Inlet stent and interventional blood pump

Abstract

The present invention relates to an inlet support (5) and an invasive blood pump. The inlet support comprises a guide cone (51), a plurality of supporting ribs (52) and a transition connection ring (53) from the distal end to the proximal end. The guide cone comprises a cone top (511), a cone tail (512), a proximal portion (513) between the two whose diameter gradually decreases toward the cone top, and a distal portion (514) that can be connected to a pigtail catheter. The supporting ribs are connected between the guide cone and the transition connection ring at intervals along the circumferential direction and comprise a radial outer side (521), a radial inner side (522) and an airfoil-shaped guide structure (523) connecting the two, the structure having a width that gradually decreases from the outside to the inside. The transition connection ring comprises an annular structure (531) located at the proximal end that can be connected to an impeller sleeve or a composite catheter and a transition structure (532) that connects the annular structure and the supporting ribs (52). The inlet support of the present application can reduce the risk of side suction, scraping of the inner wall of the heart chamber and thrombosis.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and in particular to an invasive blood pump that is percutaneously inserted into a patient's blood vessel and an inlet stent for the invasive blood pump. Background Art

[0002] Interventional catheter pump, also known as interventional blood pump, is an important ventricular assist medical device, mostly used in high-risk percutaneous coronary intervention (PCI) to reduce ventricular work, provide necessary circulatory support for cardiac recovery and early assessment of residual myocardial function. This type of blood pumping assist device is introduced into the patient's heart through blood vessels. When working, the inlet of the catheter pump is placed in the ventricle and the outlet is placed in the artery. Blood is sucked into the catheter through the inlet at the front end (i.e., the distal end) of the interventional blood pump, and then the blood is pumped directly from the outlet to the whole body through a micro axial flow impeller, which can directly reduce the ventricular load and push the ventricular blood directly into the artery.

[0003] The inlet structure involves the angle and direction of blood inflow, and is the first position where blood flows into the interventional blood pump, which directly affects the effect of blood delivery and the damage to blood. Therefore, designing an inlet structure with good fluid dynamics characteristics, little damage to the human body, and a high safety factor is a constant challenge for design researchers.

[0004] Figure 1 The figure shows an inlet support 5 of a known invasive blood pump. The main body of the support is roughly cylindrical and has a number of evenly distributed windows 54' forming a blood inlet on the wall of the cylinder along the circumferential direction. Slender support ribs 52 are arranged between these windows. The support ribs 52 are completely exposed at the outermost side like a "blade", which greatly increases the risk of scratching the inner wall of the ventricle. Moreover, the dome-shaped base 51' of the inlet support 5 has an obvious low-speed blood flow area (or "dead zone"), especially at the intersection of the support ribs 52 and the base 51', and the low-speed area is very likely to produce thrombus. In addition, these windows 54' are evenly distributed on the side, which can only form radial blood flow, causing the inner wall of the ventricle to be easily sucked due to the low pressure of the inlet (this phenomenon is also called "side suction"), and once sucked, it will cause the inlet of the invasive blood pump to be blocked, which will not only reduce the blood pumping capacity of the invasive blood pump, but also damage the inner wall tissue of the ventricle.

[0005] Therefore, improving the inlet structure of the invasive blood pump has become an urgent problem to be solved. Summary of the invention

[0006] An object of the present application is to solve at least one of the above technical problems.

[0007] To this end, the present application provides an inlet support for an invasive blood pump, which includes a guide cone, a plurality of support ribs and a transition connection ring from the distal end to the proximal end. The guide cone includes a proximal cone top, a distal cone tail, and a proximal part and a distal part located between the cone top and the cone tail. The diameter of the proximal part gradually decreases toward the cone top, and the distal part is configured to be connected to the pigtail catheter of the invasive blood pump. The plurality of support ribs are connected between the guide cone and the transition connection ring at intervals along the circumferential direction to form a plurality of spaced medium inlets, and each support rib includes a radial outer side constituting its outer surface, a radial inner side connected to the guide cone, and an airfoil guide structure connecting the radial outer side and the radial inner side, and the airfoil guide structure has a width that gradually decreases from the radial outer side to the radial inner side. The transition connection ring includes an annular structure located at the proximal end, configured to be connected to the impeller sleeve or composite catheter of the invasive blood pump, and a transition structure connecting the annular structure and the plurality of support ribs.

[0008] In the above scheme, since the guide cone and the wing-shaped guide structure that are more in line with the principles of fluid dynamics are set, the inlet stent according to the embodiment of the present application, when applied to an interventional blood pump, can effectively guide the incoming blood in both the axial and radial directions through the unique inlet shape formed by the guide cone and the wing-shaped guide structure of the supporting ribs, thereby effectively preventing the interventional blood pump from side suction and causing the ventricular inner wall tissue to block the inlet, which not only ensures that the blood pumping capacity of the interventional blood pump is not affected, but also reduces the risk of damaging the ventricular inner wall tissue, while also avoiding the existence of low-speed flow areas. The high-speed flowing blood allows the inlet stent to be effectively flushed and is not prone to thrombus formation. In addition, since the structure of the supporting ribs is more in line with the principles of fluid dynamics, the vortex formed by the separation when the blood flows through the supporting ribs is avoided, and a more stable flow field can be obtained.

[0009] According to some embodiments of the present application, the number of the plurality of supporting ribs is 2 to 4, preferably 3. This can ensure the connection strength of the inlet bracket and provide sufficient flow area without affecting the normal inflow of blood.

[0010] According to some embodiments of the present application, the plurality of supporting ribs are evenly distributed along the circumferential direction, which can make the manufacturing of the inlet stent easier and also make the blood flow at the inlet stent more uniform and stable.

[0011] According to some embodiments of the present application, the outer diameter of the transition structure gradually increases from the distal end to the proximal end and has a maximum outer diameter D1 at the connection between the transition structure and the annular structure, and the value range of D1 is 4 to 7 mm. The size of D1 depends on the overall size of the invasive blood pump with the inlet bracket installed, especially the size of the impeller sleeve to be connected to the annular structure. The inlet bracket with D1 within the above value range can match most of the current invasive blood pumps.

[0012] According to some embodiments of the present application, the wall thickness δ of the annular structure and the transition structure has a value range of (0.03-0.05) D1. In this way, the reliability and processability of the structure can be ensured, and the inlet bracket can also have a good flow capacity.

[0013] According to some embodiments of the present application, the height of the guide cone from the top to the tail is H, and the value range of H is (1.0~2.0) D1. In this way, the blood flow on the surface of the guide cone can be relatively stable, and the overall axial length of the inlet stent will not be too large, which will affect the use.

[0014] According to some embodiments of the present application, the distance from the top of the guide cone to the plane where the transition structure and the annular structure are connected is h, and the value range of h is (0.35~0.75) D1. In this way, the suction capacity of the impeller inlet can be guaranteed, and the guide cone can be effectively flushed by blood, reducing the risk of thrombosis.

[0015] According to some embodiments of the present application, the distal end of the guide cone is roughly cylindrical and has an outer diameter D2, and the value range of D2 is (0.4~0.7) D1. In this way, the blood can have a better axial flow effect and the connection reliability between the inlet stent and the pigtail catheter can be guaranteed.

[0016] According to some embodiments of the present application, the proximal portion of the guide cone is divided into a body of revolution, whose rotation generatrix is ​​an ellipse, the major axis radius of the ellipse is R1, the value range of R1 is (0.9~1.8)D1, and the minor axis radius of the ellipse is R2, which is half of the outer diameter D2 of the distal portion of the guide cone. Such a guide cone can better provide axial extension and transition to ensure that blood flows smoothly on its surface without flow separation.

[0017] According to some embodiments of the present application, the proximal portion of the guide cone is divided into a rotating body, and its rotating generatrix is ​​an arc line or a straight line. Such a guide cone is easy to process.

[0018] According to some embodiments of the present application, an angle a1 is formed between the intersection line of each supporting rib and the axial line of the inlet bracket, and the value range of a1 is 130° to 145°. In this way, the machinability of the inlet bracket can be ensured, and the kinetic energy loss of blood at the impeller inlet can be reduced.

[0019] According to some embodiments of the present application, the distance between the proximal end point of the intersecting line and the plane where the transition structure and the annular structure are connected is L1, and the value range of L1 is (0.25~0.45)D1. In this way, it can be ensured that the inlet bracket has sufficient connection strength and provides sufficient flow area.

[0020] According to some embodiments of the present application, the distance between the intersection of the outer contour line of each supporting rib and the guide cone and the plane where the transition structure and the annular structure are connected is L2, and the value range of L2 is (1.4~1.8) D1. In this way, it can be ensured that the inlet bracket has sufficient connection strength and provides sufficient flow area.

[0021] According to some embodiments of the present application, the distal end of the guide cone has a blind hole extending over its entire axial height L3, the diameter D3 of the blind hole is 2.0-2.2 mm, and L3 is 2.5-4.0 mm, which can ensure the reliability of the connection between the guide cone and the pigtail catheter.

[0022] According to some embodiments of the present application, the proximal end portion of the guide cone has an axial through hole at its center for inserting a guide wire, and the axial through hole is connected to the blind hole. In this way, the inlet stent can be used in conjunction with a hollow pigtail catheter, and the inserted guide wire can be used to achieve easy intervention and arterial transvalvular implantation during the implantation of an interventional blood pump.

[0023] According to some embodiments of the present application, the outer contour line of each supporting rib is an ellipse line or a circular arc line, which can form a smooth transition, thereby reducing the contact area between the supporting rib and the inner wall of the ventricle and reducing the risk of scratching.

[0024] According to some embodiments of the present application, the airfoil guide structure has a maximum width Δ on the radially outer side, and the value range of Δ is 0.5-2.0 mm, and has a minimum width on the radially inner side, and the minimum width is at least 0.2 mm. In this way, the outer edge of the supporting rib is prevented from having a thin-walled structure like a "blade" that is easy to damage the ventricular inner wall tissue, while also ensuring sufficient flow area and reducing energy dissipation.

[0025] According to some embodiments of the present application, the inlet stent is integrally formed of an implantable metal material. The inlet stent supported by an implantable metal material (such as pure titanium, titanium alloy, stainless steel) has good mechanical strength, is durable, and can increase the overall service life of the product. It also has excellent biocompatibility and is not easily rejected by the human body. In addition, the integrally formed inlet stent has many advantages, such as high mechanical strength, fewer processing steps, and can be customized in small quantities.

[0026] The present application also provides an invasive blood pump, comprising a solid or hollow pigtail catheter, a rotatable impeller, an impeller sleeve, and an inlet bracket as described above, wherein the distal end portion of the guide cone of the inlet bracket is connected to the pigtail catheter, the annular structure of the transition connection ring of the inlet bracket is connected to the impeller sleeve, and the medium inlet between the multiple supporting ribs of the inlet bracket constitutes a blood inlet. The invasive blood pump has the advantages of the inlet bracket as described above, which will not be repeated here.

[0027] According to some embodiments of the present application, the interventional blood pump also includes a drive unit, a flexible shaft, and a radially expandable catheter extending around the flexible shaft over at least a portion of its length, wherein the flexible shaft connects the proximal end of the impeller to the distal end of the drive unit; the distal end of the radially expandable catheter is sealingly connected to the impeller sleeve, and a blood outlet is opened at the proximal end, and when the radially expandable catheter is in a radially expanded state, the gap between it and the flexible shaft forms a blood flow channel, and the blood flow channel is connected to both the blood inlet and the blood outlet.

[0028] According to some embodiments of the present application, the outer wall of the flexible shaft and / or the inner wall of the radially expandable catheter and / or the outer wall of the radially expandable catheter are coated with an anticoagulant coating. In this way, effective anticoagulation can be achieved without injecting anticoagulants into the patient, reducing the patient's pain and possible complications.

[0029] According to some embodiments of the present application, the anticoagulant coating is a phosphorylcholine coating or a heparin coating. The phosphorylcholine coating has a simple coating process and does not contain drug components. The heparin coating is more durable but the coating process is more complicated. However, it should be understood that other anticoagulant materials that can be used in vivo can also be used.

[0030] According to some embodiments of the present application, the flexible shaft and the radially expandable catheter include a curved portion with a fixed curvature at the same axial position, and the fixed curvature is 120° to 150°. After the pump head with such a curvature crosses the valve, it is more in line with the physiological structure of the human ventricle and artery, and can reduce damage to the arterial valve and ventricular wall.

[0031] It should be understood that the above general description and the following detailed description are exemplary and explanatory only and cannot limit the present invention. Other features, objects and advantages of the present invention will become apparent from the specification, drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. It is easy for those skilled in the art to understand that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. For illustrative purposes, these drawings may not be drawn completely to scale.

[0033] Figure 1 is a schematic perspective view of an inlet bracket known in the prior art.

[0034] Figure 2 is a schematic three-dimensional diagram of an inlet bracket according to an embodiment of the present application.

[0035] Figure 3 It is a schematic three-dimensional diagram of an inlet bracket according to an embodiment of the present application at another angle.

[0036] Figure 4 is a schematic three-dimensional diagram of an inlet bracket according to an embodiment of the present application at another angle.

[0037] Figure 5 It is a schematic bottom view (i.e., a distal end view) of an inlet bracket according to an embodiment of the present application.

[0038] Figure 6 It is a schematic top view (i.e., a proximal end view) of an inlet bracket according to an embodiment of the present application.

[0039] Figure 7 is a schematic side view of an inlet bracket according to an embodiment of the present application.

[0040] Figure 8 is a schematic axial cross-sectional view of an inlet bracket according to an embodiment of the present application.

[0041] Fig. 9 is a schematic axial cross-sectional view of an inlet bracket according to an embodiment of the present application.

[0042] Fig.10 It is a schematic top view (i.e., a proximal end view) of the inlet bracket according to an embodiment of the present application.

[0043] Fig.11 and Fig.12 is along Fig.10 Cross-section along line AA.

[0044] Fig.13 is a schematic side view of an inlet bracket according to an embodiment of the present application.

[0045] Fig.14 is a schematic axial cross-sectional view of an inlet bracket according to an embodiment of the present application.

[0046] Fig.15 is along Fig.14 Cross-section along line BB.

[0047] Fig.16A and Fig. 16B They are Figure 1 The inlet bracket shown and the flow field diagram of the inlet bracket according to an embodiment of the present application.

[0048] Fig.17A and Fig. 17B The schematic diagrams show Figure 1 The inlet bracket and the supporting ribs of the inlet bracket according to an embodiment of the present application show the influence on the medium flow.

[0049] Fig.18A and Fig.18B They are Figure 1The velocity contour diagram of the inlet bracket and the inlet bracket according to an embodiment of the present application is shown.

[0050] Fig.19 It is a schematic diagram of the pump head structure of an invasive blood pump according to an embodiment of the present application.

[0051] Fig. 20 It is a schematic diagram of the pump head structure of an invasive blood pump according to another embodiment of the present application.

[0052] Fig.21 yes Fig. 20 The schematic diagram of the position of the pump head of the interventional blood pump after implantation in the heart is shown.

[0053] Reference numerals list

[0054] 51' base; 54' window; 5 inlet bracket; 51 guide cone; 511 cone top; 512 cone tail; 513 proximal part; 514 distal part; 515 blind hole; 52 support rib; 521 radial outer side; 522 radial inner side; 523 airfoil guide structure; 524 intersection line; 525 outer contour line; 53 transition connection ring; 531 ring structure; 532 transition structure; 54 medium inlet; 100 interventional blood pump; 4 pigtail catheter; 6 impeller; 7 impeller sleeve; 10 flexible shaft; 11 flat wire spring tube; 12 sealing hose; 13 radially expandable catheter; 131 blood outlet; 14 flexible shaft; 15 bending part DETAILED DESCRIPTION

[0055] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices consistent with some aspects of the present application as detailed in the appended claims.

[0056] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present application. The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "one", "said" and "the" used in this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" that may be used herein refers to and includes any or all possible combinations of one or more associated listed items. "Including" or "including" and similar words mean that the elements or objects appearing in front of "including" or "including" cover the elements or objects listed after "including" or "including" and their equivalents, and do not exclude other elements or objects. "Connected" or "connected" and similar words are not limited to physical or mechanical connections, and can include electrical connections, whether direct or indirect. "Multiple" includes two, equivalent to at least two. It should be understood that although the terms first, second, third, etc. may be used in the present invention to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information without departing from the scope of the present invention.

[0057] In the present application, unless otherwise specified, the terms “proximal” and “distal” are relative to an operator of the invasive blood pump. The portion of a component close to the operator is the proximal end, and the portion far from the operator is the distal end.

[0058] Figures 2 to 6 The inlet bracket 5 according to an embodiment of the present application is schematically shown in different views. The inlet bracket is used to be installed upstream of the impeller 6 of the invasive blood pump 100 (see, for example, FIG. Fig.19 , 20 ), when the interventional blood pump is implanted in the heart and works normally, the blood in the ventricle flows into the internal channel of the interventional blood pump through the inlet bracket 5, is pumped to the blood outlet of the interventional blood pump by the impeller, and is discharged into the artery (see Fig.21 ).

[0059] like Figures 2 to 4As shown, the inlet support 5 includes a guide cone 51, a plurality of support ribs 52 and a transition connection ring 53 from the distal end to the proximal end, wherein the plurality of support ribs 52 are connected between the guide cone 51 and the transition connection ring 53 at intervals along the circumferential direction, playing the role of connection and support, and forming a medium inlet 54 between adjacent support ribs 52. In the illustrated embodiment, the inlet support 5 has three support ribs 52 evenly distributed along the circumferential direction, and the space between them forms three medium inlets 54 evenly distributed along the circumferential direction. However, those skilled in the art should understand that the number of support ribs 52 can be more or less than 3, but generally at least 2 and no more than 4, so as to ensure the connection strength of the inlet support 5, and at the same time provide a sufficient flow area without affecting the normal inflow of blood.

[0060] like Figure 8 , Fig. 9 As shown, the guide cone 51 includes a proximal cone top 511, a distal cone tail 512, and a proximal portion 513 and a distal portion 514 located between the cone top 511 and the cone tail 512. Advantageously, the diameter of the proximal portion 513 gradually decreases toward the cone top 511. Such a structure conforms to the principles of fluid dynamics and can provide good axial guidance for the inflowing blood. The distal portion 514 is configured to be connected to the pigtail catheter 4 of the invasive blood pump 100, and the connection methods include but are not limited to welding, bonding, clamping, threaded connection or a combination thereof. Fig.12 In the illustrated embodiment, the distal portion 514 is substantially cylindrical and has a blind hole 515 extending in the axial direction for receiving the pigtail catheter 4. The proximal portion 513 may be solid or have an axial through hole in the center thereof for passing a guide wire, the axial through hole being in communication with the blind hole 515.

[0061] like Fig.15 As shown, each support rib 52 includes a radial outer side 521 constituting its outer surface, a radial inner side 522 connected to the guide cone 51, and an airfoil guide structure 523 connecting the radial outer side 521 and the radial inner side 522. The airfoil guide structure 523 has a width that gradually decreases from the radial outer side 521 to the radial inner side 522. In other words, Fig.13As shown, the airfoil guide structure 523 has a maximum width Δ at the radial outer side 521 (i.e., its radial outer surface), and a minimum width at the radial inner side 522 (i.e., the intersection with the guide cone 51), and the width between the two gradually decreases. Such a structure conforms to the principles of fluid dynamics, can effectively guide the medium (blood in the case of an invasive blood pump) in the radial direction, so that the medium passes through the inlet bracket 5 smoothly and smoothly, and can effectively reduce the low-speed flow area and reduce the risk of thrombosis. In order to avoid the existence of a thin-walled structure like a "blade" on the outer edge of the support rib 52 that is easy to damage the ventricular inner wall tissue, Δ should not be too small, and in order to ensure sufficient flow area and reduce energy dissipation, Δ should not be too large, and its preferred value range is 0.5~2.0 mm, and more preferably 1.0~1.5 mm. In addition, in order to ensure structural strength and reliability, the minimum width of the airfoil guide structure 523 is preferably at least 0.2 mm.

[0062] like Figures 7 to 9 As shown, the transition connection ring 53 includes an annular structure 531 located at the proximal end and configured to be connected to the impeller sleeve or composite catheter of the interventional blood pump 100, and a transition structure 532 connecting the annular structure 531 and a plurality of support ribs 52. The transition structure 532 smoothly and gently changes the shape of the support ribs 52 and gradually transitions to the annular structure 531. Such a design enables the inlet bracket 5 to have a smooth and fluent outer contour, which can reduce the risk of scratching the inner wall of the heart chamber.

[0063] like Figure 8 As shown, the outer diameter of the transition structure 532 gradually increases from the distal end to the proximal end and has a maximum outer diameter D1 at the connection between the transition structure 532 and the annular structure 531. The size of D1 should be determined according to the overall size of the invasive blood pump, especially the impeller sleeve 7 to be connected to the annular structure 531 (see Fig.19 ). Preferably, the value range of D1 is 4~7mm. The determination of the wall thickness δ of the annular structure 531 and the transition structure 532 needs to consider the reliability and processability of the structure. The thinner the wall thickness, the better the flow capacity of the inlet bracket 5, but it will increase its processing difficulty and reduce the reliability of the structure. Therefore, the preferred value range of the wall thickness δ is (0.03~0.05)D1.

[0064] Still reference Figure 8, the height (or axial length) of the guide cone 51 from the cone top 511 to the cone tail 512 is H. It is easy for those skilled in the art to understand that the greater the height H, the smoother the flow on the surface of the guide cone 51, but if the height H is too large, the overall axial length of the inlet bracket will be too large, affecting the use, so the preferred value range of H is (1.0~2.0)D1. In addition, the distance from the top 511 of the guide cone 51 to the plane where the transition structure 532 and the annular structure 531 are connected is h, which defines the distance between the top 511 and the impeller inlet (the impeller sleeve 7 containing the impeller 6 is, for example, sealed and fixed in the annular structure 531). If the distance is too small, the flow area of ​​the impeller inlet will be too small, resulting in poor blood flow performance and large energy dissipation, thereby affecting the suction capacity of the impeller inlet. If the distance is too large, it means that the guide cone 51 is too far away from the impeller inlet, the blood flow rate through the guide cone will be reduced, the flushing effect on the surface of the guide cone 51 will be weakened, and thrombus will be easily generated. Therefore, the selection of h should ensure both the blood flow performance at the inlet and the effective flushing of the guide cone. The preferred value range is (0.35~0.75) D1. As mentioned above, the distal part 514 of the guide cone 51 is roughly cylindrical and has an outer diameter D2. The selection of the outer diameter D2 should ensure a certain axial flow of blood. The smaller the value, the better the effect of the axial flow of blood. However, in order to ensure the reliability of the connection between the inlet bracket 5 and the pigtail catheter 4, the value cannot be too small. Therefore, preferably, the value range of D2 is (0.4~0.7) D1. Fig.12 As shown, in order to ensure the connection reliability between the guide cone 51 and the pigtail catheter 4, the blind hole 515 of the distal part 514 can be extended over its entire axial height L3, and the diameter D3 of the blind hole 515 is set to 2.0-2.2 mm, and L3 is set to 2.5-4.0 mm. In the illustrated embodiment, the proximal part 513 of the guide cone 51 is a body of revolution, and its rotation generatrix is ​​an elliptical line, and the surface of the proximal part 513 is an elliptical surface accordingly. Such a guide cone can better provide axial extension and transition to ensure that blood flows smoothly on its surface without flow separation. Fig. 9 As shown, the major axis radius of the ellipse is R1, preferably the value range of R1 is (0.9~1.8) D1, and the minor axis radius of the ellipse is R2, and R2 is preferably half of the outer diameter D2 of the distal portion 514 of the guide cone 51. According to other embodiments, the proximal portion 513 of the guide cone 51 is a body of revolution, and its rotation generatrix is ​​an arc or a straight line, and the surface of the proximal portion 513 is a spherical surface or a right cone surface accordingly. It should be understood that the rotation generatrix of the proximal portion 513 can also be any other suitable curve, as long as the body of revolution formed after its rotation conforms to the principles of fluid dynamics and can effectively guide the blood axially.

[0065] Reference now Fig.11 and Fig.12 The intersection line 524 of each supporting rib 52 (i.e., the tail of the supporting rib 52) is Fig.11 An angle a1 is formed between the intersection line 524 (the contour line in the axial section shown) and the axial line of the inlet bracket 5. Structurally, the two ends of the intersection line 524 extend to the transition connection ring 53 and the guide cone 51 respectively. Since the transition connection ring 53 and the guide cone 51 are axially spaced, the angle a1 is an obtuse angle. However, if the angle a1 is too large, the acute angle formed at the intersection of the intersection line 524 and the guide cone 51 will become smaller, which will increase the difficulty and cost of processing, and at the same time, it will be unfavorable for the configuration of the support rib 52. From a fluid dynamics point of view, if the angle a1 is too small (close to 90°), the intersection line 524 will be close to the impeller inlet, and the space at the impeller inlet is limited. Due to the thickness of the support rib 52, it occupies the impeller inlet space, squeezes the blood flow, and increases the kinetic energy loss. Therefore, the preferred value range of a1 is 130°~145°. The distance between the proximal end point of the intersection line 524 and the plane where the transition structure 532 and the annular structure 531 are connected is L1, and the preferred value range of L1 is (0.25~0.45)D1, which can ensure that the inlet stent 5 has sufficient connection strength and provides sufficient flow area. The distance between the intersection of the outer contour line 525 of each support rib 52 and the guide cone 51 and the plane where the transition structure 532 and the annular structure 531 are connected is L2. In order to ensure that the inlet stent 5 has sufficient connection strength and provides sufficient flow area, the preferred value range of L2 is (1.4~1.8)D1. In addition, advantageously, the outer contour line 525 of each support rib 52 is an elliptical line or an arc line or other curve, which can form a smooth transition, thereby reducing the contact area between the support rib 52 and the inner wall of the ventricle and reducing the risk of scratching.

[0066] According to an embodiment of the present application, the inlet stent 5 is made of an implantable metal material (e.g., pure titanium, titanium alloy, stainless steel) that is biocompatible and meets relevant national standards and can be implanted in the body. Advantageously, each part is integrally formed, for example, by an additive manufacturing process. An integrally formed inlet stent has many advantages, such as high mechanical strength, fewer processing steps, and can be customized in small quantities. Of course, the various parts of the inlet stent 5 can also be manufactured separately and then assembled together in any suitable manner.

[0067] Reference below FIG. 16A to FIG. 18B To further illustrate the advantages of the inlet bracket 5 according to the embodiment of the present application.

[0068] like Fig.16A As shown, when blood flows into the inlet of the conventional inlet stent (i.e., the side window 54'), the main flow is radial flow, which easily leads to side suction. Fig. 16BIt can be seen that the inlet shape formed by the inlet support 5 through the guide cone 51 and the wing-shaped guide structure 523 of the supporting rib 52 can provide blood with axial and radial flow, thereby effectively preventing the interventional blood pump from side suction and causing the ventricular inner wall tissue to block the inlet. This not only ensures that the blood pumping capacity of the interventional blood pump is not affected, but also reduces the risk of damaging the ventricular wall tissue.

[0069] like Fig.17A As shown, when the medium is sucked into the inlet of the inlet bracket, Figure 1 The supporting ribs of the conventional window-type inlet structure shown in FIG. 1 will form a vortex flow on the inner side of the supporting ribs. Fig. 17B As shown, since the structure of the supporting ribs according to the embodiment of the present application is more in line with the principles of fluid dynamics, vortices formed by flow separation are avoided and a more stable flow field can be obtained.

[0070] exist Fig.18A and Fig.18B In the figure, blue represents the medium low-speed flow area, and red represents the medium high-speed flow area. Fig.18A As you can see, Figure 1 The conventional inlet stent shown has an obvious low-speed flow area at the proximal position of its base 51', and thrombus is very likely to be generated in the low-speed flow area. In contrast, since the inlet stent according to the embodiment of the present application adopts a guide cone and an airfoil guide structure that are more in line with the principles of fluid dynamics, blood can be effectively guided in the radial and axial directions, avoiding the existence of the low-speed flow area, and the high-speed flowing blood can effectively flush the inlet stent, making it less likely to generate thrombus.

[0071] The embodiment of the present application also provides an invasive blood pump, such as Fig.19 and Fig. 20 As shown. Fig.19In the embodiment shown, the interventional blood pump 100 includes a hollow pigtail catheter 4 (in this case, the guide cone 51 of the inlet bracket 5 needs to be pierced in the middle and connected to the hollow pigtail catheter, and a guide wire is inserted to achieve the crossing of the aortic valve. This valve crossing method is relatively mature and reliable, has low requirements on the operator, and has a small puncture diameter, but has more intervention steps), an inlet bracket 5, a rotatable impeller 6, and an impeller sleeve 7 containing the impeller 6. The distal portion 514 of the guide cone 51 of the inlet bracket 5 is connected to the pigtail catheter 4 (for example, by bonding, clamping, threading or a combination thereof), and the proximal portion 513 of the guide cone 51 is also provided with an axial through hole for inserting a guide wire, the annular structure 531 of the transition connection ring 53 of the inlet bracket 5 is connected to the impeller sleeve 7 (for example, by welding, bonding, clamping, threading or a combination thereof), and the medium inlet 54 between the multiple supporting ribs 52 of the inlet bracket 5 constitutes a blood inlet. The interventional blood pump 100 including the inlet stent 5 as described above has an improved inlet structure. When implanted in the heart and working normally, blood flows into the interventional blood pump through the medium inlet 54 of the inlet stent 5. Since a relatively high-speed flow is generated in both the radial and axial directions, the vortex caused by the low-speed flow area and flow separation is avoided, thereby reducing the risk of side suction (i.e., the ventricular inner wall tissue is sucked to the inlet), thereby effectively preventing the ventricular inner wall tissue from blocking the inlet and causing a reduction in blood pumping performance, while also effectively protecting the ventricular inner wall tissue. In addition, the risk of thrombosis at the inlet stent is also reduced. Moreover, since the inlet stent 5 does not have a thin-walled structure like a "blade", the risk of scratching the ventricular inner wall is also reduced.

[0072] exist Fig.19In the illustrated embodiment, the invasive blood pump 100 further includes a drive unit, a flexible shaft 14, and a radially expandable catheter 13 extending around the flexible shaft 14 over at least a portion of its length. The flexible shaft 14 connects the proximal end of the impeller 6 to the distal end of the drive unit. The distal end of the radially expandable catheter 13 is sealedly connected to the impeller sleeve 7 and covers the impeller outlet, and a blood outlet 131 is provided at the proximal end. The blood outlet 131 is a plurality of openings uniformly distributed along the circumference and opened on the proximal wall of the radially expandable catheter 13. The shape of the openings can be, for example, circular, elliptical, etc., and the number is usually 3 to 6. When the radially expandable catheter 13 is in a radially expanded state, the gap between it and the flexible shaft 14 forms a blood flow channel, which is connected to both the blood inlet and the blood outlet 131. When the invasive blood pump is in a working position in the heart, the radially expandable catheter 13 crosses the corresponding arterial valve, so that the blood inlet (i.e., the medium inlet 54 of the inlet stent 5) is located in the left ventricle or the right ventricle, and the blood outlet 131 is located in the aorta or the pulmonary artery. During surgical intervention, the radially expandable catheter 13 is in a contracted state, clinging to the outer wall of the flexible shaft 14 to reduce the diameter, so that the size is smaller during intervention, which can reduce vascular damage, and is conducive to reducing vascular complications and postoperative recovery. During operation, as the impeller 6 rotates, blood is pumped from the blood inlet on the inlet bracket 5 into the gap between the impeller 6 and the impeller sleeve 7, flows through the gap and flows out from the impeller outlet, and enters the gap between the tube wall of the radially expandable catheter 13 and the flexible shaft 14. As the blood continues to enter, the tube wall of the radially expandable catheter 13 gradually expands radially until it enters a working state with a larger diameter. After the blood flows through the blood flow channel formed by the gap, the blood flows out from the blood outlet 131 at the proximal end of the radially expandable catheter 13 and enters the artery.

[0073] According to one embodiment, the length of the flexible shaft 14 is set so that the drive unit is just outside and adjacent to the blood outlet 131, and the proximal end of the radially expandable catheter 13 is sealingly connected to the housing of the drive unit. According to another embodiment, the length of the flexible shaft 14 is set so that when the interventional blood pump is in the working position in the heart, the drive unit is outside the patient's body. In this case, a portion of the flexible shaft 14 is located inside the blood vessel and a portion is located outside the blood vessel, and the radially expandable catheter 13 covers only a portion of the length of the flexible shaft 14, so its proximal end is not fixed to the housing of the drive unit, but to the outer surface of the flexible shaft 14.

[0074] Specifically, the flexible shaft 14 may include a flexible shaft 10 for transmitting the torque of the driving unit to the impeller 6 and driving it to rotate at high speed, a flat wire spring tube 11 which is sleeved outside the flexible shaft 10 for protection and rigid support, and a sealing hose 12 which is sleeved outside the flat wire spring tube 11. Preferably, the flat wire spring tube 11 and the flexible shaft 10 are both made of metal materials, such as forged stainless steel, nickel-titanium alloy, forged cobalt-chromium-molybdenum alloy, etc.

[0075] The sealing hose 12 and the radially expandable catheter 13 are made of flexible materials, including but not limited to flexible polymer materials, such as one or more materials of FEP (fluorinated ethylene propylene copolymer film), PET (polyethylene terephthalate film), E-PTFE (expanded polytetrafluoroethylene film), polyurethane, nylon, PEBAX (block polyether amide resin), and latex.

[0076] Since the sealing hose 12 and the radially expandable catheter 13 are usually made of plastic and there may be low-speed areas and eddy flow areas in the flow channel, there is a risk of thrombosis. In response to this problem, the current common solution is to inject anticoagulants into the patient to achieve anticoagulation, but the use of anticoagulants will act on the patient's entire body through blood circulation, and improper dosage may cause complications. The present application proposes that an anticoagulant coating is applied to the outer wall of the flexible shaft 14 (i.e., the outer wall of the sealing hose 12) and / or the inner wall of the radially expandable catheter 13 and / or the outer wall of the radially expandable catheter 13, preferably, the outer wall of the flexible shaft 14 and the inner and outer walls of the radially expandable catheter 13 are coated with an anticoagulant coating to achieve the purpose of anticoagulation. The anticoagulant coating can be a phosphorylcholine coating, a heparin coating, or other anticoagulant materials that can be used in vivo. The phosphorylcholine coating can reduce protein and cell adhesion, thereby playing an anticoagulant role, and the coating process is simple and does not contain drug components. Heparin is a commonly used antithrombotic drug in clinical practice, which mainly achieves the purpose of anticoagulation by indirectly inhibiting the activity of thrombin. Heparin coating is more durable but the coating process is more complicated. Those skilled in the art can select appropriate anticoagulant materials according to actual clinical conditions.

[0077] Fig. 20 The embodiment shown is Fig.19 The embodiments shown are basically the same, so the same aspects are not repeated here, and the only difference is that:

[0078] - The flexible shaft 14 and the radially expandable catheter 13 include a curved portion 15 with a fixed curvature at the same axial position, so that the entire pump head is curved. Preferably, the fixed curvature is 120° to 150°. After the curved pump head crosses the valve, it is more in line with the physiological structure of the human ventricle and artery, and can reduce damage to the arterial valve and ventricular wall;

[0079] - The pigtail catheter 4 is solid. In this case, when the interventional blood pump is implanted in the heart, the pigtail catheter is used with the help of the sheath to achieve cross-valve artery valvulation. This cross-valvular method requires a larger puncture port and a higher timing control ability of the operator, but has fewer intervention steps.

[0080] The accompanying drawings and the above description describe non-limiting specific embodiments of the present application. In order to teach the principles of the invention, some conventional aspects have been simplified or omitted. It should be understood by those skilled in the art that any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be understood by those skilled in the art that the above features can be combined in various ways to form multiple variations of the present application without conflict. Therefore, the present invention is not limited to the above specific embodiments, but is only limited by the claims and their equivalents.

Claims

1. An inlet support (5) for an invasive blood pump (100), characterized in that: The inlet support (5) comprises, from the distal end to the proximal end, a guide cone (51), a plurality of supporting ribs (52) and a transition connection ring (53). The guide cone (51) comprises a proximal cone top (511), a distal cone tail (512), and a proximal portion (513) and a distal portion (514) located between the cone top (511) and the cone tail (512); the diameter of the proximal portion (513) gradually decreases toward the cone top (511); and the distal portion (514) is substantially cylindrical and is configured to be connected to a pigtail catheter of the invasive blood pump; The plurality of support ribs (52) are connected between the guide cone (51) and the transition connection ring (53) at intervals along the circumferential direction to form a plurality of spaced medium inlets (54), and each of the support ribs (52) comprises a radial outer side (521) constituting an outer surface thereof, a radial inner side (522) connected to the guide cone (51), and an airfoil guide structure (523) connecting the radial outer side (521) and the radial inner side (522), wherein the airfoil guide structure (523) has a width that gradually decreases from the radial outer side (521) to the radial inner side (522); The transition connection ring (53) comprises an annular structure (531) located at the proximal end and configured to be connected to the impeller sleeve or the composite catheter of the interventional blood pump, and a transition structure (532) connecting the annular structure (531) and the plurality of supporting ribs (52); the outer diameter of the transition structure (532) gradually increases from the distal end to the proximal end and has a maximum outer diameter D1 at the connection between the transition structure (532) and the annular structure (531); Each of the supporting ribs (52) has two ends extending to an intersection line (524) of the transition structure (532) and the guide cone (51), respectively; the distance between the intersection point of the intersection line (524) and the transition structure (532) and the plane where the transition structure (532) and the annular structure (531) are connected is L1, and the value range of L1 is (0.25~0.45) D1; The distance between the intersection of the outer contour line (525) of each supporting rib (52) and the guide cone (51) and the plane where the transition structure (532) and the annular structure (531) are connected is L2, and the value range of L2 is (1.4~1.8) D1.

2. The inlet bracket (5) according to claim 1, characterized in that: The number of the plurality of supporting ribs (52) is 2 to 4.

3. The inlet bracket (5) according to claim 2, characterized in that: The number of the plurality of supporting ribs (52) is 3.

4. The inlet bracket (5) according to any one of claims 1 to 3, characterized in that: The multiple supporting ribs (52) are evenly distributed along the circumferential direction.

5. The inlet bracket (5) according to any one of claims 1 to 3, characterized in that: The value range of D1 is 4~7mm.

6. The inlet bracket (5) according to any one of claims 1 to 3, characterized in that: The value range of the wall thickness δ of the annular structure (531) and the transition structure (532) is (0.03-0.05) D1.

7. The inlet bracket (5) according to any one of claims 1 to 3, characterized in that: The height of the guide cone (51) from the cone top (511) to the cone tail (512) is H, and the value range of H is (1.0-2.0) D1.

8. The inlet bracket (5) according to any one of claims 1 to 3, characterized in that: The distance from the cone top (511) of the guide cone (51) to the plane where the transition structure (532) and the annular structure (531) are connected is h, and the value range of h is (0.35~0.75) D1.

9. The inlet bracket (5) according to any one of claims 1 to 3, characterized in that: The distal end portion (514) of the guide cone (51) has an outer diameter D2, and the value range of D2 is (0.4-0.7) D1.

10. The inlet support (5) according to claim 9, characterized in that The proximal portion (513) of the guide cone (51) is a body of revolution, and its rotation generatrix is ​​an ellipse. The major axis radius of the ellipse is R1, and the value range of R1 is (0.9-1.8) D1. The minor axis radius of the ellipse is R2, and R2 is half of the outer diameter D2 of the distal portion (514) of the guide cone (51).

11. The inlet support (5) according to any one of claims 1 to 3, characterized in that: The proximal end portion (513) of the guide cone (51) is a rotating body, and its rotation generatrix is ​​an arc line or a straight line.

12. The inlet support (5) according to any one of claims 1 to 3, characterized in that: An angle a1 is formed between the intersection line (524) of each supporting rib (52) and the axial line of the inlet bracket (5), and the value range of a1 is 130°-145°.

13. The inlet support (5) according to any one of claims 1 to 3, characterized in that: The distal end portion (514) of the guide cone (51) has a blind hole (515) extending over its entire axial height L3, the diameter D3 of the blind hole is 2.0-2.2 mm, and L3 is 2.5-4.0 mm.

14. The inlet support (5) according to claim 13, characterized in that The proximal end portion (513) of the guide cone (51) has an axial through hole at its center for passing a guide wire, and the axial through hole is connected to the blind hole (515).

15. The inlet support (5) according to any one of claims 1 to 3, characterized in that: The outer contour line (525) of each supporting rib (52) is an elliptical line or an arc line.

16. The inlet support (5) according to any one of claims 1 to 3, characterized in that: The airfoil guide structure (523) has a maximum width Δ at the radial outer side (521), and the value range of Δ is 0.5-2.0 mm, and has a minimum width at the radial inner side (522), and the minimum width is at least 0.2 mm.

17. The inlet support (5) according to any one of claims 1 to 3, characterized in that: The inlet bracket (5) is integrally formed from implant-grade metal material.

18. An invasive blood pump, comprising a solid or hollow pigtail catheter (4), a rotatable impeller (6) and an impeller sleeve (7), characterized in that: The invasive blood pump (100) further comprises an inlet bracket (5) as described in any one of claims 1 to 17, wherein a distal portion (514) of a guide cone (51) of the inlet bracket (5) is connected to the pigtail catheter (4), an annular structure (531) of a transition connecting ring (53) of the inlet bracket (5) is connected to the impeller sleeve (7), and a medium inlet (54) between a plurality of supporting ribs (52) of the inlet bracket (5) constitutes a blood inlet.

19. The invasive blood pump according to claim 18, characterized in that: The interventional blood pump also includes a drive unit, a flexible shaft (14) and a radially expandable catheter (13) extending around the flexible shaft over at least a portion of its length, wherein the flexible shaft (14) connects the proximal end of the impeller (6) to the distal end of the drive unit; the distal end of the radially expandable catheter (13) is sealingly connected to the impeller sleeve (7), and a blood outlet (131) is opened at the proximal end. When the radially expandable catheter (13) is in a radially expanded state, a gap between it and the flexible shaft (14) forms a blood flow channel, and the blood flow channel is connected to both the blood inlet and the blood outlet (131).

20. The invasive blood pump according to claim 19, characterized in that: The outer wall of the flexible shaft (14) and / or the inner wall of the radially expandable catheter (13) and / or the outer wall of the radially expandable catheter (13) are coated with an anticoagulant coating.

21. The invasive blood pump according to claim 20, characterized in that: The anticoagulant coating is a phosphorylcholine coating or a heparin coating.

22. The invasive blood pump according to any one of claims 19 to 21, characterized in that: The flexible shaft (14) and the radially expandable catheter (13) include a curved portion (15) with a fixed curvature at the same axial position, and the fixed curvature is 120° to 150°.

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