CN111637091A

CN111637091A - Pump rotor

Info

Publication number: CN111637091A
Application number: CN202010624407.7A
Authority: CN
Inventors: 魏润杰; 倪钰鑫; 柳光茂; 高琪
Original assignee: Zhejiang Diyuan Medical Equipment Co ltd
Current assignee: Zhejiang Diyuan Medical Equipment Co ltd
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2020-09-08

Abstract

The invention discloses a pump rotor, comprising: a cylindrical rotating shaft and a blade; the blade is provided with a hard part and a flexible part which are integrally and smoothly connected; the hard parts of the blades are fixed on the periphery of the cylindrical rotating shaft, so that the blades are distributed on the periphery of the cylindrical rotating shaft; the elastic modulus of the material of the flexible part is 8MPa to 80 MPa; when the cylindrical rotating shaft rotates, the pumping object can exert a reaction thrust on the blade, and based on the reaction thrust, the flexible part of the blade deforms to have a curvature. In the embodiment of the application, the edge of the blade of the pump rotor is the flexible part, and the part with larger damage to blood is just at the edge part of the blade, so that the blade of the pump rotor has bending deformation when pumping blood in the rotating process of the pump, the damage to the physiological indexes of the blood is smaller, red blood cells are hardly damaged, and the physiological indexes of the pumped blood can be ensured.

Description

Pump rotor

Technical Field

The embodiment of the application relates to a pump technology in medical treatment, in particular to a blood pump rotor.

Background

At present, when a large-scale operation particularly relates to a heart operation, the operation of the heart is ensured, and simultaneously, the blood of a medical object is enabled to operate normally, so that the normal circulation of the blood of the medical object is ensured, and the medical object maintains normal vital signs.

At present, a blood pump device is commonly used for promoting the normal circulation of blood of a medical object in an operation, namely, one end of the blood pump device, provided with a blood pump, is inserted into a ventricle of the medical object, the other end of the blood pump device is inserted into an artery of a heart, and the blood in the ventricle of the heart is pumped into the artery of the medical object through the operation of the blood pump, so that the normal blood circulation of the medical object is ensured, and the blood of the medical object can still normally circulate when the heart-related operation is performed on the medical object.

However, the blood pump in the current blood pump device needs to pump blood, which has a high requirement on the pump, particularly the rotor of the pump, and needs to ensure not only the operating efficiency of the pump rotor, but also the physiological index of the pumping object, i.e. blood, here, the physiological indexes of blood mainly include leukocyte indexes, erythrocyte indexes, hemoglobin indexes, serum-haptoglobin indexes, platelet indexes and other main indexes, and during the high-speed rotation of the blood pump, when the pump pumps blood, physiological indexes in the blood can be influenced, for example, the cell walls of red blood cells in the blood can be damaged during the high-speed rotation process of blades of a pump rotor, the cell walls of a large number of red blood cells in blood are damaged, so that the hemolytic effect of blood can be caused, and a medical subject is subjected to hemolytic complications and is seriously life-threatening.

However, the current blood pump device generally only focuses on the pumping efficiency, but does not focus on the physiological index of the pumped blood, and the main reason is that the blood pump in the current blood pump device is to be placed in the body of the medical object, so the volume of the blood pump is small, the blood pump generally focuses on the working efficiency of the blood pump, and the physiological index of the pumped object of the blood pump focuses less. However, since the blood pump device directly acts on the blood of the medical subject, it is inevitable to damage the blood, and for some medical subjects with poor hemolysis tolerance, especially for the medical subjects with complications, the slight change of the blood physiological index is fatal for the medical subjects with complications. Unfortunately, the pumping efficiency of the blood pump and the size of the blood pump are all concerned by the current blood pump devices, and the blood pump devices have little attention to the physiological index of blood.

Disclosure of Invention

In view of the above, an aspect of the embodiments of the present application provides a pump rotor capable of pumping sufficient blood for a medical subject, and hardly damaging various physiological indexes of the blood.

The embodiment of the application provides a pump rotor, includes: a cylindrical rotating shaft and a blade; the blade is provided with a hard part and a flexible part which are integrally and smoothly connected; the hard parts of the blades are fixed on the periphery of the cylindrical rotating shaft, so that the blades are distributed on the periphery of the cylindrical rotating shaft; the elastic modulus of the material of the flexible part is 8MPa to 80 MPa;

when the cylindrical rotating shaft rotates, the pumping object can exert a reaction thrust on the blade, and based on the reaction thrust, the flexible part of the blade deforms to have a curvature.

As one implementation, the ratio of the lengths of the flexible portion and the hard portion of the blade in the radial direction of the cylindrical rotating shaft is 1:8 to 2: 1.

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

In one implementation, the hard portion of the blade has an elastic modulus of 90Mpa to 195 Mpa.

As an implementation, the flexible part of the blade has an elastic modulus of 40Mpa to 58 Mpa.

As an implementation, the flexible portion of the blade has an elastic modulus of 47.93Mpa to 48.67 Mpa.

As one implementation, the blades are 1 to 6.

As an implementation manner, when the number of the blades is 1, the blades are wound on the periphery of the other end of the cylindrical rotating shaft from the periphery of one end of the cylindrical rotating shaft in a manner of moving towards the other end of the cylindrical rotating shaft; the number of the circumference of the blade around the cylindrical rotating shaft is 0.2 to 5.

As an implementation manner, when the number of the blades is 2 to 6, the blades move from the bisector at the circumference of one end of the cylindrical rotating shaft to the other end of the cylindrical rotating shaft, and each blade is wound around the corresponding bisector at the circumference of the other end of the cylindrical rotating shaft in a parallel manner; the number of the circumference of the blade around the cylindrical rotating shaft is 0.1 to 5.

According to the pump rotor structure, the blade part of the pump rotor is made of flexible materials, the blade is provided with a flexible part and a hard part, and the flexible part and the hard part are connected smoothly and integrally; the flexible part of the blade is arranged on the hard part, and the hard part is fixed on the periphery of the cylindrical rotating shaft so that the blade is distributed on the periphery of the cylindrical rotating shaft. This application embodiment carries out corresponding material selection through the material to the blade of pump rotor, makes pump rotor when rotatory, makes the flexible portion of the edge of pump rotor's blade produce deformation and have a curvature. In the embodiment of the application, the flexible part is arranged at the edge of the blade of the pump rotor, and the part which is damaged greatly for blood is just at the edge part of the blade, so that the blade of the pump rotor is bent and deformed when the pump rotates, the damage to the physiological indexes of the blood is small, and red blood cells are hardly damaged, so that the physiological indexes of the pumped blood can be ensured, and the pump rotor can be suitable for any medical object, particularly the medical object with complications.

Drawings

FIG. 1 is a schematic view of a pump rotor assembly according to an embodiment of the present application;

FIG. 2 is a schematic view of a vane of a pump rotor according to an embodiment of the present application;

FIG. 3 is a schematic view of a design of a cylindrical rotating shaft of a vane of a pump rotor according to an embodiment of the present application;

FIG. 4 is a schematic view of a design of a cylindrical rotating shaft of a vane of a pump rotor according to an embodiment of the present application;

FIG. 5 is a vane angle profile of a pump rotor according to an embodiment of the present application;

fig. 6 is a design graph of a cylindrical rotating shaft of a pump rotor according to an embodiment of the present application.

Detailed Description

The essence of the technical solution of the embodiments of the present application is explained in detail below with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a pump rotor according to an embodiment of the present application, and as shown in fig. 1, the pump rotor according to the embodiment of the present application includes: a cylindrical rotating shaft 10 and a vane 20.

Fig. 2 is a schematic view of a component structure of a vane of a pump rotor according to an embodiment of the present application, and fig. 3 is a schematic view of a design of a cylindrical rotating shaft of the vane of the pump rotor according to the embodiment of the present application, as shown in fig. 2 and 3, the vane 20 has a flexible portion 202 and a hard portion 201, and the flexible portion 202 and the hard portion 201 are integrally and smoothly connected; the hard portions 201 of the blades 20 are fixed to the periphery of the cylindrical rotating shaft 10 so that the blades 20 are distributed on the periphery of the cylindrical rotating shaft 10.

In the embodiment of the present application, the connection portion between the vane 20 and the cylindrical rotating shaft 10 is a hard portion, and the edge portion of the vane 20 is a flexible portion 202, so that when the pump rotor rotates to drive the vane 20 to rotate, after the vane 20 contacts with a pumping object such as blood, under the action force applied by the pumping object, the flexible portion 202 deforms, so that under the condition of high-speed rotation of the pump rotor, because the flexible portion 202 is soft, the pumping object has a certain protection effect, the vane has less damage to the pumping object such as red blood cells in blood, and when the pumping object is pumped to a target direction, the physiological indexes of the pumping object such as blood cannot be damaged.

When pumping blood to a medical subject, it is important to prevent hemolysis of the pumped blood, since hemolysis of the blood during pumping would endanger the life safety of the medical subject. Hemolysis refers to a phenomenon in which red blood cells in blood are broken, and hemoglobin in the red blood cells overflows and dissolves in the blood. Hemolysis can result in changes in the morphological and biochemical properties of red blood cells, a shortened lifespan, and even complete rupture of red blood cells, which can reduce the ability of red blood cells to deliver 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 kidney, thereby possibly causing renal impairment and multiple organ failure.

The hemolysis quantity estimation is to establish a hemolysis model suitable for a complex flow field through reasonable assumption and deformation according to the quantitative relation between the flow parameters in the cylindrical single flow field and the hemolysis destruction quantity obtained by experimental measurement. Currently, most studies for quantitative hemolysis estimation are based on power law equations. The power law equation describes the index of Hemolysis (HI) and shear (τ) in a simple flow field, the exposure time (t)_exp) The relationship of (1):

wherein the haemolytic index HI is defined as the ratio of the increase in plasma free haemoglobin concentration (Δ Hb) to the haemoglobin concentration in whole blood (Hb). C, α, β are constants obtained by regression analysis of experimental data.

In summary, the magnitude of hemolysis is related to the shearing force and the exposure time, and the tip position of the vane of the pump rotor is a region causing severe hemolysis, and for this phenomenon, when the radial tip portion of the vane is made of a flexible material with a certain elastic modulus, the vane of the pump rotor bends in the direction opposite to the rotating direction, so that the rotating speed distribution at the tip of the vane is improved, thereby reducing the magnitude of the shearing force at the tip position, and reducing the possibility of blood hemolysis at the tip position of the vane.

In the embodiment of the present application, the flexible material for manufacturing the flexible portion 202 has a certain elasticity requirement, and the material has a certain elasticity and flexibility, wherein the elastic modulus of the material of the flexible portion 202 is 8Mpa to 80 Mpa; preferably, the flexible part of the blade has an elastic modulus of 40 to 58 Mpa. The hard portion 201 has an elastic modulus of 90 to 195 Mpa.

In the embodiment of the present application, in consideration of protection of components of a pumping object, in the material selection of the flexible portion 202, the smaller the elastic modulus of the selected material is, the better, but the pumping efficiency of the pump rotor is also considered, so that the pumping efficiency is also ensured to be as high as possible on the premise that the physiological index of the pumping object, such as blood, is not damaged. In the experiment for the flexible material, the elastic modulus of the material of the flexible portion 202 is preferably 45.7Mpa to 51.6 Mpa. When the flexible material is in the elastic modulus interval, the damage to the physiological indexes of the pumping object such as blood is small, and the pumping efficiency of the pump rotor can be ensured. For example, when the flexible material with the elastic modulus of 45.7Mpa to 51.6Mpa is adopted, the pumping efficiency of the pump rotor of the embodiment of the present application can reach 97.39% of the pumping efficiency of the pump blade with full rigidity, the pumping efficiency of the pump rotor is hardly reduced, and for a pumping object such as blood, in sampling at the end of a target direction, the damage of red blood cells is hardly seen, and the occurrence of hemolysis is basically avoided. In addition, no destruction was observed in the target blood in the leukocyte index, hemoglobin index, serum-bound globin index, platelet index, and the like.

In the embodiment of the present application, because the latter half of blade 20 is still hard portion 201 that hard material made, can be as required, with flexible portion 202 in the less of the length setting of the radial direction of cylindricality pivot 10, like this, it is less to the pumping efficiency influence of pump rotor, and sets up to flexible portion 202 through the marginal portion at blade 20, can effectively protect the composition of pumping object again, avoids the pumping object to have destruction after the pumping like the physiological index of blood.

In addition, as an implementation mode, the elastic modulus of the material of the flexible portion 202 in the embodiment of the present application is more preferably between 47.93Mpa and 48.67 Mpa.

In the embodiment of the present application, the material of the flexible portion 202 is not limited to the hard material, and may be an alloy material satisfying the above elastic modulus requirement, or a material such as a resin, a synthetic resin, a mixed resin, or the like satisfying the above elastic modulus requirement. In the embodiment of the present invention, the flexible material of the flexible portion is preferably a resin material.

In the embodiment of the present application, there is no requirement for the material of the hard portion 201, as long as the material of the hard portion 201 has a higher elastic modulus than the material of the flexible portion 202. 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 40Mpa to 60Mpa under the condition that the integral processing of the hard portion 201 and the flexible portion 202 is ensured. In the embodiment of the present application, when the flexible portion 202 is made of resin, the hard portion 201 is preferably made of resin with higher hardness. When the flexible portion 202 is made of an alloy, the hard portion 201 is preferably made of an alloy or a metal having a higher hardness.

In the embodiment of the present application, when the cylindrical rotating shaft 10 rotates, the pumping object can apply a reaction thrust to the vane 20, and the flexible portion 202 of the vane 20 is deformed to have a curvature.

As shown in fig. 3, in the embodiment of the present application, the ratio of the lengths of the flexible portion 202 and the hard portion 201 of the blade 20 in the radial direction of the cylindrical rotating shaft 10 is 1:8 to 2: 1. In fig. 2, the ratio of the length of the flexible portion 202 in the radial direction of the cylindrical rotating shaft 10 to the rigid portion 201 is preferably 1:5 to 1: 1. As one implementation mode, the length ratio of the flexible part and the hard part of the blade in the radial direction of the cylindrical rotating shaft is 7: 53. 10: 57. 9:43, 3:11, 4:9, or 11: 15.

In the embodiment of the present application, as an implementation manner, the number of the blades is 1 to 6.

When the number of the blades 20 is 1, the blades 20 are wound around the periphery of the other end of the cylindrical rotating shaft 10 from the periphery of one end of the cylindrical rotating shaft 10 in a manner of moving towards the other end of the cylindrical rotating shaft 10; the number of the circumference of the blade 20 around the cylindrical rotating shaft 10 is 0.2 to 5. When the number of the blades 20 is 1, the number of the blades 20 wound around the circumference of the cylindrical rotating shaft 10 is preferably one or more, and the larger the number of the blades 20 wound around the circumference of the cylindrical rotating shaft 10 is, the higher the pumping efficiency is.

It should be noted that the design of the vanes in the pump rotor structure of the embodiment of the present application still needs to adopt the design principle of the common pump rotor vanes, that is, the pump input angle and the pump output angle need to be set.

As one way of realization, in the embodiment of the present application, as shown in fig. 1, when the vanes 20 of the pump rotor are 2 to 5, the vanes 20 move from the bisector at the circumference of one end of the cylindrical rotating shaft 10 to the other end of the cylindrical rotating shaft, and each vane 20 winds around the corresponding bisector at the circumference of the other end of the cylindrical rotating shaft 10 in a parallel manner; the number of the circumference of the blade 20 around the cylindrical rotating shaft is 0.1 to 5.

FIG. 4 is a schematic view of a cylindrical rotating shaft design of a vane of a pump rotor according to an embodiment of the present application, as shown in FIG. 4, for determining a diameter D of an impeller casing₂The range is less than 10mm, 6mm is taken as the embodiment of the application, the hub ratio range can be approximately 0.15-0.75, 0.367 is taken as the embodiment of the application, and the diameter D of the blade root is obtained₁2.2mm, the blade length L is defined as the ratio of the blade length at the blade root to the diameter of the housing is approximately 1-2, here, 1.333 is taken, so the blade length is 8mm, the ratio of the blade outlet height b to the housing diameter is approximately 0.25-1.5, 0.4167 is taken in the embodiment of the application, so the outlet length is 2.5 mm.

FIG. 5 is a distribution chart of the vane angle of the pump rotor according to the embodiment of the present application, as shown in FIG. 5, the outlet angle β is the same for each layer, and is approximately in the range of 30 to 90 from the circumferential direction (60 for the embodiment of the present application). The inlet setting angle α for each layer_mAnd β, configuring the blade angle phi to be distributed along the way, wherein the blade angle is from α along the axial direction_mThe progression to β is such that the blade centre line is obtained for each layer, whereby the blade wrap angle around the axis can be different for each layer but not less than 90, the absolute value of the difference in the different wrap angles on all layers not exceeding 20 at the most, the result of the different wrap angles being that the blade profile is flexible.

The thickness distribution is superposed on the central line to form a blade curve on each layer, and the thickness range of each layer is not more than 1.5mm (the maximum thickness of the blade root is 0.8mm, and the maximum thickness of the blade tip is 0.5mm in the embodiment). And (5) stacking the n layers of blade curves to obtain a three-dimensional blade profile, and finishing the blade design.

FIG. 6 is a graph showing the design of the cylindrical rotating shaft of the pump rotor according to the embodiment of the present invention, as shown in FIG. 6, the length of the cylindrical rotating shaft is l1 (0.95 mm in the embodiment of the present invention) and is set to 0-4 mm (0.95 mm in the embodiment of the present invention) before and after the leading edge of the vane₁And a line L1 with the constant/2, wherein when L1 is 0, the starting point and the ending point of the curves are overlapped and positioned at the front edge of the blade. Constructing a streamline curve L2 at the starting point of L1, and gradually increasing the distance from the rotating center to the upstream in the axial direction₁The/2 is reduced to 0, the axial length l 2. Starting at the downstream termination point of L1, curve L3 is constructed, gradually expanding in distance from the center of rotation axially downstream, reaching a maximum distance D at the blade root₃/2，D₃Not exceeding the diameter of the blade rotor (in the embodiment of the present application, D)₃Take 5.6 mm). The oblique angle theta of the rotating shaft (included angle with the axial direction) is 0 degree at the downstream termination point of L1, and the oblique angle theta of the rotating shaft is in the range of 20-90 degrees (50 degrees in the embodiment of the application) at the maximum distance, and the two angles are the tangent angle of the starting point and the ending point of the L3 curve and the axial length L3. After the three curves are connected, the rotation axis entity is obtained by rotating for one circle, the influence of processing precision is considered, the maximum diameter circle can be made into a boss with the thickness tau, the thickness is not more than 0.5mm, the axial length of the rotation axis is l1+ l2+ l3+ tau, and the length is 1.1-2 times of the axial length of the blade (the axial length of the embodiment of the application is 1.5 times and the axial length of the blade is 12 mm). And finishing the design of the cylindrical rotating shaft.

In the embodiment of the application, the flexible part is arranged at the edge of the blade of the pump rotor, and the part which is damaged greatly for blood is just at the edge part of the blade, so that the blade of the pump rotor is bent and deformed when the pump rotates, the damage to the physiological indexes of the blood is small, and red blood cells are hardly damaged, so that the physiological indexes of the pumped blood can be ensured, and the pump rotor can be suitable for any medical object, particularly the medical object with complications.

In addition, because the flexible part is arranged on the blades of the pump rotor in the radial direction of the rotating shaft, when the pump rotor of the embodiment of the application is conveyed into the body of a medical object, such as a ventricle, the blades of the pump rotor can be bound to reduce the whole diameter of the pump rotor, so that the pump rotor is easier to place in an arterial vessel or other organs of the medical object, and the medical treatment of the medical object is facilitated.

Furthermore, the features and benefits of the present invention are described with reference to exemplary embodiments. Accordingly, the invention is expressly not limited to these exemplary embodiments illustrating some possible non-limiting combination of features which may be present alone or in other combinations of features.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

Claims

1. A pump rotor, characterized in that the pump rotor comprises: a cylindrical rotating shaft and a blade; the blade is provided with a hard part and a flexible part which are integrally and smoothly connected; the hard parts of the blades are fixed on the periphery of the cylindrical rotating shaft, so that the blades are distributed on the periphery of the cylindrical rotating shaft; the elastic modulus of the material of the flexible part is 8MPa to 80 MPa;

2. The pump rotor according to claim 1, wherein the flexible portion and the hard portion of the vane have a length ratio of 1:8 to 2:1 in a radial direction of the cylindrical rotating shaft.

3. The pump rotor as claimed in claim 2, wherein the flexible portion and the hard portion of the vane have a length ratio in a radial direction of the cylindrical rotating shaft of 7: 53. 10: 57. 9:43, 3:11, 4:9, or 11: 15.

4. The pump rotor according to claim 1, wherein the hard portion of the vane has an elastic modulus of 90Mpa to 195 Mpa.

5. The pump rotor according to claim 1, wherein the flexible portion of the vane has an elastic modulus of 40Mpa to 58 Mpa.

6. The pump rotor as claimed in claim 5, wherein the flexible portion of the vane has an elastic modulus of 47.93Mpa to 48.67 Mpa.

7. A pump rotor according to any one of claims 1 to 6, wherein the vanes are 1 to 6 pieces.

8. The pump rotor according to claim 7, wherein when the number of the vanes is 1, the vanes are wound around the periphery of the other end of the cylindrical rotating shaft from the periphery of the one end of the cylindrical rotating shaft in such a manner as to move toward the other end of the cylindrical rotating shaft; the number of the circumference of the blade around the cylindrical rotating shaft is 0.2 to 5.

9. The pump rotor according to claim 7, wherein when the number of the vanes is 2 to 6, the vanes are moved from a bisector at the periphery of one end of the cylindrical rotating shaft toward the other end of the cylindrical rotating shaft, and each vane is wound in parallel around a corresponding bisector at the periphery of the other end of the cylindrical rotating shaft; the number of the circumference of the blade around the cylindrical rotating shaft is 0.1 to 5.