Medical device

Abstract

To provide a dilator which is flexible and can obtain a sufficient expansion diameter.SOLUTION: A dilator 1 includes: a core shaft 21 having a tapered part 23 having a diameter shrinking from a base end toward a tip end, and a straight parts 22, 24 having a constant outer diameter provided adjacent to the tapered part 23 and extending along a longitudinal axial direction; and a projection part 31 provided on an outer peripheral surface of the tapered part 23 and the straight parts 22, 24, and spirally extending with a gap between the adjacent parts along the longitudinal axial direction. The projection part 31 includes: a first projection part 32 positioned on the tapered part 23; and second projection parts 33, 34 positioned on the straight parts 22, 24. A rigidity of the first projection part 32 is lower that a rigidity of the second projection parts 33, 34.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to medical devices. [Background technology]

[0002] 2. Description of the Related Art Medical devices are known for expanding holes formed in the walls of organs such as the stomach and liver, and for expanding narrowed portions in body cavities such as the bile duct and pancreatic duct.

[0003] In such medical devices, a tapered portion is provided on the core shaft, and the hole is expanded by pushing the tapered portion into the hole. It has been proposed to provide a spiral convex portion on the outer circumferential surface of the tapered portion and the adjacent straight portion (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2014-524807 Summary of the Invention [Problem to be solved by the invention]

[0005] In the medical device of Patent Document 1, if the core shaft and the protrusions are made of a hard material (e.g., stainless steel, etc.), a sufficient expansion diameter can be obtained, but flexibility is reduced, making it difficult to pass through bent parts of blood vessels, etc. If the core shaft and the protrusions are made of a soft material (e.g., resin, etc.), flexibility is improved, but it is difficult to obtain a sufficient expansion diameter.

[0006] An object of the present disclosure is to provide a medical device that is both flexible and easy to obtain a sufficient expansion diameter. [Means for solving the problem]

[0007] In order to achieve this objective, a medical device according to one embodiment of the present disclosure is a medical device comprising: a core shaft having a tapered portion that narrows in diameter from the base end to the tip end; and a straight portion of constant outer diameter adjacent to the tapered portion and extending along the longitudinal direction; and a convex portion provided on the outer peripheral surfaces of the tapered portion and the straight portion and extending spirally with gaps between adjacent portions along the longitudinal direction, wherein the convex portion has a first convex portion located on the tapered portion and a second convex portion located on the straight portion, and the rigidity of the first convex portion is lower than the rigidity of the second convex portion.

[0008] The first protrusion may be made of a resin material, and the second protrusion may be made of a metal material.

[0009] The first convex portion and the second convex portion may have the same cross section.

[0010] The straight portion may be provided on the base end side of the tapered portion, or may be provided on both the tip end side and the base end side of the tapered portion.

[0011] A medical device according to one embodiment of the present disclosure is a medical device comprising: a core shaft having a tapered portion that narrows from the base end to the tip end; and a straight portion of constant outer diameter adjacent to the tapered portion and extending along the longitudinal axis direction; and protrusions provided on the outer peripheral surfaces of the tapered portion and the straight portion and extending spirally along the longitudinal axis direction with gaps between adjacent portions, wherein the protrusions have a first protrusion located on the tapered portion and a second protrusion located on the straight portion, and the first protrusions have higher rigidity than the second protrusions. Effect of the Invention

[0012] According to the present disclosure, it is possible to provide a medical device that is both flexible and easy to obtain a sufficient expansion diameter. [Brief description of the drawings]

[0013] [Figure 1]FIG. 1 is a schematic side view of a dilator according to a first embodiment. [Diagram 2] FIG. 11 is a schematic side view of a dilator according to a second embodiment. [Diagram 3] FIG. 11 is a schematic side view of a dilator according to a third embodiment. [Figure 4] FIG. 13 is a schematic side view of a dilator according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiments shown in the drawings. Note that the dimensions shown in the drawings are for ease of understanding of the implementation contents and do not correspond to the actual dimensions.

[0015] First Embodiment A medical device according to a first embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic side view of a dilator 1 as a medical device according to the first embodiment. In Fig. 1, the tip tip 11 side is the tip side (distal side) to be inserted into the body, and the gripping part 41 side is the base end side (hand side, proximal side) to be operated by a technician such as a doctor.

[0016] The dilator 1 includes a distal tip 11, a core shaft 21, a spiral convex portion 31, and a grip portion 41. The distal tip 11 is located at the most distal end of the dilator 1. The distal tip 11 is formed by pouring solder material (silver-tin solder material, gold-tin solder material, etc.) into the distal end of the core shaft 21, has a substantially cylindrical shape, and has an inner cavity 11a.

[0017] The core shaft 21 is a member having a tapered portion and a straight portion. The tapered portion is tapered from the base end to the tip end. The straight portion is adjacent to the tapered portion and extends along the longitudinal axis, and has a constant outer diameter.

[0018] The positional relationship (front-back relationship) between the tapered portion and the straight portion in the longitudinal direction is not particularly limited. For example, from the tip of the dilator, the tapered portion may be arranged in this order, the straight portion may be arranged in this order, or the straight portion may be arranged in this order, or the straight portion, the tapered portion, and the straight portion.

[0019] The core shaft 21 of this embodiment is configured as a coil body in which one or more metal wires 21w are spirally wound around the longitudinal axis of the core shaft 21. The core shaft 21 has an inner cavity 21a that penetrates from the base end to the tip end. For example, a guide wire (not shown) or the like is inserted into the inner cavity 21a.

[0020] The core shaft 21 has, in order from the tip side, a first straight portion 22, a tapered portion 23, a second straight portion 24, and a base end portion 25. The first straight portion 22 is connected to the base end of the tip tip 11 and extends from the base end of the tip tip 11 toward the base end side. The tapered portion 23 is connected to the base end of the first straight portion 22 and reduces in diameter from the base end toward the tip. The second straight portion 24 is connected to the base end of the tapered portion 23 and extends from the base end of the tapered portion 23 toward the base end side. The base end portion 25 is connected to the base end of the second straight portion 24 and extends from the base end of the second straight portion 24 toward the base end side. The first and second straight portions 22 and 24 have a constant outer diameter.

[0021] Since the wires 21w constituting the core shaft 21 are inserted into a body cavity, they preferably have antithrombotic properties, flexibility, and biocompatibility. Examples of materials constituting such wires include metal materials such as stainless steel and superelastic alloys such as nickel-titanium, and resin materials.

[0022] The protrusions 31 are portions provided on the outer circumferential surfaces of the tapered portion and the straight portion. The protrusions 31 extend in a spiral shape with gaps between adjacent portions along the longitudinal direction. The protrusions 31 have a first protrusion 32 located on the tapered portion 23 and second protrusions 33, 34 located on the first and second straight portions 22, 24.

[0023] The first convex portion 32 is composed of a coil body 32C in which one or more wires 32w are wound around the outer circumferential surface of the tapered portion 23 in the opposite direction to the core shaft 21. Each of the second convex portions 33 is composed of a coil body 33C, 34C in which one or more wires 33w, 34w are wound around the outer circumferential surfaces of the first and second straight portions 22, 24 in the opposite direction to the core shaft 21.

[0024] The rigidity of the first protrusion 32 is configured to be lower than the rigidity of the second protrusions 33 and 34. For example, the first protrusion 32 is made of a resin material, and the second protrusions 33 and 34 are made of a metal material. The metal material of the second protrusions 33 and 34 has a larger Young's modulus than the resin material of the first protrusion 32. Examples of materials constituting the wire 32w of the first protrusion 32 include resin materials such as polyvinyl chloride resin, urethane resin, polyolefin resin, polyamide resin, and fluororesin. Examples of materials constituting the wires 33w and 34w of the second protrusions 33 and 34 include metal materials such as stainless steel and superelastic alloy materials such as nickel-titanium alloy. The first protrusion 32 and the second protrusions 33 and 34 have substantially circular cross sections and are the same shape. The cross section of the first protrusion 32 is a cross section perpendicular to the long axis extending along the first protrusion 32 and extending in a spiral shape. The same applies to the second protrusions 33 and 34.

[0025] Methods for joining the core shaft 21 to the first convex portion 32 and the second convex portions 33, 34 include, for example, brazing with a brazing material, bonding with an adhesive, welding, and the like.

[0026] The gripping portion 41 is a portion where the operator pushes the dilator 1 into the body and rotates it. The tip of the gripping portion 41 is connected to the base end of the base end portion 25 of the core shaft 21, and has an inner cavity 41a that communicates with the inner cavity 21a of the core shaft 21. The shape of the gripping portion 41 can be formed, for example, into a shape that allows the operator to easily operate the dilator 1. The inner cavities 11a, 21a, and 41a form a lumen L. For example, a guide wire or the like is inserted into the lumen L.

[0027] Next, an example of how the dilator 1 is used will be described.

[0028] The following describes a procedure in which an introduction needle (not shown) is used to make a hole in the area to be treated (for example, the wall of an organ such as the stomach or liver, hereinafter also referred to as the "expanded portion"), and then the hole is expanded using a dilator 1. First, the introduction needle is used to puncture the expanded portion to make a hole. Next, a guidewire is inserted into the lumen of the introduction needle, and the introduction needle is then removed.

[0029] Next, the base end of the guidewire is inserted into the lumen L of the dilator 1, and the dilator 1 is inserted into the body. Next, while operating the gripping portion 41, the core shaft 21 is not rotated and is passed through a bent portion of a blood vessel or the like along the guidewire, and the tip of the dilator 1 is delivered to just before the portion to be enlarged. Next, the tip 11 is inserted into the hole of the portion to be enlarged, and the gripping portion 41 is operated to rotate the core shaft 21, pushing the dilator 1 forward and enlarging the hole of the portion to be enlarged. At this time, the tapered portion 23 advances due to the screw action of the spiral first convex portion 32 caused by the rotation of the core shaft 21, and the tapered portion 23 enlarges the hole.

[0030] As described above, in the dilator 1, the rigidity of the first convex portion 32 is configured to be lower than the rigidity of the second convex portions 33 and 34, so that the necessary flexibility can be obtained when passing through a bent portion. The second convex portions 33 and 34 have a higher rigidity than the first convex portion 32, so that a sufficient expansion diameter of the hole can be obtained. In this way, according to the dilator 1 of this embodiment, it is possible to achieve both flexibility when passing through a bent portion and ease of obtaining a sufficient expansion diameter of the hole.

[0031] <Second embodiment> A dilator according to a second embodiment of the present disclosure will be described with reference to the drawings. Fig. 2 is a schematic side view of a dilator 101 according to the second embodiment. In Fig. 2, the tip tip 11 side is the tip side (distal side) to be inserted into the body, and the gripping portion 41 side is the base end side (hand side, proximal side) to be operated by a technician such as a doctor. The dilator 101 of this embodiment has a basically same structure as the dilator 1 of the first embodiment, so the same members are given the same numbers and detailed description is omitted.

[0032] The dilator 101 comprises a distal tip 11, a core shaft 121, a helical convex portion 131, and a grip portion 41. The core shaft 121 is a member having a tapered portion and a straight portion. The tapered portion is tapered from the base end to the distal end. The straight portion is adjacent to the tapered portion and extends along the longitudinal direction, and has a constant outer diameter.

[0033] The core shaft 121 of this embodiment is configured as a coil body in which one or more metal wires 121w are wound in a spiral shape around the long axis of the core shaft 121. The core shaft 121 has an inner cavity 121a that penetrates from the base end to the tip. For example, a guide wire (not shown) or the like is inserted into the inner cavity 121a. The inner cavities 11a, 121a, and 41a form a lumen L. The core shaft 121 has, in order from the tip side, a tapered portion 23, a straight portion 24, and a base end portion 25. The tip tip 11 is connected to the tip of the tapered portion 23.

[0034] The protruding portion 131 is a portion provided on the outer circumferential surface of the tapered portion and the straight portion. The protruding portion 131 extends in a spiral shape with a gap between adjacent portions along the longitudinal direction. The protruding portion 131 has a first protruding portion 32 located on the tapered portion 23 and a second protruding portion 34 located on the straight portion 24.

[0035] Similarly to the dilator 1 of the first embodiment, the dilator 101 of this embodiment can achieve both flexibility when passing through a bent portion and ease of obtaining a sufficient expanded diameter of the hole.

[0036] <Third embodiment> A dilator according to a third embodiment of the present disclosure will be described with reference to the drawings. Fig. 3 is a schematic side view of a dilator 201 according to the third embodiment. In Fig. 3, the tip tip 11 side is the tip side (distal side) to be inserted into the body, and the gripping portion 41 side is the base end side (hand side, proximal side) to be operated by a technician such as a doctor. In the dilator 201 of this embodiment, the same members as those of the dilator 1 of the first embodiment are given the same numbers, and detailed description will be omitted.

[0037] The dilator 201 includes a distal tip 11, a core shaft 221, a helical convex portion 31, and a grip portion 41. The core shaft 221 is a member having a tapered portion and a straight portion. The tapered portion is tapered from the base end to the distal end. The straight portion is adjacent to the tapered portion and extends along the longitudinal direction, and has a constant outer diameter.

[0038] The core shaft 221 of this embodiment is configured as an integrally formed hollow shaft. The core shaft 221 has an inner cavity 221a that penetrates from the base end to the tip. The inner cavity 11a, the inner cavity 221a, and the inner cavity 41a form a lumen L. The core shaft 221 has, in order from the tip side, a first straight portion 222, a tapered portion 223, a second straight portion 224, and a base end portion 225.

[0039] The first straight portion 222 is connected to the base end of the distal tip 11 and extends from the base end of the distal tip 11 toward the base end side. The tapered portion 223 is connected to the base end of the first straight portion 222 and decreases in diameter from the base end toward the distal end. The second straight portion 224 is connected to the base end of the tapered portion 223 and extends from the base end of the tapered portion 223 toward the base end side. The base end portion 225 is connected to the base end of the second straight portion 224 and extends from the base end of the second straight portion 224 toward the base end side. The first and second straight portions 222, 224 have a constant outer diameter.

[0040] Since the material constituting the core shaft 221 is inserted into a body cavity, it is preferable that the material has antithrombotic properties, flexibility, and biocompatibility. Examples of such materials include resin materials such as polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin; and metal materials such as stainless steel and superelastic alloy (nickel-titanium alloy).

[0041] The protrusion 31 is provided on the outer circumferential surfaces of the tapered portion and the straight portion. The protrusion 31 has a first protrusion 32 located on the tapered portion 223 and second protrusions 33, 34 located on the first and second straight portions 222, 224.

[0042] Methods for joining the core shaft 221 to the first convex portion 32 and the second convex portions 33 and 34 include, for example, brazing with a brazing material, bonding with an adhesive, welding, and the like.

[0043] Similarly to the dilator 1 of the first embodiment, the dilator 201 of this embodiment can achieve both flexibility when passing through a bent portion and ease of obtaining a sufficient expanded diameter of the hole.

[0044] <Fourth embodiment> A dilator according to a fourth embodiment of the present disclosure will be described with reference to the drawings. Fig. 4 is a schematic side view of a dilator 301 according to the fourth embodiment. In Fig. 4, the tip tip 11 side is the tip side (distal side) to be inserted into the body, and the gripping portion 41 side is the base end side (hand side, proximal side) to be operated by a technician such as a doctor. In the dilator 301 of this embodiment, the same members as those of the dilator 201 of the third embodiment are given the same numbers, and detailed description will be omitted.

[0045] The dilator 301 includes a distal tip 11, a core shaft 221, a spiral convex portion 331, and a grip portion 41.

[0046] The protruding portion 331 is a portion provided on the outer peripheral surface of the tapered portion or the tapered portion and the straight portion. The protruding portion 331 has a gap between adjacent portions along the long axis direction. Specifically, the protruding portion 331 can be configured, for example, as a single or multiple protruding portion that protrudes radially outward from the outer peripheral surface of the tapered portion or the straight portion and is continuous or discontinuous in the long axis direction. In this embodiment, the protruding portion 331 and the core shaft 221 are integrally formed. The protruding portion 331 has a first protruding portion 332 located in the tapered portion 223 and second protruding portions 333 and 334 located in the first and second straight portions 222 and 224.

[0047] In this embodiment, the material constituting the core shaft 221 and the protruding portion 331 includes metal materials such as stainless steel and superelastic alloy (nickel-titanium alloy). The protruding portion 331 is integrally molded with the core shaft 221 by casting or the like. The rigidity of the first protruding portion 332 is configured to be lower than the rigidity of the second protruding portions 333 and 334 by performing a heat treatment or the like on the first protruding portion 332.

[0048] Similarly to the dilator 1 of the first embodiment, the dilator 301 of this embodiment can achieve both flexibility when passing through a bent portion and ease of obtaining a sufficient expanded diameter of the hole.

[0049] Although the embodiment of the present disclosure has been described above, it is not limited to the configuration of the above-mentioned embodiment, and is intended to include all modifications within the meaning and scope of the claims, which are indicated by the claims. A part of the configuration of the above-mentioned embodiment may be deleted or replaced with another configuration, and another configuration may be added to the configuration of the above-mentioned embodiment.

[0050] For example, in the third and fourth embodiments, the core shaft 221 has the first straight portion 222, but it does not have to have the first straight portion 222. In this case, a tapered portion 223 is connected to the base end of the distal tip 11.

[0051] In the above-described embodiment, the material constituting the first convex portion 32 is a resin material, and the material constituting the second convex portions 33 and 34 is a metal material. However, as long as the rigidity of the first convex portion 32 can be made lower than the rigidity of the second convex portions 33 and 34, the material constituting the first convex portion 32 and the material constituting the second convex portions 33 and 34 may be a resin material or a metal material. In addition, the rigidity of the first convex portions 32 and 332 is configured to be lower than the rigidity of the second convex portions 33, 34, 333, and 334. However, the rigidity of the first convex portions 32 and 332 may be configured to be higher than the rigidity of the second convex portions 33, 34, 333, and 334. A sufficient expansion diameter can be obtained by using a dilator having such a configuration. [Explanation of symbols]

[0052] 1, 101, 201, 301: Dilator 21, 121: Core shaft 22, 222: First straight section 23, 223: Tapered section 24, 224: Second straight section 31, 331: Convex 32, 332: First convex part 33, 34, 333, 334: Second convex part

Claims

1. a core shaft having a tapered portion whose diameter decreases from the base end to the tip end, and a straight portion having a constant outer diameter that is adjacent to the tapered portion and extends along the longitudinal direction; a protrusion provided on an outer peripheral surface of the tapered portion and the straight portion, the protrusion extending in a spiral shape with a gap between adjacent portions along the longitudinal axis direction, the convex portion has a first convex portion located on the tapered portion and a second convex portion located on the straight portion, A medical device in which the first convex portion has a lower rigidity than the second convex portion.

2. The medical device according to claim 1 , wherein the first convex portion is made of a resin material and the second convex portion is made of a metal material.

3. The medical device according to claim 1 or 2, wherein the first convex portion and the second convex portion have the same cross-sectional shape.

4. The medical device according to claim 1 or 2, wherein the straight portion is provided on the proximal end side of the tapered portion, or on the distal and proximal end sides of the tapered portion.

5. a core shaft having a tapered portion whose diameter decreases from the base end to the tip end, and a straight portion having a constant outer diameter that is adjacent to the tapered portion and extends along the longitudinal direction; a protrusion provided on an outer peripheral surface of the tapered portion and the straight portion, the protrusion extending in a spiral shape with a gap between adjacent portions along the longitudinal axis direction, the convex portion has a first convex portion located on the tapered portion and a second convex portion located on the straight portion, A medical device, wherein the first convex portion has higher rigidity than the second convex portion.

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