CN112473000A

CN112473000A - Position-controlled suspension centrifugal blood pump

Info

Publication number: CN112473000A
Application number: CN202011449637.0A
Authority: CN
Inventors: 彭远仪; 万峰; 李国荣; 张鹏
Original assignee: Shanghai Dongxin Biomedical Technology Co ltd
Current assignee: Shanghai Dongxin Biomedical Technology Co ltd
Priority date: 2020-12-09
Filing date: 2020-12-09
Publication date: 2021-03-12

Abstract

The embodiment of the specification relates to a position-controlled suspension centrifugal blood pump, which is a pump-motor integrated device and comprises: the device comprises a pump shell, a rotor, an impeller, a servo motor, an inner magnetic core group, an outer magnetic ring group and a position control bearing; the rotor is connected with the impeller in a seamless mode, the rotor is arranged in an inner tube of the blood pump, and the rotor is driven by the servo motor to drive the impeller to do work; the inner magnetic core group consists of a plurality of circular magnetic sheets and is arranged at the top end inside the rotor, and the outer magnetic ring group consists of a plurality of magnetic rings and is sleeved on the outer wall of the inner pipe; the position control bearing consists of a ceramic ball and a ceramic nest. The top end of the impeller blade is provided with an inclined surface, so that hydraulic pressure can be generated when the pump works. According to the technical scheme, the rotor impeller can be in omnibearing position control suspension, the friction effect of a mechanical bearing is overcome, the structure in the pump is simple and smooth, and hemolysis and thrombosis complications can be greatly reduced; the blood pump has small volume, light weight and small invasion in operation, and can improve safety and practicability.

Description

Position-controlled suspension centrifugal blood pump

Technical Field

The embodiment of the specification relates to the technical field of medical instruments, in particular to a position-control suspension centrifugal blood pump.

Background

Cardiovascular diseases seriously threaten the health of human beings, and tens of millions of people die due to heart failure every year all over the world. For patients with advanced heart failure, an effective, simple and efficient method for treating the final heart failure still does not exist so far, and the artificial heart is considered as the last life-saving straw for a plurality of patients with advanced heart failure.

The ventricle auxiliary device is an auxiliary artificial heart, which is also called a blood pump for short, and has been widely applied in clinic in recent years, and the clinical application amount is nearly ten thousand cases every year. At present, the most applied products in the international market are four major products in the United states, wherein two blood pumps are second-generation blood pumps, two blood pumps are third-generation blood pumps, and the second-generation blood pump is of a bearing type structure, and the main defects are as follows: the bearing is easy to wear, and the service life of the blood pump is seriously limited; because of bearing friction, the resulting hemolysis is relatively severe; the third generation blood pump is a magnetic suspension type structure, although the service life is long, the third generation blood pump also has new problems, main problems: firstly, the magnetic suspension structure is complex, the volume of the blood pump is increased, and the invasiveness of the operation is increased, for example, the volume and the weight of a third-generation magnetic suspension blood pump HeartMate III are more than three times that of a second-generation blood pump Jarvik 2000; secondly, the structure is complex, dead angles and even dead spaces of blood flow exist, and complications such as thrombus and the like easily occur.

Therefore, the volume and the weight of the suspension type blood pump are reduced, the internal structure of the pump is simplified, and complications such as hemolysis and thrombus are reduced, so that the suspension type blood pump is a difficult problem to solve.

Disclosure of Invention

The technical problem to be solved by the embodiments of the present specification is to overcome the defects of the prior art, and provide a position-controlled suspension centrifugal blood pump with small volume, light weight and simple structure.

In order to achieve the above purpose, the embodiments of the present specification adopt the following technical solutions:

a position-controlled suspended centrifugal blood pump comprising: the device comprises a pump shell, a rotor, an impeller, a servo motor, an inner magnetic core group, an outer magnetic ring group and a position control bearing; the rotor is connected with the impeller in a seamless mode, the rotor is arranged in an inner tube of the blood pump, and the rotor is driven by the servo motor to drive the impeller to do work;

the inner magnetic core group consists of a plurality of circular magnetic sheets and is internally arranged at the top end inside the rotor, and the outer magnetic ring group consists of a plurality of magnetic rings and is sleeved on the outer wall of the inner pipe;

the position control bearing is composed of a ceramic ball and a ceramic nest, the ceramic ball is embedded in the lower end of the rotor impeller and exposes out of the rotor, and the ceramic nest is arranged below the ceramic ball.

Optionally, the inner magnetic core group consists of three circular magnetic sheets, and the outer magnetic ring group consists of two magnetic rings; or

The inner magnetic core group consists of four round magnetic sheets, and the outer magnetic ring group consists of three magnetic rings; or

The inner magnetic core group consists of five circular magnetic sheets, and the outer magnetic ring group consists of four magnetic rings.

Optionally, the magnetic materials of the inner magnetic core group and the outer magnetic ring group are strong magnetic neodymium iron boron.

Optionally, the inclined surface at the middle part of the top of the impeller is of a hydraulic structure.

Optionally, the inclined surface has an inclination angle of 1-20 °

Optionally, the impeller is sheet-shaped and includes a plurality of blades, and the root of each blade is connected to the rotor.

Optionally, the impeller comprises 3-5 blades.

Optionally, the pump casing further comprises: an inlet conduit, a pump cavity cover and a pump cavity lower shell;

the inlet pipeline comprises an inlet bracket, an outer heat insulation sleeve, a middle sleeve and an inner pipe;

the outer heat insulation sleeve, the middle sleeve and the inner pipe are of a coaxial structure, one end of the outer heat insulation sleeve, the middle sleeve and the inner pipe is connected with the inlet support, and the other end of the outer heat insulation sleeve, the middle sleeve and the inner pipe is embedded in the pump cavity cover;

the pump cavity cover is annular and is concentrically connected with the inner pipe, and the excircle of the pump cavity cover is connected with the lower pump cavity shell;

the inner bottom of the pump cavity lower shell is provided with a convex round table, and the side edge of the pump cavity lower shell is provided with a pump outlet.

Optionally, the servo motor includes rotor magnetic steel, a stator core and a stator winding;

the rotor magnetic steel is arranged in the rotor, and the stator core and the stator winding are arranged on the inner wall of the inlet pipeline, namely, the stator core and the stator winding are arranged between the inner pipe and the middle sleeve;

the rotor magnetic steel and the rotor are integrated, and the stator core and the stator winding are integrated with the inlet pipeline.

Optionally, the servo motor further comprises a telecommunication transmission line, one end of the telecommunication transmission line is connected with the stator winding, and the other end of the telecommunication transmission line extends out of the body and is connected with the control system.

The embodiment of the specification adopts at least one technical scheme which can achieve the following beneficial effects:

the suspension bearing provided by the invention is a permanent magnet bearing, belongs to passive magnetic suspension, does not need a complex detection, feedback and control system, has a simpler structure and stable performance, and can greatly improve the technical reliability and the use safety of the blood pump; the volume and the weight of the blood pump are smaller, so that the operation invasion of the blood pump can be reduced, and the practicability is improved; the internal structure of the full-suspension blood pump is simple and smooth, has no dead space or dead angle, and can effectively prevent thrombosis.

Drawings

In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic cross-sectional view of a structure of a position-controlled suspension centrifugal blood pump according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of a position-controlled suspended centrifugal blood pump provided by an embodiment of the present disclosure at start-up;

fig. 3 is a schematic view of a force analysis of a rotor wheel provided in an embodiment of the present disclosure.

The reference numbers illustrate: the device comprises rotor magnetic steel-1, a stator iron core-2, a stator winding-3, an outer magnetic ring group-4, an inner magnetic core group-5, a telecommunication transmission line-6, an inner pipe-7, a middle sleeve-8, an outer heat insulation sleeve-9, an inlet support-10, a rotor-11, an impeller-12, an inclined surface-13, a ceramic ball-14, a ceramic socket-15, a convex circular table-16, a wedge-shaped groove-17, a pump cavity lower shell-18, a pump cavity cover-19, a pump outlet-20, a pump inlet-21, a sewing ring-22, a first backward axial force-F1, a second backward axial force-F2, a third backward axial force-F3 and a forward axial force-F4.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be described in detail below. It is to be understood that the embodiments described are only some of the embodiments of the specification and not all of them. All other embodiments obtained by a person of ordinary skill in the art without any inventive work based on the examples in the present specification fall within the scope of protection of the examples in the present specification.

The following further describes the concrete implementation of the embodiment with reference to the attached drawings of the embodiment in the specification.

Referring to fig. 1 to 3, an embodiment of the present disclosure provides a position-controlled suspended centrifugal blood pump, including: pump unit, servo motor and accuse position system.

The pump device comprises a pump housing, a rotor 11 and an impeller 12.

The pump housing comprises an inlet conduit, a pump chamber cover 19 and a pump chamber lower shell 18.

The inlet duct comprises an inlet support 10, an outer insulating jacket 9, a middle sleeve 8 and an inner pipe 7.

The outer heat insulation sleeve 9, the middle sleeve 8 and the inner pipe 7 are of a coaxial structure, one end of the outer heat insulation sleeve, the middle sleeve and the inner pipe is connected with the inlet support 10, the other end of the outer heat insulation sleeve, the middle sleeve and the inner pipe is connected with the pump cavity cover 19, and the joint needs to be welded and is leakproof.

The inlet support 10 is convex, and is used for preventing the pump from working failure and embolism caused by the negative pressure sucking the ventricular septum when the blood pump works.

A cavity is formed between the outer heat insulation sleeve 9 and the middle sleeve 8, so that the heat-resistant and cooling effects can be achieved, and the blood pump and the motor can be guaranteed to work safely and effectively.

A sewing ring 22 is arranged on the outer heat insulation sleeve 9 near the pump cavity cover 19 and is used for fixing the blood pump and the apex of the heart.

The pump cavity cover 19 is annular, the central opening is concentrically connected with the inner tube 7, the excircle is connected with the pump cavity lower shell 18, and the joint needs to be welded and is leak-proof.

The inner bottom of the pump cavity lower shell 18 is provided with a convex round table 16, the side edge is provided with a pump outlet 20, and the pump cavity cover 19 is sealed and welded after being buckled on the pump cavity lower shell 18.

The rotor 11 and the impeller 12 are seamlessly connected into a whole.

The rotor 11 is driven by the servo motor to drive the impeller 12 to do work, so that blood continuously flows in from the pump inlet 21 and flows out from the pump outlet 20 after being centrifuged.

The impeller 12 is in the form of a blade, typically 4 blades, the root of which is connected to the rotor 11, evenly distributed.

Optionally, the impeller 12 has 3 blades or 5 blades.

The servo motor mainly comprises rotor magnetic steel 1, a stator iron core 2, a stator winding 3 and a telecommunication transmission line 6.

The rotor magnetic steel 1 is arranged in the rotor 11; the stator core 2 and the stator winding 3 are arranged in the interlayer of the middle sleeve 8 and the inner tube 7.

The telecommunication transmission line 6 is used for transmitting electric energy and electric signals, one end of the telecommunication transmission line is connected with the stator winding 3, and the other end extends out of the body and is connected with the control system.

Because the servo motor and the pump device are integrated into a whole, the pump-motor integration is formed.

The position control system comprises a position control magnetic group, a position control bearing and a hydraulic structure.

The position control magnetic group comprises an inner magnetic core group 5 and an outer magnetic ring group 4. The inner magnetic core group 5 is formed by overlapping three round magnetic sheets with the same axle center and is internally arranged at the top end inside the rotor; the outer magnetic ring group 4 is formed by overlapping two magnetic rings together with the same axle center and is sleeved on the outer wall of the inner pipe, and the axial installation position of the outer magnetic ring group is close to the lower edge of the inner magnetic core group 5. The magnetic directions of the circular magnetic sheet and the magnetic ring are axial, and the stacking sequence is that the same poles are opposite and are bonded together forcibly.

Optionally, the inner magnetic core group 5 may be formed by combining four circular magnetic sheets, and the outer magnetic ring group 4 is formed by combining three magnetic rings; or the inner magnetic core group 5 is formed by combining five round magnetic sheets, the outer magnetic ring group 4 is formed by combining four magnetic rings, and the installation position is close to the lower edge.

Preferably, the magnetic material of the position control magnetic group is strong magnetic neodymium iron boron.

The position control bearing comprises a ceramic ball 14 and a ceramic nest 15, the ceramic ball 14 is embedded at the lower end of the rotor impeller 12 and is approximately half exposed, the ceramic nest 15 is embedded at the top end of the convex circular table 16, the edges of the top end are flush, and under the action of axial pressure generated by the position control magnetic group, the ceramic ball 14 abuts against the ceramic nest 15 to form a group of sliding bearings, so that the starting of the position control blood pump can be well supported, as shown in figure 2.

The hydraulic structure is that the top middle part of the impeller 12 is inclined, namely the top of the blade is inclined from the inlet flow side to the back flow side, the inclined surface 13 and the inner surface of the pump cavity cover 19 form a wedge-shaped space, and the two sides of the inclined surface are provided with edges parallel and level to the top surface, so that the liquid flow can be prevented from overflowing.

Optionally, the inclined surface 13 has an inclination angle of 1-20 °.

After the position-controlled suspension centrifugal blood pump provided by the embodiment of the specification is started smoothly, how the rotor impeller achieves suspension operation as shown in fig. 1 needs to be analyzed, and suspension can be decomposed into radial suspension and axial suspension.

The radial suspension is mainly realized by a position control magnetic group, the inner magnetic core group 5 and the outer magnetic ring group 4 are radially repelled by magnetic force, and the repulsive force can sufficiently overcome and balance various radial forces, so that the rotor impeller is always controlled to be positioned at the center of the inner tube 7, and a gyroscope dead axle effect is added when the rotor impeller rotates, thereby obtaining good radial suspension effect.

How to realize axial suspension needs to be analyzed, the blood pump can be influenced by a plurality of axial forces when working at high speed, wherein the axial forces can be divided into weak axial force and strong axial force, the weak axial force mainly comprises the axial component of the gravity of a rotor impeller and the axial force of other factors, and the weak axial force is a weak influence factor; the strong axial force mainly comprises four axial forces, which can be analyzed from the graph shown in fig. 3, F4 is a forward axial force (pointing to the pump inlet), F1, F2 and F3 are three backward axial forces (back to the pump inlet), F1 is generated by a position control magnetic group, because the inner magnetic core group 5 is more than the outer magnetic ring group 4 and is slightly higher, a backward axial pressure is generated to the rotor impeller, the force is smaller, but the magnitude is basically unchanged, and has no relation with the rotating speed of the pump; f2 is the axial component of the impulse force generated by the fluid momentum on the impeller, and the force is positively correlated with the rotating speed; f3 is the axial component of the pressure exerted by the hydraulic pressure on the inclined surface 13 of the impeller 12, the force magnitude is in positive geometric correlation with the rotation speed, but in negative correlation with the magnitude of the wedge-shaped space; f4 is generated by the pressure difference between the low hydraulic pressure of the inner surface and the suction inlet of the pump cavity cover 19 and the high hydraulic pressure of the lower cover surface when the pump works, the force is rapidly increased along with the increase of the pump rotating speed after the pump is started, when the rotating speed reaches a certain height and F4 is greater than the sum of F1, F2 and F3, F4 drives the rotor impeller and the ceramic ball 14 to separate from the ceramic socket 15 and axially move forwards, the wedge-shaped space is reduced along with the approach of the top end of the blade to the pump cavity cover 19, the generated hydraulic pressure axial component F3 is increased in geometric progression, the force can automatically resist F4, when the resultant force balance of the axial force is reached, the rotor impeller is forced to stop the axial displacement, F3 is not increased any more, that is, the axial stress of the rotor impeller can be automatically balanced in a certain rotating speed range, and the rotor impeller.

As mentioned above, the rotor impeller can realize omnibearing position control suspension by combining radial suspension and axial suspension, thereby stably operating.

The technical effects that can be achieved by the embodiments of the present description are as follows:

compared with the existing mechanical bearing blood pump, the blood pump disclosed by the embodiment of the specification has the advantages that in the suspension state when the blood pump works normally, the bearings have no friction, the hemolysis can be reduced, the service life of the blood pump is prolonged, and the thrombosis complications triggered by friction heating can be reduced.

Compared with the existing magnetic suspension blood pump, the suspension bearing in the embodiment of the specification is a permanent magnet bearing, belongs to passive magnetic suspension, does not need a complex detection, feedback and control system, has a simpler structure and stable performance, and can greatly improve the technical reliability and the use safety of the blood pump; the volume and the weight of the blood pump are smaller, so that the operation invasion of the blood pump can be reduced, and the practicability is improved; the internal structure of the full-suspension blood pump is simple and smooth, has no dead space or dead angle, and can effectively prevent thrombosis.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A position-controlled suspended centrifugal blood pump, comprising: the device comprises a pump shell, a rotor, an impeller, a servo motor, an inner magnetic core group, an outer magnetic ring group and a position control bearing; the rotor is connected with the impeller in a seamless mode, the rotor is arranged in an inner tube of the blood pump, and the rotor is driven by the servo motor to drive the impeller to do work;

2. The blood pump according to claim 1, wherein said inner magnetic core set is composed of three circular magnetic sheets, and said outer magnetic ring set is composed of two magnetic rings; or

3. The blood pump of claim 1, wherein said inner magnetic core set and said outer magnetic ring set are both strongly bonded together by like-pole repulsion of strong magnetic neodymium iron boron material.

4. The blood pump of claim 1, wherein the inclined surface at the top middle portion of said impeller is of hydrodynamic structure.

5. The blood pump of claim 4, wherein said inclined surface has an inclination angle of 1-20 °.

6. The blood pump of claim 1, wherein said impeller is in the form of a blade comprising a plurality of blades, said blade roots being attached to said rotor.

7. The blood pump of claim 6, wherein said impeller comprises 3-5 blades.

8. The blood pump of claim 1, wherein said pump housing comprises: an inlet conduit, a pump cavity cover and a pump cavity lower shell;

9. The blood pump of claim 8, wherein said servo motor comprises rotor magnetic steel, a stator core and a stator winding;

10. The blood pump of claim 9, wherein said servo motor further comprises a telecommunications line connected at one end to said stator windings and extending outside the body to a control system.