JP2022190735A - coil body - Google Patents

Abstract

To provide a coil body capable of securing excellent torque transmission property and flexibility.SOLUTION: A coil body 100 is a coil body in which a strand wire 1 is wound into a hollow spiral state, the strand wire 1 has: a coil wire 11 comprising a taper part 11b in which an outer diameter of one end 11b1 is smaller than an outer diameter of the other end 11b2; and a side wire 21 wound along a peripheral face 11ss of the taper part 11b. One end of the taper part 11b is a first end 11b1 and the other end of the taper part 11b is a second end 11b2. In the taper part 11b, the outer diameter of the strand wire 1 is almost constant, a filling ratio of the strand wire 1 is a ratio of a total sum of volume of the core wire 11 and volume of the side wire 21 occupied in an internal space of a virtual cylindrical body E passing an outermost periphery of the strand wire 1 and whose shaft core is a center shaft of the core wire 11, and a filling ratio of the strand wire 1 calculated for 1 mm along the center shaft of the core wire 11 becomes smaller, as going from the second end 11b2 to the first end 11b1.SELECTED DRAWING: Figure 1

Description

The present invention relates to coil bodies.

2. Description of the Related Art Elongated medical devices such as catheters and guidewires are known as devices that are inserted into body cavities such as blood vessels to treat lesions and the like. Such medical instruments are required to have flexibility at the distal end so that they can be smoothly inserted along curved body cavities, and to ensure that the rotational force applied to the proximal side is transmitted to the distal end. Excellent torque transmission is required.

As such a medical device, for example, a technique has been proposed in which the shape and material of the coil body are made different between the distal end portion and the base end portion of the coil body (see, for example, Patent Document 1).

WO2009/119386

However, in the conventional technique as described above, there is a possibility that the torque transmissibility may deteriorate at a portion of the coil body or the like where the winding pitch of the wires is large.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a coil body capable of ensuring excellent torque transmissibility and flexibility.

Some aspects of the disclosure include:
(1) A coil body in which a stranded wire is wound in a hollow spiral,
The twisted wire is
a core wire having a tapered portion in which the outer diameter of one end is smaller than the outer diameter of the other end;
a side wire wound along the outer peripheral surface of the tapered portion,
The one end of the tapered portion is a first end,
The other end of the tapered portion is a second end,
In the tapered portion, the outer diameter of the twisted wire is substantially constant,
The filling rate of the stranded wire is the sum of the volume of the core wire and the volume of the side wires, which is occupied in the space inside a virtual cylindrical body having the central axis of the core wire as the axis and passing through the outermost circumference of the stranded wire. , is the ratio of
A coil body characterized in that the filling factor of the twisted wire calculated for each 1 mm along the central axis of the core wire decreases from the second end toward the first end, and ( 2) The coil according to (1), wherein the side wire positioned on the outer circumference of the tapered portion is flat, and the flat surface of the flat side wire is arranged so as to be in contact with the outer peripheral surface of the core wire. body.

In this specification, the term "winding" means a linear member spirally wound to form a coil body. A “flat surface” means an outer surface in the minor axis direction of the lateral line of the flat shape.

INDUSTRIAL APPLICABILITY The present invention can provide a coil body capable of ensuring excellent torque transmissibility and flexibility.

It is a schematic sectional drawing showing the whole of one embodiment. FIG. 2 is a schematic cross-sectional view showing an enlarged part of a winding used in the coil body of FIG. 1; FIG. 1 is a schematic cross-sectional view of the winding used in the coil body of FIG. 1, (a) is a view cut along line IIIa-IIIa in FIG. 2, and (b) is cut along line IIIb-IIIb in FIG. FIG. (c) shows a view cut along line IIIc-IIIc in FIG. 2, respectively.

A coil body of the present disclosure is a coil body in which a stranded wire is wound in a hollow spiral, the stranded wire includes a core wire and a side wire wound along an outer peripheral surface of the core wire, the core wire has a tapered portion in which the outer diameter of one end is smaller than the outer diameter of the other end, and the one end of the tapered portion is the first end;
The other end of the taper portion is a second end portion, and in the taper portion, the outer diameter of the stranded wire is substantially constant, and the filling rate of the stranded wire is such that the central axis of the core wire is the axis and The ratio of the sum of the volume of the core wire and the volume of the side wire to the space inside the virtual cylinder passing through the outermost circumference of the stranded wire, and is calculated for each 1 mm along the central axis of the core wire. The filling factor of the stranded wire thus formed decreases from the second end toward the first end.

An embodiment of the present invention will be described below with reference to the drawings, but the present invention is not limited only to the embodiments described in the drawings. In addition, the dimensions of the coil body shown in each drawing are for the purpose of facilitating the understanding of the implementation, and do not correspond to the actual dimensions.

FIG. 1 is a schematic cross-sectional view showing the entirety of one embodiment. As shown in FIG. 1, the coil body 100 is a coil body in which a twisted wire 1 (hereinafter also referred to as "winding 1") is wound in a hollow spiral. The coil body 100 has a lumen 100h extending along the longitudinal direction. For example, a long thin medical device or the like is inserted through this lumen 100h. The twisted wire 1 is roughly composed of a core wire 11 and side wires 21, as shown in FIG.

The core wire 11 is a member composed of a single wire and constitutes the central axis of the winding. The core wire 11 can be configured to have, for example, a small-diameter portion 11a, a tapered portion 11b, and a large-diameter portion 11c.

The tapered portion 11b is a portion where the outer diameter of one end 11b1 (hereinafter also referred to as “first end 11b1”) is smaller than the outer diameter of the other end 11b2 (hereinafter also referred to as “second end 11b2”). be. The tapered portion 11b may gradually decrease in diameter from the second end portion 11b2 toward the first end portion 11b1 (see FIG. 2). The diameter may decrease in a stepwise (stepwise) manner (not shown).

One end (right end in the figure) of the small diameter portion 11a is continuous with the first end 11b1 and extends toward the opposite side (left side in the figure) of the one end. The small-diameter portion 11a can be configured, for example, to have the same outer shape (for example, a circular shape with a constant outer diameter) over the entire longitudinal direction.

One end (left end in the drawing) of the large diameter portion 11c is continuous with the second end 11b2 and extends toward the opposite side (right side in the drawing) of the one end. The large-diameter portion 11c can be configured, for example, to have the same outer shape (for example, a circular shape with a constant outer diameter) over the entire longitudinal direction.

The core wire 11 of the present embodiment includes a small diameter portion 11a having a circular cross section and a constant outer diameter, a tapered portion 11b gradually decreasing in diameter from the second end portion 11b2 toward the first end portion 11b1, and a cross section. It is composed of a large-diameter portion 11c having a circular surface and a constant outer diameter.

The material constituting the core wire 11 is not particularly limited as long as it has antithrombotic properties and biocompatibility. can.

The side wire 21 is a linear member wound along the outer peripheral surface 11s of the tapered portion 11b. The side wire 21 uses a single wire (single wire) or a stranded wire (a bundle of wires in which a plurality of single wires are twisted together in advance), and is wound on the outer peripheral surface 11s of the core wire 11 in a single or multiple wires. can be formed by The side wire 21 may be arranged on at least a part of the outer periphery of the tapered portion 11b, and may be arranged on the outer periphery of the small diameter portion 11a and/or the large diameter portion 11c in addition to the outer periphery of the tapered portion 11b. (See Figure 2).

The side wire 21 of the present embodiment uses three single wires, which are wound in three lines on the outer peripheral surface 11s of the small diameter portion 11a, the tapered portion 11b and the large diameter portion 11c. Moreover, the side wire 21 is arranged so as to be in contact with the outer peripheral surfaces 11s of the small diameter portion 11a, the tapered portion 11b, and the large diameter portion 11c.

Here, the "filling rate of stranded wire" is defined as the inner side of a virtual cylinder E (cylindrical body illustrated by a chain double-dashed line in FIG. 2) having the central axis of the core wire 11 as its axis and passing through the outermost circumference of the stranded wire 1. , the filling rate of the stranded wire 21 calculated for each 1 mm along the central axis of the core wire 11 is the second end portion It is configured to become smaller from 11b2 toward the first end 11b1.

Therefore, the stiffness of the coil body 100 using the winding 1 (twisted wire 1) can be gradually changed (suppressing a sudden change in stiffness) along the longitudinal direction of the coil body 100. site 100B). That is, the portion where the filling rate of the stranded wire 1 is large (particularly, the second end portion 11b2 side of the tapered portion 11b, the portion 100C side of the portion 100B in the coil body 100) has high rigidity and high torque transmissibility. The coil body 100 is formed so that flexibility is increased due to lower rigidity in the portion where the filling rate of 1 is small (particularly, the first end portion 11b1 side of the tapered portion 11b and the portion 100A side of the portion 100B in the coil body 100). can be formed.

In the present embodiment, the coil body 100 is composed of one single wire serving as the core wire 11 of the winding 1 and three single wires serving as the side wires 21 . Therefore, the filling rate of the stranded wire 1 is the volume of the core wire 11 and the volume of the side wires 21 occupied in the space inside the virtual cylindrical body E having the central axis of the core wire 11 as the axis and passing through the outermost circumference of the stranded wire 1. (the total volume of the volume of one core wire 11 and the volume of three side wires 21 (total volume of four wires)).

In the longitudinal direction of the core wire 11, the outermost diameter (outer diameter OD) of the side wire 21 wound around the core wire 11 may be constant (see FIG. 2) or may be different. When the outer diameter OD is constant, for example, in the side wire 21 positioned on the outer peripheral surface 11s of the tapered portion 11b, the side wire in the radial direction of the core wire 11 extends from the second end portion 11b2 toward the first end portion 11b1. It can be formed so that the thickness of 21 becomes large.

As a method of varying the thickness of the side wire 21 along the longitudinal direction of the core wire 11, for example, a method of swaging a wire wound around the core wire 11, and a method of swaging the core wire 11 so as to be inversely proportional to the outer diameter of the core wire 11 A method of winding a side wire with a different outer diameter around a core wire depending on a portion on the outer peripheral surface 11s may be used.

The cross-sectional shape of the side wire 21 may be circular or non-circular (elliptical, flat such as substantially rectangular, etc.). The shape of the cross section may differ between the small diameter portion 11a, the tapered portion 11b and the large diameter portion 11c.

The material forming the side wire 21 is not particularly limited as long as it has antithrombotic properties and biocompatibility.

Here, when the lateral wire 21 is flattened, the twist angle of the twisted wire 1 changes according to the degree of flatness. Therefore, the number of windings of the wire per unit length in the central axis direction of the stranded wire 1 changes according to the degree of flatness, and accordingly the rigidity of the stranded wire 1 in the central axis direction changes.

When the side wire positioned on the outer circumference of the tapered portion 11b has a flat shape, the flat surface of the flat side wire may be arranged so as to be in contact with the outer peripheral surface 11s of the core wire 11. As shown in FIGS. 3(a), 3(b), and 3(c), in the present embodiment, the cross-sectional shape of the side wire 21 on the tapered portion 11b and the large-diameter portion 11c is flat (approximately rectangular), and the cross-sectional shape of the side wire 21 on the small diameter portion 11a is circular. In the winding 1 (twisted wire 1) of the present embodiment, the flat surfaces of the side wires 21 located on the outer peripheries of the tapered portion 11b and the large diameter portion 11c are in contact with the tapered portion 11b and the large diameter portion 11c, respectively. A side wire 21 located on the outer circumference of 11a is arranged so as to be in contact with the small diameter portion 11a.

As a result, it is possible to suppress the stranded wire 1 from being crushed by an external pressure, and the winding 1 can be formed more compactly even if the stranded wire has the same outer diameter OD, and thus the coil body 100 can be made more compact. It can be formed compactly.

As described above, since the coil body 100 is configured as described above, the portion 100B having a higher filling rate of the stranded wires 1 has a higher torque transmissibility on the side of the portion 100C, and the portion having a smaller filling rate of the stranded wires 1 Higher flexibility can be imparted to the portion 100A side of 100B. In addition, since the filling rate of the stranded wire 1 decreases from the second end portion 11b2 toward the first end portion 11b1, it is possible to suppress a rapid change in rigidity of the stranded wire 1 in the direction of the central axis. 100 breakage can be prevented.

In addition, the coil body 100 of the present disclosure has excellent torque transmissibility and flexibility. Therefore, for example, the coil body 100 may be applied to a guide wire (not shown), and the coil body 100 may be used as a coil body arranged around the distal end portion of the core shaft of the guide wire. Also, the coil body 100 may be applied to a catheter (not shown) and the coil body 100 may be used as a hollow shaft of the catheter. In addition, the coil body 100 is applied to an endoscopic treatment tool (not shown, for example, an endoscope disclosed in Japanese Patent Application Laid-Open No. 2019-15796), and the coil body 100 is used as the treatment portion of the endoscopic treatment tool. It may be used as a sheath that protects the outer periphery of the core wire connected to. In such a case, the part 100A side of the coil body 100 (the small diameter portion 11a It is preferable to arrange the coil body so that the side) is located.

It should be noted that the present disclosure is not limited to the configurations of the above-described embodiments, but is indicated by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. be done. A part of the configuration of the embodiment described above may be deleted or replaced with another configuration, or another configuration may be added to the configuration of the embodiment described above.

For example, in the embodiment described above, the coil body 100 including the core wire 11 including the small diameter portion 11a, the tapered portion 11b, and the large diameter portion 11c has been described. However, the core wire is not particularly limited as long as it has a tapered portion. The core wire may have either a small-diameter portion or a large-diameter portion, or may have neither a small-diameter portion nor a large-diameter portion.

Further, in the above-described embodiment, the coil body 100 has the stranded wire 1 (winding 1) in which the side wire 21 is wound on each of the outer peripheral surfaces 11s of the small diameter portion 11a, the tapered portion 11b, and the large diameter portion 11c of the core wire 11. explained. However, the side wire should be wound at least on the tapered portion of the core wire. In addition to the tapered portion, the side wire may be wound around either the small-diameter portion or the large-diameter portion, or may be wound around neither the small-diameter portion nor the large-diameter portion. The side wire may be wound only on a part of the tapered portion or may be wound on the entire tapered portion in the longitudinal direction.

Reference Signs List 1 stranded wire 100 coil body 11 core wire 11b tapered portion 11b1 first end portion 11b2 second end portion 11s outer peripheral surface 21 side wire

Claims (2)

A coil body in which a stranded wire is wound in a hollow spiral,
The twisted wire is
a core wire having a tapered portion in which the outer diameter of one end is smaller than the outer diameter of the other end;
a side wire wound along the outer peripheral surface of the tapered portion,
The one end of the tapered portion is a first end,
The other end of the tapered portion is a second end,
In the tapered portion, the outer diameter of the twisted wire is substantially constant,
The filling rate of the stranded wire is the sum of the volume of the core wire and the volume of the side wires, which is occupied in the space inside a virtual cylindrical body having the central axis of the core wire as the axis and passing through the outermost circumference of the stranded wire. , is the ratio of
The coil body, wherein a filling factor of the twisted wire calculated for each 1 mm along the central axis of the core wire decreases from the second end toward the first end. 2. The coil body according to claim 1, wherein the side wire positioned on the outer periphery of the tapered portion is flat, and the flat surface of the flat side wire is arranged so as to be in contact with the outer peripheral surface of the core wire.

Images