CN118105615A

CN118105615A - Ventricular assist device

Info

Publication number: CN118105615A
Application number: CN202211485081.XA
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, an impeller rotor and a diversion cone; the shell is provided with a containing space and a fluid inlet which are communicated with each other; the impeller rotor and the diversion cone are both arranged in the accommodating space; the impeller rotor is provided with a through groove which axially penetrates through and comprises an impeller part and a rotor part; the diversion cone part is arranged in the through groove; when the impeller rotor rotates, the main flow enters from the fluid inlet and is sucked into the impeller under the guidance of the guide cone; after the impeller works, the main flow pressure at the periphery of the impeller part is higher than the fluid pressure in the through groove, and secondary flow is formed under the pressure difference; one part of the secondary flow enters the rotor part through one end of the through groove, flows to the impeller part under the guidance of the flow guiding cone, and the other part enters through the channel between the other end of the through groove and the flow guiding cone and flows to the impeller part under the guidance of the flow guiding cone. On one hand, the ventricular assist device can increase the width of the secondary flow channel and shorten the residence time of the secondary flow; on the other hand, the diversion cone can avoid the front side opposite flushing of the main flow and the secondary flow blood to a large extent, and reduce the mixing loss of the main flow and the secondary flow blood.

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. Thus, mechanical circulatory support using artificial hearts has become the most promising alternative technology at present. The artificial heart has the function of assisting the heart of a human body to do work so as to build an auxiliary flow passage for heart blood in the body of the patient. International artificial heart technology development began in the 50 s of the last century and underwent a revolution from the 90 s to the current century's market rotary blood pumps. The pulsatile blood pump has been used in clinic for a small number of times because of serious damage to blood, high occurrence rate of hemolysis and thrombus, and bulky and poor durability. Rotary blood pumps have undergone a development history from mechanical bearings, hydrodynamic bearings, to full-magnetic suspension bearings. The mechanical bearing and the hydraulic bearing also have larger damage to blood, and the research and development of the artificial heart technology gradually progress to the full-magnetic suspension centrifugal pump in order to reduce the blood damage probability.

An advantage of an all-magnetic suspension centrifugal pump is that the impeller is suspended and rotated by a magnetic field without mechanical contact between the impeller and the pump housing. By using actively controlled electromagnets alone or in combination with permanent magnets, the impeller can be fully suspended with the required stiffness in all degrees of freedom. Owing to no mechanical contact between the impeller and the pump casing, the full-magnetic suspension centrifugal pump greatly reduces damage to blood.

However, since the full-magnetic suspension centrifugal pump needs to be placed in the human body, the volume of the centrifugal pump needs to be ensured to be small enough to avoid damage to human tissues in the human body. Therefore, in the internal volume of the centrifugal pump which is as small as possible, a reasonable flow channel is designed, and the hemolysis risk in the flow channel is reduced; and the relative positions of the permanent magnet motor stator and the permanent magnet are reasonably designed, so that the rigidity of the magnetic suspension bearing is ensured, and the design of the internal structure of the full-magnetic suspension centrifugal pump is key. In the prior art, the relative positions of a permanent magnet motor stator and a permanent magnet and the design of a blood flow channel are very much researched and have various characteristics, but the technical problems that the main blood flow and the secondary blood flow in a centrifugal pump are mixed in a large area, the secondary blood flow path is too narrow, and the damage risk of blood in the flow path is increased still exist.

Disclosure of Invention

The invention aims to provide a ventricular assist device, which can increase the width of a secondary flow path so as to shorten the residence time of blood in the secondary flow path and reduce or even avoid the damage of the blood in the secondary flow path; on the other hand, the diversion cone can remarkably separate the main flow blood and the secondary flow blood, so that the phenomenon that the energy loss and the efficiency of the ventricular assist device are reduced due to blending and hedging of the secondary flow blood entering the impeller rotor from the periphery of the impeller rotor through the through groove and the main flow blood entering the impeller rotor from the fluid inlet are avoided, and the damage to red blood cells in the blood due to hedging of the blood is prevented.

In order to achieve the above object, the present invention provides a ventricular assist device comprising a housing, an impeller rotor, and a guide cone; the shell is provided with a containing space and a fluid inlet which are communicated; the impeller rotor and the diversion cone are both arranged in the accommodating space; the impeller rotor comprises an impeller part and a rotor part which are coaxially connected, the impeller rotor is provided with a through groove penetrating along the axial direction of the impeller rotor, and the rotor part is positioned at one side of the impeller part, which faces the fluid inlet; the diversion cone part is arranged in the through groove and is used for limiting the flow direction of fluid entering the impeller rotor, wherein the fluid comprises a main flow and a secondary flow;

When the impeller rotor rotates in a suspension mode in the accommodating space, the main flow enters the sleeve from the fluid inlet, is sucked into the impeller part through one end of the through groove, which is close to the fluid inlet, and is guided by the guide cone, and is thrown into a space between the periphery of the impeller part and the inner wall of the volute, and a main flow channel is a path through which the main flow flows;

After the main flow passes through the impeller rotor to do work, the main flow pressure at the periphery of the impeller part is increased, the main flow pressure at the periphery of the impeller part is higher than the fluid pressure in the through groove, and the secondary flow is formed under the pressure difference between the main flow pressure at the periphery of the impeller part and the fluid pressure in the through groove;

The secondary stream comprises the following two parts: one part of the fluid enters the rotor part through one end of the through groove close to the fluid inlet and flows to the impeller part under the guidance of the flow guide cone, and the other part of the fluid enters the impeller rotor through the passage between the other end of the through groove and the flow guide cone and flows to the impeller part under the guidance of the flow 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 first channel is formed between any adjacent blades, and the first channel is a part of the main flow channel;

A portion of the through slots is disposed on the rotor portion such that a portion of the secondary flow enters the impeller rotor via the one end of the through slots on the rotor portion; another portion of the through slot is provided on the impeller portion such that another portion of the secondary flow enters the impeller rotor via the other end of the through slot on the impeller portion; and a second channel is formed between the through groove and the guide cone.

Optionally, the impeller portion has an outer diameter greater than an outer diameter of the rotor portion.

Optionally, the housing further has a fluid outlet located on a side wall of the housing, and an annular third channel is provided between the periphery of the impeller portion and the side wall of the housing; the third passage gradually increases as the periphery of the impeller portion gradually approaches the fluid outlet.

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 rotor part and is connected with the rotor part, and a fourth channel is arranged between the upper cover plate and the shell along the axial direction of the impeller part; a fifth channel is arranged between the rotor part and the shell along the radial direction of the impeller part; a sixth passage is formed between the rotor part and the housing in the axial direction of the impeller part;

The secondary flow is for flowing along the periphery of the impeller rotor under the influence of a pressure difference, and a portion reenters the primary flow passage via the fourth, fifth, and sixth passages.

Optionally, a seventh channel is formed between the outer bottom surface of the lower cover plate and the shell along the axial direction of the impeller part, and an eighth channel is formed between the part of the through groove on the lower cover plate and the diversion cone;

the secondary flow is for flowing along the periphery of the impeller rotor under the influence of a pressure difference, and another portion reenters the primary flow passage via the seventh passage and the eighth passage.

Optionally, the ventricular assist device has at least one of the following features:

the width of at least one of the fourth channel, the sixth channel and the seventh channel is 0.5mm-2mm;

the width of the fifth channel is 0.5mm-2mm.

Optionally, the peripheral area of the guide cone gradually decreases toward the fluid inlet; the diversion cone comprises a round platform section and a conical section which are mutually connected along the axis direction of the diversion cone, the round platform section is connected with the shell, the outer contour surface of the round platform section is a convex surface, and the outer contour surface of the conical section is a concave surface; the outer contour surface of the circular table section is in transitional connection with the outer contour surface of the conical section through an arc surface, and the diversion cone is of an axisymmetric structure.

Optionally, on an axial section of the diversion cone, an outer contour line of the diversion cone includes a first arc section, a second arc section and an arc contact connecting the first arc section and the second arc section, the first arc section rotates around a rotation axis of the diversion cone to form the round platform section, and the second arc section rotates around the rotation axis of the diversion cone to form the conical section;

The distance from the arc contact point to the rotation axis of the guide cone is a fixed value; when the impeller rotor rotates in a suspension mode, the distance between the inner bottom surface of the lower cover plate and the bottom surface of the flow guide cone along the axial direction of the impeller part is H1, the distance between the inner contour line of the inner bottom surface of the upper cover plate and the inner bottom surface of the lower cover plate along the axial direction of the impeller part is H2, the distance between the arc contact and the bottom surface of the flow guide cone along the axial direction of the impeller part is D, and H1 is less than or equal to D and less than or equal to H1 plus 1/2H 2.

Optionally, the distance between the outer contour line of the inner bottom surface of the upper cover plate and the inner bottom surface of the lower cover plate along the axial direction of the impeller portion is H3, the ratio of H3 to H2 is 0.5-1, and the distance between the inner bottom surface of the upper cover plate and the inner bottom surface of the lower cover plate along the axial direction of the impeller portion gradually decreases from inside to outside.

Optionally, the ventricular assist device further includes a stator fixedly sleeved outside the housing and corresponding to 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 and is used for being abutted with a target object.

Optionally, the rotation axis of the impeller rotor and the rotation axis of the diversion cone coincide.

Optionally, the guide cone is located the side that the logical groove deviates from the fluid entry, just the bottom surface of guide cone with casing fixed connection, be provided with on the bottom surface of guide cone and hold the hole.

Drawings

FIG. 1 is a schematic axial sectional view of a preferred embodiment of a central chamber auxiliary device of the present invention, wherein an impeller rotor is suspended in a receiving space;

FIG. 2 is an enlarged schematic view of a portion of the central chamber auxiliary device of FIG. 1;

Fig. 3 is a schematic view showing a flow of a fluid in an impeller rotor according to a preferred embodiment of the present invention, wherein the impeller rotor is in a suspended state in a receiving space, a solid line a represents a main flow path when the fluid flows, a broken line b represents a secondary flow path when the fluid flows, and an arrow direction represents a flow direction of the fluid;

FIG. 4 is a schematic axial cross-sectional flow of a fluid in a ventricular assist device according to a preferred embodiment of the present invention, wherein solid line a represents the primary flow path of the fluid during flow, dashed line b represents the secondary flow path of the fluid during flow, and the direction of the arrows represents the direction of flow of the fluid;

FIG. 5 is a schematic view of a partial axial cross-sectional configuration of a impeller hub, housing and cone according to a preferred embodiment of the present invention;

FIG. 6 is a schematic view of the use of the auxiliary device for a central room in accordance with a preferred embodiment of the present invention;

FIG. 7 is a schematic axial sectional view of a guide cone according to a preferred embodiment of the present invention.

Reference numerals are described as follows:

A housing 1; a housing space 11; a fluid inlet 12; a sleeve 13; a volute 14; a fluid outlet 15; an impeller rotor 2; a through groove 21; an impeller portion 22; a vane 221; a third channel 222; an upper cover plate 223; a lower cover plate 224; fourth channel 225; a seventh channel 226; a rotor section 23; a rotor housing 231; a permanent magnet 232; a fifth channel 233; a sixth channel 234; a diversion cone 3; a second channel 31; an eighth channel 32; a first circular arc segment 33; a second circular arc section 34; arc contact 35; a grip hole 36; and a stator 4.

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 refers to liquid sucked into the accommodating space, and the fluid according to the present application is typically blood and is schematically illustrated by blood, but it is not excluded that the fluid is not blood.

Referring to fig. 1 to 3, an embodiment of the present invention provides a ventricular assist device including a housing 1, an impeller rotor 2, and a guide cone 3. The housing 1 has an accommodation space 11 and a fluid inlet 12, the fluid inlet 12 communicating with the accommodation space 11. The impeller rotor 2 and the guide cone 3 are both arranged in the accommodating space 11. The vane rotor 2 includes a vane portion 22 and a rotor portion 23 coaxially connected, the vane rotor 2 having a through groove 21 penetrating in the axial direction thereof, the rotor portion 23 being located on a side of the vane portion 22 facing the fluid inlet 12. The diversion cone 3 is partially arranged in the through groove 21. The main function of the flow cone 3 is to define the flow direction of the fluid entering the impeller rotor 2, which comprises a main flow and a secondary flow. When the impeller rotor 2 is rotated in a suspended manner in the accommodation space 11, the main flow enters the sleeve 13 from the fluid inlet 12, approaches one end of the fluid inlet 12 via the through groove 21, is sucked into the impeller portion 22 under the guide of the guide cone 3, and is thrown into the space between the outer periphery of the impeller portion 22 and the inner wall of the scroll 14. The main flow passage is a path through which the main flow flows, and a solid line a in fig. 3 and 4 indicates the main flow passage when the main flow flows. After the main flow passes through the impeller rotor 2 to perform work, the main flow pressure at the outer periphery of the impeller portion 22 increases, and is higher than the fluid pressure in the through groove 21. The secondary flow is formed by a pressure difference between the fluid pressure at the outer periphery of the impeller portion 22 and the fluid pressure in the through groove 21, and specifically includes the following two parts: a part of the main flow on the outer periphery of the impeller portion 22 enters the rotor portion 23 via one end of the through groove 21 near the fluid inlet 12 and flows toward the impeller portion 22 under the guide of the guide cone 3, and the other part enters the impeller rotor 2 via the passage between the other end of the through groove 21 and the guide cone 3 and flows toward the impeller portion 22 under the guide of the guide cone 3. The secondary flow path refers to a path through which the secondary flow flows, and a broken line b in fig. 3 and 4 indicates the secondary flow path when the secondary flow flows. The width of the main flow channel is larger, and the first channel, the second channel 31 and the third channel 222 are all part of the main flow channel; the secondary flow channels are narrower in width, and the fourth, fifth, sixth, seventh and eighth channels 225, 233, 234, 226, 32 are all part of the secondary flow channels.

At this time, the arrangement of the flow guide cone 3 can not only guide the main flow in the through groove 21 to be sucked into the impeller portion 22, but also avoid the front side hedging of the main flow and the secondary flow blood to a large extent, so as to avoid the energy loss and efficiency reduction of the ventricular assist device caused by the mixing loss of the secondary flow blood entering the impeller rotor 2 from the outer periphery of the impeller portion 22 through the through groove 21 and the main flow blood entering the impeller rotor 2 from the fluid inlet 12, and also prevent the destruction of red blood cells in the blood due to the hedging of the blood.

In the prior art, the secondary flow of blood basically goes around the periphery of the rotor in the impeller rotor, and because the channels on the periphery of the rotor are smaller, stagnation and blockage are easy to occur when blood flows through the channels, and the risk of hemolysis and thrombus formation exists, so that the life safety of a patient is endangered.

In the invention, the main flow is near one end of the fluid inlet 12 through the through groove 21 and is sucked into the impeller part 22 under the guide of the flow guide cone 3, and the secondary flow formed by the pressure difference between the peripheral fluid pressure of the impeller part 22 and the fluid pressure in the through groove 21 can enter the main flow channel through the two ends of the through groove 21, at the moment, the main flow and the secondary flow can be combined in the through groove 21, so that the width of a part of flow channel paths of the secondary flow entering the impeller rotor 2 during flowing can be increased, the residence time of blood entering the impeller rotor 2 in the secondary flow path can be sufficiently shortened, the damage of the blood in the secondary flow path can be reduced or even avoided, the risk of hemolysis and thrombus of the blood in the secondary flow path can be reduced, and the safety and reliability of the ventricular assist device during working can be ensured.

As shown in fig. 1 to 3, the impeller portion 2 includes a plurality of blades 221 axially spaced apart from each other, and a first passage (not shown) is formed between any adjacent blades 221, and the first passage is a part of the main flow passage. The vane 221 is capable of applying work to the fluid to pressurize the fluid. A portion of the through slot 21 is provided on the rotor portion 23 with one end facing the fluid inlet 12 such that a portion of the secondary flow enters the impeller rotor 2 via the end of the through slot 21 on the rotor portion 23; another portion of the through groove 21 is provided on the impeller portion 22 such that another portion of the secondary flow enters the impeller rotor 2 via the other end of the through groove 21 located on the impeller portion 22.

In more detail, when the impeller rotor 2 is driven to rotate in a suspended manner in the accommodating space 11, the main flow can be sucked into the main flow channel on the impeller portion 22 through the fluid inlet 12 via the end of the through groove 21 near the fluid inlet 12, so that the pressure of the main flow is significantly increased after the main flow is subjected to the work of the blades 221 rotating at a high speed to form the secondary flow, and the blood pressure of the secondary flow is significantly higher than that of the main flow. The secondary flow is driven by the pressure difference, and a part of the secondary flow flows along the channel between the peripheries of the impeller part 22 and the rotor part 23 and the shell 1, enters the rotor part 23 through one end of the through groove 21, which is close to the fluid inlet 12, and flows to the main flow channel under the guidance of the guide cone 3; the other part flows along the passage between the periphery of the impeller portion 22 and the casing 1, and enters the impeller portion 22 via the passage between the other end of the through groove 21 and the guide cone 3, and flows to the main flow passage under the guide of the guide cone 3.

It should also be understood that the housing 1 should also be provided with a fluid outlet 15, the fluid outlet 15 preferably being located on a side wall of the housing 1, and that the blood entering the receiving space 11 through the fluid inlet 12 can be forced to be thrown into the space between the periphery of the impeller portion 22 and the inner wall of the volute 14, leaving the ventricular assist device from the fluid outlet 15. In this context, the side wall of the housing 1 refers to the inner wall around the axis of rotation of the impeller rotor 2. Referring to fig. 4, at the outer periphery of the impeller portion 22, the distance from the outer edge of the impeller portion 22 to the side wall of the casing 1 becomes gradually larger near the fluid outlet 15.

As such, when the ventricular assist device provided in the present embodiment is implanted at the apex of the left ventricle, blood in the left ventricle can be continuously transported from the fluid outlet into the aorta of the human body by the pressurization of the impeller rotor 2 after being sucked into the ventricular assist device.

Referring to fig. 1 and 4, in a specific embodiment, the housing 1 includes a sleeve 13 and a scroll 14, the sleeve 13 and the scroll 14 are in communication in an axial direction of the sleeve 13, the fluid inlet 12 is located at an end of the sleeve 13, and the impeller portion 22, the rotor portion 23, and the guide cone 3 are disposed in a chamber formed by the scroll 14.

With continued reference to fig. 4, in an embodiment, the ventricular assist device further includes a stator 4, the stator 4 being fixedly sleeved outside the housing 1, the stator 4 corresponding to the position of the rotor portion 23. The stator 4 is used for driving the rotor part 23, so that the rotor part 23 drives the impeller part 22 to rotate in a suspending manner in the accommodating space 11. In this embodiment, the stator 4 is sleeved and fixed outside the sleeve 13 and the partial volute 14.

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 and 5, in the present embodiment, the rotor portion 23 includes a rotor housing 231 and a permanent magnet 232 provided inside the rotor housing 231, i.e., the rotor housing 231 is wrapped around the outside of the permanent magnet 232. The rotor housing 231 is fixedly connected to the impeller portion 22, and both are generally integrally formed.

In more detail, the stator 4 is a permanent magnet motor stator, and a driving coil and a suspension coil are arranged inside the permanent magnet motor stator. When the permanent magnet motor stator is energized, the energized drive coil can generate magnetic force with the permanent magnet 232, so that the permanent magnet 232 is subjected to circumferential driving force and can rotate along the axial direction thereof. The energized levitation coil can also generate magnetic force with the permanent magnet 232, so that the permanent magnet 232 is subjected to axial pulling force and levitated in the accommodation space 11. Since the impeller portion 22 is fixedly connected with the rotor housing 231 surrounding the permanent magnet 232, the impeller portion 22 can be suspended and rotated at a high speed in the accommodating space 11 following the permanent magnet 232, thereby sucking blood from the fluid inlet 12 into the through groove 21 and doing work on the blood. It will be appreciated that the function of the drive coils and levitation coils of the permanent magnet motor rotor may also be accomplished with only one set of coils.

Preferably, the stator 4 is adapted to abut against a target object. It should be understood that the target object is a location where the ventricular assist device needs to be implanted in the body, and in this embodiment, the target object is the apex of the heart of the human body.

Referring to fig. 6, in the present embodiment, the ventricular assist device is fixed to the left ventricle 100 while the stator 4, which is the majority of the weight in the ventricular assist device, is disposed in close proximity to the apex of the heart, and the volute, which is the smaller portion of the weight, is disposed in a position away from the apex of the heart. Since the whole ventricular assist device is a cantilever structure, the stator 4, which is the majority of the weight of the ventricular assist device, is brought closer to the fixation point of the ventricular assist device on the apex of the heart, so that the structure of the ventricular assist device is more stable and allows the patient to perform a greater degree of action.

Referring to fig. 4 and 5, in combination with fig. 1, the outer diameter of the impeller portion 22 is larger than the outer diameter of the rotor portion 23, i.e., the radial dimension of the periphery of the impeller portion 22 is larger than the radial dimension of the rotor housing 231. In the prior art, the outer diameter of the rotor is generally equal to or slightly different from the outer diameter of the impeller. In the present application, the inner volume of the scroll casing 14 is fully utilized in the housing space 11 with a strictly limited size to increase the outer diameter of the impeller portion 22 as much as possible, and the arrangement is such that the rotation speed of the blades 221 in the impeller portion 22 can be reduced as much as possible while ensuring the head required for the ventricular assist device, and on the one hand, the damage to blood caused by the blades 221 of the impeller portion 22 at high rotation speed can be reduced, and on the other hand, the whole ventricular assist device can be made more energy-saving.

As shown in fig. 4, in an example, the scroll 14 is stepped and has a first scroll section (not numbered) and a second scroll section (not numbered) that communicate in an axial direction of the sleeve 13, the first scroll section communicates with the sleeve 13, an outer diameter of the first scroll section is smaller than an outer diameter of the second scroll section, at least a part of the rotor portion 23 is disposed in a chamber formed by the first scroll section, and the impeller portion 22 is disposed in a chamber formed by the second scroll section, so that the impeller portion 22 has a larger outer diameter.

Referring to fig. 1 and 2, in a preferred embodiment, a second passage 31 is formed between the through groove 21 and the cone 3.

With continued reference to fig. 4, an annular third passage 222 is provided between the periphery of the impeller portion 22 and the side wall of the casing 1. The third passage 222 gradually increases as the periphery of the impeller portion 22 gradually approaches the fluid outlet. That is, the third passage 222 between the impeller portion 22 and the casing 1 is larger at a position near the fluid outlet; the third passage 222 between the impeller portion 22 and the casing 1 is smaller at a position distant from the fluid outlet. So configured, on the one hand, since blood needs to flow out from the fluid outlet after pressurization, a larger third channel 222 needs to be provided near the fluid outlet to avoid the decrease of the flow rate caused by the congestion of the blood at the fluid outlet. On the other hand, since the blood only needs to flow under the drive of the impeller portion 22 at a position far from the fluid outlet without requiring a large flow space, the third large passage 222 is not required to be provided at a position near the fluid outlet, so that the overall size of the ventricular assist device can be reduced to some extent to ensure smooth implantation of the ventricular assist device in the body.

With continued reference to fig. 2 and 4, the impeller portion 22 has an upper cover plate 223 and a lower cover plate 224 disposed opposite each other in the axial direction, and the upper cover plate 223 is adjacent to the rotor portion 23 and is connected to the rotor portion 23. A fourth passage 225 is provided between the upper cover plate 223 and the casing 1 in the axial direction of the impeller portion 22, a fifth passage 233 is provided between the rotor portion 23 and the casing 1 in the radial direction of the impeller portion 22, and a sixth passage 234 is provided between the rotor portion 23 and the casing 1 in the axial direction of the impeller portion 22.

Therefore, when the impeller rotor 2 is driven to rotate in a suspended manner in the accommodating space 11, the main flow of blood is sucked into the first channel through the second channel 31, and the secondary flow is formed after the working pressurization of the blades 221, and flows along the periphery of the impeller rotor 2 under the action of the pressure difference, and a part of the secondary flow reenters the main flow channel through the fourth channel 225, the fifth channel 233 and the sixth channel 234, so that the flow of a part of the secondary flow is realized.

As shown in fig. 2, a seventh passage 226 is provided between the outer bottom surface of the lower cover plate 224 and the casing 1 in the axial direction of the impeller portion 22, and an eighth passage 32 is formed between the portion of the through groove 21 located on the lower cover plate 224 and the flow guide cone 3. Therefore, when the impeller rotor 2 is driven to rotate in a suspended manner in the accommodating space 11, the main flow of blood is sucked into the first channel through the second channel 31, the secondary flow is formed after the work of the blades 221 is boosted, the secondary flow flows along the periphery of the impeller rotor 2 under the action of the pressure difference, and the other part of the secondary flow reenters the main flow channel through the seventh channel 226 and the eighth channel 32, so that the flow of the other part of the secondary flow is realized.

In more detail, in the present application, the secondary flow has two secondary flow paths, wherein the first secondary flow path is provided around the impeller portion 22 and the rotor portion 23, specifically including a flow path (a blood flow path shown by a broken line b in fig. 4) formed by the first passage, the third passage 222, the fourth passage 225, the fifth passage 233, the sixth passage 234, and the second passage 31 enclosed. The second secondary flow path is provided around the impeller portion 22, and specifically includes a flow path (a blood flow path shown by a broken line b in fig. 3 and a blood flow path shown by a broken line b in fig. 4) defined by the first passage, the third passage 222, the seventh passage 226, the eighth passage 32, and the second passage 31. After the blood flowing in from the fluid inlet 12 reaches the first channel between the blades 221 via the second channel 31 (the blood flow path shown by the solid line a in fig. 3 and the blood flow path shown by the solid line a in fig. 4). After the main flow blood is subjected to work by the blades 221 rotating at a high speed, a part of the secondary flow blood can flow into the first secondary flow path under the action of pressure, another part of the secondary flow blood can flow into the second secondary flow path, and the blood in the first secondary flow path and the second secondary flow path can enter the main flow channel of the impeller part 22 again, and then can be subjected to work boosting again by the blades 221 and flow out from the fluid outlet. It will be appreciated that a portion of the secondary flow can be reciprocally circulated in any one of the secondary flow paths until exiting at the fluid outlet.

In one embodiment, the ventricular assist device has at least one of the following features: at least one of the fourth, sixth and seventh channels 225, 234, 226 has a width of 0.5mm-2mm and the fifth channel 233 has a width of 0.5mm-2mm. It should be understood that the width of the fourth channel 225 refers to the minimum distance between the upper cover plate 223 and the casing 1 in the axial direction of the impeller portion 22; the width of the fifth passage 233 means the minimum distance between the outer wall of the rotor housing 231 and the casing 1 in the radial direction of the impeller portion 22; the width of the sixth channel 234 means the minimum distance between the outer wall of the rotor housing 231 and the casing 1 in the axial direction of the impeller portion 22; the width of the seventh passage 226 refers to the minimum distance between the lower cover plate 224 and the casing 1 in the axial direction of the impeller portion 32.

Since the channel width around the rotor is generally 0.5mm or less in the conventional arrangement, the present invention increases the widths of the fourth channel 225, the fifth channel 233, the sixth channel 234 and the seventh channel 226, thus greatly increasing the width of the flow path of the secondary flow, so that the secondary flow can be performed more smoothly to reduce the risk of stagnation and blockage of the blood in the path of the secondary flow, and the formation of hemolysis and thrombus in the path of the secondary flow can be prevented.

Referring to fig. 1 and 7, the guide cone 3 has a cone-like shape, and the outer circumferential surface area gradually decreases toward the fluid inlet 12. As a preferred embodiment, the impeller portion 22 has a first cavity (not numbered) penetrating in the axial direction thereof, and the rotor portion 23 has a second cavity (numbered) penetrating in the axial direction thereof, the first cavity and the second cavity communicating in the axial direction of the impeller portion 22. One end of the guide cone 3 is fixed with the shell 1, and the other end passes through the first cavity and extends into the second cavity. At this time, the flow guide cone 3 penetrates the first cavity to limit the blood flow in the impeller portion 22 to a certain extent, so that the blood at different positions in the impeller portion 22 is prevented from being mixed and hedging in the radial direction.

The application does not limit the fixing mode of the guide cone 3 and the shell 1, wherein the shell 1 and the guide cone 3 can be integrally formed, or can be separately prepared and then connected together for forming, and the connecting mode can be a plurality of modes such as welding or mechanical matching connection, so long as the shell 1 and the guide cone 3 can be firmly connected.

Referring to fig. 5 and 7, the flow guiding cone 3 includes a circular truncated cone section and a conical section connected to each other in the axial direction of the cone, the circular truncated cone section is connected to the inner wall of the housing 1, the outer contour surface of the circular truncated cone section is convex, and the outer contour surface of the conical section is concave. The outer contour surface of the circular table section is in transitional connection with the outer contour surface of the conical section through an arc surface, and the diversion cone 3 is of an axisymmetric structure. Convex is understood to mean a plane that makes a tangent plane at any point on the surface, with the surface always being below the tangent plane; concave refers to a plane that makes a tangent plane at any point on the surface, with the surface always being above the tangent plane. It should also be appreciated that the circular arc surface may be tangent to the outer contour surface of the circular truncated cone section and the outer contour surface of the conical section, respectively, and the circular arc surface may realize a smooth transition between the outer contour surface of the circular truncated cone section and the outer contour surface of the conical section, that is, the circular arc surface may smoothly transition the convex surface of the circular truncated cone section to the concave surface of the conical section, so as to realize a transitional connection between the circular truncated cone section and the conical section.

Fig. 5 and 7 show schematic axial sectional views of the flow guide cone 3, and referring to fig. 5 and 7, the outer contour of the flow guide cone 3 includes a first arc segment 33, a second arc segment 34, and an arc joint 35 connecting the first arc segment 33 and the second arc segment 34 in an axial section of the flow guide cone 3. The first circular arc segment 33 rotates around the rotation axis of the guide cone 3 to form a circular table segment. The second circular arc section 34 rotates around the axis of rotation of the flow cone 3 to form a conical section. Meanwhile, the arc joint 35 is a point on the outer contour of the arc surface, and is used for connecting the first arc section 33 and the second arc section 34. In this embodiment, the first arc segment 33 and the second arc segment 34 are curved in opposite directions and have the same curvature, the first arc segment 33 preferably protrudes in a direction toward the fluid inlet 12 to form a circular segment, and the second arc segment 34 preferably protrudes in a direction away from the fluid inlet 12 to form a conical segment.

With continued reference to fig. 5, in a preferred embodiment, the distance of the arcuate contact 35 from the axis of rotation of the cone 3 is a fixed value. When the impeller rotor 2 rotates in a floating manner, the distance between the inner bottom surface of the lower cover plate 224 and the bottom surface of the guide cone 3 along the axial direction of the impeller portion 22 is H1, the distance between the inner contour line of the inner bottom surface of the upper cover plate 223 and the inner bottom surface of the lower cover plate 224 along the axial direction of the impeller portion 22 is H2, the distance between the arc contact and the bottom surface of the guide cone 3 along the axial direction of the impeller portion 22 is D, and h1.ltoreq.d1+1/2×h2. It should be understood that the inner bottom surface of the upper cover plate 223 refers to the surface of the upper cover plate 223 that is close to the lower cover plate 224, and the outer bottom surface of the upper cover plate 223 refers to the surface of the upper cover plate 223 that is far from the lower cover plate 224; similarly, the inner bottom surface of the lower cover 224 refers to the surface of the lower cover 224 that is close to the upper cover 223, and the outer bottom surface of the lower cover 224 refers to the surface of the lower cover 224 that is far from the upper cover 223. It should also be understood that the inner contour of the inner bottom surface of the upper cover plate 223 refers to the contour on the inner bottom surface of the upper cover plate 223 closest to the axis of rotation of the guide cone 3; the outer contour of the inner bottom surface of the upper cover plate 223 refers to the contour of the inner bottom surface of the upper cover plate 223 furthest from the rotation axis of the flow guide cone 3.

In more detail, setting H1. Ltoreq.D, the arc joint 35 can be located on the side of the lower cover 224 close to the fluid inlet 12, since the first arc section 33 protrudes toward the side of the fluid inlet 12 (i.e. the circular stage section is convex), the gap width of the eighth channel 32 between the lower cover 224 and the diversion cone 3 can be reduced, the impact force of the blood flowing in the eighth channel 32 on the main flow blood can be reduced, and thus the large-area blending and opposite flushing of the main flow blood and the secondary flow blood can be avoided, so as to reduce unnecessary energy loss. In addition, since the first circular arc segment 33 protrudes toward one side of the fluid inlet 12 (i.e., the circular stage segment is convex), the arrangement of D is equal to or less than h1+1/2×h2s can avoid the dimension of the circular arc junction 35 and the bottom surface of the flow guiding cone 3 along the axial direction of the impeller portion 22 from being too large, and avoid the gap width of the eighth channel 32 from being too small, thereby preventing the secondary flow of blood around the impeller portion 22.

In an example, the shape of the rotor portion 23 is matched with the shape of the flow guiding cone 3, that is, the rotor portion 23 has an arc-shaped surface matched with the shape of the flow guiding cone 3, so that when configured, the second channel 31 formed between the through groove 21 and the flow guiding cone 3 can smoothly guide the blood entering the sleeve 13 into the vane 221 of the impeller portion 22, thereby reducing or even avoiding the damage of the main flow channel to the blood.

Preferably, the rotational axis of the cone 3 coincides with the rotational axis of the sleeve 13, and this arrangement allows the blood flowing from the fluid inlet 12 to be uniformly dispersed into the individual blades 221 in the impeller portion 22. More preferably, the rotation axis of the impeller rotor 2 and the rotation axis of the guide cone 3 coincide, so that uniformity of blood flow in the main channel and uniformity of pressure at the time of outflow from the fluid outlet can be ensured.

As shown in fig. 5, the distance between the outer contour of the inner bottom surface of the upper cover plate 223 and the inner bottom surface of the lower cover plate 224 along the axial direction of the impeller portion 22 is H3, the ratio of H3 to H2 is 0.5-1, and the distance between the inner bottom surface of the upper cover plate 223 and the inner bottom surface of the lower cover plate 224 along the axial direction of the impeller portion 22 gradually decreases from inside to outside. It should be understood that the inner sides of the upper cover plate 223 and the lower cover plate 224 refer to the side facing the rotation axis of the guide cone 3, and the outer sides of the upper cover plate 223 and the lower cover plate 224 refer to the side facing away from the rotation axis of the guide cone 3.

In more detail, the diameter of the outer contour line of the upper cover plate 223 is set to r1, and the diameter of the inner contour line of the upper cover plate 223 is set to r2. The flow area of blood at the outer contour of the upper cover plate 223 is 2pi r 1H 3 and the flow area of blood at the inner contour of the upper cover plate 223 is 2pi r 2H 2. Since the flow rate=flow rate/flow area of blood, the flow rate of blood flowing through the inner contour of the upper cover plate 223 is the same as the flow rate flowing through the outer contour of the upper cover plate 223. When h2=h3, since r1 is greater than r2, the flow area of blood at the outer contour of the upper cover plate 223 is greater than the flow area of blood at the inner contour of the upper cover plate 223, and it is known that the flow rate of blood at the outer contour of the upper cover plate 223 is smaller than the flow rate at the inner contour of the upper cover plate 223, that is, the flow rate of blood at the outer contour of the upper cover plate 223 is lower, the pressure of blood at the outer contour of the upper cover plate 223 is greater than the pressure of blood at the inner contour of the upper cover plate 223, so that the impeller portion 22 forms a back pressure from outside to inside. The excessive back pressure of impeller portion 22 causes the blood to always rotate adjacent the inner contour of vane 221 and not flow to the outer contour of vane 221 and out the fluid outlet.

The present application properly reduces the height H3 from the outer contour of the upper cover plate 223 to the lower cover plate 224, so that the ratio of H3 to H2 is 0.5 to 1, thus reducing the flow area of blood at the outer contour of the upper cover plate 223, increasing the flow rate of blood at the outer contour of the upper cover plate 223, reducing the pressure of blood at the outer contour of the upper cover plate 223, i.e., reducing the back pressure of the impeller portion 22, thus enabling blood to flow to the outer contour of the vane 221, and enabling part of the blood to enter the secondary flow path or flow out from the fluid outlet, thereby reducing the flow separation of blood in the vane 221, reducing the energy loss in the blood flow process, and improving the hydraulic efficiency of the ventricular assist device.

With continued reference to fig. 7, and in combination with fig. 1, in a preferred embodiment, the guide cone 3 is located on a side of the through groove 21 facing away from the fluid inlet 12, and the bottom surface of the guide cone 3 is fixedly connected to the housing 1, and a holding hole 36 is provided on the bottom surface of the guide cone 3. In this embodiment, the holding hole 36 is a blind hole with a tapered inner contour surface, and the inner surface area of the holding hole 36 gradually decreases toward the fluid inlet 12, that is, a tapered blind hole for facilitating the holding of the operator is provided on the bottom surface of the guide cone 3, so that the overall weight of the ventricular assist device can be reduced, and the operator can hold the ventricular assist device in the clinical operation process conveniently, for example, the operator can insert fingers into the blind hole formed by the holding hole 36 to hold the ventricular assist device.

In summary, in the ventricular assist device provided by the invention, the main flow blood enters the main flow channel of the impeller rotor 2 through one end of the through groove 21 of the impeller rotor 2, which is close to the fluid inlet 12, and the secondary flow blood can enter the main flow channel through two ends of the through groove 21, and the main flow blood and the secondary flow blood are converged in the through groove 21, so that the partial path width of the secondary flow blood entering the impeller rotor 2 during flowing can be increased, the residence time of the blood entering the impeller rotor 2 in the secondary flow path can be sufficiently shortened, the damage of the blood in the secondary flow path can be reduced or even avoided, the risk of hemolysis and thrombus of the blood in the secondary flow path can be reduced, and the safety and reliability of the ventricular assist device during working can be ensured.

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. The ventricular assist device is characterized by comprising a shell, an impeller rotor and a diversion cone; the shell is provided with a containing space and a fluid inlet which are communicated; the impeller rotor and the diversion cone are both arranged in the accommodating space; the impeller rotor comprises an impeller part and a rotor part which are coaxially connected, the impeller rotor is provided with a through groove penetrating along the axial direction of the impeller rotor, and the rotor part is positioned at one side of the impeller part, which faces the fluid inlet; the diversion cone part is arranged in the through groove and is used for limiting the flow direction of fluid entering the impeller rotor, wherein the fluid comprises a main flow and a secondary flow;

2. The ventricular assist device of claim 1 wherein the impeller portion has a plurality of blades circumferentially spaced therearound, a first passage being formed between any adjacent blades, the first passage being part of the primary flow path;

3. The ventricular assist device of claim 2, wherein an outer diameter of the impeller portion is greater than an outer diameter of the rotor portion.

4. The ventricular assist device of claim 2 wherein the housing further has a fluid outlet located on a side wall of the housing, the periphery of the impeller portion having an annular third passage between the periphery of the impeller portion and the side wall of the housing; the third passage gradually increases as the periphery of the impeller portion gradually approaches the fluid outlet.

5. The ventricular assist device of claim 2 wherein the impeller portion has upper and lower cover plates disposed axially opposite each other, the upper cover plate being adjacent to and connected to the rotor portion, the upper cover plate and the housing having a fourth passage therebetween in an axial direction of the impeller portion; a fifth channel is arranged between the rotor part and the shell along the radial direction of the impeller part; a sixth passage is formed between the rotor part and the housing in the axial direction of the impeller part;

6. The ventricular assist device of claim 5 wherein a seventh channel is formed between an outer bottom surface of the lower cover plate and the housing in an axial direction of the impeller portion, and an eighth channel is formed between a portion of the through groove on the lower cover plate and the flow cone;

7. The ventricular assist device of claim 6 having at least one of the following features:

the width of the fifth channel is 0.5mm-2mm.

8. The ventricular assist device of claim 5 wherein a peripheral area of the flow cone decreases gradually toward the fluid inlet; the diversion cone comprises a round platform section and a conical section which are mutually connected along the axis direction of the diversion cone, the round platform section is connected with the shell, the outer contour surface of the round platform section is a convex surface, and the outer contour surface of the conical section is a concave surface; the outer contour surface of the circular table section is in transitional connection with the outer contour surface of the conical section through an arc surface, and the diversion cone is of an axisymmetric structure.

9. The ventricular assist device of claim 8 wherein, in an axial cross-section of the flow cone, the outer contour of the flow cone comprises a first circular arc segment that rotates about an axis of rotation of the flow cone to form the frustoconical segment, a second circular arc segment that rotates about the axis of rotation of the flow cone to form the conical segment, and a circular arc junction connecting the first circular arc segment and the second circular arc segment;

10. The ventricular assist device as claimed in claim 5, wherein a distance between an outer contour of an inner bottom surface of the upper cover plate and an inner bottom surface of the lower cover plate in an axial direction of the impeller portion is H3, a ratio of H3 to H2 is 0.5 to 1, and a distance between the inner bottom surface of the upper cover plate and the inner bottom surface of the lower cover plate in the axial direction of the impeller portion is gradually decreased from inside to outside.

11. The ventricular assist device of claim 2, 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 and is used for being abutted with a target object.

12. A ventricular assist device as claimed in any one of claims 1 to 11 wherein the axis of rotation of the impeller rotor and the axis of rotation of the flow cone coincide.

13. The ventricular assist device of any one of claims 1-11, wherein the flow cone is located on a side of the channel facing away from the fluid inlet, and a bottom surface of the flow cone is fixedly connected to the housing, and a grip hole is provided on the bottom surface of the flow cone.