Medical tube distal end position detection system

Abstract

To easily, correctly, and safely detect a distal end position of a tube inserted to a patient.SOLUTION: A tube distal end position detection system 1 includes: a light source device 50 for emitting light; a hollow tube 10 having a flow path 11 in which liquid can pass; a connector 20 provided in a proximal end of the tube such that light from the light source device can enter an end surface 12 of the proximal end of the tube; and a light emission part 30 provided in a distal end of the tube. The light from the light source device passes the tube, is emitted from the light emission part, and is transmitted through a body surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a system for detecting the position of the tip of a tube inserted into the human body. [Background technology]

[0002] In clinical medicine, tube feeding is widely used to treat patients by inserting various medical tubes into their body cavities. For example, oral and nasal tube feeding is used to supply liquid nutrients from the outside to patients who have difficulty chewing or swallowing, by sending nutrients directly to the stomach through a medical tube (called an oral or nasal tube; hereafter simply referred to as "tube") inserted through the mouth or nose.

[0003] When performing oral or nasogastric tube feeding, it is necessary to ensure that the tip of the tube is positioned securely in the stomach. Incorrect insertion of the tube into the trachea or bronchus is extremely dangerous. It is necessary to accurately confirm the position of the tube tip inside the patient's body.

[0004] X-ray fluoroscopy is the most reliable method for checking the position of the tube tip. However, the patient must be moved to the X-ray device to check, which places a great burden on the patient's body. The tube is left in the patient for several days. During this time, the tip of the tube may move due to the cough reflex, vomiting, etc. For this reason, the position of the tip must be checked at regular intervals. If X-ray fluoroscopy is performed every time, the burden on the patient will be even greater and the amount of X-ray exposure will also increase.

[0005] Measuring the pH of the fluid aspirated through the tube can sometimes be used to determine whether the tip of the tube is in the stomach, but this method is less reliable in acid-suppressed patients.

[0006] Patent Document 1 describes a method for confirming the position of the tip of a tube by inserting a tube with an optical fiber already inserted into it into a patient and observing the light emitted from the tip of the optical fiber from outside the body. This method is simple and places little burden on the patient.

[0007] However, in order to send nutrients to the stomach through the tube, it is necessary to pull out the optical fiber from the tube. If the optical fiber is then reinserted into the tube, the inserted optical fiber may damage the tube, causing accidents such as the optical fiber protruding from the damaged part of the tube and damaging the wall of the digestive tract. For this reason, the method of Patent Document 1 can only be used when initially inserting a tube into a patient, and cannot be used to periodically check the position of the tip of the tube thereafter. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] WO2015 / 133119A1 [Patent Document 2] JP 2015-119837 A [Patent Document 2] JP 2018-029753 A Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to easily, accurately and safely detect the position of the tip of a tube inserted into a patient. [Means for solving the problem]

[0010] The present invention relates to a medical tube tip position detection system for detecting the position of the tip of a tube inserted into a patient. The system includes a light source device that emits light, a hollow tube having a flow path through which a liquid can pass, a connector provided at the base end of the tube so that light from the light source device can be incident on an end face of the base end of the tube, and a light emitting unit provided at the tip of the tube. The light from the light source device passes through the tube and is emitted from the light emitting unit, and the light from the light emitting unit is transmitted to the body surface. Effect of the Invention

[0011] According to the present invention, the position of the tip of a tube inserted into a patient can be detected simply, accurately and safely. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 shows a schematic configuration of a medical tubing tip position detection system according to a first embodiment of the present invention. [Diagram 2] Fig. 2A is a perspective view of the connector according to the first embodiment of the present invention, and Fig. 2B is a cross-sectional view of the connector. [Diagram 3] Fig. 3A is a perspective view of the light-emitting unit according to the first embodiment of the present invention, and Fig. 3B is a cross-sectional view of the light-emitting unit. [Figure 4] Fig. 4A is a cross-sectional view of another light-emitting unit according to the first embodiment of the present invention, and Fig. 4B is a front view of a reflecting surface of a reflecting member of the light-emitting unit. [Diagram 5] Fig. 5A is a cross-sectional view of yet another light-emitting unit according to the first embodiment of the present invention, and Fig. 5B is a front view of a reflecting surface of a reflecting member of the light-emitting unit. [Figure 6] 6A to 6C are cross-sectional views of still another light-emitting section according to the first embodiment of the present invention. [Figure 7] Fig. 7A is a perspective view of a light-emitting unit according to embodiment 2 of the present invention, and Fig. 7B is a cross-sectional view of the light-emitting unit. [Figure 8]Fig. 8A is an exploded perspective view of a light-emitting unit according to the second embodiment of the present invention as viewed from the tip end side, and Fig. 8B is an exploded perspective view of a light-emitting unit as viewed from the base end side. [Figure 9] Fig. 9A is a cross-sectional view of another light-emitting unit according to embodiment 2 of the present invention, and Fig. 9B is an exploded perspective view of the light-emitting unit as viewed from the tip side. [Figure 10] FIG. 10 is a cross-sectional view of still another light-emitting portion according to the second embodiment of the present invention. [Figure 11] Fig. 11A is a side view of a light-emitting unit according to a third embodiment of the present invention, and Fig. 11B is a perspective view of the light-emitting unit. [Figure 12] Fig. 12A is a perspective view of another light-emitting unit according to the third embodiment of the present invention, and Fig. 12B is a cross-sectional perspective view of the light-emitting unit. [Figure 13] Fig. 13A is a perspective view of yet another light-emitting unit according to the third embodiment of the present invention, and Fig. 13B is a cross-sectional perspective view of the light-emitting unit. [Figure 14] Fig. 14A is a perspective view of yet another light-emitting unit according to the third embodiment of the present invention, and Fig. 14B is a cross-sectional perspective view of the light-emitting unit. [Figure 15] Fig. 15A is a perspective view of yet another light-emitting unit according to the third embodiment of the present invention, and Fig. 15B is a cross-sectional perspective view of the light-emitting unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In the above-mentioned system of the present invention, the wavelength of the light emitted by the light source device may be 360 ​​nm to 3000 nm. Since light of this wavelength has a high transmittance to the human body, it is easy to detect the tube tip position. Furthermore, since light of this wavelength is minimally invasive to the human body, it is excellent in safety.

[0014] The connector may include a cylindrical male member into which the tube is inserted, an outer cylinder surrounding the male member, and a female screw formed on the inner peripheral surface of the outer cylinder facing the male member. This allows oral and nasal tube feeding to be performed using a tube equipped with the connector of the present invention instead of a conventional oral and nasal tube. Since the tube is inserted into the male member, it is easy to make light from a light source device incident on the end face of the base end of the tube.

[0015] The end face of the base end of the tube may be exposed to an opening at the tip end of the male member. This aspect is advantageous for irradiating light from a light source device onto the end face of the base end of the tube.

[0016] The light emitting unit may include a reflecting member that reflects the light emitted from the tube. The reflecting member reflects the light emitted from the tube in various directions including the radial direction (the direction perpendicular to the longitudinal direction of the tube). This makes it easy to observe the light from the light emitting unit from the surface of the patient's body regardless of the orientation of the light emitting unit inside the patient's body.

[0017] The reflecting member may have a spherical or conical surface on the side facing the end face of the tip of the tube, which makes it possible to reflect the light emitted from the tube in various directions, including the radial direction, with a simple structure.

[0018] The reflecting member may be made of titanium, which has excellent corrosion resistance and biocompatibility, and is therefore advantageous in maintaining good light reflecting properties for a long period of time.

[0019] The reflecting member may be provided in direct contact with the tube. This aspect is advantageous in simplifying the configuration of the light emitting section and facilitating the manufacture of the tube provided with the light emitting section. In this aspect, the housing can be omitted in the light emitting section.

[0020] The reflective member may be a vapor-deposited metal layer. According to this aspect, the reflective member can be easily provided on the tube.

[0021] The light emitting unit may include a refractive member that refracts the light emitted from the tube in various directions, including a radial direction, making it easier to observe the light from the light emitting unit from the surface of the patient's body, regardless of the orientation of the light emitting unit inside the patient's body.

[0022] The light emitting unit may include a tip of the tube that is formed so that light passing through the tube is refracted and emitted. According to this aspect, the light passing through the tube is refracted in various directions including the radial direction and emitted from the tube. This makes it easy to observe the light from the light emitting unit from the surface of the patient's body regardless of the orientation of the light emitting unit inside the patient's body.

[0023] The light emitting unit may include a hole penetrating the tube or a recessed portion provided on the inner or outer surface of the tube. According to this aspect, the light passing through the tube is refracted at the hole or recessed portion and is emitted from the tube in various directions including the radial direction. Therefore, regardless of the orientation of the light emitting unit inside the patient's body, the light from the light emitting unit can be easily observed from the surface of the patient's body.

[0024] The outer surface of the tube may be provided with a light leakage prevention layer for preventing light from leaking from the outer surface of the tube. The light leakage prevention layer may be removed from the light emitting section. According to this aspect, the light passing through the tube is refracted from the area where the light leakage prevention layer has been removed and is emitted in various directions including the radial direction. Therefore, it is possible to observe the light from the light emitting section from the surface of the patient's body in a simple manner, regardless of the orientation of the light emitting section inside the patient's body.

[0025] The light emitting unit may include a housing. The housing may be provided with a hole that allows the liquid that has passed through the tube to flow out to the outside. According to this aspect, the liquid that has passed through the flow path of the tube can be administered to a patient through the hole in the housing. In addition, by using the housing, it is possible to hold a reflective member or a refractive member at a desired position relative to the end face of the tip of the tube.

[0026] The light emitting unit may have a light-transmitting housing. According to this aspect, the light loss caused when the light emitted from the tip of the tube passes through the housing is reduced. This is advantageous in ensuring the brightness of the light emitting unit and makes it easier to detect the position of the tip of the tube.

[0027] The surface roughness Ra of the outer surface of the tube may be 1.2 μm or less. According to this embodiment, the light loss when the light passes through the tube is reduced. This is advantageous in ensuring the brightness of the light emitting part and makes it easier to detect the tube tip position.

[0028] The outer surface of the tube may be covered with a coating material having a lower refractive index than the tube. According to this aspect, the light loss when the light passes through the tube is reduced. This is advantageous in ensuring the brightness of the light emitting part and makes it easier to detect the tube tip position.

[0029] The system of the present invention may further include a stylet or an optical fiber that can be inserted into and removed from the flow path of the tube. The stylet and the optical fiber improve the insertability of the tube. The stylet also makes it possible to confirm the position of the tube by X-ray fluoroscopy. The optical fiber improves the brightness of the light-emitting part, making it easier to detect the position of the tube tip.

[0030] The present invention will be described in detail below while showing preferred embodiments. However, it goes without saying that the present invention is not limited to the following embodiments. Each drawing referred to in the following description shows a simplified view of the main components constituting the embodiment of the present invention for the convenience of explanation. Therefore, the present invention may include any components not shown in the following drawings. Furthermore, within the scope of the present invention, each component shown in the following drawings may be modified or omitted. In the drawings cited in the description of each embodiment, components corresponding to components shown in the drawings cited in the preceding embodiment are given the same reference numerals as those given in the drawings of the preceding embodiment. For such components, duplicated explanations are omitted, and the explanations of the preceding embodiment should be taken into consideration as appropriate.

[0031] (Embodiment 1) FIG. 1 shows a schematic configuration of a system 1 according to a first embodiment of the present invention, which is applied to oral and nasogastric tube feeding. An oral and nasogastric tube (hereinafter, simply referred to as a tube) 10 is inserted from the nasal cavity of a patient 90, and its tip reaches a stomach 91. The tube 10 has flexibility that allows it to be curved and deformed. The tube 10 is a hollow cylinder having a continuous flow path 11 (see FIG. 2B and FIG. 3B described later) formed over its entire length. A liquid such as a nutrient is administered to the stomach 91 of the patient through the flow path 11. A connector 20 is provided at the base end of the tube 10. A light-emitting unit 30 is provided at the tip of the tube 10. The connector 20 can be repeatedly connected to and disconnected from a light source device 50. When the connector 20 is connected to the light source device 50, light from a light source (not shown) built into the light source device 50 passes through the tube 10 and is emitted from the light-emitting unit 30. The light from the light-emitting unit 30 passes through the body of the patient 90 and illuminates the body surface. The surgeon can confirm the position of the tip of the tube 10 from the light emission position on the body surface of the patient 90.

[0032] FIG. 2A is a perspective view of the connector 20, and FIG. 2B is a cross-sectional view of the connector 20. The connector 20 is a male connector equipped with a cylindrical male member 21. The outer peripheral surface 22 of the male member 21 is a tapered surface (so-called male taper surface) in which the outer diameter becomes smaller as it approaches the tip. A cylindrical outer tube 23 is arranged coaxially with the male member 21. The outer tube 23 is radially spaced from the male member 21 and surrounds the male member 21. A female thread 24 is provided on the inner peripheral surface of the outer tube 23 facing the male member 21. The tip of the male member 21 protrudes from the tip of the outer tube 23. A cylindrical base tube 27 extends coaxially with the male member 21 toward the opposite side to the male member 21. A through hole 29 penetrates the connector 20 from the tip of the male member 21 to the tip of the base tube 27. A tube 10 is inserted into the through hole 29 from the base tube 27 to the male member 21. A flat end surface 12 is formed at the base end of the tube 10. The end surface 12 is perpendicular to the longitudinal direction of the tube 10. The end surface 12 is exposed to an opening at the tip of the male member 21 and forms a common plane with the tip surface of the male member 21. The tube 10 is fixed to the connector 20, for example at the position of the base tube 27, by bonding the inner surface of the through hole 29 to the connector 20 or the like.

[0033] The connector 20 (particularly the outer circumferential surface 22 of the male member 21 and the female thread 24) is configured to be compatible with a male connector (see, for example, Patent Documents 2 and 3) provided at the base end of an oral / nasal tube commonly used for oral / nasal tube feeding. Therefore, oral / nasal tube feeding can be performed by using the tube 10 equipped with the connector 20 instead of a conventional oral / nasal tube.

[0034] The connector 20 is made of a hard material and has a mechanical strength (rigidity) that is not substantially deformed by an external force. Specifically, the material of the connector 20 is not limited, but may be, for example, a resin such as polypropylene (PP), polycarbonate (PC), polyacetal (POM), polystyrene, polyamide, polyethylene, rigid polyvinyl chloride, or ABS (acrylonitrile-butadiene-styrene copolymer). The connector 20 can be manufactured as a single component by injection molding or the like using the above resin.

[0035] FIG. 3A is a perspective view of the light emitting unit 30, and FIG. 3B is a cross-sectional view of the light emitting unit 30. The light emitting unit 30 includes a reflecting member 31 and a housing 35. The housing 35 has a hollow bullet shape with one end (tip) in the longitudinal direction bulging in a dome shape (hemispherical shape) and the other end (base end) opening. The tip of the tube 10 is inserted into the opening of the housing 35. The housing 35 is fixed to the tube 10 in a liquid-tight manner by adhesion or the like. The reflecting member 31 has a spherical shape and is housed in the deepest part of the inner cavity 36 of the housing 35. A flat end surface 13 is formed at the tip of the tube 10. The end surface 13 is perpendicular to the longitudinal direction of the tube 10. The reflecting member 31 faces the end surface 13 and is spaced apart from the end surface 13. The center of the reflecting member 31 is located on the central axis of the tube 10. The outer diameter of the reflecting member 31 is not limited, but is preferably the same as or slightly larger than the outer diameter of the tube 10. The light that passes through the tube 10 and is emitted from the end face 13 is reflected by the spherical surface 32 of the reflecting member 31 and passes through the housing 35.

[0036] The housing 35 is provided with holes (side holes) 37 penetrating the housing 35 in the radial direction. Here, "radial direction" means the direction of a straight line perpendicular to the central axis of the tube 10 (which passes through the center of the reflecting member 31). The holes 37 communicate the inner cavity 36 of the housing 35 between the end face 13 and the reflecting member 31 with the outside of the housing 35. In the first embodiment, two holes 37 are provided, but the number of holes 37 may be one or three or more.

[0037] The reflecting member 31 may be made of a non-translucent material. The non-translucent material is not limited, but metals such as titanium, stainless steel, cobalt alloy, aluminum, and iron are preferable. Titanium, stainless steel, and cobalt alloy have excellent corrosion resistance and biocompatibility, and can maintain good light reflection characteristics for a long period of time. Among them, titanium is preferable. Stainless steel, aluminum, and iron are inexpensive. Titanium, aluminum, and the like are non-magnetic or low-magnetic, and are therefore unlikely to be sucked in during an MRI examination. The spherical surface 32 of the reflecting member 31 is preferably glossy, and is particularly preferably mirror-finished, so as to function as a reflecting surface that reflects light emitted from the end surface 13. The reflecting member 31 can also function as a weight to facilitate the insertion of the tube 10 into the digestive tract. In order to ensure a necessary load on the tip of the tube 10, a weight other than the reflecting member 31 may be accommodated in the housing 35. In this case, the other weight is disposed on the opposite side of the reflecting member 31 from the end surface 31.

[0038] The reflecting member 31 may be made of a light-transmitting material. Any light-transmitting material can be used as the reflecting member 31 as long as it can reflect at least a part of the light emitted from the end face 13. The light-transmitting material may be plastic, glass, or the like. Plastic and glass are low electrical conductors, and therefore do not cause burns due to heat generation during MRI examinations. The surface of the light-transmitting material may be subjected to a process for reflecting light (reflection process). The reflection process is not limited, and examples thereof include various coatings, matte finishes, metal deposition, and mirror finishes. The reflecting member 31 may be a mirror.

[0039] A part of the light incident on the reflecting member 31 may be reflected by the surface of the reflecting member 31, and the remaining light may be incident on the reflecting member 31. In this case, the light may be refracted when it enters the reflecting member 31 and when it exits from the reflecting member 31. That is, the reflecting member 31 may also function as a refractive member (see embodiment 2 described later).

[0040] The material of the housing 35 is not limited, but is preferably light-transmissive and flexible, and may be, for example, a resin such as polyurethane, polyethylene, silicone, acrylic, or polypropylene.

[0041] The material of the tube 10 is not limited, but is preferably flexible and translucent, and examples of the material that can be used include resins such as polyurethane, acrylic, silicone, polyethylene, styrene-based elastomers, and polybutadiene.

[0042] In this embodiment 1, light incident from the base end face 12 (see FIG. 2B) passes through the tube 10 (the portion between the inner and outer surfaces of the tube 10 that constitutes the thickness of the tube 10, hereinafter referred to as the "thickness portion of the tube 10") and exits from the tip end face 13 (see FIG. 3B), causing the light-emitting unit 30 to emit light. In order to ensure the brightness (luminous flux) of the light-emitting unit 30, it is preferable to reduce the light loss between the end face 12 and the end face 13. For this purpose, it is effective to reduce the light (leakage light) that is emitted from the outer surface of the tube 10 to the outside world between the end face 12 and the end face 13. Means for reducing leakage light include, but are not limited to, one or a combination of two or more of the following: (1) smoothing the outer surface of tube 10; (2) covering the outer surface of tube 10 with a coating material having a lower refractive index than tube 10; (3) providing a metal vapor deposition layer of silver, aluminum, etc. on the outer surface of tube 10; (4) making tube 10 into a two-layer structure consisting of an inner layer with a high refractive index and an outer layer with a low refractive index.

[0043] Regarding (1) above, it is preferable that the surface roughness Ra of the outer surface of the tube 10 is 1.2 μm or less, more preferably 1.0 μm or less, and particularly preferably 0.4 μm or less. There are no limitations on the method for smoothing the outer surface of the tube 10, but for example, when the resin material of the tube 10 is extruded through a die, a method of setting the die temperature higher than usual can be used.

[0044] Regarding (2) above, the coating material that covers the outer surface of tube 10 depends on the material of tube 10, but examples of such a coating material include silicone oil, fluorine, and UV-curable low refractive index materials. These have a lower refractive index than the resin material that constitutes tube 10, and therefore reduce the amount of light that is emitted from inside tube 10 to the coating layer. Methods for coating the outer surface of tube 10 with fluorine include, but are not limited to, a method of applying liquid fluorine to the outer surface of tube 10, a method of spraying fluorine gas onto the outer surface of tube 10, and the like.

[0045] Regarding (4) above, the two-layered tube 10 can be manufactured by co-extrusion of two materials with different refractive indices, with the high refractive index material being the inner layer and the low refractive index material being the outer layer. Alternatively, the tube 10 may have a three-layered structure consisting of inner and outer layers with low refractive index and an intermediate layer with high refractive index therebetween. The tube 10 may have a further multi-layered structure (e.g., a five-layered structure). In either case, light passes through the high refractive index layer.

[0046] In order to ensure the brightness (luminous flux) of the light-emitting part 30, it is also effective to reduce the light loss at the end faces 12, 13 of the tube 10. For this purpose, it is preferable that the end faces 12, 13 are smooth, and specifically, it is preferable that the surface roughness Ra of the end faces 12, 13 is 1.2 μm or less, more preferably 1.0 μm or less, and particularly preferably 0.4 μm or less. Such smooth end faces 12, 13 can be obtained, for example, by polishing the end faces 12, 13.

[0047] Returning to FIG. 1, the light source device 50 includes a light source (not shown) that emits light. The light is preferably visible light or near-infrared light, and the wavelength of the light is not limited, but is preferably 360 nm or more, further 630 nm or more, and 3000 nm or less, further 780 nm or less. Light with a wavelength in this range has high transmittance to the human body, is less invasive to the human body, and is highly safe. Visible light can be observed with the naked eye, so the position of the light-emitting unit 30 can be easily confirmed. Near-infrared light has better light transmittance than visible light, and can be observed through a dedicated camera such as an infrared camera. By using a camera, it is easy to keep a captured image (which may be either a still image or a video image) as a record. Specifically, light with a wavelength of 630 nm can be used as visible light, and light with a wavelength of 780 nm can be used as near-infrared light. A light-emitting diode (LED) can be used as the light source. The light source device 50 includes a socket (socket) 51 to which the connector 20 can be attached and detached. The light source is disposed so as to face the end surface 12 of the tube 10 when the connector 20 is connected to the socket 51. The light source may be provided with a lens so as to allow light to be efficiently incident on the end surface 12. The socket 51 may be provided with a switch (not shown) that turns on / off the light emission of the light source in conjunction with the attachment / detachment of the connector 20 to the socket 51. This is advantageous in reliably preventing the light emitted from the light source device 50 from entering the eyes of the surgeon or patient when the connector 20 is not connected. The light source device 50 may be provided with a plurality of sockets 51, and in this case, each of the plurality of sockets 51 may be provided with a light source that emits light of a different wavelength from each other. For example, the first socket may be provided with a light source that emits light of a wavelength of 630 nm, and the second socket may be provided with a light source that emits light of a wavelength of 780 nm. Alternatively, a single socket 51 may be configured to be able to switch between a plurality of light sources that emit light of different wavelengths (for example, a first light source that emits light of a wavelength of 630 nm and a second light source that emits light of a wavelength of 780 nm). The power source of the light source device 50 may be either a commercial power source or a battery (including a storage battery). When a battery is used as the power source, the portability of the light source device 50 can be improved and the light source device 50 can be easily made smaller and lighter.

[0048] A method of using the system 1 of the first embodiment will be described.

[0049] The tube 10 is inserted into the nasal cavity of the patient 90 in the same manner as a general oral / nasogastric tube. When the connector 20 is connected to the light source device 50, the light emitting unit 30 emits light. The light from the light emitting unit 30 passes through the human body. The surgeon can confirm the position of the light emitting unit 30 from the light emitting position on the body surface of the patient 90. The light may be observable with the naked eye depending on its wavelength. If necessary, the light emitting position may be confirmed by taking an image with an infrared camera. The connector 20 may be connected to the light source device 50 before the tube 10 is inserted into the patient 90, or may be connected to the light source device 50 when it is considered that the light emitting unit 30 has reached the stomach.

[0050] The tube 10, with a stylet already inserted into the flow path 11, may be inserted into the patient 90. The proximal end of the stylet can be led out from the connector 20. In this case, after the stylet is pulled out of the tube 10, the connector 20 is connected to the light source device 50.

[0051] The tube 10 may be inserted into the patient 90 with the optical fiber inserted into the flow path 11 so that the tip of the optical fiber reaches the light-emitting unit 30. Using the light source device 50, the tip of the optical fiber is also illuminated in addition to the light-emitting unit 30. Since the light flux from the light-emitting unit 30 is increased, the position of the light-emitting unit 30 can be confirmed more accurately. After it is confirmed that the tip of the tube 10 has reached the stomach, the optical fiber is pulled out from the tube 10.

[0052] When a stylet or optical fiber is inserted into tube 10, the flexural modulus and strength of tube 10 are increased compared to tube 10 alone, improving the insertability of tube 10 into the human body. It is preferable that the stylet or optical fiber has a flexural modulus higher than that of tube 10. A stylet or optical fiber with a flexural modulus higher than that of tube 10 is easier to assemble with tube 10 than one with a flexural modulus lower than that of tube 10.

[0053] When the tube 10 is first inserted into a patient, X-ray fluoroscopy may be used in combination to more accurately confirm the position of the tube 10. It is known that halides can be confirmed under X-ray fluoroscopy. The halide may be contained in the tube 10. Specifically, the tube 10 may be provided with X-ray contrast by coating the outer surface of the tube 10 with a halide, kneading a halide into the material constituting the tube 10, polymerizing a halide into the resin constituting the tube 10, or the like. When an optical fiber is inserted into the tube 10, the optical fiber may be provided with X-ray contrast by containing a halide in the optical fiber using the same method as above. The stylet includes a thin metal wire and has X-ray contrast. Therefore, when a stylet is inserted into the tube 10, it is not necessary to provide the tube 10 with X-ray contrast.

[0054] After confirming that the tip of the tube 10 (i.e., the light emitting unit 30) has reached the stomach, the connector 20 is connected to a connector (female connector) provided at the downstream end of the tube that conveys the nutrient (see, for example, FIG. 16A of Patent Document 3). The nutrient passes through the flow path 11 of the tube 10 and through the hole 37 of the housing 35 to be administered to the patient.

[0055] The tube 10 is left in the patient 90 for several days. During this time, the tube 10 may curl up, causing the light-emitting unit 30 to move. For this reason, at predetermined intervals (for example, immediately before administering the nutritional supplement to the patient 90), the connector 20 is connected to the light source device 50 and the light-emitting unit 30 is made to emit light to confirm its position.

[0056] As described above, according to the first embodiment, the light-emitting unit 30 provided at the tip of the tube 10 is caused to emit light, and the light from the light-emitting unit 30 is observed through the body of the patient 90. Therefore, the position of the tip of the tube 10 can be detected easily and accurately. The light emitted from the light-emitting unit 30 is different from X-rays and is highly safe. Since the reflecting member 31 reflects the light from the end surface 13 in various directions, the light from the light-emitting unit 30 can be observed from the body surface of the patient 90 regardless of the orientation of the light-emitting unit 30.

[0057] In the above-mentioned Patent Document 1, in order to confirm the position of the tube tip, it is necessary to insert an optical fiber into the tube. After inserting the tube 10 into a patient and pulling out the optical fiber, in order to reconfirm the position of the tube tip, it is necessary to reinsert the optical fiber into the tube. This may cause an accident in which the optical fiber penetrates the tube and damages the digestive tract wall. In contrast, in the present embodiment 1, the tube 10 itself serves as a light transmission path, and a light emitting unit 30 is provided at the tip of the tube 10. The optical fiber that is essential in Patent Document 1 is not necessary in the present embodiment 1. Therefore, in the present embodiment 1, the above-mentioned accident that may occur in Patent Document 1 does not occur. After inserting the tube 10 into the patient 90, the position of the tip of the tube 10 can be confirmed at any time. The system 1 of the present embodiment 1 is excellent in safety.

[0058] In the first embodiment, the tube 10 itself functions as a light guiding member, so there is no need for a light guiding member such as an optical fiber in addition to the tube 10. Therefore, the system 1 of the first embodiment has a simple configuration and is inexpensive.

[0059] In the above embodiment, the light emitting unit 30 includes a spherical reflecting member 31, and the light emitted from the end face 13 is reflected by the spherical surface 32 of the reflecting member 31. However, the reflecting member of the present invention is not limited to this.

[0060] For example, as shown in Figures 4A and 4B, the light emitting unit 30a may include a reflecting member 31a having a quadrangular pyramidal surface 32a as a reflecting surface. The quadrangular pyramidal surface 32a is arranged coaxially with the tube 10, spaced apart from and facing the end face 13. The light emitted from the end face 13 is reflected by the quadrangular pyramidal surface 32a and passes through the housing 35. The reflecting member 31a may have any pyramidal surface (preferably a regular pyramidal surface), such as a triangular pyramidal surface or a pentagonal pyramidal surface, instead of the quadrangular pyramidal surface 32a.

[0061] Alternatively, as shown in Figures 5A and 5B, the light emitting unit 30b may include a reflecting member 31b having a conical surface 32b as a reflecting surface. The conical surface 32b is disposed coaxially with the tube 10, spaced apart from and facing the end surface 13. The light emitted from the end surface 13 is reflected by the conical surface 32b and passes through the housing 35. The reflecting member 31b has a flat surface 33b opposite to the conical surface 32b, and a cylindrical surface 34b connecting the conical surface 32b and the flat surface 33b. Such a reflecting member 31b can be easily manufactured by cutting (e.g., lathe cutting) a metal material.

[0062] The reflecting member may have any convex curved surface other than the spherical surface 32 and the convex conical surfaces 32a, 32b as a reflecting surface on the side facing the end face 13. The reflecting surface of the reflecting member does not need to be a convex surface, and may be a concave surface. The reflecting member does not need to have a block shape as a whole, and may have, for example, a ring shape facing the end face 13. The ring-shaped reflecting member may be spaced apart from the end face 13, or may be in contact with the end face 13 (for example, see FIG. 6A described later). The nutrient solution flowing out from the tip of the tube 10 may pass through a central opening of the ring-shaped reflecting member.

[0063] The housing 35 itself may function as a reflecting member. For example, the housing 35 is provided with a surface facing the end face 13 as a reflecting surface. The light emitted from the end face 13 is reflected by the reflecting surface of the housing 35. The reflecting surface may have any shape, such as a spherical surface, a conical surface, or a ring shape. The reflecting surface is not limited to a convex surface, and may be a concave surface. The reflecting surface may be spaced apart from the end face 13, or may be in contact with the end face 13. When the housing 35 has a reflecting surface, the light emitting unit does not need to have a reflecting member as a separate member from the housing 35. This simplifies the configuration of the light emitting unit. Note that a part of the light incident on the reflecting surface of the housing 35 may be incident on the reflecting surface and emitted from the outer surface of the housing 35. The light may be refracted when entering the housing 35 and when exiting the housing 35. That is, the housing 35 may function as a refractive member (see embodiment 2 described later) in addition to a reflecting member. The reflective surface of the housing 35 may be provided with a metal deposition layer or various coating layers.

[0064] The reflective member may be provided in direct contact with the tube 10. In the present invention, such a reflective member is called a "direct contact type reflective member". For example, as shown in FIG. 6A, the light emitting section 30c may include a direct contact type reflective member 31c provided on the end face 13 of the tube 10. Alternatively, as shown in FIG. 6B, the light emitting section 30d may include a direct contact type reflective member 31d provided in a region near the end face 13 of the inner surface of the tube 10. Alternatively, as shown in FIG. 6C, the light emitting section 30e may include a direct contact type reflective member 31e provided in a region slightly away from the end face 13 of the inner surface of the tube 10. Examples of the direct contact type reflective member include, but are not limited to, a metal deposition layer and various coating layers, and a metal deposition layer is particularly preferable. Alternatively, a reflective member prepared as a separate member from the tube 10 may be fixed to the tube 10 to form a direct contact type reflective member. Light is incident on the direct contact type reflecting member through the thickness of the tube 10, reflected by the reflecting member, passes through the thickness of the tube 10 again, and is emitted from the tube 10 (for example, the outer surface of the tube 10). The light emitting unit including the direct contact type reflecting member has a simple configuration, and it is easy to provide the light emitting unit on the tube. In addition, the light emitting unit does not need to be provided with the housing 35. If the housing 35 is omitted, no light loss occurs due to the light passing through the housing 35. Furthermore, there is a low possibility of a situation occurring in which light loss occurs due to the presence of nutrients between the tube 10 and the reflecting member. The direct contact type reflecting member may be provided on the outer surface of the tube 10.

[0065] In general, since it is difficult to control the orientation of the light-emitting unit inside the patient's body, it is preferable that the light-emitting unit emits light in various directions including the radial direction. For this purpose, it is desirable that the light-emitting unit emits more light in a substantially radial direction rather than in the longitudinal direction of the tube 10. In FIG. 6B, a conical chamfer 13d is formed at the opening end that defines the opening at the end face 13 of the tube 10, and a reflecting member 31d is also provided on the chamfer 13d. This allows the light incident on the chamfer 13d to be reflected radially outward. The amount of light that is emitted from the end face 13 in a substantially longitudinal direction of the tube 10 is relatively small. In FIG. 6C, a reflecting member 31e is provided away from the end face 13. Most of the light is reflected by the reflecting member 31e and is emitted from the tube 10 in a substantially radial direction. The amount of light that reaches the end face 13 is small. For this reason, the amount of light that is emitted from the end face 13 in a substantially longitudinal direction of the tube 10 is relatively small.

[0066] In order to enhance the light emission from the tube 10, a low refractive index coating material, a metal deposition layer, a low refractive index material layer, etc. (hereinafter collectively referred to as "light leakage prevention layer") provided on the tube 10 to reduce leaking light may be removed from the light emission area, and in addition to this, or instead of this, fine irregularities may be provided on the outer surface of the tube 10 in the light emission area. The "fine irregularities" may be irregular irregularities such as a matte surface, or regular irregularities such as a knurled surface or a bellows shape. The fine irregularities also have a diffusing effect that causes light to be emitted from the tube 10 in various directions.

[0067] (Embodiment 2) The second embodiment differs from the first embodiment in terms of the light-emitting section. Fig. 7A is a perspective view of a light-emitting section 230 of the second embodiment. Fig. 7B is a cross-sectional view of the light-emitting section 230. As shown in Fig. 7B, the light-emitting section 230 of the second embodiment includes a refractive member 231 instead of the reflecting member 31 (see Fig. 3B) of the first embodiment. The refractive member 231 is configured by combining a first prism 233 and a second prism 237 having different refractive indices.

[0068] FIG. 8A is an exploded perspective view of the light emitting unit 230 as viewed from the tip side, and FIG. 8B is an exploded perspective view of the light emitting unit 230 as viewed from the base end side. In FIG. 8A and FIG. 8B, the housing 35 (see FIG. 7A and FIG. 7B) is omitted. The first prism 233 has a concave conical surface 234 facing the second prism 237, a flat surface 235 facing the tube 10, and a cylindrical surface 236 connecting the outer peripheral edge of the concave conical surface 234 and the outer peripheral edge of the flat surface 235. The second prism 237 has a convex conical surface 238 facing the first prism 233, and a convex curved surface (spherical surface) 239 on the opposite side to the first prism 233. The concave conical surface 234 has a shape obtained by cutting a regular square pyramidal surface by a cylindrical surface 236 coaxial with the concave conical surface. The convex conical surface 238 has the same geometric shape as the concave conical surface 234. As shown in Fig. 7B, the first prism 233 and the second prism 237 are joined and assembled so that the four side surfaces of the concave conical surface 234 and the four side surfaces of the convex conical surface 238 are in surface contact with each other. The flat surface 235 of the first prism 233 is parallel to and spaced apart from the end surface 13 of the tube 10. The cylindrical surface 236 of the first prism 233 and the convex curved surface 239 of the second prism 237 are in close contact with the inner surface of the housing 35. The first and second prisms 233, 237 are arranged coaxially with the tube 10. The outer diameters of the first and second prisms 233, 237 are not limited, but are preferably the same as or slightly larger than the outer diameter of the tube 10.

[0069] The first prism 233 and the second prism 237 are made of a hard material having light-transmitting properties. There are no limitations on the material of the first and second prisms 233, 237, but it is preferable to use a material that is generally used as an optical material, specifically, glass or a resin material such as polymethyl methacrylate resin (PMMA), polystyrene, polycarbonate, or polyolefin. The first prism 233 and the second prism 237 are made of materials with different refractive indices.

[0070] The light passing through the tube 10 and emitted from the end surface 13 is incident on the flat surface 235, and a part of the light passes through the joint surface between the concave conical surface 234 and the convex conical surface 238, the convex curved surface 239, and the housing 35 in this order, and another part of the light passes through the cylindrical surface 236 and the housing 35 in this order. The light is refracted when passing through boundary surfaces (refractive surfaces) where the refractive index changes, such as the flat surface 235, the joint surface between the concave conical surface 234 and the convex conical surface 238, the convex curved surface 239, and the cylindrical surface 236. The refractive member 231 refracts the light from the end surface 13 in various directions, so that the light from the light emitting unit 230 can be observed from the body surface of the patient 90 regardless of the orientation of the light emitting unit 230, similar to the reflecting member 31 of the first embodiment.

[0071] In the above embodiment, the shape of the joint surface (concave conical surface 234 and convex conical surface 238) between first prism 233 and second prism 237 is a part of a regular quadrangular pyramid surface, but the present invention is not limited to this. The shape of the joint surface between first prism 233 and second prism 237 may be a part of any regular polygonal pyramid surface or may be a conical surface. The shape of the joint surface between first prism 233 and second prism 237 is not limited to a conical surface, and may be a spherical surface or any curved surface. First prism 233 may have a convex surface, and second prism 237 may have a concave surface that is joined to the convex surface.

[0072] A part or all of the light incident on the refractive surface may be reflected by the cemented surface.

[0073] The refractive member may be composed of three or more prisms.

[0074] The refractive member may be composed of a single prism. For example, the refractive member may be composed of only the second prism 237. In this case, the light emitted from the end face 13 is refracted when passing through the convex conical surface 238 and the convex curved surface 239.

[0075] The second prism 237 may be integrated into the housing 35 using the same material as the housing 35. In this case, the first prism 233 may be present or may be omitted.

[0076] FIG. 9A is a cross-sectional view of another light-emitting unit 230a of the second embodiment. The light-emitting unit 230a includes a refracting member 231a made of a single prism. FIG. 9B is an exploded perspective view of the light-emitting unit 230a as viewed from the tip side. In FIG. 9B, the housing 35 (see FIG. 9A) is omitted. The refracting member (prism) 231a includes a flat surface 235a facing the tube 10, a convex conical surface 234a opposite to the flat surface 235a, and a cylindrical surface 236a connecting the outer circumferential edge of the flat surface 235a and the outer circumferential edge of the convex conical surface 234a. The convex conical surface 234a has a shape obtained by cutting a regular square pyramidal surface with a cylindrical surface 236a coaxial therewith. As shown in FIG. 9A, the flat surface 235a is parallel to and spaced from the end surface 13 of the tube 10. The cylindrical surface 236a is in close contact with the inner surface of the housing 35. The refractive member 231a is disposed coaxially with the tube 10. Light emitted from the end face 13 enters the flat surface 235a, and a portion of the light passes through the convex conical surface 234a and the housing 35 in this order, and another portion of the light passes through the cylindrical surface 236a and the housing 35 in this order. The light is refracted when passing through a boundary surface (refractive surface) where the refractive index changes, such as the flat surface 235a, the convex conical surface 234a, and the cylindrical surface 236a. The convex conical surface 234a may be any pyramidal or conical surface.

[0077] FIG. 10 is a cross-sectional view of yet another light-emitting unit 230b of the second embodiment. In the light-emitting unit 230b of FIG. 10, a refracting member (prism) 231b made of the same material as the housing 35 is integrated with the housing 35. That is, a concave conical surface 234b is provided on the inner surface of the housing 35. The concave conical surface 234b has a shape obtained by cutting a regular square pyramidal surface with a cylindrical surface (the inner peripheral surface of the housing 35) coaxial with the regular square pyramidal surface. The concave conical surface 234b is disposed coaxially with the tube 10, spaced apart from and facing the end surface 13. The light emitted from the end surface 13 is refracted when entering the concave conical surface 234b, passes through the refracting member 231b, and is emitted from the outer surface of the housing 35. The concave conical surface 234b may be any pyramidal surface or conical surface.

[0078] The shape of the refractive surface of the refractive member may be any shape, such as a convex surface (a convex curved surface or a convex conical surface), a concave surface (a concave curved surface or a concave conical surface), a flat surface, etc. The refractive surface may be provided with the fine irregularities described in the first embodiment.

[0079] Except for the above, the second embodiment is the same as the first embodiment. The description of the first embodiment also applies to the second embodiment.

[0080] (Embodiment 3) The third embodiment differs from the first and second embodiments in terms of the light emitting section. The light emitting section of the third embodiment includes a tip of the tube 10 that is formed so that light is refracted when it leaves the tube 10 and is emitted in various directions.

[0081] FIG. 11A is a side view of the light emitting unit 330 of the third embodiment, and FIG. 11B is a perspective view of the light emitting unit 330. The light emitting unit 330 does not include the reflecting members 31, 31a to 31e of the first embodiment or the refractive members 231, 231a, and 231b of the second embodiment. The light emitting unit 330 includes four wedge-shaped notches 331 formed at the tip of the tube 10. The four notches 331 are disposed adjacent to each other at equal intervals in the circumferential direction of the tube 10. Each notch 331 is composed of a first surface 331a parallel to the longitudinal direction of the tube 10 and a second surface 331b inclined relative to the first surface 331a. At the deepest part of the notch 331, the first surface 331a and the second surface 331b are connected to each other.

[0082] The light passing through the tube 10 is refracted when it is emitted from the first surface 331a and the second surface 331b. Since the first and second surfaces 331a, 331b are arranged at equal angular intervals in the circumferential direction of the tube 10, the light emitted from each of the first and second surfaces 331a, 331b travels in various directions. As in the first and second embodiments, the light from the light emitting unit 330 can be observed from the body surface of the patient 90 regardless of the orientation of the light emitting unit 330.

[0083] The light emitting unit 330 may have a housing similar to the housing 35 of the first and second embodiments. The tip of the tube 10 in which the notch 331 is formed is stored in the housing. The housing may incorporate a weight for facilitating the insertion of the tube 10 into the digestive tract. The weight is disposed at a distance from the notch 331 in the longitudinal direction of the tube 10.

[0084] The shape of the notches 331 is not limited to the above-mentioned substantially right-angled triangle, and may be any triangle, such as an isosceles triangle. Alternatively, the notches 331 may be any polygon other than a triangle (for example, a trapezoid) or any curved line. The number of the notches 331 is also not limited to that in the above-mentioned embodiment. The notches 331 do not have to be disposed at equal intervals in the circumferential direction.

[0085] In the above embodiment, the light emitting section 330 has a plurality of notches 331, but the present invention is not limited thereto. It is sufficient that a shape for refracting light is provided at the tip of the tube 10 so that the light passing through the tube 10 is emitted obliquely with respect to the longitudinal direction of the tube 10. For example, the end face at the tip of the tube 10 may be a conical surface whose inner diameter becomes larger toward the tip, or a conical surface whose outer diameter becomes smaller toward the tip. In this case as well, it is possible to refract light in various directions and emit it.

[0086] FIG. 12A is a perspective view of another light-emitting unit 330a of the third embodiment. FIG. 12B is a perspective view of the light-emitting unit 330a in cross section. The tip portion of the tube 10 is divided into a plurality of branching portions 332 by a plurality of cuts along the longitudinal direction of the tube 10. The plurality of branching portions 332 are curved in a flared shape toward the outside in the radial direction. The branching portions 332 adjacent to each other in the circumferential direction are spaced apart from each other. The light that has passed through the tube 10 is emitted from the side surface and tip surface of each branching portion 332. The light is refracted when it is emitted from each surface of the branching portion 332. Since the directions in which the plurality of branching portions 332 are curved are different from each other, the light that is emitted from each surface of each branching portion 332 travels in various directions. Regardless of the orientation of the light-emitting portion 330a, the light from the light-emitting portion 330a can be observed from the body surface of the patient 90. At the tip portion of the tube 10 where the plurality of branching portions 332 are formed, the light leakage prevention layer provided on the tube 10 may be removed.

[0087] FIG. 13A is a perspective view of yet another light-emitting unit 330b of the third embodiment. FIG. 13B is a perspective view of the light-emitting unit 330b in cross section. The tip portion of the tube 10 is curved toward the inside in the radial direction. The end face 13 of the tip of the tube 10 forms a substantially concave conical surface. The light that passes through the tube 10 is emitted from the end face 13. The light is refracted when it leaves the end face 13. Since the end face 13 is curved into a substantially concave conical surface, the light that leaves the end face 13 is first converged and then diverges, like light that leaves a convex lens. Therefore, regardless of the orientation of the light-emitting unit 330b, the light from the light-emitting unit 330b can be observed from the body surface of the patient 90.

[0088] FIG. 14A is a perspective view of yet another light-emitting unit 330c of the third embodiment. FIG. 14B is a perspective view of the light-emitting unit 330c in a cross section. Near the tip of the tube 10, a plurality of slot-shaped holes 333 are formed, which penetrate the tube 10 in the radial direction. Most of the light passing through the tube 10 exits from the side of the hole 333 (the surface that defines the hole 333 and connects the inner surface and the outer surface of the tube 10) before reaching the end face 13. The light is refracted when exiting the side. Since the plurality of holes 333 are arranged at approximately equal intervals in the circumferential direction, the light exiting the side of each hole 333 travels in various directions. The amount of light exiting from the end face 13 approximately along the longitudinal direction of the tube 10 is relatively small. Regardless of the orientation of the light-emitting unit 330c, the light from the light-emitting unit 330c can be observed from the body surface of the patient 90. The longitudinal direction of the holes 333 may be parallel to the longitudinal direction of the tube 10, but is preferably slightly inclined with respect to the longitudinal direction of the tube 10 as shown in Figures 14A and 14B. This is advantageous for diffusing light over a wide range and emitting it from the light emitting portion 330c. The number of holes 333 is arbitrary.

[0089] FIG. 15A is a perspective view of yet another light emitting unit 330d of the third embodiment. FIG. 15B is a perspective view of the light emitting unit 330d in cross section. Near the tip of the tube 10, one or more (two in this example) holes 334 of a substantially elliptical (or substantially circular) shape are formed, penetrating the tube 10 in the radial direction. A part of the light passing through the tube 10 is emitted from the side surface of the hole 334 (a surface that defines the hole 334 and connects the inner surface and the outer surface of the tube 10) before reaching the end face 13. The light is refracted when it is emitted from the side surface. Since the multiple holes 334 are arranged discretely in the circumferential direction and the side surface of each hole 334 forms a substantially elliptical (or substantially circular) closed curved surface, the light that is emitted from the side surface of each hole 334 travels in various directions. The light that is emitted from the end face 13 substantially along the longitudinal direction of the tube 10 is relatively small. Regardless of the orientation of the light-emitting unit 330d, the light from the light-emitting unit 330d can be observed from the body surface of the patient 90. The number of holes 334 is arbitrary, but the more the number, the more preferable, and specifically, the more preferable the number is four or more. The more holes 334 there are, the more widely the light can be diffused and emitted from the light-emitting unit 330d.

[0090] In the light emitting sections 330c, 330d, the holes 333, 334 may have any shape, such as an ellipse, a circle, various polygons (triangle, square, pentagon, etc.), an arc shape, or a "V" shape. The number of holes 333, 334 is arbitrary, and does not have to be multiple, and may be one. The arrangement of the holes 333, 334 is also arbitrary. When multiple holes 333, 334 are provided, they may be approximately equally spaced in the circumferential direction, or may not be approximately equally spaced in the circumferential direction. A row of multiple holes 333, 334 arranged along the circumferential direction of the tube 10 may be provided at multiple different positions in the longitudinal direction of the tube 10.

[0091] The light emitting portions 330c, 330d may have recesses that do not penetrate the tube 10, instead of the holes 333, 334 that penetrate the tube 10. The recesses may be provided on either the inner surface or the outer surface of the tube 10. Light is refracted when it leaves the surface that defines the recesses.

[0092] A high refractive index layer (a layer having a higher refractive index than the material of the tube 10) or fine irregularities as described in the first embodiment may be provided on the end surface 13 at the tip of the tube 10 and / or on the inner surface and / or outer surface of the tube 10 in the region near the tip. Alternatively, the light leakage prevention layer may be removed from the region near the tip of the inner surface and / or outer surface of the tube 10. Two or more of the provision of a high refractive index layer, provision of fine irregularities, and removal of the light leakage prevention layer may be combined. Light is refracted and emitted from the region (light emitting region) subjected to these treatments. The position of the light emitting region is arbitrary. As with the position of the direct contact type reflecting member described in the first embodiment, providing the light emitting region slightly away from the end surface 13 of the tube 10 is advantageous for emitting light in various directions, since less light reaches the end surface 13 of the tube 10.

[0093] The light emitting units 330a to 330d may each include a housing similar to the housing 35 in the first and second embodiments. The tip portion of the tube 10 configured to refract and emit light is stored in the housing. The housing may incorporate a weight for making it easier to insert the tube 10 into the digestive tract. The weight is disposed away from the tip of the tube 10 in the longitudinal direction of the tube 10.

[0094] As described above, the light emitting section of the third embodiment includes a configuration provided on the tube itself so as to emit light in various directions including the radial direction. The light emitting section of the third embodiment does not need to include the reflecting member of the first embodiment or the refractive member of the second embodiment. Therefore, the number of members constituting the light emitting section is small, and the configuration of the light emitting section is simple. In addition, the light loss that may occur due to the tube and the reflecting member or the refractive member being spaced apart does not occur in the third embodiment. However, the light emitting section of the third embodiment may be combined with the reflecting member of the first embodiment or the refractive member of the second embodiment.

[0095] Except for the above, the present embodiment 3 is the same as the embodiment 1. The description of the embodiment 1 also applies to the present embodiment 3.

[0096] The above-mentioned embodiments 1 to 3 are merely examples, and the present invention is not limited to the above-mentioned embodiments 1 to 3, and can be modified as appropriate.

[0097] In the above embodiments 1 to 3, the present invention is applied to oral and nasal tube feeding, but the present invention can be applied to any other field in which a tube is inserted into the human body. For example, the present invention can be applied to the case in which a catheter (tube) is inserted into an artery or vein. The liquid flowing through the tube can be any liquid, such as nutrients, medicine, contrast medium, or blood. The configuration of the connector, light emitting unit, tube, etc. can be changed depending on the field of application.

[0098] The connector provided at the base end of the tube is not limited to the male connector 20 shown in the above-mentioned embodiments 1 to 3. The connector does not have to have the female thread 24, and further does not have to have the outer tube 23. The shape of the male member 21 can be changed arbitrarily. The connector may be a female connector. [Industrial Applicability]

[0099] The present invention can be used in a wide range of applications in the medical field, for example, in tube feeding, particularly oral and nasal tube feeding. [Explanation of symbols]

[0100] 1. Medical tube tip position detection system 10 Tubes 11 Flow Path 12 End face of base end of tube 13 End face of tube tip 20 Connectors 21 Male member 23 Outer cylinder 24 Female thread 30, 30a~30e, 230, 230a, 230b, 330, 330a~330d Light-emitting part 31, 31a to 31e Reflective member 32 Spherical 32a,32b conical surface 35 Housing 37 Housing hole 231, 231a, 231b Refraction member 333,334 Hole through tube 50 Light source device

Claims

1. A medical tube tip position detection system for detecting the position of a tip of a tube inserted into a patient, comprising: A light source device that emits light; A hollow tube having a flow path through which a liquid can pass; a connector provided at a base end of the tube so that light from the light source device can be incident on an end face of the base end of the tube; A light emitting unit is provided at a tip of the tube, A medical tube tip position detection system, characterized in that light from the light source device is passed through the tube and emitted from the light emitting unit, and the light from the light emitting unit is transmitted to a body surface.

2. 2. The medical tube tip position detection system according to claim 1, wherein the wavelength of the light emitted by the light source device is 360 nm to 3000 nm.

3. 3. The medical tubing tip position detection system according to claim 1, wherein the connector comprises a cylindrical male member into which the tube is inserted, an outer tube surrounding the male member, and a female thread formed on an inner surface of the outer tube facing the male member.

4. 4. The system for detecting the distal end position of a medical tube according to claim 3, wherein the end face of the base end of the tube is exposed at an opening at the distal end of the male member.

5. 5. The medical tube tip position detection system according to claim 1, wherein the light emitting unit includes a reflective member that reflects the light emitted from the tube.

6. The system for detecting the tip position of a medical tube according to claim 5 , wherein the reflecting member has a spherical or conical surface on a side facing the end face of the tip of the tube.

7. 7. The system for detecting the tip position of a medical tube according to claim 5, wherein the reflecting member is made of titanium.

8. 6. The system for detecting the tip position of a medical tube according to claim 5, wherein the reflecting member is provided in direct contact with the tube.

9. 9. The system for detecting the tip position of a medical tube according to claim 8, wherein the reflective member is a vapor-deposited metal layer.

10. 5. The medical tube tip position detection system according to claim 1, wherein the light emitting unit includes a refractive member that refracts the light emitted from the tube.

11. 5. The medical tube tip position detection system according to claim 1, wherein the light emitting section includes a tip of the tube that is formed so that light passing through the tube is refracted and emitted.

12. 5. The medical tube tip position detection system according to claim 1, wherein the light emitting portion includes a hole penetrating the tube, or a recess provided on the inner or outer surface of the tube.

13. a light leakage prevention layer is provided on the outer surface of the tube to prevent light passing through the tube from emitting from the outer surface of the tube; 12. The medical tube tip position detection system according to claim 1, wherein the light leakage prevention layer is removed from the light emitting section.

14. The light emitting unit includes a housing. The medical tube tip position detection system according to any one of claims 1 to 13, wherein the housing is provided with a hole that allows liquid that has passed through the tube to flow out to the outside.

15. 15. The medical tube tip position detection system according to claim 1, wherein the light emitting unit is provided with a light-transmitting housing.

16. 16. The medical tube tip position detection system according to claim 1, wherein the surface roughness Ra of the outer surface of the tube is 1.2 μm or less.

17. 17. The medical tube tip position detection system according to claim 1, wherein an outer surface of the tube is covered with a coating material having a lower refractive index than the tube.

18. The medical tube tip position detection system according to any one of claims 1 to 17, further comprising a stylet or an optical fiber that can be inserted into or removed from the flow path of the tube.

Images