JP7807328B2 - Light irradiation medical device - Google Patents

Description

The present invention relates to a light irradiation medical device for irradiating light onto tissue containing cancer cells, etc., in body cavities such as blood vessels and the digestive tract.

In photodynamic therapy (PDT), a photosensitizer is administered intravenously or intraperitoneally, allowing it to accumulate in target tissues such as cancer cells, and then excited by irradiating them with light of a specific wavelength. 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 addition, laser light-based ablation (tissue ablation) is performed by irradiating the target tissue with laser light and cauterizing it.

In light irradiation medical devices used for photoablation, such as PDT and photoimmunotherapy, a light-guiding material is placed inside the catheter tube to irradiate light onto the target tissue.

Patent document 1 describes a device including a balloon catheter with a defined treatment window that delivers radiation to a defined area. The device has a transparent central channel through which a fiber optic probe can be inserted, and an outer sleeve with a proximal end and a distal end that is used to inflate the balloon. The outer sleeve further includes an inflatable balloon near the distal end, and the balloon is coated at both ends with a reflective material to define the treatment window.

Patent Document 2 describes a side laser irradiator comprising: a flexible outer tube; an optical fiber inserted into the outer tube so that it can rotate circumferentially; an optical tip disposed at the tip of the outer tube with its base end facing the tip end of the optical fiber and having a reflective surface formed at the tip that can totally reflect laser light incident from the optical fiber in a specific lateral direction; a sleeve that restrains the optical tip at the tip end of the optical fiber and is housed within the tip of the outer tube; a mark provided on the sleeve; and means for detecting the position of the mark.

Japanese Patent Application Laid-Open No. 2005-46640 Japanese Patent Application Publication No. 10-26709

However, the devices described in Patent Documents 1 and 2 still have room for improvement in terms of functionality and visibility to suppress heat generation caused by the catheter absorbing the light used in treatment.

The present invention was made in consideration of the above circumstances, and its purpose is to provide a light irradiation medical device that can suppress heat generation due to light absorption and has good visibility inside the body.

One embodiment of the light irradiation medical device of the present invention that can solve the above problems is as follows.
[1] A light irradiation medical device comprising a shaft having a distal end and a proximal end in the longitudinal axis direction and an inner cavity extending in the longitudinal axis direction, the shaft having a first region and a second region proximal to the first region and having a light transmittance lower than that of the first region, the second region having a chromaticity a ^* of 35 or more and 60 or less according to the L ^* a ^* b ^* color system and a hue angle h of -45° or more and 45° or less.
With the above configuration, when the photoirradiation medical device is used for phototherapy, the amount of therapeutic light absorbed in the second region can be reduced, thereby suppressing heat generation in the second region. This prevents burns to the treatment site (target tissue) and melting of the second region. Furthermore, the reduction in the amount of light reaching the treatment site can be suppressed, allowing for effective light irradiation of the treatment site. Furthermore, the presence of the second region improves the visibility of the photoirradiation medical device within the body, making it easier to adjust the position of the treatment site and the photoirradiation medical device.
[2] A light irradiation medical device described in [1], wherein the length of the second region on the outer surface of the shaft in the longitudinal direction is longer than the length of the first region on the outer surface of the shaft in the longitudinal direction.
[3] The light irradiation medical device according to [1] or [2] further comprises a light-guiding material that is arranged in the inner cavity of the shaft so as to be movable in the longitudinal axis direction and that emits light, and the wavelength of the light emitted by the light-guiding material is 600 nm or more and 700 nm or less.
[4] A light irradiation medical device described in any one of [1] to [3], in which the first section of the shaft from the proximal end of the first region to a position 10 cm proximal to the proximal end of the first region has a light transmittance of 90% or more as determined by the light transmittance measurement method described below.
[Light transmittance measurement method]
(1) The optical fiber diffuser connected to the light source device (ML6600, manufactured by Modulight) is inserted into an integrating sphere (CSTM Flux 6, manufactured by Labsphere) from the distal end to a point 10 cm proximal to the distal end of the optical fiber diffuser.
(2) Light with a wavelength of 660 nm or more and 670 nm or less is emitted from the optical fiber diffuser, and the radiant flux Ir is measured using a light intensity measuring device (FLAME-S, manufactured by Ocean Photonics) connected to an integrating sphere.
(3) The optical fiber diffuser is placed in the lumen of the shaft so that the distal end of the first section coincides with the distal end of the optical fiber diffuser, and the entire shaft except for the first section is covered with silver foil.
(4) The shaft that has been subjected to step (3) is inserted into an integrating sphere from the distal end of the first section to the proximal end of the first section.
(5) Light having a wavelength of 660 nm or more and 670 nm or less is emitted from the optical fiber diffuser that has undergone steps (3) and (4), and the radiant flux Is is measured by a light intensity measuring device connected to an integrating sphere.
(6) The value obtained by the formula Is/Ir is defined as the light transmittance of the first section.
[5] A photoirradiation medical device described in any one of [1] to [4], further comprising an extension portion at the distal end of the shaft that extends radially of the shaft.
[6] A light irradiation medical device according to [5], wherein the expansion section is a balloon, and the second region is present in the portion of the shaft that is arranged in the lumen of the balloon.
[7] A light irradiation medical device as described in [5], further comprising an outer shaft having an inner cavity extending in the longitudinal axis direction of the shaft, wherein the shaft is disposed in the inner cavity of the outer shaft.
[8] A light irradiation medical device described in [7], which has a proximal fixing portion where the proximal end of the expansion portion and the outer shaft are fixed, and the second region is located on the shaft distal to the position where the proximal fixing portion is located.
[9] A light irradiation medical device described in [7] or [8], wherein the outer shaft has a chromaticity a ^* according to the L ^* a ^* b ^* color system of 35 or more and 60 or less, and a hue angle h of -45° or more and 45° or less.
[10] A light irradiation medical device according to any one of [5], [7] to [9], wherein the expansion part is a balloon, a basket, or a self-expanding stent.

When used in phototherapy, the photoirradiation medical device of the present invention can reduce the amount of therapeutic light absorbed in the second region, thereby suppressing heat generation in the second region. This prevents burns to the treatment site (target tissue) and melting of the second region. Furthermore, since the reduction in the amount of light reaching the treatment site can be suppressed, light can be effectively irradiated onto the treatment site. Furthermore, the presence of the second region improves the visibility of the photoirradiation medical device within the body, making it easier to adjust the position of the treatment site and the photoirradiation medical device.

1 is a cross-sectional view (partial side view) of a photoirradiation medical device according to an embodiment of the present invention; FIG. 10 is a cross-sectional view (partial side view) showing a modified example of the photoirradiation medical device according to the embodiment of the present invention. FIG. 10 is a cross-sectional view (partial side view) showing another modified example of the photoirradiation medical device according to the embodiment of the present invention. 4 is a cross-sectional end view of the light irradiation medical device shown in FIG. 1 taken along line IV-IV. 3 shows an end view of the cross section taken along line VV of the light irradiation medical device shown in FIG. 2.

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 above and below-described intent, all of which are within the technical scope of the present invention. Hatching and symbols may be omitted in the drawings for convenience; in such cases, reference should be made to the specification or other drawings. Furthermore, the dimensions of various parts in the drawings may differ from their actual dimensions, as priority is given to aiding understanding of the features of the present invention.

The light irradiation medical device according to one embodiment of the present invention comprises a shaft having a distal end and a proximal end in the longitudinal axis direction and an inner cavity extending in the longitudinal axis direction, the shaft having a first region and a second region proximal to the first region and having a light transmittance lower than that of the first region, the gist being that the second region has a chromaticity a ^* according to the L ^* a ^* b ^* color system of 35 or more and 60 or less and a hue angle h of -45° or more and 45° or less.

Photoirradiation medical devices are used in PDT and photoablation to irradiate the treatment site, which is the target tissue such as cancer cells, with light of a specific wavelength in body lumens such as blood vessels and the digestive tract. The photoirradiation medical device may be delivered to the treatment site on its own, or may be used together with a delivery catheter or endoscope. In treatment using an endoscope, the photoirradiation medical device is placed inside the body through the forceps channel of the endoscope and delivered to the treatment site.

The basic configuration of a photoirradiation medical device will be described with reference to Figures 1 to 5. Figure 1 shows a cross-sectional view (partially a side view) of a photoirradiation medical device according to an embodiment of the present invention. Figure 2 shows a cross-sectional view (partially a side view) of a modified example of a photoirradiation medical device according to an embodiment of the present invention. Figure 3 shows a cross-sectional view (partially a side view) of another modified example of a photoirradiation medical device according to an embodiment of the present invention. Figure 4 shows a cross-sectional end view of the photoirradiation medical device shown in Figure 1 taken along line IV-IV. Figure 5 shows a cross-sectional end view of the photoirradiation medical device shown in Figure 2 taken along line V-V. The photoirradiation medical device shown in Figures 1 to 3 has a shaft 10. Note that in each figure, the left side of the page corresponds to the distal side of the shaft 10, and the right side of the page corresponds to the proximal side of the shaft 10.

In this specification, the proximal side refers to the side closest to the user in the direction of extension of the shaft, and the distal side refers to the side opposite the proximal side, i.e., the side to be treated. The distal portion of the shaft refers to the distal half of the shaft, and the proximal portion of the shaft refers to the proximal half of the shaft. The direction in which the shaft extends is referred to as the longitudinal axis direction. The radial direction refers to the radial direction of the shaft, and in this specification, inward refers to the radial direction toward the axial center of the shaft, and outward refers to the direction opposite to inward.

It is preferable that the materials used for each component of the photoirradiation medical device 1 are biocompatible.

The photoirradiation medical device 1 includes a shaft 10. The shaft 10 is a member having a distal end 101 and a proximal end 102 in the longitudinal direction, and having a lumen 100 extending in the longitudinal direction. The shaft 10 may have multiple lumens 100, but preferably has only one lumen 100. The shape of the shaft 10 is not particularly limited as long as the lumen 100 is present, but it can be, for example, a hollow cylinder or a hollow polygonal prism. A tubular structure is preferred so that the light-guiding material 20, described below, can be placed in the lumen 100. Hereinafter, a cross section perpendicular to the longitudinal direction of the lumen 100 of the shaft 10 will be referred to as the lumen cross section.

The cross-sectional shape of the inner cavity of the shaft 10 is not particularly limited, but can be, for example, a circle, an oval, a polygon, a star, or a combination of these. Note that oval shapes include ellipses, ovals, and rounded rectangles, and this also applies when referring to an oval shape in the following description.

The shaft 10 is preferably flexible, allowing it to be deformed to conform to the shape of the vessel within the body. It is also preferable that the shaft 10 be elastic in order to maintain its shape.

Examples of the shaft 10 include a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body with a resin coating on at least one of the inner and outer surfaces; a resin tube; or a combination of these, such as a combination of these connected in the longitudinal direction. Examples of hollow bodies with wires arranged in a predetermined pattern include a cylindrical body with a mesh structure formed by simply crossing or weaving wires, and a coil 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.

The shaft 10 can be made of 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.

The shaft 10 may have a single-layer structure or a multi-layer structure. If the shaft 10 has a multi-layer structure, for example, the shaft 10 may be structured using a metal braid such as stainless steel, carbon steel, or nickel-titanium alloy as the middle layer of the resin tube that makes up the shaft 10.

The shaft 10 preferably contains a light-transmitting material. This allows light to be efficiently irradiated onto the target tissue when the light-guiding material 20 is placed inside the shaft 10. Examples of light-transmitting materials include synthetic resins such as (meth)acrylic resins (e.g., polymethyl methacrylate (PMMA)), polycarbonate resins (e.g., polydiethylene glycol bisallyl carbonate (PC)), polystyrene-based resins (e.g., methyl methacrylate-styrene copolymer resin (MS), acrylonitrile-styrene resin (SAN)), polyamide resins (e.g., nylon), and polyolefin resins.

The shaft 10 preferably contains a light-diffusing material. This allows the light emitted from the light-guiding material 20 to be appropriately diffused as it passes through the shaft 10, making it easier to evenly irradiate the target tissue with light. Examples of light-diffusing materials include inorganic particles such as titanium oxide, barium sulfate, and calcium carbonate, and organic particles such as cross-linked acrylic particles and cross-linked styrene particles.

The shaft 10 has a first region 11. The first region 11 preferably has a higher light transmittance than the rest of the shaft 10. It is more preferable that the first region 11 has a higher light transmittance of the therapeutic light used than the rest of the shaft 10. The first region 11 is preferably transparent, and the first region 11 can be configured, for example, by having a transparent member disposed therein.

The first region 11 may be provided only on a portion of the circumference of the shaft 10. The first region 11 may be provided over the entire circumference of the shaft 10.

When the first region 11 is provided only in a portion of the circumference of the shaft 10, the shape of the first region 11 when viewed from the radial direction of the shaft 10 can be, for example, circular, elliptical, polygonal, or a combination of these.

When the first region 11 is provided around the entire circumference of the shaft 10, it can be shaped like a hollow cylinder or a hollow polygonal cylinder. In order to place the light-guiding material 20 in its lumen, the first region 11 preferably has a tubular structure. This configuration allows light emitted from the light-guiding material 20 placed in the lumen of the first region 11 to be irradiated toward the entire outside of the shaft 10.

The material constituting the first region 11 may be the resin constituting the shaft 10, or may be synthetic resin such as (meth)acrylic resin (e.g., polymethyl methacrylate (PMMA)), polycarbonate resin (e.g., polydiethylene glycol bisallyl carbonate (PC)), polystyrene-based resin (e.g., methyl methacrylate-styrene copolymer resin (MS), acrylonitrile styrene resin (SAN)), polyamide resin (e.g., nylon), or polyolefin resin. These may be used alone or in combination.

The first region 11 can be provided in one or more locations on the shaft 10, but it is preferable that only one first region 11 be provided on one shaft 10 in order to make it easier to adjust the irradiation position of the light emitted from the light-guiding material 20.

The first region 11 is preferably present in the distal portion of the shaft 10. However, the first region 11 may also be present in the proximal portion of the shaft 10. The first region 11 may also be present only in the distal portion of the shaft 10.

It is preferable that the length of the first region 11 in the longitudinal direction on the outer surface of the shaft 10 is longer than the length of the first region 11 in the circumferential direction on the outer surface of the shaft 10. This makes it easier to irradiate the treatment area, such as a lesion extending along the longitudinal direction of the biological vessel wall, with therapeutic light. When comparing the above lengths, the shortest length of the first region 11 in the circumferential direction on the outer surface of the shaft 10 is compared with the shortest length of the first region 11 in the longitudinal direction on the outer surface of the shaft 10.

The shaft 10 has a second region 12 located proximal to the first region 11, which has a lower light transmittance than the first region 11.

It is preferable that the second region 12 has a lower light transmittance for the light used in treatment than the first region 11.

The wavelength of the light used for treatment can be set appropriately depending on the treatment target, but for example, light with a wavelength of 600 nm or more and 700 nm or less may be used for treatment.

The second region 12 has a chromaticity a ^* of 35 or more and 60 or less in the L ^* a ^* b ^* color system. The chromaticity a ^* of the second region 12 is preferably 38 or more, and more preferably 40 or more. The chromaticity a ^* of the second region 12 is preferably 58 or less, and even more preferably 55 or less. This configuration can facilitate suppression of absorption of therapeutic light and also improve the visibility of the second region 12.

The second region 12 has a hue angle h of -45° or more and 45° or less. The hue angle h is calculated from the a ^* and b ^* values of the L ^* a ^* b ^* color system using the formula h = tan [(b ^* )/(a ^* )]. The hue angle h of the second region 12 is preferably -40° or more, and even more preferably -30° or more. The hue angle h of the second region 12 is more preferably 40° or less, and even more preferably 30° or less. This configuration can more easily suppress absorption of therapeutic light and also improve the visibility of the second region 12.

The lightness L ^* of the second region 12 is preferably 10 or greater, more preferably 15 or greater, and even more preferably 20 or greater. The lightness L ^* of the second region 12 is preferably 90 or less, more preferably 85 or less, and even more preferably 80 or less. This configuration can facilitate suppression of absorption of therapeutic light and also improve the visibility of the second region 12.

The color representation L ^* , a ^* , b ^* in the second region 12 of the photoirradiation medical device 1 according to the L ^* a ^* b ^* color system can be measured using a colorimeter.

Specific colors of the second region 12 can be, for example, red, orange, pink, purple, etc.

The second region 12 may be provided in only one location on the shaft 10, or in multiple locations.

The second region 12 may be provided only on a portion of the circumference of the shaft 10. The second region 12 may be provided over the entire circumference of the shaft 10.

When the second region 12 is provided only in a portion of the circumference of the shaft 10, the shape of the second region 12 when viewed from the radial direction of the shaft 10 can be, for example, circular, elliptical, polygonal, or a combination of these.

When the second region 12 is provided over the entire circumference of the shaft 10, it can be shaped like a hollow cylinder or a hollow polygonal cylinder. In order to place the light-guiding material 20 in the lumen, the second region 12 preferably has a tubular structure.

The second region 12 is preferably present in the distal portion of the shaft 10, but the second region 12 may be present only in the distal portion of the shaft 10. Alternatively, the second region 12 may be present in the proximal portion of the shaft 10.

The shaft 10 may be composed of only the first region 11 and the second region 12. In addition to the first region 11 and the second region 12, the shaft 10 may also have regions with properties different from the first region 11 and the second region 12. However, it is preferable that the portion of the shaft 10 in contact with the first region 11 does not have a white or black portion, and it is even more preferable that the distal portion of the shaft 10 does not have a white or black portion. Alternatively, the entire shaft 10 may be configured to have no white or black portions.

It is preferable that the first region 11 and the second region 12 are adjacent to each other. This configuration makes it easier to visually identify the boundary between the first region 11 and the second region 12. This makes it easier to position the first region 11 at the treatment site. Furthermore, improved visibility of the boundary between the first region 11 and the second region 12 makes it easier to adjust the position of the first region 11 and the position of the light-guiding material 20 when inserting the light-guiding material 20 into the lumen of the shaft 10. This shortens the time required for treatment.

The length of the second region 12 on the outer surface of the shaft 10 in the longitudinal direction of the shaft 10 is preferably longer than the length of the first region 11 on the outer surface of the shaft 10 in the longitudinal direction of the shaft 10. This makes it easier to improve the visibility of the shaft 10 within the body. When comparing the above lengths, the shortest length of the second region 12 on the outer surface of the shaft 10 in the longitudinal direction of the shaft 10 is compared with the shortest length of the first region 11 on the outer surface of the shaft 10 in the longitudinal direction of the shaft 10.

As described above, the photoirradiation medical device 1 includes a shaft 10 having a distal end 101 and a proximal end 102 in the longitudinal direction and an inner lumen 100 extending in the longitudinal direction. The shaft 10 includes a first region 11 and a second region 12 proximal to the first region 11, the second region 12 having a lower light transmittance than the first region 11. The second region 12 has a chromaticity a ^* in the L ^* a ^* b ^* color system of 35 to 60 and a hue angle h of -45° to 45°. This configuration reduces the amount of therapeutic light absorbed by the second region 12 when the photoirradiation medical device 1 is used for phototherapy, thereby suppressing heat generation in the second region 12. This prevents burns to the treatment site, which is the target tissue, and melting of the second region 12. Furthermore, the reduction in the amount of light reaching the treatment site is suppressed, allowing for effective light irradiation of the treatment site. Furthermore, the presence of the second region 12 can improve the visibility of the light irradiation medical device 1 inside the body, making it easier to adjust the position of the treatment area and the position of the light irradiation medical device 1.

As shown in Figure 2, the distal end of the shaft 10 is preferably closed. By closing the distal end of the shaft 10, it is possible to prevent body fluids such as gastrointestinal mucus and blood from entering the lumen of the shaft 10, which would otherwise cause deterioration of the light-guiding material 20 (described below). As shown in Figure 2, a distal tip 60 may be attached to the distal end 101 of the shaft 10. This makes it possible to avoid damage to biological tissue caused by the distal end of the shaft 10. The shape of the distal tip 60 can be, 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.

It is preferable that the light irradiation medical device 1 further includes a light-guiding material 20 that is movably disposed in the lumen 100 of the shaft 10 in the longitudinal direction of the shaft 10 and emits light.

The light-guiding material 20 functions as a light transmission path for carrying incident light. An optical fiber can be used as the light-guiding material 20. An optical fiber has a core and a cladding 22 that covers the radially outer side of the core, and preferably has a cladding-free portion 21 in a portion distal to the core. There are no particular restrictions on the materials that make up the core and cladding 22, and plastic, quartz glass, fluoride glass, and other glasses can be used.

The cladding-free portion 21 refers to at least a portion of the circumferential direction of the core where the cladding 22 is absent, and serves as the light-emitting area of the optical fiber 20. By providing such a cladding-free portion 21, a side-illumination type light irradiation medical device 1 can be constructed.

The location of the cladding-free portion 21 in the longitudinal direction of the shaft 10 is not particularly limited as long as it is part of the distal portion of the core, but it is preferably located in a portion that includes the distal end of the core. This makes it easier to form the cladding-free portion 21 and also increases the flexibility of the distal end of the light-guiding material 20.

The position of the distal end of the cladding-free portion 21 preferably coincides with the position of the distal end of the core. This eliminates the need for the difficult process of forming the cladding-free portion 21 while leaving the cladding 22 that includes the distal end of the optical fiber, thereby facilitating the process of forming the light-emitting area of the optical fiber.

The cladding-free portions 21 can be formed by removing the cladding 22, for example, by etching or polishing. It is more preferable to roughen the outer surface of the cladding-free portions 21 by sanding or other methods. This can improve light diffusion.

The length of the cladding-free portion 21 in the longitudinal direction of the shaft 10 can be configured to be shorter than the length of the first region 11 in the longitudinal direction on the outer surface of the shaft 10. When comparing the above lengths, the shortest length of the cladding-free portion 21 in the longitudinal direction of the shaft 10 is compared with the shortest length of the first region 11 in the longitudinal direction on the outer surface of the shaft 10.

When using the light irradiation medical device 1, it is preferable to insert the light-guiding material 20 into the lumen of the shaft 10 and move the light-guiding material 20 in the longitudinal direction of the shaft 10 to the position where the first region 11 is located, as shown in Figures 2, 3, and 5.

It is preferable that the section in the longitudinal direction of the shaft 10 where the first region 11 exists overlaps with the section in the longitudinal direction of the shaft 10 where the cladding-free portion 21 exists. In this case, it is sufficient that the section in the longitudinal direction of the shaft 10 where the first region 11 exists overlaps with the section in the longitudinal direction of the shaft 10 where the cladding-free portion 21 exists, but it is more preferable that they overlap entirely. A portion of the section in the longitudinal direction of the shaft 10 where the first region 11 exists may overlap with the entire section in the longitudinal direction of the shaft 10 where the cladding-free portion 21 exists. This configuration allows light emitted from the light-guiding material 20 to more easily pass through the first region 11, making it easier to irradiate the treatment area efficiently.

The photoirradiation medical device 1 further includes a light-guiding material 20 that is movably disposed in the lumen 100 of the shaft 10 in the longitudinal direction of the shaft 10 and emits light, and it is preferable that the wavelength of the light emitted by the light-guiding material 20 be 600 nm or more and 700 nm or less.

As described above, the wavelength of the light emitted from the light-guiding material 20 is preferably 600 nm or more and 700 nm or less. This means that it is preferable for the emitted light to contain light with a wavelength of 600 nm or more and 700 nm or less. For example, light with a wavelength of less than 600 nm may be temporarily emitted. Light with a wavelength greater than 700 nm may also be temporarily emitted. From the perspective of improving the effectiveness of treatment and making it easier to suppress light absorption in the second region 12, it is more preferable that the light emitted from the light-guiding material 20 be only light with a wavelength of 600 nm or more and 700 nm or less. By configuring the wavelength of the light emitted from the light-guiding material 20 as described above, it is possible to easily reduce the amount of light absorbed by the second region 12 of the photoirradiation medical device 1, and therefore it is possible to easily suppress heat generation in the second region 12 of the photoirradiation medical device 1.

It is preferable that the distal portion of the shaft 10 is further provided with an expansion section 30 that expands radially of the shaft 10. As shown in Figures 2 and 3, the expansion section 30 preferably expands radially outward at the distal portion of the shaft 10. Expanding the expansion section 30 makes it easier to fix the light irradiation medical device 1 inside the body, for example, to the wall of a biological tube, thereby preventing the light irradiation medical device 1 from shifting position inside the body.

As shown in FIG. 3 , the photoirradiation medical device 1 preferably further includes an outer shaft 40 having a lumen 400 extending in the longitudinal direction of the shaft 10. The outer shaft 40 is preferably arranged so as to have a distal end and a proximal end in the longitudinal direction of the shaft 10. The outer shaft 40 may have multiple lumens 400, but preferably has only one lumen 400. The shape of the outer shaft 40 is not particularly limited as long as the lumen 400 is present, but can be, for example, a hollow cylinder or a hollow polygonal prism. A tubular structure is preferred so that the shaft 10 can be placed in the lumen 400. Hereinafter, a cross section perpendicular to the longitudinal direction of the lumen 400 of the outer shaft 40 will be referred to as a lumen cross section.

The cross-sectional shape of the inner cavity of the outer shaft 40 is not particularly limited, but can be, for example, circular, elliptical, polygonal, star-shaped, or a combination of these.

The outer shaft 40 is preferably flexible, allowing it to be deformed to conform to the shape of the vessel within the body. It is also preferable that the outer shaft 40 be elastic in order to maintain its shape.

The outer shaft 40 may be a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body with a resin coating on at least one of the inner and outer surfaces; a resin tube; or a combination of these, such as a combination of these connected in the longitudinal direction. Examples of hollow bodies with wires arranged in a predetermined pattern include tubular bodies with 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.

The outer shaft 40 can be made of 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.

The outer shaft 40 may have a single-layer structure or a multi-layer structure. If the outer shaft 40 has a multi-layer structure, for example, the outer shaft 40 may have a resin tube that forms an intermediate layer made of a metal braid such as stainless steel, carbon steel, or nickel-titanium alloy.

It is preferable that the shaft 10 is disposed in the inner cavity 400 of the outer shaft 40. It is preferable that the shaft 10 is disposed in the inner cavity 400 of the outer shaft 40 so that it can move in at least one of the longitudinal direction and circumferential direction of the shaft 10.

As shown in FIG. 3, it is more preferable that a handle 50 be connected to the proximal portion of the outer shaft 40, allowing the surgeon to grasp the light irradiation medical device 1. The handle 50 may have, for example, a cylindrical shape with an inner cavity, and the outer shaft 40, shaft 10, and light-guiding material 20 may be inserted into the inner cavity of the handle 50.

The material of which the handle 50 is made is not particularly limited, but examples include polyolefin resins such as polypropylene (PP) and polyethylene (PE), polyester resins such as polyethylene terephthalate (PET), polycarbonate resin, ABS resin, and polyurethane resin, among other synthetic resins.

The outer shaft 40 preferably has a chromaticity a ^* range of 35 to 60 in the L ^* a ^* b ^* color system, and a hue angle h range of -45° to 45°. The outer shaft 40 more preferably has a chromaticity a ^* range of 38 or greater, and even more preferably has a range of 40 or greater. The outer shaft 40 more preferably has a chromaticity a ^* range of 58 or less, and even more preferably has a range of 55 or less. This configuration can more easily suppress absorption of therapeutic light and also improve the visibility of the outer shaft 40. While only a portion of the outer shaft 40 may have the above chromaticity, it is preferable that the entire outer shaft 40 has the above chromaticity.

The color of the shaft 10 and the color of the outer shaft 40 may be the same or different.

The outer shaft 40 preferably has a region where the hue angle h is between -45° and 45°. The hue angle h is calculated from the a ^* and b ^* values of the L ^* a ^* b ^* color system using the formula h = tan [(b ^* )/(a ^* )]. The hue angle h is more preferably -40° or greater, and even more preferably -30° or greater. The hue angle h is more preferably 40° or less, and even more preferably 30° or less. This configuration can more easily suppress absorption of therapeutic light and also improve the visibility of the outer shaft 40. While only a portion of the outer shaft 40 may have the above hue angle, it is preferable that the entire outer shaft 40 have the above hue angle.

The hue angle of the shaft 10 and the hue angle of the outer shaft 40 may be the same or different.

The outer shaft 40 preferably has a lightness L ^* of 10 or more, more preferably 15 or more, and even more preferably 20 or more. The outer shaft 40 preferably has a lightness L ^* of 90 or less, more preferably 85 or less, and even more preferably 80 or less. This configuration can easily suppress absorption of therapeutic light and also improve the visibility of the outer shaft 40. Although only a portion of the outer shaft 40 may have the above-mentioned lightness, it is preferable that the entire outer shaft 40 has the above-mentioned lightness.

The brightness of the shaft 10 and the brightness of the outer shaft 40 may be the same or different.

As shown in FIG. 3, the photoirradiation medical device 1 has a proximal fixing portion 31 to which the proximal end of the expansion portion 30 and the outer shaft 40 are fixed, and the second region 12 is preferably located on the shaft 10 distal to the position where the proximal fixing portion 31 is located. The second region 12 may also be located on the shaft 10 proximal to the position where the proximal fixing portion 31 is located. Although not shown, the second region may also be located only on the shaft distal to the position where the proximal fixing portion is located.

The expansion portion 30 is preferably a balloon, basket, or self-expanding stent.

As shown in Figure 3, the balloon may have, from the proximal side, a proximal fixing portion 31 fixed to the outer shaft 40, an inflation portion 32 not fixed to the shaft 10 or the outer shaft 40, and a distal fixing portion 33 fixed to the shaft 10. It is preferable that the shaft 10 passes through the balloon in the longitudinal direction of the shaft 10. This allows the balloon to be joined to the shaft 10.

When the expansion section 30 is a balloon, a fluid supplier (not shown) is preferably connected to the proximal portion of at least one of the shaft 10 and the outer shaft 40. The balloon is configured so that pressurized fluid is supplied to the interior of the balloon from the fluid supplier through at least one of the shaft 10 and the outer shaft 40. When pressurized fluid is supplied to the interior of the balloon, the balloon expands, and when the pressurized fluid is withdrawn, the balloon contracts. When the balloon is expanded, the outer surface of the balloon comes into contact with the walls of biological tracts such as blood vessels and the digestive tract, allowing the shaft 10 to be fixed within the body.

When the expansion section 30 is a balloon, the shaft 10 may have multiple internal cavities (not shown). For example, the shaft 10 may be configured to have a first internal cavity that serves as a passage for the light-guiding material 20, and a second internal cavity that functions as a flow path for the pressurized fluid.

The inflation section 32 of the balloon may have a straight tube section 30a and tapered sections 30b formed distally and proximally of the straight tube section 30a. In this case, the shaft 10 can be fixed inside the body by bringing the outer surface of the straight tube section 30a into contact with the biological tube wall.

The balloon is preferably made of resin. Examples of resins that can be used to make the balloon include polyamide resins, polyester resins, polyurethane resins, polyolefin resins, vinyl chloride resins, silicone resins, and natural rubber. These may be used alone or in combination of two or more. Among these, polyamide resins, polyester resins, and polyurethane resins are preferred. Elastomer resins can be used to make the balloon thinner and more flexible.

The type of fluid supplied into the balloon is not particularly limited, but can be, for example, a liquid such as saline, contrast medium, or a mixture of these, or a gas such as air, nitrogen, or carbon dioxide. Among these, it is preferable to supply a gas into the balloon, from the viewpoint of making it easier for the emitted light to pass through.

The balloon preferably has optical transparency to facilitate transmission of emitted light. It is preferable that the balloon have the same optical transmittance as the first region 11 or a higher optical transmittance than the first region 11.

The basket is formed by bundling multiple elastic wires at a first bundling section and a second bundling section that is proximal to the first bundling section. In the basket, the elastic wires may be bent or twisted helically between the first bundling section and the second bundling section. Baskets are generally used to capture foreign bodies such as stones, but in the case of the photoirradiation medical device 1, they are used to fix the position of the photoirradiation medical device 1 inside the body.

The elastic wire is a wire material with elasticity, and is preferably made of a shape memory alloy or shape memory resin. The elastic wire may be a solid or stranded metal wire material made of, for example, stainless steel such as SUS304 or SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, aluminum, gold, silver, Ni-Ti alloy, Co-Cr alloy, etc.

The number of elastic wires is not particularly limited and can be selected depending on the inner diameter of the biological tube wall, etc.

In the first bundling section and the second bundling section, it is preferable that the elastic wires are fixed to the shaft 10. The distal or proximal ends of multiple elastic wires are spaced apart around the circumference of the shaft 10, and the elastic wires can be fixed to the shaft 10 by brazing or gluing the distal or proximal ends to the shaft 10, or by placing a tubular connector over the distal or proximal end of the elastic wire and crimping the connector.

A stent is an expandable structure, e.g., composed of a network structure such as a mesh, that includes multiple struts. Stents can be formed from a pattern of interconnected structural elements that expand and contract, for example, in the circumferential and axial directions. Examples of stents include a coil-shaped type made from a single linear metal or polymer material, a type cut out of a metal tube or a polymer tube using a laser or other cutting method, a type assembled by welding linear sections, and a type made by weaving multiple linear metal segments.

Stents can be classified into balloon-expandable and self-expandable types based on their expansion mechanism. With balloon-expandable stents, the stent is mounted on the outer surface of a balloon and transported to the treatment site, such as a lesion, where it is expanded using a balloon. With self-expandable stents, the stent is transported to the lesion site using a catheter equipped with a member that inhibits expansion, and the member that inhibits expansion is removed at the treatment site, allowing the stent to expand on its own. Self-expandable stents are preferably used. Because self-expandable stents do not require an internal balloon, they can have a smaller diameter in their contracted state than balloon-expandable stents.

For the material of construction of the stent, please refer to the description of the material of construction of the basket's elastic wire.

If the expansion section is a self-expanding stent, it is preferable that the proximal end of the self-expanding stent is fixed to the distal end of the shaft. This allows the light-irradiating medical device to be fixed inside the body without the stent interfering with the emission of light.

If the expansion section 30 is a self-expanding stent and the distal end is more expandable than the proximal end, it is preferable that the distal end is not fixed to the distal end of the shaft 10. By bringing the distal end of the stent into contact with the biological vessel wall, the shaft 10 can be fixed within the body.

The stent can be secured to the shaft 10 in the same manner as the elastic wire of the basket is secured to the shaft 10. At the proximal end of the stent, multiple struts can be arranged spaced apart circumferentially around the shaft 10 and brazed or glued to the shaft 10, or a tubular connector can be placed over the proximal end of the strut and crimped.

When the expansion section 30 is a basket or stent, it is preferable that the expansion section 30 be fixed to the shaft 10, and more preferably, the distal and proximal ends of the expansion section 30 are fixed to the shaft 10, as shown in Figure 2. Furthermore, although not shown, it is preferable that the light irradiation medical device further has an outer shaft capable of accommodating the expansion section in its lumen. This prevents the basket or stent from expanding and damaging the forceps port inside the endoscope, the forceps channel, or internal tissue other than the foreign body while the light irradiation medical device is being transported from the forceps port of the endoscope through the forceps channel to the vicinity of the treatment site, such as a lesion.

It is preferable that the section in the longitudinal direction of the shaft 10 where the expansion section 30 exists overlaps with the section in the longitudinal direction of the shaft 10 where the first region 11 exists. In this case, it is sufficient for the section in the longitudinal direction of the shaft 10 where the expansion section 30 exists and the section in the longitudinal direction of the shaft 10 where the first region 11 exists to at least partially overlap, but it is more preferable that they overlap entirely. A portion of the section in the longitudinal direction of the shaft 10 where the expansion section 30 exists may overlap entirely with the section in the longitudinal direction of the shaft 10 where the first region 11 exists. This configuration makes it easier to fix the first region 11, which is easily permeable to light emitted from the light-guiding material 20, to the treatment site, making it easier to irradiate the treatment site with therapeutic light.

As shown in FIG. 3, the expansion section 30 is a balloon, and the second region 12 is preferably present in the portion of the shaft 10 that is located within the lumen of the balloon. The second region 12 may be present in part in the portion of the shaft 10 that is located within the lumen of the balloon, or in its entirety in the portion of the shaft 10 that is located within the lumen of the balloon. The presence of the second region 12 makes it easier to visually identify the location of the balloon within the body.

As shown in FIG. 3 , the light irradiation medical device 1 has a proximal fixing portion 31 to which the proximal end of the expansion portion 30 and the outer shaft 40 are fixed, and a distal fixing portion 33 to which the distal end of the expansion portion 30 and the shaft 10 are fixed. It is preferable that a first region 11 is present between the proximal fixing portion 31 and the distal fixing portion 33 in the longitudinal axis direction of the shaft 10. The entire first region 11 may be present between the proximal fixing portion 31 and the distal fixing portion 33, or only a portion of it may be present between the proximal fixing portion 31 and the distal fixing portion 33. It is more preferable that the entire first region 11 be present between the proximal fixing portion 31 and the distal fixing portion 33, as this facilitates light irradiation of the treatment area while fixing the position within the body.

In the light irradiation medical device 1, it is preferable that the first section 110 of the shaft 10 shown in Figure 1, from the proximal end of the first region 11 to a position 10 cm proximal to the proximal end of the first region 11, has a light transmittance of 90% or more as determined by the light transmittance measurement method described below.
[Light transmittance measurement method]
(1) The optical fiber diffuser connected to the light source device (ML6600, manufactured by Modulight) is inserted into an integrating sphere (CSTM Flux 6, manufactured by Labsphere) from the distal end to a point 10 cm proximal to the distal end of the optical fiber diffuser.
(2) Light with a wavelength of 660 nm or more and 670 nm or less is emitted from the optical fiber diffuser, and the radiant flux Ir is measured using a light intensity measuring device (FLAME-S, manufactured by Ocean Photonics) connected to an integrating sphere.
(3) The optical fiber diffuser is placed in the lumen 100 of the shaft 10 so that the distal end of the first section 110 coincides with the distal end of the optical fiber diffuser, and the entire shaft 10 except for the first section 110 is covered with silver foil.
(4) After the step (3), the shaft 10 is inserted into an integrating sphere from the distal end of the first section 110 to the proximal end of the first section 110.
(5) Light having a wavelength of 660 nm or more and 670 nm or less is emitted from the optical fiber diffuser that has undergone steps (3) and (4), and the radiant flux Is is measured by a light intensity measuring device connected to an integrating sphere.
(6) The value obtained by the formula Is/Ir is defined as the light transmittance of the first section 110.

The light transmittance measured using the above light transmittance measurement method will be referred to below as the specific light transmittance.

The wavelength of the light emitted from the optical fiber diffuser in (2) above must be the same as the wavelength of the light emitted from the optical fiber diffuser in (5) above.

When measuring specific light transmittance using the above light transmittance measurement method, any commercially available optical fiber diffuser can be used.

By setting the specific light transmittance as described above, it is possible to reduce the amount of therapeutic light absorbed in the first section 110 that is in contact with the first region 11 of the photoirradiation medical device 1. This makes it possible to suppress heat generation in the first section 110 of the photoirradiation medical device 1 and to prevent a reduction in the amount of light reaching the treatment site.

1: Light irradiation medical device 10: Shaft 11: First region 12: Second region 20: Light-guiding material 21: Cladding-free region 22: Cladding 30: Expanding section 30a: Straight tube section 30b: Tapered section 31: Proximal fixing section 32: Expanding section 33: Distal fixing section 40: Outer shaft 50: Handle 60: Distal tip 100: Shaft lumen 110: First section

Claims (10)

a shaft having a distal end and a proximal end in a longitudinal direction and an inner lumen extending in the longitudinal direction;
The shaft has a first region and a second region proximal to the first region that has a light transmittance lower than that of the first region, and the second region has a chromaticity a ^* according to the L ^* a ^* b ^* color system of 35 or more and 60 or less, and a hue angle h of -45° or more and 45° or less. The photoirradiation medical device according to claim 1, wherein the length of the second region on the outer surface of the shaft in the longitudinal direction is longer than the length of the first region on the outer surface of the shaft in the longitudinal direction. Further, a light guide member is provided in the inner cavity of the shaft so as to be movable in the longitudinal axis direction, and the light guide member emits light,
2. The light irradiation medical device according to claim 1, wherein the wavelength of the light emitted by the light-guiding material is 600 nm or more and 700 nm or less. The light irradiation medical device of claim 1, wherein a first section of the shaft extending from the proximal end of the first region to a position 10 cm proximal to the proximal end of the first region has a light transmittance of 90% or more as determined by the light transmittance measurement method described below.
[Light transmittance measurement method]
(1) The optical fiber diffuser connected to a light source device (ML6600, manufactured by Modulight) is inserted into an integrating sphere (CSTM Flux 6, manufactured by Labsphere) from its distal end to a point 10 cm proximal to the distal end of the optical fiber diffuser.
(2) Light having a wavelength of 660 nm or more and 670 nm or less is emitted from the optical fiber diffuser, and the radiant flux Ir is measured by a light intensity measuring device (FLAME-S, manufactured by Ocean Photonics) connected to the integrating sphere.
(3) The optical fiber diffuser is placed in the inner cavity of the shaft so that the distal end of the first section coincides with the distal end of the optical fiber diffuser, and the entire shaft except for the first section is covered with silver foil.
(4) The shaft that has been subjected to step (3) is inserted into an integrating sphere from the distal end of the first section to the proximal end of the first section.
(5) Light having a wavelength of 660 nm or more and 670 nm or less is emitted from the optical fiber diffuser that has undergone steps (3) and (4), and the radiant flux Is is measured by the light intensity measuring device connected to the integrating sphere.
(6) The value obtained by the formula Is/Ir is defined as the light transmittance of the first section. The photoirradiation medical device according to claim 1, further comprising an extension portion at the distal end of the shaft that extends radially of the shaft. the expansion portion is a balloon;
The photoirradiation medical device according to claim 5 , wherein the second region is present in a portion of the shaft that is disposed in the lumen of the balloon. an outer shaft having an inner lumen extending in the longitudinal direction;
The photoirradiation medical device according to claim 5 , wherein the shaft is disposed in the inner cavity of the outer shaft. a proximal fixing portion at which a proximal end of the expansion portion and the outer shaft are fixed;
The photoirradiation medical device according to claim 7 , wherein the second region is located on the shaft distal to a position where the proximal fixing portion is located. The photoirradiation medical device according to claim 7, wherein the outer shaft has a region where the chromaticity a ^* in the L ^* a ^* b ^* color system is 35 or more and 60 or less, and the hue angle h is -45° or more and 45° or less. The photoirradiation medical device described in any one of claims 5, 7 to 9, wherein the expansion portion is a balloon, a basket, or a self-expanding stent.