Catheter visualization device

Abstract

Provided is a catheter visualization device capable of improving operability of a catheter. The catheter visualization device is equipped with: a catheter light guide 11 that is used by being inserted into a catheter 14, that is composed of an optical fiber, and that allows light which has entered a base end part 11b to exit from a tip side 11t; a light source 12 that emits the light which enters the base end part 11b of the catheter light guide 11; and a transmission fiber 13 that is used without being inserted into the catheter 14, that is interposed between the base end part 11b of the catheter light guide 11 and the light source 12, that transmits the light from the light source 12 to the base end part 11b, and that allows the light to enter the base end part 11b.

Description

Catheter visualization device

[0001] The present invention relates to a catheter visualization device.

[0002] In conventional medical instruments, the optical fiber is made of synthetic resin and therefore has a relatively large diameter, occupying a large proportion of the space inside the catheter. Therefore, it is difficult to inject a drug into the catheter or insert another instrument into it while the optical fiber remains inserted in the catheter. Therefore, in conventional medical instruments, the catheter with the optical fiber inserted therein is inserted into a living body, the position of the catheter's tip within the living body is confirmed using light emitted from the optical fiber, and then the optical fiber is removed from the catheter, and a drug is injected into the catheter or an instrument is inserted into the catheter to treat the affected area of ​​the living body (see, for example, Patent Document 1).

[0003] The catheter visualization device is inserted into a catheter and includes a catheter light guide made of optical fiber that receives light from the proximal end and emits it from the distal end, and a light source that directs light into the proximal end of the catheter light guide. When in use, the catheter light guide is inserted into the catheter, and the distal end is positioned near the distal end of the catheter, and the catheter is then inserted into a living body through the nasal cavity or oral cavity.

[0004] In this case, the light source located at the base end is connected to a catheter light guide that is inserted into the catheter for most of its entire length, so the practitioner must operate the catheter while holding the light source in one hand. Since the light incident on the catheter light guide must be of an intensity commensurate with its purpose, there is a limit to how small and lightweight the light source can be. Therefore, holding the light source in one hand during treatment makes it difficult to operate the catheter.

[0005] In addition to the method of inputting visible light into the catheter light guide and visually confirming the catheter tip position, a method of inputting near-infrared light to improve sensitivity and confirming the catheter tip position with a near-infrared camera is also possible. In this method of inputting near-infrared light, it is desirable to integrate the display that monitors the catheter's trajectory inside the body with the light source and camera, but in this case, the light source and catheter light guide must be used at a distance.

[0006] Re-table 2019 / 215791 publication

[0007] Therefore, an object of the present invention is to provide a catheter visualization device that can improve the operability of a catheter.

[0008] The above object is achieved by the present invention as follows. That is, the aspects of the present invention are as follows: <1> A catheter visualization device comprising: a catheter light guide that is inserted into a catheter and made of an optical fiber, and that causes light that is incident at a base end to exit from a tip end; a light source that emits light that is incident at the base end of the catheter light guide; and a transmission fiber that is used without being inserted into the catheter and is interposed between the base end of the catheter light guide and the light source, and that transmits light from the light source to the base end and causes light to enter the base end.

[0009] <2> The catheter visualization device according to <1>, wherein the transmission fiber has a smaller transmission loss than the catheter light guide.

[0010] <3> The catheter visualization device according to <1>, wherein a bending loss of the transmission fiber is smaller than a bending loss of the catheter light guide.

[0011] <4> The catheter visualization device according to <1>, wherein the catheter light guide is made of a plastic fiber.

[0012] <5> The catheter visualization device according to <1>, wherein the transmission fiber is detachable from the proximal end of the catheter light guide.

[0013] <6> The catheter visualization device according to <5>, wherein the diameter of the core of the transmission fiber at the end detachable from the base end of the catheter light guide is smaller than the diameter of the core at the base end of the catheter light guide.

[0014] <7> The catheter visualization device according to <1>, wherein the transmission fiber is an optical fiber selected from the group consisting of a quartz fiber, a polymer-clad quartz fiber, a holey fiber, a hollow-core fiber, and a multi-core fiber.

[0015] <8> The catheter visualization device according to <1>, wherein one or more fluorescent marking portions are provided on the outer periphery of the transmission fiber.

[0016] <9> The catheter visualization device according to <1>, wherein an exterior covering surrounding the outer periphery of the transmission fiber is provided over the entire length or a portion of the length, and one or more fluorescent marking portions are provided on the outer periphery of the exterior covering.

[0017] <10> The catheter visualization device according to <5>, wherein the transmission fiber and the proximal end of the catheter light guide are detachably connected via a connector, and one or more fluorescent marking portions are provided on the outer periphery of the connector.

[0018] <11> The catheter visualization device according to any one of <8> to <10>, wherein the fluorescent marking portion is any one selected from the group consisting of fluorescent paint, fluorescent tape, and fluorescent sleeve that emits light under ultraviolet irradiation.

[0019] <12> The catheter visualization device according to any one of <8> to <10>, wherein the material constituting the fluorescent marking portion is resistant to autoclave sterilization and / or ethylene oxide gas sterilization.

[0020] According to the present invention, it is possible to provide a catheter visualization device that can improve the operability of a catheter.

[0021] 1 is a schematic diagram showing a state in which a catheter visualization device according to a first embodiment, an exemplary aspect of the present invention, is inserted into a catheter. FIG. 1 is a cross-sectional view showing an enlarged longitudinal section of a coupling portion between a catheter light guide and a transmission fiber in FIG. 1. FIG. 1 is a cross-sectional view showing a cross-section of an exemplary holey fiber cut midway in the longitudinal direction. FIG. 2 is a schematic diagram showing a state in which a catheter visualization device according to a second embodiment, an exemplary aspect of the present invention, is inserted into a catheter. FIG. 4 is a cross-sectional view showing an enlarged longitudinal section of a coupling portion between a catheter light guide and a transmission fiber and its vicinity in FIG. 5. FIG. 5 is a cross-sectional view similar to FIG. 5, and is an explanatory diagram for explaining an incidence angle θ of the transmission fiber into the cladding at a tapered portion. FIG. 6 is a schematic diagram showing a state in which a catheter visualization device according to a third embodiment, an exemplary aspect of the present invention, is inserted into a catheter. FIG. 6 is a schematic diagram showing a state in which a catheter visualization device according to a fourth embodiment, an exemplary aspect of the present invention, is inserted into a catheter. FIG. 7 is a cross-sectional view of a transmission fiber in a catheter visualization device according to a modified example.

[0022] Hereinafter, catheter visualization devices according to two embodiments, which are exemplary aspects of the present invention, will be specifically described with reference to the drawings.

[0023] <First Embodiment> Fig. 1 is a schematic diagram showing a catheter visualization device according to a first embodiment inserted into a catheter. As shown in Fig. 1, a catheter visualization device 10 according to the first embodiment includes a catheter light guide 11, a light source 12, and a transmission fiber 13. In Fig. 1, the proximal end direction of the catheter light guide 11 is indicated by arrow b, and the distal end direction is indicated by arrow t (the same applies to the subsequent figures). Fig. 2 is an enlarged transverse cross-sectional view showing a longitudinal cross-section of a coupling portion between the catheter light guide 11 and the transmission fiber 13 in Fig. 1.

[0024] The catheter light guide 11 is inserted into a catheter 14 and is made of an optical fiber, and emits light incident at the proximal end 11b from the distal end 11t. As shown in Figure 2, the catheter light guide 11 is made of a core 11c located radially toward the center and a cladding 11d located radially outside the core 11c.

[0025] As shown in FIG. 1, the catheter light guide 11 has a light transmission section 11A that transmits laser light incident from the base end section 11b toward the tip end section 11t, and a light emission section 11B that causes the laser light transmitted through the light transmission section 11A to exit from the outer surface by removing a portion located on the outer periphery of the cladding 11d within a predetermined range in the extension direction of the tip end section 11t.

[0026] The catheter light guide 11 may be made of quartz fiber or plastic fiber, but is preferably made of plastic fiber because it is desired to have flexibility that allows it to assume any shape inside the living body. Furthermore, plastic fiber is lightweight, easy to handle, durable, and resistant to mechanical stress, making it suitable for use as the catheter light guide 11. In this embodiment, the catheter light guide 11 is made of plastic fiber.

[0027] The light source 12 emits light that is incident on the proximal end 11b of the catheter light guide 11. Examples of the light source 12 include an LED (light-emitting diode) and a laser. There are no limitations on the light source 12 as long as it emits visible light, but an LED is preferably used as the light source 12 from the standpoints of safety and cost. In the catheter visualization device 1 according to this embodiment, a transmission fiber 13 is interposed between the proximal end 11b of the catheter light guide 11 and the light source 12. When an LED is used as the light source 12, a multimode fiber with a large core diameter is desirable as the transmission fiber 13; a multimode fiber with a core diameter of 200 to 1000 μm and an outer diameter of 250 to 1100 μm is practically used.

[0028] In this embodiment, the transmission fiber 13 is a component that transmits light from the light source 12 to the proximal end 11b and makes it incident on the proximal end 11b. The transmission fiber 13 is used without being inserted into the catheter 14. To improve operability, the length of the transmission fiber 13 is preferably about 2 to 3 m. As shown in Figure 2, the transmission fiber 13 is made up of a core 13c located on the radial center side and a cladding 13d located on the outer periphery of the core 13c.

[0029] The transmission fiber 13 and the light source 12 are connected by a connector (not shown). The light source 12 is disposed so that its light-emitting surface faces the end face of the end 13b of the transmission fiber 13 in the proximal direction b.

[0030] 2, in this embodiment, the catheter light guide 11 and the transmission fiber 13 have the same diameters for the cores 11c and 13c and for the claddings 11d and 13d, and are joined by abutting their cut surfaces together and crimping with the metal tube 15. In this case, an adhesive may also be used to fix the catheter light guide 11, the transmission fiber 13, and the metal tube 15.

[0031] By making the core 11c of the catheter light guide 11 and the core 13c of the transmission fiber 13 have the same diameter, it is possible to suppress light loss caused by interposing the transmission fiber 13 between the base end 11b of the catheter light guide 11 and the light source 3.

[0032] In this embodiment, the catheter light guide 11 and the transmission fiber 13 are fixedly coupled together. However, the catheter light guide 11 and the transmission fiber 13 may be coupled together by a method other than crimping with the metal tube 15.

[0033] The transmission fiber 13 may be made of a quartz fiber or a plastic fiber, but preferably has a transmission loss smaller than that of the catheter light guide 11. By selecting an optical fiber with a smaller transmission loss as the transmission fiber 13, light loss can be suppressed even if the transmission fiber 13 is made long so that the practitioner can easily handle it.

[0034] In this embodiment, a plastic fiber is used as the catheter light guide 11. For example, if the optical loss of the plastic fiber used as the catheter light guide 11 is 1 dB / m, and if a plastic fiber made of the same material is used as the transmission fiber 13, the optical loss will be 3 dB for a 3-m length of the transmission fiber 13, and the optical output will be halved. Therefore, it is preferable that the transmission fiber 13 be made of quartz fiber, which has a smaller transmission loss than plastic fiber.

[0035] Furthermore, it is preferable that the bending loss of the transmission fiber 13 be smaller than that of the catheter light guide 11. Generally, a single-core plastic fiber experiences an increase in optical loss of 1 dB or more when bent once with a bending radius of 10 mm. By using an optical fiber with low bending loss, the transmission fiber 13 has high resistance to bending, improving the degree of freedom during treatment. From these viewpoints, polymer-clad quartz fiber, quartz holey fiber, hollow-core fiber, quartz or plastic multi-core fiber, etc. are suitable as the transmission fiber 13. Generally, these optical fibers experience an increase in optical loss of 0.1 dB or less when bent once with a bending radius of 10 mm.

[0036] A polymer-clad quartz fiber is an optical fiber having a core made of quartz and a clad made of polymer. The polymer-clad quartz fiber has low transmission loss and is resistant to bending, making it suitable for the transmission fiber 13.

[0037] A holey fiber is an optical fiber in which cavities called "holes" are provided in the cladding of the optical fiber and are arranged to surround the core. Figure 3 is a cross-sectional view showing an example of a holey fiber cut along its longitudinal axis. The holey fiber is made of, for example, silica glass, and has a large number of holes 32 extending longitudinally (into the depth direction of the paper in Figure 3) surrounding a central transmission region 31. In the longitudinal cross section of the optical fiber, as the area occupied by the holes in the cladding increases, the effective refractive index difference between the core and the cladding increases, and the light confinement effect also increases, resulting in reduced bending loss and transmission loss.

[0038] The transmission region 31 has a high refractive index and is a region through which light propagates. On the other hand, the region in which a large number of holes 32 are provided has a low refractive index and is effective in confining light in the transmission region 31. The holes 32 are filled with air, which has a low refractive index, and the refractive index difference between the transmission region 31 and air is large, thereby strengthening the light confinement effect. Therefore, holey fibers do not require doping of impurities in the core, and therefore have low transmission loss and high transmittance stability. Furthermore, holey fibers also reduce bending loss due to the light confinement effect of the air cladding. Note that hollow-core fibers also achieve the same effects as holey fibers.

[0039] A multi-core fiber is an optical fiber in which multiple cores are arranged in a single cladding. A multi-core fiber is suitable as the transmission fiber 13 because it is strong against bending, has small transmission loss, and has highly stable transmittance.

[0040] Therefore, the transmission fiber 13 is preferably made of any optical fiber selected from the group consisting of a quartz fiber, a polymer-clad quartz fiber, a holey fiber, a hollow-core fiber, and a multi-core fiber. These optical fibers are generally less likely to break than plastic fibers. If a plastic fiber with a smaller transmission loss than the plastic fiber used as the catheter light guide 11 is used as the transmission fiber 13, it can be expected that the loss of light will be reduced in accordance with the difference in transmission loss.

[0041] The catheter light guide 11 has a length, for example, about 1 meter, which is necessary and sufficient for insertion into the catheter 14 for treatment. Therefore, if the light source 12 is connected to the proximal end 11b of the catheter light guide 11 without the transmission fiber 13, the practitioner must operate the catheter 14 while holding the light source 12 in one hand. This makes the catheter 14 difficult to operate for the practitioner.

[0042] In contrast, in this embodiment, a transmission fiber 13 is interposed between the proximal end 11b of the catheter light guide 11 and the light source 12. The transmission fiber 13 has a length, for example, about 2 to 3 meters, that is necessary and sufficient to ensure flexibility. This allows the light source 12 to be installed at a location away from the catheter 14, and the catheter 14 can be maneuvered without having to hold the light source 12 by hand, improving operability. Furthermore, by using the transmission fiber 13 made of an optical fiber with low transmission loss, it is possible to suppress a decrease in optical output even if the overall length of the optical fiber is long.

[0043] Second Embodiment Fig. 4 is a schematic diagram showing a catheter visualization device according to a second embodiment inserted into a catheter. As shown in Fig. 4, a catheter visualization device 20 according to the second embodiment includes a catheter light guide 11, a light source 12, and a transmission fiber 23. Fig. 5 is an enlarged transverse cross-sectional view showing a longitudinal cross section of the coupling portion between the catheter light guide 11 and the transmission fiber 23 and the vicinity thereof.

[0044] In this embodiment, components having the same configuration and function as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed descriptions thereof will be omitted. For example, the catheter light guide 11 and the light source 12 are components having the same configuration and function as those in the first embodiment.

[0045] In this embodiment, the transmission fiber 23 is also a component that has the function of transmitting light from the light source 12 to the proximal end 11 b and making it incident on the proximal end 11 b. The transmission fiber 23 is used without being inserted into the catheter 24. As shown in Fig. 5, the transmission fiber 23 is made up of a core 23 c located on the radial center side and a cladding 23 d located on the outer periphery of the core 23 c.

[0046] 5, in this embodiment, the catheter light guide 11 and the transmission fiber 23 are coupled (connected) by connectors 27 and 28. That is, the base end 11b of the catheter light guide 11 is inserted into the connector 28, the tip end 23t of the transmission fiber 23 is inserted into the connector 27, and the connectors 27 and 28 are locked and fixed by a locking means (not shown), thereby coupling the catheter light guide 11 and the transmission fiber 23.

[0047] The transmission fiber 23 is detachable (insertable) from the connector 27. Note that the connectors 27 and 28, or the catheter light guide 11 and the connector 28 may be detachable. In this embodiment, the transmission fiber 23 is detachable from the proximal end 11b of the catheter light guide 11, including these cases.

[0048] In this embodiment, at the joint between the catheter light guide 11 and the transmission fiber 23, the diameter of the core 23c of the transmission fiber 23 at the end (tip end 23t) that is detachable from the proximal end 11b of the catheter light guide 11 is smaller than the diameter of the core 11c at the proximal end 11b of the catheter light guide 11. By making the diameter of the core 23c of the transmission fiber 23 smaller, it is possible to reduce optical loss.

[0049] By making the difference in diameter between the core 11c and the core 23c larger than the range in which the core position may be misaligned due to the tolerance when connecting the connectors 27 and 28 (hereinafter referred to as the "connector tolerance") and the tolerance of the core diameter and cladding diameter in both the catheter light guide 11 and the transmission fiber 23 (hereinafter referred to as the "fiber tolerance"), the influence of misalignment due to the tolerance can be avoided.

[0050] For example, if the sum of the connector tolerance and fiber tolerance is approximately 0 μm to 100 μm, and the diameter of the core 11c of the catheter light guide 11 is 750 μm and the diameter of the core 23c (small diameter portion 23S, described later) of the transmission fiber 23 is 500 μm, the difference in core diameters will be 250 μm. In this case, the difference in core diameters is greater than the sum of the connector tolerance and fiber tolerance. Therefore, even if the connector tolerance and fiber tolerance are large within their respective tolerance ranges, the entire surface of the distal end portion 23t of the core 23c of the transmission fiber 23 remains in contact with the end surface of the proximal end portion 11b of the catheter light guide 11, thereby avoiding the effects of the connector tolerance and fiber tolerance.

[0051] If the aperture angle (also called the numerical aperture) of the optical fiber of the catheter light guide 11 is NA1, the diameter of the core 11c is D1, the aperture angle of the transmission fiber 23 is NA2, and the diameter of the core 23c is D2, then no light loss occurs at the connection between the connectors 27 and 28 if the following formulas (1) and (2) are satisfied: NA1>NA2 (Formula (1)) D1>D2+Connector tolerance (Formula (2))

[0052] For example, if the connector tolerance is approximately 10 to 20 μm, the diameter D1 of the optical fiber of the catheter light guide 11 is 1000 μm, the aperture angle NA1 is 0.70, and the diameter D2 of the transmission fiber is 600 μm and the aperture angle NA is 0.50, then the above formulas (1) and (2) are satisfied, and no light loss occurs due to the connection of the connectors 27 and 28.

[0053] 4 and 5, in this embodiment, the core 23c and cladding 23d of the transmission fiber 23 are both small in diameter in a small-diameter portion 23S near the coupling portion with the catheter light guide 11, but most of the longitudinal region, including the coupling portion with the light source 12, is a large-diameter portion 23L. These two portions are connected by a tapered portion 23T. In this embodiment, the core diameter in the small-diameter portion 23S is 180 μm and the cladding diameter is 200 μm, and the core diameter in the large-diameter portion 23L is 900 μm and the cladding diameter is 1000 μm.

[0054] The tapered portion 23T can be manufactured as follows: That is, when manufacturing an optical fiber by drawing, the tapered shape can be formed by changing the drawing speed at the location where the tapered portion 23T is to be provided (increasing the drawing speed narrows the diameter).

[0055] 6 is a cross-sectional view similar to FIG. 5 , illustrating the angle of incidence θ of light incident on the cladding 23d at the tapered portion 23T of the transmission fiber 23. For example, by making the length of the tapered portion 23T 3000 μm or more, the angle of incidence θ (taper) of light incident on the cladding 23d at the tapered portion 23T becomes equal to or greater than the total reflection angle of 82 degrees, making it possible to couple the optical fiber of the catheter light guide 11 and the transmission fiber 23 with almost no radiation. The angle of total reflection θ is given by arcsin (refractive index of cladding / refractive index of core), and is θ = 82 (degrees) when the refractive index of the core = 1.463 and the refractive index of the cladding = 1.45. As described above, by appropriately selecting the NA characteristic, core diameter, and taper length of the transmission fiber 23, the optical loss due to the connection of the connectors 27 and 28 can be significantly improved.

[0056] In this embodiment, a coating layer 26 is provided as an exterior covering the outer periphery of the transmission fiber 23 over substantially the entire length in the longitudinal direction (the directions of arrows b and t). The coating layer 26 is, for example, a flexible resin tube, and can protect and increase the strength of the transmission fiber 23. Note that the exterior covering the outer periphery of the transmission fiber 23 does not necessarily have to be provided over the entire length in the longitudinal direction, but may be provided over a portion of the longitudinal direction.

[0057] Since the transmission fiber 23 does not need to be inserted into the catheter 14, its strength can be improved by providing an exterior such as the coating layer 26 or by providing the tapered portion 23T as described above, thereby making most of the longitudinal area the large-diameter portion 23L. Increasing the core diameter of the transmission fiber 23 also contributes to reducing transmission loss.

[0058] In this embodiment, the transmission fiber 23 preferably has a smaller transmission loss than the catheter light guide 11, an optical fiber with a smaller transmission loss is selected, and the bending loss is preferably smaller than the bending loss of the catheter light guide 11, as with the transmission fiber 13 in the first embodiment.

[0059] In this embodiment, the transmission fiber 23 is made of any optical fiber selected from the group consisting of a quartz fiber, a polymer-clad quartz fiber, a holey fiber, and a multi-core fiber, similarly to the transmission fiber 13 in the first embodiment. Other considerations regarding the length of the transmission fiber 23 are also similar to those for the transmission fiber 13 in the first embodiment.

[0060] According to this embodiment, the light source 12 can be installed at a location away from the catheter 14, and the catheter 14 can be handled without having to hold the light source 12 by hand, improving operability. Furthermore, by using the transmission fiber 23 made of an optical fiber with low transmission loss, it is possible to suppress a decrease in optical output even if the overall length of the optical fiber is long.

[0061] Furthermore, according to this embodiment, the transmission fiber 23 is detachable from the base end 11b of the catheter light guide 11. Therefore, even if the catheter light guide 11 inserted into the living body is disposable or needs to be replaced frequently, the transmission fiber 23 can be reused any number of times, which is economical.

[0062] Furthermore, according to this embodiment, at the joint between the catheter light guide 11 and the transmission fiber 23 by the connectors 27, 28, the diameter of the core 23c of the transmission fiber 23 is smaller than the diameter of the core 11c of the catheter light guide 11. Therefore, even if the catheter light guide 11 is shaken during operation and a misalignment occurs between the core 11c and the core 23c, the loss of light at the joint does not fluctuate.

[0063] 7 is a schematic diagram showing a catheter visualization device according to a third embodiment inserted into a catheter. In this embodiment, the configuration of the transmission fiber 33 is different from that of the first embodiment, but the rest of the configuration is the same. In this embodiment, members having the same configuration and function as those in the first embodiment are assigned the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted.

[0064] In this embodiment, a plurality of fluorescent marking portions 33f are provided on the outer periphery of the transmission fiber 33. In this embodiment, the fluorescent marking portions 33f are configured as UV-reactive fluorescent sleeves attached at 30 cm intervals. The UV-reactive fluorescent sleeves are made of silicone, a material that is resistant to autoclave sterilization.

[0065] In medical settings where actual treatments are performed, optical fiber cables are often laid around patients or on the floor, and these cables are prone to reduced visibility in dark environments. There is a concern that medical personnel who cannot see the cable may step on it and damage the internal structure of the optical fiber. Furthermore, because it is difficult to see how the cable is routed, there is a concern that the optical fiber may be damaged, such as by being bent beyond its minimum bending radius, resulting in localized excessive bending and breakage. Damage to the optical fiber may result in the inability to transmit signals or insufficient transmission. Furthermore, when cables are difficult to see, there is a concern that wiping and disinfection may be inadequate, increasing the risk of infection.

[0066] In this embodiment, a fluorescent marking portion 33f is provided on the outer periphery of the transmission fiber 33 connecting the endoscope tower, the patient bed, and the operator operation area, thereby improving the visibility of the transmission fiber 33 in the area not inserted into the catheter 14, even in a dark environment. According to this embodiment, for example, even when the room lights are turned off, the position of the transmission fiber 33 can be clearly seen by irradiating it with UV light. Therefore, the occurrence of accidents such as surgeons or staff members stepping on or getting caught on it can be significantly reduced.

[0067] In addition, the risk of local excessive bending is reduced due to the improved visibility of the transmission fiber 33. Furthermore, the improved visibility of the transmission fiber 33 makes it easier to wipe and disinfect it on a daily basis, which also leads to a reduction in the risk of infection.

[0068] The fluorescent marking portion 33f is not limited to the intermittent arrangement as described above, but may be provided continuously over the entire length or a portion of the longitudinal direction of the transmission fiber 33. It may also be configured to have a striped pattern such as a tiger tape, or to be arranged in a spiral along the longitudinal direction of the transmission fiber 33. These configurations can further improve visibility and design.

[0069] As an aspect of the fluorescent marking portion 33f, two or more may be provided around the entire circumference b of the outer periphery of the transmission fiber 33 as in this embodiment, or only one may be provided. In particular, if the fluorescent marking portion 33f is provided around half or more of the outer periphery of the transmission fiber 33, sufficient visibility is ensured, which is preferable.

[0070] Furthermore, the fluorescent marking portion is not limited to the main body of the transmission fiber, and for example, one or more fluorescent marking portions may be provided on the outer periphery of the connectors 27 and 28 in the second embodiment. The fluorescent marking portion may be provided on only one of the connectors 27 and 28, or on both, and either one or two or more fluorescent marking portions may be provided on each.

[0071] The connections made by connectors 27 and 28 are frequently connected and disconnected, and there is a risk of incorrect connection or poor contact, so improving visibility is also useful from a safety perspective. In addition, by changing the appearance (color, pattern, arrangement, etc.) of the fluorescent markings on the transmission fiber body and the connector, the distinction between each part is improved, and further improvements in work efficiency and safety can be expected.

[0072] The visibility can be further improved by selecting a color for the fluorescent marking portion 33f that has a particularly high contrast with the background color (e.g., fluorescent green, fluorescent orange, etc.). In addition, when multiple cables of the same shape and color are present, low visibility can lead to misconnections and cause malfunctions in medical devices. However, by selecting a color that is easily distinguishable from other cables, these concerns can be alleviated.

[0073] In this embodiment, the fluorescent marking portions 33f are positioned at equal intervals in the longitudinal direction, but they can also be optimized according to the purpose, for example, by focusing on areas where visibility is particularly required, such as the branching portion if the transmission fiber 33 has a branch, the connection portion if there is a connection portion along the way, or the contact portion with the floor surface.

[0074] The fluorescent marking portion 33f is not limited to a fluorescent sleeve, and may be, for example, any one selected from the group consisting of fluorescent paint, fluorescent tape, and fluorescent sleeve that emits light under ultraviolet light irradiation.

[0075] The material forming the fluorescent marking portion 33f is preferably resistant to autoclave sterilization and / or ethylene oxide gas sterilization, making the fluorescent marking portion 33f particularly suitable for use in medical settings.

[0076] <Fourth embodiment> Fig. 8 is a schematic diagram showing a state in which a catheter visualization device according to a fourth embodiment is inserted into a catheter. Fig. 9 is a cross-sectional view of a transmission fiber 43 in the catheter visualization device according to the fourth embodiment, which corresponds to the A-A cross section in Fig. 8.

[0077] This embodiment differs from the first embodiment in that an exterior (shroud 49) is provided to surround the outer periphery of the transmission fiber 13', but otherwise has the same configuration. In this embodiment, members having the same configuration and function as those in the first embodiment are given the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted. Furthermore, the transmission fiber 13' in this embodiment is basically the same as the transmission fiber 13 in the first embodiment.

[0078] The jacket 49 as an exterior covering surrounding the outer periphery of the transmission fiber 13' is provided over almost the entire length in the longitudinal direction. However, the exterior covering surrounding the outer periphery of the transmission fiber 23 does not necessarily have to be provided over the entire length in the longitudinal direction, but may be provided over a part of the length in the longitudinal direction.

[0079] In this embodiment, the outer cover 49 is both abrasion-resistant and flexible. Specific examples of the material for the outer cover 49 include ethylene tetrafluoroethylene (ETFE), silicone, and polyurethane (PU). These materials are compatible with autoclave sterilization and ethylene oxide gas sterilization, making them suitable for medical applications.

[0080] Considering the balance between the flexibility of the optical fiber and the protective performance, the coating thickness of the outer jacket 49 is preferably set to, for example, 0.1 mm to 0.3 mm. By setting the coating thickness of the outer jacket 49 within an appropriate range, sufficient injury protection performance can be ensured without impairing the handleability of the catheter visualization device 40.

[0081] Furthermore, as shown in Fig. 9, the cross-sectional shape of the outer jacket 49 is formed in an ellipse rather than a circle to prevent twisting. This limits the degree of freedom in the rotational direction of the transmission fiber 13', making it possible to suppress internal damage due to twisting. Note that, from the viewpoint of preventing twisting, it is also preferable to use a triangular outer jacket 49' as the outer jacket, as shown in the modified example of Fig. 10. Here, Fig. 10 is a cross-sectional view of the transmission fiber in the catheter visualization device according to the modified example. The outer jacket as the outer jacket may have any other polygonal shape.

[0082] Furthermore, it is preferable that a reinforcing material such as Kevlar (registered trademark) fiber or stainless steel wire is embedded inside the outer cover 49. By embedding these reinforcing materials, the tensile strength and torsional rigidity are improved, resulting in a structure that is highly resistant to the pulling and twisting of the catheter visualization device 40 during treatment.

[0083] In this embodiment, a plurality of fluorescent marking portions 49f are provided on the outer periphery of the outer cover 49. Providing the fluorescent marking portions 49f on the outer periphery improves the visibility of the region of the transmission fiber 43 that is not inserted into the catheter 14, even in a dark environment. The specific configuration, aspects, actions, effects, and modifications of the fluorescent marking portions 49f are similar to those of the fluorescent marking portion 33f provided on the outer periphery of the transmission fiber 33 in the third embodiment.

[0084] In this embodiment, the jacket 49 is exemplified as the exterior covering, with an air layer interposed between it and the outer periphery of the transmission fiber 13', but it may also be a layered covering such as the covering layer 26 in the second embodiment. A fluorescent marking portion can also be provided on the outer periphery of a layered covering such as the covering layer 26.

[0085] In this embodiment, the outer jacket 49 is an exterior covering only the outer periphery of the transmission fiber 13', but it may be extended to cover the entire length or a part of the catheter light guide 11. The extended outer jacket of the catheter light guide 11 can provide the catheter light guide 11 with high resistance to pulling and twisting.

[0086] Furthermore, the exterior can be a casing tube made of a metal such as stainless steel with a bellows structure that is highly flexible. In this case, it is desirable to design the casing tube so that it cannot bend below the bending radius of the transmission fiber. By providing such an exterior casing tube, the transmission fiber can be protected from excessive bending or if it is accidentally stepped on.

[0087] The above-described embodiment merely shows a typical example of the present invention, and the present invention is not limited to the above embodiment. For example, the coating layer 26 formed on the outer periphery of the transmission fiber 23 in the second embodiment may be formed on the outer periphery of the transmission fiber 13 in the first embodiment.

[0088] In addition, those skilled in the art may implement various modifications in accordance with conventionally known knowledge without departing from the gist of the present invention. As long as such modifications still comprise the configuration of the catheter visualization device of the present invention, they are of course included in the scope of the present invention.

[0089] 10, 20, 30, 40: catheter visualization device, 11: catheter light guide, 11b: base end, 11c, 13c, 23c: core, 11d, 13d, 23d: cladding, 11t: tip side, 12: light source, 13, 13', 23, 33: transmission fiber, 14: catheter, 15: metal tube, 23t: tip (end detachable from the base end of the catheter light guide), 23S: small diameter section, 23T: tapered section, 23L: large diameter section, 26: coating layer (exterior), 27, 28: connector, 31: transmission region, 32: hole, 33f, 49f: fluorescent marking section, 49, 49': outer jacket (exterior)

Claims

1. A catheter visualization device comprising: a catheter light guide that is inserted into a catheter, is made of an optical fiber, and emits light that enters at the base end from the tip end; a light source that emits light that enters at the base end of the catheter light guide; and a transmission fiber that is used without being inserted into the catheter, is interposed between the base end of the catheter light guide and the light source, and transmits light from the light source to the base end and causes light to enter at the base end.

2. The catheter visualization device of claim 1, wherein the transmission fiber has a transmission loss less than the transmission loss of the catheter light guide.

3. The catheter visualization system of claim 1, wherein the bending loss of said transmission fiber is less than the bending loss of said catheter light guide.

4. The catheter visualization system of claim 1, wherein said catheter light guide comprises a plastic fiber.

5. The catheter visualization system of claim 1, wherein said transmission fiber is detachable from the proximal end of said catheter light guide.

6. The catheter visualization device of claim 5, wherein the core diameter of the transmission fiber at the end detachable from the proximal end of the catheter light guide is smaller than the core diameter at the proximal end of the catheter light guide.

7. The catheter visualization device according to claim 1, wherein the transmission fiber is an optical fiber selected from the group consisting of a silica fiber, a polymer-clad silica fiber, a holey fiber, a hollow-core fiber, and a multi-core fiber.

8. The catheter visualization device according to claim 1, wherein one or more fluorescent markings are provided on the outer periphery of the transmission fiber.

9. A catheter visualization device according to claim 1, wherein an exterior covering surrounds the outer periphery of the transmission fiber over the entire length or a portion of the length, and one or more fluorescent marking portions are provided on the outer periphery of the exterior covering.

10. A catheter visualization device according to claim 5, wherein the transmission fiber and the proximal end of the catheter light guide are detachably connected via a connector, and one or more fluorescent marking portions are provided on the outer periphery of the connector.

11. A catheter visualization device according to any one of claims 8 to 10, wherein the fluorescent marking portion is any one selected from the group consisting of fluorescent paint, fluorescent tape, and fluorescent sleeve that emits light under ultraviolet light irradiation.

12. A catheter visualization device according to any one of claims 8 to 10, wherein the material constituting the fluorescent marking portion is resistant to autoclave sterilization and / or ethylene oxide gas sterilization.

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