Light irradiation fiber probe

Abstract

The invention provides a light irradiation fiber probe capable of emitting light with high beam quality in a direction inclined with respect to the axial direction of an optical transmission cable. This light irradiation fiber probe (1) is mounted on a therapeutic medical device, and is provided with: an optical transmission cable (10) that transmits light emitted from a light source; and a light refraction part (20) which is provided on the front end part (13) side of the optical transmission cable (10), and which emits light inclined at a predetermined angle or more with respect to the axial direction (X) of the optical transmission cable (10) by refracting the laser light (L) emitted from the optical transmission cable (10) via two or more refraction surfaces (21).

Description

Technical Field

[0001] The invention relates to a light irradiation fiber probe. Background Art

[0002] In the past, in the medical field, a light irradiation fiber probe was used to be inserted into the human body and irradiate light to cells. For example, Patent Document 1 describes a side emission device in which a prism lens is arranged at one end of an optical fiber, and the prism lens has a front end inclined surface coated with Au. The light irradiation fiber probe is used, for example, in photoimmunotherapy, which is one of the treatments for cancer, to insert the front end side of an optical transmission cable into the human body and irradiate laser light to a drug that is administered to the human body and reaches cancer cells.

[0003] [Prior Technical Literature]

[0004] (Patent Document)

[0005] Patent Document 1: Japanese Patent No. 4659137 Summary of the invention

[0006] [Problems to be solved by the invention]

[0007] However, in photoimmunotherapy, it is necessary to irradiate light while the front end side of the optical transmission cable is inserted into the human body or positioned near the tumor surface. In the case of organs such as the intestine or esophagus, cancer cells that are the irradiation targets are mostly present on the side of the organ tube, and it is important to irradiate light efficiently at an angle relative to the axial direction of the optical transmission cable. According to Patent Document 1, although light can be irradiated in a direction inclined relative to the axial direction of the optical transmission cable by using a prism lens with a front end inclined surface, problems such as beam breakage and the inability of the beam to diffuse relative to the irradiation distance sometimes occur. In the case of applying an inclined process to the fiber end face so that it has an angle of a refractive surface and bends the light, the incident angle of the refractive surface is mostly near the critical angle. When light with an incident angle with a certain degree of diffusion is incident on the refractive surface, reflected light and transmitted light are generated, resulting in the breakage of the incident light beam.

[0008] An object of the present invention is to provide a light irradiation fiber probe capable of emitting light with high beam quality in a direction inclined with respect to the axial direction of an optical transmission cable.

[0009] [Technical means to solve the problem]

[0010] (1) A light irradiation fiber probe mounted on a therapeutic medical device, comprising: an optical transmission cable for transmitting light emitted from a light source; and a light refraction portion, disposed on the front end side of the optical transmission cable, for refracting light emitted from the optical transmission cable via two or more refraction surfaces, thereby emitting light inclined at an angle greater than a specified angle relative to the axial direction of the optical transmission cable.

[0011] (2) The light-irradiated fiber probe according to (1), wherein, with respect to the incident angles of light incident on the two or more refractive surfaces, when the incident angles are set to θi, the refractive index of the medium with a smaller refractive index among the two media divided by the refractive surfaces is set to ns, and the refractive index of the medium with a larger refractive index is set to nl, a part or all of the optical path satisfies the following formula (1);

[0012] θi≦arcsin(ns / nl)···(1).

[0013] Ideally, all optical paths satisfy the above formula (1).

[0014] (3) The light-irradiated fiber probe according to (1) or (2), wherein at least one of the two or more refractive surfaces is a curved surface.

[0015] (4) An optical fiber probe according to any one of (1) to (3), wherein the optical transmission cable has a core and a cladding formed on the periphery of the core, the light refraction portion has a spherical lens, the refraction surface is formed by the surface of the lens, and the center of the lens is arranged at a position that does not overlap with the cross-section of the core in an axial view of the core.

[0016] (5) The light-irradiating fiber probe according to (4), wherein the light-irradiating fiber probe is a polymer clad optical fiber in which the cladding is formed of a hard polymer material.

[0017] (6) A light irradiation fiber probe according to (4) or (5), wherein the outer diameter of the lens of the light refraction portion is larger than the outer diameter of the optical transmission cable, and the center is arranged at a position offset from the cross-sectional center of the core by a distance greater than 1 / 4 and less than 3 / 8 of the diameter of the lens in an axial view of the core.

[0018] (7) The light-irradiating fiber probe according to any one of (4) to (6), wherein the light-irradiating fiber probe includes a holding portion that holds the front end portion of the optical transmission cable so that the relative position with respect to the lens does not change.

[0019] (8) The light-irradiating fiber probe according to any one of (1) to (7), wherein the light-irradiating fiber probe includes a light shielding portion, and the light shielding portion is arranged on the opposite side to the emission direction of the light refracted by the light refracting portion.

[0020] (Effects of the Invention)

[0021] According to the present invention, light with high beam quality can be emitted in a direction inclined with respect to the axial direction of the optical transmission cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a side view showing the light irradiation fiber probe according to the first embodiment of the present invention.

[0023] Figure 2 yes Figure 1 Sectional view II-II.

[0024] Figure 3 yes Figure 1 III-III cross-sectional view.

[0025] Figure 4 The diagram schematically shows the relationship between the relative positions of the optical transmission cable and the ball lens of the optical irradiation fiber probe according to the first embodiment of the present invention and the path of the laser beam.

[0026] Figure 5 Diameter ratio Figure 4 The optical transmission cable shown is a schematic diagram of the relationship between the relative positions of the optical transmission cable and the spherical lens and the path of the laser light.

[0027] Figure 6 It is a side view showing a light irradiation fiber probe according to a second embodiment of the present invention.

[0028] Figure 7 It is a schematic diagram showing the relationship between the relative positions of the optical transmission cable and the spherical lens of the light irradiation fiber probe according to the third embodiment of the present invention and the path of the laser light.

[0029] Fig. 8A The figure is a schematic diagram showing an image of the light intensity distribution of laser light emitted from an optical transmission cable, which is a polymer clad optical fiber, without passing through a light refraction unit.

[0030] Figure 8B This is a schematic diagram showing an image of light intensity distribution of laser light emitted from an optical transmission cable, which is a plastic fiber, via a light refraction unit.

[0031] Figure 8C The figure is a schematic diagram showing an image of the light intensity distribution of laser light emitted from an optical transmission cable, which is a polymer clad optical fiber, via a light refraction portion.

[0032] Fig. 9 This is a schematic diagram showing the relationship between the path of the laser light and the center of the spherical lens when the center of the spherical lens is located at a position offset from the cross-sectional center of the core by a distance corresponding to 3 / 8 of the diameter of the spherical lens in the axial view of the core.

[0033] Fig.10 This is a schematic diagram showing the relationship between the path of the laser light and the center of the spherical lens when the center of the spherical lens is located at a position offset from the cross-sectional center of the core by a distance corresponding to 1 / 6 of the diameter of the spherical lens in the axial view of the core.

[0034] Fig.11 It is a side view showing a variation example of the refraction portion of the light irradiation fiber probe of the present invention. DETAILED DESCRIPTION

[0035] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the present invention is not limited to the following embodiments. In addition, the figures referred to in the following description only schematically show shapes, sizes and positional relationships to the extent that the present disclosure can be understood. That is, the present invention is not limited to the shapes, sizes and positional relationships illustrated in the figures.

[0036] <First embodiment>

[0037] Reference Figure 1 to Figure 3 , a light irradiation fiber probe 1 according to a first embodiment of the present invention will be described. Figure 1 It is a side view of the light irradiation fiber probe 1. Figure 2 yes Figure 1 The II-II cross-sectional view is shown. Figure 3 yes Figure 1 The III-III cross-sectional view is shown.

[0038] The light irradiation fiber probe 1 of this embodiment is mounted on a medical device for performing photoimmunotherapy, which is one of the treatment methods for cancer. That is, the light irradiation fiber probe 1 is mounted on a therapeutic medical device. Photoimmunotherapy treats cancer by administering the following agent to the human body, namely, an agent composed of antibodies that bind to cancer cells and an object that reacts with light, and irradiating the agent that binds to cancer cells with a laser to destroy the cancer cells. In addition, the present invention can also be used for treatment methods using lasers such as photodynamic therapy, and is not limited to photoimmunotherapy. In addition, the light irradiation fiber probe 1 is used, for example, when it is inserted into a pipeline provided in an endoscope and the front end is exposed to the outside.

[0039] like Figure 1As shown, the light irradiation fiber probe 1 includes an optical transmission cable 10, a light refraction unit 20, a holding unit 30, and a cable protection member 40. The light irradiation fiber probe 1 irradiates a laser beam L generated by a laser oscillator (not shown) as a light source. In addition, in the light irradiation fiber probe 1, a lens restraint member 33 or a cable restraint member 34 described later of the holding unit 30 is arranged at the outermost side, and the light refraction unit 20, the optical transmission cable 10, and the clamping member 32 are arranged at the innermost side. Therefore, in Figure 1 In the figure, a portion exposed to the outside is indicated by a solid line, and a portion covered by other components and not exposed to the outside is indicated by a dotted line.

[0040] The laser oscillator has a semiconductor laser, and laser oscillation is caused by energizing the semiconductor laser to generate laser light L. The laser oscillator generates red laser light L with a wavelength of more than 600 nm and less than 700 nm. The laser light L generated by the laser oscillator can be a continuous wave or a pulse wave. In addition, the beam mode of the laser light L generated by the laser oscillator can be single mode or multimode. From the perspective of being able to irradiate high-intensity light over a wide range, the beam mode of the laser light L is preferably multimode. That is, a multimode light source is preferably used.

[0041] The optical transmission cable 10 is an optical fiber cable having an optical transmission path that transmits laser light L emitted by a laser oscillator. The laser oscillator is disposed on the base end side of the optical transmission cable 10, and the light refraction portion 20 is provided on the front end 13 side. The optical transmission cable 10 transmits the laser light L generated in the laser oscillator through the optical transmission path and emits the laser light L from the front end 13 toward the light refraction portion 20.

[0042] The optical transmission cable 10 of the present embodiment is a plastic fiber, having a core 11 as a light transmission path and a cladding 12 formed on the periphery of the core 11. The optical transmission cable 10 has an outer diameter of 500 μm, and the outer diameter of the core 11 is 250 μm. The core 11 preferably has an outer diameter corresponding to a size of a multimode fiber. In addition, the optical transmission cable 10 of the present embodiment is a single-core optical fiber, but it can also be a multi-core optical fiber. Furthermore, the shape of the core can be an ellipse or a rectangle other than a perfect circle. In addition, the optical transmission cable 10 can also be an optical fiber composed of a quartz-based material. In addition, if the optical transmission cable 10 is a plastic fiber, it is easy to bend the optical transmission cable 10 itself.

[0043] The light refraction unit 20 is disposed on the front end portion 13 side of the optical transmission cable 10, and emits the laser light L emitted from the core 11 at the front end portion 13 of the optical transmission cable 10 at an angle greater than a predetermined angle relative to the axial direction X of the optical transmission cable 10. In addition, the axial direction X of the optical transmission cable 10 in this specification refers to the axial direction of the optical transmission cable 10 at the front end portion 13.

[0044] In the light refraction part 20, two or more curved refraction surfaces 21 for refracting the laser light L emitted from the optical transmission cable 10 are formed. The light refraction part 20 of the present embodiment has, for example, a spherical lens, that is, a spherical lens 22. The spherical lens 22 has, for example, a refractive index of 1.5 and a diameter of 1 mm. The refraction surface 21 of the light refraction part 20 is formed by the surface of the spherical lens 22. Specifically, the refraction surface 21 of the light refraction part 20 includes: an incident surface 211 on which light emitted from the front end portion 13 of the optical transmission cable 10 is incident; and an exit surface 212 from which the incident light exits. The incident surface 211 is formed into a curved surface convex toward the optical transmission cable 10 side. The exit surface 212 is formed into a curved surface convex toward the light emission direction. As Figure 1 As shown, the light refraction unit 20 refracts the laser light L emitted from the front end portion 13 of the optical transmission cable 10 at the incident surface 211 and then makes it incident into the spherical lens 22. Furthermore, the light refraction unit 20 refracts the laser light L incident into the spherical lens 22 at the exit surface 212 and then makes it exit out of the spherical lens 22. That is, the light refraction unit 20 refracts the laser light L emitted from the optical transmission cable 10 via two or more refraction surfaces 21, and emits the laser light L inclined at an angle greater than or equal to a predetermined angle relative to the axial direction X of the optical transmission cable 10. The angle greater than or equal to the predetermined angle may be, for example, 20 degrees or more. In addition, in the present embodiment, all the refraction surfaces 21 of the light refraction unit 20 are curved surfaces, but at least one of the two or more refraction surfaces 21 may be curved surfaces, and not all the refraction surfaces 21 may be curved surfaces. For example, the refraction surface 21 may be a plane.

[0045] The spherical lens 22 of the light refraction part 20 is arranged at a predetermined position relative to the optical transmission cable 10. Specifically, the spherical lens 22 is arranged at a position where its center 221 does not overlap with the core in the axial view of the core 11 of the front end part 13. That is, when viewed in the axial direction X, the center 221 of the spherical lens 22 is arranged at a position offset from the cross-sectional center of the core 11.

[0046] The holding part 30 holds the front end 13 of the optical transmission cable 10 in a relative position to the spherical lens 22 of the light refracting part 20. The holding part 30 includes a tubular member 31, an interposing member 32, a lens restraining member 33, and a cable restraining member 34.

[0047] The tubular member 31 is a flexible cylindrical hose. The tubular member 31 contains at least a portion of the optical transmission cable 10 and a portion of the spherical lens 22 in the inner hollow portion 311. Specifically, the optical transmission cable 10 is inserted into the tubular member 31 in such a manner that at least the front end portion 13 side is located in the hollow portion 311 of the tubular member 31. Figure 1As shown, the optical transmission cable 10 is accommodated in the hollow portion 311 of the tubular member 30 in a state extending in the axial direction of the tubular member 31. In addition, the spherical lens 22 is accommodated in the tubular member 31 in a manner that at least the incident surface 211 side is located in the hollow portion 311 of the tubular member 31 and the emission surface 212 side is exposed to the outside of the tubular member 31. Examples of the raw material of the tubular member 31 include polyimide, silicone, polytetrafluoroethylene (PTFE), and the like.

[0048] The interposing member 32 is a flexible and elongated member, and is received in the hollow portion 311 of the tubular member 31. The interposing member 32 is arranged along the optical transmission cable 10 in the tubular member 31 on the side of the front end portion 13 of the optical transmission cable, and fills the gap between the outer peripheral surface of the optical transmission cable 10 and the inner peripheral surface of the tubular member 31. Figure 3 As shown, the shape of the intervening member 32 is cylindrical, but its shape is not particularly limited. For example, the shape of the intervening member 32 can be cylindrical or plate-shaped.

[0049] The lens restraining member 33 is a member that restrains the spherical lens 22 from moving in the tubular member 31. The lens restraining member 33 of this embodiment is, for example, a cylindrical heat shrinkable tube that can shrink in diameter due to heat. Figure 1 and Figure 2 As shown in FIG. 1 , the lens restraining member 33 covers the portion of the tubular member 31 that accommodates the spherical lens 22. Figure 2 As shown in the figure, the spherical lens 22 is located at the innermost side of the light irradiation fiber probe 1, the lens restraining member 33 is located at the outermost side, and the tubular member 31 is located between the spherical lens 22 and the lens restraining member 33. In this state, the lens restraining member 33 is thermally contracted, thereby applying a force toward the inner diameter direction of the spherical lens 22. As a result, the tubular member 31 and the spherical lens 22 are in close contact with each other.

[0050] The cable restraining member 34 is a member that restrains the optical transmission cable 10 and the interposing member 32 from moving in the tubular member 31. The cable restraining member 34 of this embodiment is, for example, a cylindrical heat shrinkable tube that can shrink in diameter due to heat. Figure 1 and Figure 3 As shown, the cable restraining member 34 covers at least a portion of the portion of the tubular member 31 that accommodates the optical transmission cable 10 and the interposing member 32, and a portion of the cable protection member 40. Figure 3As shown, the optical transmission cable 10 and the clamping member 32 are located in the hollow portion 311 of the tubular member 31, and the cable restraint member 34 is located outside the tubular member 31. In this state, the cable restraint member 34 is thermally shrunk, thereby applying a force toward the inner diameter direction of the tubular member 31. As a result, the optical transmission cable 10, the clamping member 32 and the tubular member 31 are in close contact with each other. In addition, the lens restraint member 33 and the cable restraint member 34, which are heat shrinkable tubes, are thermally shrunk when the light irradiation fiber probe 1 is manufactured. In addition, as the raw material of the heat shrinkable tube, for example, FEP (a fluororesin formed by combining tetrafluoroethylene and hexafluoropropylene) and the like can be cited.

[0051] The holding portion 30 accommodates the front end portion 13 side of the optical transmission cable 10 including the front end portion 13 and at least the front end portion 13 side of the spherical lens 22 in the tubular member 31. The position of the front end portion 13 of the optical transmission cable 10 in the tubular member 31 is fixed by the clamping member 32 and the cable restraining member 34, and the position of the spherical lens 22 in the tubular member 31 is fixed by the lens restraining member 33. That is, the relative position of the optical transmission cable 10 with respect to the spherical lens 22 is held by the holding portion 30.

[0052] The cable protection member 40 is a flexible cylindrical hose for protecting the optical transmission cable 10. Figure 1 As shown, the cable protection member 40 accommodates the base end side of the optical transmission cable 10 in the inner hollow portion from the portion of the optical transmission cable 10 that is not inserted into the tubular member 31. The cable protection member 40 is arranged with a gap with respect to the cable protection member 40 in the extending direction of the optical transmission cable 10. Examples of the raw material of the cable protection member 40 include nylon, silicone, polytetrafluoroethylene (PTFE), and the like.

[0053] Next, refer to Figure 4 and Figure 5 The relationship between the relative positions of the optical transmission cable 10 and the light refraction unit 20 and the path of the laser light L will be described. Figure 4 1 is a schematic diagram showing the relationship between the relative positions of the optical transmission cable 10 and the spherical lens 22 and the path of the laser light L. FIG. Figure 5 Diameter ratio Figure 4 The optical transmission cable 10 shown is a schematic diagram of the relationship between the relative positions of the optical transmission cable 10 and the spherical lens 22 and the path of the laser light L. In addition, Figure 4 The optical transmission cable 10 shown has a diameter of 250 μm. Figure 5 The optical transmission cable 10 shown has a diameter of 500 μm. Figure 4 and Figure 5 The spherical lens 22 shown has a diameter of 1000 μm and a refractive index n2 of 1.5. Figure 4 and Figure 5The refractive index n1 of the space S around the illustrated spherical lens 22 and the optical transmission cable 10 is 1.0.

[0054] The laser light L emitted from the optical transmission cable 10 is irradiated as follows: it is refracted at the surface of the spherical lens 22, i.e., the incident surface 211, at an angle derived from Snell's Law as shown in the following equation (0), passes through the spherical lens 22, and is refracted again at the boundary between the spherical lens 22 and the space S, i.e., the exit surface 212.

[0055] sinθ1 / sinθ2=n2 / n1···Formula (0)

[0056] In addition, “θ1” is the incident angle of light entering the spherical lens 22 from the space S in the incident surface 211 . “θ2” is the refraction angle of the laser light L on the incident surface 211 .

[0057] Since the laser light L is irradiated from the front end portion 13 of the optical transmission cable 10 to the spherical lens 22, which is a sphere, the path of the laser light L varies depending on the incident position of the laser light L in the spherical lens 22. Specifically, Figure 4 and Figure 5 As shown, in the axial view of the core 11, the farther the incident surface 211 is from the center 221 of the spherical lens 22, the greater the angle at which the traveling direction of the laser light L is inclined relative to the axial direction X. Furthermore, the laser light L passing through the spherical lens 22 is refracted again at the exit surface 212, and is emitted in a direction with a larger angle relative to the axial direction X. Thus, the laser light L can also be irradiated to the side of the optical fiber probe 1. In addition, the traveling direction of the laser light L does not change drastically at one place, but changes in multiple times, so that the breakage of the light beam caused by the refraction of the laser light L can be suppressed. On the other hand, the laser light L is Figure 5 As shown, in the axial view of the core 11, the closer the incident surface 211 is to the center 221, the smaller the change in the traveling direction of the laser light L. That is, the path of the laser light L emitted from the front end portion 13 of the optical transmission cable 10 becomes straighter. In this embodiment, in order to efficiently irradiate the cells of the irradiation target that exist more to the side of the optical irradiation fiber probe 1 rather than in front, the position of the spherical lens 22 is set to a position where the center 221 is offset from the cross-sectional center of the core 11 in the axial view of the core 11.

[0058] In addition, the incident angle θi of the light incident on two or more refractive surfaces 21 is preferably such that part or all of the optical path satisfies the following formula (1) when the refractive index of the medium with a smaller refractive index among the two media divided by the refractive surface 21 is set to ns and the refractive index of the medium with a larger refractive index is set to nl. With this structure, for example, the incident angle θi becomes less than the critical angle, so that the incident light beam can be suppressed from being broken.

[0059] θi≦arcsin(ns / nl)···(1)

[0060] The right side of the above formula (1) corresponds to the critical angle, which is the angle of total reflection when incident from a medium with a high refractive index to a medium with a low refractive index. When incident to the opposite side (from a medium with a low refractive index to a medium with a high refractive index), total reflection is not achieved, but high reflection occurs, which is the main cause of beam breakage. In addition, it is more preferable that all optical paths satisfy the above formula (1).

[0061] exist Figure 4 and Figure 5 In the example shown, the incident angle θi of light including θ1 preferably satisfies the following formula (2) because the refractive index of the spherical lens 22 is larger than that of the space S.

[0062] θi≦arcsin(n1 / n2)···(2)

[0063] In addition, if Figure 4 and Figure 5 As shown, by adjusting the diameter of the optical transmission cable 10 relative to the spherical lens 22, the irradiation range of the light irradiated from the light refraction portion 20 can be expanded. This is a feature and effect when using a spherically convex refractive surface such as a spherical lens. In this way, by adjusting the relative position of the optical transmission cable 10 and the spherical lens 22, the diameter of the core 11 of the optical transmission cable 10 relative to the spherical lens 22, etc., the traveling direction of the laser L and its irradiation range can be adjusted.

[0064] <Second embodiment>

[0065] Next, refer to Figure 6 A light irradiation fiber probe 1 according to a second embodiment of the present invention will be described. Figure 6 1 is a side view of a light irradiation fiber probe 1 according to a second embodiment. In the following description of the second embodiment, the structures corresponding to those in the first embodiment are given the same regularity and corresponding symbols. The description thereof may be omitted or quoted.

[0066] The optical fiber probe 1 of this embodiment includes an optical transmission cable 10, a light refracting unit 20, a holding unit 30, a cable protection member 40, and a light shielding unit 50. The optical fiber probe 1 of this embodiment mainly differs from the optical fiber probe 1 of the first embodiment in that the light shielding unit 50 is included.

[0067] The light shielding portion 50 is disposed on the opposite side of the emission direction of the laser light L refracted by the light refracting portion 20. Specifically, the light shielding portion 50 is formed by applying a light shielding material or the like on the opposite side of the emission direction of the laser light L refracted by the light refracting portion 20 in the holding portion 30. Figure 6In the example shown, the light shielding material is applied to the lens restraining member 33, the tubular member 31 on the spherical lens 22 side, and the cable restraining member 34 on the opposite side of the emission direction of the laser light L (on the Figure 6 As the light-shielding material, for example, metal or polytetrafluoroethylene can be cited.

[0068] <Third embodiment>

[0069] Next, refer to Figure 7 A light irradiation fiber probe 1 according to a third embodiment of the present invention will be described. In the following description of the third embodiment, structures corresponding to those in the first embodiment are denoted by the same regularity and corresponding symbols, and their descriptions may be omitted or quoted. Figure 7 Schematic diagram showing the relationship between the relative positions of the optical transmission cable 10 and the spherical lens 22 of the optical irradiation fiber probe 1 according to the third embodiment and the path of the laser light L. Figure 7 In FIG. 1 , illustrations other than the optical transmission cable 10, the light refraction unit 20, and the tubular member 31 are omitted. Figure 7 The path of the central component of the light intensity distribution of the laser light L is shown, and the virtual line extending from the cross-sectional center of the core 11 toward the spherical lens 22 along the axial direction X of the optical transmission cable 10 is shown as a dotted line C.

[0070] The optical fiber probe 1 of this embodiment includes an optical transmission cable 10, a light refracting unit 20, a holding unit 30, and a cable protection member 40. The optical fiber probe 1 of this embodiment mainly differs from the optical fiber probe 1 of the first embodiment in the structure of the optical transmission cable 10.

[0071] The optical transmission cable 10 of the present embodiment is a polymer clad optical fiber whose cladding 12 is formed of a hard polymer material. The polymer clad optical fiber is an optical fiber whose core 11 is formed of a quartz material and whose cladding 12 is formed of a hard polymer material. Examples of quartz materials include quartz without impurities in the core and quartz doped with germanium. Examples of hard polymer materials include fluorine-based resins such as polytetrafluoroethylene (PTFE), polyvinylidenefluoride (PVDF), and ethylene-tetrafluoroethylene (ETFE), polyimide, or copolymers thereof. In addition, the outer diameter of the optical transmission cable 10 of the present embodiment is smaller than the outer diameter of the spherical lens 22 of the light refraction portion 20.

[0072] Here, refer to Figure 8A to Figure 8CThe light intensity distribution of the laser light L irradiated from the light irradiation fiber probe 1 according to the third embodiment will be described. Figure 8A to Figure 8C It is an explanatory diagram for explaining the light intensity distribution of the laser light L irradiated from the light irradiation fiber probe 1 according to the third embodiment. Fig. 8A 1 is a schematic diagram showing an image of light intensity distribution of laser light L emitted from the front end portion 13 of the optical transmission cable 10 as the third embodiment of the polymer clad optical fiber without passing through the light refraction portion 20 . Figure 8B 1 is a schematic diagram showing an image of light intensity distribution of laser light L emitted from the front end portion 13 of the optical transmission cable 10 of the first embodiment, which is a plastic fiber, via the light refraction portion 20 . Figure 8C 1 is a schematic diagram showing an image of light intensity distribution of the laser light L emitted from the light irradiation fiber probe 1 according to the third embodiment via the light refraction portion 20 . Figure 8A to Figure 8C The vertical axis represents the light intensity, and the horizontal axis represents the cross-sectional distance from the center of the laser L when the center of the laser L is the origin O in the cross-sectional view of the laser L. That is, Figure 8A to Figure 8C In the horizontal axis of , the origin O and its surroundings are the areas where the core 11 exists on the optical transmission cable 10 side in the optical axis direction of the laser L. Figure 8A to Figure 8C In the horizontal axis, the range indicated by the arrows on both sides of the solid line is the area where the core exists on the optical transmission cable side in the optical axis direction of the laser L, and the range indicated by the arrows on both sides of the dotted line is the area where the core and cladding exist on the optical transmission cable side in the optical axis direction of the laser L.

[0073] like Fig. 8A As shown, in the laser light L emitted from the front end portion 13 of the optical transmission cable 10, which is a polymer clad optical fiber, the light intensity distribution is concentrated in the region (referred to as the cladding region) where the cladding exists on the optical transmission cable 10 side in the optical axis direction of the laser light L. This is because the refractive index of the cladding can be controlled by adjusting the composition of the resin of the cladding in the polymer clad optical fiber. For example, by adjusting the relative refractive index difference to △ = 3 to 5% (NA = 0.37 to 0.47), the laser light can be concentrated on the cladding portion.

[0074] On the other hand, Figure 8B As shown, the laser light L emitted from the front end portion 13 of the optical transmission cable 10, which is not a polymer clad optical fiber such as a plastic fiber, via the light refraction portion 20 has an intensity distribution close to a Gaussian distribution, with the light intensity distribution concentrated at the center of the core 11 on the optical transmission cable 10 side in the optical axis direction of the laser light L. This is because the laser light L is focused by the light refraction portion 20 such as the spherical lens 22.

[0075] The laser light L emitted from the front end portion 13 of the optical transmission cable 10, which is a polymer clad optical fiber, through the spherical lens 22 has a light intensity distribution concentrated in the cladding region. Therefore, Fig. 8A The light intensity distribution shown is similar to Figure 8B The light intensity distributions shown cancel each other out, as Figure 8C The light intensity distribution becomes a flat top as shown. The so-called flat top light intensity distribution is an intensity distribution in which the light intensity changes little and evenly within a predetermined radius from the center of the laser L, and the light intensity decreases sharply beyond the predetermined radius. Thus, even when the laser L is irradiated in a direction inclined relative to the insertion direction of the optical transmission cable 10, the side farther from the optical transmission cable 10 can be irradiated with a laser L with a stronger light intensity. Thus, the irradiation target such as cancer cells existing on the side of the organ tube can be irradiated with laser L with high treatment efficiency.

[0076] Next, refer to Figure 7 , Fig. 9 and Fig.10 The relationship between the relative positions of the optical transmission cable 10 and the spherical lens 22 of the light irradiating fiber probe 1 and the path of the laser light L will be described. Figure 7 The schematic diagram shows the relationship between the path of the laser light L and the center 221 of the spherical lens 22 when the center 221 of the spherical lens 22 is located at a position offset from the cross-sectional center of the core 11 by a distance corresponding to 1 / 4 of the diameter of the spherical lens 22 in the axial view of the core 11 . Fig. 9 The schematic diagram shows the relationship between the path of the laser light L and the center 221 of the spherical lens 22 when the center 221 of the spherical lens 22 is located at a position offset from the cross-sectional center of the core 11 by a distance corresponding to 3 / 8 of the diameter of the spherical lens 22 in the axial view of the core 11 . Fig.10 2 is a schematic diagram showing the relationship between the center 221 of the spherical lens 22 and the path of the laser light L when the center 221 of the spherical lens 22 is located at a position offset from the cross-sectional center of the core 11 by a distance equivalent to 1 / 6 of the diameter of the spherical lens 22 in the axial view of the core 11. Fig. 9 and Fig.10 In FIG. 1 , illustrations other than the optical transmission cable 10, the light refraction unit 20, and the tubular member 31 are omitted. Fig. 9 and Fig.10 The path of the central component of the light intensity distribution of the laser light L is shown, and the virtual line extending from the cross-sectional center of the core 11 toward the spherical lens 22 along the axial direction X of the optical transmission cable 10 is shown as a dotted line C.

[0077] The outer diameter of the spherical lens 22 of the light refraction portion 20 of the present embodiment is larger than the outer diameter of the optical transmission cable 10. In addition, the spherical lens 22 is preferably arranged such that the center 221 thereof is offset from the cross-sectional center of the core 11 by a distance corresponding to 1 / 4 or more (1 / 4φD or more) and less than 3 / 8 (less than 3 / 8φD) of the diameter of the spherical lens 22 in the axial view of the core 11.

[0078] like Figure 7As shown, in the axial view of the core 11, when the center 221 of the spherical lens 22 is located at a position offset from the cross-sectional center of the core 11 by a distance equivalent to 1 / 4φD of the spherical lens 22, the path of the central component of the light intensity distribution can be irradiated with laser L in a direction inclined at 45° relative to the insertion direction of the optical transmission cable 10.

[0079] like Fig. 9 As shown, in the axial view of the core 11, when the center 221 of the spherical lens 22 is located at a position offset from the cross-sectional center of the core 11 by a distance equivalent to 3 / 8φD of the spherical lens 22, the path of the central component of the irradiated light intensity distribution is Figure 7 In the case of the laser light L being directed in a direction further inclined relative to the insertion direction of the optical transmission cable 10 than in the case of the laser light L being directed in a direction further inclined relative to the insertion direction of the optical transmission cable 10. On the other hand, there is a tubular member 31 on the outside of the optical transmission cable 10 for accommodating the optical transmission cable 10 and a part of the spherical lens 22. Therefore, in consideration of the interference with the tubular member 31, it is necessary to reduce the size of the optical transmission cable 10 in accordance with the offset of the core 11 from the center 221 of the spherical lens 22. From the viewpoint of irradiating the laser light L from the optical transmission cable 10 over a wide range, the spherical lens 22 is preferably arranged with its center 221 at a position offset from the cross-sectional center of the core 11 in the axial view of the core 11 by a distance equivalent to 3 / 8φD of the spherical lens 22.

[0080] On the other hand, when the distance between the center 221 of the spherical lens 22 in the axial view of the core 11 and the cross-sectional center of the core 11 is set to a distance equivalent to 1 / 4φD of the spherical lens 22, as shown in FIG. Fig.10 As shown, the angle of irradiation of the laser light L becomes shallower with respect to the insertion direction of the optical transmission cable 10. Therefore, in order to more efficiently irradiate the irradiation target such as cancer cells existing on the side of the organ with the laser light L, it is preferable to set the distance between the center 221 of the spherical lens 22 and the cross-sectional center of the core 11 to a distance equivalent to or greater than 1 / 4φD of the spherical lens 22.

[0081] According to the above-described embodiment, the following effects are achieved.

[0082] The light irradiation fiber probe 1 of this embodiment is mounted on a therapeutic medical device, and comprises: an optical transmission cable 10, which transmits light emitted from a light source; and a light refraction portion 20, which is arranged on the side of the front end portion 13 of the optical transmission cable 10, and refracts the laser L emitted from the optical transmission cable 10 via two or more refraction surfaces 21, thereby emitting light inclined at an angle greater than a specified angle relative to the axial direction X of the optical transmission cable 10.

[0083] Thus, since the light is refracted multiple times on two or more refractive surfaces 21 and then emitted, it is possible to suppress heat generation during irradiation with the laser light L and irradiate with the laser light L having less beam breakage and high beam quality in a direction oblique to the insertion direction of the optical transmission cable 10. In addition, the irradiation range of the laser light L can be expanded within a short irradiation distance, so cancer cells existing on the surface of elongated organs with narrow spaces in the human body can be irradiated with the laser light L with high efficiency.

[0084] In the light-irradiated fiber probe 1 of the present embodiment, regarding the incident angles of light respectively incident on two or more refractive surfaces 21, when the incident angles are set to θi, the refractive index of the medium with a smaller refractive index among the two media divided by the refractive surfaces 21 is set to ns, and the refractive index of the medium with a larger refractive index is set to nl, part or all of the optical path satisfies the following formula (1).

[0085] θi≦arcsin(ns / nl)···(1)

[0086] This can further suppress beam breakage, and irradiate laser light L with higher beam quality.

[0087] In addition, in the light irradiating fiber probe 1 of the present embodiment, at least one of the two or more refractive surfaces 21 is a curved surface.

[0088] Thus, since the laser light L is refracted a plurality of times by at least one curved refractive surface 21 and then irradiated, the irradiation angle of the laser light L with respect to the insertion direction of the optical transmission cable 10 can be further increased.

[0089] In addition, in the light irradiation fiber probe 1 of the present embodiment, the optical transmission cable 10 has a core 11 and a cladding 12 formed on the outer periphery of the core 11, the light refraction portion 20 has a spherical spherical lens 22, the refraction surface 21 is formed by the surface of the spherical lens 22, and the spherical lens 22 has its center 221 arranged at a position offset from the cross-sectional center of the core 11 in the axial view of the core 11.

[0090] Thus, by using the surface of the spherical lens 22 as the refractive surface 21, the laser light L can be efficiently refracted with a simpler structure, and the laser light L can be irradiated in a direction inclined with respect to the insertion direction of the optical transmission cable 10 into the human body within a short irradiation distance.

[0091] In addition, in the light irradiating fiber probe 1 of the present embodiment, the optical transmission cable 10 is a polymer clad optical fiber in which the cladding 12 is formed of a hard polymer material.

[0092] Thus, the laser light L having a light intensity distribution emitted from the optical transmission cable 10 and concentrated in the cladding region is irradiated to the outside via the spherical lens 22 that condenses the light, so that the laser light L having a flat-top light intensity distribution can be irradiated in a direction inclined with respect to the insertion direction of the optical transmission cable 10. Thus, the laser light L having a high therapeutic efficiency can be irradiated to the irradiation target such as cancer cells existing on the side of the tube.

[0093] In addition, in the light irradiation fiber probe 1 of the present embodiment, the outer diameter of the spherical lens 22 of the light refraction portion 20 is larger than the outer diameter of the optical transmission cable 10, and the center is arranged at a position offset from the cross-sectional center of the core 11 by a distance greater than 1 / 4 and less than 3 / 8 of the diameter of the spherical lens 22 in the axial view of the core 11.

[0094] Thereby, it is possible to irradiate the laser light L having a higher light intensity including a component irradiated in a direction inclined by 45° or more with respect to the insertion direction of the optical transmission cable 10 .

[0095] Furthermore, the light irradiating fiber probe 1 of the present embodiment includes a holding portion 30 that holds the relative position of the distal end portion 13 of the optical transmission cable 10 with respect to the ball lens 22 unchanged.

[0096] This can suppress the variation in the irradiation direction and irradiation range of the laser light L due to use.

[0097] Furthermore, the light irradiating fiber probe 1 of the present embodiment includes a light shielding portion 50 disposed on the opposite side to the emission direction of the light refracted by the light refracting portion 20 .

[0098] As a result, in photoimmunotherapy and photodynamic therapy in which specific cells such as cancer cells are irradiated with laser light L, irradiation of healthy cells with laser light L can be suppressed, thereby reducing the invasion of the body of the patient receiving treatment.

[0099] As mentioned above, although embodiment of this invention was demonstrated, this invention is not limited to the said embodiment, It can change suitably.

[0100] In the first embodiment, the holding portion 30 includes the tubular member 31, the clamping member 32, the lens restraint member 33 and the cable restraint member 34, but may also be configured to include only the tubular member 31 and the clamping member 32 without the lens restraint member 33, the cable restraint member 34 and the like.

[0101] In the above embodiment, the light refraction part 20 has one spherical lens 22 and the refraction surface 21 is two, but it can also be configured to have a plurality of spherical lenses 22. Specifically, it can also be configured so that the laser light L emitted from the front end portion 13 of the optical transmission cable 10 is refracted by the surfaces of the plurality of spherical lenses 22 and emitted from the light irradiation fiber probe 1. In addition, the sizes and refractive indexes of the plurality of spherical lenses can be different from each other or the same.

[0102] In the above-described embodiment, the light refraction portion 20 is configured to include the spherical lens 22 , but the structure of the light refraction portion 20 is not particularly limited.

[0103] Fig.11 FIG. 1 is a side view showing a light irradiation fiber probe 1 having a light refraction portion 20 different from the above-mentioned embodiment. Fig.11 In the figure, illustration of parts other than the optical transmission cable 10 and the light refraction unit 20 is omitted.

[0104] Fig.11 The light refraction portion 20 shown has a triangular column-shaped prism lens 23 instead of the spherical lens 22 . Fig.11 The refractive surface 21 of the light refraction portion 20 shown in FIG. 1 is formed by the planar inclined surfaces 231 and 232 of the prism lens 23. Fig.11 In the example shown, assuming that the refractive index of the space S is n1 and the refractive index of the prism lens 23 is n3, the incident angle θi of light satisfies the following equation (3).

[0105] θi≦arcsin(n1 / n3)···(3)

[0106] In addition, for example, the light refraction portion 20 may include a concave lens, which is disposed on the side of the front end portion 13 of the optical transmission cable 10, and the incident surface of the light emitted from the front end portion 13 of the optical transmission cable 10 is formed as a curved surface convex in the emitting direction of the light, and the exit surface of the emitted light is formed as a curved surface convex toward the side of the optical transmission cable 10 of the light.

[0107] Furthermore, the light irradiation fiber probe 1 is used as a disposable product in the medical field for reasons of hygiene and the like, but by recycling the product and enabling the reuse of lenses and the like, it can help ensure sustainable consumption and production patterns.

[0108] Reference numerals

[0109] 1 Light irradiation fiber probe

[0110] 10 Optical transmission cable

[0111] 13 Front end

[0112] 20 Light refraction part

[0113] 21 Refractive Surface

[0114] 211 Incident surface

[0115] 212 exit surface

[0116] Axial direction of X-ray transmission cable

Claims

1. A light irradiation fiber probe, mounted on a medical device for treatment, having: an optical transmission cable that transmits light emitted from a light source; and, The light refracting unit is provided at the front end side of the optical transmission cable, and refracts light emitted from the optical transmission cable via two or more refracting surfaces, thereby emitting light inclined at a predetermined angle or more with respect to the axial direction of the optical transmission cable.

2. The light irradiation fiber probe according to claim 1, wherein: Regarding the incident angles of light incident on the two or more refractive surfaces, when the incident angle is θi, the refractive index of the medium with a smaller refractive index among the two media divided by the refractive surfaces is ns, and the refractive index of the medium with a larger refractive index is nl, a part or all of the optical path satisfies the following formula (1); θi≦arcsin(ns / nl)···(1).

3. The light irradiation fiber probe according to claim 1, wherein: One or more of the two or more refractive surfaces are curved.

4. The light irradiation fiber probe according to claim 1, wherein: The optical transmission cable comprises a core and a cladding formed on the outer periphery of the core. The light refraction part has a spherical lens. The refractive surface is formed by the surface of the lens. The center of the lens is arranged at a position offset from a cross-sectional center of the core in an axial view of the core.

5. The light-irradiated fiber probe according to claim 4, wherein: The optical transmission cable is a polymer clad optical fiber in which the cladding is formed of a hard polymer material.

6. The light irradiation fiber probe according to claim 4 or 5, wherein: The lens of the light refraction portion has an outer diameter larger than that of the optical transmission cable, and its center is arranged at a position offset from the cross-sectional center of the core by a distance equal to or greater than 1 / 4 and less than 3 / 8 of the diameter of the lens in an axial view of the core.

7. The light-irradiated fiber probe according to claim 4, wherein: The light irradiating fiber probe includes a holding portion that holds the front end portion of the optical transmission cable so that the relative position with respect to the lens does not change.

8. The light irradiation fiber probe according to claim 1, wherein: The light irradiating fiber probe includes a light shielding portion disposed on the opposite side of the emission direction of the light refracted by the light refracting portion.

Images