Tissue clamping components and valve clamping devices

Abstract

This invention discloses a tissue clamping component, comprising a connecting frame and two clamping arms. The connecting frame includes two spaced-apart connecting pieces. The two clamping arms are respectively disposed on opposite sides of the two connecting pieces, each clamping arm extending away from the other clamping arm. Each clamping arm includes a bent section connected to the corresponding connecting piece and a clamping section connected to the bent section away from the corresponding connecting piece. The width of the bent section is smaller than the width of the clamping section and smaller than the width of the connecting pieces. This not only reduces the weight of the valve clamping device but also reduces the pulling force required to lift the two clamping arms of the valve clamping device to the central axis via the control wire, reducing the reverse force borne by the control wire, preventing control wire breakage, and facilitating operation. This invention also provides a valve clamping device equipped with a tissue clamping component.

Description

Technical Field

[0001] This invention relates to the field of interventional medical devices, and more particularly to a tissue clamping member and a valve clamping device equipped with the tissue clamping member. Background Technology

[0002] Please see Figure 1 The mitral valve I is a one-way valve located between the left atrium (2) and left ventricle (3) of the heart. A normal, healthy mitral valve I controls the flow of blood from the left atrium (2) to the left ventricle (3), while preventing blood from flowing from the left ventricle (3) to the left atrium (2). The mitral valve I consists of a pair of leaflets, called the anterior leaflet 1a and the posterior leaflet 1b. The anterior leaflet 1a and the posterior leaflet 1b are fixed to the papillary muscles of the left ventricle (3) by chordae tendineae (4). Normally, when the left ventricle (3) contracts, the edges of the anterior leaflet 1a and the posterior leaflet 1b are completely aligned, preventing blood from flowing from the left ventricle (3) to the left atrium (2). Please refer to [link to relevant documentation]. Figure 2 When the leaflets of the mitral valve 1 or its related structures undergo organic or functional changes, such as partial rupture of the chordae tendineae 4 or misalignment of the anterior leaflet 1a and posterior leaflet 1b of the mitral valve 1, the mitral valve 1 cannot close completely when the left ventricle 3 contracts, causing blood to flow back from the left ventricle 3 to the left atrium 2, thus causing a series of pathophysiological changes, known as "mitral regurgitation".

[0003] Surgical treatment for mitral regurgitation typically employs methods such as edge-to-edge suturing of the valve. However, these procedures are complex, costly, highly invasive, carry a high risk of complications, require long hospital stays, and involve painful recovery. A minimally invasive treatment based on the edge-to-edge principle involves delivering a valve clamping device via an interventional catheter to the mitral valve. This device simultaneously clamps the anterior and posterior leaflets, pulling them closer together and reducing mitral regurgitation. The valve clamping device uses a pair of concave clamping arms and a tissue clamp made of shape memory material to fix the mitral valve leaflets between the clamping arms and the tissue clamp. In other words, the clamping arms and the tissue clamp simultaneously grasp the anterior and posterior leaflets of the mitral valve, thereby fixing the leaflets and reducing mitral regurgitation.

[0004] Specifically, in the delivery state, the tissue clamping device is pulled and adhered to both sides of the central axis of the valve clamping device by a thin control wire, and then delivered to the vicinity of the mitral valve through a thin delivery catheter. The position of the valve clamping device is then adjusted, and the pull of the control wire on the tissue clamping device is released. Due to its shape memory properties, the tissue clamping device unfolds and presses the leaflet into the clamping arm, thereby cooperating with the clamping arm to clamp the leaflet. Please refer to [link to relevant documentation]. Figure 3The tissue clamping component 3a includes a base 3a1 and clamping arms 3a2 located on opposite sides of the base 3a1. Each clamping arm 3a2 has an opening 3a3 to reduce stress, reduce tension, and increase resilience in that area. However, this type of clamping arm 3a2 reduces its own fatigue resistance. If the clamping arm 3a2 does not have an opening 3a3, the tension required to pull the clamping arm 3a2 up to the central axis of the valve clamping device is greater, which places higher demands on the control wire and the proximal handle, and may easily lead to breakage of the control wire. Summary of the Invention

[0005] In view of this, the present invention provides a tissue clamping member and a valve clamping device, which can not only improve the fatigue resistance of the tissue clamping member, but also reduce the stress of the tissue clamping member when it is in the retracted state, so as to reduce the pulling force required to pull the tissue clamping member up to the retracted state and prevent the control wire from breaking.

[0006] To solve the above-mentioned technical problems, the present invention provides a tissue clamping member, which includes a connecting frame and two clamping arms. The connecting frame includes two connecting pieces spaced apart from each other. The two clamping arms are respectively disposed on opposite sides of the two connecting pieces. Each clamping arm extends away from the other clamping arm. Each clamping arm includes a bent section connected to the corresponding connecting piece and a clamping section connected to the bent section away from the corresponding connecting piece. The width of the bent section is smaller than the width of the clamping section and smaller than the width of the connecting piece.

[0007] The present invention also provides a valve clamping device, which includes a fixing seat, a pair of clamping arms that open and close relative to the fixing seat, and a tissue clamping member, wherein the tissue clamping member is disposed between the fixing seat and the clamping arms, and the two clamping arms of the tissue clamping member respectively cooperate with one of the pair of clamping arms to clamp the valve leaflet.

[0008] The valve clamping device provided by this invention has a bent section in each clamping arm, and the width of the bent section is smaller than the width of the clamping section and smaller than the width of the connecting piece. This not only reduces the weight of the valve clamping device, facilitates the rebound of the clamping arms, reduces clamping difficulty, and improves the fatigue resistance of the tissue clamping components, but also reduces the pulling force required to pull the clamping arms up to the central axis through the control wire, reduces the reverse force borne by the control wire, prevents control wire breakage, improves the fatigue resistance of the valve clamping device after long-term implantation in the human body, and improves the safety and effectiveness of the device. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the mitral valve in its normal state.

[0011] Figure 2 This is a schematic diagram of a mitral valve lesion.

[0012] Figure 3 This is a three-dimensional structural diagram of a tissue clamping component in the prior art.

[0013] Figure 4 This is a three-dimensional structural schematic diagram of a valve clamping device provided in one embodiment of the present invention.

[0014] Figure 5 yes Figure 4 A three-dimensional structural diagram of the tissue clamping component and fixation seat of the valve clamping device.

[0015] Figure 6 yes Figure 5 An exploded view of the three-dimensional structure of the tissue clamping component and the fixing seat.

[0016] Figure 7 yes Figure 6 Side view of the tissue clamping component.

[0017] Figure 8 yes Figure 6 Top view of the tissue clamping component.

[0018] Figure 9 yes Figure 7 A schematic diagram of another embodiment of the tissue clamping component.

[0019] Figure 10 yes Figure 5 Side view of the tissue clamp and fixing seat.

[0020] Figure 11 yes Figure 10 Enlarged view of section XI.

[0021] Figure 12 yes Figure 4 Side view of the valve clamping device in the middle.

[0022] Figure 13 yes Figure 4 This is a diagram showing one of the usage states of the valve clamping device.

[0023] Figure 14 This is a schematic diagram of the valve clamping device provided in another embodiment of the present invention.

[0024] Figure 15 yes Figure 14 A schematic diagram of the clamping arm of the valve clamping device.

[0025] Figure 16 These are statistical charts showing the results of fatigue testing and performance testing of the tissue clamping device of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] Furthermore, the following descriptions of the embodiments are made with reference to the accompanying illustrations to illustrate specific embodiments in which the invention can be implemented. Directional terms used in this invention, such as "up," "down," "front," "rear," "left," "right," "inner," "outer," and "side," are merely directional references to the accompanying illustrations. Therefore, the directional terms used are for better and clearer explanation and understanding of the invention, and are not intended to indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention.

[0028] In the description of this invention, it should be noted that, in the field of interventional medical devices, the proximal end refers to the end closer to the operator, while the distal end refers to the end farther from the operator; the axial direction refers to the direction parallel to the line connecting the center of the distal end and the center of the proximal end of the medical device in its natural state. The above definitions are for ease of expression only and should not be construed as limiting the invention.

[0029] Please refer to the following: Figures 4-6The first embodiment of the present invention provides a valve clamping device 100, including a fixed base 20, at least a pair of clamping arms 40 hinged to the fixed base 20, a tissue clamping member 60 connected to the fixed base 20, and a driving assembly 70 for driving the clamping arms 40 to open and close relative to the fixed base 20; the pair of clamping arms 40 open and close relative to the fixed base 20, and the tissue clamping member 60 is disposed between the fixed base 20 and the clamping arms 40 to cooperate with the clamping arms 40 to clamp the valve leaflets, and the tissue clamping member 60 includes a connecting frame 62 and two clamping arms 64. In use, the proximal end of the valve clamping device 100 is releasably connected to the delivery device. The two clamping arms 64 of the valve clamping device 100 are pulled up to the central axis via a control wire. The operator pushes the valve clamping device 100 to the patient's mitral valve and then operates the valve clamping device 100 remotely, causing the clamping arms 40 to open relative to the fixing seat 20. The tension of the control wire on the two clamping arms 64 is then released, clamping the anterior and posterior leaflets of the mitral valve together with the clamping arms 40 and the corresponding clamping arms 64, respectively, thereby aligning the leaflets of the mitral valve edge-to-edge. Then, the connection between the delivery device and the valve clamping device 100 is released, and the valve clamping device 100 remains in the patient's body as an implant to maintain the alignment of the leaflets, achieving "edge-to-edge repair" of the mitral valve and reducing mitral regurgitation in the patient.

[0030] It should be noted that the valve clamping device 100 and delivery device can be delivered to the patient using existing guide devices such as adjustable bend sheaths and shaped sheaths.

[0031] Specifically, the connecting frame 62 includes a base plate 621 and two connecting pieces 623 disposed on opposite sides of the base plate 621; two clamping arms 64 are respectively disposed on opposite sides of the two connecting pieces 623, each clamping arm 64 extending away from the other clamping arm 64; each clamping arm 64 includes a bent section 641 connected to the corresponding connecting piece 623 and a clamping section 643 connected to the bent section 641 away from the corresponding connecting piece 623, the width of the bent section 641 is smaller than the width of the clamping section 643 and smaller than the width of the connecting piece 623; the two clamping arms 64 of the tissue clamping member 60 respectively cooperate with one of a pair of clamping arms 40 to clamp the leaflet 300 (e.g. Figure 13 As shown in the figure, the clamping segment 643 of each clamping arm 64 is respectively engaged with a clamping arm 40 to clamp a leaf 300.

[0032] In this invention, each clamping arm 64 of the valve clamping device 100 has a bent section 641, and the width of the bent section 641 is smaller than the width of the clamping section 643 and smaller than the width of the connecting piece 623. This not only reduces the weight of the valve clamping device 100, facilitates the rebound of the clamping arm 64, reduces clamping difficulty, and improves the fatigue resistance of the tissue clamping component 60, but also reduces the pulling force required to pull the clamping arm 64 up to the central axis through the control wire, reduces the reverse force borne by the control wire, prevents the control wire from breaking, improves the fatigue resistance of the valve clamping device 100 after long-term implantation in the human body, and improves the safety and effectiveness of the device.

[0033] like Figure 4 As shown, in this embodiment, the valve clamping device 100 includes a pair of clamping arms 40 disposed opposite each other, each clamping arm 40 being openable and closable relative to the fixing base 20. Each clamping arm 40 includes a connecting portion 42 and a clamping frame 44 connected to the end of the connecting portion 42 away from the fixing base 20. The ends of the connecting portions 42 of the two clamping arms 40 away from the clamping frame 44 are stacked on each other and hinged to the fixing base 20. A leaflet receiving space is formed between the clamping arm 64 and the clamping arm 40. The surface of each clamping arm 40 facing the clamping arm 64 is recessed inward to form a receiving groove 45, so that in the delivery state of the valve clamping device 100, the clamping arm 64 is at least partially received in the receiving groove 45 of the clamping arm 40, thereby reducing the outer diameter and volume of the valve clamping device 100 and facilitating delivery in the body. After the clamping arm 40 and the holding arm 64 cooperate to clamp the leaflet 300, the leaflet 300 is clamped in the receiving groove 45, which can increase the contact area between the clamping arm 40 and the leaflet 300, and make the holding arm 64 press the leaflet 300 into the receiving groove 45 of the clamping arm 40, thereby increasing the clamping force on the leaflet 300.

[0034] Specifically, each clamp arm 40 includes a rectangular connecting plate 442 and side plates 444 disposed on opposite sides of the connecting plate 442, the connecting plate 442 and the two side plates 444 forming a receiving groove 45. The connecting plate 442 has a plurality of material discharge holes 446 along its length to reduce the weight of the clamp arm 40. The side plate 444 extends obliquely to one end of the fixing base 20 and is hinged to the fixing base 20 to form a connecting portion 42 of the clamp arm 40, the connecting portion 42 having a pin hole for inserting a pin.

[0035] The clamp arm 40 opens and closes relative to the fixed base 20 via a drive assembly 70. The drive assembly 70 includes a drive shaft 72 passing through the fixed base 20, a connecting seat 74 located at the distal end of the drive shaft 72, and a pair of connecting rods 76 movably connected to both sides of the connecting seat 74. One end of each connecting rod 76 is connected to a corresponding clamp arm 40, and the other end is pivotally connected to the connecting seat 74. That is, each clamp arm 40 is rotatably connected to the distal end of the connecting seat 74 of the drive assembly 70 via the connecting rod 76 on its corresponding side. The drive shaft 72 movably passes through the fixed base 20 and connects to the connecting seat 74. When the drive shaft 72 slides axially relative to the fixed base 20, the connecting seat 74 moves axially, causing the connecting rods 76 to rotate and thus opening and closing the clamp arm 40 relative to the fixed base 20.

[0036] like Figure 6 As shown, the fixing base 20 includes a rectangular fixing frame 21, a connecting block 22 disposed near the end of the fixing frame 21, and bosses 23 disposed on opposite sides of the fixing frame 21. The fixing base 20 has a through hole 24 along the axial direction, penetrating the connecting block 22 and the fixing frame 21, for inserting the drive shaft 72. The connecting block 22 has pin holes 26 at opposite ends, with the axis of the pin holes 26 perpendicular to the axis of the through holes 24. The pin holes 26 are used to connect with the connecting part 42 of the clamp arm 40 via pins. The fixing frame 21 has a first contact surface 212 and a second contact surface 214 on opposite sides of the connecting block 22, wherein the first contact surface 212 is closer to the connecting block 22 than the second contact surface 214. The radius of curvature of the first contact surface 212 is K1, and the radius of curvature of the second contact surface 214 is K2.

[0037] The tissue clamp 60 is at least partially made of shape memory material and undergoes heat setting treatment. The tissue clamp 60 has both a naturally unfolded and retracted state. During manufacturing, the shape memory material is first cut into the required shape using laser cutting, and then placed in a mold and heat-set at approximately 550°C to achieve a specific shape. For example... Figure 7As shown, in its natural state, the clamping arms 64 on both sides of the tissue clamp 60 extend outward relative to the connecting frame 62. Preferably, the clamping arms 64 extend obliquely to the distal end to cooperate with the clamping arms 40 to clamp the valve tissue. That is, the angle between the clamping arms 64 on both sides in the naturally unfolded state should be slightly larger than the angle between the two clamping arms 40 to provide a more stable clamping force, thereby ensuring that there is a certain clamping force between the clamping arms 64 and the clamping arms 40 to clamp the valve leaflet located between them. Specifically, the angle α between the length direction of the clamping segment 643 of each clamping arm 64 and the axial direction of the fixing seat 20 is greater than the angle between the clamping arm 40 and the axial direction of the fixing seat 20 when the clamping arm 40 corresponding to the clamping arm 64 is fully opened relative to the fixing seat 20, so that the free end of each clamping arm 64 and the corresponding clamping arm 40 are close to each other and have a certain clamping force to provide a more stable clamping force. Specifically, in its natural state, the angle α between the length direction of the clamping segment 643 and the axial direction of the fixed base 20 ranges from 0 to 150 degrees. That is, the angle between the two clamping segments 643 can reach a maximum of 300 degrees, preferably 160-200 degrees. In this embodiment, the angle between the two clamping segments 643 is greater than 180 degrees.

[0038] In this embodiment, the tissue clamp 60 is made of a super-elastic nickel-titanium alloy, which provides elasticity to drive the clamping arm 64 to move closer to the clamp arm 40 to clamp the valve tissue, thereby reducing the difficulty of the manufacturing process, simplifying the process flow, and reducing the production cost.

[0039] In other embodiments, different parts of the clamping arm 64 can be made separately from different materials and then fixedly connected. For example, the clamping section 643 of the clamping arm 64 is made of stainless steel to improve the clamping force, and the bending section 641 should have a bending function to provide the tissue clamp 60 with a natural unfolded state and a retracted state that facilitates transport. Therefore, the bending section 641 is made of shape memory material.

[0040] In this embodiment, each connecting piece 623 is connected to its corresponding bent segment 641 by a bent fixing piece 625. The fixing piece 625 on each connecting piece 623 is bent toward the other connecting piece 623, and each bent segment 641 is bent away from the other bent segment 641. Each connecting piece 623 has a slot 6230 along its length, which extends into the corresponding fixing piece 625 for fixing with the fixing seat 20. The slot 6230 can be rectangular, elliptical, prismatic, or other shapes. In this embodiment, a rectangular shape is preferred for higher stability. The substrate 621, the two connecting pieces 623, and the two fixing pieces 625 form a connecting frame 62 with an open proximal end. The fixing seat 20 is housed in the inner cavity of the connecting frame 62, and the drive shaft 72 passes through the open proximal end of the connecting frame 62 and is inserted into the fixing seat 20 and the connecting frame 62. Specifically, the substrate 621 has a through hole 6210. After the fixing seat 20 is housed in the inner cavity of the connecting frame 62, the through hole 24 of the fixing seat 20 corresponds to the through hole 6210 of the substrate 621. The drive shaft 72 passes through the through hole 24 of the fixing seat 20 and the through hole 6210 of the substrate 621. It can be understood that the fixing piece 625 should have a certain deformation capacity to be held outside the fixing seat 20. Therefore, the fixing piece 625 should be made of shape memory material. Other parts of the connecting frame 62 can be made of harder materials such as stainless steel to improve the connection strength. That is, the fixing piece 625 of the connecting frame 62 and the bent section 641 connected to it can be integrally formed of nickel-titanium alloy. The substrate 621 and the connecting piece 623 of the connecting frame 62 are integrally formed of stainless steel and then welded or bonded to the fixing piece 625. Each bent section 641 is then welded or bonded to the clamping section 643.

[0041] like Figures 6-8As shown, the bending segment 641 includes a first end 6412 connected to the corresponding fixing piece 625 and a second end 6414 connected to the corresponding clamping segment 643. The bending segment 641 has a variable diameter structure, that is, the width of the bending segment 641 at the first end 6412 is greater than the width of the bending segment 641 at the second end 6414, and the width of the bending segment 641 gradually decreases from the first end 6412 to the second end 6414. In this embodiment, the width of the first end 6412 of the bending segment 641 is equal to the width of the fixing piece 625, and the width of the second end 6414 of the bending segment 641 is equal to the width of the clamping segment 643. The first end 6412 and the second end 6414 of the bending segment 641 have a smooth transition. Since the valve clamping device 100 often needs to be repeatedly opened and closed and the leaflets need to be grasped multiple times during surgery, if the rebound stress of the clamping arm 64 is too large, the pulling force required for the control wire will be higher, which will increase the risk of control wire breakage. The variable diameter structure of the bending section 641 effectively reduces the stress on the clamping arm 64 in the retracted state, thereby lowering the risk of control wire breakage. Furthermore, in existing technologies, a hole is made in the middle of the bending section to reduce stress; however, microcracks are prone to appear at the hole location, and these microcracks are often difficult to observe. Under long-term stress after the valve clamping device is implanted in the human body, microcracks near the hole location are prone to fatigue fracture. Therefore, this embodiment reduces stress through a variable diameter structure while avoiding the risk of fatigue fracture caused by the hole.

[0042] Preferably, the width ratio of the second end 6414 to the first end 6412 of the bent section 641 is in the range of 0.4-0.8; more preferably, the width ratio of the second end 6414 to the first end 6412 of the bent section 641 is in the range of 0.5-0.65. If the width ratio of the second end 6414 to the first end 6412 is too large, that is, the width of the second end 6414 is too large, the stress of the bent section 641 is large when the clamping arm 64 is in the retracted state, the required tensile force is large, and the risk of breakage of the control wire is high; if the width ratio of the second end 6414 to the first end 6412 is too small, that is, the width of the second end 6414 is too small, it will affect the clamping force of the clamping arm 64 on the tissue, causing the clamping device 100 to easily slip out.

[0043] like Figures 5-8 As shown, each clamping arm 64 has at least one row of barbs 6433 along its length, and the end of each barb 6433 is rounded to avoid piercing the leaflet. Specifically, the clamping section 643 includes a clamping piece 6431 connected to the second end 6414 of the bent section 641, and two rows of barbs 6433 connected to both sides of the clamping piece 6431. In this embodiment, the number of barbs 6433 on each side of the clamping piece 6431 is four.

[0044] Each barb 6433 has an angle with the clamping plate 6431, ranging from 30 degrees to 85 degrees, preferably from 45 degrees to 65 degrees. An angle that is too large or too small will increase the difficulty of capturing the leaflets. The included angle A between each barb 6433 and the clamping plate 6431 can be the same or different. In this embodiment, the included angle A between each barb 6433 and the clamping plate 6431 is 60 degrees.

[0045] The effective length of each barb 6433 ranges from 0.3 mm to 2.0 mm, preferably from 0.5 mm to 1.2 mm. The effective lengths of the barbs 6433 can be the same or different. In this embodiment, the extension lengths of the barbs in each row of barbs 6433 are the same; specifically, the effective lengths of the four barbs 6433 on the same side of the clamping piece 6431 from one end of the adjacent bending section 641 to the end are L1, L2, L3, and L4, respectively, and L1 = L2 = L3 = L4; in this embodiment, the effective lengths of L1, L2, L3, and L4 are all 0.8 mm.

[0046] like Figure 9 As shown, in another embodiment of the tissue clamp 60, the angle between the barbs in at least one row of barbs 6433 of each clamping segment 643 and the corresponding clamping segment 643 gradually increases along the extension direction of the clamping arm, and the effective length of the barbs 6433 from one end of the adjacent bending segment 641 to the end also gradually increases. Specifically, there are four barbs 6433 in each row, and the angles between the barbs 6433 from one end of the adjacent bending segment 641 to the end and the clamping segment 643 are A1, A2, A3, and A4, respectively, and A1≤A2≤A3≤A4; the effective lengths of the barbs 6433 from one end of the adjacent bending segment 641 to the end are L1, L2, L3, and L4, respectively, and L1≤L2≤L3≤L4. In this embodiment, the angles of A1 are 45 degrees, A2 is 50 degrees, A3 is 55 degrees, and A4 is 60 degrees; the effective lengths of L1 are 0.4 mm, L2 is 0.8 mm, L3 is 1.0 mm, and L4 is 1.2 mm. This arrangement is because the leaflet thickness is uneven, with the thinnest at the leaflet edge and gradually increasing in thickness towards the junction of the leaflet and the annulus. Based on the anatomical structure of the leaflet gradually thickening from the leaflet edge to the center, to ensure that the force depth at different contact points between each barb 6433 and the leaflet tissue is approximately the same, and to guarantee the clamping force of the clamping segment 643 on the leaflet without piercing it, the angle of the barb 6433 is adjusted to accommodate the force depth of leaflet tissue of different thicknesses.

[0047] like Figure 8As shown, the ratio of the width D1 of the clamping section 643 (width D1 = width of the clamping piece 6431 + width of the barbs 6433 on both sides), the width D2 of the second end 6414 of the bent section 641, to the width D3 of the fixing piece 625 is (1.5~2):1:(1.5~2), that is, D1:D2:D3 = (1.5~2):1:(1.5~2). In this embodiment, the ratio of the width D1 of the clamping section 643 to the width D2 of the second end 6414 of the bent section 641 to the width D3 of the fixing piece 625 is 1.5:1:1.5. If the width of D2 is too narrow, it will reduce the fatigue resistance and tensile strength of the valve clamping device 100; if D2 is too wide, it means that the weight of the valve clamping device 100 will increase, which will cause the valve clamping device 100 to fall under the valve for a long time after implantation. It is not only easy to slip out, but may also tear the target tissue or even cause cardiac dysfunction. Furthermore, since the tissue clamping member 60 is made of shape memory alloy, if D2 is too wide, the leaflet compressed by the bent segment 641 will be subjected to greater pressure during the expansion and contraction of the heart, which will lead to excessive tissue damage.

[0048] like Figure 10 and Figure 11 As shown, the distal end of the fixation piece 625 is connected to the connecting frame 62, and the proximal end of the fixation piece 625 is connected to the bent section 641. The fixation piece 625 is used to achieve the function of interlocking and fixing the tissue clamp 60 and the fixation seat 20, preventing the tissue clamp 60 from shifting or loosening relative to the fixation seat 20 under the unilateral relay force of the control wire, thereby ensuring the reliability of the tissue clamp 60 in the process of capturing the valve.

[0049] In this embodiment, the fixing piece 625 includes a first fastening position 6251 and a second fastening position 6253. The first fastening position 6251 prevents the connecting frame 62 from moving up and down after engaging with the fixing seat 20, thus acting as a proximal and distal limit; the second fastening position 6253 prevents the connecting frame 62 from moving left and right after engaging with the fixing seat 20, thus acting as a left and right limit. The radius of curvature of the proximal portion of the fixing seat 20 is greater than the radius of curvature of the fixing piece 625. Specifically, the first fastening position 6251 is a curved piece corresponding to the first contact surface 212 of the fixing seat 20, and the second fastening position 6253 is a curved piece corresponding to the second contact surface 214 of the fixing seat 20, wherein the radius of curvature of the first fastening position 6251 is K3, and the radius of curvature of the second fastening position 6253 is K4. The radius of curvature K3 of the first engagement position 6251 is greater than the radius of curvature K1 of the first contact surface 212 of the fixing seat 20, and the radius of curvature K4 of the second engagement position 6253 is less than the radius of curvature K2 of the second contact surface 212 of the fixing seat 20. Thus, a first clearance position P1 is reserved between the first contact surface 212 and the first engagement position 6251, and a second clearance position P2 is reserved between the second contact surface 214 and the second engagement position 6523. The contact point between the fixing piece 625 and the fixing frame 21 is just set between the first clearance position P1 and the second clearance position P2 to prevent interference between the connection between the fixing piece 625 and the fixing seat 20, thereby ensuring the stability of the first engagement position 6251, that is, ensuring the stability of the near and far end limit.

[0050] like Figure 5 and Figure 6 As shown, when the fixing seat 20 is housed in the connecting frame 62, the two protrusions 23 of the fixing seat 20 are respectively engaged in the two slots 6230 of the tissue clamp 60, so that the fixing seat 20 and the tissue clamp 60 are engaged with each other to prevent the tissue clamp 60 and the fixing seat 20 from moving back and forth, that is, to play the role of front and back limit.

[0051] To ensure safety after implantation, the fixation base 20 and the clamp arm 40 are made of biocompatible metallic materials such as stainless steel, cobalt alloy, cobalt-chromium alloy, titanium alloy, or nickel-titanium alloy; the drive assembly 70 is made of biocompatible polymeric materials or metallic materials such as polyester, silicone resin, stainless steel, cobalt alloy, cobalt-chromium alloy, or titanium alloy. In this embodiment, the fixation base 20, clamp arm 40, and drive assembly 70 are all made of stainless steel.

[0052] like Figure 12As shown, when the drive assembly 70 drives the clamping arms 40 to open and close relative to the fixed base 20, the clamping arms 40 can open and close within a large range relative to the fixed base 20. The maximum angle between the two clamping arms 40 can reach 300 degrees. That is, after the clamping arms 40 are opened relative to the fixed base 20, they can be flipped downwards to a certain extent, which is beneficial for clamping the valve in motion, improving the clamping success rate. Furthermore, if the effect is not ideal after clamping, the valve leaflet can be released by flipping the clamping arms 40 downwards and re-clamping. In this embodiment, the angle range between the two clamping arms 40 is preferably 0-240 degrees, and more preferably 120-180 degrees.

[0053] Preferably, an anti-slip structure (not shown) may be provided on the surface of the clamping arm 40 facing the clamping section 643 to enhance the friction when the clamping arm 40 contacts the leaflet 300, thereby providing a stable clamping force and preventing the clamping arm 40 from damaging the leaflet 300. The anti-slip structure may be a protrusion, a groove, or a pad made of a biocompatible material with a high coefficient of friction affixed to the inner surface of the receiving groove 45 of the clamping frame 44.

[0054] Preferably, an active drug may also be applied to the inner surface of the receiving groove 45 of the clamp arm 40 and / or each clamping segment 643 to promote the endothelial cell migration and growth of valve tissue on the inner surface of the clamp arm 40 and on the clamping arm 64.

[0055] It should be noted that the two clamping sections 643 of the tissue clamping member 60 are also equipped with control wires. By pulling or releasing the control wires, the clamping section 643 can be pulled up to fit against the central axis for easy transport; or the tension on the clamping section 643 can be released, allowing the clamping arm 64 to rebound due to its own elastic memory property and return to its natural state, and the clamping section 643 can unfold relative to the fixing base 20 to press the leaflet 300 against the clamping arm 40 to clamp the leaflet 300. Specifically, the control wires can be metal wires made of nickel-titanium alloy, etc., which are not related to the improvement and creation of this invention and will not be described in detail here.

[0056] The following uses the mitral valve repair process as an example to illustrate the operation method of the valve clamping device of the present invention, which mainly includes the following steps:

[0057] Step 1: Detachably connect the valve clamping device 100 to the distal end of the delivery device, and tighten the control wire towards the proximal end to control the clamping arm 64 to retract relative to the fixing base 20, so that the clamping section 643 of the clamping arm 64 fits against the surface of the fixing base 20. Then move the drive shaft 72 towards the proximal end to drive the connecting rod 76 to drive the clamping arm 40 to close relative to the fixing base 20, so that the valve clamping device 100 is in a fully retracted state, and the tissue clamping member 60 and the clamping arm 40 are close to the surface of the fixing base 20, maintaining the retracted state.

[0058] Step 2: Femoral vein puncture, using the transatrial septal approach, the distal end of the delivery device and the valve clamping device 100 are advanced from the left atrium through the adjustable curved sheath, passing through the mitral valve to reach the left ventricle.

[0059] Step 3: Adjust the relative position of the valve clamping device 100 and the mitral valve so that the valve clamping device 100 is close to the anterior and posterior leaflets of the mitral valve.

[0060] Step 4: Move the drive shaft 72 to the far end, thereby driving the connecting rod 76 to open the clamp arm 40 relative to the fixed seat 20.

[0061] Step 5: Retract the entire valve clamping device 100 proximally so that the clamp arm 40 supports the valve leaflet on the left ventricular side.

[0062] Step 6: Release the control wire from the corresponding clamping arm 64 to release the clamping arms 64 on both sides. Each clamping arm 64 presses against the leaflet 300 on the atrial side and cooperates with the clamping arm 40 on that side to clamp the leaflet (e.g., Figure 13 (As shown).

[0063] Step 7: Move the drive shaft 72 towards the proximal end. The drive shaft 72 drives the connecting rod to close the clamp arm 40 relative to the fixed seat 20 until the valve clamping device 100 is fully retracted.

[0064] Step 9: Disconnect the valve clamping device 100 from the delivery device and control wire, and remove the delivery device and control wire from the patient's body. At this time, the valve clamping device 100 pulls the anterior and posterior leaflets of the mitral valve towards each other to obtain a double-perforated mitral valve, completing the edge-to-edge repair of the mitral valve. The valve clamping device 100 remains in the patient's body.

[0065] Please see Figure 14 and Figure 15 The valve clamping device 100a provided in the second embodiment of the present invention has a structure similar to that of the valve clamping device 100 in the first embodiment, except that the structure of the clamping arm 64a in the second embodiment is slightly different from that in the first embodiment. Specifically, a bending portion 645 is provided between the clamping section 643 and the corresponding bending section 641 of each clamping arm 64a. The bending portion 645 bends away from the connecting frame 62, so that the clamping section 643 of the clamping arm 64 of the valve clamping device 100a is approximately parallel to the clamping frame 44 of the clamping arm 40 in its natural state. As a result, when the clamping arm 64a captures the leaflet, the gap between the barbs 6433 and the clamping frame 44 of the clamping arm 40 is relatively uniform, and the barbs 6433 can simultaneously contact the leaflet 300, thereby improving the success rate and stability of capturing the leaflet 300.

[0066] Performance tests were conducted on the tissue clamping components, and fatigue tests were conducted on the valve clamping device.

[0067] Tissue clamping component performance test

[0068] Three sets of clamping arms were fabricated using the same nickel-titanium alloy material and manufacturing process, with the first set being the tissue clamping component used in this invention. Figure 16 The first group consists of the reduced diameter (A1-A4) of the embodiments in the middle, and the second group consists of the non-diameter (equal diameter and equal width) tissue clamping components in the prior art. Figure 16 The third group consists of tissue clamps with constant width and constant diameter (comparative examples B1-B4 in the text), and is a tissue clamp in the prior art where openings are formed by laser cutting on a tissue clamp with constant width. Figure 16 The same width openings (C1-C4 in the comparative examples) were used to perform the following performance tests on several groups of tissue clamps. The test results are as follows: Figure 16 As shown.

[0069] 1. Fatigue resistance test of tissue clamping components

[0070] The fatigue resistance of the tissue clamp itself was tested using the AWT-1000 artificial heart valve fatigue resistance tester from Shanghai Heart Valve Testing Equipment Co., Ltd. The test examined whether the tissue clamp fractured or cracked due to load during the fatigue test cycle. The test results are as follows: Figure 16 As shown.

[0071] The fatigue test parameters are as follows: cyclic tensile force (peak): 0.80N±0.30N, amplitude: 1mm, frequency: 50Hz, water bath temperature: 37℃±0.5℃, cycle: ≥400 million times.

[0072] 2. Test of the contraction force of the control wire on the tissue clamp.

[0073] The same control wires were used to test the closing force of three sets of tissue clamps. The testing equipment was a HY-0580 electronic universal tensile testing machine manufactured by Shanghai Hengyi Precision Instruments Co., Ltd. The testing method was as follows: The valve clamping device was connected to a simple handle. Two U-shaped control wires were passed through the control holes at the two free ends of each clamping arm, with the control wires exiting from the proximal end of the simple handle. The simple handle was fixed to the machine platform. The moving end of the tensile testing machine hooked onto the proximal end of the control wires and moved at a uniform speed of 4.5 mm / min. The force value when the tissue clamps closed to the point where the two clamping sections were basically parallel was recorded. The test results are as follows: Figure 16 As shown.

[0074] 3. Control wire fatigue resistance test

[0075] The fatigue resistance of the control wires of three sets of tissue clamping devices was tested. The testing equipment was a HY-0580 electronic universal tensile testing machine manufactured by Shanghai Hengyi Precision Instruments Co., Ltd. The testing method was as follows: The valve clamping device was connected to a simple handle. Two U-shaped control wires were passed through the control holes at the two free ends of each clamping arm, with the control wires exiting from the proximal end of the simple handle. The simple handle was fixed to the machine platform, and the moving end of the tensile testing machine hooked onto the proximal end of the control wires. The action of the tissue clamping device being retracted and released under the control of the control wires was repeated 50 times. After the test, the control wires were observed. If any scratches, wear, cracks, or breakage occurred, the test was deemed unsuccessful. The test results are as follows: Figure 16 As shown.

[0076] from Figure 16 The test results shown indicate that:

[0077] 1) By setting a variable diameter structure on the tissue clamp, the present invention can effectively reduce the closing force required to control the closing of the tissue clamp, which can ensure both the fatigue resistance of the control wire and the fatigue resistance of the tissue clamp itself.

[0078] 2) Existing tissue clamps do not have a variable diameter structure, and the required closing size for controlling the tissue clamp to close is significantly larger. Although this can ensure the fatigue resistance of the tissue clamp itself, it cannot guarantee the fatigue resistance of the control wire.

[0079] 3) Existing tissue clamping devices with openings can reduce the closing force required to control the tissue clamping device and ensure the fatigue resistance of the control wire, but cannot guarantee the fatigue resistance of the tissue clamping device itself.

[0080] In summary, compared with the prior art, the tissue clamp of the present invention has better fatigue resistance, requires less tensile and retraction force, and has a lower risk of control wire breakage.

[0081] Valve clamping device fatigue test

[0082] The fatigue test verified whether the valve clamping device using the tissue clamping component of this invention could meet the load requirements for 10 years of use as a medical device implant after clamping the two leaflets of the mitral valve. Before the test, the artificial mitral valve model was fixed with the valve clamping device to simulate the edge-to-edge treatment effect. Then, the mitral valve model with the valve clamping device was placed in a fatigue testing machine that simulates the beating of the left ventricular system of the human heart for non-destructive fatigue testing. The slippage of the valve clamping device due to load and the damage to the leaflets were recorded during the fatigue test period.

[0083] Testing equipment: AWT-1000 artificial heart valve fatigue resistance tester from Shanghai Heart Valve Testing Equipment Co., Ltd.

[0084] Test standard: The test was conducted according to the "fatigue test" method in ISO 5840 and GB12279—2008 "Cardiovascular Implants - Artificial Heart Valves". The test cycle was ≥400 million cycles. The test results showed that the valve clamping device in this embodiment met the relevant requirements. No valve clamping device slipped during the test cycle, and the valve clamping device did not cause damage to the valve leaflets.

[0085] It should be noted that the above description uses the valve clamping device for alleviating or treating mitral regurgitation as an example. It is understood that in other embodiments, the valve clamping device can also be used to alleviate or treat tricuspid regurgitation. Its principle and structure are largely the same as those of the valve clamping device used to resolve mitral regurgitation in this embodiment of the invention. It simply involves multiple clamps formed by multiple sets of proximal and distal clips, with each clamp clamping one leaflet. Further details are omitted here.

[0086] The above are the embodiments of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the embodiments of the present invention, and these improvements and modifications are also considered to be within the protection scope of the present invention.

Claims

1. A tissue clamp, characterized in that, include: A connecting frame, the connecting frame including a substrate and two connecting pieces disposed on opposite sides of the substrate and spaced apart from each other; Two clamping arms are respectively disposed on opposite sides of the two connecting pieces. Each clamping arm extends away from the other clamping arm. Each clamping arm includes a bent section connected to the corresponding connecting piece and a clamping section connected to the bent section and away from the corresponding connecting piece. The width of the bent section is smaller than the width of the clamping section and smaller than the width of the connecting piece.

2. The tissue clamping member as described in claim 1, characterized in that, The bending segment includes a first end connected to the corresponding connecting piece and a second end connected to the corresponding clamping segment, wherein the width of the bending segment at the first end is greater than the width of the bending segment at the second end.

3. The tissue clamping member as described in claim 2, characterized in that, The width of the bent section gradually decreases from the first end toward the second end.

4. The tissue clamping member as described in claim 1, characterized in that, Each of the connecting pieces is connected to the corresponding bending segment by a bent fixing piece, the fixing piece on each of the connecting pieces is bent toward the other connecting piece, and each of the bending segments is bent away from the other bending segment.

5. The tissue clamp as described in claim 4, characterized in that, The bending segment includes a first end connected to the corresponding fixing piece and a second end connected to the corresponding clamping segment. The width of the first end of the bending segment is equal to the width of the fixing piece, and the width of the second end of the bending segment is equal to the width of at least a portion of the clamping segment. The first end and the second end of the bending segment have a smooth transition.

6. The tissue clamp as described in claim 1, characterized in that, Each of the clamping arms has a clamping segment having a main body portion and at least one row of barbs arranged along the length direction of the main body portion, and the end of each barb is rounded.

7. The tissue clamp as described in claim 6, characterized in that, The extension length of the barbs in the at least one row of barbs gradually increases along the extension direction of the clamping arm, and the angle between the barbs in the at least one row of barbs and the corresponding clamping segment gradually increases along the extension direction of the clamping arm.

8. The tissue clamping member as described in claim 1, characterized in that, The tissue clamp is at least partially made of shape memory material, and has a naturally unfolded state and a retracted state. In the naturally unfolded state, the angle between the clamping segments of the two clamping arms is greater than 180 degrees.

9. A valve clamping device, characterized in that, The device includes a fixed base, a pair of clamping arms that open and close relative to the fixed base, and a tissue clamping member as described in claim 1, wherein the tissue clamping member is disposed between the fixed base and the clamping arms, and the two clamping arms of the tissue clamping member respectively cooperate with one of the pair of clamping arms to clamp the leaflet.

10. The valve clamping device as described in claim 9, characterized in that, The fixing seat is housed in the connecting frame, at least one of the connecting pieces of the connecting frame is provided with a slot, and the fixing seat is provided with a protrusion that snaps into the slot.

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