JP2021133124A - Medical equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical device having high operation reliability.
SOLUTION: An outer sheath 22 through which an inner sheath 21 is inserted is pulled into a housing 31 of an operation unit 3, and a coil member 22a having an outer convex portion is attached to a proximal end portion of the outer sheath 22. ing. The surface of the coil member 22a on the distal end side of the convex portion is inclined so that the inner side of the coil member 22a is located closer to the proximal end side than the outer side in the radial direction. When the button 33 is pushed against the urging force of the coil spring 35, the tip of the leaf spring 33a is pressed against the surface on the distal end side of the convex portion of the coil member 22a, and the outer sheath 22 is slid toward the proximal end side. ..
[Selection diagram] Fig. 5

Description

The present invention relates to a medical device for treating an internal tissue by an operation outside the body, such as a stent delivery device used for placing a stent in the body by using an endoscope, for example.

A medical method is known in which a stent is placed at a narrowed site in order to secure the patency of a lumen in the body such as a narrowed gastrointestinal tract or a blood vessel. A stent is a device that is placed to ensure patency of the lumen by dilating the site of stenosis. Examples of the stent include a balloon dilated type and a self-expanding type, and as a device for indwelling a self-expanding type stent in a lumen, for example, the one described in Patent Document 1 below is known.

The stent delivery device described in Patent Document 1 has an inner sheath (inner tube) and an outer sheath (outer tube) into which the inner sheath is slidably inserted, and is provided near the distal end of the inner sheath. A stent is placed in the stent placement portion, and the stent is held inside the vicinity of the distal end of the outer sheath in a state of being reduced in diameter by elastic deformation. Then, the stent is released from the outer sheath by operating the operation portion (handle) provided on the proximal end side and sliding it toward the proximal end side so as to pull back the outer sheath with respect to the inner sheath. , The stent is expanded and released by the self-expanding force of the stent.

The stent delivery device described in Patent Document 1 has a substantially polygonal cross section at the proximal end including the portion drawn into the operating portion (housing) of the outer sheath from the viewpoint of reducing the size and weight of the operating portion. A coil member formed by winding an elastic wire into a coil is fitted and fixed, and a leaf spring fixed to a push button that can slide diagonally from the distal end to the proximal end with respect to the outer sheath is provided. There is. By pressing the push button, the tip of the leaf spring engages with the surface on the distal end side of the convex portion of the coil member, the outer sheath is slid by a certain amount, and the push button is repeatedly pressed and released. , Slide the outer sheath relative to the inner sheath to the proximal end by the amount required to open the stent.

However, in this conventional technique, when the push button is pressed to engage the tip of the leaf spring with the surface on the distal end side of the convex portion of the coil member and the outer sheath is pushed in, the tip of the leaf spring is outward. It may slip off (disengage). For this reason, there is a problem that the slide amount of the outer sheath is insufficient and the stent cannot be sufficiently deployed, resulting in low reliability of operation.

International Publication No. 2018/043719

The present invention has been made in view of such a point, and an object of the present invention is to provide a medical device having high operational certainty.

In order to achieve the above object, the medical device according to the present invention is
A tubular first member with distal and proximal ends,
A second member that has a distal end and a proximal end and is slidably inserted through the first member.
A housing in which the proximal end side portion of the first member is pulled into the inside and the second member is fixed, and the housing.
A pressing member provided on the housing so as to be slidable in a direction diagonally intersecting from the distal end side to the proximal end side with respect to the extending direction of the portion of the first member existing in the housing.
A coil member having a shape in which a wire rod provided in at least a part of a portion of the first member existing in the housing and having a substantially triangular cross-sectional shape is wound in a coil shape so as to form a convex portion on the outside. When,
An elastic member whose base end is fixed to the pressing member, its tip is pressed against a part of the surface of the coil member on the distal end side, and the first member is slid toward the proximal end. And have
This is a medical device in which the surface on the distal end side of the convex portion of the coil member is inclined so that the inner side is located on the proximal end side from the outer side in the radial direction.

In the medical instrument according to the present invention, when the pressing member is pressed and pushed in, the tip of the elastic member is pressed against a part of the surface on the distal end side of the convex portion of the coil member, and the first member is in contact with the second member. Then, it is slid by a certain amount according to the stroke of the pressing member. Since the surface of the convex portion of the coil member on the distal end side is inclined so that the inner side of the convex portion in the radial direction is located on the proximal end side, the tip of the elastic member is coiled by pressing the pressing member. When the first member is slid by being pressed against the surface on the distal end side of the convex portion of the member, it is possible to prevent the tip of the elastic member from slipping outward and coming off, and the first member becomes the second member. On the other hand, the required amount can be reliably slid, and the certainty of operation can be increased.

In the medical device according to the present invention, the cross-sectional shape of the wire rod constituting the coil member is a substantially right-angled isosceles triangle, one of the equilateral surfaces is the distal end side, and the other is the equilateral side. The distal end side of the surface can be brought into contact with the first member. For example, when a coiled coil member is manufactured by winding a wire rod having a substantially right-angled isosceles triangle shape around a columnar member, the distal end side of the other equilateral surface abuts on the columnar member and the proximal end. By performing the winding while tilting so that the sides are separated from each other, it is possible to easily obtain a coil member whose surface on the distal end side of the convex portion is tilted so that the inner side is located on the proximal end side rather than the outer side in the radial direction. be able to.

In the medical device according to the present invention, the portion related to the apex angle in the cross section of the wire rod constituting the coil member can be R-chamfered. Manufacture is easy when the wire rod constituting the coil member is manufactured by deformed wire drawing.

In the medical device according to the present invention, the coil member can be provided so that its distal end is located outside the housing. With this configuration, the coil member can reinforce a part of the first member on the housing side in a bendable manner, and it is not necessary to separately provide a member for reinforcement. Therefore, the configuration can be simplified. , The operation unit can be made smaller and lighter.

The medical device according to the present invention has an outer sheath as the first member, an inner sheath as the second member, and a stent placement portion in which a stent is placed at the distal end of the inner sheath. By sliding the outer sheath with respect to the inner sheath, it can be particularly preferably used as a stent delivery device that releases the stent arranged in the stent arrangement portion.

FIG. 1 is a front view showing the overall configuration of the stent delivery device according to the embodiment of the present invention. FIG. 2 is a side view showing the configuration of the distal end portion of the stent delivery device shown in FIG. FIG. 3 is a partial cross-sectional view showing the configuration of the distal end portion of the stent delivery device shown in FIG. FIG. 4 is a side view showing an example of a stent applied to the stent delivery device shown in FIG. FIG. 5 is a cross-sectional view showing the configuration of the operation unit of the stent delivery device shown in FIG. 1, and is a diagram showing a state in which the push button is not pressed. FIG. 6 is a cross-sectional view showing the configuration of the operation unit of the stent delivery device shown in FIG. 1, and is a view showing a state in which the push button is pressed and pushed. FIG. 7 is a cross-sectional view showing the configuration of the operation unit of the stent delivery device shown in FIG. 1, and is a view showing a state in which the outer sheath is slid to the stroke end. FIG. 8 is a partial cross-sectional view showing an enlarged main part of the operation portion of the stent delivery device shown in FIG. FIG. 9 is a cross-sectional view of a coil member used in the operation unit of the stent delivery device shown in FIG. FIG. 10 is an enlarged cross-sectional view showing a main part of the coil member shown in FIG. FIG. 11 is a cross-sectional view showing a configuration of a modified example of the operation unit of the stent delivery device shown in FIG. FIG. 12 is a partial cross-sectional view showing an enlarged main part of a modified example of the operation portion of the stent delivery device shown in FIG. FIG. 13 is a development view showing an example of a stent applied to the stent delivery device shown in FIG. FIG. 14 is a developed view showing another example of a stent applied to the stent delivery device shown in FIG.

Hereinafter, as an embodiment of the medical device according to the present invention, in order to secure the patency of a lumen (for example, the large intestine) such as a stenotic or occluded digestive organ, the stenosis or the stenosis is performed by using an endoscope. A stent delivery device used to place a self-expanding stent in an occluded site will be described with reference to the drawings.

However, the medical device of the present invention is a stent delivery for placing a stent for not only patency of a lumen such as a digestive organ but also for patency of a bile duct, a ureter, a blood vessel, and other lumens. It can be used as a device. It can also be used as a stent delivery device for placing a stent for bypassing between a luminal organ and another luminal organ such as the stomach and intrahepatic bile duct, duodenum and common bile duct. Further, it can be used not only as a delivery device for a self-expandable stent but also as a delivery device for a tube stent having a fixed diameter.

The medical device of the present invention is not limited to the stent delivery device, and the tubular or proximal end, which also has the distal end and the proximal end, is contained in the tubular first member having the distal end and the proximal end. A medical device (inside) in which a wire-shaped second member is slidably inserted and the first member is slid toward the proximal end side or the distal end side with respect to the second member. It can be widely applied to (including surgical treatment tools for endoscopes).

First, refer to FIG. The stent delivery device 1 is connected to the elongated catheter portion 2 inserted into the patient's body (lumen) and the proximal end side of the catheter portion 2 via a treatment tool guide tube of an endoscope (not shown), and is connected to the body. It is configured to roughly include an operating portion (handle) 3 for operating the catheter portion 2 in the body from the outside and a stent 5 as an indwelling target.

The catheter portion 2 includes an inner sheath (inner tube) 21 having a distal end and a proximal end, and an outer sheath (outer tube) 22 having a distal end and a proximal end.

Contrast-enhanced markers (not shown) may be attached in the vicinity of the distal ends of the inner sheath 21 and / or the outer sheath 22, respectively. The position of the contrast marker is detected by X-ray fluoroscopy and serves as a marker in the body. For example, the contrast marker is formed of a metal material such as gold, platinum, or tungsten, or a polymer blended with barium sulfate or bismuth oxide. ..

The inner sheath 21 is made of an elongated tube having flexibility, and a guide wire 4 used as a guide for inserting the catheter portion 2 into the patient's body is inserted into the inner sheath 21. After inserting the guide wire 4 into the body to secure a path between the outside and the inside of the body, the catheter portion 2 is pushed (advanced) along the guide wire 4 to make the distal end side of the catheter portion 2 the purpose of the body. Can be inserted into the site. The outer diameter of the inner sheath 21 is about 0.5 to 4.0 mm.

A tip tip 24 formed so as to become thinner toward the tip (distal end) of the inner sheath 21 is attached to the distal end of the inner sheath 21. The tip tip 24 has an opening 24a that communicates with the distal end of the lumen of the inner sheath 21 along its central axis, and its proximal end is the distal end of the lumen of the outer sheath 22. It is a small diameter portion 24b having an outer diameter that can be inserted into the portion (see FIGS. 2 and 3). The tip tip 24 plays a role of reducing the insertion resistance of the catheter portion 2 and facilitating insertion into the body, and is made of polyamide, polyamide elastomer, polyurethane, fluororesin such as polytetrafluoroethylene, polyethylene and the like. It can be formed from a polyolefin resin or the like.

A fixing ring 25 is integrally fixed in the vicinity of the distal end of the inner sheath 21, and the fixing ring 25 is for defining the position of the proximal end of the stent 5, from the fixing ring 25. The part on the distal end side is the stent placement part. A stent 5 is arranged in the stent arrangement portion so as to cover the inner sheath 21.

The outer sheath 22 is made of a flexible elongated tube, has an inner diameter slightly larger than the outer diameter of the inner sheath 21, and the inner sheath 21 is slidably inserted inside the outer sheath 22. The inner diameter of the outer sheath 22 is about 0.5 to 4.5 mm, and the outer diameter is about 1.0 to 5.0 mm. The outer sheath 22 can slide (relatively move) in the axial direction with respect to the inner sheath 21 by operating the operation unit 3.

Examples of the material of the inner sheath 21 and the outer sheath 22 include polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyurethane, ethylene-vinyl acetate copolymer, polyester such as polyethylene terephthalate and polybutylene terephthalate, polyamide, and polyether polyamide. , Polyester polyamide, polyether ether ketone, polyetherimide, various resin materials such as fluororesins such as polytetrafluoroethylene and tetrafluoroethylene / hexafluoropropylene copolymer, polystyrene-based, polyolefin-based, polyurethane-based, polyester Various thermoplastic elastomers such as based, polyamide-based, and polybutadiene-based can be used. Two or more of these can be used in combination.

In some cases, an outer sheath tube made of a flexible elongated tube into which the outer sheath 22 is slidably inserted is provided, but in the present embodiment, the outer sheath tube is not provided.

The stent 5 is a self-expanding covered stent that expands in diameter by its own elastic force from a state of being contracted and reduced in diameter by elastic deformation, and as shown in FIG. 4, a tubular bare stent formed by a frame. It has 51 and a coating film portion (not shown) that covers the outer periphery of the bare stent 51. The bare stent 51 is made of a superelastic metal such as a nickel-titanium alloy or a cobalt-chromium alloy, a shape memory metal, or the like. The surface of the bare stent 51 is covered with a coating film that spreads so as to fill the space between adjacent frames, and the outer periphery of the bare stent 51 covered with the coating film is covered with a coating film portion such as a polymer film. ..

The total length and diameter of the stent 5 are determined according to the intended use, but the total length is about 30 to 200 mm, and the outer diameter at the time of expansion is about φ2 to φ30 mm. The outer diameter of the stent 5 when the diameter is reduced is about a fraction of the outer diameter when the diameter is expanded. The total length of the large intestine stent is about 40 to 150 mm, and the outer diameter at the time of expansion is about φ16 to φ22 mm. As an example of a stent for the large intestine, FIG. 13 shows a development view of a stent having an outer diameter of φ = 18 mm and a total length of L = 60 mm when the diameter is expanded, and an outer diameter of φ = 22 mm and a total length of L = 60 mm when the diameter is expanded. A development view of the stent is shown in FIG. In the present embodiment, the stent 5 is described as one of the constituent members of the stent delivery device 1, but the stent 5 can be replaced as a separate member from the stent delivery device 1.

Returning to FIG. 1, the guide wire 4 is inserted into the lumen of the inner sheath 21 when the stent delivery device 1 is inserted into the lumen of the body, and the distal end thereof is the distal end of the tip tip 24 of the inner sheath 21. 24a (see FIGS. 2 and 3), and its proximal end is exposed to the outside through the opening of the protrusion 21a at the proximal end of the inner sheath 21 arranged so as to penetrate the operating portion 3. Arranged to do.

Next, the operation unit 3 will be described with reference to FIGS. 5 to 8. The operation unit 3 has a handle that is a means for the operator to grip the stent 5 by hand and perform a release operation of the stent 5. The housing 31 constituting the handle has a substantially linear lower side portion 31a so that the index finger, middle finger, ring finger and little finger (or one or more of them) can be arranged when gripped by the operator's hand. It has an upper side portion 31b having a loose inverted arcuate recess so that a portion of the base of the thumb and a portion of the palm near the base of the thumb can be arranged.

The housing 31 has a sheath accommodating portion 32 that defines a substantially columnar space into which the proximal end side of the inner sheath 21 and the outer sheath 22 is drawn. The distal end of the sheath accommodating portion 32 has an opening 32a for retracting these sheaths 21 and 22, and the proximal end of the sheath accommodating portion 32 is in contact with the proximal end of the outer sheath 22 to form the outer. The sheath 22 is closed by a bottom surface 32b that defines the stroke end when slid. A through hole is formed in the central portion of the bottom surface 32b, and the proximal end of the inner sheath 21 is inserted into the through hole and fixed by adhesion or the like on the outer peripheral surface thereof. At the proximal end of the housing 31, a protrusion 21a having a through hole communicating with the through hole is provided.

A push button (pressing member) 33 is located near the distal end of the upper side portion 31b of the housing 31 in the extending direction of the portion of the outer sheath 22 existing in the housing 31 (the axial center direction of the sheath accommodating portion 32). It is slidably held in the direction A1 intersecting from the distal end side to the proximal end side at a predetermined angle θ1. That is, the housing 31 is provided with a button accommodating portion 34 that defines a substantially cylindrical space, and the axial core direction A1 of the button accommodating portion 34 is the axial core direction (outer) of the sheath accommodating portion 32. It is formed so as to substantially coincide with the direction in which the sheath 22 extends) at a predetermined angle θ1.

The tip end side of a substantially columnar push button 33 is inserted into the opening side of the button accommodating portion 34, and the push button 33 is slidably held along the axial center direction of the button accommodating portion 34. Although not shown, a part of the push button 33 is provided with a mechanism for engaging with a part of the button accommodating portion 34 to prevent the push button 33 from coming out of the button accommodating portion 34. ing. A spring support portion 34a is provided in the intermediate portion of the button accommodating portion 34, and a coil spring (biasing member) 35 is interposed between one surface of the spring support portion 34a and the tip surface of the push button 33. Has been done.

When no external force acts on the push button 33 (when it is not pressed so as to be pushed into the button accommodating portion 34), as shown in FIG. 5, the push button 33 is separated from the outer sheath 22 at a predetermined first position (exit described above). It is urged by the coil spring 35 so as to be located at a position (position defined by the prevention mechanism). Further, when the push button 33 is pressed so as to be pushed into the button accommodating portion 34, as shown in FIG. 6, the push button 33 is placed on the outer sheath 22 rather than the first position against the urging force of the coil spring 35. It is possible to move to a predetermined second position in close proximity.

When the pressure on the push button 33 is released, the push button 33 returns to the original first position by the urging force of the coil spring 35. The second position of the push button 33 is defined by the position of the spring support portion 34a and the dimension in the longitudinal direction when the coil spring 35 is compressed.

The push button 33 places the abdomen of the index finger, middle finger, ring finger and little finger (or one or more of them) on the lower side portion 31a by the operator's hand, and the base portion of the thumb and the base portion of the thumb of the palm. It is configured so that it can be pressed or released by the belly of the tip of the thumb (the part beyond the first joint) by bending and stretching the thumb in a state where the vicinity portion of the thumb is arranged on the upper side portion 31b and gripped. There is.

Considering that the push button 33 can be pressed and released by the thumb ergonomically without stress, the position (first position) and the amount of pushing (first position and first position) of the end face on the distal end side of the push button 33. The dimension between the two positions) is set.

The pushing amount (stroke length) of the push button 33 is set to an optimum value in relation to the above-mentioned ergonomic viewpoint and the feed amount of the coil member 22a (outer sheath 22) by pressing the push button 33 once. NS.

Similarly, in consideration of the fact that the push button 33 can be pressed and released by the thumb ergonomically without stress, the axis direction (sliding direction of the push button 33) A1 of the button accommodating portion 34 accommodates the sheath. It is set so as to be inclined toward the distal end side and obliquely intersect with respect to the axial center direction of the portion 32. A predetermined position formed by the axis of the button accommodating portion 34 (pushing direction A1 of the push button 33) and the axis of the sheath accommodating portion 32 (extending direction of the outer sheath 22 in the housing 31 or extending direction of the lower side portion 31a). The angle θ1 can be set in a range larger than 0 ° and smaller than 90 °. This angle θ1 is set to an optimum value in relation to the ergonomic viewpoint and the configuration of the coil member 22a described later.

The tip end side (back side opposite to the opening side) of the button accommodating portion 34 communicates with a part (side surface) of the sheath accommodating portion 32 via the connection space 36. A base end portion of a leaf spring (plate-shaped elastic member) 33a is fixed to the tip of the push button 33. The tip side of the leaf spring 33a passes through the connection space 36, and in a state where the push button 33 is set to the first position (the state shown in FIG. 5), the tip thereof slightly protrudes into the sheath accommodating portion 32. It is arranged like this.

A coil member 22a that forms a plurality of convex portions (or concave portions) on the surface of the outer sheath 22 is attached to a part of the proximal end side. The coil member 22a is formed by winding a wire rod made of an elastic metal or the like having a substantially polygonal cross section in a coil shape, and the proximal end of the outer sheath 22 is fitted inside the outer sheath. It is fixed at 22.

As the coil member 22a, a wire rod having a substantially triangular cross-sectional shape and wound in a coil shape (spiral shape) so that a convex portion is formed on the outside can be used. The convex portion of the coil member 22a is a single one that is continuous in a coil shape as a whole, but a plurality of convex portions (portions corresponding to one round) are arranged in the axial core direction to form a coil as a whole. Since it can be considered that a single continuous convex portion is formed, in the specification of the present application, a portion corresponding to one round of the convex portion may also be simply referred to as a convex portion.

The surface of the convex portion of the coil member 22a on the distal end side is inclined so that the inner side of the coil member 22a is located closer to the proximal end side than the outer side in the radial direction. That is, the coil member 22a has an angle (interval angle on the distal end side) formed at an arbitrary position in the circumferential direction between the axial core of the coil member 22a and the surface on the distal end side of the convex portion, which is less than 90 °. It is configured to be.

The cross-sectional shape of the wire rod constituting the coil member 22a may be any of an obtuse triangle, an acute angle triangle, a right angle triangle, an obtuse isosceles triangle, an acute isosceles triangle, and a right angle isosceles triangle. Further, as the wire rod constituting the coil member 22a, a wire rod having a portion related to the apex angle in the cross section of which is R-chamfered or C-chamfered may be used.

In the present embodiment, as shown in FIGS. 8 to 10, as the coil member 22a, a wire rod constituting the coil member 22a has a substantially right-angled isosceles triangle shape. Then, the surface related to one of the equal sides is wound so as to be the surface DP on the distal end side, and the surface related to the bottom side is to be the surface PP on the proximal end side. Further, since the surface DP on the distal end side is inclined so that the inner IS is located on the proximal end side with respect to the outer OS in the radial direction, the distal end side of the other equilateral surface abuts on the outer sheath 22. The one wound with a slight inclination so that the proximal end side is separated from the outer sheath 22 is used. The portion related to the apex angle in the cross section of the wire rod constituting the coil member 22a is R-chamfered.

The angle θ2 formed by the surface DP on the distal end side of the convex portion of the coil member 22a and the axial core direction of the coil member 22a (or the outer sheath 22) is the configuration (shape, size) of the tip portion of the leaf spring 33a, etc. In relation to the above, the push button 33 was pressed to engage (contact) the tip of the leaf spring 33a with the surface DP on the distal end side of the convex portion of the coil member 22a, and the outer sheath 22 was pushed (press-contacted). At that time, the tip of the leaf spring 33a is set to minimize slipping outward (disengagement). The angle θ2 can be appropriately selected in a range of preferably 70 ° or more and less than 90 °, more preferably in a range of 80 ° or more and 85 ° or less. The equilateral dimensions of the wire rod constituting the coil member 22a can be set in the range of 0.5 to 1.0 mm. The R chamfer of the portion related to the apex angle in the cross section of the wire rod constituting the coil member 22a can be set in the range of R = 0.05 to 0.15 mm. If R = 0.15 or more, the tip of the leaf spring 33a slides outward and easily comes off, so this or less is preferable.

As the wire rod constituting the coil member 22a, for example, a round wire formed into a substantially right-angled isosceles triangle shape by deformed wire drawing can be used. By manufacturing the wire rod constituting the coil member 22a by deformed wire drawing of a round wire, it is possible to easily manufacture a wire rod in which the portion related to the apex angle in the cross section is appropriately R-chamfered.

In the manufacture of the coil member 22a, a wire rod having a substantially right-angled isosceles triangle shape with a portion related to the apex angle in the cross section being rounded is wound around a columnar columnar member (mold) having a predetermined diameter as appropriate. A method of forming a coil by heating, cooling, or the like can be used. In this case, the distal end side of the surface related to the other equilateral side abuts on the columnar member, and the surface on the distal end side of the convex portion is radially oriented by performing winding while tilting so that the proximal end side is separated. It is possible to easily obtain a coil member that is inclined so that the inside side of the outside side is located on the proximal end side. The diameter of the columnar member is slightly smaller than the outer diameter of the outer sheath 22 to be mounted. In the present embodiment, the coil member 22a is tightly wound, but it does not have to be tightly wound.

If a wire rod having an apex angle of (180 ° -θ2) and an obtuse-angled isosceles triangle shape is used as the wire rod constituting the coil member 22a, the other wire rod is wound into the columnar member to form a coil. The entire distal end side and proximal end side of the equilateral surface can be wound while being pressed against the columnar member, and more stable winding can be performed.

When the push button 33 is pressed and pushed to the second position, the tip of the leaf spring 33a is pressed (engaged) with the surface DP on the distal end side of one of the convex portions of the coil member 22a mounted on the outer sheath 22. The outer sheath 22 is slid toward the proximal end side of the inner sheath 21 by a certain amount according to the stroke length of the push button 33 (see the leaf spring 33a shown by the alternate long and short dash line in FIG. 8).

When the pressure on the push button 33 is released, the push button 33 returns to the original first position by the urging force of the coil spring 35, and the tip of the leaf spring 33a engages with the coil member 22a mounted on the outer sheath 22 accordingly. Without doing so, the leaf spring 33a returns to its original position (see the leaf spring 33a shown by the solid line in FIG. 8). By repeating pressing and releasing the push button 33, the outer sheath 22 can be slid toward the proximal end side with respect to the inner sheath 21 by a predetermined amount.

The feed amount of the coil member 22a (outer sheath 22) by pressing the push button 33 once is not particularly limited, but is, for example, 2.5 mm to 10 mm (for example, 2.5 mm, 5 mm, 7.5 mm, or 10 mm). The stroke length of the push button 33 can be a value corresponding to this.

When the push button 33 is released from the surface PP on the proximal end side of the convex portion of the coil member 22a, the tip end portion of the leaf spring 33a engages with the convex portion in the vicinity of the tip end portion of the coil member 22a. The push button 33 is set so as to smoothly return to the original position (first position). The angle (interval angle on the distal end side) θ3 formed by the surface PP on the proximal end side of the convex portion of the coil member 22a and the axial direction of the coil member 22a (or the outer sheath 22) is preferably 25 ° or more and 45. It can be selected in the range of less than °, more preferably in the range of 35 ° or more and 40 ° or less. In this embodiment, θ3 is (θ2-45 °) because the cross section of the wire is a substantially right-angled isosceles triangle.

As a method of attaching the coil member 22a to the proximal end of the outer sheath 22, the proximal end of the outer sheath 22 is inserted with the coil member 22a expanded so that its inner diameter is slightly widened, and the coil is attached. It can be fixed by reducing the diameter by the restoring force of the member 22a. The coil member 22a can be fixed to the outer sheath 22 by its own diameter-reducing force without using an adhesive or the like, but it may be adhesively fixed by an adhesive or the like.

The longitudinal dimension of the coil member 22a is set to be larger than the stroke length (slide length of the outer sheath 22 with respect to the inner sheath 21) required to release the stent 5 arranged in the stent arrangement portion.

The position of the proximal end of the coil member 22a is a state in which the outer sheath 22 is pulled out by the maximum amount (that is, a state in which the distal end portion of the outer sheath 22 is arranged so as to cover the stent 5 arranged in the stent arrangement portion). ), The push button 33 is set closer to the proximal end side than the portion where the tip of the leaf spring 33a is located in a state where no external force acts on the push button 33.

As for the position of the distal end of the coil member 22a, the push button 33 is in a state where the outer sheath 22 is pulled in by the maximum amount (a state in which the proximal end of the outer sheath 22 is in contact with the bottom surface 32b of the sheath accommodating portion 32). It is set on the distal end side of the portion where the tip of the leaf spring 33a is located in a state where no external force acts.

In the present embodiment, the position of the distal end of the coil member 22a is such that the outer sheath 22 is pulled in by the maximum amount (the proximal end of the outer sheath 22 is in contact with the bottom surface 32b of the sheath accommodating portion 32). It is set so as to protrude toward the distal end side by a predetermined dimension from the opening 32a of the sheath accommodating portion 32. The predetermined dimension in this case can be about 30 to 220 mm.

When only the slide of the outer sheath 22 is considered, if the position of the distal end of the coil member 22a is on the distal end side of the portion where the tip of the leaf spring 33a is located, the housing 31 (sheath accommodating portion 32). ), But in the present embodiment, the position of the distal end of the coil member 22a is projected from the opening of the sheath accommodating portion 32 toward the distal end side by a predetermined dimension, so that the outer sheath 22 is located. It is designed to reinforce a part of the proximal end side of the.

Since the coil member 22a in the present embodiment is formed by winding a wire rod made of elastic metal in a coil shape, it has flexibility, and by being arranged around the outer sheath 22, the outer sheath 22 is arranged. Even when a local force such as bending is applied to the portion on the housing 31 side of the outer sheath 22, the outer sheath 22 can be uniformly curved and reinforced so as to prevent the outer sheath 22 from being kinked.

The portion of the coil member 22a arranged inside the housing 31 in the present embodiment provides a function for more effectively engaging with the tip of the leaf spring 33a when the outer sheath 22 is slid. It provides a function as a reinforcing member that protects the outer sheath 22 from damage (crushing, etc.) due to engagement with the tip of the leaf spring 33a.

In addition to this, the portion of the coil member 22a arranged on the outside (distal end side) of the housing 31 (and its vicinity) is protected from local bending or the like in the portion of the outer sheath 22 on the housing 31 side. It provides a function as a reinforcing member. As described above, since the coil member 22a in the present embodiment is a single member and provides three functions, the number of parts can be reduced as compared with the case where the corresponding functions are realized by different members. The configuration is simple.

In the present embodiment, as shown in FIG. 6, when the push button 33 is pressed and pushed in, the tip of the leaf spring 33a engages with the surface on the distal end side of the convex portion of the coil member 22a. , The coil member 22a (outer sheath 22) is slid toward the proximal end side. When the push button 33 is released, the push button 33 returns to its original position due to the urging force of the coil spring 35 as shown in FIG. 5, but at this time, the tip of the leaf spring 33a is close to the convex portion of the coil member 22a. The coil member 22a (outer sheath 22) may slide (reverse) toward the distal end side by interfering with the surface on the position end side. Therefore, in the present embodiment, a slide regulating means is provided in order to surely prevent the outer sheath 22 from sliding toward the distal end side.

That is, in the portion near the distal end on the lower side portion 31a side of the housing 31, the release switch 37 extends in the extending direction of the portion of the outer sheath 22 existing in the housing 31 (the axial direction of the sheath accommodating portion 32). It is held so that it can slide in a direction substantially parallel to. A switch accommodating portion 38 defining a substantially rectangular parallelepiped space is defined in the housing 31, and the longitudinal direction of the switch accommodating portion 38 is the axial direction of the sheath accommodating portion 32 (outer sheath 22). It is formed in a direction substantially parallel to the extending direction).

A substantially rectangular parallelepiped release switch 37 is slidably accommodated in the switch accommodating portion 38, and an operation protrusion 37a integrally formed with the release switch 37 is accommodated in the lower side portion of the switch accommodating portion 38. It is arranged so as to project through the opening 38a formed in a part of the 31a side.

By the operator's hand, the abdomen of the index finger, middle finger, ring finger and little finger (or one or more of them) is placed on the lower side portion 31a, and the portion near the base of the thumb and the portion of the palm near the base of the thumb is placed on the upper side. By arranging the portion 31b and gripping the housing 31 as described above, the operation protrusion 37a is pressed by the tip of the index finger toward the proximal end side or the distal end side along the longitudinal direction thereof. The release switch 37 can be slid.

The proximal end side of the switch accommodating portion 38 communicates with a part (side surface) of the sheath accommodating portion 32 via the connection space 39. At the proximal end of the release switch 37, a base end portion of a leaf spring 37b made of elastic metal or the like extending diagonally in the slide direction of the release switch 37 is fixed. When the release switch 37 is set to a fixed position slid toward the proximal end side of the leaf spring 37b, the tip thereof passes through the connection space 39 and is one distal end of the convex portion of the coil member 22a. It is arranged so as to slightly protrude into the sheath accommodating portion 32 so as to engage with the side surface.

When the release switch 37 is set to the fixed position, the tip of the leaf spring 37b is engaged with the surface on the distal end side of the convex portion of the coil member 22a, so that the coil member 22a (outer sheath 22) is far away. Regulate the slide to the end side. When the coil member 22a (outer sheath 22) is slid toward the proximal end side, the tip of the leaf spring 37b is elastically deformed along the shape of the convex portion of the coil member 22a and escapes, so that the coil member 22a escapes. The slide of the (outer sheath 22) toward the proximal end side is not restricted.

When the release switch 37 is slid toward the distal end side and set to the release position, the base end side of the leaf spring 37b is elastically deformed with a part of the housing 31 as a fulcrum, and the coil member 22a of the leaf spring 37b at the tip thereof is elastically deformed. Is disengaged from the convex portion (see the leaf spring 37b shown by the alternate long and short dash line in FIG. 8). Therefore, when the release switch 37 is set to the release position, the slide of the coil member 22a (outer sheath 22) to the distal end side is not restricted, and if necessary, the outer sheath 22 is moved to the distal end side. It becomes possible to slide to.

In the present embodiment, by sliding the release switch 37, the leaf spring 37b is disengaged from the convex portion of the coil member 22a so that the outer sheath 22 can be slid toward the distal end side. When it is not necessary to slide the outer sheath 22 toward the distal end side, the leaf spring 37b is set at a fixed position on the proximal end side of the leaf spring 37b without providing a release mechanism such as the release switch 37. It may be fixed to the housing 31 in the same posture as the case.

When the outer sheath 22 is pulled out from the housing 31 by the maximum amount (the state of FIG. 5), the distal end of the outer sheath 22 reaches the tip tip 24 and is inside the outer sheath 22 as shown in FIGS. 2 and 3. A small diameter portion 24b of the tip tip 24 is inserted into the distal end of the lumen, and in this state, the stent 5 arranged in the stent arrangement portion of the inner sheath 21 is held inside the stent 5 in a reduced diameter state. It is in a state of being.

When the push button 33 is repeatedly pressed and released a predetermined number of times from this state, the outer sheath 22 is slid toward the proximal end side with respect to the inner sheath 21, and the stent 5 is distal to the outer sheath 22. It is pushed out relatively from the edge and released (diameter expanded) by self-expanding force.

In the above-described embodiment, when the push button 33 is pressed and pushed in, the tip of the leaf spring 33a is pressed against a part of the surface DP on the distal end side of the convex portion of the coil member 22a, and the outer sheath 22 is the inner sheath 21. On the other hand, the push button 33 is slid by a certain amount according to the stroke. Since the surface DP on the distal end side of the convex portion of the coil member 22a is inclined so that the inner IS is located on the proximal end side with respect to the outer OS in the radial direction, the push button 33 is pressed to press the plate. When the tip of the spring 33a is pressed against the surface DP on the distal end side of the convex portion of the coil member 22a and the push button 33 is slid, the tip of the leaf spring 33a is less likely to slip outward and come off. can. Therefore, the outer sheath 22 can be reliably slid with respect to the inner sheath 21 by a required amount, and the certainty of operation can be improved.

Further, in the above-described embodiment, a push mechanism composed of a push button 33, a button accommodating portion 34, a coil spring 35, a leaf spring 33a, a connection space 36, and the like, and a coil member 22a mounted on the outer sheath 22 are provided. By repeating pressing and releasing the push button 33, the outer sheath 22 is slid with respect to the inner sheath 21, and the configuration is simple, and the operation unit can be made smaller and lighter.

Further, in the above-described embodiment, the shape of the housing 31, the pressing position of the push button 33, the pressing direction, the stroke length, and the like are ergonomically optimized. It is basically possible to operate with one hand while gripping in a good shape, and the operability is good.

In the above-described embodiment, the outer sheath 22 is slid in cooperation with the push mechanism (push button 33, button accommodating portion 34, coil spring 35, leaf spring 33a, connection space 36, etc.), so that the outer sheath 22 is convex toward the surface side. A coil member 22a having a portion (a plurality of convex portions) is attached to a part of the outer sheath 22 on the proximal end side.

Further, in the above-described embodiment, as the slide restricting means, a leaf spring 37b whose tip engages with the surface on the distal end side of the convex portion of the coil member 22a is provided, so that the outer sheath 22 is retrograde (distal). (Slide to the end side) can be effectively prevented. In addition to this, the leaf spring 37b is attached to the release switch 37, and the engagement of the coil member 22a at the tip of the leaf spring 37b with respect to the distal end side surface of the convex portion is released as necessary. It is convenient.

Further, in the above-described embodiment, a push mechanism (push button 33, button accommodating portion 34, coil spring 35, leaf spring 33a, connection space 36, etc.) is provided to press the push button 33 provided in the housing 31. The outer sheath 22 is slid through the coil member 22a by repeating the pressing and releasing. The mechanism (sliding means) for sliding the outer sheath 22 by engaging (pressing) with a part of the convex portion of the coil member 22a is not limited to the push mechanism.

As shown in FIGS. 11 and 12, the release switch 37 (37a) may be omitted and the leaf spring 37b may be directly fixed to the housing 31. In FIGS. 11 and 12, the shapes (structures) of the housing 31, the push button 33, and the like are illustrated to be different from those shown in FIGS. 5 to 8, but they are functionally the same. The same reference numerals as those shown in FIGS. 5 to 8 are assigned, and the description thereof will be omitted. Other members or parts substantially the same as those shown in FIGS. 5 to 8 are designated by the same reference numerals as those shown in FIGS. 5 to 8 and the description thereof will be omitted.

The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above-described embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

1 ... Stent delivery device (medical equipment)
2 ... Catheter part 21 ... Inner sheath (second member)
22 ... Outer sheath (first member)
22a ... Coil member 24 ... Tip tip 3 ... Operation unit 31 ... Housing 32 ... Sheath accommodating unit 33 ... Push button (pressing member)
33a ... Leaf spring (elastic member)
34 ... Button accommodating part 35 ... Coil spring 36 ... Connection space 37 ... Release switch 37b ... Leaf spring 4 ... Guide wire 5 ... Stent DP ... Surface on the distal end side of the convex part of the coil member PP ... Near the convex part of the coil member Surface on the side of the position

Claims (5)

A tubular first member with distal and proximal ends,
A second member that has a distal end and a proximal end and is slidably inserted through the first member.
A housing in which the proximal end side portion of the first member is pulled into the inside and the second member is fixed, and the housing.
A pressing member provided on the housing so as to be slidable in a direction diagonally intersecting from the distal end side to the proximal end side with respect to the extending direction of the portion of the first member existing in the housing.
A coil member having a shape in which a wire rod provided in at least a part of a portion of the first member existing in the housing and having a substantially triangular cross-sectional shape is wound in a coil shape so as to form a convex portion on the outside. When,
An elastic member whose base end portion is fixed to the pressing member, whose tip is pressed against a part of the surface on the distal end side of the coil member, and which slides the first member toward the proximal end side. Have and
A medical device in which the surface on the distal end side of the convex portion of the coil member is inclined so that the inner side is located on the proximal end side from the outer side in the radial direction. The cross-sectional shape of the wire rod constituting the coil member is a substantially right-angled isosceles triangle, the surface related to one equilateral side is the surface on the distal end side, and the distal end side of the surface related to the other equilateral side is the first. The medical device according to claim 1, which comes into contact with a member. The medical device according to claim 1 or 2, wherein the portion related to the apex angle in the cross section of the wire rod constituting the coil member has an R chamfered shape. The medical device according to any one of claims 1 to 3, wherein the coil member is provided so that its distal end is located outside the housing. The outer sheath is provided as the first member, the inner sheath is provided as the second member, the stent is provided at the distal end of the inner sheath, and the outer sheath is slid with respect to the inner sheath. The medical device according to any one of claims 1 to 4, which is a stent delivery device that releases a stent placed in the stent placement portion by causing the stent to be delivered.

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