Blood pump

Abstract

The present invention relates to a blood pump, which comprises a casing provided with a liquid inlet and a liquid outlet; and an impeller, at least a part of which is rotatably arranged in the casing to convey liquid from the liquid inlet to the liquid outlet. The impeller includes a hub and blades, the blades protrude radially from the hub along the casing, and the minimum clearance between the blades and the inner wall of the casing is δ, and the inner diameter of the casing is D, wherein 2% ≤ δ / D ≤ 3%. In this way, it is possible to avoid the destruction of blood in this minimum clearance, thereby avoiding hemolysis, and it is also possible to eliminate secondary flow to improve the hydraulic performance of blood flow, improve the pumping efficiency of the blood pump, and reduce the processing and assembly difficulty of the impeller, avoid damage to the impeller and the casing during the assembly process, and then avoid the damaged impeller and casing from damaging the blood, further eliminating hemolysis, and finally enabling the blood pump to improve the pumping efficiency on the basis of avoiding hemolysis.

Description

Technical Field

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

[0002] An intravascular blood pump is a blood pumping device that can be inserted into a patient's heart through the patient's blood vessels. The intravascular blood pump is placed within the opening of the heart valve so that blood can flow through the blood pump and into the arterial blood vessels. However, for traditional blood pumps, during the process of transporting blood, there are usually defects such as low pumping efficiency and hemolysis phenomenon caused by blood damage, making it difficult to meet the surgical requirements. Summary of the Invention

[0003] One technical problem solved by the present invention is how to improve the pumping efficiency of the blood pump on the basis of avoiding hemolysis phenomenon; the present invention solves the above technical problem through the following technical solutions.

[0004] The present invention provides a blood pump, comprising:

[0005] A sleeve, the sleeve is provided with a liquid inlet and a liquid outlet; and

[0006] An impeller, at least part of the impeller is rotatably arranged within the sleeve to transport liquid from the liquid inlet to the liquid outlet. The impeller includes a hub and blades. The blades protrude radially from the hub along the sleeve. The minimum clearance between the blades and the inner wall of the sleeve is δ, and the inner diameter of the sleeve is D, where 2% ≤ δ / D ≤ 3%.

[0007] In one embodiment, the range of the minimum clearance δ between the blades and the inner wall of the sleeve is: 0.05 - 0.3 mm, and the range of the inner diameter D of the sleeve is 3 - 10 mm.

[0008] In one embodiment, the hub includes a guiding section where no blades are provided. The diameter of the guiding section gradually increases from the distal end to the proximal end. The length of the guiding section is L1, and the total length of the hub is L, where 1 / 10 ≤ L1 / L ≤ 1 / 5.

[0009] In one embodiment, the hub further includes a boosting section. The boosting section is connected to the proximal end of the guiding section. The diameter of the boosting section gradually increases from the distal end to the proximal end. The blades are arranged on the boosting section. The length of the boosting section is L2, where 1 / 3 ≤ L2 / L ≤ 3 / 4.

[0010] In one embodiment, the hub further includes a flow-discharging section connected to the proximal end of the pressurizing section. The blades are also provided on the flow-discharging section. The diameter of the flow-discharging section gradually increases from the distal end to the proximal end, and the increasing manner of the diameters of the pressurizing section and the flow-discharging section is different. The length of the flow-discharging section is L3, where 1 / 4 ≤ L3 / L ≤ 2 / 5.

[0011] In one embodiment, the number of the blades is multiple, and the multiple blades are arranged at intervals in the circumferential direction of the hub. The angle occupied by a single blade in the circumferential direction of the hub is denoted as the included angle θ, where 90° ≤ θ ≤ 220°.

[0012] In one embodiment, the casing is further provided with a conveying cavity. The impeller is at least partially rotatably arranged in the conveying cavity. The liquid outlet is arranged on the outer peripheral wall of the casing and communicates with the conveying cavity. The height of the liquid outlet in the axial direction of the casing is H, and the total length of the hub is L, where 1 / 5 ≤ H / L ≤ 1 / 3.

[0013] In one embodiment, the liquid outlet includes a first outlet and a second outlet. The connection line between one ends of the first outlet and the second outlet in the axial direction of the casing is the first connection line, and the connection line between the other ends of the first outlet and the second outlet in the axial direction of the casing is the second connection line. Both the first connection line and the second connection line extend along the circumferential direction of the casing. The first contour line where the first outlet is close to the second outlet is connected between the first connection line and the second connection line. The area surrounded by the first connection line, the second connection line, the first contour line and the second contour line is the blocking area. The area of the positive projection of the blocking area in the radial direction of the casing is S, where 10% ≤ S / (πHD 2 / 4) ≤ 30%.

[0014] In one embodiment, the blood pump further includes a driving assembly. The driving assembly is in transmission connection with the impeller. The casing is sleeved on one end of the driving assembly. The tangent line of the end of the hub close to the driving assembly intersects with the contour line on the side of the liquid outlet close to the driving assembly.

[0015] In one embodiment, along the direction away from the hub, the thickness of the blade remains unchanged; and / or, the thickness of the blade is T, where 3% ≤ T / D ≤ 7%.

[0016] In one embodiment, the blade includes a working surface and a back surface. Both the working surface and the back surface are connected to the outer peripheral surface of the hub. One end of the working surface close to the liquid outlet and one end of the back surface close to the liquid outlet face away from each other. One end of the working surface close to the liquid inlet and one end of the back surface close to the liquid inlet are transitioned by a rounded corner.

[0017] Compared with the prior art, for the blood pump provided by the present invention, the ratio of the minimum clearance δ between the blade and the inner wall of the casing to the inner diameter D of the casing satisfies: 2% ≤ δ / D ≤ 3%. This can prevent blood from being damaged in this minimum clearance, thereby avoiding hemolysis; it can also eliminate secondary flow to improve the hydraulic performance of blood flow and increase the pumping efficiency of the blood pump; and it can reduce the processing and assembly difficulty of the impeller, prevent damage to the impeller and the casing during the assembly process, and then avoid damage to the blood caused by the damaged impeller and casing, further eliminating hemolysis. Ultimately, the blood pump can improve the pumping efficiency on the basis of avoiding hemolysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic three-dimensional structure diagram of the blood pump provided by the present invention.

[0019] Figure 2 is Figure 1 a partial structure diagram of the shown blood pump after removing the drive assembly.

[0020] Figure 3 is Figure 2 a partial enlarged view at A.

[0021] Figure 4 is Figure 2 a sectional view along the direction of B - B.

[0022] Figure 5 is Figure 1 a schematic three-dimensional view of the impeller of the shown blood pump.

[0023] Figure 6 is Figure 1 a top view of the shown blood pump. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0025] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "inner", "outer", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation.

[0026] In this article, "proximal end" is defined as the end close to the medical staff; "distal end" is defined as the end far from the medical staff, that is, the end close to the patient's heart.

[0027] The inventors of the present application found that a blood pump generally includes an impeller, a casing and a drive assembly. The drive assembly is used to drive the impeller to rotate in the casing, so that blood is pumped through the casing to the arterial blood vessel. However, in the process of using a traditional blood pump, on the one hand, there are defects such as low pumping efficiency due to poor hydraulic performance, and on the other hand, there are also defects such as hemolysis phenomenon due to blood damage, so that the blood pump is difficult to meet the needs of intensive surgery.

[0028] To improve at least some of the above problems, refer to Figure 1 This application proposes a blood pump 10. The blood pump 10 can improve the pumping efficiency on the basis of avoiding hemolysis phenomenon. The following is a detailed description of the blood pump 10 provided by this application.

[0029] Please refer to Figures 1 to 3 As shown in, the blood pump 10 provided by the embodiment of the present invention includes a casing 100, an impeller 200 and a drive assembly 300. The drive assembly 300 includes a driver (not shown in the figure) and a housing 310. The driver is housed in the housing 310. The housing 310 plays a role of housing and protecting the driver. One end of the housing 310 is connected to the casing 100. For example, the casing 100 can be sleeved on one end of the housing 310. The driver is connected to the impeller 200 through an output shaft. When the driver drives the output shaft to rotate, the impeller 200 fixedly connected to the output shaft will rotate synchronously with the output shaft. The rotating impeller 200 generates a pumping force on the blood, so as to realize the transportation of blood by the entire blood pump 10.

[0030] Please refer to Figures 2 to 4, in some embodiments, the cannula 100 may be a cylindrical tubular structure, that is, the cross-sectional profile of the cannula 100 is circular. The cannula 100 defines a delivery cavity 110. An inlet 120 is formed at one end of the delivery cavity 110 away from the drive assembly 300. An outlet 130 is provided on the outer peripheral surface of the cannula 100, and the outlet 130 communicates the delivery cavity 110 with the outside. The impeller 200 is at least partially received in the delivery cavity 110. When the drive assembly 300 drives the impeller 200 to rotate, under the action of the pumping force generated by the rotation of the impeller 200, blood will flow into the delivery cavity 110 from the inlet 120 and finally flow out of the delivery cavity 110 through the outlet 130, thereby realizing the delivery of blood.

[0031] Refer to Figure 4 , in some embodiments, the width of the minimum clearance between the impeller 200 and the cannula 100 in the radial direction of the cannula 100 is denoted as δ, that is, δ is the minimum clearance between the impeller 200 and the inner wall of the cannula 100. The inner diameter of the cannula 100 is denoted as D. Obviously, the inner diameter D is the diameter of the delivery cavity 110. Among them, 2% ≤ δ / D ≤ 3%. Such a setting can avoid the destruction of blood in the minimum clearance, thereby avoiding hemolysis; it can also eliminate secondary flow to improve the hydraulic performance of blood flow and improve the pumping efficiency of the blood pump 10; and it can reduce the processing and assembly difficulty of the impeller 200, avoid damage to the impeller 200 and the cannula 100 during the assembly process, and then avoid the damaged impeller 200 and cannula 200 from damaging the blood, further eliminating hemolysis. Finally, the blood pump 10 can improve the pumping efficiency on the basis of avoiding hemolysis. In this application, the specific value of δ / D can be 2%, 2.5%, 2.8% or 3%, etc. In other embodiments, the specific value of δ / D can be other values, which can be set according to the actual situation.

[0032] When the value of δ / D is less than 2%, that is, when the value of the minimum clearance δ is too small, it will affect the machining accuracy and assembly accuracy between the impeller 200 and the casing 100, causing interference between the impeller 200 and the casing 100 during the assembly process, resulting in damage to the impeller 200 and increasing the assembly difficulty of the impeller 200. In addition, when the value of the minimum clearance δ is too small, the blood flowing through the clearance will be damaged to form a hemolysis phenomenon. When the value of δ / D is greater than 3%, that is, when the value of the minimum clearance δ is too large, the blood is likely to cause secondary flow in the delivery chamber 110, thus affecting the pumping efficiency. Therefore, when δ / D takes a value within the above range, firstly, it can avoid the damage of blood in the clearance, thereby avoiding the hemolysis phenomenon; secondly, it can eliminate the secondary flow to improve the hydraulic performance of blood flow and improve the pumping efficiency of the blood pump 10; thirdly, it can reduce the machining and assembly difficulty of the impeller 200, avoid damage to the impeller 200 and the casing 100 during the assembly process, and then avoid the damaged impeller 200 and casing 100 from damaging the blood, further eliminating the hemolysis phenomenon.

[0033] The value range of the above-mentioned minimum clearance δ is 0.05 - 0.3 mm. For example, the specific value of δ can be 0.05 mm, 0.2 mm or 0.3 mm, etc. The range of the inner diameter D of the above-mentioned casing is 3 - 10 mm. For example, the specific value of D can be 3 mm, 5 mm or 10 mm, etc.

[0034] Refer to Figure 2 、 Figure 3 and Figure 4 Referring to

[0035] and Figure 3 In some embodiments, the number of the liquid outlets 130 is multiple, and the multiple liquid outlets 130 are arranged at intervals along the radial direction of the casing 100. The length occupied by the liquid outlet 130 in the axial direction of the casing 100 is H. The length of H can also be understood as the extension length of the liquid outlet 130 in the axial direction of the casing 100, and the length H can also be understood as the height of the liquid outlet 130. In this embodiment, the orthographic projection of the liquid outlet 130 along the radial direction of the casing 100 can be approximately rectangular. In other embodiments, the orthographic projection of the liquid outlet 130 along the radial direction of the casing 100 can also be approximately elliptical, oblong or other shapes, which can be specifically set according to the actual situation. Figure 3, each liquid outlet 130 has opposite first end 131 and second end 132 in the axial direction of the sleeve 100. Among them, the first end 131 is closer to the driving assembly 300 than the second end 132. The liquid outlet 130 includes a first outlet 1301 and a second outlet 1302. Denote the line connecting the first end 131 of the first outlet 1301 and the first end 131 of the second outlet 1302 as the first connection line 141, and denote the line connecting the second end 132 of the first outlet 1301 and the second end 132 of the second outlet 1302 as the second connection line 142. Therefore, both the first connection line 141 and the second connection line 142 extend along the circumferential direction of the sleeve 100, and the two are spaced apart in the axial direction of the sleeve 100. The first outlet 1301 has a first contour line 133, and the first contour line 133 is arranged closer to the second outlet 1302 than other contour lines of the first outlet 1301. One end of the first contour line 133 is connected to the first connection line 141, and the other end of the first contour line 133 is connected to the second connection line 142, so that the first contour line 133 is connected between the first connection line 141 and the second connection line 142. The second outlet 1302 has a second contour line 134, and the second contour line 134 is arranged closer to the first outlet 1301 than other contour lines of the second outlet 1302. One end of the second contour line 134 is connected to the first connection line 141, and the other end of the second contour line 134 is connected to the second connection line 142, so that the second contour line 134 is connected between the first connection line 141 and the second connection line 142. Therefore, the first contour line 133 and the second contour line 134 are spaced apart along the circumferential direction of the sleeve 100.

[0036] The area enclosed by the above-mentioned first connection line 141, second connection line 142, first contour line 133 and second contour line 134 can be denoted as the blocking area 150 (i.e., Figure 3 the shaded part in the figure), and the blocking area 150 is the solid area of the sleeve 100 between the first outlet 1301 and the second outlet 1302. Define the area of the positive projection of the blocking area 150 in the radial direction of the sleeve 100 as S. Among them, 10% ≤ S / (πHD 2 / 4) ≤ 30%. For example, the specific value of S / (πHD 2 / 4) can be 10%, 15%, 20% or 30%, etc. When the values of H and D remain unchanged, when the value of S / (πHD 2 / 4) is less than 10%, it will make the value of S too small, resulting in a reduction in the structural strength of the entire sleeve 100; when the value of S / (πHD 2 / 4) is greater than 30%, it will make the value of S too large, thus compressing the length occupied by the liquid outlet 130 in the circumferential direction of the sleeve 100, thereby compressing the length of the blood outflow path, and further affecting the maximum blood flow. At the same time, when 10% ≤ S / (πHD2 When S / (πHD / 4) ≤ 30%, it is also possible to make the blood flow in the cannula 100 have the best hydraulic performance, thereby improving the pumping efficiency of the blood pump 10. Therefore, when S / (πHD 2 / 4) takes a value within the above range, it is possible to increase the structural strength of the cannula 100 and the blood output, and at the same time improve the pumping efficiency of the blood pump 10.

[0037] Referring to Figure 1 、 Figure 4 and Figure 5 , in some embodiments, the impeller 200 includes a hub 210 and blades 220. The number of the blades 220 is multiple. The multiple blades 220 are arranged at intervals along the circumferential direction of the hub 210. The blades 220 are arranged on the hub 210. Therefore, the hub 210 is the installation carrier of the blades 220. The blades 220 are spiral. Each blade 220 protrudes radially from the hub 210 along the cannula 100, so that the blades 220 protrude a certain height radially relative to the hub 210 along the cannula 100. It can be understood that the minimum clearance between the blade 220 and the inner wall of the cannula 100 is the minimum clearance between the entire impeller 200 and the inner wall of the cannula 100.

[0038] Referring to Figure 1 、 Figure 4 and Figure 5 , the hub 210 includes a diversion section 211, a pressurization section 212, and a drainage section 213. The diversion section 211, the pressurization section 212, and the drainage section 213 are arranged in sequence along the axial direction of the hub 210. The diversion section 211 is relatively farthest from the driving assembly 300 and is used to guide the liquid to flow to the pressurization section 212 and the drainage section 213. The pressurization section 212 is connected between the diversion section 211 and the drainage section 213. The drainage section 213 is relatively closest to the driving assembly 300. At least part of the diversion section 211 can be located outside the delivery chamber 110 of the cannula 100. For example, a part of the diversion section 211 is located within the delivery chamber 110, while another part of the diversion section 211 is located outside the delivery chamber 110. The diameter of the diversion section 211 gradually increases from the distal end to the proximal end. One end of the pressurization section 212 far from the driving assembly 300 is connected to the diversion section 211, and one end of the pressurization section 212 close to the driving assembly 300 is connected to the drainage section 213, so that the pressurization section 212 is connected between the diversion section 211 and the drainage section 213. The diameters of both the pressurization section 212 and the drainage section 213 gradually increase from the distal end to the proximal end, but the increasing methods of the diameters of the pressurization section 212 and the drainage section 213 are different. For example, the increase amplitude of the diameter of the drainage section 213 per unit length can be greater than the increase amplitude of the diameter of the pressurization section 212 per unit length.

[0039] There are no blades 220 provided on the diversion section 211, while blades 220 are provided on both the pressurization section 212 and the drainage section 213. Among them, the part of the blade 220 corresponding to the pressurization section 212 is the main part that does work on the liquid, which is used to convert mechanical energy into the internal energy and kinetic energy of the fluid, increasing the liquid flow pressure; the part of the blade 220 corresponding to the drainage section 213 does less work on the liquid, and the internal energy of the fluid is further converted into kinetic energy, shooting the liquid out radially at a high speed along the hub 210. The length of the diversion section 211 can be denoted as L1, the length of the pressurization section 212 can be denoted as L2, and the length of the drainage section 213 can be denoted as L3; the length L2 of the pressurization section 212 can be the largest, the length L3 of the drainage section 213 is the second largest, and the length L1 of the diversion section 211 can be the smallest. The total length of the hub 210 is L, and L = L1 + L2 + L3. The diversion section 211 is closer to the liquid inlet 120 than the pressurization section 212 and the drainage section 213, and the drainage section 213 is farther from the liquid inlet 120 than the pressurization section 212 and the diversion section 211. During the process of the blood pump 10 pumping blood, the blood flows through the diversion section 211, the pressurization section 212, and the drainage section 213 in sequence, which can also be understood as the diversion section 211, the pressurization section 212, and the drainage section 213 are arranged in sequence along the blood flow direction.

[0040] In some embodiments, the length L1 of the diversion section 211 and the total length L of the hub 210 have the following relationship: 1 / 10 ≤ L1 / L ≤ 1 / 5. For example, the specific value of L1 / L can be 1 / 10, 1 / 8, 1 / 7, or 1 / ⑤, etc. When the value of L1 / L is less than 1 / 10, it will make the value of L1 too small. During the process of the blood flowing through the diversion section 211, the blood flow rate is relatively large, which will increase the turbulence of the blood, cause blood shunt, change the flow direction of some blood, thus affecting the hydraulic performance of the blood flow, and ultimately reducing the pumping efficiency of the blood pump 10. When the value of L1 / L is greater than 1 / 5, it will make the value of L1 too large, resulting in too large total length and weight of the entire impeller 200, which is not conducive to the miniaturization and lightweight design of the impeller 200 and the entire blood pump 10. Therefore, when L1 / L takes values within the above range, on the one hand, it can improve the hydraulic performance of the blood flow, enabling as much of the output energy of the blood pump 10 to be converted into the flow energy of the blood, thereby improving the pumping efficiency of the blood pump 10. On the other hand, it can also achieve the miniaturization and lightweight design of the blood pump 10.

[0041] In some embodiments, the length L2 of the pressurization section 212 and the total length L of the impeller 210 have the following relationship: 1 / 3 ≤ L2 / L ≤ 3 / 4. For example, the specific value of L2 / L can be 1 / 3, 2 / 3, 1 / 2, 3 / 4, etc. When the value of L2 / L is less than 1 / 3, the value of L2 will be too small. When the blood reaches the bleed-off section 213, the efficacy of the impeller 200 is not fully exerted, resulting in insufficient work done by the entire impeller 200, and the fluid energy of the blood cannot meet the set requirements, thus causing the pumping efficiency of the entire blood pump 10 to be low. When the value of L2 / L is greater than 3 / 4, the value of L2 will be too large. On the one hand, when the impeller 200 continues to do work, the fluid energy of the blood has reached the required upper limit value, resulting in waste of energy of the blood pump 10 and also causing the pumping efficiency of the entire blood pump 10 to be low. On the other hand, it also makes the total length and weight of the entire impeller 200 too large, which is not conducive to the miniaturization and lightweight design of the impeller 200 and the entire blood pump 10. Therefore, when L2 / L takes a value within the above range, it can not only make as much of the output energy of the blood pump 10 be converted into the flow energy of the blood, thereby improving the pumping efficiency of the blood pump 10; but also realize the miniaturization and lightweight design of the blood pump 10.

[0042] In some embodiments, the length L3 of the flow discharge section 213 and the total length L of the impeller 210 have the following relationship: 1 / 4 ≤ L3 / L ≤ 2 / 5. For example, the specific value of L3 / L can be 1 / 4, 1.5 / 4, 2 / 5, etc. When the value of L3 / L is less than 1 / 4, the value of L3 will be too small. Since the liquid outlet 130 mainly corresponds to the flow discharge section 213, the length H of the liquid outlet 130 in the axial direction of the casing 100 will be too small. When blood flows out of the liquid outlet 130, the liquid outlet 130 will impose a relatively large resistance on the blood flow, increasing the frictional resistance of the liquid flow, restricting the maximum blood flow rate, thereby affecting the hydraulic performance of the blood flow, and ultimately resulting in a relatively low pumping efficiency of the entire blood pump 10. When the value of L3 / L is greater than 2 / 5, the value of L3 will be too large. On the one hand, since the contribution of the flow discharge section 213 to the blood velocity and flow rate is relatively small, the flow discharge section 213 with an excessive length will consume relatively more energy during rotation, thereby reducing the pumping efficiency of the blood pump 10. On the other hand, it also makes the total length and weight of the entire impeller 200 too large, which is not conducive to the miniaturization and lightweight design of the impeller 200 and the entire blood pump 10. On the other hand, it also makes the length H of the liquid outlet 130 in the axial direction of the casing 100 too large. During the implantation of the blood pump 10 into the body, there is a risk that the casing 100 may scratch the tissue. Therefore, when L3 / L is within the above range, it is possible to reduce the frictional resistance of the blood, so that as much of the output energy of the blood pump 10 as possible is converted into the flow energy of the blood, thereby improving the pumping efficiency of the blood pump 10; it is also possible to achieve the miniaturization and lightweight design of the blood pump 10; and it is also possible to reduce the risk of the casing 100 scratching the tissue during the implantation into the body.

[0043] Refer to Figure 2 and Figure 5, in some embodiments, the length H occupied by the liquid outlet 130 in the axial direction of the sleeve 100 and the total length L of the hub 210 have the following relationship, that is, 1 / 5 ≤ H / L ≤ 1 / 3. For example, the specific value of H / L can be 1 / 5, 1 / 4, or 1 / 3, etc. When the value of H / L is less than 1 / 5, the length H occupied by the liquid outlet 130 in the axial direction of the sleeve 100 will be too small. When the blood flows out from the liquid outlet 130, the liquid outlet 130 will have a greater hindrance to the blood flow, increasing the frictional resistance along the blood flow, restricting the maximum blood flow, thereby affecting the hydraulic performance of the blood flow and reducing the pumping efficiency of the entire blood pump 10. When the value of H / L is greater than 1 / 3, the length H occupied by the liquid outlet 130 in the axial direction of the sleeve 100 will be too large. During the process of implanting the blood pump 10 into the body, there will be a risk of the sleeve 100 scratching the tissue. Therefore, when H / L takes a value within the above range, on the one hand, it can reduce the frictional resistance and energy loss during the blood flow, so that as much of the output energy of the blood pump 10 as possible is converted into the flow energy of the blood, thereby improving the pumping efficiency of the blood pump 10; on the other hand, it reduces the risk of the sleeve 100 scratching the tissue during the process of implanting it into the body.

[0044] Refer to 4, Figure 5 and Figure 6 , in some embodiments, the angle occupied by a single blade 220 in the circumferential direction of the hub 210 is denoted as the wrap angle θ. In other words, the two ends of the blade 220 in the axial direction of the hub 210 are respectively denoted as the first edge end and the second edge end, and the angle separated by the first edge end and the second edge end in the circumferential direction of the hub 210 is the above-mentioned wrap angle θ. The wrap angle θ has the following value range, that is, 90° ≤ θ ≤ 220°. For example, the specific value of θ can be 90°, 100°, 200°, or 220°, etc. When the wrap angle θ is less than 90°, it will cause insufficient work of the impeller 200, that is, under the conditions of the set rotational speed and size of the impeller 200, the impeller 200 cannot output the required energy, thereby reducing the pumping efficiency of the blood pump 10. When the wrap angle θ is greater than 220°, the blade 220 will constitute an obstructive effect on the delivery chamber 110, increasing the frictional resistance during the blood flow, making the pumping efficiency of the entire blood pump 10 relatively low. Therefore, when the wrap angle θ takes a value within the above range, it can not only ensure sufficient work of the impeller 200 to output sufficient energy, so that the flow energy of the blood flow meets the set requirements, but also reduce the frictional resistance during the blood flow, and finally improve the pumping efficiency of the entire blood pump 10.

[0045] Refer to Figure 5, in some embodiments, along the direction away from the hub 210, that is, along the radial direction of the impeller 200, the thickness of the blade 220 remains unchanged, which is conducive to accurately controlling the machining accuracy and surface roughness of the impeller 200 and reducing the risk of hemolysis. The thickness of the blade 220 is T, and the following relationship exists between the thickness T of the blade 220 and the total length L of the hub 210, that is, 3% ≤ T / D ≤ 7%. For example, the specific value of T / D can be 3%, 4%, 6% or 7%, etc. When the value of H / L is less than 3%, the thickness of the blade 220 is too small, and the machining difficulty is large, which will also cause the impeller 200 to generate vibrations with a large frequency during rotation, thereby damaging the blood. When the value of H / L is greater than 3%, the thickness of the blade 220 is too large, which causes the impeller 200 to occupy too much space in the conveying cavity 110, thereby compressing the flow space of the blood, increasing the frictional resistance during the blood flow, and reducing the pumping efficiency of the entire blood pump 10. Therefore, when T / D is within the above range, it can not only prevent the impeller 200 from damaging the blood, thereby eliminating the hemolysis phenomenon, but also reduce the frictional resistance during the blood flow, further improve the hydraulic performance during the blood flow, and ultimately further improve the pumping efficiency of the blood pump 10.

[0046] In other embodiments, along the direction away from the hub 210, the thickness of the blade 220 changes, that is, the thickness T of the blade 220 can also be a variable, and the following relationship can also exist between the thickness T of the blade 220 and the total length L of the hub 210, 3% ≤ T / D ≤ 7%. In other embodiments, along the direction away from the hub 210, the thickness of the blade 220 remains unchanged, and the ratio T / D of the thickness T of the blade 220 to the total length L of the hub 210 can be less than 3% or greater than 7%.

[0047] The blade 220 includes a working surface 221 and a back surface 223. Both the working surface 221 and the back surface 223 are connected to the outer peripheral surface of the hub 210. One end of the working surface 221 close to the liquid outlet 130 and one end of the back surface 223 close to the liquid outlet 130 are opposite to each other. One end of the working surface 221 close to the liquid inlet 120 and one end of the back surface 223 close to the liquid inlet 120 are transitioned by a fillet to achieve the effect of smoothly guiding the blood and avoid hemolysis caused by the sharp edge damaging the blood. Among them, the fillet radius can be 0.05 mm - 0.1 mm to improve the blood guiding effect.

[0048] Refer to Figure 3 and Figure 4, in some embodiments, with reference to the tangent line 215 at the end of the hub 210 close to the drive assembly 300, the tangent line 215 intersects the contour line of the liquid outlet 130 on the side close to the drive assembly 300. In this way, the relative positions of the impeller 200 and the liquid outlet 130 can be well positioned, optimizing the hydraulic performance of blood flow and avoiding the phenomenon of hemolysis caused by blood damage. Specifically, when the tangent line 215 is above the contour line of the first end 131, that is, the tangent line 215 is closer to the second end 132 relative to the first end 131, the space of the liquid outlet 130 cannot be fully utilized in this way, and the gap between the impeller 200 and the driver is increased, resulting in an increase in the blood backflow area at the bottom of the impeller 200, thereby increasing the ability to damage blood and the phenomenon of hemolysis; when the tangent line 215 is below the contour line of the first end 131, that is, the tangent line 215 is farther from the second end 132 relative to the first end 131, in this way, part of the blood will not be directed to the liquid outlet 130 but directly to the inner wall of the sleeve 100, and this will also damage the blood and form the phenomenon of hemolysis.

[0049] When the pumping efficiency of the blood pump 10 is improved, the higher the energy conversion rate of the driver, on the one hand, the energy consumption of the entire blood pump 10 can be reduced, thereby reducing the operating cost of the blood pump 10, and on the other hand, the heat generated during the operation of the blood pump 10 can be reduced.

[0050] In summary, the blood pump 10 provided by the present invention includes a sleeve 100 and an impeller 200. The sleeve 100 is provided with a liquid inlet 120 and a liquid outlet 130. At least part of the impeller 200 is rotatably disposed in the sleeve 100 to transport liquid from the liquid inlet 120 to the liquid outlet 130. The impeller 200 includes a hub 210 and blades 220. The blades 220 protrude radially from the hub 210 along the sleeve 100. The minimum gap between the blades 220 and the inner wall of the sleeve 100 is δ, and the inner diameter of the sleeve 100 is D. Among them, 2% ≤ δ / D ≤ 3%. In this way, blood damage in this minimum gap can be avoided, thereby avoiding the phenomenon of hemolysis; secondary flow can also be eliminated to improve the hydraulic performance of blood flow and improve the pumping efficiency of the blood pump 10; and the processing and assembly difficulty of the impeller 200 can be reduced, avoiding damage to the impeller 200 and the sleeve 100 during the assembly process, and then avoiding damage to the impeller 200 and the sleeve 100 after damage from damaging blood and further eliminating the phenomenon of hemolysis. Finally, the blood pump 10 can improve the pumping efficiency on the basis of avoiding the phenomenon of hemolysis.

[0051] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0052] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A blood pump, characterized in that, Comprising: A casing provided with a liquid inlet and a liquid outlet; And An impeller, at least part of which is rotatably arranged in the casing to convey liquid from the liquid inlet to the liquid outlet. The impeller includes a hub and blades. The blades protrude radially from the hub along the casing, and the minimum clearance between the blades and the inner wall of the casing is δ, and the inner diameter of the casing is D. Wherein, 2% ≤ δ / D ≤ 3%; The height of the liquid outlet along the axial direction of the sleeve is H. The liquid outlet includes a first outlet and a second outlet. The connection line between one ends of the first outlet and the second outlet in the axial direction of the sleeve is the first connection line, and the connection line between the other ends of the first outlet and the second outlet in the axial direction of the sleeve is the second connection line. Both the first connection line and the second connection line extend along the circumferential direction of the sleeve. The first outlet has a first contour line disposed close to the second outlet, and the first contour line is connected between the first connection line and the second connection line. The second outlet has a second contour line disposed close to the first outlet, and the second contour line is connected between the first connection line and the second connection line. The region enclosed by the first connection line, the second connection line, the first contour line, and the second contour line is the blocking region, and the area of the orthographic projection of the blocking region in the radial direction of the sleeve is S. Wherein, 10% ≤ S / (πHD 2 / 4) ≤ 30%.

2. The blood pump according to claim 1, wherein The range of the minimum clearance δ between the blades and the inner wall of the casing is 0.05 - 0.3 mm, and the range of the inner diameter D of the casing is 3 - 10 mm.

3. The blood pump according to claim 1, characterized in that, The hub includes a guiding section without blades, and the diameter of the guiding section gradually increases from the distal end to the proximal end. The length of the guiding section is L1, and the total length of the hub is L. Wherein, 1 / 10 ≤ L1 / L ≤ 1 / 5.

4. The blood pump according to claim 3, wherein The hub further includes a boosting section connected to the proximal end of the guiding section. The diameter of the boosting section gradually increases from the distal end to the proximal end. The blades are arranged on the boosting section. The length of the boosting section is L2. Wherein, 1 / 3 ≤ L2 / L ≤ 3 / 4.

5. The blood pump according to claim 4, characterized in that, The hub further includes a flow discharging section connected to the proximal end of the boosting section. The blades are also arranged on the flow discharging section. The diameter of the flow discharging section gradually increases from the distal end to the proximal end, and the increasing manner of the diameters of the boosting section and the flow discharging section is different. The length of the flow discharging section is L3. Wherein, L1 + L2 + L3 = L.

6. The blood pump according to claim 1, wherein The number of the blades is multiple, and the multiple blades are arranged at intervals along the circumferential direction of the hub. The angle occupied by a single blade in the circumferential direction of the hub is denoted as the included angle θ. Wherein, 90° ≤ θ ≤ 220°.

7. The blood pump according to claim 1, characterized in that, The casing is further provided with a conveying cavity, at least part of the impeller is rotatably arranged in the conveying cavity. The liquid outlet is arranged on the outer peripheral wall of the casing and communicates with the conveying cavity. The height of the liquid outlet along the axial direction of the casing is H, and the total length of the hub is L. Wherein, 1 / 5 ≤ H / L ≤ 1 / 3.

8. The blood pump according to claim 1, wherein, S / (πHD 2 / 4) has a value of 10%, 15%, 20% or 30%.

9. The blood pump according to claim 1, characterized in that, The blood pump further includes a driving assembly, the driving assembly is in transmission connection with the impeller. The casing is sleeved on one end of the driving assembly, and the tangent line of the end of the hub close to the driving assembly intersects with the contour line of the liquid outlet on the side close to the driving assembly.

10. The blood pump according to claim 1, wherein Along the direction away from the hub, the thickness of the blade remains unchanged; and / or, the thickness of the blade is T. Wherein, 3% ≤ T / D ≤ 7%.

11. The blood pump according to claim 1, wherein, The blade includes a working surface and a back surface. Both the working surface and the back surface are connected to the outer peripheral surface of the hub. The end of the working surface close to the liquid outlet and the end of the back surface close to the liquid outlet are opposite to each other. The end of the working surface close to the liquid inlet and the end of the back surface close to the liquid inlet are transitioned by a fillet.

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