JP2023009439A - Light irradiation medical device - Google Patents

Abstract

To provide a light irradiation medical device that can contribute to the efficiency of procedures.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 having a lumen 11 extending in the longitudinal axis direction x, an optical fiber 20 disposed in the lumen 11, and a cylindrical member 40 disposed in the lumen 11 that covers part of a distal part of the optical fiber 20. The optical fiber 20 extends in the longitudinal axis direction x in a predetermined section of the distal part, and includes a light diffusion part 21 for diffusing light outward in a radial direction of the shaft 10. The cylindrical member 40 covers part of the light diffusion part 21. The cylindrical member 40 has a shape in which a distal end 401 side is closed while a proximal end 402 side is open. The inner peripheral surface of the proximal part 404 of the cylindrical member 40 is fixed to the outer peripheral surface 23 of the light diffusion part 21 while the inner peripheral surface of the distal part 403 of the cylindrical member 40 is not fixed to the outer peripheral surface 23 of the light diffusion part 21.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a light irradiation medical device for irradiating tissues such as cancer cells with light in body lumens such as blood vessels and gastrointestinal tracts.

In photodynamic therapy (PDT), a photosensitizer is administered into the body by intravenous injection or intraperitoneal injection, and the photosensitizer is accumulated in target tissues such as cancer cells, and light of a specific wavelength is used. to excite the photosensitizer. An energy transfer occurs when the excited photosensitizer returns to the ground state, generating reactive oxygen species. Target tissue can be removed by attacking the target tissue with reactive oxygen species. In ablation using laser light, a target tissue is irradiated with laser light and cauterized. An apparatus for performing such light irradiation has been proposed.

Patent Document 1 discloses a device for laser treatment comprising an optical fiber, a flexible tube that surrounds the periphery of the optical fiber with a gap, and a holder that holds the output-side end of the optical fiber substantially coaxially within the tube. A fiber optic probe is disclosed. Further, it is disclosed that the holding part is composed of one coil spring, and the first cylindrical coil part of the coil spring is passed through the optical fiber and fixed to the coating of the optical fiber.

Patent Literature 2 discloses a medical light guide that includes an optical fiber and a cover tube that covers the optical fiber. An optical fiber has a core, a clad, and a coating covering the clad. The exposed first cladding portion, the second covering portion in which the core and the cladding are covered with the covering, the core portion in which the covering and the cladding are removed and the core is exposed, and the third in which the core and the cladding are covered with the covering , a second cladding portion from which the cladding is removed and the cladding is exposed, and a tip portion.

JP-A-11-309155 JP 2019-51023 A

In order to irradiate the entire target tissue such as a tumor, the front-illumination type light irradiation device as described in Patent Document 1 emits light at a certain location, and then shifts the position of the light-emitting portion with respect to the target tissue for a while. It was necessary to perform the operation of shifting and emitting light again multiple times. In addition, irradiation may be difficult depending on the location and shape of the tumor. The side irradiation type light irradiation device has the advantage of being able to irradiate a wide range in the circumferential direction at once. However, in the device as described in Patent Document 2, the emission intensity distribution may be uneven in the circumferential direction of the device. In that case, as with the front irradiation type, even with the side irradiation type, in order to irradiate the entire target tissue, it is necessary to repeatedly adjust the position of the light emission and the light emitting site, which lengthens the procedure and increases the patient's discomfort. And there was a risk of causing a burden on the operator. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a light irradiation medical device that contributes to the efficiency of procedures.

One embodiment of the light irradiation medical device of the present invention that has achieved the above object is 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 within the lumen of the shaft; and a tubular member disposed within the lumen of the shaft and covering a portion of the distal portion of the optical fiber, the optical fiber being located at the distal portion thereof. has a light diffusing portion that extends in the longitudinal direction in a predetermined section of the shaft and emits light outward in the radial direction of the shaft; a cylindrical member covers a part of the light diffusing portion; is closed on the distal end side and open on the proximal end side, the inner peripheral surface of the proximal portion of the tubular member is fixed to the outer peripheral surface of the light diffusion portion, and the distal portion of the tubular member is not fixed to the outer peripheral surface of the light diffusing portion. According to the light irradiation medical device, the portion of the light diffusing portion covered by the cylindrical member reflects the light emitted from the light diffusing portion on the inner surface of the cylindrical member. It becomes easier to diffuse in various directions from the exposed portion, which is the portion not covered with the member. As a result, the emission intensity distribution of the exposed portion tends to be uniform in the circumferential direction of the shaft. As a result, it is possible to reduce the number of times the target tissue such as a tumor is irradiated and the number of times the position of the exposed portion is adjusted with respect to the target tissue, thereby improving the efficiency of the procedure. In addition, since the inner peripheral surface of the proximal portion of the tubular member is fixed to the outer peripheral surface of the light diffusing portion, even if the light irradiation medical device is inserted into the body, the proximal end of the tubular member in the longitudinal axis direction of the shaft will remain unchanged. is fixed so as not to shift with respect to the light diffusing portion, the irradiation position can be stabilized. Furthermore, since the inner peripheral surface of the distal portion of the tubular member is not fixed to the outer peripheral surface of the light diffusing portion, the distal end side of the tubular member does not stiffen even when the light irradiation medical device passes through a bend in the body. In addition, it becomes easier to follow the curvature of the shaft, and the risk of breakage of the optical fiber can be reduced.

In the above light irradiation medical device, the distal end face of the light diffusing portion may not be fixed to the tubular member. A proximal portion of the tubular member may be adhered to the light diffusing portion. The average inner diameter of the proximal portion of the tubular member may be smaller than the average inner diameter of the distal portion of the tubular member. A proximal portion of the tubular member may be crimped to secure the tubular member to the light diffusing portion.

In the above light irradiation medical device, the proximal end of the cylindrical member may be located on the distal side of the midpoint of the light diffusing portion in the longitudinal direction. The outer peripheral surface of the light diffusing portion may be arranged apart from the inner peripheral surface of the shaft. The outer peripheral surface of the tubular member may be in contact with the inner peripheral surface of the shaft.

In the above light irradiation medical device, the cylindrical member may have a coil portion in which a wire is spirally wound around the light diffusing portion. The coil portion may have a first pitch portion having a pitch equal to or less than twice the wire diameter of the wire.

In the above light irradiation medical device, the optical fiber has a core extending in a longitudinal direction, the optical fiber has a first section having a first clad disposed around the core, The optical fiber has, in the light diffusing portion, a second clad disposed on the outer periphery of the core and having a surface roughness of the outer peripheral surface larger than that of the first clad, and the second clad positioned distally of the first section. It may have intervals. The optical fiber has a core extending longitudinally, the optical fiber has a first section having a first cladding disposed around the core, and the optical fiber has a light diffusing portion. , a third section that is devoid of cladding and located distally of the first section.

According to the light irradiation medical device, the portion of the light diffusing portion covered by the cylindrical member reflects the light emitted from the light diffusing portion on the inner surface of the cylindrical member. It becomes easier to diffuse in various directions from the exposed portion, which is the portion not covered with the member. As a result, the emission intensity distribution of the exposed portion tends to be uniform in the circumferential direction of the shaft. As a result, it is possible to reduce the number of times the target tissue such as a tumor is irradiated and the number of times the position of the exposed portion is adjusted with respect to the target tissue, thereby improving the efficiency of the procedure. In addition, even if the light irradiation medical device is inserted into the body, the position of the proximal end of the cylindrical member is fixed so as not to shift with respect to the light diffusing portion in the longitudinal direction of the shaft, so that the irradiation position can be stabilized. can. Furthermore, even when the light irradiation medical device passes through a bend in the body, the distal end side of the tubular member is not stretched and can easily follow the bending of the shaft, thereby reducing the risk of optical fiber breakage.

1 is a cross-sectional view (partial side view) of a light irradiation medical device according to an embodiment of the present invention; FIG. FIG. 2 is an enlarged cross-sectional view (partial side view) of the distal side of the light irradiation medical device shown in FIG. 1 ; FIG. 3 is a cross-sectional end view of the light irradiation medical device shown in FIG. 2 taken along line III-III; 3 is a cut end view of the cylindrical member shown in FIG. 2. FIG. 3 is a cross-sectional view (partial side view) showing a modification of the light irradiation medical device shown in FIG. 2. FIG. 3 is a cross-sectional view (partial side view) showing a modification of the light irradiation medical device shown in FIG. 2. FIG. 3 is a cross-sectional view (partial side view) showing a modification of the light irradiation medical device shown in FIG. 2. FIG. 8 is a cut end view of the cylindrical member shown in FIG. 7. FIG. 3 is a cross-sectional view (partial side view) showing a modification of the light irradiation medical device shown in FIG. 2. FIG. 3 is an enlarged cross-sectional view of the distal side of the optical fiber shown in FIG. 2; FIG. FIG. 11 is a cross-sectional view showing a modification of the optical fiber shown in FIG. 10; FIG. 11 is a cross-sectional view showing another modification of the optical fiber shown in FIG. 10;

Hereinafter, the present invention will be described in more detail based on the following embodiments, but the present invention is not limited by the following embodiments, and can be modified appropriately within the scope of the above and later descriptions. It is of course possible to carry out in addition, and all of them are included in the technical scope of the present invention. In each drawing, for the sake of convenience, hatching, member numbers, etc. may be omitted. In such cases, the specification and other drawings shall be referred to. In addition, the dimensions of various members in the drawings may differ from the actual dimensions, since priority is given to helping to understand the features of the present invention.

One embodiment of the photomedical device of the present invention includes a shaft having longitudinally distal and proximal ends and having a longitudinally extending lumen; and a tubular member disposed within the lumen of the shaft and covering a portion of the distal portion of the optical fiber, the optical fiber extending longitudinally through a predetermined section of the distal portion. and has a light diffusing portion that emits light outward in the radial direction of the shaft, a cylindrical member covers a portion of the light diffusing portion, and the cylindrical member is closed at its distal end The inner peripheral surface of the proximal portion of the tubular member is fixed to the outer peripheral surface of the light diffusing portion, and the inner peripheral surface of the distal portion of the tubular member is the light diffusing portion. The gist is that it is not fixed to the outer peripheral surface of the part. According to the light irradiation medical device, the portion of the light diffusing portion covered by the cylindrical member reflects the light emitted from the light diffusing portion on the inner surface of the cylindrical member. It becomes easier to diffuse in various directions from the exposed portion, which is the portion not covered with the member. As a result, the emission intensity distribution of the exposed portion tends to be uniform in the circumferential direction of the shaft. As a result, it is possible to reduce the number of times the target tissue such as a tumor is irradiated and the number of times the position of the exposed portion is adjusted with respect to the target tissue, thereby improving the efficiency of the procedure. In addition, since the inner peripheral surface of the proximal portion of the tubular member is fixed to the outer peripheral surface of the light diffusing portion, even if the light irradiation medical device is inserted into the body, the proximal end of the tubular member in the longitudinal axis direction of the shaft will remain unchanged. is fixed so as not to shift with respect to the light diffusing portion, the irradiation position can be stabilized. Furthermore, since the inner peripheral surface of the distal portion of the tubular member is not fixed to the outer peripheral surface of the light diffusing portion, the distal end side of the tubular member does not stiffen even when the light irradiation medical device passes through a bend in the body. It becomes easy to follow the curvature of the shaft, and the risk of breakage of the optical fiber can be reduced.

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

The basic configuration of the apparatus will be described with reference to FIGS. 1 to 12. FIG. FIG. 1 is a sectional view (partial side view) of a light irradiation medical device according to one embodiment of the present invention. FIG. 2 is a cross-sectional view (partial side view) enlarging the distal side of the light irradiation medical device shown in FIG. FIG. 3 is an end view of the light irradiation medical device shown in FIG. 2 taken along line III-III. 4 is a cut end view of the cylindrical member shown in FIG. 2. FIG. 5 to 7 and 9 are cross-sectional views (partial side views) showing modifications of the light irradiation medical device shown in FIG. 8 is a cut end view of the cylindrical member shown in FIG. 7. FIG. 10 is an enlarged cross-sectional view of the distal side of the optical fiber shown in FIG. 11 and 12 are sectional views showing modifications of the optical fiber shown in FIG. The light irradiation medical device 1 has a shaft 10 , an optical fiber 20 and a cylindrical member 40 . In the following, the light irradiation medical device may be simply referred to as the device. In order to facilitate understanding of the positional relationship between the optical fiber 20 and the tubular member 40, the shaft 10 is omitted from FIGS.

In this specification, the distal side of the device 1 refers to the distal end side of the shaft 10 in the longitudinal direction x and the treatment target side. The proximal side of the device 1 refers to the proximal end side of the shaft 10 in the longitudinal direction x and the user's hand side. When each member is divided into two halves in the longitudinal direction x of the shaft 10, the proximal side may be called the proximal portion, and the distal side may be called the distal portion. In the radial direction of the device 1, the inner side refers to the direction toward the central axis c extending in the longitudinal direction x of the shaft 10, and the outer side refers to the radial direction opposite to the inner side.

The shaft 10 has a longitudinal direction x, a radial direction and a circumferential direction p. As shown in FIG. 1, shaft 10 has a distal end and a proximal end in longitudinal direction x and has a lumen 11 extending in longitudinal direction x. The shaft 10 may have only one lumen 11 or may have a plurality of them. Shaft 10 has a tubular shape for arranging optical fiber 20 and tubular member 40 in lumen 11 thereof. 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. Shaft 10 has an inner peripheral surface 12 and an outer peripheral surface 13 .

The shaft 10 is a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body having at least one of its inner surface or outer surface coated with a resin; a resin tube; , such as those connected in the longitudinal direction. A hollow body in which wires are arranged in a predetermined pattern includes a cylindrical body having a mesh structure formed by simply crossing or weaving wires, and a coil in which wires are wound. The wire may be one or more solid wires or one or more twisted wires. A resin tube can be manufactured, for example, by extrusion molding. When the shaft 10 is a resin tube, the shaft 10 can 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 a plurality of layers.

The shaft 10 is made of, for example, polyolefin resin (eg, polyethylene or polypropylene), polyamide resin (eg, nylon), polyester resin (eg, PET), aromatic polyether ketone resin (eg, PEEK), polyether polyamide resin, polyurethane. It can be made of synthetic resin such as resin, polyimide resin, fluorine resin (for example, PTFE, PFA, ETFE), or metal such as stainless steel, carbon steel, nickel-titanium alloy. These may be used individually by 1 type, and may be used in combination of 2 or more types. It is preferable that at least a portion of the shaft 10 that overlaps the light diffusing portion 21 is made of a resin having optical transparency. At least a portion of the shaft 10 that overlaps the light diffusing portion 21 may be made of a transparent resin.

A distal tip 15 may be attached to the distal end of shaft 10 as shown in FIG. Damage to living tissue by the distal end of the shaft 10 can be avoided. Examples of the shape of the distal tip 15 include a cylindrical shape, an oval cylindrical shape, a hemispherical shape, an oval spherical shape, a truncated pyramid shape, a truncated cone shape, a long truncated cone shape, a rounded truncated pyramid shape, or a combination thereof. can be done.

In FIG. 1, a handle 60 is connected to the proximal portion of shaft 10 . By holding the handle 60 by the operator, the device 1 can be easily operated. The handle 60 extends, for example, in the longitudinal direction x. Handle 60 may be constructed from one or more members. In FIG. 1, the handle 60 has a hollow portion extending in the longitudinal 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 through the hollow portion of the handle 60 .

Although the material of the handle 60 is not particularly limited, for example, polyolefin resins such as polypropylene (PP) and polyethylene (PE), polyester resins such as polyethylene terephthalate (PET), polycarbonate resins, ABS resins, and synthetic resins such as polyurethane resins are used. be able to.

The optical fiber 20 is a transmission line that transmits optical signals to the target tissue. As shown in FIGS. 1-2, optical fiber 20 is disposed within lumen 11 of shaft 10 . The optical fiber 20 has a light diffusing portion 21 extending in the longitudinal direction x in a predetermined section of its distal portion and emitting light outward in the radial direction of the shaft 10 . The light diffusing portion 21 functions as a light emitting area. The light diffusing portion 21 is arranged to extend in the longitudinal direction x and the circumferential direction p of the shaft 10 . The light diffusing portion 21 has an outer peripheral surface 23 . An outer peripheral surface 23 of the light diffusion portion 21 faces the inner peripheral surface 12 side of the shaft 10 . In FIG. 1, the proximal end of optical fiber 20 extends proximally from handle 60 . The proximal end of optical fiber 20 is connected to a light source such as a semiconductor laser.

The device 1 is inserted through the endoscope to a position where the target tissue is located within the body cavity. At this time, the target tissue is positioned radially outward of the outer peripheral surface 13 of the shaft 10 . The light emitted from the light diffusing portion 21 passes through at least a portion of the shaft 10 that overlaps the light diffusing portion 21 , so that the light reaches the target tissue around the device 1 .

From the light diffusing portion 21 , it is sufficient that light is emitted at least outward in the radial direction of the shaft 10 , and from the light diffusing portion 21 , the radial direction of the shaft 10 extends over the entire circumferential direction p of the shaft 10 . It is preferable that the light is emitted outward. Light may be emitted further from the light diffusing portion 21 toward the distal direction of the shaft 10, that is, toward the front. However, it is preferable that the device 1 does not include a device that emits light only in the distal direction of the shaft 10 from the light diffusing portion 21 .

As shown in FIGS. 1 and 2, part of the light diffusing section 21 is covered with a cylindrical member 40. As shown in FIGS. In this specification, a portion through which light is emitted at least radially outward when the tubular member 40 is removed from the optical fiber 20 is referred to as a light diffusion portion 21 . When the cylindrical member 40 partially covers the light diffusing section 21, at least one of the distal end and the proximal end of the light diffusing section 21 may be hidden by the cylindrical member 40 and may not be visible. It may be difficult to know the location of the distal and proximal ends of 21 . Therefore, the positions of the distal end and the proximal end of the light diffusing portion 21 are specified with the cylindrical member 40 removed from the optical fiber 20 .

In this specification, the portion of the light diffusing portion 21 that is not covered with the cylindrical member 40 and is exposed to the shaft 10 side is referred to as an exposed portion 22 . In the radial direction of the shaft 10 , it is preferable that there be no separate member between the exposed portion 22 and the shaft 10 , but any member that does not block the light emitted from the exposed portion 22 may be provided.

The light diffusing part 21 is not a diffusing member (for example, a diffusion plate or a prism) separate from the optical fiber 20 , but a part forming part of the optical fiber 20 . Optical fiber 20 has a core and a clad. The clad is arranged on the outer circumference of the core and covers a part of the radially outer side of the core. The light diffusion part 21 has (i) a mode in which only the core is arranged, (ii) a mode in which the core and the clad are arranged, or (iii) a part in which only the core is arranged and the other part in which the core and the clad are arranged. is preferably configured from any of the aspects in which is arranged. A covering material for protection may be arranged outside the clad in the radial direction, but it is preferable that the light diffusing portion 21 is not arranged with members other than the core and the clad.

The material constituting the core and clad is not particularly limited, and glass such as plastic, quartz glass, and fluoride glass can be used.

At least in the portion of the shaft 10 that overlaps the light diffusing portion 21, the resin forming the shaft 10 contains inorganic particles such as titanium oxide, barium sulfate, and calcium carbonate, and organic particles such as crosslinked acrylic particles and crosslinked styrene particles. Light diffusing materials can be added. Light emitted from the light diffusing portion 21 is more easily diffused by the shaft 10 .

The light diffusion part 21 is preferably arranged on the most distal side of the optical fiber 20 . This makes it easier to form the light diffusing portion 21 and increases the flexibility of the distal end portion of the optical fiber 20 .

The length of the light diffusion portion 21 in the longitudinal direction x may be set to 1/50 or more, 1/45 or more, or 1/30 or more of the total length of the optical fiber 20 . By setting such a length, it becomes easy to irradiate the entire target tissue with a single irradiation. Also, the length of the light diffusing portion 21 in the longitudinal axis direction x may be set to 1/20 or less, 1/25 or less, or 1/30 or less of the total length of the optical fiber 20 . By setting such a length, it is possible to prevent irradiation of non-target tissues.

The light diffusing portion 21 may be arranged only in a part of the shaft 10 in the circumferential direction p, but as shown in FIG. preferably. Since a wide range in the circumferential direction p can be irradiated at once, efficiency of the procedure can be improved.

A configuration example of the optical fiber 20 will be described with reference to FIGS. 10 to 12. FIG. 10-12, the optical fiber 20 has a core 25 extending in the longitudinal direction x, and the optical fiber 20 has a first clad 26 disposed around the core 25. It has one section 31 . In the first section 31, the light is likely to be totally reflected at the boundary between the core 25 and the first clad 26. Therefore, in the first section 31, the light is confined within the core 25 and propagates to the distal side of the optical fiber 20. .

Preferably, one core 25 is arranged in one first clad 26 in the first section 31 . In the first section 31, the optical fiber can be rephrased as a single-core optical fiber.

In order to prevent the profile of the optical fiber 20 from increasing, the first clad 26 may be positioned radially outwardly of the optical fiber 20 in the first section 31 . That is, the first section 31 does not need to be provided with other members such as a covering material.

Although not shown, the first section 31 of the optical fiber 20 may have a coating material arranged around the outer circumference of the first clad 26 . It is possible to protect the outside of the first section 31 , and it is also possible to suppress light leakage and emission to the outside in the first section 31 . The coating material may be a coating layer arranged on the outer peripheral surface of the first clad 26 or a sheath enclosing the first clad 26 . The covering material can be made of a resin such as an ultraviolet curable resin.

In FIG. 10 , the optical fiber 20 has a second clad 27 disposed on the outer periphery of the core 25 in the light diffusion portion 21 and has a larger surface roughness of the outer peripheral surface than the first clad 26 . It has a distally located second section 32 . By making the clad surface roughness larger in the second section 32 than in the first section 31, part of the light is confined within the core 25 and propagated to the distal side of the optical fiber 20, and the remaining light is transmitted to the second section 31. It leaks out from the clad 27 and is injected radially outward. It is preferable that the first section 31 does not emit light radially outward, or that the amount of light leakage is smaller than that of the second section 32 .

As in the first section 31 , in the second section 32 , one core 25 is preferably arranged in one second clad 27 . The first clad 26 of the first section 31 and the second clad 27 of the second section 32 may be integrally molded, and the optical fiber for the first section 31 and the optical fiber for the second section 32 are spliced in the longitudinal direction x. may have been

In the second section 32 , the second cladding 27 is preferably positioned radially outwardly of the optical fiber 20 . That is, in the second section 32, it is preferable that no member (for example, a covering material) other than the core 25 and the second clad 27 is arranged. With this configuration, light can be emitted outward in the radial direction of the shaft 10 from the second section 32 .

The surface roughness of the outer peripheral surface of the second clad 27 in the second section 32 is greater than the surface roughness of the outer peripheral surface of the first clad 26 in the first section 31 . Here, the surface roughness is the arithmetic mean roughness Ra between the reference lengths of the roughness curve in the longitudinal axis 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, and is, for example, 200 μm. The arithmetic mean roughness Ra corresponds to the arithmetic mean roughness Ra defined in JIS B 0601 (2001) and is measured according to JIS B 0633 (2001). For the measurement, a measuring machine specified in JIS B 0651 (2001) (for example, laser microscope VK-X3000 manufactured by Keyence Corporation) is used.

The average value of the surface roughness of the outer peripheral surface of the second clad 27 in the second section 32 is preferably larger than the average value of the surface roughness of the outer peripheral surface of the first clad 26 in the first section 31 . In the first section 31 , light is likely to be confined within the core 25 , and in the second section 32 , light is likely to be emitted radially outward from the second clad 27 . As a result, the light emission intensity distribution of the light diffusing portion 21 is easily made uniform in the longitudinal direction x. The average value of the surface roughness is the average value of the surface roughness values of 10 or more measurement points set so as to be aligned in the longitudinal axis direction x in the section to be measured (for example, the first section 31). .

As shown in FIG. 10, when the second section 32 is divided into a distal portion 323 and a proximal portion 324 in the longitudinal direction x, the surface roughness of the outer peripheral surface of the second clad 27 in the proximal portion 324 is is preferably smaller than the average surface roughness of the outer peripheral surface of the second clad 27 in the distal portion 323 . With this configuration, the proximal portion 324 enhances the effect of confining light within the core 25 more than the distal portion 323, while the distal portion 323 facilitates the radially outward emission of light from the second clad 27. Therefore, the emission intensity distribution of the second section 32 is easily uniformed in the longitudinal direction x.

As can be seen from FIGS. 1 and 10, the second section 32 is preferably shorter than the first section 31 in the longitudinal direction x. It becomes easier to form the light diffusing portion 21, and the flexibility of the distal end portion of the optical fiber 20 can also be increased. The length of the second section 32 in the longitudinal 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 . Also, 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. good.

As can be understood from FIG. 10 , the average thickness of the second clad 27 in the second section 32 is preferably smaller than the average thickness of the first clad 26 in the first section 31 . By adjusting the thickness of the clad in this way, light is more likely to be confined in the core 25 in the first section 31, and light is more likely to be emitted radially outward from the second clad 27 in the second section 32. . Here, the clad thickness can be measured using a laser microscope VK-X3000 manufactured by Keyence Corporation.

As shown in FIGS. 11 and 12, when the optical fiber 20 has the first section 31, the optical fiber 20 has no cladding in the light diffusing portion 21 and is located distal to the first section 31. You may have the 3rd area 33 which is carrying out. Since there is no clad in the third section 33, the light from the core 25 is emitted radially outward.

In the third section 33 , it is preferable that no clad exists in at least a part of the core 25 in the circumferential direction, and more preferably, no clad exists in the entire circumferential direction of the core 25 .

In the third section 33 , the core 25 is preferably located radially outermost in the optical fiber 20 . However, it is preferable that at least part of the third section 33 is covered with the tubular member 40 . That is, in the third section 33, it is preferable that not only the clad but also any member (for example, a covering material) other than the core 25 and the tubular member 40 is arranged.

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 a different value depending on the position in the longitudinal axis direction x.

As shown in FIGS. 11-12, the distal end of the third section 33 is preferably at the same position as the distal end of the core 25 in the longitudinal direction x. It becomes easier to form the third section 33, and the flexibility at the distal end of the optical fiber 20 can also be increased.

The surface roughness of the outer peripheral surface of the core 25 in the third section 33 is preferably larger than the surface roughness of the outer peripheral surface of the first clad 26 in the first section 31 . Light is likely to be confined within the core 25 in the first section 31 , and light is likely to be emitted radially outward from the core 25 in the third section 33 .

At least one of the second section 32 and the third section 33 is preferably arranged in the light diffusion portion 21, and both the second section 32 and the third section 33 may be arranged. As shown in FIG. 11, it is preferable that the light diffusing portion 21 has a second section 32 and a third section 33 arranged in order from the proximal side to the distal side. With this configuration, the light emission intensity distribution of the light diffusing portion 21 can be easily uniformed in the longitudinal direction x. In order to enhance this effect, it is preferable that the first section 31, the second section 32 and the third section 33 are adjacent in the longitudinal direction x.

If the optical fiber 20 has a second section 32 and a third section 33, the third section 33 is preferably shorter than the second section 32 in the longitudinal direction x as shown in FIG. With this configuration, it becomes easier to uniform the emission intensity distribution of the entire exposed portion 22 in the longitudinal direction x. A mode in which the second section 32 is shorter than the third section 33 in the longitudinal direction x is also allowed.

The length of the third section 33 in the longitudinal direction x is preferably 20% or less of the total length of the second section 32 and the third section 33, and is preferably 18% or less. More preferably, the size is 15% or less. In addition, the length of the third section 33 in the longitudinal 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 emission intensity distribution of the exposed portion 22 in the longitudinal direction x.

The average value of the surface roughness of the outer peripheral surface of the second clad 27 in the second section 32 is preferably smaller than the average value of the surface roughness of the outer peripheral surface of the core 25 in the third section 33 . This configuration makes it easier to uniformize the emission intensity distribution in the longitudinal axis direction x in each of the second section 32 and the third section 33 .

As shown in FIG. 10, 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 have to have the third section 33 in the light diffusing portion 21 . Even with the configuration having only the second section 32, the emission intensity distribution of the exposed portion 22 in the longitudinal axis direction x can be made uniform. Since the core 25 is not exposed, it also has the effect of preventing damage to the optical fiber 20 due to bending of the device 1 during the procedure.

When the optical fiber 20 has only the second section 32 in the light diffusing portion 21, the distal end of the second section 32 is preferably at the same position as the distal end of the core 25 in the longitudinal direction x. .

As shown in FIG. 12, the optical fiber 20 may have only the third section 33 in the light diffusing portion 21 . That is, the optical fiber 20 does not have to have the second section 32 in the light diffusing portion 21 . Even with the configuration having only the third section 33, the emission intensity distribution of the exposed portion 22 in the longitudinal axis direction x can be made uniform.

The second section 32 and the third section 33 can be formed by removing the clad by etching or polishing. In order to adjust the surface roughness of the second section 32 and the third section 33, the outer peripheral surface of the second clad 27 and the outer peripheral surface of the core 25 of the third section 33 may be uneven. The unevenness can be formed by mechanically or chemically roughening the surface of the core 25 of the second clad 27 or the third section 33 . Examples of methods for roughening the surface include etching, blasting, a method using a scribe, a wire brush, or sandpaper.

It is sufficient that the light diffusing portion 21 emits the first light beam for treatment. The first light beam is preferably laser light with a wavelength suitable for phototherapy such as PDT and PIT for irradiating internal tissue. In addition to the first beam, a second targeting beam may be emitted. The second light beam is a light beam emitted to grasp the treatment site before the first light beam is emitted, and preferably has a lower radiant energy than the first light beam.

As shown in FIGS. 1-2, tubular member 40 is disposed within lumen 11 of shaft 10 and covers a portion of the distal portion of optical fiber 20 . Specifically, the cylindrical member 40 partially covers the light diffusion section 21 . As can be understood from FIG. 4, the cylindrical member 40 has a shape in which the distal end 401 side is closed and the proximal end 402 side is open. 21 , and the inner peripheral surface of the distal portion 403 of the tubular member 40 is not fixed to the outer peripheral surface 23 of the light diffusing portion 21 . According to the light irradiation medical device 1, the light emitted from the light diffusing section 21 is reflected on the inner surface of the cylindrical member 40 at the portion of the light diffusing section 21 covered with the cylindrical member 40. It becomes easy to diffuse in various directions from the exposed portion 22 that is the portion of the diffusion portion 21 that is not covered with the cylindrical member 40 . As a result, the emission intensity distribution of the exposed portion 22 is more likely to be uniform in the circumferential direction p of the shaft 10 . As a result, it is possible to reduce the number of times the target tissue such as a tumor is irradiated and the number of times the position of the exposed portion 22 is adjusted with respect to the target tissue, thereby improving the efficiency of the procedure. In addition, since the inner peripheral surface of the proximal portion 404 of the cylindrical member 40 is fixed to the outer peripheral surface 23 of the light diffusing portion 21, even if the light irradiation medical device 1 is inserted into the body, the longitudinal axis direction x of the shaft 10 is maintained. Since the position of the proximal end 402 of the cylindrical member 40 is fixed so as not to shift with respect to the light diffusing portion 21, the irradiation position can be stabilized. Furthermore, since the inner peripheral surface of the distal portion 403 of the tubular member 40 is not fixed to the outer peripheral surface of the light diffusing portion 21, even when the light irradiation medical device 1 passes through a bend in the body, the distal portion 403 of the tubular member 40 is It becomes easy to follow the bending of the shaft 10 without the proximal end 401 side being stretched. As a result, the risk of breakage of the optical fiber can be reduced, and the emission intensity distribution of the exposed portion 22 can be easily made uniform in the circumferential direction p of the shaft 10 . 2 shows how the light traveling from the proximal side toward the distal side is directly emitted from the exposed portion 22, and how the light is emitted from the exposed portion 22 after being reflected by the cylindrical member 40. An example is indicated by a thick arrow.

The cylindrical member 40 covers only a part of the light diffusing section 21 and does not cover the entire light diffusing section 21 . That is, the exposed portion 22 is always formed in the light diffusion portion 21 .

The tubular member 40 is formed to extend in the longitudinal direction x of the shaft 10 . The tubular member 40 has a shape in which the distal end 401 side is closed and the proximal end 402 side is open. This shape can also be rephrased as a bottomed tubular shape in which the closed portion on the distal end 401 side is the tubular bottom. A direction parallel to the longitudinal axis direction x of the shaft 10 in the tubular member 40 is referred to as an axial direction of the tubular member 40 . As shown in FIG. 4, the tubular member 40 has an inner peripheral surface 43, an outer peripheral surface 44, an outer end surface 45 on the distal end 401 side, and an inner end surface 46 on the distal end 401 side. The inner peripheral surface 43 extends in the circumferential direction p of the shaft 10 and faces the outer peripheral surface 23 side of the optical fiber 20 . The outer peripheral surface 44 extends in the circumferential direction p of the shaft 10 and faces the inner peripheral surface 12 side of the shaft 10 . The outer end surface 45 on the distal end 401 side is a visible surface when the tubular member 40 is viewed from the distal side toward the proximal side. The inner end surface 46 on the distal end 401 side corresponds to the inner bottom surface of the bottomed cylindrical shape.

As shown in FIGS. 2 and 4 to 9, the cylindrical member 40 has a shape in which the distal end 401 side is closed and the proximal end 402 side is open. It is preferable that the light is reflected by the inner peripheral surface 43 and the inner end surface 46 of the tubular member 40 . The inner peripheral surface 43 may be composed of only the curved surface portion, may be composed of only the flat surface portion, or may be composed of a combination of the curved surface portion and the flat surface portion. The inner peripheral surface 43 preferably has a curved surface portion in order to facilitate diffusion of the light reflected by the inner peripheral surface 43 in multiple directions. Further, the inner end surface 46 may be composed of only the flat portion, may be composed of only the curved surface portion, or may be composed of a combination of the curved surface portion and the flat surface portion.

The cylindrical member 40 preferably has one lumen. Although the shape of the cylindrical member 40 is not particularly limited, it may be cylindrical, long cylindrical, or polygonal. The axial length of the tubular member 40 may be larger or smaller than the maximum outer diameter of the tubular member 40 .

As shown in FIGS. 2 and 4 to 5, the cylindrical member 40 preferably has a coil portion 41 in which a wire 42 is helically wound around the light diffusing portion 21. As shown in FIG. In the portion of the light diffusing portion 21 covered with the coil portion 41 , the light emitted from the light diffusing portion 21 is reflected by the inner surface of the coil portion 41 . It becomes easy to diffuse in various directions from the exposed portion 22 that is not exposed. The configuration of the coil portion 41 will be described later.

The cylindrical member 40 may not have a coil shape around which the wire 42 is wound, and may be a cylindrical body such as a resin tube or a metal pipe as shown in FIGS.

In order to enhance the effect of reflecting light by the inner peripheral surface 43 of the tubular member 40 , it is preferable that the light emitted from the light diffusing portion 21 does not pass through the tubular member 40 outward in the radial direction of the shaft 10 .

In the longitudinal direction x, the distal end 401 of the cylindrical member 40 is preferably located at the same position as the distal end of the light diffusing section 21 or on the distal side of the distal end of the light diffusing section 21. .

The light diffusing portion 21 has a longitudinal axis direction, and the longitudinal axis direction of the light diffusing portion 21 is parallel to the longitudinal axis direction x of the shaft 10 . As shown in FIG. 2 , the proximal end 402 of the tubular member 40 is preferably positioned distally of the midpoint 211 of the light diffusing portion 21 in the longitudinal direction. Since the exposed portion 22 can be formed long in the longitudinal direction of the light diffusing portion 21, a wide range in the longitudinal direction can be irradiated at once.

It is preferable that the tubular member 40 be arranged at a position including the distal end of the light diffusion section 21 . It is preferable that the cylindrical member 40 is not located on the proximal side of the midpoint 211 of the light diffusing portion 21 in the longitudinal direction.

It is preferable that the entire cylindrical member 40 is arranged in the lumen 11 of the shaft 10 in the longitudinal direction x.

In the longitudinal axis direction x, the length of the cylindrical member 40 can be set to be one-half or less, one-third or less, or one-fourth or less of the length of the exposed portion 22 . In addition, the length of the cylindrical member 40 in the longitudinal axis direction x may be set to 1/20 or more, 1/18 or more, or 1/15 or more of the length of the exposed portion 22 .

The tubular member 40 is preferably made of a material having a higher reflectance than the shaft 10 . This configuration makes it easier for the reflected light to diffuse on the inner surface of the cylindrical member 40 . Here, the reflectance refers to the reflectance of light emitted from the light diffusing portion 21, and the unit is %. The reflectance can be measured using a reflectance measurement system OP-RF-VIS-GT50 manufactured by Ocean Photonics.

The cylindrical member 40 is preferably made of metal, for example, radiopaque metals such as gold, silver, platinum, palladium, tungsten, tantalum, iridium and alloys thereof, stainless steel, Ni—Ti alloys. and other superelastic alloys.

The tubular member 40 may have a tubular member main body and a reflective layer disposed on the inner surface of the tubular member main body. The light from the light diffusing portion 21 can be reflected by the reflective layer regardless of the material of the cylindrical member main body. For example, a coil body or a resin tube around which a resin wire is wound may be used as the tubular member main body. The reflective layer may be provided by applying a coating agent containing a reflective material to the inner surface of the cylindrical member body, and the reflective material is applied to the inner surface of the cylindrical member body by a method such as vapor deposition, sputtering, electroplating, or chemical plating. It may be arranged by adhering. Note that the reflective layer may be a metal thin film. Reflective materials include, for example, aluminum, gold, silver, copper, tin, titanium dioxide, tantalum pentoxide, aluminum oxide, silicon dioxide, magnesium fluoride, or combinations thereof. When the tubular member 40 has a reflective layer, any of the materials listed as the constituent materials of the shaft 10 can be used for the tubular member main body.

By heating and deforming the distal end 401 side of the cylindrical member 40, the cylindrical member 40 with the distal end 401 side closed as shown in FIG. 4 can be obtained. Alternatively, a tubular coil having one lumen and a metallic member separate from the tubular coil are prepared, and the metallic member is heated and welded so as to close the opening on the distal side of the tubular coil. It is also possible to obtain a cylindrical member 40 closed at the proximal end 401 side.

When the light diffusing portion 21 is arranged at the distal end of the optical fiber 20, the light diffusing portion 21 has a distal end surface 212 as shown in FIG. In that case, it is preferable that the distal end surface 212 of the light diffusing portion 21 is not fixed to the tubular member 40 . By unfixing the distal end face 212 in this way, even when the device 1 passes through a bend in the body, the distal end 401 side of the tubular member 40 is not stretched and can easily follow the bending of the shaft 10 . As a result, the risk of breakage of the optical fiber 20 can be reduced, and the emission intensity distribution of the exposed portion 22 can be easily made uniform in the circumferential direction of the shaft 10 . The distal end surface 212 of the light diffusing portion 21 need only be fixed so as not to move with respect to the tubular member 40. As shown in FIG. It is permissible to have

The distal end surface 212 of the light diffusing portion 21 preferably has a planar shape perpendicular to the longitudinal axis direction of the optical fiber 20 as shown in FIG. It may have a planar shape, or may have a curved shape.

The fixing between the cylindrical member 40 and the light diffusing portion 21 can be performed by bonding the cylindrical member 40 and the light diffusing portion 21 or by caulking the cylindrical member 40 to fix the cylindrical member 40 to the light diffusing portion 21 . .

As shown in FIGS. 2 and 6-7, the proximal portion 404 of the tubular member 40 is preferably adhered to the light diffusing portion 21. As shown in FIG. As a result, it is possible to fix the cylindrical member 40 to the light diffusing portion 21 so as not to shift while avoiding damage to the optical fiber 20 . 2 and 6 to 7, the cylindrical member 40 and the light diffusion portion 21 are joined by the adhesive layer 38. In FIG.

Only a portion of the proximal portion 404 of the tubular member 40 may be adhered to the light diffusion portion 21 , or the entire proximal portion 404 may be adhered to the light diffusion portion 21 . Only a portion of the proximal portion 404 of the cylindrical member 40 in the circumferential direction may be adhered to the light diffusion portion 21 , or the entire circumferential direction of the proximal portion 404 may be adhered to the light diffusion portion 21 . The adhesive layer 38 may be arranged continuously or intermittently in the axial direction of the proximal portion 404 of the tubular member 40 . The adhesive layer 38 may be arranged continuously or intermittently in the circumferential direction of the proximal portion 404 of the tubular member 40 .

A polyurethane-based, epoxy-based, cyano-based, or silicone-based adhesive can be used for bonding the cylindrical member 40 and the light diffusion portion 21 . For example, the cylindrical member 40 and the light diffusing section 21 can be fixed by applying an adhesive to the outer peripheral surface of the light diffusing section 21 and then inserting the light diffusing section 21 into the inner cavity of the cylindrical member 40 .

The outer diameter of the cylindrical member 40 may be constant in the longitudinal axis direction x of the shaft 10, or the outer diameter of the cylindrical member 40 may vary depending on the position in the longitudinal axis direction x. For example, as shown in FIG. 5, it is preferable that the average inner diameter of the proximal portion 404 of the tubular member 40 is smaller than the average inner diameter of the distal portion 403 of the tubular member 40 . The proximal portion 404 is easily brought into close contact with the light diffusing portion 21 , and the cylindrical member 40 is less likely to come off from the optical fiber 20 .

Preferably, the proximal portion 404 of the cylindrical member 40 is crimped to fix the cylindrical member 40 to the light diffusing portion 21 as shown in FIG. The proximal portion 404 of the tubular member 40 is pressed radially inward and plastically deformed, so that the tubular member 40 can be crimped to the light diffusion portion 21 . While preventing an increase in the profile of the optical fiber 20 to which the tubular member 40 is attached, the tubular member 40 can be fixed to the light diffusing portion 21 so as not to shift.

Only a portion of the proximal portion 404 of the cylindrical member 40 may be crimped in the longitudinal direction x of the shaft 10, or the entire proximal portion 404 may be crimped.

A portion of the light diffusing portion 21 that is covered by the proximal portion 404 of the tubular member 40 may be tightened by the tubular member 40 to reduce its diameter. The average inner diameter of the proximal portion 404 of the tubular member 40 may be smaller than the average outer diameter of the exposed portion 22 of the light diffusing portion 20 . Since the proximal portion 404 of the tubular member 40 can be attached so as to bite into the outer surface of the light diffusing portion 20 , the tubular member 40 is less likely to come off from the optical fiber 20 .

The tubular member 40 can be crimped using a crimping tool (not shown).

The proximal portion 404 of the cylindrical member 40 may be adhered to the light diffusing portion 21 and the proximal portion 404 of the cylindrical member 40 may be crimped to fix the cylindrical member 40 to the light diffusing portion 21 . By using both the bonding method and the crimping method, the tubular member 40 can be firmly fixed to the light diffusing portion 21 so as not to be displaced.

Concavities and convexities may be arranged on the inner peripheral surface 43 of the tubular member 40 . By roughening the surface of the inner peripheral surface 43 to form fine unevenness on the order of micrometers or nanometers, reflected light can be easily diffused in multiple directions.

The concave-convex structure of the inner peripheral surface 43 of the tubular member 40 may be formed by etching, blasting, roughening the inner peripheral surface 43 of the tubular member 40 with a scribe, wire brush, or sandpaper.

In the longitudinal axis direction x of the shaft 10 , the unevenness may be arranged only on a part of the tubular member 40 , or the unevenness may be arranged on the entirety of the tubular member 40 . Moreover, in the circumferential direction of the shaft 10 , the unevenness may be provided only on a part of the tubular member 40 , or the unevenness may be provided on the entirety of the tubular member 40 .

As shown in FIG. 9 , it is preferable that a reflector 17 that reflects light from the light diffusing portion 21 is arranged on the distal end 401 side of the tubular member 40 . The reflector 17 is, for example, a mirror arranged so that the reflecting surface faces the proximal side. With this configuration, light can be reflected not only by the inner peripheral surface of the cylindrical member 40 but also by the reflector 17, so that the reflected light can be easily diffused from the exposed portion 22 in various directions.

The surface of reflector 17 is preferably made of aluminum, gold, silver, copper, tin, titanium dioxide, tantalum pentoxide, aluminum oxide, silicon dioxide, or magnesium fluoride.

As shown in FIG. 9, the reflector 17 may be arranged on the most distal side of the lumen of the coil member 40 . In that case, the inner end surface 46 of the coil member 40 and the distal end surface of the reflector 17 may be in contact with each other.

If the optical fiber 20 has a second section 32, the tubular member 40 preferably covers a portion of the second section 32 and a portion of the distal portion of the second section 32, as shown in FIG. is more preferably covered. The light emitted radially outward from the light diffusing portion 21 can be reflected by the portion of the second section 32 covered with the cylindrical member 40 . In addition, it is preferable that the cylindrical member 40 does not cover the entire second section 32 .

As shown in FIGS. 11 and 12, when the optical fiber 20 has the third section 33, the tubular member 40 preferably covers at least a portion of the third section 33. As shown in FIGS. More preferably, the cylindrical member 40 covers at least a portion of the third section 33 in the longitudinal direction x. The light emitted radially outward from the light diffusing portion 21 can be reflected by the portion of the third section 33 covered with the cylindrical member 40 . In the longitudinal direction x, the tubular member 40 may cover only a portion of the third section 33 as shown in FIG. In that case, the tubular member 40 preferably covers a portion of the distal portion of the third section 33 . Moreover, in the longitudinal axis direction x, the tubular member 40 may cover the entire third section 33 as shown in FIG. 11 .

If the optical fiber 20 has the second section 32 and the third section 33 , the proximal end 402 of the tubular member 40 may be positioned distally from the distal end of the second section 32 . Thus, the cylindrical member 40 may be arranged only in the third section 33 and not arranged in the second section 32 .

When the optical fiber 20 has the second section 32 and the third section 33 , the proximal end 402 of the tubular member 40 may be positioned closer to the proximal side than the distal end of the second section 32 . In this manner, the cylindrical member 40 may be arranged in part of the second section 32 and at least part of the third section 33 .

When the cylindrical member 40 partially covers the second section 32 , it is preferable that the cylindrical member 40 is in contact with the outer peripheral surface of the second clad 27 of the second section 32 . Moreover, when the tubular member 40 covers at least a portion of the third section 33 , it is preferable that the tubular member 40 is in contact with the outer peripheral surface of the core 25 of the third section 33 .

As shown in FIG. 2 , it is preferable that the outer peripheral surface 23 of the light diffusing portion 21 is arranged apart from the inner peripheral surface 12 of the shaft 10 . More preferably, the outer peripheral surface 23 of the light diffusing portion 21 is arranged apart from the inner peripheral surface 12 of the shaft 10 in the exposed portion 22 . Further, it is more preferable that the outer peripheral surface 23 of the light diffusing portion 21 is separated from the inner peripheral surface 12 of the shaft 10 over the entire lengthwise direction x. By arranging the light diffusing portion 21 in the lumen 11 of the shaft 10 in this way, the flexibility of the shaft 10 at the light diffusing portion 21 can be maintained.

It is preferable that the outer peripheral surface 23 of the light diffusion portion 21 be separated from the inner peripheral surface 12 of the shaft 10 over the entire circumferential direction p of the shaft 10 . Moreover, it is preferable that the distance between the outer peripheral surface 23 of the light diffusion portion 21 and the inner peripheral surface 12 of the shaft 10 in the radial direction of the shaft 10 be uniform at any position in the circumferential direction p of the shaft 10 . As a result, the emission intensity distribution of the exposed portion 22 can be easily uniformed in the circumferential direction p.

As shown in FIG. 2 , the outer peripheral surface 44 of the cylindrical member 40 is preferably in contact with the inner peripheral surface 12 of the shaft 10 . With this configuration, the position of the cylindrical member 40 relative to the shaft 10 is less likely to shift, and the position of the exposed portion 22 is fixed, so that the irradiation position can be stabilized. The tubular member 40 may be inserted into the inner cavity 11 of the shaft 10 , and the outer peripheral surface 44 of the tubular member 40 may not be fixed to the inner peripheral surface 12 of the shaft 10 .

Below, the coil portion 41 preferably included in the cylindrical member 40 and the wire rod 42 forming the coil portion 41 will be described.

The wire 42 has a distal end and a proximal end along its longitudinal axis. The wire 42 may be composed of a single linear member from the distal end to the proximal end, or the wire 42 may be composed of a plurality of linear members connected to each other in the longitudinal direction thereof.

The cross-sectional shape of the wire rod 42 perpendicular to the longitudinal axis direction may be circular, oval, polygonal, or a combination thereof. The oval shape includes an elliptical shape, an egg shape, and a rounded rectangular shape. The same applies to other descriptions in this specification.

The wire diameter (thickness) of the wire 42 forming the coil portion 41 and the number of turns of the wire 42 are not particularly limited. The axial length of the coil portion 41 may be larger or smaller than the maximum outer diameter of the coil portion 41 .

The coil part 41 may be a single-layer wound coil or a multi-layer wound coil. FIG. 1 shows an example in which the coil portion 41 is composed only of a single-layer wound coil. The coil portion 41 may have a first coil portion that is wound in a single layer and a second coil portion that is wound in multiple layers.

The pitch P of the coil portions 41 is not particularly limited, and may be constant in the axial direction or may vary depending on the position in the axial direction. The pitch P is the distance between the central axes of two adjacent wire rods 42 forming the coil portion 41 in the axial direction, as shown in FIG.

Although the coil portion 41 may have a gap between the wire rods 42 adjacent in the axial direction, it is preferable that the gap between the wire rods 42 adjacent to each other is not too large. This is because if too much light leaks through the gaps between the adjacent wires 42, the light emission intensity at the exposed portion 22 may be reduced. Therefore, as shown in FIG. 1, the coil portion 41 preferably has a first pitch portion 48 having a pitch of twice or less than the wire diameter of the wire rod 42 .

As shown in FIG. 1 , in the first pitch portion 48 , the coil portion 41 may have the same pitch as the wire diameter of the wire rod 42 . Such coils are commonly referred to as tight wound coils. A tightly wound coil is preferable because there is no gap between two adjacent wire rods 42 and light is less likely to leak from the coil portion 41 .

When the wire diameter of the wire 42 changes in its longitudinal axis direction (for example, when there is a large-diameter portion and a small-diameter portion with a smaller wire diameter than the large-diameter portion), the first pitch portion 48 , the coil portion 41 may have a pitch smaller than the wire diameter of the wire 42 .

In the first pitch portion 48, the coil portion 41 may have a pitch of 1.1 times or more that of the wire 42, or may have a pitch of 1.2 times or more. Further, in the first pitch portion 48, the coil portion 41 may have a pitch of 1.9 times or less the wire diameter of the wire rod 42, or may have a pitch of 1.8 times or less. By setting the pitch in this way, it is possible to suppress leakage of light from the coil portion 41, which is preferable.

The first pitch portion 48 may constitute only a part of the coil portion 41 in the axial direction. Further, the first pitch portion 48 may constitute the entire axial direction of the coil portion 41 .

It is preferable that the coil portion 41 constitutes only a part of the tubular member 40 in the axial direction. For example, when the cylindrical member 40 has a trunk portion extending in the circumferential direction of the shaft 10 and a bottom portion positioned distally from the trunk portion, the trunk portion may be the coil portion 41 . preferable.

When the cylindrical member 40 has the coil portion 41, at least the first pitch of the coil portion 41 counted from the proximal side is fixed to the light diffusing portion 21 as shown in FIGS. More preferably, at least the first and second pitches of the coil portion 41 are fixed to the light diffusion portion 21, and at least the first and third pitches of the coil portion 41 are fixed to the light diffusion portion 21. is more preferred. In addition, counting from the distal side, it is preferable that at least the first pitch of the coil portion 41 is not fixed to the light diffusion portion 21, and at least the first and second pitches of the coil portion 41 are fixed to the light diffusion portion 21. More preferably, at least the first to third pitches of the coil portion 41 are not fixed to the light diffusing portion 21 .

When the cylindrical member 40 has the coil portion 41, at least the first pitch of the coil portion 41 counted from the proximal side as shown in FIG. More preferably, at least the first to second pitches of the coil portion 41 are adhered to the outer peripheral surface of the light diffusion portion 21, and at least the first to third pitches of the coil portion 41 are adhered to the outer peripheral surface of the light diffusion portion 21. It is even more preferable that it is adhered to the

When the tubular member 40 has the coil portion 41, as shown in FIG. More preferably, at least the first and second pitches of the coil portion 41 are crimped, and more preferably at least the first and third pitches of the coil portion 41 are crimped.

A plurality of protrusions 491 may be arranged on the inner peripheral surface 43 of the cylindrical member 40 as shown in FIGS. 2 and 4 or FIGS. As a result, it is preferable that the recess 492 is arranged between the two protrusions 491 . Reflected light is easily diffused in multiple directions by the protrusions 491 and the recesses 492 of the inner peripheral surface 43 .

It is preferable that a plurality of protrusions 491 be arranged in the longitudinal axis direction x on the inner peripheral surface 43 of the cylindrical member 40 . As a result, it is preferable that the recess 492 is arranged between the two protrusions 491 . Reflected light is easily diffused in multiple directions by the protrusions 491 and the recesses 492 of the inner peripheral surface 43 .

The protrusions 491 and the recesses 492 may be periodically arranged on the inner peripheral surface 43 of the tubular member 40, or the protrusions 491 and the recesses 492 may be randomly arranged.

As shown in FIGS. 4 and 8 , in the cross section along the longitudinal axis direction x of the shaft 10 , the protrusions 491 and the recesses 492 are alternately arranged in the longitudinal axis direction x of the shaft 10 on the inner peripheral surface of the cylindrical member 40 . You can stay. Although not shown, in a cross section perpendicular to the longitudinal axis direction x of the shaft 10, the convex portions 491 and the concave portions 492 may be alternately arranged in the circumferential direction p of the shaft 10 on the inner peripheral surface 43 of the tubular member 40. .

The inner peripheral surface of the proximal portion 404 of the tubular member 40 may have a greater surface roughness than the inner peripheral surface of the distal portion 403 of the tubular member 40 . The inner peripheral surface of the proximal portion 404 of the tubular member 40 and the inner peripheral surface of the distal portion 403 of the tubular member 40 may have the same surface roughness.

When the tubular member 40 has the coil portion 41, the wire rod 42 is wound, and as a result, in the cross section along the longitudinal axis direction x of the shaft 10 as shown in FIG. may be arranged so that the convex portions 491 of In order to form the convex portion 491 with the wire rod 42, the shape of the cross section perpendicular to the longitudinal axis direction of the wire rod 42 is preferably circular or oval.

As shown in FIG. 8 , the convex portion 491 may be a protrusion that is arranged on the inner peripheral surface 43 of the tubular member 40 and protrudes toward the axial center of the tubular member 40 . The provision of such protrusions also facilitates diffusion of the reflected light in multiple directions.

1: Light irradiation medical device 10: Shaft 20: Optical fiber 21: Light diffusion part 22: Exposed part 25: Core 26: First clad 27: Second clad 31: First section 32: Second section 33: Third section 40 : Cylindrical member 41: Coil portion 60: Handle x: Longitudinal axis direction p: Circumferential direction

Claims (12)

a shaft having longitudinal distal and proximal ends and having a lumen extending longitudinally;
an optical fiber disposed in the lumen of the shaft;
a tubular member disposed in the lumen of the shaft and covering a portion of the distal portion of the optical fiber;
The optical fiber has a light diffusing portion extending in the longitudinal direction in a predetermined section of the distal portion thereof and emitting light outward in the radial direction of the shaft,
The cylindrical member covers a part of the light diffusing section,
The cylindrical member has a shape with a distal end side closed and a proximal end side open,
The inner peripheral surface of the proximal portion of the cylindrical member is fixed to the outer peripheral surface of the light diffusion portion,
The light irradiation medical device, wherein the inner peripheral surface of the distal portion of the tubular member is not fixed to the outer peripheral surface of the light diffusing portion. 2. The light irradiation medical device according to claim 1, wherein a distal end face of said light diffusing portion is not fixed to said cylindrical member. The light irradiation medical device according to claim 1 or 2, wherein the proximal portion of the cylindrical member is adhered to the light diffusion portion. The light irradiation medical device according to any one of claims 1 to 3, wherein the average inner diameter of the proximal portion of the tubular member is smaller than the average inner diameter of the distal portion of the tubular member. The light irradiation medical device according to any one of claims 1 to 4, wherein the proximal portion of the tubular member is crimped to fix the tubular member to the light diffusing section. The light irradiation medical device according to any one of claims 1 to 5, wherein the proximal end of the tubular member is located on the distal side of the midpoint of the light diffusing portion in the longitudinal direction. The light irradiation medical device according to any one of claims 1 to 6, wherein the outer peripheral surface of the light diffusing portion is arranged apart from the inner peripheral surface of the shaft. The light irradiation medical device according to any one of claims 1 to 7, wherein the outer peripheral surface of the tubular member is in contact with the inner peripheral surface of the shaft. The light irradiation medical device according to any one of claims 1 to 8, wherein the cylindrical member has a coil portion in which a wire is spirally wound around the light diffusing portion. The light irradiation medical device according to any one of claims 1 to 9, wherein the coil portion has a first pitch portion having a pitch of twice or less than the wire diameter of the wire. The optical fiber has a core extending along the longitudinal axis,
The optical fiber has a first section having a first clad disposed around the core,
The optical fiber has, in the light diffusing portion, a second clad disposed on the outer periphery of the core and having a surface roughness of an outer peripheral surface larger than that of the first clad, and located on the distal side of the first section. The light irradiation medical device according to any one of claims 1 to 10, which has a second section that The optical fiber has a core extending along the longitudinal axis,
The optical fiber has a first section having a first clad disposed around the core,
12. The optical fiber according to any one of claims 1 to 11, wherein the light diffusing portion has a third section in which the clad does not exist and which is located on the distal side of the first section. light irradiation medical device.

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