A tube having a double helix structure with alternating spiral-shaped soft sections and spiral-shaped hard sections.

Abstract

To provide a tracheostomy tube to be inserted into trachea through tracheostomy opening, which is used when tracheostomy is performed.SOLUTION: A tube and an internal cylinder 8 have a double spiral structure 32 having alternately a spiral soft part 13 and a spiral hard part 11.SELECTED DRAWING: Figure 3

Description

[[Technical Field]]

[0001] The present invention relates to a tube having a double helix structure in which helical soft portions and helical hard portions are alternately arranged, an inner cylinder having said structure, and a medical instrument including said inner cylinder, particularly to a tracheostomy tube used after tracheostomy and inserted into the trachea through the tracheostoma.

[0002] (Tracheostomy Tube) Tracheostomy tubes are used for patients with insufficient respiratory function. To ensure respiratory function, a tracheostomy tube is inserted into the trachea through a tracheostoma formed by tracheostomy and left in place. In this way, inhaled air is delivered from the outside to the lungs through the tracheostomy tube and the trachea, and exhaled air is discharged from the lungs to the outside through the trachea and the tracheostomy tube, enabling the patient to breathe adequately.

[0003] Tracheostomy tubes are available in cuffed and uncuffed types. For the cuffed type, inflating the cuff can block the gap between the tracheostomy tube and the trachea. Therefore, when a ventilator is connected to the tracheostomy tube, the air delivered from the ventilator can be reliably delivered to the lungs.

[0004] Tracheostomy tubes are classified into single-lumen types and double-lumen types, which are selectively used according to the patient's condition. The single-lumen type has a simple structure and the advantage of a large inner lumen. The double-lumen type consists of an outer cannula and an inner cannula that can be inserted and removed, and the inner cannula is replaceable. Therefore, it is used for patients who produce a large amount of sputum and are prone to blockage of the tracheostomy tube. Furthermore, tracheostomy tubes are available in types with a side opening and types without a side opening, which are selectively used according to the patient's condition. For the type with a side opening, exhaled air can escape toward the glottis, enabling phonation.

[0005] In a double-lumen tracheostomy tube, inserting the inner cannula into the inner lumen of the outer cannula narrows said inner lumen. Therefore, the inner cannula is required to have a small wall thickness so as not to reduce ventilation function, and to be inserted in close contact with the inner lumen of the outer cannula.

[0006] The inner surface of the inner tube needs to be smooth to prevent sputum buildup and narrowing. Furthermore, a suction catheter may be inserted to remove sputum from within the tracheostomy tube or trachea, or an endoscope may be inserted to observe the condition of the trachea. The inner tube surface needs to be smooth to prevent the tips of these catheters from getting caught. In tracheostomy tubes with an arc-shaped tube section, flexibility in the inner cannula is not required, so a rigid material with a smooth inner surface can be used. However, if the tube section has curves other than an arc shape (including straight sections), flexibility in the inner cannula is required, so a bellows-like tube with many irregularities on the inner surface of the inner cannula is used.

[0007] When inserting a thin-walled inner tube into the lumen of an outer tube of a tracheostomy tube, frictional resistance from the contact between the outer surface of the inner tube and the lumen of the outer tube applies a compressive force to the inner tube in its axial direction (the direction of insertion). Therefore, the inner tube must have sufficient strength to prevent it from shrinking, twisting, or buckling.

[0008] Patent Document 1 discloses that "the inner cylinder has a smooth inner surface and is strong, and includes reinforcing elements that extend in the longitudinal direction of the inner cylinder across multiple corrugations to increase the strength against compression in the axial direction of the inner cylinder during insertion." The corrugation differs in structure from the "double helix structure having alternating helical soft parts and helical hard parts" of the present invention, and furthermore, there is a direction in which the inner cylinder is difficult to bend. Patent Document 2 discloses "an inner cylinder in which fibers are included in a corrugated plastic layer so that the inner cylinder does not shrink, twist, or buckle when inserted." The corrugation differs in structure from the "double helix structure having alternating spiral soft and spiral hard sections" of the present invention, and furthermore, the inner cylinder is entirely formed of soft material. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Special table number 2016-508405 [Patent Document 2] U.S. Patent Application Publication No. 2010 / 0108075 [Overview of the project] [Problems that the invention aims to solve]

[0010] In conventional tracheostomy tubes, the inner tube inserted into the lumen of the outer tube, which consists of a straight section and a roughly arc-shaped section, experiences increased frictional resistance when the outer surface of the inner tube comes into contact with the inner surface of the outer tube during insertion. This increases the compressive force applied to the inner tube in the longitudinal direction, which can cause the inner tube to shrink, twist, or buckle. Therefore, in these tracheostomy tubes, reinforcing elements were used to suppress the shrinking, twisting, and buckling of the inner tube. [Means for solving the problem]

[0011] The present invention solves the problem and completes the present invention by having a double helix structure (32) in which a helical soft portion (13) and a helical hard portion (11) are alternately located in the tube and inner cylinder (8) of the present invention.

[0012] In other words, the present invention is as follows: 1. A tube having a double helix structure (32) in which a spirally flexible portion (13) and a spirally rigid portion (11) are alternately arranged. 2. An inner cylinder (8) having a double helix structure (32) in which a spiral-shaped soft part (13) and a spiral-shaped hard part (11) are alternately arranged, and which can be inserted into and removed from the outer cylinder. 3. A medical device (1) comprising an outer cylinder (2) and an inner cylinder (8) that can be inserted into and removed from the lumen of the outer cylinder (2), The outer cylinder (2) includes a substantially arc-shaped portion (6), The inner cylinder (8) has a pipe (35), wherein the pipe (35) has a double helix structure (32) in which a spiral soft portion (13) and a spiral hard portion (11) alternately are present in all of the portions that are in contact with the lumen of the substantially arc-shaped portion (6) of the outer cylinder (2). Medical device (1). 4. The medical device (1) described in item 3 above, wherein the medical device (1) is a tracheostomy tube. 5. The medical device (1) described in item 3 or 4 above, wherein the helical rigid part (11) is substantially V-shaped. 6. The medical device (1) according to any one of items 3 to 5 above, wherein the spiral soft part (13) has a groove (14). 7. A medical device (1) according to any one of items 3 to 6 above, wherein a ring-shaped rigid part (29) is installed at the tip of the double helix structure (32). 8. The medical device (1) described in paragraph 7 above, wherein the helical hard portion (11) is substantially V-shaped, the helical soft portion (13) has grooves (14), and the annular hard portion (11) located at the tip of the double helix structure (32) is substantially V-shaped. 9. A medical device (1) as described in any one of items 3 to 7 above, wherein the width (16) of the spiral rigid part is X, and the width (17) of the spiral soft part is 0.3X to 0.5X. 10. A medical device (1) as described in any one of items 3 to 9 above, wherein the thickness of the helical rigid part (33) is Y, and the thickness of the helical soft part (34) is 0.8Y or less. [Effects of the Invention]

[0013] The present invention provides a medical device that suppresses shrinkage, twisting, and buckling of the inner cylinder or tube inserted into the lumen of the outer cylinder, etc. [Brief explanation of the drawing]

[0014] [Figure 1] (1) Front view of the tracheostomy tube. (2) Side view of the tracheostomy tube (inflation tube, seal valve, and suction tube are omitted). [Figure 2](1) A side view of the outer cannula of a tracheostomy tube, (2) a side view of an outer cannula of a tracheostomy tube (with a side hole) [Figure 3] (1) A side view of the inner cannula, (2) an enlarged cross-sectional view (side view) of the wall thickness of the inner cannula [Figure 4] A side view of a state where a one-way valve is connected to an outer cannula of a tracheostomy tube (with a side hole). MODE FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, the present invention will be described with reference to the drawings, but the present invention is not limited to the medical instrument described in the drawings. In the following description, a view of FIG. 1 as seen from the front is defined as a front view, and the up and down direction of the drawing when viewing FIG. 1 from the front is taken as the up and down direction of the medical instrument (1) of the present invention. In addition, the side indicated by reference numeral 3 in FIG. 2 is defined as the proximal end side of the medical instrument (1), and the side indicated by reference numeral 4 in FIG. 2 is defined as the distal end side of the medical instrument (1). The direction extending from the proximal end side to the distal end side is defined as the extension direction of the medical instrument (the longitudinal axis direction, which is the direction in which the inner cannula is inserted into the outer cannula).

[0016] (Tube) The tube of the present invention has a double helical structure (32) in which helical soft portions (13) and helical hard portions (11) are alternately arranged, and in particular, has the double helical structure (32) in the thick-walled portion of the tube. In addition, it is preferable that the helical soft portions and the helical hard portions are alternately arranged without gaps. Also, the tube of the present invention preferably does not include the reinforcing elements described above.

[0017] The inner cannula (8) of the present invention can be inserted into and removed from an outer cannula, and has a double helical structure (32) in which helical soft portions (13) and helical hard portions (11) are alternately arranged, and in particular, has the double helical structure (32) in the thick-walled portion of the tube.

[0018] (Medical Instrument) The medical instrument (1) of the present invention is not particularly limited, and targets a tracheostomy tube or the like, and has the following configuration. It comprises an outer cannula (2) and an inner cannula (8) that can be inserted into and removed from the lumen of the outer cannula (2). The outer cylinder (2) includes at least a substantially arc-shaped portion (6), and optionally a straight base portion (5-1) and a straight tip portion (5-2). The inner cylinder (8) includes at least a pipe (35) and, if necessary, a connector (10). The pipe includes at least a double helix structure, preferably including an annular rigid portion at the tip of the double helix structure. When the inner cylinder is inserted into the outer cylinder, the portion of the outer cylinder from near the base end of the substantially arc-shaped portion towards the tip must have a double helix structure. The portion of the outer cylinder from near the base end of the substantially arc-shaped portion towards the base end may have a double helix structure or may be a straight cylinder. In this specification, "to be in contact with" does not mean contacting the entire area, but rather contacting part or all of a certain area (e.g., 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, 100%). Furthermore, the medical device (1) of the present invention preferably does not include the reinforcing elements described above.

[0019] (Tracheostomy tube) A tracheostomy tube, an example of the medical device (1) of the present invention, is illustrated in Figures 1, 2, and 4. The tracheostomy tube includes an outer tube (2) and an inner tube (8) that can be inserted into and removed from the outer tube (2). The outer tube (2) includes at least a substantially arc-shaped section (6) and, if necessary, a proximal straight section (5-1), an apical straight section (5-2), a double-tube lock receiver (20) provided on the proximal straight section (5-1) side, and a neck plate (21) for securing the outer tube (2) to the patient's neck. The straight tip section (5-2) is provided with a cuff (22) as needed. The cuff (22) is an inflatable balloon that is supplied with air from the seal valve (23) through the inflation tube (24) to inflate the cuff (22), thereby eliminating the gap between the trachea and the tracheostomy tube, preventing aspiration into the lower airway and preventing air supplied from the ventilator from leaking into the upper airway. If the cuff (22) is provided on the outer cylinder (2), a suction tube (25) for aspirating saliva and other fluids accumulated at the top of the cuff may also be provided. In addition, types with a side hole (7) on the back side of the outer cylinder (2) may be equipped with a lock receiver (19) for a one-way valve (18) to which a one-way valve can be connected to facilitate vocalization.

[0020] {Outer cylinder (2)} As described above, the outer cylinder (2) includes at least a substantially arc-shaped portion (6), and optionally a straight base portion (5-1) and a straight tip portion (5-2), and is formed of a material known to the public.

[0021] {Inner cylinder(8)} The inner cylinder (8) includes, as described above, at least a pipe (35) and optionally a connector (10). The pipe (35) includes at least a double helix structure (32) and optionally a straight cylinder (28), and is formed of a material known to the present day. The pipe (35) needs to be flexible at least in the portion that contacts the lumen of the substantially arc-shaped portion (6) of the outer cylinder (2). On the other hand, the portion of the pipe (35) that contacts the straight base portion (5-1) of the outer cylinder (2) does not necessarily need to be flexible. The connector (10) may be formed in a cylindrical or truncated cone shape from a material known to the present day (e.g., a hard material). The straight cylinder (28) may be formed in a cylindrical shape from a material known to the present day (for example, a hard material). One feature of the medical device (1) of the present invention is that the spiral rigid part (11) and the straight cylinder (28) may be integrally molded from the same material. Furthermore, in the medical device (1) of the present invention, the connector (10), the helical rigid part (11), and the straight cylinder (28) may be integrally molded from the same material.

[0022] 1) Shape of the spiral-shaped hard part When the inner cylinder (8) is inserted into and removed from the outer cylinder (2), in order to reduce the insertion and removal resistance caused by contact between the inner surface of the outer cylinder (2) and the helical rigid part (11) of the inner cylinder (8), it is preferable to make the shape of the helical rigid part (11) of the inner cylinder (8) that contacts the inner surface of the outer cylinder (2) into a roughly V-shape in order to reduce the contact area with the inner surface of the outer cylinder (2). Specifically, the helical rigid part (11) is made of a hard material and forms a smooth, roughly V-shape (12) with a radius of R0.5 mm.

[0023] 2) Width of the spiral hard part and width of the spiral soft part When the inner cylinder (8) is inserted into the outer cylinder (2), the inner surface of the outer cylinder (2) and the outer surface of the inner cylinder (8) come into contact, resulting in frictional resistance during insertion of the inner cylinder (8). The insertion resistance varies depending on the ratio of the width of the helical rigid portion (16) to the width of the helical flexible portion (17) in the longitudinal axial cross-section of the helical rigid portion (11) and helical flexible portion (13) of the inner cylinder (8). When the width of the helical rigid portion (16) is long and the width of the helical flexible portion (17) is short, the pipe (35) becomes difficult to bend, and the outer surface of the inner cylinder (8) comes into strong contact with the inner surface of the outer cylinder (2), increasing frictional resistance and thus increasing the insertion resistance. On the other hand, when the width of the helical rigid portion (16) is short and the width of the helical flexible portion (17) is long, the inner cylinder (8) is compressed in the longitudinal axial direction due to frictional resistance, causing the helical flexible portion (13) to be compressed and bulge, coming into contact with the inner surface of the outer cylinder (2), further increasing frictional resistance and thus increasing the insertion resistance. Therefore, if the width (16) of the helical rigid portion of the inner cylinder cross-section is X, it is preferable that the width (17) of the helical soft portion is 0.3X to 0.5X. Specifically, if the width (16) of the helical rigid portion of the inner cylinder cross-section is set to 2.0 to 4.0 mm, the width (17) of the helical soft portion will be 0.6 mm to 2.0 mm.

[0024] 3) Thickness of the spiral hard part and thickness of the spiral soft part When the inner cylinder (8) is inserted into the outer cylinder (2), the frictional resistance increases as the inner surface of the outer cylinder (2) and the outer surface of the inner cylinder (8) come into contact, and the inner cylinder (8) is compressed in the longitudinal direction. As a result, the helical soft part (13) is compressed and bulges outwards (in the direction that contacts the inner surface of the outer cylinder (2)). As the spiral-shaped soft part (13) expands and comes into contact with the inner surface of the outer cylinder (2), the frictional resistance increases further, and the insertion resistance increases. Therefore, by making the thickness of the spiral-shaped soft part (34) 80% or less of the thickness of the spiral-shaped hard part (33), it is possible to prevent the spiral-shaped soft part (13) from coming into contact with the inner surface of the outer cylinder (2) even if it expands outward due to its upward bulge. Therefore, if the thickness of the helical hard portion (33) is Y, it is preferable that the thickness of the helical soft portion (34) be 0.8Y or less.

[0025] 4) Groove When the inner cylinder (8) is inserted into the outer cylinder (2), the frictional resistance increases due to the contact between the inner surface of the outer cylinder (2) and the outer surface of the inner cylinder (8), thus increasing the insertion resistance. To reduce the frictional resistance and insertion resistance caused by the contact between the outer surface of the inner cylinder (8) and the inner surface of the outer cylinder (2) by making the inner cylinder (8) more flexible, it is preferable to form a groove (14) near the center of the cross-section of the helical soft part (13) with a width of 0.15X to 0.3X and a depth of 30% to 60% from the longest point of the thickness (34) of the helical soft part. Specifically, a groove (14) with a width of 0.5 to 0.8 mm and a depth of 0.15 to 0.2 mm may be provided near the center of the cross-section of the helical soft part (13).

[0026] 5) Annular hard part For patients whose symptoms have recovered to some extent, when they are awake, the inner tube may be removed, and a one-way valve (18) may be attached to the outer tube (2), which has side holes (7) for the purpose of vocalization. On the other hand, when sleeping, the one-way valve (18) is removed and the inner tube (8) is inserted to manage breathing, and a ventilator is connected to the connector (10). In this case, a cuffed tracheostomy tube is usually used. When using this, it is preferable that the tip of the double helix structure (32) be an annular rigid part (29) so that air from the lung side does not leak into the upper airway through the side hole (7) via the lumen of the tip end (4) of the outer tube, the spiral soft part (13) and the groove (14) of the tip end (15) of the inner tube. Furthermore, in order to prevent aspirated saliva from dripping into the lungs through the side holes (7) of the outer cylinder (2) and the gaps in the spiral soft parts (13) and grooves (14) on the inner surface of the outer cylinder (2) and the outer surface of the inner cylinder (8), it is preferable that the leading edge of the double helix structure (32) be an annular hard part (29). In other words, the medical device (1) of the present invention is characterized in that the leading edge of the double helix structure (32) is an annular rigid part (29) so as to prevent air supplied by a ventilator from leaking into the upper airway through the gap between the outer cylinder (2) and the inner cylinder (8) and through the side hole (7), and so aspirated saliva from the side hole (7) from reaching the lungs through the gap between the outer cylinder (2) and the inner cylinder (8).

[0027] 6) Method for manufacturing the inner cylinder The manufacturing method for the inner cylinder (8) of the present invention is not particularly limited, but mainly the following two manufacturing methods can be employed. Here, the inner cylinder includes a connector (10), a straight cylinder (28), and a double helix structure (32), and the connector, straight cylinder, and helical rigid part (11) are integrally molded from the same material. Here, the connector, straight cylinder, and helical rigid part together are referred to as the rigid part. <Manufacturing method in which the hard part is molded, and then the hard part is inserted into a mold for molding the soft part.> It can be molded using a standard molding machine. For example, 10 cores should be prepared. Molding procedure 1. Set the mold for the hard part into the molding machine and load the hard part material. 2. The core is placed in the mold for forming the hard part, and the hard part is formed. 3. Separate the molded hard part, along with the core, from the mold used for molding the hard part. Repeat steps 2 and 3 for 10 cores. 4. Remove the mold for the hard part from the molding machine and take out the hard part material. 5. Set the mold for the soft part into the molding machine and load the soft part material. 6. Insert the hard part and core into the mold for molding the soft part. 7. Form the spiral-shaped soft part. 8. Remove the molded product, which consists of a hard part and a spiral-shaped soft part, from the mold and remove the core. Repeat steps 5-8 for 10 cores.

[0028] <A two-color molding method in which a hard part is molded first, and then a spiral-shaped soft part is molded in a single cycle.> The manufacturing method using two-color molding, which is performed in one cycle, utilizes a two-color molding machine. For example, two cores are prepared. Molding procedure 1. Set the molds for the hard and soft parts into the molding machine, and feed the hard and soft parts materials into their respective input ports. 2. The core is placed in the mold for forming the hard part, and the hard part is formed. 3. The mold is automatically replaced from the mold for molding the hard part to the mold for molding the soft part. 4. Form the spiral-shaped soft part. 5. The molded product, which consists of a hard part and a spiral-shaped soft part, is released from the mold, and the core is removed. 6. While performing steps 2-5 using the other core, remove the core from the molded product.

[0029] Since the spiral-shaped soft part (13) is formed after the spiral-shaped hard part (11), the spiral-shaped soft part (13) is welded to the spiral-shaped hard part (11) during the forming process. To improve the welding strength of the welded part, two curved sections (26) and a step (27) are provided on the spiral-shaped hard part (11) to increase the contact area between the spiral-shaped hard part (11) and the spiral-shaped soft part (13). Furthermore, the surface of the spiral-shaped hard part (11) may be textured to increase the contact area between the surface of the spiral-shaped hard part (11) and the surface of the spiral-shaped soft part (13).

[0030] As explained above, when the inner cylinder (8) is inserted into the lumen of the outer cylinder (2), a compressive force is applied in the longitudinal direction. However, it is preferable that a hard olefin resin is used so that the helical rigid part (11) does not twist or buckle and can withstand the compressive force applied in the axial direction during insertion. Furthermore, in order to reduce the frictional resistance with the outer cylinder (2) and thereby reduce the compressive force on the inner cylinder (8) in the longitudinal direction, it is preferable to also use a material blended with 2-5% dimethylpolysiloxane. The spiral-shaped soft part (13) is preferably made of a material that blends 1-30% of a hard olefin resin with a styrene-based elastomer or olefin-based elastomer so as to maintain flexibility and strength against compression in the longitudinal direction of the inner cylinder (8). Furthermore, even when the spiral-shaped soft part (13) comes into contact with the inner surface of the outer cylinder (2), it is preferable to also use a material blended with 2-5% dimethylpolysiloxane in order to reduce frictional resistance and thereby reduce the compressive force on the inner cylinder (8) in the longitudinal direction. Specific examples of materials for the helical rigid section include, but are not limited to, a blend of polypropylene and dimethylpolysiloxane. Specific examples of materials for the helical flexible part include, but are not limited to, blends of polypropylene, styrene elastomer, and dimethylpolysiloxane. [Industrial applicability]

[0031] The present invention provides a tube, an inner tube, and a medical device that suppress the shrinking, twisting, and buckling of the inner tube inserted into the lumen of the outer tube. [Explanation of symbols]

[0032] 1. Medical device (tracheostomy tube) 2. Outer cylinder 3. Proximal end 4. Tip side 5-1 Proximal straight section 5-2 Straight tip section 6. Approximately arc-shaped section (curved section) 7. Side hole 8.Inner cylinder 9. Inner cylinder base end 10. Connectors 11. Spiral hard part 12. Slightly mountain-shaped 13. Spiral soft part 14. Mizo 15. Inner cylinder tip side 16. Width of the spiral hard section 17. Width of the spiral soft section 18. One-way valve 19. Lock receiver for double pipes 20. Speech lock receiver 21. Neck plate 22. Cuff 23. Seal valve 24. Inflation tube 25. Suction tube 26. Curved section 27. Steps 28. Straight cylinder 29. Annular hard part 32.Double helix structure 33. Thickness of the spiral-shaped hard section 34. Thickness of the spiral soft section 35. Pipe

Claims

1. A medical device comprising an outer cylinder and an inner cylinder that can be inserted into and removed from the lumen of the outer cylinder, The outer cylinder includes a substantially arc-shaped portion, The inner cylinder has a pipe, where the pipe has a double helix structure in which a helical soft portion and a helical hard portion alternately are present in all of the portions that are in contact with the lumen of the substantially arc-shaped portion of the outer cylinder. The width of the helical rigid portion in the longitudinal direction is X, and the width of the helical soft portion in the longitudinal direction is narrower than X. Here, the inner cylinder does not include any reinforcing elements, or the hard part and the soft part are made only of resin. Medical devices.

2. The medical device according to claim 1, wherein the inner cylinder does not include a reinforcing element.

3. The medical device according to claim 1, wherein the hard part and the soft part are made solely of resin.

4. The medical device according to any one of claims 1 to 3, wherein the width in the longitudinal direction of the helical rigid portion is X, and the width in the longitudinal direction of the helical soft portion is 0.3X to 0.5X.

5. The medical device according to any one of claims 1 to 3, wherein the pipe is in direct contact with at least the lumen of the substantially arc-shaped portion of the outer cylinder.

6. The medical device according to any one of claims 1 to 3, wherein the inner cylinder further has a connector and a straight cylinder, and the straight cylinder and the helical rigid part are made of the same material.

7. The medical device according to any one of claims 1 to 3, wherein the inner cylinder further has a connector and a straight cylinder, and the straight cylinder and the helical rigid part are integrally molded from the same material.

8. The medical device according to any one of claims 1 to 3, wherein the medical device is a tracheostomy tube.

9. The medical device according to any one of claims 1 to 3, wherein the spiral rigid portion has a substantially mountain-like shape.

10. The medical device according to any one of claims 1 to 3, wherein the spiral soft portion has grooves.

11. The medical device according to any one of claims 1 to 3, wherein a rigid annular portion is provided at the leading edge of the double helix structure.

12. The medical device according to claim 11, wherein the helical rigid portion is substantially V-shaped, the helical soft portion has grooves, and the annular rigid portion located at the tip of the double helix structure is substantially V-shaped.

13. A medical device according to any one of claims 1 to 3, wherein the thickness of the helical rigid part is Y, and the thickness of the helical soft part is 0.8Y or less.

14. The medical device according to any one of claims 1 to 3, wherein the pipe does not include a reinforcing element.

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