Light irradiation medical device

Abstract

A light-emitting medical apparatus (1) has: a shaft (10) having a distal end and a proximal end in a longitudinal axial direction (x) and having an inner cavity (11) extending in the longitudinal axial direction (x); an optical fiber (20) disposed in the inner cavity (11); and a first coil member (40) disposed in the inner cavity (11) and having a line material (42) helically wound around a distal portion of the optical fiber (20). The optical fiber (20) has a light diffusion part (21) that extends in the longitudinal axial direction (x) in a predetermined section of the distal portion thereof, and emits light outward in the radial direction of the shaft (10). The first coil member (40) partially covers the light diffusion part (21).

Description

Technical Field

[0001] The present invention relates to a light irradiation medical device for irradiating light to tissues such as cancer cells in a body lumen such as a blood vessel or a digestive tract.

Background Art

[0002] In photodynamic therapy (PDT), a photosensitizer is administered into the body by intravenous injection or intraperitoneal administration, the photosensitizer is accumulated in a target tissue such as cancer cells, and the photosensitizer is excited by irradiating light of a specific wavelength. When the excited photosensitizer returns to the ground state, energy conversion occurs, generating reactive oxygen species. By attacking the target tissue with the reactive oxygen species, the target tissue can be removed. In ablation using laser light, the target tissue is irradiated with laser light and cauterized. Devices for performing such light irradiation have been proposed.

[0003] Patent Document 1 discloses a laser treatment optical fiber probe including an optical fiber, a flexible tube surrounding the optical fiber with a gap, and a holder that holds the end portion on the emission side of the optical fiber substantially coaxially within the tube. Further, it is disclosed that the holding portion is composed of a single coil spring, and the first cylindrical coil portion of the coil spring is passed through the optical fiber and fixed to the coating of the optical fiber.

[0004] Patent Document 2 discloses a medical light guide including an optical fiber and a cover tube covering the optical fiber. The optical fiber has a core, a cladding, and a coating covering the cladding, and in the longitudinal direction in which the optical fiber extends, in order, a first coating portion in which the core and the cladding are covered by the coating, a first cladding portion in which the coating is removed and the cladding is exposed, a second coating portion in which the core and the cladding are covered by the coating, a core portion in which the coating and the cladding are removed and the core is exposed, a third coating portion in which the core and the cladding are covered by the coating, a second cladding portion in which the coating is removed and the cladding is exposed, and a tip portion.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-309155 [Patent Document 2] Japanese Patent Publication No. 2019-51023 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In the case of forward-illuminating light irradiation devices, such as those described in Patent Document 1, it was necessary to perform multiple operations to irradiate the entire target tissue, such as a tumor, by emitting light at a certain point, slightly shifting the position of the light-emitting part relative to the target tissue, and emitting light again. Furthermore, depending on the location and shape of the tumor, irradiation could be difficult. Lateral-illuminating light irradiation devices have the advantage of being able to irradiate a wide area in the circumferential direction at once. However, in devices such as those described in Patent Document 2, uneven distribution of light emission intensity occurred in the circumferential direction of the device. In such cases, similar to forward-illuminating devices, even with lateral-illuminating devices, it was necessary to repeatedly emit light and adjust the position of the light-emitting part in order to irradiate the entire target tissue, which could lead to prolonged procedures and burdens on both the patient and the operator. In view of the above circumstances, the first objective is to provide a light irradiation medical device that contributes to the efficiency of the procedure.

[0007] The lateral irradiation type light irradiation device described in Patent Document 2 has the advantage of being able to irradiate a wide area in the circumferential direction at once. However, in devices like the one described in Patent Document 2, unevenness in the emission intensity distribution occurred in the circumferential direction of the device. In such cases, it was necessary to repeatedly adjust the position of the light emission site and the light emission area in order to irradiate the entire target tissue, which could lead to prolonged procedures and burdens on both the patient and the operator. In view of the above circumstances, the second objective is to provide a light irradiation medical device that contributes to the efficiency of the procedure. [Means for solving the problem]

[0008] A first embodiment of the light irradiation medical device of the present invention that has achieved the first objective described above is as follows. [1] A light irradiation medical device comprising: a shaft having a distal end and a proximal end in the longitudinal direction and a lumen extending in the longitudinal direction; an optical fiber disposed in the lumen of the shaft; and a first coil member disposed in the lumen of the shaft and having a wire spirally wound around the distal portion of the optical fiber, wherein the optical fiber has a light diffusing portion that extends in the longitudinal direction in a predetermined section of its distal portion and emits light radially outward from the shaft, and the first coil member covers a part of the light diffusing portion. According to the above-described light irradiation medical device, in the portion of the light diffusion section covered by the first coil member, the light emitted from the light diffusion section is reflected by the inner surface of the first coil member. As a result, the reflected light is more easily diffused in various directions from the exposed portion of the light diffusion section that is not covered by the first coil member. Consequently, the light emission intensity distribution of the exposed portion becomes more uniform in the circumferential direction of the shaft. This reduces the number of irradiations to target tissues such as tumors and the number of adjustments to the position of the exposed portion relative to the target tissue, thereby improving the efficiency of the procedure. [2] The light irradiation medical device according to [1], wherein the proximal end of the first coil member is located distal to the midpoint in the longitudinal axis direction of the light diffusion portion. [3] The first coil member is made of a material with a higher reflectivity than the shaft. [1] or [2] The light irradiation medical device. [4] The light diffusing section is arranged around the entire circumference of the shaft. [1] to [3] The light irradiation medical device according to any one of these items. [5] A light irradiation medical device according to any one of [1] to [4], wherein the optical fiber has a core extending in the longitudinal direction, the optical fiber has a first section having a first cladding arranged on the outer circumference of the core, and the optical fiber has a second section in the light diffusion portion that is located distal to the first section and has a second cladding arranged on the outer circumference of the core having a surface roughness greater on the outer surface than the first cladding. [6] A light irradiation medical device according to any one of [1] to [5], wherein the optical fiber has a core extending in the longitudinal direction, the optical fiber has a first section having a first cladding arranged on the outer circumference of the core, and the optical fiber has a third section in the light diffusion portion that does not have cladding and is located distal to the first section. [7] The optical fiber has a second section located distal to the first section, which is arranged on the outer circumference of the core and has a second cladding which has a greater surface roughness on its outer surface than the first cladding, and the optical fiber has a second section and a third section arranged in order from the proximal side toward the distal side, as described in [6]. [8] The photoirradiation medical device according to [7], wherein the third section is shorter than the second section in the longitudinal direction. [9] The photoirradiation medical device according to any one of the items [6] to [8], wherein the first coil member covers at least a portion of the third section.

[10] The optical fiber having only a second section in the light diffusion portion [5].

[11] The first coil member has a first pitch portion having a pitch of no more than twice the diameter of the wire material. The photoirradiation medical device according to any one of [1] to

[10] .

[12] A reflective material that reflects light from the light diffusion section is provided on the distal end side of the first coil member, as described in any one of [1] to

[11] .

[13] The first coil member has a closed distal end and an open proximal end, as described in any one of [1] to

[12] .

[14] The distal end face of the light diffusing section is not fixed to the first coil member. [1] to

[13] The light irradiation medical device according to any one of these items.

[15] A light irradiation medical device according to any one of the items [1] to

[14] , wherein the first coil member is fixed to the outer surface of the light diffusion section.

[16] The light irradiation medical device according to any one of the items [1] to

[15] , wherein the outer surface of the light diffusion section is arranged away from the inner surface of the shaft.

[17] The light irradiation medical device according to any one of the items [1] to

[16] , wherein the outer surface of the first coil member is in contact with the inner surface of the shaft.

[0009] A second embodiment of the light irradiation medical device of the present invention that achieves the second objective described above is as follows.

[18] A light irradiation medical device comprising: a shaft having a distal end and a proximal end in the longitudinal direction and a lumen extending in the longitudinal direction; an optical fiber disposed in the lumen of the shaft; a cylindrical member disposed in the lumen of the shaft and covering a part of the distal portion of the optical fiber; a second coil member disposed proximal to the cylindrical member in the lumen of the shaft and having a wire spirally wound around the optical fiber; and a handle connected to the proximal portion of the shaft, wherein the optical fiber has a light diffusing portion that extends in the longitudinal direction in a predetermined section of its distal portion and emits light radially outward from the shaft, the cylindrical member covers a part of the light diffusing portion, the proximal portion of the second coil member is fixed to the handle, and the entire second coil member is disposed in the lumen of the shaft in the longitudinal direction. According to the above-described light irradiation medical device, in the portion of the light diffusion section covered by the cylindrical member, the light emitted from the light diffusion section is reflected by the inner surface of the cylindrical member. As a result, the reflected light is more easily diffused in various directions from the exposed portion of the light diffusion section that is not covered by the cylindrical member. Consequently, the emission intensity distribution of the exposed portion becomes more uniform in the circumferential direction of the shaft. This reduces the number of irradiations to target tissues such as tumors and the number of adjustments to the position of the exposed portion relative to the target tissue, thereby improving the efficiency of the procedure. Furthermore, because the second coil member is positioned proximal to the cylindrical member in the lumen of the shaft, and the entire second coil member is positioned within the lumen of the shaft in the longitudinal direction, the torque from the proximal side is more easily transmitted to the distal side, improving operability. The provision of the second coil member makes it easier for the optical fiber to be positioned coaxially with the cylindrical member, preventing the light diffusion section from becoming uneven, thus further improving the uniformity of the emission intensity distribution of the exposed portion in the circumferential direction of the shaft. In addition, because the proximal portion of the second coil member is fixed to the handle, the second coil member can be fixed so as not to move in the longitudinal direction relative to the optical fiber.

[19] The light irradiation medical device described in

[18] , wherein the second coil member covers a portion of the light diffusion section.

[20] The light irradiation medical device according to

[19] , wherein a portion of the light diffusion section is not covered by the cylindrical member and the second coil member.

[21] A light irradiation medical device according to any one of the items

[18] to

[20] , wherein the cylindrical member is in contact with the outer surface of the light diffusion part.

[22] The distal portion of the second coil member is not fixed to the optical fiber.

[18] to

[21] The photoirradiation medical device according to any one of these items.

[23] A light irradiation medical device according to any one of the items

[18] to

[22] , wherein the second coil member is longer than the cylindrical member in the longitudinal axis direction.

[24] A light irradiation medical device according to any one of the items

[18] to

[23] , wherein the outer surface of the cylindrical member is in contact with the inner surface of the shaft.

[25] A light irradiation medical device according to any one of the items

[18] to

[24] , wherein the outer surface of the second coil member is in contact with the inner surface of the shaft.

[26] A light irradiation medical device according to any one of the items

[18] to

[25] , wherein the minimum inner diameter of the cylindrical member is smaller than the minimum inner diameter of the second coil member.

[27] The light irradiation medical device according to any one of the following items

[18] to

[26] , the cylindrical member having a first coil portion in which a wire is wound spirally around the light diffusion portion.

[28] The photoirradiation medical device according to

[27] , wherein the first coil portion is single-layer wound and the second coil member has a second coil portion that is multi-layer wound.

[29] The photoirradiation medical device described in

[28] , wherein the first coil section is made of a radiopaque material and the second coil section is made of a material that is more permeable to radiation than the first coil section.

[30] The photoirradiation medical device according to any one of the claims

[18] to

[29] , wherein the second coil member has a second coil portion which is multi-layer wound and a third coil portion which is located distal to the second coil portion and is single-layer wound.

[31] The third coil section is made of a radiopaque material that is less permeable to radiation than the second coil section.

[30] The photoirradiation medical device described above.

[32] A light irradiation medical device according to any one of

[18] to

[31] , wherein the optical fiber has a core extending in the longitudinal direction, the optical fiber has a first section having a first cladding arranged on the outer circumference of the core, and the optical fiber has a second section in the light diffusion portion that is located distal to the first section and has a second cladding arranged on the outer circumference of the core having a surface roughness greater on the outer surface than the first cladding.

[33] A light irradiation medical device according to any one of the claims

[18] to

[32] , wherein the optical fiber has a core extending in the longitudinal direction, the optical fiber has a first section having a first cladding arranged on the outer circumference of the core, and the optical fiber has a third section in the light diffusion portion that does not have cladding and is located distal to the first section. [Effects of the Invention]

[0010] According to the light irradiation medical device according to the first embodiment, in the portion of the light diffusion part covered by the first coil member, the light emitted from the light diffusion part is reflected by the inner surface of the first coil member, so the reflected light is likely to be diffused in various directions from the exposed part which is the portion of the light diffusion part not covered by the first coil member. As a result, the light emission intensity distribution of the exposed part in the circumferential direction of the shaft is likely to be uniformized. Thereby, the number of irradiations to the target tissue such as a tumor and the number of position adjustments of the exposed part with respect to the target tissue can be reduced, so that the efficiency of the procedure can be improved. According to the light irradiation medical device according to the second embodiment, in the portion of the light diffusion part covered by the cylindrical member, the light emitted from the light diffusion part is reflected by the inner surface of the cylindrical member, so the reflected light is likely to be diffused in various directions from the exposed part which is the portion of the light diffusion part not covered by the cylindrical member. As a result, the light emission intensity distribution of the exposed part in the circumferential direction of the shaft is likely to be uniformized. Thereby, the number of irradiations to the target tissue such as a tumor and the number of position adjustments of the exposed part with respect to the target tissue can be reduced, so that the efficiency of the procedure can be improved. Further, since the second coil member is disposed closer to the proximal side than the cylindrical member in the lumen of the shaft and the entire second coil member is disposed in the lumen of the shaft in the longitudinal axis direction, the torque on the proximal side is likely to be transmitted to the distal side, and the operability can be improved. By providing the second coil member, the optical fiber is likely to be disposed coaxially with the cylindrical member, and the deviation of the light diffusion part can be prevented, so that the light emission intensity distribution of the exposed part in the circumferential direction of the shaft is more likely to be further uniformized. Furthermore, since the proximal part of the second coil member is fixed to the handle, the second coil member can be fixed so as not to move in the longitudinal axis direction with respect to the optical fiber.

Brief Description of Drawings

[0011] [Figure 1] It is a cross-sectional view (partial side view) of the light irradiation medical device according to the first embodiment of the present invention. [Figure 2] It is a cross-sectional view (partial side view) of the distal side of the light irradiation medical device shown in FIG. 1 enlarged. [Figure 3]It is an end face view of a cut portion in the III-III line of the light irradiation medical device shown in FIG. 2. [Figure 4] It is an end face view of a cut portion of the first coil member shown in FIG. 2. [Figure 5] FIG. 5 is a cross-sectional view (partial side view) showing a modified example of the light irradiation medical device shown in FIG. 2. [Figure 6] It is an enlarged cross-sectional view of the distal side of the optical fiber shown in FIG. 2. [Figure 7] It is a cross-sectional view showing a modified example of the optical fiber shown in FIG. 6. [Figure 8] It is a cross-sectional view showing another modified example of the optical fiber shown in FIG. 6. [Figure 9] It is a cross-sectional view (partial side view) of the light irradiation medical device according to the second embodiment of the present invention. [Figure 10] It is an enlarged cross-sectional view (partial side view) of the distal side of the light irradiation medical device shown in FIG. 9. [Figure 11] It is an end face view of a cut portion in the XI-XI line of the light irradiation medical device shown in FIG. 10. [Figure 12] It is an end face view of a cut portion of the cylindrical member shown in FIG. 10. [Figure 13] It is a cross-sectional view (partial side view) showing a modified example of the light irradiation medical device shown in FIG. 10. [Figure 14] It is a cross-sectional view (partial side view) showing another modified example of the light irradiation medical device shown in FIG. 10. [Figure 15] It is a cross-sectional view (partial side view) showing yet another modified example of the light irradiation medical device shown in FIG. 10. [Figure 16] It is an enlarged cross-sectional view of the distal side of the optical fiber shown in FIG. 10. [Figure 17] It is a cross-sectional view showing a modified example of the optical fiber shown in FIG. 16. [Figure 18] It is a cross-sectional view showing another modified example of the optical fiber shown in FIG. 16.

Embodiments for Carrying Out the Invention

[0012] The present invention will be described in more detail below based on the embodiments described below. However, the present invention is not limited by the embodiments described below, and it is certainly possible to implement it with appropriate modifications within the scope that is consistent with the spirit of the preceding and following descriptions, and all such modifications are included within the technical scope of the present invention. In addition, hatching and component reference numerals may be omitted in the drawings for convenience, in which case please refer to the specification or other drawings. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, as priority has been given to helping to understand the features of the present invention.

[0013] First, a photoirradiation medical device according to the first embodiment of the present invention will be described.

[0014] The light irradiation medical device according to the first embodiment of the present invention comprises a shaft having a distal end and a proximal end in the longitudinal axis direction and a lumen extending in the longitudinal axis direction, an optical fiber disposed in the lumen of the shaft, and a first coil member disposed in the lumen of the shaft and having a wire spirally wound around the distal portion of the optical fiber, wherein the optical fiber has a light diffusion portion in a predetermined section of its distal portion, and the first coil member covers a part of the light diffusion portion. According to the above light irradiation medical device, in the portion of the light diffusion portion covered by the first coil member, the light emitted from the light diffusion portion is reflected by the inner surface of the first coil member, so that the reflected light is easily diffused in various directions from the exposed portion, which is the portion of the light diffusion portion not covered by the first coil member. As a result, the light emission intensity distribution of the exposed portion in the circumferential direction of the shaft is more easily made uniform. This reduces the number of irradiations to target tissues such as tumors and the number of adjustments to the position of the exposed portion relative to the target tissue, thereby improving the efficiency of the procedure.

[0015] Light therapy devices are used in PDT and photoablation to irradiate a treatment site, which is the target tissue such as cancer cells, with light of a specific wavelength in the internal lumen of blood vessels, the digestive tract, etc. The light therapy device may be delivered to the treatment site independently, or it may be used in conjunction with a delivery catheter or endoscope. In endoscopic treatment, the light therapy device is placed inside the body through the forceps channel of the endoscope and delivered to the treatment site.

[0016] The basic configuration of the apparatus according to the first embodiment will be described with reference to Figures 1 to 8. Figure 1 is a cross-sectional view (partial side view) of the light irradiation medical apparatus according to the first embodiment of the present invention. Figure 2 is an enlarged cross-sectional view (partial side view) of the distal side of the light irradiation medical apparatus shown in Figure 1. Figure 3 is an end view of the section along line III-III of the light irradiation medical apparatus shown in Figure 2. Figure 4 is an end view of the section of the first coil member shown in Figure 2. Figure 5 is a cross-sectional view (partial side view) showing a modified example of the light irradiation medical apparatus shown in Figure 2. Figure 6 is an enlarged cross-sectional view of the distal side of the optical fiber shown in Figure 2. Figures 7 to 8 are cross-sectional views showing other modified examples of the optical fiber shown in Figure 6. The light irradiation medical apparatus 1 has a shaft 10, an optical fiber 20, and a first coil member 40. Hereinafter, the light irradiation medical apparatus may be simply referred to as the apparatus. To make it easier to understand the positional relationship between the optical fiber 20 and the first coil member 40, the shaft 10 is omitted in Figures 6 to 8.

[0017] In this specification, the distal side of the device 1 refers to the distal end of the shaft 10 in the longitudinal axis direction x, which is the side to be treated. The proximal side of the device 1 refers to the proximal end of the shaft 10 in the longitudinal axis direction x, which is the side to the user's hand. When each component is divided into two equal parts in the longitudinal axis direction x of the shaft 10, the proximal side may be referred to as the proximal part, and the distal side as the distal part. In the radial direction of the device 1, the inward direction refers to the direction toward the central axis c extending in the longitudinal axis direction x of the shaft 10, and the outward direction refers to the radial direction opposite to the inward direction.

[0018] The shaft 10 has a longitudinal axis direction x, a radial direction and a circumferential direction p. As shown in Figure 1, the shaft 10 has a distal end and a proximal end in the longitudinal axis direction x, and has a lumen 11 extending in the longitudinal axis direction x. The shaft 10 may have only one lumen 11 or may have multiple lumen 11s. The shaft 10 has a cylindrical shape to accommodate the optical fiber 20 and the first coil member 40 in its lumen 11. It is preferable that the shaft 10 has a cylindrical shape with only one lumen 11. Since the shaft 10 is inserted into the body, it is preferable that it is flexible. The shaft 10 has an inner circumferential surface 12 and an outer circumferential surface 13.

[0019] The shaft 10 can be a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body with at least one of its inner or outer surfaces coated with resin; a resin tube; or a combination thereof, for example, connected in the longitudinal direction. Examples of a hollow body in which wires are arranged in a predetermined pattern include a cylindrical body having a mesh structure by simply crossing or weaving the wires, or a coil in which the wires are wound. The wires may be one or more single wires, or one or more stranded wires. The resin tube can be manufactured, for example, by extrusion molding. If the shaft 10 is a resin tube, the shaft 10 can be composed of a single layer or multiple layers. The shaft 10 may be composed of a single layer in part in the longitudinal direction x or circumferential direction p, and the other part may be composed of multiple layers.

[0020] The shaft 10 can be made of synthetic resins such as polyolefin resin (e.g., polyethylene or polypropylene), polyamide resin (e.g., nylon), polyester resin (e.g., PET), aromatic polyetherketone resin (e.g., PEEK), polyetherpolyamide resin, polyurethane resin, polyimide resin, or fluororesin (e.g., PTFE, PFA, ETFE), or metals such as stainless steel, carbon steel, or nickel-titanium alloy. These may be used individually or in combination of two or more. Preferably, at least the portion of the shaft 10 that overlaps with the light-diffusing portion 21 is made of a light-transmitting resin. At least the portion of the shaft 10 that overlaps with the light-diffusing portion 21 may be made of a transparent resin.

[0021] As shown in Figure 1, a tip 15 may be attached to the distal end of the shaft 10. This can prevent damage to biological tissue caused by the distal end of the shaft 10. Examples of the shape of the tip 15 include a cylindrical shape, an oblong cylindrical shape, a hemispherical shape, an oblong spherical shape, a frustum of pyramids, a frustum of cones, an oblong frustum of cones, a rounded frustum of corners, or a combination thereof.

[0022] In Figure 1, a handle 60 is connected to the proximal end of the shaft 10. The operator can easily operate the device 1 by grasping the handle 60. The handle 60 extends, for example, in the longitudinal axis direction x. The handle 60 can be made up of one or more members. In Figure 1, the handle 60 has a hollow portion that extends in the longitudinal axis direction x. The handle 60 may have, for example, a cylindrical shape. In Figure 1, the shaft 10 and optical fiber 20 are inserted through the hollow portion of the handle 60.

[0023] The material used to construct the handle 60 is not particularly limited, but for example, polyolefin resins such as polypropylene (PP) and polyethylene (PE), polyester resins such as polyethylene terephthalate (PET), synthetic resins such as polycarbonate resin, ABS resin, and polyurethane resin can be used.

[0024] The optical fiber 20 is a transmission path that transmits optical signals to the target tissue. As shown in Figures 1 and 2, the optical fiber 20 is located in the lumen 11 of the shaft 10. The optical fiber 20 has an optical diffusion section 21 that extends in the longitudinal axis direction x in a predetermined section of its distal end and emits light radially outward from the shaft 10. The optical diffusion section 21 functions as an emission area. The optical diffusion section 21 is arranged to extend in the longitudinal axis direction x and the circumferential direction p of the shaft 10. The optical diffusion section 21 has an outer circumferential surface 23. The outer circumferential surface 23 of the optical diffusion section 21 faces the inner circumferential surface 12 of the shaft 10. In Figure 1, the proximal end of the optical fiber 20 extends proximally from the handle 60. The proximal end of the optical fiber 20 is connected to a light source such as a semiconductor laser.

[0025] The device 1 is inserted through the endoscope to the location of the target tissue within the body cavity. At this time, the target tissue is positioned radially outward from the outer surface 13 of the shaft 10. Light emitted from the light diffusing section 21 passes through at least the portion of the shaft 10 that overlaps with the light diffusing section 21, thereby reaching the target tissue surrounding the device 1.

[0026] It is sufficient that light is emitted from the light diffusing section 21 at least radially outward from the shaft 10, and preferably light is emitted from the light diffusing section 21 radially outward from the shaft 10 over the entire circumferential direction p of the shaft 10. Light may also be emitted from the light diffusing section 21 distally, i.e., forward, of the shaft 10. However, it is preferable that the device 1 does not include any light diffusing section 21 that emits light only distally from the shaft 10.

[0027] As shown in Figures 1 and 2, a portion of the light diffusion section 21 is covered by the first coil member 40. In this specification, the portion from which light is emitted at least radially outward when the first coil member 40 is removed from the optical fiber 20 is referred to as the light diffusion section 21. When the first coil member 40 covers a portion of the light diffusion section 21, at least one of the distal end or proximal end of the light diffusion section 21 may be hidden by the first coil member 40 and not visible, making it difficult to determine the positions of the distal and proximal ends of the light diffusion section 21. For this reason, the positions of the distal and proximal ends of the light diffusion section 21 are determined when the first coil member 40 is removed from the optical fiber 20.

[0028] In this specification, the portion of the light diffusion section 21 that is not covered by the first coil member 40 and is exposed to the shaft 10 side is referred to as the exposed portion 22. In the radial direction of the shaft 10, it is preferable that there are no other members between the exposed portion 22 and the shaft 10, but any member that does not obstruct the light emitted from the exposed portion 22 may be placed there.

[0029] The light diffusion section 21 is not a separate diffusion member (e.g., a diffuser plate or prism) from the optical fiber 20, but rather a part that constitutes a portion of the optical fiber 20. The optical fiber 20 has a core and a cladding. The cladding is arranged around the outer circumference of the core and covers a portion of the core's radially outward side. The light diffusion section 21 is preferably composed of one of the following: (i) a configuration in which only the core is provided, (ii) a configuration in which both the core and cladding are provided, or (iii) a configuration in which only the core is provided in part and the other part consists of both the core and cladding. A protective covering material may be provided on the radially outward side of the cladding, but it is preferable that no members other than the core and cladding are provided in the light diffusion section 21.

[0030] The materials that make up the core and cladding are not particularly limited, and can be plastics, quartz glass, fluoride glass, or other types of glass.

[0031] In at least the portion of the shaft 10 that overlaps with the light-diffusing section 21, light-diffusing materials such as inorganic particles like titanium dioxide, barium sulfate, and calcium carbonate, or organic particles like cross-linked acrylic and cross-linked styrene can be added to the resin constituting the shaft 10. This makes it easier for the light emitted from the light-diffusing section 21 to be further diffused by the shaft 10.

[0032] The light diffusion section 21 is preferably located at the most distal end of the optical fiber 20. This facilitates the formation of the light diffusion section 21 and also increases the flexibility of the distal end of the optical fiber 20.

[0033] In the longitudinal axis x direction, the length of the light diffusion section 21 may be set to a length of 1 / 50, 1 / 45, or 1 / 30 or more of the total length of the optical fiber 20. Setting it to such a length makes it easier to irradiate the entire target tissue in a single irradiation. Alternatively, in the longitudinal axis x direction, the length of the light diffusion section 21 may be set to a length of 1 / 20, 1 / 25, or 1 / 30 or less of the total length of the optical fiber 20. Setting it to such a length prevents irradiation of unintended tissue.

[0034] The light diffusion section 21 may be located only on a portion of the circumferential direction p of the shaft 10, but as shown in Figure 3, it is preferable that the light diffusion section 21 be located along the entire circumferential direction p of the shaft 10. This allows for simultaneous irradiation of a wide area in the circumferential direction p, thereby improving the efficiency of the procedure.

[0035] An example of the configuration of the optical fiber 20 will be explained with reference to Figures 6 to 8. In Figures 6 to 8, the optical fiber 20 has a core 25 extending in the longitudinal axis direction x, and a first section 31 having a first cladding 26 arranged on the outer circumference of the core 25. In the first section 31, light is more likely to undergo total internal reflection at the boundary between the core 25 and the first cladding 26, so in the first section 31, light is confined within the core 25 and propagates toward the distal end of the optical fiber 20.

[0036] In the first section 31, it is preferable that one core 25 is arranged within one first cladding 26. In the first section 31, the optical fiber can be referred to as a single-core optical fiber.

[0037] To prevent an increase in the profile of the optical fiber 20, the first cladding 26 may be located on the outermost radial side of the optical fiber 20 in the first section 31. In other words, other components such as covering material may not be provided in the first section 31.

[0038] Although not shown in the diagram, a covering material may be provided on the outer circumference of the first cladding 26 in the first section 31 of the optical fiber 20. This makes it possible to protect the outside of the first section 31 and suppress light leakage and emission to the outside in the first section 31. The covering material may be a covering layer provided on the outer surface of the first cladding 26, or it may be a sheath enclosing the first cladding 26. The covering material can be made of a resin such as an ultraviolet curing resin.

[0039] In Figure 6, the optical fiber 20 has a light diffusion section 21 which has a second cladding 27 located on the outer circumference of the core 25 and having a second cladding surface roughness greater than that of the first cladding 26, and a second section 32 located distal to the first section 31. By increasing the surface roughness of the cladding in the second section 32 compared to the first section 31, some of the light is confined within the core 25 and propagates distally to the optical fiber 20, while the remaining light leaks out from the second cladding 27 and is emitted radially outward. It is preferable that no light is emitted radially outward in the first section 31, or that the amount of light leakage in the first section 31 is smaller than in the second section 32.

[0040] Similar to the first section 31, it is preferable that in the second section 32, one core 25 is arranged within one second cladding 27. The first section 31 and the second section 32 may be composed of a single optical fiber. The first cladding 26 of the first section 31 and the second cladding 27 of the second section 32 may be integrally molded. The optical fiber 20 may be formed by joining the optical fiber for the first section 31 and the optical fiber for the second section 32 in the longitudinal axis direction x. The first cladding 26 of the first section 31 and the second cladding 27 of the second section 32 may be joined after being formed separately.

[0041] In the second section 32, it is preferable that the second cladding 27 is located on the outermost radial side of the optical fiber 20. That is, it is preferable that no other components (e.g., covering material) other than the core 25 and the second cladding 27 are present in the second section 32. With this configuration, light can be emitted from the second section 32 radially outward along the shaft 10.

[0042] The surface roughness of the outer surface of the second cladding 27 in the second section 32 is greater than the surface roughness of the outer surface of the first cladding 26 in the first section 31. Here, surface roughness is the arithmetic mean roughness Ra of the roughness curve in the longitudinal axis direction of the outer surface of the optical fiber 20 over a reference length. The reference length can be set according to the magnification of the laser microscope used, but for example, it is 200 μm. The above arithmetic mean roughness Ra corresponds to the arithmetic mean roughness Ra specified in JIS B 0601 (2001) and is measured in accordance with JIS B 0633 (2001). For measurement, a measuring instrument specified in JIS B 0651 (2001) (for example, a laser microscope VK-X3000 manufactured by Keyence Corporation) is used.

[0043] It is preferable that the average surface roughness of the outer surface of the second cladding 27 in the second section 32 is greater than the average surface roughness of the outer surface of the first cladding 26 in the first section 31. In the first section 31, light is more easily confined within the core 25, while in the second section 32, light is more easily emitted radially outward from the second cladding 27. As a result, the emission intensity distribution of the light diffusion section 21 is more easily made uniform in the longitudinal axis direction x. The average surface roughness is the average of the surface roughness values ​​of 10 or more measurement points set to be aligned in the longitudinal axis direction x in the section to be measured (for example, the first section 31).

[0044] As shown in Figure 6, when the second section 32 is divided into a distal section 323 and a proximal section 324 in the longitudinal axis direction x, it is preferable that the average surface roughness of the outer surface of the second cladding 27 in the proximal section 324 is smaller than the average surface roughness of the outer surface of the second cladding 27 in the distal section 323. With this configuration, the effect of confining light within the core 25 is enhanced in the proximal section 324 compared to the distal section 323, while in the distal section 323, light is more easily emitted radially outward from the second cladding 27, thus making it easier to uniformize the emission intensity distribution of the second section 32 in the longitudinal axis direction x.

[0045] As can be seen from Figures 1 and 6, it is preferable that the second section 32 is shorter than the first section 31 in the longitudinal axis direction x. This makes it easier to form the light diffusion section 21 and also increases the flexibility of the distal end of the optical fiber 20. The length of the second section 32 in the longitudinal axis direction x can be set to a length of 1 / 20th or less, 1 / 25th or less, or 1 / 30th or less of the length of the first section 31. Alternatively, the length of the second section 32 in the longitudinal axis direction x may be set to a length of 1 / 50th or more, 1 / 45th or more, or 1 / 30th or more of the length of the first section 31.

[0046] As can be seen from Figure 6, it is preferable that the average thickness of the second cladding 27 in the second section 32 is smaller than the average thickness of the first cladding 26 in the first section 31. By adjusting the cladding thickness in this way, light is more easily confined within the core 25 in the first section 31, and light is more easily emitted radially outward from the second cladding 27 in the second section 32. Here, the cladding thickness can be measured using a Keyence VK-X3000 laser microscope.

[0047] As shown in Figures 7 and 8, if the optical fiber 20 has a first section 31, the optical fiber 20 may also have a third section 33 in the light diffusion section 21 that is located distal to the first section 31 and does not have cladding. Because there is no cladding in the third section 33, light from the core 25 is emitted radially outward.

[0048] In the third section 33, it is preferable that cladding is absent in at least a portion of the circumferential direction of the core 25, and more preferably that cladding is absent throughout the entire circumferential direction of the core 25.

[0049] In the third section 33, it is preferable that the core 25 is located radially on the outermost side of the optical fiber 20. However, it is preferable that at least a portion of the third section 33 is covered by the first coil member 40. That is, it is preferable that in the third section 33, not only cladding but also any other members (e.g., covering material) other than the core 25 and the first coil member 40 are not present.

[0050] In the longitudinal axis direction x, the outer diameter of the core 25 in the third section 33 may be a constant value, or the outer diameter of the core 25 may be different depending on the position in the longitudinal axis direction x.

[0051] As shown in Figures 7 and 8, it is preferable that the distal end of the third section 33 is in the same position as the distal end of the core 25 in the longitudinal axis direction x. This makes it easier to form the third section 33 and also increases the flexibility of the distal end of the optical fiber 20.

[0052] The surface roughness of the outer circumferential surface of the core 25 in the third section 33 is preferably greater than the surface roughness of the outer circumferential surface of the first cladding 26 in the first section 31. In the first section 31, light is more easily confined within the core 25, while in the third section 33, light is more easily emitted radially outward from the core 25.

[0053] The light diffusion section 21 preferably has at least one of the second section 32 and the third section 33, and may have both the second section 32 and the third section 33. As shown in Figure 7, it is preferable that the second section 32 and the third section 33 are arranged in order from the proximal side to the distal side of the light diffusion section 21. This configuration makes it easier to uniformize the emission intensity distribution of the light diffusion section 21 in the longitudinal axis direction x. To enhance this effect, it is preferable that the first section 31, the second section 32, and the third section 33 are adjacent in the longitudinal axis direction x, and more specifically, that the first section 31 and the second section 32 are adjacent, and the second section 32 and the third section 33 are adjacent.

[0054] When the optical fiber 20 has a second section 32 and a third section 33, it is preferable that the third section 33 is shorter than the second section 32 in the longitudinal axis direction x, as shown in Figure 7. This configuration makes it easier to uniformize the overall light emission intensity distribution of the exposed portion 22 in the longitudinal axis direction x. However, an configuration in which the second section 32 is shorter than the third section 33 in the longitudinal axis direction x is also acceptable.

[0055] In the longitudinal axis direction x, the length of the third section 33 is preferably 20% or less of the total length of the second section 32 and the third section 33, more preferably 18% or less, and even more preferably 15% or less. Alternatively, the length of the third section 33 in the longitudinal axis direction x may be 5% or more, 8% or more, or 10% or more of the total length of the second section 32 and the third section 33. This configuration makes it easier to equalize the light emission intensity distribution of the exposed portion 22 in the longitudinal axis direction x.

[0056] It is preferable that the average surface roughness of the outer surface of the second cladding 27 in the second section 32 is smaller than the average surface roughness of the outer surface of the core 25 in the third section 33. This configuration makes it easier to equalize the luminescence intensity distribution in the longitudinal axis direction x in both the second section 32 and the third section 33.

[0057] As shown in Figure 6, the optical fiber 20 may have only the second section 32 in the light diffusion section 21. That is, the optical fiber 20 may not have the third section 33 in the light diffusion section 21. Even with a configuration having only the second section 32, the light emission intensity distribution of the exposed section 22 in the longitudinal axis direction x can be made uniform. Since the core 25 is not exposed, it also has the effect of preventing damage to the optical fiber 20 due to bending of the device 1 during the procedure.

[0058] If the optical fiber 20 has only a second section 32 in the optical diffusion section 21, it is preferable that the distal end of the second section 32 is in the same position as the distal end of the core 25 in the longitudinal axis direction x.

[0059] As shown in Figure 8, the optical fiber 20 may have only the third section 33 in the light diffusion section 21. In other words, the optical fiber 20 may not have the second section 32 in the light diffusion section 21. Even with a configuration having only the third section 33, the light emission intensity distribution of the exposed section 22 in the longitudinal axis direction x can be made uniform.

[0060] The second section 32 and the third section 33 can be formed by removing the cladding through etching or polishing. To adjust the surface roughness of the second section 32 and the third section 33, irregularities may be present on the outer circumferential surface of the second cladding 27 and the outer circumferential surface of the core 25 of the third section 33. These irregularities can be formed by mechanically or chemically roughening the surface of the second cladding 27 or the core 25 of the third section 33. Methods for roughening the surface include etching, blasting, using a scribing needle, a wire brush, or sandpaper.

[0061] The light diffusion unit 21 should emit a first therapeutic ray. The first ray is preferably a laser light with a wavelength suitable for phototherapy such as PDT or PIT, which irradiates internal tissue. In addition to the first ray, a second targeting ray may also be emitted. The second ray is emitted to identify the treatment site before emitting the first ray, and it is preferable that it has a lower radiant energy than the first ray.

[0062] As shown in Figures 1 and 2, the first coil member 40 is positioned in the lumen 11 of the shaft 10, and a wire 42 is spirally wound around the distal end of the optical fiber 20, with the first coil member 40 covering a portion of the light diffusion section 21. According to the apparatus 1, in the portion of the light diffusion section 21 covered by the first coil member 40, the light emitted from the light diffusion section 21 is reflected by the inner surface of the first coil member 40, making it easier for the reflected light to diffuse in various directions from the exposed portion 22, which is the portion of the light diffusion section 21 not covered by the first coil member 40. As a result, the emission intensity distribution of the exposed portion 22 in the circumferential direction p of the shaft 10 becomes more uniform. This reduces the number of irradiations to target tissues such as tumors and the number of adjustments to the position of the exposed portion 22 relative to the target tissue, thereby improving the efficiency of the procedure. Figure 2 shows, with thick arrows, an example of how light traveling from the proximal to the distal side is directly emitted from the exposed portion 22, and how it is reflected by the first coil member 40 before being emitted from the exposed portion 22.

[0063] The first coil member 40 covers only a portion of the light diffusion section 21, and does not cover the entire light diffusion section 21. An exposed portion 22 is always formed on the light diffusion section 21.

[0064] The first coil member 40 is formed to extend in the longitudinal axis direction x of the shaft 10. The direction of the first coil member 40 parallel to the longitudinal axis direction x of the shaft 10 is referred to as the axial direction of the first coil member 40. As shown in Figures 2 and 4, the first coil member 40 has an inner circumferential surface 43 and an outer circumferential surface 44. The inner circumferential surface 43 extends in the circumferential direction p of the shaft 10 and faces the outer circumferential surface 23 side of the optical fiber 20. The outer circumferential surface 44 extends in the circumferential direction p of the shaft 10 and faces the inner circumferential surface 12 side of the shaft 10. It is preferable that the light emitted from the light diffusion section 21 is reflected by at least the inner circumferential surface 43 of the first coil member 40.

[0065] As shown in Figures 2 and 4, the first coil member 40 may have a shape in which the distal end 401 side is closed and the proximal end 402 side is open. In that case, the first coil member 40 has an outer end face 45 on the distal end 401 side and an inner end face 46 on the distal end 401 side. This shape can also be described as a bottomed cylindrical shape with the closed portion on the distal end 401 side as the bottom. The outer end face 45 on the distal end 401 side is a surface that is visible when the first coil member 40 is viewed from the distal side towards the proximal side. The inner end face 46 on the distal end 401 side corresponds to the inner bottom surface of the bottomed cylindrical shape. With this configuration, light can be reflected not only from the inner circumferential surface 43 of the first coil member 40 but also from the inner end face 46 on the distal end 401 side, so that the reflected light is easily diffused in various directions from the exposed portion 22. As shown in Figure 5, the first coil member 40 may be cylindrical in shape with openings at the distal end 401 and the proximal end 402.

[0066] The inner circumferential surface 43 may consist only of curved portions, only of flat portions, or a combination of curved and flat portions. It is preferable that the inner circumferential surface 43 has curved portions in order to facilitate the diffusion of light reflected by the inner circumferential surface 43 in multiple directions. The inner end surface 46 may consist only of flat portions, only of curved portions, or a combination of curved and flat portions.

[0067] The wire 42 has a tip and a base in the direction of its longitudinal axis. The wire 42 may be composed of a single linear member from tip to base, or it may be composed of multiple linear members connected to each other in the direction of its longitudinal axis.

[0068] The shape of the cross-section of the wire 42 perpendicular to the longitudinal axis may be circular, oval, polygonal, or a combination thereof. The oval shape includes elliptical, egg-shaped, and rounded rectangular shapes. The same applies to other descriptions herein.

[0069] The cross-sectional shape of the wire 42 perpendicular to the longitudinal axis is preferably circular or oval. With such a cross-sectional shape, as shown in Figure 4, in a cross-section along the longitudinal axis x of the shaft 10, multiple protrusions 491 are arranged on the inner circumferential surface 43 of the first coil member 40 in the longitudinal axis x direction. As a result, it is preferable that a recess 492 is placed between two protrusions 491. The protrusions 491 and recesses 492 on the inner circumferential surface 43 make it easier for reflected light to diffuse in multiple directions.

[0070] The diameter (thickness) of the wire 42 constituting the first coil member 40 and the number of turns of the wire 42 are not particularly limited. The axial length of the first coil member 40 may be greater than or less than the maximum outer diameter of the first coil member 40.

[0071] The first coil member 40 may be a single-layer wound coil or a multi-layer wound coil. Figure 1 shows an example in which the first coil member 40 is composed only of a single-layer wound coil. The first coil member 40 may have both a single-layer wound portion and a multi-layer wound portion.

[0072] The pitch P of the first coil member 40 is not particularly limited and may be constant in the axial direction or may vary depending on the axial position. The pitch P is the distance between the central axes of two adjacent wires 42 that form the first coil member 40 in the axial direction, as shown in Figure 1.

[0073] In order to enhance the effect of light reflection by the inner circumferential surface 43 of the first coil member 40, it is preferable that the light emitted from the light diffusion section 21 does not pass through the wire 42 constituting the first coil member 40 toward the radially outward direction of the shaft 10.

[0074] The first coil member 40 may have gaps between adjacent wires 42 in the axial direction, but it is preferable that the gaps between adjacent wires 42 are not too large. This is because if too much light leaks through the gaps between adjacent wires 42, the light emission intensity at the exposed portion 22 may decrease. Therefore, it is preferable that the first coil member 40 has a first pitch portion 48 having a pitch of no more than twice the wire diameter of the wires 42.

[0075] As shown in Figure 1, in the first pitch section 48, the first coil member 40 may have the same pitch as the wire diameter of the wire 42. Such a coil is generally called a tightly wound coil. A tightly wound coil is preferable because there is no gap between two adjacent wires 42, and light is less likely to leak from the first coil member 40.

[0076] If the diameter of the wire 42 changes along its longitudinal axis (for example, if there is a thicker diameter section and a thinner diameter section with a smaller diameter than the thicker section), the first coil member 40 may have a pitch smaller than the diameter of the wire 42 in the first pitch section 48.

[0077] In the first pitch section 48, the first coil member 40 may have a pitch of 1.1 times or more the wire diameter of the wire 42, or a pitch of 1.2 times or more. Also, in the first pitch section 48, the first coil member 40 may have a pitch of 1.9 times or less the wire diameter of the wire 42, or a pitch of 1.8 times or less. Setting the pitch in this way is preferable because it can suppress light leakage from the first coil member 40.

[0078] The first pitch portion 48 may constitute only a part of the axial direction of the first coil member 40. Alternatively, the first pitch portion 48 may constitute the entire axial direction of the first coil member 40.

[0079] In the longitudinal axis direction x, it is preferable that the distal end 401 of the first coil member 40 is located at the same position as the distal end of the light diffusion section 21, or distal to the distal end of the light diffusion section 21.

[0080] The light diffusion section 21 has a longitudinal axis direction, and the longitudinal axis direction of the light diffusion section 21 is parallel to the longitudinal axis direction x of the shaft 10. As shown in Figure 2, it is preferable that the proximal end 402 of the first coil member 40 is located distal to the midpoint 211 in the longitudinal axis direction of the light diffusion section 21. Since the exposed portion 22 can be formed to be long in the longitudinal axis direction of the light diffusion section 21, it is possible to irradiate a wide area in the longitudinal axis direction with light at once.

[0081] The first coil member 40 is preferably positioned to include the distal end of the light diffusion section 21. The first coil member 40 is preferably not located proximal to the midpoint 211 in the longitudinal axis direction of the light diffusion section 21.

[0082] It is preferable that the entire first coil member 40 is positioned within the lumen 11 of the shaft 10 in the longitudinal axis direction x.

[0083] In the longitudinal axis direction x, the length of the first coil member 40 can be set to a length of 1 / 2, 1 / 3, or 1 / 4 of the length of the exposed portion 22. Alternatively, in the longitudinal axis direction x, the length of the first coil member 40 may be set to a length of 1 / 20, 1 / 18, or 1 / 15 of the length of the exposed portion 22.

[0084] The outer diameter of the first coil member 40 may be constant in the longitudinal axis direction x of the shaft 10, or it may differ depending on the position in the longitudinal axis direction x. For example, when the first coil member 40 is divided into a distal part and a proximal part in the longitudinal axis direction x, the average outer diameter of the distal part of the first coil member 40 may be larger than the average outer diameter of the proximal part of the first coil member 40.

[0085] The first coil member 40 is preferably made of a material with a higher reflectivity than the shaft 10. This configuration makes it easier for reflected light to be diffused on the inner surface of the first coil member 40. Here, reflectivity refers to the reflectivity of the light emitted from the light diffusion section 21, and its unit is %. The reflectivity can be measured using the Ocean Photonics OP-RF-VIS-GT50 reflectivity measurement system.

[0086] The first coil member 40 is preferably made of a metal, and may be a radiopaque metal such as gold, silver, platinum, palladium, tungsten, tantalum, iridium and their alloys, or a superelastic alloy such as stainless steel or Ni-Ti alloy.

[0087] A portion of the first coil member 40 may be made of resin. The first coil member 40 may have a first coil member body and a reflective layer disposed on the inner surface of the first coil member body. Regardless of the material of the first coil member body, the reflective layer can reflect light from the light diffusion section 21. For example, the first coil member body may be a coil body or resin tube around which resin wire is wound. The reflective layer may be provided by applying a coating agent containing a reflective material to the inner surface of the first coil member body, or by adhering the reflective material to the inner surface of the first coil member body by methods such as vapor deposition, sputtering, electroplating, or chemical plating. The reflective layer may also be a thin metal film. Examples of reflective materials include aluminum, gold, silver, copper, tin, titanium dioxide, tantalum pentoxide, aluminum oxide, silicon dioxide, magnesium fluoride, or combinations thereof. When the first coil member 40 has a reflective layer, at least one of the materials listed as constituent materials for the shaft 10 can be used for the first coil member body.

[0088] By heating and deforming the distal end 401 side of the first coil member 40, a first coil member 40 with a closed distal end 401 side can be obtained as shown in Figure 4. Alternatively, a cylindrical coil having one lumen and a separate metal member can be prepared, and the metal member can be heated and welded to close the distal opening of the cylindrical coil, thereby obtaining a first coil member 40 with a closed distal end 401 side.

[0089] The inner circumferential surface 43 of the first coil member 40 may have irregularities. By roughening the surface of the inner circumferential surface 43 to form fine irregularities on the order of micrometers or nanometers, reflected light is more easily diffused in multiple directions.

[0090] The uneven surface 43 of the first coil member 40 can be formed by etching, blasting, roughening the inner surface 43 of the first coil member 40 using a scribing needle, wire brush, or sandpaper.

[0091] In the longitudinal axis x of the shaft 10, the irregularities may be distributed only to a part of the first coil member 40, or they may be distributed over the entire first coil member 40. Similarly, in the circumferential direction of the shaft 10, the irregularities may be distributed only to a part of the first coil member 40, or they may be distributed over the entire first coil member 40.

[0092] As shown in Figure 5, it is preferable that a reflective material 17 that reflects light from the light diffusion section 21 is placed on the distal end 401 side of the first coil member 40. The reflective material 17 is, for example, a mirror positioned so that its reflective surface faces the proximal side. With this configuration, light can be reflected not only by the inner circumferential surface of the first coil member 40 but also by the reflective material 17, making it easier for the reflected light to diffuse in various directions.

[0093] The surface of the reflective material 17 is preferably composed of aluminum, gold, silver, copper, tin, titanium dioxide, tantalum pentoxide, aluminum oxide, silicon dioxide, or magnesium fluoride.

[0094] As shown in Figure 5, the reflective material 17 may be positioned distal to the first coil member 40. Although not shown, the reflective material 17 may be positioned at the most distal end of the lumen of the first coil member 40. If the distal end 401 side of the first coil member 40 is closed, the inner end face 46 of the first coil member 40 and the distal end face of the reflective material 17 may be in contact.

[0095] When the optical fiber 20 has a second section 32, as shown in Figure 6, it is preferable that the first coil member 40 covers a part of the second section 32, and more preferably that it covers a part of the distal portion of the second section 32. Light emitted radially outward from the light diffusion section 21 can be reflected by the portion of the second section 32 covered by the first coil member 40. It is preferable that the first coil member 40 does not cover the entire second section 32.

[0096] As shown in Figures 7 and 8, when the optical fiber 20 has a third section 33, it is preferable that the first coil member 40 covers at least a portion of the third section 33. Light emitted radially outward from the light diffusion section 21 can be reflected by the portion of the third section 33 covered by the first coil member 40. In the longitudinal axis direction x, as shown in Figure 8, the first coil member 40 may cover only a portion of the third section 33. In that case, it is preferable that the first coil member 40 covers a portion of the distal part of the third section 33. Alternatively, in the longitudinal axis direction x, as shown in Figure 7, the first coil member 40 may cover the entire third section 33.

[0097] If the optical fiber 20 has a second section 32 and a third section 33, the proximal end 402 of the first coil member 40 may be located distal to the distal end of the second section 32. In this way, the first coil member 40 may be located only in the third section 33 and not in the second section 32.

[0098] If the optical fiber 20 has a second section 32 and a third section 33, the proximal end 402 of the first coil member 40 may be located proximal to the distal end of the second section 32. In this way, the first coil member 40 may be arranged in part of the second section 32 and at least part of the third section 33.

[0099] It is preferable that the first coil member 40 is fixed to the light diffusion section 21. As shown in Figure 2, it is even more preferable that the first coil member 40 is fixed to the outer circumferential surface 23 of the light diffusion section 21. Furthermore, as can be seen from Figures 2 and 4, it is even more preferable that the inner circumferential surface 43 of the first coil member 40 is fixed to the outer circumferential surface 23 of the light diffusion section 21. Even when the device 1 is inserted into the body, the position of the proximal end 402 of the first coil member 40 is fixed so as not to shift relative to the light diffusion section 21 in the longitudinal axis direction x, thereby stabilizing the irradiation position. Even when the first coil member 40 is fixed to the outer circumferential surface 23 of the light diffusion section 21, it is preferable that the first coil member 40 also curves in accordance with the curvature of the device 1.

[0100] Methods for fixing the first coil member 40 and the light diffusion section 21 include bonding the first coil member 40 and the light diffusion section 21 together, and fixing the first coil member 40 to the light diffusion section 21 by crimping the first coil member 40.

[0101] When fixing the first coil member 40 to the light diffusion section 21, it is preferable that the first coil member 40 is in contact with the outer circumferential surface 23 of the light diffusion section 21, and more preferably that the inner circumferential surface 43 of the first coil member 40 is in contact with the outer circumferential surface 23 of the light diffusion section 21. This prevents an increase in the profile of the optical fiber 20 to which the first coil member 40 is attached, and makes it easier for light to be reflected by the first coil member 40.

[0102] As shown in Figure 6, when the first coil member 40 covers a portion of the second section 32, it is preferable that the first coil member 40 is in contact with the outer circumferential surface of the second cladding 27 of the second section 32. Also, as shown in Figures 7 and 8, when the first coil member 40 covers at least a portion of the third section 33, it is preferable that the first coil member 40 is in contact with the outer circumferential surface of the core 25 of the third section 33.

[0103] When the light diffusing section 21 is positioned at the most distal end of the optical fiber 20, the light diffusing section 21 has a distal end face 212, as shown in Figure 2. In this case, it is preferable that the distal end face 212 of the light diffusing section 21 is not fixed to the first coil member 40. By making the distal end face 212 unfixed, even when the device 1 passes through a bend in the body, the distal end 401 side of the first coil member 40 does not become stiff and can easily follow the curvature of the shaft 10. As a result, the risk of damage to the optical fiber 20 can be reduced, and the light emission intensity distribution of the exposed portion 22 in the circumferential direction p of the shaft 10 can be made more uniform. Note that the distal end face 212 of the light diffusing section 21 does not need to be fixed to the first coil member 40 so as not to move, and it is permissible for the distal end face 212 of the light diffusing section 211 to be in contact with the first coil member 40, as shown in Figure 2.

[0104] The distal end face 212 of the light diffusion section 21 preferably has a planar shape perpendicular to the longitudinal axis direction of the optical fiber 20, as shown in Figure 2, but it may also have a planar shape inclined with respect to the longitudinal axis direction of the optical fiber 20, or it may have a curved shape.

[0105] As shown in Figure 2, it is preferable that the outer circumferential surface 44 of the first coil member 40 is in contact with the inner circumferential surface 12 of the shaft 10. This configuration makes it difficult for the position of the first coil member 40 to shift relative to the shaft 10, and the position of the exposed portion 22 is fixed, thereby stabilizing the irradiation position. The first coil member 40 only needs to be inserted into the lumen 11 of the shaft 10, and the outer circumferential surface 44 of the first coil member 40 does not need to be fixed to the inner circumferential surface 12 of the shaft 10.

[0106] As shown in Figure 2, it is preferable that the outer circumferential surface 23 of the light diffusing portion 21 is positioned away from the inner circumferential surface 12 of the shaft 10. It is even more preferable that the outer circumferential surface 23 of the light diffusing portion 21 is positioned away from the inner circumferential surface 12 of the shaft 10 in the exposed portion 22. Furthermore, it is even more preferable that the outer circumferential surface 23 of the light diffusing portion 21 is positioned away from the inner circumferential surface 12 of the shaft 10 along the entire longitudinal axis x. By positioning the light diffusing portion 21 in the lumen 11 of the shaft 10 in this way, the flexibility of the shaft 10 in the light diffusing portion 21 can be maintained.

[0107] It is preferable that the outer circumferential surface 23 of the light diffusion portion 21 is positioned away from the inner circumferential surface 12 of the shaft 10 along the entire circumferential direction p of the shaft 10. Furthermore, it is preferable that the distance between the outer circumferential surface 23 of the light diffusion portion 21 and the inner circumferential surface 12 of the shaft 10 in the radial direction of the shaft 10 is uniform at any position along the circumferential direction p of the shaft 10. This makes it easier to uniformize the light emission intensity distribution of the exposed portion 22 along the circumferential direction p.

[0108] Next, a photoirradiation medical device according to a second embodiment of the present invention will be described. Note that components and parts identical to those described in the first embodiment may be denoted by the same reference numerals and their descriptions may be omitted.

[0109] A photoirradiation medical device according to a second embodiment of the present invention comprises a shaft having a distal end and a proximal end in the longitudinal axis direction and a lumen extending in the longitudinal axis direction; an optical fiber disposed in the lumen of the shaft; a cylindrical member disposed in the lumen of the shaft and covering a part of the distal portion of the optical fiber; a second coil member disposed proximal to the cylindrical member in the lumen of the shaft and having a wire spirally wound around the optical fiber; and a handle connected to the proximal portion of the shaft. The optical fiber has a light-diffusing portion that extends in the longitudinal axis direction in a predetermined section of its distal portion and emits light radially outward from the shaft. The cylindrical member covers a part of the light-diffusing portion, the proximal portion of the second coil member is fixed to the handle, and the entire second coil member is disposed in the lumen of the shaft in the longitudinal axis direction. According to the above-described light irradiation medical device, in the portion of the light diffusion section covered by the cylindrical member, the light emitted from the light diffusion section is reflected by the inner surface of the cylindrical member. As a result, the reflected light is more easily diffused in various directions from the exposed portion of the light diffusion section that is not covered by the cylindrical member. Consequently, the emission intensity distribution of the exposed portion becomes more uniform in the circumferential direction of the shaft. This reduces the number of irradiations to target tissues such as tumors and the number of adjustments to the position of the exposed portion relative to the target tissue, thereby improving the efficiency of the procedure. Furthermore, because the second coil member is positioned proximal to the cylindrical member in the lumen of the shaft, and the entire second coil member is positioned within the lumen of the shaft in the longitudinal direction, the torque from the proximal side is more easily transmitted to the distal side, improving operability. The provision of the second coil member makes it easier for the optical fiber to be positioned coaxially with the cylindrical member, preventing the light diffusion section from becoming uneven, thus further improving the uniformity of the emission intensity distribution of the exposed portion in the circumferential direction of the shaft. In addition, because the proximal portion of the second coil member is fixed to the handle, the second coil member can be fixed so as not to move in the longitudinal direction relative to the optical fiber.

[0110] The basic configuration of the apparatus according to the second embodiment will be described with reference to Figures 9 to 18. Figure 9 is a cross-sectional view (partial side view) of the light irradiation medical apparatus according to the second embodiment of the present invention. Figure 10 is an enlarged cross-sectional view (partial side view) of the distal side of the light irradiation medical apparatus shown in Figure 9. Figure 11 is an end view of the section between lines XI and XI of the light irradiation medical apparatus shown in Figure 10. Figure 12 is an end view of the section of the cylindrical member shown in Figure 10. Figures 13 to 15 are cross-sectional views (partial side views) showing modified examples of the light irradiation medical apparatus shown in Figure 10. Figure 16 is an enlarged cross-sectional view of the distal side of the optical fiber shown in Figure 10. Figures 17 to 18 are cross-sectional views showing modified examples of the optical fiber shown in Figure 16. The light irradiation medical apparatus 2 has a shaft 10, an optical fiber 20, a cylindrical member 39, a second coil member 50, and a handle 60. Hereinafter, the light irradiation medical apparatus may be simply referred to as the apparatus. To make it easier to understand the positional relationship between the optical fiber 20 and the cylindrical member 39, the shaft 10 is omitted in Figures 16 to 18.

[0111] In this specification, the distal side of the device 2 refers to the distal end of the shaft 10 in the longitudinal axis direction x, which is the side to be treated. The proximal side of the device 2 refers to the proximal end of the shaft 10 in the longitudinal axis direction x, which is the side to the user's hand. When each component is divided into two equal parts in the longitudinal axis direction x of the shaft 10, the proximal side may be referred to as the proximal part, and the distal side as the distal part. In the radial direction of the device 2, the inward direction refers to the direction toward the central axis c extending in the longitudinal axis direction x of the shaft 10, and the outward direction refers to the radial direction opposite to the inward direction.

[0112] As shown in Figure 9, the device 2 has a shaft 10 having a distal end and a proximal end in the longitudinal axis direction x, and a lumen 11 extending in the longitudinal axis direction x. The shaft 10 has a cylindrical shape to accommodate the optical fiber 20, the cylindrical member 39, and the second coil member 50 in its lumen 11.

[0113] As shown in Figure 9, a tip 15 may be attached to the distal end of the shaft 10.

[0114] As shown in Figure 9, a handle 60 is connected to the proximal end of the shaft 10. In Figure 9, the handle 60 has a hollow portion 61 that extends in the longitudinal axis direction x. In Figure 9, the shaft 10, the optical fiber 20, and the second coil member 50 are inserted through the hollow portion 61.

[0115] As shown in Figures 9 and 10, the apparatus 2 has an optical fiber 20 positioned in the lumen 11 of the shaft 10. The optical fiber 20 has a light diffusing section 21 that extends in the longitudinal axis direction x in a predetermined section of its distal end and emits light radially outward from the shaft 10. The light diffusing section 21 is positioned to extend in the longitudinal axis direction x and the circumferential direction p of the shaft 10. The light diffusing section 21 has an outer circumferential surface 23. The outer circumferential surface 23 of the light diffusing section 21 faces the inner circumferential surface 12 of the shaft 10. In Figure 9, the proximal end of the optical fiber 20 extends proximally from the handle 60. The proximal end of the optical fiber 20 is connected to a light source such as a semiconductor laser.

[0116] The device 2 is inserted through the endoscope to the location of the target tissue within the body cavity. At this time, the target tissue is positioned radially outward from the outer surface 13 of the shaft 10. The light emitted from the light diffusing section 21 passes through at least the portion of the shaft 10 that overlaps with the light diffusing section 21, thereby reaching the target tissue surrounding the device 2.

[0117] It is sufficient that light is emitted from the light diffusing section 21 at least radially outward from the shaft 10, and preferably light is emitted radially outward from the light diffusing section 21 over the entire circumferential direction p of the shaft 10. Light may also be emitted distally from the light diffusing section 21, i.e., forward. However, it is preferable that the device 2 does not include any light diffusing section 21 that emits light only distally from the shaft 10.

[0118] As shown in Figure 9, the device 2 is positioned proximal to the cylindrical member 39 in the lumen 11 of the shaft 10 and has a second coil member 50 in which a wire 52 is helically wound around the optical fiber 20. The entire second coil member 50 is positioned in the lumen 11 of the shaft 10 in the longitudinal axis direction x.

[0119] The proximal portion of the second coil member 50 is fixed to the handle 60. The second coil member 50 may be directly fixed to the handle 60, or it may be indirectly fixed via another member. The method of fixing the second coil member 50 and the handle 60 is not particularly limited, but examples include physical fixing methods such as welding, crimping, bonding with adhesive, engagement, connection, binding, ligation, etc., or combinations thereof. Figure 9 shows an example in which the outer circumferential surface of the proximal portion of the second coil member 50 is fixed to the inner circumferential surface 12 of the shaft 10, and the outer circumferential surface 13 of the shaft is fixed to the handle 60.

[0120] The proximal end of the second coil member 50 is preferably located distal to the proximal end of the handle 60, and may also be located distal to the distal end of the handle 60. Also, as shown in Figure 9, the proximal end of the second coil member 50 is distal to the proximal end of the handle 60, and may also be located proximal to the distal end of the handle 60.

[0121] Apparatus 2 is positioned in the lumen 11 of shaft 10 and has a cylindrical member 39 that covers a portion of the distal end of optical fiber 21. As shown in Figures 9 to 10, a portion of the light diffusion portion 21 is covered by the cylindrical member 39. In this specification, the portion from which light is emitted at least radially outward when the cylindrical member 39 is removed from the optical fiber 20 is referred to as the light diffusion portion 21. When the cylindrical member 39 covers a portion of the light diffusion portion 21, at least one of the distal end and proximal end of the light diffusion portion 21 may be hidden by the cylindrical member 39 and not visible, making it difficult to determine the positions of the distal and proximal ends of the light diffusion portion 21. For this reason, the positions of the distal and proximal ends of the light diffusion portion 21 are determined when the cylindrical member 39 is removed from the optical fiber 20. Furthermore, if a portion of the light diffusion section 21 is also covered by the second coil member 50, the portion from which light is emitted at least radially outward when the cylindrical member 39 and the second coil member 50 are removed from the optical fiber 20 is referred to as the light diffusion section 21.

[0122] In this specification, the portion of the light diffusion section 21 that is not covered by the cylindrical member 39 and is exposed to the shaft 10 side is referred to as the exposed portion 22. In the radial direction of the shaft 10, it is preferable that there are no other members between the exposed portion 22 and the shaft 10, but any member that does not obstruct the light emitted from the exposed portion 22 may be placed there.

[0123] The light diffusion section 21 may be located only on a portion of the circumferential direction p of the shaft 10, but as shown in Figure 11, it is preferable that the light diffusion section 21 be located along the entire circumferential direction p of the shaft 10. This allows light to be irradiated over a wide area of ​​the circumferential direction p at once, thereby improving the efficiency of the procedure.

[0124] An example of the configuration of the optical fiber 20 will be explained with reference to Figures 16 to 18. In Figures 16 to 18, the optical fiber 20 has a core 25 extending in the longitudinal axis direction x, and the optical fiber 20 has a first section 31 having a first cladding 26 arranged on the outer circumference of the core 25. In the first section 31, light is more likely to undergo total internal reflection at the boundary between the core 25 and the first cladding 26, so in the first section 31, light is confined within the core 25 and propagates toward the distal side of the optical fiber 20.

[0125] In the first section 31, it is preferable that one core 25 is arranged within one first cladding 26. In the first section 31, the optical fiber can be referred to as a single-core optical fiber.

[0126] To prevent an increase in the profile of the optical fiber 20, the first cladding 26 may be located on the outermost radial side of the optical fiber 20 in the first section 31. In other words, other components such as covering material may not be provided in the first section 31.

[0127] Although not shown in the diagram, a covering material may be provided on the outer circumference of the first cladding 26 in the first section 31 of the optical fiber 20. This makes it possible to protect the outside of the first section 31 and suppress light leakage and emission to the outside in the first section 31. The covering material may be a covering layer provided on the outer surface of the first cladding 26, or it may be a sheath enclosing the first cladding 26. The covering material can be made of a resin such as an ultraviolet curing resin.

[0128] In Figure 16, the optical fiber 20 has a light diffusion section 21 which has a second cladding 27 located on the outer circumference of the core 25 and having a second cladding surface roughness greater than that of the first cladding 26, and a second section 32 located distal to the first section 31. By increasing the surface roughness of the cladding in the second section 32 compared to the first section 31, some of the light is confined within the core 25 and propagates distally to the optical fiber 20, while the remaining light leaks out from the second cladding 27 and is emitted radially outward. It is preferable that no light is emitted radially outward in the first section 31, or that the amount of light leakage in the first section 31 is smaller than in the second section 32.

[0129] Similar to the first section 31, it is preferable that in the second section 32, one core 25 is arranged within one second cladding 27. The first section 31 and the second section 32 may be composed of a single optical fiber. The first cladding 26 of the first section 31 and the second cladding 27 of the second section 32 may be integrally molded. The optical fiber 20 may be formed by joining the optical fiber for the first section 31 and the optical fiber for the second section 32 in the longitudinal axis direction x. The first cladding 26 of the first section 31 and the second cladding 27 of the second section 32 may be joined after being formed separately.

[0130] In the second section 32, it is preferable that the second cladding 27 is located on the outermost radial side of the optical fiber 20. That is, it is preferable that no other components (e.g., covering material) other than the core 25 and the second cladding 27 are present in the second section 32. With this configuration, light can be emitted from the second section 32 radially outward along the shaft 10.

[0131] The surface roughness of the outer surface of the second cladding 27 in the second section 32 is greater than the surface roughness of the outer surface of the first cladding 26 in the first section 31. Here, surface roughness is the arithmetic mean roughness Ra of the roughness curve in the longitudinal axis direction of the outer surface of the optical fiber 20 over a reference length. The reference length can be set according to the magnification of the laser microscope used, but for example, it is 200 μm. The above arithmetic mean roughness Ra corresponds to the arithmetic mean roughness Ra specified in JIS B 0601 (2001) and is measured in accordance with JIS B 0633 (2001). For measurement, a measuring instrument specified in JIS B 0651 (2001) (for example, a laser microscope VK-X3000 manufactured by Keyence Corporation) is used.

[0132] It is preferable that the average surface roughness of the outer surface of the second cladding 27 in the second section 32 is greater than the average surface roughness of the outer surface of the first cladding 26 in the first section 31. In the first section 31, light is more easily confined within the core 25, while in the second section 32, light is more easily emitted radially outward from the second cladding 27. As a result, the emission intensity distribution of the light diffusion section 21 is more easily made uniform in the longitudinal axis direction x. The average surface roughness is the average of the surface roughness values ​​of 10 or more measurement points set to be aligned in the longitudinal axis direction x in the section to be measured (for example, the first section 31).

[0133] As shown in Figure 16, when the second section 32 is divided into a distal section 323 and a proximal section 324 in the longitudinal axis direction x, it is preferable that the average value of the surface roughness of the outer surface of the second cladding 27 in the proximal section 324 is smaller than the average value of the surface roughness of the outer surface of the second cladding 27 in the distal section 323. With this configuration, the effect of confining light within the core 25 is enhanced in the proximal section 324 compared to the distal section 323, while in the distal section 323, light is more easily emitted radially outward from the second cladding 27, thus making it easier to uniformize the emission intensity distribution of the second section 32 in the longitudinal axis direction x.

[0134] As can be seen from Figures 9 and 16, it is preferable that the second section 32 is shorter than the first section 31 in the longitudinal axis direction x. This makes it easier to form the light diffusion section 21 and also increases the flexibility of the distal end of the optical fiber 20. The length of the second section 32 in the longitudinal axis direction x can be set to a length of 1 / 20, 1 / 25, or 1 / 30 of the length of the first section 31. Alternatively, the length of the second section 32 in the longitudinal axis direction x may be set to a length of 1 / 50 or more, 1 / 45 or more, or 1 / 30 or more of the length of the first section 31.

[0135] As can be seen from Figure 16, it is preferable that the average thickness of the second cladding 27 in the second section 32 is smaller than the average thickness of the first cladding 26 in the first section 31. By adjusting the cladding thickness in this way, light is more easily confined within the core 25 in the first section 31, and light is more easily emitted radially outward from the second cladding 27 in the second section 32. The cladding thickness can be measured using a Keyence VK-X3000 laser microscope.

[0136] As shown in Figures 17 and 18, if the optical fiber 20 has a first section 31, the optical fiber 20 may also have a third section 33 in the light diffusion section 21 that is located distal to the first section 31 and does not have cladding. Because there is no cladding in the third section 33, light from the core 25 is emitted radially outward.

[0137] In the third section 33, it is preferable that cladding is absent in at least a portion of the circumferential direction of the core 25, and more preferably that cladding is absent throughout the entire circumferential direction of the core 25.

[0138] In the third section 33, it is preferable that the core 25 is located radially on the outermost side of the optical fiber 20. However, it is preferable that at least a portion of the third section 33 is covered by the cylindrical member 39. That is, it is preferable that in the third section 33, not only cladding but also any other members (e.g., covering material) other than the core 25 and the cylindrical member 39 are not present.

[0139] In the longitudinal axis direction x, the outer diameter of the core 25 in the third section 33 may be a constant value, or the outer diameter of the core 25 may be different depending on the position in the longitudinal axis direction x.

[0140] As shown in Figures 17 and 18, it is preferable that the distal end of the third section 33 is in the same position as the distal end of the core 25 in the longitudinal axis direction x. This makes it easier to form the third section 33 and also increases the flexibility of the distal end of the optical fiber 20.

[0141] The surface roughness of the outer circumferential surface of the core 25 in the third section 33 is preferably greater than the surface roughness of the outer circumferential surface of the first cladding 26 in the first section 31. In the first section 31, light is more easily confined within the core 25, while in the third section 33, light is more easily emitted radially outward from the core 25.

[0142] The light diffusion section 21 preferably has at least one of the second section 32 and the third section 33, and may have both the second section 32 and the third section 33. As shown in Figure 17, it is preferable that the second section 32 and the third section 33 are arranged in order from the proximal side to the distal side of the light diffusion section 21. This configuration makes it easier to uniformize the emission intensity distribution of the light diffusion section 21 in the longitudinal axis direction x. To enhance this effect, it is preferable that the first section 31, the second section 32, and the third section 33 are adjacent in the longitudinal axis direction x, and more specifically, that the first section 31 and the second section 32 are adjacent, and the second section 32 and the third section 33 are adjacent.

[0143] When the optical fiber 20 has a second section 32 and a third section 33, it is preferable that the third section 33 is shorter than the second section 32 in the longitudinal axis direction x, as shown in Figure 17. This configuration makes it easier to uniformize the overall light emission intensity distribution of the exposed portion 22 in the longitudinal axis direction x. However, an configuration in which the second section 32 is shorter than the third section 33 in the longitudinal axis direction x is also acceptable.

[0144] In the longitudinal axis direction x, the length of the third section 33 is preferably 20% or less of the total length of the second section 32 and the third section 33, more preferably 18% or less, and even more preferably 15% or less. Alternatively, the length of the third section 33 in the longitudinal axis direction x may be 5% or more, 8% or more, or 10% or more of the total length of the second section 32 and the third section 33. This configuration makes it easier to equalize the light emission intensity distribution of the exposed portion 22 in the longitudinal axis direction x.

[0145] It is preferable that the average surface roughness of the outer surface of the second cladding 27 in the second section 32 is smaller than the average surface roughness of the outer surface of the core 25 in the third section 33. This configuration makes it easier to equalize the luminescence intensity distribution in the longitudinal axis direction x in both the second section 32 and the third section 33.

[0146] As shown in Figure 16, the optical fiber 20 may have only the second section 32 in the light diffusion section 21. That is, the optical fiber 20 may not have the third section 33 in the light diffusion section 21. Even with a configuration having only the second section 32, the light emission intensity distribution of the exposed section 22 in the longitudinal axis direction x can be made uniform. Since the core 25 is not exposed, it also has the effect of preventing damage to the optical fiber 20 due to bending of the device 2 during the procedure.

[0147] If the optical fiber 20 has only a second section 32 in the optical diffusion section 21, it is preferable that the distal end of the second section 32 is in the same position as the distal end of the core 25 in the longitudinal axis direction x.

[0148] As shown in Figure 18, the optical fiber 20 may have only the third section 33 in the light diffusion section 21. In other words, the optical fiber 20 may not have the second section 32 in the light diffusion section 21. Even with a configuration having only the third section 33, the light emission intensity distribution of the exposed section 22 in the longitudinal axis direction x can be made uniform.

[0149] The second section 32 and the third section 33 can be formed by removing the cladding through etching or polishing. To adjust the surface roughness of the second section 32 and the third section 33, irregularities may be present on the outer circumferential surface of the second cladding 27 and the outer circumferential surface of the core 25 of the third section 33. These irregularities can be formed by mechanically or chemically roughening the surface of the second cladding 27 or the core 25 of the third section 33. Methods for roughening the surface include etching, blasting, using a scribing needle, a wire brush, or sandpaper.

[0150] As shown in Figures 9 and 10, the cylindrical member 39 is positioned in the lumen 11 of the shaft 10 and covers a portion of the distal end of the optical fiber 20. More specifically, the cylindrical member 39 covers a portion of the light diffusion section 21. According to the device 2, in the portion of the light diffusion section 21 covered by the cylindrical member 39, the light emitted from the light diffusion section 21 is reflected by the inner surface of the cylindrical member 39, making it easier for the reflected light to diffuse in various directions from the exposed portion 22, which is the portion of the light diffusion section 21 not covered by the cylindrical member 39. As a result, the emission intensity distribution of the exposed portion 22 becomes more uniform in the circumferential direction p of the shaft 10. This reduces the number of irradiations to target tissues such as tumors and the number of adjustments to the position of the exposed portion 22 relative to the target tissue, thereby improving the efficiency of the procedure. Figure 10 shows, with thick arrows, an example of light traveling from the proximal side to the distal side being emitted directly from the exposed portion 22 and being reflected by the cylindrical member 39 before being emitted from the exposed portion 22.

[0151] The cylindrical member 39 covers only a portion of the light-diffusing section 21, and does not cover the entire light-diffusing section 21. In other words, an exposed portion 22 is always formed on the light-diffusing section 21.

[0152] The cylindrical member 39 is formed to extend in the longitudinal axis direction x of the shaft 10. The direction of the cylindrical member 39 parallel to the longitudinal axis direction x of the shaft 10 is referred to as the axial direction of the cylindrical member 39. As shown in Figures 10 and 12, the cylindrical member 39 has an inner circumferential surface 43 and an outer circumferential surface 44. The inner circumferential surface 43 extends in the circumferential direction p of the shaft 10 and faces the outer circumferential surface 23 side of the optical fiber 20. The outer circumferential surface 44 extends in the circumferential direction p of the shaft 10 and faces the inner circumferential surface 12 side of the shaft 10. It is preferable that the light emitted from the light diffusion section 21 is reflected by at least the inner circumferential surface 43 of the cylindrical member 39.

[0153] As shown in Figures 10, 12, and 13-14, the cylindrical member 39 may have a shape in which the distal end 401 side is closed and the proximal end 402 side is open. In that case, the cylindrical member 39 has an outer end surface 45 on the distal end 401 side and an inner end surface 46 on the distal end 401 side. This shape can also be described as a bottomed cylindrical shape with the closed portion on the distal end 401 side as the bottom. The outer end surface 45 on the distal end 401 side is a surface that is visible when viewing the cylindrical member 39 from the distal side towards the proximal side. The inner end surface 46 on the distal end 401 side corresponds to the inner bottom surface of the bottomed cylindrical shape. With this configuration, light can be reflected not only from the inner circumferential surface 43 of the cylindrical member 39 but also from the inner end surface 46 on the distal end 401 side, so that the reflected light is easily diffused in various directions from the exposed portion 22. As shown in Figure 15, the cylindrical member 39 may have a cylindrical shape with openings at the distal end 401 and the proximal end 402.

[0154] The inner circumferential surface 43 may consist only of curved portions, only of flat portions, or a combination of curved and flat portions. It is preferable that the inner circumferential surface 43 has curved portions in order to facilitate the diffusion of light reflected by the inner circumferential surface 43 in multiple directions. The inner end surface 46 may consist only of flat portions, only of curved portions, or a combination of curved and flat portions.

[0155] The cylindrical member 39 preferably has a single internal lumen. The shape of the cylindrical member 39 is not particularly limited, but it may be cylindrical, elongated cylindrical, or polygonal cylindrical. The axial length of the cylindrical member 39 may be greater than or less than the maximum outer diameter of the cylindrical member 39.

[0156] As shown in Figures 10, 12, and 13, it is preferable that the cylindrical member 39 has a first coil portion 41 in which a wire 42 is wound spirally around the light diffusion portion 21. In the portion of the light diffusion portion 21 covered by the first coil portion 41, the light emitted from the light diffusion portion 21 is reflected by the inner surface of the coil portion 41, so that the reflected light is easily diffused in various directions from the exposed portion 22 of the light diffusion portion 21 that is not covered by the cylindrical member 39. The configuration of the first coil portion 41 will be described later.

[0157] The cylindrical member 39 does not have to be in the shape of a coil around which the wire 42 is wound; it may be a cylindrical body such as a resin tube or a metal pipe, as shown in Figure 14.

[0158] In order to enhance the effect of light reflection by the inner circumferential surface 43 of the cylindrical member 39, it is preferable that the light emitted from the light diffusion section 21 does not pass through the cylindrical member 39 toward the radially outward direction of the shaft 10.

[0159] In the longitudinal axis x, it is preferable that the distal end 401 of the cylindrical member 39 is located at the same position as the distal end of the light diffusion section 21, or distal to the distal end of the light diffusion section 21.

[0160] The light diffusion section 21 has a longitudinal axis direction, and the longitudinal axis direction of the light diffusion section 21 is parallel to the longitudinal axis direction x of the shaft 10. As shown in Figure 10, it is preferable that the proximal end 402 of the cylindrical member 39 is located distal to the midpoint 211 in the longitudinal axis direction of the light diffusion section 21. Since the exposed portion 22 can be formed to be long in the longitudinal axis direction of the light diffusion section 21, a wide area in the longitudinal axis direction can be irradiated with light at once.

[0161] It is preferable that the cylindrical member 39 is positioned to include the distal end of the light diffusion section 21. It is also preferable that the cylindrical member 39 is not located proximal to the midpoint 211 in the longitudinal axis direction of the light diffusion section 21.

[0162] It is preferable that the entire cylindrical member 39 is positioned within the lumen 11 of the shaft 10 in the longitudinal axis direction x.

[0163] In the longitudinal axis direction x, the length of the cylindrical member 39 can be set to a length of 1 / 2, 1 / 3, or 1 / 4 of the length of the exposed portion 22. Alternatively, in the longitudinal axis direction x, the length of the cylindrical member 39 may be set to a length of 1 / 20, 1 / 18, or 1 / 15 or more of the length of the exposed portion 22.

[0164] The outer diameter of the cylindrical member 39 may be constant in the longitudinal axis direction x of the shaft 10, or it may differ depending on the position in the longitudinal axis direction x. For example, when the cylindrical member 39 is divided into a distal part and a proximal part in the longitudinal axis direction x, the average outer diameter of the distal part of the cylindrical member 39 may be larger than the average outer diameter of the proximal part of the cylindrical member 39.

[0165] It is preferable that the cylindrical member 39 is made of a material with a higher reflectivity than the shaft 10. This configuration makes it easier for reflected light to be diffused on the inner surface of the cylindrical member 39. Here, reflectivity refers to the reflectivity of the light emitted from the light diffusion section 21, and the unit is %. The reflectivity can be measured using the Ocean Photonics OP-RF-VIS-GT50 reflectivity measurement system.

[0166] The cylindrical member 39 is preferably made of metal, and may be a radiopaque metal such as gold, silver, platinum, palladium, tungsten, tantalum, iridium, and alloys thereof, or a superelastic alloy such as stainless steel or Ni-Ti alloy.

[0167] The cylindrical member 39 may have a cylindrical member body and a reflective layer disposed on the inner surface of the cylindrical member body. Regardless of the material of the cylindrical member body, the reflective layer can reflect light from the light diffusion section 21. For example, the cylindrical member body may be a coil body with a resin wire wound around it or a resin tube. The reflective layer may be provided by applying a coating agent containing a reflective material to the inner surface of the cylindrical member body, or by attaching a reflective material to the inner surface of the cylindrical member body by methods such as vapor deposition, sputtering, electroplating, or chemical plating. The reflective layer may also be a thin metal film. Examples of reflective materials include aluminum, gold, silver, copper, tin, titanium dioxide, tantalum pentoxide, aluminum oxide, silicon dioxide, magnesium fluoride, or combinations thereof. When the cylindrical member 39 has a reflective layer, any of the materials listed as constituent materials for the shaft 10 can be used for the cylindrical member body.

[0168] By heating and deforming the distal end 401 side of the cylindrical member 39, a cylindrical member 39 with a closed distal end 401 side can be obtained as shown in Figure 12. Alternatively, a cylindrical coil having one lumen and a separate metal member can be prepared, and the metal member can be heated and welded to close the distal opening of the cylindrical coil, thereby obtaining a cylindrical member 39 with a closed distal end 401 side.

[0169] The inner circumferential surface 43 of the cylindrical member 39 may have irregularities. By roughening the surface of the inner circumferential surface 43 to form fine irregularities on the order of micrometers or nanometers, reflected light is more easily diffused in multiple directions.

[0170] The uneven surface 43 of the cylindrical member 39 can be formed by etching, blasting, roughening the inner surface 43 of the cylindrical member 39 using a scribing needle, wire brush, or sandpaper.

[0171] In the longitudinal axis x of the shaft 10, the irregularities may be distributed only on a part of the cylindrical member 39, or they may be distributed over the entire cylindrical member 39. Similarly, in the circumferential direction of the shaft 10, the irregularities may be distributed only on a part of the cylindrical member 39, or they may be distributed over the entire cylindrical member 39.

[0172] As shown in Figure 15, it is preferable that a reflective material 17 that reflects light from the light diffusion section 21 is placed on the distal end 401 side of the cylindrical member 39. The reflective material 17 is, for example, a mirror positioned so that its reflective surface faces the proximal side. With this configuration, light can be reflected not only by the inner circumferential surface of the cylindrical member 39 but also by the reflective material 17, making it easier for the reflected light to diffuse in various directions.

[0173] As shown in Figure 15, it is preferable that the reflective material 17 is positioned distal to the cylindrical member 39. Although not shown, the reflective material 17 may be positioned at the most distal end of the lumen of the cylindrical member 39. If the distal end 401 side of the cylindrical member 39 is closed, the inner end surface 46 of the cylindrical member 39 and the distal end surface of the reflective material 17 may be in contact.

[0174] When the optical fiber 20 has a second section 32, it is preferable that the cylindrical member 39 covers a part of the second section 32, as shown in Figure 16, and more preferably that it covers a part of the distal portion of the second section 32. Light emitted radially outward from the light diffusion section 21 can be reflected by the portion of the second section 32 covered by the cylindrical member 39. It is preferable that the cylindrical member 39 does not cover the entire second section 32.

[0175] As shown in Figures 17 and 18, when the optical fiber 20 has a third section 33, it is preferable that the cylindrical member 39 covers at least a portion of the third section 33. Light emitted radially outward from the light diffusion section 21 can be reflected by the portion of the third section 33 covered by the cylindrical member 39. In the longitudinal axis direction x, as shown in Figure 18, the cylindrical member 39 may cover only a portion of the third section 33. In that case, it is preferable that the cylindrical member 39 covers a portion of the distal part of the third section 33. Alternatively, in the longitudinal axis direction x, as shown in Figure 17, the cylindrical member 39 may cover the entire third section 33.

[0176] If the optical fiber 20 has a second section 32 and a third section 33, the proximal end 402 of the cylindrical member 39 may be located distal to the distal end of the second section 32. In this way, the cylindrical member 39 may be located only in the third section 33 and not in the second section 32.

[0177] If the optical fiber 20 has a second section 32 and a third section 33, the proximal end 402 of the cylindrical member 39 may be located proximal to the distal end of the second section 32. In this way, the cylindrical member 39 may be positioned in part of the second section 32 and at least part of the third section 33.

[0178] The configuration of the first coil section 41 will be described in detail below. The wire 42 constituting the first coil section 41 has a tip and a base in the longitudinal direction. The wire 42 constituting the first coil section 41 may be composed of a single linear member from tip to base, or it may be composed of multiple linear members connected to each other in the longitudinal direction.

[0179] The cross-sectional shape of the wire 42 constituting the first coil section 41, perpendicular to the longitudinal axis, may be circular, oval, polygonal, or a combination thereof.

[0180] The cross-sectional shape of the wire 42 constituting the first coil section 41, perpendicular to the longitudinal axis direction, is preferably circular or oval. With such a cross-sectional shape, as shown in Figure 12, in a cross-section along the longitudinal axis direction x of the shaft 10, multiple protrusions 491 are arranged on the inner circumferential surface 43 of the cylindrical member 39 in the longitudinal axis direction x. As a result, it is preferable that a recess 492 is placed between two protrusions 491. The protrusions 491 and recesses 492 on the inner circumferential surface 43 make it easier for reflected light to diffuse in multiple directions.

[0181] The wire diameter (thickness) of the wire 42 constituting the first coil section 41 and the number of turns of the wire 42 constituting the first coil section 41 are not particularly limited. Figures 9 to 10 show an example in which the first coil section 41 is single-layer wound, but it may also be multi-layer wound, or a combination of single-layer and multi-layer winding may be used. The axial length of the first coil section 41 may be greater or less than the maximum outer diameter of the first coil section 41.

[0182] The pitch P1 of the first coil section 41 is not particularly limited and may be constant in the axial direction or may vary depending on the axial position. The pitch P1 is the distance between the central axes of two adjacent wires 42 that form the first coil section 41 in the axial direction, as shown in Figure 9.

[0183] In the first coil section 41, gaps may be formed between adjacent wires 42 in the axial direction, but it is preferable that the gaps between adjacent wires 42 are not too large. This is because if too much light leaks through the gaps between adjacent wires 42, the light emission intensity at the exposed section 22 may decrease. Therefore, it is preferable that the first coil section 41 has a first pitch section 48 having a pitch of no more than twice the wire diameter of the wires 42.

[0184] As shown in Figure 9, in the first pitch section 48, the first coil section 41 may have the same pitch as the wire diameter of the wire 42. Such a coil is generally called a tightly wound coil. A tightly wound coil is preferable because there is no gap between two adjacent wires 42, and light is less likely to leak from the first coil section 41.

[0185] If the diameter of the wire 42 changes along its longitudinal axis (for example, if there is a thicker diameter section and a thinner diameter section with a smaller diameter than the thicker section), the cylindrical member 39 in the first pitch section 48 may have a pitch smaller than the diameter of the wire 42.

[0186] In the first pitch section 48, the first coil section 41 may have a pitch of 1.1 times or more the wire diameter of the wire 42, or a pitch of 1.2 times or more. Also, in the first pitch section 48, the first coil section 41 may have a pitch of 1.9 times or less the wire diameter of the wire 42, or a pitch of 1.8 times or less. Setting the pitch in this way is preferable because it can suppress light leakage from the first coil section 41.

[0187] The first pitch portion 48 may constitute only a part of the axial direction of the first coil portion 41. Alternatively, as shown in Figure 9, the first pitch portion 48 may constitute the entire axial direction of the first coil portion 41.

[0188] It is preferable that the first coil portion 41 constitutes only a part of the axial direction of the cylindrical member 39. For example, if the cylindrical member 39 has a body portion that extends in the circumferential direction of the shaft 10 and a bottom portion located distal to the body portion, it is preferable that the body portion is the first coil portion 41.

[0189] As shown in Figures 9 to 10, the second coil member 50 is positioned proximal to the cylindrical member 39 in the lumen 11 of the shaft 10, and the wire 52 is wound spirally around the optical fiber 20. Furthermore, the entire second coil member 50 is positioned in the lumen 11 of the shaft 10 in the longitudinal axis direction x. By covering the optical fiber 20 in this way, torque from the proximal side is more easily transmitted to the distal side, thereby improving the operability of the device 2. By providing the second coil member 50, the optical fiber 20 is more easily positioned coaxially with the cylindrical member 39, and uneven distribution of the light diffusion portion 21 can be prevented, so the light emission intensity distribution of the exposed portion 22 in the circumferential direction p of the shaft 10 becomes more uniform. In addition, the proximal part of the second coil member 50 is fixed to the handle 60. With this configuration, the second coil member 50 can be fixed so that it does not move in the longitudinal axis direction x relative to the optical fiber 20.

[0190] The second coil member 50 is formed to extend in the longitudinal axis direction x of the shaft 10. The direction of the second coil member 50 that is parallel to the longitudinal axis direction x of the shaft 10 is referred to as the axial direction of the second coil member 50. As shown in Figure 10, the second coil member 50 has an inner circumferential surface 53 and an outer circumferential surface 54. The inner circumferential surface 53 extends in the circumferential direction p of the shaft 10 and faces the outer circumferential surface 23 of the optical fiber 20. The outer circumferential surface 54 extends in the circumferential direction p of the shaft 10 and faces the inner circumferential surface 12 of the shaft 10.

[0191] As shown in Figure 9, it is preferable that the second coil member 50 has an open shape at both the distal end 501 and the proximal end 502.

[0192] As shown in Figure 9, the entire second coil member 50 is positioned in the lumen 11 of the shaft 10 in the longitudinal axis direction x, so the proximal end 502 of the second coil member 50 is located distal to the proximal end of the shaft 10.

[0193] As shown in Figure 10, it is preferable that the second coil member 50 covers a portion of the light diffusion section 21. By arranging the second coil member 50 in this manner, the length of the exposed portion 22 in the longitudinal axis direction x can be determined. Normally, due to the presence of the cladding of the optical fiber 20, the incident light from the light source should be totally reflected and propagated distally. However, when the device 2 is bent, the incident light becomes smaller than the critical angle, and light may leak radially outward from the optical fiber 20. Even in such cases, because the second coil member 50 covers a portion of the light diffusion section 21, the light emitted from the light diffusion section 21 can also be reflected on the inner surface of the second coil member 50. As a result, leakage of light from the proximal side of the light diffusion section 21 can be suppressed, and light from the light source can be efficiently guided to the light diffusion section 21.

[0194] As shown in Figure 10, it is preferable that a portion of the light diffusion section 21 is not covered by the cylindrical member 39 and the second coil member 50. That is, it is preferable that the proximal end 402 of the cylindrical member 39 and the distal end 501 of the second coil member 50 are separated in the longitudinal axis direction x. By arranging the cylindrical member 39 and the second coil member 50 in this way, an exposed portion 22 is formed, making it possible to emit light radially outward from the exposed portion 22.

[0195] It is preferable that the light emitted from the light diffusion section 21 is reflected by the inner circumferential surface 53 of the portion of the second coil member 50 that covers the light diffusion section 21. The reflected light is then easily diffused in various directions from the exposed portion 22 of the light diffusion section 21 that is not covered by the second coil member 50.

[0196] The inner circumferential surface 53 of the second coil member 50 may consist only of curved portions, only of flat portions, or a combination of curved and flat portions. It is preferable that the inner circumferential surface 53 has curved portions in order to facilitate the diffusion of light reflected by the inner circumferential surface 53 in multiple directions.

[0197] In order to enhance the effect of light reflection by the inner surface of the second coil member 50, it is preferable that the light emitted from the light diffusion section 21 does not pass through the second coil member 50 toward the radially outward direction of the shaft 10.

[0198] As shown in Figure 9, it is preferable that the second coil member 50 is longer than the cylindrical member 39 in the longitudinal axis direction x. Since the second coil member 50 can cover a wide area in the longitudinal axis direction of the optical fiber, torque transmission can be improved.

[0199] Preferably, the portion of the second coil member 50 covering the light diffusion section 21 is made of a material with a higher reflectivity than the shaft 10. This configuration makes it easier for reflected light to be diffused on the inner surface of the second coil member 50. Here, reflectivity refers to the reflectivity of the light emitted from the light diffusion section 21, and the unit is %. The reflectivity of the second coil member 50 can be measured in the same way as the cylindrical member 39.

[0200] The second coil member 50 is preferably made of a metal, and may be a radiopaque metal such as gold, silver, platinum, palladium, tungsten, tantalum, iridium, and their alloys, or a superelastic alloy such as stainless steel or Ni-Ti alloy.

[0201] A portion of the second coil member 50 may be made of resin. The second coil member 50 may have a second coil member body and a reflective layer disposed on the inner surface of the second coil member body. Regardless of the material of the second coil member body, the reflective layer can reflect light from the light diffusion section 21. For example, the second coil member body may be a coil body or resin tube around which resin wire is wound. The reflective layer may be provided by applying a coating agent containing a reflective material to the inner surface of the second coil member body, or by adhering the reflective material to the inner surface of the second coil member body by methods such as vapor deposition, sputtering, electroplating, or chemical plating. The reflective layer may also be a thin metal film. As the reflective material, those listed in the description of the cylindrical member 39 can be used. If the second coil member 50 has a reflective layer, at least one of the materials listed as constituent materials of the shaft 10 can be used for the second coil member body.

[0202] The wire 52 constituting the second coil member 50 has a tip and a base in the longitudinal direction. The wire 52 may be composed of a single linear member from tip to base, or it may be composed of multiple linear members connected to each other in the longitudinal direction.

[0203] The cross-sectional shape of the wire 52 perpendicular to the longitudinal axis may be circular, oval, polygonal, or a combination thereof. The oval shape includes elliptical, egg-shaped, and rounded rectangular shapes.

[0204] The cross-sectional shape of the wire 52 perpendicular to the longitudinal axis is preferably circular or oval. With such a cross-sectional shape, similar to the cylindrical member 39, in the cross-section along the longitudinal axis x of the shaft 10, multiple protrusions are arranged on the inner circumferential surface 53 of the second coil member 50 in the longitudinal axis x direction, with recesses between two protrusions. The protrusions and recesses on the inner circumferential surface 53 make it easier for reflected light to be diffused in multiple directions on the proximal side of the light diffusion section 21.

[0205] The diameter (thickness) of the wire 52 constituting the second coil member 50 and the number of turns of the wire 52 are not particularly limited. The axial length of the second coil member 50 may be greater than or less than the maximum outer diameter of the second coil member 50.

[0206] The pitch P2 of the second coil member 50 is not particularly limited and may be constant in the axial direction or may vary depending on the axial position. The pitch P2 is the distance between the central axes of two adjacent wires 52 that form the second coil member 50 in the axial direction, as shown in Figure 9.

[0207] The second coil member 50 may have gaps between adjacent wires 52 in the axial direction, but in order to facilitate the transmission of torque from the proximal side to the distal side, it is preferable that the second coil member 50 has a second pitch portion 58 having a pitch of no more than twice the wire diameter of the wires 52, as shown in Figure 9. In the second pitch portion 58, the second coil member 50 may have the same pitch as the wire diameter of the wires 52. That is, there may be no gap between two adjacent wires 52. If the wire diameter of the wires 52 changes in the longitudinal direction (for example, if there is a large diameter portion and a small diameter portion with a smaller diameter than the large diameter portion), the second coil member 50 may have a pitch smaller than the wire diameter of the wires 52 in the second pitch portion 58.

[0208] In the second pitch section 58, the second coil member 50 may have a pitch of 1.1 times or more the wire diameter of the wire 52, or a pitch of 1.2 times or more. Also, in the second pitch section 58, the second coil member 50 may have a pitch of 1.9 times or less the wire diameter of the wire 52, or a pitch of 1.8 times or less. By setting the pitch in this way, torque on the proximal side is more easily transmitted to the distal side, and light leakage from the second coil member 50 can also be suppressed.

[0209] The second pitch portion 58 may constitute only a part of the axial direction of the second coil member 50. Alternatively, as shown in Figure 9, the second pitch portion 58 may constitute the entire axial direction of the second coil member 50.

[0210] The second coil member 50 may be a single-layer coil, a multi-layer coil, or a combination of both. For example, Figure 9 shows an example where the second coil member 50 is a single-layer coil. With this configuration, when the second coil member 50 covers a part of the proximal portion of the light diffusion section 21, the reflected light is more easily diffused in multiple directions on the inner surface of the second coil member 50.

[0211] As shown in Figure 13, it is preferable that the first coil portion 41 of the cylindrical member 39 is single-layer wound, and the second coil member 50 has a second coil portion 51a that is multi-layer wound. The single-layer wound first coil portion 41 makes it easier for reflected light to diffuse in multiple directions on the inner circumferential surface 43 of the cylindrical member 39. In addition, the multi-layer wound second coil portion 51a makes it easier for torque on the proximal side to be transmitted to the distal side, thereby improving the operability of the device 2.

[0212] The first coil section 41 is preferably made of a radiopaque material. Since the first coil section 41 can be used as a radiopaque marker, it becomes easier for the operator to determine the distal position of the light diffusion section 21. The second coil section 51a is preferably arranged to extend over a wide area in the axial direction, so if it is made of a radiopaque material, it becomes more difficult to determine the position of the light diffusion section 21. For this reason, the second coil section 51a is preferably made of a material that transmits radiation more easily than the first coil section 41.

[0213] The first coil portion 41 is preferably made of, for example, gold, silver, platinum, palladium, tungsten, tantalum, iridium, or an alloy thereof. The second coil portion 51a is preferably made of, for example, stainless steel, carbon steel, nickel-titanium alloy, or other metal.

[0214] In Figure 13, the second coil member 50 has a multi-layer wound second coil section 51a and a single-layer wound third coil section 51b located distal to the second coil section 51a. In the second coil section 51a, wire 52a is wound spirally around the optical fiber 20 in three layers. In the third coil section 51b, wire 52b is wound spirally around the optical fiber 20 in one layer. By providing the second coil section 51a in this way, torque from the proximal side is more easily transmitted to the distal side, thereby improving the operability of the device 2. Furthermore, by providing the third coil section 51b, a different function from that of the second coil section 51a can be assigned to the third coil section 51b. For example, the third coil section 51b can be used as a radiopaque marker, or it can be made of a material suitable for reflecting light from the light diffusion section 21.

[0215] In the longitudinal axis direction x, it is preferable that the second coil section 51a is longer than the third coil section 51b. This configuration makes it easier for torque on the proximal side to be transmitted to the distal side, thereby improving the operability of the device 2.

[0216] Although not shown in the diagram, in the second coil member 50, the multi-layer wound second coil portion 51a may be located distal to the single-layer wound third coil portion 51b.

[0217] As shown in Figure 13, it is preferable that the third coil portion 51b covers a part of the light diffusion portion 21 and the second coil portion 51a is located proximal to the light diffusion portion 21. More specifically, it is preferable that the distal end of the third coil portion 51b is located distal to the proximal end of the light diffusion portion 21, and the proximal end of the third coil portion 51b is located proximal to the proximal end of the light diffusion portion 21. This configuration makes it easier to provide the third coil portion 51b with both the function of reflecting light from the light diffusion portion 21 and good torque transmission.

[0218] Preferably, the third coil section 51b is made of a radiopaque material that is less permeable to radiation than the second coil section 51a. This allows the third coil section 51b to be used as a radiopaque marker, making it easier for the operator to determine the proximal position of the light diffusion section 21.

[0219] The third coil section 51b is preferably composed of, for example, gold, silver, platinum, palladium, tungsten, tantalum, iridium, or an alloy thereof. The third coil section 51b may be composed of the same material as the second coil section 51a, but it is preferable that it be composed of a different material. Each layer of the second coil section 51a may be composed of a different material, but it is preferable that it be composed of the same material. The third coil section 51b may be composed of a different material than the first coil section 41, but it is preferable that it be composed of the same material.

[0220] As shown in Figures 17 and 18, the minimum inner diameter of the cylindrical member 39 may be smaller than the minimum inner diameter of the second coil member 50. This is preferable because the cylindrical member 39 is firmly fixed to the optical fiber 20, preventing it from falling off the optical fiber 20. For example, this size relationship can be achieved by crimping the cylindrical member 39 to fix it to the optical fiber 20.

[0221] It is preferable that the cylindrical member 39 is fixed to the light diffusion section 21. As shown in Figure 10, it is even more preferable that the cylindrical member 39 is fixed to the outer circumferential surface 23 of the light diffusion section 21. Furthermore, as can be seen from Figures 10 and 12, it is even more preferable that the inner circumferential surface 43 of the cylindrical member 39 is fixed to the outer circumferential surface 23 of the light diffusion section 21. Even when the device 2 is inserted into the body, the position of the proximal end 402 of the cylindrical member 39 is fixed so as not to shift relative to the light diffusion section 21 in the longitudinal axis direction x, thereby stabilizing the irradiation position. Even when the cylindrical member 39 is fixed to the outer circumferential surface 23 of the light diffusion section 21, it is preferable that the cylindrical member 39 also curves in accordance with the curvature of the device 2.

[0222] Methods for fixing the cylindrical member 39 and the light diffusion part 21 include bonding the cylindrical member 39 and the light diffusion part 21 together, and fixing the cylindrical member 39 to the light diffusion part 21 by crimping the cylindrical member 39.

[0223] When fixing the cylindrical member 39 to the light diffusion section 21, it is preferable that the cylindrical member 39 is in contact with the outer circumferential surface 23 of the light diffusion section 21, and more preferably that the inner circumferential surface 43 of the cylindrical member 39 is in contact with the outer circumferential surface 23 of the light diffusion section 21. This prevents an increase in the profile of the optical fiber 20 to which the cylindrical member 39 is attached, and also makes it easier for light to be reflected by the cylindrical member 39.

[0224] When the light diffusing section 21 is positioned at the most distal end of the optical fiber 20, the light diffusing section 21 has a distal end face 212, as shown in Figure 10. In this case, it is preferable that the distal end face 212 of the light diffusing section 21 is not fixed to the cylindrical member 39. By making the distal end face 212 unfixed, even when the device 2 passes through a bend in the body, the distal end 401 side of the cylindrical member 39 does not become stiff and can easily follow the curvature of the shaft 10. As a result, the risk of damage to the optical fiber 20 can be reduced, and the light emission intensity distribution of the exposed portion 22 in the circumferential direction p of the shaft 10 can be made more uniform. Note that the distal end face 212 of the light diffusing section 21 does not need to be fixed to the cylindrical member 39 so as to not move, and it is permissible for the distal end face 212 of the light diffusing section 211 to be in contact with the cylindrical member 39, as shown in Figure 10.

[0225] The distal end face 212 of the light diffusion section 21 preferably has a planar shape perpendicular to the longitudinal axis direction of the optical fiber 20, as shown in Figure 10, but it may also have a planar shape inclined with respect to the longitudinal axis direction of the optical fiber 20, or it may have a curved shape.

[0226] As shown in Figure 10, it is preferable that the outer circumferential surface 44 of the cylindrical member 39 is in contact with the inner circumferential surface 12 of the shaft 10. This configuration makes it difficult for the position of the cylindrical member 39 to shift relative to the shaft 10, and the position of the exposed portion 22 is fixed, thus stabilizing the irradiation position. The cylindrical member 39 only needs to be inserted into the lumen 11 of the shaft 10, and the outer circumferential surface 44 of the cylindrical member 39 does not need to be fixed to the inner circumferential surface 12 of the shaft 10.

[0227] Preferably, the distal portion of the second coil member 50 is not fixed to the optical fiber 20. This configuration allows the distal portion of the second coil member 50 to easily follow the curvature of the shaft 10 without becoming rigid, even when the device 2 passes through a curved portion inside the body. However, it is acceptable for the distal portion of the second coil member 50 to be in contact with the optical fiber 20 (for example, the inner circumferential surface of the distal portion of the second coil member 50 is in contact with the outer circumferential surface of the optical fiber 20). At least a portion of the inner circumferential surface of the distal portion of the second coil member 50 may be positioned away from the outer circumferential surface of the optical fiber 20.

[0228] As shown in Figures 16 and 17, if the second coil member 50 covers a portion of the second section 32, the second coil member 50 may be in contact with the outer circumferential surface of the second cladding 27 of the second section 32. Although not shown, if the second coil member 50 covers at least a portion of the third section 33, the second coil member 50 may be in contact with the outer circumferential surface of the core 25 of the third section 33. As shown in Figure 18, if the second coil member 50 covers at least a portion of the third section 33, the second coil member 50 does not have to be in contact with the outer circumferential surface of the core 25 of the third section 33.

[0229] As shown in Figure 10, it is preferable that the outer circumferential surface 54 of the second coil member 50 is in contact with the inner circumferential surface 12 of the shaft 10. This configuration makes it difficult for the position of the second coil member 50 to shift relative to the shaft 10, and the position of the exposed portion 22 is fixed, thereby stabilizing the irradiation position. The second coil member 50 only needs to be inserted into the lumen 11 of the shaft 10, and the outer circumferential surface 54 of the second coil member 50 does not need to be fixed to the inner circumferential surface 12 of the shaft 10.

[0230] As shown in Figure 10, it is preferable that the outer circumferential surface 23 of the light diffusing portion 21 is positioned away from the inner circumferential surface 12 of the shaft 10. It is even more preferable that in the exposed portion 22, the outer circumferential surface 23 of the light diffusing portion 21 is positioned away from the inner circumferential surface 12 of the shaft 10. Furthermore, it is even more preferable that the outer circumferential surface 23 of the light diffusing portion 21 is positioned away from the inner circumferential surface 12 of the shaft 10 along the entire longitudinal axis x. By positioning the light diffusing portion 21 in the lumen 11 of the shaft 10 in this way, the flexibility of the shaft 10 in the light diffusing portion 21 can be maintained.

[0231] It is preferable that the outer circumferential surface 23 of the light diffusion portion 21 is positioned away from the inner circumferential surface 12 of the shaft 10 along the entire circumferential direction p of the shaft 10. Furthermore, it is preferable that the distance between the outer circumferential surface 23 of the light diffusion portion 21 and the inner circumferential surface 12 of the shaft 10 in the radial direction of the shaft 10 is uniform at any position along the circumferential direction p of the shaft 10. This makes it easier to uniformize the light emission intensity distribution of the exposed portion 22 along the circumferential direction p.

[0232] This application claims the benefit of priority based on Japanese Patent Application No. 2021-112714 and Japanese Patent Application No. 2021-112715, filed on July 7, 2021. The entire contents of the specifications of Japanese Patent Application No. 2021-112714 and Japanese Patent Application No. 2021-112715, filed on July 7, 2021, are incorporated herein by reference. [Explanation of symbols]

[0233] 1: Light irradiation medical device 10: Shaft 11:Lumen 17: Reflective material 20: Optical fiber 21: Light Diffusion Section 22:Exposed part 25: Core 26: First Clad 27: Second Clad 31: Section 1 32: Section 2 323: Distal part 324: Proximal part 33: Third Section 39: Cylindrical member 40: First coil member 41: First coil section 42: Wire rod 48: First pitch section 50: Second coil member 51a: Second coil section 51b: Third coil section 52:Wire rod 58: Second pitch section 60: Handle x: Longitudinal axis p: Circumferential direction

Claims

1. A shaft having a distal end and a proximal end in the longitudinal direction, and having a lumen extending in the longitudinal direction, An optical fiber is disposed in the lumen of the shaft, The shaft has a first coil member which is positioned in the lumen of the shaft and in which a wire is spirally wound around the distal portion of the optical fiber, The optical fiber has a light-diffusing section that extends in the longitudinal direction in a predetermined section of its distal end and emits light radially outward from the shaft. A light irradiation medical device in which the first coil member covers a part of the light diffusion section.

2. The light irradiation medical device according to claim 1, wherein the proximal end of the first coil member is located distal to the midpoint in the longitudinal axis direction of the light diffusion portion.

3. The light irradiation medical device according to claim 1, wherein the first coil member is made of a material with a higher reflectivity than the shaft.

4. The light-diffusing portion is arranged around the entire circumference of the shaft, as described in claim 1.

5. The optical fiber has a core that extends in the longitudinal direction, The optical fiber has a first section having a first cladding arranged on the outer circumference of the core, The optical fiber has a second cladding disposed on the outer circumference of the core and having a surface roughness greater on its outer surface than that of the first cladding, and the second cladding is located distal to the first cladding, as described in claim 1.

6. The optical fiber has a core that extends in the longitudinal direction, The optical fiber has a first section having a first cladding arranged on the outer circumference of the core, The optical fiber has a third section in the light diffusion portion that is located distal to the first section and does not have a cladding, as described in claim 1.

7. The optical fiber has a second cladding in the light diffusion portion that is arranged on the outer circumference of the core and has a second cladding whose outer surface roughness is greater than that of the first cladding, and a second section located distal to the first section. The light irradiation medical device according to claim 6, wherein the light diffusion section has the second section and the third section arranged in order from the proximal side to the distal side.

8. The light irradiation medical device according to claim 7, wherein the third section is shorter than the second section in the longitudinal axis direction.

9. The light irradiation medical device according to claim 6, wherein the first coil member covers at least a portion of the third section.

10. The optical fiber having only the second section in the light diffusion portion, as described in claim 5.

11. The light irradiation medical device according to claim 1, wherein the first coil member has a first pitch portion having a pitch of no more than twice the wire diameter of the wire.

12. The light irradiation medical device according to claim 1, wherein a reflective material that reflects light from the light diffusion portion is disposed on the distal end side of the first coil member.

13. The photoirradiation medical device according to claim 1, wherein the first coil member has a shape in which the distal end is closed and the proximal end is open.

14. The light irradiation medical device according to claim 1, wherein the distal end face of the light diffusion portion is not fixed to the first coil member.

15. The light irradiation medical device according to claim 1, wherein the first coil member is fixed to the outer circumferential surface of the light diffusion portion.

16. The light irradiation medical device according to claim 1, wherein the outer circumferential surface of the light diffusing portion is arranged away from the inner circumferential surface of the shaft.

17. The light irradiation medical device according to any one of claims 1 to 16, wherein the outer circumferential surface of the first coil member is in contact with the inner circumferential surface of the shaft.

18. A shaft having a distal end and a proximal end in the longitudinal direction, and having a lumen extending in the longitudinal direction, An optical fiber is disposed in the lumen of the shaft, A cylindrical member is positioned within the lumen of the shaft and covers a portion of the distal end of the optical fiber, A second coil member is positioned proximal to the cylindrical member in the lumen of the shaft, and a wire is spirally wound around the optical fiber. It has a handle connected to the proximal part of the shaft, The optical fiber has a light-diffusing section that extends in the longitudinal direction in a predetermined section of its distal end and emits light radially outward from the shaft. The cylindrical member covers a part of the light-diffusing portion, The proximal portion of the second coil member is fixed to the handle, In the longitudinal axis direction, the entirety of the second coil member is positioned within the lumen of the shaft. A light irradiation medical device in which the second coil member covers a part of the light diffusion section.

19. The light irradiation medical device according to claim 18, wherein a portion of the light diffusion portion is not covered by the cylindrical member and the second coil member.

20. The light irradiation medical device according to claim 18, wherein the cylindrical member is in contact with the outer surface of the light diffusion portion.

21. The light irradiation medical device according to claim 18, wherein the distal portion of the second coil member is not fixed to the optical fiber.

22. The light irradiation medical device according to claim 18, wherein the second coil member is longer than the cylindrical member in the longitudinal axis direction.

23. The light irradiation medical device according to claim 18, wherein the outer circumferential surface of the cylindrical member is in contact with the inner circumferential surface of the shaft.

24. The light irradiation medical device according to claim 18, wherein the outer circumferential surface of the second coil member is in contact with the inner circumferential surface of the shaft.

25. The light irradiation medical device according to claim 18, wherein the minimum inner diameter of the cylindrical member is smaller than the minimum inner diameter of the second coil member.

26. The light irradiation medical device according to claim 18, wherein the cylindrical member has a first coil portion in which a wire is wound spirally around the light diffusion portion.

27. The photoirradiation medical device according to claim 26, wherein the first coil portion is single-layer wound, and the second coil member has a second coil portion that is multi-layer wound.

28. The photoirradiation medical device according to claim 27, wherein the first coil portion is made of a radiation-impermeable material, and the second coil portion is made of a material that is more permeable to radiation than the first coil portion.

29. The photoirradiation medical device according to claim 18, wherein the second coil member has a second coil portion that is multi-layer wound and a third coil portion that is located distal to the second coil portion and is single-layer wound.

30. The photoirradiation medical device according to claim 29, wherein the third coil portion is made of a radiopaque material that is less permeable to radiation than the second coil portion.

31. The optical fiber has a core that extends in the longitudinal direction, The optical fiber has a first section having a first cladding arranged on the outer circumference of the core, The optical fiber has a second cladding disposed on the outer circumference of the core and having a surface roughness greater on its outer surface than that of the first cladding, and a second section located distal to the first section, as described in claim 18.

32. The optical fiber has a core that extends in the longitudinal direction, The optical fiber has a first section having a first cladding arranged on the outer circumference of the core, The optical fiber having a third section in the light diffusion portion that is located distal to the first section and does not have a cladding, according to any one of claims 18 to 30.

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