CN116999688A - Impeller and right ventricle auxiliary device thereof - Google Patents

Abstract

The application provides an impeller which is suitable for assisting in pumping blood by a right heart and has good water conservancy performance and hemolysis performance, and a right ventricle assisting device thereof, wherein blood is pumped from a lower vena cava, bypasses a right atrium and a right ventricle and is pumped into a pulmonary artery, so that the direction of the impeller pumping blood is from the near end of the impeller to the far end of the impeller, and the flow speed of the blood can be increased because the diameter of a hub is gradually increased in the process of conveying the blood from the near end of the impeller to the far end of the impeller, but the flow loss of the blood can be reduced, the blood damage can be reduced, the formation of a flow dead zone can be avoided, the outflow direction of the blood can be effectively regulated, the mixing loss of the blood along the axial direction can be reduced, the pumping blood efficiency can be further improved, and the pumping blood quantity can be increased.

Description

Impeller and right ventricle auxiliary device thereof

Technical Field

The application relates to the technical field of medical equipment, in particular to an impeller and a right ventricle auxiliary device thereof.

Background

A percutaneous implantable artificial ventricular assist device (VAD, hereinafter referred to as a catheter pump) is a miniaturized blood pumping device that may be introduced into the heart and may be configured to assist or replace natural heart function by circulatory pumping or continuous pumping of blood, providing hemodynamic support for cardiogenic shock and acute heart failure. When the catheter pump is deployed on the left side of the heart, the catheter pump pumps from the blood of the left ventricle of the heart into the aorta; when the catheter pump is deployed on the right side of the heart, the catheter pump pumps blood from the inferior vena cava, bypasses the right atrium and right ventricle, and pumps the blood into the pulmonary artery. The blood flow force of the catheter pump is derived from the high-speed rotation of the impeller, and the structural design of the impeller has an important influence on the hydraulic performance and the hemolytic performance of the catheter pump.

Disclosure of Invention

The application aims to provide an impeller which is suitable for right heart auxiliary blood pumping and has good water conservancy performance and hemolysis performance.

In order to achieve the above purpose, the technical scheme adopted by the application is as follows: an impeller comprising a hub and at least one blade secured to the periphery of the hub, the blade being adapted to rotate under the drive of the hub to convey blood from the proximal end of the impeller to the distal end of the impeller;

the hub comprises a hub distal end and a hub main body which are sequentially connected from the distal end to the proximal end;

the hub distal end is a spherical dome or an approximately spherical dome end obtained by rounding the outer edge of a cylinder;

the hub main body is of a conical structure with the radius gradually decreasing from the far end to the near end, and the generatrix of the hub main body is parabolic or linear;

the blade comprises an action surface, the action surface is a three-dimensional space curved surface, the contour line of the action surface comprises an inlet edge, an outer edge molded line, a hub molded line and an outlet edge, and the outer edge molded line and the hub molded line are exponential gradual-change arc lines or Bezier curve arc lines.

Further, the end point of the outer edge profile close to the proximal end is a profile start point, the end point of the outer edge profile close to the distal end is a profile end point, the outer edge profile is a smooth space curve, the curvature of the outer edge profile along the axial direction of the hub is gradually reduced from the profile start point to the profile end point, and meanwhile, the curvature change rate of the outer edge profile along the axial direction of the hub is also gradually reduced.

Further, an included angle between a tangent line of the initial point of the molded line and the tangential speed is an inlet included angle alpha of the outer edge molded line; the combined speed of the axial speed and the tangential speed of the molded line starting point is a relative speed, the included angle between the relative speed and the tangential speed of the molded line starting point is an inlet installation angle beta of the outer edge molded line, and the inlet included angle alpha is larger than the inlet installation angle beta.

Further, the included angle alpha of the inlet is 15-25 degrees.

Further, the formula of the outer edge profile spiral curve is:

x= 0.0548z³ - 0.7026z² + 2.9604z - 0.0239；

y= 2.4798ln(z) - 0.7291；

wherein the line start point of the outer edge line is defined as z=0.

Further, an included angle between an axial plane where the molded line start point is located and an axial plane where the molded line end point is located is a blade deflection angle theta, and the angle of the blade deflection angle theta is 90-180 degrees.

Further, when the impeller is projected along the axial direction of the hub, an axial included angle between the inlet edge and the starting point of the molded line is a tangential forward glancing angle gamma, the tangential forward glancing angle gamma is 5-12 degrees, when the impeller is projected along the radial direction of the hub, an included angle between the inlet edge and the horizontal line is an axial forward glancing angle delta, and the axial forward glancing angle delta is 12-25 degrees.

Further, the radius R of the far end of the hub is 1.6 mm-1.8 mm; the diameter D1 of the proximal end of the hub main body is 0.7-1.0 mm, and the diameter D2 of the distal end of the hub main body is 3.0-4.0 mm; the axial length L of the hub is 7.1 mm-8.5 mm.

Further, the round angles are rounded at the inlet part where the outer edge molded line is connected with the inlet edge and the outlet part where the outer edge molded line is connected with the outlet edge, the round angle radius at the inlet part is 0.08-0.3 mm, and the round angle radius at the outlet part is 0.08-0.3 mm; the joint of the hub and the working surface of the blade is rounded, and the radius of the rounded corner is 0.08-0.3 mm; and the working surface of the blade is rounded with the inlet edge, the outer edge molded line and the outlet edge, and the radius of the rounded angle is 0.1-0.3 mm.

Further, the inlet side is an arc line, and the outlet side is a straight line.

Further, the number of the blades is 2 or 3, and the blades are uniformly distributed along the circumferential direction of the hub main body.

Further, the radius D3 of the blade is 5.5 mm-6.0 mm, the axial length of the blade is 5.8 mm-6.4 mm, and the thickness of the blade is 0.4 mm-0.5 mm.

Another object of the present application is to provide a right ventricular assist device that has good hydraulic and hemolytic properties.

In order to achieve the above purpose, the technical scheme adopted by the application is as follows: a right ventricular assist device includes a catheter and an impeller disposed in the catheter.

In the above scheme, blood is pumped from the inferior vena cava, bypasses the right atrium and the right ventricle and is pumped into the pulmonary artery, so that the direction of impeller pumping is from the proximal end of the impeller to the distal end of the impeller, and the flow speed of the blood can be increased because the diameter of the hub is gradually increased in the process of conveying the blood from the proximal end of the impeller to the distal end of the impeller, but the flow loss of the blood can be reduced, the blood damage is reduced, the formation of a flow dead zone is avoided based on the spherical dome structure at the distal end of the hub, the outflow direction of the blood can be effectively regulated, the blood flows out along the axial direction, the mixing loss of the flow is reduced, the blood pumping efficiency is further improved, and the blood pumping quantity is increased.

Drawings

FIG. 1 is a front view of an impeller according to an embodiment of the present application;

FIG. 2 is a side view of an impeller according to an embodiment of the present application;

FIG. 3 is a bottom view of an impeller according to an embodiment of the present application;

FIG. 4 is a cross-sectional flow field comparison plot for four cases of blade deflection angles θ of 90, 110, 140, and 180;

FIG. 5 is a three-dimensional flow field alignment graph for four cases of blade deflection angles θ of 90, 110, 140, and 180;

FIG. 6 is a graph of radial cross-sectional vorticity comparison for four cases of blade deflection angle θ of 90, 110, 140, and 180;

FIG. 7 is a radial cross-sectional pressure ratio versus graph for four cases of blade deflection angle θ of 90, 110, 140, and 180;

FIG. 8 is a table showing blade deflection angle θ versus head, hemolysis index, and impeller wall shear stress for four conditions of 90, 110, 140, and 180;

fig. 9 is a schematic view of the right ventricular assist device.

Reference numerals illustrate:

10. a hub; 11. a hub distal end; 12. a hub main body; 20. a blade; 21. an action surface; 22. an inlet edge; 23. an outer edge profile; 24. a hub molded line; 25. an outlet edge.

Detailed Description

For ease of understanding, we first define the orientations referred to hereinafter: "proximal", "proximal" refers to the side proximal to the operator/physician, and "distal" refers to the side distal to the operator/physician, i.e., the side proximal to the heart.

The hydraulic performance and the hemolytic performance of the catheter pump are closely related to the structure of the impeller, and the structure of the impeller of the catheter pump needs to be compatible with the hydraulic performance and the hemolytic performance. The consideration of the hydraulic performance is mainly output flow and pressure difference between the inlet end and the outlet end of the conduit pump, and the consideration of the hemolysis performance is mainly shear stress suffered by blood in the pumping process and flow smoothness of the blood. Through optimizing and improving impeller structure, reach the improvement hydraulic property and simultaneously, reduce the blood damage that hemolysis caused.

The present application will be further described in detail below with reference to specific embodiments and with reference to the accompanying drawings, in order to make the objects, technical solutions and advantages of the present application more apparent.

Referring to fig. 1 and 2, an impeller comprises a hub 10 and at least one blade 20 fixed to the periphery of the hub 10, the blade 20 being adapted to rotate under the drive of the hub 10 to convey blood from the proximal end of the impeller to the distal end of the impeller; for the right heart assist device, blood is pumped from the inferior vena cava, around the right atrium and right ventricle, and into the pulmonary artery, so the impeller pumps blood in a direction from the proximal end of the impeller to the distal end of the impeller, and as such, the impeller is configured accordingly.

The hub 10 comprises a hub distal end 11 and a hub main body 12 which are sequentially connected from the distal end to the proximal end;

the hub distal end 11 is a spherical dome or an end of an approximately spherical dome obtained by rounding the outer edge of a cylinder;

the hub main body 12 is of a conical structure with the radius gradually decreasing from the distal end to the proximal end, and the generatrix of the hub main body 12 is parabolic or linear;

that is, the proximal end of the impeller is a blood inlet, the distal end is a blood outlet, the hub main body 12 gradually decreases from the distal end to the proximal end to form a cone shape, the diameter of the proximal end of the hub main body 12 is the smallest, the diameter of the distal end of the hub main body 12 is the largest, the distal end of the hub main body 12 is the hub distal end 11, and the diameter of the distal end of the hub main body 12 is equal to or similar to the diameter of the hub distal end 11. In the process of conveying blood from the proximal end to the distal end of the impeller, the diameter of the hub 10 gradually becomes larger, so that the flow speed of the blood can be increased, but based on the fact that the hub distal end 11 is of a spherical dome structure, the flow loss of the blood can be reduced, the damage of the blood can be reduced, the formation of a flow dead zone can be avoided, the outflow direction of the blood can be effectively regulated, the blood can flow out along the axial direction, the mixing loss of the flow can be reduced, the blood pumping efficiency can be further improved, and the blood pumping quantity can be increased.

Specifically, the blade 20 includes an active surface 21, where the active surface 21 is a three-dimensional curved surface, and a contour line of the active surface 21 includes an inlet edge 22, an outer edge profile 23, a hub profile 24, and an outlet edge 25, and the outer edge profile 23 and the hub profile 24 are both exponentially graded arcs or arcs of a bezier curve. When the blade 20 rotates with the hub 10, the acting surface 21 of the blade 20 pumps blood, so that the structure of the acting surface 21 plays a key role in the overall performance of the impeller and the catheter pump, and after the contour line of the acting surface 21 is determined, the overall curved surface structure of the acting surface 21 can be determined. The outer edge profile 23 is a smooth space curve, which indicates that the action surface 21 smoothly transitions from a side near the inlet end to a side near the outlet end, and the curved surface structure along the action surface 21 smoothly flows during the blood flowing from the inlet to the outlet of the impeller, which helps to reduce the flow loss. At the same time, the smooth and even distribution of the velocity of the blood during the flow along the action surface 21 helps to reduce dead flow areas and blood damage.

Further, the end point of the outer edge profile 23 near the proximal end is a profile start point, the end point near the distal end is a profile end point, the outer edge profile 23 is a smooth space curve, the curvature of the outer edge profile 23 along the axial direction of the hub gradually decreases from the profile start point to the profile end point, and meanwhile, the curvature change rate of the outer edge profile 23 along the axial direction of the hub 10 also gradually decreases.

Further, the included angle between the tangent line of the start point of the profile and the tangential velocity is the inlet included angle α of the outer edge profile 23; the combined speed of the axial speed and the tangential speed of the profile starting point is a relative speed, the included angle between the relative speed and the tangential speed of the profile starting point is an inlet installation angle beta of the outer edge profile 23, and the inlet included angle alpha is larger than the inlet installation angle beta. When the inlet included angle alpha is larger than the inlet installation angle beta, an angle difference is generated between the inlet included angle alpha and the inlet installation angle beta, the angle difference is also called an inflow attack angle or an inflow attack angle, and under the condition that blood flows at a low speed, the inflow attack angle can inhibit the flow separation of the blood when flowing through the acting surface 21, reduce the inflow flow loss generated when the blood enters the impeller, increase the hydraulic performance, and simultaneously help to reduce the blood damage.

As a preferable scheme of the application, the included angle alpha of the inlet is 15-25 degrees.

The formula of the outer edge molded line spiral curve is as follows:

x= 0.0548z³ - 0.7026z² + 2.9604z - 0.0239；

y= 2.4798ln(z) - 0.7291；

the included angle between the axial plane where the molded line initial point is located and the axial plane where the molded line terminal point is located is a blade deflection angle theta, and the angle of the blade deflection angle theta is 90-180 degrees. As shown in fig. 3, the blade deflection angle θ can be more intuitively understood as, in the top projection view of the impeller, a line connecting the start point of the molded line and the axis of the hub 10, and a line connecting the end point of the molded line and the axis of the hub 10, where an included angle formed by the two lines is the blade deflection angle θ. The magnitude of the blade deflection angle θ reflects the length of each blade 20 extending circumferentially on the hub 10, and the blade deflection angle θ is too small to meet the requirement for flow under high pressure conditions and too large to be small under low pressure conditions.

In a typical but non-limiting embodiment of the application, the blade deflection angle θ is at four angles of 90 °, 110 °, 140 ° and 180 °.

FIG. 4 is a comparison graph of the cross-sectional flow fields of the blade deflection angle θ at four conditions of 90 °, 110 °, 140 ° and 180 °, and the results show that the backflow of blood and secondary flow are less when the blade helical deflection angle θ is 140 °, so that the flow loss is reduced and the hydraulic performance is improved.

Fig. 5 is a three-dimensional flow field comparison diagram of the four cases of the deflection angle theta of the blade at 90 degrees, 110 degrees, 140 degrees and 180 degrees, and the result shows that when the deflection angle theta of the blade spiral line is 140 degrees, the flow velocity change is more stable and uniform in the process of flowing through the impeller, so that the flow loss is reduced, and meanwhile, the blood damage is reduced.

Fig. 6 is a graph of radial section vorticity comparison for four cases of blade deflection angle θ of 90 °, 110 °, 140 ° and 180 °, and the results show that when the blade helix deflection angle θ is 180 °, the vorticity generated by blood flowing through the impeller is minimal, and the distribution is relatively uniform, thereby avoiding vortex concentration, making the blood flowing through the impeller more stable, helping to reduce flow loss, and reducing blood damage.

Fig. 7 is a graph of radial cross-sectional pressure versus the four cases of 90 °, 110 °, 140 ° and 180 ° for a vane deflection angle θ, and the results show that when the vane helix deflection angle θ is 140 °, there is a more significant pressure difference between the inlet and outlet of the impeller, which can provide a greater head and reduce cavitation.

Fig. 8 is a table showing the blade deflection angle θ in terms of lift, hemolysis index, and impeller wall shear stress at four conditions of 90 °, 110 °, 140 °, and 180 °. The results show that the lift of the impeller is maximum in a structure with a blade deflection angle theta of 140 degrees; in a structure with a blade deflection angle theta of 180 degrees, the hemolysis index is the lowest; in a structure in which the blade deflection angle θ is 180 °, the impeller wall shear stress is minimal.

When the impeller is projected along the axial direction of the hub 10, the axial included angle between the inlet edge 22 and the starting point of the molded line is a tangential forward glancing angle gamma, and the angle of the tangential forward glancing angle gamma is 5-12 degrees. When entering the impeller inlet, the tangential forward sweep angle gamma can enable the tangential velocity to generate a component velocity towards the central shaft of the hub 1, and the component velocity can enable the blood to gather towards the hub 10 in the process of flowing from the impeller inlet to the impeller outlet in a rotating way, so that the shearing stress of the blood is reduced, the generation of secondary flow is avoided, and the flowing of the blood is more stable. By secondary flow is meant that the blood is subjected to lateral forces (i.e., radial forces of the hub 10) during flow, resulting in a deflection in the radial direction of the hub 10. The secondary flow is a medium flow superimposed on the main flow (flow of blood in the axial direction of the hub 10). In addition to the lateral forces, the separation flow and the vortex, etc. also cause a corresponding secondary flow.

In the impeller of the present embodiment, since the blades 20 have a tangential forward-swept angle γ, the blood generates a partial velocity toward the central axis of the hub 10 during flowing through the impeller, and the partial velocity can generate a certain gathering effect on the blood, so that the blood keeps flowing around the hub 10, and a stable flow field is formed. The impeller effectively avoids secondary flow generated by blood under the influence of factors such as transverse force or separation flow, is beneficial to reducing the flow loss of the blood, improves the hydraulic performance of the impeller, reduces the damage to the blood, and has better hemolysis performance.

When the impeller is projected along the radial direction of the hub 10, the included angle between the inlet edge 22 and the horizontal line is an axial forward sweep angle delta, and the angle of the axial forward sweep angle delta is 12-25 degrees. When blood enters the impeller inlet, the axial forward sweep angle delta can enable the axial speed to generate a component speed towards the central shaft of the hub 1, and the component speed can enable the blood to gather towards the hub 10 in the process of flowing from the impeller inlet to the impeller outlet in a rotating way, so that the shearing stress of the blood is reduced, the generation of secondary flow is avoided, and the flowing of the blood is more stable.

In the impeller of the present embodiment, since the blades 20 have the structure of the axial forward sweep angle δ, the blood generates a component velocity toward the central axis of the hub 10 during flowing through the impeller, and the component velocity cooperates with the component velocity generated by the tangential forward sweep angle γ structure, so as to generate a certain gathering effect on the blood, so that the blood keeps flowing around the hub 10, and a stable flow field is formed. The impeller effectively avoids secondary flow generated by blood under the influence of factors such as transverse force or separation flow, is beneficial to reducing the flow loss of the blood, improves the hydraulic performance of the impeller, reduces the damage to the blood, and has better hemolysis performance.

The radius R of the hub distal end 11 is 1.6 mm-1.8 mm; the diameter D1 of the proximal end of the hub main body 12 is 0.7-1.0 mm, and the diameter D2 of the distal end is 3.0-4.0 mm; the axial length L of the hub 10 is 7.1 mm-8.5 mm. The hub 10 has an oversized radius, and can cause the impeller pump to have smaller blood flow under the condition of low pressure difference; too small a radius of hub 10 can cause impeller pump blood flow to be small and flow to be unstable under high pressure differential conditions. Too short an axial length L of the hub 10 tends to cause insufficient blood flow in the impeller pump, and too long an axial length tends to cause a high hemolysis value in the impeller pump. In the case of meeting the flow and rotational speed requirements, the axial length of the hub 10 is minimized in view of the low mechanical hemolysis performance.

In order to reduce the hemolysis, the round angles of the inlet part connected with the inlet edge 22 and the outlet part connected with the outlet edge 25 are respectively 0.08-0.3 mm, and the round angles of the outlet part are respectively 0.08-0.3 mm; the connection part of the hub 10 and the working surface 21 of the blade is rounded, and the radius of the rounded corner is 0.08-0.3 mm; the working surface 21 of the blade is rounded at the positions of the inlet edge 22, the outer edge molded line 23 and the outlet edge 25, and the radius of the rounded angle is 0.1 mm-0.3 mm. The diameter of the round angle is smaller, so that the hemolysis value of the impeller is larger, and the blood flow of the pump is smaller.

The inlet edge 22 is an arcuate line and the outlet edge 25 is a straight line.

The number of the blades 20 is 2 or 3, and the blades 20 are uniformly distributed along the circumferential direction of the hub main body 12. Too few blades 20 can cause unstable flow fields in the impeller, too many blades 20 can cause smaller impeller flow and larger hemolysis value.

The radius D3 of the blade is 5.5-6.0 mm, the axial length of the blade is 5.8-6.4 mm, and the thickness of the blade is 0.4-0.5 mm. Too short axial length of the blade 20 is easy to cause that the impeller flow cannot meet the design requirement, too long axial length of the blade 2 is easy to cause that the impeller hemolysis value is too large. Under the condition of meeting the flow and rotating speed requirements, considering lower mechanical hemolytic performance and installation requirements, taking the radius of the blade 20 as the minimum value; in the case of meeting the flow requirement, considering the lower mechanical hemolytic performance, the rotation speed takes the lowest rotation speed and the radius of the blade 20 takes the maximum value. The axial length takes the minimum value under the condition of determining the rotating speed and the radius by considering lower mechanical hemolytic performance when the flow requirement is met. Too small a thickness of the blade 20 easily causes the decrease of mechanical strength of the impeller, the increase of processing difficulty, and too large a thickness of the blade 20 easily causes the decrease of blood flow of the pump.

The outer diameter of hub 10 increases gradually from the proximal end to the distal end, while the outer diameter of blades 20 remains unchanged.

A right ventricular assist device includes a catheter and an impeller disposed in the catheter. The right ventricular assist device operates on the principle that blood from the inferior vena cava is drawn into the catheter from the inlet of the catheter by rotating the impeller, the catheter bypasses the right atrium and right ventricle, and pumps the blood into the pulmonary artery to achieve heart assist.

The ventricular assist device of the foregoing embodiments pumps blood by means of the corresponding impeller of any of the foregoing embodiments, and has the beneficial effects of the corresponding impeller embodiments, which are not described in detail herein.

It should be noted that the foregoing describes some embodiments of the present application. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments described above and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims (13)

1. Impeller comprising a hub (10) and at least one blade (20) fixed to the periphery of said hub (10), characterized in that: the blades (20) are adapted to rotate under the drive of the hub (10) to transport blood from the proximal impeller end to the distal impeller end;

the hub (10) comprises a hub distal end (11) and a hub main body (12) which are sequentially connected from the distal end to the proximal end;

the hub distal end (11) is a spherical dome or an end of an approximately spherical dome obtained by rounding the outer edge of a cylinder;

the hub main body (12) is of a conical structure with the radius gradually decreasing from the far end to the near end, and a generatrix of the hub main body (12) is parabolic or linear;

the blade (20) comprises an action surface (21), the action surface (21) is a three-dimensional space curved surface, the contour line of the action surface (21) comprises an inlet edge (22), an outer edge molded line (23), a hub molded line (24) and an outlet edge (25), and the outer edge molded line (23) and the hub molded line (24) are exponentially graded arcs or Bezier curve arcs.

2. The impeller of claim 1, wherein: the end point of the outer edge molded line (23) close to the near end is a molded line initial point, the end point of the outer edge molded line (23) close to the far end is a molded line end point, the outer edge molded line (23) is a smooth space curve, the curvature of the outer edge molded line (23) along the axial direction of the hub is gradually reduced from the molded line initial point to the molded line end point, and meanwhile, the curvature change rate of the outer edge molded line (23) along the axial direction of the hub (10) is also gradually reduced.

3. The impeller of claim 2, wherein: the included angle between the tangent line of the initial point of the molded line and the tangential speed is an inlet included angle alpha of the outer edge molded line (23); the combined speed of the axial speed and the tangential speed of the profile starting point is a relative speed, the included angle between the relative speed and the tangential speed of the profile starting point is an inlet installation angle beta of the outer edge profile (23), and the inlet included angle alpha is larger than the inlet installation angle beta.

4. An impeller according to claim 3, wherein: the included angle alpha of the inlet is 15-25 degrees.

5. The impeller of claim 1, wherein: the formula of the outer edge molded line spiral curve is as follows:

x= 0.0548z³ - 0.7026z² + 2.9604z - 0.0239；

y= 2.4798ln(z) - 0.7291；

wherein the line start point of the outer edge line (23) is defined as z=0.

6. The impeller of claim 2, wherein: the included angle between the axial plane where the molded line initial point is located and the axial plane where the molded line terminal point is located is a blade deflection angle theta, and the angle of the blade deflection angle theta is 90-180 degrees.

7. The impeller of claim 2, wherein: when the impeller is projected along the axial direction of the hub (10), the axial included angle between the inlet edge (22) and the starting point of the molded line is a tangential forward glancing angle gamma, the tangential forward glancing angle gamma is 5-12 degrees, when the impeller is projected along the radial direction of the hub (10), the included angle between the inlet edge (22) and the horizontal line is an axial forward glancing angle delta, and the axial forward glancing angle delta is 12-25 degrees.

8. The impeller of claim 1, wherein: the radius R of the hub far end (11) is 1.6 mm-1.8 mm; the diameter D1 of the proximal end of the hub main body (12) is 0.7-1.0 mm, and the diameter D2 of the distal end is 3.0-4.0 mm; the axial length L of the hub (10) is 7.1 mm-8.5 mm.

9. The impeller of claim 2, wherein: the round corners of the inlet part connected with the inlet edge (22) and the outlet part connected with the outlet edge (25) are rounded, the round corner radius of the inlet part is 0.08-0.3 mm, and the round corner radius of the outlet part is 0.08-0.3 mm; the connection part of the hub (10) and the working surface (21) of the blade is rounded, and the radius of the rounded corner is 0.08-0.3 mm; the blade working surface (21), the inlet edge (22), the outer edge molded line (23) and the outlet edge (25) are rounded, and the radius of the rounded corners is 0.1-0.3 mm.

10. The impeller of claim 9, wherein: the inlet edge (22) is an arc line, and the outlet edge (25) is a straight line.

11. The impeller of claim 1, wherein: the number of the blades (20) is 2 or 3, and the blades (20) are uniformly distributed along the circumferential direction of the hub main body (12).

12. The impeller of claim 11, wherein: the radius D3 of the blade (20) is 5.5 mm-6.0 mm, the axial length of the blade (20) is 5.8 mm-6.4 mm, and the thickness of the blade (20) is 0.4 mm-0.5 mm.

13. A right ventricular assist device, comprising: a conduit and an impeller according to any one of claims 1 to 12 disposed in the conduit.