WO2025127089A1 - Light irradiation device and light irradiation system - Google Patents

Abstract

This light irradiation device has an oblong shape and is for medical use, the light irradiation device including a device body, a laser light source, and a cooling liquid flow path. The device body has an oblong shape. The laser light source is provided at the distal end of the oblong device body and emits laser light. The cooling liquid flow path runs to the laser light source side of the device body, and allows a cooling liquid for cooling the laser light source to pass to the laser light source side.

Description

Light irradiation device and light irradiation system

The present disclosure relates to a light irradiation device and a light irradiation system that are inserted into a biological lumen and irradiate light.

Photodynamic therapy (PDT) is known as one of the techniques for treating diseases. In PDT, a photosensitive substance is administered to the living body, and then the body is irradiated with light. As a result, there is a possibility that the cancer cells will be killed by the active oxygen generated in the cancer cells. However, with PDT, it is difficult to selectively accumulate the photosensitive substance in cancer cells. One issue with PDT is the occurrence of side effects caused by the photosensitive substance being taken up by normal cells.

In response to this, NIR-PIT (Near-infrared photoimmunotherapy) has been proposed in recent years. NIR-PIT uses a complex that combines two compounds: an antibody against a specific antigen in cancer cells and a photosensitive substance. When the complex is administered to a living body, it tends to selectively accumulate in cancer cells in the body. The complex is then activated by being irradiated with light of an excitation wavelength (e.g., a wavelength including 690 nm) of the photosensitive substance in the complex (see, for example, Patent Document 1, etc.). In NIR-PIT, the complex is selectively accumulated in cancer cells by the antibody, and when light is locally irradiated to the cancer cells, side effects are less likely to occur compared to PDT.

Light in the wavelength range including 690 nm does not penetrate deep into the body even when irradiated from the surface of the body, making it difficult to treat cancer deep inside the body by irradiating it from the surface. Therefore, technology has been proposed for irradiating light from a position closer to the cancer cells, rather than irradiating it from the surface of the body. For example, the device described in Patent Document 2 is inserted into a blood vessel and irradiates light from deep inside the body.

Special table 2014-523907 publication JP 2018-867 A

In conventional devices, light emitted from an external light source must be transmitted to the tip of the device by an optical transmission member (e.g., optical fiber, etc.). When an optical transmission member is used, bending of the optical transmission member in the cavity of the living body may cause the light to leak or attenuate before being transmitted to the tip of the device. If light leaks or attenuates, problems such as a decrease in the efficiency of light transmission or a decrease in safety may occur. In addition, the characteristics of the light (e.g., wavelength, etc.) may change during the process of light transmission by the optical transmission member, making it difficult to achieve 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, unless the laser light source is made smaller and its heat dissipation is improved, problems caused by temperature rise (e.g., failure of the laser light source, etc.) may occur.

A typical object of the present disclosure is to provide a light irradiation device and a light irradiation system that can more efficiently and appropriately irradiate light to a specific position within a lumen of a living body.

The light irradiation device provided by a typical embodiment of the present disclosure is a long-shaped medical light irradiation device, and includes a laser light source that is provided at the tip of the long-shaped device body and emits laser light, and a cooling liquid flow path that leads to the laser light source side of the device body and passes a cooling liquid that cools the laser light source to the laser light source side.

The light irradiation system provided by a typical embodiment of the present disclosure is a medical light irradiation system, and includes a catheter formed in a long tubular shape, and a long light irradiation device inserted into the inner cavity of the catheter. The light irradiation device includes a laser light source that is provided at the tip of the long device body and emits laser light, and a cooling liquid flow path that leads to the laser light source side of the device body and passes a cooling liquid that cools the laser light source to the laser light source side, and at least a part of the tip of the catheter is formed with a light transmitting portion that transmits the laser light emitted by the laser light source provided in the light irradiation device to the outside.

The light irradiation device and light irradiation system disclosed herein allow light to be irradiated more efficiently and appropriately to a specific location within a lumen of a living body.

(First aspect)
The light irradiation device of the present disclosure is a long-shaped medical light irradiation device, and includes a device body, a laser light source, and a coolant flow path. The device body is long. The laser light source is provided at a tip of the long-shaped device body and emits laser light. The coolant flow path leads to the laser light source side of the device body, and allows a coolant for cooling the laser light source to pass to the laser light source side.

In the light irradiation device disclosed herein, the cooling liquid that passes through the cooling liquid flow path and is supplied to the laser light source side appropriately suppresses the temperature rise of the laser light source and its vicinity. Therefore, malfunctions caused by the temperature rise of the tip part due to the laser light source (e.g., at least one of failure of the laser light source and blood coagulation) are appropriately suppressed. Note that it is sufficient that the cooling liquid flow path extends to the laser light source side to an extent that the cooling liquid can be supplied to the laser light source. Therefore, the tip part of the cooling liquid flow path does not necessarily need to reach the position of the laser light source or a position further tip than the laser light source.

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

The device body may be formed in a long tubular shape, so that 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 perpendicular to the extension direction of the device body is taken as the flow path area, the flow path area at the site on the base end side of the laser light source may be larger than the flow path area at the site where the laser light source is installed.

In this case, pressure loss of the cooling liquid in the path to the vicinity of the laser light source inside the device is less likely to occur, and the cooling liquid is more likely to flow appropriately near the laser light source. Therefore, the laser light source is more likely to be cooled more efficiently. The range in which the flow path area is made wider than the part where the laser light source is installed (i.e., the range of the "part on the base end side of the laser light source") can be set appropriately. For example, the flow path area of the entire range extending from the base end of the laser light source itself to the base end side may be made wider than the flow path area of the part where the laser light source is installed. In addition, a certain distance (for example, a distance equal to or less than the length L, where L is the length of the laser light source in the axial direction of the device body) may be provided between the range in which the flow path area is made wider than the part where the laser light source is installed and the base end of the laser light source itself.

A specific method for making the flow path area of the portion where the laser light source is installed narrower than the flow path area of the adjacent portion on the base end side of the laser light source can be appropriately selected. For example, the inner diameter of the coolant flow path can be constant, while the cross-sectional area of the member adjacent to the base end side of the laser light source can be made smaller than the cross-sectional area of the member at the portion where the laser light source is located. In this case, while the shape of the coolant flow path is simplified, the flow path area of the portion where the laser light source is installed can be made narrower than the flow path area of the adjacent portion on the base end side of the laser light source. Also, the inner diameter of the coolant flow path at the portion where the laser light source is installed can be made narrower than the inner diameter of the coolant flow path at the adjacent portion on the base end side of the laser light source. In this case, the diameter of the light irradiation device in the vicinity of the laser light source can be reduced, while the flow path area of the portion where the laser light source is installed can be made narrower than the flow path area of the adjacent portion on the base end side of the laser light source.

The light irradiation device may further include a power supply line. The power supply line 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. The power supply line may be exposed in the cooling liquid flow path. In this case, heat generated from the laser light source is more easily released to the cooling liquid through the power supply line. Therefore, the laser light source is more easily cooled efficiently.

The cross-sectional area of the connection portion of the power supply line that connects to the laser light source may be larger than the cross-sectional area of the portion on the base end side of the connection portion. In this case, heat generated from the laser light source is more easily transmitted to the power supply line than when the cross-sectional area of the power supply line is constant. This makes it easier to cool the laser light source more efficiently.

At least a portion of the surface of the power supply line may be covered with an insulating material. The thickness of the insulating material covering the power supply line may be smaller than the thickness of the power supply line when not covered with the insulating material. In this case, heat propagated from the laser light source to the power supply line is more easily released to the outside through the insulating material than when the insulating material is thicker than the power supply line. This makes it easier to cool the laser light source more efficiently.

The thickness of the insulating material covering the power supply line may more preferably be 25% or less of the thickness of the power supply line, and even more preferably 10% or less. In this case, heat propagated from the laser light source to the power supply line is more easily dissipated to the outside.

The light irradiation device may further include a supply detection unit that detects whether or not 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 properly grasp whether or not coolant is being supplied into the coolant flow path. Therefore, various problems caused by laser light being emitted without coolant being supplied are less likely to occur.

The specific configuration of the supply detection unit can be appropriately selected. For example, the light irradiation device may be provided with a flow path valve that prevents backflow of the coolant in the coolant flow path toward the base end side (details will be described later). The supply detection unit may detect whether the flow path valve is open or not, thereby detecting whether the coolant is being supplied into the coolant flow path. In this case, the presence or absence of the supply of coolant is appropriately detected depending on whether the flow path valve is open or not. The supply detection unit may also be a flow sensor or the like that is provided in at least a part of the coolant flow path 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 coolant.

The light irradiation device may further include a temperature detection unit that detects the temperature of the laser light source (or may be in the vicinity of the laser light source), and a temperature notification unit that notifies the result of detection by the temperature detection unit. In this case, the user can easily know whether the temperature of the laser light source is being maintained appropriately.

The specific configuration of the temperature detection unit can be selected as appropriate. For example, the temperature detection unit may be installed in the laser light source. The temperature detection unit may also detect the temperature in the vicinity of the laser light source (for example, cooling water in the vicinity of the laser light source). The state of the laser light source may also be monitored to detect whether the temperature of the laser light source is below a threshold value.

The light irradiation device may further include a flow path valve. The flow path valve is provided on the base end side of the cooling liquid flow path relative to the laser light source, and prevents the cooling liquid from flowing back toward the base end. By providing the flow path valve, the cooling liquid is prevented from flowing back in the cooling liquid flow path. As a result, it becomes easier to more appropriately suppress the temperature rise of the laser light source and its vicinity.

The light irradiation device may further include a Peltier element provided at the tip of the device body. The Peltier element may be disposed in contact with or in close proximity to the laser light source with the cooling surface facing the laser light source. By providing the Peltier element, problems caused by a rise in temperature at the tip due to the laser light source are appropriately suppressed by the cooling effect of the element.

When the Peltier element is placed close to the laser light source, the cooling surface of the Peltier element and the laser light source may be spaced apart to an extent that the cooling effect of the laser light source by the Peltier element can be adequately obtained. The cooling surface of the Peltier element and the laser light source may be placed close to each other with at least one of an adhesive and a member having high thermal conductivity placed between the cooling surface of the Peltier element and the laser light source. Even in this case, as long as 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 adequately obtained.

The outer periphery of the Peltier element may be covered with a covering material (e.g., resin, etc.) that prevents liquid from entering the inside. In this case, malfunctions such as breakdown of the Peltier element due to liquid intrusion are appropriately suppressed.

At least one of the heat generating surface of the Peltier element, located opposite the cooling surface, and the indirect heat dissipation member that has a thermal conductivity equal to or greater than that of the heat generating surface and is in contact with the heat generating surface, may be exposed to the outside and exposed to a liquid (e.g., a cooling liquid, etc.). In this case, the heat generated from the heat generating surface of the Peltier element is more easily dissipated appropriately than when the heat generating surface is not directly or indirectly exposed.

In addition, a member with high thermal conductivity (for example, at least one of a heat pipe, carbon nanotube, ceramics (AIN, SiC, etc.), metal plate (platinum, titanium, copper), torque wire, etc.) may be placed on the heat generating surface of the Peltier element. In this case, the heat generated from the heat generating surface of the Peltier element can be dissipated more efficiently. In addition, if a metal plate is used, the metal plate may be an alloy, or the surface of the metal plate may be plated.

In addition, instead of a Peltier element, a member having high thermal conductivity (for example, at least one of a heat pipe, carbon nanotube, ceramics (AIN, SiC, etc.), metal plate (platinum, titanium, copper), torque wire, etc.) may be placed in contact with or close to the laser light source. In this case, too, the heat generated from the laser light source is easily dissipated appropriately. As mentioned above, when a metal plate is used, the metal plate may be an alloy, or the surface of the metal plate may be plated.

The light irradiation system disclosed herein is a medical light irradiation system, and includes a catheter formed in a long tubular 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 coolant flow path. The laser light source is provided at the tip of the long device body, and emits laser light. The coolant flow path leads to the laser light source side of the device body, and allows the coolant that cools the laser light source to pass to the laser light source side. At least a part of the tip of the catheter is formed with a light-transmitting portion that transmits the laser light emitted by the laser light source provided in the light irradiation device to the outside.

In the light irradiation system disclosed herein, the cooling liquid that passes through the cooling liquid flow path and is supplied to the laser light source side appropriately suppresses the temperature rise of the laser light source and its vicinity. Therefore, problems caused by the temperature rise of the tip part due to the laser light source (for example, at least one of a failure of the laser light source and blood coagulation, etc.) are appropriately suppressed. Furthermore, the light emitted from the laser light source passes through the light-transmitting part of the catheter and is irradiated to the biological tissue. Therefore, light is more efficiently and appropriately irradiated to a specific position inside the lumen of the living body.

At least a part of the tip of the catheter may be formed with an outlet for discharging the cooling liquid discharged from the cooling liquid flow path of the light irradiation device to the outside of the catheter. In this case, the cooling liquid supplied through the cooling liquid flow path of the light irradiation device passes near the laser light source and is discharged to the outside from the outlet of the catheter. As a result, the cooling liquid is continuously supplied to the vicinity of the laser light source, which makes it easier to more appropriately suppress temperature rise at the laser light source and its vicinity. In addition, the possibility of blood outside the catheter coming into contact with the laser light source is appropriately reduced.

The specific form of the outlet can be selected as appropriate. For example, the tip of the catheter may be provided with a passage hole for passing a guidewire. The guidewire passage hole may also serve as an outlet for the cooling liquid. Also, a coolant outlet may be formed at the tip of the catheter, separate from the guidewire passage hole.

The catheter outlet may be provided with an outlet valve that allows liquid to be discharged to the outside of the catheter through the outlet, while preventing liquid from flowing from the outside of the catheter into the inside. In this case, the outlet valve prevents blood and other liquids from the outside of the catheter from flowing into the inside of the catheter through the outlet. As a result, the possibility of blood coming into contact with the laser light source is further reduced.

(Second Aspect)
The light irradiation device of the present disclosure is a long-shaped medical light irradiation device, and includes a device body, a laser light source, and a Peltier element. The device body is long-shaped. The laser light source is provided at the tip of the long-shaped device body and emits laser light. The Peltier element is provided at the tip of the device body. The Peltier element is disposed in contact with or in close proximity to the laser light source with the cooling surface side facing the laser light source.

In the light irradiation device disclosed herein, problems caused by temperature rise at the tip due to the laser light source are appropriately suppressed by the cooling effect of the Peltier element.

When the Peltier element is placed close to the laser light source, the cooling surface of the Peltier element and the laser light source may be spaced apart to an extent that the cooling effect of the laser light source by the Peltier element can be adequately obtained. The cooling surface of the Peltier element and the laser light source may be placed close to each other with at least one of an adhesive and a member having high thermal conductivity placed between the cooling surface of the Peltier element and the laser light source. Even in this case, as long as 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 adequately obtained.

The outer periphery of the Peltier element may be covered with a covering material (e.g., resin, etc.) that prevents liquid from entering the inside. In this case, malfunctions such as breakdown of the Peltier element due to liquid intrusion are appropriately suppressed.

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

At least one of the heat generating surface of the Peltier element, located opposite the cooling surface, and the indirect heat dissipation member that has a thermal conductivity equal to or greater than that of the heat generating surface and is in contact with the heat generating surface, may be exposed to the outside and exposed to a liquid (e.g., a cooling liquid, etc.). In this case, the heat generated from the heat generating surface of the Peltier element is more easily dissipated appropriately than when the heat generating surface is not directly or indirectly exposed.

In addition, a member with high thermal conductivity (for example, at least one of a heat pipe, carbon nanotube, ceramics (AIN, SiC, etc.), metal plate (platinum, titanium, copper), torque wire, etc.) may be placed on the heat generating surface of the Peltier element. In this case, the heat generated from the heat generating surface of the Peltier element can be dissipated more efficiently. In addition, if a metal plate is used, the metal plate may be an alloy, or the surface of the metal plate may be plated.

In addition, instead of a Peltier element, a member having high thermal conductivity (for example, at least one of a heat pipe, carbon nanotube, ceramics (AIN, SiC, etc.), metal plate (platinum, titanium, copper), torque wire, etc.) may be placed in contact with or close to the laser light source. In this case, too, the heat generated from the laser light source is easily dissipated appropriately. As mentioned above, when a metal plate is used, the metal plate may be an alloy, or the surface of the metal plate may be plated.

The light irradiation device may further include a coolant flow path. The coolant flow path leads 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 coolant that passes through the coolant flow path and is supplied to the laser light source side appropriately suppresses temperature rise at the laser light source and its vicinity. Therefore, malfunctions caused by temperature rise at the tip due to the laser light source (for example, at least one of failure of the laser light source and blood coagulation) are appropriately suppressed. Note that it is sufficient that the coolant flow path extends to the laser light source side to an extent that 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.

The device body may be formed in a long tubular shape, so that 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 perpendicular to the extension direction of the device body is taken as the flow path area, the flow path area at the site adjacent to the base end side of the laser light source may be larger than the flow path area at the site where the laser light source is installed.

In this case, pressure loss of the cooling liquid in the path to the vicinity of the laser light source inside the device is less likely to occur, and the cooling liquid is more likely to flow appropriately near the laser light source. Therefore, the laser light source is more likely to be cooled more efficiently. The range in which the flow path area is made wider than the part where the laser light source is installed (i.e., the range of the "part on the base end side of the laser light source") can be set appropriately. For example, the flow path area of the entire range extending from the base end of the laser light source itself to the base end side may be made wider than the flow path area of the part where the laser light source is installed. In addition, a certain distance (for example, a distance equal to or less than the length L, where L is the length of the laser light source in the axial direction of the device body) may be provided between the range in which the flow path area is made wider than the part where the laser light source is installed and the base end of the laser light source itself.

A specific method for making the flow path area of the portion where the laser light source is installed narrower than the flow path area of the adjacent portion on the base end side of the laser light source can be appropriately selected. For example, the inner diameter of the coolant flow path can be constant, while the cross-sectional area of the member adjacent to the base end side of the laser light source can be made smaller than the cross-sectional area of the member at the portion where the laser light source is located. In this case, while the shape of the coolant flow path is simplified, the flow path area of the portion where the laser light source is installed can be made narrower than the flow path area of the adjacent portion on the base end side of the laser light source. Also, the inner diameter of the coolant flow path at the portion where the laser light source is installed can be made narrower than the inner diameter of the coolant flow path at the adjacent portion on the base end side of the laser light source. In this case, the diameter of the light irradiation device in the vicinity of the laser light source can be reduced, while the flow path area of the portion where the laser light source is installed can be made narrower than the flow path area of the adjacent portion on the base end side of the laser light source.

The light irradiation device may further include a power supply line. The power supply line 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. The power supply line may be exposed in the cooling liquid flow path. In this case, heat generated from the laser light source is more easily released to the cooling liquid through the power supply line. Therefore, the laser light source is more easily cooled efficiently.

The cross-sectional area of the connection portion of the power supply line that connects to the laser light source may be larger than the cross-sectional area of the portion on the base end side of the connection portion. In this case, heat generated from the laser light source is more easily transmitted to the power supply line than when the cross-sectional area of the power supply line is constant. This makes it easier to cool the laser light source more efficiently.

At least a portion of the surface of the power supply line may be covered with an insulating material. The thickness of the insulating material covering the power supply line may be smaller than the thickness of the power supply line when not covered with the insulating material. In this case, heat propagated from the laser light source to the power supply line is more easily released to the outside through the insulating material than when the insulating material is thicker than the power supply line. This makes it easier to cool the laser light source more efficiently.

The thickness of the insulating material covering the power supply line may more preferably be 25% or less of the thickness of the power supply line, and even more preferably 10% or less. In this case, heat propagated from the laser light source to the power supply line is more easily dissipated to the outside.

The light irradiation device may further include a supply detection unit that detects whether or not 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 properly grasp whether or not coolant is being supplied into the coolant flow path. Therefore, various problems caused by laser light being emitted without coolant being supplied are less likely to occur.

The specific configuration of the supply detection unit can be appropriately selected. For example, the light irradiation device may be provided with a flow path valve that prevents backflow of the coolant in the coolant flow path toward the base end side (details will be described later). The supply detection unit may detect whether the flow path valve is open or not, thereby detecting whether the coolant is being supplied into the coolant flow path. In this case, the presence or absence of the supply of coolant is appropriately detected depending on whether the flow path valve is open or not. The supply detection unit may also be a flow sensor or the like that is provided in at least a part of the coolant flow path 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 coolant.

The light irradiation device may further include a temperature detection unit that detects the temperature of the laser light source (or may be in the vicinity of the laser light source), and a temperature notification unit that notifies the result of detection by the temperature detection unit. In this case, the user can easily know whether the temperature of the laser light source is being maintained appropriately.

The specific configuration of the temperature detection unit can be selected as appropriate. For example, the temperature detection unit may be installed in the laser light source. The temperature detection unit may also detect the temperature in the vicinity of the laser light source (for example, cooling water in the vicinity of the laser light source). The control unit may also detect whether the temperature of the laser light source is below a threshold by monitoring the state of the laser light source.

The light irradiation device may further include a flow path valve. The flow path valve is provided on the base end side of the cooling liquid flow path relative to the laser light source, and prevents the cooling liquid from flowing back toward the base end. By providing the flow path valve, the cooling liquid is prevented from flowing back in the cooling liquid flow path. As a result, it becomes easier to more appropriately suppress the temperature rise of the laser light source and its vicinity.

The light irradiation system disclosed herein is a medical light irradiation system, and includes a catheter formed in a long tubular 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 placed in contact with or in close proximity to the laser light source, with the cooling surface side facing the laser light source. At least a part of the tip of the catheter is formed with a light transmission section that transmits the laser light emitted by the laser light source provided in the light irradiation device to the outside.

According to the light irradiation system disclosed herein, the malfunction caused by the temperature rise of the tip due to the laser light source is appropriately suppressed by the cooling effect of the Peltier element. Furthermore, the light emitted from the laser light source is transmitted through the light transmitting portion of the catheter and irradiated to the living tissue. Thus, the light is more efficiently and appropriately irradiated to a specific position within 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 an extent that the cooling effect of the laser light source by the Peltier element is appropriately obtained. Furthermore, 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 high thermal conductivity disposed between the cooling surface of the Peltier element and the laser light source.

At least one of the heat generating surface of the Peltier element, located opposite the cooling surface, and the indirect heat dissipation member that has a thermal conductivity equal to or greater than that of the heat generating surface and is in contact with the heat generating surface, may be exposed to the outside and exposed to a liquid (e.g., a cooling liquid, etc.). In this case, the heat generated from the heat generating surface of the Peltier element is more easily dissipated appropriately than when the heat generating surface is not directly or indirectly exposed.

When the light irradiation device is inserted into the catheter, a cooling liquid may be flowed 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 more likely to come into contact with the cooling liquid 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 dissipated efficiently.

FIG. 2 is a longitudinal sectional view of the light irradiation system 1 in a state in which the light irradiation device 2 and the catheter 3 are separated. 1 is a longitudinal sectional view of the light irradiation system 1 in a state in which the light irradiation device 2 is attached to a catheter 3 (in use state). 3 is an enlarged vertical cross-sectional view of the vicinity of a tip portion of the light irradiation system 1 in FIG. 2. 2 is a cross-sectional view of the power supply line 231 in a direction perpendicular to the axis O2 of the light irradiation device 2. FIG. FIG. 11 is an enlarged vertical cross-sectional view of the vicinity of a tip portion of the light irradiation system 1 of a first modified example. FIG. 11 is an enlarged vertical cross-sectional view of the vicinity of a tip portion of the light irradiation system 1 of a second modified example. FIG. 13 is an enlarged vertical cross-sectional view of the vicinity of a tip portion of the light irradiation system 1 of a third modified example.

Below, a typical embodiment of the present disclosure will be described with reference to the drawings. The light irradiation system 1 of this embodiment is used by being inserted inside a lumen of a living body (for example, at least one of a blood vessel, lymph node, urethra, airway, digestive organ, secretory gland, and reproductive organ). The light irradiation system 1 irradiates light (laser light in this embodiment) to the living tissue while inserted into the lumen of the living body. The light irradiation system can be used for at least one of the therapies such as PDT (Photodynamic Therapy) and NIR-PIT (Near-infrared photoimmunotherapy).

The light irradiation system 1 of this embodiment includes a light irradiation device 2 and a catheter 3. When using the light irradiation system 1, first, the catheter 3 is inserted into a biological lumen. Next, the light irradiation device 2 is inserted into the lumen 311 of the catheter 3, which has a long tubular shape. Once the insertion is complete, light is irradiated from the light irradiation device 2 to the biological tissue. However, it is also possible to use only the light irradiation device 2 alone, without using the catheter 3.

FIGS. 1 to 3 and 5 to 7 show mutually orthogonal X and Y axes. In these drawings, the lower side (+X direction) of the drawings is the "tip side", the upper side (-X direction) of the drawings is the "base side", the left side (+Y direction) of the drawings is the "left side", and the right side (-Y direction) of the drawings is the "right side". The light irradiation system 1, light irradiation device 2, and catheter 3 are inserted into the body lumen from the tip side. The base side is operated by a medical professional (e.g., a doctor, etc.).

(Light Irradiation Device)
The light irradiation device 2 of this embodiment will be described with reference to FIGS. 1 to 4. As shown in FIG. 1, the light irradiation device 2 has an elongated shape. The light irradiation device 2 includes a connector 201, a device body 210, a laser light source 211, and a tip tip 220. The connector 201 is located on the base end side of the light irradiation device 2 and is held by an operator. The connector 201 includes a pair of wing parts 202 and a connection part 203. The connection part 203 is a substantially cylindrical member. The wing part 202 is connected to the base end of the connection part 203. The device body 210 is connected to the tip of the connection part 203. The wing part 202 and the connection part 203 may be formed integrally. 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 of the elongated device body 210. As an example, in this embodiment, the laser light source 211 is installed at the tip of the long 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 of the device body 210. The tip tip 220 is connected to the tip of the device body 210, further to the tip side than the laser light source 211. The outer diameter of the tip tip 220 is approximately the same as the outer diameter Φ1 of the device body 210.

It is desirable that the device body 210 has antithrombotic properties, flexibility, and biocompatibility. At least one of resin materials and metal materials can be used as the material of the device body 210. For example, polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin can be used as the resin material. The device body 210 of this 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 a transparent portion that transmits the laser light in the device body 210. However, when a transparent portion that transmits the laser light emitted from the laser light source 211 is formed in the device body 210, or when the laser light source 211 is exposed to the outside of the device body 210, the device body 210 may be formed of a material that does not transmit the laser light (for example, a metal material, etc.). For example, stainless steel such as SUS304, nickel titanium alloy, cobalt chromium alloy, platinum, and tungsten steel can be used as the metal material. It is also possible to construct the device body 210 by combining multiple materials.

The device body 210 includes a coolant flow path 213. The coolant flow path 213 runs from the base end side (-X side in the figure) of the device body 210 to the laser light source side (+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 (i.e., the tip side of the device body 210). Therefore, in the light irradiation device 2 of this embodiment, the coolant supplied to the laser light source 211 side through the coolant flow path 213 appropriately suppresses the temperature rise of the laser light source 211 and its vicinity. Therefore, defects caused by the temperature rise of the tip part by the laser light source 211 (for example, at least one of a failure of the laser light source 211 and blood coagulation) are appropriately suppressed. In this embodiment, the device body 210 is formed in a long tube shape, and thus the coolant flow path 213 is provided in the lumen of the device body 210. The coolant flow path 213 of this embodiment extends to a position further to the tip 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 the extent that the coolant can be supplied to the laser light source 211. Therefore, the tip of the coolant flow path 213 may be located closer to the base end than the laser light source 211.

As shown in FIG. 1, the cooling liquid is supplied from the base end side of the cooling liquid flow path 213 to the inside. The light irradiation device 2 includes a flow path valve 214. The flow path valve 214 is provided on the base end side of the cooling liquid flow path 213 relative to the laser light source 211. The flow path valve 214 prevents the cooling liquid from flowing back to the base end side in the cooling liquid flow path 213, and allows the cooling liquid to flow to the tip end side. As a result, the problem of the cooling liquid not being supplied to the laser light source 211 and its vicinity is suppressed, and the temperature rise of the laser light source 211 and its vicinity is more appropriately suppressed. Note that various liquids that do not affect living tissue (e.g., saline solution, etc.) can be used as the cooling liquid.

At the tip of the device body 210, an outlet 221 is formed to discharge the cooling liquid supplied from the base end side of the cooling liquid flow path 213 to the outside. Therefore, the cooling liquid supplied to the inside of the cooling liquid flow path 213 flows smoothly near the laser light source 211 without stagnating inside. As a result, it becomes easier to more appropriately suppress the temperature rise of the laser light source 211 and its vicinity.

In this embodiment, the exhaust outlet 221 is formed in the distal tip 220 provided at the distal end of the device body 210. However, the specific configuration of the exhaust outlet can be changed. For example, an exhaust outlet may be formed in the side of the device body 210, which has a long tube shape, separately from the exhaust outlet 221 of the distal tip 220, or together with the exhaust outlet 221 of the distal tip 220. It is preferable that the exhaust outlet is formed further toward the distal end than the position where the laser light source 211 is installed in the extension direction (direction of axis O2) of the device body 210.

Furthermore, in this embodiment, at least a part of the tip tip 220 (in this embodiment, the entire tip tip 220) provided at the tip of the light irradiation device 2 is formed from a material having radiopaque properties. Therefore, when a medical professional (e.g., a surgeon, etc.) irradiates biological tissue with laser light using the light irradiation device 2 while taking an image of the inside of a living body using radiation (e.g., X-rays, etc.), the medical professional can appropriately adjust the irradiation position of the laser light by checking the position of the tip tip 220 that appears in the captured image. This makes it easier to improve the accuracy of treatment.

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 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 properly grasp whether or not coolant is being supplied into the coolant flow path 213. This makes it less likely that various problems will occur due to laser light being emitted without coolant being supplied.

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 this embodiment detects whether the flow path valve 214 is open, thereby detecting whether the coolant is being supplied into the coolant flow path 213. Therefore, the presence or absence of the supply of coolant is appropriately detected depending on whether the flow path valve 214 is open. In addition, the control unit 5 notifies the user of the detection result by controlling the drive of the supply notification unit 51 (for example, at least one of the drive of turning on/off/flashing the light source, outputting audio, and displaying an image) according to the detection result by the supply detection unit 216. However, the configurations of the supply detection unit 216 and the supply notification unit 51 can also be changed. For example, the supply detection unit may be a flow 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. In addition, a temperature sensor can be used 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 coolant.

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 know whether the temperature of the laser light source 211 (or the vicinity thereof) is being maintained appropriately.

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 this embodiment is installed in 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 near the laser light source 211 (for example, the cooling liquid near the laser light source 211). The control unit 5 may also detect whether the temperature of the laser light source 211 is below a threshold by monitoring the state of the laser light source 211. In this embodiment, the control unit 5 controls the driving of the temperature notification unit 52 (for example, driving at least one of turning on/off/flashing the light source, outputting a sound, and displaying an image) 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 below a threshold, or may notify the detected temperature itself.

The configuration of the tip of the light irradiation device 2 of this embodiment will be described with reference to FIG. 3. FIG. 3 is an enlarged vertical cross-sectional view 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 at its tip, which emits laser light in a predetermined wavelength range. In detail, the laser light source 211 is formed in a rectangular shape, and is installed in the cooling liquid flow path 213, which is the inner cavity (lumen) of the light irradiation device 2, which has a long tube shape. However, it is also possible to change the method of fixing the laser light source 211. For example, at least a part of the laser light source 211 (for example, a light emitting portion that emits a laser) may be exposed to the outside of the device body 210.

The laser light source 211 emits laser light in a direction intersecting the long axis direction (direction of the axis O2) of the light irradiation device 2 (in the example shown in FIG. 3, the direction of the arrow perpendicularly intersecting the axis O2). Therefore, the light irradiation device 2 can directly irradiate light from the laser light source 211 provided at the tip to a specific position of the living body without using an optical transmission member such as an optical fiber. Therefore, various problems that occur when using an optical transmission member (for example, at least one of the problems of light leakage and attenuation in the middle of the optical transmission member and the problem of the characteristics of light changing during the process of light transmission) are appropriately suppressed. In addition, 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 is easier to emit light that is less likely to diverge and has high directivity than a light-emitting diode. Therefore, the light irradiation device 2 of this 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 (e.g., side effects, etc.) caused by light being irradiated to unintended positions are less likely to occur. Furthermore, the laser light source 211 has the property of being able to irradiate light with a wavelength having a narrower spectral width than a light-emitting diode. Therefore, by providing the laser light source 211 at the tip of the light irradiation device 2, various problems (e.g., at least one of a decrease in irradiation efficiency and unintended changes in tissue) caused by irradiating tissue with a wavelength different from the wavelength required for treatment (e.g., the excitation wavelength of a photosensitive substance, etc.) are also suppressed. Therefore, it becomes easier to irradiate light more efficiently and appropriately to a specific position in the lumen of a living body.

The laser light source 211 can be a surface-emitting laser that irradiates laser light in a direction perpendicular to the substrate. By using a surface-emitting laser, the light-irradiating device 2 can emit laser light appropriately with low power and has high resistance to temperature changes. Furthermore, since the surface-emitting laser can emit laser light in a direction perpendicular to the substrate surface, it becomes easier to adjust the irradiation position of the laser light more accurately.

In addition, the laser light source 211 can also be a semiconductor laser, which is a circuit element manufactured using semiconductor materials. Semiconductor lasers are easy to miniaturize, so they can be easily incorporated into light irradiation devices 2 with small diameters. Semiconductor lasers can also emit highly directional laser light with a uniform phase using small power. This makes it easier to stabilize the treatment effect.

The laser light source 211 may emit laser light with a wavelength of 300 nm or more and 2000 nm or less. More preferably, the laser light source 211 may emit laser light with a wavelength of 600 nm or more and 1000 nm or less. In this case, by using the light irradiation device 2 to treat a disease using a photosensitive substance, it becomes easier to obtain an appropriate therapeutic effect. In this embodiment, the central wavelength of the laser light emitted by the laser light source 211 is approximately 690 nm.

The light irradiation device 2 includes a power supply line 231 (a pair of power supply lines 231 in this embodiment). The power supply line 231 extends from the base end side to the tip end side of the device 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 this embodiment is connected to the control unit 5 (see Figures 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 body 210. Therefore, 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 easily cooled more efficiently. In this embodiment, a metal material with high thermal conductivity (for example, at least one of copper and nickel) is used as the material of the power supply line 231. Therefore, heat generated from the laser light source 211 is easily propagated to the power supply line 231. The heat transmitted to the power supply line 231 is smoothly released into the cooling liquid.

As shown in FIG. 3, the outer diameter of the connection part 231B of the power supply line 231 (each of the pair of power supply lines 231 in this embodiment) that connects to the laser light source 211 is larger than the outer diameter of the base end part 231A extending from the connection part 231B to the base end side (the +X side in FIG. 3). In other words, when the cross-sectional area of the power supply line 231 is viewed in a cross section perpendicular to the axis O2 of the light irradiation device 2, the cross-sectional area of the connection part 231B that connects to the laser light source 211 is larger than the cross-sectional area of the base end part 231A that extends from the connection part 231B to the base end side. Therefore, compared to a 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 easily propagated to the power supply line 231. The heat propagated to the power supply line 231 is smoothly released into the coolant. Therefore, the laser light source 211 is more easily cooled efficiently.

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 portion of the power supply line 231 of this embodiment (in this embodiment, both the base end portion 231A and the connection portion 231B of the power supply line 231) 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. The insulating material 232 may be made of at least one of insulating materials such as polyurethane, polyester, polyesterimide, polyamideimide, and polyimide.

In this embodiment, the cross-sectional shape of the long power supply line 231 perpendicular to the axis O2 is circular. However, the cross-sectional shape of the power supply line 231 may be a shape other than circular (e.g., rectangular or elliptical).

4, in this 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 (specifically, the thickness of the base end portion 231A of the power supply line 231) when it is not covered with the insulating material 232. "Thickness" means the thickness in a cross section perpendicular to the extension direction of the power supply line 231. In other words, in this 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 is thin, heat propagated from the laser light source 211 to the power supply line 231 is easily released to the outside (to the cooling liquid in this embodiment) through the thin insulating material 232. Therefore, the laser light source 211 is easily cooled more 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. The thickness of the insulating material 232 that covers the power supply line 231 may more desirably be 25% or less of the thickness of the power supply line 231, and even more desirably be 10% or less. In this case, the heat propagated from the laser light source to the power supply line is more easily released to the outside.

As shown in FIG. 3, in this embodiment, the device body 210 is formed in a long tube shape, and a coolant flow path 213 is provided in the inner cavity (lumen) of the device body 210. Here, the area of the coolant flow path 213 in a cross section perpendicular to the extension direction (direction of axis O2) of the device body 210 is defined as the flow path area. In this embodiment, the flow path area FA2 of the coolant flow path 213 at the portion on the base side of the laser light source 211 is larger than the flow path area FA1 of the coolant flow path 213 at the portion where the laser light source 211 is installed in the extension direction (direction of axis O2) of the device body 210. As a result, pressure loss of the coolant is less likely to occur in the path to the vicinity of the laser light source 211 in the device body 210, and the coolant is more likely to flow appropriately near the laser light source 211. Therefore, the laser light source is more easily cooled efficiently.

The range in which the flow path area is made larger than the portion where the laser light source 211 is installed (i.e., the range of the "portion on the base end side of the laser light source") can be set appropriately. As an example, in this embodiment, the flow path area of the entire range extending from the base end of the laser light source 211 itself to the base end side is larger than the flow path area of the portion where the laser light source 211 is installed. However, a certain distance (for example, a distance equal to or smaller than the length L, where L is the length of the laser light source 211 in the direction of the axis O2) may be provided between the range in which the flow path area is made larger than the portion where the laser light source 211 is installed and the base end of the laser light source 211 itself.

In this embodiment, as shown in FIG. 3, while the inner diameter of the coolant flow path 213 is constant, the cross-sectional area of the member adjacent to the base end side of the laser light source 211 is made smaller than the cross-sectional area of the member at the portion where the laser light source 211 is located (in this 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 simplified, the flow path area FA1 at the portion where the laser light source 211 is installed can be made narrower than the flow path area FA2 at the adjacent portion on the base end 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 portion 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 portion on the base end side of the laser light source 211. In this case, the diameter of the light irradiation device 2 in the vicinity of the laser light source 211 can be reduced, while the flow path area FA1 of the portion where the laser light source 211 is installed can be made narrower than the flow path area FA2 of the adjacent portion on the base end side of the laser light source 211.

As shown in FIG. 3, the light irradiation device 2 of this embodiment includes a Peltier element 230 at the tip of the device body 210. A wiring 233 extending from the base end side along the extension direction (direction of the axis O2) of the light irradiation device 2 is connected to the Peltier element 230 (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 is applied to the Peltier element 230, the cooling surface 230B absorbs heat, while 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 facing the laser light source 211. However, the cooling surface 230B of the Peltier element 230 may be disposed in a position close to the laser light source 211 (i.e., at a position where a gap is generated between the laser light source 211) while facing the laser light source 211. That is, the cooling surface 230B of the Peltier element 230 and the laser light source 211 may be spaced apart to such an extent that the cooling effect of the laser light source 211 by the Peltier element 230 can be appropriately obtained. In addition, the cooling surface 230B of the Peltier element 230 and the laser light source 211 may be close to each other with at least one of an adhesive and a member having high thermal conductivity 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 of the tip portion due to the laser light source 211 are appropriately suppressed by the cooling effect of the Peltier element 230.

In this embodiment, the outer periphery of the Peltier element 230 is covered with a covering material (e.g., resin, etc.) that prevents liquid from entering the interior. As a result, problems such as breakdowns of the Peltier element 230 due to the intrusion of liquid are appropriately suppressed.

The heat generating surface 230A of the Peltier element 230 is exposed to the outside and is exposed to the liquid. In particular, in this embodiment, the heat generating surface 230A is exposed to the space within the coolant flow path 213 through which the coolant flows. Therefore, when coolant is supplied into the coolant flow path 213, the heat generating surface 230A of the Peltier element 230 is exposed to (comes into contact with) the coolant. Therefore, compared to when 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 easily released appropriately to the outside.

In this embodiment, at least some of the components of the Peltier element 230 (for example, at least one of the heating surface 230A and the cooling surface 230B) are made of a material that is radiopaque. Therefore, when the medical staff irradiates the biological tissue with laser light using the light irradiation device 2 while taking an image of the inside of the living body using radiation, the medical staff can appropriately adjust the irradiation position of the laser light by checking the position of the Peltier element 230 that appears in the captured image. In detail, in this embodiment, the installation position of the Peltier element 230 in the light irradiation device 2 is shifted from the axis O2 of the light irradiation device 2. Therefore, the medical staff 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 relative to the axis O2 of the light irradiation device 2 on the captured image.

(catheter)
The catheter 3 of this embodiment will be described with reference to Figures 1 to 3. As shown in Figure 1, the catheter 3 has a long tubular shape. The catheter 3 includes a connector 301, a shaft 310, and a distal tip 320. The connector 301 is located on the base end side of the catheter 3 and is held by the surgeon. The connector 301 includes a pair of wings 302 and a connecting portion 303. The connecting portion 303 is a substantially cylindrical member. The wings 302 are connected to the base end of the connecting portion 303. The shaft 310 is connected to the distal end of the connecting portion 303. The wings 302 and the connecting portion 303 may be formed integrally.

The shaft 310, like the device body 210 of the light irradiation device 2, is preferably antithrombotic, flexible, and biocompatible. The material of the shaft 310 can be the same as that of the device body 210 of the light irradiation device 2. The shaft 310 is a long tubular member extending along the axis O3. The shaft 310 of this embodiment is formed in a hollow cylindrical shape with both the tip and base ends open. The lumen 311 inside the shaft 310 functions as a guidewire lumen for inserting a guidewire into the catheter 3 during delivery of the catheter 3. The lumen 311 functions as a device lumen for inserting the light irradiation device 2 into the catheter 3 after delivery of the catheter 3.

The tip tip 320 is connected to the tip of the shaft 310. The tip tip 320 has an outer shape that tapers from the base end to the tip end in order to allow the catheter 3 to move smoothly through the biological lumen. A through hole 321 is formed in the approximate center of the tip tip 320, penetrating in the direction of the axis O2. The inner diameter of the through hole 321 is smaller than the inner diameter of the lumen 311 of the shaft 310, and smaller than the outer diameter Φ1 of the tip tip 220 of the light irradiation device 2. In addition, the outer diameter Φ1 of the device body 210 and the tip tip 220 of the light irradiation device 2 is 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 advanced inside the lumen 311 of the catheter 3, the distal tip 220 of the light irradiation device 2 comes into contact with the distal tip 320 of the catheter 3, and the light irradiation device 2 is positioned in the axial direction O2, O3 relative to the catheter 3. At least a part of the distal tip 320 (in this embodiment, the entire distal tip 320) is made of a material that is radiopaque. Therefore, the position of the distal end of the catheter 3 can be appropriately grasped by a radiographic image.

In this embodiment, a coolant is supplied into the lumen 311 of the catheter 3 (the space between the outer circumferential surface of the light irradiation device 2 and the inner circumferential surface of the lumen 311 of the catheter 3). That is, in this embodiment, a 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 a rise in temperature at the tip due to the laser light source 211 are further easily suppressed.

As shown in FIG. 3, the distal end side of the shaft 310 of the catheter 3 (in this embodiment, a part of the distal end side) is provided with a light transmitting section 330 that transmits the laser light emitted by the laser light source 211 of the light irradiation device 2 to the outside. Therefore, the light irradiation system 1 of this embodiment is capable of selectively irradiating a specific position of a 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.

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

The shaft 310 of the catheter 3 is provided with a catheter side marker section 332 that is radiopaque, located close to the light-transmitting section 330. Therefore, when a medical professional uses radiation to photograph the inside of a living body and irradiates living tissue with laser light using the light irradiation device 2, the medical professional can align the position of the laser light source 211 of the light irradiation device 2 with the position of the catheter side marker section 332 that appears in the captured image, thereby allowing the laser light to be appropriately irradiated to the outside from the light-transmitting section 330. This makes it easier to further improve the accuracy of treatment.

As shown in FIG. 3, the tip of the catheter 3 is provided with an outlet 341 for discharging the cooling liquid from inside the lumen 311 to the outside of the catheter 3. Therefore, the cooling liquid supplied to the inside of the catheter 3 (in this embodiment, both the cooling liquid supplied to the cooling liquid flow path 213 of the light irradiation device 2 and the cooling liquid 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 to the outside of the catheter 3 from the outlet 341. As a result, the cooling liquid is continuously supplied to the vicinity of the laser light source 211, so that the temperature rise of the laser light source 211 and its vicinity can be more appropriately suppressed. In addition, the possibility that blood outside the catheter 3 will come into contact with the internal components of the catheter 3 (e.g., the laser light source 211, etc.) is appropriately reduced. Therefore, blood coagulation due to the heat of the laser light source 211 is less likely to occur.

In the catheter 3 of this embodiment, the through hole 321 of the distal tip 320, through which the guide wire is inserted when the catheter 3 is delivered, also serves as the outlet 341 for the coolant. Therefore, both the delivery of the catheter 3 and the cooling near the laser light source 211 are appropriately performed while preventing the configuration of the catheter 3 from becoming complicated. However, it is also possible to change the specific configuration of the outlet of the catheter 3. For example, an outlet may be formed on the side of the shaft 310, which has a long tubular shape, separately from the through hole 321 of the distal tip 320, or together with the through hole 321 of the distal tip 320. It is preferable that the outlet is formed further toward the tip side than the position where the laser light source 211 is disposed during use in the extension direction (direction of the axis O3) of the catheter 3.

As shown in FIG. 3, the outlet 341 of the catheter 3 is provided with an outlet valve 322 that allows liquid to be discharged to the outside of the catheter 3 through the outlet 341 while preventing liquid from flowing from the outside to the inside of the catheter 3. As a result, the outlet valve 322 prevents blood and other liquids from the outside of the catheter 3 from flowing into the inside of the catheter 3 through the outlet 341. This makes it even less likely that blood coagulation or the like will occur due to the heat of the laser light source 211.

(How to use)
An example of a method of using the light irradiation system 1 of this embodiment will be described. First, the surgeon inserts a guidewire (not shown) into the body lumen. Next, the surgeon inserts the base end side of the guidewire into the lumen 311 from the through hole 321 of the distal tip 320 of the catheter 3, and protrudes it to the base end side of the connector 301. The surgeon pushes the catheter 3 along the guidewire, and moves the light transmitting portion 330 of the catheter 3 to the target site of light irradiation. When moving the catheter 3 in the body lumen, the surgeon can appropriately move the catheter 3 to the target site by checking the position of the catheter side marker portion 332 by a radiographic image. Thereafter, the surgeon removes the guidewire from the catheter 3.

The operator supplies the cooling liquid to the cooling liquid 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 base end opening of the connector 301 of the catheter 3 and pushes the light irradiation device 2 along the lumen 311 of the catheter 3 in the living body cavity. When the light irradiation device 2 is sufficiently pushed inside the lumen 311 of the catheter 3, the distal tip 220 of the light irradiation device 2 comes into contact with the distal tip 320 of the catheter 3. As shown in FIG. 3, the light transmitting portion 330 in the catheter 3 is formed at a position in the direction of the axes O2 and O3 where the laser light source 211 is disposed with the distal tip 220 of the light irradiation device 2 in contact with the distal end of the lumen of the catheter 3 (the distal tip 320 of the catheter 3). Therefore, the position of the laser light source 211 and the position of the light transmitting portion 330 in the direction of the axes O2 and O3 are automatically aligned by simply pushing the light irradiation device 2 until it comes into contact with the distal tip 320 of the catheter 3. Furthermore, while checking the position of the Peltier element 230 relative to the axes O2 and O3 on the radiographic image, the surgeon rotates the light irradiation device 2 around the axis O2 to adjust the emission direction of the laser light from the laser light source 211. In this state, the laser light is emitted from the laser light source 211, so that the laser light is selectively irradiated onto the target area.

(Modification)
The techniques disclosed in the above embodiments are merely examples. Therefore, it is possible to modify the techniques exemplified in the above embodiments. Some modified examples of the above embodiments will be described with reference to FIGS. 5 to 7. Note that the same configuration as the above-described embodiment can be adopted for some configurations of the first modified example shown in FIG. 5, the second modified example shown in FIG. 6, and the third modified example shown in FIG. 7. Therefore, the same numbers as the above-described embodiment are assigned to the parts of the configurations of the first modified example to the third modified example that can adopt the same configuration as the above-described embodiment, and the description thereof will be omitted or simplified.

In the light irradiation system 1 of the first modified example shown in FIG. 5, the 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 is made of a material having a thermal conductivity equal to or higher than that of the heat generating surface 230A (for example, at least one of a heat pipe, a carbon nanotube, ceramics (AIN, SiC, etc.), a metal plate (platinum, titanium, copper, etc.), a torque wire, etc.). When a metal plate is used, the metal plate may be an alloy, or the surface of the metal plate may be plated. The indirect heat dissipation member 235 is exposed to the outside where it is exposed to 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 of the device body 210 of the light irradiation device 2. Therefore, the indirect heat dissipation member 235 is exposed to the coolant supplied to 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). This makes it easier for the heat generated from the heat generating surface 230A of the Peltier element 230 to be properly released to the outside through the indirect heat dissipation member 235.

In the light irradiation system 1 of the second modified example shown in FIG. 6, unlike the 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 arranged 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 arranged over a wide area of the surface of the laser light source 211 opposite to the side from which the laser light is emitted. The heat dissipation member 236 is made of a material having high thermal conductivity (for example, at least one of a heat pipe, carbon nanotube, ceramics (AIN, SiC, etc.), metal plate (platinum, titanium, copper, etc.), 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 a metal plate is used, the metal plate may be an alloy, or the surface of the metal plate may be plated.

Furthermore, the heat dissipation member 236 shown in FIG. 6 is exposed to the outside from the side of the device body 210 of the light irradiation device 2. Therefore, the heat dissipation member 236 is exposed to the coolant supplied to the inside of 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). This makes it easier for the heat generated from the laser light source 211 to be appropriately dissipated to the outside through the heat dissipation member 236. It is more preferable that the heat dissipation member 236 be 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, as long as 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.

Unlike the other embodiments, the light irradiation system 1 of the third modified example shown in FIG. 7 does not use a discharge valve 322 at the discharge port 341 of the catheter 3. 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 prevents liquid from flowing from the outside of the cooling liquid flow path 213 to the inside while allowing liquid to be discharged from the inside to the outside of the cooling liquid flow path 213 through the discharge port 341. As a result, the discharge valve 238 appropriately prevents blood and the like outside the cooling liquid flow path 213 from flowing into the inside through the discharge port 221.

It is also possible to employ only a part of the configurations exemplified in the above embodiments and modifications in the light irradiation system, light irradiation device, or catheter. For example, only one of the coolant flow path 213 and the Peltier element 230 may be employed in the light irradiation device. It is also possible to combine multiple configurations shown in different embodiments. As mentioned above, it is also possible to use only the light irradiation device 2 alone, without using the catheter 3.

The technology of the first aspect according to the present disclosure can also be expressed as follows.
(1)
A long-shaped medical light irradiation device,
a laser light source provided at a tip of a long device body and configured to emit laser light;
a cooling liquid flow path that leads to the laser light source side of the device body and allows a cooling liquid for cooling the laser light source to pass to the laser light source side;
A light irradiation device comprising:
(2)
The light irradiation device according to (1),
The device main body is formed into a long tubular shape, and the coolant flow path is provided in an inner cavity of the device main body.
A light irradiation device characterized in that, when the area of the coolant flow path in a cross section in a direction perpendicular to the extension direction of the device body is taken as the flow path area, the flow path area at a portion on the base end side of the laser light source is larger than the flow path area at a portion where the laser light source is installed.
(3)
The light irradiation device according to (1) or (2),
a power supply line extending from a base end side to a tip end side of the device body and connected to the laser light source to supply power to the laser light source;
The light irradiation device, wherein the power supply line is exposed in the cooling liquid flow path.
(4)
The light irradiation device according to (3),
A light irradiation device, characterized in that a cross-sectional area of a connection portion of the power supply line that connects to the laser light source is larger than a cross-sectional area of a portion of the power supply line that is closer to a base end than the connection portion.
(5)
The light irradiation device according to (3) or (4),
At least a portion of a surface of the power supply line is covered with an insulating material,
A light irradiation device, characterized in that 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.
(6)
The light irradiation device according to any one of (1) to (5),
a supply detection unit that detects whether or not a coolant is being supplied to the coolant flow path;
a supply notification unit that notifies a result of detection by the supply detection unit;
A light irradiation device further comprising:
(7)
The light irradiation device according to any one of (1) to (6),
A temperature detection unit that detects a temperature of the laser light source;
a temperature notification unit that notifies a result of detection by the temperature detection unit;
A light irradiation device further comprising:
(8)
A light irradiation device according to any one of (1) to (7),
The light irradiation device further comprises a flow passage valve provided on the base end side of the cooling liquid flow passage relative to the laser light source, the flow passage valve preventing backflow of the cooling liquid toward the base end side.
(9)
The light irradiation device according to any one of (1) to (8),
The device further includes a Peltier element provided at a tip portion of the device body,
The light irradiation device is characterized in that the Peltier element is disposed in contact with or in close proximity to the laser light source with a cooling surface side facing the laser light source.
(10)
The light irradiation device according to (9),
A light irradiation device characterized in that at least one of the heat generating surface of the Peltier element located opposite the cooling surface and an indirect heat dissipation member having a thermal conductivity equal to or higher than that of the heat generating surface and in contact with the heat generating surface is exposed to the outside and exposed to liquid.
(11)
A medical light irradiation system, comprising:
A catheter formed into a long tubular shape;
a long light irradiation device that is inserted into the lumen of the catheter;
Equipped with
The light irradiation device is
a laser light source provided at a tip of a long device body and configured to emit laser light;
a cooling liquid flow path that leads to the laser light source side of the device body and allows a cooling liquid for cooling the laser light source to pass to the laser light source side;
Equipped with
A light irradiation system, characterized in that a light transmitting portion 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)
The light irradiation system according to (11),
A light irradiation system characterized in that an outlet is formed in at least a portion of the tip of the catheter, for discharging the cooling liquid discharged from the cooling liquid flow path of the light irradiation device to the outside of the catheter.
(13)
The light irradiation system according to (12),
A light irradiation system characterized in that the outlet of the catheter is provided with an outlet valve that allows liquid to be discharged to the outside of the catheter through the outlet while preventing liquid from flowing from the outside to the inside of the catheter.

The technology of the second aspect according to the present disclosure can also be expressed as follows.
(1)
A long-shaped medical light irradiation device,
a laser light source provided at a tip of a long device body and configured to emit laser light;
A Peltier element provided at a tip portion of the device body;
Equipped with
The light irradiation device is characterized in that the Peltier element is disposed in contact with or in close proximity to the laser light source with a cooling surface side facing the laser light source.
(2)
The light irradiation device according to (1),
A light irradiation device characterized in that at least one of the heat generating surface of the Peltier element located opposite the cooling surface and an indirect heat dissipation member having a thermal conductivity equal to or higher than that of the heat generating surface and in contact with the heat generating surface is exposed to the outside and exposed to liquid.
(3)
The light irradiation device according to (1) or (2),
A light irradiation device further comprising a cooling liquid flow path that leads to the laser light source side of the device body and allows a cooling liquid 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),
The device main body is formed into a long tubular shape, and the coolant flow path is provided in an inner cavity of the device main body.
A light irradiation device characterized in that, when the cross-sectional area of the coolant flow path in a cross section in a direction perpendicular to the extension direction of the device body is taken as the flow path area, the flow path area at a portion on the base end side of the laser light source is larger than the flow path area at a portion where the laser light source is installed.
(5)
The light irradiation device according to (3) or (4),
a power supply line extending from a base end side to a tip end side of the device body and connected to the laser light source to supply power to the laser light source;
The light irradiation device, wherein the power supply line is exposed in the cooling liquid flow path.
(6)
The light irradiation device according to (5),
A light irradiation device, characterized in that a cross-sectional area of a connection portion of the power supply line that connects to the laser light source is larger than a cross-sectional area of a portion of the power supply line that is closer to a base end than the connection portion.
(7)
The light irradiation device according to (5) or (6),
At least a portion of a surface of the power supply line is covered with an insulating material,
A light irradiation device, characterized in that 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.
(8)
The light irradiation device according to any one of (3) to (7),
a supply detection unit that detects whether or not a coolant is being supplied to the coolant flow path;
a supply notification unit that notifies a result of detection by the supply detection unit;
A light irradiation device further comprising:
(9)
The light irradiation device according to any one of (1) to (8),
A temperature detection unit that detects a temperature of the laser light source;
a temperature notification unit that notifies a result of detection by the temperature detection unit;
A light irradiation device further comprising:
(10)
The light irradiation device according to any one of (3) to (9),
The light irradiation device further comprises a flow passage valve provided on the base end side of the cooling liquid flow passage relative to the laser light source, the flow passage valve preventing backflow of the cooling liquid toward the base end side.
(11)
A medical light irradiation system, comprising:
A catheter formed into a long tubular shape;
a long light irradiation device that is inserted into the lumen of the catheter;
Equipped with
The light irradiation device is
a laser light source provided at a tip of a long device body and configured to emit laser light;
A Peltier element provided at a tip portion of the device body;
Equipped with
the Peltier element is disposed in contact with or in close proximity to the laser light source with a cooling surface side facing the laser light source,
A light irradiation system, characterized in that a light transmitting portion 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)
The light irradiation system according to (11),
A light irradiation system characterized in that at least one of the heat generating surface of the Peltier element, which is located opposite the cooling surface, and an indirect heat dissipation member having a thermal conductivity equal to or higher than that of the heat generating surface and in contact with the heat generating surface, is exposed to the outside and exposed to liquid.
(13)
The light irradiation system according to (11) or (12),
A light irradiation system, characterized in that a cooling liquid is flowed into an inner cavity of the catheter while the light irradiation device is inserted into the catheter.

Claims (15)

A long-shaped medical light irradiation device,
a laser light source provided at a tip of a long device body and configured to emit laser light;
a cooling liquid flow path that leads to the laser light source side of the device body and allows a cooling liquid for cooling the laser light source to pass to the laser light source side;
A light irradiation device comprising: 2. The light irradiation device according to claim 1,
The device main body is formed into a long tubular shape, and the coolant flow path is provided in an inner cavity of the device main body.
A light irradiation device characterized in that, when the area of the coolant flow path in a cross section in a direction perpendicular to the extension direction of the device body is taken as the flow path area, the flow path area at a portion on the base end side of the laser light source is larger than the flow path area at a portion where the laser light source is installed. 2. The light irradiation device according to claim 1,
a power supply line extending from a base end side to a tip end side of the device body and connected to the laser light source to supply power to the laser light source;
The light irradiation device, wherein the power supply line is exposed in the cooling liquid flow path. 4. The light irradiating device according to claim 3,
A light irradiation device, characterized in that a cross-sectional area of a connection portion of the power supply line that connects to the laser light source is larger than a cross-sectional area of a portion of the power supply line that is closer to a base end than the connection portion. 4. The light irradiating device according to claim 3,
At least a portion of a surface of the power supply line is covered with an insulating material,
A light irradiation device, characterized in that 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. 2. The light irradiation device according to claim 1,
a supply detection unit that detects whether or not a coolant is being supplied to the coolant flow path;
a supply notification unit that notifies a result of detection by the supply detection unit;
A light irradiation device further comprising: 2. The light irradiation device according to claim 1,
A temperature detection unit that detects a temperature of the laser light source;
a temperature notification unit that notifies a result of detection by the temperature detection unit;
A light irradiation device further comprising: 2. The light irradiation device according to claim 1,
The light irradiation device further comprises a flow passage valve provided on the base end side of the cooling liquid flow passage relative to the laser light source, the flow passage valve preventing backflow of the cooling liquid toward the base end side. 2. The light irradiation device according to claim 1,
The device further includes a Peltier element provided at a tip of the device body,
The light irradiation device is characterized in that the Peltier element is disposed in contact with or in close proximity to the laser light source with a cooling surface side facing the laser light source. 10. The light irradiating device according to claim 9,
A light irradiation device characterized in that at least one of the heat generating surface of the Peltier element located opposite the cooling surface and an indirect heat dissipation member having a thermal conductivity equal to or higher than that of the heat generating surface and in contact with the heat generating surface is exposed to the outside and exposed to liquid. A long-shaped medical light irradiation device,
a laser light source provided at a tip of a long device body and configured to emit laser light;
A Peltier element provided at a tip portion of the device body;
Equipped with
The light irradiation device is characterized in that the Peltier element is disposed in contact with or in close proximity to the laser light source with a cooling surface side facing the laser light source. A medical light irradiation system, comprising:
A catheter formed into a long tubular shape;
a long light irradiation device that is inserted into the lumen of the catheter;
Equipped with
The light irradiation device is
a laser light source provided at a tip of a long device body and configured to emit laser light;
a cooling liquid flow path that leads to the laser light source side of the device body and allows a cooling liquid for cooling the laser light source to pass to the laser light source side;
Equipped with
A light irradiation system, characterized in that a light transmitting portion 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. The lighting system according to claim 12,
A light irradiation system characterized in that an outlet is formed in at least a portion of the tip of the catheter, for discharging the cooling liquid discharged from the cooling liquid flow path of the light irradiation device to the outside of the catheter. The lighting system according to claim 13,
A light irradiation system characterized in that the outlet of the catheter is provided with an outlet valve that allows liquid to be discharged to the outside of the catheter through the outlet while preventing liquid from flowing from the outside to the inside of the catheter. A medical light irradiation system, comprising:
A catheter formed into a long tubular shape;
a long light irradiation device that is inserted into the lumen of the catheter;
Equipped with
The light irradiation device is
a laser light source provided at a tip of a long device body and configured to emit laser light;
A Peltier element provided at a tip portion of the device body;
Equipped with
the Peltier element is disposed in contact with or in close proximity to the laser light source with a cooling surface side facing the laser light source,
A light irradiation system, characterized in that a light transmitting portion 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.

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