Balloon, light irradiation device, and treatment method

Abstract

The present disclosure provides a balloon insertable into a living body. The balloon comprises an expansion part that defines a central axis extending along an insertion direction from a proximal side toward a distal side. The expansion part includes: a transmission layer that can transmit light emitted inside the expansion part to the outside; and a light-shielding layer that covers the transmission layer and has a lower transmittance for the light than the transmission layer. The expansion part further includes: a window region in which the transmission layer is not covered by the light-shielding layer; and a light-shielding region in which the transmission layer is covered by the light-shielding layer. The window region of the expansion part in an expanded state includes: a first window part, and a second window part spaced from the first window part, located further toward the proximal side than the first window part, and inclined with respect to the central axis compared to the first window part.

Description

Balloon, light irradiation device and treatment method

[0001] The present disclosure relates to balloons, light delivery devices and treatment methods.

[0002] A light irradiation device used to irradiate abnormal tissue with therapeutic light is known. Patent Document 1 discloses such a light irradiation device. The light irradiation device described in Patent Document 1 includes a balloon coated with a reflective material, which can improve the efficiency and uniformity of light distribution in the treatment area.

[0003] Japanese Patent Application Laid-Open No. 2005-46640

[0004] A light irradiation device intended to irradiate a target site, such as abnormal tissue, with therapeutic light is required to achieve a stable phototherapy effect by defining the light irradiation area and maintaining a more uniform light irradiation intensity within the light irradiation area. Patent Document 1 describes a balloon catheter device as a light irradiation device that distributes light more uniformly and efficiently throughout the entire light irradiation area. However, the balloon of the light irradiation device described in Patent Document 1 has a front (proximal) end coated with a reflective material to define the light irradiation area. This makes it difficult for the surgeon to visually confirm the light irradiation area of ​​the light irradiation device from the front (proximal) side when irradiating light onto a target site, such as abnormal tissue, from within the living body, which can make it difficult to perform reliable treatment.

[0005] An object of the present disclosure is to provide a balloon that allows a light irradiation area to be visualized from the proximal side inside a living body, a light irradiation device including this balloon, and a treatment method using this balloon.

[0006] A balloon according to a first aspect of the present disclosure is: (1) a balloon that can be inserted into a living body, the balloon comprising an expansion portion that defines a central axis extending along an insertion direction from the proximal side to the distal side, the expansion portion comprising: a transparent layer that can transmit light emitted from inside to the outside; and a light-shielding layer that covers the transparent layer and has a lower light transmittance than the transparent layer, the expansion portion comprising: a window region where the transparent layer is not covered by the light-shielding layer; and a light-shielding region where the transparent layer is covered by the light-shielding layer, the window region of the expansion portion in an expanded state comprising: a first window portion; and a second window portion that is spaced apart proximally from the first window portion and is inclined more with respect to the central axis than the first window portion.

[0007] A balloon according to one embodiment of the present disclosure is (2) the balloon according to (1) above, in which the first window portion is substantially parallel or parallel to the central axis.

[0008] A balloon according to one embodiment of the present disclosure is (3) the balloon described in (1) or (2) above, in which the second window portion is provided over the entire circumferential area around the central axis.

[0009] A balloon according to one embodiment of the present disclosure is (4) a balloon according to any one of (1) to (3) above, wherein in the expansion section, the distal side of the first window section is constituted only by the light-shielding region.

[0010] A balloon according to one embodiment of the present disclosure is (5) the balloon described in any one of (1) to (4) above, wherein the expansion portion, in an expanded state, comprises: a cylindrical expansion main body portion surrounding the central axis; and an expansion proximal portion connected to the proximal side of the expansion main body portion and inclined so as to approach the central axis toward the proximal side, wherein the first window portion is disposed in the expansion main body portion, and the second window portion is disposed in the expansion proximal portion.

[0011] A balloon according to one embodiment of the present disclosure is (6) the balloon according to (5) above, in which the expansion proximal portion protrudes proximally from the expansion main body portion in a semispherical shape.

[0012] A balloon according to one embodiment of the present disclosure is (7) the balloon described in any one of (1) to (6) above, in which the first window portion is provided over a limited angular range in the circumferential direction around the central axis of the expansion portion, but not over the entire circumference.

[0013] A balloon according to one embodiment of the present disclosure is (8) the balloon described in (7) above, in which at least a portion of the second window portion is positioned at a different position in the circumferential direction from the first window portion.

[0014] A light irradiation device according to a second aspect of the present disclosure is (9) a light irradiation device including: the balloon according to any one of (1) to (8) above; and a tubular body defining an internal storage space that contains or can contain a light irradiation unit that emits light, wherein the balloon covers the radial periphery of the tubular body.

[0015] A treatment method as a third aspect of the present disclosure is (10) a treatment method using a balloon described in any one of (1) to (8) above, which includes a balloon position adjustment step of adjusting the position of the first window portion while visually observing the first window portion through the second window portion.

[0016] A treatment method according to one embodiment of the present disclosure is (11) the treatment method described in (10) above, wherein in the balloon position adjustment step, the position of the first window portion is adjusted by moving the balloon in a direction parallel to the central axis.

[0017] (12) The treatment method according to (10) or (11) above, wherein in the balloon position adjusting step, the position of the first window portion is adjusted by rotating the balloon in a circumferential direction around the central axis.

[0018] A treatment method as a fourth aspect of the present disclosure is (13) a treatment method using the balloon described in any one of (1) to (8) above, the treatment method including: an imaging device insertion step of inserting an imaging device into the living body; a balloon insertion step of inserting the balloon into the living body through a through-path of the imaging device or by running the balloon parallel to an outer surface of the imaging device; an expansion step of expanding the balloon inside the living body; a lens position adjustment step of bringing a lens at the tip of the imaging device closer to the second window of the balloon; a balloon position adjustment step of adjusting the position of the first window while visually observing the first window from the second window so that a region to be irradiated with light inside the living body is aligned with the position of the first window; and a light irradiation step of irradiating the light into the living body when the region to be irradiated with light is aligned with the position of the first window.

[0019] A treatment method according to a fifth aspect of the present disclosure is (14) a treatment method using the balloon according to any one of (1) to (8) above, the treatment method including: an imaging device insertion step of inserting an imaging device into the living body; a balloon insertion step of inserting the balloon into the living body through a through-path of the imaging device or by running the balloon parallel to an outer surface of the imaging device; a first expansion step of adjusting the balloon to a first expansion amount and expanding it in the living body; a lens position adjustment step of bringing a lens at the tip of the imaging device closer to the second window of the balloon; a balloon position adjustment step of adjusting the position of the first window of the balloon adjusted to the first expansion amount while visually checking the first window from the second window so that a region to be irradiated with light in the living body and the position of the first window align; and a second expansion step of adjusting the balloon to a second expansion amount greater than the first expansion amount and expanding it in the living body after the balloon position adjustment step. a light irradiation step of irradiating the light into the living body after the second expansion step, with the intended light irradiation area and the first window portion aligned in position.

[0020] According to the present disclosure, it is possible to provide a balloon that allows a light irradiation area to be visually recognized from the proximal side inside a living body, a light irradiation device including this balloon, and a treatment method using this balloon.

[0021] 2C is a diagram showing a state in which the expansion portion of the balloon is further expanded and an optical fiber serving as a light-emitting portion is made to emit light, from the state of FIG. 2C. FIG. 3A is a plan view of the balloon shown in FIG. 3A from the proximal side in the axial direction. FIG. 3B is a cross-sectional view taken at line a-a in FIG. 3B. FIG. 3C is a perspective view showing an expanded state of a balloon as a modification of the balloon shown in FIG. 1. FIG. 5A is a plan view of the balloon shown in FIG. 5A from the proximal side in the axial direction. FIG. 6A is a perspective view showing an expanded state of a balloon as a modification of the balloon shown in FIG. 1. FIG. 6A is a plan view of the balloon shown in FIG. 6A from the proximal side in the axial direction. FIG. 6B is a diagram showing an expanded state of a balloon as a modification of the balloon shown in FIG. 1.

[0022] Hereinafter, embodiments of a balloon, a light irradiation device, and a treatment method according to the present disclosure will be illustrated and described with reference to the drawings. The same reference numerals are used to designate common components in the various drawings.

[0023] FIG. 1 is a diagram illustrating an endoscopic system 200 including a light irradiation device 1 according to an embodiment of the present disclosure, which includes a balloon 2 according to an embodiment of the present disclosure. The endoscopic system 200 includes the light irradiation device 1 and an endoscope 40. FIG. 1 illustrates a state in which the light irradiation device 1 is inserted into a through-hole 40a1 of the endoscope 40. The light irradiation device 1 can be used for, for example, photodynamic therapy (PDT) treatment or photoimmunotherapy (PIT) treatment. In this embodiment, the light irradiation device 1 is used for photoimmunotherapy, which is taught in Japanese Patent No. 6127045, in which light is irradiated onto a drug adsorbed to target cells to destroy the target cells. The target cells are tumor cells, such as cancer cells or cells of precancerous lesions. This treatment method uses a photosensitizer, which is composed of an antibody that specifically binds only to a specific antigen on the surface of tumor cells and a photosensitizer that pairs with the antibody. The antibody is not particularly limited, but examples include panitumumab, trastuzumab, HuJ591, pertuzumab, lapatinib, palbociclib, and olaparib. The photosensitizer is, for example, but not limited to, a hydrophilic phthalocyanine (IR700), which is a substance that responds to near-infrared light with a wavelength of approximately 700 nm. When IR700 is exposed to near-infrared light with a wavelength of approximately 660-740 nm, the ligand of the functional group that ensures water solubility is cleaved, causing a structural change from water-soluble to hydrophobic. This structural change extracts membrane proteins, opening holes in the cell membrane and allowing water to enter the cell, resulting in the rupture and destruction of tumor cells. Furthermore, IR700 is excited by near-infrared light and emits fluorescence at a wavelength different from the excitation wavelength. For example, when IR700 is excited by near-infrared light with a wavelength of around 690 nm, it emits fluorescence with a wavelength of around 700 nm. IR700 undergoes a structural change while emitting fluorescence due to a photoreaction, and ceases to emit fluorescence once it has destroyed tumor cells and fulfilled its role as a drug. While FIG. 1 shows an example in which the light irradiation device 1 is inserted into the through-hole 40a1 of the endoscope 40 for use, the use is not limited to this example. For example, the light irradiation device 1 may be used with an imaging device other than the endoscope 40 that can image the balloon 2 (described later) from the proximal side.Furthermore, the light irradiation device 1 may be inserted into a target tissue such as a hollow organ 80 along the outer surface of the endoscope 40 without being inserted through the through-path 40a1. Furthermore, the light irradiation device 1 may be used alone without using an imaging device such as the endoscope 40.

[0024] In the present disclosure, the longitudinal direction parallel to the central axis O of the light irradiation device 1 is referred to as the "axial direction A of the light irradiation device 1" or simply as the "axial direction A." Furthermore, the direction around the central axis O of the light irradiation device 1 is referred to as the "circumferential direction B of the light irradiation device 1" or simply as the "circumferential direction B." Furthermore, the radial direction of the circle around the central axis O of the light irradiation device 1 is referred to as the "radial direction C of the light irradiation device 1" or simply as the "radial direction C."

[0025] As shown in FIG. 1 , the light irradiation device 1 includes an insertion section 1a and an operation section 1b. The insertion section 1a is located at one end of the light irradiation device 1 and can be inserted into a living organ having a tubular structure, such as the digestive tract (e.g., esophagus, stomach, small intestine, large intestine), urinary tract, or blood vessel. Organs having a tubular structure include, for example, the external auditory canal, Eustachian tube, and a hollow organ 80. Examples of the hollow organ 80 include the digestive tract (e.g., esophagus, stomach, small intestine, large intestine, bile duct), urinary tract (e.g., ureter, urethra), blood vessels, nasal cavity, trachea, vagina, cervical canal, uterine cavity, and fallopian tube. The operation section 1b is located outside the living body while the insertion section 1a is inserted into the living body and is operated by an operator. In the present disclosure, the side of the light irradiation device 1 that is operated outside the living body in the axial direction A is referred to as the "proximal side." Furthermore, the side of the light irradiation device 1 that is inserted into the living body in the axial direction A is referred to as the "distal side." Hereinafter, the direction from the proximal side to the distal side may be referred to as an "insertion direction A1," and the direction from the distal side to the proximal side may be referred to as a "removal direction A2."

[0026] 2A to 2D are diagrams illustrating an example of a treatment method using the light irradiation device 1. FIG. 2A is a diagram illustrating a state in which an endoscope 40 is inserted into a hollow organ 80. FIG. 2B is a diagram illustrating a state in which the light irradiation device 1 including a balloon 2 is inserted into a hollow organ 80, from the state of FIG. 2A. FIG. 2C is a diagram illustrating a state in which the expansion section 2a of the balloon 2 is expanded from the state of FIG. 2B. FIG. 2D is a diagram illustrating a state in which the expansion section 2a of the balloon 2 is further expanded and the optical fiber 100a serving as the light irradiation section 100 is made to emit light, from the state of FIG. 2C. The optical fiber 100a may be, for example, a side-emitting optical fiber that emits light outward in the radial direction C all around. FIG. 3A is a perspective view illustrating the expanded state of the balloon 2 of this embodiment. FIG. 3B is a plan view of the balloon 2 illustrated in FIG. 3A, viewed from the proximal side in the axial direction A. FIG. 4 is a cross-sectional view taken along line a-a in FIG. 3B. 4 is a diagram showing an example of a cross section that includes the central axis P of the expansion portion 2a of the balloon 2 in an expanded state and is parallel to the central axis P. Furthermore, the cross section shown in FIG. 4 is a cross section that passes through the first window 20a and the second window 20b of the expansion portion 2a of the balloon 2.

[0027] As shown in FIG. 2B and other figures, the light irradiation device 1 of this embodiment includes a balloon 2 insertable into a hollow organ 80, a tubular member 25, a hub 28, and a tip member 32. The tip member 32 forms the distal end (hereinafter referred to as the "distal end") of the light irradiation device 1. The first tubular body 26 of the tubular member 25 is connected to the proximal side of the tip member 32 and extends to the proximal end (hereinafter referred to as the "proximal end") of the light irradiation device 1. The balloon 2 is attached to the distal end (hereinafter referred to as the "distal end") of the tubular member 25. The hub 28 is attached to the tubular member 25 and includes a port 28a to which a fluid supply tool can be connected. The insertion section 1a of this embodiment is composed of the balloon 2 and a distal portion of the tubular member 25. The operation section 1b of this embodiment is composed of the hub 28 and a proximal portion of the tubular member 25. Here, the central axis O of the light irradiation device 1 of this embodiment coincides with the central axes of the first tubular body 26 and the second tubular body 27 of the tubular member 25. That is, the axial direction A of the light irradiation device 1 of this embodiment is the same as the axial direction of the first tubular body 26 and the second tubular body 27 of the tubular member 25, which is parallel to the central axes of the first tubular body 26 and the second tubular body 27 of the tubular member 25. Furthermore, the circumferential direction B of the light irradiation device 1 of this embodiment is the same as the circumferential direction of the first tubular body 26 and the second tubular body 27 of the tubular member 25 around the central axes of the first tubular body 26 and the second tubular body 27 of the tubular member 25. Furthermore, the radial direction C of the light irradiation device 1 of this embodiment is the same as the radial direction of the first tubular body 26 and the second tubular body 27 of the tubular member 25, which is the radial direction of a circle around the central axes of the first tubular body 26 and the second tubular body 27 of the tubular member 25.

[0028] The tip member 32 of this embodiment is a disc plate portion that is arranged approximately coaxially with the tubular member 25. The distal side surface of the disc plate portion serving as the tip member 32 of this embodiment is configured as a curved convex surface that protrudes distally. By making the distal side surface of the disc plate portion a curved convex surface, it is less likely to cause damage to the living body when the insertion section 1a is inserted into a living body such as a tubular organ 80. However, the shape of the tip member 32 is not limited to this. Furthermore, the light irradiation device 1 does not need to include the tip member 32 as long as the tip is configured to be closed.

[0029] The tubular member 25 defines an interior space 26a capable of accommodating the light irradiation unit 100 and an inflation lumen 25a capable of supplying a fluid such as air into the balloon 2. More specifically, the tubular member 25 of this embodiment includes a first tubular body 26 and a second tubular body 27. The first tubular body 26 and the second tubular body 27 are concentrically arranged. The second tubular body 27 is arranged to surround the outside of the first tubular body 26 in the radial direction C. The first tubular body 26 protrudes distally beyond the second tubular body 27. The first tubular body 26 protrudes proximally beyond the second tubular body 27. Furthermore, the first tubular body 26 of this embodiment protrudes proximally beyond a hub 28 connected to the proximal side of the second tubular body 27. However, the proximal end of the first tubular body 26 may terminate within the hub 28 as long as an optical fiber 100a serving as the light irradiation unit 100, which will be described later, can be inserted therein. An accommodating space 26a is defined within the first tubular body 26. The distal end of the accommodating space 26a is closed. More specifically, a blocking member 31 is disposed inside the distal end portion of the first tubular body 26 of this embodiment. The distal end of the accommodating space 26a is blocked by the blocking member 31. However, the distal end of the accommodating space 26a does not have to be blocked by the blocking member 31. In this case, for example, the accommodating space 26a may be partially reduced in diameter to a diameter that prevents the light emitting unit 100a1 of the optical fiber 100a serving as the light irradiation unit 100 from being inserted therethrough, so that the light emitting unit 100a1 can be positioned at an appropriate position within the balloon 2. When the tip member 32 and the blocking member 31 are not provided, by flowing physiological saline into the living body before inserting the optical fiber 100a serving as the light irradiation unit 100 into the accommodation space 26a, it is possible to prevent the optical fiber 100a serving as the light irradiation unit 100 from being contaminated with bodily fluids such as blood. The inflation lumen 25a is defined between the inner surface of the second tubular body 27 and the outer surface of the first tubular body 26.

[0030] The light irradiation unit 100 is capable of emitting light outward in the radial direction C. The light irradiation unit 100 of this embodiment is an optical fiber 100a. The optical fiber 100a includes, at its distal end, a light emitting unit 100a1 that emits light outward in the radial direction C (see FIG. 2B , etc.). The first tubular body 26 is capable of transmitting light emitted from inside to the outside. More specifically, the first tubular body 26 is capable of transmitting light emitted by the light irradiation unit 100 housed in the housing space 26a toward the outside in the radial direction C of the first tubular body 26. The first tubular body 26 is formed of a light-transmitting material that can transmit not only the treatment light emitted by the light irradiation unit 100 but also light of a wavelength visible by the endoscope 40, and may be formed of, for example, a transparent resin material. The first tubular body 26 may have, for example, an opening that allows light to pass through.

[0031] The light irradiation device 1 of this embodiment does not include a light irradiation unit 100. That is, the light irradiation device 1 of this embodiment is used together with an optical fiber 100a as the light irradiation unit 100 that is separately accommodated in the accommodation space 26a of the first tubular body 26. However, the light irradiation device 1 may also include the light irradiation unit 100. In this case, the light irradiation unit 100 may be accommodated in the accommodation space 26a and integrated with the light irradiation device 1.

[0032] The optical fiber 100a as the light irradiation unit 100 accommodated in the accommodation space 26a of the first tubular body 26 is inserted into the accommodation space 26a until the light emitting unit 100a1 is positioned within the balloon 2 in the axial direction A. In this embodiment, the optical fiber 100a is inserted into the accommodation space 26a until the light emitting unit 100a1 provided on the distal side of the optical fiber 100a abuts against the occlusion member 31. By inserting the light emitting unit 100a1 until the position where it abuts against the occlusion member 31, in this embodiment, the light emitting unit 100a1 of the optical fiber 100a can be reliably positioned at a predetermined position within the balloon 2.

[0033] The light irradiation device 1 does not need to include the first tubular body 26. In this case, the balloon 2 may define an internal storage space that contains or can contain the light irradiation unit 100. However, by including the first tubular body 26 that defines the storage space 26a in the light irradiation device 1, it is easy to stabilize the position of the light irradiation unit 100 in the axial direction A and the radial direction C.

[0034] The material forming the first tubular body 26 and the second tubular body 27 of the tubular member 25 is not particularly limited, and may be, for example, a resin material. Examples of resin materials for forming the first tubular body 26 and the second tubular body 27 include polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymers; ethylene-vinyl acetate copolymers (EVA); polyvinyl chloride; polyvinylidene chloride; polystyrene; polyamide; polyamide-based elastomers; polyimide; polyamideimide; polycarbonate; poly-(4-methylpentene-1); ionomers; acrylic resins; polymethyl methacrylate; acrylonitrile-butadiene-styrene copolymers (ABS resins); acrylonitrile-styrene copolymers (AS resins); and butadiene-styrene. Examples of suitable resin materials include copolymers; polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polycyclohexane terephthalate (PCT); polyether; polyether ketone (PEK); polyether ether ketone (PEEK); polyetherimide; polyacetal (POM); polyphenylene oxide; modified polyphenylene oxide; polysulfone; polyethersulfone; polyphenylene sulfide; polyarylate; aromatic polyester (liquid crystal polymer); polytetrafluoroethylene, polyvinylidene fluoride, and other fluorine-based resins. Blends containing one or more of these may also be used. The second tubular body 27 may also be made of metals such as stainless steel, iron, nickel-titanium alloy, and aluminum.

[0035] The balloon 2 of this embodiment covers the periphery of the first tubular body 26 of the tubular member 25 in the radial direction C. More specifically, the balloon 2 of this embodiment is an endless membrane body that covers the entire circumferential direction B of the first tubular body 26 outside the radial direction C of the first tubular body 26. As shown in FIG. 1 , the balloon 2 of this embodiment includes an expandable / contractable expansion section 2a and a protruding section 2b. The protruding section 2b includes a distal protruding section 2b2 that is connected to the distal end of the expansion section 2a and protrudes distally, and a proximal protruding section 2b1 that is connected to the proximal end of the expansion section 2a and protrudes proximally. The distal protruding section 2b2 is bonded by adhesive or the like to the distal end of the first tubular body 26 over the entire circumferential direction B. The proximal protruding section 2b1 is bonded by adhesive or the like to the distal end of the second tubular body 27 over the entire circumferential direction B. In this embodiment, the distal protrusion 2b2 and the proximal protrusion 2b1 are provided with a light-shielding layer 11, which will be described later, but the proximal protrusion 2b1 may not be provided with the light-shielding layer 11, which will be described later. The expansion section 2a is not joined to the first tubular body 26 or the second tubular body 27 of the tubular member 25, and defines an annular space 5 capable of containing a fluid between the expansion section 2a and the first tubular body 26. The distal opening of the inflation lumen 25a defined between the first tubular body 26 and the second tubular body 27 communicates with this annular space 5. The expansion section 2a of the balloon 2 expands outward in the radial direction C when fluid is supplied to the annular space 5 through the inflation lumen 25a. Conversely, the expansion section 2a of the balloon 2 contracts inward in the radial direction C when fluid is discharged from the annular space 5 through the inflation lumen 25a. The greater the pressure of the fluid supplied to the annular space 5, the greater the amount of outward expansion of the expansion portion 2a of the balloon 2 in the radial direction C.

[0036] However, the balloon 2 is not limited to the configuration including the expansion portion 2 a and the protrusion 2 b described above. For example, the balloon 2 may be configured to include the expansion portion 2 a but not the protrusion 2 b. In this case, the expansion portion 2 a may be bonded to the distal end portions of the first tubular body 26 and the second tubular body 27 by adhesive or the like over the entire area in the circumferential direction B.

[0037] As shown in FIGS. 2C to 4 , the expansion section 2a of the balloon 2, in its expanded state, defines a central axis P extending along the insertion direction A1 from the proximal side to the distal side. The central axis P substantially coincides with the central axis O of the light irradiation device 1. In other words, in this embodiment, the direction parallel to the central axis P defined by the expansion section 2a in its expanded state is the same as the axial direction A of the light irradiation device 1. Hereinafter, the direction around the central axis P defined by the expansion section 2a in its expanded state will be referred to as the "circumferential direction E of the expansion section 2a" or simply as the "circumferential direction E." Furthermore, the radial direction of the circle around the central axis P defined by the expansion section 2a in its expanded state will be referred to as the "radial direction F of the expansion section 2a" or simply as the "radial direction F."

[0038] As will be described in detail later, the expansion section 2a of the balloon 2 includes a transparent layer 10 that allows light emitted from the inside to pass therethrough to the outside, and a light-shielding layer 11 that covers the transparent layer 10 and has a lower light transmittance than the transparent layer 10. The expansion section 2a of the balloon 2 also includes a window region 20 in which the transparent layer 10 is not covered by the light-shielding layer 11, and a light-shielding region 21 in which the transparent layer 10 is covered by the light-shielding layer 11. In an expanded state, the window region 20 of the expansion section 2a includes a first window 20a and a second window 20b that is disposed proximally and spaced apart from the first window 20a and is tilted more toward the central axis P than the first window 20a. By including the first window 20a in the expansion section 2a of the balloon 2, in treatment using the balloon 2, it is possible to irradiate the light irradiation region defined as the first window 20a with light at a more uniformly maintained irradiation intensity, thereby enabling efficient light irradiation. Furthermore, by providing the second window 20b in the expansion section 2a of the balloon 2, during treatment using the balloon 2, the first window 20a can be viewed through the second window 20b using an imaging device such as an endoscope 40. The light irradiation area refers to an area of ​​the balloon 2 that is defined as a range to be irradiated with light, and in this embodiment refers to the entire area of ​​the first window 20a.

[0039] As shown in Figure 1 and other figures, a hub 28 is attached to the proximal end of the second tubular body 27 of the tubular member 25 of this embodiment. As described above, the hub 28 has a port 28a to which a fluid supply device can be connected. A fluid supply device such as a syringe connected to the port 28a can supply liquid or gas to the annular space 5 of the balloon 2 through the inflation lumen 25a. The hub 28 of this embodiment also defines a through-hole 28b through which the first tubular body 26 is inserted.

[0040] As shown in FIG. 1 and other figures, the endoscope 40 used in the endoscopic system 200 of this embodiment as an imaging device includes a main body 40a and a lens 40b. The main body 40a is an elongated member extending along the axial direction A. The main body 40a defines a through passage 40a1 through which the light irradiation device 1 can be inserted. The through passage 40a1 extends from the proximal end to the distal end of the main body 40a and penetrates the main body 40a. The light irradiation device 1 inserted into the through passage 40a1 of the endoscope 40 is fixed to the endoscope 40 so that relative movement in the axial direction A with respect to the endoscope 40 is restricted. The lens 40b is located at the tip (distal end) of the endoscope 40 and focuses light incident from the distal side to create an optical image. When the light irradiation device 1 is inserted into the through passage 40a1 of the endoscope 40, the lens 40b can be positioned adjacent to the proximal side of the second window 20b of the balloon 2. By disposing the lens 40b adjacent to the proximal side of the second window 20b of the balloon 2, light reflected from the target site X (see FIG. 2A, etc.), which is the target of light irradiation, can pass through the second window 20b via the first window 20a and enter the lens 40b. The optical image created by the lens 40b can be displayed in real time on a display unit, such as a liquid crystal monitor, of an image display device connected to the endoscope 40. Furthermore, a light capable of emitting light of a different wavelength from the light of the light irradiation unit 100 may be provided at the tip (distal end) of the endoscope 40, and this light may be used to illuminate the inside of a living body (for example, the inside of a hollow organ 80).

[0041] 2A to 2D and 7, an example of a treatment method using the balloon 2 will be described. FIG. 7 is a flowchart showing an example of a treatment method using the balloon 2.

[0042] 7, the treatment method using the balloon 2 of this embodiment includes a light irradiation unit preparation step S1, an imaging device insertion step S2, a balloon insertion step S3, a first balloon position adjustment step S4, a first expansion step S5, a lens position adjustment step S6, a second balloon position adjustment step S7, a second expansion step S8, and a light irradiation step S9. In the following description of the treatment method, a photosensitive substance is administered to a patient as a drug in advance, causing the photosensitive substance to be adsorbed into the cancer tissue.

[0043] In the light irradiation unit preparation step S1, an optical fiber 100a serving as the light irradiation unit 100 is inserted into the accommodation space 26a of the first tubular body 26 from the proximal side of the light irradiation device 1 including the balloon 2. At this time, the light emitting unit 100a1 of the optical fiber 100a is inserted in the axial direction A up to the position where the balloon 2 is provided. The optical fiber 100a serving as the light irradiation unit 100 may be fixed in a state where it has been inserted in advance into the accommodation space 26a of the first tubular body 26. In this case, the light irradiation preparation step S1 can be skipped.

[0044] In the imaging device inserting step S2, after the light irradiation unit preparing step S1, as shown in FIG. 2A, an endoscope 40 as an imaging device is inserted into a hollow organ 80 including a target site X that is the treatment target.

[0045] In the balloon insertion step S3, after the imaging device insertion step S2, as shown in FIG. 2B , the balloon 2 is inserted into the hollow organ 80 through the through passage 40a1 of the endoscope 40 inserted into the hollow organ 80. More specifically, in the balloon insertion step S3 of this embodiment, the light irradiation device 1 including the balloon 2, with the optical fiber 100a as the light irradiation unit 100 inserted therein, is pushed forward in the insertion direction A1 and inserted into the hollow organ 80 through the through passage 40a1 of the endoscope 40 inserted into the hollow organ 80. At this time, the expansion section 2a of the balloon 2 is in a contracted state. The balloon insertion step S3 may also be performed by inserting the balloon 2 into the hollow organ 80 by running it parallel to the outer surface of the endoscope 40 without passing through the through passage 40a1.

[0046] In the first balloon position adjustment step S4, after the balloon insertion step S3, the position of the first window portion 20a of the balloon 2 is adjusted to align with the intended light irradiation region including the target site X to be irradiated with light. The first balloon position adjustment step S4 is performed while the expansion portion 2a of the balloon 2 is in a deflated state (see FIG. 2B ). Specifically, the position of the first window portion 20a can be adjusted by operating the operation unit 1b of the light irradiation device 1 to move the balloon 2 in a direction parallel to the central axis P (in this embodiment, the axial direction A). Furthermore, as will be described later, if the first window portion 20a is provided over a limited angular range in the circumferential direction E around the central axis P of the expansion portion 2a, but not over the entire circumference (see FIGS. 6A and 6B ), the position of the first window portion 20a may be adjusted by operating the operation unit 1b of the light irradiation device 1 to move the balloon 2 in the circumferential direction E around the central axis P. One or both of the movement of the balloon 2 in the direction parallel to the central axis P (axial direction A in this embodiment) and the movement in the circumferential direction E are performed as necessary. The first balloon position adjustment step S4 is performed while checking the position of the balloon 2, for example, with an endoscope 40 as an imaging device. The first balloon position adjustment step S4 may be performed repeatedly. The light irradiation area refers to an area in the living body that has been predetermined as an area to be irradiated with light.

[0047] In the first inflation step S5, after the first balloon position adjustment step S4, the inflation portion 2a of the balloon 2 is inflated to change from a contracted state to an expanded state, as shown in Fig. 2C. At this time, the inflation portion 2a of the balloon 2 is adjusted to an inflation amount of a first amount, which is an inflation amount that does not contact or lightly contacts the inner wall of the tubular organ 80 and the target site X.

[0048] In the lens position adjustment step S6, after the first expansion step S5, the lens 40b at the tip of the endoscope 40 serving as an imaging device is brought closer to the second window 20b of the balloon 2. The lens position adjustment step S6 is performed, for example, by moving the endoscope 40 serving as an imaging device relative to the light irradiation device 1 in one or both of the axial direction A and the circumferential directions B and E. At this time, a liquid may be introduced between the second window 20b and the lens 40b of the endoscope 40 so as to reduce the difference in refractive index between the interior of the balloon 2 and the space between the second window 20b and the lens 40b of the endoscope 40. In this way, by bringing the lens 40b closer to the second window 20b of the balloon 2, the first window 20a can be viewed through the second window 20b.

[0049] In the second balloon position adjustment step S7, after the lens position adjustment step S6, the position of the first window portion 20a of the balloon 2 is adjusted to align with the intended light irradiation region including the target site X to be irradiated with light. Specifically, the position of the first window portion 20a can be adjusted by operating the operation unit 1b of the light irradiation device 1 to move the balloon 2 in a direction parallel to the central axis P (in the present embodiment, the axial direction A). Furthermore, as will be described later, if the first window portion 20a is provided over a limited angular range that does not extend over the entire circumference in the circumferential direction E around the central axis P of the expansion portion 2a (see FIGS. 6A and 6B ), the position of the first window portion 20a may be adjusted by operating the operation unit 1b of the light irradiation device 1 to move the balloon 2 in the circumferential direction E around the central axis P. One or both of the movement of the balloon 2 in the direction parallel to the central axis P (in the present embodiment, the axial direction A) and the movement in the circumferential direction E can be performed as needed. At this time, by using the endoscope 40 as an imaging device, the position of the first window 20a can be adjusted while visually observing the first window 20a through the second window 20b. In other words, the position of the first window 20a can be adjusted while checking whether the intended light irradiation area, including the target site X, is located within the range of the first window 20a. Therefore, the position of the first window 20a can be adjusted more accurately compared to the first balloon position adjustment step S4. Thus, by performing the first balloon position adjustment step S4 and the second balloon position adjustment step S7 in a stepwise manner, the position of the first window 20a can be efficiently adjusted. The second balloon position adjustment step S7 may be repeatedly performed. Furthermore, at this time, a light provided at the distal end of the endoscope 40, capable of emitting light of a different wavelength from the light of the light irradiation unit 100, can be used to illuminate the interior of the tubular organ 80 as needed. In this way, using light of a different wavelength from the light of the light irradiation unit 100 can prevent unintended activation of photosensitizers.

[0050] In the second inflation step S8, after the second balloon position adjustment step S7, as shown in FIG. 2D , the inflation portion 2 a of the balloon 2 is adjusted to a second inflation amount greater than the first inflation amount in the first inflation step S5, and is then inflated, bringing the first window 20 a into close proximity to or in close contact with the target site X. By bringing the first window 20 a into close proximity to or in close contact with the target site X, light can be more reliably irradiated onto the target site X in the light irradiation step S9, which will be described later. Furthermore, the condition of the target site X can be more clearly visualized through the first window 20 a, and displacement of the balloon 2 during treatment can be prevented.

[0051] In the light irradiation step S9, after the second expansion step S8, as shown in FIG. 2D, the optical fiber 100a serving as the light irradiation unit 100 is caused to emit light, and light is irradiated onto the intended light irradiation area including the target site X through the first tubular body 26 and the first window portion 20a.

[0052] After the above-described series of steps are performed, the expansion portion 2a of the balloon 2 is deflated, and the light irradiation device 1 is pulled out in the removal direction A2 and removed to the outside of the living body through the through passage 40a1 of the endoscope 40. However, the insertion portion 1a of the light irradiation device 1 may be removed to the outside of the living body together with the endoscope 40.

[0053] Next, the balloon 2 will be described in further detail.

[0054] The expansion section 2a of the balloon 2 includes a light-transmitting layer 10 made of a light-transmitting material and a light-shielding layer 11 made of a light-reflecting or light-absorbing material. The light-shielding layer 11 covers the light-transmitting layer 10. More specifically, the light-shielding layer 11 of this embodiment is laminated on the outer surface of the light-transmitting layer 10 in the radial direction C. The light-transmitting layer 10 is transparent and can transmit light emitted from the interior of the expansion section 2a to the exterior of the expansion section 2a. More specifically, the light-transmitting layer 10 can transmit light emitted from an optical fiber 100a serving as a light irradiation section 100 located within the expansion section 2a to the exterior of the expansion section 2a. The wavelength of light from the light irradiation section 100 may be selected appropriately depending on the treatment, and may be, for example, visible light. On the other hand, the light-shielding layer 11 is less likely to transmit light emitted from the light irradiation section 100 than the light-transmitting layer 10. More specifically, the light-shielding layer 11 has a lower transmittance for the light emitted from the light emitting unit 100 than the light-transmitting layer 10 .

[0055] Examples of light-transmitting materials for forming the transmissive layer 10 include resin materials such as polyethylene terephthalate, polyurethane, polyamide, polyamide-based elastomer, and silicone rubber. Examples of light-reflecting materials for forming the light-blocking layer 11 include various metal materials such as titanium oxide, barium sulfate, and zinc oxide, and light-absorbing pigments such as carbon black. The light-blocking layer 11 may be formed, for example, by coating on the surface of the transmissive layer 10. The coating method is not particularly limited, and examples of methods that may be used include dipping, spray coating, roll coating, and screen printing. The light-blocking layer 11 may also be formed on the surface of the transmissive layer 10 by vapor deposition. The light-blocking layer 11 may be formed on the inner surface of the balloon 2 or integrally with the balloon 2.

[0056] 1 and 2B to 3B , the balloon 2 includes a window region 20 and a light-shielding region 21. The light-shielding region 21 is a region where the transmissive layer 10 is covered with the light-shielding layer 11. On the other hand, the window region 20 is a region where the transmissive layer 10 is not covered with the light-shielding layer 11. Because the transmissive layer 10 is covered with the light-shielding layer 11, the light-shielding region 21 is less likely to transmit light from the optical fiber 100a serving as the light irradiation unit 100 than the window region 20. More specifically, the light-shielding region 21 has a lower light transmittance for the optical fiber 100a serving as the light irradiation unit 100 than the window region 20.

[0057] When the expansion section 2a is in an expanded state, the window region 20 includes a first window 20a and a second window 20b that is spaced apart proximally from the first window 20a and is tilted more inclined with respect to the central axis P than the first window 20a. Because the second window 20b is located proximally from the first window 20a, the surgeon can visually recognize the first window 20a, which is located distal to the second window 20b, through the second window 20b. Furthermore, because the second window 20b is spaced apart from the first window 20a (in other words, because at least a portion of the light-shielding region 21 is located between the first window 20a and the second window 20b), the outer edge of the first window 20a can be defined by the light-shielding region 21. As a result, the extent of the first window 20a can be clearly recognized when viewing the first window 20a through the second window 20b. Conversely, if the second window 20b is not spaced apart from the first window 20a (i.e., if the second window 20b and the first window 20a are connected), the boundary between the first window 20a and the second window 20b cannot be seen when the first window 20a is viewed through the second window 20b. Therefore, from the viewpoint of usability, it is preferable that the second window 20b be spaced apart from the first window 20a.

[0058] Light from the optical fiber 100a emitted inside the expansion section 2a passes through the first tubular body 26 and is irradiated outward in the radial direction C of the expansion section 2a through the first window 20a. Light from the optical fiber 100a can also be irradiated from the second window 20b. However, because the second window 20b is located closer to the light-emitting section 100a1 of the optical fiber 100a, the intensity of the light irradiated from the second window 20b is lower than the intensity of the light irradiated from the first window 20a. Furthermore, the expansion section 2a includes a light-shielding region 21 other than the portions where the first and second windows 20a and 20b are formed. The light-shielding region 21 has a lower transmittance for the light of the optical fiber 100a than the window region 20. Therefore, the intensity of the light irradiated outward in the radial direction C through the light-shielding region 21 is lower than the intensity of the light irradiated from the first window 20a. With this configuration, light can be irradiated into the light irradiation region defined as the first window portion 20a with a more uniformly maintained irradiation intensity, enabling efficient light irradiation.

[0059] In the extension section 2a of this embodiment, the distal side of the first window 20a is composed only of the light-shielding region 21. This makes it possible to prevent light from being irradiated to areas other than the intended light irradiation area, which includes the target site X (see FIGS. 2A to 2D) that is the treatment target in the living body and is located distal to the first window 20a.

[0060] Furthermore, the first window 20a in this embodiment is provided over the entire circumference in the circumferential direction E around the central axis P of the expansion section 2a. As a result, even if the target site X located outside the radial direction C of the balloon 2 exists over the entire area in the circumferential direction E of the balloon 2, light can be irradiated to the entire area in the circumferential direction E of the target site X through the first window 20a.

[0061] The second window 20b may have a maximum length of, for example, 1.8 cm or less in a planar view seen from the axial direction A. Furthermore, the second window 20b may have a maximum length of 1.5 cm or less, or may have a maximum length of 1.2 cm or less in a planar view seen from the axial direction A. This makes it easy to position the second window 20b within the diameter of the tip face (distal end face) of the endoscope 40 in the radial direction F. As a result, light from the optical fiber 100a leaking from the second window 20b is easily blocked by the tip face (distal end face) of the endoscope 40, and light irradiation through the second window 20b onto areas other than the intended light irradiation region, including the target site X, can be suppressed.

[0062] As described above, when the expansion section 2a is in an expanded state, the second window 20b is more inclined with respect to the central axis P than the first window 20a. Here, "the second window 20b is inclined with respect to the central axis P" means that, in a cross section that includes the central axis P and is parallel to the central axis P at any position in the circumferential direction E passing through the second window 20b, a straight line L1 connecting two ends (the distal end 50b and the proximal end 50a in the embodiment shown in FIG. 4) of a continuous line (hereinafter referred to as a "continuous line") formed by the surface of the second window 20b is inclined with respect to the central axis P (see FIG. 4). When the second window 20b includes a boundary between the expansion section 2a and the proximal protruding section 2b1, the position of one end may be regarded as the boundary position between the expansion section 2a and the proximal protruding section 2b1.

[0063] In this way, because the second window 20b is inclined with respect to the central axis P, it becomes easier to view the area distal to the second window 20b through the second window 20b using the endoscope 40. Specifically, the endoscope 40 attached to the light irradiation device 1 is often positioned so that the surface of the lens 40b intersects perpendicularly with the central axis P. Therefore, because the second window 20b is inclined with respect to the central axis P, it becomes easier for the second window 20b and the lens 40b of the endoscope 40 to face each other. As a result, it becomes easier to view the area distal to the second window 20b through the second window 20b using the endoscope 40. Conversely, if the second window 20b is not inclined with respect to the central axis P, the second window 20b and the lens 40b of the endoscope 40 do not face each other, making it difficult to view the area distal to the second window 20b through the second window 20b.

[0064] As described above, when the expansion section 2a is in an expanded state, the second window 20b is more inclined with respect to the central axis P than the first window 20a. Here, "the second window 20b is more inclined with respect to the central axis P than the first window 20a" means that the inclination angle of the second window 20b is greater than the inclination angle of the first window 20a. The "inclination angle of the second window 20b" refers to the magnitude of the minor angle formed by the central axis P and a line L1 connecting two ends of a continuous line formed by the surface of the second window 20b (the distal end 50b and the proximal end 50a in the embodiment shown in FIG. 4 ) in a cross section that includes the central axis P and is parallel to the central axis P at any position in the circumferential direction E passing through the second window 20b. For example, when this line L1 is perpendicular to the central axis P, the inclination angle of the second window 20b is 90°. In this embodiment, the straight line L1 is inclined at an acute angle less than 90° with respect to the central axis P. The "inclination angle of the first window portion 20a" refers to the magnitude of the minor angle formed by the central axis P and a straight line L2 connecting two ends (the distal end 60b and the proximal end 60a in the embodiment shown in FIG. 4) of a continuous line formed by the surface of the first window portion 20a in a cross section including the central axis P and parallel to the central axis P at any position in the circumferential direction E passing through the first window portion 20a. For example, when this straight line L2 is parallel to the central axis P, the inclination angle of the first window portion 20a is 0°. In this embodiment, the straight line L2 is parallel to the central axis P (the inclination angle of the first window portion 20a is 0°).

[0065] In this way, since the second window portion 20b is inclined more with respect to the central axis P than the first window portion 20a, it is easier to see the first window portion 20a from the second window portion 20b compared to when the second window portion 20b is not inclined more with respect to the central axis P than the first window portion 20a.

[0066] The first window 20a may be substantially parallel or parallel to the central axis P. Here, "the first window 20a is substantially parallel to the central axis P" means that the above-mentioned "tilt angle of the first window 20a" is 5° or less. Furthermore, "the first window 20a is parallel to the central axis P" means that the above-mentioned "tilt angle of the first window 20a" is 0°. By having the first window 20a be substantially parallel or parallel to the central axis P, it is easier to tilt the second window 20b with respect to the central axis P than the first window 20a, and light can be easily irradiated to the intended light irradiation region including the target site X located outside the radial direction F of the balloon 2.

[0067] In the expanded state, the expansion section 2a of this embodiment includes a cylindrical expansion main body section 2a1 that surrounds the central axis P, an expansion proximal section 2a2 that is connected to the proximal side of the expansion main body section 2a1 and inclined toward the central axis P as it approaches the proximal side, and an expansion distal section 2a3 that is connected to the distal side of the expansion main body section 2a1. In this embodiment, the first window 20a is formed in the expansion main body section 2a1 of the expansion section 2a, and the second window 20b is formed in the expansion proximal section 2a2 of the expansion section 2a.

[0068] Furthermore, in this embodiment, the expansion proximal section 2a2 protrudes proximally from the expansion main body section 2a1 in a hemispherical shape when the expansion section 2a is in an expanded state. By making the expansion proximal section 2a2 hemispherical, the second window 20b provided in the expansion proximal section 2a2 also has a spherical shape. Because the second window 20b has a spherical shape, it is easier to bring the lens 40b of the endoscope 40 closer to the second window 20b than, for example, when the second window 20b has a conical shape. Bringing the lens 40b of the endoscope 40 closer to the second window 20b makes it easier to view the first window 20a through the second window 20b. In particular, when a liquid is contained inside the balloon 2 as a fluid, a difference in the refractive index of light is likely to occur between the inside of the balloon 2 and the space between the second window 20b and the lens 40b of the endoscope 40. As a result, light reflected within the living body is less likely to be focused on the lens 40b via the first window 20a and the second window 20b, and it may be difficult to view the first window 20a through the second window 20b. In response to this, by making the expansion proximal portion 2a2 of the balloon 2 hemispherical, when the lens 40b of the endoscope 40 is brought close to the second window 20b, liquid (for example, liquid for cleaning the lens 40b, gel applied in advance before inserting the balloon 2 into the endoscope 40, or bodily fluid) is more likely to accumulate between the second window 20b and the lens 40b of the endoscope 40 due to surface tension. In other words, by making the expanded proximal portion 2a2 of the balloon 2 hemispherical and storing liquid between the second window portion 20b and the lens 40b of the endoscope 40, the refractive index difference between the inside of the balloon 2 and the space between the second window portion 20b and the lens 40b of the endoscope 40 is reduced, making it easier to see the first window portion 20a through the second window portion 20b.

[0069] FIG. 5A is a diagram showing a modified example of the balloon 2. More specifically, FIG. 5A is a perspective view showing the inflated state of the modified balloon 2. FIG. 5B is a plan view of the balloon 2 shown in FIG. 5A as viewed from the proximal side in the axial direction A. In the modified examples shown in FIGS. 5A and 5B , the second window 20b is provided over the entire circumferential direction E around the central axis P of the expansion section 2a. This makes it easy to view the first window 20a through the second window 20b, regardless of the position of the lens 40b of the endoscope 40 in the circumferential direction E relative to the balloon 2. Furthermore, light from a light provided at the tip (distal end) of the endoscope 40 passes through the first window 20a via the second window 20b, making it easier to reach the inside of the living body, thereby ensuring a brighter field of view when using the endoscope 40.

[0070] FIG. 6A is a diagram showing another modified example of the balloon 2. More specifically, FIG. 6A is a perspective view showing the inflated state of the modified balloon 2. FIG. 6B is a plan view of the balloon 2 shown in FIG. 6A as viewed from the proximal side in the axial direction A. In the modified example shown in FIGS. 6A and 6B , the first window portion 20a is provided over a limited angular range that does not extend over the entire circumference in the circumferential direction E around the central axis P of the expansion portion 2a. This allows for a more limited area of ​​light irradiation by the light irradiation device 1 compared to when the first window portion 20a is provided over the entire circumference in the circumferential direction E (see FIG. 3A , etc.). In this embodiment, the angular range of the first window portion 20a in the circumferential direction E is 180 degrees. However, the angular range of the first window portion 20a in the circumferential direction E is not limited to this and can be changed as appropriate.

[0071] 6A and 6B , the second window portions 20b are arranged at positions different from the first window portions 20a in the circumferential direction E of the extension portion 2a. By arranging the second window portions 20b in this manner, the first window portions 20a are more easily visible from the second window portions 20b than when the second window portions 20b are arranged at the same positions as the first window portions 20a in the circumferential direction E. In this modification, all of the second window portions 20b are arranged at positions different from the first window portions 20a in the circumferential direction E. However, a similar effect can be obtained as long as at least a portion of the second window portions 20b are arranged at positions different from the first window portions 20a in the circumferential direction E.

[0072] The range of the second window portion 20b in the axial direction A is not particularly limited as long as the second window portion 20b is disposed proximally of and spaced from the first window portion 20a. The second window portion 20b may be formed, for example, over the entire expanded proximal portion 2a2 of the expansion portion 2a.

[0073] The balloon, light irradiation device, and treatment method according to the present disclosure are not limited to the specific configurations and steps shown in the above-described embodiments and modified examples, and various modifications, changes, combinations, step substitutions, etc. are possible as long as they do not deviate from the scope of the claims.

[0074] The present disclosure relates to balloons, light delivery devices and treatment methods.

[0075] DESCRIPTION OF SYMBOLS 1: Light irradiation device 1a: Insertion section 1b: Operation section 2: Balloon 2a: Expansion section 2a1: Expansion main body section 2a2: Expansion proximal section 2a3: Expansion distal section 2b: Protrusion section 2b1: Proximal protrusion section 2b2: Distal protrusion section 5: Annular space 10: Transmission layer 11: Light-blocking layer 20: Window region 20a: First window section 20b: Second window section 21: Light-blocking region 25: Tubular member 25a: Inflation lumen 26: First tubular body 26a: Storage space 27: Second tubular body 28: Hub 28a: Port section 28b: Through hole 31: Obstruction member 32: Tip member 40: Endoscope 40a: Main body section 40a1: Through passage 40b: Lens 50a: Proximal end of continuous line formed by second window section 50b: Distal end of the continuous line formed by the second window portion 60a: Proximal end of the continuous line formed by the first window portion 60b: Distal end of the continuous line formed by the first window portion 80: Hollow organ 100: Light irradiation unit 100a: Optical fiber 100a1: Light emitting unit 200: Endoscope system A: Axial direction of the light irradiation device A1: Insertion direction A2: Removal direction B: Circumferential direction of the light irradiation device C: Radial direction of the light irradiation device (an example of the radial direction of the tubular body) E: Circumferential direction of the expansion part of the balloon F: Radial direction of the expansion part of the balloon L1: Straight line connecting the proximal end and distal end of the continuous line formed by the second window portion L2: Straight line connecting the proximal end and distal end of the continuous line formed by the first window portion O: Central axis of the light irradiation device P: Central axis of the expansion part of the balloon X: Target site

Claims

1. A balloon insertable into a living body, the balloon having an expansion portion defining a central axis extending along an insertion direction from a proximal side to a distal side, the expansion portion comprising: a transparent layer capable of transmitting light emitted inside to the outside; and a light-shielding layer covering the transparent layer and having a lower light transmittance than the transparent layer, the expansion portion comprising: a window region where the transparent layer is not covered by the light-shielding layer; and a light-shielding region where the transparent layer is covered by the light-shielding layer, the window region of the expansion portion in an expanded state comprising: a first window portion; and a second window portion disposed proximally away from the first window portion and inclined with respect to the central axis relative to the first window portion.

2. The balloon of claim 1, wherein said first window portion is substantially parallel or parallel to said central axis.

3. The balloon according to claim 1 or 2, wherein the second window portion is provided over the entire circumferential area around the central axis.

4. The balloon according to claim 1 or 2, wherein in said expansion section, the distal side of said first window section is constituted only by said light-shielding region.

5. The balloon according to claim 1 or 2, wherein, in an expanded state, the expansion section comprises: a cylindrical expansion main body section surrounding the central axis; and an expansion proximal section connected to the proximal side of the expansion main body section and inclined so as to approach the central axis line toward the proximal side, wherein the first window section is disposed in the expansion main body section, and the second window section is disposed in the expansion proximal section.

6. The balloon of claim 5, wherein said expanding proximal portion projects proximally from said expanding body portion in a semi-spherical shape.

7. The balloon according to claim 1 or 2, wherein the first window portion is provided over a limited angular range not covering the entire circumference in the circumferential direction around the central axis of the expansion portion.

8. The balloon according to claim 7, wherein at least a portion of said second window portion is disposed at a different position in the circumferential direction from said first window portion.

9. A light irradiation device comprising: a balloon according to claim 1 or 2; and a tubular body that defines an internal storage space that contains or can contain a light irradiation unit that emits light, wherein the balloon covers the radial circumference of the tubular body.

10. A treatment method using the balloon described in claim 1, comprising a balloon position adjustment step of adjusting the position of the first window portion while visually observing the first window portion through the second window portion.

11. The treatment method according to claim 10, wherein in the balloon position adjustment step, the position of the first window portion is adjusted by moving the balloon in a direction parallel to the central axis.

12. A treatment method as described in claim 10 or 11, wherein in the balloon position adjustment step, the position of the first window portion is adjusted by rotating the balloon in a circumferential direction around the central axis.

13. A therapeutic method using a balloon as described in claim 1, comprising: an imaging device insertion step of inserting an imaging device into the living body; a balloon insertion step of inserting the balloon into the living body through a through passage of the imaging device or by running the balloon parallel to an outer surface of the imaging device; an expansion step of expanding the balloon inside the living body; a lens position adjustment step of bringing a lens at the tip of the imaging device closer to the second window portion of the balloon; a balloon position adjustment step of adjusting the position of the first window portion while visually observing the first window portion through the second window portion so that a region to be irradiated with light inside the living body and a position of the first window portion are aligned; and a light irradiation step of irradiating the light into the living body with the position of the region to be irradiated with light being aligned with the position of the first window portion.

14. A therapeutic method using a balloon as described in claim 1, comprising: an imaging device insertion step of inserting an imaging device into the living body; a balloon insertion step of inserting the balloon into the living body through a through passage of the imaging device or by running the balloon parallel to an outer surface of the imaging device; a first expansion step of adjusting the balloon to a first expansion amount and expanding it inside the living body; a lens position adjustment step of bringing a lens at the tip of the imaging device closer to the second window portion of the balloon; a balloon position adjustment step of adjusting the position of the first window portion of the balloon adjusted to the first expansion amount while visually checking the first window portion through the second window portion so that a region to be irradiated with light inside the living body and a position of the first window portion are aligned; a second expansion step of adjusting the balloon to a second expansion amount larger than the first expansion amount and expanding it inside the living body after the balloon position adjustment step; and a light irradiation step of irradiating the light into the living body after the second expansion step, with the region to be irradiated with light being aligned with the position of the first window portion.

Images