Impeller rotor of axial flow blood pump

Abstract

The utility model discloses an impeller rotor of an axial flow blood pump, which comprises a hub, blades, a shaft hole and back blades, and the outer diameter of the hub is gradually increased from the head to the tail; each blade comprises a blade root close to the hub, a blade tip away from the hub, a blade front edge and a blade tail edge, and the two blades are arranged on the surface of the hub in a central symmetry mode. The shaft hole is formed in the tail end face of the impeller rotor and can be used for installing an impeller shaft. The back blades are arranged on the end face of the tail of the impeller rotor and arranged outside the shaft hole in a surrounding mode. The impeller is simple in structure, the blood low-speed area disturbance effect of the near wall face of the impeller shaft can be improved, and therefore the risk that blood forms thrombus between the impeller rotor and the bearing is reduced, and the blood compatibility of the blood pump is improved.

Description

Technical Field

[0001] This utility model belongs to the field of medical devices, specifically relating to an impeller rotor of an axial flow blood pump. Background Technology

[0002] Miniature axial flow pumps are percutaneously implanted into the ventricle to drain blood into the arterial system, partially or completely replacing the heart's pumping function. This aims to reduce left ventricular load, myocardial load and oxygen consumption, while increasing cardiac output and perfusion to the coronary arteries and end organs. However, this treatment does not avoid serious adverse events. Serious complications related to thrombosis, such as hemorrhage and stroke, have been observed, which may negate the benefits of this treatment and may require subsequent pump replacement surgery or lead to premature death. The rate of pump thrombosis has risen sharply in recent years, causing serious concern in the medical community. While the inherent thrombotic risk of these devices is well-known, the exact mechanisms of its occurrence and development are not fully understood. The impeller's wake region and bearing region are the main areas where blood clots form. The Impella series of interventional artificial hearts, which has received post-marketing approval from the U.S. Food and Drug Administration, is installed on a 9Fr catheter shaft. This catheter shaft integrates a purge-sealing system for a drive motor that prevents blood from entering the Impella catheter. The system uses a glucose heparin solution as a purification fluid, which continuously delivers the purification fluid to the bearing region to reduce clot formation. Utility Model Content

[0003] The purpose of this invention is to provide an impeller rotor for an axial flow blood pump, which improves blood circulation through back blades, reduces blood adhesion to the impeller shaft surface, and enhances the antithrombotic performance of the blood pump.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] An impeller rotor for an axial flow blood pump includes a hub, blades, a shaft bore, and back blades, wherein,

[0006] The outer diameter of the wheel hub gradually increases from the front to the rear;

[0007] The two blades each include a blade root near the hub, a blade tip away from the hub, a blade leading edge, and a blade trailing edge, and the two blades are centrally symmetrically placed on the hub surface;

[0008] The shaft hole is located inside the tail end face of the impeller rotor and can be used to install the impeller shaft.

[0009] The back blades are located on the tail end face of the impeller rotor and are arranged around the shaft hole.

[0010] The blade, the back blade, and the hub are machined as a single unit; the material used for machining is 316LVM stainless steel, nickel-titanium alloy, or other biocompatible polymer materials.

[0011] The hub includes a guide section, a booster section, and a wake section. The diameters of the guide section, booster section, and wake section gradually increase from the near end to the far end. The total length of the hub 11 is [missing information]. h The heights of the guide section 111, the pressurization section 112, and the wake section 113 are, in order: h 1. h 2 and h 3; among which h= h 1+ h 2+ h 3, 1 / 8≤ h 1 / h ≤1 / 5, 2 / 4≤ h 2 / h ≤3 / 5.

[0012] The blade includes a blade tip, a blade root, a blade leading edge, and a blade trailing edge. The connection point between the blade root and the outer circumference of the hub has a rounded corner, and the radius of the rounded corner ε is between 0.1mm and 0.3mm. The blade wrap angle is the angle between the line connecting the blade leading edge and the center of the circle and the line connecting the blade trailing edge and the center of the circle, and the blade wrap angle is between 100° and 120°.

[0013] The back blade has a straight blade structure, and the width of the back blade is... w 1. Length w 2. Back blade width w 1. It needs to satisfy 1 / 8 ≤ w 1 / d2≤1 / 6, back blade length w 2 should satisfy 1 / 3 ≤ w 2 / d2≤1 / 2.

[0014] The back blade has a curved blade structure, and the width of the back blade is... w 3. Length w 4. The bending angle ϕ of the back blades; the back blades adopt a curved structure; the width of the back blades is... w 3 should satisfy 1 / 8 ≤ w 3 / d² ≤ 1 / 6, length w 4. It should satisfy 1 / 3 ≤ w 4 / d2≤1 / 2, the bending angle ϕ satisfies 30°≤ϕ≤45°.

[0015] The beneficial effects of this invention are: This invention has a simple structure, requires no additional perfusion system, can accelerate blood circulation near the impeller shaft, thereby improving the blood flushing effect and ultimately playing an antithrombotic role. Attached Figure Description

[0016] To more clearly illustrate the embodiments of this utility model, the embodiments will be described below in conjunction with the accompanying drawings.

[0017] Figure 1 This is a front view of the impeller rotor structure according to an embodiment of the present invention.

[0018] Figure 1A for Figure 1 A three-dimensional structural diagram of the impeller rotor.

[0019] Figure 1B for Figure 1 The bottom view of the impeller rotor structure.

[0020] Figure 2A This is a three-dimensional structural diagram of the impeller rotor according to another embodiment of the present invention.

[0021] Figure 2B for Figure 2A A schematic diagram of the impeller rotor structure from the bottom.

[0022] Figure 3 Assembly drawing of the impeller rotor and housing provided for this utility model.

[0023] Figure 4 Comparison curves of numerical simulation results of blood flushing inside blood pumps with and without back blades. Detailed Implementation

[0024] The following examples illustrate possible implementations of the present invention, but are not intended to limit the scope of protection of the present invention.

[0025] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0026] The term "head" used in the instruction manual refers to the direction closer to the heart, while "tail" refers to the direction further away from the heart.

[0027] Please refer to Figure 1 and Figure 1A This is the first embodiment of the present invention. An impeller rotor 100 of an axial flow blood pump includes a hub 11, blades 12, a shaft hole 13, and a back blade 14. Along the axial direction A of the impeller 100... x The hub 11 includes a guide section 111, a booster section 112, and a wake section 113 connected sequentially from the near end to the far end. The diameters of the guide section 111, booster section 112, and wake section 113 gradually increase from the near end to the far end. The total length of the hub 11 is... hThe heights of the guide section 111, the pressurization section 112, and the wake section 113 are, in order: h 1. h 2 and h 3; among which h= h 1+ h 2+ h 3, 1 / 8≤ h 1 / h ≤1 / 5, 2 / 4≤ h 2 / h ≤3 / 5.

[0028] The guide section 111 is located near the end of the hub 11 and is used to guide blood flow towards the booster section 112. The guide section 111 is similar to a bullet tip, which, compared to a pointed tip, prevents excessive changes in blood flow direction, improves the overall stability of the impeller, and is beneficial for production. The booster section 112 and the wake section 113 are located at axial A... x The diameter increases linearly from proximal to distal, reducing blood turbulence. The pressurization section 112 is equipped with blades 12, with at least two blades. The tail section 113 has a dorsal blade 14 at its distal end. See... Figure 2B In the design, the maximum diameter of the wake section of the hub 11 is d2, and the outer diameter d1 of the impeller 10 is determined by the blades 12. Where 1 / 3 ≤ d2 / d1 ≤ 1 / 2.

[0029] The continuous rotation of the impeller blades converts energy from the impeller into the fluid working medium, increasing blood flow rate and pressure. The height of blade 12 is its length along a direction perpendicular to the axial direction A. x The radial direction Ra is the height of the blade protruding from the hub 11. The blade 12 is located on the supercharger section 112 of the hub 11, with a height of [missing information]. h 2. The blade 12 includes a blade tip 121, a blade root 122, a leading edge 123, and a trailing edge 124. The connection point between the blade root 122 and the outer circumferential surface of the hub 11 has a rounded corner. This rounded corner design reduces sharp edges at the connection point, lowering the risk of hemolysis. The radius of the rounded corner ε is between 0.1 mm and 0.3 mm. (See reference...) Figure 2B The blade wrap angle is the angle between the line connecting the leading edge 123 of blade 12 to the center of the circle and the line connecting the trailing edge 124 of blade 12 to the center of the circle. The blade wrap angle of blade 12 is between 100° and 120°, and this design can ensure high hydraulic efficiency.

[0030] The tail section 113 is designed with multiple back blades 14. The design of the back blades 14 allows for accelerated blood flow out of the tail section 113, reducing blood stagnation time and helping to reduce the risk of thrombosis. The number of back blades 14 is at least two, located along the axial direction A. x The height of the upper back blades is h 4. Height of the back blades h 4 is less than or equal to the overall height of the wake section 113h 3.

[0031] like Figure 1B The diagram shows one embodiment of the back blade, where the back blade 14 is a straight blade structure. The width of the back blade 14 is... w 1. Length w 2. Back blade width w 1 and back blade length w 2. Affects blood flow rate. Taking into account the difficulty of processing technology and impeller structure, the width of the back blades... w 1. It needs to satisfy 1 / 8 ≤ w 1 / d2≤1 / 6, back blade length w 2 should satisfy 1 / 3 ≤ w 2 / d2≤1 / 2.

[0032] like Figure 2A and Figure 2B As shown, this is the second embodiment of the present invention. The main difference between the second embodiment and the first embodiment is the structure of the back blade. In this embodiment, the back blade 14a is a curved blade structure, and the width of the back blade 14a is... w 3. Length w 4. The bending angle ϕ of the back blade 14a. The back blade 14a adopts a curved structure, increasing its length within a limited area, increasing the working area for blood flow, and facilitating the flow of blood along the arc out of the tail section 113. Further, the width of the back blade 14a is... w 3 should satisfy 1 / 8 ≤ w 3 / d² ≤ 1 / 6, length w 4. It should satisfy 1 / 3 ≤ w 4 / d2≤1 / 2. The bending angle ϕ satisfies 30°≤ϕ≤45°.

[0033] refer to Figure 3 In the blood pump 10, there are impeller 100, pump housing 200, base 300, motor shaft 400 and bearing 500. Figure 4The motor shaft 400 is assembled with the impeller 10's bore shaft 13 via a tight fit, welding, or glue. The pump casing has an inlet 101 and an outlet 102. The inlet 101 is very close to the guide section 111 of the impeller hub 11. The casing 200 includes multiple support columns 210, with the outlet 102 formed between two supports 210. The outlet 102 is located entirely at the tail end of the impeller hub 11's tail section 113, allowing blood to be injected into the blood vessels at a certain angle. The impeller 100 is mounted in the pump casing 200 with the rotation of the motor shaft 400 to transport blood from the inlet 101 to the outlet 102. The pump casing 200 is mounted in the base 300 with the same diameter. The base 300 and the motor shaft 400 are designed with bearings 500 to ensure that the motor shaft 400 can rotate freely, thereby driving the impeller 100 to rotate freely at high speed. As the impeller 100 of the blood pump 10 rotates at high speed, the blood pressure at the inlet 201 is low, causing the blood to enter the blood pump 10 along the inlet direction 51. Under the rotation of the impeller 10, the mechanical energy of the impeller 100 is converted into the kinetic energy of most of the blood, causing the blood to be injected into the blood vessels from the outlet direction 52. A small portion of the blood flows out of the outlet 102 along the drainage direction 53 under the action of the back blade 14.

[0034] The impeller rotor can be made of 316LVM or a biocompatible polymer material, with the back blades integrally machined with the hub. The pump casing, impeller shaft, bearings, and base need to be made of biocompatible metallic materials, such as 316LVM or titanium alloys. The impeller shaft is fitted to the impeller rotor via a shaft hole and is bonded using biocompatible adhesive. The outer and inner diameters of the bearings are fitted to the base and impeller shaft respectively, and are also bonded using biocompatible adhesive. The pump casing and base are connected by laser welding or bonding, with a gap of 0.05-0.2 mm between the pump casing and the impeller tip.

[0035] See Figure 4 As shown, numerical calculations and analysis reveal that the impeller rotor with back blades can accelerate the flushing efficiency of old blood, reducing flushing time by approximately 40%. Therefore, it can be concluded that the present invention significantly improves the blood flushing effect, thereby reducing the probability of blood pooling near the impeller shaft.

Claims

1. An impeller rotor for an axial flow blood pump, characterized in that, Includes hub, blades, shaft bore, and back blades, among which, The outer diameter of the wheel hub gradually increases from the front to the rear; The two blades each include a blade root near the hub, a blade tip away from the hub, a blade leading edge, and a blade trailing edge, and the two blades are centrally symmetrically placed on the hub surface; The shaft hole is located inside the tail end face of the impeller rotor and can be used to install the impeller shaft. The back blades are located on the tail end face of the impeller rotor and are arranged around the shaft hole.

2. The impeller rotor of an axial flow blood pump according to claim 1, characterized in that, The blade, the back blade, and the hub are machined as a single unit; the material used for machining is 316LVM stainless steel, nickel-titanium alloy, or a biocompatible polymer material.

3. The impeller rotor of an axial flow blood pump according to claim 2, characterized in that, The hub includes a guide section, a booster section and a wake section. The diameter of the guide section, booster section and wake section gradually increases from the near end to the far end. The total length of the hub (11) is h. The heights of the guide section (111), booster section (112) and wake section (113) are h1, h2 and h3 respectively. Where h = h1 + h2 + h3, 1 / 8 ≤ h1 / h ≤ 1 / 5, 2 / 4 ≤ h2 / h ≤ 3 / 5.

4. The impeller rotor of an axial flow blood pump according to claim 3, characterized in that, The blade includes a blade tip, a blade root, a blade leading edge, and a blade trailing edge. The connection point between the blade root and the outer circumference of the hub has a fillet ε, the radius of which is between 0.1mm and 0.3mm. The blade wrap angle θ is the angle between the line connecting the blade leading edge and the center of the circle and the line connecting the blade trailing edge and the center of the circle, and the blade wrap angle θ is between 100° and 120°.

5. The impeller rotor of an axial flow blood pump according to claim 4, characterized in that, The back blade is a straight blade structure with a width of w1 and a length of w2. The width w1 of the back blade needs to satisfy 1 / 8≤w1 / d2≤1 / 6, and the length w2 of the back blade should satisfy 1 / 3≤w2 / d2≤1 / 2.

6. The impeller rotor of an axial flow blood pump according to claim 4, characterized in that, The back blade is a curved blade structure with a width of w3, a length of w4, and a bending angle of φ. The width of the back blade w3 should satisfy 1 / 8 ≤ w3 / d2 ≤ 1 / 6, the length of w4 should satisfy 1 / 3 ≤ w4 / d2 ≤ 1 / 2, and the bending angle φ should satisfy 30° ≤ φ ≤ 45°.

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