JP7006604B2 - Medical equipment - Google Patents

Description

The present invention relates to a medical device used by moving a member on the distal end side by an operation outside the body, such as a stent delivery device used for indwelling a stent in the body.

A medical method is known in which a stent is placed at a stenotic site in order to secure the patency of an internal lumen 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 the stenosis. Examples of the stent include a balloon-expandable type and a self-expandable type, and as a device for indwelling a self-expandable 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 in a state of being reduced in diameter by elastic deformation inside the vicinity of the distal end of the outer sheath, and an operation portion (handle) provided on the proximal end side thereof. Is operated to slide the outer sheath toward the proximal end side so as to pull back with respect to the inner sheath, thereby releasing the stent from the outer sheath, and expanding and releasing the stent by the self-expanding force of the stent.

In the stent delivery device described in Patent Document 1, in the operation unit for sliding the outer sheath with respect to the inner sheath, a tubular shaft for reinforcing the outer sheath is fixed to the outside of the outer sheath, and the shaft of the shaft is fixed. The shaft is inserted into a through hole of a drive plate provided so as to be inclined with respect to the core. The drive plate is in a slidable state with respect to the shaft when the posture is substantially perpendicular to the shaft core, and is engaged with the shaft when the posture is inclined with respect to the shaft core. It will be in a stopped state.

When a lever rotatably provided in the housing of the operation unit is gripped and rotated against the urging force of the spring, the drive plate is tilted and moved to the proximal end side in a state of being locked to the shaft. Then, the outer sheath is slid toward the proximal end side with respect to the inner sheath. When the grip of the lever is released, the posture of the drive plate returns to the original substantially vertical posture due to the urging force of the spring, the lock to the shaft is released, the outer sheath remains as it is, and only the drive plate is on the distal end side. Move to. By repeatedly gripping and releasing the lever, the outer sheath can be slid toward the proximal end side by a predetermined amount with respect to the inner sheath.

However, according to this conventional technique, there is a problem that the mechanism for sliding the outer sheath with respect to the inner sheath is complicated, and it is difficult to reduce the size and weight of the operation unit.

International Publication No. WO2007 / 122901 Pamphlet

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 capable of reducing the size and weight of the operation unit.

In order to achieve the above object, the medical device according to the present invention is
The first tubular member and
A second member slidably inserted through the first member and
A housing in which the proximal end side portion of the first member and the second member is pulled into the inside thereof and the proximal end of the second member is fixed.
The proximal end of the first member is fitted and fixed inside the member, and a wire rod having a substantially polygonal cross section is wound in a coil shape so as to form irregularities on the outside thereof. The coil member is provided so that at least the proximal end of both ends thereof is located inside the housing.

Further, the medical device according to the present invention further has a sliding means provided in the housing and engaged with a part of the unevenness of the coil member to slide the first member with respect to the second member. be able to. With such a configuration, the first member can be slid by utilizing the unevenness on the outside of the coil member, and it is not necessary to separately provide a slide or a member for reinforcement, so that the configuration can be simplified. , The operation unit can be made smaller and lighter.

Further, the coil member may 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 so that it can be bent, and it is not necessary to separately provide a member for reinforcement. Therefore, the configuration is simplified. , The operation unit can be made smaller and lighter.

Further, 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 arrangement portion in which a stent is arranged 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 an overall configuration of a stent delivery device according to an embodiment of the present invention. FIG. 2 is a side view showing the configuration of the distal end of the stent delivery device shown in FIG. FIG. 3 is a partial cross-sectional view showing the configuration of the distal end 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 diagram 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 showing a configuration of a modified example of the operation unit of the stent delivery device shown in FIG. FIG. 10 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.

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 narrowed 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 can be used as a stent delivery device for ensuring not only the patency of a lumen such as a digestive organ but also the patency of a bile duct, a ureter, a blood vessel, and other lumens. .. It can also be used as a stent delivery device 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 first member having the distal end and the proximal end is contained in the tubular first member having the distal end and the proximal end. Endoscopic treatment 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 tools or other medical devices.

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 operation unit (handle) 3 for operating the catheter portion 2 in the body from the outside and a stent 5 as an indwelling target. The vicinity of the distal end of the catheter portion 2 including the stent 5 may be curved in a curved state depending on the shape of the site to be placed, but it is drawn linearly in FIG. 1.

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, and is formed of, for example, 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 inside 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 inside 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 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 used for polyamides, polyamide elastomers, polyurethanes, fluororesins 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, polyethylene terephthalate, and polyester such as polybutylene terephthalate, polyamide, and polyether polyamide. , Polyamide polyamide, polyether ether ketone, polyetherimide, various resin materials such as fluororesin such as polytetrafluoroethylene and tetrafluoroethylene / hexafluoropropylene copolymer, and 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-expandable 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 a 51 and a coating film portion 52 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 spread 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 52 such as a polymer film. There is.

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 φ20 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. 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 through 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 which 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 in the vicinity of the portion of 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 provide the outer. The sheath 22 is closed by a bottom surface 32b that defines a 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 on the outer peripheral surface thereof by adhesion or the like. 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 existing in the housing 31 of the outer sheath 22 (the axis direction of the sheath accommodating portion 32). It is slidably held in the direction A1 where it intersects at a predetermined angle θ1. That is, the housing 31 is provided with a button accommodating portion 34 that defines a substantially columnar 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 core 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 (urging member) 35 is interposed between one surface of the spring support portion 34a and the tip end 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), the push button 33 has a predetermined first position separated from the outer sheath 22 (exit as described above) as shown in FIG. It is urged by a coil spring 35 so as to be located at a position (position defined by a preventive 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 more than the outer sheath from the first position against the urging force of the coil spring 35. It is possible to move to a predetermined second position close to 22.

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 placed on the upper side portion 31b and gripped. There is.

Considering that the push button 33 can be pressed and released by the thumb without stress ergonomically, the position (first position) and the pushing amount (first position) of the end face on the distal end side of the push button 33 (first position and first position). 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 feeding amount of the coil member 22a (outer sheath 22) by pressing the push button 33 once. To.

Similarly, in consideration of the fact that the push button 33 can be pressed and released by the thumb without stress in terms of ergonomics, the axial core 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 diagonally intersect with respect to the axial core 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 °. The optimum value is set in relation to the ergonomic viewpoint and the configuration of the coil member 22a described later.

For example, when the apex angle θ2 (see FIG. 8) of the thread (convex portion) of the coil member 22a described later is 60 °, if it is set to about θ1≈30 ° (θ2 / 2), the leaf spring 33a The tip of the coil member 22a intersects the surface of the coil member 22a on the distal end side at approximately 90 °, and the most reliable engagement can be obtained. However, it is not necessary to set it so strictly, and the angle may be such that the tip end portion of the leaf spring 33a can engage with the surface on the distal end side of the thread (convex portion) of the coil member 22a. Preferably, the predetermined angle θ1 is in the range of 15 ° to 60 °. Further, the apex angle θ2 of the screw thread is not particularly limited. The angle θ2a of the surface on the distal end side of the thread (convex portion) within the apex angle θ2 (= θ2a + θ2b) of the screw thread and the angle θ2b on the surface on the proximal end side are substantially the same but different. Is also good. In the present embodiment, it is preferable that the angle θ2a of the thread surface on the distal end side with respect to the surface A2 perpendicular to the axis direction of the sheath accommodating portion 32 is substantially the same as the predetermined angle θ1.

The tip end side (back side opposite to the opening side) of the button accommodating portion 34 is communicated 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 end side of the leaf spring 33a passes through the connection space 36, and the push button 33 is set to the first position (the state shown in FIG. 5), and 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 protrusions (or recesses) 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 portion of the outer sheath 22 is fitted inside the coil member 22a. It is fixed to the sheath 22.

As the coil member 22a, a wire rod having a substantially triangular cross section can be wound in a coil shape so that a thread is formed as a convex portion on the surface side thereof. The coil member 22a is made by winding a wire rod having a substantially rhombic cross section in a coil shape so that threads are formed on both the front surface side and the inner surface side thereof (like a so-called insert screw). You may use the one having the same structure. The uneven inner peripheral surface of the coil member 22a having threads formed on both the surface side and the inner surface side thereof bites into the outer peripheral surface of the outer sheath 22 and is fixed so as not to move relative to each other in the axial direction. It is fixed.

When the push button 33 is pressed and pushed to the second position, the tip of the leaf spring 33a engages with one distal end surface of the thread of the coil member 22a mounted on the outer sheath 22, and 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. The leaf spring 33a returns to its original position (see the leaf spring 33a shown by the solid line in FIG. 8). By repeatedly 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.

The apex angle θ2 of the screw thread (convex portion) of the coil member 22a may be 60 ° as in a general screw, but may be other than 60 °. Further, the threads of the coil member 22a may have different flank angles θ2a on the distal end side and flank angles θ2b on the proximal end side. The apex angle (or flank angle) of the thread of the coil member 22a is such that when the push button 33 is pressed and pushed in, the tip of the leaf spring 33a is the surface on the distal end side of one of the threads of the coil member 22a. It suffices if the outer sheath 22 can be slid toward the proximal end side by securely engaging with the outer sheath 22. Moreover, the top angle (or flank angle) of the thread of the coil member 22a is such that when the push button 33 is released, the tip of the leaf spring 33a is engaged with the thread near the tip of the coil member 22a. The push button 33 is set to smoothly return to the original position (first position) without fitting.

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 used. It can be fixed by reducing the diameter by the restoring force of the member 22a. By arranging the threads on the inner surface side of the coil member 22a, it can be securely fixed to the outer sheath 22 without using an adhesive or the like. However, it may be adhesively fixed with 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 such that the outer sheath 22 is pulled out by the maximum amount (that is, 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 retracted 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 retracted 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. In this case, the predetermined dimension 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) is located. ), But in the present embodiment, the outer sheath 22 is formed by projecting the position of the distal end of the coil member 22a from the opening of the sheath accommodating portion 32 toward the distal end by a predetermined dimension. I am trying to reinforce a part of the proximal end side of.

Since the coil member 22a in the present embodiment is configured 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 to reinforce the outer sheath 22 so as to prevent kinking.

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 of the coil member 22a on the distal end side of the thread. , The coil member 22a (outer sheath 22) is slid toward the proximal end side. When the pressure of the push button 33 is released, the push button 33 returns to its original position as shown in FIG. 5 due to the urging force of the coil spring 35, but at this time, the tip of the leaf spring 33a interferes with the thread of the coil member 22a. As a result, the coil member 22a (outer sheath 22) may slide (reverse) toward the distal end side. Therefore, in the present embodiment, a slide restricting 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 slidably 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 on the upper side. By arranging the housing 31 in the portion 31b and gripping the housing 31 as described above, the operation protrusion 37a is pressed toward the proximal end side or the distal end side along the longitudinal direction by the tip portion of the index finger. 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 an elastic metal or the like extending diagonally in the slide direction of the release switch 37 is fixed. The leaf spring 37b, in a state where the release switch 37 is set to a fixed position slid toward the proximal end side, has its tip passing through the connection space 39 and one distal end of the thread 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 of the coil member 22a on the distal end side of the thread, so that the coil member 22a (outer sheath 22) is far away. Regulate sliding 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 thread of the coil member 22a and escapes, so that the coil member 22a escapes. It does not restrict the slide of the (outer sheath 22) toward the proximal end side.

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 thread (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 coil member 22a of the leaf spring 37b can be disengaged from the thread (convex portion) and the outer sheath 22 can be slid toward the distal end side. However, when it is not necessary to slide the outer sheath 22 to the distal end side, the leaf spring 37b and the release switch 37 are fixed to the proximal end side without providing a release mechanism such as a release switch 37. It may be fixed to the housing 31 in the same posture as when it is set to the position.

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 in the distal end of the lumen, and in this state, the stent 5 arranged in the stent placement 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, the push button 33, the button accommodating portion 34, the coil spring 35, the leaf spring 33a, the push mechanism including the connection space 36, and the coil member 22a mounted on the outer sheath 22 are provided, and the push button is provided. The outer sheath 22 is slid with respect to the inner sheath 21 by repeatedly pressing and releasing the pressure 33, and the configuration is simpler than that of the conventional technique, and the operation unit is made smaller and lighter. Can be planned.

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.

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 thread (convex portion) of the coil member 22a is provided, so that the outer sheath 22 is provided with a leaf spring 37b. Retrograde (sliding to the distal end side) can be effectively prevented. In addition to this, the leaf spring 37b is attached to the release switch 37, and the coil member 22a at the tip of the leaf spring 37b is engaged with the surface of the thread (convex portion) on the distal end side, if necessary. It can be canceled for convenience.

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 with a part of the thread (convex portion) of the coil member 22a is not limited to the push mechanism.

For example, instead of the push mechanism, a gear member is rotatably supported by the housing 31, a part of the gear member is exposed to the outside of the housing 31, and a part of the gear member is meshed with the coil member 22a. , The exposed part of the gear member may be configured so that the operator can rotate it with, for example, a thumb.

Further, as a mechanism for sliding the outer sheath 22, instead of the push mechanism, a member (claw or female screw) that meshes with the screw thread of the coil member 22a is fixed to the housing 31, and the outer sheath 22 is rotated to obtain the same. An outer sheath 22 that is slid by the principle of a ball screw may be used.

Since the above-described embodiment is a stent delivery device for a self-expandable stent, the sliding direction of the outer sheath 22 with respect to the inner sheath 21 at the time of release of the stent 5 is from the distal end side to the proximal end side. It is in the direction of going. On the other hand, in the case of a stent delivery device for a tube stent having a fixed diameter, the tube stent is extruded at the distal end of the outer sheath 22 and released, so that the outer sheath 22 slides with respect to the inner sheath 21. The direction is from the proximal end side to the distal end side.

In this case, the tips of the leaf springs 33a and the leaf springs 37b are arranged so as to engage with the surface on the proximal end side of the thread (convex portion) of the coil member 22a, and the slide of the push mechanism or the like is performed. By means, the coil member 22a (outer sheath 22) may be configured to be extruded toward the distal end side.

In the above-described embodiment, the leaf spring 33a fixed to the tip of the push button 33 has a substantially linear shape extending in the direction along the moving direction of the push button 33 in a state where no external force acts. This means that when the push button 33 is pressed and pushed in, a strong engagement with the thread of the coil member 22a is obtained, and the pressing force of the push button 33 is efficiently transmitted to the coil member 22a. On the contrary, when the pressure of the push button 33 is released, the push button 33 is not engaged or is weakly engaged so that the push button 33 can be smoothly returned.

However, when an external force acts on the outer sheath 22 in the direction of pulling the outer sheath 22 during non-operation (when the push button 33 is not pressed or released), the thread of the coil member 22a of the leaf spring 33a is threaded. Since the engagement with the coil member 22a is weak, the outer sheath 22 (coil member 22a) may move in the pulling direction. To deal with this, it may be configured as shown in FIGS. 9 and 10. That is, in the leaf spring 33a'in FIGS. 9 and 10, the portion in the middle thereof is curved (or bent), and the tip portion of the leaf spring 33a'(the portion engaging with the thread of the coil member 22a) is a coil. It is designed to be substantially perpendicular to the axis of the member 22a.

With this configuration, when the outer sheath 22 receives an external force in the direction in which it is pulled in (the direction from the left side to the right side in FIGS. 9 and 10), the tip of the leaf spring 33a'is the tip of the coil member 22a. A stronger engagement can be obtained with respect to. Therefore, the slide of the outer sheath 22 (coil member 22a) can be more suppressed when the outer sheath 22 is not operated, that is, the relative positions of the outer sheath 22 and the inner sheath 21 can be more reliably fixed. With this configuration, the engagement when the push button 33 is released becomes stronger, so that the coil member 22a is pushed out in the direction in which the outer sheath 22 is pushed out (in the direction from the right side to the left side in FIGS. 9 and 10). However, the outer sheath 22 is not pushed out by the action of the leaf spring 37b as a slide restricting means for preventing retrograde movement.

In addition, in FIGS. 9 and 10, the release switch 37 (37a) is not provided, and the leaf spring 37b is exemplified by being directly fixed to the housing 31. Further, although the shapes (structures) of the housing 31, the push button 33, and the like are different from those shown in FIGS. 5 to 8, they are functionally the same, and are shown in FIGS. 5 to 8. The same reference numerals as those shown are used, and the description thereof will be omitted. In addition, the same members or parts 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, 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

Claims (2)

A tubular first member with the distal end inserted into the body and made of resin or thermoplastic elastomer .
A second member slidably inserted through the first member and
A housing in which the first member and the portion on the proximal end side of the second member are pulled into the inside thereof, and the proximal end of the second member is fixed.
The proximal end of the first member is fitted and fixed inside the first member, and a wire rod having a substantially polygonal cross section is wound in a coil shape so as to form irregularities on the outside thereof. A coil member made of metal and provided so that at least the proximal end of both ends thereof is located inside the housing.
It has a sliding means provided in the housing, which engages with a part of the unevenness of the coil member and slides the first member with respect to the second member.
A medical device in which the proximal end of the first member and the coil member are fixed by fixing the outer peripheral surface of the proximal end of the first member and the inner peripheral surface of the coil member. The medical device according to claim 1, wherein the coil member is provided so that its distal end is located on the outside of the housing.

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