Impeller and ventricular assist device

Abstract

The present invention provides an impeller and a ventricular assist device. The impeller includes at least one cover plate and a plurality of blades. The cover plate has a first assembly surface and a second assembly surface facing each other. The plurality of blades are disposed on the first assembly surface. The second assembly surface includes a connected supporting surface and an inclined surface. The inclined surface has a first side edge and a second side edge facing each other along the radial direction of the impeller. The first side edge is connected to the supporting surface. From the first side edge to the second side edge, the inclined surface extends obliquely toward a side close to the blade. The angle between the inclined surface and the supporting surface is no greater than 5°. In a cross section passing through the central axis of the impeller, the ratio of the length of the supporting surface to the length of the second assembly surface is 1 / 5 to 3 / 5. The impeller and ventricular assist device of the present invention reduce the axial force on the impeller as a whole by controlling the pressure on the upper and lower surfaces of the impeller, making the impeller easier to levitate and control.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to an impeller and a ventricular assist device. Background Art

[0002] As an effective means of treating patients with heart failure, the ventricular assist device is an artificial mechanical device that draws blood from the venous system or the heart and pumps it directly into the arterial system, partially or completely replacing the work of the ventricles.

[0003] VADs often use a rotating impeller to increase pressure. The impellers achieve equilibrium through hydraulic thrust or magnetic forces, allowing them to levitate within the VAD cavity. When the impeller is stationary, it rests against the inner wall of the VAD. However, when the impeller is activated, it slides against the inner wall, generating frictional resistance. Excessive frictional resistance can hinder impeller levitation and hinder control. Summary of the Invention

[0004] In view of at least one of the above-mentioned deficiencies, the present invention is necessary to provide an impeller and a ventricular assist device that are easy to suspend and control.

[0005] The present invention provides an impeller, comprising at least one cover plate and a plurality of blades, wherein the cover plate has a first assembly surface and a second assembly surface facing each other, and the plurality of blades are arranged on the first assembly surface, and is characterized in that the second assembly surface includes a connected supporting surface and an inclined surface, and the inclined surface has a first side edge and a second side edge relative to each other along the radial direction of the impeller, the first side edge is connected to the supporting surface, and along the direction from the first side edge to the second side edge, the inclined surface extends obliquely toward the side close to the blade, and the angle between the inclined surface and the supporting surface is not greater than 5°. In the cross section passing through the central axis of the impeller, the ratio of the length of the supporting surface to the length of the second assembly surface is 1 / 5 to 3 / 5.

[0006] In the impeller of the present invention, the angle between the inclined surface and the supporting surface is 1° to 3°.

[0007] In the impeller of the present invention, a fillet is provided at the connection between the supporting surface and the inclined surface, and the radius of the fillet is not less than 0.05 mm.

[0008] In the impeller of the present invention, the inclined surface is located on the inner side and / or the outer side of the cover plate.

[0009] In the impeller of the present invention, the impeller comprises two cover plates, the plurality of blades are located between the first assembly surfaces of the two cover plates, and a blood passage separated by the plurality of blades is formed between the two cover plates;

[0010] The two cover plates are respectively a first cover plate and a second cover plate, and the supporting surface and the inclined surface are provided on the second assembly surface of the first cover plate and / or the second cover plate.

[0011] In the impeller described in the present invention, the impeller includes a cover plate, the first assembly surface includes a connected mounting surface and a control surface, the control surface has a third side and a fourth side opposite to each other along the radial direction of the impeller, the third side is connected to the mounting surface, and along the direction from the third side to the fourth side, the control surface extends obliquely toward the side away from the blade.

[0012] In the impeller described in the present invention, the angle between the control surface and the mounting surface is no more than 5°, and on the cross section passing through the central axis of the impeller, the ratio of the length of the mounting surface to the length of the first assembly surface is 1 / 5 to 3 / 5.

[0013] In the impeller of the present invention, a fillet is provided at the connection between the control surface and the mounting surface, and the radius of the fillet is not less than 0.05 mm.

[0014] The present invention also provides a ventricular assist device, comprising a shell and a positioning column disposed in the shell, wherein a first inner cavity is provided in the shell, the positioning column is fixed to the bottom wall of the first inner cavity, the shell is provided with a liquid inlet and a liquid outlet respectively connected to the first inner cavity, and also includes the above-mentioned impeller, which is rotatably arranged around the positioning column and can be suspended in the first inner cavity.

[0015] In the ventricular assist device described in the present invention, the supporting surface and the inclined surface of the impeller are arranged opposite to the inner wall of the first inner cavity. When the impeller is not rotating, the supporting surface of the impeller is in contact with the inner wall of the first inner cavity.

[0016] In summary, the implementation of the blood pump and ventricular assist device of the present invention has the following beneficial effects: the present application provides a connected supporting surface and an inclined surface on the second assembly surface opposite to the impeller and the casing. By adjusting the angle between the inclined surface and the supporting surface, and the proportion of the supporting surface on the second assembly surface, not only can the pressure on the upper and lower surfaces of the impeller be controlled, the axial force on the impeller as a whole can be reduced, and the stability of the impeller rotation can be improved, but also the impeller can be guaranteed to have sufficient hydraulic supporting force, effectively reducing the starting friction of the impeller, making the impeller easier to suspend and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in describing the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 is a cross-sectional view of a ventricular assist device provided by a first embodiment of the present invention;

[0019] Figure 2 yes Figure 1 A perspective view of an impeller of the ventricular assist device shown;

[0020] Figure 3 yes Figure 2 A cross-sectional view of the impeller shown;

[0021] Figure 4 yes Figure 1 A cross-sectional view of an impeller of another structure of a ventricular assist device is shown;

[0022] Figure 5 yes Figure 1 A cross-sectional view of an impeller of another structure of a ventricular assist device is shown;

[0023] Figure 6 is a cross-sectional view of a ventricular assist device provided by a second embodiment of the present invention;

[0024] Figure 7 yes Figure 6 a perspective view of an impeller of the ventricular assist device shown;

[0025] Figure 8 yes Figure 7 A cross-sectional view of the impeller shown;

[0026] Figure 9 yes Figure 6 A cross-sectional view of an impeller of another structure of a ventricular assist device is shown. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0028] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may be an intermediate component. When a component is referred to as being "connected to" another component, it may be directly connected to the other component or there may be an intermediate component.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] See also Figure 1 A first embodiment of the present invention provides a ventricular assist device 100 , which includes at least a housing 10 , and an impeller 20 , a positioning post 30 , a motor 40 , and a control unit 50 disposed in the housing 10 .

[0031] The housing 10 defines a first inner cavity 110 and a second inner cavity 120, each separated from the other. A positioning post 30 is axially fixed to the bottom wall of the first inner cavity 110. The impeller 20 is rotatably disposed within the first inner cavity 110 around the positioning post 30. A motor 40 and a control unit 50 are respectively disposed within the second inner cavity 120. The motor 40 is controlled by the control unit 50 to generate a magnetic field that drives the impeller 20 to rotate, causing the impeller 20 to levitate and rotate.

[0032] The housing 10 is provided with a liquid inlet 101 and a liquid outlet (not shown), each of which is connected to the first inner cavity 110. When the impeller 20 rotates, blood flows into the first inner cavity 110 through the liquid inlet 101 and flows out of the liquid outlet under the action of the centrifugal force of the impeller 20.

[0033] See also Figure 2 The impeller 20 includes two cover plates 21 and a plurality of blades 22 arranged between the two cover plates 21. The plurality of blades 22 are evenly distributed around the central axis of the impeller 20. A plurality of blood passages 23 separated by the plurality of blades 22 are formed between the two cover plates 21.

[0034] The end surface of each cover plate 21 facing the blade 22 is a first assembly surface 211 , and the blade 22 is located between the first assembly surfaces 211 of the two cover plates 21 .

[0035] The end surface of each cover plate 21 facing away from the blades 22 serves as a second mounting surface 212. The second mounting surface 212 comprises a connected supporting surface 2121 and an inclined surface 2122. The inclined surface 2122 is inclined relative to the supporting surface 2121. The second mounting surface 212 is the end surface facing the inner wall of the first inner cavity 110. When the impeller 20 is not rotating, the supporting surface 2121 of the impeller 20 abuts against the inner wall of the first inner cavity 110, while the inclined surface 2122 faces the inner wall of the first inner cavity 110 but does not contact it.

[0036] Specifically, the inclined surface 2122 has a first side and a second side (both unnumbered) relative to each other along the radial direction of the impeller 20. The first side of the inclined surface 2122 is connected to the supporting surface 2121. Along the direction from the first side to the second side, the inclined surface 2122 extends obliquely toward the side close to the blade 22.

[0037] See also Figure 3 The angle a1 between the inclined surface 2122 and the supporting surface 2121 is not greater than 5°. On the cross section passing through the central axis of the impeller 20, the ratio of the length m1 of the supporting surface 2121 to the length n1 of the second assembly surface 212 is 1 / 5 to 3 / 5. Figure 3 is a cross-sectional view of the impeller 20, wherein the projections of the inclined surface 2122, the supporting surface 2121 and the second assembly surface 212 are line segments r1, s1 and t1 respectively. Figure 3 In the embodiment shown, the inclined surface 2122 and the supporting surface 2121 of each cover plate 21 are both planes, and the line segments r1 and s1 are both straight line segments. It can be understood that this embodiment does not limit the specific shapes of the inclined surface 2122 and the supporting surface 2121. In other embodiments, the inclined surface 2122 and the supporting surface 2121 can also be arc surfaces or other curved surfaces.

[0038] It should be noted that the "angle a1 between the inclined surface 2122 and the supporting surface 2121" here refers to the angle a1 between the line between the two end points of the line segment r1 and the line between the two end points of the line segment s1; the "length m1 of the supporting surface 2121" refers to the vertical distance m1 between the two end points of the line segment s1; and the "length n1 of the second assembly surface 212" refers to the vertical distance n1 between the two end points of the line segment t1.

[0039] In this embodiment, a connected supporting surface 2121 and an inclined surface 2122 are provided on the second assembly surface 212 opposite to the impeller 20 and the housing 10. By adjusting the angle between the inclined surface 2122 and the supporting surface 2121, and the proportion of the supporting surface 2121 on the second assembly surface 212, the pressure on the upper and lower surfaces of the impeller can be controlled to reduce the axial force on the impeller as a whole, improve the stability of the impeller rotation, and make the impeller easier to suspend and control.

[0040] When the impeller 20 starts to rotate, it slides against the inner wall of the first inner cavity 110, generating a starting friction force. Excessive starting friction force can hinder the levitation of the impeller 20, hindering the levitation control of the impeller 20. Furthermore, when the impeller 20 and the first inner cavity 110 slide relative to each other, excessive starting friction force can easily damage the contact surface between the impeller 20 and the first inner cavity 110, causing minor surface damage on the contact surface and potentially inducing thrombosis.

[0041] Therefore, in this embodiment, the inclined surface 2122 is provided on the second assembly surface 212 of the impeller 20, which can also reduce the contact area between the second assembly surface 212 and the inner wall of the first inner cavity 110, effectively reducing the starting friction of the impeller 20, so that the impeller 20 can easily float in the first inner cavity 110 even when rotating at a low speed. Furthermore, by reducing the starting friction of the impeller 20, the impeller 20 can easily float in the first inner cavity 110, and the risk of hemolysis caused by the relative sliding of the impeller 20 and the first inner cavity 110, or the risk of thrombosis caused by minor surface damage caused by relative sliding, can be avoided.

[0042] The space enclosed by the supporting surface 2121 and the inner wall of the first inner cavity 110 (the inner wall opposite to the supporting surface 2121) constitutes a hydraulic bearing, which is configured to generate a hydraulic supporting force that pushes the impeller 20 away from the inner wall under the action of blood when the impeller 20 rotates, so that the impeller 20 is suspended in the first inner cavity 110. The larger the area of ​​the supporting surface 2121, the greater the hydraulic supporting force, and the easier it is for the impeller 20 to be suspended in the first inner cavity 110. If the hydraulic supporting force is too small, the stability of the operation of the impeller 20 will be reduced. When the impeller 20 rotates, it is easy for the impeller 20 to vibrate, disrupting the flow field in the first inner cavity 110 and exacerbating the occurrence of hemolysis. In addition, the unstable and unreliable suspension of the impeller 20 is also prone to the impeller 20 touching the housing 10 and causing it to stop rotating.

[0043] In this embodiment, the angle a1 between the inclined surface 2122 and the supporting surface 2121 is no more than 5°, and the ratio of the length m1 of the supporting surface 2121 to the length n1 of the second assembly surface 212 is 1 / 5 to 3 / 5. This can not only effectively reduce the starting friction of the impeller 20, but also enable the impeller 20 to have sufficient hydraulic supporting force, ensure the stable rotation of the impeller 20, avoid the vibration of the impeller 20 that disrupts the flow field, and make the impeller 20 easier to suspend and control.

[0044] To enhance the hydraulic support, the shape of the supporting surface 2121 matches the shape of the inner wall of the first inner cavity 110 opposite to the supporting surface 2121, so that the supporting surface 2121 is better attached to the inner wall of the first inner cavity 110. For example, when the inner wall of the first inner cavity 110 is a curved surface, the supporting surface 2121 is a corresponding curved surface.

[0045] Preferably, the connection between the supporting surface 2121 and the inclined surface 2122 has a rounded corner of at least 0.05 mm to reduce the occurrence of hemolysis.

[0046] Please refer again Figure 1 A first magnet 33 is provided in the positioning column 30, and a second magnet (not shown) is provided on the cover plate 21. The impeller 20 is suspended in the first inner cavity 110 under the combined action of the first magnet 33 and the second magnet and the hydraulic support force. At this time, the impeller 20 and the first inner cavity 110 are in a non-contact state.

[0047] Given the size of the impeller 20, if the angle between the inclined surface 2122 of the cover plate 21 and the supporting surface 2121 is too large, or if the proportion of the supporting surface 2121 on the second assembly surface 212 is too small, the assembly space for the second magnet will be reduced. This application ensures that the angle a1 between the inclined surface 2122 and the supporting surface 2121 is no greater than 5°, and that the ratio of the length m1 of the projection of the supporting surface 2121 to the length n1 of the projection of the second assembly surface 212 is 1 / 5 to 3 / 5. This minimizes the space loss of the impeller 20, reserves more installation space for the second magnet, ensures a more reasonable magnetic force distribution, and makes the impeller 20 easier to levitate and control.

[0048] The structure of ventricular assist device 100 will be described in detail below.

[0049] exist Figure 1 In the illustrated embodiment, the housing 10 is made of a non-magnetic material and includes a first housing 11 and a second housing 12, both of which are cylindrical structures. A first inner cavity 110 is located within the first housing 11, and a second inner cavity 120 is located within the second housing 12. The first and second housings 11, 12 can be fixedly connected by bonding, welding, or snap-fit ​​connections.

[0050] The first housing 11 includes a first upper housing 11a and a first lower housing 11b, which are connected in a removable manner, such as by fasteners such as screws. A first inner cavity 110 is formed between the first upper housing 11a and the first lower housing 11b. A positioning post 30 is axially fixed to the bottom wall of the first inner cavity 110. The impeller 20 is rotatably disposed within the first inner cavity 110 around the positioning post 30.

[0051] The second housing 12 includes a second upper housing 12a and a second lower housing 12b. The second upper housing 12a and the second lower housing 12b are detachably connected, for example, by fasteners such as screws. A second inner cavity 120 is formed between the second upper housing 12a and the second lower housing 12b. The motor 40 and the control unit 50 are respectively disposed in the second inner cavity 120.

[0052] A liquid inlet pipe 13 and a liquid outlet pipe (not shown) are respectively provided at the liquid inlet 101 and the liquid outlet of the first shell 11. The liquid inlet pipe 13 and the liquid outlet pipe are both cylindrical structures. Blood flows into the first inner cavity 110 through the liquid inlet pipe 13 and flows out from the liquid outlet pipe under the action of the impeller 20.

[0053] The positioning column 30 includes a connected body 31 and a guide head 32. One end of the body 31 away from the liquid inlet 101 is fixed to the bottom wall of the first inner cavity 110, and the other end is connected to the guide head 32. The end of the guide head 32 facing the liquid inlet 101 is a conical structure with a smooth curved surface for guiding and diverting blood. When blood flows into the liquid inlet pipe 13, under the diversion guidance of the guide head 32, the blood will change its flow direction and flow into the blood passage 23 of the impeller 20 along the four sides of the guide head 32, and finally flow out from the liquid outlet pipe. Preferably, the positioning column 30 and the liquid inlet pipe 13 are coaxial, and the guide head 32 can extend from the first inner cavity 110 to the liquid inlet pipe 13 to better guide the flow direction of the blood.

[0054] A first magnet 33 is disposed within the positioning post 30, and a second magnet (not shown) is disposed on the cover plate 21. The second magnet is mounted on the supporting surface 2121 of the cover plate 21. The impeller 20 is suspended within the first inner cavity 110 under the combined action of the first and second magnets 33 and the hydraulic support force. At this time, the impeller 20 is in a non-contact state with the first inner cavity 110. It will be understood that in other embodiments, no magnetic structure is disposed within the positioning post 30, and the second magnet mounted on the impeller 20 directly interacts with the rotating magnetic field generated by the motor 40, causing the impeller 20 to levitate and rotate.

[0055] Combine Figure 1 and Figure 2 As shown, the impeller 20 has a through hole 210 distributed along the axial direction, and the impeller 20 is rotatably sleeved on the outside of the positioning column 30 through the through hole 210. The impeller 20 includes two cover plates 21, each of which is a circular plate structure, and the through hole 210 is located at the center of the cover plate 21. The cover plate 21 includes a connected supporting surface 2121 and an inclined surface 2122, and the inclined surface 2122 is located on the inner side of the cover plate 21 (the side close to the central axis). Under the condition that the radial dimensions of the inclined surface 2122 are the same, compared with setting the inclined surface 2122 on the outside of the cover plate 21, setting the inclined surface 2122 on the inside of the cover plate 21 will increase the area of ​​the supporting surface 2121 on the cover plate 21, thereby increasing the hydraulic supporting force, so that the impeller 20 has sufficient hydraulic supporting force, ensuring the stable rotation of the impeller 20, and avoiding the vibration of the impeller 20 that disrupts the flow field.

[0056] exist Figure 1In the illustrated embodiment, each cover plate 21 is provided with a connected supporting surface 2121 and an inclined surface 2122. The inclined surface 2122 is located on the inner side of the cover plate 21. The supporting surface 2121 and the inclined surface 2122 are both arranged opposite to the inner wall of the first inner cavity 110. The angle a1 between the inclined surfaces 2122 and the supporting surface 2121 of the two cover plates 21 is the same, and on the cross section passing through the central axis of the impeller 20, the ratio of the length m1 of the supporting surface 2121 of the two cover plates 21 to the length n1 of the second assembly surface 212 is also the same.

[0057] In the CFD simulation, the values ​​of m1 / n1 of the two cover plates 21 are both 1 / 2. Under the pressure difference condition of 300 mmHg, when the angle a1 of the two cover plates 21 is 0, that is, both cover plates 21 are flat surfaces, the axial force Fz on the impeller 20 as a whole is in the range of 6N to 6.7N; when a1 is 1°, the value of Fz is 0.2N to 0.7N; when a1 is 1.5°, the value of Fz is -0.4N to 0; when a1 is 2°, the value of Fz is -0.7N to -0.3N; when a1 is 2.5°, the value of Fz is -0.9N to -0.6N; when a1 is 3°, the value of Fz is -1.1N to -0.8N; when a1 is 4°, the value of Fz is -1.6N to -1.2N; when a1 is 5°, The value of Fz is -2N to -1.3N; when a1 is 6°, the value of Fz is -3.1N to -2.4N.

[0058] The CFD simulation results above show that when both cover plates 21 of the impeller 20 are provided with inclined surfaces, the Fz value first gradually decreases as the surface inclination increases. After decreasing to 0, the Fz value immediately increases in the opposite direction. In other words, there exists an optimal angle that achieves an Fz value of 0. Because the smaller the Fz value, the more stable the rotation of the impeller 20, the angle a1 between the inclined surface 2122 of the cover plate 21 and the supporting surface 2121 of this embodiment is preferably 1° to 3°, and optimally 1.5° to 2.5°, to ensure stable rotation of the impeller 20.

[0059] It should be noted that this embodiment does not limit the specific structure of the two cover plates 21. It only needs to ensure that the second assembly surface 212 of one cover plate 21 has a connected supporting surface 2121 and an inclined surface 2122, and the angle between the connected supporting surface 2121 and the inclined surface 2122, and the proportion of the supporting surface 2121 on the second assembly surface 212 meet the above-mentioned limited conditions. During design, the angle of the inclined surface of the cover plate 21 and its proportion on the second assembly surface can be set according to actual needs.

[0060] For example, in Figure 4In the illustrated embodiment, the second assembly surface 212 of one cover plate 21 is provided with a connected supporting surface 2121 and an inclined surface 2122, while the second assembly surface 212 of the other cover plate 21 is a flat surface. The cover plate 21 with the inclined surface 2122 is the cover plate 21 that is away from the liquid inlet 101, and the inclined surface 2122 is located on the inner side of the cover plate 21.

[0061] In the CFD simulation, the m1 / n1 of the cover plate 21 with the inclined surface is 1 / 2. Under the pressure difference of 300 mmHg, when the angle a1 of the cover plate 21 with the inclined surface 2122 is 0, that is, the cover plate 21 is also a flat surface, the axial force Fz on the impeller 20 as a whole is in the range of 6N to 6.7N; when a1 is 1°, The value of Fz is 0.6N~1.1N; when a1 is 1.5°, the value of Fz is -0.2N~0.7N; when a1 is 2°, the value of Fz is -1.1N~-0.4N; when a1 is 2.5°, the value of Fz is -1.4N~-0.9N; when a1 is 3°, the value of Fz is -1.7N~-1.2N; when a1 is 4°, the value of Fz is -2.2N~-1.5N; when a1 is 5°, the value of Fz is -2.9N~-2.3N; when a1 is 6°, the value of Fz is -4.1N~-3.3 N.

[0062] The CFD simulation results above show that when only one of the cover plates 21 of the impeller 20 is provided with an inclined surface, the Fz value gradually decreases as the surface inclination increases. After decreasing to 0, the Fz value immediately increases in the opposite direction. In other words, there is an optimal angle that achieves an Fz value of 0. Preferably, the angle a1 between the inclined surface 2122 of the cover plate 21 and the supporting surface 2121 is 1° to 3°, and optimally 1.5° to 2.5°.

[0063] By comparing the two CFD simulation results, it can be seen that under the conditions that the values ​​of the angle a1 and m1 / n1 are the same, compared with only providing an inclined surface on one cover plate 21 of the impeller 20, when both cover plates 21 of the impeller 20 are provided with inclined surfaces, the average value of the axial force Fz exerted on the impeller 20 as a whole is smaller, and the fluctuation range of Fz is also smaller, and the operation of the impeller 20 is more stable.

[0064] Or, in Figure 5In the illustrated embodiment, the two cover plates 21 are respectively a first cover plate 21a and a second cover plate 21b. The second assembly surfaces 212 of both cover plates 21 are provided with a connected supporting surface 2121 and an inclined surface 2122. The inclined surface 2122 is located on the outer side of the cover plate (away from the central axis). The angle a1 between the inclined surface 2122 and the supporting surface 2121 of the first cover plate 21a is greater than the aforementioned angle a1 of the second cover plate 21b. In a cross section passing through the central axis of the impeller 20, the ratio of the length m1 of the supporting surface 2121 of the first cover plate 21a to the length n1 of the second assembly surface 212 is greater than the aforementioned ratio of the second cover plate 21b.

[0065] Alternatively, in other embodiments, the angle a1 between the inclined surface 2122 of the first cover plate 21a and the supporting surface 2121 is smaller than the aforementioned angle a1 of the second cover plate 21b. In a cross section passing through the central axis of the impeller 20, the ratio of the length m1 of the supporting surface 2121 of the first cover plate 21a to the length n1 of the second mounting surface 212 is smaller than the aforementioned ratio of the second cover plate 21b. In other words, the angles of the inclined surfaces of the two cover plates 21, or their proportions on the second mounting surface, can be designed separately according to actual needs to control the pressure on the upper and lower surfaces of the impeller 20, thereby reducing the axial force on the impeller 20 as a whole, improving the rotational stability of the impeller 20, and making the impeller 20 easier to levitate and control.

[0066] Alternatively, in other embodiments, the inclined surface 2122 of one cover plate 21 is located on the outside of the cover plate 21, while the inclined surface 2122 of the other cover plate 21 is located on the inside of the cover plate 21. Alternatively, in other embodiments, each cover plate 21 includes a supporting surface 2121 and two inclined surfaces 2122 connected to either side of the supporting surface 2121, i.e., each cover plate 21 is provided with the aforementioned inclined surfaces 2122 on both the inside and outside of the cover plate 21. Specifically, the positions of the inclined surfaces on the two cover plates 21 can be designed separately according to actual needs to control the pressure on the upper and lower surfaces of the impeller 20, thereby reducing the axial force on the impeller 20 as a whole, improving the rotational stability of the impeller 20, and making the impeller 20 easier to levitate and control.

[0067] See also Figure 6 The second embodiment of the present invention provides a ventricular assist device 100, which includes at least a housing 10, and an impeller 20, a positioning column 30, a motor 40 and a control unit 50 arranged in the housing 10. The difference between the second embodiment and the first embodiment is that the structure of the impeller 20 is different.

[0068] See also Figure 7 The impeller 20 includes a cover plate 21 and a plurality of blades 22 arranged on the cover plate 21 . The plurality of blades 22 are evenly distributed around the central axis of the impeller 20 and separate a plurality of blood passages 23 . The blood passages 23 are located between two blades 22 .

[0069] The end surface of the cover plate 21 facing the blade 22 is a first assembly surface 211 , on which the blade 22 is fixed. The end surface of the cover plate 21 facing away from the blade 22 is a second assembly surface 212 , which is opposite to the inner wall of the first inner cavity 110 .

[0070] See also Figure 8 As in the first embodiment, the second assembly surface 212 includes a connected supporting surface 2121 and an inclined surface 2122. The inclined surface 2122 has a first side and a second side (both unnumbered) opposite to each other along the radial direction of the impeller 20. The first side of the inclined surface 2122 is connected to the supporting surface 2121. From the first side to the second side, the inclined surface 2122 extends obliquely toward the side close to the blade 22. When the impeller 20 is not rotating, the supporting surface 2121 of the impeller 20 is in contact with the inner wall of the first inner cavity 110, and the inclined surface 2122 does not contact the inner wall of the first inner cavity 110. The angle a1 between the inclined surface 2122 of the second assembly surface 212 and the supporting surface 2121 is no greater than 5°. In the cross section passing through the central axis of the impeller 20, the ratio of the length m1 of the supporting surface 2121 to the length n1 of the second assembly surface 212 is 1 / 5 to 3 / 5.

[0071] Since the structure of the second assembly surface 212 of the second embodiment is the same as that of the first embodiment, its specific structure and function are not described in detail here.

[0072] Unlike the first embodiment, the first assembly surface 211 includes a connected mounting surface 2111 and a control surface 2112, and the control surface 2112 is arranged at an angle relative to the mounting surface 2111. Specifically, the control surface 2112 has a third side and a fourth side (both unnumbered) that are opposite to each other along the radial direction of the impeller 20. The third side of the control surface 2112 is connected to the mounting surface 2111, and the control surface 2112 extends obliquely toward a side away from the blades 22 along the direction from the third side to the fourth side.

[0073] Among them, the angle a2 between the control surface 2112 and the mounting surface 2111 is not greater than 5°, preferably 1°~3°, and optimally 1.5°~2.5°. On the section passing through the central axis of the impeller 20, the ratio of the length m2 of the mounting surface 2111 to the length n2 of the first assembly surface 211 is 1 / 5~3 / 5. Figure 8 is a cross-sectional view of the impeller 20, and the projections of the control surface 2112, the mounting surface 2111 and the first assembly surface 211 are line segments r2, s2 and t2 respectively. Figure 8In the embodiment shown, the control surface 2112 and the mounting surface 2111 are both planes, and the line segment r2 and the line segment s2 are both straight line segments. It can be understood that this embodiment does not limit the specific shapes of the control surface 2112 and the mounting surface 2111. In other embodiments, the control surface 2112 and the mounting surface 2111 can also be arc surfaces or other curved surfaces.

[0074] It should be noted that the "angle a2 between the control surface 2112 and the installation surface 2111" here refers to the angle a2 between the line between the two endpoints of the line segment r2 and the line between the two endpoints of the line segment s2; the "length m2 of the installation surface 2111" refers to the vertical distance m2 between the two endpoints of the line segment s2; and the "length n2 of the first assembly surface 211" refers to the vertical distance n2 between the two endpoints of the line segment t2.

[0075] Since the impeller 20 of this embodiment includes only one cover plate 21, the blood flowing in from the liquid inlet pipe 13 directly collides with the first assembly surface 211 of the cover plate 21. In this embodiment, an inclined control surface 2112 is provided on the first assembly surface 211. By adjusting the angle a2 between the control surface 2112 and the mounting surface 2111, and adjusting the proportion of the mounting surface 2111 on the first assembly surface 211, the pressure on the upper and lower surfaces of the impeller 20 can be controlled, thereby reducing the axial force on the impeller 20 as a whole, improving the rotation stability of the impeller 20, avoiding the disturbance of the flow field due to the vibration of the impeller 20, and making the impeller 20 easier to suspend and control.

[0076] Preferably, the connection between the control surface 2112 and the mounting surface 2111 has a fillet of at least 0.05 mm to reduce the occurrence of hemolysis.

[0077] It can be understood that this embodiment does not limit the specific structure of the cover plate 21. It only needs to ensure that the second assembly surface 212 of the cover plate 21 has a connected supporting surface 2121 and an inclined surface 2122, and the angle between the connected supporting surface 2121 and the inclined surface 2122, and the proportion of the supporting surface 2121 on the second assembly surface 212 meet the above-mentioned limited conditions. During design, the angle between the mounting surface 2111 and the control surface 2112 on the first assembly surface 211 and the proportion of the mounting surface 2111 on the first assembly surface 211 can be set according to actual needs.

[0078] For example, in Figure 9In the illustrated embodiment, the cover plate 21 has a first assembly surface 211 and a second assembly surface 212 that face each other. The second assembly surface 212 includes a connected support surface 2121 and an inclined surface 2122. The first assembly surface 211 has a connected mounting surface 2111 and a control surface 2112. The inclined surface 2122 and the control surface 2112 are both located on the outside (away from the central axis) of the cover plate 21. The angle a1 of the second assembly surface 212 differs from the angle a2 of the first assembly surface 211. The ratio m1 / n1 on the second assembly surface 212 also differs from the ratio m2 / n2 on the first assembly surface 211.

[0079] It can be understood that, without violating the purpose of the present invention, new technical solutions formed by freely combining the technical solutions in various embodiments are also within the scope of protection to be applied for by the present invention.

[0080] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0081] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An impeller capable of suspending and rotating within a housing of a ventricular assist device, the impeller comprising at least one cover plate and a plurality of blades, the cover plate having a first mounting surface and a second mounting surface facing each other, the plurality of blades being disposed on the first mounting surface, characterized in that: The second assembly surface includes a connected supporting surface and an inclined surface, the inclined surface having a first side and a second side opposite to each other along the radial direction of the impeller, the first side being connected to the supporting surface, and the inclined surface extending obliquely toward the side close to the blade along the direction from the first side to the second side, the angle between the inclined surface and the supporting surface is not greater than 5°, and on the cross section passing through the central axis of the impeller, the ratio of the length of the supporting surface to the length of the second assembly surface is 1 / 5~3 / 5.

2. The impeller according to claim 1, characterized in that The angle between the inclined surface and the supporting surface is 1° to 3°.

3. The impeller according to claim 1, characterized in that A fillet is provided at the connection between the supporting surface and the inclined surface, and the radius of the fillet is not less than 0.05 mm.

4. The impeller according to claim 1, characterized in that The inclined surface is located on the inner side and / or the outer side of the cover plate.

5. The impeller according to claim 1, characterized in that The impeller includes two cover plates, the plurality of blades are located between the first assembly surfaces of the two cover plates, and a blood passage separated by the plurality of blades is formed between the two cover plates; The two cover plates are respectively a first cover plate and a second cover plate, and the supporting surface and the inclined surface are provided on the second assembly surface of the first cover plate and / or the second cover plate.

6. The impeller according to claim 1, characterized in that The impeller includes a cover plate, the first assembly surface includes a connected mounting surface and a control surface, the control surface has a third side and a fourth side opposite to each other along the radial direction of the impeller, the third side is connected to the mounting surface, and along the direction from the third side to the fourth side, the control surface extends obliquely toward a side away from the blade.

7. The impeller according to claim 6, characterized in that The included angle between the control surface and the mounting surface is no greater than 5°, and on a cross section passing through the central axis of the impeller, a ratio of the length of the mounting surface to the length of the first assembly surface is 1 / 5 to 3 / 5.

8. The impeller according to claim 6, characterized in that A fillet is provided at the connection between the control surface and the mounting surface, and the radius of the fillet is not less than 0.05 mm.

9. A ventricular assist device comprising a housing and a positioning post disposed within the housing, wherein a first inner cavity is disposed within the housing, the positioning post is fixed to a bottom wall of the first inner cavity, the housing is provided with a liquid inlet and a liquid outlet respectively connected to the first inner cavity, the liquid inlet and the liquid outlet are respectively provided with a liquid inlet pipe and a liquid outlet pipe, wherein: It also includes an impeller as described in any one of claims 1-8, wherein the impeller is rotatably arranged around the positioning column and can be suspended in the first inner cavity.

10. The ventricular assist device according to claim 9, wherein: The supporting surface and the inclined surface of the impeller are arranged opposite to the inner wall of the first inner cavity. When the impeller does not rotate, the supporting surface of the impeller is in contact with the inner wall of the first inner cavity.

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