Flexible tube and application apparatus

Abstract

To provide a flexible tube and an application apparatus capable of improving operability in use while suppressing time and cost for manufacturing.SOLUTION: The flexible tube constituting a movable shaft 2B comprises: a hollow first tube 11 made of porous material; and a second tube 12 which is made of a braided body 18 using strands 17, has a main lumen 7 inside, and is inserted into the first tube 11. The first tube 11 and the second tube 12 are interconnected partially in a longitudinal direction.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a flexible tube, such as a catheter or endoscope, used in diagnosis, examination, etc., and to an application device using the same. [Background technology]

[0002] Flexible tubes such as catheters and endoscopes are medical devices that are inserted into body cavities, lumens, or blood vessels for the purpose of diagnosis or testing. Some flexible tubes are configured so that the distal end portion can be curved in any direction in response to manipulation on the proximal side, making it possible to easily advance the tube to a target position inside the body (see Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-167101 A [Patent Document 2] JP 2010-259478 A [Patent Document 3] International Publication No. 2019 / 203061 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, the catheter of Patent Document 1 has a first section and a second section with different rigidity around the main lumen to improve the bending operability of the distal end section. In this case, it is considered that the first section with low rigidity is more easily deformed than the second section with high rigidity, making it easier to bend the distal end section. However, since there is a bias in rigidity in the distal end section, the bending state may become habitual after multiple uses, which may impair operability.

[0005] In addition, the flexible endoscope in Patent Document 2 has a structure in which adjacent joint rings are arranged in a row and connected by a connecting shaft. Therefore, it can be bent in any direction with the same operability, and it is thought that it will not become habitual even after multiple uses. However, it has a large number of parts, and it takes a lot of time and effort to manufacture and is expensive.

[0006] Moreover, the movable catheter of Patent Document 3 has a sheath body made of a hollow tube, and the distal end portion is deflected by operating a wire passed through a wire lumen formed around the main lumen. The sheath body has a multi-layered tube structure including a braided layer and multiple resin layers, and is configured so that the rigidity decreases toward the distal end. However, in the case of a multi-layered structure including a braided layer and a resin layer, a decrease in flexibility is unavoidable, and it is difficult to obtain good operability.

[0007] Therefore, an object of the present disclosure is to provide a flexible tube that can further improve operability during use while reducing manufacturing effort and costs, and an application device using the same. [Means for solving the problem]

[0008] A flexible tube according to a first aspect of the present disclosure comprises a hollow first tube made of a porous material, and a second tube made of a braided body using wires, having an internal lumen, and being inserted into the first tube, wherein the first tube and the second tube are partially connected in the longitudinal direction.

[0009] In this way, the flexible tube can ensure good flexibility because it has the first tube made of a porous material. In addition, since the first tube is porous, there is a concern that the holes will become deformed after multiple uses, causing the flexible tube to become shorter, but such deformation is suppressed by the second tube made of a braid supporting the first tube. In addition, since the first tube and the second tube are partially connected, they are less likely to hinder each other's deformation when bent, and good flexibility can be ensured. Furthermore, in the case of the flexible tube described above, the number of parts is small, so manufacturing effort is reduced and costs can be reduced.

[0010] In addition, the flexible tube of the second aspect may be the first aspect, in which one ends of the first tube and the second tube are connected to each other by adhesive and the other ends of the first tube and the second tube are connected to each other by adhesive, and the other parts are not connected.

[0011] This allows the shape of the first tube made of a porous material to be stably restored by the support of the second tube made of a braided body, while limiting the adhesive to preventing the first tube from deforming by limiting the adhesive to a certain portion, thereby achieving both high flexibility and stable shape restoration.

[0012] In addition, the flexible tube according to a third aspect may be the flexible tube of the first aspect, wherein the porous material constituting the first tube is made of expanded polytetrafluoroethylene (ePTFE).

[0013] Expanded polytetrafluoroethylene is obtained by expanding polytetrafluoroethylene, and has properties completely different from those of polytetrafluoroethylene. For example, it is chemically inert, has a low coefficient of friction, and is a porous material that is extremely flexible. Therefore, by applying this to the first tube in the above-mentioned configuration, it is possible to further improve operability.

[0014] In addition, in the flexible tube according to a fourth aspect, in the third aspect, the expanded polytetrafluoroethylene may have a porosity of 30% or more and 50% or less.

[0015] This ensures high flexibility while also ensuring shape recovery so that the hole does not easily become streaked even after multiple uses, thereby preventing the flexible tube from becoming shorter in size after multiple uses.

[0016] Further, in the flexible tube according to a fifth aspect, in the first aspect, the wire constituting the second tube may have a rectangular cross section perpendicular to a longitudinal direction of the wire.

[0017] When the flexible tube is bent during use, the two adjacent wires in the braid of the second tube approach each other at the inner diameter side of the bent shape. If one of the two wires approaches the other, they may come into contact with each other and interfere with each other, making it difficult for the flexible tube to return to a straight shape. In response to this, by using wires with a rectangular cross section as described above, it is possible to prevent one wire from running over the other, thereby improving the shape recovery of the flexible tube.

[0018] The applied device according to a sixth aspect includes a shaft body having an internal lumen, and the flexible tube according to any one of the first to fifth aspects connected to the tip of the shaft body.

[0019] Such applied equipment can reduce manufacturing effort and costs while further improving operability during use. Effect of the Invention

[0020] According to the present disclosure, it is possible to realize a flexible tube and applied equipment that can further improve operability during use while reducing manufacturing effort and costs. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a front view showing an endoscope to which a flexible tube according to the present embodiment is applied. [Diagram 2] FIG. 2 is a side view of the endoscope shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view of the shaft body. [Figure 4] FIG. 4 is a cross-sectional view of a movable shaft made of a flexible tube. [Diagram 5] FIG. 5 is a schematic diagram showing the configuration of the movable shaft. [Figure 6] FIG. 6 is a graph showing the relationship between the number of trials and the overall length of a flexible tube when the flexible tube is repeatedly deformed from a straight state to a bent state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] A flexible tube and an application device according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that the following describes an aspect in which the flexible tube is applied to an endoscope, which is an example of an application device. However, the endoscope is only an example of an application device to which the flexible tube can be applied, and the application device may also be a catheter or other examination tool.

[0023] As shown in the front view of Fig. 1 and the side view of Fig. 2, an endoscope 1 according to this embodiment includes a shaft 2, a tip 3 attached to one end of the shaft 2, and a handpiece 4 attached to the other end of the shaft 2. In the following, the direction in which the tip 3 is located relative to the shaft 2 will be referred to as the "distal side" or "distal side", and the opposite direction in which the handpiece 4 is located relative to the shaft 2 will be referred to as the "base side" or "proximal side".

[0024] The tip 3 is hollow and cylindrical, and is equipped therein with an imaging device, a light source, and the like. The imaging device has an optical system, such as a lens, and an imaging element, such as a CCD or CMOS. The light source is, for example, a light-emitting diode (LED). Therefore, when the endoscope 1 is inserted into a lumen in the body, the imaging device can capture an image while illuminating the direction in which the tip 3 travels with the light source, and the state of the lumen in the body can be visually confirmed on an external monitor.

[0025] The shaft 2 comprises a shaft body 2A and a movable shaft 2B. The shaft body 2A constitutes the base end portion of the shaft 2, and has a dimension longer than half the overall length of the shaft 2. The movable shaft 2B constitutes the tip portion of the shaft 2, and is connected to the tip of the shaft body 2A. Inside the shaft 2, a main lumen 7 and a sub-lumen 8 are formed across both the shaft body 2A and the movable shaft 2B (see Figures 3 and 4).

[0026] FIG. 3 is a cross-sectional view of the shaft body 2A. The shaft body 2A is made of a tube 10 with a hollow structure, and the tube 10 has a main lumen 7 with a circular cross section that penetrates from the tip to the base end at the center of a cross section perpendicular to the longitudinal direction. The tube 10 also has a plurality of sub-lumens 8 that extend parallel to the main lumen 7 and penetrate from the tip to the base end at positions surrounding the main lumen 7. The tube 10 has one such main lumen 7 and 12 sub-lumens 8 (#1 to #12). The sub-lumens 8 are arranged at approximately equal intervals in the circumferential direction centered on the main lumen 7. The number of sub-lumens 8 that the tube 10 has is not limited to 12, and may be 11 or less or 13 or more.

[0027] The tube 10 of the shaft body 2A is made of a resin material such as nylon, and has flexibility and pushability to the extent that the endoscope 1 can be inserted into a curved lumen in the body. To ensure pushability, the shaft body 2A may be configured such that the tube 10 made of a resin material is reinforced with, for example, a braided body made of metal wire. Although the shaft body 2A according to this embodiment has a single-layer structure made of only the tube 10, it may have a multi-layer structure, for example, by providing a protective layer covering the outer surface of the tube 10.

[0028] FIG. 4 is a cross-sectional view of a movable shaft 2B made of a flexible tube. The movable shaft 2B is configured independent of the shaft body 2A, and has a lower bending rigidity and higher flexibility than the shaft body 2A. The movable shaft 2B according to this embodiment is configured of a flexible tube according to the present disclosure. That is, the movable shaft 2B includes a hollow first tube 11 made of a porous material, and a second tube 12 made of a braided body using wires, having a main lumen 7 therein, and being inserted into the first tube 11. Note that the braided body is not shown in the cross-sectional view of FIG. 4.

[0029] The first tube 11 has a hollow structure and has twelve sublumens 8 (#1-12) arranged at approximately equal intervals in the circumferential direction. The sublumens 8 are formed penetrating from the distal end to the proximal end of the first tube 11. The second tube 12 has a hollow structure and has a main lumen 7 with a circular cross section formed in the center of a cross section perpendicular to the longitudinal direction, penetrating from the distal end to the proximal end.

[0030] In Fig. 3, the twelve sublumens 8 of the shaft body 2A are numbered #1 to #12 to distinguish them from one another, and in Fig. 4, the twelve sublumens 8 of the movable shaft 2B are numbered #1 to #12 to distinguish them from one another. The sublumens 8, 8 that are numbered the same in Figs. 3 and 4 are located at the same circumferential positions.

[0031] Fig. 5 is a schematic diagram showing the configuration of the movable shaft 2B (flexible tube). In Fig. 5, in addition to an external view of the movable shaft 2B, windows W1 to W3 show enlarged views of each part. Specifically, the window W1 shows an enlarged vertical cross-sectional view of the tip part of the movable shaft 2B, the window W2 shows an enlarged vertical cross-sectional view of the base part, and the window W3 shows an enlarged external view of the inner second tube 12 with the first tube 11 opened at the middle part. Here, the vertical cross-sectional view means a cross-sectional view when each part is cut by a plane including the axis of the movable shaft 2B.

[0032] 5, the first tube 11 and the second tube 12 are partially connected in the longitudinal direction. In the case of this embodiment, more specifically, the tip portions of the first tube 11 and the second tube 12 are connected to each other by adhesive 15 as shown in window W1, and the base portions of the first tube 11 and the second tube 12 are connected to each other by adhesive 15 as shown in window W2. On the other hand, the other portions are not connected to each other.

[0033] The application area of ​​the adhesive 15 is an area covering the entire circumference in the circumferential direction at each of the tip portion and the base portion. However, the application area of ​​the adhesive 15 in the circumferential direction is not limited to the area covering the entire circumference, and may be a part of the entire circumference. Meanwhile, the application area in the longitudinal direction is an area having a dimension sufficiently shorter than the overall length of the movable shaft 2B. The specific dimension of the adhesive 15 in the longitudinal direction can be appropriately determined according to the mobility required for the movable shaft 2B (in other words, ease of bending) and other required specifications. Therefore, although not particularly limited, it can be typically 2 mm or more and 10 mm or less, and more preferably 5 mm or more and 8 mm or less.

[0034] The adhesive 15 is not particularly limited as long as it has adhesive properties to the inner circumferential surface of the first tube 11 and the outer circumferential surface of the second tube 12. Since the first tube 11 according to the present disclosure is made of ePTFE as described below, it is possible to use an adhesive capable of bonding PTFE to other materials, such as PTFE adhesives of model numbers 6-5662-02 or 6-5662-03 manufactured by AS ONE Corporation.

[0035] 5, the portion between the first tube 11 and the second tube 12 where the adhesive 15 is not present is illustrated as if there were a gap therebetween, but this is for convenience of explanation. Therefore, the portion does not necessarily need to have a gap therebetween, and for example, the inner peripheral surface of the first tube 11 and the outer peripheral surface of the second tube 12 may be in contact with each other.

[0036] The first tube 11 is made of a porous material as described above. For example, a nonwoven fabric member made of synthetic resin fibers can be used as the porous material. Such a porous material is soft and has good flexibility. The first tube 11 according to this embodiment uses expanded polytetrafluoroethylene (ePTFE) as the porous material. This makes it possible to ensure extremely good flexibility due to the nonwoven fabric structure, and also to realize chemical stability and reduced friction.

[0037] Furthermore, the expanded polytetrafluoroethylene used for the first tube 11 is not limited in porosity, but from the viewpoint of flexibility and shape recovery, a porosity in the range of, for example, 30% to 50% can be used, and even within this range, a porosity in the range of 35% to 45% can be preferably used. This makes it possible to achieve a particularly optimal balance between flexibility and shape recovery in the first tube 11 that uses expanded polytetrafluoroethylene.

[0038] There is no particular limitation on the method for measuring the porosity of ePTFE. For example, if the specific gravity of void-free (completely solid) ePTFE is Gx (e.g., 2.20) and the measured specific gravity of the target ePTFE is Gy, the porosity can be calculated using the following formula (1). Porosity (%)=(1-Gy / Gx)×100 (Formula 1) Here, the specific gravity may be measured in accordance with, for example, JIS K7222.

[0039] On the other hand, the second tube 12 is made of a braid using wires as described above. More specifically, one example of the configuration is that the braid 18 made by braiding wires 17 is sandwiched between an inner layer made of expanded polytetrafluoroethylene and an outer layer made of thermoplastic elastomer, and the braid 18 is welded by applying pressure from the inside and outside while heating.

[0040] The wires 17 constituting the braid 18 may be metal wires such as stainless steel, or wires made of synthetic resin such as nylon or polyetherketone. The shape of the wires 17 is not particularly limited. However, for example, a wire 17 having a rectangular cross section perpendicular to the longitudinal direction is preferable. That is, when the movable shaft 2B is curved, adjacent wires 17 approach each other on the inner diameter side. At this time, if one wire 17 rides over the other wire 17, the contact friction between them may prevent the movable shaft 2B from returning to a straight shape. Therefore, a wire 17 having a rectangular cross section is preferable from the viewpoint of preventing the adjacent wires 17 from riding over each other.

[0041] The width dimension D1 of the wire 17 (the dimension perpendicular to the longitudinal direction of the wire 17 and perpendicular to the radial direction of the movable shaft 2B) can be appropriately selected, for example, from 0.076 mm to 0.100 mm, and more preferably from 0.088 mm or less within this range. The thickness dimension D2 of the wire 17 can be appropriately selected, for example, from 0.0127 mm to 0.0200 mm, and more preferably from 0.0164 mm or less within this range. The pitch D3 of adjacent wires 17 can be appropriately selected, for example, from 1.6 mm to 3.0 mm, and more preferably from 2.5 mm or less within this range. This further optimizes the balance between the shape restoring property (e.g., shrinkage prevention effect) and the ease of bending (i.e., flexibility) when the movable shaft 2B is bent multiple times.

[0042] Such a second tube 12 is inserted into the first tube 11, as shown in Figures 4 and 5. A main lumen 7 is formed inside the second tube 12, and a plurality of sub-lumens 8 are formed in the first tube 11. The main lumen 7 has an inner diameter larger than that of the sub-lumens 8, and when the endoscope 1 is in use, electrical wiring and a channel tube through which treatment tools such as forceps are passed are inserted through the main lumen 7. As will be described later, a manipulation wire 9 is inserted through some of the sub-lumens 8.

[0043] As shown in window W1 in Fig. 5, a hard member 20 is fixed to the tips of the first tube 11 and the second tube 12 at the tip of the movable shaft 2B. The hard member 20 is a hard member made of synthetic resin, metal, or the like, and has an approximately annular shape. The hard member 20 has a central hole 21 corresponding to the main lumen 7 in its central portion, and has twelve peripheral holes 22 corresponding to the sub-lumens 8 around the central hole 21. The central hole 21 constitutes the tip of the main lumen 7, and the peripheral holes 22 constitute the tip of the sub-lumen 8.

[0044] The operation wires 9 are made of a metal material such as medical stainless steel, and in this embodiment, four operation wires 9 (9a, 9b, 9c, 9d) are inserted into the sub-lumen 8. Each operation wire 9 is folded back at the center in the longitudinal direction to form a bifurcated shape. That is, the operation wire 9 has two extension portions extending from each end and a folded back portion connecting these extension portions. The extension portions of the operation wire 9 are inserted into the two sub-lumens 8, 8, and the folded back portions are fixed to the hard member 20.

[0045] In other words, the operation wire 9 has a folded-back portion fixed between two adjacent peripheral holes 22 in the hard member 20. One extended portion is inserted from one of the two adjacent peripheral holes 22 into the corresponding sub-lumen 8 of the movable shaft 2B, and an end of the extended portion is positioned so as to protrude toward the proximal end side from the proximal end of the shaft 2. The other extended portion is inserted from the other of the two adjacent peripheral holes 22 into the corresponding sub-lumen 8 of the movable shaft 2B, and an end of the extended portion is positioned so as to protrude toward the proximal end side from the proximal end of the shaft 2.

[0046] Moreover, each extension portion is inserted into sublumens 8 at different positions in the circumferential direction on the movable shaft 2B and the shaft body 2A. For example, in the case of the operation wire 9a, one extension portion passes through the #1 sublumen 8 on the movable shaft 2B and the #11 sublumen 8 on the shaft body 2A. The other extension portion passes through the #2 sublumen 8 on the movable shaft 2B and the #4 sublumen 8 on the shaft body 2A.

[0047] In this way, the operation wire 9a passes through adjacent sub-lumens 8 #1 and #2 in the movable shaft 2B, whereas in the shaft main body 2A, it passes through sub-lumens 8 #11 and #4 that are nearly opposed across the axis of the shaft main body 2A. As a result, when the operation wire 9a is pulled, the operation force acts on a position offset from the axis in the movable shaft 2B, whereas the operation force acts on a position opposed to the axis in the shaft main body 2A. As a result, the movable shaft 2B bends with good responsiveness, whereas the shaft main body 2A is difficult to bend when operated.

[0048] The same is true for the other operation wires 9b to 9d. Specifically, as shown in Figs. 3 and 4, the operation wire 9b passes through the sub-lumens 8 #4 and #5 in the movable shaft 2B, and through the sub-lumens 8 #2 and #7 in the shaft main body 2A. The operation wire 9c passes through the sub-lumens 8 #7 and #8 in the movable shaft 2B, and through the sub-lumens 8 #5 and #10 in the shaft main body 2A. The operation wire 9d passes through the sub-lumens 8 #10 and #11 in the movable shaft 2B, and through the sub-lumens 8 #8 and #1 in the shaft main body 2A.

[0049] 1 and 2, the endoscope 1 includes a handpiece 4. The handpiece 4 includes a housing 30, and a first operating handle 31 and a second operating handle 32 that are rotatably provided relative to the housing 30. The housing 30 has a roughly rectangular parallelepiped shape, and a kink-resistant tube 33 is provided at one end in the longitudinal direction thereof so as to communicate between the inside and the outside of the housing 30. The base end of the shaft 2 is attached to the housing 30 while being inserted into the kink-resistant tube 33.

[0050] The first operating handle 31 and the second operating handle 32 are provided to protrude from the housing 30 so that their rotation axes are concentric. In addition, the first operating handle 31 is positioned farther from the housing 30 than the second operating handle 32, and the first operating handle 31 is configured to have a smaller maximum outer diameter than the second operating handle 32. Therefore, it is easy for an operator to operate the first operating handle 31 and the second operating handle 32.

[0051] The respective ends of the operation wires 9a and 9c are connected to the rotating shaft of the first operation handle 31. When the first operation handle 31 is rotated in one direction, the operation wire 9a is pulled toward the base end, and when the first operation handle 31 is rotated in the other direction, the operation wire 9c is pulled toward the base end. Moreover, the respective ends of the operation wires 9b and 9d are connected to the rotating shaft of the second operation handle 32. When the second operation handle 32 is rotated in one direction, the operation wire 9b is pulled toward the base end, and when the second operation handle 32 is rotated in the other direction, the operation wire 9d is pulled toward the base end.

[0052] In this way, when the first operating handle 31 or the second operating handle 32 is rotated, one of the four operating wires 9 is pulled toward the base end. Therefore, the movable shaft 2B can be bent in any corresponding direction among up, down, left, and right. Also, when both the first operating handle 31 and the second operating handle 32 are rotated, two of the four operating wires 9 are pulled toward the base end. Therefore, the movable shaft 2B can be bent in any diagonal direction between up, down, left, and right.

[0053] As described above, the endoscope 1 includes the movable shaft 2B made of the flexible tube according to the present disclosure. Therefore, high flexibility and stable shape recovery are compatible. In particular, the contraction rate of the movable shaft 2B in the axial direction when used multiple times can be reduced, and shortening of the movable shaft 2B in the axial direction can be suppressed.

[0054] 6 is a graph showing the relationship between the number of trials and the total length of a flexible tube when the flexible tube is repeatedly deformed from a straight state to a bent state. Graph G1 shows the test results of an example in which the flexible tube according to the present disclosure is used. Graph G2 shows the test results of a comparative example in which the flexible tube according to the present disclosure is configured without the second tube (consisting only of the first tube).

[0055] The flexible tube used in the Example had a length of 75 mm in the initial state (number of trials: zero). The flexible tube used in the Comparative Example had a length of 73 mm in the initial state. The number of trials was 200 for both the Example and the Comparative Example. As a result, at the end of the 200 trials, the flexible tube in the Comparative Example had shrunk from 73 mm to 69 mm, with a shrinkage rate of approximately 5.5%, whereas the flexible tube in the Example had shrunk from 75 mm to 74 mm, with a shrinkage rate of approximately 1.3%.

[0056] (Modification) The above-mentioned embodiment is an example of a specific embodiment of the flexible tube according to the present disclosure, and the flexible tube according to the present disclosure is not limited to this and can have other embodiments. For example, in the movable shaft 2B, the adhesive 15 connecting the first tube 11 and the second tube 12 is provided at one location each at the tip and base end of the movable shaft 2B, but this is not limited to this. It is also possible to use the adhesive 15 to bond the first tube 11 and the second tube 12 at two locations each, or at three or more locations each at either or both of the tip and base end.

[0057] In addition, the bonding positions with the adhesive 15 are not limited to the tip and base ends. For example, the adhesive may be applied to a position a predetermined distance from the tip to the base end side in the longitudinal direction of the movable shaft 2B, or a position a predetermined distance from the base end to the tip side. [Industrial Applicability]

[0058] The present disclosure can be applied to a flexible tube and an application device using the same. [Explanation of symbols]

[0059] 1 Endoscope (applied equipment) 2 Shaft 2A Shaft body 2B Movable shaft (flexible tube) 7 Main Lumens 8 Sublumen 11 1st Tube 12 2nd Tube 15. Glue 17 Wire 18 Braid body

Claims

1. The device comprises a hollow first tube made of a porous material, and a second tube made of a braid using wires, having an internal lumen, and being inserted into the first tube; The first tube and the second tube are partially connected in the longitudinal direction. Flexible tubing.

2. The first tube and the second tube are connected to each other at one end and at the other end by an adhesive, and other portions are not connected. The flexible tube of claim 1 .

3. The porous material constituting the first tube is made of expanded polytetrafluoroethylene (ePTFE); The flexible tube of claim 1 .

4. The expanded polytetrafluoroethylene has a porosity of 30% or more and 50% or less. The flexible tube of claim 3.

5. The wire constituting the second tube has a rectangular cross section perpendicular to the longitudinal direction of the wire. The flexible tube of claim 1 .

6. A shaft body having an internal lumen; The flexible tube according to any one of claims 1 to 5, which is connected to a tip of the shaft body; An application device comprising:

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