Impeller for miniature axial flow blood pump
By designing a drainage section and drainage hole in the impeller of the miniature axial flow blood pump, the problem of thrombosis between the impeller and the base was solved, thereby improving the stability of blood flow and the reliability of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2026-03-31
AI Technical Summary
Blood clots can easily form in the fluid area between the impeller and the base of a miniature axial flow blood pump, affecting blood flow and equipment stability.
Design an impeller including a hub, twisted blades, shaft hole and drainage hole, so that some blood can be forced into the fluid area between the impeller and the base through the drainage section and drainage hole to flush and prevent thrombosis.
Effective flushing of the fluid area between the impeller and the base reduces the risk of thrombosis, improves blood flow stability, and enhances the operational reliability of the equipment.
Smart Images
Figure CN224056461U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of medical devices, specifically relating to an impeller for a miniature axial flow blood pump. Background Technology
[0002] Miniature axial flow blood pumps are inserted percutaneously into the ventricle via interventional methods. They draw blood into the arterial system through pumping action, partially or completely replacing the heart's pumping function. The aim is to reduce left ventricular load, myocardial load and oxygen consumption, while increasing cardiac output and perfusion of the coronary arteries and end organs. A typical miniature axial flow blood pump consists of a pump housing with a blood inlet and a blood outlet. An impeller is rotatably supported within the pump housing and rotates at high speed, converting mechanical energy into kinetic energy of the blood, resulting in high-speed and high-pressure perfusion of blood into the blood vessels. The impeller is driven by a motor shaft, which is constrained by bearings in the base to rotate at high speed. Low blood flow or even cessation of flow can easily occur in the fluid region between the impeller and the base. Summary of the Invention
[0003] The purpose of this invention is to provide an impeller for a miniature axial flow blood pump, which solves the problem of easy thrombosis in the fluid area between the impeller and the base.
[0004] To achieve the above objectives, the present invention adopts the following technical solution:
[0005] An impeller for a miniature axial flow blood pump includes a hub, twisted blades, a shaft bore, and a drainage hole, wherein...
[0006] The outer diameter of the wheel hub gradually increases from the front to the rear;
[0007] The twisted blade is placed on the hub surface and includes a blade root near the hub, a blade tip away from the hub, a blade leading edge, and a blade trailing edge.
[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 drainage hole is located at the rear of the wheel hub.
[0010] Along the axial direction A of the impeller x The hub includes a guide section, a booster section, a wake section, and a diversion section. The diameters of the guide section, booster section, and wake section gradually increase linearly from the near end to the far end along the axial direction, and the rate of increase in diameter remains constant. The diversion section increases along the axial direction, but its rate of increase in diameter is not equal to that of the wake section. The guide section is located at the head of the hub. The booster section is provided with twisted blades, and the diversion section is provided with several diversion holes.
[0011] The total length of the hub is h, and the heights of the guide section, booster section, wake section, and diversion section are h1, h2, h3, and h4, respectively; where h = h1 + h2 + h3 + h4, 1 / 8≤h1 / h≤1 / 6, 1 / 4≤h2 / h≤3 / 6, 1 / 10≤h3 / h≤1 / 8, h4≤h3, the guide section is located at the head of the hub, the twisted blade is located on the booster section of the hub, the height is h2, the maximum diameter of the wake section of hub 11 is d2, the outer diameter of the impeller d3 is determined by the twisted blade, where 1 / 3≤d2 / d3≤1 / 2, the initial diameter of the guide section of the hub is d1, its diameter increase rate is k1, the booster section and the wake section increase linearly along the diameter increase rate k1, the end diameter of the wake section is d2, the guide section increases linearly along the diameter increase rate k2, the end diameter is d4, the end diameter of the guide section is d4 is less than or equal to the outer diameter of the impeller d3, the diameter increase rate of the guide section k1 is less than or equal to the diameter increase rate of the guide section k2.
[0012] The blade has a height of h2 and 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 0.3mm and 0.5mm.
[0013] The beneficial effects of this invention are as follows: By designing a flow-guiding section on the impeller and a flow-guiding hole on the section, a small portion of blood is directed to flow into the fluid area between the impeller and the base, effectively flushing this area. Simultaneously, the flow-guiding section and the pump housing outlet are at the same axial height, ensuring that most of the blood flows out along the outlet. Attached Figure Description
[0014] To more clearly illustrate the embodiments of this utility model, the embodiments will be described below in conjunction with the accompanying drawings.
[0015] Figure 1 This is a front view of the impeller structure of this utility model.
[0016] Figure 2 This is a three-dimensional structural diagram of the impeller of this utility model.
[0017] Figure 3 This is an axial cross-sectional view of the impeller of this utility model.
[0018] Figure 4 This is an assembly drawing of the impeller and pump housing of the blood pump of this utility model.
[0019] Figure 5 This is a schematic diagram of the blood flow area of the impeller and pump housing of the blood pump of this utility model. Detailed Implementation
[0020] The following examples illustrate possible implementations of the present invention, but are not intended to limit the scope of protection of the present invention.
[0021] 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.
[0022] Please see Figure 1 and Figure 2 This utility model discloses an impeller 100 for a miniature axial flow blood pump, comprising a hub 11, twisted blades 12, a shaft hole 13, and a drainage hole 14. Along the axial direction A of the impeller 100... x The hub 11 includes a guide section 111, a booster section 112, a wake section 113, and a diversion section 114. The guide section 111, booster section 112, and wake section 113 are aligned along the axial direction A. x The diameter gradually increases linearly from proximal to distal, with a constant rate of increase. Drainage segment 114 is along the axial direction A. x The diameter increase rate is not equal to the diameter increase rate of the wake section 113. The total length of the hub 11 is h, and the heights of the guide section 111, the booster section 112, the wake section 113, and the diversion section 114 are h1, h2, h3, and h4, respectively; where h = h1 + h2 + h3 + h4, 1 / 8 ≤ h1 / h ≤ 1 / 6, 1 / 4 ≤ h2 / h ≤ 3 / 6, 1 / 10 ≤ h3 / h ≤ 1 / 8, and h4 ≤ h3.
[0023] 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 guide section 111, booster section 112, and tail section 113 are aligned along the axial direction A. x The diameter increases linearly from proximal to distal, which reduces blood turbulence. The pressurization section 112 is designed with twisted blades 12, and the number of twisted blades is at least two. The drainage section 114 is provided with drainage holes 14.
[0024] The continuous rotation of the impeller and the twisting blades convert energy from the impeller into the working fluid, increasing blood flow rate and pressure. The height of the twisted blade 12 is its radial height R perpendicular to the axial direction Ax, protruding from the hub 11. The twisted blade 12 is located on the pressurization section 112 of the hub 11, with a height of h2. The twisted blade 12 includes a blade tip 121, a blade root 122, a blade leading edge 123, and a blade trailing edge 124. The connection point between the blade root 122 and the outer circumferential surface of the hub 11 has a rounded corner. The rounded corner design reduces sharp edges at the connection, lowering the risk of hemolysis. The radius of the rounded corner ε is between 0.3mm and 0.5mm.
[0025] Figure 1 and Figure 2 As shown, the drainage section 114 is designed with multiple drainage holes 14, which are inclined and extend through the entire drainage section 114. The design of the drainage holes 14 allows some blood in the tail section 113 to flow in more quickly, reducing blood stagnation time and helping to reduce the risk of thrombosis. The number of drainage holes 14 is at least two.
[0026] Now Figure 3 In the design, the maximum diameter of the wake section of hub 11 is d2, and the outer diameter d3 of impeller 10 is determined by the twisted blade 12. Where 1 / 3 ≤ d2 / d3 ≤ 1 / 2. The initial diameter of guide section 111 of hub 11 is d1, and its diameter increases at a rate of k1. The booster section 112 and wake section 113 increase linearly along the diameter increase rate k1, with the final diameter of wake section 113 being d2. The diversion section 114 increases linearly along the diameter increase rate k2, with a final diameter of d4. The diameter of twisted blade 12 is d3. Further, the final diameter of diversion section 114, d4, is less than or equal to the diameter of twisted blade 12, d3. The diameter increase rate k1 of guide section 111 is less than or equal to the diameter increase rate k2 of diversion section 114.
[0027] refer to Figure 4 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 adjacent to the guide section 111 of the impeller hub 11. The pump casing 200 has multiple supports 210, with the outlet 102 formed between two supports 210. The upper end of the outlet 102 faces the tail of the impeller hub 11's tail section 113. The outlet 102 allows blood to be infused into the blood vessels at an angle of less than 60 degrees along the outlet direction. The impeller 100 can be mounted in the pump casing 200 under the rotation of the motor shaft 400 to transport blood from the inlet 101 to the outlet 102. The pump casing 200 is assembled 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.
[0028] Figure 5 This is a schematic diagram illustrating the flow of blood in a blood pump. Figure 5 The linear object fills the area 120 where blood is present. Under the high-speed rotation of the impeller 100 of the blood pump 10, the blood pressure at the inlet 201 is low, causing blood to enter the blood pump 10 along the inlet direction 20. Under the high-speed rotation of the impeller 100, the mechanical energy of the impeller 100 is converted into the kinetic energy of most of the blood, and the accelerated blood flows from the acceleration direction 30 to the tail section. Most of the blood flows along the outlet direction 31 through the outlet 102 into the blood vessels, while a small portion flows out of the outlet 102 along the drainage direction 32 under the action of the drainage hole 14.
[0029] To further explain, the impeller 100 is a rotating part, while the base 300 is a stationary part. The gap region 130 between the impeller 100 and the base 300 is a region with relatively slow fluid velocity, where blood flow stagnation, blood coagulation, and blood clots are prone to occur. By designing a drainage section 114 on the impeller and drainage holes 14 on the drainage section 114, a small amount of blood is encouraged to enter the gap region 130 along the drainage holes 14, effectively flushing this area. Simultaneously, the drainage section 114 and the outlet 102 are axially aligned. x The blood is at the same height, ensuring that most of the blood flows out along the outlet direction 31.
Claims
1. An impeller for a micro axial flow blood pump, characterized in that, The wheel hub, the twisted blade, the shaft hole and the flow guide hole, wherein, The outer diameter of the wheel hub gradually increases from the head to the tail; The twisted blade is arranged on the surface of the wheel hub, including the blade root close to the wheel hub, the blade tip away from the wheel hub, the blade leading edge and the blade trailing edge; The shaft hole is arranged in the tail end surface of the impeller rotor and can be used for mounting the impeller shaft; The flow guide hole is arranged at the tail of the wheel hub.
2. An impeller for a micro axial flow blood pump according to claim 1, wherein, along an axial direction A of the impeller x The hub comprises a guide section, a booster section, a wake section and a lead-in section. The guide section, the booster section and the wake section have a gradually linearly increasing diameter from a proximal end to a distal end along the axial direction, and the diameter increasing rate remains unchanged. The lead-in section has an increasing diameter along the axial direction, and the diameter increasing rate is not equal to that of the wake section. The guide section is located at the head of the hub, the booster section is provided with twisted blades, and the lead-in section is provided with a plurality of lead-in holes.
3. An impeller for a micro axial flow blood pump according to claim 2, wherein, The total length of the wheel hub is h, and the heights of the guide section, the pressurization section, the tail flow section and the flow guide section are h1, h2, h3 and h4 in sequence; wherein h = h1+h2+h3+h4, 1 / 8≤h1 / h≤1 / 6, 1 / 4≤h2 / h≤3 / 6, 1 / 10≤h3 / h≤1 / 8, h4≤h3, the guide section is located at the head of the wheel hub, the twisted blade is located on the pressurization section of the wheel hub, the height is h2, the maximum diameter of the tail flow section of the wheel hub 11 is d2, the outer diameter d3 of the impeller is determined by the twisted blade, wherein 1 / 3≤d2 / d3≤1 / 2, the initial diameter of the guide section of the wheel hub is d1, the diameter increasing rate is k1, the pressurization section and the tail flow section increase linearly along the diameter increasing rate k1, the end diameter of the tail flow section is d2, the flow guide section increases linearly along the diameter increasing rate k2, the end diameter is d4, the end diameter d4 of the flow guide section is less than or equal to the outer diameter d3 of the impeller, and the diameter increasing rate k1 of the guide section is less than or equal to the diameter increasing rate k2 of the flow guide section.
4. An impeller for a micro axial flow blood pump according to claim 3, wherein, The height of the blade is h2, the blade includes the blade tip, the blade root, the blade leading edge and the blade trailing edge, the connecting point of the blade root and the outer circumferential surface of the wheel hub has a round corner, and the radius of the round corner ε is between 0.3mm-0.5mm.