A valve ring shrinking device

Abstract

The present invention discloses a valve ring shrinking device, which includes a valve ring positioning mechanism and an anchoring shrinking mechanism. The valve ring positioning mechanism includes a stent body, a developing connecting tube and a developing fixing tube. The stent body is made of memory alloy wire bent and heat-set, including a left wing, a right wing and a plurality of positioning legs extending downward. The stent body can be shrunk and installed in a catheter before surgery, and can be automatically expanded and opened in the heart after being released from the catheter during surgery. After opening, the left wing and the right wing are adaptively fitted and abutted with the atrial wall, and the positioning legs are inserted and positioned at the junction of the two leaflets of the valve ring. The ends of the left wing and the right wing that are close to each other are fixedly connected to the bottom end of the developing fixing tube after crossing twice and forming a stress buffer ring extending forward. The present invention has the advantages of having a valve ring positioning mechanism and an anchoring shrinking mechanism, the former realizes the positioning of the valve ring, and facilitates the latter to be accurately anchored, thereby ensuring that the transcatheter tricuspid regurgitation repair technology has a better surgical effect.

Description

Technical Field

[0001] The invention belongs to the field of medical devices, and in particular relates to a valve ring contraction device. Background Art

[0002] Valve ring contraction includes mitral valve ring contraction and tricuspid valve ring contraction. The main purpose is to reduce the patient's valve ring to improve the closure effect of the valve leaflets. It is a common method for treating mitral valve and tricuspid valve regurgitation. Taking tricuspid valve ring contraction as an example, it is used to treat tricuspid valve regurgitation; tricuspid valve regurgitation refers to the failure of the tricuspid valve to close normally during the contraction of the right ventricle, resulting in part of the blood flowing back from the right ventricle to the right atrium. Treatments for tricuspid valve regurgitation include medication, surgery, and catheter intervention. Some patients cannot undergo traditional surgery because of past heart disease, advanced age, and other systemic diseases. Patients with all types of tricuspid valve regurgitation face extremely high risks when undergoing surgery, and a large number of patients with moderate tricuspid valve regurgitation cannot undergo surgery due to surgical contraindications.

[0003] In recent years, with the advancement of technology, a variety of interventional valve treatment techniques have begun to be applied to the treatment of tricuspid regurgitation, and have achieved reliable treatment effects in early clinical trials, which provides a new strategy for the treatment of moderate to severe tricuspid regurgitation. Transcatheter tricuspid regurgitation repair technology is basically to replicate the effect of tricuspid valve surgery. Currently, tricuspid valve surgery mainly includes Kay bivalvuloplasty, DeVega annuloplasty, clover technique, artificial annuloplasty and tricuspid valve replacement. The common problem encountered in transcatheter tricuspid valve treatment is how to effectively find the tricuspid valve ring and replicate the surgery based on the positioning of the valve ring. Summary of the invention

[0004] The purpose of the present invention is to provide a valve ring shrinking device, aiming to overcome the above-mentioned deficiencies in the prior art.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: a valve ring shrinking device, which includes a valve ring positioning mechanism and an anchoring shrinking mechanism, the valve ring positioning mechanism includes a stent body, a developing connecting tube and a developing fixing tube, the stent body is made of memory alloy wire bent and heat-set, including a left branch wing extending to the upper left, a right branch wing extending to the upper right and a plurality of positioning legs extending downward, the stent body can be retracted and installed in a catheter before surgery, and can be automatically expanded and opened in the heart after being released from the catheter during surgery, and after opening, the left branch wing and the right branch wing are adaptively fitted and abutted against the atrial wall and the positioning legs Inserted and positioned at the junction of the two leaflets of the valve ring, the developing fixing tube is located directly above the central area of ​​the valve ring, and the ends of the left and right wing that are close to each other are fixedly connected to the bottom end of the developing fixing tube after crossing twice and forming a stress buffer ring extending forward, and the other ends each wrap around a circle at a position aligned with the valve ring surface to form a positioning ring. There are multiple developing connecting tubes and they are fixedly sleeved on the uppermost ends of the left and right wings and the lowermost ends of each of the positioning legs. The anchoring ring contraction mechanism is used to pass the rivet through the positioning ring to anchor it in the valve ring and move each of the rivets toward the center of the valve ring to contract the valve ring.

[0006] Based on the above technical solution, the present invention can also be improved as follows.

[0007] Furthermore, a mounting tube is fixed inside the positioning ring, and the rivet is pre-installed inside the mounting tube.

[0008] The beneficial effect of adopting the above further scheme is that it is convenient to insert the rivet into the installation tube to achieve pre-installation, thereby ensuring that after the positioning ring positions the valve ring, the rivet is aligned with the valve ring, and then the rivet can be accurately riveted into the valve ring under the action of the push tube.

[0009] Furthermore, the anchoring ring contraction mechanism includes a connecting wire and a pushing tube, the connecting wire is connected to the tail of the rivet, and the pushing tube is slidably sleeved outside the connecting wire and can push the rivet out of the installation tube and rivet into the valve ring.

[0010] The beneficial effect of adopting the above further scheme is that the connection between the connecting wire and the tail of the rivet makes it easy for the push tube to be guided by the connecting wire after being sleeved on the connecting wire and thus accurately act on the rivet. On the other hand, after the rivet is anchored, the valve ring can be driven to contract by pulling the connecting wire.

[0011] Furthermore, the anchoring ring contraction mechanism also includes a locking wire block, and the connecting wires corresponding to the multiple rivets all pass through the locking wire block. When the locking wire block approaches each rivet along the connecting wire, it pulls the rivet toward the center of the valve ring to contract the valve ring.

[0012] The beneficial effect of adopting the above further solution is that the wire locking block can gather multiple connecting wires together and as the wire locking block approaches the center of the valve ring, the valve ring can be pulled toward the center to achieve the purpose of ring contraction.

[0013] Furthermore, there are only two positioning legs, one end of the two positioning legs close to each other extends upward and is fixedly connected to the bottom of the developing fixed tube, and the other end is respectively connected to the left branch wing and the right branch wing on the corresponding side.

[0014] The beneficial effect of adopting the above-mentioned further scheme is that the two positioning legs can be respectively inserted into the gap between the rear lobe and the front lobe and the gap between the rear lobe and the septum lobe, thereby realizing the overall positioning of the stent body. Due to the structural design of the stent body itself, when the two positioning legs of the stent body are correspondingly inserted into the corresponding gaps, its positioning ring is naturally positioned and aligned with the valve ring, thereby realizing the positioning of the valve ring.

[0015] Furthermore, there is only one positioning foot, which is located in the vertical symmetry plane between the left wing and the right wing. The positioning foot is independently looped by a memory alloy wire and both ends are fixed to the bottom of the developing fixed tube above.

[0016] The beneficial effect of adopting the above further scheme is that when only one positioning leg is provided, it is located in the center below the left and right wings. When it is inserted into the gap between the front petal and the rear petal, the positioning rings of the left and right wings are also aligned with the petal rings to achieve positioning. A single positioning leg has a simpler main structure and lower cost than a stent with two legs.

[0017] Furthermore, the development connecting tube is a single-lumen tube, and the development fixing tube is a multi-lumen tube.

[0018] The beneficial effect of adopting the above further solution is that the multi-lumen tube has multiple cavities for the memory alloy wire to pass through, which is convenient for positioning and fixing the head end and the bend of the memory alloy wire and also convenient for connecting the sheath tube.

[0019] Furthermore, the support body is formed by heat setting a memory alloy wire.

[0020] The beneficial effects of adopting the above further solution are good integrity and convenient production.

[0021] Furthermore, the upper end of the developing fixed tube is connected to one end of the sheath tube with adjustable bending.

[0022] The beneficial effect of adopting the above further solution is that it is easy to adjust the position of the bracket body.

[0023] Furthermore, the plane where the stress buffer ring is located is perpendicular to the axial direction of the developer fixed tube, and the left branch wing and the right branch wing gradually rise toward the left rear upper side and the right rear upper side respectively as the distance from the developer fixed tube increases.

[0024] The beneficial effect of adopting the above further scheme is that, because the left and right sides are crossed to form a ring, the stent structure forms a self-locking structure when it is retracted into the conveyor sheath and subjected to force, and cannot be separated to the outside to form two separate stent parts; during the right ventricular contraction period, the valve ring will also contract when the heart contracts, and at this time the stent structure can buffer the force due to the folding structure.

[0025] Compared with the prior art, the technical effects and advantages of the present invention are:

[0026] The valve ring shrinking device provided by the present invention has a valve ring positioning mechanism and an anchoring shrinking mechanism. The former can be shrunk as a whole and loaded into the catheter before the operation, and can be released from the catheter during the operation and automatically unfolded in the atrium. The positioning legs at the lower part of the unfolded stent body can be stuck in the junction between two adjacent leaflets to achieve the positioning of the valve ring, and provide a precise reference position for the subsequent anchoring shrinking mechanism to anchor, thereby ensuring that the transcatheter tricuspid regurgitation repair technology has a better effect of replicating surgical operations. After the operation, the stent body can be evacuated from the heart after shrinking, without destroying the native valve ring to better protect the heart function, with small surgical trauma and low risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of a stent body, a developing connection tube and a developing fixing tube of a valve ring shrinking device provided by the present invention in an unfolded state after being connected;

[0028] Figure 2 for Figure 1 a front view of the device shown;

[0029] Figure 3 for Figure 1 The force expansion diagram of the device shown when viewed from the rear side (the stress buffer ring is in a reduced state at this time);

[0030] Figure 4 for Figure 1 a top view of the device shown;

[0031] Figure 5 for Figure 1 A schematic diagram of the deployed state of the device after it is connected to the sheath and enters the right atrium tricuspid valve;

[0032] Figure 6 for Figure 5 The middle diagram is a schematic diagram of the stent body being located at the tricuspid valve annulus when viewed downward along the normal direction of the tricuspid valve annulus;

[0033] Figure 7 for Figure 5 A schematic diagram showing two positioning legs at the lower part of the middle bracket body being inserted into the gaps between the left and right sides of the rear petal and the front petal and the septum petal for positioning;

[0034] Figure 8 for Figure 5 Schematic diagram of the left wing of the central stent body being attached to the atrial wall and deforming and shifting with the heart contraction;

[0035] Fig. 9 for Figure 8 Schematic diagram of the middle bracket body connected with the mounting tube and rivets and connected with the anchor ring shrinking mechanism (connecting wire, push tube, etc.);

[0036] Fig.10 for Fig. 9 Schematic diagram of the rivets of the middle anchoring ring shrinking mechanism causing the valve ring to shrink due to the action of the locking wire block on the connecting wire;

[0037] Fig.11 An axonometric view of a support body provided by the present invention having only one positioning foot;

[0038] Fig.12 for Fig.11 The schematic diagram of the stent body being positioned at the tricuspid valve of the heart;

[0039] Fig.13 for Fig.11 A schematic diagram showing a positioning foot at the bottom of the stent body being inserted into the gap between the rear petal and the front petal for positioning;

[0040] Fig.14 It is a three-dimensional cross-sectional view of the developer fixed tube.

[0041] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0042] 1. Development connecting tube; 2. Development fixing tube; 3. Left branch wing; 4. Right branch wing; 5. Positioning foot; 6. Stress buffer ring; 7. Positioning ring; 8. Rivet; 9. Installation tube; 10. Connecting wire; 11. Push tube; 12. Locking wire block; 13. Sheath tube; 100. Posterior lobe; 101. Anterior lobe; 102. Septal lobe; 103. Atrial wall; 104. Ventricular wall; 105. Valve ring. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] In the description of the present invention, if terms indicating orientation such as "up", "down", "left", "right", "top", "bottom", "inside" and "outside" are used, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] like Figures 1 to 14 As shown, the present invention provides a valve ring shrinking device, which includes a valve ring positioning mechanism and an anchoring shrinking mechanism, the valve ring positioning mechanism includes a stent body, a developing connecting tube 1 and a developing fixing tube 2, the stent body is formed by bending and heat-setting a memory alloy wire, and includes a left branch 3 extending to the upper left, a right branch 4 extending to the upper right and a plurality of positioning legs 5 extending downward, the stent body can be shrunk and installed in a catheter before surgery, and can be automatically expanded and opened in the heart after being released from the catheter during surgery, and after opening, the left branch 3 and the right branch 4 are adaptively fitted and abutted against the atrial wall, and the positioning legs 5 are inserted and positioned in the valve ring. At the junction of the two leaflets, the developing fixed tube 2 is located just above the central area of ​​the valve ring. The ends of the left branch wing 3 and the right branch wing 4 that are close to each other are fixedly connected to the bottom end of the developing fixed tube 2 after crossing twice and forming a stress buffer ring 6 that extends forward. The other ends each wrap around a circle at a position aligned with the valve ring surface to form a positioning ring 7. The developing connecting tube 1 has multiple and fixed sleeves on the uppermost ends of the left branch wing 3 and the right branch wing 4 and the lowermost ends of each positioning leg 5. The anchoring ring contraction mechanism is used to pass the rivet 8 through the positioning ring 7 to anchor it in the valve ring and move each rivet 8 toward the center of the valve ring to contract the valve ring.

[0046] It should be noted that the valve ring shrinking device provided by the present invention is delivered to the right atrium through the jugular vein by minimally invasive technology. After being released at the upper end of the right atrium, the stent is released from the top to the bottom in the vertical direction of the valve ring surface at the position of the posterior leaflet 100 and the anterior leaflet 101 of the tricuspid valve, and the valve ring 105 is found through the junction of the leaflets. The developing connecting tube and the fixing tube on the stent body have the function of developing the position of the heart valve ring, realizing the positioning of the valve ring 105, and providing an accurate reference position for subsequent surgical steps. The stent body will be evacuated from the heart after surgery, and the native valve ring will not be destroyed to better protect the heart function. The surgery is less invasive and has low risk.

[0047] In addition, the stent body is formed by heat setting of nickel-titanium alloy wire, and has good morphological stability after forming. It can be contracted and installed in the catheter before surgery, and released in the right atrium of the heart during surgery. After complete release, the stent is placed down to the posterior leaflet of the tricuspid valve against the atrial wall, and the lower end of the stent is respectively stuck on both sides of the posterior leaflet 100: the junction of the front leaflet 101 and the posterior leaflet 100, and the junction of the posterior leaflet 100 and the septal leaflet 102, so as to display the display position of the valve ring. Before surgery, the stent body is installed in the front end catheter of the adjustable bend conveyor sheath 13, and the installation direction is that the developing connecting tube on the positioning foot is located in the direction of the conveyor sheath head end, and the developing connecting tubes on the left and right wings are in the direction of the conveyor handle end.

[0048] The stent body provided by the present invention is crossed twice at the end where the left branch 3 and the right branch 4 are close to each other to form a stress buffer ring 6 extending forward, that is, a clever double fold is performed in the middle part of the stent body, including a large bend and a small bend structure, and the two bent nickel-titanium alloy wires cross each other to form: a small bend "right wire" is on the top and the "left wire" is on the bottom, and a large bend "right wire" is on the bottom and the "left wire" is on the top. The advantage of this structure is that due to the left and right crossing, the stent structure forms a self-locking structure when it is retracted into the conveyor sheath and subjected to force, and cannot be separated to the outside to form two separate stent parts; during the right ventricular contraction period, the valve ring will also contract when the heart contracts. At this time, the stent structure can buffer the force due to the folding structure.

[0049] In one embodiment of the present invention, a mounting tube 9 is fixed inside the positioning ring 7 , and the rivet 8 is pre-installed inside the mounting tube 9 .

[0050] It should be noted that the rivet is movably connected in the installation tube. When subjected to an axial force exceeding a certain degree, the rivet moves out of the installation tube and anchors into the petal ring. That is, a section of installation tube (metal or plastic material) is fixed at the position of the positioning ring. The tube is connected to the positioning ring by welding or gluing. The rivet is pre-installed in the installation tube, and the rivet is connected to the external device through a connecting wire or cable.

[0051] In one embodiment of the present invention, the anchoring ring contraction mechanism includes a connecting wire 10 and a pushing tube 11, the connecting wire 10 is connected to the tail of the rivet 8, and the pushing tube 11 is slidably sleeved outside the connecting wire 10 and can push the rivet 8 out of the mounting tube 9 and rivet into the valve ring.

[0052] In one embodiment of the present invention, the anchoring ring contraction mechanism also includes a locking wire block 12, and the connecting wires 10 corresponding to the multiple rivets 8 all pass through the locking wire block 12. When the locking wire block 12 approaches each rivet 8 along the connecting wire 10, it pulls the rivet 8 toward the center of the valve ring to contract the valve ring.

[0053] It should be noted that the wire locking block is an existing component, which can enable the connecting wire to pass through and slide relatively therein, and can lock the connecting wire in place after sliding into place.

[0054] In one embodiment of the present invention, Figure 1 As shown, there are only two positioning legs 5, one end of the two positioning legs 5 close to each other extends upward and is fixedly connected to the bottom of the developing fixed tube 2, and the other end is respectively connected to the left branch 3 and the right branch 4 on the corresponding side.

[0055] In another embodiment of the present invention, Fig.11 As shown, there is only one positioning foot 5, and the positioning foot 5 is located in the vertical symmetry plane between the left wing 3 and the right wing 4. The positioning foot 5 is independently looped by a memory alloy wire and both ends are fixed to the bottom of the developing fixed tube 2 above.

[0056] It should be noted that, when viewed from the top view of the bracket body ( Figure 4 ), which is composed of a "right half stent" and a "left half stent" (left wing and right wing) after heat setting, and the angle formed by the two side stents is equivalent to the angle formed by the two sides of the posterior leaflet 100 of the tricuspid valve: the junction of the front leaflet 101 and the posterior leaflet 100, and the junction of the posterior leaflet 100 and the septal leaflet 102; in the middle part of the stent body, a positioning ring is heat-set by nickel-titanium alloy wire, and after the stent is accurately placed on both sides of the posterior leaflet of the tricuspid valve, the positioning ring can locate the position of the tricuspid valve ring and provide a reference channel for subsequent surgical operations;

[0057] Observe from the side of the bracket body ( Figures 8 to 10 ), the upper end of the positioning ring of the stent body is designed in an arc shape. When the stent body is released into the right atrium, the upper end of the positioning ring will be close to the atrial wall to achieve a supporting effect because the shaping angle is greater than the angle of the atrial wall 103. The valve ring 105 (the area in the blank box in the figure represents the valve ring) has the atrial wall 103 above and the ventricular wall 104 below.

[0058] In one embodiment of the present invention, the imaging connection tube 1 is a single-lumen tube, and the imaging fixed tube 2 is a multi-lumen tube (such as Fig.14 As shown), specifically, one end of the developing fixing tube is designed as a multi-cavity to fix the stent body, and the other end is designed as a hole to connect the sheath tube.

[0059] In one embodiment of the present invention, the support body is formed by heat setting a memory alloy wire.

[0060] It should be noted that the memory alloy wire is preferably a nickel-titanium alloy wire; in addition, the developing connecting tube and the developing fixed tube connected thereto are preferably made of developing materials such as platinum-iridium alloy and gold.

[0061] In one embodiment of the present invention, the upper end of the developer fixed tube 2 is connected to one end of the sheath tube 13 which can be adjusted to bend.

[0062] In one embodiment of the present invention, the plane where the stress buffer ring 6 is located is perpendicular to the axial direction of the developer fixed tube 2, and the left branch wing 3 and the right branch wing 4 gradually rise toward the left rear upper side and the right rear upper side respectively as the distance from the developer fixed tube 2 increases.

[0063] The steps of performing a ring contraction operation using the valve ring contraction device provided by the present invention are briefly described as follows (taking the stent body with double positioning legs as an example):

[0064] Ⅰ. Deliver the sheath tube equipped with the valve ring shrinking device (including the stent body, fixing tube, rivet, etc.) into the right atrium through the jugular vein.

[0065] Ⅱ. Adjust the angle of the adjustable curved sheath tube so that the axial direction of the sheath tube tip is consistent with the normal direction of the valve ring plane.

[0066] III. Slowly release the valve ring shrinking device in the right atrium, and rotate and adjust the direction of the device with the assistance of X-ray so that the device is located above the posterior leaflet of the tricuspid valve. Push the device downward and place the two positioning legs at the lower end of the shrinking device into the two sides of the posterior leaflet: the junction of the anterior leaflet and the posterior leaflet, and the junction of the posterior leaflet and the septal leaflet.

[0067] IV. After the annulus contraction device is correctly placed, manipulate the push tube on the connecting wire to push the rivet into the annulus.

[0068] V. After multiple rivets are driven into the valve ring, the push tube is withdrawn first, and then the valve ring positioning mechanism is withdrawn, leaving the rivets and the connecting wires, and then the connecting wires enter the locking wire block to shrink the rivet wires, thereby achieving the valve ring shrinkage effect.

[0069] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A valve ring shrinking device, characterized in that: The invention comprises a valve ring positioning mechanism and an anchoring ring contraction mechanism, wherein the valve ring positioning mechanism comprises a stent body, a developing connection tube (1) and a developing fixing tube (2), wherein the stent body is made of memory alloy wire, and comprises a left branch wing (3) extending to the upper left, a right branch wing (4) extending to the upper right and one or two positioning legs (5) extending downward, wherein the stent body can be contracted and installed in a catheter before surgery, and can be automatically expanded and opened in the heart after being released from the catheter during surgery, wherein after opening, the left branch wing (3) and the right branch wing (4) are adaptively fitted and abutted against the atrial wall, and the positioning legs (5) are inserted and positioned at the junction of the two leaflets of the valve ring, and the developing fixing tube (2 ) is located just above the center area of ​​the valve ring. The ends of the left wing (3) and the right wing (4) that are close to each other are fixedly connected to the bottom end of the developing fixed tube (2) after crossing twice and forming a stress buffer ring (6) that extends forward. The other ends are each wound around once at a position aligned with the valve ring surface to form a positioning ring (7). The developing connecting tube (1) has a plurality of fixed sleeves on the uppermost ends of the left wing (3) and the right wing (4) and the lowermost ends of each positioning leg (5). The anchoring ring contraction mechanism is used to pass the rivet (8) through the positioning ring (7) to anchor it in the valve ring and move each rivet (8) toward the center of the valve ring to contract the valve ring. A mounting tube (9) is fixed inside the positioning ring (7), and the rivet (8) is pre-installed inside the mounting tube (9); The anchoring ring contraction mechanism comprises a connecting wire (10) and a pushing tube (11), wherein the connecting wire (10) is connected to the tail of the rivet (8), and the pushing tube (11) is slidably sleeved outside the connecting wire (10) and can push the rivet (8) out of the mounting tube (9) and riveted into the valve ring.

2. A valve ring shrinking device according to claim 1, characterized in that: The anchoring ring contraction mechanism also includes a locking wire block (12), and the connecting wires (10) corresponding to the multiple rivets (8) all pass through the locking wire block (12). When the locking wire block (12) approaches each rivet (8) along the connecting wire (10), it pulls the rivet (8) toward the center of the valve ring to contract the valve ring.

3. A valve ring shrinking device according to claim 1, characterized in that: The number of the positioning legs (5) is two and only two, and one end of the two positioning legs (5) close to each other extends upward and is fixedly connected to the bottom of the developing fixed tube (2), and the other end is respectively connected to the left branch wing (3) and the right branch wing (4) on the corresponding side.

4. A valve ring shrinking device according to claim 1, characterized in that: The number of the positioning foot (5) is one and only one. The positioning foot (5) is located in the vertical symmetry plane between the left wing (3) and the right wing (4). The positioning foot (5) is independently looped by a memory alloy wire and both ends are fixed to the bottom of the upper developing fixed tube (2).

5. The valve ring shrinking device according to claim 1, characterized in that: The developing connection tube (1) is a single-lumen tube, and the developing fixed tube (2) is a multi-lumen tube.

6. A valve ring shrinking device according to claim 1, characterized in that: The support body is formed by heat setting a memory alloy wire.

7. A valve ring shrinking device according to claim 1, characterized in that: The upper end of the developing fixed tube (2) is connected to one end of the adjustable sheath tube (13).

8. A valve ring shrinking device according to any one of claims 1 to 7, characterized in that: The plane where the stress buffer ring (6) is located is perpendicular to the axial direction of the developer fixed tube (2), and the left branch wing (3) and the right branch wing (4) gradually rise toward the left rear upper side and the right rear upper side respectively as the distance from the developer fixed tube (2) increases.

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