CN116271503A - Pump rotor, blood pump and ventricular assist device - Google Patents

Abstract

The invention provides a pump rotor, a blood pump and a ventricular assist device, wherein the pump rotor is used for the blood pump, and comprises: a hub and at least two first blades; at least two of the first blades are coiled on the hub, and the first blades have at least two wavy sections with opposite curvatures. The axial velocity distribution, the circumferential velocity distribution and the velocity of the fluid at the outlet are effectively adjusted, the instability of flow is restrained, and the energy loss of the fluid at the outlet when the fluid at the pump outlet is mixed into the main flow of a blood vessel is reduced, so that the overall hydraulic performance of the pump rotor and the blood pump device is improved, the pressurizing capacity is improved, the damage to erythrocytes is reduced, the hemolytic performance is improved, and the pump efficiency is improved.

Description

Pump rotors, blood pumps and ventricular assist devices

technical field

The invention relates to the technical field of medical instruments, in particular to a pump rotor, a blood pump and a ventricular assist device.

Background technique

For patients with heart failure, because the pumping volume of the heart cannot maintain the blood supply required by the normal metabolism of body tissues, tens of millions of patients die every year around the world. At present, the most common treatment methods for heart failure include: drug therapy, heart transplantation, and ventricular assist device therapy etc. For patients with severe heart failure, the therapeutic effect of drug therapy is quite limited, and most of them need to use heart transplantation and ventricular assist device for treatment, but the source of heart transplantation is limited, so ventricular assist device has become the main choice for patients and doctors. A key component of a ventricular assist device is usually a blood pump, also known as an impeller pump, which is driven by an integrated electric motor and uses the high-speed rotation of the impeller to increase the energy required for blood flow to achieve blood flow to the whole body.

At present, there is a kind of impeller whose blades mostly adopt a single concave-convex design. The curvature of the blade changes greatly in the range of the first 50% of the chord length, which is responsible for applying energy to the fluid. The design of the small curvature in the last 50% range adjusts the flow of the fluid. Angle, the axial velocity of the fluid at the pump outlet of this leaf design is relatively high, and after being directly mixed into the low-speed mainstream in the blood vessel, the energy loss of the fluid is relatively large, and at the same time, the damage to the red blood cells is relatively large. Therefore, this impeller design has the disadvantages of low pump efficiency and high-speed rotation of the pump blades, which seriously damages red blood cells in the blood. It is one of the difficulties encountered by this type of product to reduce the damage to red blood cells while improving the pump efficiency, which has attracted more and more attention of engineers and technicians.

Therefore, it is necessary to develop a pump rotor, a blood pump and a ventricular assist device to solve at least one of the above-mentioned problems.

Contents of the invention

The object of the present invention is to provide a pump rotor, a blood pump and a ventricular assist device to solve the problems of low pump efficiency and serious damage to red blood cells in the blood caused by high-speed rotation of the pump rotor.

In order to solve the above technical problems, the present invention provides a pump rotor for a blood pump, the pump rotor includes: a hub and at least two first blades; at least two of the first blades are coiled on the hub, the The first blade has at least two wavy sections with opposite curvatures.

Optionally, there is at least one wave inflection point between the at least two wavy sections with opposite curvatures, and the chord length of the wave inflection point from the leading edge of the blade is not less than the chord length from the trailing edge of the blade.

Optionally, the first blade is divided into at least two layers of blades along the blade height direction, and the inlet installation angle and outlet installation angle of the blade near the blade root direction are both smaller than the inlet installation angle and outlet installation angle farther from the blade root direction.

Optionally, the first blade has a root layer, a middle layer and a top layer along the height direction, the middle layer is located between the root layer and the top layer along the height direction, the root layer, The leaf middle layer and the leaf top layer are connected by a curved surface.

Optionally, the middle leaf layer is located at the midpoint of the first blade along the blade height direction.

Optionally, the pump rotor further includes at least one second blade, and the second blade is arranged on the hub; the second blade is located in the flow channel formed by the at least two first blades, and the The chord length of the second blade is not greater than half of the chord length of the first blade; the first blade has a leading edge and a trailing edge, and the axial position of the second blade is closer to the The trailing edge is set; the blade height of the second blade is not greater than the blade height of the first blade.

Optionally, the second blade has a straight blade structure; or, at the same axial position, the curvature of the blade shape of the second blade is consistent with the curvature of the blade shape of the first blade.

Optionally, at least one corrugated structure is provided on at least one pressure surface of the first blade, the corrugated structure adopts a streamline adaptive structure, and the corrugated structure is a corrugated protrusion.

In order to solve the above technical problems, the present invention also provides a blood pump, comprising: a pump housing and the above-mentioned pump rotor, the pump rotor is arranged inside the pump housing for pumping blood.

In order to solve the above technical problems, the present invention also provides a ventricular assist device, comprising: the above-mentioned blood pump.

In the pump rotor, blood pump and ventricular assist device provided by the present invention, the pump rotor is used in a blood pump, and the pump rotor includes: a hub and at least two first blades; at least two of the first blades Coiled on the hub, the first blade has at least two corrugated sections of opposite curvature. Such setting can effectively adjust the axial velocity distribution, circumferential velocity distribution and velocity of the fluid at the outlet, suppress the instability of the flow, reduce the energy loss when the fluid at the pump outlet is mixed into the main flow of the blood vessel, thereby improving the performance of the pump rotor and the blood pump. The overall hydraulic performance of the device, improve pressurization capacity, reduce damage to red blood cells, improve hemolysis performance, and improve pump efficiency.

Description of drawings

Those of ordinary skill in the art will understand that the provided drawings are for better understanding of the present invention, but do not constitute any limitation to the scope of the present invention. in:

FIG. 1 is a schematic diagram of a wavy section with opposite curvatures of a first blade according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a pump rotor according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of the meridional flow path of the first vane of the pump rotor shown in Fig. 2 .

Fig. 4(a) is a schematic diagram of the blade root layer of the first blade of the pump rotor shown in Fig. 2 .

FIG. 4( b ) is a schematic diagram of the middle layer of the first blade of the pump rotor shown in FIG. 2 .

Fig. 4(c) is a schematic diagram of the blade top layer of the first blade of the pump rotor shown in Fig. 2 .

FIG. 5 is a schematic view of the mid-blade of the first blade of the pump rotor shown in FIG. 2 .

Fig. 6 is a schematic diagram of a pump rotor provided by an embodiment of the present invention with a second vane.

Fig. 7 is a schematic diagram of another second vane provided by a pump rotor provided by an embodiment of the present invention.

Fig. 8 is a schematic diagram of a pump rotor with a corrugated structure provided by an embodiment of the present invention.

FIG. 9 is a schematic diagram of a cross-section of the corrugated structure on the first vane in the pump rotor shown in FIG. 8 .

In the attached picture:

A-wave anti-inflection point;

10-wheel hub;

20-first leaf, 201-leaf root layer, 202-leaf middle layer, 203-leaf top layer;

30 - the second blade;

40 - Corrugated structure.

Detailed ways

In order to make the purpose, advantages and features of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in very simplified form and not drawn to scale, and are only used to facilitate and clearly assist the purpose of illustrating the embodiments of the present invention. In addition, the structures shown in the drawings are often a part of the actual structure. In particular, each drawing needs to display different emphases, and sometimes uses different scales.

As used in this specification, the singular forms "a", "an" and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise. The term "several" is usually used in the meaning including "at least one", and the term "at least two" is usually used in the meaning including "two or more". In addition, the term "first "," "Second" and "Third" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of these features, and the terms "installation", "connection" and "connection" shall be used as In a broad sense, for example, it can be a fixed connection, a detachable connection, or an integration; it can be directly connected, or indirectly connected through an intermediary, and it can be the internal communication of two elements or the interaction relationship between two elements . The "distal end" refers to the end far away from the operation of the medical staff, and the "near end" refers to the end close to the operation of the medical staff. In addition, as used in the present invention, an element is arranged on another element, usually only means that there is a connection, coupling, cooperation or transmission relationship between the two elements, and the relationship between the two elements can be direct or indirect through an intermediate element. connection, coupling, fit or transmission, but cannot be understood as indicating or implying the spatial positional relationship between two elements, that is, one element can be in any orientation such as inside, outside, above, below or on one side of another element, unless the content Also clearly point out. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations. Additionally, in the following description, numerous specific details are given in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without one or more of these details. In other examples, some technical features known in the art are not described in order to avoid confusion with the present invention.

The present invention provides a pump rotor, a blood pump and a ventricular assist device. The pump rotor is used in a blood pump, and the pump rotor includes: a hub and at least two first blades; at least two of the first blades are coiled around the On the hub, the first blade has at least two wavy sections with opposite curvatures. Such setting can effectively adjust the axial velocity distribution, circumferential velocity distribution and velocity of the fluid at the outlet, suppress the instability of the flow, reduce the energy loss when the fluid at the pump outlet is mixed into the main flow of the blood vessel, thereby improving the performance of the pump rotor and the blood pump. The overall hydraulic performance of the device, improve pressurization capacity, reduce damage to red blood cells, improve hemolysis performance, and improve pump efficiency.

Description is made below with reference to the accompanying drawings.

Fig. 1 is a schematic diagram of the wavy sections with opposite curvatures of the first blade according to an embodiment of the present invention; Fig. 2 is a schematic diagram of a pump rotor according to an embodiment of the present invention; Fig. 3 is the first blade of the pump rotor shown in Fig. 2 Fig. 4 (a) is the schematic diagram of the blade root layer of the first blade of the pump rotor shown in Fig. 2; Fig. 4 (b) is the blade middle layer of the first blade of the pump rotor shown in Fig. 2 Fig. 4 (c) is a schematic diagram of the blade top layer of the first blade of the pump rotor shown in Fig. 2; Fig. 5 is a schematic diagram of the first blade of the pump rotor shown in Fig. 2 when it is in the middle layer of the blade; Fig. 6 is A schematic diagram of a pump rotor provided by an embodiment of the present invention with a second blade; FIG. 7 is a schematic diagram of a pump rotor provided by an embodiment of the present invention with another second blade; FIG. 8 is a schematic diagram of a pump rotor provided by an embodiment of the present invention with Schematic diagram of the corrugated structure; FIG. 9 is a schematic diagram of the cross-section of the corrugated structure on the first blade in the pump rotor shown in FIG. 8 .

This embodiment provides a pump rotor, which is suitable for axial flow pumps, especially for blood pumps. The pump rotor includes: a hub 10 and at least two first blades 20 . The pump rotor is used, for example, to pump a fluid, preferably blood.

As shown in FIG. 2 , at least two first blades 20 are coiled on the hub 10 . For example, the first blade 20 is helically wound on the hub 10, so that the first blade 20 connected to the hub 10 has a certain angle with the axial direction of the hub 10, so that the first blade 20 rotates fluid can be pumped. The hub 10 is, for example, a conical hub, one side of the top end of the cone allows fluid to flow in, and one side of the bottom end of the cone allows fluid to flow out. Specifically, as shown in FIG. 2 , the arrow indicates the direction of fluid flow, and the first vane 20 is arranged counterclockwise along the hub 10 from the fluid inflow end to the fluid outflow end. Viewed from the perspective of the fluid inflow end towards the fluid outflow end, when the hub 10 rotates counterclockwise, the pump rotor realizes the function of pumping blood. The first blade 20 has at least two corrugated sections with opposite curvatures. For example, as shown in Figure 1, if the curvature of the concave wavy section on the right side of the curve in Figure 1 is set to be positive, then the curvature of the convex wavy section on the left side of Figure 1 is negative and the curvature is positive The point where the curvature of the wavy section is connected to the wavy section with negative curvature is zero is the inflection point A of the wave. In this embodiment, the first blade 20 has two wavy sections with opposite curvatures. Set near the fluid inflow end, the curvature of the first blade 20 is negative, this section is mainly responsible for applying energy to the fluid (blood) to do work, increasing the fluid (blood) flow rate and pressure; correspondingly, near the fluid outflow end, The curvature of the first vane 20 is positive, increasing the pressure of the fluid here reduces the ability of the first vane 20 to work on the fluid at the outlet, thereby reducing the speed of the fluid outflow and effectively adjusting the flow rate of the fluid at the outlet. The axial velocity distribution, the circumferential velocity distribution and the magnitude of the velocity can suppress the instability of the flow and reduce the energy loss when the pump outlet fluid is mixed into the main flow of the blood vessel, thereby improving the overall hydraulic performance of the pump rotor and the blood pump device, and increasing the boost pressure. Ability to reduce damage to red blood cells, improve hemolytic performance, and improve pump efficiency. In other embodiments, the first blade 20 may also have a plurality of wavy sections with opposite curvatures. Preferably, at least two of the first blades 20 are evenly distributed along the hub 10 . The number of the first blades 20 may be two or more.

Preferably, as shown in Figure 1, there is at least one wave inflection point A between the at least two wavy sections with opposite curvatures, and the chord length of the wave inflection point A from the leading edge of the blade is not less than Chord length. The leading edge of the blade represents the end from which fluid flows in, and the trailing edge of the blade represents the end from which fluid flows out. The wavy section before the wave inflection point A is used to store and deliver the inflowing fluid, and the wavy section after the wave inflection point A is used to pump out the inflowing fluid. In this embodiment, the first blade 20 has two wavy sections with opposite curvatures, and correspondingly has an inflection point A of the wave. When the first blade 20 has multiple wavy sections with opposite curvatures, there may be two or more wave inflection points A.

Preferably, as shown in FIGS. 3 to 5 , the first blade 20 is divided into at least two layers of blades along the blade height direction. As shown in Figure 4(a) to Figure 4(c), the inlet installation angle α ₁ and outlet installation angle α ₂ of the blade near the blade root direction are smaller than the inlet installation angle α ₁ and outlet installation angle α in the direction away from the blade root ₂ . The blade height direction is perpendicular to the hub 10 direction. For example, as shown in Figure 4(a) and Figure 4(c), at the leading edge of the blade, the installation angle of the inlet at the blade root is different from that at the blade top, and the range of difference is within 20 degrees. The installation angle is smaller than the inlet installation angle at the tip of the blade. Similarly, at the trailing edge of the blade, the outlet installation angle of the blade root is different from the outlet installation angle of the blade top, and the range difference is within 15 degrees, and the outlet installation angle at the blade root is smaller than that at the blade top. Optionally, the inlet installation angle _α1 and the outlet installation angle _α2 of the blades of each layer may be the same. Preferably, the inlet installation angle _α1 and the outlet installation angle _α2 of the blades of each layer may be different. Preferably, the blades of different layers are evenly distributed in the blade height direction, thereby facilitating the control of the fluid flow direction.

Further, in this embodiment, as shown in FIG. 2 to FIG. 4(c), the first blade 20 has a blade root layer 201, a blade middle layer 202, and a blade top layer 203 along the blade height direction, and the blade middle layer 202 Located between the blade root layer 201 and the blade top layer 203 along the blade height direction, the blade root layer 201 , the blade middle layer 202 and the blade top layer 203 are connected by a curved surface. Specifically, when the three layers of blades are connected, a point in the leaf root layer 201, a point in the leaf middle layer 202, and a point in the leaf top layer 203 are connected by a curve, and then a curved surface is formed between the three layers, so that The pressure surface of the first vane 20 is a smooth closed curved surface, thereby making the fluid flow more smoothly during the blood pumping process, which can moderately reduce the secondary flow loss of the vane, improve the flow efficiency, and improve the stability of the fluid flow. Of course, in other embodiments, the first blade 20 may also have a blade root layer 201 and a blade top layer 203 along the blade height direction, and the blade root layer 201 and the blade top layer 203 are connected by a straight line to form a ruled surface. Specifically, when connecting, a point in the blade root layer 201 and a corresponding point in the blade top layer 203 are connected by a straight line.

More preferably, the mid-leaf layer 202 is located at the midpoint of the first blade 20 along the blade height direction, so that the blade root layer 201 , the blade mid-layer 202 and the blade top layer 203 can be evenly distributed, improving the stability of fluid flow. Refer to FIG. 5 for the schematic diagram of the mid-leaf layer 202 .

More preferably, the pump rotor further includes at least one second vane 30 , and the second vane 30 is arranged on the hub 10 . The second vane 30 is located in the flow channel formed by the at least two first vanes 20, and the chord length of the second vane 30 is not greater than half of the chord length of the first vane 20, thereby improving the pumping time. , the guiding effect on the fluid. The first blade 20 has a leading edge and a trailing edge, and the axial position of the second blade 30 is arranged closer to the trailing edge than the leading edge. Further, the second vane 30 is arranged within the range of 50%-100% of the chord length of the first vane (that is, the second half of the main vane), so as to improve the flow stability of the fluid outlet. The blade height of the second blade 30 is not greater than the blade height of the first blade 10, which facilitates maintaining the overall structure of the pump rotor. The height range of the second blade 30 is preferably 20%-100% of the height of the first blade 20 . The setting of the second vane 30 can effectively suppress the vortex phenomenon that occurs near the fluid outlet when the suction surface and the hub get along, so that the fluid can be output stably and the hemolysis phenomenon is weakened. The number of the second blades 30 can be set according to the actual situation.

Preferably, please refer to FIG. 6 , the second blade 30 is a straight blade structure. The angle between the second blade 30 and the axial direction of the hub 10 can be between 10-60°, and those skilled in the art can set it according to actual needs. Preferably, please refer to FIG. 7 , in the same axial position, the curvature of the airfoil of the second blade 30 is consistent with the curvature of the airfoil of the first blade 20 , thereby improving the stability of the fluid flow while , it is also possible to further optimize the size and direction of the fluid outflow velocity.

Preferably, at least one corrugated structure 40 is provided on at least one pressure surface of the first blade 20 . The corrugated structure 40 can weaken the diffusion of the fluid flow in the pump, improve the ability of the pump to transport the medium, weaken the mixing of the flow, and weaken the hemolysis phenomenon. Preferably, the corrugated structure 40 adopts a streamline adaptive structure to further reduce the diffusion of fluid flow. The corrugated structure 40 is a corrugated protrusion, and the height of the protrusion is, for example, between 0.1mm-0.3mm. Preferably, the corrugated structure 40 is located on the pressure surfaces of both sides of the first blade 20 . As shown in FIG. 8 and FIG. 9 , a smooth transition is adopted between the corrugated structure 40 and the first vane 20 . As shown in Figure 9, h is the height of the corrugated protrusion, b is the thickness of the blade, and the chamfering radius R. The specific number of the corrugated structures 40 is not limited, and each of the corrugated structures 40 is preferably evenly distributed. More preferably, the corrugated structure 40 is located within the range of 50%-100% of the chord length of the first blade 20 (ie, the second half of the main blade). In other embodiments, the corrugated structure 40 can also be arranged on the second blade 30 .

This embodiment also provides a blood pump, including: a pump housing and the above-mentioned pump rotor, the pump rotor is arranged inside the pump housing and is used for pumping blood. The blood pump has the beneficial effects brought by the pump rotor, which will not be repeated here. For the structure and principle of other components of the blood pump, reference may be made to the prior art, which will not be further described here.

This embodiment also provides a ventricular assist device, including: the above-mentioned blood pump. The ventricular assist device has the beneficial effect brought by the blood pump, which will not be repeated here. For the structures and principles of other components of the ventricular assist device, reference may be made to the prior art, which will not be further described here.

In summary, in the pump rotor, blood pump and ventricular assist device provided by the present invention, the pump rotor is used in a blood pump, and the pump rotor includes: a hub and at least two first blades; at least two The first blade is coiled on the hub, and the first blade has at least two wavy sections with opposite curvatures. Such setting can effectively adjust the axial velocity distribution, circumferential velocity distribution and velocity of the fluid at the outlet, suppress the instability of the flow, reduce the energy loss when the fluid at the pump outlet is mixed into the main flow of the blood vessel, thereby improving the performance of the pump rotor and the blood pump. The overall hydraulic performance of the device, improve pressurization capacity, reduce damage to red blood cells, improve hemolysis performance, and improve pump efficiency.

In addition, it should be understood that although the present invention has been disclosed above with preferred embodiments, the above embodiments are not intended to limit the present invention. For any person skilled in the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or be modified to be equivalent to equivalent changes. Example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention, which do not deviate from the content of the technical solution of the present invention, still belong to the scope of protection of the technical solution of the present invention.

Claims (10)

1. A pump rotor for a blood pump, the pump rotor comprising: a hub and at least two first blades;

at least two of the first blades are coiled on the hub, and the first blades have at least two wavy sections with opposite curvatures.

2. The pump rotor of claim 1, wherein the at least two oppositely curved wave sections have at least one wave inflection point therebetween, the wave inflection point having a chord length from the leading edge of the vane that is no less than a chord length from the trailing edge of the vane.

3. The pump rotor of claim 1, wherein the first blade is divided into at least two layers of blades in a blade height direction, and inlet and outlet mounting angles of the blades in a blade root direction are smaller than inlet and outlet mounting angles in a blade root direction.

4. A pump rotor according to claim 3, wherein the first blade has a blade root layer, a blade middle layer and a blade tip layer in a blade height direction, the blade middle layer being located between the blade root layer and the blade tip layer in the blade height direction, and the blade root layer, the blade middle layer and the blade tip layer being connected by a curved surface.

5. The pump rotor of claim 4, wherein the vane middle layer is located at a midpoint of the first vane in a vane height direction.

6. The pump rotor of claim 1, further comprising at least one second vane disposed on the hub; the second blades are positioned in the flow channel formed by the at least two first blades, and the chord length of the second blades is not more than half of the chord length of the first blades; the first blade has a leading edge and a trailing edge, the axial position of the second blade being disposed closer to the trailing edge than the leading edge; the second blade has a blade height not greater than a blade height of the first blade.

7. The pump rotor of claim 1, wherein the second vane is a straight vane structure; alternatively, in the same axial position, the curvature of the profile of the second blade coincides with the curvature of the profile of the first blade.

8. The pump rotor of claim 1, wherein at least one corrugated structure is provided on at least one pressure surface of the first vane, the corrugated structure employing a streamline adaptive structure, the corrugated structure being corrugated protrusions.

9. A blood pump, comprising: pump housing and a pump rotor according to any of the preceding claims 1-8, which is arranged inside the pump housing for pumping blood.

10. A ventricular assist device, comprising: the blood pump according to claim 9.

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