Interventional blood pump

Abstract

The invention provides an intrusive blood pump. The intrusive blood pump comprises a mesh basket and a flow channel covering film, the mesh basket comprises a cylindrical section which extends along the axial direction of the mesh basket; the runner covering film is arranged around the axis of the mesh basket in the circumferential direction in a surrounding mode. The flow channel covering film comprises a straight section and a flaring section which are arranged and connected in the axial direction of the net basket, the straight section wraps the cylindrical section in the circumferential direction of the net basket, the far end of the flaring section is connected with the near end of the straight section, the flaring section expands and extends in the direction from the far end to the near end, and the flow channel covering film is arranged on the flow channel covering film. And the net basket extends beyond the near end of the cylindrical section in the axial direction of the net basket. Through the configuration, the blood pumping lift and efficiency can be improved; the flow speed at the impeller outlet is reduced, and the pipeline loss is reduced; furthermore, under the condition that sufficient blood flow support is guaranteed, the necessary rotating speed of the impeller can be reduced, and therefore the risk of hemolysis and thrombus occurrence is reduced. In addition, due to the arrangement of the flaring section, the diameter of the flow channel is increased equivalently, and blood blockage is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an invasive blood pump. Background Art

[0002] Current percutaneous interventional blood pump products have certain technical limitations and cannot simultaneously meet the balance between intervention size and auxiliary flow. Blood pumps with larger intervention size can provide the necessary blood flow support, but the intervention process is likely to damage the blood vessel wall and cause complications; blood pumps with smaller intervention size are easy to implement intervention, but it is difficult to provide the necessary blood flow support.

[0003] In order to balance the intervention size and auxiliary flow, it is necessary to increase the flow rate while keeping the intervention size small. However, at higher rotation speeds, the outlet velocity circulation of existing blood pumps is difficult to convert into pressure energy, and reflux is prone to occur, resulting in a decrease in the flow rate and efficiency of the blood pump, increasing the risk of hemolysis and thrombosis, and a higher rotation speed is likely to lead to higher pathway friction losses; blood is also prone to shaking and kinking when flowing through a flexible pathway, which also increases the risk of hemolysis and thrombosis. Summary of the invention

[0004] The object of the present invention is to provide an invasive blood pump to solve the problems existing in the existing blood pump at a higher rotation speed.

[0005] To solve the above technical problems, the present invention provides an interventional blood pump, comprising: an interventional blood pump, characterized in that it comprises: a mesh basket and a flow channel coating; the mesh basket comprises a cylindrical section extending along its own axial direction; the flow channel coating is circumferentially arranged around the axis of the mesh basket; the flow channel coating comprises a straight section and a flared section connected and arranged along the axial direction of the mesh basket, the straight section is coated on the cylindrical section along the circumference of the mesh basket, the distal end of the flared section is connected to the proximal end of the straight section, the flared section expands and extends from the distal end to the proximal end, and extends in the axial direction of the mesh basket beyond the proximal end of the cylindrical section.

[0006] Optionally, an angle formed between an extension direction of the membrane wall of the expanded section toward the distal end and the axis of the basket is 2° to 12°.

[0007] Optionally, the invasive blood pump further comprises an impeller, which is rotatably disposed in the basket around the axis of the basket; wherein the distal end of the flared section overlaps with the impeller in the axial direction of the basket.

[0008] Optionally, the distal end of the straight section is flush with the distal end of the cylindrical section, and the axial length of the straight section along the basket is not less than 1 / 2 of the axial length of the cylindrical section along the basket, and not greater than the axial length of the cylindrical section along the basket.

[0009] Optionally, the axial length of the straight section along the mesh basket is not less than 2 / 3 of the axial length of the cylindrical section along the mesh basket, and not more than 5 / 6 of the axial length of the cylindrical section along the mesh basket.

[0010] Optionally, the ratio of the maximum outer diameter of the flow channel coating to the outer diameter of the tubular section is 1-5; the ratio of the axial length of the flow channel coating along the basket to the axial length of the tubular section is not less than 2.

[0011] Optionally, the axial length of the flow channel coating along the basket satisfies:

[0012]

[0013] The outer diameter of the cylindrical section is D1, the maximum outer diameter of the flow channel coating is D2, the angle formed between the extension direction of the membrane wall of the expanded section to the distal end and the axis of the basket is θ, and the axial length of the flow channel coating along the basket is L1.

[0014] Optionally, the flow channel coating further includes an extension section, the distal end of the extension section is connected to the proximal end of the expansion section;

[0015] The extension section extends along the axial direction of the basket; or

[0016] The extension section expands and extends from the distal end to the proximal end, and the angle formed by the membrane wall of the extension section and the axis of the basket is not greater than the angle formed by the membrane wall of the expansion section and the axis of the basket.

[0017] Optionally, the extension section is connected to the flared section in a smooth transition.

[0018] Optionally, the basket also includes an expansion section, the distal end of the expansion section is connected to the proximal end of the tubular section, and the distal end of the flaring section is flush with the distal end of the expansion section; the expansion section expands and extends from the distal end to the proximal end and fits with the flaring section, and the proximal end of the expansion section is located between the distal end and the proximal end of the flaring section.

[0019] Optionally, the flow channel coating further includes an outlet section located at the proximal end, the outlet section is provided with a plurality of openings, and the outlet section is in a tapered shape that narrows toward the proximal end.

[0020] Optionally, both ends of the opening along the axial direction of the basket are arc-shaped.

[0021] In summary, the present invention provides an invasive blood pump comprising: a basket and a flow channel coating; the basket comprises a cylindrical section extending along its own axial direction; the flow channel coating is circumferentially arranged around the axis of the basket; the flow channel coating comprises a straight section and a flared section connected and arranged along the axial direction of the basket, the straight section is coated on the cylindrical section along the circumference of the basket, the distal end of the flared section is connected to the proximal end of the straight section, the flared section expands and extends from the distal end to the proximal end, and extends in the axial direction of the basket beyond the proximal end of the cylindrical section.

[0022] With such a configuration, based on the setting of the flared section, the kinetic energy of the higher rotation speed at the impeller outlet can be converted into pressure energy, which can improve the blood pumping head and efficiency; it also reduces the flow velocity at the impeller outlet and reduces pipeline losses; further, the rotation speed at the impeller outlet can be transitioned to the axial velocity component, which can reduce the shaking and kinking caused by blood flowing through the flow channel coating. More importantly, due to the improvement of blood pumping head and efficiency, the necessary speed of the impeller can be reduced while ensuring sufficient blood flow support, thereby reducing the risk of hemolytic thrombosis. In addition, due to the centrifugal force when the impeller rotates at high speed, the blood close to the hub will be squeezed to the tip of the blade, which can easily cause blockage of the flow channel at the periphery of the impeller outlet and cause backflow. The setting of the flared section is equivalent to increasing the diameter of the flow channel, effectively reducing blood blockage. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0024] Figure 1 is a schematic diagram of an invasive blood pump system according to an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of an invasive blood pump according to an embodiment of the present invention being inserted into a ventricle;

[0026] Figure 3 is a schematic diagram of an invasive blood pump according to an embodiment of the present invention;

[0027] Figure 4 is a schematic diagram of an impeller according to an embodiment of the present invention;

[0028] Figure 5 is a side view of an invasive blood pump according to an embodiment of the present invention;

[0029] Figure 6 yes Figure 5 A partial enlarged schematic diagram of

[0030] Figure 7 is a graph of flow rate and head at different flaring angles of an embodiment of the present invention;

[0031] Figure 8 is an efficiency chart of different flaring angles of an embodiment of the present invention;

[0032] Fig. 9 1 is a diagram of head and hemolysis index at different flaring angles of an embodiment of the present invention;

[0033] Figure 10a to Figure 10c Schematic diagrams of several examples of outlet sections of embodiments of the present invention;

[0034] Fig.11a yes Figure 10a to Figure 10c A diagram of flow rate and head for the outlet section is shown;

[0035] Fig.11b yes Figure 10a to Figure 10c Efficiency diagram of the outlet section shown;

[0036] Fig.11c yes Figure 10a to Figure 10c The head and hemolysis index diagram of the outlet section is shown;

[0037] Fig.12 is a schematic diagram of an invasive blood pump according to another embodiment of the present invention.

[0038] In the attached figure:

[0039] 10-interventional blood pump; 20-transmission delivery assembly; 30-drive assembly; 40-control assembly;

[0040] 11-pigtail catheter; 12-net basket; 121-cylindrical section; 122-conical section; 13-impeller; 130-hub; 131-blades; 14-bearing; 15-channel coating; 151-straight section; 152-expanding section; 153-exit section; 154-opening; 155-extension section. DETAILED DESCRIPTION

[0041] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0042] As used in the present invention, the singular forms "one", "an", "one" and "the" include plural objects, the term "or" is generally used in a sense that includes "and / or", the term "several" is generally used in a sense that includes "at least one", and the term "at least two" is generally used in a sense that includes "two or more". In addition, the terms "first", "second" and "third" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of the features, and "one end" and "the other end" as well as "proximal end" and "distal end" generally refer to two corresponding parts, which include not only the endpoints. The terms "proximal end" and "distal end" are defined herein relative to an invasive blood pump having an end for intervention in the human body and a control end extending outside the body. The term "proximal end" refers to a position closer to the control end of the invasive blood pump extending outside the body, and the term "distal end" refers to a position closer to the end of the invasive blood pump that intervenes in the human body and is therefore farther away from the control end of the invasive blood pump. Optionally, in a manual or hand-operated application scenario, the terms "proximal end" and "distal end" are defined herein relative to an operator such as a surgeon or clinician. The term "proximal end" refers to a position closer to the operator, and the term "distal end" refers to a position closer to the invasive blood pump and is therefore farther away from the operator. In addition, as used in the present invention, "installed", "connected", "connected", and one element "set" to another element should be understood in a broad sense, usually only indicating that there is a connection, coupling, matching or transmission relationship between the two elements, and the connection, coupling, matching or transmission between the two elements can be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element can be in any orientation such as inside, outside, above, below or one side of another element, unless the content clearly indicates otherwise. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, directional terms such as above, below, up, down, upward, downward, left, right, etc. are used with respect to the exemplary embodiments as they are shown in the figures, with the upward or upper direction toward the top of the corresponding figure and the downward or lower direction toward the bottom of the corresponding figure.

[0043] The object of the present invention is to provide an invasive blood pump to solve the problems existing in the existing blood pumps at a higher rotation speed.

[0044] Please refer to Figure 1 The embodiment of the present invention provides an interventional blood pump system, which includes: an interventional blood pump 10, a transmission and delivery component 20 and a drive component 30; the interventional blood pump 10 is located at the distal end and is used for intervention in the human body. Figure 2 and Figure 3 , the proximal end of the interventional blood pump 10 is connected to the drive assembly 30 through the transmission and delivery assembly 20, and the drive assembly 30 drives the impeller of the interventional blood pump 10 through the transmission and delivery assembly 20. Optionally, in some embodiments, the drive assembly 30 can be integrated into a handle. Optionally, the interventional blood pump system may also include a control assembly 40, which is used to monitor and control other components of the interventional blood pump system. Those skilled in the art can understand the various components of the interventional blood pump system based on the prior art, which will not be introduced in detail here.

[0045] Please refer to Figure 2 and Figure 3 The interventional blood pump 10 includes a basket 12 and a flow channel coating 15, wherein the basket 12 is made of a shape memory metal such as nickel-titanium alloy, which can be compressed, folded, unfolded and expanded, and in the unfolded state, is used to form a space for the impeller 13 to rotate. The flow channel coating 15 is circumferentially arranged around the axis of the basket 12, and at least a portion of the flow channel coating 15 is coated on the outer wall of the skeleton of the basket 12, so as to form a passage for blood after being pumped out of the basket 12.

[0046] Furthermore, in an alternative exemplary embodiment, the invasive blood pump 10 further includes a pigtail catheter 11, an impeller 13, and a bearing 14. The pigtail catheter 11 is preferably a polymer hose, and its material can be a polymer material such as PEBAX, TPU, etc. The pigtail catheter 11 is the farthest end of the invasive blood pump 10, and plays a role in reducing or avoiding damage to blood vessels and ventricular walls during transportation and fixation.

[0047] Please refer to Figure 4 The impeller 13 is rotatably arranged in the basket 12 around the axis of the basket 12. Optionally, the impeller 13 includes a hub 130 and blades 131. The impeller 13 is preferably made of a polymer elastic material, such as thermoplastic elastomer (TPE) and silicone rubber, so as to facilitate compression during transportation. The material constituting the impeller 13 can be a single material or a combination of multiple materials. For example, the root of the hub 130 and the blade 131 (referring to the side where the blade 131 is connected to the hub 130) can be made of an elastomer with a lower hardness, which can ensure sufficient strength and can also achieve compression smoothly, while the tip of the blade that is easily deformed (referring to the side where the blade 131 is away from the hub 130) is made of an elastomer with a higher hardness to avoid excessive deformation that causes the blade 131 to collapse. The two ends of the hub 130 are preferably connected to the basket 12 through bearings 14, and the bearings 14 play a role in supporting and fixing the impeller 13. Furthermore, the proximal end of the hub 130 is connected to the transmission and delivery assembly 20, and rotates around its own axis under the drive of the drive assembly 30, thereby being able to pump blood.

[0048] Please refer to Figure 5 and Figure 6 In order to solve the problems existing in the existing blood pumps at higher speeds, in the invasive blood pump 10 provided in this embodiment, the basket 12 includes a cylindrical section 121 extending along its own axial direction; the flow channel coating 15 is arranged around the axis of the basket 12 (the axis is Figure 5 and Figure 6 The flow channel coating 15 includes a straight section 151 and a flared section 152 connected along the axial direction of the basket 12, the straight section 151 is coated on the cylindrical section 121 along the circumferential direction of the basket 12, and the distal end of the flared section 152 ( Figure 5 and Figure 6 The left end in the middle) and the proximal end of the straight section 151 ( Figure 5 and Figure 6 The expansion section 152 is connected from the distal end to the proximal end ( Figure 5 and Figure 6 The net basket 12 is extended and expanded (from left to right in the figure), and extends beyond the proximal end of the cylindrical section 121 in the axial direction of the net basket 12. Optionally, the net basket 12 also includes conical sections 122 located at both ends of its own axial direction, and the entire net basket 12 is roughly spindle-shaped. Preferably, the cross section of the net basket 12 is circular, and the cylindrical section 121 is cylindrical.

[0049] With such configuration, based on the setting of the flared section 152, the kinetic energy of the higher rotation speed at the outlet of the impeller 13 can be converted into pressure energy, which can improve the blood pumping head and efficiency; it also reduces the flow velocity at the outlet of the impeller 13, reducing pipeline losses; further, the rotation speed at the outlet of the impeller 13 can be transitioned to the axial velocity component, which can reduce the shaking and kinking caused by the blood flowing through the flow channel coating 15. More importantly, due to the improvement of the blood pumping head and efficiency, the necessary rotation speed of the impeller 13 can be reduced while ensuring sufficient blood flow support, thereby reducing the risk of hemolytic thrombosis. In addition, due to the centrifugal force when the impeller 13 rotates at high speed, the blood close to the hub 130 will be squeezed to the tip of the blade, which can easily cause blockage of the flow channel at the periphery of the outlet of the impeller 13, causing backflow. The setting of the flared section 152 is equivalent to increasing the diameter of the flow channel, effectively reducing blood blockage.

[0050] In an exemplary embodiment, the straight section 151 and the flared section 152 are preferably both flexible films, and the material thereof may be a polymer material such as TPU. The straight section 151 may be connected to the cylindrical section 121 by heat shrinking or hot melting, and the straight section 151 and the flared section 152 may be connected by hot melting, or the straight section 151 and the flared section 152 may be integrally formed.

[0051] Optionally, the angle formed by the extension direction of the membrane wall of the flared section 152 to the distal end and the axis of the basket 12 is 2° to 12°. It should be noted that the membrane wall of the flared section 152 refers to the inner wall of the flexible membrane of the flared section 152. For the convenience of description, the angle formed by the extension direction of the membrane wall of the flared section 152 to the distal end and the axis of the basket 12 is called the flaring angle θ. Studies have shown that the flaring angle θ of the flared section 152 is correlated with parameters such as the flow rate, blood pumping head, efficiency and hemolytic index of the blood pump, and the flow rate, blood pumping head, efficiency and hemolytic index are not consistent with the changes in the flaring angle θ, which results in the same flaring angle θ being advantageous for the selection of some parameters but disadvantageous for the selection of other parameters. It should be noted that if the membrane wall of the expanded section 152 is in an ideal truncated cone shape, the membrane wall of the expanded section 152 is a straight line in the cross section, and the angle formed by the membrane wall and the axis of the basket 12 is the same everywhere, which is the expansion angle θ. In other embodiments, if the membrane wall of the expanded section 152 is not in an ideal truncated cone shape, for example, it has a certain curvature and is in a curved surface shape, then the expansion angle θ is the angle formed by the extension direction of the membrane wall at the distal end and the axis of the basket 12.

[0052] Please refer to Figure 7 and Figure 8 , and compare the effects of different flaring angles θ on the performance of the interventional blood pump 10. At the same preset speed, within the range of 2° to 12°, the interventional blood pump 10 has good performance and efficiency. And as the flaring angle θ increases, the performance and efficiency of the interventional blood pump 10 are significantly improved. However, when the flaring angle θ exceeds 12°, eddy currents are likely to occur at the diffuser, resulting in a decrease in efficiency, and blood is likely to stagnate and form thrombi here.

[0053] Please refer to Fig. 9 , the effect of the flaring angle θ on the hemolytic performance was further analyzed. Under the design working conditions of 4 L / min and 60 mmHg, the setting of the flaring section 152 reduced the necessary rotation speed of the impeller 13 (from 25000 rpm when the flaring section 152 was not set to 23500 rpm when the flaring section 152 was set, a reduction of 1500 rpm), thereby reducing the wear caused by high-speed rotation and improving the reliability of the entire system.

[0054] Furthermore, from the hemolysis results (MIH value represents the hemolysis index, the larger the value, the more severe the hemolysis), within the range of 2° to 12°, the hemolysis index is within an acceptable range, and as the expansion angle θ increases, the hemolysis index first decreases and then increases. Based on the changes in the above parameters, the expansion angle θ is more preferably 4° to 6°.

[0055] Optionally, the distal end of the flared section 152 overlaps with the impeller 13 in the axial direction of the wire basket 12. It can be understood that, based on the function of the flared section 152, it needs to axially cover at least part of the impeller 13. Preferably, when the blade 131 is divided into a distal half region and a proximal half region along the axial direction of the wire basket 12, the distal end of the flared section 152 is located in the proximal half region of the blade 131 of the impeller 13, that is, the distal end of the flared section 152 is close to the outlet part of the blade 131 but does not exceed half of the blade 131. Such a configuration can prevent the flare from appearing prematurely in the main section where the impeller 13 does work, thereby reducing the gap between the impeller 13 and the outer flow channel and reducing or avoiding the occurrence of backflow.

[0056] Optionally, the distal end of the straight section 151 is flush with the distal end of the cylindrical section 121. The axial length of the straight section 151 along the axial direction of the wire basket 12 is not less than 1 / 2 of the axial length of the cylindrical section 121 along the axial direction of the wire basket 12 and not greater than the axial length of the cylindrical section 121 along the axial direction of the wire basket 12. The axial length of the straight section 151 cannot be too short. If the axial length of the straight section 151 is too short, the connection area between the entire flow channel film 15 and the wire basket 12 will be too small, and its connection strength will be difficult to guarantee. And if the axial length of the straight section 151 is too short, it means that the distal end of the flared section 152 will be close to the distal end, which will cause the flare to appear prematurely in the main section where the impeller 13 does work and reduce the efficiency. It has been verified that when the axial length of the straight section 151 is not less than 1 / 2 of the axial length of the cylindrical section 121 and not greater than the axial length of the cylindrical section 121, better efficiency can be achieved. Preferably, when the axial length of the straight section 151 along the axial direction of the wire basket 12 is not less than 2 / 3 of the axial length of the cylindrical section 121 along the axial direction of the wire basket 12 and not greater than 5 / 6 of the axial length of the cylindrical section 121 along the axial direction of the wire basket 12, the efficiency is higher.

[0057] Optionally, the ratio of the maximum outer diameter D2 of the flow channel film 15 to the outer diameter D1 of the cylindrical section 121 is 1 to 5. According to the diameters of the ascending aortas of different patients, 1 < D2 / D1 ≤ 5 can be selected, and preferably 1 < D2 / D1 ≤ 3.

[0058] Optionally, the ratio of the axial length L1 of the flow channel film 15 along the axial direction of the wire basket 12 to the axial length L2 of the cylindrical section 121 is not less than 2. After the interventional blood pump 10 is intervened, the flow channel film 15 crosses the valve, and the proximal outlet of the flow channel film 15 is located in the ascending aorta. In order to enable the wake of the impeller 13 to fully develop, L1 ≥ 2L2 should be satisfied. Preferably, L1 ≥ 4L2.

[0059] Furthermore, the axial length of the flow channel film 15 satisfies:

[0060]

[0061] Regardless of whether the membrane wall of the expanded section 152 is in an ideal truncated cone shape or a curved surface with an arc, its axial length should satisfy the above formula.

[0062] Please refer to Figures 10a to 10c The flow channel coating 15 also includes an outlet section 153 at the proximal end, and a plurality of openings 154 are provided on the outlet section 153. The number, distribution and shape of the openings 154 can be set according to the prior art. The proximal end of the outlet section 153 is fixedly connected to the outer sheath of the transmission delivery assembly 20, and the openings 154 are used for blood to flow out.

[0063] Please refer to Figures 11a to 11c , which are Figures 10a to 10c The simulation test results of different outlet sections 153 are shown. Fig.11a yes Figure 10a to Figure 10c A graph of flow rate and head for the outlet section 153 shown; Fig.11b yes Figure 10a to Figure 10c An efficiency diagram of the outlet section 153 is shown; Fig.11c yes Figure 10a to Figure 10c The head and hemolysis index diagram of the outlet section 153 shown; Figures 11a to 11c In the figure, curve A corresponds to Fig.10a The outlet section 153 shown, curve B corresponds to Fig.10b The outlet section 153 shown, curve C corresponds to Fig.10c The outlet section 153 is shown. Figures 11a to 11c It can be seen from the simulation results that Fig.10a The outlet section 153 shown has a better effect. Therefore, preferably, the outlet section 153 is tapered toward the proximal end. More preferably, the two ends of the opening 154 along the axial direction of the basket 12 are arc-shaped.

[0064] In some embodiments, the proximal end of the expanded section 152 can be extended all the way and directly connected to the distal end of the outlet section 153. When the axial length of the flow channel coating 15 is long, the expanded section 152 is not as long as possible. In other embodiments, the flow channel coating 15 further includes an extension section 155, the distal end of which is connected to the proximal end of the expanded section 152; the extension section 155 extends along the axial direction of the basket 12. The proximal end of the extension section 155 is connected to the distal end of the outlet section 153, that is, the expanded section 152 is connected to the outlet section 153 through the extension section 155.

[0065] Please refer to Fig.12In some other embodiments, the extension section 155 is not limited to extending along the axial direction of the basket 12. The extension section 155 can also expand and extend from the distal end to the proximal end, and the angle between the membrane wall of the extension section 155 and the axis of the basket 12 is not greater than the angle between the membrane wall of the expansion section 152 and the axis of the basket 12. For the convenience of description, the angle between the membrane wall of the extension section 155 and the axis of the basket 12 is called the diffusion angle α. When the wake flow fully develops to a certain extent in the expansion section 152, that is, the uniform axial speed is greater than the rotation speed, the constraint angle of the surrounding membrane wall on the blood can be gradually reduced. At this time, the extension section 155 can select a relatively small diffusion angle α, or even the diffusion angle α=0, that is, the extension section 155 extends along the axial direction of the basket 12. Preferably, the extension section 155 is smoothly connected to the expansion section 152.

[0066] In some embodiments, both ends of the cylindrical section 121 are connected to the conical section 122, and the proximal end of the cylindrical section 121 extends into the flared section 152, and the proximal end of the cylindrical section 121 is located between the distal end and the proximal end of the flared section 152, that is, the proximal end of the cylindrical section 121 is located within the axial coverage of the flared section 152. However, in this arrangement, the skeleton of the cylindrical section 121 extending into the flared section 152 is directly exposed to the high-speed flowing blood, and the collision impact may cause the blood cells to deform and rupture, thereby inducing hemolysis.

[0067] For this purpose, preferably, in other embodiments, the basket 12 further includes an expansion section (not shown), the distal end of the expansion section is connected to the proximal end of the cylindrical section 121, and the distal end of the flared section 152 is flush with the distal end of the expansion section; the expansion section expands and extends from the distal end to the proximal end and fits with the flared section 152, and the proximal end of the expansion section is located between the distal end and the proximal end of the flared section 152. Then the proximal end of the expansion section is connected to the conical section 122. That is, the diameter of the expansion section is adaptively expanded along with the expansion of the flared section 152, so that the skeleton of the expansion section can always fit with the flared section 152, reducing the collision between the blood and the skeleton, and reducing the deformation and rupture of blood cells.

[0068] In summary, the present invention provides an interventional blood pump including: a basket and a flow channel coating; the basket includes a cylindrical section extending along its own axial direction; the flow channel coating is circumferentially arranged around the axis of the basket; the flow channel coating includes a straight section and a flared section connected along the axial arrangement of the basket, the straight section is coated on the cylindrical section along the circumference of the basket, the distal end of the flared section is connected to the proximal end of the straight section, the flared section expands and extends from the distal end to the proximal end, and extends in the axial direction of the basket beyond the proximal end of the cylindrical section. With such a configuration, based on the setting of the flared section, the kinetic energy of the higher rotation speed at the impeller outlet can be converted into pressure energy, which can improve the blood pumping head and efficiency; it also reduces the flow velocity at the impeller outlet and reduces pipeline losses; further, the rotation speed at the impeller outlet can be transitioned to the axial velocity component, which can reduce the shaking and kinking caused by blood flowing through the flow channel coating. More importantly, due to the improvement of blood pumping head and efficiency, the necessary speed of the impeller can be reduced while ensuring sufficient blood flow support, thereby reducing the risk of hemolytic thrombosis. In addition, due to the centrifugal force when the impeller rotates at high speed, the blood close to the hub will be squeezed to the tip of the impeller, which can easily cause blockage of the flow channel at the periphery of the impeller outlet and cause backflow. The setting of the expansion section is equivalent to increasing the diameter of the flow channel, effectively reducing blood blockage.

[0069] It should be noted that the above embodiments can be combined with each other. The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the protection scope of the present invention.

Claims

1. An invasive blood pump, characterized in that: include: A mesh basket and a flow channel coating; the mesh basket includes a cylindrical section extending along its own axial direction; the flow channel coating is circumferentially arranged around the axis of the mesh basket; the flow channel coating includes a straight section and a flared section connected along the axial direction of the mesh basket, the straight section is coated on the cylindrical section along the circumference of the mesh basket, the distal end of the flared section is connected to the proximal end of the straight section, the flared section expands and extends from the distal end to the proximal end, and extends in the axial direction of the mesh basket beyond the proximal end of the cylindrical section.

2. The invasive blood pump according to claim 1, characterized in that: The angle formed between the extending direction of the membrane wall of the expanded section toward the distal end and the axis of the basket is 2° to 12°.

3. The invasive blood pump according to claim 1, characterized in that: It also includes an impeller, which is rotatably arranged in the net basket around the axis of the net basket; wherein the distal end of the expanded section overlaps with the impeller in the axial direction of the net basket.

4. The invasive blood pump according to claim 1, characterized in that: The distal end of the straight section is flush with the distal end of the cylindrical section, and the axial length of the straight section along the basket is not less than 1 / 2 of the axial length of the cylindrical section along the basket, and not greater than the axial length of the cylindrical section along the basket.

5. The invasive blood pump according to claim 4, characterized in that: The axial length of the straight section along the mesh basket is not less than 2 / 3 of the axial length of the cylindrical section along the mesh basket, and is not greater than 5 / 6 of the axial length of the cylindrical section along the mesh basket.

6. The invasive blood pump according to claim 1, characterized in that: The ratio of the maximum outer diameter of the flow channel coating to the outer diameter of the tubular section is 1-5; the ratio of the axial length of the flow channel coating along the basket to the axial length of the tubular section is not less than 2.

7. The invasive blood pump according to claim 1, characterized in that: The axial length of the flow channel coating along the basket satisfies: The outer diameter of the cylindrical section is D1, the maximum outer diameter of the flow channel coating is D2, the angle formed between the extension direction of the membrane wall of the expanded section to the distal end and the axis of the basket is θ, and the axial length of the flow channel coating along the basket is L1.

8. The invasive blood pump according to claim 1, characterized in that: The flow channel coating further comprises an extension section, the distal end of which is connected to the proximal end of the flared section; The extension section extends along the axial direction of the basket; or The extension section expands and extends from the distal end to the proximal end, and the angle formed by the membrane wall of the extension section and the axis of the basket is not greater than the angle formed by the membrane wall of the expansion section and the axis of the basket.

9. The invasive blood pump according to claim 8, characterized in that: The extension section is connected to the flared section in a smooth transition.

10. The invasive blood pump according to claim 1, characterized in that: The basket further comprises an expansion section, the distal end of the expansion section is connected to the proximal end of the cylindrical section, and the distal end of the flared section is flush with the distal end of the expansion section; The expansion section expands and extends from the distal end to the proximal end and fits with the flaring section, and the proximal end of the expansion section is located between the distal end and the proximal end of the flaring section.

11. The invasive blood pump according to claim 1, characterized in that: The flow channel coating also includes an outlet section located at the proximal end. The outlet section is provided with a plurality of openings, and the outlet section is in a tapered shape that narrows toward the proximal end.

12. The invasive blood pump according to claim 11, characterized in that: Both ends of the opening along the axial direction of the basket are arc-shaped.

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