pump rotor

Abstract

The present invention discloses a pump rotor, comprising: a cylindrical shaft and blades; the blades have a hard portion and a flexible portion, the hard portion and the flexible portion being smoothly connected as one piece; the hard portion of the blades is fixed to the periphery of the cylindrical shaft, so that the blades are distributed on the periphery of the cylindrical shaft; the elastic modulus of the material of the flexible portion is 8Mpa to 80Mpa; when the cylindrical shaft rotates, the pumping object can exert a reaction thrust on the blades, and based on the reaction thrust, the flexible portion of the blades deforms and has a curvature. In the embodiment of the present application, since the edges of the blades of the pump rotor are flexible portions, and the portion that causes greater damage to the blood is precisely at the edge of the blades, during the rotation of the pump, the blades of the pump rotor will bend and deform when pumping blood, which has less damage to the physiological indicators of the blood and almost no damage to the red blood cells, thereby ensuring the physiological indicators of the pumped blood.

Description

Technical Field

[0001] The embodiments of the present application relate to pump technology in medical treatment, and in particular to a blood pump rotor. Background Art

[0002] At present, in some large-scale operations, especially those involving heart operations, while ensuring the surgical operation on the heart, it is also necessary to ensure the normal circulation of the blood of the medical subject and the normal vital signs of the medical subject.

[0003] Currently, blood pump devices are commonly used to promote normal blood circulation in medical subjects undergoing surgery. That is, one end of the blood pump device is inserted into the medical subject's ventricle, and the other end of the blood pump device is inserted into the heart artery. Through the operation of the blood pump, the blood in the heart ventricle is pumped into the medical subject's artery, thereby ensuring normal blood circulation in the medical subject, so that the medical subject's blood can still circulate normally when undergoing heart-related surgery on the medical subject.

[0004] However, the blood pump in the current blood pump device needs to pump blood, which places extremely high requirements on the pump, especially the pump rotor. It is necessary not only to ensure the operating efficiency of the pump rotor, but also to ensure that the physiological indicators of the pumped object, that is, the blood, are not affected. Here, the physiological indicators of the blood mainly include white blood cell indicators, red blood cell indicators, hemoglobin indicators, serum ligand globin indicators, platelet indicators and other major indicators. During the high-speed rotation process of the blood pump, while pumping the blood, it will also affect the physiological indicators in the blood. For example, during the high-speed rotation process, the blades of the pump rotor will destroy the cell walls of the red blood cells in the blood. After the cell walls of a large number of red blood cells in the blood are destroyed, it will cause a hemolytic effect of the blood, causing the medical object to suffer from hemolytic complications, which is seriously life-threatening.

[0005] However, current blood pump devices generally only focus on pumping efficiency, but do not pay attention to the physiological indicators of the pumped blood. The main reason is that the blood pump in the current blood pump device is relatively small because it is placed in the body of the medical subject. Generally, the focus is on the working efficiency of the blood pump, and less attention is paid to the physiological indicators of the blood of the pumped subject. However, since the blood pump device directly acts on the blood of the medical subject, it will inevitably cause corresponding damage to the blood. For some medical subjects with poor hemolysis tolerance, especially those with complications, even a slight change in the physiological indicators of the blood can be fatal to the medical subjects with complications. Unfortunately, current blood pump devices all focus on the pumping efficiency of the blood pump and the size of the blood pump device, but pay almost no attention to the physiological indicators 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 for a medical subject without substantially damaging various physiological indicators of the blood.

[0007] The present application provides a pump rotor, comprising: a cylindrical shaft and blades; the blades having a hard portion and a flexible portion, the hard portion and the flexible portion being integrally and smoothly connected; the hard portion of the blades being fixed to the periphery of the cylindrical shaft, such that the blades are distributed along the periphery of the cylindrical shaft; the elastic modulus of the material of the flexible portion is 8 MPa to 80 MPa;

[0008] When the cylindrical shaft rotates, the pumping object can exert a reaction thrust on the blades. Based on the reaction thrust, the flexible portion of the blades is deformed to have a curvature.

[0009] As an implementation manner, the length ratio of the flexible portion and the hard portion of the blade in the radial direction of the cylindrical shaft is 1:8 to 2:1.

[0010] Preferably, the length ratio of the flexible portion and the hard portion of the blade in the radial direction of the cylindrical shaft is: 7:53, 10:57, 9:43, 3:11, 4:9 or 11:15.

[0011] As an implementation manner, the elastic modulus of the hard portion of the blade is 90 MPa to 195 MPa.

[0012] As an implementation manner, the elastic modulus of the flexible portion of the blade is 40 MPa to 58 MPa.

[0013] As an implementation manner, the elastic modulus of the flexible portion of the blade is 47.93 MPa to 48.67 MPa.

[0014] As an implementation manner, the number of the blades is 1 to 6.

[0015] As an implementation method, when there is one blade, the blade is arranged around the periphery of the other end of the cylindrical shaft in a manner of moving from the periphery of one end of the cylindrical shaft toward the other end of the cylindrical shaft; the number of times the blade is arranged around the periphery of the cylindrical shaft is 0.2 to 5 times.

[0016] As an implementation method, when there are 2 to 6 blades, the blades move from the equal divisions of the circumference of one end of the cylindrical shaft toward the other end of the cylindrical shaft, and each blade is arranged in parallel around the corresponding equal divisions of the circumference of 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.

[0017] In the pump rotor structure of the embodiment of the present application, the blade portion of the pump rotor is made of a flexible material. The blade has a flexible portion and a hard portion, and the flexible portion and the hard portion are smoothly connected in one piece. The flexible portion of the blade is arranged on the hard portion, and the hard portion is fixed to the periphery of the cylindrical shaft, so that the blades are distributed around the periphery of the cylindrical shaft. In the embodiment of the present application, by selecting the material of the pump rotor blades accordingly, the flexible portion at the edge of the pump rotor blades deforms and has a curvature when the pump rotor rotates. In the embodiment of the present application, because the edge of the pump rotor blade is the flexible portion, the portion that causes the greatest damage to the blood is precisely at the edge of the blade. Thus, during the rotation of the pump, the blades of the pump rotor will bend and deform when pumping blood. This has minimal impact on the physiological indicators of the blood and almost no damage to red blood cells. Therefore, the physiological indicators of the pumped blood can be guaranteed, and the pump is suitable for any medical subject, especially those with complications. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the pump rotor structure of an embodiment of the present application;

[0019] Figure 2 This is a schematic diagram of the composition structure of the blades of the pump rotor in an embodiment of the present application;

[0020] Figure 3 This is a schematic diagram of the design of a blade cylindrical shaft of a pump rotor according to an embodiment of the present application;

[0021] Figure 4 This is a schematic diagram of the design of a blade cylindrical shaft of a pump rotor according to an embodiment of the present application;

[0022] Figure 5 This is a diagram showing the blade angle distribution along the pump rotor of an embodiment of the present application;

[0023] Figure 6 This is a design curve diagram of the cylindrical rotating shaft of the pump rotor according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] The essence of the technical solution of the embodiment of the present application is explained in detail below with reference to the accompanying drawings.

[0025] Figure 1 This is a schematic diagram of the pump rotor structure of the embodiment of the present application, as shown in FIG. Figure 1 As shown, the pump rotor of the embodiment of the present application includes: a cylindrical rotating shaft 10 and blades 20.

[0026] Figure 2 This is a schematic diagram of the composition structure of the blades of the pump rotor in an embodiment of the present application. Figure 3 This is a schematic diagram of the design of the blade cylindrical shaft of the pump rotor of the embodiment of the present application, as shown in FIG. Figure 2 、 Figure 3As shown, the blade 20 has a flexible portion 202 and a hard portion 201, and the flexible portion 202 and the hard portion 201 are smoothly connected as a whole; the hard portion 201 of the blade 20 is fixed on the periphery of the cylindrical shaft 10 so that the blade 20 is distributed on the periphery of the cylindrical shaft 10.

[0027] In the embodiment of the present application, the connection portion between the blade 20 and the cylindrical shaft 10 is set as a hard portion, and the edge portion of the blade 20 is set as a flexible portion 202. In this way, when the pump rotor rotates and drives the blade 20 to rotate, when the blade 20 comes into contact with the pumping object such as blood, the flexible portion 202 is deformed under the force exerted by the pumping object. Therefore, when the pump rotor rotates at a high speed, the flexible portion 202 has a relatively soft texture and has a certain protective effect on the pumping object. The blade causes less damage to the pumping object, such as red blood cells in the blood. When the pumping object is pumped to the target direction, the physiological indicators of the pumping object, such as blood, will not be damaged.

[0028] When pumping blood to a medical subject, it is very important to prevent hemolysis of the pumped blood, because if the blood hemolyzes during pumping, it will endanger the life of the medical subject. Hemolysis refers to the phenomenon that red blood cells in the blood rupture, causing the hemoglobin in the red blood cells to overflow and dissolve in the blood. Hemolysis can cause changes in the morphology and biochemical properties of red blood cells, shorten their lifespan, or even completely rupture, thereby reducing the ability of red blood cells to transport oxygen to tissues and organs. In addition, the concentration of plasma free hemoglobin increases after hemolysis, and the excess free hemoglobin needs to be excreted through the kidneys, which may cause renal damage and multiple organ failure.

[0029] The estimation of hemolysis volume is based on the quantitative relationship between the flow parameters and the hemolysis damage in a single flow field obtained by experimental measurement. After reasonable assumptions and deformation, a hemolysis model suitable for complex flow fields is established. At present, most of the research on quantitative hemolysis estimation is based on the power law equation. The power law equation describes the relationship between the hemolysis index (HI) and the shear force (τ) and exposure time (t exp )

[0030]

[0031] 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.

[0032] To sum up, the magnitude of hemolysis is related to the shear force and exposure time, and the tip position of the pump rotor blade is the area where hemolysis is more serious. To address this phenomenon, the pump rotor in the embodiment of the present application sets the radial tip part of the blade to a flexible material with a certain elastic modulus. The blades of the pump rotor will bend in the direction opposite to the rotation direction, so that the rotation speed distribution at the tip of the blade is improved, thereby reducing the magnitude of the shear force at the tip position and reducing the possibility of hemolysis of blood at the tip position of the blade.

[0033] In the embodiment of the present application, the flexible material used to make the flexible portion 202 has certain elasticity requirements and has a certain elasticity and flexibility. The elastic modulus of the material of the flexible portion 202 is 8 MPa to 80 MPa. Preferably, the elastic modulus of the flexible portion of the blade is 40 MPa to 58 MPa. The elastic modulus of the material of the hard portion 201 is 90 MPa to 195 MPa.

[0034] In the embodiments of the present application, to protect the components of the pumped object, the material selected for the flexible portion 202 preferably has a lower elastic modulus than the material selected for the flexible portion 202. However, the pumping efficiency of the pump rotor must also be considered. Therefore, while ensuring that the physiological parameters of the pumped object, such as blood, are not damaged, the pumping efficiency must be as high as possible. During experiments with flexible materials, the elastic modulus of the flexible portion 202 was preferably between 45.7 MPa and 51.6 MPa. Within this elastic modulus range, the damage to the physiological parameters of the pumped object, such as blood, is minimal, while maintaining the pumping efficiency of the pump rotor. For example, when using a flexible material with an elastic modulus between 45.7 MPa and 51.6 MPa, the pumping efficiency of the pump rotor of the embodiments of the present application can reach 97.39% of the pumping efficiency of a fully rigid pump blade, with virtually no decrease in pump rotor efficiency. Furthermore, for the pumped object, such as blood, during sampling at the target end, almost no red blood cell damage was observed, essentially eliminating the occurrence of hemolysis. In addition, no damage was observed in the white blood cell index, hemoglobin index, serum haptoglobin index, platelet index, etc. in the blood of the target side.

[0035] In the embodiment of the present application, since the lower half of the blade 20 is still the hard part 201 made of hard material, the length of the flexible part 202 in the radial direction of the cylindrical shaft 10 can be set to be smaller as needed. In this way, the pumping efficiency of the pump rotor is less affected. By setting the flexible part 202 at the edge of the blade 20, the components of the pumping object can be effectively protected, thereby avoiding damage to the physiological indicators of the pumping object such as blood after pumping.

[0036] In addition, as an implementation method, the elastic modulus of the material of the flexible portion 202 in the embodiment of the present application is further preferably between 47.93 MPa and 48.67 MPa.

[0037] In the embodiment of the present application, the material of the flexible portion 202 has no rigidity requirement and can be an alloy material that meets the elastic modulus requirement, or a resin, synthetic resin, mixed resin, etc. that meets the elastic modulus requirement. In the embodiment of the present application, the flexible material of the flexible portion is preferably a resin material.

[0038] In the embodiment of the present application, there are no corresponding requirements for the material of the hard portion 201, as long as the elastic modulus of the material of the hard portion 201 is greater than the elastic modulus of the material of the flexible portion 202. Under the condition of ensuring that the hard portion 201 and the flexible portion 202 are processed as one piece, the difference between the elastic modulus of the material of the hard portion 201 and the elastic modulus of the material of the flexible portion 202 is preferably between 40Mpa and 60Mpa. In the embodiment of the present application, when the material of the flexible portion 202 is resin, the material of the hard portion 201 is preferably also selected from a resin or similar material with higher hardness. When the material of the flexible portion 202 is alloy, the material of the hard portion 201 is preferably also selected from an alloy or metal with higher hardness.

[0039] In the embodiment of the present application, when the cylindrical shaft 10 rotates, the pumping object can exert a reaction thrust on the blade 20, and the flexible portion 202 of the blade 20 is deformed to have a curvature.

[0040] like Figure 3 As shown, in the embodiment of the present application, the length ratio of the flexible portion 202 and the hard portion 201 of the blade 20 in the radial direction of the cylindrical shaft 10 is 1:8 to 2:1. As a preferred embodiment, Figure 2 The ratio of the length of the flexible portion 202 in the radial direction of the cylindrical shaft 10 to the length of the hard portion 201 is between 1:5 and 1:1. As an implementation, the length ratio of the flexible portion to the hard portion of the blade in the radial direction of the cylindrical shaft is 7:53, 10:57, 9:43, 3:11, 4:9, or 11:15.

[0041] In an embodiment of the present application, as an implementation method, the number of blades is 1 to 6.

[0042] When there is a single blade 20, the blade 20 is wound around the circumference of the cylindrical shaft 10 from one end thereof in a manner moving toward the other end thereof. The number of times the blade 20 wraps around the circumference of the cylindrical shaft 10 is 0.2 to 5 times. When there is a single blade 20, the number of times the blade 20 wraps around the circumference of the cylindrical shaft 10 is preferably at least one time. The greater the number of times the blade 20 wraps around the circumference of the cylindrical shaft 10, the higher the pumping efficiency.

[0043] It should be noted that the blade design in the pump rotor structure of the embodiment of the present application still needs to adopt the design principle of ordinary pump rotor blades, that is, the pump input angle and output angle, etc. need to be set.

[0044] As an implementation method, in the embodiment of the present application, Figure 1 As shown, when the number of blades 20 of the pump rotor is 2 to 5, the blades 20 move from the equal divisions of the circumference of 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 equal divisions of the circumference of the other end of the cylindrical shaft 10; the number of times the blades 20 are arranged around the circumference of the cylindrical shaft is 0.1 to 5.

[0045] Figure 4 This is a schematic diagram of the design of the blade cylindrical shaft of the pump rotor of the embodiment of the present application, as shown in FIG. Figure 4 As shown, it is determined that the impeller shell diameter D2 is less than 10 mm, and the embodiment of the present application takes 6 mm. The hub ratio range can be approximately 0.15 to 0.75, and the embodiment of the present application takes 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 shell diameter, which is approximately in the range of 1 to 2. Here, 1.333 is taken, so the blade length is 8 mm. The ratio of the blade outlet height b to the shell diameter is approximately in the range of 0.25 to 1.5. The embodiment of the present application takes 0.4167, so the outlet length is 2.5 mm.

[0046] Figure 5 The blade angle distribution diagram of the pump rotor in the embodiment of the present application is as follows: Figure 5 As shown, the outlet angle β is the same for each layer, and the angle range with the circumferential direction is approximately 30° to 90° (60° is taken in the embodiment of the present application). m With β, the blade angle φ is distributed along the process, and the blade angle is axially from α m The blade center line of each layer is obtained by gradually changing to β. The blade wrap angle around the axis obtained in this way can be different for each layer, but no less than 90°. The absolute value of the maximum difference between different wrap angles on all layers does not exceed 20°. The result of different wrap angles is that the blade profile is bendable.

[0047] The thickness distribution is superimposed on the center line to form the blade curve on each layer. The thickness range of each layer does not exceed 1.5mm (the maximum thickness at the blade root is 0.8mm, and the maximum thickness at the blade tip is 0.5mm). N layers of blade curves are superimposed to obtain a three-dimensional blade surface, completing the blade design.

[0048] Figure 6 This is a design curve diagram of the cylindrical rotating shaft of the pump rotor of the embodiment of the present application, such as Figure 6 As shown, at the leading edge of the blade, a section before and after it is formed to form a straight line L1 with a length l1 ranging from 0 to 4 mm (0.95 mm in the embodiment of the present application), and a constant distance D1 / 2 from the center of rotation. When l1 is 0, the starting and ending points of the curve coincide at the leading edge of the blade. A streamlined curve L2 is constructed at the starting point of L1, and the distance from the center of rotation gradually decreases from D1 / 2 to 0 in the axial upstream direction, with an axial length of l2. Curve L3 is constructed at the downstream end point of L1, and the distance from the center of rotation gradually increases in the axial downstream direction, reaching a maximum distance D3 / 2 at the root of the blade, and D3 does not exceed the diameter of the blade rotor (in the embodiment of the present application, D3 is 5.6 mm). At the downstream end point of L1, the oblique angle θ of the rotation axis (the angle with the axial direction) is 0°. At the maximum distance, the oblique angle θ of the rotation axis is in the range of 20° to 90° (50° in the embodiment of the present application). These two angles are the tangent angles of the starting and ending points of the L3 curve, with an axial length of l3. After connecting the three curves and rotating them once, the rotating shaft entity is obtained. Considering the influence of machining accuracy, the maximum diameter circle can be made into a boss with a thickness τ, which does not exceed 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, 12mm, is used in this embodiment). This completes the design of the cylindrical rotating shaft.

[0049] In the embodiment of the present application, since the edges of the blades of the pump rotor are flexible, and the part that causes greater damage to the blood is precisely at the edge of the blades, during the rotation of the pump, the blades of the pump rotor will bend and deform when pumping blood, which causes less damage to the physiological indicators of the blood and hardly damages the red blood cells. Therefore, the physiological indicators of the pumped blood can be guaranteed, and the method is suitable for any medical subject, especially medical subjects with complications.

[0050] In addition, since the blades of the pump rotor are provided with a flexible portion in the radial direction of the rotating shaft, when the pump rotor of the embodiment of the present application is delivered to the body of the medical subject, such as the ventricle, the blades of the pump rotor can be constrained and its overall diameter can be reduced, thereby making it easier to place the pump rotor in the artery or other organs of the medical subject, thereby facilitating the medical treatment of the medical subject.

[0051] In addition, the features and benefits of the present invention are described by reference to exemplary embodiments. Accordingly, the present invention should clearly not be limited to these exemplary embodiments which illustrate some possible non-limiting combinations of features, which may exist alone or in other combinations of features.

[0052] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, and the true scope and spirit of the present invention are to be determined by the claims.

Claims

1. A pump rotor, characterized in that: The pump rotor includes: a cylindrical shaft and blades; the blades have a hard portion and a flexible portion, the hard portion and the flexible portion being integrally and smoothly connected; the hard portion of the blades is fixed to the periphery of the cylindrical shaft, and the flexible portion is connected to a side of the hard portion away from the cylindrical shaft in the radial direction 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 portion is 8 MPa to 80 MPa; When the cylindrical shaft rotates, the pumping object can exert a reaction thrust on the blades. Based on the reaction thrust, the flexible portion of the blades is deformed to have a curvature.

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

1.

3. The pump rotor according to claim 2, characterized in that The length ratio of the flexible part and the hard part of the blade in the radial direction of the cylindrical shaft is: 7:53, 10:57, 9:43, 3:11, 4:9 or 11:

15.

4. The pump rotor according to claim 1, characterized in that The elastic modulus of the hard portion of the blade is 90 MPa to 195 MPa.

5. The pump rotor according to claim 1, characterized in that The elastic modulus of the flexible portion of the blade is 40 MPa to 58 MPa.

6. The pump rotor according to claim 5, characterized in that The elastic modulus of the flexible portion of the blade is 47.93 MPa to 48.67 MPa.

7. The pump rotor according to any one of claims 1 to 6, characterized in that The number of the leaves is 1 to 6.

8. The pump rotor according to claim 7, characterized in that When there is one blade, the blade is arranged around the periphery of the other end of the cylindrical shaft in a manner of moving from the periphery of one end of the cylindrical shaft toward the other end of the cylindrical shaft; the number of times the blade is arranged 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 6 blades, the blades move from the equal divisions of the circumference of one end of the cylindrical shaft toward the other end of the cylindrical shaft, and each blade is arranged in parallel around the corresponding equal divisions of the circumference of 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.

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