Irradiation system, irradiation sheet, scattering light fiber, manufacturing method of scattering light fiber, and sterilization method

Abstract

To provide an irradiation system capable of appropriately sterilizing the surface of an instrument arranged in the body tissue or in the body.SOLUTION: An irradiation system includes a light source (11) and an irradiation sheet (12). The irradiation sheet includes one or more optical fibers (5) arranged in a sheet form for propagating an ultraviolet ray and emitting an ultraviolet ray from the lateral face, is deformable along the body tissue or deformable along an instrument arranged in the body, and sterilizes the body tissue opposed to the irradiation sheet or the surface of the instrument with the emitted ultraviolet ray.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an irradiation system, an irradiation sheet, a light-scattering optical fiber, a method for manufacturing a light-scattering optical fiber, and a sterilization method. [Background technology]

[0002] Conventionally, a method has been proposed for efficiently sterilizing bacteria present on the surface of an instrument (medical instrument) by irradiating the surface with light. For example, Patent Document 1 discloses an optical transmission device that irradiates the surface of an instrument with light (visible light, near ultraviolet light) scattered from a light diffusing fiber embedded in the surface of the instrument, thereby sterilizing bacteria present on the surface.

[0003] Patent Document 2 discloses an ultraviolet irradiation device that sterilizes the inside of the human body through an optical fiber inserted into the body. Patent Document 3 discloses a wound irradiation method that irradiates a wound tissue area and a wound cavity surface with light through an optical fiber inserted into the body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-072862 A [Patent Document 2] JP 2017-221473 A [Patent Document 3] JP 2019-509783 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, Patent Document 1 is intended, for example, to sterilize instruments outside the body, and is not intended to sterilize instruments placed inside the body or bacteria present in body tissue (for example, bacteria present at the interface between an instrument placed inside the body and body tissue).

[0006] Furthermore, Patent Documents 2 and 3 do not disclose sterilization of bacteria present at the interface between an instrument placed inside the body and body tissue.

[0007] One aspect of the present invention has been made in consideration of the above problems, and provides an irradiation system that can appropriately sterilize body tissue or the surface of an instrument to be placed inside the body. [Means for solving the problem]

[0008] In order to solve the above problems, an irradiation system according to one embodiment of the present invention includes a light source that generates ultraviolet light and an irradiation sheet, the irradiation sheet including one or more optical fibers arranged in a sheet shape that propagates ultraviolet light and emits ultraviolet light from the side, and is deformable along body tissue or along an instrument placed inside the body, and the emitted ultraviolet light sterilizes the body tissue facing the irradiation sheet or the surface of the instrument.

[0009] The irradiation sheet may include a plurality of the optical fibers arranged in a sheet shape.

[0010] The optical fibers may be bonded to one another. The irradiation sheet may be a fabric in which the optical fibers are woven.

[0011] The optical fiber may also include scattering particles that scatter ultraviolet light.

[0012] The optical fiber may have a hollow core and a light-reflecting coating that reflects ultraviolet light from the hollow core, and the light-reflecting coating may cover a portion of the inner wall of the hollow core without covering the remainder.

[0013] The irradiation system may also include the device to be placed inside the body, and the irradiation sheet may be arranged on an outer surface of the device.

[0014] In order to solve the above problems, an irradiation sheet according to one embodiment of the present invention includes one or more optical fibers arranged in a sheet shape, which propagate ultraviolet light and emit the ultraviolet light from a side, and is deformable along body tissue or along an instrument placed inside the body.

[0015] In order to solve the above problems, a method for manufacturing a light-scattering optical fiber according to one embodiment of the present invention includes a first introduction step of introducing scattering particles into a hollow core by immersing an end face of an optical fiber having a hollow core into a suspension containing scattering particles.

[0016] The method for producing the light-scattering optical fiber may also include an evaporation step of evaporating a liquid contained in the suspension introduced into the hollow core.

[0017] In addition, the manufacturing method of the light-scattering optical fiber may include a transporting step of transporting the scattering particles within the hollow core by immersing the end face of the optical fiber in a liquid that does not contain the scattering particles after the introduction step, thereby forming the optical fiber having a section in which the scattering particles are arranged and a section in which the scattering particles are not arranged.

[0018] In addition, the manufacturing method for the light-scattering optical fiber may include, after the introduction step, a second introduction step of introducing the scattering particles into the hollow core by immersing an end face of an optical fiber having a hollow core in a suspension having a different concentration of the scattering particles than that in the first introduction step.

[0019] In order to solve the above problems, a light-scattering optical fiber according to one embodiment of the present invention comprises a hollow core and a light-reflecting coating that reflects ultraviolet light from the hollow core, the light-reflecting coating covering a portion of the inner wall of the hollow core and not covering the remainder.

[0020] In order to solve the above problems, a light-scattering optical fiber according to one aspect of the present invention comprises a hollow core and scattering particles disposed within the hollow core.

[0021] In order to solve the above problems, a sterilization method according to one embodiment of the present invention includes the steps of placing an irradiation sheet, which is arranged in a sheet-like shape and includes one or more optical fibers that propagate ultraviolet light and emit ultraviolet light from the sides, along body tissue of a non-human animal or inside the body of a non-human animal, and sterilizing the body tissue with the ultraviolet light emitted from the optical fibers. Effect of the Invention

[0022] According to one aspect of the present invention, the surface of body tissue or an instrument to be placed inside the body can be appropriately sterilized. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of an irradiation system according to a first embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing the killing of bacteria by the irradiation system. [Diagram 3] FIG. 2 is a diagram showing an example of a configuration of an irradiation sheet of the irradiation system. [Figure 4] 11A and 11B are diagrams illustrating another example of the configuration of the irradiation sheet. [Diagram 5] 4A and 4B are diagrams illustrating an example of the configuration of an optical fiber included in the irradiation sheet. [Figure 6] 4A to 4C are diagrams illustrating another example of the configuration of the optical fiber. [Figure 7] 11A and 11B are diagrams illustrating still another example of the configuration of the optical fiber. [Figure 8] 11A and 11B are diagrams showing the results of a simulation of light irradiation from the side surface of the optical fiber. [Figure 9] 11A and 11B are diagrams illustrating still another example of the configuration of the optical fiber. [Figure 10] 11A and 11B are diagrams illustrating still another example of the configuration of the optical fiber. [Figure 11] 11A and 11B are diagrams illustrating still another example of the configuration of the optical fiber. [Figure 12] 11A and 11B are diagrams illustrating still another example of the configuration of the optical fiber. [Figure 13]3A to 3C are diagrams illustrating an example of the configuration of an end portion of the optical fiber. [Figure 14] 4A to 4C are diagrams illustrating another example of the configuration of the end portion of the optical fiber. [Figure 15] 1 is a flow chart illustrating a method for making a light scattering optical fiber. [Figure 16] 4 is a flowchart showing a sterilization method using the irradiation system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] [Embodiment 1] (Schematic configuration of the irradiation system 10) Fig. 1 is a schematic diagram showing the configuration of an irradiation system 10 applied to an instrument (medical instrument) placed inside the body. Fig. 2 is a schematic diagram showing sterilization of bacteria by the irradiation system 10. In this embodiment, a drive line 2 connecting an auxiliary artificial heart 1 placed inside the body and a power source 3 placed outside the body will be described as an example of an instrument placed inside the body.

[0025] The driveline 2 extends from the outside of the body to the inside of the body by penetrating a surface layer 4, which is a body tissue that separates the inside of the body from the outside of the body. The surface layer 4 includes, from the outside of the body, skin 4a, subcutaneous tissue 4b, and muscle 4c.

[0026] 1 and 2, the irradiation system 10 includes a light source 11 and an irradiation sheet 12. The irradiation system 10 in this embodiment is a system for sterilizing the interface between a driveline 2 and body tissue.

[0027] The light source 11 generates light in a predetermined wavelength range. For example, the light source 11 is an ultraviolet light emitting device that generates ultraviolet light.

[0028] The irradiation sheet 12 includes one or more optical fibers 5 arranged in a sheet shape. Here, the one or more optical fibers 5 being "arranged in a sheet shape" refers to the one or more optical fibers 5 being arranged to form a flat or curved surface (for example, a side surface of a cylindrical three-dimensional object). A detailed configuration of the irradiation sheet 12 will be described later with reference to Figs. 3 and 4. Each of the one or more optical fibers 5 is connected to the light source 11 via an arbitrary optical path.

[0029] The optical fiber 5 propagates ultraviolet light. Specifically, the optical fiber 5 propagates ultraviolet light generated by the light source 11 and incident from one end. The material of the core of the optical fiber 5 may be a material capable of propagating ultraviolet light, such as quartz. The material of the core of the optical fiber 5 is preferably pure quartz, but may also be quartz doped with a dopant such as germanium, which has an absorption peak and an absorption edge outside the wavelength region of ultraviolet light (does not have an absorption band within the wavelength region of ultraviolet light). Furthermore, the optical fiber 5 may be a fiber with a hollow light propagation region, such as a photonic band gap fiber, in which the hollow portion is filled with a vacuum or an inert gas.

[0030] The optical fiber 5 is configured to emit ultraviolet light from a side surface. That is, the optical fiber 5 functions as a light scattering optical fiber that propagates ultraviolet light and emits a portion of the propagated ultraviolet light from a side surface. The optical fiber 5 may be configured to emit ultraviolet light from a side surface at a predetermined position in the axial direction. The emitted ultraviolet light is irradiated onto body tissue facing the irradiation sheet 12 (see FIG. 2). A detailed configuration of the optical fiber 5, which enables the optical fiber 5 to function as a light scattering optical fiber, will be described later with reference to FIGS. 5 to 12.

[0031] The irradiation sheet 12 is deformable along the body tissue or along the instrument placed in the body. That is, the irradiation sheet 12 is deformable to match the shape of the body tissue or the instrument placed in the body. In this embodiment, the irradiation sheet 12 is placed on the outer surface of the driveline 2, which has a circular cross-sectional shape. The irradiation sheet 12 may be placed so as to surround the outer surface of the driveline 2 at least at the interface between the driveline 2 and the body tissue.

[0032] As described above, the irradiation system 10 sterilizes the body tissue facing the irradiation sheet 12 or the surface of the instrument placed inside the body (specifically, the outer surface of the instrument (the surface facing the body tissue)) by the emitted ultraviolet light. With this configuration, the irradiation system 10 can irradiate the ultraviolet light to a desired area of ​​the body tissue or a desired area of ​​the surface of the instrument. For example, by disposing the irradiation sheet 12 on the outer peripheral surface of the driveline 2 extending from outside the body to inside the body through a penetration part of the human skin, bacteria present at the interface between the driveline 2 and the body tissue at the penetration part can be sterilized. Since the irradiation sheet 12 can be deformed along the body tissue or the instrument placed inside the body, the irradiation sheet 12 can be disposed between the instrument placed inside the body and the body tissue. Therefore, even if a minute wound or bleeding occurs in the skin around the driveline 2 and bacteria enters, the irradiation system 10 can appropriately sterilize the outer surface of the body tissue or the instrument placed inside the body.

[0033] (About ultraviolet rays) In this embodiment, the wavelength region of the light irradiated to the body tissue is 100 to 400 nm, which is the wavelength region of ultraviolet light. That is, the light irradiated to the body tissue is ultraviolet light. Ultraviolet light can effectively sterilize or inactivate bacteria. Preferably, the wavelength region of the light irradiated to the body tissue is 200 to 300 nm. Ultraviolet light with a wavelength of 200 to 300 nm can sterilize or inactivate bacteria more efficiently than ultraviolet light outside the range. The wavelength region of the light irradiated to the body tissue may be 200 nm to 250 nm. Since the absorption peak of DNA is at 260 nm, it is preferable that the light irradiated to the body tissue does not include light with a wavelength of 260 nm. More preferably, the light irradiated to the body tissue includes light with a wavelength of 222 nm. In addition to having a sufficient bactericidal effect, ultraviolet light with a wavelength of 222 nm has been confirmed to be safe when irradiated to body tissue in a specified amount. The peak wavelength of the light irradiated to the body tissue may be 222 nm. Moreover, the light irradiated to the body tissue may be continuous light or pulsed light.

[0034] (Configuration of irradiation sheet) 3 and 4 are diagrams showing some examples of the configuration of the irradiation sheet 12. Hereinafter, a detailed configuration of the irradiation sheet 12 for disposing the irradiation sheet 12 on the outer surface of the driveline 2 will be described.

[0035] Reference numeral 3001 in FIG. 3 indicates a state in which an example of the irradiation sheet 12 is arranged along the outer surface of the driveline 2. Reference numeral 3002 in FIG. 3 indicates a state in which the irradiation sheet 12 is virtually unfolded. As shown in FIG. 3, the irradiation sheet 12 includes a plurality of optical fibers 5 arranged in a sheet shape. The plurality of optical fibers 5 are wound in a spiral shape (so that the winding angle θ is constant) on the outer surface of the driveline 2. The plurality of optical fibers 5 are each provided at a predetermined interval in the circumferential direction of the driveline 2. The diagram indicated by reference numeral 3002 in FIG. 3 is merely a virtually unfolded diagram, and each optical fiber 5 is connected in a spiral shape without being broken.

[0036] The winding angle θ of the optical fiber 5 has a minimum winding angle determined from the diameter of the drive line 2. When the optical fiber 5 is wound around the drive line 2 at a winding angle θ equal to or greater than the minimum winding angle, the optical fiber 5 can propagate light. For example, the diameter of the drive line 2 of the auxiliary artificial heart 1 is typically 8 mm. In this case, the minimum winding angle is 75.5°, on the assumption that the minimum bending radius of the optical fiber when propagating light is approximately 10 times the diameter of the optical fiber. The winding angle θ is the angle between the optical fiber 5 and a straight line perpendicular to the axial direction of the optical fiber 5 when the irradiation sheet 12 is deployed. The optical fibers 5 may be connected to each other, or may not be connected to each other. The irradiation sheet 12 may be a collection of multiple optical fibers 5 wound around the drive line 2 individually. The irradiation sheet 12 may also be a biocompatible resin film on which multiple optical fibers 5 are bonded. The resin film on which the multiple optical fibers 5 are provided may be wound around the drive line 2.

[0037] According to such a configuration, for example, a plurality of optical fibers 5 can be arranged along the surface of a linear instrument (driveline 2) so as to cover the surface.

[0038] Reference numeral 4001 in Fig. 4 indicates a state in which another example of the irradiation sheet 12 is arranged along the outer surface of the driveline 2. Reference numeral 4002 in Fig. 4 indicates a state in which the irradiation sheet 12 is unfolded. As shown in Fig. 4, the irradiation sheet 12 includes a plurality of optical fibers 5 arranged in a sheet shape. The plurality of optical fibers 5 are arranged on the outer surface of the driveline 2 along the axial direction of the driveline 2. The plurality of optical fibers 5 are each provided at a predetermined interval in the circumferential direction of the driveline 2.

[0039] The irradiation sheet 12 further includes a plurality of connecting members 6 for interweaving and connecting the plurality of optical fibers 5. The plurality of connecting members 6 are arranged along the circumferential direction of the driveline 2. The plurality of connecting members 6 are each provided at a predetermined interval in the axial direction of the driveline 2. That is, the plurality of optical fibers 5 and the plurality of connecting members 6 are arranged in a lattice pattern when the irradiation sheet 12 is unfolded.

[0040] The optical fibers 5 may be bonded to each other. In particular, the coupling member 6 is, for example, a biocompatible fiber (for example, polyester). The optical fibers 5 may be bonded to each other via such a fiber.

[0041] The irradiation sheet 12 may also be a fabric in which a plurality of optical fibers are woven. In particular, the connecting member 6 is, for example, a biocompatible fiber or optical fiber. In this case, the irradiation sheet 12 is a fabric in which a plurality of optical fibers 5 arranged along the axial direction of the driveline 2 and a plurality of optical fibers as a plurality of connecting members 6 arranged along the circumferential direction of the driveline 2 are woven. If the plurality of optical fibers 5 that propagate ultraviolet light are treated as warp threads, the plurality of connecting members 6 function as weft threads. The irradiation sheet may also be a fabric in which a plurality of optical fibers 5 are woven with a plurality of connecting members 6. The optical fibers as the connecting members 6 may not propagate ultraviolet light.

[0042] According to such a configuration, the irradiation sheet 12 can be arranged according to the size of the instrument to be placed inside the body. In addition, the bending radius of the optical fibers 5 that scatter ultraviolet light can be made larger than that of the example in Fig. 3, and the ultraviolet light can be propagated appropriately.

[0043] (Optical fiber configuration) 5 is a diagram showing an example of the configuration of the optical fiber. Hereinafter, a detailed configuration of the optical fiber 5 included in the irradiation sheet 12, so that the optical fiber 5 functions as a light scattering optical fiber, will be described.

[0044] Reference numeral 5001 in Fig. 5 indicates a schematic perspective view of an optical fiber 5 which is a glass fiber. Reference numeral 5002 in Fig. 5 indicates a cross-sectional view of the optical fiber 5 taken along a longitudinal section including a scatterer 53. As shown in Fig. 5, the optical fiber 5 includes a core 51 which is glass having a relatively high refractive index, and a cladding 52 which is glass having a relatively low refractive index.

[0045] The refractive indices of the core 51 and the cladding 52 are designed so that light (ultraviolet light used in the irradiation system 10) incident on the core undergoes total reflection and propagates through the optical fiber 5. The material of the core 51 is, for example, quartz with a high refractive index. The material of the core 51 is preferably pure quartz, but may be quartz doped with a dopant that increases the refractive index, such as germanium or phosphorus. The material of the cladding 52 is, for example, quartz with a lower refractive index than the core 51. The material of the cladding 52 may be quartz doped with a dopant that decreases the refractive index, such as fluorine or boron.

[0046] Moreover, the optical fiber 5 includes a scatterer 53 at a predetermined position in the core 51 in the axial direction of the optical fiber 5 (a position where light is desired to be scattered from the outer surface of the optical fiber 5). The scatterer 53 may be a scattering particle having an absorption band (from one absorption end to the other absorption end) outside the wavelength region of the ultraviolet light used in the irradiation system 10 (i.e., scattering ultraviolet light). The scattering particle is, for example, boron nitride. The scatterer 53 may be an air bubble having an absorption band outside the wavelength region of the ultraviolet light used in the irradiation system 10. The air bubble is, for example, air or an inert gas. A manufacturing method of the optical fiber 5 in which the scatterer 53 is disposed at a predetermined position in the axial direction of the optical fiber 5 will be described later with reference to FIG. 15.

[0047] Reference numeral 5003 in Fig. 5 indicates a state in which light propagating through the optical fiber 5 is emitted from the side surface of the optical fiber 5. As shown by reference numeral 5003 in Fig. 5, when light propagating through the optical fiber 5 is irradiated onto the scatterer 53, scattered light is generated that is incident on the cladding 52 at an incident angle less than the critical angle. This achieves light irradiation from the side surface of the optical fiber 5. In other words, the optical fiber 5 functions as a light scattering optical fiber.

[0048] Fig. 6 is a diagram showing another example of the configuration of the optical fiber. The optical fiber included in the irradiation sheet 12 may be an optical fiber 5A shown in Fig. 6, instead of the optical fiber 5 shown in Fig. 5. The optical fiber 5A differs from the optical fiber 5 in that, as a configuration for achieving light irradiation from the side surface of the optical fiber, a scattering structure 53A is formed on the outer surface of the core 51, instead of a configuration in which a scatterer 53 is disposed in the core 51. The detailed configuration of such an optical fiber 5A will be described below.

[0049] Reference numeral 6001 in Fig. 6 indicates a schematic perspective view of an optical fiber 5A, which is a glass fiber. Reference numeral 6002 in Fig. 6 indicates a cross-sectional view of the optical fiber 5A cut along a longitudinal section including a scattering structure 53A. As shown in Fig. 6, the optical fiber 5A includes a scattering structure 53A on the outer surface of a core 51 at a predetermined position in the axial direction of the optical fiber 5A.

[0050] Reference numeral 6003 in FIG. 6 indicates a state in which light propagating through the optical fiber 5 is emitted from the side surface of the optical fiber 5. As indicated by reference numeral 6003 in FIG. 6, the scattering structure 53A is, for example, an uneven structure formed on the outer surface of the core 51. The light propagating through the optical fiber 5 is incident on the cladding 52 at an incident angle less than the critical angle in the scattering structure 53A. This is because the direction of the interface between the core 51 and the cladding 52 is changed from the direction along the side surface of the optical fiber 5 (to the direction perpendicular to the side surface of the optical fiber 5 in the example shown in FIG. 6) in the scattering structure 53A. This achieves light irradiation from the side surface of the optical fiber 5.

[0051] 7 is a diagram showing another example of the configuration of the optical fiber. As the optical fiber included in the irradiation sheet 12, the optical fiber 5B shown in FIG. 7 may be adopted instead of the optical fiber 5 shown in FIG.

[0052] Reference numeral 7001 in Fig. 7 indicates a schematic perspective view of an optical fiber 5B, which is a glass fiber having a hollow structure. Reference numeral 7002 in Fig. 7 indicates a cross-sectional view of the optical fiber 5B in a first region R1. Reference numeral 7003 in Fig. 7 indicates a cross-sectional view of the optical fiber 5B in a second region R2. As shown in Fig. 7, the optical fiber 5B includes a core region 51B (hollow core), a cladding 52B, and a light reflecting film 54B.

[0053] The core region 51B is hollow and is a vacuum, air, or an inert gas. The material of the cladding 52B is, for example, quartz. The material of the cladding 52B is preferably pure quartz, but may be quartz doped with a dopant such as fluorine having an absorption band outside the wavelength region of the ultraviolet light used in the irradiation system 10. The light reflecting film 54B is applied to the inner wall of the core region 51B, and reflects the ultraviolet light propagating through the core region 51B to confine it within the core region 51B. The light reflecting film 54B preferably includes a material having a high reflectance of ultraviolet light, such as aluminum.

[0054] The light reflecting film 54B covers a part of the inner wall of the core region 51B, but does not cover the rest. In an example shown in FIG. 7, the light reflecting film 54B is provided in a second region R2 excluding a predetermined first region R1 in the axial direction of the optical fiber 5B. The light reflecting film 54B is not provided in the first region R1 of the optical fiber 5B. When the light source 11 is an optical lamp, a part of the ultraviolet light enters the optical fiber 5B from a direction other than the axial direction of the optical fiber 5B. Therefore, the ultraviolet light propagating through the optical fiber 5B enters the cladding 52B (which has a refractive index larger than that of the core region 51B) in the first region R1, and light irradiation from the side of the optical fiber 5B is achieved. That is, the light reflecting film 54B is provided in a region where it is not desired to irradiate the ultraviolet light from the side of the optical fiber 5B, and the light reflecting film 54B is not provided in a region where it is desired to irradiate the ultraviolet light from the side of the optical fiber 5B, thereby enabling light irradiation in a desired region.

[0055] FIG. 8 shows the results of a simulation of light irradiation from the side of the optical fiber 5B shown in FIG. 7. In this simulation, the inner diameter of the optical fiber 5B was set to 1 mm, the outer diameter to 1.6 mm, and the total length to 150 mm. The optical fiber 5B was given the physical properties of Silica glass in the material library of COMSOL Multiphysics ver6.1. The hollow region (core region 51B) and the outer region of the optical fiber 5B were assumed to be air, with a refractive index of 1. The second region R2 was set to a region from the position where the ultraviolet light is incident to 100 mm (a position 100 mm away from the position where the ultraviolet light is incident in the axial direction of the optical fiber 5B), and the first region R1 was set to a region from 100 mm to 150 mm. In this simulation, a mirror condition was set as a boundary condition for the inner wall of the optical fiber 5B as a reflective coating. For the incidence of ultraviolet light, ultraviolet light with a wavelength of 222 nm was applied with an initial intensity of 10,000 W / m 2 A total source power of 1 W was applied to optical fiber 5B. Ultraviolet light with a light beam direction vector of (x, y, z) = (1, 3.7320508, 0) (in the coordinate system shown in FIG. 8) was applied so that the light beam was inclined at 15° from the end face of optical fiber 5B with respect to the axial direction of optical fiber 5B.

[0056] 8, it can be seen that the ultraviolet light with a wavelength of 222 nm is guided in the region (second region R2) of the optical fiber 5B where the light reflecting film 54B is provided, and is scattered in the region (first region R1) where the light reflecting film 54B is not provided. Therefore, it can be seen that light irradiation from the side surface of the optical fiber 5B is achieved.

[0057] 9 is a diagram showing another example of the configuration of the optical fiber. As the optical fiber included in the irradiation sheet 12, an optical fiber 5E shown in FIG. 9 may be adopted instead of the optical fiber 5 shown in FIG.

[0058] Reference numeral 9001 in Fig. 9 indicates a schematic perspective view of an optical fiber 5E, which is a glass fiber having a hollow structure. Reference numeral 9002 in Fig. 9 indicates a cross-sectional view of the optical fiber 5E cut along a longitudinal section including the scatterer 53E. Reference numeral 9003 in Fig. 9 indicates a cross-sectional view of the optical fiber 5E cut along a longitudinal section including the light reflecting film 54B. As shown in Fig. 9, the optical fiber 5E differs from the optical fiber 5B shown in Fig. 7 in that it further includes a scatterer 53E.

[0059] The scatterer 53E is a scattering particle having an absorption band outside the wavelength region of the ultraviolet light used in the irradiation system 10. The scatterer 53E is disposed in the core region 51B. In an example shown in FIG. 9, the scatterer 53E is disposed on the inner wall of the core region 51B in the first region R1. The scatterer 53E may be, for example, a particle containing quartz. When the light propagating through the optical fiber 5B is irradiated onto the scatterer 53E, scattered light is generated that enters the cladding 52B. This further promotes light irradiation from the side surface of the optical fiber 5B.

[0060] 10 is a diagram showing another example of the configuration of the optical fiber. As the optical fiber included in the irradiation sheet 12, an optical fiber 5F shown in FIG. 10 may be adopted instead of the optical fiber 5 shown in FIG.

[0061] Reference numeral 10001 in Fig. 10 indicates a schematic perspective view of an optical fiber 5F which is a glass fiber having a hollow structure. Reference numeral 10002 in Fig. 10 indicates a cross-sectional view of the optical fiber 5F in the first region R1. Reference numeral 10003 in Fig. 10 indicates a cross-sectional view of the optical fiber 5F in the second region R2. As shown in Fig. 10, the optical fiber 5F differs from the optical fiber 5B which does not have a light reflecting film 54B in the first region R1 in that a light reflecting film 54B is provided on a part of the inner wall of the core region 51B in the first region R1.

[0062] 10, the light reflecting film 54B is provided on a part of the inner wall of the core region 51B in the first region R1, and is not provided on the remaining part of the inner wall. This achieves light irradiation from the side surface of the optical fiber 5F, as in the case of the optical fiber 5B. Also, by providing the light reflecting film 54B on a part of the inner wall of the core region 51B in the first region R1, the amount of light irradiation from the side surface of the optical fiber 5F can be adjusted.

[0063] The optical fiber 5F can be configured such that the light reflecting film 54B is provided on a portion of the inner wall of the core region 51B in the first region R1 by the following method. First, an optical fiber is prepared, which is a glass fiber having a hollow structure, with an aluminum light reflecting film provided on the entire inner wall of the hollow region. Next, a desired portion of the optical fiber is immersed in an acidic liquid. This causes an oxidation-reduction reaction of the aluminum light reflecting film at the desired portion, and the light reflecting film at the desired portion can be dissolved. This allows the above-mentioned optical fiber 5F to be realized.

[0064] 11 is a diagram showing another example of the configuration of the optical fiber. As the optical fiber included in the irradiation sheet 12, an optical fiber 5C shown in FIG. 11 may be adopted instead of the optical fiber 5 shown in FIG.

[0065] Reference numeral 11001 in Fig. 11 indicates a schematic perspective view of optical fiber 5C, which is a photonic crystal fiber. Reference numeral 11002 in Fig. 11 indicates a cross-sectional view of optical fiber 5C taken along a longitudinal section including scatterer 53C. As shown in Fig. 11, optical fiber 5C includes core region 51C, cladding region 52C, and scatterer 53C.

[0066] The material of the core region 51C and the cladding region 52C is, for example, quartz having a high refractive index. The material of the core region 51C and the cladding region 52C is preferably pure quartz, but may be quartz doped with a dopant such as germanium or fluorine having an absorption band outside the wavelength region of the ultraviolet light used in the irradiation system 10. A plurality of voids 55C are periodically formed in the cladding region 52C so as to surround the core region 51C. The voids 55C make the average refractive index of the cladding region 52C lower than the refractive index of the core region 51C, causing total reflection.

[0067] The optical fiber 5C includes a scatterer 53C at a predetermined position in the axial direction of the optical fiber 5C in the core region 51C and the cladding region 52C. The scatterer 53C may be present at least in the core region 51C. The scatterer 53C may be the same as the scatterer 53 described above.

[0068] 12 is a diagram showing another example of the configuration of the optical fiber. As the optical fiber included in the irradiation sheet 12, an optical fiber 5D shown in FIG. 12 may be adopted instead of the optical fiber 5 shown in FIG.

[0069] Reference numeral 12001 in Fig. 12 indicates a schematic perspective view of an optical fiber 5D that is a photonic crystal fiber. Reference numeral 12002 in Fig. 12 indicates a cross-sectional view of the optical fiber 5D taken along a longitudinal section including a scatterer 53D. As shown in Fig. 12, the optical fiber 5D includes a core region 51D, a cladding region 52D, and a scatterer 53D.

[0070] The optical fiber 5D has the same configuration as the optical fiber 5C shown in Fig. 11 except that the core region 51D is hollow. In the optical fiber 5D, light propagates through the core region 51D by two-dimensional Bragg reflection.

[0071] (Optical fiber end) FIG. 13 is a schematic perspective view showing an example of the configuration of the end portion of the optical fiber 5. The optical fiber 5 may be provided with a light reflecting film 56 formed on the end face (end portion) opposite to the light incident end. The same applies to the other optical fibers described above. The light reflecting film 56 reflects the ultraviolet light propagating through the core 51 toward the incident end. The reflected ultraviolet light propagates in the reverse direction through the core 51. On this assumption, the reflected ultraviolet light is scattered by the scatterer 53 and emitted from the side surface of the optical fiber 5. This makes it possible to prevent excessive ultraviolet light from being irradiated into the body from the end portion of the optical fiber 5. In addition, the reflected ultraviolet light can be effectively utilized by being scattered by the scatterer 53. In particular, at a location far from the incident end, the intensity of the ultraviolet light propagating through the core 51 is smaller due to scattering and absorption than at a location close to the incident end. By reflecting the ultraviolet light that has reached the optical reflecting film 56, the intensity distribution of the ultraviolet light emitted from the side surface in the axial direction of the optical fiber 5 can be made uniform. Instead of the light reflecting film 56, the optical fiber 5 may be provided with a retroreflector (light reflecting device) at the end portion.

[0072] Fig. 14 is a schematic perspective view showing another example of the configuration of the end portion of the optical fiber 5. The optical fiber 5 may include a grating 57 formed near the end face (end portion) of the core 51 opposite the light incident end. The same applies to the other optical fibers described above. The grating 57 has a structure having a periodic refractive index change. The grating 57 selectively reflects light of a specific wavelength. The grating 57 reflects ultraviolet light propagating through the core 51 toward the incident end side.

[0073] The optical fiber 5 may include a shielding portion that absorbs and blocks ultraviolet rays, instead of the light reflecting film 56. This makes it possible to prevent excessive ultraviolet rays from being irradiated into the body from the end portion of the optical fiber 5.

[0074] (Method of manufacturing light scattering optical fiber) Fig. 15 is a diagram showing a manufacturing flow of a hollow-core light scattering optical fiber. A first suspension in which scatterers are dispersed in a liquid at a first concentration is prepared. An end face of an optical fiber with a hollow core is immersed in the first suspension (first introduction step S1). This causes the first suspension containing the scatterers to move into the hollow core due to capillary action. In other words, scattering particles are introduced into the hollow core.

[0075] When the first suspension liquid has moved to a predetermined position on the optical fiber, the end face of the optical fiber is then immersed in a liquid that does not contain scatterers (transportation step S2). This causes the liquid that does not contain scatterers to move into the hollow core due to capillary action. Also, the first suspension liquid that was already in the hollow core moves further ahead. Thus, the scattering particles are transported in the hollow core, and an optical fiber is formed that has a section where the scattering particles are arranged and a section where they are not arranged.

[0076] When the first suspension has moved to a predetermined position on the optical fiber, the end face of the optical fiber is then immersed in a second suspension (second introduction step S3). The second suspension is a suspension in which scatterers are dispersed in a liquid at a second concentration. This causes the second suspension containing scatterers to move into the hollow core due to capillary action. In addition, the first suspension and the liquid not containing scatterers that were already in the hollow core move further ahead.

[0077] When the first suspension liquid has moved to a predetermined location on the optical fiber, the end face of the optical fiber is then immersed in a liquid that does not contain scatterers (transportation step S4). By combining such processes, it is possible to distribute the scatterers 53 at a desired concentration at a desired location on the optical fiber.

[0078] Thereafter, the optical fiber is left for a predetermined time with or without heating to evaporate the liquid in the hollow core of the optical fiber (evaporation step S5). As a result, the scatterers remain in the hollow core, and an optical fiber is obtained in which the scatterers are distributed in the hollow core with a desired density distribution.

[0079] In the first suspension, the second suspension, and the liquid not containing scatterers, the liquid may be water or an organic liquid such as alcohol. The second concentration may be different from or the same as the first concentration. S2 and S4 may be omitted. Also, only S1 and S5 may be performed. Any combination of S1, S2, S3, and / or S4 may be performed depending on the desired distribution of scatterers.

[0080] Also, a light-reflecting film may be formed in advance partially on the inner surface of the hollow core of the optical fiber, the portion where the light-reflecting film is formed being a portion where ultraviolet light does not need to be emitted.

[0081] (sterilization method) FIG. 16 is a diagram showing a sterilization flow using an irradiation sheet. The practitioner places the irradiation sheet on the outer surface of the instrument (driveline) to be placed inside the body (S11). A light source may be connected to the irradiation sheet in advance. The practitioner places the irradiation sheet inside the body together with the instrument (S12). If no bacterial infection is found after the operation, ultraviolet light does not need to be irradiated. If bacterial infection is found or suspected at the interface between the instrument and the body tissue after the operation, the medical staff outputs ultraviolet light from the light source (S13). This causes ultraviolet light to be irradiated from the irradiation sheet to the body tissue, sterilizing the body tissue. Therefore, it is possible to appropriately sterilize the body tissue facing the instrument or the surface of the instrument placed inside the body, which is difficult to sterilize from the outside.

[0082] For example, if a bacterial infection occurs around the driveline connected to an artificial heart, removing the driveline for sterilization is not realistic given the burden it would place on the patient, and it is not possible to sterilize body tissue.

[0083] According to the above-described embodiment, it is possible to sterilize the surface of body tissue or an instrument placed inside the body without placing additional strain on the patient, while leaving the artificial heart and driveline in place inside the body.

[0084] The irradiation sheet can also be used on injured body tissue. For example, in negative pressure wound therapy, the irradiation sheet can be placed along the surface of the affected tissue between the affected tissue and a porous body that is a treatment device. If the irradiation sheet is woven, it can also pass body fluids. If the affected tissue becomes infected with bacteria, it can be sterilized by irradiating it with ultraviolet light from the irradiation sheet.

[0085] The irradiation sheet and the above-mentioned sterilization method may be used for humans or non-human animals. Note that ultraviolet rays may be irradiated from the irradiation sheet to body tissue as a preventative measure before bacterial infection is detected.

[0086] 〔summary〕 The irradiation system according to aspect 1 of the present invention comprises a light source that generates ultraviolet light and an irradiation sheet, the irradiation sheet including one or more optical fibers arranged in a sheet shape that propagate ultraviolet light and emit ultraviolet light from the side, the irradiation sheet being deformable along body tissue or along an instrument placed inside the body, and the emitted ultraviolet light sterilizes the body tissue facing the irradiation sheet or the surface of the instrument.

[0087] The irradiation sheet of the irradiation system according to aspect 2 of the present invention may include a plurality of the optical fibers arranged in a sheet shape in accordance with aspect 1 above.

[0088] In the illumination system according to the third aspect of the present invention, the optical fibers may be bonded to each other in the second aspect.

[0089] The irradiation sheet of the irradiation system according to the fourth aspect of the present invention may be a woven fabric having a plurality of the optical fibers woven therein in the above-mentioned second aspect.

[0090] The optical fiber of the illumination system according to aspect 5 of the present invention, in any one of aspects 1 to 4 above, may include scattering particles that scatter ultraviolet light.

[0091] The optical fiber of the irradiation system according to aspect 6 of the present invention, in any one of aspects 1 to 5 above, has a hollow core and a light-reflecting coating that reflects ultraviolet light from the hollow core, and the light-reflecting coating may cover a portion of the inner wall of the hollow core without covering the remainder.

[0092] An irradiation system according to aspect 7 of the present invention, in any one of aspects 1 to 6 above, includes the device that is placed inside the body, and the irradiation sheet may be arranged on an outer surface of the device.

[0093] The irradiation sheet of aspect 8 of the present invention includes one or more optical fibers arranged in a sheet-like shape that propagate ultraviolet light and emit the ultraviolet light from the side, and is deformable along body tissue or along an instrument placed inside the body.

[0094] A method for manufacturing a light-scattering optical fiber according to a ninth aspect of the present invention includes a first introduction step of introducing scattering particles into an optical fiber having a hollow core by immersing an end face of the optical fiber in a suspension containing scattering particles.

[0095] A tenth aspect of the present invention relates to a method for producing a light-scattering optical fiber according to the ninth aspect, which may further include an evaporation step of evaporating a liquid contained in the suspension introduced into the hollow core.

[0096] The method for manufacturing a light-scattering optical fiber according to aspect 11 of the present invention may, in the above-mentioned aspect 9 or 10, include a transporting step of transporting the scattering particles within the hollow core by immersing the end face of the optical fiber in a liquid that does not contain the scattering particles after the introduction step, thereby forming the optical fiber having a section in which the scattering particles are arranged and a section in which the scattering particles are not arranged.

[0097] The method for manufacturing a light-scattering optical fiber according to aspect 12 of the present invention, in any one of aspects 9 to 11 above, may include, after the introduction step, a second introduction step of introducing the scattering particles into the hollow core by immersing an end face of an optical fiber having a hollow core in a suspension having a different concentration of the scattering particles than that in the first introduction step.

[0098] A light-scattering optical fiber according to a thirteenth aspect of the present invention comprises a hollow core and a light-reflecting coating that reflects ultraviolet light from the hollow core, the light-reflecting coating covering a portion of the inner wall of the hollow core and not covering the remainder.

[0099] A light-scattering optical fiber according to a fourteenth aspect of the present invention comprises a hollow core and scattering particles disposed within the hollow core.

[0100] A sterilization method according to aspect 15 of the present invention includes the steps of placing an irradiation sheet, which is arranged in a sheet-like shape and includes one or more optical fibers that propagate ultraviolet light and emit ultraviolet light from the sides, along body tissue of a non-human animal or inside the body of a non-human animal, and sterilizing the body tissue with the ultraviolet light emitted from the optical fibers.

[0101] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0102] 2 Driveline (instrument placed inside the body) 5, 5A, 5B, 5C, 5D Optical Fiber 6 Connecting members 10 Irradiation System 11 Light source 12 Irradiation sheet 53, 53B, 53C, 53D scatterer 53A Scattering structure

Claims

1. A light source that generates ultraviolet light; An irradiation sheet; The irradiation sheet is The optical fiber includes one or more optical fibers arranged in a sheet shape, which transmit ultraviolet light and emit the ultraviolet light from a side surface, The device is deformable along body tissue or along an instrument to be placed within the body; An irradiation system that sterilizes the surface of the body tissue or the instrument facing the irradiation sheet by emitted ultraviolet light.

2. The illumination system according to claim 1 , wherein the illumination sheet includes a plurality of the optical fibers arranged in a sheet shape.

3. The illumination system of claim 2 , wherein the optical fibers are glued together.

4. The illumination system according to claim 2 , wherein the illumination sheet is a fabric in which a plurality of the optical fibers are woven.

5. 5. The illumination system according to claim 1, wherein the optical fiber comprises scattering particles for scattering ultraviolet light.

6. The optical fiber has a hollow core and a light reflecting film that reflects ultraviolet light from the hollow core, The illumination system of claim 1 , wherein the light-reflecting film covers a portion of the inner wall of the hollow core and does not cover a remainder of the inner wall.

7. The device is disposed within the body, The illumination system according to claim 1 , wherein the illumination sheet is arranged on an outer surface of the device.

8. The optical fiber includes one or more optical fibers arranged in a sheet shape, which transmit ultraviolet light and emit the ultraviolet light from a side surface, An irradiation sheet that is deformable along body tissue or along an instrument placed inside the body.

9. A method for producing a light-scattering optical fiber, comprising a first introduction step of introducing scattering particles into a hollow core by immersing an end face of an optical fiber having a hollow core in a suspension containing the scattering particles.

10. 10. The method of claim 9, further comprising the step of evaporating the liquid contained in the suspension introduced into the hollow core.

11. 10. The method for producing a light-scattering optical fiber of claim 9, further comprising a transport step of transporting the scattering particles within the hollow core by immersing an end face of the optical fiber in a liquid not containing the scattering particles after the first introduction step, thereby forming the optical fiber having a section in which the scattering particles are arranged and a section in which the scattering particles are not arranged.

12. 10. A method for producing a light-scattering optical fiber as described in claim 9, further comprising a second introduction step of introducing the scattering particles into the hollow core by immersing an end face of the optical fiber having a hollow core in a suspension having a different concentration of the scattering particles than that of the first introduction step after the first introduction step.

13. A hollow core; a light reflecting film that reflects ultraviolet light from the hollow core; The light-scattering optical fiber, wherein the light-reflecting coating covers a portion of the inner wall of the hollow core and does not cover the remainder.

14. A hollow core; and scattering particles disposed within the hollow core.

15. A step of placing an irradiation sheet including one or more optical fibers arranged in a sheet shape that propagates ultraviolet light and emits the ultraviolet light from a side along a body tissue of a non-human animal or inside the body of a non-human animal; and sterilizing body tissue with ultraviolet light emitted from the optical fiber.

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