Light irradiation device and light irradiation system

Abstract

To provide a light irradiation device and a light irradiation system capable of emitting light more efficiently and more appropriately to a specific position in the lumen of a living body.SOLUTION: A light irradiation device is a long-sized medical light irradiation device, and includes a device body, a laser beam source, and a Peltier element. The device body is long-sized. The laser beam source is provided at the tip of the long-sized device body and emits a laser beam. The Peltier element is provided at the tip of the device body. The Peltier element is arranged in contact with or close to the laser beam source in the state that the cooling surface side is opposed to the laser beam source.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a light irradiation device and a light irradiation system that are inserted into a living body lumen and irradiate light.

Background Art

[0002] As one of the techniques for treating diseases, PDT (Photodynamic Therapy) is known. In PDT, after a photosensitive substance is administered to a living body, the living body is irradiated with light. As a result, cancer cells may be killed by reactive oxygen species generated in cancer cells. However, in PDT, it is difficult to selectively accumulate the photosensitive substance in cancer cells. The occurrence of side effects due to the photosensitive substance being taken up by normal cells has been a problem in PDT.

[0003] On the other hand, in recent years, NIR-PIT (Near-infrared photoimmunotherapy) has been proposed. In NIR-PIT, a complex in which an antibody against a specific antigen of cancer cells and two compounds of a photosensitive substance are bound is used. When the complex is administered to a living body, it is likely to selectively accumulate in cancer cells in the body. Thereafter, the complex is activated by irradiating light having an excitation wavelength (for example, a wavelength including 690 nm, etc.) of the photosensitive substance in the complex (see, for example, Patent Document 1, etc.). In NIR-PIT, when the complex is selectively accumulated in cancer cells by the antibody and light is locally irradiated to the cancer cells, side effects are less likely to occur compared to PDT.

[0004] Light in the wavelength range including 690 nm is difficult to penetrate to the inside of the body even when irradiated from the body surface, so it is difficult to treat deep-seated cancers in the body by irradiation from the body surface. Therefore, a technique for irradiating light from a position closer to cancer cells rather than irradiating light from the body surface has been proposed. For example, the device described in Patent Document 2 is inserted into a blood vessel to irradiate light from the deep part of the body.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-523907 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2018-867 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] In conventional devices, it is necessary to transmit the light emitted by a light source provided outside to the tip of the device by an optical transmission member (such as an optical fiber). When using an optical transmission member, bending or the like may occur in the optical transmission member within the lumen of the living body, and the light may leak or attenuate before being transmitted to the tip of the device. When the light leaks or attenuates, problems such as a decrease in the light transmission efficiency or a decrease in safety may occur. Also, during the process of transmitting light by the optical transmission member, the characteristics of the light (such as wavelength) may change, making it difficult to obtain the intended therapeutic effect. Therefore, it is desirable to use a laser light source that can be inserted into the body without using an optical transmission member. However, when a laser light source is inserted into the body and used, if the laser light source is miniaturized without improving the heat dissipation of the laser light source, problems caused by temperature rise (such as failure of the laser light source) may occur.

[0007] A typical object of the present disclosure is to provide a light irradiation device and a light irradiation system capable of more efficiently and appropriately irradiating light at a specific position within the lumen of a living body. [Means for Solving the Problems]

[0008] The light irradiation device provided by a typical embodiment in the present disclosure is a medical light irradiation device having a long shape, and includes a laser light source provided at a tip portion of the long device main body and configured to emit laser light, and a Peltier element provided at the tip portion of the device main body. The Peltier element is arranged in contact with or in proximity to the laser light source with the cooling surface side facing the laser light source.

[0009] The light irradiation system provided by a typical embodiment in the present disclosure is a medical light irradiation system, and includes a catheter formed in a long tube shape, and a long light irradiation device inserted into the lumen of the catheter. The light irradiation device includes a laser light source provided at a tip portion of the long device main body and configured to emit laser light, and a Peltier element provided at the tip portion of the device main body. The Peltier element is arranged in contact with or in proximity to the laser light source with the cooling surface side facing the laser light source, and a light transmission portion for transmitting the laser light emitted by the laser light source included in the light irradiation device to the outside is formed in at least a part of the tip portion of the catheter.

[0010] According to the light irradiation device and the light irradiation system according to the present disclosure, light can be irradiated more efficiently and appropriately at a specific position within the lumen of a living body.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0012] <Summary> The light irradiation device of the present disclosure is a medical light irradiation device having a long shape, and includes a device main body, a laser light source, and a Peltier element. The device main body has a long shape. The laser light source is provided at the tip of the long device main body and emits laser light. The Peltier element is provided at the tip of the device main body. The Peltier element is arranged in contact with or close to the laser light source with the cooling surface side facing the laser light source.

[0013] According to the light irradiation device of the present disclosure, problems caused by the temperature rise at the tip due to the laser light source are appropriately suppressed by the cooling effect of the Peltier element.

[0014] When the Peltier element is arranged close to the laser light source, the cooling surface of the Peltier element and the laser light source may be separated to such an extent that the cooling effect of the laser light source by the Peltier element can be appropriately obtained. Further, the cooling surface of the Peltier element and the laser light source may be close to each other with at least one of an adhesive and a member having a high thermal conductivity arranged between the cooling surface of the Peltier element and the laser light source. Even in this case, if the cooling surface of the Peltier element and the laser light source are thermally connected, the cooling effect of the laser light source by the Peltier element can be appropriately obtained.

[0015] The outer periphery of the Peltier element may be covered with a covering member (for example, resin, etc.) that prevents the intrusion of liquid into the inside. In this case, problems such as failure of the Peltier element due to the intrusion of liquid are appropriately suppressed.

[0016] The laser light source may emit laser light in a direction intersecting the long axis direction of the light irradiation device. In this case, the light irradiation device can selectively irradiate a specific position of the living body with the laser light emitted from the laser light source.

[0017] Among the Peltier elements, at least either the heat generating surface located on the opposite side of the cooling surface or at least one of the indirect heat radiating members having a thermal conductivity equal to or higher than that of the heat generating surface and contacting the heat generating surface may be exposed to the outside and exposed to a liquid (for example, a coolant or the like). In this case, compared with the case where the heat generating surface is not directly or indirectly exposed, the heat generated from the heat generating surface of the Peltier element is more likely to be appropriately radiated.

[0018] Note that a member having a high thermal conductivity (for example, at least one of a heat pipe, a carbon nanotube, ceramics (AlN, SiC, etc.), a metal plate (platinum, titanium, copper), a torque wire, etc.) may be installed on the heat generating surface of the Peltier element. In this case, the heat generated from the heat generating surface of the Peltier element is more likely to be radiated more efficiently. When using a metal plate, the metal plate may be an alloy or the surface of the metal plate may be plated.

[0019] Also, instead of the Peltier element, a member having a high thermal conductivity (for example, at least one of a heat pipe, a carbon nanotube, ceramics (AlN, SiC, etc.), a metal plate (platinum, titanium, copper), a torque wire, etc.) may be arranged in contact with or in proximity to the laser light source. In this case as well, the heat generated from the laser light source is more likely to be appropriately radiated. As described above, when using a metal plate, the metal plate may be an alloy or the surface of the metal plate may be plated.

[0020] The light irradiation device may further include a coolant flow path. The coolant flow path communicates to the laser light source side of the device body, and allows coolant for cooling at least one of the laser light source and the Peltier element to pass to the laser light source side. In this case, the temperature rise of the laser light source and its vicinity is appropriately suppressed by the coolant supplied to the laser light source side through the coolant flow path. Therefore, problems caused by the temperature rise of the tip due to the laser light source (for example, at least one of a failure of the laser light source and coagulation of blood, etc.) are appropriately suppressed. Note that the coolant flow path only needs to extend to the laser light source side to such an extent that the coolant can be supplied to the laser light source. Therefore, the tip of the coolant flow path does not necessarily have to reach the laser light source.

[0021] By forming the device body in a long tube shape, a coolant flow path may be provided in the inner cavity of the device body. When the area of the coolant flow path in a cross section in a direction perpendicular to the extending direction of the device body is defined as the flow path area, the flow path area of the portion adjacent to the proximal side with respect to the laser light source may be wider than the flow path area at the portion where the laser light source is installed.

[0022] In this case, the pressure loss of the coolant in the path to the vicinity of the laser light source in the device is less likely to occur, and the coolant can flow appropriately in the vicinity of the laser light source. Therefore, the laser light source is more easily cooled efficiently. Note that the range in which the flow path area is made wider than the portion where the laser light source is installed (that is, the range of the "portion on the proximal side with respect to the laser light source") can be set as appropriate. For example, the flow path area of all ranges extending from the proximal end of the laser light source itself to the proximal side may be made wider than the flow path area of the installation portion of the laser light source. Also, a certain distance (for example, when the length of the laser light source in the axial direction of the device body is L, a distance of length L or less) may be provided between the range in which the flow path area is made wider than the portion where the laser light source is installed and the proximal end of the laser light source itself.

[0023] In addition, a specific method for making the flow path area of the part where the laser light source is installed narrower than the flow path area of the adjacent part on the proximal end side of the laser light source can be appropriately selected. For example, while keeping the inner diameter of the coolant flow path constant, the cross-sectional area of the member adjacent to the proximal end side of the laser light source may be made smaller than the cross-sectional area of the member at the part where the laser light source is located. In this case, with the shape of the coolant flow path simplified, the flow path area of the part where the laser light source is installed can be made narrower than the flow path area of the adjacent part on the proximal end side of the laser light source. Also, the inner diameter of the coolant flow path at the part where the laser light source is installed may be made smaller than the inner diameter of the coolant flow path at the adjacent part on the proximal end side of the laser light source. In this case, while reducing the diameter of the light irradiation device in the vicinity of the laser light source, the flow path area of the part where the laser light source is installed can be made narrower than the flow path area of the adjacent part on the proximal end side of the laser light source.

[0024] The light irradiation device may further include a power supply line. The power supply line extends from the proximal end side to the distal end side of the device body and supplies power to the laser light source by connecting to the laser light source. The power supply line may be exposed in the coolant flow path. In this case, the heat generated from the laser light source is likely to be released to the coolant through the power supply line. Therefore, the laser light source is more easily cooled efficiently.

[0025] Among the power supply lines, the cross-sectional area of the connection part connected to the laser light source may be larger than the cross-sectional area of the part on the proximal end side of the connection part. In this case, compared with the case where the cross-sectional area of the power supply line is constant, etc., the heat generated from the laser light source is more likely to propagate to the power supply line. Therefore, the laser light source is more easily cooled efficiently.

[0026] At least a part of the surface of the power supply line may be coated with an insulating material. The thickness of the insulating material coating the power supply line may be smaller than the thickness of the power supply line in a state where it is not coated with the insulating material. In this case, compared with the case where the thickness of the insulating material is equal to or greater than the thickness of the power supply line, the heat propagated from the laser light source to the power supply line is more likely to be further released to the outside through the insulating material. Therefore, the laser light source is more easily cooled efficiently.

[0027] The thickness of the insulating material covering the power supply wire may more desirably be 25% or less, and even more desirably 10% or less, of the thickness of the power supply wire. In this case, the heat propagated from the laser light source to the power supply wire is more likely to be released to the outside.

[0028] The light irradiation device may further include a supply detection unit that detects whether or not the coolant is being supplied into the coolant flow path, and a supply notification unit that notifies the detection result by the supply detection unit. In this case, the user can appropriately grasp whether or not the coolant is being supplied into the coolant flow path. Therefore, various problems caused by the laser light being emitted without the coolant being supplied are less likely to occur.

[0029] Note that the specific configuration of the supply detection unit can be appropriately selected. For example, the light irradiation device may include a flow path valve that prevents the backflow of the coolant to the base end side of the coolant in the coolant flow path (details will be described later). The supply detection unit may detect whether or not the coolant is being supplied into the coolant flow path by detecting whether or not the flow path valve is open. In this case, the presence or absence of the supply of the coolant can be appropriately detected based on whether or not the flow path valve is open. Also, the supply detection unit may be a flow rate sensor or the like that is provided in at least a part of the flow path of the coolant to detect the flow of the coolant. It is also possible to use a temperature sensor as the supply detection unit. In this case, the temperature sensor may be used for both detecting the ambient temperature and detecting the presence or absence of the supply of the coolant.

[0030] The light irradiation device may further include a temperature detection unit that detects the temperature of the laser light source (which may be near the laser light source), and a temperature notification unit that notifies the detection result by the temperature detection unit. In this case, the user can easily grasp whether or not the temperature of the laser light source is appropriately maintained.

[0031] Note that the specific configuration of the temperature detection unit can be appropriately selected. For example, the temperature detection unit may be installed on the laser light source. Further, the temperature detection unit may detect the temperature of the vicinity of the laser light source (for example, cooling water or the like in the vicinity of the laser light source). Further, the control unit may detect whether the temperature of the laser light source is below a threshold value by monitoring the state of the laser light source.

[0032] The light irradiation device may further include a flow path valve. The flow path valve is provided on the proximal end side of the laser light source in the coolant flow path to prevent the backflow of the coolant to the proximal end side. By providing the flow path valve, the backflow of the coolant in the coolant flow path is prevented. As a result, the temperature rise of the laser light source and its vicinity is more easily and appropriately suppressed.

[0033] The light irradiation system of the present disclosure is a medical light irradiation system, and includes a catheter formed in a long tube shape and a long light irradiation device inserted into the lumen of the catheter. The light irradiation device includes a laser light source and a Peltier element. The laser light source is provided at the tip of the long device body and emits laser light. The Peltier element is arranged in contact with or close to the laser light source with the cooling surface side facing the laser light source. A light transmission portion that transmits the laser light emitted by the laser light source included in the light irradiation device to the outside is formed in at least a part of the tip portion of the catheter.

[0034] According to the light irradiation system of the present disclosure, problems caused by the temperature rise of the tip portion due to the laser light source are appropriately suppressed by the cooling effect of the Peltier element. Further, the light emitted from the laser light source passes through the light transmission portion of the catheter and irradiates the living tissue. Therefore, the light is irradiated more efficiently and appropriately at a specific position in the lumen of the living body. As described above, the cooling surface of the Peltier element and the laser light source may be separated to such an extent that the cooling effect of the laser light source by the Peltier element is appropriately obtained. Further, the cooling surface of the Peltier element and the laser light source may be close to each other with at least one of an adhesive and a member having a high thermal conductivity disposed therebetween.

[0035] Of the Peltier elements, at least either the heat generating surface located on the side opposite to the cooling surface, or the indirect heat radiating member having a thermal conductivity equal to or higher than that of the heat generating surface and contacting the heat generating surface may be exposed to the outside where it is exposed to a liquid (for example, a coolant or the like). In this case, compared with the case where the heat generating surface is not directly or indirectly exposed, the heat generated from the heat generating surface of the Peltier element is more likely to be appropriately radiated.

[0036] With the light irradiation device inserted into the catheter, coolant may flow into the lumen of the catheter. In this case, the heat generating surface of the Peltier element, or the vicinity of the heat generating surface, is likely to come into contact with the coolant flowing into the lumen of the catheter. As a result, the heat generated from the heat generating surface of the Peltier element is more likely to be radiated efficiently.

[0037] <Embodiment> Hereinafter, typical embodiments of the present disclosure will be described with reference to the drawings. The light irradiation system 1 of the present embodiment is used by being inserted into the lumen of a living body (for example, at least any one of blood vessels, lymph glands, urethra, airway, digestive organs, secretory glands, and reproductive organs). The light irradiation system 1 irradiates light (laser light in this embodiment) to living tissue in a state of being inserted into the lumen of a living body. The light irradiation system can be used for at least any one of therapies such as PDT (Photodynamic Therapy) and NIR-PIT (Near-infrared photoimmunotherapy).

[0038] The light irradiation system 1 of the present embodiment includes a light irradiation device 2 and a catheter 3. When the light irradiation system 1 is used, first, the catheter 3 is inserted into the lumen of a living body. Next, the light irradiation device 2 is inserted into the lumen 311 of the catheter 3 having a long tubular shape. When the insertion is completed, the living tissue is irradiated with light from the light irradiation device 2. However, it is also possible to use only the light irradiation device 2 alone without using the catheter 3.

[0039] In FIGS. 1 to 3 and FIGS. 5 to 7, XY axes orthogonal to each other are illustrated. In these drawings, the lower side of the drawing (+X direction) is defined as the "tip side", the upper side of the drawing (-X direction) is defined as the "base end side", the left side of the drawing (+Y direction) is defined as the "left side", and the right side of the drawing (-Y direction) is defined as the "right side". The light irradiation system 1, the light irradiation device 2, and the catheter 3 are inserted into the living body lumen from the tip side. The base end side is operated by medical staff (such as a doctor, etc.).

[0040] (Light Irradiation Device) Referring to FIGS. 1 to 4, the light irradiation device 2 of the present embodiment will be described. As shown in FIG. 1, the shape of the light irradiation device 2 is elongated. The light irradiation device 2 includes a connector 201, a device body 210, a laser light source 211, and a tip chip 220. The connector 201 is located at the base end side of the light irradiation device 2 and is gripped by the operator. The connector 201 includes a pair of blade portions 202 and a connection portion 203. The connection portion 203 is a substantially cylindrical member. The blade portions 202 are connected to the base end portion of the connection portion 203. The device body 210 is connected to the tip portion of the connection portion 203. Note that the blade portions 202 and the connection portion 203 may be integrally formed. The device body 210 is an elongated member extending along the axis O2. The laser light source 211 is a small laser light source that emits laser light in a predetermined wavelength range. The laser light source 211 is provided at the tip portion of the elongated device body 210. As an example, in the present embodiment, the laser light source 211 is installed at the tip of an elongated torque coil 215 provided inside the device body 210. However, it is also possible to change the specific method for installing the laser light source 211. For example, other members may be used instead of the torque coil 215. The laser light source 211 may be directly fixed to the tip portion of the device body 210. The tip chip 220 is connected to the tip side of the tip portion of the device body 210 further than the laser light source 211. The outer diameter of the tip chip 220 is substantially the same as the outer diameter Φ1 of the device body 210.

[0041] The device main body 210 desirably has antithrombogenicity, flexibility, and biocompatibility. At least one of a resin material and a metal material, etc. can be adopted as the material of the device main body 210. As the resin material, for example, polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicon resin, fluororesin, etc. can be adopted. The device main body 210 of the present embodiment is formed of a resin material that transmits the laser light emitted from the laser light source 211 described later. Therefore, it is not necessary to separately form the device main body 210 of the transmission part that transmits the laser light. However, when forming a transmission part that transmits the laser light emitted from the laser light source 211 in the device main body 210, or when exposing the laser light source 211 to the outside of the device main body 210, etc., the device main body 210 may be formed of a material that does not transmit the laser light (for example, a metal material, etc.). As the metal material, for example, stainless steel such as SUS304, nickel-titanium alloy, cobalt-chromium alloy, platinum, tungsten steel, etc. can be adopted. Note that it is also possible to configure the device main body 210 by combining a plurality of materials.

[0042] The device main body 210 is provided with a coolant flow path 213. The coolant flow path 213 communicates from the proximal end side (the -X side in the figure) of the device main body 210 to the laser light source side (the +X side in the figure), and allows the coolant for cooling the laser light source 211 to pass to the laser light source 211 side (that is, the distal end side of the device main body 210). Therefore, in the light irradiation device 2 of the present embodiment, the temperature rise of the laser light source 211 and its vicinity is appropriately suppressed by the coolant that passes through the coolant flow path 213 and is supplied to the laser light source 211 side. Thus, problems (for example, at least any one of a failure of the laser light source 211 and coagulation of blood, etc.) caused by the temperature rise of the distal end portion due to the laser light source 211 are appropriately suppressed. In the present embodiment, since the device main body 210 is formed in a long tube shape, the coolant flow path 213 is provided in the lumen of the device main body 210. The coolant flow path 213 of the present embodiment extends to a position further on the distal end side than the laser light source 211. However, the coolant flow path 213 only needs to extend to the laser light source 211 side to such an extent that the coolant can be supplied to the laser light source 211. Therefore, the distal end portion of the coolant flow path 213 may be located on the proximal end side of the laser light source 211.

[0043] As shown in FIG. 1, the coolant is supplied from the proximal end side of the coolant flow path 213 to the inside. The light irradiation device 2 is provided with a flow path valve 214. The flow path valve 214 is provided on the proximal end side of the laser light source 211 in the coolant flow path 213. The flow path valve 214 prevents the coolant from flowing backward to the proximal end side in the coolant flow path 213 and allows the coolant to flow to the distal end side. As a result, the problem that the coolant is not supplied to the laser light source 211 and its vicinity is suppressed, so that the temperature rise of the laser light source 211 and its vicinity is more easily and appropriately suppressed. Note that various liquids (for example, physiological saline, etc.) that do not affect living tissues can be used as the coolant.

[0044] At the tip of the device body 210, a discharge port 221 is formed to discharge the coolant supplied from the proximal end side of the coolant flow path 213 to the outside. Therefore, the coolant supplied into the coolant flow path 213 smoothly flows near the laser light source 211 without staying inside. As a result, the temperature rise of the laser light source 211 and its vicinity is more easily and appropriately suppressed.

[0045] In this embodiment, the discharge port 221 is formed in the tip chip 220 provided at the tip of the device body 210. However, it is also possible to change the specific configuration of the discharge port. For example, a discharge port may be formed on the side surface of the device body 210 having a long tube shape separately from the discharge port 221 of the tip chip 220 or together with the discharge port 221 of the tip chip 220. Note that the discharge port is preferably formed on the more distal end side than the position where the laser light source 211 is installed in the extension direction (the direction of the axis O2) of the device body 210.

[0046] Furthermore, in this embodiment, at least a part (in this embodiment, all of the tip chip 220) of the tip chip 220 provided at the tip of the light irradiation device 2 is formed of a material having radiation impermeability. Therefore, when a medical worker (for example, a surgeon, etc.) irradiates a living tissue with laser light by the light irradiation device 2 while imaging the inside of the living body using radiation (for example, X-rays, etc.), the position of the tip chip 220 appearing in the captured image can be confirmed, and thus the irradiation position of the laser light can be appropriately adjusted. Therefore, the accuracy of the treatment is likely to be improved.

[0047] The light irradiation device 2 includes a supply detection unit 216 and a supply notification unit 51. The supply detection unit 216 detects whether or not the coolant is being supplied into the coolant flow path 213. The supply notification unit 51 notifies the user of the detection result by the supply detection unit 216. Therefore, the user can appropriately grasp whether or not the coolant is being supplied into the coolant flow path 213. Therefore, various problems due to the emission of laser light without the supply of the coolant are less likely to occur.

[0048] The specific configurations of the supply detection unit 216 and the supply notification unit 51 can be appropriately selected. As an example, the supply detection unit 216 of the present embodiment detects whether the coolant is supplied into the coolant flow path 213 by detecting whether the flow path valve 214 is open. Therefore, the presence or absence of the coolant supply is appropriately detected based on whether the flow path valve 214 is open. Further, the control unit 5 controls the driving of the supply notification unit 51 (for example, at least any one of driving such as lighting, extinguishing, and blinking of a light source, voice output, and image display) according to the detection result by the supply detection unit 216, and notifies the user of the detection result. However, it is also possible to change the configurations of the supply detection unit 216 and the supply notification unit 51. For example, the supply detection unit may be a flow rate sensor or the like that detects the flow of the coolant by being provided in at least a part of the coolant flow path. It is also possible to use a temperature sensor as the supply detection unit. In this case, the temperature sensor may be used for both detecting the ambient temperature and detecting the presence or absence of the coolant supply.

[0049] The light irradiation device 2 includes a temperature detection unit 218 and a temperature notification unit 52. The temperature detection unit 218 detects the temperature of at least one of the laser light source 211 and the vicinity of the laser light source 211. The temperature notification unit 52 notifies the user of the detection result by the temperature detection unit 218. Therefore, the user can easily grasp whether the temperature of the laser light source 211 (or in the vicinity) is appropriately maintained.

[0050] The specific configurations of the temperature detection unit 218 and the temperature notification unit 52 can be appropriately selected. As an example, the temperature detection unit 218 of the present embodiment is installed on the laser light source 211 to detect the temperature of the laser light source 211. However, the temperature detection unit 218 may detect the temperature of the vicinity of the laser light source 211 (for example, the coolant or the like in the vicinity of the laser light source 211). Further, the control unit 5 may detect whether the temperature of the laser light source 211 is equal to or lower than a threshold value by monitoring the state of the laser light source 211. Further, in the present embodiment, the control unit 5 controls the driving of the temperature notification unit 52 (for example, at least any one of driving such as lighting, extinguishing, and blinking of the light source, voice output, and image display) according to the detection result by the temperature detection unit 218, thereby notifying the user of the detection result. The control unit 5 may notify whether the temperature detected by the temperature detection unit 218 is equal to or lower than the threshold value, or may notify the detected temperature itself.

[0051] Referring to FIG. 3, the configuration of the tip of the light irradiation device 2 of the present embodiment will be described. FIG. 3 is an enlarged longitudinal sectional view of the vicinity of the tip of the light irradiation system 1 in FIG. 2. As described above, the light irradiation device 2 includes a small laser light source 211 that emits laser light in a predetermined wavelength range at the tip. Specifically, the laser light source 211 is formed in a rectangular shape, and the laser light source 211 is installed in a coolant flow path 213 that is an inner cavity (lumen) of the light irradiation device 2 having a long tubular shape. However, it is also possible to change the fixing method of the laser light source 211. For example, at least a part of the laser light source 211 (for example, a light emitting part that emits laser light) may be exposed outside the device main body 210.

[0052] The laser light source 211 emits laser light in a direction intersecting the major axis direction (the direction of the axis O2) of the light irradiation device 2 (in the example shown in FIG. 3, the arrow direction intersecting perpendicularly to the axis O2). Therefore, the light irradiation device 2 can directly irradiate a specific position of the living body with light from the laser light source 211 provided at the tip without using an optical transmission member such as an optical fiber. Thus, various problems that occur when using an optical transmission member (for example, at least any one of problems such as light leakage and attenuation in the middle of the optical transmission member, and problems such as changes in the characteristics of light during the process of light transmission) are appropriately suppressed. Further, the laser light source 211 emits laser light from the tip of the light irradiation device 2 in a direction intersecting the direction of the axis O2. The laser light source 211 can easily emit light with high directivity that is difficult to diverge compared to a light emitting diode. Therefore, the light irradiation device 2 of the present embodiment can selectively irradiate a specific position of the living body with the laser light emitted from the laser light source 211. As a result, various problems (for example, occurrence of side effects, etc.) due to light being irradiated to an unintended position are also less likely to occur. Furthermore, the laser light source 211 has the property of being able to irradiate light with a narrow spectral width compared to a light emitting diode. Therefore, by providing the laser light source 211 at the tip of the light irradiation device 2, various problems (for example, at least any one of a decrease in irradiation efficiency and an unintended change in tissue, etc.) due to light with a wavelength different from the wavelength required for treatment (for example, the excitation wavelength of a photosensitive substance, etc.) being irradiated to the tissue are also suppressed. Thus, it becomes easier to irradiate light more efficiently and appropriately to a specific position within the lumen of the living body.

[0053] As the laser light source 211, a surface emitting laser that irradiates laser light in a direction perpendicular to the substrate can be employed. By using a surface emitting laser, a light irradiation device 2 that appropriately emits laser light with a small amount of power and has high resistance to temperature changes can be obtained. Further, since the surface emitting laser can emit laser light in a direction perpendicular to the substrate surface, it becomes easier to more accurately adjust the irradiation position of the laser light.

[0054] In addition, a semiconductor laser, which is a circuit element manufactured using a semiconductor as a material, can also be adopted as the laser light source 211. Since the semiconductor laser is easily miniaturized, it is easily incorporated into the small-diameter light irradiation device 2. In addition, the semiconductor laser can emit highly directional laser light with a uniform phase using a small amount of power. Therefore, the therapeutic effect is also likely to be stabilized.

[0055] The laser light source 211 may emit laser light having a wavelength of 300 nm or more and 2000 nm or less. More desirably, the laser light source 211 may emit laser light having a wavelength of 600 nm or more and 1000 nm or less. In this case, by using the light irradiation device 2 for the treatment of diseases using a photosensitive substance, the therapeutic effect is likely to be appropriately obtained. In the present embodiment, the central wavelength of the laser light emitted by the laser light source 211 is set to about 690 nm.

[0056] The light irradiation device 2 includes a power supply line 231 (in this embodiment, a pair of power supply lines 231). The power supply line 231 extends from the base end side to the tip end side of the device main body 210 and supplies at least power to the laser light source 211 by connecting to the laser light source 211. The base end side of the power supply line 231 in the present embodiment is connected to the control unit 5 (see FIGS. 1 and 2). The power supply line 231 (both of the pair of power supply lines 231 in this embodiment) is exposed in the coolant flow path 213 in the device main body 210. Therefore, the heat generated from the laser light source 211 is easily released to the coolant through the power supply line 231. As a result, the laser light source 211 is more efficiently cooled. In the present embodiment, a metal material having a high thermal conductivity (for example, at least one of copper and nickel) is adopted as the material of the power supply line 231. Therefore, the heat generated from the laser light source 211 easily propagates to the power supply line 231. The heat propagated to the power supply line 231 is smoothly released to the coolant.

[0057] As shown in FIG. 3, among the power supply lines 231 (each of the pair of power supply lines 231 in this embodiment), the outer diameter of the connection portion 231B connected to the laser light source 211 is larger than the outer diameter of the proximal end side portion 231A extending from the connection portion 231B toward the proximal end side (+X side in FIG. 3). In other words, when looking at the cross-sectional area of the power supply line 231 in a cross-section perpendicular to the axis O2 of the light irradiation device 2, the cross-sectional area of the connection portion 231B connected to the laser light source 211 is larger than the cross-sectional area of the proximal end side portion 231A extending from the connection portion 231B toward the proximal end side. Therefore, compared to the case where the cross-sectional area of the power supply line 231 is constant, the heat generated from the laser light source 211 is more likely to be further propagated to the power supply line 231. The heat propagated to the power supply line 231 is smoothly released to the coolant. Thus, the laser light source 211 is more easily cooled efficiently.

[0058] FIG. 4 is a cross-sectional view of the power supply line 231 in a direction perpendicular to the axis O of the light irradiation device 2. As shown in FIG. 4, at least a part of the power supply line 231 of this embodiment (both the proximal end side portion 231A and the connection portion 231B of the power supply line 231 in this embodiment) is covered with an insulating material 232. As a result, leakage of electricity from the power supply line 231 to the outside is appropriately suppressed. As the material of the insulating material 232, for example, at least any one of materials having insulating properties such as polyurethane, polyester, polyesterimide, polyamideimide, polyimide, etc. can be adopted.

[0059] In this embodiment, the shape of the cross-section perpendicular to the axis O2 of the long power supply line 231 is circular. However, the cross-sectional shape of the power supply line 231 may be a shape other than circular (for example, rectangular or elliptical, etc.).

[0060] As shown in FIG. 4, in the present embodiment, the thickness TI of the insulating material 232 covering the power supply line 231 is designed to be smaller than the thickness TF of the power supply line 231 in a state where it is not covered by the insulating material 232 (specifically, the thickness of the proximal end side portion 231A of the power supply line 231). The "thickness" means the thickness in a cross section perpendicular to the extending direction of the power supply line 231. In other words, in the present embodiment, the thickness TI of the insulating material 232 is designed to be smaller than the diameter TF of the power supply line 231. As a result, since the thickness TI of the insulating material 232 becomes thinner, the heat propagated from the laser light source 211 to the power supply line 231 is easily released to the outside (cooling liquid in the present embodiment) through the thinly formed insulating material 232. Therefore, the laser light source 211 is more easily cooled efficiently. As an example, the thickness of the power supply line 231 may be designed to be 0.05 mm to 0.20 mm, and the thickness of the insulating material 232 may be designed to be 0.003 mm to 0.02 mm. Note that the thickness of the insulating material 232 covering the power supply line 231 may be more desirably 25% or less, and even more desirably 10% or less of the thickness of the power supply line 231. In this case, the heat propagated from the laser light source to the power supply line is more easily released to the outside.

[0061] As shown in FIG. 3, in the present embodiment, since the device main body 210 is formed in a long tube shape, a coolant flow path 213 is provided in the lumen of the device main body 210. Here, the area of the coolant flow path 213 in a cross section in a direction perpendicular to the extending direction (direction of the axis O2) of the device main body 210 is defined as the flow path area. In the present embodiment, the flow path area FA2 of the coolant flow path 213 in a portion on the proximal end side of the laser light source 211 is larger than the flow path area FA1 of the coolant flow path 213 in a portion where the laser light source 211 is installed in the extending direction (direction of the axis O2) of the device main body 210. As a result, the pressure loss of the coolant in the path up to the vicinity of the laser light source 211 in the device main body 210 is less likely to occur, and the coolant easily flows appropriately in the vicinity of the laser light source 211. Therefore, the laser light source is more easily cooled efficiently.

[0062] The range in which the flow path area is made wider than the part where the laser light source 211 is installed (that is, the range of the "part on the proximal side of the laser light source") can be set as appropriate. As an example, in the present embodiment, the flow path area of all ranges extending from the proximal end of the laser light source 211 itself to the proximal side is wider than the flow path area of the installation part of the laser light source 211. However, a certain distance (for example, when the length of the laser light source 211 in the direction of the axis O2 is L, a distance of L or less) may be provided between the range in which the flow path area is made wider than the part where the laser light source 211 is installed and the proximal end of the laser light source 211 itself.

[0063] In the present embodiment, as shown in FIG. 3, while the inner diameter of the coolant flow path 213 is made constant, the cross-sectional area of the member adjacent to the proximal side of the laser light source 211 is smaller than the cross-sectional area of the member at the position where the laser light source 211 is located (in the present embodiment, the sum of the cross-sectional area of the laser light source 211 and the cross-sectional area of the Peltier element 230 described later). In this case, with the shape of the device body 210 forming the coolant flow path 213 being simplified, the flow path area FA1 of the part where the laser light source 211 is installed can be made narrower than the flow path area FA2 of the adjacent part on the proximal side of the laser light source 211. However, it is also possible to change the method of making the flow path area FA2 wider than the flow path area FA1. For example, the inner diameter of the coolant flow path 213 at the part where the laser light source 211 is installed may be made narrower than the inner diameter of the coolant flow path 213 at the adjacent part on the proximal side of the laser light source 211. In this case, while reducing the diameter of the light irradiation device 2 in the vicinity of the laser light source 211, the flow path area FA1 of the part where the laser light source 211 is installed can be made narrower than the flow path area FA2 of the adjacent part on the proximal side of the laser light source 211.

[0064] As shown in FIG. 3, the light irradiation device 2 of the present embodiment includes a Peltier element 230 at the tip of the device main body 210. A wiring 233 extending from the base end side along the extension direction (the direction of the axis O2) of the light irradiation device 2 is connected to the Peltier element 230 (the illustration of the wiring 233 is omitted in FIGS. 1 and 2). The Peltier element 230 is a semiconductor element using the Peltier effect, and has a heat generating surface 230A and a cooling surface 230B. When a direct current flows through the Peltier element 230, while the cooling surface 230B absorbs heat, the heat generating surface 230A generates heat. The Peltier element 230 is disposed in contact with the laser light source 211 with the cooling surface 230B side facing the laser light source 211. However, the cooling surface 230B of the Peltier element 230 may be disposed at a position close to the laser light source 211 (that is, at a position where a gap is formed between the laser light source 211) in a state where the cooling surface 230B of the Peltier element 230 faces the laser light source 211. That is, the cooling surface 230B of the Peltier element 230 and the laser light source 211 may be separated as long as the cooling effect of the laser light source 211 by the Peltier element 230 can be appropriately obtained. Further, the cooling surface 230B of the Peltier element 230 and the laser light source 211 may be close to each other in a state where at least one of an adhesive and a member having a high thermal conductivity is disposed between the cooling surface 230B of the Peltier element 230 and the laser light source 211. By facing the cooling surface 230B side of the Peltier element 230 to the laser light source 211, various problems caused by the temperature rise at the tip by the laser light source 211 are appropriately suppressed by the cooling effect of the Peltier element 230.

[0065] In the present embodiment, the outer periphery of the Peltier element 230 is covered with a covering member (for example, resin or the like) that prevents the intrusion of liquid into the inside. As a result, problems such as failure of the Peltier element 230 due to the intrusion of liquid are appropriately suppressed.

[0066] The heat generating surface 230A of the Peltier element 230 is exposed to the outside and is exposed to the liquid. Specifically, the heat generating surface 230A of the present embodiment is exposed to the space in the coolant flow path 213 through which the coolant flows. Therefore, when the coolant is supplied into the coolant flow path 213, the heat generating surface 230A of the Peltier element 230 is exposed to (contacts) the coolant. Thus, compared with the case where the heat generating surface 230A is not exposed to the outside, the heat generated from the heat generating surface 230A of the Peltier element 230 is more likely to be appropriately released to the outside.

[0067] In the present embodiment, at least a part of the members of the Peltier element 230 (for example, at least one of the heat generating surface 230A and the cooling surface 230B) is formed of a radiation-impermeable material. Therefore, when a medical practitioner irradiates a living tissue with laser light by the light irradiation device 2 while imaging the inside of the living body using radiation, the medical practitioner can appropriately adjust the irradiation position of the laser light by checking the position of the Peltier element 230 shown in the captured image. Specifically, in the present embodiment, the installation position of the Peltier element 230 in the light irradiation device 2 is deviated from the axis O2 of the light irradiation device 2. Therefore, the medical practitioner can appropriately grasp the emission direction of the laser light from the laser light source 211 by checking the position of the Peltier element 230 with respect to the axis O2 of the light irradiation device 2 on the captured image.

[0068] (Catheter) With reference to FIGS. 1 to 3, the catheter 3 of the present embodiment will be described. As shown in FIG. 1, the shape of the catheter 3 is a long tube shape. The catheter 3 includes a connector 301, a shaft 310, and a tip 320. The connector 301 is located on the proximal end side of the catheter 3 and is gripped by the operator. The connector 301 includes a pair of blades 302 and a connecting portion 303. The connecting portion 303 is a substantially cylindrical member. The blades 302 are connected to the proximal end portion of the connecting portion 303. The shaft 310 is connected to the distal end portion of the connecting portion 303. Note that the blades 302 and the connecting portion 303 may be integrally formed.

[0069] Similar to the device body 210 of the light irradiation device 2, the shaft 310 desirably has antithrombogenicity, flexibility, and biocompatibility. As the material of the shaft 310, the same material as that of the device body 210 of the light irradiation device 2 can be adopted. The shaft 310 is a long tubular member extending along the axis O3. The shaft 310 of the present embodiment is formed in a hollow cylindrical shape with both the tip end portion and the base end portion open. The lumen 311 inside the shaft 310 functions as a guide wire lumen for inserting a guide wire through the catheter 3 during the delivery of the catheter 3. After the delivery of the catheter 3, the lumen 311 functions as a device lumen for inserting the light irradiation device 2 through the catheter 3.

[0070] The tip 320 is connected to the tip end portion of the shaft 310. The tip 320 has an outer shape with a reduced diameter from the base end side to the tip end side in order to smoothly advance the catheter 3 within the body lumen. A through hole 321 penetrating in the direction of the axis O2 is formed substantially at the center of the tip 320. The inner diameter of the through hole 321 is smaller than the inner diameter of the lumen 311 of the shaft 310 and also smaller than the outer diameter Φ1 of the tip 220 of the light irradiation device 2. Further, the outer diameters Φ1 of the device body 210 and the tip 220 of the light irradiation device 2 are equal to or smaller than the inner diameter of the lumen 311 of the catheter 3. Therefore, the light irradiation device 2 moves along the axis O2 within the lumen 311 of the catheter 3. When the light irradiation device 2 is sufficiently pushed forward within the lumen 311 of the catheter 3, the tip 220 of the light irradiation device 2 contacts the tip 320 of the catheter 3, thereby positioning the light irradiation device 2 with respect to the catheter 3 in the directions of the axes O2 and O3. Note that at least a part (in the present embodiment, all of the tip 320) of the tip 320 is formed of a material having radiopacity. Therefore, the position of the tip end portion of the catheter 3 is appropriately grasped by a radiographic image.

[0071] In this embodiment, a coolant is supplied into the lumen 311 of the catheter 3 (the space between the outer peripheral surface of the light irradiation device 2 and the inner peripheral surface of the lumen 311 of the catheter 3). That is, in this embodiment, the coolant is supplied to both the coolant flow path 213 of the light irradiation device 2 and the lumen 311 of the catheter 3. As a result, problems caused by the temperature rise at the tip due to the laser light source 211 are more likely to be suppressed.

[0072] As shown in FIG. 3, on the tip-side side surface of the shaft 310 in the catheter 3 (a part of the tip-side side surface in this embodiment), a light transmission portion 330 is provided that transmits the laser light emitted by the laser light source 211 included in the light irradiation device 2 to the outside. Therefore, the light irradiation system 1 of this embodiment can selectively irradiate a specific position of the living body with the laser light emitted by the laser light source 211 of the light irradiation device 2 in a direction intersecting the axes O2 and O3.

[0073] In this embodiment, the light transmission portion 330 is provided by partially forming, with a material that transmits laser light, the portion of the shaft 310 in the catheter 3 that transmits the laser light emitted by the laser light source 211. However, it is also possible to change the configuration of the light transmission portion. For example, the light transmission portion may be provided in the catheter by making the entire material of the shaft 310 itself or the tip portion of the shaft 310 a material that transmits laser light.

[0074] On the shaft 310 of the catheter 3, a catheter-side marker portion 332 having radiopacity is provided at a position close to the light transmission portion 330. Therefore, when a medical staff irradiates a living tissue with laser light using the light irradiation device 2 while imaging the inside of the living body using radiation, by aligning the position of the laser light source 211 of the light irradiation device 2 with the position of the catheter-side marker portion 332 appearing in the captured image, the laser light can be appropriately irradiated from the light transmission portion 330 to the outside. Thus, the accuracy of the treatment is more likely to be further improved.

[0075] As shown in FIG. 3, at the tip of the catheter 3, a discharge port 341 for discharging the coolant from the inside of the lumen 311 to the outside of the catheter 3 is formed. Therefore, the coolant supplied to the inside of the catheter 3 (in this embodiment, both the coolant supplied to the coolant flow path 213 of the light irradiation device 2 and the coolant supplied into the lumen 311 of the catheter 3) passes near the tip of the light irradiation device 2 where the laser light source 211 is installed, and is discharged from the discharge port 341 to the outside of the catheter 3. As a result, since the coolant continues to be supplied near the laser light source 211, it becomes easier to more appropriately suppress the temperature rise of the laser light source 211 and its vicinity. Also, the possibility that the blood outside the catheter 3 comes into contact with the members (such as the laser light source 211) inside the catheter 3 is appropriately reduced. Therefore, it is less likely that the blood coagulates due to the heat of the laser light source 211 and the like.

[0076] In the catheter 3 of this embodiment, the through-hole 321 of the tip tip 320 for inserting the guide wire during the delivery of the catheter 3 also serves as the discharge port 341 for the coolant. Therefore, while suppressing the complication of the configuration of the catheter 3, both the delivery of the catheter 3 and the cooling near the laser light source 211 are appropriately performed. However, it is also possible to change the specific configuration of the discharge port of the catheter 3. For example, a discharge port may be formed on the side surface of the shaft 310 having a long tube shape separately from the through-hole 321 of the tip tip 320, or together with the through-hole 321 of the tip tip 320. Note that the discharge port is preferably formed on the more distal side than the position where the laser light source 211 is arranged during use in the extending direction (the direction of the axis O3) of the catheter 3.

[0077] As shown in FIG. 3, a discharge valve 322 is provided at the discharge port 341 of the catheter 3 to allow the liquid to be discharged from the inside of the catheter 3 to the outside through the discharge port 341 while preventing the liquid from flowing into the inside of the catheter 3 from the outside of the catheter 3. As a result, the blood or the like outside the catheter 3 flowing into the inside of the catheter 3 through the discharge port 341 is suppressed by the discharge valve 322. Therefore, it is even less likely that the blood coagulates due to the heat of the laser light source 211 and the like.

[0078] (Usage method) An example of the usage method of the light irradiation system 1 of this embodiment will be described. First, the operator inserts a guide wire (not shown) into the biological lumen. Next, the operator inserts the proximal end side of the guide wire from the through hole 321 of the tip chip 320 of the catheter 3 into the lumen 311 and projects it to the proximal end side of the connector 301. The operator advances the catheter 3 along the guide wire and moves the light transmission portion 330 of the catheter 3 to the target site for light irradiation. When moving the catheter 3 within the biological lumen, the operator can appropriately move the catheter 3 to the target site by checking the position of the catheter side marker portion 332 based on the radiographic image. Then, the operator removes the guide wire from the catheter 3.

[0079] The operator supplies the coolant to the coolant flow path 213 of the light irradiation device 2 and the lumen 311 of the catheter 3. The operator inserts the light irradiation device 2 from the proximal end side opening of the connector 301 of the catheter 3 and advances the light irradiation device 2 within the biological lumen along the lumen 311 of the catheter 3. When the light irradiation device 2 is sufficiently advanced within the lumen 311 of the catheter 3, the tip chip 220 of the light irradiation device 2 contacts the tip chip 320 of the catheter 3. As shown in FIG. 3, the light transmission portion 330 in the catheter 3 is formed at a position where the laser light source 211 is arranged in a state where the tip chip 220 of the light irradiation device 2 contacts the tip of the inner cavity of the catheter 3 (the tip chip 320 of the catheter 3) in the directions of the axes O2 and O3. Therefore, just by advancing the light irradiation device 2 until it contacts the tip chip 320 of the catheter 3, the positions of the laser light source 211 and the light transmission portion 330 in the directions of the axes O2 and O3 automatically coincide. Further, the operator adjusts the emission direction of the laser light from the laser light source 211 by rotating the light irradiation device 2 around the axis O2 while checking the position of the Peltier element 230 with respect to the axes O2 and O3 on the radiographic image. In this state, when the laser light is emitted from the laser light source 211, the target site is selectively irradiated with the laser light.

[0080] (Modification example) The technology disclosed in the above embodiment is merely an example. Therefore, it is also possible to change the technology exemplified in the above embodiment. With reference to FIGS. 5 to 7, a part of the modification example of the above embodiment will be described. Note that, for a part of the configurations of the first modification example shown in FIG. 5, the second modification example shown in FIG. 6, and the third modification example shown in FIG. 7, it is possible to adopt the same configurations as those of the above-described embodiment. Therefore, among the configurations of the first to third modification examples, for the parts where the same configurations as those of the above-described embodiment can be adopted, the same numbers as those of the above embodiment are assigned, and the description thereof is omitted or simplified.

[0081] In the light irradiation system 1 of the first modification example shown in FIG. 5, an indirect heat dissipation member 235 is arranged in contact with the heat generating surface 230A of the Peltier element 230. The indirect heat dissipation member 235 employs a member having a thermal conductivity equal to or higher than that of the heat generating surface 230A (for example, at least any one of a heat pipe, a carbon nanotube, ceramics (AlN, SiC, etc.), a metal plate (platinum, titanium, copper, etc.), a torque wire, etc.). When using a metal plate, the metal plate may be an alloy or may be plated on the surface of the metal plate. The indirect heat dissipation member 235 is exposed to the outside where it is exposed to a liquid. As an example, the indirect heat dissipation member 235 of the light irradiation system 1 shown in FIG. 5 is exposed to the outside from the side surface of the device main body 210 of the light irradiation device 2. Therefore, the indirect heat dissipation member 235 is exposed to the coolant supplied into the lumen 311 of the catheter 3 (the space between the outer peripheral surface of the light irradiation device 2 and the inner peripheral surface of the lumen 311 of the catheter 3). Thus, the heat generated from the heat generating surface 230A of the Peltier element 230 is likely to be appropriately released to the outside through the indirect heat dissipation member 235.

[0082] In the light irradiation system 1 of the second modification shown in FIG. 6, unlike other embodiments, a Peltier element for cooling the laser light source 211 is not used. However, in the light irradiation system 1 shown in FIG. 6, a heat dissipation member 236 is disposed in contact with the laser light source 211. As an example, in the light irradiation system 1 shown in FIG. 6, the heat dissipation member 236 is disposed over a wide range of the surface of the laser light source 211 on the side opposite to the side that emits the laser light. The heat dissipation member 236 employs a member having high thermal conductivity (for example, at least any one of a heat pipe, a carbon nanotube, ceramics (AlN, SiC, etc.), a metal plate (platinum, titanium, copper, etc.), a torque wire, etc.). As a result, the heat generated from the laser light source 211 is conducted to the heat dissipation member 236 and then dissipated to the surroundings. As described above, when using a metal plate, the metal plate may be an alloy or may be plated on the surface of the metal plate.

[0083] Furthermore, the heat dissipation member 236 shown in FIG. 6 is exposed to the outside from the side surface of the device body 210 of the light irradiation device 2. Therefore, the heat dissipation member 236 is exposed to the coolant supplied into the lumen 311 of the catheter 3 (the space between the outer peripheral surface of the light irradiation device 2 and the inner peripheral surface of the lumen 311 of the catheter 3). Thus, the heat generated from the laser light source 211 is more likely to be appropriately released to the outside through the heat dissipation member 236. It is more desirable that the heat dissipation member 236 is in contact with the laser light source 211. However, even if the heat dissipation member 236 is not in contact with the laser light source 211, if it is close to the laser light source 211, the effect of suppressing the temperature rise of the laser light source 211 can be obtained.

[0084] In the light irradiation system 1 of the third modification example shown in FIG. 7, different from other embodiments, the discharge valve 322 at the discharge port 341 of the catheter 3 is not used. However, in the light irradiation system 1 shown in FIG. 7, a discharge valve 238 is provided at the discharge port 221 formed at the tip of the light irradiation device 2. The discharge valve 238 allows the discharge of liquid from the inside to the outside of the coolant flow path 213 through the discharge port 341 while preventing the inflow of liquid from the outside to the inside of the coolant flow path 213. As a result, the discharge valve 238 appropriately suppresses the inflow of blood or the like outside the coolant flow path 213 into the inside through the discharge port 221.

[0085] It is also possible to adopt only a part of the configurations exemplified in the above-described embodiments and modification examples in the light irradiation system, the light irradiation device, or the catheter. For example, only one of the coolant flow path 213 and the Peltier element 230 may be adopted in the light irradiation device. It is also possible to combine a plurality of configurations shown in different embodiments. As described above, it is also possible to use only the light irradiation device 2 alone without using the catheter 3.

[0086] The technology according to the present disclosure can also be expressed as follows. (1) A medical light irradiation device having a long shape, a laser light source provided at the tip of the long device body and emitting laser light, a Peltier element provided at the tip of the device body, comprising: The Peltier element is arranged in contact with or close to the laser light source with the cooling surface side facing the laser light source. A light irradiation device characterized by this. (2) The light irradiation device according to (1), Among the Peltier elements, at least one of the heat generating surface located on the opposite side of the cooling surface and the indirect heat radiating member having a thermal conductivity equal to or higher than that of the heat generating surface and contacting the heat generating surface is exposed to the outside where it is exposed to liquid. A light irradiation device characterized by this. (3) The light irradiation device according to (1) or (2), further comprising a coolant flow path that communicates to the laser light source side of the device body and allows a coolant for cooling at least one of the laser light source and the Peltier element to pass to the laser light source side. (4) The light irradiation device according to (3), wherein the device body is formed in a long tube shape, and the coolant flow path is provided in the inner cavity of the device body, when the cross-sectional area of the coolant flow path in a cross-section in a direction perpendicular to the extending direction of the device body is defined as the flow path area, the flow path area of a portion on the base end side of the laser light source is larger than the flow path area of the portion where the laser light source is installed. (5) The light irradiation device according to (3) or (4), further comprising a power supply line that extends from the base end side to the tip end side of the device body and supplies power to the laser light source by connecting to the laser light source, wherein the power supply line is exposed in the coolant flow path. (6) The light irradiation device according to (5), wherein, among the power supply lines, the cross-sectional area of the connection portion connecting to the laser light source is larger than the cross-sectional area of the portion on the base end side of the connection portion. (7) The light irradiation device according to (5) or (6), wherein at least a part of the surface of the power supply line is coated with an insulating material, and the thickness of the insulating material coating the power supply line is smaller than the thickness of the power supply line in a state where it is not coated with the insulating material. (8) The light irradiation device according to any one of (3) to (7), A supply detection unit that detects whether or not coolant is being supplied into the coolant flow path; A supply notification unit that notifies the detection result by the supply detection unit; A light irradiation device, further comprising the above. (9) A light irradiation device according to any one of (1) to (8), A temperature detection unit that detects the temperature of the laser light source; A temperature notification unit that notifies the detection result by the temperature detection unit; A light irradiation device, further comprising the above. (10) A light irradiation device according to any one of (3) to (9), A light irradiation device, further comprising a flow path valve provided on the base end side of the coolant flow path relative to the laser light source to prevent backflow of the coolant to the base end side. (11) A medical light irradiation system, A catheter formed in a long tube shape, A long light irradiation device inserted into the lumen of the catheter, Comprising: The light irradiation device is A laser light source provided at the tip of a long device body and emitting laser light, A Peltier element provided at the tip of the device body, Comprising: The Peltier element is arranged in contact with or close to the laser light source with the cooling surface side facing the laser light source, A light irradiation system, wherein a light transmission part that transmits laser light emitted by the laser light source provided in the light irradiation device to the outside is formed in at least a part of the tip of the catheter. (12) A light irradiation system according to (11), Among the Peltier elements, at least either the heat generating surface located on the side opposite to the cooling surface, or the indirect heat radiating member having a thermal conductivity equal to or higher than that of the heat generating surface and contacting the heat generating surface, is exposed to the outside where it is exposed to a liquid. A light irradiation system characterized by this. (13) The light irradiation system according to (11) or (12), A light irradiation system characterized in that, with the light irradiation device inserted into the catheter, a cooling liquid flows into the lumen of the catheter.

Explanation of symbols

[0087] 1 Light irradiation system 2 Light irradiation device 3 Catheter 51 Supply notification unit 210 Device main body 211 Laser light source 213 Cooling liquid flow path 214 Flow path valve 216 Supply detection unit 218 Temperature detection unit 221 Discharge port 230 Peltier element 230A Heat generating surface 230B Cooling surface 231 Power supply wire 232 Insulating material 235 Indirect heat radiating member 236 Heat radiating member 238 Discharge valve 322 Discharge valve 330 Light transmission part 341 Discharge port

Claims

1. A medical light irradiation device having a long shape, a laser light source provided at the tip of the long device body and emitting laser light, and a Peltier element provided at the tip of the device body, comprising: The Peltier element is arranged in contact with or close to the laser light source with the cooling surface side facing the laser light source. A light irradiation device characterized by this.

2. The light irradiation device according to claim 1, Among the Peltier elements, at least the heat generating surface located on the opposite side of the cooling surface and / or at least one of the indirect heat dissipation members having a thermal conductivity equal to or higher than that of the heat generating surface and contacting the heat generating surface are exposed to the outside where they are exposed to a liquid. A light irradiation device characterized by this.

3. The light irradiation device according to claim 1, A coolant passage that communicates to the laser light source side of the device body and allows a coolant that cools at least one of the laser light source and the Peltier element to pass through to the laser light source side is further provided. A light irradiation device characterized by this.

4. The light irradiation device according to claim 3, Since the device body is formed in a long tube shape, the coolant passage is provided in the inner cavity of the device body, When the cross-sectional area of the coolant passage in the cross-section in the direction perpendicular to the extending direction of the device body is defined as the flow surface area, the flow surface area of the portion on the base end side of the laser light source is larger than the flow surface area of the portion where the laser light source is installed. A light irradiation device characterized by this.

5. The light irradiation device according to claim 3, A power supply line that extends from the base end side to the tip end side of the device body and supplies power to the laser light source by connecting to the laser light source is further provided, A light irradiation device characterized in that the power supply line is exposed in the coolant passage.

6. The light irradiation device according to claim 5, Among the power supply lines, the cross-sectional area of the connection portion connecting to the laser light source is larger than the cross-sectional area of the portion on the base end side of the connection portion. A light irradiation device characterized by this.

7. The light irradiation device according to claim 5, At least a part of the surface of the power supply line is covered with an insulating material, The thickness of the insulating material covering the power supply line is smaller than the thickness of the power supply line in a state where it is not covered with the insulating material. A light irradiation device characterized by this.

8. The light irradiation device according to claim 3, wherein a supply detection unit that detects whether or not coolant is being supplied into the coolant flow path; a supply notification unit that notifies the detection result by the supply detection unit; The light irradiation device is further provided with the above.

9. The light irradiation device according to claim 1, wherein a temperature detection unit that detects the temperature of the laser light source; a temperature notification unit that notifies the detection result by the temperature detection unit; The light irradiation device is further provided with the above.

10. The light irradiation device according to claim 3, wherein a flow path valve is further provided on the base end side of the coolant flow path with respect to the laser light source to prevent the backflow of the coolant to the base end side. The light irradiation device is characterized by this.

11. A medical light irradiation system, comprising a catheter formed in a long tube shape; a long light irradiation device inserted into the lumen of the catheter; With The light irradiation device is a laser light source provided at the tip of a long device body and emitting laser light; a Peltier element provided at the tip of the device body; With The Peltier element is arranged in contact with or close to the laser light source with the cooling surface side facing the laser light source. A light irradiation system, characterized in that a light transmission part for transmitting the laser light emitted by the laser light source included in the light irradiation device to the outside is formed in at least a part of the tip of the catheter.

12. The light irradiation system according to claim 11, wherein at least one of the heat generating surface located on the opposite side of the cooling surface and the indirect heat radiating member having a thermal conductivity equal to or higher than that of the heat generating surface and contacting the heat generating surface of the Peltier element is exposed to the outside where it is exposed to liquid. The light irradiation system is characterized by this.

13. The light irradiation system according to claim 11, wherein Coolant flows into the lumen of the catheter with the light irradiation device inserted into the catheter. The light irradiation system is characterized by this.

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