer cladding portion.

[0050] ・Fiber bundle: A bundle of multiple optical fiber strands.

[0051] ・Image guide (also called image guide section): Optical fiber (generally a fiber bundle) that transmits images ・Light guide (also called light guide section): Optical fiber (generally a fiber bundle) that transmits illumination light (light from a light source such as a xenon lamp or LED) ・Laser guide (also called laser guide section or laser irradiation section): Optical fiber that transmits laser light used for treatment, excitation, etc. This laser guide is generally composed of a single optical fiber strand, but may also be composed of multiple optical fiber strands.

[0052] Fiberscope: A device equipped with an image guide and a light guide, used for observing, treating, or exciting the inside of a lumen, and which may also include a laser guide if necessary.

[0053] (Embodiment 1) Figure 1 is a diagram for explaining an optical fiber 100 according to embodiment 1 of the present invention, where Figure 1(a) shows the appearance of the optical fiber 100, and Figure 1(b) shows the relationship between the field of view Vr of the optical fiber 100 and the bending angle K1.

[0054] As shown in Fig. 1(a), the optical fiber 100 of this embodiment 1 has a main body portion (also referred to as an optical fiber main body portion) 110 and a tip portion (also referred to as an optical fiber tip portion) 120, and the optical fiber tip portion 120 is pre-bent with respect to the optical fiber main body 110. Here, as shown in Fig. 1(b), the pre-bent bending angle K1 is set so that a light receiving range (field of view range) Vr centered on the axis Ax2 of the optical fiber tip portion 120 includes an area along the axis Ax1 of the optical fiber main body 110. Furthermore, the optical fiber 100 has a structure (fiber bundle) in which a plurality of optical fiber bodies (optical fiber strands) each consisting of a core portion as a core material and a cladding portion surrounding the core portion are bundled together.

[0055] The specific configuration of this optical fiber 100 will now be described.

[0056] Figure 2 shows an example of a specific structure of the optical fiber 100 shown in Figure 1, where Figure 2(a) shows the image guide section 100a and the light guide section 100b included in the optical fiber 100, and Figure 2(b) specifically shows the cross-sectional structure taken along line IIa-IIa in Figure 2(a). Also, Figure 2(c) specifically shows a cross-sectional structure different from that in Figure 2(b).

[0057] 2(a), the optical fiber 100 includes an image guide section 100a that transmits an image and a light guide section 100b that transmits illumination light from a light source (not shown). Note that a laser guide section (not shown) that is a laser irradiation section that irradiates laser light may be included between the plurality of optical fiber strands 101b that make up the light guide section 100b.

[0058] Here, the image guide portion 100a is provided on one side of the axis Ax1 of the optical fiber main body portion 110, and the optical fiber tip portion 120 is bent in advance toward the side where the image guide portion 100a is located relative to the axis Ax1 of the optical fiber main body portion 110 (Figure 2(a)).

[0059] This optical fiber 100 is configured so that the bending angle (K1) (see FIG. 1(b)) between the axis Ax1 of the optical fiber main body 110 and the axis Ax2 of the optical fiber tip 120 is set according to the numerical aperture (NA) of the optical fiber 100, and specifically, is set based on the following equation (1):

[0060] K1<arcsin NA (1) Preferably, the relationship between the bending angle (K1) and the numerical aperture (NA) satisfies the following formula (2). The reason for this is, as described above, that the practically required light intensity and optical performance can be obtained in the axial direction of the optical fiber: K1<(arcsin NA) / 3 (2) In addition, in optical fiber 100, when image guide section 100a and light guide section 100b are made of optical fibers with different numerical apertures, the numerical aperture of image guide section 100a is used as the numerical aperture of optical fiber 100.

[0061] More specifically, the numerical aperture of the optical fiber 100 is approximately 0.22, and accordingly, the angle K1 formed by the axis Ax2 of the optical fiber tip 120 with respect to the axis Ax1 of the optical fiber main body 110 is set to approximately 13 degrees (preferably approximately 4 degrees). However, if the numerical aperture differs, the angle K1 also differs, and when the numerical aperture of the optical fiber is approximately 0.3 to approximately 0.9, the angle K1 is set to approximately 17 degrees to approximately 64 degrees (preferably approximately 6 degrees to approximately 21 degrees).

[0062] Next, the specific configuration of the image guide section 100a and the light guide section 100b will be described with reference to FIG.

[0063] 2(b), the image guide section 100a constituting the optical fiber 100 has a structure in which a plurality of core wires 101a, which are bundled together so that each core wire forms a pixel, are embedded in a cladding medium 102a, and these are covered with a coating layer 103a, and is housed in a housing tube 100d, which forms the outer peripheral wall of the optical fiber 100, at a position shifted to one side with respect to the axis of the optical fiber 100. Note that the image guide section 100a is not limited to a structure in which a plurality of core wires 101a are embedded in a cladding medium 102a, but may also have a structure (fiber bundle section) in which optical fiber strands 101b, each consisting of a core and a cladding, are bundled together.

[0064] The light guide section 100b constituting the optical fiber 100 has a structure (fiber bundle section) in which optical fiber strands 101b consisting of a core and a clad are bundled together, and is housed in an area other than the area occupied by the image guide section 100a within the housing tube 100d.

[0065] The location where the light guide section 100b is housed may be provided with a treatment or excitation laser irradiation section that irradiates treatment or excitation laser light for cauterizing an affected area, etc., or for exciting a drug, etc. This laser irradiation section is generally a laser guide section that transmits laser light and is made up of a single line (optical fiber strand), but may also be a laser guide section made up of multiple optical fiber strands.

[0066] Next, a method for using this optical fiber 100 will be described.

[0067] 3A and 3B are diagrams for explaining how to use the optical fiber 100 shown in FIG. 1, in which FIG. 3A shows the field of view (observation area) Vr1 when the tip of the optical fiber 100 is not bent, FIG. 3B shows the field of view (observation area) Vr when the tip of the optical fiber 100 is bent, superimposed on the field of view Vr1 when the tip is not bent, FIG. 3C shows how the field of view (observation area) or irradiation range Vr moves as the optical fiber 100 rotates around the main body axis Ax1, and FIG. 3D shows the field of view or irradiation range Vr2 that can be observed when the optical fiber 100 with a bent tip is rotated once around the axis Ax1 of the main body 110.

[0068] For example, when the optical fiber 100 of this embodiment 1 is used to observe the inside of a narrow lumen such as digestive organs such as the stomach, large intestine, and esophagus, respiratory organs such as the lungs and trachea, or the piping of mechanical equipment (machines, buildings), if the optical fiber 100 is inserted into the lumen from the optical fiber tip 120 and the optical fiber main body 110 is rotated around the axis Ax1, the field of view (observation region) Vr corresponding to the optical fiber tip 120 bent with respect to the optical fiber main body 110 will rotate around the field of view (observation region) Vr1 corresponding to the optical fiber tip 120 that is not bent with respect to the optical fiber main body 110, as shown in Figures 3(b) and (c) .

[0069] Therefore, the field of view Vr2 of the optical fiber 100 in which the optical fiber tip 120 is bent relative to the optical fiber main body 110 can be a wide field of view that is an enlarged version of the field of view Vr1 of the optical fiber in which the optical fiber tip 120 is not bent relative to the optical fiber main body 110 (FIG. 3(d)). (Optical Fiber Rotating Jig) Next, a jig for rotating the optical fiber 100 will be described.

[0070] FIG. 4 is a diagram showing a jig for rotating the optical fiber 100 of the present invention.

[0071] FIG. 4 shows an example of a jig for rotating the optical fiber of the present invention, the tip of which is bent in advance.

[0072] For example, as shown in FIG. 4A , the optical fiber 100 is inserted into a guide tube 300 in a state in which it can move freely within the tube. A rotation operation piece 310 is fixed to the optical fiber 100, and an operator can rotate the optical fiber by holding the rotation operation piece 310 in his / her hand and rotating the rotation operation piece 310. The guide tube 300 and the rotation operation piece 310 may be provided with engagement portions 300 a, 310 b that enable them to engage with each other. In this case, the operator can grasp the rotation operation piece 310 to move the optical fiber 100 in the axial direction, and then engage the engagement portion 300 a with the engagement portion 310 b at a predetermined position to rotate the guide tube 300.

[0073] 4(b) shows a rotation operation piece 400 including a pair of gripping portions 402 and an optical fiber fixing portion 401 disposed between them. With the optical fiber 100 inserted through the optical fiber fixing portion 401, the pair of gripping portions 402 are folded so that they overlap, and the overlapping portion serves as a handle for rotation operation. The optical fiber 100 can be rotated by repeatedly holding the handle to move the optical fiber, releasing it, and returning the jig, and then gripping and rotating it at a predetermined position. The optical fiber fixing portion 401 may be provided with multiple protrusions, and the optical fiber 100 may be inserted between the multiple protrusions to improve the fixing force of the optical fiber.

[0074] As shown in FIG. 4( c), the rotation operation piece 500 may be configured from a pair of upper and lower optical fiber fixing pieces 501, 502. The optical fiber is moved by holding the pair of optical fiber fixing pieces 501, 502, and then released and the jig is returned, and the process is repeated until the optical fiber is gripped and rotated at a predetermined position. Each of the pair of optical fiber fixing pieces 501, 502 has multiple protrusions. By inserting the optical fiber 100 between these protrusions, it is possible to improve the fixing force of the optical fiber 100. The multiple protrusions may be provided on only one of the pair of optical fiber fixing pieces.

[0075] (Effects of Embodiment 1) (1) As described above, the optical fiber 100 of this embodiment 1 has the main body 110 and the tip 120, and the tip 120 is bent in advance relative to the main body 110. This makes it possible to easily expand the field of view and irradiation range without being restricted by the material used, while avoiding an increase in the diameter of the optical fiber capable of image transmission, etc. Furthermore, since the tip is bent, it is also possible to improve the ease of insertion into bent or curved digestive organs such as the intestinal tract or stomach, respiratory organs such as the lungs or trachea, or the piping of mechanical equipment.

[0076] (2) The pre-bent bending angle K1 is set so that the light receiving range (field of view) or irradiation range Vr centered on the axis Ax2 of the tip portion 120 includes an area along the axis Ax1 of the main body portion 110. This makes it possible to include the area around the frontal area in the field of view or irradiation range without losing the area along the axis Ax1 of the main body portion 110 (also called the frontal area) from the field of view or irradiation range Vr. As a result, the positional relationship between the expanded field of view or irradiation range and the frontal area can be easily recognized, facilitating the analysis of image information transmitted from the optical fiber. Furthermore, it is possible to accurately apply illumination light or laser light for treatment or excitation to the target object, preventing damage to the digestive or respiratory organs, etc.

[0077] (3) In this optical fiber 100, when the image guide unit 100a that transmits an image or the light irradiation unit (light guide unit 100b and / or laser irradiation unit) that irradiates light is provided on one side of the axis Ax1 of the optical fiber main body 110, the optical fiber tip 120 is bent in advance toward the side where the image guide unit 110a or the light irradiation unit is located with respect to the axis Ax1 of the optical fiber main body 110. This makes it possible to capture an image of an area along a direction more inclined with respect to the axis Ax1 of the optical fiber main body 110, or to irradiate light such as laser light or illumination light onto an area along a direction more inclined with respect to the axis Ax1 of the optical fiber main body 110, compared to when the optical fiber tip 120 is bent on the opposite side of the image guide unit 100a or the light irradiation unit. As a result, the range (field of view) over which the image is captured by the image guide unit 100a or the range over which the light irradiation unit irradiates can be further expanded.

[0078] (4) In this optical fiber 100, the bending angle K1 formed by the axis Ax2 of the optical fiber tip 120 relative to the axis Ax1 of the optical fiber main body 110 can be set in accordance with the numerical aperture of the optical fiber 100, thereby easily determining the bending angle K1 of the optical fiber tip 120 that can expand the field of view or irradiation range without causing the front area to deviate from the field of view or irradiation range.

[0079] (5) By rotating the optical fiber 100, it is possible to make the distribution of the Gaussian-distributed laser light or illumination light output from the optical fiber uniform.

[0080] In other embodiments, the optical fiber 100 of embodiment 1 may be used in a flexible endoscopic tube for use in an endoscope, in which case the endoscopic tube comprises the optical fiber of the present invention described above.

[0081] Furthermore, in this case, the endoscope tube may include one optical fiber or a plurality of optical fibers.

[0082] When the endoscopic tube includes a plurality of optical fibers, one of the plurality of optical fibers may include an image guide section for transmitting an image, and another of the plurality of optical fibers may include a light irradiation section for irradiating light (e.g., an illumination light irradiation section, a laser irradiation section). In this case, it is preferable that at least one of the optical fibers including the image guide section has its tip bent relative to the axis of the main body section toward the side where the image guide section is located. The reason for this is that, as described above, the range over which image information can be acquired can be further expanded.

[0083] The optical fibers may be configured to have an image guide section, a light guide section, and a laser guide section, or may include other optical fibers.

[0084] A specific endoscope system 1000 in which the optical fiber of the first embodiment is used will be described below.

[0085] FIG. 5 is a diagram showing an endoscope system 1000 including the optical fiber 100 shown in FIG.

[0086] This endoscope system 1000 includes an optical fiber 100 and a system main body 40 that processes optical signals from the optical fiber 100. Here, the optical fiber 100 has a distal end portion 10 thereof that is inserted into an endoscope tube (not shown).

[0087] The endoscope tube may be provided with a hollow tube for inserting a biopsy forceps or a treatment fiber. The biopsy forceps and the treatment fiber may be inserted into a single hollow tube, or they may be inserted into separate hollow tubes.

[0088] In addition to the above-mentioned biopsy forceps and treatment fibers, the objects to be inserted into the hollow tube may also include various other devices such as a thermocouple for measuring the temperature of biological tissue and a biopsy needle for collecting biological tissue.

[0089] In particular, since therapeutic laser light has a high output, there is a concern that the temperature of biological tissue may rise. However, the distribution of the Gaussian-distributed laser light or illumination light output from the optical fiber of the present invention is made uniform, thereby making it possible to suppress local temperature rises in biological tissue.

[0090] In conventional endoscopes without bending sections, it was difficult to bring a thermocouple into contact with the wall of a tubular tissue such as a trachea. However, by rotating the tube (fiber) with a bent tip of the present invention, it is possible to place a thermocouple on the desired wall of the tubular tissue.

[0091] The laser optical fiber 100 is a fiberscope having an image guide section 100a that transmits an image, a light guide section 100b that transmits illumination light, and a laser guide section 100c that transmits laser light, and the multiple optical fiber strands that make up the distal end section 10 of each guide section are housed integrally in a single housing tube 100d (see FIG. 2(a)). This distal end section 10 includes a distal end section 120 and the remaining main body section 110, and the distal end section 120 is bent relative to the main body section 110.

[0092] At the branching section 20 connected to one of the housing tubes 100d, the optical fiber strands housed in the one of the housing tubes 100d are grouped and extracted into those constituting the image guide section 100a, those constituting the light guide section 100b, and those constituting the laser guide section 100c, and the extracted optical fiber strands are connected to the corresponding image guide connector 11a, light guide connector 11b, and laser guide connector 11c.

[0093] On the other hand, the system main body 40 has an imaging device 40a that captures an image from the image guide section 100a, an illumination light source 40b that outputs illumination light to the light guide section 100b, a laser light source 40c that outputs laser light to the laser guide section 100c, and a control device 40d that controls the imaging device 40a, the illumination light source 40b, and the laser light source 40c in accordance with the operation of the operator.

[0094] Here, the imaging device 40a is connected to the image guide section 100a via an image guide connector 11a, the illumination light source 40b is connected to the light guide section 100b via a light guide connector 11b, and the laser light source 40c is connected to the laser guide section 100c via a laser guide connector 11c. A display device 41 is also connected to the system main body 40, and the display device 41 displays operations performed by the operator, images captured by the imaging device 40a, and the like.

[0095] Furthermore, the structure in which the tip 120 of the optical fiber 100 of embodiment 1 is bent relative to its main body 110 can also be applied to flexible tubes for use in endoscopes, particularly those that do not have an optical fiber, and such an endoscopic tube will be described below as embodiment 2 of the present invention.

[0096] In this case, the tube has a main body and a tip, and the tip is equipped with a camera provided on one side of its axis, and the tip is bent toward the side where the camera is located, so other configurations are not limited.

[0097] (Embodiment 2) Figure 6 is a diagram for explaining an endoscopic tube 200 according to embodiment 2 of the present invention, in which Figure 6(a) shows the appearance of this endoscopic tube 200, Figure 6(b) shows the structure of the tip surface of this endoscopic tube 200, and Figure 6(c) shows the relationship between the field of view (observation area) Vr2 of the camera 200a mounted on this endoscopic tube 200 and the bending angle K2 of the tip.

[0098] This endoscopic tube 200 is a flexible tube for use in an endoscope, and as shown in Figure 6 (a), it has a main body portion (also called a tube main body portion) 210 and a tip portion (also called a tube tip portion) 220.

[0099] Here, the tube tip 220 has a camera unit 200a provided on one side of its axis Bx2 and a light-emitting unit 200b provided on the other side of its axis Bx2, and the tube tip 220 is bent toward the side where the camera unit 200a is located.

[0100] Here, the bending angle (K2) is the angle between the axis Bx2 of the tube tip 220 and the axis Bx1 of the tube main body 210, and is set based on the numerical aperture (NA2) of the optical system of the camera 200a. Here again, the bending angle K2 can be calculated from the numerical aperture NA2 based on the above formula (1) or formula (2).

[0101] The endoscope tube 200 may be bent so as to maintain the bending angle by inserting it into a bent metal pipe or by filling it with adhesive.

[0102] In the endoscope tube 200 of the second embodiment of the present invention having such a configuration, it is possible to easily achieve an enlargement of the field of view of the camera unit while avoiding an increase in the size of the camera unit that captures images.

[0103] In addition, although the second embodiment describes the expansion of the field of view of the camera unit, by using the camera unit as a light irradiation unit that irradiates illumination light or treatment light, it is possible to easily expand the irradiation range without being restricted by the materials used and while avoiding an increase in size.

[0104] As described above, the present invention has been illustrated using preferred embodiments of the present invention, but the present invention should not be construed as being limited to these embodiments. It is understood that the scope of the present invention should be interpreted only by the claims. It is understood that a person skilled in the art can implement an equivalent scope based on the description of the present invention and common general technical knowledge from the description of specific preferred embodiments of the present invention. It is understood that the contents of the documents cited in this specification should be incorporated by reference into this specification as if the contents themselves were specifically set forth in this specification.

[0105] The present invention is useful in the field of optical fibers as it can easily expand the field of view and irradiation range without being restricted by the materials used, while avoiding the need for larger optical fibers, and it also maintains insertability into curved parts of lumens such as those of the digestive system and respiratory system, or curved parts of piping in mechanical equipment.

[0106] 10 Tip side portion 11a Image guide connector 11b Light guide connector 11c Laser guide connector 40 System main body 40a Imaging device 40b Illumination light source 40c Laser light source 40d Control device 41 Display device 100 Optical fiber 100a Image guide section 100b Light guide section 100c Laser irradiation section (laser guide section) 100d Enclosure tube 101a Core wire 101b Optical fiber wire 102a Cladding medium 103a Coating layer 110 Optical fiber main body section (main body section) 120 Optical fiber tip section (tip section) 200 Endoscope tube 200a Camera section 200b Light emitting section 210 Tube main body section (main body section) 220 Tube tip section (tip section) 300 Guide tube 300a, 310b Engagement section 310, 400, 500 Rotation operation piece 401 Optical fiber fixing part 402 Grip part 501, 502 Optical fiber fixing piece 1000 Endoscope system Ax1, Bx1 Axis center of main body part Ax2, Bx2 Axis center of tip part K1, K2 Bending angle Vr, Vr1, Vr2 Field of view range

Claims

1. An optical fiber including an image guide section for transmitting an image and / or a laser irradiation section for irradiating laser light, and a housing tube for housing the image guide section and / or the laser irradiation section, The optical fiber has a main body and a tip, and the image guide and / or the laser irradiation unit are provided on one side of the axis of the main body, and the tip is pre-bent toward the side on which the image guide and / or the laser irradiation unit are located, with respect to the axis of the main body.

2. The pre-bent bending angle is: The optical fiber according to claim 1 , wherein a light receiving or irradiating range centered on an axis of the tip portion is set to include a region along the axis of the main body portion.

3. 2. The optical fiber according to claim 1, wherein the optical fiber has a structure in which a plurality of optical fiber bodies, each of which has a core portion as a core material and a cladding portion on the outer side thereof, are bundled together.

4. The optical fiber according to claim 1 , wherein the bending angle is configured to be set according to a numerical aperture of the optical fiber.

5. The optical fiber according to claim 4 , wherein the bending angle K is set based on the following formula: K<arcsin NA (NA=numerical aperture)

6. The optical fiber according to claim 4 , wherein the bending angle K is set based on the following formula: K<(arcsin NA) / 3 (NA=numerical aperture)

7. The angle between the axis of the body and the axis of the tip is:

6. The optical fiber of claim 5, wherein the optical fiber is set to be about 17 degrees to about 64 degrees or about 6 degrees to about 21 degrees when the numerical aperture of the optical fiber is about 0.3 to about 0.9, or about 13 degrees or about 4 degrees when the numerical aperture of the optical fiber is about 0.

22.

8. A flexible tube for use in an endoscope, comprising: A tube comprising the optical fiber of claim 1.

9. The optical fiber includes a plurality of optical fibers, One of the optical fibers includes an image guide portion that transmits an image; Another optical fiber of the plurality of optical fibers includes a light guide portion that transmits illumination light or a laser irradiation portion that irradiates laser light, The tube according to claim 8 , wherein the tip of at least one of the optical fibers is bent with respect to the main body portion toward a side where the image guide portion is disposed with respect to an axis of the main body portion.

10. 10. The tube of claim 9, further comprising a hollow tube therein into which a biopsy forceps, a therapeutic fiber, a thermocouple and / or a biopsy needle can be inserted.