Mitral valve capture device for transcatheter interventional therapy
By designing a line-driven mitral valve capture mechanism, the problem of valve floating and shaking during TEER surgery was solved, achieving stable valve clamping in minimally invasive surgery and improving the success rate and safety of the operation.
Patent Information
- Application Number
- CN202610495896.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-15
- Publication Date
- 2026-05-26
AI Technical Summary
In transcatheter mitral valve edge-to-edge repair (TEER) surgery, the irregular floating and shaking of the mitral valve leaflets makes it difficult for the clamp to hold the valve accurately. Existing technology is unable to effectively suppress valve floating, which affects the surgical outcome.
A mitral valve capture mechanism for transcatheter interventional therapy was designed. It adopts a wire-driven approach and includes a capture unit, a shape memory alloy unit, a rigid unit, and a limiting ring. It is driven by a first-line cable control unit and a second-line cable control unit to achieve stable valve clamping. The radial folding ratio is greater than 2.5, which can effectively suppress valve floating.
It achieves stable clamping of the mitral valve in minimally invasive surgery, reducing patient trauma and recovery time. It is compatible with the existing TEER clamping system, requires no modification to the surgical procedure, and improves the success rate and safety of the surgery.
Smart Images
Figure CN122075188A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of interventional transcatheter mitral valve edge-to-edge repair (TEER) technology, and particularly relates to a mitral valve capture mechanism for transcatheter interventional therapy. Background Technology
[0002] Valves are membranous structures in the organs of humans and some animals that can open and close. For example, everyone has four valves in their heart: the aortic valve, pulmonary valve, mitral valve, and tricuspid valve. Taking the mitral valve as an example, it is located between the left atrium and left ventricle. When the left ventricle contracts, the mitral valve acts as a check valve, tightly closing the atrioventricular orifice to prevent blood from flowing back from the left ventricle into the left atrium. However, when the mitral valve is diseased, it may be difficult for the left ventricle to close completely during contraction, leading to a large amount of regurgitated blood entering the left atrium. This can cause a sharp increase in pressure in the left atrium and pulmonary veins, increased diastolic volume load in the left ventricle, and further lead to a series of pathological changes such as left ventricular enlargement and pulmonary hypertension. Ultimately, this can result in clinical manifestations such as heart failure and arrhythmias, and in severe cases, can be life-threatening. When repairing a diseased mitral valve, a mitral valve repair device can be used to clamp the opposite sides of the mitral valve, turning the large opening between the mitral leaflets into two smaller openings. This reduces the regurgitation area and effectively prevents mitral regurgitation. Similarly, the mitral valve repair device can also be used to repair other heart valves, such as the tricuspid valve, by clamping the leaflets on both sides to reduce the regurgitation area.
[0003] Transcatheter mitral valve edge-to-edge repair (TEER) is a minimally invasive interventional technique that has rapidly gained popularity in the last decade. Its core principle involves delivering a clamp, such as the Abbott MitraClip or Edwards PASCAL, to the mitral valve via a peripheral blood vessel. The clamp's double arms hold the prolapsed areas of the anterior and posterior leaflets together, creating a "two-hole" blood flow channel, thereby blocking or significantly reducing mitral regurgitation. Compared to traditional open-heart surgery, TEER offers advantages such as being minimally invasive (requiring only a 2-3mm puncture incision), low-risk (complication rate <5% within 30 days post-surgery), and having a rapid recovery (average hospital stay of 3-5 days). It has become a first-line treatment option for elderly, high-risk, and severely mitral regurgitated patients. As of 2025, the annual number of TEER procedures performed globally has exceeded 200,000, and the annual number in China has also exceeded 10,000.
[0004] However, a key challenge in the core procedures of TEER surgery remains unresolved: the irregular floating and jittering of the mitral valve leaflets makes precise clamping of the clamp difficult. Specifically, during the clamping phase of TEER surgery, the regurgitation velocity of blood during left ventricular systole can reach 1-3 m / s. This high-speed blood flow continuously impacts the mitral valve leaflets, causing an axial displacement of 2-5 mm and irregular jittering of 5-10 Hz. In patients with mitral valve prolapse, the leaflet mobility can further increase to 3-7 mm, and the jittering trajectory is unpredictable.
[0005] Therefore, there is an urgent need in the field for an auxiliary capture mechanism that is adaptable to the space constraints of TEER surgery, has a fast response speed, and can effectively suppress valve floating. Summary of the Invention
[0006] The purpose of this invention is to provide a mitral valve capture mechanism for transcatheter interventional therapy, suitable for mitral valve repair during TEER surgery. It effectively solves the problem of valve floating due to blood flow during mitral valve edge-to-edge repair, leading to clamping failure. The technical solution adopted is as follows: A mitral valve capture mechanism for transcatheter interventional therapy includes: The capture unit 1, which unfolds relative to the control lever 2 and abuts against the mitral valve to capture it, is sleeved outside the control lever 2 and located behind the clamp 3, and includes: The base 11 has a through hole extending axially and through which the control rod 2 passes, and its front end is connected to a number of shape memory alloy units 12 distributed circumferentially. Rigid unit 13, which is correspondingly arranged and connected to shape memory alloy unit 12, includes front rigid plate 131 and rear rigid plate 132, and there is no contact between the front rigid plate 131 and the rear rigid plate 132, nor between the rear rigid plate 132 and the base 11. and a limiting ring 14, which is located in front of the shape memory alloy unit 12 and connected to the front rigid plate 131; The No. 1 cable control unit 4 is used to drive the corresponding shape memory alloy unit 12 to deform in order to unfold, and its output end is connected to the rigid plate 132. And the second cable control unit 5, which is used to drive the base 11 to generate axial displacement relative to the clamp 3.
[0007] Preferably, the shape memory alloy unit 12 includes at least one nickel-titanium alloy wire extending along the axial direction.
[0008] Preferably, the limiting ring 14 is an elastic ring.
[0009] Preferably, the first cable control unit 4 includes: The base 41 is movable along the axial direction; The feed unit 42 is mounted on the machine base 41; Preload block 43 is located at the output end of feed unit 42; And the No. 1 drive line 44, which forms the output end of the No. 1 cable control unit 4, has its front end connected to the corresponding rear rigid plate 132, its rear end connected to the pre-tightening block 43, and passes through the base 11 and the machine base 41 in sequence along the axial direction.
[0010] Preferably, the first drive line 44 is made of a biocompatible material.
[0011] Preferably, the second cable control unit 5 includes: Servo motor 51, which is mounted on the base 41, includes servo motor output disk 511; Guide frame 52 is mounted on base 41 and is located in front of servo output disk 511; And at least one No. 2 drive line 53, which is always taut, is connected to the base 11. It enters the middle channel of the control lever 2 through the wire hole 21 from outside the control lever 2, passes through the base 41 and the guide frame 52 in sequence, and is connected to the outer edge of the servo output disk 511. The threading hole 21 is radially opened on the control rod 2 and located between the limiting ring 14 and the clamp 3; the control rod 2 is connected to the front end face of the machine base 41.
[0012] Preferably, the second drive line 53 passes through the base 11 axially, and the second drive line 53 has knots at both the front and rear of the base 11.
[0013] Preferably, the second drive line 53 is made of a biocompatible material.
[0014] Preferably, the radial unfolding ratio is greater than 2.5; Wherein, the radial unfolding ratio = the maximum radial length of the unfolded limiting ring 14 / the radial length of the limiting ring 14 before unfolding.
[0015] Preferably, the thickness of both the front rigid plate 131 and the rear rigid plate 132 is 0.1 mm.
[0016] The capture mechanism of this invention is designed to address the above-mentioned needs: it adopts a line-driven method, has a large folding ratio, and can effectively control valve floating, fundamentally solving the core pain point of valve stabilization during TEER surgery. At the same time, it is compatible with existing mainstream TEER clamping systems and can be directly applied clinically without modifying the surgical procedure.
[0017] Compared with the prior art, the advantages of the present invention are: 1. Wire drive is adopted.
[0018] It meets the requirements of interventional medical devices, is highly minimally invasive, has a small-sized wire drive system, and the control rod 2 can be easily integrated into the slender catheter 6, enabling the capture unit 1 to enter the heart through peripheral blood vessels, avoiding the huge trauma of traditional open-chest surgery, and reducing patient pain and recovery time.
[0019] During the procedure, the stent excluding the support catheter 6 is not used.
[0020] Drive line 1, drive line 2, control lever 2, and capture unit 1 are all integrated into conduit 6.
[0021] Second, the number of capture mechanism drivers is small and the driving process is simple.
[0022] The folding, unfolding, and relative displacement of the capture mechanism are driven by a uniformly distributed drive rope, and after synchronous pre-tensioning by the pre-tensioning block 43 and the feeding unit 42, the multiple ropes only require a single drive. The relative movement of the capture mechanism is fixed to the servo output disk through symmetrical wiring and uses an equal path routing method, requiring only a single drive. The entire function of the mechanism only requires two drives.
[0023] Third, it has high biocompatibility.
[0024] The main structure of the capture mechanism consists of an end elastic ring, a stainless steel patch, a nickel-titanium alloy wire, and a base.
[0025] The distal elastic ring is made of medical-grade elastic material, the base is made of medical-grade stainless steel, and the nickel-titanium alloy wire is made of shape memory alloy. These materials all possess excellent biocompatibility, reducing the risk of rejection or adverse reactions after implantation.
[0026] Fourth, a radial folding ratio greater than 2.5 can effectively suppress valve floating and solve the core pain point.
[0027] Irregular floating and jittering of the mitral valve leaflets during TEER surgery is a key challenge that makes precise clamping of the clamp difficult. The capture mechanism has a folding-out ratio greater than 2.5, meaning that it can provide sufficient radial support and coverage area in the deployed state, thereby effectively stabilizing and suppressing valve floating. Attached Figure Description
[0028] Figure 1 This is a diagram illustrating the principle that the mitral valve is not clamped due to the impact of blood flow during mitral valve repair surgery. Figure 2 A 3D view of the capture unit; Figure 3 A diagram showing the positional relationship between the capture unit, control lever, and clamp; Figure 4A schematic diagram of the surgical procedure for mitral valve edge-to-edge repair with the addition of a capture unit; Figure 5 A three-dimensional view of a mitral valve capture mechanism for transcatheter interventional therapy; Figure 6 for Figure 5 A magnified view of the middle and later sections; Figure 7 This is a connection diagram of drive line number two, servo output disk, and guide frame. Figure 8 A photograph of the actual object used to measure the expansion ratio; Figure 9 A prototype diagram of a mitral valve capture mechanism for transcatheter interventional therapy; Figure 10 for Figure 9 A magnified view of a portion of the image; Figure 11 This is an enlarged view of state three; Figure 12 This is a magnified view of state four; Figure 13 This is an enlarged view of state five; Figure 14 Here is a structural diagram of the control lever; Figure 15 This is an assembly drawing of the preload block and the slider.
[0029] Wherein, 1-capture unit, 11-Base, 12-Shape memory alloy unit, 13-Rigid element, 131-Front rigid plate, 132-Rear rigid plate 14-Limiting ring, 2-Control lever, 21-Wire hole 3-Clamping device, 31-Upper clamping arm, 32-Lower clamping arm; 4-Cable control unit No. 1, 41-Base, 42-Feed unit, 43-Pretension block, 44-Drive line No. 1 5-Cable control unit #2, 51-Servo motor, 511-Servo motor output disc, 52-Guide frame, 53-Drive cable #2 6-Catheter, 7-Slider, 8-Slide rail 9-Slider. Detailed Implementation
[0030] The mitral valve capture mechanism for transcatheter interventional therapy of the present invention will now be described in more detail with reference to schematic diagrams, which illustrate preferred embodiments of the invention. It should be understood that those skilled in the art can modify the invention described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the invention.
[0031] like Figures 1-15 A mitral valve capture mechanism for transcatheter interventional therapy includes: capture unit 1, first cable control unit 4, and second cable control unit 5.
[0032] According to existing technology, clamp 3 is connected to the front end of control lever 2.
[0033] The capture unit 1, which unfolds relative to the control lever 2 and abuts against the mitral valve of the heart to capture the mitral valve, is sleeved outside the control lever 2 and located behind the clamp 3.
[0034] The capture unit 1 includes: a base 11, a shape memory alloy unit 12, a rigid unit 13, and a limiting ring 14.
[0035] The base 11 has an axially extending through hole through which the control rod 2 passes, and its front end is connected to a plurality of circumferentially distributed shape memory alloy units 12. The base 11 is in contact with the control rod 2.
[0036] The shape memory alloy unit 12 includes two axially extending nickel-titanium alloy wires. The nickel-titanium alloy wires are arranged circumferentially along the base, driving the limiting ring to expand and contract.
[0037] The principle of restoring the original shape of nickel-titanium alloy wire: the preload block 43 returns to its original position and restores the original shape (straight state).
[0038] Rigid unit 13, which is correspondingly arranged and connected to shape memory alloy unit 12, includes front rigid plate 131 and rear rigid plate 132, and there is no contact between the front rigid plate 131 and the rear rigid plate 132, nor between the rear rigid plate 132 and the base 11. The thickness of both the front rigid plate 131 and the rear rigid plate 132 is 0.1 mm.
[0039] The reason why the nickel-titanium alloy wire in the shape memory alloy unit 12 can support the front rigid plate 131, the rear rigid plate 132, and the limiting ring 14 is as follows: The shape memory alloy wire (nickel-titanium alloy wire) is 20mm long and 0.1mm in diameter. The rigid sheet is made of 316 stainless steel and is 7mm long. The spacing between the two rigid sheets and between the rigid sheet and the base 11 is 2mm. The titanium alloy wire inserted into the base 11 is 2mm long.
[0040] The limiting ring 14 is located in front of the shape memory alloy unit 12 and connected to the front rigid plate 131; specifically, as shown in... Figure 2 As shown, the front rigid plate 131 includes a snap fastener that engages with the limiting ring 14 and is fixed to the limiting ring 14 with a light-curing adhesive.
[0041] Furthermore, the limiting ring 14 is an elastic ring. The elastic ring unfolds into a quadrilateral to fit the valve and contracts into a circle for easy transport.
[0042] If the limiting ring 14 is a rigid ring, it will interfere with the upper clamping arm 31. The reason is: Both the conduit 6 and the clamp 3 use existing components. The diameter of the middle sheath of catheter 6 is 5 mm, therefore the maximum diameter of the limiting ring 14 is 5 mm.
[0043] The upper clamping arm 31 of clamping device 3 has a length of 7.79 mm. In state 5, the maximum radial length of the upper clamping arm 31 is close to 7.79*2>5 mm. Therefore, in state 5, the upper clamping arm 31 will press on the rigid limiting ring 14 and will not press on the mitral valve.
[0044] The No. 1 cable control unit 4 is used to drive the corresponding shape memory alloy unit 12 to deform in order to unfold, and its output end is connected to the rigid plate 132.
[0045] like Figure 4 As shown, the deformation area mainly occurs between the front rigid plate 131 and the rear rigid plate 132, and between the rear rigid plate 132 and the base 11 in the nickel-titanium alloy wire.
[0046] like Figure 6 As shown, the No. 1 cable control unit 4 includes: a base 41, a feed unit 42, a pre-tightening block 43, and a No. 1 drive line 44.
[0047] The base 41 can move axially; when the base 41 moves axially, it can drive the control rod 2 to generate axial displacement.
[0048] Specifically, the base 41 is connected to the slider 7 by fasteners, and the slider 7 is slidably connected to the slide rail 8.
[0049] How to drive the slider 7 is a matter of existing technology.
[0050] The feed unit 42 is bolted to the machine base 41; The preload block 43 is set at the output end of the feed unit 42 by fasteners; the preload block 43 has a threaded hole and is connected to the pan-tilt head of the lead screw motor of the feed unit 42 by bolts.
[0051] The first drive line 44 forms the output end of the first cable control unit 4. Its front end is connected to the corresponding rear rigid plate 132, and its rear end is connected to the pre-tightening block 43. It passes through the base 11 and the base 41 in sequence along the axial direction.
[0052] The feed unit 42 is a linear screw motor, and its output end is a motor gimbal.
[0053] Connection method between drive line 44 and rear rigid plate 132: After the first drive wire 44 passes through the wiring hole on the rear rigid plate 132, it is knotted on the side near the nickel-titanium alloy wire to form a knot. The outer diameter of the knot is larger than the outer diameter of the wiring hole. Then, the knot is bonded and fixed to the rear rigid plate 132 with light-curing adhesive.
[0054] Connection method between drive line 44 and preload block 43: After each drive wire 44 passes through the corresponding hole on the pre-tightening block 43, it is knotted and fixed on the handle reserved at the front end of the corresponding slider 9, using bolts ( Figure 15 (Not shown in the image) is threaded to the rear end face of slider 9.
[0055] Pre-tightening principle: The rotating bolt drives the slider to produce linear displacement within the track of the pre-tightening block 43, thereby adjusting the tension of the first drive line 44.
[0056] Pre-tightening principle: The knob bolt drives the slider to move within the pre-tightening mechanism track, thereby adjusting the tension of the drive rope.
[0057] The second cable control unit 5 is used to drive the base 11 to generate axial displacement relative to the clamp 3.
[0058] like Figures 6-7 As shown, the No. 2 cable control unit 5 includes: a servo motor 51, a guide frame 52, and two No. 2 drive cables 53.
[0059] Servo motor 51 is mounted on base 41 and includes servo motor output disk 511. Threaded holes are provided at the servo motor mounting positions on base 41 for fixing servo motor 51 with bolts.
[0060] The guide frame 52 is mounted on the base 41 and is located in front of the servo output disk 511. The lower end of the guide frame 52 is designed with a connecting rod, and the base 41 has a corresponding hole for connection through clearance fit.
[0061] Two drive cables 53, always taut, are both connected to base 11, as shown. Figure 14 As shown, all of them enter the hollow channel of the control lever 2 through the wire hole 21 from outside the control lever 2, and then pass through the base 41 and guide frame 52 in sequence before connecting to the outer edge of the servo output disk 511. The wire hole 21 is radially opened on the control rod 2 and located between the limiting ring 14 and the clamp 3.
[0062] Connection method between drive line 53 and base 11: The second drive line 53 passes through the through hole on the base 11 along the axial direction, and the second drive line 53 is provided with a limiting knot (rope knot) in front of and behind the base 11. The outer diameter of the limiting knot is larger than the inner diameter of the through hole.
[0063] Figure 10 In the middle, the threading hole 21, the limiting knot, the two second drive lines 53, the first drive line 44, and the base 1 can be clearly shown.
[0064] Drive line 44 is made of biocompatible nylon. Alternatively, drive line 44 may be a medical-grade ultra-high molecular weight polyethylene cord.
[0065] The second drive line 53 is made of biocompatible nylon. Alternatively, the second drive line 53 may be a medical-grade ultra-high molecular weight polyethylene rope. Two second drive lines 53 can enhance the stability of the base 11's back-and-forth movement.
[0066] The specific connection method between drive line 53 (number two) and the outer edge of servo output disk 511 is as follows: Both ends of the second drive line 53 are fixed in the grooves opened on the outer edge of the servo output disk 511 by fasteners.
[0067] Among them, drive line 44, drive line 53 and control lever 2 all pass through guide tube 6.
[0068] Figure 7 The image shown is only a schematic diagram of drive line 53 (number 2). Therefore, Figure 7 The length of the second drive line 53 shown in the image is not the actual length.
[0069] To distinguish the two drive lines 53, one of them is made darker and thicker. However, in the actual product, the two drive lines 53 have the same diameter.
[0070] Taking one of the second drive lines, 53 (the darker one), as an example, let's illustrate its positional relationship with the base 11: The section of the second drive line 53 located to the left of the center line of the guide frame 52 is called section A; the section of the second drive line 53 located to the right of the center line of the guide frame 52 is called section B. Section A is connected to base 11, and section B passes through the hollow channel of control rod 2.
[0071] The servo output disk 511 rotates clockwise, and the capture unit moves forward relative to the control stick.
[0072] The servo output disk 511 rotates counterclockwise, and the capture unit moves backward relative to the control stick; because Figure 7 This is not a top view; therefore, a section of the outer edge of the servo output disk 511 appears thickened.
[0073] In addition, to clearly demonstrate the winding path of drive line 53, Figure 7 The No. 2 drive line 53 is not in contact with the servo output disk 511.
[0074] In this embodiment, as Figure 8 As shown, the radial unfolding ratio is 3.9. When the driving force reaches 5N, the angle between the lower patch of the capture unit and the horizontal is 43.94°, and the maximum radial length is 19.17mm.
[0075] Wherein, the radial unfolding ratio = the maximum radial length of the unfolded limiting ring 14 / the radial length of the limiting ring 14 before unfolding.
[0076] 3.9 = 19.17 / 4.84.
[0077] The maximum radial length of the extended limiting ring 14 is the diagonal length of the limiting ring 14. The radial length of the limiting ring 14 before unfolding, i.e. the diameter of the limiting ring 14.
[0078] Firstly, the medical devices used in interventional therapy need to reach the target treatment site through the body's blood vessels. The size of the guiding tube (catheter 6) responsible for guidance is limited to an outer diameter of less than 8.4 mm and an inner diameter of 7.2 mm. Simultaneously, the capture unit 1 also requires an internal control rod 2 that can control the clamp; the outer diameter of control rod 2 is 4.6 mm. Therefore, the size of the capture unit 1 is limited to between 4.6 mm and 7.2 mm. Furthermore, the normal operation of unit 1 should not interfere with the existing clamp 3. Additionally, the area of the mitral valve is approximately 9 cm². 2 The diameter is approximately 35mm, such as Figure 9 As shown, the radial folding ratio of the capture unit 1 should be no less than 2.5. A larger folding ratio allows the capture mechanism to fit the valve more closely, thereby effectively suppressing valve movement. The auxiliary clamp 3 completes the valve repair surgery.
[0079] The guiding tube consists of a large sheath and a middle sheath; the middle sheath is inserted into the large sheath; The outer diameter of the large sheath is less than 8.4 mm and the inner diameter is 7.2 mm. The capture unit needs to be placed inside the middle sheath, which has an inner diameter of about 5 mm. The outer diameter of the capture unit is slightly less than 5 mm. The control rod 2 needs to pass through the capture unit, and the inner diameter of the capture unit should be no less than 4.6 mm. Therefore, the size of the capture unit 1 is limited to between 4.6 and 5 mm.
[0080] like Figure 4As shown, the working principle is as follows: State 1: The capture unit and clamp 3 are aligned with the mitral valve of the heart.
[0081] Specifically, align control lever 2 with the center of the mitral valve.
[0082] The mitral valve of the heart, hereinafter referred to as the mitral valve.
[0083] In this state, the first drive line 44 is in a pre-tightened state, so that the four first drive lines 44 maintain the same pre-tightening force.
[0084] State 2: Clamping device 3 passes through the mitral valve and the lower clamping arm 32 clamps the mitral valve.
[0085] Specifically, the control lever 2 moves forward axially to approach the mitral valve, while the capture unit 1 remains stationary.
[0086] State 3: Capture unit deployment.
[0087] Specifically, the feed unit 42 drives the preload block 43 to move backward, and the first drive line 44 tightens.
[0088] At this time, the servo output disk 511 remains stationary.
[0089] State 4: The capture unit depresses to suppress the mitral valve; Combination Figure 5 , Figure 7 When the servo output disk 511 rotates clockwise, both No. 2 drive lines 53 drive the base 11 to move axially forward toward the mitral valve.
[0090] State 5: Upper clamp arm 31 clamps the mitral valve.
[0091] Specifically: the upper clamping arm 31 unfolds toward the mitral valve under the drive of the drive rope to clamp the mitral valve, which is a prior art.
[0092] State 6: The capture unit is folded and retracted.
[0093] Specifically, the servo output disk 511 rotates counterclockwise, and both drive cables 53 drive the base 11 to move backward along the axial direction.
[0094] Folding: Feed unit 42 is reset, and capture unit 1 is restored to its original state.
[0095] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.
Claims
1. A mitral valve capture mechanism for transcatheter interventional therapy, characterized in that, include: A capture unit (1), which, after unfolding relative to the control lever (2), abuts against the mitral valve to capture the mitral valve, is sleeved outside the control lever (2) and located behind the clamp (3), and includes: The base (11) has a through hole extending axially and through which the control rod (2) passes, and its front end is connected to several shape memory alloy units (12) distributed circumferentially. A rigid unit (13) is provided and connected to a shape memory alloy unit (12). It includes a front rigid plate (131) and a rear rigid plate (132). The front rigid plate (131) and the rear rigid plate (132) do not contact each other, nor do the rear rigid plate (132) and the base (11). and a limiting ring (14), which is located in front of the shape memory alloy unit (12) and connected to the front rigid plate (131); The No. 1 cable control unit (4) is used to drive the corresponding shape memory alloy unit (12) to deform in order to unfold, and its output end is connected to the rigid plate (132). and the second cable control unit (5), which is used to drive the base (11) to generate axial displacement relative to the clamp (3).
2. The mitral valve capture mechanism for transcatheter interventional therapy according to claim 1, characterized in that, The shape memory alloy unit (12) includes at least one nickel-titanium alloy wire extending along the axial direction.
3. The mitral valve capture mechanism for transcatheter interventional therapy according to claim 1, characterized in that, The limiting ring (14) is an elastic ring.
4. The mitral valve capture mechanism for transcatheter interventional therapy according to claim 1, characterized in that, The No. 1 cable control unit (4) includes: The base (41) is movable along the axial direction; The feed unit (42) is mounted on the machine base (41); A preload block (43) is provided at the output end of the feed unit (42); And the No. 1 drive line (44), which forms the output end of the No. 1 cable control unit (4), its front end is connected to the corresponding rear rigid plate (132), its rear end is connected to the pre-tightening block (43), and it passes through the base (11) and the machine base (41) in sequence along the axial direction.
5. The mitral valve capture mechanism for transcatheter interventional therapy according to claim 4, characterized in that, The first drive line (44) is made of a biocompatible material.
6. The mitral valve capture mechanism for transcatheter interventional therapy according to claim 4, characterized in that, The second cable control unit (5) includes: A servo motor (51) is mounted on a base (41) and includes a servo output disk (511). A guide frame (52) is mounted on the base (41) and is located in front of the servo output disk (511); And at least one No. 2 drive line (53), always taut, both connected to the base (11), both entering the middle channel of the control rod (2) through the wire hole (21) from outside the control rod (2), and then passing through the base (41) and the guide frame (52) in sequence before connecting to the outer edge of the servo output disk (511); The threading hole (21) is radially opened on the control rod (2) and located between the limiting ring (14) and the clamp (3); the control rod (2) is connected to the front end face of the machine base (41).
7. The mitral valve capture mechanism for transcatheter interventional therapy according to claim 6, characterized in that, The second drive line (53) passes through the base (11) axially, and the second drive line (53) has knots in front of and behind the base (11).
8. The mitral valve capture mechanism for transcatheter interventional therapy according to claim 6, characterized in that, The second drive line (53) is made of a biocompatible material.
9. The mitral valve capture mechanism for transcatheter interventional therapy according to claim 1, characterized in that, The radial expansion ratio is greater than 2.5; Wherein, the radial unfolding ratio = the maximum radial length of the unfolded limiting ring (14) / the radial length of the limiting ring (14) before unfolding.
10. The mitral valve capture mechanism for transcatheter interventional therapy according to claim 1, characterized in that, The thickness of both the front rigid plate (131) and the rear rigid plate (132) is 0.1 mm.