pump rotor

Abstract

This invention discloses a pump rotor, comprising: a cylindrical shaft and blades; the blades have a flexible portion and a rigid portion, which are integrally and smoothly connected; the flexible portion of the blades is fixed to the periphery of the cylindrical shaft, thus distributing the blades around the periphery of the cylindrical shaft; the elastic modulus of the material of the flexible portion is 8 MPa to 80 MPa; the material of the rigid portion is 35 MPa to 195 MPa, and the elastic modulus of the material of the flexible portion is less than that of the material of the rigid portion; when the cylindrical shaft rotates, the pumped object can exert a reaction thrust on the blades, causing the flexible portion of the blades to deform and bend along the direction of the reaction thrust, and the pumped object is pumped to the target direction under the influence of the bent blades. Because the flexible portion of the blades is fixed to the periphery of the cylindrical shaft, it will naturally deform along the direction of rotation due to the reaction force of the pumped object. During the pump rotation, the blades of the pump rotor will bend and deform when pumping blood, which has less impact on the physiological indicators of the blood.

Description

Technical Field

[0001] This application relates to pump technology in medicine, and more particularly to a blood pump rotor. Background Technology

[0002] Currently, in some major surgeries, especially those involving the heart, it is necessary to ensure the normal circulation of blood in the patient while performing the surgical procedure, so as to maintain the patient's normal vital signs.

[0003] Currently, blood pump devices are commonly used to ensure normal blood flow to patients during surgery. One end of the blood pump device is inserted into the ventricle of the patient's heart, and the other end is inserted into the artery of the heart. By operating the blood pump, blood is drawn from the ventricle of the heart into the artery of the patient, thus ensuring normal blood circulation and allowing the patient's blood to flow normally during heart-related surgeries.

[0004] However, current blood pump devices, which pump blood, place particularly high demands on the pump, especially the pump rotor. Not only must the pump rotor operate efficiently, but the physiological parameters of the pumped blood must also be preserved. These physiological parameters mainly include white blood cell count, red blood cell count, hemoglobin count, serum haptoglobin count, and platelet count. During high-speed rotation, the blood pump, while pumping blood, can also affect these physiological parameters. For example, the pump rotor blades can damage the cell walls of red blood cells during high-speed rotation. The destruction of a large number of red blood cell walls can lead to hemolysis, causing hemolytic complications in the patient and potentially endangering their life.

[0005] However, current blood pump devices generally only focus on pumping efficiency, neglecting the physiological parameters of the pumped blood. This is primarily because the blood pumps in these devices are small because they are implanted inside the patient's body, leading to a focus on pump efficiency rather than the physiological parameters of the pumped blood. However, since blood pump devices directly act on the patient's blood, they inevitably cause some damage. For patients with poor hemolysis tolerance, especially those with complications, even minor changes in blood physiological parameters can be fatal. Unfortunately, current blood pump devices primarily focus on pumping efficiency and device size, with almost no attention paid to the physiological parameters of the blood. Summary of the Invention

[0006] In view of this, one embodiment of the present application provides a pump rotor that can pump sufficient blood to a medical subject with almost no disruption to the physiological parameters of the blood.

[0007] This application provides a pump rotor, including: a cylindrical shaft and blades; the blades have a flexible portion and a rigid portion, the flexible portion and the rigid portion being integrally and smoothly connected; the flexible portion of the blades is fixed to the periphery of the cylindrical shaft so that the blades are distributed around the periphery of the cylindrical shaft;

[0008] The elastic modulus of the material of the flexible part is 8 MPa to 80 MPa; the elastic modulus of the material of the rigid part is 35 MPa to 195 MPa, and the elastic modulus of the material of the flexible part is less than that of the material of the rigid part.

[0009] When the cylindrical shaft rotates, the pumped object can exert a reaction thrust on the blade. The flexible part of the blade deforms, causing the blade as a whole to bend in the direction of the reaction thrust. The pumped object is pumped to the target direction under the drive of the bent blade.

[0010] In one implementation, the ratio of the length of the flexible part and the rigid part of the blade in the radial direction of the cylindrical shaft is 1:8 to 5:1.

[0011] In one implementation, the ratio of the length of the flexible part and the rigid part of the blade in the radial direction of the cylindrical shaft is 10:37, 9:26, 11:24, 4:7 or 11:14.

[0012] In one implementation, the flexible part of the blade is composed of at least two sections of material with different elastic moduli;

[0013] From the input side of the pumped object to the target direction, the elastic modulus of the different material segments of the flexible part of the blade decreases from large to small.

[0014] In one implementation, the flexible portion of the blade, from the input side of the pumped object to the target direction, sequentially includes a first material segment and a second material segment; the elastic modulus of the material of the first material segment is greater than the elastic modulus of the material of the second material segment;

[0015] The elastic modulus of the material in the first material segment is 25 MPa to 80 MPa, and the elastic modulus of the material in the second material segment is 8 MPa to 50 MPa.

[0016] In one implementation, the flexible part of the blade is composed of a first material segment, a second material segment, and a third material segment in sequence from the input side of the pumped object to the target direction; the elastic modulus of the material of the first material segment is greater than the elastic modulus of the material of the second material segment, and the elastic modulus of the material of the second material segment is greater than the elastic modulus of the material of the third material segment.

[0017] The elastic modulus of the material in the first material segment is 40 MPa to 80 MPa, the elastic modulus of the material in the second material segment is 20 MPa to 60 MPa, and the elastic modulus of the material in the third material segment is 8 MPa to 40 MPa.

[0018] In one implementation, the flexible part of the blade, from the input side of the pumped object to the target direction, is composed of a first material segment, a second material segment, a third material segment, and a fourth material segment in sequence; the elastic modulus of the material of the first material segment is greater than the elastic modulus of the material of the second material segment, the elastic modulus of the material of the second material segment is greater than the elastic modulus of the material of the third material segment, and the elastic modulus of the material of the third material segment is greater than the elastic modulus of the material of the fourth material segment;

[0019] The elastic modulus of the material in the first material segment is 50 MPa to 80 MPa, the elastic modulus of the material in the second material segment is 30 MPa to 60 MPa, the elastic modulus of the material in the third material segment is 10 MPa to 40 MPa, and the elastic modulus of the material in the fourth material segment is 8 MPa to 30 MPa.

[0020] In one implementation, the blades are 1 to 5.

[0021] In one implementation, when there is one blade, the blade is wound around the periphery of the other end of the cylindrical shaft in a manner that moves from the periphery of one end of the cylindrical shaft to the other end of the cylindrical shaft; the number of times the blade wound around the periphery of the cylindrical shaft is 0.2 to 5 times.

[0022] In one implementation, when there are 2 to 5 blades, the blades move from the equidistant points at one end of the cylindrical shaft to the other end of the cylindrical shaft, and each blade is arranged in parallel around the corresponding equidistant points at the equidistant points at the other end of the cylindrical shaft; the number of times the blades are arranged around the circumference of the cylindrical shaft is 0.1 to 5 times.

[0023] In this embodiment of the pump rotor structure, the blade portion of the pump rotor is made of a flexible material. The blade has a flexible part and a rigid part, which are seamlessly connected. The flexible part of the blade is fixed to the periphery of the cylindrical shaft, causing the blades to be distributed around the periphery of the shaft. The elastic modulus of the flexible part is less than that of the rigid part. This embodiment of the application, by selecting appropriate materials for the pump rotor blades, causes the blades to deform and bend during rotor rotation. These bent blades form the pump rotor blades, pumping blood to the desired direction. In this embodiment, because the flexible part of the blade is fixed to the periphery of the cylindrical shaft, it naturally deforms along the rotation direction due to the reaction force of the pumped object, thus forming the pump blades. In addition, since the blades of the pump rotor in this embodiment are made of a flexible material, the blades of the pump rotor will bend and deform when pumping blood during the pump rotation process. This causes less damage to the physiological indicators of the blood and hardly damages red blood cells. Therefore, the physiological indicators of the pumped blood can be guaranteed, and it can be applied to any medical patient, especially those with complications. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the pump rotor assembly structure according to an embodiment of this application;

[0025] Figure 2 This is a schematic diagram of the composition structure of the pump rotor blades according to an embodiment of this application;

[0026] Figure 3 This is a schematic diagram of the composition structure of the pump rotor blades according to an embodiment of this application;

[0027] Figure 4 This is a schematic diagram of the composition structure of the pump rotor blades according to an embodiment of this application;

[0028] Figure 5 This is a schematic diagram of the composition structure of the pump rotor blades according to an embodiment of this application;

[0029] Figure 6 This is a schematic diagram of the composition structure of the pump rotor blades according to an embodiment of this application;

[0030] Figure 7 This is a schematic diagram of the cylindrical rotor blade design of the pump rotor according to an embodiment of this application.

[0031] Figure 8 This is a diagram showing the blade angle distribution along the friction length of the pump rotor according to an embodiment of this application;

[0032] Figure 9 This is a design curve diagram of the cylindrical shaft of the pump rotor according to an embodiment of this application. Detailed Implementation

[0033] The essence of the technical solutions of the embodiments of this application will be explained in detail below with reference to the accompanying drawings.

[0034] Figure 1 This is a schematic diagram of the pump rotor assembly structure according to an embodiment of this application, as shown below. Figure 1 As shown, the pump rotor of this embodiment includes a cylindrical shaft 10 and blades 20.

[0035] Figure 2 This is a schematic diagram of the composition structure of the pump rotor blades according to an embodiment of this application. Figure 3 This is a schematic diagram of the composition structure of the pump rotor blades according to an embodiment of this application; as shown Figure 2 , Figure 3 As shown, the blade 20 has a flexible part 201 and a rigid part 202, and the flexible part 201 and the rigid part 202 are integrally and smoothly connected; the flexible part 201 of the blade 20 is fixed to the periphery of the cylindrical rotating shaft 10 so that the blade 20 is distributed on the periphery of the cylindrical rotating shaft 10.

[0036] In this embodiment, the connection between the blade 20 and the cylindrical shaft 10 is made flexible. When the pump rotor rotates, causing the blade 20 to rotate, and the blade 20 comes into contact with the pumped object, such as blood, the flexible part 201 deforms under the force applied by the pumped object, thus forming a pump blade structure for pumping blood, thereby pumping the blood to the target direction. Furthermore, because the blade 20 is made of a flexible material, the pump rotor provides a certain degree of protection for the pumped object during rotation; that is, the blade 20 of the pump rotor will not damage the physiological indicators of the pumped object, such as blood, ensuring that the various physiological indicators of the pumped blood are not damaged.

[0037] Preventing hemolysis of the pumped blood is crucial during medical procedures, as it can endanger the patient's life. Hemolysis occurs when red blood cells rupture, causing hemoglobin to leak out and dissolve in the blood. Hemolysis alters the morphology and biochemical properties of red blood cells, shortens their lifespan, and can even lead to complete rupture, thus reducing their ability to transport oxygen to tissues and organs. Furthermore, hemolysis increases the concentration of free hemoglobin in the plasma; excess free hemoglobin must be excreted through the kidneys, potentially leading to kidney damage and multiple organ failure.

[0038] Hemolysis refers to the rupture of red blood cells in the blood, causing the hemoglobin within the red blood cells to leak out and dissolve in the blood. Hemolysis leads to changes in the morphology and biochemical properties of red blood cells, shortens their lifespan, or even causes complete rupture, thereby reducing the ability of red blood cells to transport oxygen to tissues and organs. Furthermore, the concentration of free hemoglobin in plasma increases after hemolysis, and the excess free hemoglobin needs to be excreted through the kidneys, potentially leading to kidney damage and multiple organ failure. In this embodiment, the blood volume estimation is based on the quantitative relationship between flow parameters in a simple flow field and the amount of hemolysis damage obtained from experimental measurements. After reasonable assumptions and modifications, a hemolysis model suitable for complex flow fields is established. Currently, most studies on quantitative hemolysis estimation are based on power-law equations. Power-law equations describe the relationship between the hemolysis index (HI) and shear force (τ), exposure time (t) in a simple flow field. exp The relationship between )

[0039]

[0040] The hemolysis index HI is defined as the ratio of the increase in plasma free hemoglobin concentration (ΔHb) to the whole blood hemoglobin concentration (Hb). C, α, and β are constants obtained through regression analysis of experimental data.

[0041] In summary, the magnitude of hemolysis is related to shear force and exposure time. When the blade 20 adopts the structural design proposed in the embodiments of this application, and the root part of the blade 20 is made of flexible material, the rotor blade 20 will bend in the opposite direction of rotation, thereby improving the velocity distribution at the blade tip, reducing the magnitude of shear force at the blade tip, and reducing the possibility of hemolysis at the blade tip.

[0042] Furthermore, the pump rotor structure design in this application embodiment can also prevent thrombus formation. The formation, movement, and relationship of thrombi with hemodynamics have always been a research hotspot. Thrombus formation and development are influenced by various factors, such as hemodynamic factors like blood wall shear force and wall pressure, and humoral factors like intravascular active growth mediators and inflammatory mediators. Blood flow velocity, viscosity, vessel shape, and vascular stenosis all significantly affect thrombus formation, distribution, and movement. For example, mural thrombi on blood vessels can slowly calcify and even cause vascular obstruction; smaller thrombi can also travel with the bloodstream, obstructing small blood vessels at narrow points and causing lesions. Therefore, a deep understanding of the relationship between hemodynamics and thrombi, and the analysis of changes in wall shear force and pressure on the vessel wall, are of certain significance for the prevention and treatment of thrombosis.

[0043] Interactions between blood cells, primarily between platelets and clotting proteins, lead to thrombus formation at the site of arterial lesions. This process typically causes changes in the surface properties of the blood vessel wall, such as in atherosclerotic lesions. Blood flow turbulence, procoagulant factors, and increases in platelet count and hematocrit may accelerate thrombus formation. Considering the interaction between blood and thrombi, a mathematical model of blood (red blood cells and plasma) is introduced, with the following incompressible flow equations:

[0044]

[0045]

[0046] Where v f T represents blood velocity. f Let ρ be the stress tensor of the fluid. f For the density of blood, b f For volume force, v T Where C2 is the velocity of the thrombus, C2 = 1e9 is the resistance coefficient, and φ is the volume fraction of deposited platelets.

[0047] In the above mathematical model of thrombosis (platelet), the chemical and biological reaction processes of platelet deposition are described by the convection-diffusion-reaction equation, as follows:

[0048]

[0049] Among them, D i This refers to the diffusion coefficient of material i in the blood, [C i [S] represents the concentration of material i. i Let i be the chemical reaction source term for material i.

[0050] In summary, the interaction between blood cells in a confined space is the main cause of thrombus formation. In the blade 20 structure of this embodiment, by providing a flexible portion at the root of the blade, when the pump rotor blade 20 pumps blood, the root of the blade 20 deforms, preventing blood deposition or adhesion in the narrow corner area where the blade meets the rotating shaft. Furthermore, by using a flexible material at the root of the blade 20, the blade bends at the root during pump rotor rotation, changing the size of the corner area between the blade and the rotating shaft, reducing the likelihood of blood adhesion in the corner area, and decreasing the formation of thrombi at the corner where the blade root meets the rotating shaft.

[0051] In this embodiment of the application, the flexible material used to fabricate the flexible part 201 has certain elasticity requirements. The material has certain elasticity and flexibility. The elastic modulus of the material of the flexible part 201 is 8 MPa to 80 MPa. The elastic modulus of the material of the rigid part 202 is 35 MPa to 195 MPa. The elastic modulus of the material of the flexible part 201 is less than the elastic modulus of the material of the rigid part 202.

[0052] In this embodiment, while a lower elastic modulus is preferred for the material used in the flexible part 201, the pumping efficiency of the pump rotor must also be considered. Therefore, while ensuring that the pumping efficiency is as high as possible without damaging the physiological indicators of the pumped object, such as blood, it is also necessary to ensure that the pumping efficiency is as high as possible. During the experiment with flexible materials, the elastic modulus of the material used in the flexible part 201 is preferably between 45.7 MPa and 51.6 MPa. When the flexible material is within this range of elastic modulus, the damage to the physiological indicators of the pumped object, such as blood, is minimal, and the pumping efficiency of the pump rotor can be guaranteed. For example, when using a flexible material with an elastic modulus of 45.7 MPa to 51.6 MPa, the pumping efficiency of the pump rotor in this embodiment can reach 90.3% of the pumping efficiency using fully rigid pump blades. The decrease in pumping efficiency of the pump rotor is not significant, and for the pumped object, such as blood, almost no damage to red blood cells is observed in the sampling at the target direction end, essentially eliminating the occurrence of hemolysis. In addition, no damage was observed in the white blood cell count, hemoglobin count, serum haptoglobin count, platelet count, etc. in the target blood.

[0053] In addition, as an implementation, the elastic modulus of the material of the flexible part 201 in this embodiment is preferably between 47.93 MPa and 48.67 MPa.

[0054] In this embodiment, the material of the flexible part 201 is not subject to rigid requirements; it can be an alloy material that meets the aforementioned elastic modulus requirement, or a resin, synthetic resin, or mixed resin material that meets the aforementioned elastic modulus requirement. In this embodiment, the flexible material of the flexible part is preferably a resin material.

[0055] In this embodiment, there are no specific requirements for the material of the rigid part 202, as long as the elastic modulus of the material of the rigid part 202 is greater than that of the material of the flexible part 201. Under the condition that the rigid part 202 and the flexible part 201 are integrally processed, the difference between the elastic modulus of the material of the rigid part 202 and the elastic modulus of the material of the flexible part 201 is preferably between 40 MPa and 60 MPa. In this embodiment, when the material of the flexible part 201 is resin, the material of the rigid part 202 is preferably also a resin or similar material with higher hardness. When the material of the flexible part 201 is an alloy, the material of the rigid part 202 is preferably also an alloy or metal with higher hardness.

[0056] In this embodiment of the application, when the cylindrical shaft 10 rotates, the pumping object can apply a reaction thrust to the blade 20. The flexible part 201 of the blade 20 deforms, causing the blade 20 as a whole to bend in the direction of the reaction thrust. The pumping object is pumped to the target direction under the drive of the bent blade.

[0057] like Figure 2 , Figure 3 As shown in the embodiment of this application, the radial length ratio of the flexible portion 201 and the rigid portion 202 of the blade 20 on the cylindrical rotating shaft 10 is 1:8 to 5:1. That is... Figure 2 The ratio between the height of the flexible portion 201 at the lower end and the height of the rigid portion 202 at the upper end is between 1:8 and 5:1. As a preferred embodiment, Figure 2 The ratio between the height of the flexible portion 201 at the lower end and the rigid portion 202 at the upper end is between 1:5 and 2:1. Alternatively, the ratio of the radial lengths of the flexible and rigid portions of the blade on the cylindrical shaft is 10:37, 9:26, 11:24, 4:7, or 11:14.

[0058] Figure 4 This is a schematic diagram of the composition structure of the pump rotor blades according to an embodiment of this application, as shown below. Figure 4 As shown in the embodiment of this application, the flexible part 201 of the blade 20 is composed of at least two sections of material with different elastic moduli; from the input side of the pumping object to the target direction, the elastic moduli of the different material sections of the flexible part 201 of the blade 20 decrease from large to small.

[0059] like Figure 4 As shown in the embodiment of this application, the flexible part 201 of the blade 20 includes a first material segment 2010 and a second material segment 2011 in sequence from the input side of the pumping object to the target direction; the elastic modulus of the material of the first material segment 2010 is greater than the elastic modulus of the material of the second material segment 2011.

[0060] The elastic modulus of the first material segment 2010 is between 25 MPa and 80 MPa, and the elastic modulus of the second material segment 2011 is between 8 MPa and 50 MPa. As one implementation, in this embodiment, the elastic modulus of the first material segment 2010 is preferably between 43 MPa and 58 MPa, and the elastic modulus of the second material segment 2011 is preferably between 35 MPa and 54 MPa.

[0061] Figure 5 This is a schematic diagram of the composition structure of the pump rotor blades according to an embodiment of this application, as shown below. Figure 5 As shown, the flexible portion 201 of the blade 20 in this embodiment of the application is composed of a first material segment 2010, a second material segment 2011 and a third material segment 2012 in sequence from the input side of the pumping object to the target direction; the elastic modulus of the material of the first material segment 2010 is greater than the elastic modulus of the material of the second material segment 2011, and the elastic modulus of the material of the second material segment 2011 is greater than the elastic modulus of the material of the third material segment 2012.

[0062] The elastic modulus of the material in the first material segment 2010 is 40 MPa to 80 MPa, the elastic modulus of the material in the second material segment 2011 is 20 MPa to 60 MPa, and the elastic modulus of the material in the third material segment 2012 is 8 MPa to 40 MPa.

[0063] Figure 6 This is a schematic diagram of the composition structure of the pump rotor blades according to an embodiment of this application, as shown below. Figure 6 As shown, the flexible portion 20 of the blade 20, from the input side of the pumped object to the target direction, is composed of a first material segment 2010, a second material segment 2011, a third material segment 2012, and a fourth material segment 2013 in sequence; the elastic modulus of the material of the first material segment 2010 is greater than that of the material of the second material segment 2011, the elastic modulus of the material of the second material segment 2011 is greater than that of the material of the third material segment 2012, and the elastic modulus of the material of the third material segment 2012 is greater than that of the material of the fourth material segment 2013;

[0064] The elastic modulus of the material in the first material segment 2010 is 50 MPa to 80 MPa, the elastic modulus of the material in the second material segment 2011 is 30 MPa to 60 MPa, the elastic modulus of the material in the third material segment 2012 is 10 MPa to 40 MPa, and the elastic modulus of the material in the fourth material segment 2013 is 8 MPa to 30 MPa.

[0065] In this embodiment, the flexible part 20 of the blade 20 is made of a flexible material with a different elastic modulus so that the blade 20 can form a corresponding deformation around the periphery of the cylindrical shaft 10, thereby forming a bending deformation of the pump blade and improving the pumping efficiency of the pump rotor in this embodiment.

[0066] In one embodiment of this application, the blades are 1 to 5.

[0067] When there is one blade 20, the blade 20 is wound around the periphery of the other end of the cylindrical shaft 10, moving from the periphery of one end towards the other end of the cylindrical shaft 10; the number of times the blade 20 wraps around the periphery of the cylindrical shaft 10 is 0.2 to 5 times. When there is one blade 20, it is preferable that the blade 20 wraps around the periphery of the cylindrical shaft 10 more than once; the more times it wraps around the periphery of the cylindrical shaft 10, the higher the pumping efficiency.

[0068] It should be noted that, although the blade 20 adopts the design of the flexible part 201 in this embodiment, the blade design in the pump rotor structure of this embodiment still needs to adopt the design principle of ordinary pump rotor blades, that is, it is necessary to set the pump input angle and output angle, etc. By adopting a partially flexible part design for the blade 20, this embodiment can partially replace the input angle and output angle of the pump rotor blades. That is, compared with the angle of conventional pump rotor blades, it can be designed to be slightly smaller, so that based on the deformation of the flexible part 201 of the blade 20, the same effect as the design of conventional pump rotor blades can be achieved.

[0069] As one implementation method, in the embodiments of this application, such as Figure 1 As shown, when the pump rotor has 2 to 5 blades, the blades 20 move from the equidistant points at one end of the cylindrical shaft 10 toward the other end of the cylindrical shaft, and each blade 20 is arranged in parallel around the corresponding equidistant points at the other end of the cylindrical shaft 10; the number of times the blades 20 are arranged around the periphery of the cylindrical shaft is 0.1 to 5 times.

[0070] Figure 7 This is a schematic diagram of the cylindrical shaft design of the pump rotor blades according to an embodiment of this application, as shown below. Figure 7As shown, the impeller casing diameter D2 is determined to be less than 10 mm, and in this embodiment, it is taken as 6 mm. The hub ratio is approximately 0.15 to 0.75, and in this embodiment, it is taken as 0.367. The blade root diameter D1 is 2.2 mm. The blade length L is defined as the ratio of the blade length at the blade root to the casing diameter, which is approximately 1 to 2. Here, it is taken as 1.333, so the blade length is 8 mm. The ratio of the blade outlet height b to the casing diameter is approximately 0.25 to 1.5, and in this embodiment, it is taken as 0.4167, so the outlet length is 2.5 mm.

[0071] Figure 8 This is a diagram showing the blade angle distribution along the friction length of the pump rotor according to an embodiment of this application. Figure 8 As shown, the exit angle β of the blades is the same for each layer, and the angle between the blades and the circumferential direction is approximately 30° to 90° (60° in this embodiment). The inlet installation angle α of each layer... m With β, the blade angle φ is distributed along the blade path, and the blade angle along the axial direction changes from α. m As β gradually changes, the centerline of the blade in each layer is obtained. The wrap angle around the blade axis obtained in this way can be different for each layer, but it is not less than 90°. The absolute value of the difference between different wrap angles in all layers does not exceed 20°. The result of different wrap angles is that the blade profile is bendable.

[0072] The thickness distribution is superimposed along the centerline to form the blade curve of each layer, with the thickness of each layer not exceeding 1.5 mm (in this embodiment, the maximum thickness at the blade root is 0.8 mm, and the maximum thickness at the blade tip is 0.5 mm). The three-dimensional blade profile is obtained by superimposing n layers of blade curves, thus completing the blade design.

[0073] Figure 9 This is a design curve diagram of the cylindrical shaft of the pump rotor according to an embodiment of this application, as shown below. Figure 9As shown, a straight line L1 with a length of l1 ranging from 0 to 4 mm (0.95 mm in this embodiment) is formed at the leading edge of the blade, with a constant distance D1 / 2 from the center of rotation. When l1 is 0, the beginning and end points of the curve coincide at the leading edge of the blade. A streamlined curve L2 is constructed at the starting point of L1, with the distance from the center of rotation gradually decreasing from D1 / 2 to 0 axially upstream, with an axial length of l2. A curve L3 is constructed starting at the downstream end point of L1, with the distance from the center of rotation gradually increasing axially downstream, reaching a maximum distance D3 / 2 at the blade root. D3 does not exceed the blade rotor diameter (5.6 mm in this embodiment). At the downstream end point of L1, the rotation axis oblique angle θ (the angle between the rotation axis and the axial direction) is 0°. At the maximum distance, the rotation axis oblique angle θ ranges from 20° to 90° (50° is taken). These two angles are the tangent angles at the beginning and end points of the L3 curve, with an axial length of l3. After connecting the three curves, rotating one revolution yields the solid rotating shaft. Considering the influence of machining accuracy, the largest diameter circle can be made into a boss with a thickness τ, not exceeding 0.5mm. The axial length of the rotating shaft is l1+l2+l3+τ, which is 1.1 to 2 times the axial length of the blade (1.5 times in this embodiment, with a length of 12mm). The design of the cylindrical rotating shaft 10 is completed.

[0074] In this embodiment of the pump rotor structure, the blade portion of the pump rotor is made of a flexible material. The blade has a flexible part and a rigid part, which are seamlessly connected. The flexible part of the blade is fixed to the periphery of the cylindrical shaft, causing the blades to be distributed around the periphery of the shaft. The elastic modulus of the flexible part is less than that of the rigid part. This embodiment of the application, by selecting appropriate materials for the pump rotor blades, causes the blades to deform and bend during rotor rotation. These bent blades form the pump rotor blades, pumping blood to the desired direction. In this embodiment, because the flexible part of the blade is fixed to the periphery of the cylindrical shaft, it naturally deforms along the rotation direction due to the reaction force of the pumped object, thus forming the pump blades. In addition, since the blades of the pump rotor in this embodiment are made of a flexible material, the blades of the pump rotor will bend and deform when pumping blood during the pump rotation process. This causes less damage to the physiological indicators of the blood and hardly damages red blood cells. Therefore, the physiological indicators of the pumped blood can be guaranteed, and it can be applied to any medical patient, especially those with complications.

[0075] In addition, since the pump rotor blades have flexible parts arranged radially on the shaft, when the pump rotor of the present application embodiment is delivered to the body of a medical subject, such as the ventricle, the blades of the pump rotor can be bound to reduce its overall diameter, making it easier to place the pump rotor in the artery or other organs of the medical subject, thus facilitating medical treatment.

[0076] Furthermore, the features and benefits of the present invention are described with reference to exemplary embodiments. Accordingly, the present invention should not be limited to these exemplary embodiments that illustrate combinations of some possible non-limiting features, which may exist alone or in other combinations of features.

[0077] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are defined by the claims.

Claims

1. A pump rotor for pumping blood, characterized in that, The pump rotor includes a cylindrical shaft and blades; the blades have a flexible portion and a rigid portion, which are integrally and smoothly connected; the flexible portion of the blades is fixed to the periphery of the cylindrical shaft so that the blades are distributed around the periphery of the cylindrical shaft. The elastic modulus of the material of the flexible part is 8 MPa to 80 MPa; the elastic modulus of the material of the rigid part is 35 MPa to 195 MPa, and the elastic modulus of the material of the flexible part is less than that of the material of the rigid part. When the cylindrical shaft rotates, the pumped object can apply a reaction thrust to the blade. The flexible part of the blade deforms, causing the blade as a whole to bend in the direction of the reaction thrust. The pumped object is pumped to the target direction under the action of the bent blade. The flexible part is wound from one end of the cylindrical shaft along the axial direction to the other end of the cylindrical shaft along the axial direction; The flexible part of the blade is composed of at least two sections of material with different elastic moduli; From the input side of the pumped object to the target direction, the elastic modulus of the different material segments of the flexible part of the blade decreases from large to small.

2. The pump rotor according to claim 1, characterized in that, The ratio of the radial length of the flexible portion and the rigid portion of the blade to that of the cylindrical shaft is 1:8 to 5:

1.

3. The pump rotor according to claim 2, characterized in that, The ratio of the length of the flexible part and the rigid part of the blade in the radial direction of the cylindrical shaft is 10:37, 9:26, 11:24, 4:7 or 11:

14.

4. The pump rotor according to claim 1, characterized in that, The flexible portion of the blade, from the input side of the pumped object to the target direction, sequentially includes a first material segment and a second material segment; the elastic modulus of the material of the first material segment is greater than the elastic modulus of the material of the second material segment; The elastic modulus of the material in the first material segment is 25 MPa to 80 MPa, and the elastic modulus of the material in the second material segment is 8 MPa to 50 MPa.

5. The pump rotor according to claim 1, characterized in that, The flexible part of the blade, from the input side of the pumped object to the target direction, is composed of a first material segment, a second material segment, and a third material segment in sequence; the elastic modulus of the material of the first material segment is greater than the elastic modulus of the material of the second material segment, and the elastic modulus of the material of the second material segment is greater than the elastic modulus of the material of the third material segment. The elastic modulus of the material in the first material segment is 40 MPa to 80 MPa, the elastic modulus of the material in the second material segment is 20 MPa to 60 MPa, and the elastic modulus of the material in the third material segment is 8 MPa to 40 MPa.

6. The pump rotor according to claim 1, characterized in that, The flexible part of the blade, from the input side of the pumped object to the target direction, is composed of a first material segment, a second material segment, a third material segment, and a fourth material segment in sequence; the elastic modulus of the material of the first material segment is greater than that of the material of the second material segment, the elastic modulus of the material of the second material segment is greater than that of the material of the third material segment, and the elastic modulus of the material of the third material segment is greater than that of the material of the fourth material segment. The elastic modulus of the material in the first material segment is 50 MPa to 80 MPa, the elastic modulus of the material in the second material segment is 30 MPa to 60 MPa, the elastic modulus of the material in the third material segment is 10 MPa to 40 MPa, and the elastic modulus of the material in the fourth material segment is 8 MPa to 30 MPa.

7. The pump rotor according to claim 1, characterized in that, The number of blades is 1 to 5.

8. The pump rotor according to claim 7, characterized in that, When there is one blade, the blade moves from the periphery of one end of the cylindrical shaft to the periphery of the other end of the cylindrical shaft and is wound around the periphery of the other end of the cylindrical shaft; the number of times the blade is wound around the periphery of the cylindrical shaft is 0.2 to 5 times.

9. The pump rotor according to claim 7, characterized in that, When there are 2 to 5 blades, the blades move from the equidistant points at one end of the cylindrical shaft to the other end of the cylindrical shaft, and each blade is arranged in parallel around the corresponding equidistant points at the equidistant points at the other end of the cylindrical shaft; the number of times the blades are arranged around the circumference of the cylindrical shaft is 0.1 to 5 times.

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