CN217548792U - Centrifugal blood pump rotor and centrifugal blood pump - Google Patents

Abstract

The utility model provides a centrifugal blood pump rotor and a centrifugal blood pump, which comprises a rotor body; the rotor body is provided with a first surface and a second surface which are opposite, the first surface is provided with a main blade, and the second surface is provided with a back blade; the main blades are used for generating centrifugal force for driving blood to move along the rotor body; the back blade is used for accelerating the blood flow at the periphery of the second surface; the rotor body is provided with a through hole which is communicated with the first surface and the second surface and can enable part of blood pushed by the main blade to flow among the periphery of the rotor body, the back blade, the through hole and the main blade; the upper end, the lower end and the periphery of the blood pump rotor are prevented from generating stagnation areas and reducing the pressure at the lower end of the rotor, so that damage to red blood cells and activation to platelets are reduced, blood sedimentation is avoided, and damage to the red blood cells and risk of thrombus formation are reduced.

Description

Centrifugal blood pump rotor and centrifugal blood pump

Technical Field

The application relates to the field of medical equipment, in particular to a centrifugal blood pump rotor and a centrifugal blood pump.

Background

The blood pump is a medical apparatus for assisting the blood circulation of the human body, and can be used as a Ventricular Assist Device (VAD) for treating severe heart failure, and also used in combination with an oxygenator to replace the function of the heart and lung in the Extracorporeal Membrane Oxygenation (ECMO) technique. The blood pump which is commonly used in clinic at present is a centrifugal magnetic coupling driving blood pump. The blood pump consists of a pump head and a magnetic coupling driving device. The pump head has complicated internal geometric structure and consists of a rotor and a shell rotating at high speed, the rotor is provided with blades, the center of the rotor is provided with a through hole, and a secondary flow passage is formed between the rotor and the upper and lower shells. When the blood pump works, the magnetic coupling driving device drives the rotor in the pump head to rotate at a high speed, the blood circulation is pushed through the blades, but a complex flow field is also caused in the pump head, and meanwhile, a flow stagnation area (such as a secondary flow channel area, a supporting position of a contact point of the rotor and a shell and the like) is also generated, so that the deposition of substances (such as platelets, red blood cells, fibrinogen and the like) in blood is caused, and the generation of thrombus is caused; meanwhile, the high-speed rotation of the centrifugal blood pump rotor and the complex flow field in the blood pump can also generate extremely high non-physiological shearing force (often greater than 100 Pa), which can cause the damage of red blood cells and the activation of platelets and the release of blood coagulants (such as ADP, TXA2 and the like), and further increase the risk of hemolysis and thrombosis.

At present, blood pumps widely applied comprise a semi-open impeller and a closed impeller. The semi-open impeller is provided with two mechanical bearings, so that the lift force of the blood pump rotor in the axial direction can be well balanced, but a large number of flow stagnation areas can be generated in the mechanical bearing area, the possibility of thrombus generation is greatly improved, and larger pressure can be generated between the stagnation areas and the impeller, so that damage to red blood cells is larger; the use of a closed impeller and an upper cover plate can better reduce the axial lifting force, but can cause the contact area of the rotor and blood to increase, thereby causing the increase of the shearing force, causing the damage of the closed impeller to red blood cells to increase and causing hemolysis. Although the use of mechanical bearings can balance the axial force and keep the rotor axially stable, the high heat and shear force generated by the mechanical bearings during rotation can greatly destroy red blood cells and activate platelets, resulting in blood damage. In addition, no matter the existing closed impeller or semi-open impeller, the flow rate of blood in the lower cavity is relatively slow, so that the blood is easy to silt up in the lower cavity of the blood pump, and thrombus is guided.

Disclosure of Invention

The blood damage such as blood cell destruction, platelet activation and thrombus formation that the blood flow is slow in order to overcome friction between blood pump mechanical bearings and secondary flow channel etc. and lead to is this application.

In a first aspect, the present application provides a centrifugal blood pump rotor comprising:

a rotor body;

the rotor body is provided with a first surface and a second surface which are opposite, the first surface is provided with a main blade, and the second surface is provided with a back blade; the main blades are used for generating centrifugal force of blood along the rotor body;

the dorsal leaflet is used for accelerating blood flow at the periphery of the second surface; the rotor body is provided with a through hole which is communicated with the first surface and the second surface, so that part of blood pushed by the main blade can circulate among the periphery of the rotor body, the back blade, the through hole and the main blade.

Further, the height of the back vane is gradually reduced from the outer periphery of the rotor body to the center direction.

Further, the height of the main blade increases from the outer periphery of the rotor body to the center direction.

Further, the number of the back blades is greater than or equal to the number of the main blades.

Further, the average height of the back blades is smaller than the average height of the main blades.

Further, the bending direction of the back blade coincides with the bending direction of the main blade.

Further, the bending angle of the back blade is smaller than or equal to the bending angle of the main blade.

Another aspect of the present application proposes a centrifugal blood pump, which includes the blood pump rotor of any one of the above technical solutions;

the permanent magnet is arranged in the magnet accommodating cavity and is used for being magnetically coupled with an external magnet driver and driving the blood pump rotor to rotate;

and the shell is used for accommodating the blood pump rotor.

Furthermore, one axial side of the shell is connected with the liquid inlet pipe through a large chamfer;

a volute flow channel communicated with the inside of the shell is arranged on the periphery of the shell; and a liquid outlet pipe is arranged on the volute flow channel and is tangent to the base circle of the volute.

The application provides a centrifugal blood pump rotor and a blood pump, wherein the centrifugal blood pump rotor comprises a rotor body; the rotor body is provided with a first surface and a second surface which are opposite, the first surface is provided with a main blade, and the second surface is provided with a back blade; the main blades are used for generating centrifugal force for driving blood to move along the rotor body; the back blade is at least used for enabling part of blood pushed by the main blade to flow along the edge of the rotor body to the central direction; the rotor body is provided with a through hole which is communicated with the first surface and the second surface, so that part of blood pushed by the main blade can circulate among the periphery of the rotor body, the back blade, the through hole and the main blade. In the blood pump rotor, the main blades are used for generating centrifugal force for driving blood to move along the rotor body in the rotating process; the back blade is used for preventing blood from rotating along with the rotor body and shortening the passing time of the blood on the periphery of the second surface; avoid producing stagnation area and high-pressure region at the upper and lower end of blood pump rotor and peripheral edge, and then reduce the destruction to erythrocyte and blood platelet, reduced the possibility of blood siltation to the risk of taking place hemolysis and formation thrombus has been reduced. Meanwhile, the reduction of high pressure areas at the upper end, the lower end and the peripheral edge of the blood pump rotor is beneficial to reducing the lift force of the blood pump rotor in the axial direction and improving the dynamic balance of the blood pump rotor.

Drawings

In order to more clearly illustrate the embodiments of the present application or technical solutions in the conventional technology, the drawings needed to be used in the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is an axial half-section schematic view of a centrifugal blood pump according to one embodiment of the present application;

fig. 2 is a perspective view of a centrifugal blood pump rotor according to an embodiment of the present application.

Wherein, the correspondence between the reference numbers and the component names in fig. 1 to 2 is:

1. a liquid inlet pipe; 2. a main blade; 3. a volute flow channel; 4. an upper cavity; 5. a rotor body; 6. a lower cavity; 7. and (4) carrying out back blades.

Detailed Description

It is to be noted that, in the description of the present invention, the terms "plurality" or "a plurality" mean two or more, unless otherwise specifically defined, the terms "upper" and "lower" or the like indicate orientations or positional relationships based on the drawings, which are merely for convenience of description of the present invention and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be interpreted as limiting the present invention; the terms "connected," "mounted," "secured," and the like are to be construed broadly and include, for example, fixed connections, removable connections, or integral connections; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the description of the present invention, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In the present disclosure, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

At present, mechanical bearings and secondary flow channels are used in the prior art in order to balance the axial lift of the blood pump and to avoid flow stagnation. The use of mechanical bearings allows for areas of high thermal and shear forces at their contact points, which are prone to cause red blood cell destruction and platelet activation. The existence of the secondary flow channel enables the flow velocity of blood in the secondary flow channel to slowly form a flow stagnation area, so that blood is deposited, and the risk of thrombosis is increased. The pressure between the stagnation area and the blood pump rotor and the interaction between the flow area and the stagnation area cause the increase of shearing force, destroy red blood cells and activate platelets, and further deteriorate the blood compatibility of the blood pump.

In order to improve the blood compatibility of the blood pump while balancing the axial force of the blood pump, as shown in fig. 1 and fig. 2, an embodiment of the present application provides a blood pump rotor without a mechanical bearing, comprising a rotor body 5; the rotor body 5 is provided with a first surface and a second surface which are opposite, the first surface is provided with a main blade 2, and the second surface is provided with a back blade 7; the main blades 2 are used to generate the centrifugal force that drives the movement of the blood along the rotor body 5; the back blades 7 are at least used for enabling part of blood pushed by the main blades 2 to flow towards the center direction along the edge of the rotor body 5; the rotor body 5 is provided with a through hole which is communicated with the first surface and the second surface, and partial blood pushed by the main blade 2 can circulate among the periphery of the rotor body 5, the back blade 7, the through hole and the main blade 2.

In this technical scheme, rotor body 5's magnet holds the chamber and can fix and place the permanent magnet, and the magnet forms the magnetic coupling with outside magnet driver, and under outside magnet driver drove, the magnet rotation drove rotor body 5 rotation thereupon. The rotor body 5 is provided with a first surface and a second surface which are opposite, the first surface is provided with a main blade 2, and the second surface is provided with a back blade 7; the main blades 2 are used to generate the centrifugal force that drives the movement of the blood along the rotor body 5; the back blades 7 are at least used for enabling part of blood pushed by the main blades 2 to flow towards the center direction along the edge of the rotor body 5; according to Bernoulli's principle, kinetic energy + gravitational potential energy + pressure potential energy = constant in the fluid. The energy obtained by the fluid due to stress + the energy lost by the fluid due to acting by gravity = the kinetic energy obtained by the fluid, and in the same stable fluid system, the faster the blood flow speed is, the smaller the pressure potential energy is brought, whereas the slower the speed is, the larger the pressure potential energy is brought. In the prior art, the blood pump rotor forms a blood stagnation area easily in a lower cavity 6 of the blood pump under the condition that a back blade 7 is not arranged, and an upper cavity 4 forms a blood flowing area due to the fact that a main blade 2 drives blood to flow, therefore, the relative speed of the blood at the upper end and the blood at the lower end of the blood pump rotor is different from that of the blood at the lower end of the blood pump rotor, the pressure generated by the stagnation area at the lower end is far greater than the pressure brought by the flowing area at the upper end, the pressure difference between the upper end and the lower end of the rotor is large, the lift force is high, and the dynamic balance of the rotor is influenced. In addition, the presence of such a pressure differential can cause extremely high non-physiological shear forces between the rotor and the blood, which can cause damage to red blood cells leading to hemolysis and platelet activation to form thrombus. In the application, the blood pump rotor rotates, and then the main blades 2 are used for generating the radial driving force of blood along the rotor body 5; when the blood pump rotor rotates, no matter the rotor body 5 or the blades, the closer to the axis line, the smaller the speed is, the smaller the relative speed between the blood and the blood pump rotor is, and the larger the pressure potential energy between the blood and the blood pump rotor is, the more the back blades 7 are used for enabling at least part of the blood pushed by the main blades 2 to flow towards the center direction along the edge of the rotor body 5; be formed with the through-hole on rotor body 5, the through-hole intercommunication first surface and second surface can make the circulation of partial blood that main blade 2 promoted between rotor body 5 periphery, back of the body blade 7, through-hole and main blade 2, avoid producing stagnation area at the upper and lower extreme and the peripheral edge of blood pump rotor to avoid blood siltation and the risk of formation thrombus.

Further, the height of the back blade 7 decreases from the outer periphery of the rotor body 5 toward the center. In the technical scheme, the back blade 7 flow channel is formed between every two back blades 7, each back blade 7 flow channel is gradually widened from the axis of the blood pump rotor to the peripheral direction, after the height of the back blades 7 is set to be gradually reduced from the periphery of the rotor body 5 to the central direction, the sectional area of blood contained in the back blade 7 flow channel tends to be uniform, and further after a stable fluid system is formed, the blood flowing speed in the back blade 7 flow channel also tends to be uniform, so that the damage of the blood accelerated speed to the blood is reduced; the back blades 7 are used for enabling blood to flow towards the center direction along the edges of the rotor body 5, and after the sectional area of the blood contained in the flow channels of the back blades 7 is approximately uniform, the blood on the periphery of the blood pump rotor can more easily flow to the axis of the blood pump rotor.

Further, the height of the main blade 2 increases from the outer periphery of the rotor body 5 toward the center. In the above technical scheme, the main blade 2 flow channel is formed between every two main blades 2, each main blade 2 flow channel gradually widens from the axis of the blood pump rotor to the peripheral direction, and after the height of the back blade 7 is reduced from the periphery of the rotor body 5 to the central direction, the sectional area of blood contained in the main blade 2 flow channel tends to be uniform, so that after a stable fluid system is formed, the blood flowing speed in the main blade 2 flow channel also tends to be uniform, and the damage of the blood acceleration to the blood is reduced.

Further, the number of the back blades 7 is greater than or equal to the number of the main blades 2; the average height of the back blades 7 is smaller than the average height of the main blades 2. When the blood pump rotor rotates, blood at the upper end of the rotor body 5 flows from the axis of the blood pump rotor to the peripheral direction under the driving of the reaction force of the centripetal force generated by the main blades 2, and a part of the blood is subjected to pressure and flows from the periphery of the rotor body 5 to the area of the back blade 7 at the lower end and flows to the axis of the blood pump rotor under the guiding of the flow channel of the back blade 7. The main blades 2 are for generating centrifugal force for driving blood to move along the rotor body 5; the back blades 7 are used for enabling blood to flow along the edge of the rotor body 5 to the central direction; the main blade 2 is the source power of the blood flow, and the back blade 7 is the axis which guides the blood at the lower end of the rotor body 5 under pressure to flow to the blood pump rotor; the back vane 7 is used for enabling blood to flow towards the center direction along the edge of the rotor body 5, and the phenomenon that the blood generates overlarge centrifugal force reaction force along with the rotation of the back vane 7 and the pressure from the upper end of the periphery of the blood pump rotor is flushed with the same pressure to form a stagnation area on the periphery of the blood pump rotor is avoided. Preferably, the distance between one end of the back blade 7 far away from the outer periphery of the rotor body 5 and the axis is far smaller than the distance between one end of the main blade 2 far away from the outer periphery of the rotor body 5 and the axis, so that the reaction force of the centripetal force formed by the rotation of the back blade 7 is far smaller than the reaction force of the centripetal force formed by the rotation of the main blade 2, and further, the blood at the outer periphery of the rotor body 5 can flow to the axis of the rotor body 5 under the guidance of the back blade 7, thereby avoiding forming stagnation areas at the outer periphery and the lower end of the rotor body 5, not only keeping the dynamic balance of the blood pump rotor, reducing the vibration of the blood pump, but also reducing the occurrence of hemolysis and thrombosis.

Further, the bending direction of the back blade 7 is the same as that of the main blade 2, and the bending angle of the back blade 7 is smaller than or equal to that of the main blade 2. The main blades 2 are bent along the radial direction on the first surface and the back blades 7 are bent along the radial direction on the second surface, so that the blood in the lower cavity 6 can flow, and the formation of a flow dead zone in the lower cavity 6 due to the use of the back blades can be avoided. Meanwhile, the forward prewhirl in the secondary flow is reduced to a certain extent, so that the energy loss and the generated high shear force caused by the collision of the secondary flow and the main flow are reduced. Is beneficial to improving the hydraulic performance of the blood pump and reducing the damage to blood.

Further, the end of the back vane 7 remote from the rotor body 5 has an arc-shaped portion. Because the back blades 7 guide the circumferential blood of the rotor body 5 to flow to the axis, and a stagnation area is prevented from being formed at the lower end and the periphery of the rotor body 5, one end of each blade, which is far away from the rotor body 5, is provided with an arc-shaped part, a turbulent flow area with proper strength can be formed in the lower end area of the rotor body 5, the proper strength means that the turbulent flow cannot damage the blood, the turbulent flow can enable the surface of the back blades 7 to form irregular blood flow, the forward reaction force applied to the blades is reduced, and the pressure applied to the blood per se is also reduced; but also can make the blood not in the rotating area of the back vane 7 flow, and avoid the different layering phenomena which form obvious flow velocity in the rotating range of the back vane 7; preferably, a raised structure is provided at the end of the back-vane 7 remote from the rotor body 5, so that blood can form a turbulent flow zone of suitable intensity at the lower end region of the rotor body 5.

In another aspect of the present application, a centrifugal blood pump is provided, which is a centrifugal blood pump rotor in the above technical solution, and therefore, the centrifugal blood pump in the technical solution has all the advantages and benefits of the centrifugal blood pump rotor; the magnet is arranged in the magnet accommodating cavity, is magnetically coupled with an external magnet driver and drives the blood pump rotor to move; and the shell is used for accommodating the blood pump rotor.

Further, the centrifugal blood pump comprises a housing; the axial one side of shell links to each other with feed liquor pipe 1 through big chamfer, perhaps, the axial one side of shell is passed through transition portion and is linked to each other with feed liquor pipe 1, and the diameter of transition portion is crescent to the shell periphery by feed liquor pipe 1 in the axial, and this is favorable to restraining the backward flow that the blood pump rotation produced in the feed liquor pipe, has reduced the blood damage because of the existence of backward flow. A volute flow channel 3 communicated with the inside of the shell is arranged on the periphery of the shell; the volute flow channel is provided with a liquid outlet pipe which is tangent with the base circle of the volute so as to ensure that blood smoothly flows out and avoid blood stasis and thrombus formation caused by the flow and the shunt of the blood at the volute tongue.

Furthermore, the reduction of the axial lift force of the blood pump rotor is beneficial to reducing the reaction force applied to the blood pump by the magnetic suspension system, so that the power consumption of the motor of the blood pump is reduced, and further blood damage caused by high heat in the running process of the motor of the blood pump is avoided.

The centrifugal blood pump works as follows: the permanent magnet is fixedly arranged in the magnet accommodating cavity and forms magnetic coupling with an external magnet driver, the magnetic coupling system applies axial and radial balance force to the blood pump rotor, the balance force is accurately balanced with hydraulic force, axial force and radial force of the rotor, the blood pump rotor is kept suspended in the rotor accommodating cavity and can stably rotate along with the rotation of the magnet driver; blood enters a shell of the blood pump from a liquid inlet pipe 1, flows to a peripheral area through the acceleration of a main blade 2 on a rotor of the blood pump, and most of the blood enters a flow channel and flows to a liquid outlet pipe; a small part of blood flows to the lower end of the rotor body 5 from the edge of the rotor body 5 under the action of pressure, flows to the axis of the blood pump rotor under the guidance of the back blades 7, enters the flow channel of the main blades 2 or returns to the liquid inlet pipe 1 through the through hole, and is pushed by the main blades 2 again. Blood in the blood pump can make each regional blood flow under the drive of main leaf 2 and back of the body blade 7, avoids appearing stagnation area, and then avoids the appearance of hemolysis and thrombus.

It is to be understood that the above-described embodiments of the present application are merely illustrative of or illustrative of the principles of the present application and are not to be construed as limiting the present application. Therefore, any modifications, equivalents, improvements and the like which are made without departing from the spirit and scope of the present application shall be included in the protection scope of the present application. Further, it is intended that the appended claims cover all such changes and modifications that fall within the scope and range of equivalents of the appended claims, or the equivalents of such scope and range.

Claims (9)

1. A centrifugal blood pump rotor, comprising:

a rotor body (5);

the rotor body (5) is provided with a first surface and a second surface which are opposite, the first surface is provided with a main blade (2) and the second surface is provided with a back blade (7);

the main blades (2) are used for generating centrifugal force for driving blood to move along the rotor body (5);

the back blade (7) is used for accelerating the blood flow at the periphery of the second surface; the back blade (7) is at least used for enabling part of blood pushed by the main blade (2) to flow along the edge of the rotor body (5) to the center direction;

the rotor body (5) is provided with a through hole which is communicated with the first surface and the second surface, so that part of blood pushed by the main blade (2) can circulate among the periphery of the rotor body (5), the back blade (7), the through hole and the main blade (2).

2. The centrifugal blood pump rotor according to claim 1, characterized in that the height of the back blades (7) decreases from the outer circumference of the rotor body (5) in the central direction.

3. The centrifugal blood pump rotor according to claim 1, characterized in that the height of the main blades (2) increases from the outer circumference of the rotor body (5) in the central direction.

4. The centrifugal blood pump rotor according to claim 1, characterized in that the number of the back blades (7) is greater than or equal to the number of the main blades (2).

5. The centrifugal blood pump rotor according to claim 1, characterized in that the average height of the dorsal blades (7) is smaller than the average height of the main blades (2).

6. The centrifugal blood pump rotor according to claim 1, characterized in that the direction of curvature of the back blades (7) coincides with the direction of curvature of the main blades (2), the angle of curvature of the back blades (7) being smaller than or equal to the angle of curvature of the main blades (2).

7. The centrifugal blood pump rotor according to claim 1, characterized in that the end of the back blade (7) remote from the rotor body (5) has an arc-shaped portion.

8. A centrifugal blood pump comprising a centrifugal blood pump rotor according to any of claims 1 to 7;

the permanent magnet is arranged in the magnet accommodating cavity and is used for being magnetically coupled with an external magnet driver and driving the blood pump rotor to rotate;

a housing for housing the blood pump rotor.

9. The centrifugal blood pump of claim 8,

one axial side of the shell is connected with the liquid inlet pipe (1) through a large chamfer;

a volute flow channel (3) communicated with the inside of the shell is arranged on the periphery of the shell; and a liquid outlet pipe is arranged on the volute flow channel (3) and is tangent to the base circle of the volute.

Images