CN113153806A - Impeller and ventricular assist device - Google Patents

Abstract

The invention provides an impeller and a ventricular assist device, wherein the impeller comprises at least one cover plate and a plurality of blades, the cover plate is provided with a first assembling surface and a second assembling surface which are opposite, the blades are arranged on the first assembling surface, the second assembling surface comprises a bearing surface and an inclined surface which are connected, the inclined surface is provided with a first side edge and a second side edge which are opposite along the radial direction of the impeller, the first side edge is connected with the bearing surface, the inclined surface extends obliquely towards one side close to the blades along the direction from the first side edge to the second side edge, the included angle between the inclined surface and the bearing surface is not more than 5 degrees, and the ratio of the length of the bearing surface to the length of the second assembling surface on a section passing through a central axis of the impeller is 1/5-3/5. The impeller and the ventricle auxiliary device reduce the axial force borne by the whole impeller by controlling the pressure borne by the upper surface and the pressure borne by the lower surface of the impeller, so that the impeller is easier to suspend and control.

Description

Impeller and ventricular assist device

Technical Field

The invention relates to the field of medical instruments, in particular to an impeller and a ventricular assist device.

Background

The ventricular assist device is an effective means for treating heart failure patients, and is an artificial mechanical device which leads blood out of a venous system or a heart and directly pumps the blood into an arterial system to partially or completely replace ventricles to do work.

The ventricular assist device mostly adopts the impeller to rotate and pressurize, and the impeller is balanced mutually through acting forces such as hydraulic thrust or magnetic force, so that the impeller is suspended in the inner cavity of the ventricular assist device. When the impeller does not rotate, the impeller is attached to the inner wall of the ventricular assist device, when the impeller starts to rotate, the impeller slides relative to the inner wall to generate friction resistance, the excessive friction resistance can prevent the impeller from suspending, and the impeller is not beneficial to suspension control.

Disclosure of Invention

In view of at least one of the above-mentioned drawbacks, it is desirable to provide an impeller and ventricular assist device that is easy to suspend and control.

The invention provides an impeller, which comprises at least one cover plate and a plurality of blades, wherein the cover plate is provided with a first assembling surface and a second assembling surface which are opposite, and the blades are arranged on the first assembling surface.

In the impeller, the included angle between the inclined surface and the bearing surface is 1-3 degrees.

In the impeller, a fillet is arranged at the joint of the bearing surface and the inclined surface, and the radius of the fillet is not less than 0.05 mm.

In the impeller according to the present invention, the inclined surface is located inside or/and outside the cover plate.

In the impeller according to the present invention, the impeller includes two cover plates, the plurality of blades are positioned between first fitting surfaces of the two cover plates, and a blood passage partitioned 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 bearing surface and the inclined surface are arranged on the second assembly surface of the first cover plate and/or the second cover plate.

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

In the impeller, an included angle between the control surface and the mounting surface is not more than 5 degrees, and on a section passing through a central axis of the impeller, the ratio of the length of the mounting surface to the length of the first assembling surface is 1/5-3/5.

In the impeller, a fillet is arranged at the joint of the control surface and the mounting surface, and the radius of the fillet is not less than 0.05 mm.

The invention also provides a ventricular assist device, which comprises a shell and a positioning column arranged in the shell, wherein a first inner cavity is arranged in the shell, the positioning column is fixed on the bottom wall of the first inner cavity, a liquid inlet and a liquid outlet which are respectively communicated with the first inner cavity are arranged on the shell, and the ventricular assist device also comprises the impeller, and the impeller is rotatably arranged around the positioning column and can be suspended in the first inner cavity.

In the ventricular assist device according to the present invention, the bearing surface and the inclined surface of the impeller are disposed opposite to the inner wall of the first inner chamber, and when the impeller does not rotate, the bearing surface of the impeller abuts against the inner wall of the first inner chamber.

In summary, the blood pump and the ventricular assist device of the present invention have the following advantages: this application sets up continuous bearing surface and inclined plane on impeller and casing relative second assembly surface, through the contained angle of adjusting inclined plane and bearing surface, and the bearing surface accounts for on the second assembly surface, not only can control the pressure that the upper and lower surface of impeller bore, reduce the whole axial force that receives of impeller, improve the rotatory stability of impeller, can also guarantee that the impeller has sufficient hydraulic bearing power, effectively reduce the start-up frictional force of impeller, it changes suspension control to make the impeller.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive exercise.

FIG. 1 is a cross-sectional view of a ventricular assist device according to a first embodiment of the present invention;

FIG. 2 is a perspective view of the impeller of the ventricular assist device shown in FIG. 1;

FIG. 3 is a cross-sectional view of the impeller shown in FIG. 2;

FIG. 4 is a cross-sectional view of an impeller of an alternative configuration of the ventricular assist device shown in FIG. 1;

FIG. 5 is a cross-sectional view of an impeller of an alternative configuration of the ventricular assist device shown in FIG. 1;

FIG. 6 is a cross-sectional view of a ventricular assist device in accordance with a second embodiment of the present invention;

FIG. 7 is a perspective view of the impeller of the ventricular assist device shown in FIG. 6;

FIG. 8 is a cross-sectional view of the impeller shown in FIG. 7;

fig. 9 is a cross-sectional view of an impeller of an alternative configuration of the ventricular assist device shown in fig. 6.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, a ventricular assist device 100 according to a first embodiment of the present invention at least includes a housing 10, and an impeller 20, a positioning column 30, a motor 40 and a control unit 50 disposed in the housing 10.

A first inner cavity 110 and a second inner cavity 120 are disposed in the housing 10, the positioning column 30 is axially and fixedly disposed on a bottom wall of the first inner cavity 110, and the impeller 20 is rotatably disposed in the first inner cavity 110 around the positioning column 30. The motor 40 and the control unit 50 are respectively disposed in the second inner cavity 120, and the motor 40 is controlled by the control unit 50 to generate a magnetic field for driving the impeller 20 to rotate, so that the impeller 20 is suspended and rotated.

The housing 10 is provided with a liquid inlet 101 and a liquid outlet (not shown), and the liquid inlet 101 and the liquid outlet are respectively communicated with the first inner cavity 110. When the impeller 20 rotates, the blood flowing into the first inner chamber 110 from the liquid inlet 101 flows out from the liquid outlet by the centrifugal force of the impeller 20.

Referring to fig. 2, the impeller 20 includes two cover plates 21 and a plurality of blades 22 disposed between the two cover plates 21, the plurality of blades 22 are uniformly distributed around a central axis of the impeller 20, and a plurality of blood passages 23 partitioned by the plurality of blades 22 are formed between the two cover plates 21.

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

The end surface of each cover plate 21 facing away from the blade 22 is a second mounting surface 212, and the second mounting surface 212 includes a bearing surface 2121 and an inclined surface 2122 connected with each other, and the inclined surface 2122 is obliquely arranged relative to the bearing surface 2121. The second mounting surface 212 is an end surface opposite to the inner wall of the first cavity 110, and when the impeller 20 is not rotating, the bearing surface 2121 of the impeller 20 abuts against the inner wall of the first cavity 110, and the inclined surface 2122 is opposite to but not in contact with the inner wall of the first cavity 110.

Specifically, the inclined surface 2122 has a first side and a second side (neither of which is numbered) opposite to each other in the radial direction of the impeller 20, the first side of the inclined surface 2122 is connected to the bearing surface 2121, and the inclined surface 2122 extends obliquely toward the blade 22 in the direction from the first side to the second side.

Referring to fig. 3, an included angle a1 between the inclined surface 2122 and the bearing surface 2121 is not greater than 5 °, and a ratio of a length m1 of the bearing surface 2121 to a length n1 of the second mounting surface 212 is 1/5 to 3/5 on a cross section passing through a central axis of the impeller 20. Fig. 3 is a sectional view of the impeller 20, and the projections of the inclined surface 2122, the bearing surface 2121, and the second mounting surface 212 are a line segment r1, a line segment s1, and a line segment t1, respectively. In the embodiment shown in fig. 3, the inclined surface 2122 and the supporting surface 2121 of each cover plate 21 are both flat surfaces, and the line segments r1 and s1 are both straight line segments, it should be understood that the present embodiment is not limited to the specific shapes of the inclined surface 2122 and the supporting surface 2121, and in other embodiments, the inclined surface 2122 and the supporting surface 2121 may also be curved surfaces or other curved surfaces.

Here, the "included angle a1 between the inclined surface 2122 and the support surface 2121" means an included angle a1 between a line connecting two ends of the line segment r1 and a line connecting two ends of the line segment s 1; "the length m1 of the bearing surface 2121" means the perpendicular distance m1 between the two ends of the line segment s 1; the "length n1 of the second fitting surface 212" means a perpendicular distance n1 between both ends of the line segment t 1.

In this embodiment, the bearing surface 2121 and the inclined surface 2122 connected to each other are disposed on the second assembling surface 212 of the impeller 20 opposite to the housing 10, and the pressure borne by the upper and lower surfaces of the impeller can be controlled by adjusting the included angle between the inclined surface 2122 and the bearing surface 2121 and the occupation ratio of the bearing surface 2121 on the second assembling surface 212, so as to reduce the axial force borne by the impeller as a whole, improve the stability of the rotation of the impeller, and make the impeller more easily suspended and controlled.

When the impeller 20 starts to rotate, the impeller 20 slides relative to the inner wall of the first inner cavity 110, a starting friction force is generated, and an excessive starting friction force hinders the impeller 20 from suspending, which is not beneficial to suspension control of the impeller 20. When the impeller 20 slides relative to the first inner chamber 110, the contact surface between the impeller 20 and the first inner chamber 110 is easily damaged by an excessive starting friction force, so that the contact surface is slightly damaged, and thrombus is generated.

Therefore, in the present embodiment, the inclined surface 2122 is provided on the second mounting surface 212 of the impeller 20, so that the contact area between the second mounting surface 212 and the inner wall of the first inner cavity 110 can be reduced, the starting friction of the impeller 20 can be effectively reduced, and the impeller 20 can be easily suspended in the first inner cavity 110 even when rotating at a low speed. Further, by reducing the starting frictional force of the impeller 20, the impeller 20 is easily suspended in the first inner chamber 110, and the risk of hemolysis due to the relative sliding between the impeller 20 and the first inner chamber 110 or the occurrence of thrombus due to minute surface damage caused by the relative sliding can be avoided.

The space enclosed by the support surface 2121 and the inner wall of the first internal cavity 110 (the inner wall opposite to the support surface 2121) constitutes a hydrodynamic bearing, and the hydrodynamic bearing is configured to generate a hydrodynamic support 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 internal cavity 110. The greater the area of the bearing surface 2121, the greater this hydrodynamic bearing force, and the easier it is for the impeller 20 to float within the first interior chamber 110. The hydrodynamic bearing force is too small, which may reduce the stability of the operation of the impeller 20, and the impeller 20 may vibrate easily during rotation, thereby disturbing the flow field in the first inner cavity 110 and aggravating the occurrence of hemolysis. Also, the unstable and unreliable levitation of the impeller 20 is also prone to failure of the impeller 20 to touch the housing 10, resulting in stalling.

In this embodiment, the included angle a1 between the inclined surface 2122 and the bearing surface 2121 is not greater than 5 °, and the ratio of the length m1 of the bearing surface 2121 to the length n1 of the second mounting surface 212 is 1/5 to 3/5, which not only can effectively reduce the starting friction of the impeller 20, but also can make the impeller 20 have sufficient hydraulic bearing force, ensure stable rotation of the impeller 20, avoid the situation that the impeller 20 vibrates to disturb the flow field, and the like, and make the impeller 20 more easily perform suspension control.

In order to increase the hydrodynamic bearing force, the shape of the bearing surface 2121 is adapted to the shape of the inner wall of the first cavity 110 opposite to the bearing surface 2121, so that the bearing surface 2121 better abuts against the inner wall of the first cavity 110. For example, when the inner wall of the first cavity 110 is a curved surface, the supporting surface 2121 is a corresponding curved surface.

Preferably, the junction between the support surface 2121 and the inclined surface 2122 has a rounded corner of at least 0.05mm to reduce hemolysis.

Referring to fig. 1 again, a first magnet 33 is disposed in the positioning column 30, a second magnet (not shown) is disposed on the cover plate 21, and the impeller 20 is suspended in the first inner cavity 110 under the combined action of the acting force of the first magnet 33 and the second magnet and the acting force of the hydraulic support force, and at this time, the impeller 20 and the first inner cavity 110 are in a non-contact state.

If the angle between the inclined surface 2122 of the cover 21 and the bearing surface 2121 is too large or the occupation ratio of the bearing surface 2121 on the second mounting surface 212 is too small, the mounting space for the second magnet is reduced when the volume of the impeller 20 is constant. This application makes inclined plane 2122 and bearing face 2121's contained angle a1 be not more than 5 to make the ratio of bearing face 2121 projected length m1 and second mounting surface 212 projected length n1 be 1/5 ~ 3/5, can reduce impeller 20's space loss as far as possible, reserve more installation space for the second magnet, ensure that magnetic force distributes more rationally, make impeller 20 change in the suspension control more easily.

The structure of the ventricular assist device 100 will be specifically described below.

In the embodiment shown in fig. 1, the housing 10 is made of a non-magnetic material, and includes a first housing 11 and a second housing 12 fixedly connected to each other, and the first housing 11 and the second housing 12 are both cylindrical structures. The first internal cavity 110 is located within the first housing 11 and the second internal cavity 120 is located within the second housing 12. The first housing 11 and the second housing 12 may be fixedly connected by bonding, welding, or snap-fit connection.

The first housing 11 includes a first upper housing 11a and a first lower housing 11b connected together, and the first upper housing 11a and the first lower housing 11b are detachably connected, for example, fixedly connected by a fastener such as a screw. A first inner cavity 110 is formed between the first upper casing 11a and the first lower casing 11b, the positioning column 30 is axially and fixedly disposed on the bottom wall of the first inner cavity 110, and the impeller 20 is rotatably disposed in the first inner cavity 110 around the positioning column 30.

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

A liquid inlet pipe 13 and a liquid outlet pipe (not shown) are respectively arranged at the liquid inlet 101 and the liquid outlet of the first casing 11, the liquid inlet pipe 13 and the liquid outlet pipe are both of a cylindrical structure, and 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.

The positioning column 30 includes a main body 31 and a guiding head 32 connected to each other, wherein one end of the main 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 guiding head 32. The end of the guide head 32 facing the liquid inlet 101 is of a conical structure having a smooth curved surface for guiding and shunting blood. After the blood flows in from the liquid inlet tube 13, the blood changes its flow direction under the diversion guide of the guide head 32, flows into the blood passage 23 of the impeller 20 along the periphery of the guide head 32, and finally flows out from the liquid outlet tube. Preferably, the positioning column 30 is coaxial with the inlet tube 13, and the guiding head 32 can extend from the first inner cavity 110 into the inlet tube 13 to better guide the flow direction of the blood.

A first magnet 33 is disposed in the positioning column 30, a second magnet (not shown) is disposed on the cover plate 21, the second magnet is mounted on the bearing surface 2121 of the cover plate 21, and the impeller 20 is suspended in the first inner cavity 110 under the combined action of the acting force of the first magnet 33 and the second magnet and the hydraulic bearing force, at this time, the impeller 20 and the first inner cavity 110 are in a non-contact state. It is understood that in other embodiments, no magnet structure is provided in 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 to levitate and rotate the impeller 20.

Referring to fig. 1 and fig. 2, the impeller 20 has through holes 210 distributed along the axial direction, and the impeller 20 is rotatably sleeved outside the positioning column 30 through the through holes 210. The impeller 20 includes two cover plates 21, each cover plate 21 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 support surface 2121 and an inclined surface 2122 connected to each other, and the inclined surface 2122 is located on the inner side (side close to the central axis) of the cover plate 21. Under the condition that the radial dimension of the inclined surface 2122 is the same, the area of the bearing surface 2121 on the cover plate 21 is increased compared with the case that the inclined surface 2122 is arranged on the outer side of the cover plate 21 and the inclined surface 2122 is arranged on the inner side of the cover plate 21, so that the hydrodynamic bearing force is increased, the impeller 20 has sufficient hydrodynamic bearing force, the impeller 20 is ensured to stably rotate, and the condition that the impeller 20 vibrates to disturb a flow field is avoided.

In the embodiment shown in fig. 1, each cover plate 21 is provided with a bearing surface 2121 and an inclined surface 2122 connected to each other, the inclined surface 2122 is located at the inner side of the cover plate 21, the bearing surface 2121 and the inclined surface 2122 are both disposed opposite to the inner wall of the first cavity 110, the included angle a1 between the inclined surface 2122 and the bearing surface 2121 of the two cover plates 21 is the same, and the ratio of the length m1 of the bearing surface 2121 of the two cover plates 21 to the length n1 of the second mounting surface 212 is the same in a cross section passing through the central axis of the impeller 20.

In the CFD simulation, the values of m1/N1 of the two cover plates 21 are both 1/2, and under the condition of 300mmHg pressure difference, when the included angle a1 of the two cover plates 21 is 0, that is, the two cover plates 21 are both flat surfaces, the axial force Fz borne by the impeller 20 as a whole is in the range of 6N to 6.7N; when a1 is 1 degree, the value of Fz is 0.2N-0.7N; when a1 is 1.5 degrees, the value of Fz is-0.4N-0; when a1 is 2 degrees, the value of Fz is-0.7N to-0.3N; when a1 is 2.5 degrees, the value of Fz is-0.9N to-0.6N; when a1 is 3 degrees, the value of Fz is-1.1N to-0.8N; when a1 is 4 degrees, the value of Fz is-1.6N to-1.2N; when a1 is 5 degrees, the value of Fz is-2N to-1.3N; when a1 is 6 DEG, Fz has a value of-3.1N to-2.4N.

As can be seen from the above CFD simulation results, when the two cover plates 21 of the impeller 20 are both provided with the inclined surfaces, the value of Fz gradually decreases with the increase of the surface inclination, and then increases in the opposite direction after decreasing to 0. That is, there is an optimum angle such that Fz has a value of 0. Since the smaller the value of Fz, the more stable the rotation of the impeller 20, the included angle a1 between the inclined surface 2122 of the cover plate 21 and the bearing surface 2121 in the present embodiment is preferably 1 ° to 3 °, and more preferably 1.5 ° to 2.5 °, in order to ensure stable rotation of the impeller 20.

It should be noted that the present embodiment does not limit the specific structure of the two cover plates 21, and the angle of the inclined surface of the cover plate 21 and the occupation ratio of the inclined surface on the second mounting surface 212 may be set according to actual requirements during design as long as the continuous support surface 2121 and the inclined surface 2122 are provided on the second mounting surface 212 of one cover plate 21, and the included angle between the continuous support surface 2121 and the inclined surface 2122 and the occupation ratio of the support surface 2121 on the second mounting surface 212 satisfy the above-mentioned limit conditions.

For example, in the embodiment shown in fig. 4, the second mounting surface 212 of one cover plate 21 is provided with a bearing surface 2121 and an inclined surface 2122 which are connected, and the second mounting surface 212 of the other cover plate 21 is a flat surface. The cover plate 21 having the inclined surface 2122 is the cover plate 21 away from the liquid inlet 101, and the inclined surface 2122 is located inside the cover plate 21.

In the CFD simulation, m1/N1 of the cover plate 21 having the inclined surface is 1/2, and when the included angle a1 of the cover plate 21 having the inclined surface 2122 is 0 under the pressure difference of 300mmHg, that is, the cover plate 21 is also a flat surface, the axial force Fz applied to the impeller 20 as a whole is in the range of 6N to 6.7N; when a1 is 1 degree, the value of Fz is 0.6N-1.1N; when a1 is 1.5 degrees, the value of Fz is-0.2N-0.7N; when a1 is 2 degrees, the value of Fz is-1.1N to-0.4N; when a1 is 2.5 degrees, the value of Fz is-1.4N to-0.9N; when a1 is 3 degrees, the value of Fz is-1.7N to-1.2N; when a1 is 4 degrees, the value of Fz is-2.2N to-1.5N; when a1 is 5 degrees, the value of Fz is-2.9N to-2.3N; when a1 is 6 DEG, Fz has a value of-4.1N to-3.3N.

As can be seen from the above CFD simulation results, when the inclined surface is provided only on one cover plate 21 of the impeller 20, the value of Fz gradually decreases as the surface inclination increases, and then increases in the opposite direction when the value of Fz decreases to 0. That is, there is an optimum angle at this time, and Fz is set to 0. Preferably, the inclined surface 2122 of the cover plate 21 forms an angle a1 with the bearing surface 2121 of 1 to 3 degrees, and most preferably 1.5 to 2.5 degrees.

Comparing the two CFD simulation results, it can be seen that under the condition that the values of the included angle a1 and the included angle m1/n1 are the same, when the two cover plates 21 of the impeller 20 are both provided with the inclined surfaces, the average value of the axial force Fz applied to the impeller 20 is smaller, and the fluctuation range of Fz is smaller, so that the operation of the impeller 20 is more stable, compared with the case that only one cover plate 21 of the impeller 20 is provided with the inclined surfaces.

Alternatively, in the embodiment shown in fig. 5, the two cover plates 21 are respectively a first cover plate 21a and a second cover plate 21b, the bearing surface 2121 and the inclined surface 2122 are provided on the second mounting surfaces 212 of the two cover plates 21, and the inclined surface 2122 is located on the outer side (the side away from the central axis) of the cover plates. The angle a1 between the inclined surface 2122 of the first cover plate 21a and the bearing surface 2121 is greater than the angle a1 of the second cover plate 21b, and the ratio of the length m1 of the bearing surface 2121 of the first cover plate 21a to the length n1 of the second mounting surface 212 is greater than the ratio of the second cover plate 21b in the cross section passing through the central axis of the impeller 20.

Alternatively, in other embodiments, the angle a1 between the inclined surface 2122 of the first cover plate 21a and the bearing surface 2121 is smaller than the angle a1 of the second cover plate 21b, and the ratio of the length m1 of the bearing surface 2121 of the first cover plate 21a to the length n1 of the second mounting surface 212 is smaller than the ratio of the second cover plate 21b in a cross section passing through the central axis of the impeller 20. That is, the angles of the inclined surfaces of the two cover plates 21 or the ratio of the inclined surfaces to the second assembling surface can be designed according to actual needs to control the pressure borne by the upper and lower surfaces of the impeller 20, so as to reduce the axial force borne by the impeller 20 as a whole, improve the stability of the rotation of the impeller 20, and make the impeller 20 more easily suspended and controlled.

Alternatively, in other embodiments, the inclined surface 2122 of one cover plate 21 is located on the outer side of the cover plate 21, and the inclined surface 2122 of the other cover plate 21 is located on the inner side of the cover plate 21. Alternatively, in another embodiment, each cover plate 21 includes a supporting surface 2121 and two inclined surfaces 2122 connected to two sides of the supporting surface 2121, i.e., the inclined surfaces 2122 are disposed inside and outside each cover plate 21. That is, the positions of the inclined surfaces of the two cover plates 21 can be designed according to actual needs to control the pressure applied to the upper and lower surfaces of the impeller 20, so as to reduce the axial force applied to the impeller 20 as a whole, improve the stability of the rotation of the impeller 20, and make the impeller 20 easier to suspend and control.

Referring to fig. 6, a ventricular assist device 100 according to a second embodiment of the present invention at least includes a housing 10, and an impeller 20, a positioning post 30, a motor 40 and a control unit 50 disposed in the housing 10, wherein the second embodiment is different from the first embodiment in that the impeller 20 has a different structure.

Referring to fig. 7, the impeller 20 includes a cover plate 21 and a plurality of blades 22 disposed on the cover plate 21, the plurality of blades 22 are uniformly distributed around a central axis of the impeller 20 and divide a plurality of blood passages 23, and the blood passages 23 are located between the two blades 22.

The end surface of the cover plate 21 facing the blade 22 is a first mounting surface 211, and the blade 22 is fixed to the first mounting surface 211. The end surface of the cover plate 21 facing away from the blade 22 is a second mounting surface 212, and the second mounting surface 212 is opposite to the inner wall of the first inner cavity 110.

Referring to fig. 8, the second mounting surface 212 includes a supporting surface 2121 and an inclined surface 2122 connected to each other, as in the first embodiment. The inclined surface 2122 has a first side and a second side (both not numbered) facing each other in the radial direction of the impeller 20, the first side of the inclined surface 2122 is connected to the bearing surface 2121, and the inclined surface 2122 extends obliquely toward the blade 22 in the direction from the first side to the second side. When the impeller 20 does not rotate, the bearing surface 2121 of the impeller 20 abuts against the inner wall of the first inner cavity 110, and the inclined surface 2122 does not contact with the inner wall of the first inner cavity 110. An included angle a1 between the inclined surface 2122 of the second mounting surface 212 and the bearing surface 2121 is not greater than 5 °, and on a section passing through a central axis of the impeller 20, a ratio of a length m1 of the bearing surface 2121 to a length n1 of the second mounting surface 212 is 1/5-3/5.

Since the structure of the second assembling surface 212 of the second embodiment is the same as that of the first embodiment, the detailed structure and function thereof will not be described herein.

Unlike the first embodiment, the first mounting surface 211 includes a mounting surface 2111 and a control surface 2112 connected to each other, and the control surface 2112 is disposed obliquely to the mounting surface 2111. Specifically, the control surface 2112 has opposite third and fourth sides (neither of which is numbered) in 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 the side away from the blade 22 in the direction from the third side to the fourth side.

An included angle a2 between the control surface 2112 and the mounting surface 2111 is not more than 5 degrees, preferably 1 to 3 degrees, and most preferably 1.5 to 2.5 degrees, and on a section passing through a central axis of the impeller 20, a ratio of a length m2 of the mounting surface 2111 to a length n2 of the first mounting surface 211 is 1/5 to 3/5. Fig. 8 is a sectional view of the impeller 20, and the control surface 2112, the mounting surface 2111, and the first mounting surface 211 are projected by a line segment r2, a line segment s2, and a line segment t2, respectively. In the embodiment shown in fig. 8, the control surface 2112 and the mounting surface 2111 are both planar, and the line segments r2 and s2 are both straight line segments, it is understood that the embodiment is not limited to the specific shapes of the control surface 2112 and the mounting surface 2111, and in other embodiments, the control surface 2112 and the mounting surface 2111 may also be curved surfaces or other curved surfaces.

Here, the "included angle a2 between the control surface 2112 and the mounting surface 2111" refers to an included angle a2 between a connection line between two end points of the line segment r2 and a connection line between two end points of the line segment s 2; "the length m2 of the mounting surface 2111" means the perpendicular distance m2 of the two end points of the line segment s 2; the "length n2 of the first fitting surface 211" means a perpendicular distance n2 between both ends of the line segment t 2.

Because the impeller 20 of the present embodiment only includes one cover plate 21, the blood flowing in from the liquid inlet pipe 13 directly collides with the first assembling surface 211 of the cover plate 21, the present embodiment sets the inclined control surface 2112 on the first assembling surface 211, and by adjusting the included angle a2 between the control surface 2112 and the mounting surface 2111 and adjusting the proportion of the mounting surface 2111 on the first assembling surface 211, the pressure borne by the upper and lower surfaces of the impeller 20 can be controlled, thereby reducing the axial force borne by the impeller 20 as a whole, improving the stability of the rotation of the impeller 20, avoiding the occurrence of conditions such as disturbance of the flow field due to the vibration of the impeller 20, and making the impeller 20 more easily suspended and controlled.

Preferably, the connection between the control surface 2112 and the mounting surface 2111 has a rounded corner of at least 0.05mm or more to reduce the occurrence of hemolysis.

It should be understood that the specific structure of the cover plate 21 is not limited in this embodiment, as long as the second mounting surface 212 of the cover plate 21 has the continuous supporting surface 2121 and the inclined surface 2122, and the included angle between the continuous supporting surface 2121 and the inclined surface 2122 and the occupation ratio of the supporting surface 2121 on the second mounting surface 212 satisfy the above-mentioned limitation condition, and the included angle between the mounting surface 2111 and the control surface 2112 on the first mounting surface 211 and the occupation ratio of the mounting surface 2111 on the first mounting surface 211 can be set according to actual requirements during design.

For example, in the embodiment shown in fig. 9, the cover plate 21 has a first mounting surface 211 and a second mounting surface 212 that are opposite. The second mounting surface 212 includes a bearing surface 2121 and an inclined surface 2122 connected to each other, the first mounting surface 211 includes a mounting surface 2111 and a control surface 2112 connected to each other, and the inclined surface 2122 and the control surface 2112 are located on the outer side (the side away from the central axis) of the cover plate 21. The included angle a1 of the second assembling surface 212 is different from the included angle a2 of the first assembling surface 211, and the ratio of m1/n1 on the second assembling surface 212 is different from the ratio of m2/n2 on the first assembling surface 211.

It is understood that the present invention is not limited to the above embodiments, and various modifications and changes can be made without departing from the spirit and scope of the present invention.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. The utility model provides an impeller, includes at least one apron to and a plurality of blade, the apron has first fitting surface and second fitting surface back to back, and is a plurality of the blade set up in first fitting surface, its characterized in that, the second fitting surface is including continuous bearing surface and inclined plane, the inclined plane is followed the radial first side and the second side that have of impeller, first side with bearing surface is connected, follows first side arrives the direction of second side, the inclined plane is close to the lopsidedness of blade extends, the inclined plane with bearing surface's contained angle is not more than 5, the process on the cross-section of the axis of impeller, bearing surface's length with the ratio of the length of second fitting surface is 1/5 ~ 3/5.

2. The impeller of claim 1, wherein the angle between the inclined surface and the bearing surface is 1 ° to 3 °.

3. The impeller according to claim 1, characterized in that the junction of the bearing surface and the inclined surface is provided with a fillet, and the radius of the fillet is not less than 0.05 mm.

4. The impeller according to claim 1, characterized in that said inclined surface is located inside or/and outside said cover plate.

5. The impeller according to claim 1, characterized in that it comprises two said cover plates, a plurality of said blades being located between the first assembling surfaces of the two said cover plates, a blood passage being formed between the two said cover plates, divided by the plurality of said blades;

the two cover plates are respectively a first cover plate and a second cover plate, and the bearing surface and the inclined surface are arranged on the second assembly surface of the first cover plate and/or the second cover plate.

6. The impeller of claim 1, wherein said impeller includes a said cover plate, said first mounting surface includes a mounting face and a control face joined thereto, said control face having third and fourth opposite sides in a radial direction of said impeller, said third side being joined to said mounting face, said control face extending obliquely away from a side of said blade in a direction from said third side to said fourth side.

7. The impeller of claim 6, wherein the control surface is at an angle of no more than 5 ° to the mounting surface, and wherein, in a cross-section through a central axis of the impeller, a ratio of a length of the mounting surface to a length of the first mounting surface is 1/5-3/5.

8. The impeller as claimed in claim 6, characterized in that the connection of the control surface to the mounting surface is provided with a fillet, the radius of which is not less than 0.05 mm.

9. A ventricular assist device, comprising a housing and a positioning column disposed in the housing, wherein a first inner cavity is disposed in the housing, the positioning column is fixed to a bottom wall of the first inner cavity, and the housing is provided with a liquid inlet and a liquid outlet respectively communicated with the first inner cavity, and further comprising an impeller according to any one of claims 1 to 8, the impeller being rotatably disposed around the positioning column and being capable of suspending in the first inner cavity.

10. A ventricular assist device as claimed in claim 9, wherein the bearing surface and the inclined surface of the impeller are disposed opposite the inner wall of the first chamber, the bearing surface of the impeller abutting the inner wall of the first chamber when the impeller is not rotating.

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