Light irradiation medical device

Abstract

To provide a light irradiation medical device in which an amount of light reaching an affected part hardly decreases, and uneven irradiation hardly occurs, so that treatment efficiency can be easily enhanced, and damage to a light diffusion part can be easily prevented.SOLUTION: A light irradiation medical device 1 includes: a shaft 10 having a distal end and a proximal end in a longitudinal axis direction x, and a lumen 11 extending in the longitudinal axis direction x; an optical fiber 20 disposed in the lumen 11 of the shaft 10; and a coil member 40 disposed in the lumen 11 of the shaft 10, around which a wire 42 is wound in a spiral shape so as to surround a distal part of the optical fiber 20. The optical fiber 20 includes a light diffusion part 21 extending in the longitudinal axis direction x in a predetermined section at the distal part and emitting light toward the outer side in a radial direction of the shaft 10. In the predetermined section, the coil member 40 includes a first region 40a in which the coil member has a pitch P1 which is 1.8 or more times larger than the wire diameter of the wire 42, and a second region 40b closer to a proximal side than the first region 40a in which a pitch P2 is shorter than that of the first region 40a.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a light irradiation medical device for irradiating light onto tissues such as cancer cells in body cavities such as blood vessels and the digestive tract. [Background technology]

[0002] In photodynamic therapy (PDT), a photosensitizer is administered intravenously or intraperitoneally, allowing it to accumulate in target tissues such as cancer cells, and then irradiated with light of a specific wavelength to excite the photosensitizer. When the excited photosensitizer returns to its ground state, energy conversion occurs, generating reactive oxygen species. The reactive oxygen species attack the target tissue, allowing it to be removed. In laser light ablation, the target tissue is irradiated with laser light to cauterize it. Devices have been proposed for performing this type of light irradiation.

[0003] Patent Document 1 discloses an optical fiber probe for laser treatment that includes an optical fiber, a flexible tube that surrounds the optical fiber with a gap, and a holder that holds the end of the optical fiber on the emission side approximately coaxially within the tube. It also discloses that the holder is composed of a coil spring, and that a first cylindrical coil part of the coil spring is passed through the optical fiber and fixed to the coating of the optical fiber. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-309155 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to irradiate the entire target tissue, such as a tumor, with a forward-illumination type light irradiation device such as that described in Patent Document 1, it was necessary to perform the operation of emitting light at a certain location, then slightly shifting the position of the light-emitting site relative to the target tissue and emitting light again, performing this operation multiple times. Furthermore, depending on the location and shape of the tumor, irradiation can be difficult. The object of the present invention is to provide a light irradiation medical device that is less likely to reduce the amount of light reaching the affected area and is less likely to cause uneven irradiation, is capable of performing treatment efficiently, and is highly resistant to breakage. [Means for solving the problem]

[0006] One embodiment of the photoirradiation medical device of the present invention that achieves the above-mentioned object comprises a shaft having a distal end and a proximal end in a longitudinal direction and a lumen extending in the longitudinal direction, an optical fiber disposed in the lumen of the shaft, and a coil member disposed in the lumen of the shaft and having a wire wound helically around the distal end of the optical fiber. The optical fiber has a light diffusing section extending in the longitudinal direction in a predetermined section of the distal section and emitting light radially outward from the shaft. In the predetermined section, the coil member has a first region having a pitch at least 1.8 times the wire diameter of the wire, and a second region proximal to the first region and having a shorter pitch than the first region. With this photoirradiation medical device, light is emitted radially from the light diffusing section, which facilitates improving treatment efficiency. Furthermore, by disposing the coil member in the light diffusing section as described above, light irradiated onto the surface of the coil member is more likely to be scattered in various directions, which facilitates improving treatment efficiency. Furthermore, since the coil member has a first region with a pitch of 1.8 times or more the wire diameter of the wire, a sufficient amount of light reaches the affected area in the circumferential direction of the device, preventing uneven irradiation. Furthermore, when an external force is applied, the coil member absorbs the impact, making it easier to prevent damage to the light diffusing section.

[0007] The maximum outer diameter of the first region may be smaller than the maximum outer diameter of the second region.

[0008] The first region may be longer than the second region in the longitudinal direction.

[0009] In the predetermined section, the coil member may have a third region located distal to the first region and having a shorter pitch than the first region.

[0010] The first region may be longer than the third region in the longitudinal direction.

[0011] The maximum outer diameter of the first region may be smaller than the maximum outer diameter of the third region.

[0012] The coil member may have a fourth region located proximal to the first region, the fourth region having a shorter pitch than the second region and a larger maximum outer diameter than the second region.

[0013] The coil member may have a fifth region distal to the first region, the fifth region having a shorter pitch than the third region and a larger maximum outer diameter than the third region.

[0014] The device may further include a handle connected to the proximal end of the shaft, with the proximal end of the coil member fixed to the handle.

[0015] The second region may have a pitch that is 1.5 times or more the wire diameter.

[0016] The coil member may have a multi-layered winding at its proximal portion. [Effects of the Invention]

[0017] According to the above-described light irradiation medical device, light is emitted radially from the light diffusing portion, which facilitates improving treatment efficiency. Furthermore, by arranging the coil member in the light diffusing portion as described above, light irradiated onto the surface of the coil member is easily scattered in various directions, which facilitates improving treatment efficiency. Furthermore, since the coil member has a first region with a pitch of at least 1.8 times the wire diameter of the wire, a sufficient amount of light reaches the affected area in the circumferential direction of the device, which prevents uneven irradiation. Furthermore, when external force is applied, the coil member absorbs the impact, which facilitates preventing damage to the light diffusing portion. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a side view (partial cross-sectional view) of a photoirradiation medical device according to one embodiment of the present invention. [Figure 2] 2 is a cross-sectional end view of the light irradiation medical device shown in FIG. 1 taken along line II-II. [Figure 3] 1. FIG. 4 is a side view (partial cross-sectional view) showing a modification of the light irradiation medical device shown in FIG. [Figure 4] 1. FIG. 4 is a side view (partial cross-sectional view) showing a modification of the light irradiation medical device shown in FIG. [Figure 5] 1. FIG. 4 is a side view (partial cross-sectional view) showing a modification of the light irradiation medical device shown in FIG. [Figure 6] 1. FIG. 4 is a side view (partial cross-sectional view) showing a modification of the light irradiation medical device shown in FIG. [Figure 7] 2 is an enlarged cross-sectional view of the distal end of the optical fiber shown in FIG. 1. [Figure 8] FIG. 2 is a cross-sectional view showing a modified example of the optical fiber shown in FIG. [Figure 9] 1. FIG. 4 is a cross-sectional view showing another modified example of the optical fiber shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the illustrated examples, and appropriate modifications may be made within the scope of the spirit described above and below, and all such modifications are within the technical scope of the present invention. In the drawings, hatching and symbols may be omitted for convenience. In such cases, reference should be made to the specification and other drawings. Furthermore, the dimensions of various parts in the drawings may differ from the actual dimensions, as priority is given to helping understand the features of the present invention.

[0020] One embodiment of the photoirradiation medical device of the present invention comprises 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 coil member disposed in the lumen of the shaft and having a wire wound helically around the distal end of the optical fiber. The optical fiber has a light diffusing section extending in the longitudinal direction in a predetermined section of the distal section and emitting light radially outward from the shaft. Within the predetermined section, the coil member has a first region having a pitch at least 1.8 times the wire diameter of the wire, and a second region proximal to the first region and having a shorter pitch than the first region. With this photoirradiation medical device, light is emitted radially from the light diffusing section, which facilitates improving treatment efficiency. Furthermore, by disposing the coil member on the light diffusing section as described above, light irradiated onto the surface of the coil member is more likely to be scattered in various directions, which facilitates improving treatment efficiency. Furthermore, since the coil member has a first region with a pitch of 1.8 times or more the wire diameter of the wire, a sufficient amount of light reaches the affected area in the circumferential direction of the device, preventing uneven irradiation. Furthermore, when an external force is applied, the coil member absorbs the impact, making it easier to prevent damage to the light diffusing section.

[0021] Photoirradiation medical devices are used in PDT and photoablation to irradiate a treatment site, which is a target tissue such as cancer cells, with light of a specific wavelength in a body lumen such as a blood vessel or the digestive tract. The photoirradiation medical device may be delivered to the treatment site alone or may be used together with a delivery catheter or endoscope. In endoscopic treatment, the photoirradiation medical device is placed inside the body through the forceps channel of the endoscope and delivered to the treatment site.

[0022] The basic configuration of the device will be described with reference to FIGS. 1 to 9. FIG. 1 is a side view (partial cross-sectional view) of a light irradiation medical device according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of the light irradiation medical device shown in FIG. 1 taken along line II-II. FIG. 3 is a side view (partial cross-sectional view) of a modified example of the light irradiation medical device shown in FIG. 1. FIG. 4 is a side view (partial cross-sectional view) of a modified example of the light irradiation medical device shown in FIG. 1. FIG. 5 is a side view (partial cross-sectional view) of a modified example of the light irradiation medical device shown in FIG. 1. FIG. 6 is a side view (partial cross-sectional view) of a modified example of the light irradiation medical device shown in FIG. 1. FIG. 7 is an enlarged cross-sectional view of the distal end of the optical fiber shown in FIG. 1. FIG. 8 is a cross-sectional view of a modified example of the optical fiber shown in FIG. 1. FIG. 9 is a cross-sectional view of another modified example of the optical fiber shown in FIG. 1. The light irradiation medical device 1 shown in FIGS. 1 to 6 includes a shaft 10, an optical fiber 20, and a coil member 40. Hereinafter, the light irradiation medical device may be simply referred to as the device.

[0023] In this specification, the distal side of the device 1 refers to the distal end side 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 side of the shaft 10 in the longitudinal axis direction x, which is the side closest to the user. 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 portion, and the distal side may be referred to as the distal portion. In the radial direction of the device 1, the inward side refers to the direction toward the central axis c extending in the longitudinal axis direction x of the shaft 10, and the outward side refers to the radial direction opposite to the inward side.

[0024] The device 1 includes a shaft 10. The shaft 10 has a longitudinal axis direction x, a radial direction, and a circumferential direction p. The shaft 10 has a distal end and a proximal end in the longitudinal axis direction x, and has an inner lumen 11 extending in the longitudinal axis direction x. The shaft 10 may have only one lumen 11 or may have multiple lumen 11. The shaft 10 has a cylindrical shape so that the optical fiber 20 and the coil member 40 can be disposed in the inner lumen 11. The shaft 10 preferably has a cylindrical shape with only one lumen 11. Since the shaft 10 is inserted into the body, it is preferably flexible. The shaft 10 has an inner circumferential surface 12 and an outer circumferential surface 13.

[0025] The shaft 10 may be a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body coated with a resin on at least one of the inner and outer surfaces; a resin tube; or a combination thereof, such as a combination of these, connected in the longitudinal direction. Examples of hollow bodies in which wires are arranged in a predetermined pattern include tubular bodies having a mesh structure formed by simply crossing or weaving wires, and coils formed by winding wires. The wires may be one or more solid wires or one or more twisted wires. Resin tubes can be manufactured, for example, by extrusion molding. When the shaft 10 is a resin tube, the shaft 10 may be composed of a single layer or multiple layers. A portion of the shaft 10 in the longitudinal direction x or the circumferential direction p may be composed of a single layer, and the other portion may be composed of multiple layers.

[0026] The shaft 10 can be made of, for example, synthetic resins such as polyolefin resins (e.g., polyethylene and polypropylene), polyamide resins (e.g., nylon), polyester resins (e.g., PET), aromatic polyether ketone resins (e.g., PEEK), polyether polyamide resins, polyurethane resins, polyimide resins, and fluororesins (e.g., PTFE, PFA, and ETFE), or metals such as stainless steel, carbon steel, and nickel-titanium alloys. These materials may be used alone or in combination of two or more. At least the portion of the shaft 10 that overlaps with the light diffusion section 21 (described later) is preferably made of a light-transmitting resin. At least the portion of the shaft 10 that overlaps with the light diffusion section 21 may be made of a transparent resin.

[0027] As shown in Figure 1, a tip 15 may be attached to the distal end of the shaft 10. This makes it possible to prevent damage to biological tissue by the distal end of the shaft 10. The tip 15 may have, for example, a cylindrical shape, an oblong cylindrical shape, a hemispherical shape, an oblong spherical shape, a truncated pyramid shape, a truncated cone shape, an oblong truncated cone shape, a truncated rounded cone shape, or a combination thereof.

[0028] The device 1 has an optical fiber 20 disposed in the lumen 11 of the shaft 10. The optical fiber 20 is a transmission line for transmitting an optical signal to the target tissue. As shown in FIG. 1, the optical fiber 20 is disposed in the lumen 11 of the shaft 10. In FIG. 1, the proximal end of the optical fiber 20 extends proximally from a handle 60, which will be described later. The proximal end of the optical fiber 20 is connected to a light source such as a semiconductor laser.

[0029] The optical fiber 20 has a light diffusing portion 21 that extends in the longitudinal axis direction x in a predetermined section of its distal portion and emits light radially outward of the shaft 10. The light diffusing portion 21 functions as a light-emitting area that can emit light radially outward. The light diffusing portion 21 is arranged to extend in the longitudinal axis direction x and the circumferential direction p of the shaft 10. The light diffusing portion 21 has an outer peripheral surface 23. The outer peripheral surface 23 of the light diffusing portion 21 faces the inner peripheral surface 12 of the shaft 10.

[0030] Device 1 is inserted through an endoscope to a position within a body cavity where a target tissue is located. At this time, the target tissue is positioned radially outward of outer circumferential surface 13 of shaft 10. Light emitted from light diffusing section 21 passes through at least the portion of shaft 10 that overlaps with light diffusing section 21, and thereby reaches the target tissue around device 1.

[0031] As described above, it is preferable that light is emitted from the light diffusion section 21 at least radially outward of the shaft 10, and it is preferable that light is emitted from the light diffusion section 21 radially outward of the shaft 10 over the entire circumferential direction p of the shaft 10. The light diffusion section 21 may also emit light distally of the shaft 10, i.e., forward.

[0032] The light diffusion section 21 is not a diffusion member (e.g., a diffusion plate or a prism) separate from the optical fiber 20, but is a portion that constitutes part of the optical fiber 20. The optical fiber 20 has a core and a clad. The clad is disposed around the core and covers a radially outer portion of the core. The light diffusion section 21 is preferably configured in any one of the following modes: (i) a mode in which only the core is disposed, (ii) a mode in which the core and clad are disposed, or (iii) a mode in which only the core is disposed in a portion and the core and clad are disposed in another portion. A protective coating material may be disposed radially outside the clad, but it is preferable that the light diffusion section 21 does not include any components other than the core and clad.

[0033] The material for forming the core and cladding is not particularly limited, and plastic, quartz glass, fluoride glass, and other glass may be used.

[0034] At least in the portion of the shaft 10 that overlaps with the light diffusion portion 21, a light diffusing material such as inorganic particles such as titanium oxide, barium sulfate, or calcium carbonate, or organic particles such as cross-linked acrylic particles or cross-linked styrene particles can be added to the resin that constitutes the shaft 10. This makes it easier for the shaft 10 to diffuse the light emitted from the light diffusion portion 21.

[0035] The light diffusing portion 21 is preferably disposed on the most distal side of the optical fiber 20. This makes it easier to form the light diffusing portion 21 and also increases the flexibility of the distal end of the optical fiber 20.

[0036] The length of the light diffusing portion 21 in the longitudinal axis direction x may be set to be 1 / 50 or more, 1 / 45 or more, or 1 / 30 or more of the total length of the optical fiber 20. Setting such a length makes it easier to irradiate the entire target tissue with a single irradiation. Furthermore, the length of the light diffusing portion 21 in the longitudinal axis direction x may be set to be 1 / 20 or less, 1 / 25 or less, or 1 / 30 or less of the total length of the optical fiber 20. Setting such a length makes it possible to prevent irradiation of tissue other than the target tissue.

[0037] The light diffusing portion 21 may be disposed in only a part of the circumferential direction p of the shaft 10, but as shown in Fig. 2, the light diffusing portion 21 is preferably disposed over the entire circumferential direction p of the shaft 10. Since a wide range in the circumferential direction p can be irradiated at once, the efficiency of the procedure is improved.

[0038] 3, a reflector 200 is preferably provided on the distal end surface of the optical fiber 20. The reflector 200 is, for example, a mirror arranged with its reflective surface facing the proximal side. With this configuration, light can be reflected not only by the inner circumferential surface of the coil member 40 but also by the reflector 200, making it easier for the reflected light to be diffused in various directions.

[0039] The surface of the reflector 200 is preferably composed of aluminum, gold, silver, copper, tin, titanium dioxide, tantalum pentoxide, aluminum oxide, silicon dioxide, or magnesium fluoride.

[0040] The device 1 includes a coil member 40 disposed in the lumen 11 of the shaft 10, the coil member 40 having a wire 42 wound helically around the distal portion of the optical fiber 20. The coil member 40 is preferably disposed such that the wire 42 surrounds the light diffusing portion 21. The entire coil member 40 is preferably disposed in the lumen 11 of the shaft 10 in the longitudinal axis direction x. Covering the optical fiber 20 or the light diffusing portion 21 with the coil member 40 in this manner can improve the operability of the device 1 and can more easily prevent damage to the optical fiber 20 or the light diffusing portion 21. The provision of the coil member 40 makes it easier to dispose the optical fiber 20 coaxially with the coil member 40 and can also prevent the light diffusing portion 21 from being misaligned in the radial direction, thereby making it easier to homogenize the emission intensity distribution of the light diffusing portion 21 in the circumferential direction p of the shaft 10.

[0041] The wire 42 has a distal end and a proximal end in the longitudinal direction. The wire 42 may be composed of a single linear member from the distal end to the proximal end, or may be composed of multiple linear members connected to each other in the longitudinal direction.

[0042] The cross-sectional shape of the wire 42 perpendicular to the longitudinal axis direction may be a circle, an oval, a polygon, or a combination thereof. The oval shape includes an ellipse, an egg, and a rounded rectangle. The same applies to other descriptions in this specification.

[0043] There are no particular limitations on the wire diameter (thickness) of the wire 42 constituting the coil member 40 or the number of turns of the wire 42. The axial length of the coil member 40 may be greater or smaller than the maximum outer diameter of the coil member 40.

[0044] The 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 coil member 40. Here, reflectivity refers to the reflectivity of light emitted from the light diffusing portion 21, and is expressed in %. The reflectivity can be measured using a reflectivity measurement system OP-RF-VIS-GT50 manufactured by Ocean Photonics.

[0045] The coil member 40 is preferably constructed from a metal, which may be, for example, a radiopaque metal such as gold, silver, platinum, palladium, tungsten, tantalum, iridium, and alloys thereof, or a superelastic alloy such as stainless steel or a Ni-Ti alloy.

[0046] A portion of the coil member 40 may be made of resin. The coil member 40 may have a coil member main body and a reflective layer disposed on the inner surface of the coil member main body. Regardless of the material of the coil member main body, the reflective layer can reflect light from the light diffusion unit 21. For example, the coil member main body may be a coil body wound with a resin wire or a resin tube. The reflective layer may be formed by applying a coating containing a reflective material to the inner surface of the coil member main body, or by attaching a reflective material to the inner surface of the coil member main 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 a combination thereof. When the coil member 40 has a reflective layer, the coil member main body may be made of at least one of the materials listed as constituent materials of the shaft 10.

[0047] The coil member 40 may be fixed to the optical fiber 20. The coil member 40 may be fixed directly to the optical fiber 20, or may be fixed indirectly via another member. The method for fixing the coil member 40 and the optical fiber 20 is not particularly limited, and examples include methods such as welding, crimping, bonding with an adhesive, physical fixing such as engagement, connection, binding, and ligation, or a combination of these. It is also possible for the coil member 40 and the optical fiber 20 to be unfixed.

[0048] In the predetermined section, the coil member 40 has a first region 40a having a pitch P1 that is 1.8 times or more the wire diameter of the wire 42, and a second region 40b that is proximal to the first region 40a and has a pitch P2 that is shorter than that of the first region 40a. The pitch is the distance between the central axes of two adjacent wires 42 that form the coil member 40 in the axial direction, as indicated by P1 and P2 in FIG. 1 . This also applies in the following description to the distance between the central axes of two adjacent wires 42 that form the coil member 40 in the axial direction. The pitch of the coil member 40 may be constant in the axial direction or may vary depending on the axial position. It is preferable that the pitch P2 of the second region 40b is shorter than the pitch P1 of the first region 40a. By having the above-mentioned pitch in the predetermined section, light is emitted radially from the light diffusing section 21, making it easier to improve treatment efficiency. Furthermore, by arranging the coil member 40 on the light diffusing section 21 as described above, light irradiated onto the surface of the coil member 40 is more likely to be scattered in various directions, making it easier to improve treatment efficiency. Furthermore, since the coil member 40 has the first region 40a with a pitch P1 that is 1.8 times or more the wire diameter of the wire 42, a sufficient amount of light reaches the affected area in the circumferential direction of the device 1, making it possible to prevent uneven irradiation. Furthermore, when an external force is applied, the coil member 40 absorbs the impact, making it easier to prevent damage to the light diffusing section 21.

[0049] The first region 40a of the coil member 40 preferably has a pitch P1 that is 1.9 times or more the wire diameter of the wire material 42, but may also have a pitch P1 that is 2.0 times or more, or may even have a pitch P1 that is 2.1 times or more. Furthermore, the first region 40a of the coil member 40 may have a pitch P1 that is 3.0 times or less the wire diameter of the wire material 42, or may even have a pitch P1 that is 2.5 times or less. This configuration makes it easier to ensure that a sufficient amount of light reaches the affected area in the circumferential direction of the device 1, and makes it easier to prevent uneven irradiation.

[0050] The second region 40b of the coil member 40 may have a pitch P2 that is 1.5 times or more the wire diameter, or 1.6 times or more. The second region 40b of the coil member 40 may have a pitch P2 that is 3.0 times or less the wire diameter of the wire material 42, or 2.5 times or less. This configuration makes it easier to ensure that a sufficient amount of light reaches the affected area in the circumferential direction of the device 1, even in the second region 40b, and makes it easier to prevent uneven irradiation. The pitch P2 may be less than 1.8 times the wire diameter, or 1.7 times or less.

[0051] The outer diameter of the coil member 40 may be constant in the longitudinal axis direction x of the shaft 10, or may vary depending on the position in the longitudinal axis direction x. For example, when the coil member 40 is divided into two equal parts in the longitudinal axis direction x into a distal portion and a proximal portion, the average outer diameter of the distal portion of the coil member 40 may be larger than the average outer diameter of the proximal portion of the coil member 40.

[0052] As shown in FIG. 1 , the maximum outer diameter of the first region 40a may be smaller than the maximum outer diameter of the second region 40b. The outer diameter of a portion of the first region 40a may be smaller than the maximum outer diameter of the second region 40b. The entire outer diameter of the first region 40a may be smaller than the maximum outer diameter of the second region 40b. The maximum outer diameter of the first region 40a may be larger than the maximum outer diameter of the second region 40b. The outer diameter of a portion of the first region 40a may be larger than the maximum outer diameter of the second region 40b. The entire outer diameter of the first region 40a may be larger than the maximum outer diameter of the second region 40b. With this configuration, the distance between the coil member 40 and the light diffusion section 21 tends to be short in the first region 40a, and light irradiated onto the surface of the first region 40a tends to be scattered in various directions. This makes it easier to ensure a sufficient amount of light reaching the affected area in the circumferential direction of the device 1, making it easier to suppress uneven irradiation and improve treatment efficiency.

[0053] Although not shown, the coil member 40 may further have a region between the first region 40a and the second region 40b, the region having a shorter pitch than the second region 40b. The pitch of the region between the first region 40a and the second region 40b may be shorter than the pitch of the second region 40b and may be equal to or greater than the wire diameter of the wire material 42.

[0054] 1, the first region 40a may be longer than the second region 40b in the longitudinal axis direction x. This increases the amount of light emitted from the light diffusing unit 21 in the radial direction, making it easier to improve treatment efficiency. Furthermore, it also makes it easier to ensure a sufficient amount of light reaching the affected area in the circumferential direction of the device 1, making it easier to prevent uneven irradiation. Although not shown, the first region 40a may be shorter than the second region 40b in the longitudinal axis direction x.

[0055] 3, in a predetermined section, the coil member 40 may have a third region 40c located distal to the first region 40a and having a shorter pitch than the first region 40a. Although only a portion of the pitch P3 of the third region 40c may be shorter than the pitch P1 of the first region 40a, it is preferable that the pitch P3 of the third region 40c be entirely shorter than the pitch P1 of the first region 40a.

[0056] Although not shown, the coil member 40 may further have a region between the first region 40a and the third region 40c, the region having a shorter pitch than the third region 40c. The pitch of the region between the first region 40a and the third region 40c may be shorter than the third region 40c and may be equal to or greater than the wire diameter of the wire material 42.

[0057] The third region 40c of the coil member 40 may have a pitch P3 that is 1.5 times or more the wire diameter, or may have a pitch P3 that is 1.6 times the wire diameter. The third region 40c of the coil member 40 may have a pitch P3 that is 3.0 times or less the wire diameter of the wire material 42, or may have a pitch P3 that is 2.5 times or less. This configuration makes it easier to ensure that a sufficient amount of light reaches the affected area in the circumferential direction of the device 1, even in the third region 40c, and makes it easier to prevent uneven irradiation.

[0058] As shown in Fig. 3, the first region 40a may be longer than the third region 40c in the longitudinal axis direction x. This increases the amount of light emitted in the radial direction from the light diffusing portion 21, making it easier to improve treatment efficiency. Furthermore, it makes it easier to ensure a sufficient amount of light reaching the affected area in the circumferential direction of the device 1, making it easier to suppress uneven irradiation. Although not shown, the first region 40a may be shorter than the third region 40c in the longitudinal axis direction x.

[0059] The maximum outer diameter of the first region 40a may be smaller than the maximum outer diameter of the third region 40c. The outer diameter of a portion of the first region 40a may be smaller than the maximum outer diameter of the third region 40c. The entire outer diameter of the first region 40a may be smaller than the maximum outer diameter of the third region 40c. The maximum outer diameter of the first region 40a may be larger than the maximum outer diameter of the third region 40c. The outer diameter of a portion of the first region 40a may be larger than the maximum outer diameter of the third region 40c. The entire outer diameter of the first region 40a may be larger than the maximum outer diameter of the third region 40c. With this configuration, the distance between the coil member 40 and the light diffusion section 21 tends to be short in the first region 40a, and light irradiated onto the surface of the first region 40a tends to be scattered in various directions. This makes it easier to ensure a sufficient amount of light reaching the affected area in the circumferential direction of the device 1, making it easier to suppress uneven irradiation and improve treatment efficiency.

[0060] As shown in Figure 4, the coil member 40 may have a fourth region 40d located proximal to the first region 40a and having a shorter pitch than the second region 40b. While only a portion of the pitch P4 of the fourth region 40d may be shorter than the pitch P2 of the second region 40b, it is preferable that the entire pitch P4 of the fourth region 40d be shorter than the pitch P2 of the second region 40b. It is preferable that the fourth region 40d be located proximal to the second region 40b. With the above configuration, light irradiated onto the surface of the fourth region 40d of the coil member 40 is more likely to scatter in various directions, making it easier to improve treatment efficiency.

[0061] As shown in FIG. 4, the fourth region 40d may have a larger maximum outer diameter than the second region 40b. The outer diameter of a portion of the fourth region 40d may be larger than the maximum outer diameter of the second region 40b. The outer diameter of the entire fourth region 40d may be larger than the maximum outer diameter of the second region 40b. The maximum outer diameter of the fourth region 40d may be smaller than the maximum outer diameter of the second region 40b. The outer diameter of a portion of the fourth region 40d may be smaller than the maximum outer diameter of the second region 40b. The outer diameter of the entire fourth region 40d may be smaller than the maximum outer diameter of the second region 40b.

[0062] As shown in Figure 5, the coil member 40 may have a fifth region 40e distal to the first region 40a, the fifth region 40e having a shorter pitch than the third region 40c. While only a portion of the pitch P5 of the fifth region 40e may be shorter than the pitch P3 of the third region 40c, it is preferable that the entire pitch P5 of the fifth region 40e be shorter than the pitch P3 of the third region 40c. The fifth region 40e is preferably located distal to the third region 40c. With the above configuration, light irradiated onto the surface of the fifth region 40e of the coil member 40 is more likely to scatter in various directions, which can improve treatment efficiency.

[0063] The pitch P4 of the fourth region 40d and the pitch P5 of the fifth region 40e may be the same or different. The pitch P4 of the fourth region 40d and the pitch P5 of the fifth region 40e are preferably the same as the wire diameter of the wire 42.

[0064] As shown in FIG. 5, the fifth region 40e may have a larger maximum outer diameter than the third region 40c. The outer diameter of a portion of the fifth region 40e may be larger than the maximum outer diameter of the third region 40c. The entire outer diameter of the fifth region 40e may be larger than the maximum outer diameter of the third region 40c. The maximum outer diameter of the fifth region 40e may be smaller than the maximum outer diameter of the third region 40c. The outer diameter of a portion of the fifth region 40e may be smaller than the maximum outer diameter of the third region 40c. The entire outer diameter of the fifth region 40e may be smaller than the maximum outer diameter of the third region 40c.

[0065] 6, the coil member 40 may have a multi-layered winding portion 40f wound in multiple layers at its proximal portion. The multi-layered winding portion 40f makes it easier to transmit torque to the distal side, thereby improving the operability of the device 1.

[0066] The device 1 may further include a handle 60 connected to the proximal end of the shaft 10. In FIG. 1, the handle 60 is connected to the proximal portion of the shaft 10. The operator can easily operate the device 1 by gripping the handle 60. The handle 60 extends, for example, in the longitudinal axis direction x. The handle 60 can be composed of one or more members. In FIG. 1, the handle 60 has a hollow portion extending in the longitudinal axis direction x. The handle 60 may have, for example, a cylindrical shape. In FIG. 1, the shaft 10 and the optical fiber 20 are inserted into the hollow portion of the handle 60. In FIG. 6, the shaft 10, the optical fiber 20, and the coil member 40 are inserted into the hollow portion of the handle 60.

[0067] As shown in Fig. 6, the coil member 40 may extend to the handle 60, and the proximal end of the coil member 40 may be fixed to the handle 60. The coil member 40 may be fixed directly to the handle 60, or may be fixed indirectly via another member. The method of fixing the coil member 40 to the handle 60 is not particularly limited, and examples include methods such as welding, crimping, adhesive bonding, physical fixation such as engagement, coupling, knotting, and ligation, or combinations of these. It is also possible for the proximal end of the coil member 40 to be unfixed to the handle 60.

[0068] The material of which the handle 60 is made is not particularly limited, but examples thereof include polyolefin resins such as polypropylene (PP) and polyethylene (PE), polyester resins such as polyethylene terephthalate (PET), polycarbonate resin, ABS resin, and polyurethane resin.

[0069] The distal end of the coil member 40 preferably has a lid portion 450 whose area, when viewed from the distal side, is larger than the lumen of the distal end of the coil member 40. The lid portion 450 can be formed, for example, by heating and deforming the distal end 401 side of the coil member 40. This makes it possible to obtain a coil member 40 whose distal end 401 side is closed, as shown in FIG. 6. Alternatively, the lid portion 450 can be formed by preparing a cylindrical coil having one lumen and a metal member separate from the cylindrical coil, and heating and welding the metal member to close the opening on the distal side of the cylindrical coil. In this manner, a coil member 40 whose distal end 401 side is closed can also be obtained.

[0070] 7 to 9, an example of the configuration of the optical fiber 20 will be described. In Fig. 7 to 9, 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 clad 26 arranged on the outer periphery of the core 25. In the first section 31, light is likely to be totally reflected at the boundary between the core 25 and the first clad 26, so in the first section 31, the light is confined within the core 25 and propagates to the distal side of the optical fiber 20.

[0071] In the first section 31, it is preferable that one core 25 is disposed in one first cladding 26. In other words, the optical fiber in the first section 31 can be called a single-core optical fiber.

[0072] To prevent an increase in the profile of the optical fiber 20, the first cladding 26 may be located at the outermost position in the radial direction of the optical fiber 20 in the first section 31. In other words, the first section 31 may not be provided with other members such as a coating material.

[0073] Although not shown, a coating material may be disposed on the outer periphery of the first clad 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 also to suppress light leakage or emission to the outside in the first section 31. The coating material may be a coating layer disposed on the outer periphery of the first clad 26, or may be a sheath that encases the first clad 26. The coating material may be made of a resin such as an ultraviolet-curable resin.

[0074] 7, the optical fiber 20 has a second section 32 located distal to the first section 31 in the light diffusing section 21. The second section 32 has a second clad 27 that is disposed around the core 25 and has a larger outer peripheral surface roughness than the first clad 26. By making the surface roughness of the clad larger in the second section 32 than in the first section 31, part of the light is confined within the core 25 and propagates distally of the optical fiber 20, while the remaining light leaks out from the second clad 27 and is emitted radially outward. Preferably, light is not emitted radially outward in the first section 31, or the amount of light leakage is smaller than in the second section 32.

[0075] As with the first section 31, the second section 32 preferably has one core 25 disposed in one second cladding 27. The first cladding 26 of the first section 31 and the second cladding 27 of the second section 32 may be integrally molded, or the optical fiber for the first section 31 and the optical fiber for the second section 32 may be joined in the longitudinal axis direction x.

[0076] In the second section 32, it is preferable that the second cladding 27 is located at the outermost position in the radial direction of the optical fiber 20. That is, it is preferable that no members (e.g., coating material) other than the core 25 and the second cladding 27 are arranged in the second section 32. This configuration makes it easier for light to be emitted from the second section 32 toward the outside in the radial direction of the shaft 10.

[0077] The surface roughness of the outer peripheral surface of the second cladding 27 in the second section 32 is greater than the surface roughness of the outer peripheral surface of the first cladding 26 in the first section 31. Here, the surface roughness is the arithmetic mean roughness Ra over a reference length of a roughness curve in the longitudinal direction of the outer peripheral surface of the optical fiber 20. The reference length may be set according to the magnification of the laser microscope used, but is, for example, 200 μm. The 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 the measurement, a measuring instrument specified in JIS B 0651 (2001) (for example, a Keyence VK-X3000 laser microscope) is used.

[0078] It is preferable that the average surface roughness of the outer circumferential surface of the second cladding 27 in the second section 32 be greater than the average 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, and 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 diffusing section 21 in the longitudinal axis direction x is more easily homogenized. The average surface roughness is the average surface roughness value of 10 or more measurement points set in line in the longitudinal axis direction x in the section to be measured (for example, the first section 31).

[0079] 7 , when the second section 32 is divided into two equal parts, a distal section 323 and a proximal section 324, in the longitudinal axis direction x, the average surface roughness of the outer circumferential surface of the second cladding 27 in the proximal section 324 is preferably smaller than the average surface roughness of the outer circumferential 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 light is more easily emitted radially outward from the second cladding 27 in the distal section 323, and therefore the emission intensity distribution of the second section 32 in the longitudinal axis direction x is more easily uniform.

[0080] 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 diffusing 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 1 / 20 or less, 1 / 25 or less, or 1 / 30 or less of the length of the first section 31. Furthermore, the length of the second section 32 in the longitudinal axis direction x may be set to 1 / 50 or more, 1 / 45 or more, or 1 / 30 or more of the length of the first section 31.

[0081] 7, the average thickness of the second cladding 27 in the second section 32 is preferably smaller than the average thickness of the first cladding 26 in the first section 31. By adjusting the cladding thickness in this manner, 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 laser microscope VK-X3000 manufactured by Keyence Corporation.

[0082] 8 and 9, when the optical fiber 20 has the first section 31, the optical fiber 20 may have a third section 33 in the light diffusing portion 21, which has no cladding and is located distal to the first section 31. Since the third section 33 has no cladding, light from the core 25 is emitted radially outward.

[0083] In the third section 33, it is preferable that no cladding exists in at least a portion of the core 25 in the circumferential direction, and it is more preferable that no cladding exists in the entire core 25 in the circumferential direction.

[0084] In the third section 33, it is preferable that the core 25 is located at the outermost radial position in the optical fiber 20. That is, it is preferable that not only the cladding but also any members (e.g., coating material) other than the core 25 and the coil member 40 are not arranged in the third section 33.

[0085] 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.

[0086] 8 and 9, the distal end of the third section 33 is preferably located at 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 optical fiber 20 at the distal end.

[0087] The surface roughness of the outer peripheral surface of the core 25 in the third section 33 is preferably greater than the surface roughness of the outer peripheral 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, and in the third section 33, light is more easily emitted radially outward from the core 25.

[0088] The light diffusing unit 21 preferably includes at least one of the second section 32 and the third section 33, and may include both the second section 32 and the third section 33. As shown in Fig. 8 , the light diffusing unit 21 preferably includes the second section 32 and the third section 33 in this order from the proximal side to the distal side. This configuration makes it easier to homogenize the luminescence intensity distribution of the light diffusing unit 21 in the longitudinal axis direction x. To enhance this effect, the first section 31, the second section 32, and the third section 33 are preferably adjacent to each other in the longitudinal axis direction x.

[0089] When the optical fiber 20 has the second section 32 and the 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 Fig. 8. This configuration makes it easier to homogenize the overall emission intensity distribution of the light diffusing section 21 in the longitudinal axis direction x. Note that an embodiment in which the second section 32 is shorter than the third section 33 in the longitudinal axis direction x is also acceptable.

[0090] The length of the third section 33 in the longitudinal axis direction x is preferably 20% or less, more preferably 18% or less, and even more preferably 15% or less of the total length of the second section 32 and the third section 33. 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 uniformize the luminous intensity distribution of the light diffusion section 21 in the longitudinal axis direction x.

[0091] The average surface roughness of the outer circumferential surface of the second cladding 27 in the second section 32 is preferably smaller than the average surface roughness of the outer circumferential surface of the core 25 in the third section 33. This configuration makes it easier to homogenize the emission intensity distribution in the longitudinal axis direction x in each of the second section 32 and the third section 33.

[0092] 7, the optical fiber 20 may have only the second section 32 in the light diffusing portion 21. That is, the optical fiber 20 does not need to have the third section 33 in the light diffusing portion 21. Even if the optical fiber 20 has only the second section 32, the emission intensity distribution of the light diffusing portion 21 in the longitudinal axis direction x can be made uniform. Since the core 25 is not exposed, this also has the effect of preventing damage to the optical fiber 20 due to bending of the device 1 during a procedure.

[0093] When the optical fiber 20 has only the second section 32 in the light diffusing portion 21, it is preferable that the distal end of the second section 32 is at the same position as the distal end of the core 25 in the longitudinal axis direction x.

[0094] 9, the optical fiber 20 may have only the third section 33 in the light diffusing section 21. That is, the optical fiber 20 does not need to have the second section 32 in the light diffusing section 21. Even if the optical fiber 20 has only the third section 33, the luminous intensity distribution of the light diffusing section 21 in the longitudinal axis direction x can be made uniform.

[0095] The second section 32 and the third section 33 can be formed by removing the cladding by etching or polishing. To adjust the surface roughness of the second section 32 or the third section 33, the outer surface of the second cladding 27 or the outer surface of the core 25 of the third section 33 may be provided with an asperity. The asperity 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, and methods using a scriber, wire brush, or sandpaper.

[0096] The light diffusing unit 21 may emit a first light beam for treatment. The first light beam is preferably a laser beam that irradiates internal tissue and has a wavelength suitable for phototherapy such as PDT or PIT. In addition to the first light beam, a second light beam for targeting may also be emitted. The second light beam is emitted to identify the treatment site before the emission of the first light beam, and preferably has lower radiation energy than the first light beam. [Explanation of symbols]

[0097] 1: Light irradiation medical device 10: Shaft 20: Optical fiber 21: Light diffusion section 25: Core 26: First clad 27: Second clad 31: First Section 32: Second Section 33: Third Section 40: Coil material 40a: 1st area 40b:Second area 40c: Third area 40d: 4th area 40e: 5th area 40f: Multilayer winding part 60: Handle x: longitudinal axis direction p: Circumferential direction

Claims

1. a shaft having a distal end and a proximal end in a longitudinal direction and having an inner lumen extending in the longitudinal direction; an optical fiber disposed in the lumen of the shaft; a coil member disposed in the lumen of the shaft and having a wire wound helically around the distal portion of the optical fiber; the optical fiber has a light diffusing portion extending in the longitudinal axis direction in a predetermined section of the distal portion thereof and emitting light radially outward from the shaft; A light irradiation medical device in which, in the specified section, the coil member has a first region having a pitch that is 1.8 times or more the wire diameter of the wire, and a second region that is proximal to the first region and has a pitch that is shorter than the first region.

2. The photoirradiation medical device according to claim 1 , wherein the maximum outer diameter of the first region is smaller than the maximum outer diameter of the second region.

3. The photoirradiation medical device according to claim 1 or 2, wherein the first region is longer than the second region in the longitudinal axis direction.

4. A photoirradiation medical device according to any one of claims 1 to 3, wherein in the specified section, the coil member has a third region distal to the first region and having a shorter pitch than the first region.

5. The photoirradiation medical device according to claim 4 , wherein the first region is longer than the third region in the longitudinal axis direction.

6. The photoirradiation medical device according to claim 4 or 5, wherein the maximum outer diameter of the first region is smaller than the maximum outer diameter of the third region.

7. The photoirradiation medical device according to any one of claims 1 to 6, wherein the coil member has a fourth region proximal to the first region, which has a shorter pitch than the second region and a larger maximum outer diameter than the second region.

8. The photoirradiation medical device according to any one of claims 4 to 6, wherein the coil member has a fifth region distal to the first region, which has a shorter pitch than the third region and a larger maximum outer diameter than the third region.

9. a handle connected to the proximal end of the shaft; The photoirradiation medical device according to any one of claims 1 to 8, wherein the proximal end of the coil member is fixed to the handle.

10. The photoirradiation medical device according to any one of claims 1 to 9, wherein the second region has a pitch that is 1.5 times or more the wire diameter.

11. The photoirradiation medical device according to any one of claims 1 to 10, wherein the coil member has a multi-layered winding portion wound in multiple layers at its proximal portion.

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