Light irradiation device and light irradiation system

Abstract

A light irradiation device 2 has an elongated shape. The light irradiation device 2 comprises, at the leading end thereof, a light emission part that emits a laser beam in a predetermined wavelength region; and an optical member 281 that is capable of changing the direction of the laser beam. The optical member 281 irradiates, in a state of being inserted inside a lumen of a living body, biological tissue with a laser beam by changing the direction of the laser beam in a direction intersecting the long-axis direction of the light irradiation device 2. The light irradiation device 2 is capable of selectively irradiating a specific position of the living body with a laser beam emitted from a laser beam source 230A, 230B.

Description

Light irradiation device and light irradiation system

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

[0002] Photodynamic therapy (PDT) is known as one of the techniques for treating diseases. In PDT, a photosensitive substance is administered to a 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 reactive oxygen species generated in the cancer cells. However, in PDT, it is difficult to selectively accumulate the photosensitive substance in cancer cells. The occurrence of side effects due to the uptake of the photosensitive substance into normal cells is a problem with PDT.

[0003] In response to this, near-infrared photoimmunotherapy (NIR-PIT) has been proposed in recent years. NIR-PIT uses a complex that combines two compounds: an antibody against a cancer cell-specific antigen and a photosensitizer. When administered to a living body, the complex tends to selectively accumulate in cancer cells within the body. The complex is then activated by irradiation with light of an excitation wavelength (e.g., a wavelength including 690 nm) of the photosensitizer in the complex (see, for example, Patent Document 1). In NIR-PIT, the complex is selectively accumulated in cancer cells by the antibody, and when light is locally irradiated onto the cancer cells, side effects are less likely to occur compared to PDT.

[0004] The wavelength range including 690 nm is also known as the spectroscopic window of the living body, and is a wavelength range in which light is less absorbed by biological components than other wavelength ranges. However, light in the wavelength range including 690 nm has difficulty penetrating into the body even when irradiated from the body surface, making it difficult to treat cancer deep inside the body by irradiating it from the body surface.

[0005] Therefore, technologies have been proposed for irradiating light from a position closer to cancer cells, rather than irradiating light from the body surface. For example, the device described in Patent Document 2 is inserted into a blood vessel and irradiates light from deep within the body. The device described in Patent Document 3 has a radiopaque marker provided near the light irradiation site to make it easier to position the light irradiation site compared to the device described in Patent Document 2. Furthermore, the device described in Patent Document 4 has multiple light-emitting diodes provided in a hollow shaft.

[0006] JP-T-2014-523907 A JP-A-2018-867 JP-A-2020-185257 JP-T-2007-528752 A

[0007] An object of one aspect of the present disclosure is to provide a light irradiation device and a light irradiation system that are capable of more efficiently and appropriately irradiating a specific position inside a lumen of a living body with light.

[0008] The light irradiation device provided by the embodiments is a long-shaped medical light irradiation device, and includes a light emitting section that emits laser light in a predetermined wavelength range along the longitudinal axis direction of the light irradiation device, and an optical element at the tip that can change the direction of the laser light, and when inserted inside a lumen of a living body, the optical element changes the direction of the laser light in a direction that intersects with the longitudinal axis direction of the light irradiation device, thereby irradiating the laser light onto living tissue.

[0009] The light irradiation system provided by the embodiment 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 light emitting unit that emits laser light in a predetermined wavelength range, and an optical element at its tip that can change the direction of the laser light. When inserted inside the lumen of a living body, the optical element changes the direction of the laser light in a direction that intersects with the longitudinal axis direction of the light irradiation device, thereby irradiating the living tissue with the laser light.

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

[0011] The light irradiation device disclosed herein is a long-shaped medical light irradiation device that includes a light emitting unit at a distal end thereof that emits laser light in a predetermined wavelength range. The light emitting unit emits the laser light in a predetermined direction. For example, the light emitting unit emits the laser light in a direction intersecting the longitudinal axis direction of the light irradiation device. The light emitting unit is, for example, a laser light source or an optical fiber.

[0012] First, we will explain the case where a laser light source is used as the light emitter. The light irradiation device of the present disclosure can directly irradiate light from a laser light source provided at the tip to a specific location on a living body without using an optical transmission member (e.g., an optical fiber, etc.). Therefore, various problems that arise when using an optical transmission member (e.g., at least one of the problems of light leakage during the optical transmission member and changes in the characteristics of the light during transmission) are appropriately suppressed. Furthermore, the laser light source emits laser light from the tip of the light irradiation device in a direction intersecting the longitudinal axis. Compared to light-emitting diodes, laser light sources are more likely to emit light that is less likely to diverge and has high directionality. Therefore, the light irradiation device of the present disclosure can selectively irradiate a specific location on a living body with laser light emitted from the laser light source. As a result, various problems (e.g., side effects) caused by irradiating light to unintended locations are less likely to occur. Furthermore, laser light sources have the property of irradiating light with wavelengths having a narrower spectral width than light-emitting diodes. Therefore, by providing a laser light source at the tip of the light irradiation device, various problems (e.g., reduced efficiency and / or unintended changes in tissue) caused by irradiation of tissue with a wavelength different from the wavelength required for treatment (e.g., the excitation wavelength of a photosensitizer) can be suppressed, making it easier to irradiate specific locations in a living body with light more efficiently and appropriately.

[0013] Note that the "tip" of the light irradiation device does not refer only to the exact tip of the light irradiation device. In other words, the case where the light irradiation unit is provided closer to the base end than the exact tip within a range that allows selective irradiation of laser light to a specific site is also included in the scope of "provided at the tip" in the present disclosure.

[0014] The light irradiation device may be provided with multiple laser light sources at its distal end. By providing multiple laser light sources in one light irradiation device, the degree of freedom of laser irradiation (e.g., ease of adjusting at least one of the laser irradiation area, irradiation density, irradiation direction, etc.) is improved compared to when only one laser light source is provided. As a result, it becomes easier to obtain an appropriate therapeutic effect.

[0015] The emission of laser light from at least some of the multiple laser light sources may be controllable independently of the other laser light sources. In this case, the degree of freedom in laser irradiation is further improved. For example, by adjusting the number of laser light sources that emit laser light, it is possible to change at least one of the laser irradiation area, irradiation density, irradiation direction, etc. Furthermore, by switching the laser light source that emits laser light, it is possible to change the area to be irradiated with laser light.

[0016] However, the laser light emission from the plurality of laser light sources may be controlled collectively. Even in this case, the degree of freedom in laser irradiation can be appropriately improved by appropriately designing the number and arrangement of the plurality of laser light sources.

[0017] The multiple laser light sources may emit laser light in the same wavelength range. In this case, the laser light in the same wavelength range can be irradiated to a specific area with a higher degree of freedom (e.g., by appropriately adjusting at least one of the laser irradiation area, irradiation density, etc.). As a result, it becomes easier to obtain an appropriate therapeutic effect.

[0018] Some of the multiple laser light sources may include laser light sources that emit laser light in a wavelength range different from the wavelength ranges of the other laser light sources. In this case, for example, it becomes possible to selectively or multiplex laser light in different wavelength ranges to irradiate biological tissue. This further improves the flexibility of treatment.

[0019] The laser light source may be contained within the elongated device body. At least the portion of the device body containing the laser light source may be formed from a material that transmits the laser light emitted by the laser light source. By containing the laser light source within the device body, the laser light source is held in a stable state within the device body, and defects such as failure of the laser light source are less likely to occur, compared to when the laser light source is exposed to the outside of the device body. Furthermore, the laser light emitted from the laser light source passes through the device body and is appropriately irradiated onto biological tissue. This makes it easier to perform treatment more appropriately.

[0020] However, the configuration of the device body can be changed. For example, a laser light transmission window, which does not include a component, may be formed in the device body at a portion through which the laser light emitted from the laser light source passes. In this case, the material of the portion of the device body near the laser light source is not limited to a material that transmits laser light.

[0021] The inventors of the present application have conducted a first evaluation test and a second evaluation test (described later) to newly find a desirable range (upper and lower limits) of the light irradiation density of the laser light emitted from the light emitting portion when the laser light is emitted to the outside from the light emitting device. The light irradiation density of the laser light emitted from the light emitting portion when the laser light is emitted to the outside from the light emitting device is 80 W / cm ２ More than 1600W / cm ２ In this case, it becomes easier to obtain an appropriate therapeutic effect by irradiating the photosensitizer with laser light.

[0022] The light irradiation density at the time of being emitted from the light irradiation device to the outside is more preferably 300 W / cm ２ More than 1300W / cm ２ or less, more preferably 600 W / cm ２ More than 1300W / cm ２ As an example, in the present disclosure, the light irradiation density at the time of being emitted to the outside from the light irradiation device may be about 1273 W / cm ２ It is said that.

[0023] Furthermore, when a laser light source is used as the light emitting unit, the above-described condition for the light irradiation density can be applied regardless of the number of laser light sources provided in the light irradiation device. For example, when laser light is simultaneously emitted from a plurality of laser light sources and the laser light is combined, the above-described condition for the light irradiation density of the combined laser light may be used.

[0024] The light irradiation device may include a radiopaque marker at the tip where the laser light source is provided. In this case, a medical professional (e.g., a doctor) can appropriately adjust the irradiation position of the laser light by checking the position of the marker that appears on the captured image while imaging the inside of a living body using radiation (e.g., X-rays) and irradiating the living tissue with laser light using the light irradiation device. This further facilitates improving the accuracy of treatment.

[0025] At least some of the components of the laser light source may be formed from a radiopaque material, so that the laser light source itself functions as a marker. In this case, even if a marker is not provided separately from the laser light source, the position of the laser light source can be properly determined by radiography. Furthermore, since the laser light source itself functions as a marker, the position of the laser light source can be more accurately determined by medical personnel. This makes it easier to perform treatment more appropriately.

[0026] However, the configuration of the marker unit may be changed. For example, a marker unit may be provided separately from the laser light source. For example, a tip tip may be provided at the tip of the light irradiation member. At least a portion of the tip tip may be formed from a radiopaque material, so that the tip tip functions as the marker unit. In this case, since the tip tip also functions as the marker unit, adjustment of the laser light irradiation position is appropriately assisted while suppressing an increase in the number of parts. Furthermore, a marker unit may be provided separately from the laser light source and the tip tip. When multiple laser light sources are used in one light irradiation device, a marker unit may be provided for each laser light source. In this case, it becomes easier to appropriately grasp the position of each of the multiple laser light sources.

[0027] The laser light source may be a surface-emitting laser that emits laser light perpendicular to the substrate. By using a surface-emitting laser, the laser light can be appropriately emitted with low power, and the light-emitting device has high resistance to temperature changes. Furthermore, since the surface-emitting laser can emit laser light perpendicular to the substrate surface, it becomes easier to adjust the irradiation position of the laser light more accurately.

[0028] The laser light source may be a semiconductor laser, which is a circuit element manufactured using semiconductor materials. Semiconductor lasers are easily miniaturized and can be easily incorporated into small-diameter light-emitting devices. Furthermore, semiconductor lasers can emit highly directional laser light with a uniform phase using low power. This facilitates stable therapeutic effects. The semiconductor material and composition of the semiconductor laser are designed to emit laser light of a desired wavelength. When the laser light source is used as an ultraviolet laser (wavelength 370 nm to 399 nm), a violet laser (wavelength 400 nm to 429 nm), a blue laser (wavelength 430 nm to 489 nm), or a green laser (wavelength 490 nm to 550 nm), GaN-based materials such as GaN, InGaN, and AlGaN may be used. When the laser light source is used as a red laser (wavelength 640 nm or more and 770 nm or less) or an infrared laser (wavelength 780 nm or more and 1000 nm or less), GaAs-based materials such as GaAs and AlGaAs, or InP-based materials such as InAlGaP and GaInP may be used.

[0029] The light irradiation device may further include a light detection transmission member that transmits light incident on the tip to the light sensor, or an optical sensor provided at the tip. In this case, the state of light incident on the tip of the light irradiation device is appropriately detected by the optical sensor. When a light detection transmission member that transmits light incident on the tip to the optical sensor is provided, the state of light at the tip is appropriately detected while preventing the configuration of the tip of the light irradiation device from becoming complicated. Furthermore, when an optical sensor is provided at the tip, the state of light at the tip is directly detected by the optical sensor at the tip. In other words, the light detected by the optical sensor is less likely to undergo changes in the light characteristics that may occur during the transmission process. This makes it easier to detect the state of light more accurately.

[0030] In addition to or in addition to the optical sensor, other sensors may be provided at the tip of the light irradiation device. For example, a temperature sensor may be provided at the tip of the light irradiation device. In this case, the temperature at the tip of the light irradiation device is appropriately detected. Therefore, for example, at least one of a temperature increase caused by the operation of a laser light source provided at the tip and a temperature increase caused by the emission of laser light to biological tissue can be appropriately detected. The light irradiation device may further include a light detection transmission member that transmits light incident on the tip to a spectroscopic sensor, or a spectroscopic sensor provided at the tip. The spectroscopic sensor detects light emitted by a substance that absorbs light irradiated from the laser light source. By checking the detection results of the spectroscopic sensor, it is possible to confirm whether the laser light is being appropriately irradiated to the target site (e.g., an affected area where a photosensitive substance has accumulated). Furthermore, it is possible to monitor the change over time in the emission intensity of light emitted by the light-absorbing substance to check the progress of treatment. The light irradiation device may also include a pressure sensor at the tip. When the photosensitive substance reacts to the laser light, the cellular contents are dispersed into the surrounding area. By checking the detection results from the pressure sensor, it is possible to determine whether the photosensitive substance has reacted appropriately. The light irradiation device may also include a pH sensor at its tip. In this case, by checking the detection results from the pH sensor, it is possible to properly grasp the pH near the tip of the light irradiation device. The light irradiation device may also include a flow rate sensor at its tip. In this case, by checking the detection results from the flow rate sensor, it is possible to determine whether the photosensitive substance has reacted appropriately. As described above, by including various sensor systems, the light irradiation device can provide various information useful for treatment.

[0031] The light irradiation device may include multiple temperature sensors. The temperature measurement positions of the multiple temperature sensors may be located at multiple locations on the distal end of the light irradiation device. In this case, useful information can be obtained based on the temperature detection results at each of the multiple measurement positions. For example, by checking which of the multiple measurement positions has a higher temperature than the other measurement positions, it is possible to determine the direction in which the laser light is being irradiated. Furthermore, by more accurately understanding the temperature at each measurement position, medical professionals can improve the accuracy of treatment.

[0032] The light irradiation device may further include wiring extending from the base end side to the tip end. At least one of the wirings may be arranged in a spiral shape in the main body of the light irradiation device. By arranging the wiring in a spiral shape, it becomes easier to ensure appropriate rigidity of the elongated light irradiation device compared to when the wiring is arranged straight along the axial direction. This makes it easier to further improve the accuracy of treatment.

[0033] The wiring to be arranged in a spiral shape can be selected as appropriate. For example, the wiring of a temperature sensor (e.g., a thermocouple, etc.) may be arranged in a spiral shape. Furthermore, when the measurement positions (measurement points) of multiple temperature sensors are arranged at the tip of the light irradiation device, the measurement positions of the temperature sensors may be arranged at each of multiple positions of the wiring arranged in a spiral shape. In this case, it is possible to easily and appropriately arrange the measurement positions of multiple temperature sensors in each of the axial direction and circumferential direction of the elongated light irradiation device. Furthermore, the wiring of a laser light source, etc. may be arranged in a spiral shape.

[0034] At least one of the wires may contain a radiopaque material. In this case, the position of the elongated light irradiation device can be easily and appropriately determined by radiography. In addition, when the radiopaque wires are arranged in a spiral shape, the position of the light irradiation device can be even more easily determined.

[0035] The light irradiation device may further include a position detection member for detecting the position of the tip portion within the lumen of the living body. In this case, by detecting the position of the position detection member provided in the light irradiation device, it becomes easier to appropriately grasp the position of the tip portion of the light irradiation device within the lumen of the living body. Note that the position detection member can be various members for detecting the position within the lumen (for example, at least one of a small ultrasonic oscillator and a magnet).

[0036] The light irradiation device may further include a magnetic member that guides at least one of the position and direction of the tip of the light irradiation device in the living body by a magnetic force generated when the light irradiation device is placed in a magnetic field. In this case, at least one of the position and direction of the tip of the light irradiation device is appropriately guided when the light irradiation device is inserted in the living body. This makes it easier to perform treatment more appropriately.

[0037] The specific configuration of the magnetic member can be selected as appropriate. For example, the magnetic member may be provided on a portion of the laser light source opposite to the side from which the laser light is emitted. In this case, the orientation of the magnetic member provided on the laser light source (i.e., the circumferential orientation around the axial direction of the light irradiation device) is adjusted by magnetic force, making it easier to appropriately control the irradiation direction of the laser light.

[0038] The light irradiation device may also include a light-emitting member at its tip that emits light via wireless power supply to indicate the position of the tip. At least a portion of the light-emitting member may be made of a magnetic member. In this case, not only is the position of the tip of the light irradiation device indicated by emitting light from the light-emitting member, but it is also possible to guide at least one of the position and direction of the tip by generating a magnetic force in the light-emitting member. The magnetic member may also serve as the position detection member described above. In this case, the light irradiation device is endowed with multiple useful functions while suppressing an increase in the number of parts.

[0039] The light emitting unit may emit laser light having a wavelength of 300 nm or more and 2000 nm or less. More preferably, the light emitting unit may emit laser light having a wavelength of 600 nm or more and 1000 nm or less. In this case, by using the light irradiation device of the present disclosure in the treatment of a disease using a photosensitive substance, it becomes easier to obtain an appropriate therapeutic effect.

[0040] The light irradiation system of the present disclosure includes a catheter and a light irradiation device. The catheter is formed in a long tubular shape and is flexible. The light irradiation device is used by being inserted into the lumen of the catheter and is flexible like the catheter. The light irradiation device includes a laser light source at its tip that emits laser light in a predetermined wavelength range. The laser light source emits laser light in a direction intersecting with the longitudinal axis direction of the light irradiation device. At least a portion of the side surface of the tip side of the catheter is formed with a light-transmitting portion that transmits laser light emitted by the laser light source included in the light irradiation device to the outside of the catheter.

[0041] The light irradiation system of the present disclosure can directly irradiate a specific location in a living body with laser light emitted from a light source through a light-transmitting portion of a catheter, without using a light transmission member (e.g., an optical fiber, etc.). Therefore, various problems that arise when using a light transmission member (e.g., at least one of problems of light leakage during the light transmission member and problems of the characteristics of the light changing during light transmission) are appropriately suppressed. Furthermore, the laser light source emits laser light from the tip of the light irradiation device in a direction intersecting the longitudinal axis. The laser light is irradiated to the outside through the light-transmitting portion of the catheter. Therefore, the light irradiation system of the present disclosure can selectively irradiate a specific location in a living body with laser light emitted from the laser light source. As a result, various problems (e.g., side effects) caused by irradiating light to an unintended location are less likely to occur. This makes it easier to irradiate a specific location in a living body lumen more efficiently and appropriately. The configuration of the light irradiation device used in the light irradiation system can employ at least one of the configurations of the light irradiation device described above.

[0042] At least the distal end portion of the catheter, which is adjacent to the laser light source of the light irradiation device, may be made of a material with a thermal conductivity of 0.1 W / m·K or more. In this case, the laser light source is more easily cooled by, for example, blood flow or saline. This reduces the possibility of malfunction of the laser light source due to heat generated by emitting laser light. As a result, treatment can be more appropriately performed.

[0043] A cooling fluid may be flowed into the lumen of the catheter while the light irradiation device is inserted into the catheter, in which case the cooling fluid appropriately suppresses problems caused by a temperature rise at the tip end due to the laser light source (for example, failure of the laser light source).

[0044] The catheter may include multiple temperature sensors. The temperature measurement positions of the multiple temperature sensors may be located at multiple sites on the catheter. In this case, useful information can be obtained based on the temperature detection results at each of the multiple measurement positions. For example, by checking which of the multiple measurement positions has a higher temperature than the other measurement positions, it is possible to determine the direction in which the laser light is being irradiated. Furthermore, by more accurately understanding the temperature at each measurement position, medical professionals can improve the accuracy of treatment.

[0045] The catheter may further include wires extending from the base end to the tip end. At least one of the wires may be arranged in a spiral shape in the catheter. By arranging the wires in a spiral shape, it becomes easier to ensure appropriate rigidity of the long tubular catheter compared to when the wires are arranged straight along the axial direction. This makes it easier to further improve the accuracy of treatment.

[0046] The spirally arranged wiring can be selected as appropriate. For example, the wiring of a temperature sensor (e.g., a thermocouple) may be arranged spirally. Furthermore, when multiple temperature sensor measurement positions (measurement points) are arranged on the catheter, the temperature sensor measurement positions may be arranged at each of the multiple positions on the spirally arranged wiring. In this case, it is possible to easily and appropriately arrange the measurement positions of the multiple temperature sensors in both the axial and circumferential directions of the long catheter.

[0047] At least one of the wires may contain a radiopaque material. In this case, the position of the long catheter can be more easily determined by radiography. If the radiopaque wires are arranged in a spiral, the position of the catheter can be more easily determined.

[0048] The catheter may include a radiopaque catheter marker located close to the light-transmitting portion. In this case, when a medical professional (e.g., a doctor) irradiates biological tissue with laser light using a light irradiation device while capturing images of the inside of a living body using radiation (e.g., X-rays), the medical professional can align the laser light source of the light irradiation device with the position of the catheter marker that appears in the captured image, thereby allowing the laser light to be appropriately irradiated from the light-transmitting portion to the outside. This further facilitates improving the accuracy of treatment.

[0049] However, the catheter marker may be omitted. For example, if the entire vicinity of the distal end of the catheter is made of a material that transmits laser light, the emission direction of the laser light from the laser light source can be easily adjusted even without the catheter marker.

[0050] The catheter may further include a catheter distal tip joined to the distal end. The catheter distal tip may have a through-hole formed therein that penetrates the catheter in the axial direction and has a diameter smaller than that of the light irradiation device. At least a portion of the catheter distal tip may be formed from a radiopaque material. In this case, a medical professional (e.g., a doctor) can position the catheter in an appropriate position by understanding the position of the distal tip that appears in a radiographic image. This facilitates further improvement in the accuracy of treatment.

[0051] The light transmitting portion of the catheter may be formed at a position in the axial direction of the catheter where the laser light source of the light emitting portion is disposed with the tip of the light emitting device in contact with the tip of the lumen of the catheter. In this case, simply by pushing the light emitting device until it contacts the tip of the lumen of the catheter, the position of the laser light source and the position of the light transmitting portion in the axial direction automatically coincide with each other. This makes it easier to perform treatment more appropriately.

[0052] 3 is a longitudinal sectional view of the light irradiation system 1 in a state where the light irradiation device 2 and the catheter 3 are separated. FIG. 3 is a longitudinal sectional view of the light irradiation system 1 in a state where the light irradiation device 2 is attached to the catheter 3 (in use state). FIG. 4 is an enlarged longitudinal sectional view of the vicinity of the distal end of the light irradiation system 1 in FIG. 2. FIG. 5 is a sectional view taken along the arrows A-A in FIG. 3. FIG. 6 is a sectional view taken along the arrows B-B in FIG. 3. FIG. 7 is a view showing an example of a catheter side marker unit 332A provided on the catheter 3. FIG. 8 is a view showing an example of a catheter side marker unit 332A provided on the catheter 3. FIG. 9 is an enlarged longitudinal sectional view of the vicinity of the distal end of the light irradiation system 1 of the first modified example. FIG. 10 is an enlarged longitudinal sectional view of the vicinity of the distal end of the light irradiation system 1 of the second modified example. FIG. 11 is an enlarged view of the vicinity of the distal end of the light irradiation device 2 of the third modified example. FIG. 12 is an enlarged view of the vicinity of the distal end of the catheter 3 of the fourth modified example. FIG. 13 is an enlarged view of the vicinity of the distal end of the light irradiation system 1 of the fifth modified example. FIG. 14 is an enlarged view of the vicinity of the distal end of the light irradiation system 1 of the sixth modified example. FIG. 15 is a view showing the results of a first evaluation test.

[0053] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. A light irradiation system 1 of this embodiment is used by being inserted into a lumen of a living body (for example, at least one of a blood vessel, lymph node, urethra, respiratory tract, digestive organ, secretory gland, and reproductive organ). The light irradiation system 1 irradiates biological tissue with light (laser light in this embodiment) while inserted into the lumen of the living body. The light irradiation system can be used for at least one of therapies such as PDT (Photodynamic Therapy) and NIR-PIT (Near-infrared Photoimmunotherapy).

[0054] 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 onto biological tissue from the light irradiation device 2. However, it is also possible to use only the light irradiation device 2 alone, without using the catheter 3.

[0055] 1 to 3 and 8 to 11 show mutually orthogonal X and Y axes. In these figures, the lower side (+X direction) of the figure is the "distal side," the upper side (-X direction) of the figure is the "proximal side," the left side (+Y direction) of the figure is the "left side," and the right side (-Y direction) of the figure is the "right side." The light irradiation system 1, light irradiation device 2, and catheter 3 are inserted into a biological lumen from the distal side. The proximal side is operated by a medical professional (e.g., a doctor).

[0056] (Light Irradiation Device) The light irradiation device 2 of this embodiment will be described with reference to FIGS. 1 to 5. As shown in FIG. 1, the light irradiation device 2 has an elongated shape. The light irradiation device 2 includes a connector 201, a shaft 210, and a distal tip 220. The connector 201 is located on the proximal end side of the light irradiation device 2 and is held by the surgeon. The connector 201 includes a pair of wing portions 202 and a connecting portion 203. The connecting portion 203 is a substantially cylindrical member. The wing portion 202 is connected to the proximal end of the connecting portion 203. The shaft 210 is connected to the distal end of the connecting portion 203. The wing portion 202 and the connecting portion 203 may be formed integrally.

[0057] The shaft 210 is preferably antithrombogenic, flexible, and biocompatible. The shaft 210 can be made of at least one of a resin material and a metal material. Examples of resin materials that can be used include polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin. Examples of metal materials that can be used include stainless steel such as SUS304, nickel-titanium alloy, cobalt-chromium alloy, and tungsten steel. The shaft 210 can also be made of a combination of multiple materials.

[0058] The shaft 210 is an elongated member extending along the axis O2. Various wirings (e.g., wirings 231A and 231B, which will be described later) are arranged inside the shaft 210. The distal tip 220 is connected to the distal end of the shaft 210. The distal tip 220 has a substantially cylindrical shape. The outer diameter of the distal tip 220 is substantially the same as the outer diameter Φ1 of the shaft 210.

[0059] The configuration of the distal end of the light irradiation device 2 of this embodiment will be described with reference to FIG. 3 . FIG. 3 is an enlarged longitudinal cross-sectional view of the distal end and its vicinity of the light irradiation system 1 in FIG. 2 . As shown in FIG. 3 , the light irradiation device 2 includes a small laser light source 230 (230A, 230B) at its distal end, which emits laser light in a predetermined wavelength range. The laser light source 230 is an example of a light emitting unit. The laser light source 230 is contained inside an elongated shaft 210 (which can also be referred to as a "device main body"). However, the method of fixing the laser light source 230 can be changed. For example, the shaft may be formed in a long tubular shape having a lumen therein. In this case, the laser light source 230 (230A, 230B) may be fixed to the inner wall of the lumen of the shaft.

[0060] The laser light source 230 (230A, 230B) emits laser light in a direction intersecting the longitudinal 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 intersecting perpendicularly to the axis O2). Therefore, the light irradiation device 2 can directly irradiate a specific position of a living body with light from the laser light source 230 provided at the tip without using an optical transmission member such as an optical fiber. Therefore, various problems that occur when an optical transmission member is used (for example, at least one of problems of light leakage and attenuation midway through the optical transmission member and problems of light characteristics changing during the light transmission process) are appropriately suppressed.

[0061] Furthermore, the laser light source 230 emits laser light from the distal end of the light irradiation device 2 in a direction intersecting the direction of the axis O2. Compared to light-emitting diodes, the laser light source 230 is less likely to diverge and more easily emits light with high directivity. Therefore, the light irradiation device 2 of this embodiment is capable of selectively irradiating a specific location of a living body with laser light emitted from the laser light source 230. As a result, various problems (e.g., side effects) caused by light irradiation at unintended locations are less likely to occur. Furthermore, the laser light source 230 has the property of being able to irradiate light with wavelengths having a narrower spectral width than light-emitting diodes. Therefore, by providing the laser light source 230 at the distal end of the light irradiation device 2, various problems (e.g., reduced irradiation efficiency and / or unintended tissue changes) caused by irradiating tissue with a wavelength different from the wavelength required for treatment (e.g., the excitation wavelength of a photosensitizer) are also suppressed. This makes it easier to irradiate specific locations within a living body lumen with light more efficiently and appropriately.

[0062] A surface-emitting laser that emits laser light in a direction perpendicular to the substrate can be used as the laser light source 230. By using a surface-emitting laser, laser light can be appropriately emitted with low power, and the light-emitting device 2 has high resistance to temperature changes. Furthermore, since a 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.

[0063] It is also possible to use a semiconductor laser, which is a circuit element manufactured using semiconductor materials, for the laser light source 230. Semiconductor lasers are easy to miniaturize, so they can be easily incorporated into light irradiation devices 2 with small diameters. Furthermore, semiconductor lasers can emit highly directional laser light with a uniform phase using low power. This makes it easier to stabilize the therapeutic effect.

[0064] 3, the light irradiation device 2 of this embodiment is provided with a plurality of laser light sources 230A, 230B at its distal end. By providing a plurality of laser light sources 230A, 230B in one light irradiation device 2, the degree of freedom of laser irradiation (e.g., ease of adjustment of at least one of the laser irradiation area, irradiation density, irradiation direction, etc.) is improved compared to when only one laser light source is provided. As a result, it becomes easier to obtain an appropriate therapeutic effect.

[0065] A wiring 231A extending from the control unit 5 (see FIGS. 1 and 2) is connected to the laser light source 230A. A wiring 231B extending from the control unit 5 is also connected to the laser light source 230B. Power is supplied to the laser light sources 230A and 230B via the wiring 231A and 231B. The wiring 231A and 231B are provided along the longitudinal axis direction (direction of the axis O2) of the light irradiation device 2. However, as will be described in detail later, the wiring 231A and 231B can also be arranged in a spiral shape or the like. In this embodiment, the wiring 231A and 231B extend from the control unit 5 and are connected to the laser light sources 230A and 230B through the inside of the light irradiation device 2. In FIGS. 1 to 3, the wiring 231A and 231B are indicated by dotted lines. FIG. 4 is a cross-sectional view taken along the arrow A-A in FIG. 3. FIG. 3 shows the state in which the wiring 231A is connected to the laser light source 230A. 5 is a cross-sectional view taken along the line BB in FIG. 3. In FIG. 5, cross sections of two wires 231A and 231B passing through the inside of shaft 210 are shown.

[0066] In this embodiment, the emission of laser light from at least some of the multiple laser light sources 230A and 230B can be controlled independently of the other laser light sources. That is, the control unit 5 can independently control the emission of laser light from the two laser light sources 230A and 230B. As a result, the degree of freedom in laser irradiation is further improved.

[0067] Specifically, in this embodiment, as shown in Fig. 3, the installation directions of the laser light sources 230A and 230B are determined so that the laser light irradiation directions of the laser light from each of the multiple laser light sources 230A and 230B are different from each other. Specifically, the laser light irradiation surface of the laser light source 230A faces the +Y direction, and the laser light irradiation surface of the laser light source 230B faces the -Y direction. Therefore, the laser light emission from the two laser light sources 230A and 230B is independently controlled by the control unit 5, so that the emission direction of the laser light is appropriately changed. This further improves the flexibility of treatment.

[0068] In this embodiment, the multiple laser light sources 230A and 230B emit laser light in the same wavelength range. Therefore, the light irradiation device 2 can irradiate a specific area with laser light in the same wavelength range with a higher degree of freedom (i.e., by selecting an appropriate direction for irradiating the laser light). As a result, it becomes easier to obtain an appropriate therapeutic effect.

[0069] The laser light source 230 may emit laser light having a wavelength of 300 nm or more and 2000 nm or less. More preferably, the laser light source 230 may emit laser light having a wavelength of 600 nm or more and 1000 nm or less. In this case, by using the light irradiation device 2 in the treatment of a disease using a photosensitive substance, it becomes easier to obtain an appropriate therapeutic effect. In this embodiment, the center wavelength of the laser light emitted by the laser light source 230 is approximately 690 nm.

[0070] In this embodiment, at least the portions of the elongated shaft (device main body) 210 that house the laser light sources 230A and 230B are formed from a material that transmits the laser light emitted by the laser light sources 230A and 230B. By housing the laser light sources 230A and 230B inside the shaft 210, the laser light sources 230A and 230B are stably held in the shaft 210, and malfunctions of the laser light sources 230A and 230B are less likely to occur, compared to when the laser light sources 230A and 230B are exposed to the outside of the shaft 210. Furthermore, the laser light emitted from the laser light sources 230A and 230B passes through the material of the shaft 210 and is appropriately irradiated onto biological tissue. This facilitates more appropriate treatment.

[0071] In this embodiment, the entire shaft 210 is formed from a material that transmits the laser light emitted by the laser light sources 230A and 230B. Therefore, compared to when only a portion of the shaft 210 is formed from a material that is laser light transmissive, the configuration of the shaft 210 is simplified and the possibility that the laser light will be blocked by a portion of the shaft 210 is reduced.

[0072] By carrying out a first evaluation test and a second evaluation test (described later), the inventors of the present application have newly found a desirable range of the light irradiation density of the laser light emitted from the light emitting unit (the laser light sources 230A and 230B in this embodiment) at the time of being emitted to the outside from the light irradiation device 2. In this embodiment, based on the results of the evaluation tests, the light irradiation density of the laser light emitted from the light emitting unit at the time of being emitted to the outside from the light irradiation device 2 is set to 80 W / cm. ２ More than 1600W / cm ２ In this case, it is easier to obtain an appropriate therapeutic effect by irradiating the photosensitizer with laser light. It is more preferable that the light irradiation density at the time of emission from the light irradiation device 2 to the outside is 300 W / cm or less. ２ More than 1300W / cm ２ or less, more preferably 600 W / cm ２ More than 1300W / cm ２ As an example, in this embodiment, the light irradiation density at the time when the light is emitted from the light irradiation device 2 to the outside may be about 1273 W / cm ２ It is said that...

[0073] 3 and other figures, the light irradiation device 2 of this embodiment includes radiopaque light source position markers 232A and 232B at the distal end where the laser light sources 230A and 230B are provided. Therefore, when a medical professional (e.g., a surgeon) irradiates biological tissue with laser light using the light irradiation device 2 while capturing an image of the inside of a living body using radiation (e.g., X-rays), the medical professional can appropriately adjust the irradiation position of the laser light by checking the positions of the light source position markers 232A and 232B that appear in the captured image. This facilitates further improvement in the accuracy of treatment.

[0074] Specifically, in this embodiment, at least some components of the laser light sources 230A and 230B are formed from a radiopaque material, and the laser light sources 230A and 230B themselves function as the light source position markers 232A and 232B. Therefore, even if a marker is not provided separately from the laser light sources 230A and 230B, the positions of the laser light sources 230A and 230B can be properly determined by radiography. Furthermore, since the laser light sources 230A and 230B themselves function as the light source position markers 232A and 232B, the positions of the laser light sources 230A and 230B can be more accurately determined by medical personnel. This facilitates more appropriate treatment. As an example, in this embodiment, each of the laser light sources 230A and 230B has a multilayer structure, and some of the layers are formed from a radiopaque material. Therefore, the positions of the laser light sources 230A and 230B can be more accurately determined.

[0075] Furthermore, in this embodiment, at least a part of the distal tip 220 (in this embodiment, the entire distal tip 220) provided at the distal end of the light irradiation device 2 is made of a radiopaque material, and functions as a marker. Therefore, the position of the distal end of the light irradiation device 2 can be properly grasped without providing a separate marker.

[0076] As shown in FIG. 3 and other figures, the light irradiation device 2 includes optical sensors 240 (240A, 240B) at its tip. Therefore, the state of light at the tip of the light irradiation device 2 is directly detected by the optical sensors 240 at the tip. In other words, the light detected by the optical sensors 240 is less susceptible to changes in the light characteristics that may occur during transmission. This facilitates more accurate detection of the state of light. In this embodiment, optical sensors 240A and 240B are separately provided to detect light emitted by the laser light source 230A (including reflected light, etc.). Therefore, the state of light for each of the two laser light sources 230A and 230B can be properly grasped. Providing multiple optical sensors 240 also makes it possible to confirm the direction in which the light is actually emitted. To simplify the drawing, the wiring extending from the optical sensors 240 is omitted.

[0077] As shown in Figure 3 and other figures, a position detection member 250 is provided at the distal end of the light irradiation device 2 of this embodiment to detect the position of the distal end of the light irradiation device 2 within a lumen of a living body. Therefore, by detecting the position of the position detection member 250, it becomes easier to appropriately grasp the position of the distal end of the light irradiation device 2 within a lumen of a living body. Note that various members for detecting a position within a lumen can be used for the position detection member 250. For example, when a small ultrasonic oscillator is used as the position detection member 250, the position of the position detection member 250 is detected using an ultrasonic diagnostic device or the like. Furthermore, when a magnetic member is used as the position detection member 250, the position of the position detection member 250 is detected using a magnetic sensor or the like.

[0078] The light irradiation device 2 may include a magnetic member (e.g., the position detection member 250) at its tip. The magnetic member may function as a guide member that guides at least one of the position and direction of the tip of the light irradiation device 2 within a lumen of a living body by a magnetic force generated when the light irradiation device 2 is placed in a magnetic field. In this case, when the light irradiation device 2 is inserted into a lumen of a living body, at least one of the position and direction of the tip is appropriately guided.

[0079] The position detection member 250 may be made of a magnetic material so that it also functions as a guide member. In this case, the light irradiation device 2 is endowed with a plurality of useful functions while suppressing an increase in the number of parts.

[0080] Furthermore, magnetic members 232A, 232B may be provided on at least a portion of the laser light sources 230A, 230B (in this embodiment, portions of the laser light sources 230A, 230B located on the side opposite to the side from which the laser light is emitted). In this case, the orientation of the magnetic members 232A, 232B provided on the laser light sources 230A, 230B (i.e., the circumferential orientation centered on the direction of the axis O2 of the light irradiation device 2) is adjusted by magnetic force, making it easier to appropriately control the irradiation direction of the laser light. Note that the light source position marker units 232A, 232B may also serve as magnetic members, or magnetic members may be provided separately from the light source position marker units 232A, 232B.

[0081] Furthermore, the light irradiation device 2 may be provided with a light-emitting member at its tip that indicates the position of the tip by emitting light via wireless power supply. For example, the position detection member 250 described above may be a light-emitting member. When a light-emitting member is provided, at least a portion of the light-emitting member may be made of a magnetic member. In this case, not only is the position of the tip of the light irradiation device indicated by emitting light from the light-emitting member, but it is also possible to guide at least one of the position and direction of the tip by generating a magnetic force in the light-emitting member.

[0082] (Catheter) The catheter 3 of this embodiment will be described with reference to Figures 1 to 3, 6, and 7. 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 proximal 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 proximal 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.

[0083] Like the shaft 210 of the light irradiation device 2, the shaft 310 desirably has antithrombogenicity, flexibility, and biocompatibility. The same material as that of the shaft 210 of the light irradiation device 2 can be used for the shaft 310. The shaft 310 is a long tubular member extending along the axis O3. The shaft 310 of this embodiment is formed into a hollow cylindrical shape with both the distal end and the proximal end open. A 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. After delivery of the catheter 3, the lumen 311 functions as a device lumen for inserting the light irradiation device 2 into the catheter 3.

[0084] The distal tip 320 is connected to the distal end of the shaft 310. The distal tip 320 has an outer shape that tapers from the proximal end to the distal end to allow the catheter 3 to move smoothly within a biological lumen. A through-hole 321 penetrating the distal tip 320 in the direction of the axis O2 is formed approximately at the center of the distal tip 320. As shown in FIG. 3 , the inner diameter Φ2 of the through-hole 321 is smaller than the inner diameter Φ3 of the lumen 311 of the shaft 310 and smaller than the outer diameter Φ1 of the shaft 210 and the distal tip 220 of the light irradiation device 2. Furthermore, the outer diameter Φ1 of the shaft 210 and the distal tip 220 of the light irradiation device 2 is equal to or smaller than the inner diameter Φ3 of the lumen 311 of the catheter 3. Therefore, the light irradiation device 2 moves within the lumen 311 of the catheter 3 along the axis O2. When the light irradiation device 2 is pushed sufficiently 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, thereby positioning the light irradiation device 2 in the directions of the axes O2 and O3 relative to the catheter 3.

[0085] The configuration of the distal end of the catheter 3 of this embodiment will be described with reference to Figures 3, 6, and 7. As shown in Figure 3, the distal end side surface (in this embodiment, a part of the distal end side surface) of the shaft 310 of the catheter 3 is provided with light transmitting sections 330A and 330B that transmit laser light emitted by the light emitting sections (in this embodiment, laser light sources 230A and 230B) included in the light irradiation device 2 to the outside. Therefore, the light irradiation system 1 of this embodiment can selectively irradiate a specific position of a living body with laser light emitted by the light emitting section of the light irradiation device 2 in a direction intersecting the axes O2 and O3.

[0086] In this embodiment, the light-transmitting portions 330A and 330B are provided by partially forming portions of the shaft 310 of the catheter 3 that transmit the laser light emitted by the light emitting portion using a material that transmits laser light. However, the configuration of the light-transmitting portions can be changed. For example, the light-transmitting portions may be provided in the catheter by using a material that transmits laser light for the shaft 310 itself or the entire tip of the shaft 310.

[0087] Radiopaque catheter markers 332A and 332B are provided on the shaft 310 of the catheter 3 in positions close to the light-transmitting portions 330A and 330B, respectively. Therefore, when a medical professional (e.g., a surgeon) irradiates biological tissue with laser light using the light irradiation device 2 while capturing an image of the inside of a living body using radiation (e.g., X-rays), the medical professional can align the position from which the laser light is emitted by the light-emitting portion of the light irradiation device 2 with the positions of the catheter markers 332A and 332B that appear in the captured image, thereby allowing the laser light to be appropriately irradiated to the outside from the light-transmitting portions 330A and 330B. This further facilitates improving the accuracy of treatment.

[0088] The specific configuration of the catheter-side markers 332A, 332B can be selected as appropriate. For example, as shown in Fig. 6, the catheter-side marker 332A may be formed so as to surround the periphery of the light-transmitting portion 330A. In this case, medical personnel can more accurately determine the position of the light-transmitting portion 330A by checking the area surrounded by the catheter-side marker 332A on a radiographic image. The shape of the catheter-side markers 332A, 332B surrounding the light-transmitting portions 330A, 330B may be a shape other than rectangular (for example, annular).

[0089] 7, the catheter marker 332A may be provided adjacent to each of the distal and proximal ends of the light-transmitting portion 330A. In this case, medical personnel can properly grasp the position of the light-transmitting portion 330A in the direction along the axes O2 and O3. Alternatively, the catheter marker 332A, 332B may be provided only on either the distal or proximal end of the light-transmitting portion 330A.

[0090] 3 and other figures, in this embodiment, at least a portion (in this embodiment, the entire distal tip 320) of the distal tip 320 provided at the distal end of the shaft 310 of the catheter 3 is made of a radiopaque material and functions as a marker portion, thereby allowing the position of the distal end of the catheter 3 to be properly grasped.

[0091] The catheter 3 may be provided with a magnetic member (e.g., the distal tip 320) at its distal end. The magnetic member may function as a guide member that guides at least one of the position and direction of the distal end of the catheter 3 within the lumen of the living body by a magnetic force generated when the catheter 3 is placed in a magnetic field. In this case, at least one of the position and direction of the distal end is appropriately guided when the catheter 3 is inserted into the lumen of the living body.

[0092] The distal tip 320 may be made of a magnetic material so that it also functions as a guide member. In this case, the catheter 3 is endowed with multiple useful functions while suppressing an increase in the number of parts.

[0093] Of the shaft 310 of the catheter 3, at least the distal end portion (the entire shaft 310 in this embodiment) that the laser light sources 230A, 230B of the light irradiation device 2 approach during laser irradiation is made of a material with a thermal conductivity of 0.1 W / m·K or more. This makes it easier for the laser light sources 230A, 230B to be cooled by, for example, blood flow or physiological saline. This reduces the possibility of malfunctions in the laser light sources 230A, 230B due to heat generated when the laser light sources 230A, 230B emit laser light. This makes it easier to perform treatment more appropriately.

[0094] (Method of 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 a biological lumen. Next, the surgeon inserts the proximal end of the guidewire into the lumen 311 through the through-hole 321 of the distal tip 320 of the catheter 3, causing it to protrude from the proximal end of the connector 301. The surgeon advances the catheter 3 along the guidewire, moving at least one of the light-transmitting portions 330A and 330B of the catheter 3 to the target site for light irradiation. Note that, when moving the catheter 3 within the biological lumen, the surgeon can appropriately move the catheter 3 to the target site by checking the positions of the catheter marker portions 332A and 332B using a radiographic image. Thereafter, the surgeon removes the guidewire from the catheter 3.

[0095] The surgeon inserts the light irradiation device 2 from the proximal opening of the connector 301 of the catheter 3 and advances the light irradiation device 2 along the lumen 311 of the catheter 3 within the biological lumen. When the light irradiation device 2 is sufficiently advanced within 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 transmission portions 330A, 330B of the catheter 3 are formed at positions along the axes O2, O3 where the laser light sources 230A, 230B are to be disposed when the distal tip 220 of the light irradiation device 2 comes into contact with the distal end of the lumen of the catheter 3 (the distal tip 320 of the catheter 3). Therefore, simply by advancing the light irradiation device 2 until it comes into contact with the distal tip 320 of the catheter 3, the positions of the light emission portions (the laser light sources 230A, 230B in this embodiment) and the light transmission portions 330A, 330B automatically coincide with each other in the directions of the axes O2, O3. In this state, laser light is emitted from the light emitting portion, whereby the laser light is selectively irradiated onto the target area.

[0096] With the light irradiation device 2 inserted into the catheter 3, the surgeon can inject a cooling fluid into the lumen 311 of the catheter 3. Therefore, problems caused by a rise in temperature at the tip end due to the laser light sources 230A and 230B (for example, failure of the laser light sources 230A and 230B) are appropriately suppressed by the cooling fluid.

[0097] (Modifications) The techniques disclosed in the above embodiments are merely examples. Therefore, it is possible to modify the techniques exemplified in the above embodiments. Some modifications of the above embodiments will be described with reference to FIGS. 8 to 13. Note that the first modification shown in FIG. 8, the second modification shown in FIG. 9, the third modification shown in FIG. 10, the fourth modification shown in FIG. 11, the fifth modification shown in FIG. 12, and the sixth modification shown in FIG. 13 may employ configurations similar to those of the above-described embodiments. Therefore, among the configurations of the first to sixth modifications, parts that can employ configurations similar to those of the above-described embodiments are assigned the same numbers as those of the above-described embodiments, and their descriptions will be omitted or simplified.

[0098] In the light irradiation system 1 of the first modified example shown in Fig. 8, the multiple laser light sources 230C, 230D emit laser light in different wavelength ranges. The installation directions of the multiple laser light sources 230C, 230D are determined so that the irradiation directions of the laser light from each of the multiple laser light sources 230C, 230D are parallel. The control unit 5 can independently control the emission of laser light from the two laser light sources 230C, 230D. Therefore, the light irradiation system 1 of the first modified example can selectively emit laser light in different wavelength ranges to biological tissue.

[0099] The configuration of the light irradiation system 1 of the first modified example can be further modified. For example, in the light irradiation system 1 shown in Fig. 8, the emission of laser light from the multiple laser light sources 230C and 230D may be controlled collectively. Furthermore, the multiple laser light sources 230C and 230D may emit laser light in the same wavelength range. In this case, the irradiation area of ​​the laser light is expanded compared to when only one laser light source is used.

[0100] The light irradiation device 2 of the second modified example shown in Fig. 9 includes one laser light source 230E. As described above, the number of laser light sources provided in the light irradiation device 2 may be one or more. Furthermore, in the second modified example, radiopaque marker parts 232E are provided on the distal end side and proximal end side of the position where the laser light from the laser light source 230E is emitted to the outside in the device body 209 of the light irradiation device 2. As described above, it is also possible to provide the marker parts 232E separately from the laser light source 230E.

[0101] The light irradiation device 2 of the second modified example is provided with a light detection transmission member 241 that transmits light incident on the tip portion (in this embodiment, near the position where the laser light is emitted to the outside) to an optical sensor (not shown). The light detection transmission member 241 of this embodiment is an optical fiber that is inserted from the side of the device main body 209 through the inside of the device main body 209 to the base end side and connected to the optical sensor. In the second modified example, the configuration of the tip portion of the light irradiation device 2 is prevented from becoming complicated by the optical sensor, and the state of light at the tip portion is appropriately detected.

[0102] The light irradiation device 2 of the second modified example includes a temperature sensor 260 at the tip portion thereof. Therefore, for example, at least one of a temperature rise caused by driving the laser light source 230E provided at the tip portion and a temperature rise caused by emitting laser light to living tissue can be appropriately detected.

[0103] In the catheter 3 of the second modification, a light-transmitting portion 330E (which may also be expressed as a "laser light-transmitting window") is formed by opening a portion of the shaft 310 that transmits the laser light emitted by the laser light source 230E. As described above, the method of forming the light-transmitting portion is not limited to the method of using a material that transmits laser light.

[0104] The light irradiation device 2 of the third modified example shown in FIG. 10 includes multiple temperature sensors 260 (260A, 260B, and 260C). The measurement positions of the multiple temperature sensors 260 (measurement points indicated by 260A, 260B, and 260C in this embodiment) are respectively disposed at multiple locations on the distal end of the light irradiation device 2. Therefore, useful information can be obtained based on the temperature detection results at each of the multiple measurement positions. For example, by determining which of the multiple measurement positions has a higher temperature than the other measurement positions, it is possible to determine the direction in which the laser light is being irradiated. Furthermore, by more accurately determining the temperature at each measurement position, medical professionals can improve the accuracy of treatment.

[0105] In the light irradiation device 2 of the third modified example, the wiring of the temperature sensor 260 is arranged in a spiral shape in the main body of the light irradiation device 2. Therefore, compared to when the wiring is arranged straight along the axial direction, it is easier to ensure appropriate rigidity of the elongated light irradiation device 2. This makes it easier to further improve the accuracy of treatment. As an example, in this embodiment, an elongated thermocouple with multiple measurement points is used as the temperature sensor 260. The rigidity of the light irradiation device 2 is ensured by arranging the wiring of the elongated temperature sensor 260 in a spiral shape.

[0106] In the light irradiation device 2 of the third modified example, the wiring of the temperature sensor 260 contains a radiopaque material. Therefore, it becomes easier to properly grasp the position of the elongated light irradiation device 2 by radiography. Note that in the third modified example, the wiring of the temperature sensor 260, which is radiopaque, is arranged in a spiral shape, which makes it even easier to grasp the position of the light irradiation device 2.

[0107] The catheter 3 of the fourth modification shown in FIG. 11 includes multiple temperature sensors 360 (360A, 360B, 360C, 360D, and 360E). The measurement positions of the multiple temperature sensors 360 (in this embodiment, the measurement points indicated by 360A, 360B, 360C, 360D, and 360E) are located at multiple locations on the distal end of the catheter 3. Therefore, useful information can be obtained based on the temperature detection results at each of the multiple measurement positions. For example, by determining which of the multiple measurement positions has a higher temperature than the other measurement positions, it is possible to determine the direction in which the laser light is being irradiated. Furthermore, by more accurately determining the temperature at each measurement position, medical personnel can improve the accuracy of treatment.

[0108] In the catheter 3 of the fourth modified example, the wiring of the temperature sensor 360 is arranged in a spiral shape on the shaft 310 of the catheter 3. Therefore, compared to when the wiring is arranged straight along the axial direction, it is easier to ensure appropriate rigidity of the elongated catheter 3. This makes it easier to further improve the accuracy of treatment. As an example, in this embodiment, an elongated thermocouple with multiple measurement points is used as the temperature sensor 360. By arranging the wiring of the elongated temperature sensor 360 in a spiral shape, the rigidity of the catheter 3 is ensured.

[0109] In the catheter 3 of the fourth modified example, the wiring of the temperature sensor 360 contains a radiopaque material. This makes it easier to properly determine the position of the long catheter 3 by radiography. In the fourth modified example, the wiring of the temperature sensor 360, which is radiopaque, is arranged in a spiral shape, making it even easier to determine the position of the catheter 3.

[0110] 12 includes a laser light source 280 and an optical member 281 at its tip end that can change the direction of laser light emitted from the laser light source 280. The laser light source 280 is an edge-emitting semiconductor laser that emits laser light in a predetermined wavelength range along the major axis direction of the light irradiation device 2. The optical member 281 changes the direction of the laser light to a direction intersecting the major axis direction of the light irradiation device 2. The laser light source 280 and the optical member 281 are mounted on a support 283.

[0111] The optical member 281 is a mirror including a reflecting surface 282 that intersects with the long axis direction of the light irradiation device 2. The optical member 281 reflects the light emitted from the laser light source 280 at the reflecting surface 282, thereby directing the light in a direction that intersects with the long axis direction. Note that the optical member 281 is not limited to a mirror, and may be a prism, a lens, a diffractive optical element, or the like, as long as it is capable of changing the light into a predetermined direction.

[0112] The optical member 281 can be made of a material including a resin material, a glass material, a metal material, or the like. The optical member 281 may be formed integrally with the support 283. When the optical member 281 and the support 283 are formed integrally, they may be formed integrally from the same material. Aluminum nitride (AlN) may be included as a main component because of its high thermal conductivity. Examples of methods for forming the optical member 281 and the support 283 integrally include injection molding and pressing a ceramic green sheet.

[0113] 12, a lens 284 may be disposed between the laser light source 280 and the optical member 281. In the example shown in Fig. 12, the lens 284 does not change the direction of the laser light but adjusts the spread of the light. As a result, the lens 284 can adjust the irradiation size and light irradiation density of the light at the time of being emitted from the light irradiation device 2 to the outside at any location inside a case 288 described later.

[0114] The light irradiation device 2 further includes insulated wires 286A and 286B electrically connected to the laser light source 280. The insulated wires 286A and 286B include metal wiring and an insulating coating, and the metal wiring is covered with the insulating coating. The light irradiation device 2 also includes a case 288 and an insulating sealant 289 that seals the opening of the case 288. The case 288 houses the laser light source 280, the optical member 281, the support 283, and the connection portions between the laser light source 280 and the insulated wires 286A and 286B. The sealant 289 seals the laser light source 280, the optical member 281, the support 283, and the connection portions between the laser light source 280 and the insulated wires 286A and 286B within the case 288.

[0115] The interior of the case 288 is hollow, and no sealing material such as resin is present between the laser light source 280 and the optical member 281. This eliminates the effect of light refraction due to the sealing material, making it easier to control the spread of light emitted from the laser light source 280. At least the portion of the case 288 onto which light reflected by the optical member 281 is incident is optically transparent, and the light emitted from the case 288 passes through the light-transmitting portion 330A of the catheter 3 and is emitted to the outside from the light irradiation device 2.

[0116] The support 283 is made of silicon (Si), aluminum nitride (AlN), silicon nitride (SiN), sapphire (Al ２ O ３ The support 283 is made of an insulating material such as glass, quartz, or ceramics. Conductor wiring is provided on the support 283 for electrically connecting to the electrodes of the laser light source 280. The electrodes of the laser light source 280 and the conductor wiring of the support are joined via a conductive joining member 287.

[0117] The case 288 is a transparent cylindrical body made of glass, quartz, biocompatible plastic, or the like. The sealing material 289 sealing both ends of the case 288 along the longitudinal direction of the support 283 is an insulating resin sealing material. Examples of resin sealing materials that can be used include epoxy resin, silicone resin, acrylic resin, and thermoplastic resin. A biocompatible insulating resin may also be used as the sealing material 289. More preferably, a biocompatible insulating resin with high thermal conductivity is used for the sealing material 289. Examples of such resin materials include polycarbonate (PC), polyethylene terephthalate (PET), polyimide (PI), polyurethane, and polyesterimide, whose components and compositions have been adjusted to mitigate adverse effects on living bodies. The sealing material 289 seals the electrical connection between the laser light source 280 and the insulated wires 286A and 286B within the case 288. While the case 288 remains sealed, the insulated wires 286A and 286B are pulled out from at least one end of the case 288 to the outside.

[0118] The insulated electric wire 286A is electrically connected directly or indirectly to one electrode of the laser light source 280 on the surface of the support 283 on which the laser light source 280 is mounted. The other insulated electric wire 286B is electrically connected to the other electrode of the laser light source 280 on the back surface of the support 283 (the surface opposite to the surface on which the laser light source 280 is mounted).

[0119] The light irradiation device 2 of the fifth modified example is provided at its tip with an optical member 281 that can change the direction of the laser light emitted from the laser light source 280. This makes it easier to change the direction of the laser light emitted from the laser light source 280.

[0120] As described above, the light irradiation device of the present disclosure is not limited to a configuration including a light emitting unit that efficiently and appropriately emits light from the light emitting unit in a desired direction, but may also be a configuration including a light emitting unit and an optical member that modifies the light emitted from the light emitting unit in a predetermined direction and then emits the light efficiently and appropriately in the desired direction. Note that the "desired direction" here refers to the direction in which the laser light should travel at the light emission point where the light is emitted from the light irradiation device to the outside (e.g., the direction in which the laser light travels toward the biological tissue to be treated), and is the direction in which the laser light travels from the light emission point to the outside of the light irradiation device. To give a more specific example, it can be referred to as a direction intersecting the longitudinal axis direction of the light irradiation device.

[0121] In the above-described embodiment and the modified example of the embodiment, an example in which a laser light source is used as the light emitting unit has been described, but an optical fiber may also be used as the light emitting unit. As mentioned above, when an optical fiber is used, problems such as light leakage along the way and changes in the characteristics of the light during transmission can occur. These problems are more pronounced when the optical fiber has a large curvature. When the optical fiber has a large curvature, the angle of light incident on the boundary between the core and cladding of the optical fiber becomes smaller than the critical angle, and the light is no longer totally reflected, resulting in light leakage during transmission.

[0122] The light irradiation device 2 of the sixth modified example shown in Fig. 13 includes an optical fiber 290 as a light emitting section. However, since the sixth modified example includes an optical member 281 for changing the direction of the laser light in a direction intersecting the longitudinal axis direction of the light irradiation device 2, it is not necessary to bend the optical fiber 290 with a large curvature to change the direction of the laser light. This makes it possible to reduce light leakage even when an optical fiber is used. Furthermore, as in the fifth modified example, it becomes easier to change the direction of the laser light emitted from the optical fiber 290.

[0123] The light irradiation device 2 further includes a support 283 that supports at least the end of the optical fiber 290 and the optical element 281. As shown in the cross-sectional views along the arrows CC and DD in FIG. 13 , a V-shaped groove is formed on the main surface of the support 283 along the longitudinal axis direction of the light irradiation device 2. The optical fiber 290 is placed on the support 283 so that the two inclined surfaces forming the V-shaped groove are in contact with the outer circumferential surface of the optical fiber 290. Furthermore, the end of the support 283, where the optical element 281 and the lens 284 are placed, is thinner than the portion where the optical fiber 290 is placed, and the size of the V-shaped groove relative to the main surface of the support 283 is smaller. This allows the optical element 281 and the lens 284 to be placed on the flat portion of the upper surface of the support 283, even when the optical element 281 and the lens 284 are placed on the V-shaped groove.

[0124] (First Evaluation Test) With reference to FIG. 14 , the results of a first evaluation test for evaluating the lower limit of the light irradiation density of the laser light emitted from the light emitting unit (laser light source or optical fiber) at the time of emission from the light irradiation device 2 to the outside will be described. In the first evaluation test, the inventor connected an optical fiber to the laser light source and positioned a sensor for detecting the laser light in the direction of emission of the laser light from the tip of the optical fiber. Next, the inventor changed the state of the optical path of the laser light between the tip of the optical fiber and the sensor to each of the following states: (1) a “blank state” in which nothing was placed; (2) a “carotid artery placement state” in which a porcine carotid artery (approximately 1.7 mm thick) was placed; and (3) an “aorta placement state” in which a porcine aorta was placed. The inventor confirmed the detection results of the laser light by the sensor while changing the light irradiation density of the laser light in each state. In the (2) “carotid artery placement state” and (3) “aorta placement state,” the detection results by the sensor were the detection results of the laser light that had passed through the carotid artery or aorta and reached the sensor.

[0125] The core diameter of the fiber used in the first evaluation test was 400 μm (surface area was 0.001256 cm ２) The "blank state output" shown in FIG. 14 is approximately equal to the output of the laser light emitted from the fiber tip. Therefore, the light irradiation density of the laser light emitted from the fiber tip can be calculated by dividing the "blank state output" by the surface area of ​​the fiber core. The laser light source used in the first evaluation test was the "MLL-III-690" manufactured by CNI Optoelectronics Technology, which emits laser light with a wavelength of 690 nm. The sensor used in the first evaluation test was the "S310C" manufactured by THORLABS. The lower limit of the detectable output of the sensor used in the first evaluation test was 10 mW. While this sensor may detect an output of less than 10 mW, detection results below 10 mW are unreliable. Therefore, in the first evaluation test, when the detection result by the sensor was 10 mW or greater, it was determined that the laser light that had passed through the blood vessel had been properly detected (i.e., "detected").

[0126] As shown in FIG. 14, the light irradiation density of the laser light was set to 584.4 W / cm ２ When the laser beam was placed at a light irradiation density of 78.8 W / cm, a sufficient output of 10 mW or more was detected in both (2) "carotid artery placement state" and (3) "aorta placement state." ２ When the laser beam was placed in the carotid artery, a sufficient output of 21.1 mW was detected, but in the aorta, a sufficient output could not be detected. ２ In the following cases, sufficient output was not detected in both (2) "carotid placement state" and (3) "aortic placement state."

[0127] From the above results, the light irradiation density of the laser light was set to about 80 W / cm ２ In this case, if the blood vessel is thick, such as the aorta, the laser light may not penetrate the blood vessel sufficiently, making it difficult to obtain a therapeutic effect. However, if the blood vessel is thin, such as the carotid artery, the laser light irradiation density can be set to approximately 80 W / cm. ２From the above results, it is found that the lower limit of the light irradiation density of the laser light emitted from the laser light source 230 when it is emitted to the outside from the light irradiation device 2 is 80 W / cm ２ It is desirable that the higher the output of the laser light irradiated onto the tissue, the more efficiently the therapeutic effect can be obtained. Therefore, the lower limit of the light irradiation density at the time when the light is emitted from the light irradiation device 2 to the outside is 300 W / cm. ２ Furthermore, as shown in FIG. 14, it is more desirable to set the light irradiation density of the laser light to 584.4 W / cm. ２ This means that the laser light can penetrate even a thick aorta and be properly irradiated onto the tissue. Therefore, the lower limit of the light irradiation density at the time of emission from the light irradiation device 2 to the outside is 600 W / cm ２ It would be even more desirable to do so.

[0128] (Second Evaluation Test) The results of a second evaluation test for evaluating the upper limit of the light irradiation density of the laser light emitted from the light emitting unit (laser light source or optical fiber) at the time of emission from the light irradiation device 2 to the outside will be described. In the second evaluation test, the inventor connected an optical fiber to the laser light source and arranged a sensor for detecting the laser light in the emission direction of the laser light emitted from the tip of the optical fiber. Next, the inventor changed the state of the optical path of the laser light between the tip of the optical fiber and the sensor to (1) a "blank state" in which nothing was arranged, and (2) a "carotid artery arrangement state" in which a pig's carotid artery (approximately 1.7 mm thick) was arranged, and emitted the laser light from the tip of the optical fiber in each state. The inventor evaluated the upper limit of the light irradiation density at the time of emission from the light irradiation device 2 to the outside based on the light irradiation density when the carotid artery was burned in (2) the "carotid artery arrangement state."

[0129] The core diameter of the fiber used in the second evaluation test was 400 μm (surface area was 0.001256 cm ２), and the NA is 0.39. As in the first evaluation test, the output of the laser light detected by the sensor in the "blank state" is approximately equal to the output of the laser light emitted from the fiber tip. Therefore, the light irradiation density of the laser light emitted from the fiber tip can be determined by dividing the output detected in the "blank state" by the surface area of ​​the fiber core. The laser light source used in the second evaluation test was the "Brix690-2500UHP" manufactured by Omicron, which emits laser light with a wavelength of 690 nm. The sensor used in the second evaluation test was the "S425C" manufactured by THORLABS.

[0130] First, the inventor set the output of the laser light source to the maximum setting of 2500 mW and checked the output of the laser light detected by the sensor in (1) the "blank state." The detected output varied between 1800 mW and 2100 mW. Next, the inventor set the output of the laser light source to the aforementioned maximum setting of 2500 mW and checked the output of the laser light detected by the sensor in (2) the "carotid artery placement state." As a result, the output of the laser light transmitted through the carotid artery and detected by the sensor varied between 300 mW and 350 mW. Therefore, in (2) the "carotid artery placement state," the output of the laser light emitted from the fiber tip is estimated to be approximately 1800 mW when the sensor detects 300 mW. Furthermore, the output of the laser light emitted from the fiber tip is estimated to be approximately 2100 mW when the sensor detects 350 mW. (2) When the laser beam was continuously emitted in the "carotid artery placement state," the carotid artery was not burned as long as the sensor detection result was less than 350 mW. However, when the sensor detection result reached 350 mW, the carotid artery wall was burned. (2) In the "carotid artery placement state," the light irradiation density of the laser beam emitted from the tip of the fiber when the sensor detected 350 mW was approximately 1670 W / cm. ２ This becomes:

[0131] From the above results, the light irradiation density of the laser light was set to 1670 W / cm ２ However, if the laser light irradiation density is set to 1600 W / cm, the blood vessel wall may be damaged, making it difficult to ensure safety during treatment.２ From the above results, the upper limit of the light irradiation density of the laser light emitted from the light emitting part at the time of being emitted to the outside from the light irradiation device 2 is set to 1600 W / cm ２ In order to further increase safety during treatment (i.e., to further reduce the possibility of damaging the blood vessel wall), the upper limit of the light irradiation density at the time of emission from the light irradiation device 2 to the outside is set to 1300 W / cm. ２ It is desirable to set the above as follows. Note that the absorbance of the laser light by substances in biological tissues, such as hemoglobin, changes depending on the wavelength of the laser light emitted from the light emitting unit. Therefore, at least one of the upper and lower limits of the light irradiation density of the laser light may be adjusted as appropriate, taking into consideration the absorbance of the laser light according to the wavelength and the thickness of the blood vessel wall to be irradiated with the laser light.

[0132] It is also possible to employ only some of the configurations exemplified in the above-described embodiments and modifications in the light irradiation system, light irradiation device, or catheter. It is also possible to combine multiple configurations illustrated in different embodiments. As described above, it is also possible to use only the light irradiation device 2 alone, without using the catheter 3. Furthermore, the shaft 210 of the light irradiation device 2 may be formed with a fluid flow path that penetrates from the base end to the tip end. In this case, by flowing a cooling fluid through the flow path of the shaft 210, various problems caused by temperature increases (e.g., failure of the laser light source 230 due to high temperatures) can be appropriately suppressed.

Claims

1. A long medical light irradiation device comprising: a light emitting section that emits laser light in a predetermined wavelength range along the longitudinal direction of the light irradiation device; and an optical element at the tip that can change the direction of the laser light; wherein the optical element, when inserted inside a lumen of a living body, changes the direction of the laser light in a direction that intersects with the longitudinal direction of the light irradiation device, thereby irradiating living tissue with laser light.

2. A light irradiation device according to claim 1, wherein, when inserted into a blood vessel of a living body, the light irradiation device emits laser light in a direction intersecting the longitudinal axis of the light irradiation device, thereby transmitting the laser light through the blood vessel wall and irradiating the living tissue outside the blood vessel, and the light irradiation density of the laser light at the time of being emitted from the light irradiation device to the outside is 80 W / cm ２ More than 1600W / cm ２ A light irradiation device characterized by:

3. A light irradiation device according to claim 1, wherein the light emitting portion is a laser light source, and a plurality of the laser light sources are provided at the tip portion.

4. A light irradiation device according to claim 3, characterized in that the emission of laser light from at least some of the plurality of laser light sources can be controlled independently of the other laser light sources.

5. A light irradiation device according to claim 3, characterized in that the plurality of laser light sources emit laser light in the same wavelength range.

6. A light irradiation device according to claim 3, characterized in that some of the plurality of laser light sources include a laser light source that emits laser light in a wavelength range different from the wavelength range of the other laser light sources.

7. A light irradiation device according to claim 1, characterized in that the optical member is contained inside an elongated device body, and at least the portion of the device body containing the optical member is formed from a material that transmits the laser light.

8. The light irradiation device according to claim 1, characterized in that the tip portion is provided with a radiopaque marker portion.

9. A light irradiation device according to claim 8, wherein the light emitting section is a laser light source, and at least a portion of the laser light source is made of a material that is opaque to radiation, so that the laser light source functions as the marker section.

10. The light irradiation device according to claim 1, wherein the light emitting portion is an optical fiber.

11. A light irradiation device according to claim 1, wherein the light emitting section is a laser light source, and the laser light source is a semiconductor laser, which is a circuit element manufactured using a semiconductor material.

12. A light irradiation device according to claim 1, further comprising a light detection transmission member that transmits light incident on the tip to an optical sensor, or an optical sensor provided at the tip.

13. A light irradiation device according to claim 1, further comprising a plurality of temperature sensors, wherein the temperature measurement positions of the plurality of temperature sensors are arranged at a plurality of locations on the tip portion.

14. The light irradiation device according to claim 1, further comprising wiring extending from the base end side to the tip end, the wiring being arranged in a spiral shape.

15. A light irradiation device according to claim 1, further comprising a position detection member at the tip for detecting the position of the tip within the lumen of the living body.

16. A light irradiation device according to claim 1, further comprising a magnetic member that guides at least one of the position and direction of the tip within a living body by a magnetic force generated when the light irradiation device is placed in a magnetic field.

17. A medical light irradiation system comprising: a catheter formed in a long tubular shape; and a long light irradiation device inserted into the lumen of the catheter, wherein the light irradiation device has a light emitting section that emits laser light in a predetermined wavelength range and an optical element at its tip that can change the direction of the laser light, and wherein the optical element, when inserted inside a lumen of a living body, changes the direction of the laser light in a direction that intersects with the longitudinal axis direction of the light irradiation device, thereby irradiating living tissue with laser light.

18. A light irradiation system according to claim 17, wherein, when inserted into a blood vessel of a living body, the light irradiation device emits laser light in a direction intersecting the longitudinal axis of the light irradiation device, thereby transmitting the laser light through the blood vessel wall and irradiating the living tissue outside the blood vessel, and the light irradiation density of the laser light at the time of being emitted from the light irradiation device to the outside is 80 W / cm ２ More than 1600W / cm ２ A light irradiation system characterized by the following:

19. A light irradiation system as described in claim 17, characterized in that at least the tip portion of the catheter, which is adjacent to the light emitting portion of the light irradiation device, is made of a material having a thermal conductivity of 0.1 W / m·K or more.

20. A light irradiation system according to claim 17, characterized in that, with the light irradiation device inserted into the catheter, a cooling fluid is introduced into the inner cavity of the catheter.

21. A light irradiation system according to claim 17, wherein the catheter further comprises a plurality of temperature sensors, and the temperature measurement positions of the plurality of temperature sensors are each disposed at a plurality of locations on the catheter.

22. A light irradiation system according to claim 17, wherein the catheter further comprises wiring extending from the base end to the tip end, the wiring being arranged in a spiral.

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