Light radiation device and in-vivo light radiation assembly using same

Abstract

Provided is a small-sized light radiation device having heat-dissipation properties and electrically-insulating properties. The light radiation device comprises: a light-emitting element that emits light having a prescribed wavelength; a support body on which the light-emitting element is mounted; an insulated wire that is electrically connected to the light-emitting element; a case that accommodates the light-emitting element, a connecting portion that connects the insulated wire and the light-emitting element, and a portion of the support body; and an insulating seal material that seals the light-emitting element, said portion of the support body, and said connecting portion, inside the case. Another portion of the support body protrudes from the seal material to the outside of the case.

Description

Light irradiation device and in vivo light irradiation assembly using the same

[0001] The present disclosure relates to a light irradiation device and an in-vivo light irradiation assembly using the same.

[0002] Endoscopes are used for in vivo diagnosis and treatment. Treatments that combine endoscopy with laser irradiation are also being performed. In photoimmunotherapy, which has recently attracted attention, if the affected area is located on the body surface or shallow from the body surface, light of a specific wavelength that reacts with a photosensitizer accumulated in cancer cells is irradiated from the body surface. If the affected area is located deep from the body surface, laser light is irradiated to the affected area inside the body by puncturing. Specifically, an optical fiber is inserted into a blood vessel, digestive tract, or other lumen, and laser light of a specific wavelength is irradiated to the affected area inside the body. A deployable balloon light for endoscopic examination has been proposed (see, for example, Patent Document 1).

[0003] Special Publication No. 2022-535144

[0004] The present disclosure provides a compact light irradiation device that has heat dissipation and electrical insulation properties, and is also suitable for use in a laser irradiation device that uses an optical fiber.

[0005] In one embodiment, the light irradiation device comprises: a light emitting element that emits light of a predetermined wavelength; a support on which the light emitting element is mounted; an insulated wire electrically connected to the light emitting element; a light-transmitting case that houses the light emitting element, a portion of the support, and a connection portion between the insulated wire and the light emitting element; and an insulating sealing material that seals the light emitting element, the connection portion, and a portion of the support inside the case, and another portion of the support protrudes from the sealing material to the outside of the case.

[0006] A compact light-emitting device having heat dissipation and electrical insulation properties can be realized.

[0007] 2B 。 FIG. 2C is a diagram showing an example of an in vivo light-illuminating assembly using the light-illuminating device of the first embodiment. FIG. 2D is a schematic diagram of the light-illuminating device of the first embodiment. FIG. 2E is a diagram showing another example of the sealed state of the light-illuminating device of FIG. 2A. FIG. 2F is a side view showing the appearance of the light-emitting element mounting portion of the light-illuminating device of FIGS. 2A and 2B. FIG. 2F is a schematic diagram showing an example of the configuration of optical components. FIG. 2G is a schematic diagram of a light-emitting element mounted on a support body. FIG. 2H is a schematic diagram showing a sealed state of the light-illuminating device. FIG. 2I is a schematic diagram showing an example of lamination of a support body and a light-emitting element. FIG. 2G is a diagram showing an example of an in vivo light-illuminating assembly using the light-illuminating device of the second embodiment. FIG. 2H is a schematic diagram of the light-illuminating device of the second embodiment. FIG. 2I is a schematic diagram of a light-illuminating device of the third embodiment. FIG. 2I is a schematic diagram showing an example of a light-emitting element used in the third embodiment. FIG. 2I is a perspective view of the light-emitting element mounting surface side of the support body used in the third embodiment. FIG. 2I is a perspective view of the back side of the support body used in the third embodiment.

[0008] Hereinafter, embodiments for carrying out the present disclosure will be described with reference to the drawings. The following description is intended to embody the technical concept of the present disclosure, and unless otherwise specified, the present disclosure is not limited to the following description. In each drawing, components having the same function may be assigned the same reference numerals. For convenience, the embodiments may be shown separately in consideration of ease of explanation or understanding of the main points, but partial substitution or combination of configurations shown in different embodiments or examples is possible. In the embodiments shown later, differences from the previously shown embodiments will be mainly described, and redundant description of matters common to the previously shown embodiments may be omitted. The size and positional relationship of components shown in each drawing may be exaggerated for clarity.

[0009] First Embodiment FIG. 1 is a diagram showing an example of an in vivo light irradiation assembly 100 using a light irradiation device 10 according to a first embodiment. The in vivo light irradiation assembly 100 includes a catheter 50 and a light irradiation device 10 inserted into the catheter 50. The catheter 50 is filled with a refrigerant 51 at least during use. The in vivo light irradiation assembly 100 is used for treatment, diagnosis, sensing, and the like. The light irradiation device 10 is inserted into the catheter 50 in the direction indicated by the white arrow "insertion direction" in the figure, and introduced into a living body. Because the light irradiation device 10 is a heat-generating body, a refrigerant 51 is supplied into the catheter 50, and the heat-generating part is cooled during use. The refrigerant 51 may be, for example, saline, blood, lymph, or the like, and the refrigerant temperature is, for example, approximately 10°C to 36°C. The light irradiation device 10 is inserted into the vicinity of a target site such as an affected area in a living body using a catheter 50, so that it is possible to directly irradiate light onto an affected area such as a tumor, and to inspect and confirm a target site for diagnosis, sensing, etc., without using an optical fiber.

[0010] FIG. 2A is a schematic diagram of a light irradiation device 10. The light irradiation device 10 includes a light emitting element 11 that emits light of a predetermined wavelength, a support 12 on which the light emitting element 11 is mounted, and insulated wires 14a and 14b electrically connected to the light emitting element 11. The insulated wires 14a and 14b include metal wiring and an insulating coating, and the metal wiring is covered with the insulating coating. The light irradiation device 10 also includes a case 15 and an insulating sealant 16 that seals the case 15. The case 15 accommodates the light emitting element 11, a portion of the support 12, and the connection portions between the light emitting element 11 and the insulated wires 14a and 14b. The sealant 16 seals the light emitting element 11, a portion of the support 12, and the connection portions between the light emitting element 11 and the insulated wires 14a and 14b within the case 15. Another portion of the support 12 protrudes from the sealant 16 to the outside of the case 15. At least the light exit portion of the case 15 is light-transmitting.

[0011] In the coordinate system of FIG. 2A, the optical axis direction is the Z direction, the mounting direction of the light emitting element 11 on the support 12 is the Y direction, and the direction perpendicular to the Z direction and the Y direction is the X direction. In this configuration example, the longitudinal direction of the support 12 is parallel to the Z direction. The light irradiation device 10 of the first embodiment is inserted into the catheter 50 in the +Z direction, and the insulated electric wires 14a and 14b extend in the -Z direction. The support 12 is made of silicon (Si), aluminum nitride (AlN), silicon nitride (SiN), sapphire (Al ２ O ３ , glass, quartz, ceramics or other insulating material, and the light emitting element 11 is mounted on a light emitting element mounting surface 121 of the support 12 .

[0012] One of the features of the light irradiation device 10 is that the length L of the support 12 is longer than the length of the case 15 in the Z direction, and at least one of the leading end (+Z side) and the trailing end (-Z side) of the support 12 protrudes from the sealing material 16 to the outside of the case 15. As shown in FIG. 2A , with the connection between the light emitting element 11 and the insulated wires 14a and 14b housed inside the case 15, both ends of the support 12 in the longitudinal direction (Z direction) may be protruded from the case 15 and sealed with the sealing material 16. By protruding at least one of both ends of the support 12 in the longitudinal direction to the outside of the sealing material 16, the support 12 comes into contact with the refrigerant 51 to cool the light irradiation device 10 and prevent the refrigerant 51 from entering the case 15.

[0013] The case 15 is a transparent cylindrical body made of glass, quartz, biocompatible plastic, or the like. The outer diameter of the case 15 is, for example, 0.4 mm to 2.0 mm, and the inner diameter is 0.3 mm to 1.5 mm. As an example, a biocompatible plastic tube with an outer diameter of 0.5 mm and an inner diameter of 0.38 mm is used. The width W of the support 12 is smaller than the inner diameter of the case 15, but may be set as wide as possible within the range that can be accommodated within the case 15 in order to increase the contact area with the refrigerant 51. The height H of the support 12 is a thickness that can stably support the light-emitting element 11, and is, for example, approximately 0.1 to 0.3 mm. The length L of the support 12 is longer than the length of the cylindrical case 15 in the axial direction and is determined according to the length of the case 15. When the length of the cylindrical case 15 in the axial direction is 1.0 mm, the length L of the support 12 is, for example, 1.3 mm to 3.0 mm.

[0014] The sealing material 16 sealing both ends of the case 15 along the longitudinal direction of the support is an insulating resin sealing material that prevents the refrigerant 51 from entering the case 15. Examples of resin sealing materials that can be used include epoxy resin, silicone resin, acrylic resin, and thermoplastic resin. A biocompatible insulating resin may be used as the sealing material 16. More preferably, a biocompatible insulating resin with high thermal conductivity is used for the sealing material 16. Examples of such resin materials include polycarbonate (PC), polyethylene terephthalate (PET), polyimide (PI), polyurethane, and polyesterimide, whose components and compositions have been adjusted to mitigate adverse effects on living bodies. The sealing material 16 seals the electrical connection between the light-emitting element 11 and the insulated wires 14a and 14b within the case 15. In the example of FIG. 2A , a portion of the light-emitting element 11 is covered with a sealant 16 at the rear end of the case 15 to efficiently dissipate heat from the light-emitting element 11. However, the light-emitting element 11 does not necessarily need to be in contact with the sealant 16, as long as it is possible to prevent the refrigerant 51 from entering the case 15. FIG. 2B shows another example of a sealed state of the light irradiation device 10. At the rear end of the case 15, the sealant 16 seals the case 15 without touching the light-emitting element 11. In this case, the light-emitting element 11 is housed in the internal space of the case 15 without contacting the sealant 16. While maintaining the sealed state of FIG. 2A or 2B , the insulated wires 14 a and 14 b are pulled out from at least one end of the case 15 to the outside. In the configuration examples of FIGS. 2A and 2B , the insulated wires 14 a and 14 b are pulled out from the rear end of the case 15 in the −Z direction so as not to interfere with the light emission of the light-emitting element 11 in the Y direction.

[0015] The insulated wires 14a and 14b extending outside the case 15 are cooled by the refrigerant 51 and also function as heat dissipation materials. The insulated wires 14a and 14b are, for example, enameled wires, in which metal wiring made of a good conductor such as Cu or Ni is coated with an insulating coating of polyurethane. Instead of polyurethane, insulating resins such as polyester, polyesterimide, polyamideimide, and polyimide may be used. Using the insulating coating, which is the surface coating of the insulated wires 14a and 14b, as a heat dissipation material prevents heat from building up inside the case 15. When rectangular enameled wires are used as the insulated wires 14a and 14b, the resulting wiring is wider, allowing for a larger bonding area with the support 12. Furthermore, for the same cross-sectional area, rectangular enameled wires can be thinner than round enameled wires, allowing for greater miniaturization.

[0016] The light-emitting element 11 is, for example, an edge-emitting laser element that resonates in a direction parallel to the Z axis. When an edge-emitting laser element is used as the light-emitting element 11, one end face in the resonance direction serves as the light-emitting surface. An optical component 17 is disposed inside the case 15 so as to face the light-emitting surface of the light-emitting element 11, and guides the light emitted from the edge-emitting laser element in a direction intersecting with the light-emitting element mounting surface 121. The direction intersecting with the light-emitting element mounting surface 121 is any direction except for directions parallel to the light-emitting element mounting surface 121, but can be, for example, in the range of 50° to 130° relative to the light-emitting element mounting surface 121. It may also be a direction perpendicular to the light-emitting element mounting surface 121. Here, the "perpendicular" direction does not need to be strictly perpendicular to the light-emitting element mounting surface 121, and includes a range of 90° ± 5° taking into account manufacturing errors and surface conditions of the support body 12 and the optical component 17. The light emitted from the light-emitting element 11 is reflected by the optical component 17 and extracted to the outside of the case 15. The optical component 17 is a mirror or a prism having a reflective surface. A metapolarizing element with a thin metasurface element inserted therein may be used as the optical component 17. Alternatively, the optical component 17 may be an optical element having a lens function that controls the divergence angle of the light emitted from the light-emitting element 11.

[0017] The insulated electric wires 14a and 14b are arranged so as not to interfere with the laser light output. The insulated electric wire 14a is electrically connected directly or indirectly to one electrode of the laser element on the light-emitting element mounting surface 121 side of the support body 12. The other insulated electric wire 14b is electrically connected to the other electrode of the laser element on the back surface of the support body 12 (the surface opposite the light-emitting element mounting surface 121). The insulated electric wires 14a and 14b are drawn out of the case 15 from the side opposite the light-emitting surface of the laser element. The insulated electric wire 14a electrically connected to the light-emitting element on the light-emitting element mounting surface 121 side is also referred to as the first insulated electric wire. The insulated electric wire 14b electrically connected to the light-emitting element on the surface of the support body 12 opposite the light-emitting element mounting surface 121 is also referred to as the second insulated electric wire.

[0018] 3A is a side view showing the appearance of the light-emitting element mounting portion of the light irradiation device 10 shown in FIGS. 2A and 2B . The configuration in FIG. 3A shows the state before the light-emitting element mounting portion is inserted into the light-transmitting case 15 and sealed with the sealing material 16. The surface of the light-emitting element 11 facing the optical component 17 is the light-emitting surface 111. The rear end surface 112 opposite the light-emitting surface is a reflective surface, and may be coated with a highly reflective film. A laser cavity is formed between the light-emitting surface 111 and the rear end surface 112. Light emitted from the light-emitting element 11 is reflected by the optical component 17, and output light Lout from the light irradiation device 10 is extracted in the direction of the dashed arrow.

[0019] A portion of the insulating coating of the insulated wire 14a is removed, and the internal metal wiring is connected to one electrode of the light-emitting element 11. A portion of the insulating coating of the insulated wire 14b is removed, and the internal metal wiring is electrically connected to the other electrode of the light-emitting element 11. In the example of FIG. 3A , a conductive film 124 is formed from the light-emitting element mounting surface 121 of the support 12, passing through the side surface and to the back surface 122, and the internal metal wiring of the insulated wire 14b is connected to the conductive film 124. This provides an electrical connection between the other electrode of the light-emitting element 11 and the insulated wire 14b. By providing the conductive film 124 for electrical connection on the surface of the support 12, the conductive film 124 can be used as a heat dissipation member.

[0020] FIG. 3B is a schematic diagram illustrating an example configuration of the optical component 17. FIG. 3B shows the structure before it is housed in the case 15. The optical component 17 may have two or more optical elements. For example, the optical component 17 may have an optical element 171 having a lens function that controls the spread angle of light emitted from the light-emitting element 11, and an optical element 172 that reflects the light whose spread angle has been controlled by the optical element 171 at a predetermined angle or in a predetermined direction. In this configuration example, the incident surface of the optical element 171 is formed as a convex surface, but the reflecting surface of the optical element 172 may be formed as a concave surface. By integrating multiple optical elements 171 and 172 to form the optical component 17, the overall size of the optical component 17 can be reduced, thereby enabling the light irradiation device 10 to be miniaturized.

[0021] FIG. 4 is a schematic diagram of the light-emitting element 11 mounted on the support 12. The light-emitting element 11 is, for example, an edge-emitting laser element having a ridge structure. The light-emitting element 11 includes an n-side electrode 113, an n-side semiconductor layer 114, an active layer 115, a p-side semiconductor layer 116, and a p-side electrode 118. The n-side semiconductor layer 114 may include an optical guide layer, a cladding layer, a contact layer, etc., doped with n-type impurities. The p-side semiconductor layer 116 may include an optical guide layer, a cladding layer, a contact layer, etc., doped with p-type impurities. The p-side electrode 118 is electrically connected to the insulated wire 14a. When an ITO electrode is used as the p-side electrode 118, the p-side electrode 118 may also serve as the cladding layer. The n-side electrode 113 is electrically connected to the other insulated wire 14b via a conductive film 124 formed on the support 12. 4, the p-side electrode 118 and the insulated wire 14a are directly connected, but they may be indirectly connected, for example, a second support may be disposed between the p-side electrode 118 and the insulated wire 14a. As will be described later with reference to FIG. 6, by sandwiching the light-emitting element 11 between two supports 12, heat dissipation can be improved.

[0022] The semiconductor material and its composition of the light-emitting element 11 are designed to emit laser light of a desired wavelength. When the light-emitting element 11 is used as an ultraviolet laser, a violet laser, a blue laser, or a green laser, GaN-based materials such as GaN, InGaN, and AlGaN are used. When the light-emitting element 11 is used as a red laser, an infrared laser, or a near-infrared laser, GaAs-based materials such as GaAs and AlGaAs, or InP-based materials such as InAlGaP and GaInP are used. From the viewpoint of sealing the light-emitting element 11 in the case 15, the resonance length of the laser element may be short and the ridge width may be wide to ensure the gain of the active layer 115. The ridge width may be designed to be, for example, 2 μm to 100 μm. The transverse mode may be multimode or single mode.

[0023] Unlike fiber-based irradiation devices, the light emitted by the light-emitting element 11 is linearly polarized, and the direction of the linear polarization after emission can be changed by changing the reflection direction using an optical component 17 such as a mirror. This makes it possible, for example, to reduce the reflectance when the light is incident on a living body and improve the transmittance through the living body. Even light that is in a specific polarization state when emitted as laser light may change its polarization state or become depolarized while passing through a transmission medium such as an optical fiber. In this embodiment, light can be directly irradiated onto an affected area inside the body without using an optical fiber, so light can be irradiated onto a target location such as an affected area while maintaining a specific polarization state.

[0024] FIG. 5 is a schematic diagram showing the sealed state of the case 15. The optical component 17 is placed on the light-emitting element mounting surface 121 of the support 12, facing the light-emitting element 11's light-emitting surface 111, and the support 12 where the light-emitting element 11 is located is inserted into the case 15. The light irradiation device 10 is obtained by sealing both ends of the case 15 with a sealant 16 while at least one of the longitudinal ends of the support 12 protrudes outside the case 15. In the light irradiation device 10, the support 12 protruding from the case 15 comes into contact with the refrigerant 51 (see FIG. 1 ), ensuring heat dissipation. Furthermore, heat dissipation is improved by using the surfaces of the insulated wires 14a and 14b as heat dissipation members. Sealing both ends of the case 15 with the sealant 16 prevents short circuits caused by the refrigerant 51. The overall thickness and width of the light irradiation device 10, including the case 15, are reduced to approximately 0.5 mm, resulting in an ultra-compact light irradiation device 10 that can be mounted on a catheter 50.

[0025] 6 is a schematic diagram showing an example of a stack of the support 12 and the light-emitting element 11. In this configuration example, the light-emitting element 11 is sandwiched between a first support 12-1 and a second support 12-2. The first support 12-1 contacts the top surface of the light-emitting element 11, and the second support 12-2 contacts the bottom surface of the light-emitting element 11. By sandwiching the light-emitting element 11 between the first support 12-1 and the second support 12-2, heat can be efficiently dissipated to the upper and lower sides of the light-emitting element 11, thereby improving the heat dissipation performance of the light irradiation device 10. The rear end of at least one of the first support 12-1 and the second support 12-2 may be extended in the −Z direction. In Figure 6, it is assumed that the optical component 17 extracts light in a direction (for example, the Y direction) that is non-parallel to the optical axis (Z axis). However, as described in the second embodiment, if light is extracted in a direction parallel to the light-emitting element mounting surface 121 of the support body 12, the tip sides of the first support body 12-1 and the second support body 12-2 may be extended long in the +Z direction.

[0026] Second Embodiment FIG. 7 is a diagram showing an example of an in vivo light irradiation assembly 200 using a light irradiation device 20 according to a second embodiment. The in vivo light irradiation assembly 200 includes a catheter 50 and a light irradiation device 20 inserted into the catheter 50. The catheter 50 is filled with a refrigerant 51 at least during use. The in vivo light irradiation assembly 200 is used for treatment, diagnosis, sensing, and the like. Similar to the light irradiation device 10 according to the first embodiment, the light irradiation device 20 is inserted into the catheter 50 in the "insertion direction" indicated by the white arrow in the figure and introduced into a living body. The catheter 50 is filled with a refrigerant 51. The light irradiation device 20 is used with its heat-generating portion cooled. In the second embodiment, the insulated electric wires 24a and 24b are pulled out from both ends of the case 15 to the outside of the case to enhance heat dissipation. The lengths of the insulated wires 24a and 24b drawn out from both ends of the case 15 to the outside of the case may be such that the length drawn out of the case 15 on the opposite side to the light emitting surface side of the light emitting element 11 is longer than the length drawn out of the case 15 on the opposite side. To achieve this configuration, the light emitted from the light emitting element 11 is guided in a direction parallel to the light emitting element mounting surface or in a direction that does not interfere with the insulated wires 24a and 24b.

[0027] FIG. 8 is a schematic diagram of a light irradiation device 20. The light irradiation device 20 includes a light emitting element 11 that emits light of a predetermined wavelength, a support 12 on which the light emitting element 11 is mounted, and insulated wires 24a and 24b electrically connected to the light emitting element 11. The light irradiation device 20 further includes a case 15 and an insulating sealant 16 that seals the case 15. The case 15 accommodates the light emitting element 11, a portion of the support 12, and the connection portions between the light emitting element 11 and the insulated wires 24a and 24b. The sealant 16 seals the light emitting element 11, a portion of the support 12, and the connection portions between the light emitting element 11 and the insulated wires 24a and 24b within the case 15. One or both longitudinal ends of the support 12 protrude from the sealant 16 to the outside of the case 15. At least the light emitting portion of the case 15 is optically transparent.

[0028] One insulated wire 24a is electrically connected to the light emitting element 11 on the light emitting element mounting surface 121 side of the support body 12. The other insulated wire 24b is electrically connected to the light emitting element 11 on the back surface of the support body 12 (the surface opposite to the light emitting element mounting surface 121). The insulated wires 24a and 24b are arranged with the light emitting element 11 and the support body 12 sandwiched therebetween, as in the first embodiment.

[0029] The light-emitting element 11 is, for example, an edge-emitting laser element. The light-emitting element 11 may be a laser element having a wide ridge structure similar to that of the first embodiment. The direction parallel to the Z axis of the light-emitting element 11 is the resonance direction. An optical component 27 is disposed inside the case 15, and guides light emitted from the emission surface of the laser element in a direction parallel to the light-emitting element mounting surface 121 of the support body 12. The insulated electric wires 24a and 24b extend in the +Z direction and the -Z direction, sandwiching the light-emitting element 11 and the support body 12 therebetween, so that light from the light-emitting element 11 is extracted to the outside of the case 15 in a direction that does not interfere with the insulated electric wires 24a and 24b.

[0030] The optical component 27 reflects light emitted from the light-emitting surface of the light-emitting element 11, for example, in the X direction parallel to the light-emitting element mounting surface 121. Here, the "parallel" direction does not necessarily have to be strictly parallel to the light-emitting element mounting surface 121; it may have an error of approximately ±10°, taking into account the surface condition of the support 12, manufacturing errors of the optical component 27, etc. As long as the laser light reflected by the optical component 27 does not interfere with the insulated electric wires 24a and 24b, it may be extracted at an angle other than parallel. The optical component 27 is preferably as thick as or thinner than the light-emitting element 11. The optical component is a thin, flat-machined mirror or prism, or a metapolarizing element with a thin metasurface element inserted. The optical component 27 may also be an optical element having a lens function that controls the divergence angle of the light emitted from the light-emitting element 11. As described with reference to FIG. 3B, the optical component 27 may have two or more optical elements. For example, it may have an optical element having a lens function that controls the spread angle of the light emitted from the light emitting element 11, and an optical element that reflects the light whose spread angle has been controlled by the optical element at a predetermined angle.

[0031] The sealing material 16 seals the case 15 with at least one of the ends of the support 12 protruding outside the case 15 and with the insulated wires 24a and 24b extended from both ends of the case 15 to the outside. The electrical connection portions between the light-emitting element 11 and the insulated wires 24a and 24b, and the optical component 27 are sealed inside the case 15 and isolated from the coolant 51. The sealing material 16 is preferably a biocompatible resin with high thermal conductivity. As shown in FIG. 2B , the sealing material 16 may seal the rear end of the case 15 so as not to come into contact with the light-emitting element 11 on the rear end side of the case 15.

[0032] The support 12 protruding from the case 15 comes into contact with the refrigerant 51, thereby ensuring heat dissipation of the light irradiation device 20. Furthermore, by drawing the insulated wires 24a and 24b to both longitudinal sides of the case 15, heat dissipation is further improved compared to the first embodiment. As with the first embodiment, the overall thickness and width of the light irradiation device 20, including the case 15, are approximately 0.5 mm, thereby realizing an ultra-compact light irradiation device 20 that can be mounted on a catheter 50. In the configuration of the second embodiment, the light emitting element 11 may be sandwiched between two support members 12-1 and 12-2, as shown in FIG. 6 . In the second embodiment, light emitted from the light emitting element 11 is extracted in a direction that is not obstructed by the support member 12. Therefore, by sandwiching the light emitting element 11 between the two support members 12-1 and 12-2, the heat dissipation of the light irradiation device 20 can be further improved.

[0033] 9 is a schematic diagram of a light irradiation device 30 according to a third embodiment. As in the first and second embodiments, the light irradiation device 30 is also mounted on a catheter 50 (see FIGS. 1 and 7 ) for use, and the light irradiation device 30 and the catheter 50 can form an in-vivo light irradiation assembly. In the third embodiment, a vertical cavity surface emitting laser (VCSEL) is used as the light emitting element 31.

[0034] The light irradiation device 30 includes two light-emitting elements 31 that emit light of a predetermined wavelength, a support 12 on which the light-emitting elements 31 are mounted, and insulated wires 34a and 34b electrically connected to the light-emitting elements 31. The light irradiation device 30 further includes a case 15 and an insulating sealant 16 that seals the case 15. The case 15 accommodates the light-emitting elements 31, a portion of the support 12, and the connection portions between the light-emitting elements 31 and the insulated wires 34a and 34b. The sealant 16 seals the light-emitting elements 31, a portion of the support 12, and the connection portions between the light-emitting elements 31 and the insulated wires 34a and 34b within the case 15. Another portion of the support 12 protrudes from the sealant 16 to the outside of the case 15. At least the light-emitting portion of the case 15 is optically transparent.

[0035] The light emission surface of the VCSEL used in light emitting element 31 faces case 15 in a direction perpendicular to light emitting element mounting surface 121 of support body 12. As shown by the white arrow in the figure, laser light emitted from the VCSEL passes through case 15 in the Y direction, which is perpendicular to light emitting element mounting surface 121, so no optical components such as mirrors are required. Sealant 16, which seals both ends of case 15, is provided in a range that does not interfere with the light emission of the VCSEL.

[0036] The insulated wires 34a and 34b are, for example, two-core enameled wires. One insulated wire 34a is electrically connected to the light emitting element 31 on the light emitting element mounting surface 121 side of the support body 12, and the other insulated wire 34b is electrically connected to the light emitting element 31 on the back surface (the surface opposite the light emitting element mounting surface 121) of the support body 12. The insulated wires 34a and 34b are drawn out of the case 15 from at least one of both ends in the longitudinal direction of the case 15, with the support body 12 sandwiched between them.

[0037] FIG. 10 is a schematic diagram showing an example of a light-emitting element 31 used in the third embodiment. The VCSEL of the light-emitting element 31 has a layered structure in which a semiconductor substrate 401, an n-side reflective film 402, an n-type semiconductor layer 403, an active layer 404, a p-type semiconductor layer 405, and a p-side reflective film 406 are layered in this order in the −Y direction. The light emission direction is the +Y direction. The p-type and n-type conductivity types may be reversed. The semiconductor substrate 401 may be removed. The n-type semiconductor layer 403 has a flat portion and a convex portion protruding from the flat portion in the −Y direction. An active layer 404 is provided on the upper surface of the convex portion of the n-type semiconductor layer 403. A p-type semiconductor layer 405 is provided on the upper surface of the active layer 404, and a p-side reflective film 406 is provided on the upper portion of the p-type semiconductor layer 405 except for the peripheral region. A p-side contact layer may be provided between the p-type semiconductor layer 405 and the p-side reflective film 406.

[0038] The light-emitting element 31 includes an insulating layer 407 that covers the upper surface of the flat portion and the side surfaces of the convex portion of the n-type semiconductor layer 403, the side surfaces of the active layer 404, and the peripheral region of the side surfaces and upper surface of the p-type semiconductor layer 405. The light-emitting element 31 includes a p-side electrode 408 electrically connected to the p-type semiconductor layer 405 and an n-side electrode 409 electrically connected to the n-type semiconductor layer 403. The side on which the p-side electrode 408 and the n-side electrode 409 are provided is disposed on the light-emitting element mounting surface 121 of the support 12. A conductive connection layer (or bump) connected to the light-emitting element mounting surface 121 of the support 12 may be provided so that the heights of the p-side electrode 408 and the n-side electrode 409 in the -Y direction are aligned. When the light-emitting element 31 is flip-chip mounted on the support 12 using the conductive connection layer connected to the p-side electrode 408 and the n-side electrode 409, the p-side reflective film 406 does not interfere with the light-emitting element mounting surface of the support 12.

[0039] The n-side reflective film 402 and the p-side reflective film 406 may each be formed of, for example, a distributed Bragg reflector (DBR). A DBR has a structure in which multiple high-refractive index layers and multiple low-refractive index layers are alternately stacked. The DBR has a wavelength range of high reflectivity called a stop band. The center wavelength and wavelength width of the stop band are determined by the refractive index and thickness of the high-refractive index layers and the refractive index and thickness of the low-refractive index layers. The reflectivity in the stop band of the DBR increases with the refractive index difference between the high-refractive index layers and the number of layers stacked.

[0040] In the example shown in FIG. 10 , a standing wave is formed between the n-side reflective film 402 and the p-side reflective film 406. The wavelength of the standing wave in air is within the stop band of the n-side reflective film 402 and the p-side reflective film 406, and this wavelength is the oscillation wavelength of the laser light. An integer multiple of half the oscillation wavelength is equal to the optical distance between the opposing reflective surfaces of the n-side reflective film 402 and the p-side reflective film 406. The optical distance is the distance obtained by multiplying the actual propagation distance of light through a medium by the refractive index of that medium. Current can be injected into the active layer 404 by applying a forward voltage between the p-side electrode 408 and the n-side electrode 409. This current injection causes a population inversion in the active layer 404, resulting in light amplification by stimulated emission at the oscillation wavelength, i.e., laser oscillation. As described above, the VCSEL of this embodiment is intended to be mounted on the p-side electrode 408 and n-side electrode 409 side, with laser light extracted from the semiconductor substrate 401 side.

[0041] The configuration of the VCSEL shown in FIG. 10 is an example. The components included in the VCSEL may be formed from known materials. The shapes of some of the components included in the VCSEL may be modified, or other components may be further included. A configuration in which laser light is extracted from the side opposite to the semiconductor substrate 401 may also be used.

[0042] FIG. 11A is a perspective view of the light-emitting element mounting surface 121 side of the support 12 used in the third embodiment, and FIG. 11B is a perspective view of the back surface 122 side of the support. Here, the surface opposite the light-emitting element mounting surface 121 is referred to as the "back surface." Conductive films 124 and 125 are formed on the light-emitting element mounting surface 121 of the support 12. The conductive film 124 is formed only on the light-emitting element mounting surface 121 of the support 12 and is electrically insulated from the conductive film 125. The conductive film 124 has a connection region 124c that is connected to one electrode of the light-emitting element 31, and a wide portion 124w at the end on the -Z side of the support 12 that is wider than the connection region 124c. The wide portion 124w is used for electrical connection with the insulated wire 34a. The conductive film 125 is formed from the side surface of the support 12 to the back surface 122.

[0043] The p-side electrode 408 and the n-side electrode 409 of the light-emitting element 31 are connected to the conductive films 124 and 125 on the light-emitting element mounting surface 121, respectively, via conductive connection layers (or bumps). The wide portion 124w of the conductive film 124 is electrically connected to one of the insulated wires 34a. A portion of the insulating coating of the insulated wire 34a is removed, and the internal metal wiring is connected to the conductive film 124. On the back surface 122 of the support 12, the conductive film 125 is electrically connected to the other insulated wire 34b. A portion of the insulating coating of the insulated wire 34b is removed, and the internal metal wiring is connected to the conductive film 125.

[0044] The insulated wires 34a and 34b sandwich the support 12 and extend in the longitudinal direction (Z direction) of the support, so as not to interfere with the light emission of the VCSEL. In the configuration shown in Fig. 9, the insulated wire 34b connected to the rear surface 122 of the support 12 may be extended to the vicinity of the tip of the support 12 on the +Z side. The insulated wires 34a and 34b are cooled by contact with a refrigerant outside the case 15. The support 12 also protrudes from at least one longitudinal end of the case 15 and is cooled by the refrigerant. The conductive films 124 and 125 formed on the surface of the support 12 also function as a heat sink.

[0045] The VCSEL chip used as the light-emitting element 31 has a side length and height of 200 μm or less, is mounted on the support 12, and is housed inside the case 15. The overall thickness and width of the light-emitting device 30 including the case 15 are about 0.5 mm, realizing an ultra-compact light-emitting device 30 that can be mounted on the catheter 50.

[0046] Although the above description has been based on specific configuration examples, the present disclosure is not limited to the above configuration examples. For example, in the first embodiment, the insulated wire 14b, which does not interfere with light emission, may be extended from the tip of the case 15 in the +Z direction to function as a heat dissipation member. In the configurations of the first or third embodiment, a light-emitting element and a photodetector such as a photodiode may be disposed on the light-emitting element mounting surface 121 of the support 12, thereby serving as a biosensor. In the configuration of the third embodiment, instead of mounting two light-emitting elements 31 on the support 12, one light-emitting element 31 and one light-receiving element may be mounted. When using two-core enameled wires as the insulated wires 14a, 14b, 34a, and 34b, one metal wire may be used to supply an electrical signal to the light-emitting element 11 or 31, and the other metal wire may be used as a readout wire for signals output from the photodetector.

[0047] The light irradiation devices 10, 20, and 30 of the first to third embodiments may be used in combination with an endoscope. The light emitting elements 11 and 31 can be used not only as laser light sources for treatment but also as sensing light sources or illumination light sources. In either case, they have heat dissipation properties that allow heat from the light emitting elements to be dissipated to the outside, electrical insulation properties sufficient to ensure insulation in a refrigerant, and are effective as light irradiation devices that can be mounted on a catheter. Unlike optical fibers, insulated wires with insulating coatings are highly flexible. Furthermore, a configuration in which the light emitting elements themselves are mounted on the support 12 has excellent integration properties and a wide range of applications for sensors.

[0048] A temperature simulation was performed using the configuration of the second embodiment, with the length L of the SiN support 12 set to 1.7 mm, two-core enameled wires used as the insulated wires 24a and 24b, and a glass tube with an outer diameter of 0.5 mm and a length of 1.0 mm used as the case 15. The cooling conditions were as follows: physiological saline solution at a temperature of 35°C was supplied at a flow rate of 1 cm / sec. When the optical output of the light-emitting element 11 was 50 mW, the temperature at the center of the light-emitting element was 50°C, the temperature at the center of the support 12 was 46°C, and the coolant temperature at the catheter outlet was 38°C. When the optical output of the light-emitting element 11 was 30 mW, the temperature at the center of the light-emitting element was 45°C, the temperature at the center of the support 12 was 42°C, and the coolant temperature at the catheter outlet was 37°C. Practical application is highly anticipated.

[0049] The present invention can be used not only as a light irradiation device inserted into a medical catheter but also in other medical applications, such as sensors that require localized light irradiation in combination with a refrigerant.

[0050] Embodiments of the present disclosure may include, for example, the following configurations: (Item 1) A light irradiation device comprising: a light emitting element that emits light of a predetermined wavelength; a support on which the light emitting element is mounted; an insulated wire electrically connected to the light emitting element; a case that houses the light emitting element, a connection portion between the insulated wire and the light emitting element, and a part of the support; and an insulating sealing material that seals the light emitting element, the part of the support, and the connection portion inside the case, wherein another part of the support protrudes from the sealing material to the outside of the case. (Item 2) The light irradiation device according to item 1, wherein both ends of the case along the longitudinal direction of the support are sealed with the sealing material with the light emitting element and the connection portion housed inside the case, and the support protrudes to the outside of the case from at least one of the ends of the case. (Item 3) The light irradiation device according to item 1 or 2, wherein both ends of the case along the longitudinal direction of the support body are sealed with the sealing material with the light-emitting element and the connection portion housed inside the case, and the insulated wire is drawn out from at least one of the ends of the case to the outside of the case. (Item 4) The light irradiation device according to item 3, wherein the insulated wire includes a first insulated wire electrically connected to the light-emitting element on the side of the support body on which the light-emitting element is mounted, and a second insulated wire electrically connected to the light-emitting element on the surface of the support body opposite the light-emitting element mounting surface, and the first insulated wire and the second insulated wire are arranged so that the light-emitting element and the support body are sandwiched between them. (Item 5) The light irradiation device according to item 4, wherein the first insulated wire and the second insulated wire are drawn out from both ends of the case to the outside of the case. (Item 6) The light irradiation device according to Item 5, wherein the lengths of the first insulated wire and the second insulated wire drawn out from both ends of the case to the outside of the case are longer on the side of the light emission surface of the light emitting element than on the opposite side.(Item 7) The light irradiation device according to any one of Items 1 to 3, wherein the light-emitting element is an edge-emitting laser element, and an optical component is disposed inside the case to guide light emitted from the edge-emitting laser element in a direction intersecting the light-emitting element mounting surface of the support. (Item 8) The insulated wires include a first insulated wire electrically connected to the light-emitting element on the side of the support that faces the light-emitting element mounting surface, and a second insulated wire electrically connected to the light-emitting element on the surface of the support opposite the light-emitting element mounting surface, and the first insulated wire and the second insulated wire are drawn out of the case on the side opposite to the light emission surface of the edge-emitting laser element. (Item 9) The light irradiation device according to any one of Items 1 to 3, wherein the light-emitting element is an edge-emitting laser element, and an optical component is disposed inside the case to guide light emitted from the edge-emitting laser element in a direction parallel to the light-emitting element mounting surface of the support. (Item 10) The light irradiation device according to Item 9, wherein the insulated wires include a first insulated wire electrically connected to the light emitting element on the side of the support body facing the light emitting element mounting surface, and a second insulated wire electrically connected to the light emitting element on the surface of the support body opposite the light emitting element mounting surface, and light emitted from the edge-emitting laser element is extracted in a direction parallel to the light emitting element mounting surface or in a direction not interfering with the first insulated wire and the second insulated wire. (Item 11) The light irradiation device according to any one of Items 1 to 3, wherein the light emitting element is a vertical-cavity surface-emitting laser, and a light emission surface of the vertical-cavity surface-emitting laser faces the case in a direction perpendicular to the light emitting element mounting surface of the support body. (Item 12) The light irradiation device according to any one of Items 1 to 11, wherein one or both of the case and the sealing material is a biocompatible resin. (Item 13) An in vivo light irradiation assembly comprising: a catheter; and the light irradiation device according to any one of items 1 to 12, which is inserted into the catheter, wherein the inside of the catheter is filled with a refrigerant at least during use.

[0051] This application claims priority based on Japanese Patent Application No. 2023-211659 filed with the Japan Patent Office on December 15, 2023, and includes the entire contents of this Japanese patent application.

[0052] 10, 20, 30 Light irradiation device 11, 31 Light emitting element 111, 317 Light emitting surface 12, 12-1, 12-2 Support 121 Light emitting element mounting surface 122 Back surface 124, 125 Conductive film 14a, 14b, 24a, 24b, 34a, 34b Insulated wire 15 Case 16 Sealant 17, 27 Optical component 171, 172 Optical element 50 Catheter 51 Refrigerant 100, 200 In-vivo light irradiation assembly

Claims

1. A light irradiation device comprising: a light emitting element that emits light of a predetermined wavelength; a support on which the light emitting element is mounted; an insulated electric wire electrically connected to the light emitting element; a case that houses the light emitting element, a connection portion between the insulated electric wire and the light emitting element, and a part of the support; and an insulating sealing material that seals the light emitting element, the part of the support, and the connection portion inside the case, wherein another part of the support protrudes outside the case from the sealing material.

2. The light irradiation device according to claim 1, wherein both ends of the case along the longitudinal direction of the support are sealed with the sealing material with the light-emitting element and the connection part housed inside the case, and the support protrudes outside the case from at least one of the both ends of the case.

3. The light irradiation device according to claim 1 or 2, wherein both ends of the case along the longitudinal direction of the support are sealed with the sealing material while the light-emitting element and the connection part are housed inside the case, and the insulated wire is pulled out to the outside of the case from at least one of the both ends of the case.

4. The light irradiation device described in claim 3, wherein the insulated electric wire includes a first insulated electric wire electrically connected to the light-emitting element on the side of the support body on which the light-emitting element is mounted, and a second insulated electric wire electrically connected to the light-emitting element on the surface of the support body opposite the light-emitting element mounting surface, and the first insulated electric wire and the second insulated electric wire are arranged to sandwich the light-emitting element and the support body therebetween.

5. The light irradiation device according to claim 4, wherein the first insulated wire and the second insulated wire are pulled out from both ends of the case to the outside of the case.

6. The light irradiation device according to claim 5, wherein the lengths of the first insulated wire and the second insulated wire pulled out from both ends of the case to the outside of the case are longer on the opposite side to the light emission surface of the light-emitting element than on the opposite side.

7. A light irradiation device according to any one of claims 1 to 3, wherein the light-emitting element is an edge-emitting laser element, and an optical component is disposed inside the case for guiding light emitted from the edge-emitting laser element in a direction intersecting with a light-emitting element mounting surface of the support.

8. The light irradiation device according to claim 7, wherein the insulated electric wires include a first insulated electric wire electrically connected to the light-emitting element on the side of the support body on which the light-emitting element is mounted, and a second insulated electric wire electrically connected to the light-emitting element on the surface of the support body opposite the light-emitting element mounting surface, and the first insulated electric wire and the second insulated electric wire are pulled out to the outside of the case on the side opposite the light emission surface of the edge-emitting laser element.

9. A light irradiation device according to any one of claims 1 to 3, wherein the light-emitting element is an edge-emitting laser element, and an optical component is provided inside the case for guiding light emitted from the edge-emitting laser element in a direction parallel to a light-emitting element mounting surface of the support.

10. The light irradiation device according to claim 9, wherein the insulated wires include a first insulated wire electrically connected to the light-emitting element on the side of the support body on which the light-emitting element is mounted, and a second insulated wire electrically connected to the light-emitting element on the surface of the support body opposite the light-emitting element mounting surface, and light emitted from the edge-emitting laser element is extracted to the outside of the case from between the first insulated wire and the second insulated wire.

11. The light irradiation device according to any one of claims 1 to 3, wherein the light emitting element is a vertical cavity surface emitting laser, and a light emission surface of the vertical cavity surface emitting laser faces the case in a direction perpendicular to a light emitting element mounting surface of the support.

12. The light irradiation device according to any one of claims 1 to 11, wherein one or both of the case and the sealing material are made of a biocompatible resin.

13. An in vivo light irradiation assembly comprising: a catheter; and a light irradiation device according to any one of claims 1 to 12, which is inserted into the catheter, and the inside of the catheter is filled with a refrigerant at least during use.

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