A centrifugal pump

Abstract

The present invention discloses a centrifugal pump, wherein the pump casing includes a front end cover, an upper casing, and a lower casing. The upper casing is centrally provided with a through hole, the front end cover covers the through hole and is connected to the top surface of the upper casing. A first annular cavity is formed between the front end cover and the upper casing, and the first annular cavity is connected to an inlet pipe. The lower casing is connected below the upper casing. An impeller is disposed between the upper and lower casings, and a main flow channel is formed between the inner side of the lower casing and the impeller. The main flow channel is connected to an outlet pipe, and the spatial angle between the inlet pipe and the outlet pipe is less than 45 degrees. The present invention can reduce occupied space, shorten the length of the connecting pipe, reduce the blood priming volume, and improve portability.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a centrifugal pump. Background Art

[0002] In recent years, mechanical circulatory support (MCS) devices, such as artificial hearts, have gradually replaced heart transplants as an effective treatment for heart failure. Since 2006, nearly 30,000 patients have received artificial heart implants; since 2013, the number of artificial heart implants has exceeded 2,500 per year, exceeding the number of heart transplants. Artificial hearts are also the core component of ECMO (extracorporeal membrane oxygenation) systems, used to provide continuous extracorporeal respiration and circulation to sustain life in patients with severe heart and lung failure.

[0003] As a life-saving medical device, an artificial heart pump (also known as a blood pump) and its wearable peripherals (controller and power supply) must function absolutely safely and flawlessly. They must be technically robust and bug-free, with an intuitive interface that prevents misoperation by different user groups (patients, caregivers, staff, and even novice users assisting patients in emergency situations). Artificial heart systems must be as small and lightweight as possible, ensuring they do not interfere with patients' daily activities or exercise. Wearable MCS systems were introduced in the early 1990s and have seen significant improvements in reliability, failure frequency, and ease of use over the past decade. Focus has been placed on technologies such as physiological control, wireless energy transmission, and remote monitoring to enhance the usability and practicality of wearable MCS systems. For extracorporeal MCS systems, the blood pump is connected to the body and other devices via tubing outside the body. Currently, wearability has not been considered in the design of the pump itself. Most extracorporeal blood pumps are centrifugal, with perpendicular inlet and outlet tubing, significantly increasing the length and space required, making them less wearable. In addition to the controller requiring a stand, a separate stand is often required for the blood pump, significantly hindering patients' daily activities and activities. Therefore, wearability and ease of use need to be considered during the structural design of the pump to increase patient satisfaction and quality of life. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a centrifugal pump that can reduce the occupied space, reduce the length of the connecting pipeline and the blood priming volume, thereby improving portability.

[0005] In order to solve the above technical problems, the present invention provides a centrifugal pump, wherein the pump casing includes a pump casing and an impeller, the pump casing includes a front end cover, an upper shell and a lower shell, a through hole is provided in the center of the upper shell, the front end cover is connected to the top surface of the upper shell and covers the through hole, a first annular cavity is formed between the front end cover and the upper shell, the first annular cavity is connected to an inlet pipe, the lower shell is connected to the bottom of the upper shell, the impeller is arranged between the upper shell and the lower shell, a main flow channel is formed between the inner side surface of the lower shell and the impeller, the main flow channel is connected to an outlet pipe, and the spatial angle between the inlet pipe and the outlet pipe is less than 45°.

[0006] Furthermore, the through hole, the first annular cavity, the impeller and the main flow channel are coaxially arranged.

[0007] Furthermore, the inlet pipe and the outlet pipe extend outward along the tangential directions of the first annular cavity and the main flow channel respectively.

[0008] Furthermore, the inlet pipe and the outlet pipe are arranged to be inclined to the same side, and the angle between the inlet pipe and the outlet pipe and the vertical plane of the impeller shaft is 10°-30°.

[0009] Furthermore, the included angle between the inlet pipe and the outlet pipe on the top projection plane is 5-30°.

[0010] Furthermore, a first guide cone and a second guide cone are relatively arranged at the center of the front end cover and the lower shell, and the lower surface of the upper shell is set to be an inclined surface matching the second guide cone.

[0011] Furthermore, the lower part of the impeller is connected to a coaxially arranged annular groove, the magnetic rotor is arranged in the annular groove, and a second annular cavity cooperating with the annular groove is provided below the lower shell, and the gap between the annular groove and the second annular cavity forms a secondary flow channel.

[0012] Furthermore, a plurality of blades are evenly installed along the circumferential direction on the upper portion of the impeller. The blades include long blades and short blades arranged at intervals, and the outer end edges of the long blades and the short blades are on a circumferential trajectory.

[0013] Furthermore, the long blades and the short blades are airfoil plates whose thickness gradually decreases from the front end to the trailing edge, and the trailing edges of the long blades and the short blades extend out of the periphery of the impeller.

[0014] Furthermore, the radius of the through hole is smaller than the inlet radius of the long blade, and the front installation angle of the long blade and the short blade is 0°~45°.

[0015] Furthermore, the inlet radius of the long blade is smaller than the radius of the through hole, and the front installation angle of the long blade and the short blade is 45°~90°.

[0016] Compared with the prior art, the centrifugal pump of the present invention has the beneficial effects of reducing occupied space, reducing the length of the connecting pipeline and reducing the blood priming volume, thereby improving portability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 1 is a schematic diagram of the overall structure of embodiment 1 of the present invention;

[0018] Figure 2 This is a projection view of embodiment 2 of the present invention;

[0019] Figure 3 is a cross-sectional view of embodiment 1 of the present invention;

[0020] Figure 4 This is a schematic diagram of the explosion structure of Example 1 of the present invention;

[0021] Figure 5 This is a top view of the structure of the impeller of Example 1 of the present invention;

[0022] Figure 6 This is a top view of the structure of the impeller of Example 2 of the present invention;

[0023] Figure 7 It is a working schematic diagram of the present invention.

[0024] Explanation of the numbers in the figure: 10, pump housing, 11, front end cover, 12, upper housing, 13, lower housing, 14, through hole, 15, first annular cavity, 16, main flow channel, 17, first guide cone, 18, second guide cone, 19, second annular cavity,

[0025] 21. Import pipeline, 22. Export pipeline,

[0026] 30. Impeller, 31. Buffer space, 32. Annular groove, 33. Magnetic rotor, 34. Secondary flow channel, 35. Long blades, 36. Short blades. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0028] The centrifugal pump of the present invention is used to transport sensitive fluids such as blood, protein macromolecular drugs, ultra-clean raw materials, fuels, etc. In this embodiment, the transport of blood is used as an example for description.

[0029] Reference Figure 1 、 Figure 3 and Figure 4FIG2 is a schematic diagram of a first embodiment of a centrifugal pump according to the present invention. The centrifugal pump according to the present invention includes a pump casing 10. To facilitate the processing and assembly of the pump casing 10, in this embodiment, the pump casing 10 comprises a front cover 11, an upper casing 12, and a lower casing 13. The front cover 11, upper casing 12, and lower casing 13 are detachably connected together by snap-fitting or bolting. A through-hole 14 is centrally located in the upper casing 12. The front cover 11 is connected to the top surface of the upper casing 12 and covers the through-hole 14. A first annular cavity 15 is formed between the front cover 11 and the upper casing 12. The first annular cavity 15 is connected to an inlet conduit 21. Blood first enters the first annular cavity 15 from the inlet conduit 21, where it is initially buffered before entering the centrifugal pump body. This effectively addresses the turbulence, shearing, impact, and flow discontinuity issues that arise in existing centrifugal pumps due to direct blood flow into the centrifugal pump body. This provides excellent downstream and ejection functions, thereby preventing the development of blood clots. To prevent the sharp corners of the through hole 14 from affecting blood flow, in this embodiment, the through hole 14 is configured as a circular hole. The lower shell 13 is connected to the lower portion of the upper shell 12, and the impeller 30 is disposed between the upper shell 12 and the lower shell 13. A main channel 16 is formed between the inner side of the lower shell 13 and the impeller 30. The main channel 16 is connected to the outlet pipe 22, and the spatial angle between the inlet pipe 21 and the outlet pipe 22 is less than 45°. That is, in any of the three views of the centrifugal pump, the angle between the inlet pipe and the outlet pipe is less than 45°. In the present invention, the theoretical range of the spatial angle between the inlet pipe 21 and the outlet pipe 22 is 0° to 180°. At this time, no matter at what angle the blood enters the first annular cavity 15 from the inlet pipe 21, due to the inertia of blood flow, the blood can be guided by the first annular cavity 15 and rotate along the first annular cavity 15 and then rush out downward from the through hole 14, and the velocity component parallel to the plane of the first annular cavity 15 is converted into a velocity component perpendicular to the plane of the first annular cavity 15, and poured into the space between the upper shell 12 and the lower shell 13, so that the blood disperses vertically downward and flows into the impeller 30. The impeller 30 rotates to provide centrifugal force for the inflowing blood, so that the blood enters the main channel 16 and then flows out from the outlet pipe 22, so that the spatial angle between the inlet pipe 21 and the outlet pipe 22 can be set to be less than 45°. Furthermore, in order to ensure that when the blood enters the impeller 30 from a vertical direction and flows downward from the top of the impeller 30 to the surrounding areas, the positions of the scattered blood are symmetrical about the rotation axis of the impeller 30, and the blood can enter the impeller 30 evenly, ensuring the balance and stability of the force on the impeller 30, the through hole 14, the first annular cavity 15, the impeller 30 and the main channel 16 are coaxially arranged.

[0030] Reference Figure 7As shown, compared to the prior art arrangement of inlet conduit 21 parallel to the impeller 30 axis, the present invention eliminates the need for auxiliary brackets to prevent the connecting pipeline from bending when connecting the heart and the centrifugal pump. This reduces the complexity of the device and significantly shortens the length of the connecting pipeline, thereby reducing the blood priming volume. To facilitate manufacturing, the non-metallic materials such as the front cover 11, inlet conduit 21, upper shell 12, lower shell 13, outlet conduit 22, and impeller 30 can be manufactured using 3D printing or injection molding.

[0031] In the first embodiment of the present invention, to ensure smooth blood flow into and out of the centrifugal pump, the inlet conduit 21 and the outlet conduit 22 extend outwardly along the tangent lines of the first annular cavity 15 and the main channel 16, respectively. That is, there are no inflection points at the junctions of the inlet conduit 21 and the first annular cavity 15, and at the junctions of the main channel 16 and the outlet conduit 22, thereby preventing obstruction to blood flow. In this embodiment, although the inlet pipe 21 is not arranged parallel to the rotation axis of the impeller 30, the cooperation between the first annular cavity 15 and the through hole 14 allows the blood to enter the impeller range from the vertical direction, and disperse downward from the top of the impeller 30 to the surrounding areas, without directly impacting the impeller 30 from the side of the impeller 30. In this way, when the blood contacts the top surface of the impeller 30 and begins to accelerate under the centrifugal action of the impeller 30, the angle between the blood velocity direction and the rotation direction of the impeller 30 is symmetrical about the rotation axis of the impeller 30 in the circumferential direction, that is, the pressure on the impeller 30 in the lateral direction can be balanced with each other, thereby avoiding causing additional vibration of the impeller 30 near the through hole 14, and thus avoiding the adverse phenomenon of hemolysis as much as possible. Further, referring to Figure 7 As shown, since the centrifugal pump is located below the heart during use, the connecting pipeline is connected to the inlet pipe 21 and the outlet pipe 22 and extends upward to connect to the heart. To ensure that the connecting pipeline does not bend at the connection with the inlet pipe 21 and the outlet pipe 22, the inlet pipe and the outlet pipe are parallel to each other in a top projection plane. At this time, the angle between the inlet pipe and the outlet pipe is 0°.

[0032] Reference Figure 2The figure shows a schematic projection diagram of a second embodiment of the present invention. In this embodiment, the inlet and outlet pipes 21 and 22 are tilted toward the same side, and the angle between the inlet and outlet pipes 21 and 22 and the perpendicular plane of the impeller 30 is 10°-30°. The inlet and outlet pipes 21 and 22 are tilted at a small angle toward one side of the centrifugal pump. When worn, one side of the centrifugal pump is against the body, while the inlet and outlet pipes 21 and 22 are tilted away from the body. This ensures that the connection between the connecting line and the inlet and outlet pipes 21 and 22 is smooth and prevents friction with clothing at the connection, which could affect the stability of the connection. In this embodiment, the angle between the inlet and outlet pipes is preferably 20°. To prevent obstruction of blood flow within the centrifugal pump, the connection between the inlet and outlet pipes 21 and the first annular cavity 15 and the connection between the outlet pipe 22 and the main channel 16 are both smooth. Furthermore, in order to match the distance between the ends of the inlet pipe 21 and the outlet pipe 22 with the distance between the two connection points of the heart, and to ensure smooth and smooth connection between the connecting pipeline, the centrifugal pump and the heart, the angle between the inlet pipe and the outlet pipe in the top projection plane is 5-30°. In other embodiments of the present invention, the inclination angle of the inlet pipe 21 and the outlet pipe 22 along the direction of the impeller 30 can be different, and the angle of access to the first annular cavity 15 and the main flow channel 16 can also be different, as long as the spatial angle between the inlet pipe 21 and the outlet pipe 22 is less than 45°. That is, the angle between the inlet pipe and the outlet pipe can also be any angle, such as 10° or 30°.

[0033] Reference Figure 3 As shown, the front end cover 11 and the lower shell 13 are centrally positioned with a first guide cone 17 and a second guide cone 18. The lower surface of the upper shell 12 is configured as an inclined surface that matches the curvature of the second guide cone 18, thereby forming a buffer zone 31 between the upper shell 12 and the impeller 30. The configuration of the first guide cone 17 maximizes the circular or elliptical cross-section of the first annular cavity 15, preventing the formation of dead zones within the first annular cavity 15 that could lead to blood clotting. The configuration of the second guide cone 18 and the inclined surface of the upper shell 12 ensures that the cross-sectional area of ​​the buffer zone 31 varies approximately linearly, meaning that the cross-sectional area through which blood flows varies approximately linearly. The fluid velocity theoretically decreases linearly, reducing the likelihood of flow separation.

[0034] Reference Figure 3As shown, to prevent the formation of dead zones within the centrifugal pump that can lead to blood clotting while driving the impeller 30, a coaxial annular groove 32 is connected to the lower portion of the impeller 30. A magnetic rotor 33 is disposed within the annular groove 32. A second annular cavity 19 is disposed below the lower shell 13, cooperating with the annular groove 32. The gap between the annular groove 32 and the second annular cavity 19 forms a secondary flow channel 34, allowing blood to flow through. This avoids the formation of dead zones, ensures good blood flushing, prevents thrombosis, and achieves excellent biocompatibility. In this embodiment, the gap in the secondary flow channel is 1.0 mm to 1.5 mm. This larger gap ensures good blood compatibility.

[0035] In this embodiment, the impeller 30 is equipped with a plurality of blades evenly distributed along the circumference of the upper portion, extending away from the axis of rotation. To prevent blood from clogging the through-hole 14 and to enhance the flow guidance at the inlet, reducing flow turbulence, the blades include spaced long blades 35 and short blades 36. The outer edges of the long blades 35 and short blades 36 align on a circular trajectory. Specifically, the long blades 35 and short blades 36 have different inlet radii but the same outlet radii. This prevents the different extension lengths of the blades from hindering blood flow within the main channel 16. This ensures consistent blood flow rate and direction upon entering the main channel 16 after being driven and guided by the impeller 30, achieving orderly blood outflow. Furthermore, the long blades 35 and short blades 36 are airfoil-shaped plates whose thickness gradually decreases from the leading edge to the trailing edge. The trailing edges of the long blades 35 and short blades 36 extend beyond the periphery of the impeller 30. This reduces stress concentration, generates a sufficient pressure head, and provides sufficient power for blood flow. The wrap angle φ of the long blade 35 is 30-60°, preferably 45°. For a pump that transports biomacromolecule media, such as blood, this angle can reduce the total media contact area in the pump, lower the probability of platelet activation, and reduce the risk of thrombosis.

[0036] Reference Figure 5 The figure shows the structure of the impeller in the first embodiment of the present invention. In this embodiment, the radius of the through hole 14 is smaller than the inlet radius r1 of the long blade 35, and the front installation angle β of the long blade 35 and the short blade 36 is 0°~45°. When the blood flows downward through the through hole, the blood first enters the middle position of each blade. At this time, since the blood is not blocked on all sides, the blood tends to diffuse rapidly outward along the radius of the pump housing 10. In order to slow down the impact speed of the blood, each blade should be set as perpendicular to the direction of blood impact as possible. Therefore, the front installation angles of the long blade and the short blade set in this embodiment are relatively small. The blood collides with the surface of the blade, and the blade absorbs the impact force of the blood, reducing the degree of flow disorder, guiding the flow of blood, and making the blood flow out in an orderly manner.

[0037] Reference Figure 6As shown, the structure of the impeller in the second embodiment of the present invention is shown. In this embodiment, the inlet radius r1 of the long blades 35 is smaller than the radius of the through hole 14, and the front installation angle β of the long blades 35 and the short blades 36 is 45° to 90°. When blood flows downward through the through hole, the blood directly enters the flow channel formed by the intervals between the blades. At the same time, due to the presence of the secondary flow channel 34, the actual flow rate in the flow channel between the blades is higher than the inlet flow rate. In order to quickly discharge the blood, the liquid flow angle at the leading edge of the blades needs to be larger. Therefore, in this embodiment, the front installation angle of the long blades and the short blades is set larger.

[0038] During operation, blood flowing from the human body enters the first annular cavity 15 through the inlet pipe 21, rotates around the first annular cavity 15 for buffering, then enters the buffer space 31 from top to bottom through the through hole 14. Guided by the second guide cone 18, it is dispersed into the surrounding impeller 30. Driven by the magnetic rotor 33, the impeller 30 rotates, providing power for the blood flowing into it, causing the blood to flow into the main channel 16 and out toward the outlet pipe 22. A portion of the blood in the main channel 16 flows into the secondary channel 34, then flows back into the middle of the impeller 30 and into the impeller 30. Driven by the impeller 30, it flows back into the main channel 16, then out of the outlet pipe 22 and into the human body again, completing the extracorporeal circulation of blood. In the present invention, since the angle between the inlet pipe 21 and the outlet pipe 22 is small, when the connecting pipeline is connected to the inlet pipe 21 and the outlet pipe 22 respectively and extends in the same direction, no large bends will be generated at the connection between the connecting pipeline and the inlet pipe 21 and the outlet pipe 22, thereby reducing the complexity of the equipment during use, greatly shortening the length of the connecting pipeline, and reducing the blood priming volume.

[0039] The above embodiments are merely preferred embodiments for the purpose of fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

Claims

1. A centrifugal pump, characterized in that: The pump casing includes a front end cover, an upper shell and a lower shell, a through hole is provided in the center of the upper shell, the front end cover is connected to the top surface of the upper shell and covers the through hole, a first annular cavity is formed between the front end cover and the upper shell, a first guide cone is provided in the center of the front end cover, the setting of the first guide cone makes the cross-section of the first annular cavity form a circle or an ellipse, the first annular cavity is connected to an inlet pipe, the lower shell is connected to the bottom of the upper shell, the impeller is arranged between the upper shell and the lower shell, a main flow channel is formed between the inner side surface of the lower shell and the impeller, the main flow channel is connected to an outlet pipe, the inlet pipe and the outlet pipe extend outward along the tangent direction of the first annular cavity and the main flow channel respectively, and the spatial angle between the inlet pipe and the outlet pipe is less than 45°.

2. A centrifugal pump according to claim 1, characterized in that: The through hole, the first annular cavity, the impeller and the main flow channel are coaxially arranged.

3. A centrifugal pump according to claim 1, characterized in that: The through hole is a circular hole.

4. A centrifugal pump according to claim 1, characterized in that: The inlet pipe and the outlet pipe are parallel to each other in a top projection plane.

5. A centrifugal pump according to claim 1, characterized in that: The inlet pipe and the outlet pipe are arranged to be inclined to the same side, and the angle between the inlet pipe and the outlet pipe and the vertical plane of the impeller shaft is 10°-30°.

6. A centrifugal pump according to claim 5, characterized in that: The included angle between the inlet pipe and the outlet pipe on the top projection plane is 5-30°.

7. A centrifugal pump according to claim 1, characterized in that: The spatial angle between the inlet pipe and the outlet pipe is 0°, 10°, 20° or 30°.

8. A centrifugal pump according to claim 1, characterized in that: A first guide cone and a second guide cone are arranged opposite to each other in the center of the front end cover and the lower shell, and the lower surface of the upper shell is arranged to be an inclined surface matching the second guide cone.

9. A centrifugal pump according to claim 1, characterized in that: The lower part of the impeller is connected to a coaxial annular groove, the magnetic rotor is arranged in the annular groove, and a second annular cavity cooperating with the annular groove is arranged below the lower shell, and the gap between the annular groove and the second annular cavity forms a secondary flow channel.

10. A centrifugal pump according to claim 9, characterized in that: The gap of the secondary flow channel is 1.0mm-1.5mm.

11. A centrifugal pump according to claim 1, characterized in that: A plurality of blades are evenly mounted on the upper portion of the impeller along the circumferential direction. The blades include long blades and short blades that are spaced apart. The outer end edges of the long blades and the short blades are on a circumferential track.

12. A centrifugal pump according to claim 11, characterized in that: The long blades and the short blades are airfoil plates whose thickness gradually decreases from the front end to the trailing edge, and the trailing edges of the long blades and the short blades extend out of the periphery of the impeller.

13. A centrifugal pump according to claim 11, characterized in that: The radius of the through hole is smaller than the inlet radius of the long blade, and the front installation angle of the long blade and the short blade is 0°~45°.

14. A centrifugal pump according to claim 11, characterized in that: The inlet radius of the long blade is smaller than the radius of the through hole, and the front installation angle of the long blade and the short blade is 45° to 90°.

15. A centrifugal pump according to claim 1, characterized in that: The connection between the inlet pipe and the first annular cavity and the connection between the main channel and the outlet pipe both have smooth transitions.

16. A centrifugal pump according to claim 1, characterized in that: The front end cover, the upper shell and the lower shell are detachably connected together by snap connection or bolts.

17. A centrifugal pump according to claim 1, characterized in that: The front end cover, inlet pipe, upper shell, lower shell, outlet pipe and impeller are processed and formed by 3D printing or injection molding.

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