CN118105614A

CN118105614A - Ventricular assist device

Info

Publication number: CN118105614A
Application number: CN202211484781.7A
Authority: CN
Inventors: 康环; 蒋海洋; 黄霖; 杨迁红
Original assignee: Shanghai Xinhengrui Medical Technology Co ltd
Current assignee: Shanghai Xinhengrui Medical Technology Co ltd
Priority date: 2022-11-24
Filing date: 2022-11-24
Publication date: 2024-05-31

Abstract

The invention provides a ventricular assist device, which comprises a shell and an impeller rotor, wherein the shell is provided with an accommodating space and a fluid inlet, the fluid inlet is communicated with the accommodating space, the impeller rotor is arranged in the accommodating space and comprises an impeller part and a rotor part which are connected, the rotor part is coaxially arranged with the impeller part, the rotor part is positioned at one side of the impeller part, which is far away from the fluid inlet, the rotor part is provided with a through groove which penetrates through along the axial direction of the rotor part, when the impeller rotor is suspended and rotated in the accommodating space, fluid is sucked into the impeller part, after the impeller part works and is pressurized, the peripheral fluid pressure of the impeller part is higher than the fluid pressure in the through groove, a secondary flow is formed under the pressure difference between the peripheral fluid pressure of the impeller part and the fluid pressure in the through groove, and the secondary flow enters a main runner again through the periphery of the impeller rotor and the through groove. After the ventricular assist device provided by the invention is adopted, the total path of the secondary fluid flow can be reduced, the risk of flow stagnation during the secondary fluid flow can be reduced, and the reliability and stability of the ventricular assist device during operation are ensured.

Description

Ventricular assist device

Technical Field

The invention relates to the technical field of medical treatment, in particular to a ventricular assist device.

Background

Heart failure is the final stage of heart disease development, and the only way to go out of the heart of the final stage heart failure patient is to change heart, but is limited by the number of donors, matching conditions of the donors, high operation difficulty and other factors, and many patients cannot be cured by the donors finally. The artificial heart is implanted in the human body for treatment in clinic, and the artificial heart has the action principle similar to a mechanical pump and has the function of assisting the heart of the human body to build an auxiliary flow passage for the blood of the heart of the patient. Artificial heart technology research and development has undergone a revolution from pulsatile to rotary blood pumps. Blood pumps are effective in the treatment of heart failure, but the side effects of blood cell damage (hemolytic reaction) and blood cell coagulation (thrombosis) are also inevitable. The pulsatile blood pump has serious damage to blood, high occurrence rate of hemolysis and thrombus, huge volume of the device and poor durability, and is used for clinic at present. Rotary blood pumps have undergone a development history from mechanical bearings, hydrodynamic bearings, to full-magnetic suspension bearings. In the mechanical bearing, blood flow stagnation and thrombus formation easily occur in narrow gaps between the bearing seal ring, the rolling bearing ball and the inner and outer rings. For the hydrodynamic bearing, the hydrodynamic suspension supporting channel is a micron-sized channel, and is easy to cause hemolysis due to the damage of blood cells caused by high shearing stress on blood.

At present, the development of artificial heart technology is gradually advanced to a full-magnetic suspension centrifugal pump, and the full-magnetic suspension centrifugal pump has the advantages that an impeller is suspended and rotated by a magnetic field, that is, no mechanical contact exists between the impeller and a pump housing, and the impeller is suspended in the inner space of the pump housing by means of magnetic force. By using two groups of electromagnets that are actively controlled or using a combination of electromagnets that are actively controlled and permanent magnets, the rotor can be fully suspended with the required stiffness in all degrees of freedom. The magnetic suspension centrifugal pump has the advantages that no mechanical contact exists between the impeller and the pump shell, and the magnetic suspension supporting channel is large, so that the shearing stress can be greatly reduced, and the damage to blood is greatly reduced by the magnetic suspension centrifugal pump.

But the full-magnetic suspension centrifugal pump is arranged in the human body, so that the volume of the heart pump is ensured to be small enough, and the damage to human tissues is avoided. Therefore, in the internal volume of the pump housing which is as small as possible, a reasonable runner is designed, and the risk of hemolysis and thrombus in the runner is reduced; and the relative positions of the stator and the rotor of the permanent magnet motor are reasonably designed, so that the rigidity of the ventricular assist device is ensured, and the key of the internal structural design of the full-magnetic suspension centrifugal pump is realized. The prior art has very many researches on the relative positions of a stator and a rotor of a permanent magnet motor and the design of a blood flow channel, has various characteristics, but still has the problems that the tension between a stator coil and a permanent magnet of the rotor is weak, the rigidity of a ventricular assist device is low, the secondary flow path channel is small, blood is extremely easy to flow and stagnate in the secondary flow path, and hemolysis, thrombus and the like are likely to occur.

Disclosure of Invention

The invention aims to provide a ventricular assist device, wherein fluids entering a secondary flow path are all converged in a through groove of a rotor part, so that the risk of stagnation of blood in the secondary flow path can be reduced, and the reliability and stability of the ventricular assist device during operation are better ensured.

In order to achieve the above object, the present invention provides a ventricular assist device, comprising a housing and an impeller rotor; the housing has an accommodation space and a fluid inlet in communication with the accommodation space; the impeller rotor is arranged in the accommodating space and comprises an impeller part and a rotor part which are connected with each other, the rotor part and the impeller part are coaxially arranged, the rotor part is positioned at one side of the impeller part, which is away from the fluid inlet, and the rotor part is provided with a through groove which penetrates along the axial direction of the rotor part;

When the impeller rotor is driven to rotate in a suspension mode in the accommodating space, fluid is sucked into the impeller part, after working and pressurizing of the impeller part, the fluid pressure at the periphery of the impeller part is higher than the fluid pressure in the through groove, a secondary flow is formed under the pressure difference between the fluid pressure at the periphery of the impeller part and the fluid pressure in the through groove, and the secondary flow reenters the main flow channel through the periphery of the impeller rotor and the through groove.

Optionally, a first channel is provided between the periphery of the rotor portion and the housing, and the inner diameter of the through groove is larger than the width of the first channel.

Optionally, the ventricular assist device further includes a first flow guiding cone fixed in the impeller portion, the first flow guiding cone is used for limiting a flow direction of the fluid in the impeller portion, an outline of the first flow guiding cone is conical, an outer peripheral surface area of the first flow guiding cone gradually decreases towards the fluid inlet direction, a second channel communicated with the through groove is formed between a bottom of the first flow guiding cone and an inner side bottom of the impeller portion, and the fluid flowing out of the through groove reenters the main channel through the second channel.

Optionally, the impeller part is provided with an upper cover plate and a lower cover plate which are oppositely arranged in the axial direction, the upper cover plate is adjacent to the fluid inlet, and the rotor part is connected with one side of the lower cover plate, which is away from the fluid inlet; the first diversion cone is connected with one side of the lower cover plate adjacent to the fluid inlet, and the second channel is arranged between the bottom of the first diversion cone and the lower cover plate.

Optionally, the lower cover plate has a first through hole penetrating along an axial direction of the impeller portion, and the through groove is communicated with the second channel through the first through hole.

Optionally, the upper cover plate has a second through hole penetrating in an axial direction of the impeller portion, an inner diameter of the second through hole is larger than an inner diameter of the first through hole, and fluid before pressurization is sucked into the impeller portion through the second through hole and flows into the main flow passage between the blades of the impeller portion under the guidance of the first guide cone.

Optionally, the impeller part is provided with a plurality of blades which are distributed at intervals along the circumferential direction of the impeller part, and a third channel is formed between every two adjacent blades, and the third channel is a part of the main flow channel;

when the impeller rotor rotates in a suspension mode, a fourth channel is arranged between the periphery of the impeller part and the shell, and the secondary flow sequentially reenters the main flow channel along the first channel, the through groove and the second channel.

Optionally, when the impeller rotor is in suspended rotation, the ventricular assist device has at least one of the following features:

The width of the fourth channel is 1 mm-10 mm;

the width of the first channel is 0.5 mm-3 mm;

the inner diameter of the through groove is 0.5 mm-15 mm.

Optionally, a flow guiding groove for fluid to flow is arranged on the first flow guiding cone, and the flow guiding groove and the lower cover plate are enclosed to form the second channel.

Optionally, the guiding gutter includes main flow groove and a plurality of splitter box, the main flow groove with logical groove intercommunication, every the one end of splitter box with main flow groove intercommunication, the other end extends to the periphery of first guiding cone, a plurality of splitter boxes are in the circumference of first guiding cone is upwards evenly arranged, every the splitter box can with a corresponding channel intercommunication.

Optionally, the height of the diversion trench along the axial direction of the impeller part is 0.5 mm-3 mm.

Optionally, a guiding portion protrudes from a groove wall of the main flow groove in a direction away from the fluid inlet, and the guiding portion is used for limiting a flow direction of the fluid in the second channel.

Optionally, the rotation axis of the first diversion cone, the rotation axis of the impeller rotor and the rotation axis of the guiding part are all coincident.

Optionally, a conical seat protruding towards the fluid inlet is arranged on the bottom surface of the inner side of the lower cover plate, the first diversion cone is arranged on the conical seat, and the conical seat is used for separating the first diversion cone from the lower cover plate, so that a second channel is formed between the first diversion cone and the lower cover plate.

Optionally, the inner side of each blade extends partially towards the direction approaching the first guide cone to form one cone seat, the heights of a plurality of cone seats in the axial direction of the impeller part are equal, and the height of the cone seat is smaller than the height of the blade.

Optionally, the height of the conical seat along the axial direction of the impeller part is 0.5 mm-3 mm.

Optionally, the ventricular assist device further includes a stator fixedly sleeved outside the housing and corresponding to the position of the rotor portion; the stator is used for driving the rotor part to drive the impeller part to rotate in a suspending manner in the accommodating space.

Optionally, the ventricular assist device further includes a second guide cone fixed in the accommodating space, the second guide cone is disposed on a side of the rotor portion away from the impeller portion, and the second guide cone is used for guiding a flow direction of fluid at a periphery of the impeller rotor, so that the fluid flows in a direction of the through groove, the second guide cone is fixedly connected with the housing, an outline of the second guide cone is conical, and an outer peripheral area of the second guide cone gradually decreases toward the fluid inlet direction.

The present invention provides a ventricular assist device comprising: the impeller rotor is provided with a through groove penetrating along the axial direction of the impeller rotor, when the impeller rotor floats in the accommodating space to rotate, fluid is sucked into the impeller portion, after the impeller portion does work and is pressurized, the peripheral fluid pressure of the impeller portion is higher than the fluid pressure in the through groove, secondary flow is formed under the pressure difference between the peripheral fluid pressure of the impeller portion and the fluid pressure in the through groove, and the secondary flow enters the main runner again through the periphery of the impeller rotor and the through groove. After the ventricular assist device provided by the invention is adopted, the total path of the secondary fluid flow can be reduced, the risk of flow stagnation during the secondary fluid flow can be reduced, and the reliability and stability of the ventricular assist device during operation are ensured.

After the ventricular assist device provided by the invention is adopted, the pressurized blood at the periphery of the impeller rotor is converged in the through groove of the rotor part, and part of the secondary flow channels are overlapped at the through groove, so that the total path of the secondary flow passing through during the flow of the fluid can be reduced, the risk of flow stagnation of the blood during the secondary flow can be reduced, the hemolysis and thrombus of the fluid in the path of the secondary flow can be prevented, and the reliability and the stability of the ventricular assist device during the operation are further ensured. In addition, the rotor part is arranged on one side away from the fluid inlet, so that the radial size of the rotor part is greatly increased under the condition that the size of the shell is limited, the radial pulling force and the axial suspension force borne by the rotor part are increased, and the rigidity of the ventricular assist device is improved.

Drawings

Fig. 1 is a schematic view of an overall axial sectional structure of a central chamber auxiliary device according to a preferred embodiment of the present invention, in which an impeller rotor is in a suspended state in a receiving space, a solid line a represents a main flow path when fluid flows, a broken line b represents a path when fluid flows secondarily, and an arrow direction represents a flow direction of fluid;

FIG. 2 is a schematic axial sectional view of the impeller rotor and the first cone, wherein a solid line a represents the main flow path of the fluid during the flow and a broken line b represents the path of the fluid during the secondary flow, according to the first preferred embodiment of the present invention;

FIG. 3 is a schematic view of an axial sectional exploded structure of an impeller rotor and a first cone according to a preferred embodiment of the present invention, wherein a broken line x is a theoretical position of the first cone placed on a lower cover plate of the impeller portion along a z direction;

FIG. 4 is a schematic perspective view of a first cone according to a first preferred embodiment of the present invention;

FIG. 5 is a schematic top view of the impeller portion and the first cone according to the first preferred embodiment of the present invention, wherein curve c shows the flow direction of the fluid during the secondary flow;

FIG. 6 is a schematic axial sectional view of the impeller rotor and the first cone, wherein a solid line a represents the primary flow path of the fluid during flow and a broken line b represents the secondary flow path of the fluid, according to the second preferred embodiment of the present invention;

Fig. 7 is an axial sectional exploded view of the impeller rotor and the first cone of the second preferred embodiment of the present invention, wherein the first cone of the first cone is placed on the cone seat along the z-direction.

Reference numerals are described as follows:

A housing 1; a fluid inlet 11; a housing space 12; a first housing section 13; a second housing section 14; a third housing section 15; an impeller section 2; an upper cover plate 21; a lower cover plate 22; a blade 23; a third channel 24; a fourth channel 25; a conical seat 26; a rotor section 3; a through groove 31; a first channel 32; a rotor case 33; a permanent magnet 34; a stator 4; a first diversion cone 5; a second channel 51; a diversion trench 52; a main launder 521; a shunt slot 522; a guide 53; a second flow cone 6.

Detailed Description

The invention is described in further detail below with reference to the drawings and the specific examples. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention.

The terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counter-clockwise," "axial," "radial," "circumferential," etc. refer to an orientation or positional relationship based on that shown in the drawings, merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the invention.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and include, for example, either fixedly attached, detachably attached, or integrally formed; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly, or through an intermediary, may be internal to the two elements or in an interactive relationship with the two elements, unless explicitly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present document, "axial" generally refers to a direction along an axis, such as along the axis of rotation of the impeller rotor; "radial" generally refers to a direction along a diameter, such as along a diameter of an impeller rotor; "circumferential" generally refers to a direction about an axis, such as a direction about the axis of rotation of the impeller rotor.

The invention will now be described in detail with reference to the drawings and a preferred embodiment. The following embodiments and features of the embodiments may be complemented or combined with each other without conflict. In the following description, fluid means a liquid that needs to flow into the accommodating space to be pressurized, and the fluid is typically blood, and in this embodiment, the fluid is schematically illustrated as blood.

[ Embodiment one ]

Referring to fig. 1, a preferred embodiment of the present invention provides a ventricular assist device comprising a housing 1 and an impeller rotor disposed in the housing 1. The housing 1 has a fluid inlet 11 and a receiving space 12, the fluid inlet 11 being in communication with the receiving space 12, an external fluid being accessible through the fluid inlet 11 into the receiving space 12. The impeller rotor is arranged in the accommodation space 12 and can be driven to rotate in a suspended manner in the accommodation space 12 of the housing 1. The impeller rotor comprises an impeller portion 2 and a rotor portion 3 which are interconnected. The rotor part 3 and the impeller part 2 are coaxially arranged, the rotor part 3 is positioned on one side of the impeller part 2 away from the fluid inlet 11, namely, the rotor part 3 and the fluid inlet 11 are respectively arranged on two sides of the impeller part 2, so that the radial dimension of the rotor part 3 is greatly increased on the premise that the dimension of the shell 1 is limited, and then the dimension of the permanent magnet 34 in the rotor part 3 is increased, so that the radial pulling force and the axial suspension force borne by the rotor part 3 are increased, and the rigidity of the ventricular assist device is improved. The rotor portion 3 has a through groove 31 penetrating in its own axial direction so as to achieve a secondary flow of fluid.

When the impeller rotor is driven to rotate in a suspended manner in the accommodation space 12, the main fluid enters the sleeve 13 from the fluid inlet 11, is sucked into the impeller portion 2 under the guidance of the first guide cone 5, and is thrown into the space between the outer periphery of the impeller portion 2 and the inner wall of the volute 14. The main flow passage is a path through which the main flow flows, and a solid line a in fig. 1, 2, and 6 indicates the main flow passage when the main flow flows. After the working and pressurizing of the impeller portion 2, the fluid pressure at the periphery of the impeller portion 2 is higher than the fluid pressure in the through groove 31, and a secondary flow is formed under the pressure difference between the fluid pressure at the periphery of the impeller portion 2 and the fluid pressure in the through groove 31, and the secondary flow reenters the primary flow passage through the periphery of the impeller rotor and the through groove 31, and a broken line b in fig. 1, 2 and 6 represents the secondary flow passage when the primary flow is flowing. The width of the main flow channel is large, and the third channel 24 and the fourth channel 25 are part of the main flow channel; the secondary flow channels are narrower in width, and both the first channel 32 and the second channel 51 are part of the secondary flow channels.

Thus, when the ventricular assist device provided in this embodiment is implanted in the apex of the left ventricle, fluid in the left ventricle can be continuously delivered from the outlet port into the aorta of the human body by the pressurization of the impeller rotor after being sucked into the ventricular assist device.

In the prior art, since the rotor portion and the fluid inlet are provided on the same side of the impeller, there is an overlap in the axial positions of the rotor portion and the axial main flow passage in the inflow sleeve, and the maximum radial dimension of the pump casing is determined by the dimensions of the axial main flow passage and the rotor portion. Thus, in the prior art, in order to control the maximum radial dimension of the pump casing, the size of the rotor portion is as small as possible, and the passage between the rotor portion and the pump casing is as small as possible. Since the secondary flow of blood substantially goes around the periphery of the rotor, the passage between the rotor portion and the pump housing is small, and stagnation and clogging are liable to occur when blood flows through the passage, so that the life safety of a patient at risk of hemolysis and thrombosis can be increased. In the application, the rotor part 3 is arranged on one side of the impeller part 2, which is away from the fluid inlet 11, the rotor part 3 is not overlapped with the axial main flow channel on the inflow sleeve in the axial direction, under the same radial dimension of the shell 1, the radial dimension of the rotor part 3 and the channel between the rotor part 3 and the pump shell can be increased, even if blood flows secondarily along the periphery of the impeller rotor, the channel is larger, so that the blood is not easy to stagnate and block when passing through the channel, and the risks of hemolysis and thrombus formation are reduced.

In more detail, as shown in fig. 2, the rotor portion 3 has an annular structure such that the rotor portion 3 has a through groove 31 (i.e., a center inner hole) penetrating in its own axial direction. When the impeller rotor is driven to rotate in a suspension manner in the accommodating space 12, blood can be sucked into the accommodating space 12 through the fluid inlet 11 and further sucked into the main flow channel of the impeller part 2, so that the pressure of the blood is obviously improved after the impeller part 2 rotating at a high speed works, the fluid pressure near the outlet of the main flow channel is obviously higher than the fluid pressure at the position of the fluid inlet 11, and at the moment, the blood can firstly follow the channel between the periphery of the impeller rotor and the shell 1 under the driving of the pressure difference, then enters the main flow channel of the impeller part 2 again after passing through the through groove 31, and then can be boosted after the impeller part 2 works again.

In the present invention, the blood on the outer periphery of the impeller rotor is converged in the through groove 31 of the rotor part 3, and part of the secondary flow paths are overlapped at the through groove 31, so that the total path of the secondary flow passing through when the blood flows can be reduced; therefore, the risk of flow stagnation of blood in the secondary flow can be reduced, and hemolysis and thrombus of the blood in the path of the secondary flow can be prevented, so that the reliability and stability of the ventricular assist device in operation can be ensured.

As shown in fig. 1, in a preferred embodiment, a first passage 32 is provided between the outer periphery of the rotor portion 3 and the housing 1, and the inner diameter of the through groove 31 of the rotor portion 3 is larger than the width of the first passage 32. At this time, the inner diameter of the through groove 31 of the rotor portion 3 is large, and smooth flow of blood in the through groove 31 of the rotor portion 3 can be ensured. It should be understood that the width of the first channel 32 refers to the minimum distance between the periphery of the rotor portion 3 and the housing 1.

With continued reference to fig. 1, in an embodiment, the ventricular assist device further includes a stator 4, where the stator 4 is fixedly sleeved outside the housing 1, and the stator 4 corresponds to the position of the rotor portion 3. The stator 4 is used for driving the rotor part 3, so that the rotor part 3 drives the impeller part 2 to rotate in a suspending manner in the accommodating space 12.

In a specific embodiment, the rotor portion 3 comprises a rotor housing 33 and permanent magnets 34 arranged inside the rotor housing 33, i.e. the rotor housing 33 is wrapped around the outside of the permanent magnets 34. The rotor housing 33 is fixedly connected to the impeller portion 2, and both are usually integrally formed. Whereby the impeller rotor is driven to float and rotate in the accommodation space 12 by means of the magnetic field under the action of the stator 4 and the rotor part 3.

In more detail, the stator 4 is internally provided with a driving coil and a levitation coil. When the levitation coil is energized, the levitation coil can generate a levitation magnetic field and form a levitation magnetic circuit with the permanent magnet 34, and the rotor portion 3 can levitate in the accommodation space 12 after receiving levitation force applied by the levitation coil. Similarly, when the drive coil is energized, the drive coil can generate a rotating magnetic field, and the drive coil and the permanent magnet 34 can form a rotating magnetic circuit, so that the rotor portion 3 can rotate in the housing space 12 in its own axial direction after receiving the steering force applied by the drive coil. Since the impeller portion 2 is fixedly connected to the rotor case 33 surrounding the permanent magnet 34, the impeller portion 2 can be suspended and rotated at a high speed in the accommodating space 12 following the permanent magnet 34, thereby sucking blood from the fluid inlet 11 into the accommodating space 12. It should be noted that the levitation coil and the driving coil may operate independently, and may set the current, frequency, and waveform of the levitation coil and the driving coil, so as to avoid the levitation rotation of the permanent magnet 34 caused by the magnetic field coupling between the levitation magnetic field generated by the levitation coil and the rotating magnetic field generated by the driving coil.

The fixing mode of the rotor part 3 and the impeller part 2 is not limited in the application, and the rotor part 3 and the impeller part 2 can be integrally formed or connected together by welding or mechanical matching after being formed separately. The fixing manner of the stator 4 and the housing 1 is not limited in the present application, wherein the housing 1 and the stator 4 may be integrally formed, or may be separately prepared and then connected together by welding or mechanical fit.

As shown in fig. 1, as an example, the casing 1 has a first casing section 13, a second casing section 14, and a third casing section 15 that are connected in this order in the axial direction of the impeller portion 2, and the outer diameters of the first casing section 13 and the third casing section 15 are each smaller than the outer diameter of the second casing section 14. The fluid inlet 11 is arranged at the end of the first housing section 13. The impeller portion 2 is placed in a chamber formed by the second casing section 14. At least part of the rotor portion 3 is placed in the chamber formed by the third housing section 15. The stator 4 is sleeved outside the third casing section 15 and is fixedly connected with the second casing section 14 and the third casing section 15.

In the prior art, a rotor, a stator and a fluid inlet are usually arranged on the same side of an impeller, wherein the rotor is sleeved outside the fluid inlet, and the stator is sleeved outside the rotor. Since the fluid inlet itself has a certain outer diameter and the overall outer diameter of the ventricular assist device has been defined, the radial dimensions of both the rotor and stator in prior constructions have been defined. Since the rotor and the stator are smaller in size at this time, the radial tension and the axial levitation force between the stator and the rotor are smaller. According to the application, the rotor part 3 and the stator 4 are arranged on the other side of the impeller part 2, which is away from the fluid inlet 11, and the fluid inlet 11 and the rotor part 3 are not arranged on the same side, so that the overall radial dimension of the rotor part 3 and the stator 4 can be increased under the condition that the overall radial dimension is unchanged, and the radial dimension of the rotor part 3 and/or the stator 4 is larger, so that the radial pulling force and the axial suspension force between the stator 4 and the rotor part 3 can be increased, the rigidity of the ventricular assist device can be further improved, and the long-term use safety of the ventricular assist device can be ensured.

Preferably, the height of the third casing section 15 in the axial direction of the impeller portion 2 is greater than the height of the second casing section 14 in the axial direction of the impeller portion 2, so that the permanent magnets 34 in the rotor portion 3 can have a greater height in the axial direction of the impeller portion 2, and the volumes of the permanent magnets 34 and the stator 4 can be further increased, so as to further increase the radial tension and the axial levitation force between the stator 4 and the rotor portion 3.

Preferably, the inner volume in the second housing section 14 can be fully utilized within the severely limited size accommodation space 12 to increase the outer diameter of the impeller portion 2 as much as possible. Therefore, on the premise of ensuring the required lift of the ventricular assist device, the rotating speed of the blades in the impeller part 2 is reduced as much as possible, so that on one hand, the damage to blood caused by the high-speed rotation of the blades of the impeller part 2 can be reduced, and on the other hand, the whole ventricular assist device can be more energy-saving.

Referring to fig. 2, in a preferred embodiment, the ventricular assist device further comprises a first flow cone 5 fixed in the impeller portion 2, the first flow cone 5 being adapted to define a flow direction of the fluid in the impeller portion 2. The first diversion cone 5 has a tapered outer shape, and the outer circumferential surface area gradually decreases toward the fluid inlet 11, and a second passage 51 communicating with the through groove 31 is formed between the bottom of the first diversion cone 5 and the inner bottom of the impeller portion 2, and the fluid flowing out of the through groove 31 re-enters the main passage through the second passage 51. Therefore, the secondary flow of the blood can be arranged along a shorter path without being influenced by the first diversion cone 5, so that the residence time of the blood in the secondary flow path can be shortened, and the smooth passing of the blood in the first diversion cone 5 can be ensured. The first diversion cone 5 is arranged, on one hand, blood can be smoothly and slowly led into the impeller part 2 through the first diversion cone 5, so that the damage of a main runner to the blood is reduced or even avoided; on the other hand, the first guide cone 5 can significantly separate the fluid in the primary flow path from the secondary flow path to avoid mixing and hedging of the blood flowing in at the fluid inlet 11 with the blood in the secondary flow path, thereby preventing energy loss and efficiency degradation of the ventricular assist device and also preventing destruction of red blood cells in the blood stream due to hedging of the blood stream.

Referring to fig. 3, in the present embodiment, the impeller portion 2 has an upper cover plate 21 and a lower cover plate 22 disposed opposite to each other in the axial direction, the upper cover plate 21 being adjacent to the fluid inlet 11, and the rotor portion 3 being connected to a side of the lower cover plate 22 remote from the fluid inlet 11. The first diversion cone 5 is fixedly connected with the lower cover plate 22, and a second channel 51 is arranged between the bottom of the first diversion cone 5 and the lower cover plate 22.

The broken line x shown in fig. 3 is the theoretical position of the first guide cone 5 placed on the lower cover plate 22 of the impeller portion 2 in the z direction; when the first guide cone 5 is placed on the lower cover plate 22 in the z-direction (i.e., the axial direction of the impeller portion 2), the outer contour of the first guide cone 5 can coincide with the broken line x.

As a specific embodiment, the lower cover plate 22 has a first through hole (not numbered) penetrating in the axial direction of the impeller portion 2, through which the through groove 31 communicates with the second passage 51. So configured, blood flowing out of the through groove 31 can flow along the second passage 51 between the lower cover plate 22 and the first guide cone 5 after entering from the lower cover plate 22, so that a short flow path of the secondary flow can be ensured.

In a preferred embodiment, the inner diameter of the first through hole is equal to the inner diameter of the through groove 31, so that blood can flow from the through groove 31 into the first through hole more conveniently.

The fixing manner of the first diversion cone 5 and the lower cover plate 22 is not limited in the application, wherein the lower cover plate 22 and the first diversion cone 5 can be integrally formed, or can be separately prepared and then connected together for forming, and the connection manner can be various manners such as welding or mechanical matching connection, so long as the lower cover plate 22 and the first diversion cone 5 can be firmly connected.

Further, the upper cover plate 21 has a second through hole penetrating in the axial direction of the impeller portion 2, the second through hole having an inner diameter larger than that of the first through hole. As shown by a solid line a in fig. 1, blood before pressurization is sucked into the impeller portion 2 through the second through-hole, and flows into a main flow passage between the blades of the impeller portion 2 under the guidance of the first guide cone 5.

Referring to fig. 1 to 3, in an embodiment, the impeller portion 2 has a plurality of blades 23 circumferentially spaced apart from each other, and the blood flowing into the accommodating space 12 can be driven by the blades 23 to increase the flow velocity, i.e., the blades 23 can apply work to the blood to pressurize the blood. A third passage 24 (see fig. 5) is formed between adjacent ones of the vanes 23, the third passage 24 constituting the main flow passage. When the impeller rotor is rotated in a floating manner, a fourth passage 25 (see fig. 1) is provided between the periphery of the impeller portion 2 and the casing 1. The fourth passage 25 includes an annular fourth passage 25 formed between the outer periphery of the impeller portion 2 and the inner wall of the casing 1, and a fourth passage 25 formed between the lower cover plate 22 of the impeller portion 2 and the casing 1.

Further, the first passage 32 provided between the rotor portion 3 and the housing 1 includes a first passage 32 formed between the outer side wall of the rotor case 33 and the inner wall of the housing 1, and a first passage 32 formed between the bottom wall of the rotor case 33 and the bottom wall of the housing 1. As indicated by a broken line b in fig. 1, the pressurized fluid reenters the primary flow path along the third passage 24, the first passage 32, the through groove 31, and the second passage 51 in this order.

Specifically, after the blood reaches the third channel 24 between the blades 23, the working pressure of the blood in the main channel is significantly increased by the blades 23 rotating at high speed, so that the pressure of the blood at the outlet is significantly higher than the pressure at the fluid inlet 11. At this point part of the blood will be driven by the pressure difference into the fourth channel 25 between the impeller part 2 and the housing 1. The blood can then flow again along the first channel 32, through groove 31, second channel 51 into the third channel 24 between the vanes 23 in this order, so that the blood can again collect in the main flow channel and flow out of the outlet. It will be appreciated that a portion of the blood can be circulated back and forth in the path of the secondary flow until exiting from the outlet.

In one embodiment, the ventricular assist device has at least one of the following characteristics when the impeller rotor is in suspended rotation: the width of the fourth channel 25 is 1mm to 10mm, the width of the first channel 32 is 0.5mm to 3mm, and the inner diameter of the through groove 31 is 0.5mm to 15mm. It should be understood that the width of the fourth channel 25 refers to the minimum distance between the lower cover plate 22 and the housing 1 in the axial direction of the impeller portion 2. The width of the first passage 32 refers to the minimum distance between the outer side wall of the rotor housing 33 and the inner wall of the casing 1, and the minimum distance between the bottom wall of the rotor housing 33 and the bottom wall of the casing 1.

Since the distance between the rotor and the housing, and the distance between the rotor and the fixing member are generally 0.5mm or less in the conventional arrangement, while the present invention increases the widths of the fourth passage 25 and the first passage 32, particularly the inner diameter of the through groove 31 is set to 0.5mm or more, the path width of the secondary flow is increased to such a large extent that the secondary flow can be made smoother by the blood, so that the risk of stagnation and clogging of the blood in the path of the secondary flow can be reduced, and hemolysis and thrombus formation in the path of the secondary flow can be prevented.

Referring to fig. 3 and 4, the first cone 5 is provided with a flow guide groove 52 for the fluid to flow, the flow guide groove 52 and the lower cover plate 22 are enclosed to form a second channel 51, and the blood flowing out of the through groove 31 can flow into the third channel 24 of the vane 23 through the flow guide groove 52.

In a preferred embodiment, the diversion trench 52 includes a main trench 521 and a plurality of diversion trenches 522, the main trench 521 communicates with the through trench 31, one end of each diversion trench 522 communicates with the main trench 521, and the other end extends to the periphery of the first diversion cone 5. The plurality of shunt grooves 522 are uniformly arranged in the circumferential direction of the first guide cone 5, and each shunt groove 522 can communicate with a corresponding one of the third passages 24. As shown by curve c in fig. 5, when so configured, blood flowing out of the through groove 31 can flow into the main flow groove 521 first, then flow synchronously from the main flow groove 521 to the respective shunt grooves 522, and then flow into the third passage 24 of the vane 23. Since each of the shunt grooves 522 is in communication with one of the third channels 24, the blood in each of the shunt grooves 522 can smoothly flow into the third channel 24 and can sequentially flow to various positions in the impeller portion 2, so that energy loss during fluid flow can be reduced.

The number of the separation grooves 522 is not limited in the present application. In the present embodiment, the number of the shunt grooves 522 preferably corresponds to the number of the third passages 24 between the blades 23 so that fluid can be introduced into each of the third passages 24 through the shunt grooves 522. In another embodiment, the number of shunt channels 522 may also be different from the number of third channels 24 between the vanes 23.

The shape of the main flow channel 521 and the shunt channel 522 is not limited in the present application. In the present embodiment, the shape of the main flow groove 521 is a circle, and the shape of the diversion groove 522 is a straight line, so that it is possible to ensure that the fluid in the main flow groove 521 flows into the plurality of diversion grooves 522 simultaneously, and also to shorten the length of the diversion grooves 522, so that the residence time of the fluid in the path of the secondary flow can be sufficiently shortened, and the damage of the fluid in the path of the secondary flow can be avoided as much as possible. Of course, in other embodiments, the main flow channel 521 and the shunt channel 522 may be configured in other shapes as desired, for example, the main flow channel 521 may be configured in an elliptical shape and the shunt channel 522 may be configured in a curved shape.

In a specific embodiment, the height of the diversion trench 52 in the axial direction of the impeller portion 2 is 0.5 mm-3 mm, that is, the width of the second channel 51 in the axial direction of the impeller portion 2 is 0.5 mm-3 mm, so that the path width of the secondary flow can be greatly increased to ensure that the blood flows smoothly in the path of the secondary flow.

Referring to fig. 2 to 4, the groove wall of the main runner 521 protrudes toward the direction away from the fluid inlet 11, and the guiding portion 53 is used for limiting the flowing direction of the fluid in the second channel 51, that is, the guiding portion 53 is used for limiting the flowing direction of the fluid after leaving the open groove 31, so that on one hand, energy loss caused by direct impact of the fluid flowing out of the open groove 31 on the groove wall of the main runner 521 can be avoided; on the other hand, the fluid in the main flow groove 521 can be guided to flow into the different diversion grooves 522 more uniformly, so that the uniformity of the fluid flowing in the impeller portion 2 is ensured.

Preferably, the rotation axis of the first guide cone 5, the rotation axis of the impeller rotor and the rotation axis of the guide portion 53 are all coincident, so that the fluid flowing in from the fluid inlet 11 can be uniformly dispersed to each position in the impeller portion 2, and uniformity of flow of the fluid in the path of the secondary flow and uniformity of pressure when the fluid flows out from the outlet can be ensured.

As shown in fig. 1, the ventricular assist device further comprises a second flow guiding cone 6 fixed in the accommodating space 12, the second flow guiding cone 6 being arranged on the side of the rotor portion 3 facing away from the impeller portion 2, the second flow guiding cone 6 being configured to guide the flow direction of the fluid at the periphery of the impeller rotor such that the fluid flows in the direction of the through groove 31.

In the present embodiment, the second flow guiding cone 6 is fixedly connected to the third housing section 15, the outer contour of the second flow guiding cone 6 is conical, and the outer peripheral surface area gradually decreases toward the fluid inlet 11. When so arranged, the second flow guide cone 6 is capable of guiding the fluid flowing through the first passage 32 between the bottom wall of the rotor housing 33 and the bottom wall of the casing 1, so that the fluid can smoothly enter the through groove 31 without collision in the radial direction when flowing out of the first passage 32, thereby avoiding damage to blood and loss of fluid energy.

[ Example two ]

The same portions as those of the first embodiment in this embodiment will not be described in detail, and only the differences will be described below.

Referring to fig. 6 and 7, a cone seat 26 protruding toward the fluid inlet 11 is provided on the inner bottom surface of the lower cover plate 22, and the first guide cone 5 is provided on the cone seat 26, and the cone seat 26 is used to separate the first guide cone 5 from the inner bottom surface of the lower cover plate 22 so that a second passage 51 is formed between the first guide cone 5 and the inner bottom surface of the lower cover plate 22.

The application does not limit the fixing mode of the first diversion cone 5 and the cone seat 26, and the cone seat 26 and the first diversion cone 5 can be integrally formed, or can be formed by welding or mechanically matching after being separately prepared.

In the present embodiment, the inner side of each vane 23 is partially extended toward the direction approaching the first guide cone 5 to form one cone seat 26, that is, each cone seat 26 can be connected with the inner side end of the vane 23, and the extension direction of the cone seat 26 is the same as the extension direction of the vane 23. The heights of the plurality of cone seats 26 in the axial direction of the impeller portion 2 are equal, and the height of the cone seats 26 is smaller than the height of the blades 23, at this time, the cone seats 26 can form the second channel 51 between the first guide cone 5 and the lower cover plate 22, and can also have a drainage function, so that the fluid in the second channel 51 uniformly flows into the third channel 24 of the different blades 23 under the guidance of the cone seats 26.

In one example, the height of the conical seat 26 in the axial direction of the impeller portion 2 is 0.5mm to 3mm, so that the path width of the secondary flow is greatly increased, and smooth flow of blood in the path of the secondary flow can be ensured.

In summary, in the ventricular assist device provided by the present invention, the fluids in the secondary flow paths are all merged in the through groove 31 of the rotor portion 3, so that the fluids in different positions partially overlap in the secondary flow, so that the total path of the secondary flow passing through in the fluid flow can be reduced, the risk of stagnation in the secondary flow of blood can be reduced, and the fluids can be prevented from hemolysis and thrombosis in the path of the secondary flow, thereby ensuring the reliability and stability in the operation of the ventricular assist device.

The above description is only illustrative of the preferred embodiments of the present invention and is not intended to limit the scope of the present invention, and any alterations and modifications made by those skilled in the art based on the above disclosure shall fall within the scope of the present invention.

Claims

1. A ventricular assist device comprising a housing and an impeller rotor; the housing has an accommodation space and a fluid inlet in communication with the accommodation space; the impeller rotor is arranged in the accommodating space and comprises an impeller part and a rotor part which are connected with each other, the rotor part and the impeller part are coaxially arranged, the rotor part is positioned at one side of the impeller part, which is away from the fluid inlet, and the rotor part is provided with a through groove which penetrates along the axial direction of the rotor part;

2. The ventricular assist device of claim 1 wherein a first channel is provided between a periphery of the rotor portion and the housing, the inner diameter of the through slot being greater than the width of the first channel.

3. The ventricular assist device of claim 2 further comprising a first flow cone secured in the impeller portion, the first flow cone defining a flow direction of fluid in the impeller portion, the first flow cone having a tapered profile with an outer peripheral surface area that decreases toward the fluid inlet, a second channel in communication with the channel being formed between a bottom of the first flow cone and an inside bottom of the impeller portion, the fluid exiting the channel reentering the main channel through the second channel.

4. A ventricular assist device as claimed in claim 3 wherein the impeller portion has upper and lower axially opposed cover plates, the upper cover plate being adjacent the fluid inlet, the rotor portion being connected to a side of the lower cover plate facing away from the fluid inlet; the first diversion cone is connected with one side of the lower cover plate adjacent to the fluid inlet, and the second channel is arranged between the bottom of the first diversion cone and the lower cover plate.

5. The ventricular assist device of claim 4 wherein the lower cover plate has a first through-hole extending therethrough in an axial direction of the impeller portion, the through-slot communicating with the second channel through the first through-hole.

6. The ventricular assist device of claim 5, wherein the upper cover plate has a second through hole penetrating in an axial direction of the impeller portion, an inner diameter of the second through hole being larger than an inner diameter of the first through hole, and fluid before pressurization is sucked into the impeller portion through the second through hole and flows into the main flow passage between the blades of the impeller portion under the guide of the first guide cone.

7. The ventricular assist device of claim 4 wherein the impeller portion has a plurality of blades circumferentially spaced therearound, adjacent said blades defining a third passage therebetween, said third passage being part of the primary flow path;

8. The ventricular assist device of claim 7 wherein when the impeller rotor is in suspended rotation, the ventricular assist device has at least one of the following features:

The width of the fourth channel is 1 mm-10 mm;

the width of the first channel is 0.5 mm-3 mm;

the inner diameter of the through groove is 0.5 mm-15 mm.

9. The ventricular assist device of claim 7 wherein the first cone is provided with a channel for fluid flow, the channel circumscribing the lower cover plate to form the second channel.

10. The ventricular assist device of claim 9 wherein the flow guide groove includes a main flow groove and a plurality of flow dividing grooves, the main flow groove being in communication with the flow dividing grooves, one end of each of the flow dividing grooves being in communication with the main flow groove, the other end extending to the periphery of the first flow guiding cone, the plurality of flow dividing grooves being uniformly arranged in the circumferential direction of the first flow guiding cone, each of the flow dividing grooves being capable of communicating with a corresponding one of the third passages.

11. A ventricular assist device as claimed in claim 9, wherein the height of the flow guide groove in the axial direction of the impeller portion is 0.5mm to 3mm.

12. A ventricular assist device as claimed in claim 10 wherein the walls of the primary flow channel project away from the fluid inlet with a guide portion for defining the direction of fluid flow in the second channel.

13. The ventricular assist device of claim 12, wherein the rotational axis of the first flow cone, the rotational axis of the impeller rotor, and the rotational axis of the guide portion all coincide.

14. The ventricular assist device of claim 7 wherein a conical seat protruding toward the fluid inlet is provided on an inside bottom surface of the lower cover plate, the first flow cone being provided on the conical seat for separating the first flow cone from the lower cover plate such that the second channel is formed between the first flow cone and the lower cover plate.

15. A ventricular assist device as claimed in claim 14, wherein an inner side of each of the blades extends partially in a direction approaching the first guide cone to form one of the cones, heights of the plurality of cones in an axial direction of the impeller portion are equal, and the height of the cone is smaller than the height of the blade.

16. A ventricular assist device as claimed in claim 15 wherein the height of the conical seat in the axial direction of the impeller portion is 0.5mm to 3mm.

17. The ventricular assist device of claim 1, further comprising a stator fixedly sleeved outside the housing and corresponding to a position of the rotor portion; the stator is used for driving the rotor part to drive the impeller part to rotate in a suspending manner in the accommodating space.

18. The ventricular assist device of claim 17 further comprising a second flow cone secured in the receiving space, the second flow cone being disposed on a side of the rotor portion facing away from the impeller portion, the second flow cone for directing a flow direction of fluid at a periphery of the impeller rotor such that the fluid flows in a direction of the through slot, the second flow cone being fixedly connected to the housing, the second flow cone having a tapered profile with an outer peripheral surface area that gradually decreases toward the fluid inlet.