CN116036465B

CN116036465B - Blood pump

Info

Publication number: CN116036465B
Application number: CN202211702965.6A
Authority: CN
Inventors: 娄厦; 余顺周
Original assignee: Shenzhen Core Medical Technology Co Ltd
Current assignee: Shenzhen Core Medical Technology Co Ltd
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2025-08-01
Anticipated expiration: 2042-12-29
Also published as: CN116036465A

Abstract

The invention relates to a blood pump, which comprises a sleeve, an impeller and a pump body, wherein the sleeve is provided with a liquid inlet and a liquid outlet, the impeller is at least partially rotatably arranged in the sleeve so as to convey liquid from the liquid inlet to the liquid outlet, the impeller comprises a hub and blades, the blades protrude out of the hub along the radial direction of the sleeve, the minimum gap between the blades and the inner wall of the sleeve is delta, and the inner diameter of the sleeve is D, wherein delta/D is more than or equal to 2% and less than or equal to 3%. So can avoid blood to produce the destruction in this minimum clearance to avoid the hemolysis phenomenon, also can eliminate the secondary flow in order to improve the hydraulic property of blood flow, improve the pumping efficiency of blood pump, can also reduce the processing and the assembly degree of difficulty of impeller, avoid impeller and sleeve pipe to produce the damage in the assembly process, then avoid impeller and sleeve pipe after damaging to produce the destruction to blood, further eliminate the hemolysis phenomenon, finally make the blood pump improve pumping efficiency on the basis of avoiding the hemolysis phenomenon.

Description

Blood pump

Technical Field

The invention relates to the technical field of medical equipment, in particular to a blood pump.

Background

An intravascular blood pump is a blood pumping device that can be advanced into a patient's heart through the patient's blood vessel, with the intravascular blood pump being positioned within an opening of a heart valve so that blood can flow through the blood pump and into an arterial blood vessel. However, in the conventional blood pump, there are generally defects such as low pumping efficiency and hemolysis of blood due to damage during the blood transport, so that it is difficult to meet the operation requirements.

Disclosure of Invention

The invention solves the technical problems of improving the pumping efficiency of the blood pump on the basis of avoiding the hemolysis phenomenon by adopting the following technical scheme.

The present invention provides a blood pump comprising:

A sleeve pipe provided with a liquid inlet and a liquid outlet, and

The impeller is at least partially rotatably arranged in the sleeve so as to convey liquid from the liquid inlet to the liquid outlet, the impeller comprises a hub and blades, the blades protrude out of the hub along the radial direction of the sleeve, the minimum clearance between the blades and the inner wall of the sleeve is delta, and the inner diameter of the sleeve is D, wherein delta/D is more than or equal to 2% and less than or equal to 3%.

In one embodiment, the minimum clearance delta between the blades and the inner wall of the sleeve is in the range of 0.05-0.3mm, and the inner diameter D of the sleeve is in the range of 3-10mm.

In one embodiment, the hub comprises a guide section without the blades, the diameter of the guide section gradually increases from the distal end to the proximal end, the length of the guide section is L ₁, and the total length of the hub is L, wherein L ₁/L is more than or equal to 1/10 and less than or equal to 1/5.

In one embodiment, the hub further comprises a pressurizing section, the pressurizing section is connected to the proximal end of the flow guiding section, the diameter of the pressurizing section gradually increases from the distal end to the proximal end, the blades are arranged on the pressurizing section, and the length of the pressurizing section is L ₂, wherein L ₂/L is more than or equal to 1/3 and less than or equal to 3/4.

In one embodiment, the hub further comprises a drain section, the drain section is connected to the proximal end of the pressurizing section, the blades are further arranged on the drain section, the diameter of the drain section gradually increases from the distal end to the proximal end, the diameter of the pressurizing section and the diameter of the drain section are different in increasing manners, and the length of the drain section is L ₃, wherein 1/4 is less than or equal to L ₃/L is less than or equal to 2/5.

In one embodiment, the number of the blades is a plurality, the blades are arranged at intervals along the circumferential direction of the hub, and the angle occupied by a single blade in the circumferential direction of the hub is denoted as a wrap angle theta, wherein theta is more than or equal to 90 degrees and less than or equal to 220 degrees.

In one embodiment, the sleeve 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 circumferential wall of the sleeve and is communicated with the conveying cavity, the height of the liquid outlet along the axial direction of the sleeve is H, and the total length of the hub is L, wherein H/L is more than or equal to 1/5 and less than or equal to 1/3.

In one embodiment, the liquid outlet comprises a first outlet and a second outlet, a connection line between one end of the first outlet and one end of the second outlet in the axial direction of the sleeve is a first connection line, a connection line between the other end of the first outlet and the second outlet in the axial direction of the sleeve is a second connection line, the first connection line and the second connection line extend along the circumferential direction of the sleeve, a first contour line of the first outlet, which is arranged close to the second outlet, is connected between the first connection line and the second connection line, a region enclosed by the first connection line, the second connection line, the first contour line and the second contour line is a blocking region, and an orthographic projection area of the blocking region in the radial direction of the sleeve is S, wherein S/(Pi ²/4) is more than or equal to 10%.

In one embodiment, the blood pump further comprises a driving assembly, the driving assembly is in transmission connection with the impeller, the sleeve is sleeved at one end of the driving assembly, and a tangent line of the end, close to the driving assembly, of the hub is intersected with a contour line of the liquid outlet, close to one side of the driving assembly.

In one embodiment, the thickness of the blade is constant in a direction away from the hub, and/or the thickness of the blade is T, wherein 3% T/D7%.

In one embodiment, the blade includes a working surface and a back surface, the working surface and the back surface are both connected with the outer circumferential surface of the hub, one end of the working surface, which is close to the liquid outlet, and one end of the back surface, which is close to the liquid outlet, are opposite, and one end of the working surface, which is close to the liquid inlet, and one end of the back surface, which is close to the liquid inlet, are in transition through a rounded corner.

Compared with the prior art, the ratio of the minimum gap delta between the blades and the inner wall of the sleeve to the inner diameter D of the sleeve is 2% -delta/D & lt 3%, so that the damage of blood in the minimum gap can be avoided, the hemolysis phenomenon can be avoided, secondary flow can be eliminated, the hydraulic performance of blood flow can be improved, the pumping efficiency of the blood pump can be improved, the difficulty in processing and assembling the impeller can be reduced, the impeller and the sleeve are prevented from being damaged in the assembling process, the damage of the damaged impeller and sleeve to the blood can be avoided, the hemolysis phenomenon can be further eliminated, and finally the pumping efficiency of the blood pump can be improved on the basis of avoiding the hemolysis phenomenon.

Drawings

Fig. 1 is a schematic perspective view of a blood pump according to the present invention.

Fig. 2 is a schematic view of a part of the blood pump shown in fig. 1 after the driving assembly is removed.

Fig. 3 is a partial enlarged view of fig. 2 at a.

Fig. 4 is a cross-sectional view of fig. 2 taken along the direction B-B.

Fig. 5 is a perspective view of an impeller of the blood pump shown in fig. 1.

Fig. 6 is a top view of the blood pump shown in fig. 1.

Detailed Description

In order that the invention may be readily understood, a more complete description of the invention will be rendered by reference to the appended drawings. The drawings illustrate preferred embodiments of the invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "inner", "outer", "left", "right" and the like are used herein for illustrative purposes only and do not represent the only embodiment.

As used herein, "proximal" is defined as the end proximal to the healthcare worker and "distal" is defined as the end distal to the healthcare worker, i.e., the end proximal to the heart of the patient.

The inventors of the present application have discovered that a blood pump generally includes an impeller, a cannula, and a drive assembly for driving the impeller into rotation within the cannula so that blood is pumped through the cannula to an arterial vessel. However, in the use process of the conventional blood pump, on one hand, there is a defect that pumping efficiency is low due to poor hydraulic performance, and on the other hand, there is a defect that hemolysis phenomenon is caused due to damage of blood, so that the blood pump is difficult to meet the requirement of a tight operation.

In order to improve at least part of the above problems, referring to fig. 1, the present application proposes a blood pump 10, in which the blood pump 10 can improve the pumping efficiency while avoiding the hemolysis phenomenon, and the following description will explain the blood pump 10 provided by the present application.

Referring to fig. 1 to 3, a blood pump 10 according to an embodiment of the present invention includes a casing 100, an impeller 200, and a driving assembly 300, wherein the driving assembly 300 includes a driver (not shown) and a housing 310, the driver is accommodated in the housing 310, the housing 310 accommodates and protects the driver, one end of the housing 310 is connected to the casing 100, for example, the casing 100 may be sleeved at one end of the housing 310. The driver is connected with the impeller 200 through the output shaft, when the driver drives the output shaft to rotate, the impeller 200 fixedly connected to the output shaft synchronously rotates along with the output shaft, and the rotating impeller 200 generates pumping force on blood, so that the whole blood pump 10 is used for conveying the blood.

Referring to fig. 2-4, in some embodiments, the sleeve 100 may be a cylindrical tubular structure, i.e., the sleeve 100 may have a circular cross-sectional profile. The sleeve 100 encloses a conveying cavity 110, one end of the conveying cavity 110, which is far away from the driving assembly 300, forms a liquid inlet 120, a liquid outlet 130 is arranged on the outer circumferential surface of the sleeve 100, and the liquid outlet 130 is communicated with the conveying cavity 110 and the outside. The impeller 200 is at least partially accommodated in the delivery cavity 110, and when the driving assembly 300 drives the impeller 200 to rotate, blood flows into the delivery cavity 110 from the liquid inlet 120 and finally flows out of the delivery cavity 110 from the liquid outlet 130 under the action of pumping force generated by rotation of the impeller 200, so that the delivery of the blood is realized.

Referring to fig. 4, in some embodiments, the width of the minimum gap between the impeller 200 and the sleeve 100 in the radial direction of the sleeve 100 is denoted as δ, i.e., δ is the minimum gap between the impeller 200 and the inner wall of the sleeve 100, and the inner diameter of the sleeve 100 is denoted as D, obviously the inner diameter D is the diameter of the delivery lumen 110. The delta/D is more than or equal to 2 percent and less than or equal to 3 percent, so the arrangement can avoid the damage of blood in a minimum gap, thereby avoiding the hemolysis phenomenon, can eliminate secondary flow to improve the hydraulic performance of blood flow and improve the pumping efficiency of the blood pump 10, can reduce the processing and assembling difficulty of the impeller 200, avoid the damage of the impeller 200 and the sleeve 100 in the assembling process, further avoid the damage of the impeller 200 and the sleeve 200 after the damage to the blood, further eliminate the hemolysis phenomenon, and finally ensure that the pumping efficiency of the blood pump 10 is improved on the basis of avoiding the hemolysis phenomenon. In the present application, the specific value of δ/D may be 2%, 2.5%, 2.8%, 3%, or the like. In other embodiments, the specific value of δ/D may be other numerical values, and may be specifically set according to practical situations.

When the value of δ/D is less than 2%, that is, the value of the minimum gap δ is too small, the machining precision and the assembly precision between the impeller 200 and the sleeve 100 are affected, so that the impeller 200 interferes with the sleeve 100 in the assembly process, the impeller 200 is damaged, and the assembly difficulty of the impeller 200 is also improved. In addition, too small a value of the minimum gap δ may cause the blood flowing through the gap to be destroyed, resulting in hemolysis. When the value of δ/D is greater than 3%, i.e., the value of the minimum gap δ is too large, the secondary flow is easily induced in the blood in the delivery chamber 110, thereby affecting the pumping efficiency. Therefore, when δ/D is taken in the above range, firstly, the destruction of blood in the gap can be avoided, so as to avoid the hemolysis phenomenon, secondly, the secondary flow can be eliminated to improve the hydraulic performance of the blood flow, and the pumping efficiency of the blood pump 10, thirdly, the difficulty in processing and assembling the impeller 200 can be reduced, the impeller 200 and the sleeve 100 are prevented from being damaged in the assembling process, and then the damage of the impeller 200 and the sleeve 100 after the damage to the blood is avoided, so that the hemolysis phenomenon is further eliminated.

The minimum gap delta is in the range of 0.05-0.3mm, for example, the specific delta value can be 0.05mm, 0.2mm or 0.3 mm. The diameter D of the sleeve is 3-10mm, for example, D may be 3mm, 5mm or 10 mm.

Referring to fig. 2, 3 and 4, in some embodiments, the number of the liquid outlets 130 is plural, and the plurality of liquid outlets 130 are spaced apart along the radial direction of the sleeve 100. The length H of the liquid outlet 130 in the axial direction of the sleeve 100 may be understood as the extending length of the liquid outlet 130 in the axial direction of the sleeve 100, and the length H may 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 sleeve 100 may be substantially rectangular. In other embodiments, the orthographic projection of the liquid outlet 130 along the radial direction of the sleeve 100 may be generally elliptical, oblong, or other shapes, and may be specifically set according to practical situations.

Referring to fig. 3, each of the liquid outlets 130 has a first end 131 and a second end 132 opposite to each other in the axial direction of the sleeve 100, wherein 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, a line connecting the first end 131 of the first outlet 1301 and the first end 131 of the second outlet 1302 is denoted as a first line 141, and a line connecting the second end 132 of the first outlet 1301 and the second end 132 of the second outlet 1302 is denoted as a second line 142, so that the first line 141 and the second line 142 both extend along the circumferential direction of the casing 100 and are disposed at intervals in the axial direction of the casing 100. The first output port 1301 has a first contour line 133, the first contour line 133 is disposed closer to the second output port 1302 than other contour lines of the first output port 1301, and 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 such that the first contour line 133 is connected between the first connection line 141 and the second connection line 142. The second output port 1302 has a second contour 134, the second contour 134 is disposed closer to the first output port 1301 than other contours of the second output port 1302, and one end of the second contour 134 is connected to the first connecting line 141 and the other end of the second contour 134 is connected to the second connecting line 142, such that the second contour 134 is connected between the first connecting line 141 and the second connecting line 142, so that the first contour 133 and the second contour 134 are disposed at intervals along the circumference of the sleeve 100.

The area surrounded by the first line 141, the second line 142, the first contour line 133, and the second contour line 134 may be referred to as a blocking area 150 (i.e., a hatched portion in fig. 3), where the blocking area 150 is a solid area of the casing 100 between the first output port 1301 and the second output port 1302. The area of the orthographic projection of the blocking area 150 in the radial direction of the sleeve 100 is defined as S. Wherein, S/(pi HD ²/4) is less than or equal to 10 percent and less than or equal to 30 percent, for example, the specific value of S/(pi HD ²/4) can be 10 percent, 15 percent, 20 percent or 30 percent, etc. Under the condition that the values of H and D are unchanged, when the value of S/(pi HD ²/4) is smaller than 10%, the value of S is too small, so that the structural strength of the whole sleeve 100 is reduced, and when the value of S/(pi HD ²/4) is larger than 30%, the value of S is too large, so that the length occupied by the liquid outlet 130 in the circumferential direction of the sleeve 100 is compressed, and the length of a blood outflow path is compressed, so that the maximum flow rate of blood is influenced. Meanwhile, when S/(pi HD ²/4) is less than or equal to 10% and less than or equal to 30%, the flow of blood in the cannula 100 can be made to have the best hydraulic performance, thereby improving the pumping efficiency of the blood pump 10. Therefore, when S/(pi HD ²/4) is taken within the above range, not only the structural strength of the cannula 100 and the output amount of blood can be increased, but also the pumping efficiency of the blood pump 10 can be improved.

Referring to fig. 1, 4 and 5, in some embodiments, the impeller 200 includes a hub 210 and a plurality of blades 220, the plurality of blades 220 being disposed at intervals along a circumference of the hub 210, the blades 220 being disposed on the hub 210, so that the hub 210 is a mounting carrier for the blades 220. The blades 220 are spirally formed, and each blade 220 is protruded on the hub 210 in the radial direction of the sleeve 100 such that the blade 220 is protruded at a certain height with respect to the hub 210 in the radial direction of the sleeve 100. It is understood that the minimum clearance between the blades 220 and the inner wall of the casing 100 is the minimum clearance between the impeller 200 and the inner wall of the casing 100.

Referring to fig. 1, 4 and 5, hub 210 includes a inducer section 211, a booster section 212 and a bleeder section 213. The flow guiding section 211, the pressure increasing section 212 and the draining section 213 are sequentially arranged along the axial direction of the hub 210, the flow guiding section 211 is relatively farthest from the driving assembly 300 and is used for guiding the liquid to flow to the pressure increasing section 212 and the draining section 213, the pressure increasing section 212 is connected between the flow guiding section 211 and the draining section 213, the draining section 213 is relatively closest to the driving assembly 300, at least part of the flow guiding section 211 can be located outside the conveying cavity 110 of the sleeve 100, for example, one part of the flow guiding section 211 is located inside the conveying cavity 110, the other part of the flow guiding section 211 is located outside the conveying cavity 110, and the diameter of the flow guiding section 211 gradually increases from the distal end to the proximal end. The end of the boost section 212 away from the drive assembly 300 is connected with the guide section 211, and the end of the boost section 212 close to the drive assembly 300 is connected with the drain section 213, so that the boost section 212 is connected between the guide section 211 and the drain section 213, and the diameters of the boost section 212 and the drain section 213 are gradually increased from the distal end to the proximal end, but the diameters of the boost section 212 and the drain section 213 are increased in different manners, for example, the increase of the diameter of the drain section 213 in unit length may be larger than the increase of the diameter of the boost section 212 in unit length.

The flow guiding section 211 is not provided with blades 220, the pressurizing section 212 and the discharging section 213 are both provided with blades 220, wherein the part of the blades 220 corresponding to the pressurizing section 212 is a main part for acting on liquid and is used for converting mechanical energy into internal energy and kinetic energy of the fluid so as to increase the pressure of the liquid flow, the part of the blades 220 corresponding to the discharging section 213 is used for acting on the liquid so as to reduce the work of the liquid, the internal energy of the fluid is further converted into kinetic energy, and the liquid is ejected along the radial direction of the hub 210 at a high speed. The length of the flow guiding section 211 may be denoted as L ₁, the length of the pressure increasing section 212 may be denoted as L ₂, the length of the draining section 213 may be denoted as L ₃, the length of the pressure increasing section 212 may be denoted as L ₂, the length of the draining section 213 may be denoted as L ₃ times, and the length of the flow guiding section 211 may be denoted as L ₁. The hub 210 has an overall length L, l=l ₁+L₂+L₃. The flow guiding section 211 is closer to the liquid inlet 120 than the pressure increasing section 212 and the flow discharging section 213, the flow discharging section 213 is further away from the liquid inlet 120 than the pressure increasing section 212 and the flow guiding section 211, and in the process of pumping blood by the blood pump 10, the blood sequentially flows through the flow guiding section 211, the pressure increasing section 212 and the flow discharging section 213, which can be also understood that the flow guiding section 211, the pressure increasing section 212 and the flow discharging section 213 are sequentially arranged along the flowing direction of the blood.

In some embodiments, the length L ₁ of the inducer 211 is in the following relationship with the total length L of the hub 210, 1/10≤L ₁/L≤1/5, e.g., L ₁/L may have a specific value of 1/10, 1/8, 1/7, 1/5, etc. When the value of L ₁/L is smaller than 1/10, the value of L ₁ will be too small, and the flow velocity of blood is large in the process of flowing through the flow guiding section 211, so that the turbulence of blood is increased, the blood split is initiated, the flowing direction of part of blood is changed, the hydraulic performance of the blood flowing is affected, and finally the pumping efficiency of the blood pump 10 is reduced. When the value of L ₁/L is greater than 1/5, the value of L ₁ will be too large, resulting in excessive overall length and weight of the entire impeller 200, which is detrimental to the miniaturized and lightweight design of the impeller 200 and the entire blood pump 10. Therefore, when L ₁/L is taken in the above range, on the one hand, the hydraulic performance of the blood flow can be improved, so that the output energy of the blood pump 10 is converted into the flow energy of the blood as much as possible, thereby improving the pumping efficiency of the blood pump 10. On the other hand, the blood pump 10 can be miniaturized and lightweight.

In some embodiments, the length L ₂ of the plenum section 212 is related to the total length L of the hub 210 by 1/3≤L ₂/L≤3/4, e.g., L ₂/L may have a specific value of 1/3, 2/3, 1/2, 3/4, etc. When the value of L ₂/L is smaller than 1/3, the value of L ₂ is too small, and when the blood reaches the leakage section 213, the efficacy of the impeller 200 is not fully exerted, so that the whole impeller 200 does not work sufficiently, the fluid energy of the blood cannot meet the set requirement, and the pumping efficiency of the whole blood pump 10 is low. When the value of L ₂/L is greater than 3/4, the value of L ₂ will be too large, on the one hand, when the impeller 200 is working continuously, the fluid energy of the blood has reached the required upper limit value, which results in waste of the energy of the blood pump 10 and lower pumping efficiency of the whole blood pump 10. On the other hand, the overall length and weight of the entire impeller 200 are too large, which is detrimental to the miniaturization and weight-saving design of the impeller 200 and the entire blood pump 10. Therefore, when L ₂/L is within the above range, the output energy of the blood pump 10 can be converted into the flow energy of the blood as much as possible, so that the pumping efficiency of the blood pump 10 can be improved, and the miniaturization and light-weight design of the blood pump 10 can be realized.

In some embodiments, the length L ₃ of the leakage section 213 is related to the total length L of the hub 210 by 1/4≤L ₃/L≤2/5, e.g., L ₃/L may have a specific value of 1/4, 1.5/4, 2/5, etc. When the value of L ₃/L is smaller than 1/4, the value of L ₃ will be too small, and the value of the length H occupied by the liquid outlet 130 in the axial direction of the sleeve 100 will be too small because the liquid outlet 130 mainly corresponds to the drainage section 213, and when the blood flows out from the liquid outlet 130, the liquid outlet 130 will have a larger blocking effect on the flow of the blood, increase the on-way resistance of the flow of the liquid, limit the maximum flow rate of the blood, thereby affecting the water performance of the flow of the blood, and finally making the pumping efficiency of the whole blood pump 10 lower. When the value of L ₃/L is greater than 2/5, the value of L ₃ will be too large, on the one hand, considering that the contribution of the leakage section 213 to the speed and flow rate of blood is relatively small, resulting in that the leakage section 213 with too large length consumes relatively much energy during rotation, thereby reducing the pumping efficiency of the blood pump 10. On the other hand, the overall length and weight of the entire impeller 200 are too large, which is detrimental to the miniaturization and weight-saving design of the impeller 200 and the entire blood pump 10. Yet another aspect also provides that the length H taken up by the fluid outlet 130 in the axial direction of the cannula 100 is too large, which may risk scraping tissue from the cannula 100 during implantation of the blood pump 10 into the body. Therefore, when L ₃/L is within the above range, the on-way resistance of blood can be reduced, so that the output energy of the blood pump 10 is converted into the flowing energy of the blood as much as possible, thereby improving the pumping efficiency of the blood pump 10, realizing the miniaturization and light-weight design of the blood pump 10, and reducing the risk of scratching tissues in the process of implanting the cannula 100 into the body.

Referring to FIGS. 2 and 5, in some embodiments, the length H of the liquid outlet 130 along the axial direction of the sleeve 100 is related to the total length L of the hub 210 by 1/5≤H/L≤1/3, for example, the specific value of H/L may be 1/5, 1/4, 1/3, etc. When the value of H/L is smaller than 1/5, the length H occupied by the outlet 130 in the axial direction of the cannula 100 will be too small, and when the blood flows out from the outlet 130, the outlet 130 will have a larger blocking effect on the blood flow, increasing the along-path resistance of the blood flow, limiting the maximum flow of the blood, thereby affecting the hydraulic performance of the blood flow and reducing the pumping efficiency of the whole blood pump 10. When the value of H/L is greater than 1/3, the length H occupied by the fluid outlet 130 in the axial direction of the cannula 100 will be excessive, and the cannula 100 will be at risk of scratching tissue during implantation of the blood pump 10 into the body. Therefore, when H/L is taken in the above range, on one hand, the on-way resistance and energy loss of blood in the flowing process can be reduced, so that the output energy of the blood pump 10 is converted into the flowing energy of blood as much as possible, thereby improving the pumping efficiency of the blood pump 10, and on the other hand, the risk of scratching tissues during the implantation of the cannula 100 into the body is reduced.

Referring to fig. 4, 5, and 6, in some embodiments, the angle that a single blade 220 occupies in the circumferential direction of hub 210 is denoted as 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 a first edge and a second edge, and the angle between the first edge and the second edge in the circumferential direction of the hub 210 is the wrap angle θ. The wrap angle theta has a value range that is 90 DEG≤theta≤220 DEG, for example, the specific value of theta can be 90 DEG, 100 DEG, 200 DEG or 220 DEG, etc. When the wrap angle θ is smaller than 90 °, the impeller 200 does not work sufficiently, that is, the impeller 200 cannot output the energy that should be provided under the condition that the rotation speed and the size of the impeller 200 are set, thereby reducing the pumping efficiency of the blood pump 10. When the wrap angle θ is greater than 220 °, the blade 220 will form an obstruction to the delivery cavity 110, increasing the resistance of blood in the flow process, and making the pumping efficiency of the whole blood pump 10 lower. Therefore, when the wrap angle θ is set within the above range, it is ensured that the impeller 200 works sufficiently and outputs sufficient energy, so that the flow energy of the blood flow meets the set requirement, and the on-way resistance of the blood in the flow process can be reduced, and finally the pumping efficiency of the whole blood pump 10 is improved.

Referring to fig. 5, in some embodiments, the thickness of the blades 220 is constant in a direction away from the hub 210, i.e., in a radial direction of the impeller 200, which is advantageous for precisely controlling the machining accuracy and surface roughness of the impeller 200 and reducing the risk of hemolysis. The thickness T of the blade 220 is T, and the thickness T of the blade 220 is 3% T/D7% or less relative to the total length L of the hub 210, e.g., T/D may be 3%, 4%, 6%, 7%, etc. When the H/L value is less than 3%, the thickness of the blade 220 is too small, and the processing difficulty is high, so that the impeller 200 generates relatively high-frequency vibration during rotation, thereby damaging the blood. When the value of H/L is greater than 3%, the thickness of the vane 220 is too large, so that the impeller 200 occupies too much space of the delivery chamber 110, thereby compressing the flowing space of the blood, increasing the on-way resistance of the blood in the flowing process, and reducing the pumping efficiency of the whole blood pump 10. Therefore, when T/D is taken in the above range, the impeller 200 is prevented from damaging the blood, so that the hemolysis phenomenon is eliminated, the on-way resistance of the blood in the flowing process is reduced, the hydraulic performance of the blood in the flowing process is further improved, and finally the pumping efficiency of the blood pump 10 is further improved.

In other embodiments, the thickness of the blade 220 varies in a direction away from the hub 210, i.e., the thickness T of the blade 220 may also be variable, and the thickness T of the blade 220 may also have the following relationship 3% T/D7% with the overall length L of the hub 210. In other embodiments, the thickness of the blade 220 is constant in a direction away from the hub 210, and the ratio T/D of the thickness T of the blade 220 to the total length L of the hub 210 may be less than 3% or greater than 7%.

The blade 220 includes a working surface 221 and a back surface 223, the working surface 221 and the back surface 223 are both connected with the 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, 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 in transition through round angles, so that smooth flow guiding of blood is realized, and hemolysis phenomenon caused by blood damage by sharp edges is avoided. The radius of the round angle can be 0.05mm-0.1mm so as to improve the flow guiding effect on blood.

Referring to fig. 3 and 4, in some embodiments, referring to a tangent line 215 at an end of the hub 210 near the driving assembly 300, the tangent line 215 intersects with a contour line of the liquid outlet 130 near the driving assembly 300. The relative positions of the impeller 200 and the liquid outlet 130 can be well positioned, the hydraulic performance of blood flow is optimized, and the phenomenon of hemolysis caused by the damage of blood is avoided. Specifically, when the tangent line 215 is located above the contour line of the first end 131, that is, the tangent line 215 is located closer to the second end 132 than the first end 131, the space of the liquid outlet 130 is not fully utilized, and the gap between the impeller 200 and the driver is increased, so that the blood backflow area at the bottom of the impeller 200 is increased, and the damage capability and the hemolysis phenomenon of blood are increased, and when the tangent line 215 is located below the contour line of the first end 131, that is, the tangent line 215 is located farther from the second end 132 than the first end 131, a part of the blood is not led to the liquid outlet 130, but is directly led to the inner wall of the sleeve 100, and the blood is destroyed to form the hemolysis phenomenon.

When the pumping efficiency of the blood pump 10 is improved, the higher the energy conversion rate of the driver, the energy consumption of the whole blood pump 10 can be reduced, so that the operation cost of the blood pump 10 can be reduced, and the heat generated by the blood pump 10 in the working process can be reduced.

In summary, the blood pump 10 provided by the invention comprises a sleeve 100 and an impeller 200, wherein the sleeve 100 is provided with a liquid inlet 120 and a liquid outlet 130, the impeller 200 is at least partially rotatably arranged in the sleeve 100to convey liquid from the liquid inlet 120 to the liquid outlet 130, the impeller 200 comprises a hub 210 and blades 220, the blades 220 are radially protruded from the hub 210 along the sleeve 100, the minimum clearance between the blades 220 and the inner wall of the sleeve 100 is delta, the inner diameter of the sleeve 100 is D, wherein delta/D is more than or equal to 2% and less than or equal to 3%, so that the blood is prevented from being damaged in the minimum clearance, the hemolysis phenomenon is avoided, the secondary flow is eliminated, the hydraulic performance of the blood flow is improved, the pumping efficiency of the blood pump 10 is improved, the processing and assembling difficulties of the impeller 200 are reduced, the impeller 200 and the sleeve 100 are prevented from being damaged in the assembling process, the damaged impeller 200 and the sleeve 100 are prevented from further the hemolysis phenomenon is further eliminated, and finally the blood pump 10 is improved on the basis of preventing the hemolysis phenomenon.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. A blood pump, comprising:

A sleeve pipe provided with a liquid inlet and a liquid outlet, and

The impeller is at least partially rotatably arranged in the sleeve so as to convey liquid from the liquid inlet to the liquid outlet, the impeller comprises a hub and blades, the blades protrude out of the hub along the radial direction of the sleeve, the minimum clearance between the blades and the inner wall of the sleeve is delta, and the inner diameter of the sleeve is D, wherein delta/D is more than or equal to 2% and less than or equal to 3%;

The height of the liquid outlet along the axial direction of the sleeve is H, the liquid outlet comprises a first output port and a second output port, a connecting line between one end of the first output port and one end of the second output port in the axial direction of the sleeve is a first connecting line, a connecting line between the other end of the first output port and the other end of the second output port in the axial direction of the sleeve is a second connecting line, the first connecting line and the second connecting line extend along the circumferential direction of the sleeve, the first output port is provided with a first contour line which is arranged close to the second output port, the first contour line is connected between the first connecting line and the second connecting line, the second contour line is connected between the first connecting line and the second connecting line, a region surrounded by the first connecting line, the second connecting line, the first contour line and the second contour line is a blocking region, and the blocking region is a positive projection S/(S) of the sleeve is more than or equal to 10 percent and is less than or equal to 5 percent, and is more than or equal to 5 percent of the positive projection S/(S in the positive projection of the sleeve is more than or equal to 10 percent and less than or equal to 5 percent of S.

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

3. The blood pump of claim 1, wherein the hub comprises a inducer without the blades, the inducer having a diameter that increases gradually from a distal end to a proximal end, the inducer having a length of L ₁, the hub having a total length of L, wherein 1/10 ∈l ₁/L ∈1/5.

4. The blood pump of claim 3, wherein the hub further comprises a booster section connected to the proximal end of the inducer section, the booster section having a diameter that increases gradually from the distal end to the proximal end, the blades being disposed in the booster section, the booster section having a length of L ₂, wherein 1/3≤l ₂/l≤3/4.

5. The blood pump of claim 4, wherein the hub further comprises a relief segment connected to the proximal end of the pressure boost segment, the vane is further disposed in the relief segment, the diameter of the relief segment increases gradually from the distal end to the proximal end, and the diameters of the pressure boost segment and the relief segment increase in a different manner, the length of the relief segment being L ₃, wherein L ₁+L₂+L₃ = L.

6. The blood pump of claim 1, wherein the number of said blades is plural, a plurality of said blades are arranged at intervals along the circumferential direction of said hub, and an angle occupied by a single said blade in the circumferential direction of said hub is denoted as a wrap angle θ, wherein θ is 90 ° or more and 220 °.

7. The blood pump of claim 1, wherein the sleeve 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 peripheral wall of the sleeve and communicated with the conveying cavity, the height of the liquid outlet along the axial direction of the sleeve is H, the total length of the hub is L, and 1/5≤H/L≤1/3.

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

9. The blood pump of claim 1, further comprising a drive assembly in driving connection with the impeller, wherein the sleeve is disposed at one end of the drive assembly, and a tangent line of the end of the hub near the drive assembly intersects a contour line of the liquid outlet near one side of the drive assembly.

10. The blood pump of claim 1, wherein the thickness of the blades is constant in a direction away from the hub, and/or wherein the thickness of the blades is T, wherein 3% T/D7%.

11. The blood pump of claim 1, wherein the blade comprises a working surface and a back surface, the working surface and the back surface are both connected with the outer circumferential surface of the hub, one end of the working surface near the liquid outlet and one end of the back surface near the liquid outlet are opposite, and one end of the working surface near the liquid inlet and one end of the back surface near the liquid inlet are transited by a rounded corner.