CN114668967B

CN114668967B - Centrifugal magnetic suspension blood pump with high hydraulic property

Info

Publication number: CN114668967B
Application number: CN202210244602.6A
Authority: CN
Inventors: 萨沙·格罗斯哈特; 颜翊凡; 徐博翎; 吴婷婷
Original assignee: Xinqing Medical Suzhou Co ltd
Current assignee: Xinqing Medical Suzhou Co ltd
Priority date: 2022-03-14
Filing date: 2022-03-14
Publication date: 2023-09-12
Anticipated expiration: 2042-03-14
Also published as: WO2023173920A1; CN114668967A; CN116920265A

Abstract

A centrifugal magnetic suspension blood pump with high hydraulic performance is disclosed, which comprises a motor and a pump head detachably connected with the motor. The pump head includes a pump housing having a blood inlet connector and a blood outlet connector, and an impeller housed within the pump housing. The impeller may be suspended within the pump housing and driven by the motor to rotate about an axis of rotation to pump blood from the blood inlet connector to the blood outlet connector. The impeller comprises an impeller shell and blades arranged on the impeller shell, the blades comprise main blades and splitter blades which are distributed in a circumferential staggered mode, the radial length of each main blade is larger than that of each splitter blade, the outer normal circle of each main blade is overlapped with the outer normal circle of each splitter blade, and the diameter of the inner normal circle of each main blade is smaller than that of the corresponding splitter blade.

Description

Centrifugal magnetic suspension blood pump with high hydraulic property

Technical Field

The present disclosure relates generally to the field of medical devices, and more particularly to a high hydraulic centrifugal magnetic levitation blood pump.

Background

Blood pumps are divided into implantable, extracorporeal and interventional types, with centrifugal pump technology being used for implantable and extracorporeal blood pumps. Through the evolution of the third generation technology, the third generation magnetic suspension type blood pump is the pump with the best blood compatibility. The magnetic suspension type blood pump uses a magnetic suspension system to suspend an impeller in the pump shell, so that the damage of blood cells caused by friction of a mechanical bearing is avoided, and better blood compatibility is obtained. The design of blood pumps is typically a balance between blood compatibility and hydrodynamic properties, and factors affecting blood compatibility are the shear stress to which the blood is subjected and the length of time that it is exposed to the shear stress.

Most of the existing implantable blood pump designs are aimed at ventricular assist and lack scalability. The extracorporeal blood pump can increase membranous lung and expand into ECMO system, and has high hydraulic performance and may be used even in cardiac operation cardiopulmonary bypass machine.

For in vivo blood pumps that can be used in an extended manner, the hydraulic performance requirements of the blood pump will be higher and there will be even higher blood compatibility requirements than for ventricular assist applications. Currently, most in-vivo blood pumps suitable for ECMO are mechanical bearings, and only one company in the United states applies the magnetic suspension blood pump technology. While most cardiopulmonary bypass machines are peristaltic pumps that are bulky and have low blood compatibility.

Disclosure of Invention

In view of the above-mentioned shortcomings, an object of the present invention is to design a centrifugal magnetic suspension blood pump with high hydrodynamic performance, which achieves higher pressure head and higher flow rate at lower rotation speed, and excellent blood compatibility, and can be applied to ventricular assist systems, ECMO systems, and even cardiopulmonary bypass machines.

In order to achieve the above purpose, the invention adopts the following technical scheme:

a high hydraulic performance centrifugal magnetic levitation blood pump comprising: a motor, a pump head removably engaged with the motor. The pump head includes: a pump housing having a blood inlet connector and a blood outlet connector, and an impeller housed within the pump housing. The impeller may be suspended within the pump housing and driven by the motor to rotate about an axis of rotation to pump blood from the blood inlet connector to the blood outlet connector. The impeller comprises an impeller shell and blades arranged on the impeller shell, the blades comprise main blades and splitter blades which are distributed in a circumferential staggered mode, the radial length of each main blade is larger than that of each splitter blade, the outer normal circle of each main blade is overlapped with the outer normal circle of each splitter blade, and the diameter of the inner normal circle of each main blade is smaller than that of the corresponding splitter blade.

Preferably, the diameter of the inner normal circle of the main blade is 8.311 mm-15.632 mm, the diameter of the outer normal circle is 40.361 mm-52.632 mm, and the diameter of the inner normal circle of the splitter blade is 18.874 mm-25.671 mm. Further, the diameter of the inner normal circle of the main blade is 11.552-13.868 mm, the diameter of the outer normal circle is 46.235-49.528 mm, and the diameter of the inner normal circle of the splitter blade is 21.113-23.995 mm.

Preferably, the outlet angle of the main blade is greater than the inlet angle thereof, the outlet angle thereof is 40-90 degrees, and the inlet angle is 0-50 degrees. Further, the inlet angle of the main blade is between 15 degrees and 25 degrees, and the outlet angle is between 70 degrees and 85 degrees.

Preferably, the outlet angle of the main blade is equal to the outlet angle of the splitter blade, and the inlet angle of the main blade is equal to the inlet angle of the splitter blade.

Preferably, the pump casing has a pump chamber accommodating the blades and an annular accommodating chamber accommodating the impeller casing, the annular accommodating chamber and the blood inlet connector being located on both sides of the pump chamber in the axial direction, respectively. The depth of the annular accommodating cavity is between 12mm and 25mm, and further between 15.6mm and 21.87mm.

Preferably, the upper surface of the impeller shell is a mounting disc surface fixedly connected with the main blades and the splitter blades, the mounting disc surface is an annular complete plane perpendicular to the rotation axis and continuously extending along the circumferential direction, and no concave or convex structure is arranged on the mounting disc surface.

Preferably, the main blades and the splitter blades have a leading edge close to the axis of rotation and a trailing edge remote from the axis of rotation in the radial direction. The leading edge of the main blade is higher than the leading edge of the splitter blade with respect to the mounting surface. Further, the top point of the front edge of the main blade is higher than the mounting disc surface 8.256 mm-12.568 mm, and the top point of the front edge of the splitter blade is higher than the mounting disc surface by 6.254 mm-9.658 mm. Still further, the apex of the leading edge of the main blade is located between 9.853mm and 11.984mm above the mounting plate face and the apex of the leading edge of the splitter blade is located between 7.854mm and 8.677mm above the mounting plate face.

Preferably, the leading edge of the main blade is higher than the trailing edge thereof, and the leading edge of the splitter blade is higher than the trailing edge thereof, relative to the mounting plate surface. Further, the height of the main blade gradually decreases from the leading edge to the trailing edge, and the height of the splitter blade gradually decreases from the leading edge to the trailing edge.

Preferably, the top surface of the main blade has a first slope and a second slope arranged in a radial direction, the first slope is positioned on the inner side of the second slope, and the slope of the first slope is larger than that of the second slope. Alternatively, the top surface of the main blade is a smooth curved surface extending continuously from the front edge to the rear edge, and the longitudinal section of the smooth curved surface is a smooth curve.

Preferably, the leading edge of the main blade extends radially inwardly beyond the inner edge of the mounting plate surface and the trailing edge extends radially outwardly beyond the outer edge of the mounting plate surface. The leading edge of the splitter vane does not extend radially beyond the inner edge of the mounting plate surface and the trailing edge extends radially outwardly beyond the outer edge of the mounting plate surface.

Preferably, the main blade and the splitter blade are both substantially perpendicular to the mounting plate surface.

Preferably, the pump housing further has a guide cone protruding axially toward the inside of the pump chamber, and the impeller is disposed around the guide cone. The top of the guide cone is higher than the installation disc surface but lower than the front edge of the splitter blade.

Preferably, the top of the diversion cone is 2.25 mm-6.35 mm in height, and the cone angle is 90-130 degrees. Further, the top end of the guide cone is 3.15 mm-5.35 mm, and the cone angle is 95.563-125.506 degrees.

Preferably, the cross section of the main blade perpendicular to the rotation axis is of an arc-shaped configuration, and the cross section of the splitter blade perpendicular to the rotation axis is of an arc-shaped configuration. The extension of the central arc of the cross section of the main blade and/or the splitter blade is eccentric to the rotation axis.

Preferably, the centre line of the pump chamber is offset from the axis of rotation.

Preferably, the pump chamber is provided with a circumferential flow passage surrounding the vane radially outside the vane, the circumferential flow passage having an area of flow passage of at least a part of the length increasing gradually in the flow direction.

Preferably, a secondary flow channel is provided between the impeller and the pump casing, the secondary flow channel having a U-shaped longitudinal section on the side of the rotation axis. The secondary flow path includes an inner annular gap located inside the impeller housing, a bottom annular gap located at the bottom side of the impeller housing, and an outer annular gap located outside the impeller housing. Wherein, the gap width of the inner annular gap is between 0.1mm and 1mm, the gap width of the outer annular gap is between 0.3mm and 1mm, and the gap width of the bottom annular gap is between 0.5mm and 2mm. Further, the gap width of the inner annular gap is between 0.342 and 0.854mm, the gap width of the outer annular gap is between 0.566 and 0.954mm, and the gap width of the bottom annular gap is between 0.935 and 1.433 mm.

The magnetic suspension blood pump of this embodiment through to main blade and the reasonable structural design of dividing blade, increase the working face of blade to blood from this, reduce the clearance size between blade and the pump case, improve the blood hydraulic properties of pump.

Drawings

FIG. 1 is a perspective view of a suspension pump structure provided in one embodiment of the present disclosure;

FIG. 2 is another view of FIG. 1;

FIG. 3 is a schematic diagram of the mating of FIG. 1 with a magnetic coupling assembly;

FIG. 4 is an exploded view of FIG. 1;

FIG. 5 is a rear view of FIG. 1;

FIG. 6 is a section A-A of FIG. 5;

FIG. 7 is an enlarged view of a portion of FIG. 6;

FIG. 8 is a front view of the impeller of FIG. 1;

fig. 9 is a top view of fig. 8.

Detailed Description

The terms "upper", "lower", "high", "low", "top" and "bottom" as used in this disclosure are directional definitions of the pump in the state shown in fig. 6, and "left" and "right" are defined in the state facing fig. 6. The rotating axis MN of the impeller is taken as a reference, the edge of the blade (main blade/splitter blade) close to the rotating axis MN is taken as a front edge, the edge far away from the rotating axis MN is taken as a rear edge, one end of the blade (main blade/splitter blade) close to the rotating axis MN is taken as an inner end, and one end far away from the rotating axis MN is taken as an outer end.

Referring to fig. 3, the centrifugal magnetic levitation blood pump with high hydraulic performance of the present embodiment includes a motor 112 and a pump head 101 detachably coupled with the motor 112. The operative engagement between the pump head 101 and the motor 112 may take place or conform to existing techniques or features described in the publication CN209187707U, CN209204247U, CN209204246U, which are not described in detail herein.

The pump head 101 includes a pump casing 102, and an impeller 113 accommodated in the pump casing 102. The impeller 113 may be suspended within the pump housing 102 and may be driven by the motor 112 to rotate about the axis of rotation MN to pump blood from the blood inlet connector 106 to the blood outlet connector 107 of the pump housing 102.

The suspension of the impeller 113 in the pump casing 102 may be achieved by a known embodiment provided by the publication CN111561519B or CN112546425B, which will not be described herein.

The driving of the impeller 113 may be achieved by means of magnetic coupling. The method comprises the following steps: as shown in fig. 3, the output shaft 300 of the motor 112 is provided with an active magnet (not shown), and the rotor 155 (shown in fig. 6) provided in the impeller housing 150 of the impeller 113 contains a passive magnet. After the pump head 101 is coupled to the motor 112, the output shaft 300 of the motor 112 is inserted into the pump housing 102 (specifically, a magnetic coupling cavity 108 described below) of the pump head 101, and the active and passive magnets are magnetically coupled, so that rotation of the motor 112 can be transmitted to the impeller 113, and rotation driving of the impeller 113 is achieved.

The blood outlet fitting 107 of the pump housing 102 has an outlet flow path tangentially into the pump chamber 110, the outer end of which has a blood outlet. The blood inlet connector 106 has an inlet flow path 1060 that opens axially into the pump chamber 110 and has a blood inlet port at its upper end. The flow direction (extending direction) of the output flow channel is perpendicular to the flow direction of the input flow channel 1060.

Pump housing 102 is plastic to reduce interference with the magnetic levitation system. As shown in fig. 4, the pump casing 102 includes an upper cover 104 and a lower cover 105, and the upper cover 104 is fixedly covered on the lower cover 105 to constitute the pump casing 102. The blood inlet connector 106 is located on the upper cover 104, and the blood outlet connector 107 is located mostly on the lower cover 105. The lower cover 105 provides an open structure that is covered by the upper cover 104 to form the pump chamber 110.

The pump housing 102 has a pump chamber 110 accommodating the blades 103 of the impeller 113, and the pump housing 102 also has an annular accommodating chamber 109 accommodating the impeller housing 150, the annular accommodating chamber 109 being located below and communicating with the pump chamber 110, the annular accommodating chamber 109 and the blood inlet connector 106 being located on both sides of the pump chamber 110 in the axial direction, respectively. The annular accommodating chamber 109 communicates with the lower side of the pump chamber 110, and the blood inlet connector 106 communicates with the upper side of the pump chamber 110. As shown in fig. 7, the depth H4 (length in the axial direction) of the annular accommodating chamber 109 (in the axial direction) is entirely larger than the axial length of the pump chamber 110. Specifically, the depth H4 of the accommodating chamber 109 is 12mm to 25mm, and further, the depth of the accommodating chamber 109 is 15.6mm to 21.87mm.

The pump chamber 110 is a flat chamber having a non-circular cross section (a cross section perpendicular to the rotation axis MN). The center line of the pump chamber 110 is offset from the rotation axis MN, and the two are not overlapped with each other so as to form a flow path satisfying blood compatibility outside the vane 103. The top of the central portion of the pump chamber 110 has a flare 117 above the magnetic coupling chamber 108, the flare 117 communicating with the downstream end of the input flow channel 1060. As shown in fig. 6 and 7, the pump chamber 110 has upper and lower parallel top and bottom walls 118 and 119, and the upper and lower top and bottom walls 118 and 119 each have a ring-shaped structure. The upper top wall 118 surrounds the flare 117 and the lower bottom wall 119 surrounds the upper opening of the annular receiving cavity 109 or the mounting plate surface 151.

The flow passage areas of the blades 103 are different on both sides in the radial direction in a longitudinal section parallel to the rotation axis MN. The pump chamber 110 is provided with a surrounding flow passage 116 surrounding the vane 103 radially outside the vane 103, and the flow passage 116 has an area of flow passage that gradually increases in the flow direction. Wherein the flow area surrounding the flow channel 116 is the cross-sectional area perpendicular to the flow direction.

The circumferential flow channel 116 gradually expands along the flow path area to achieve uniform pressure increase and to meet blood compatibility. Specifically, the circumferential flow channel 116 has an upstream end adjacent the outlet flow channel, and the pump housing 102 has a tangential output port that communicates between the pump chamber 110 and the outlet flow channel. The flow area at the upstream end is minimal and increases gradually as the circumferential flow channel 116 extends from the upstream end to the tangential output. The surrounding flow channel 116 is a spiral flow channel, and the surrounding flow channel 116 extends spirally along an upstream end toward the tangential output port.

As shown in fig. 6, the pump housing 102 includes a cavity portion 176 that encloses the pump chamber 110, and a power housing portion 175 located below the cavity portion 176, the power housing portion 175 having an outer diameter smaller than the outer diameter of the cavity portion 176. The power housing portion 175 defines an annular receiving cavity 109 and surrounds the magnetic coupling cavity 108, the magnetic coupling cavity 108 being a generally cylindrical cavity.

The upper surface of the impeller housing 150 is a mounting plate surface 151 fixedly connected to the blades 103, and the mounting plate surface 151 is perpendicular to the rotation axis MN and rotates around the rotation axis MN together with the blades 103. The mounting plate surface 151 is an annular complete plane extending continuously in the circumferential direction perpendicular to the rotation axis MN, and does not include any concave or convex structure thereon. The lower surface of the impeller housing 150 (the surface facing away from the mounting plate surface 151) is also an annular complete plane extending continuously in the circumferential direction with or without any concave or convex structures. The impeller housing 150 provides a flat outer wall surface to smooth the blood flow path and avoid damage to the blood.

The impeller housing 150 and the pump housing 102 form a secondary flow passage having a (longitudinal) cross section of a U shape, and the U-shaped flow passages on both sides of the rotation axis MN communicate to form a substantially W-shaped flow passage. Because the damage of the blood comes from the high shear stress and the exposure time under the high shear stress, the design can reduce the retention time (also called exposure time and flushing time) of the blood in the U-shaped flow channel, reduce the damage of the shear stress in the flow channel to the blood, and can effectively reduce the adverse effect of the pumping on the blood transportation. The secondary flow path in this embodiment can ensure that the complete flushing time is less than 0.5s.

As shown in connection with fig. 7, to reduce the exposure time of blood, the U-shaped secondary flow path includes an inner annular gap 154 inside the impeller housing 150, a bottom annular gap 152 at the bottom side of the impeller housing 150, and an outer annular gap 153 outside the impeller housing 150. Wherein, the gap width of the inner annular gap 154 is between 0.1 and 1mm, the gap width of the outer annular gap 153 is between 0.3 and 1mm, and the gap width of the bottom annular gap 152 is between 0.5 and 2mm. To further reduce the residence time of the blood and to ensure stable rotation of the impeller housing 150, the gap width of the inner annular gap 154 is between 0.342 and 0.854mm, the gap width of the outer annular gap 153 is between 0.566 and 0.954mm, and the gap width of the bottom annular gap 152 is between 0.935 and 1.433 mm.

As shown in fig. 6 to 9, the blades 103 include the main blades 10 and the splitter blades 20 which are distributed in a staggered manner along the circumferential direction, and by designing the splitter blades 20, the effective flow area can be increased, the flow field is stabilized, the pressure head and the pumping efficiency of the pump are further improved, and better hydraulic performance can be provided at a lower rotation speed. For example, a flow rate of 8L/min can be achieved at 3000 revolutions.

As shown in fig. 6 and 7, the pump housing 102 has a guide cone 1055 protruding toward the inside of the pump chamber 110 in the axial direction, and a lower cylinder supporting the guide cone 1055 has a concave structure, thereby forming a magnetic coupling chamber 108. The guide cone 1055 can guide the blood entering the pump shell 102, reduce the generation of vortex and high shearing area, and reduce the shearing of the blood and the adverse effect of pumping on the blood by arranging the guide cone 1055 in the scene applied to ventricular assist.

As shown in fig. 7, the tip of the guide cone 1055 is higher than the height H3 of the mounting plate surface 151 but lower than the height H1 of the leading edge 121 of the main blade 10 and lower than the height H2 of the leading edge 221 of the splitter blade 20. That is, in this embodiment, the guide cone 1055 does not extend into the blood inlet fitting 106. This design may allow blood entering from the blood inlet connector 106 to be partially split radially and retain a partial split axially, thereby reducing blade shear damage to the blood. The vanes 103 are disposed about the guide cone 1055.

The bottom surface of the guide cone 1055 is substantially at the same height as the mounting plate surface 151. In order to have better diversion guiding effect, the top end height H3 of the diversion cone 1055 is between 2.25 and 6.35mm, and further between 3.15 and 5.35 mm. The cone angle b of the flow cone 1055 is between 90 and 130 degrees, further between 95.563 and 125.506 degrees, and still further between 105.325 and 115.635 degrees.

The main blades 10 and the splitter blades 20 are uniformly spaced apart, one splitter blade 20 is spaced between two adjacent main blades 10 in the circumferential direction, one main blade 10 is spaced between two adjacent splitter blades 20 in the circumferential direction, and the central angle between the adjacent main blades 10 and the splitter blades 20 is approximately 45 degrees.

As shown in fig. 9, the cross section of the main blade 10 perpendicular to the rotation axis MN is of a slightly curved configuration (arc-shaped configuration), and the curvatures of the circumferential inner and outer edges are the same. The curvature of the cross section of the splitter blade 20 is the same as the curvature of the main blade 10, or the curvature of the center camber line of the cross section of the main blade 10 is the same as the curvature of the cross section of the splitter blade 20.

The extension of the center curve of the cross section of the main blade 10 is offset from the rotation axis MN, that is, the center curve of the cross section of the main blade 10 is eccentrically disposed with respect to the rotation axis MN, or the extension of the center curve of the cross section of the main blade 10 does not pass through the center of the impeller housing 150. Similarly, the extension of the center arc of the cross section of splitter vane 20 is also offset from axis of rotation MN, offset from axis of rotation MN.

With the above description in mind, the radial length of the main blade 10 is greater than the radial length of the splitter blade 20, the outer normal circle 33 of the main blade 10 coincides with the outer normal circle 33 of the splitter blade 20, and the diameter of the inner normal circle 30 of the main blade 10 is smaller than the diameter of the inner normal circle 31 of the splitter blade 20. Specifically, the diameter of the inner normal circle 30 of the main blade 10 is 8.311 mm-15.632 mm, and further 11.552 mm-13.868 mm. The diameter of the inner normal circle 31 of the splitter vane 20 is 18.874 mm-25.671 mm.

Further, the diameter of the inner normal circle 31 of the splitter vane 20 is between 21.113mm and 23.995 mm. The diameter of the outer circle 33 of the main blade 10 and the splitter blade 20 is 40.361 mm-52.632 mm, and further 46.235 mm-49.528 mm. The radial extension length and the corresponding curvature of the main blade 10 and the splitter blade 20 can be defined by the diameter, the inlet angle a, and the outlet angle B of the inner circle 30 and the outer circle 33, thereby limiting the configuration of the main blade 10 and the splitter blade 20 to a state capable of providing high hydrodynamic performance at low rotational speeds.

It is noted that any numerical value in this disclosure includes all values of the lower value and the upper value that increment by one unit from the lower value to the upper value, and that there is at least two units of space between any lower value and any higher value.

For example, the illustrated inner normal circle 30 of the main blade 10 has a diameter between 8.311mm and 15.632mm, and further between 11.552mm and 13.868mm, for purposes of illustration of the non-explicitly recited values such as 11.553mm, 11.554mm, 11.555mm, 11.660mm, 12.552mm, 12.553mm, 13.867mm, etc.

As mentioned above, the exemplary ranges given in 0.001 interval units do not exclude increases in interval units of appropriate units, e.g., 0.1, 0.0001, 0.03, 0.004, 0.5, etc. numerical units. These are merely examples that are intended to be explicitly recited in this description, and all possible combinations of values recited between the lowest value and the highest value can be considered to be explicitly stated in this description in a similar manner.

Unless otherwise indicated, all ranges include endpoints and all numbers between endpoints. "about" or "approximately" as used with a range is applicable to both endpoints of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30," including at least the indicated endpoints.

Other descriptions of the numerical ranges presented herein are not repeated with reference to the above description.

In the present embodiment, the outlet angle B of the main blade 10 and the outlet angle of the splitter blade 20 are equal, and the inlet angle a of the main blade 10 and the inlet angle of the splitter blade 20 are equal. As shown in fig. 9, the outlet angle B of the main blade 10 is greater than the inlet angle a (Attaching Angle) thereof. The outlet angle B is between 40 and 90 degrees, the inlet angle a is between 0 and 50 degrees, further, the inlet angle a is between 15 and 25 degrees, and the outlet angle B is between 70 and 85 degrees. The inlet angle of the blade 103 is also called an inlet angle (Entrance Blade Angle), which is the blade angle of the inlet (inner inlet) of the blade 103, and the specific geometric expression is an included angle between a connecting line between the vertex of the front edge of the blade and the center of the impeller 113 and an extension line of the central arc of the blade 103. The Exit Angle (Exit Blade Angle) of the Blade 103, which is the Blade Angle of the outlet of the Blade 103 (outer end outlet), is expressed in terms of the Angle between the tangent to the Blade trailing edge apex at the outer normal circle 33 and the center camber line of the Blade 103.

In order to achieve both hydrodynamic and hemolytic properties, the main blade 10 and the splitter blade 20 are both substantially perpendicular to the mounting plate surface 151. Specifically, the "substantially" may be 90±10 degrees, further may be 90±5 degrees, and still further may be 90 degrees, that is, vertically disposed.

The smaller the angle between the direction in which the blades 103 extend and the direction in which the blades 113 rotate, for example, the acute angle smaller than 90 degrees, the better the hydrodynamic performance of the blades 103, but the greater the damage to blood, the worse the hemolytic performance. Conversely, the greater the angle between the direction of extension of the blades 103 and the direction of rotation of the impeller 113, for example, an obtuse angle greater than 90 degrees, the less the impeller 103 is rotated to damage blood, the better the hemolysis performance, but the worse the hydrodynamic performance.

In this embodiment, the blades 103 are arranged substantially vertically, and the advantages of both the hydrodynamic properties and the blood compatibility can be combined.

The contour lines of the cross section of any two height positions of the main blade 10 or the splitter blade 20 on (at least) both circumferential sides coincide with the projection of the contour lines on the mounting disk surface 151 in the axial direction, and the leading edge 121 and the trailing edge of the main blade 10 are both perpendicular to the mounting disk surface 151. The top of the leading edge 121 of the main blade 10 is higher than the upper top wall 118, i.e. the upper end of the leading edge 121 of the main blade 10 extends into the flare 117.

The apex of the front edge 121 of the main blade 10 is located at a height of 8.256mm to 12.568mm above the mounting plate surface, and further at a height of 9.853mm to 11.984mm above the mounting plate surface. The apex of the leading edge 221 of the splitter vane 20 is 6.254mm to 9.658mm above the mounting plate face, and further is 7.854mm to 8.677mm above the mounting plate face.

The blade leading edge 121 of the main blade 10 is higher than the blade leading edge 221 of the splitter blade 20 with respect to the mounting surface 151. The leading edge 121 (apex) of the main blade 10 is higher than the trailing edge 111 (apex). The leading edge 221 of the splitter blade 20 is higher than the trailing edge 211 thereof. The leading edge 121 (inner end 12) of the main blade 10 extends radially inwardly beyond the inner edge 1051 of the mounting plate surface 151 and the trailing edge 111 (outer end 11) extends radially outwardly beyond the outer edge 1052 of the mounting plate surface 151. The length of the inner edge 1051 from which the leading edge 121 (inner end 12) of the main blade 10 extends is greater than the length of the trailing edge 1052 from which the trailing edge 111 (outer end 11) extends. The leading edge 121/221 is the inner edge of the vane inner end 12/22 and the outer edge 111/211 is the outer edge of the vane outer end 11/21.

The trailing edge 211 of the splitter blade 20 extends radially outwardly beyond the outer edge 1052 of the mounting plate surface 151 and the length of the outer edges 1052 of the main blade 10 and splitter blade 20 extending radially outwardly beyond the mounting plate surface 151 are equal. The leading edge 221 of the splitter vane 20 does not protrude radially beyond the inner edge 1051 of the mounting plate surface 151. As shown in fig. 7 and 8, the inner end 12 and the outer end 11 of the main blade 10 are suspended, and the outer end 21 of the splitter blade 20 is suspended. The outer ends 11/21 of the blades 103 form an excess flow gap thereunder. The inner end 12 of the main vane 10 extends above the conical surface of a portion of the deflector cone 1055.

The outer end 11 of the main blade 10 is disposed at least from the outer edge 1052 of the mounting plate surface 151 above the mounting plate surface 151, and correspondingly, the inner end 12 of the main blade 10 is disposed at least from the inner edge 1051 of the mounting plate surface 151 above the mounting plate surface 151. The bottom surface of the inner end 12 of the main blade 10 is 1 mm-3 mm higher than the installation surface, and the bottom surfaces of the outer ends of the main blade 10 and the splitter blade 20 are 1 mm-3 mm higher than the installation surface.

By extending the front and rear edges 11, 12 of the main vane 10 beyond the mounting plate surface 151, respectively, the acting surface of the vane 103 on blood is increased, the gap between the vane 103 and the pump casing 102 is reduced, and the hydraulic performance of the pump is improved.

As shown in fig. 8, the height of the main blade 10 gradually decreases from the leading edge 12 to the trailing edge 11. The top surface 18 of the main blade 10 has a first slope and a second slope in the radial direction, the first slope being located inside the second slope, the slope of the first slope being greater than the slope of the second slope, the radial length of the second slope being greater than the radial length of the first slope. The inner end 12 of the main blade 10 extends generally diagonally upward to accommodate the flare 117.

The splitter blade 20 is similar to the main blade 10 in that its height gradually decreases from the leading edge to the trailing edge. The top surface 28 of the splitter vane 20 also has a first ramp surface and a second ramp surface in the radial direction, the first ramp surface being located inboard of the second ramp surface, the first ramp surface having a greater slope than the second ramp surface, the second ramp surface having a greater radial length than the first ramp surface.

In another embodiment, the top surface 18 of the main blade 10 is a smooth curved surface extending continuously from the leading edge to the trailing edge, the tangent to the smooth curved surface (of the contour line in longitudinal section) gradually decreasing in gradient from the leading edge to the trailing edge relative to the mounting plate surface 151.

Similarly, the top surface 28 of the splitter blade 20 is a smooth curved surface extending continuously from the leading edge to the trailing edge, the tangent to the smooth curved surface (of the contour line in longitudinal section) gradually decreasing in gradient from the leading edge to the trailing edge relative to the mounting plate surface 151.

Unless otherwise specifically indicated or defined, a is higher than B in the present disclosure, and it is understood that the top (apex/top/tip) of a is higher than the top (apex/top/tip) of B with respect to the mounting plate surface 151. In the present embodiment, the leading edge height, the trailing edge height, and the blade height are respectively the peak/tip height of the leading edge, the peak/tip height of the trailing edge, and the tip/top height of the blade, with respect to the mounting plate surface 151 as a reference surface.

The foregoing is merely a few embodiments of the present invention and those skilled in the art, based on the disclosure herein, may make numerous changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the invention.

Claims

1. A high hydraulic performance centrifugal magnetic levitation blood pump comprising:

a motor;

a pump head in removable engagement with the motor, comprising:

a pump housing having a blood inlet connector and a blood outlet connector;

an impeller housed within the pump housing and configured to be suspended within the pump housing and driven by the motor to rotate about an axis of rotation to pump blood from the blood inlet connector to the blood outlet connector; the impeller includes: an impeller shell and blades arranged on the impeller shell; the blades comprise main blades and splitter blades which are distributed in a staggered manner along the circumferential direction, the radial length of the main blades is larger than that of the splitter blades, the outer normal circles of a plurality of the main blades are overlapped with the outer normal circles of a plurality of the splitter blades, and the diameter of the inner normal circles of a plurality of the main blades is smaller than that of the inner normal circles of a plurality of the splitter blades; the upper surface of the impeller shell is a mounting disc surface, and the main blades and the splitter blades are fixedly connected to the mounting disc surface; the pump shell is provided with a pump cavity for accommodating the blades, an annular accommodating cavity for accommodating the impeller shell, a guide cone protruding towards the inside of the pump cavity along the axial direction, and the impeller is arranged around the guide cone; the top end of the guide cone is higher than the mounting disc surface but lower than the front edge of the splitter blade;

the outlet angle of the main blade is larger than the inlet angle of the main blade, the outlet angle of the main blade is equal to the outlet angle of the splitter blade,

the inlet angle of the main blade is equal to the inlet angle of the splitter blade; the pump cavity is provided with a surrounding flow passage surrounding the blades on the radial outer side of the blades, and the flow passage with at least part of the length gradually increases in the flow direction.

2. A magnetic levitation blood pump according to claim 1 wherein the main blades have an inner normal circle diameter of between 8.311mm and 15.632mm, an outer normal circle diameter of between 40.361mm and 52.632mm and an inner normal circle diameter of between 18.874mm and 25.671 mm.

3. A magnetic levitation blood pump according to claim 1 wherein the main blades have an inner normal circle diameter of between 11.552mm and 13.868mm, an outer normal circle diameter of between 46.235mm and 49.528mm and an inner normal circle diameter of between 21.113mm and 23.995 mm.

4. A magnetic levitation blood pump according to claim 1 wherein the outlet angle of the main vane is 40-90 degrees and the inlet angle is 0-50 degrees.

5. A magnetic levitation blood pump according to claim 1 wherein the inlet angle of the main vane is between 15 degrees and 25 degrees and the outlet angle is between 70 degrees and 85 degrees.

6. A magnetic levitation blood pump according to any of claims 1-5 wherein the annular accommodation chamber and the blood inlet connector are located on either side of the pump chamber in the axial direction; the depth of the annular accommodating cavity is between 12mm and 25 mm.

7. A magnetic levitation blood pump according to claim 6 wherein the annular containment chamber has a depth of between 15.6mm and 21.87mm.

8. A magnetic levitation blood pump according to claim 6 wherein the mounting plate surface is an annular complete plane perpendicular to the axis of rotation and extending continuously in a circumferential direction without any concave or convex structure provided thereon.

9. A magnetic levitation blood pump as defined in claim 8, wherein the edges of the main and shunt blades radially proximate to the axis of rotation are leading edges and the edges distal to the axis of rotation are trailing edges; the leading edge of the main blade is higher than the leading edge of the splitter blade with respect to the mounting surface.

10. A magnetic levitation blood pump according to claim 9 wherein the apex of the leading edge of the main blade is between 8.256mm and 12.568mm above the mounting plate surface and the apex of the leading edge of the splitter blade is between 6.254mm and 9.658mm above the mounting plate surface.

11. A magnetic levitation blood pump according to claim 9 wherein the apex of the leading edge of the main blade is between 9.853mm and 11.984mm above the mounting plate face and the apex of the leading edge of the splitter blade is between 7.854mm and 8.677mm above the mounting plate face.

12. A magnetic levitation blood pump as in claim 9 wherein the leading edge of the main blade is higher than the trailing edge thereof and the leading edge of the shunt blade is higher than the trailing edge thereof relative to the mounting plate surface.

13. A magnetic levitation blood pump according to claim 12 wherein the height of the main blade decreases gradually from the leading edge to the trailing edge and the height of the shunt blade decreases gradually from the leading edge to the trailing edge.

14. A magnetic levitation blood pump according to claim 12 wherein the top surface of the main blade has first and second ramps arranged radially, the first ramp being inboard of the second ramp, the first ramp having a slope greater than the slope of the second ramp; or the top surface of the main blade is a smooth curved surface extending continuously from the front edge to the rear edge, and the longitudinal section of the smooth curved surface is a smooth curve.

15. A magnetic levitation blood pump as defined in claim 8, wherein the leading edge of the main blade extends radially inward beyond the inner edge of the mounting plate surface and the trailing edge extends radially outward beyond the outer edge of the mounting plate surface; the leading edge of the splitter vane does not extend radially beyond the inner edge of the mounting plate surface and the trailing edge extends radially outwardly beyond the outer edge of the mounting plate surface.

16. A magnetic levitation blood pump according to claim 8 wherein the main blade and the shunt blade are both substantially perpendicular to the mounting plate surface.

17. A magnetic levitation blood pump according to claim 1 wherein the height of the tip of the flow guide cone is between 2.25mm and 6.35mm and the cone angle is between 90 degrees and 130 degrees.

18. A magnetic levitation blood pump according to claim 17 wherein the height of the tip of the flow guide cone is between 3.15mm and 5.35mm and the cone angle is between 95.563 degrees and 125.506 degrees.

19. A magnetic levitation blood pump as defined in claim 1, wherein a cross section of said main blade perpendicular to said rotation axis is of arcuate configuration and a cross section of said shunt blade perpendicular to said rotation axis is of arcuate configuration; wherein the extension line of the central arc of the cross section of the main blade and/or the splitter blade is eccentric to the rotation axis.

20. A magnetic levitation blood pump according to claim 6 wherein the centre line of the pump chamber is offset from the axis of rotation.

21. A magnetic levitation blood pump according to claim 1 wherein there is a secondary flow path between the impeller and the pump housing, the secondary flow path having a U-shaped longitudinal section on the side of the rotation axis; the secondary flow channel comprises an inner annular gap positioned at the inner side of the impeller shell, a bottom annular gap positioned at the bottom side of the impeller shell and an outer annular gap positioned at the outer side of the impeller shell;

the gap width of the inner annular gap is between 0.1mm and 1mm, the gap width of the outer annular gap is between 0.3mm and 1mm, and the gap width of the bottom annular gap is between 0.5mm and 2mm.

22. A magnetic levitation blood pump according to claim 21 wherein the gap width of the inner annular gap is between 0.342 and 0.854mm, the gap width of the outer annular gap is between 0.566 and 0.954mm and the gap width of the bottom annular gap is between 0.935 and 1.433 mm.