阅读说明：本技术 一种微创介入式人工心脏轴流血泵 (Minimally invasive intervention type artificial heart axial flow blood pump ) 是由 张锡文 吴啸 陈成瀚 于 2021-01-27 设计创作，主要内容包括：一种微创介入式人工心脏轴流血泵,用于辅助衰竭心脏的血液循环。该血泵包括前置导管、套筒以及设置在套筒内的泵体和微型电机,微型电机固定在套筒上；泵体包括转子轮毂、转子叶片、后导叶轮毂和后导叶叶片。该血泵的主要特点该采用渐变内径,渐变内径的最小截面积与转子中部流场区域的截面积相同,且转子轮毂与后导叶轮毂之间通过齿状密封结构连接。本发明在保证转子区域流场截面积基本不变的情况下,有效降低了因流场区域截面积变化带来的能量损失,从而提高了血泵的工作效率。同时避免了缝隙区域血细胞的侵入,解决了现有微创介入式轴流血泵转子轮毂和后导叶轮毂的缝隙区域血细胞损伤较大的问题,从而显著增强了血泵的可靠性。(A minimally invasive intervention type artificial heart axial flow blood pump is used for assisting the blood circulation of a failing heart. The blood pump comprises a preposed conduit, a sleeve, a pump body and a micro motor, wherein the pump body and the micro motor are arranged in the sleeve; the pump body comprises a rotor hub, rotor blades, a rear guide vane hub and rear guide vane blades. The blood pump is mainly characterized in that a gradually-changed inner diameter is adopted, the minimum sectional area of the gradually-changed inner diameter is the same as the sectional area of a flow field area in the middle of a rotor, and a rotor hub is connected with a back guide impeller hub through a toothed sealing structure. The invention effectively reduces the energy loss caused by the change of the sectional area of the flow field area under the condition of ensuring that the sectional area of the flow field of the rotor area is basically unchanged, thereby improving the working efficiency of the blood pump. Meanwhile, the invasion of blood cells in the gap area is avoided, and the problem that the blood cells in the gap area of the rotor hub and the rear guide impeller hub of the existing minimally invasive intervention type axial flow blood pump are greatly damaged is solved, so that the reliability of the blood pump is obviously enhanced.)

1. A minimally invasive intervention type artificial heart axial flow blood pump comprises a preposed catheter (1), a sleeve (2), a pump body and a micro motor (3), wherein the pump body and the micro motor (3) are arranged in the sleeve, the micro motor is fixed on the sleeve, and a flow outlet (10) is formed in the sleeve; the pump body comprises a rotor and a rear guide vane, the rotor comprises a rotor hub (4) and rotor blades (5), and the rear guide vane comprises a rear guide impeller hub (6) and rear guide vane blades (7); the micro motor output shaft (9) passes the back stator and is connected with the rotor, its characterized in that: the inlet of the sleeve is provided with a gradually changing inner diameter (11) which comprises a gradually reducing section (13) and a gradually expanding section (14), the minimum sectional area of the gradually changing inner diameter is the same as the sectional area of a flow field area in the middle of the rotor, the change curve of the gradually reducing section and the change curve of the gradually expanding section are smooth integrally, and the derivatives at the beginning and the end are 0.

2. The minimally invasive interventional instrument of claim 1An artificial heart axial flow blood pump is characterized in that: the change curve of the tapered section is obtained by calculating the energy loss in the tapered section at the sleeve inlet pressure of 10000Pa and the flow rate of 4L/min by using FLUENT software, and optimizing the change curve of the tapered section based on the minimum energy loss as follows: 0.6468x²-0.1467x³-0.0258x⁴(ii) a The divergent section extends to the position of the rotor, and a divergent section change curve obtained based on the constant optimization of the flow field sectional area is as follows: y 1-0.2132x²+0.0441x³-0.0016x⁴；

In the above formula, x represents an axial coordinate, and x ═ 0 represents the position where the curve starts, in mm; y represents the reduction of the inner diameter in mm.

3. The minimally invasive interventional artificial heart axial blood pump of claim 1 or 2, characterized in that: the rotor hub and the back guide impeller hub are connected through a tooth-shaped sealing structure (12).

4. The minimally invasive interventional artificial heart axial blood pump of claim 1, wherein: the rotor hub, the rear guide vane hub, the rotor blades and the rear guide vane blades are of an integrated streamline structure.

5. The minimally invasive interventional artificial heart axial blood pump of claim 1, wherein: the micro motor output shaft (9) penetrates through the rear guide vane and is connected with the rotor, and the rotor is supported by the output shaft of the micro motor on one side.

6. The minimally invasive interventional artificial heart axial blood pump of claim 1, wherein: the outflow port (10) adopts a streamline self-adaptive structure.

Technical Field

The invention relates to a minimally invasive intervention type artificial heart axial flow blood pump which can be used for assisting the blood circulation of a failing heart and belongs to the technical field of biomedical engineering.

Background

An implanted artificial heart blood pump is one of effective ways for treating end-stage heart failure, but the existing artificial heart blood pumps applied clinically are installed by opening the chest, so that the operation difficulty is high, and the wound area is large; the minimally invasive technique is adopted to intervene the miniature axial flow blood pump from the femoral artery, a safer and more effective technical means is provided, the preposed catheter is downwards extended to the left ventricle from the aorta, then the catheter passes through the artery valve, the blood flow is lifted by the pump to increase the pressure and flow to enter the aortic arch, thereby reducing the heart load and providing the blood auxiliary flow for the whole body. However, the minimally invasive interventional axial blood pump has a small size, so that the flow velocity is high, and further high energy loss is easily caused, mainly expressed by loss caused by sectional area change at an inlet of the sleeve, loss of a rotor and a rear guide vane area and loss caused by disturbance at an outlet. On the other hand, the minimally invasive interventional axial blood pump has the characteristics of small volume, large flow speed and large energy loss, so that the requirement of human body circulation can be met only by achieving higher rotating speed (20000 + 30000rpm), and the damage of blood cells in the gap area of the rotor hub and the rear guide impeller hub can be increased.

Disclosure of Invention

The invention aims to provide a minimally invasive intervention type artificial heart axial flow blood pump, which effectively reduces energy loss caused by the change of the sectional area of a flow field area under the condition of ensuring that the sectional area of the flow field of a rotor area is basically unchanged, and further improves the working efficiency of the blood pump; meanwhile, the invasion of blood cells in the gap area is avoided, and the problem that the blood cells in the gap area of the rotor hub and the rear guide impeller hub of the existing minimally invasive intervention type axial flow blood pump are greatly damaged is solved, so that the reliability of the blood pump is enhanced, and the life safety of a patient is ensured.

The technical scheme of the invention is as follows: a minimally invasive intervention type artificial heart axial flow blood pump comprises a preposed catheter, a sleeve, a pump body and a micro motor, wherein the pump body and the micro motor are arranged in the sleeve; the pump body comprises a rotor and a rear guide vane, the rotor comprises a rotor hub and rotor blades, and the rear guide vane comprises a rear guide impeller hub and rear guide vane blades; the micro motor output shaft is connected with back stator and rotor, its characterized in that: the inlet of the sleeve is provided with a gradually changing inner diameter, the gradually changing inner diameter comprises a gradually reducing section and a gradually expanding section, the minimum sectional area of the gradually changing inner diameter is the same as the sectional area of the flow field area in the middle of the rotor, the change curve of the gradually reducing section and the change curve of the gradually expanding section are smooth integrally, and the derivative of the beginning and the ending is 0.

In the above technical solution, the energy loss in the tapering section is calculated by using FLUENT software when the sleeve inlet pressure is 10000Pa and the flow rate is 4L/min, and the tapering section variation curve obtained based on the optimization with the minimum energy loss is: 0.6468x²-0.1467x³-0.0258x⁴(ii) a The divergent section extends to the position of the rotor, and a divergent section change curve obtained based on the constant optimization of the cross section area of the flow field is as follows: y 1-0.2132x²+0.0441x³-0.0016x⁴；

In the above formula, x represents an axial coordinate, and x ═ 0 represents the position where the curve starts, in mm; y represents the reduction of the inner diameter in mm.

Further, the rotor hub and the rear guide impeller hub are connected through a tooth-shaped sealing structure.

Furthermore, the rotor hub, the rear guide vane hub, the rotor blades and the rear guide vane blades adopt an integrated streamline structure; the outflow port is of a streamline self-adaptive structure.

The invention is also characterized in that: the output shaft of the micro motor is connected with the rear guide vane and the rotor in a mode that the output shaft of the micro motor penetrates through the rear guide vane and is connected with the rotor, and the rotor is supported by one side of the output shaft of the micro motor.

Compared with the prior art, the invention has the following advantages and prominent technical effects: firstly, the inlet of the sleeve is designed with a gradually-changed inner diameter, so that the energy loss caused by the sectional area can be effectively reduced, and the working efficiency of the blood pump is finally improved by 30 percent; meanwhile, the rotor can be prevented from being separated from the sleeve when extreme conditions occur, and the life safety of a patient is further ensured; a toothed sealing structure is arranged between the rotor hub and the rear guide impeller hub, so that the lubrication effect can be realized, the inflow and the damage of blood cells can be prevented, and the reliability of the blood pump is obviously enhanced; the rotor hub, the rear guide vane hub, the rotor blades and the rear guide vane blades are all in an integrated streamline design, so that vortexes generated in the rear guide vane region can be avoided; and fourthly, the streamline adaptive design of the outflow port can effectively reduce the resistance and disturbance when the blood flows out, and further improve the mechanical efficiency of the blood pump.

Drawings

Fig. 1 is a schematic structural diagram of a minimally invasive interventional artificial heart axial flow blood pump provided by the invention.

Fig. 2 is a structural view of a rotor portion.

FIG. 3 is a block diagram of the aft guide vane section.

FIG. 4 is a schematic view of the tooth seal arrangement existing between the rotor hub and the back guide vane hub.

FIG. 5 is a tapered section curve obtained by optimization under the conditions of sleeve inlet pressure 10000Pa and flow 4L/min.

FIG. 6 is a diverging curve optimized under the conditions of sleeve inlet pressure 10000Pa and flow 4L/min.

In the figure: 1-a front catheter; 2-a sleeve; 3-a micro motor; 4-a rotor hub; 5-rotor blades; 6-rear guide vane wheel hub; 7-rear guide vane blade; 8-percutaneous lead; 9-output shaft of micro motor; 10-an outflow port; 11-a tapered inner diameter; 12-a toothed structure; 13-a tapered section; 14-divergent section.

Detailed Description

The details of the structure, principles and operation of the present invention are described in detail below with reference to the accompanying drawings and examples.

As shown in figure 1, the minimally invasive interventional artificial heart axial flow blood pump provided by the invention comprises a preposed catheter 1, a sleeve 2, a pump body arranged in the sleeve and a micro motor 3, wherein the micro motor 3 is connected with the sleeve 2; the pump body comprises a rotor positioned in the sleeve and a rear guide vane fixed in the sleeve, wherein the rotor comprises a rotor hub 4 and rotor blades 5; the rear guide vane comprises a rear guide vane hub 6 and a rear guide vane blade 7. The micro motor is powered by a percutaneous lead 8, a micro motor output shaft 9 penetrates through the rear guide vane and is connected with the rotor, the rotor is supported by the single side of the micro motor output shaft, and the micro motor output shaft drives the rotor to rotate, so that blood is driven to be sucked from the preposed catheter 1 and then flows out of an outflow port 10 at the rear end of the sleeve.

The inlet of the blood pump sleeve is designed with a gradually-changed inner diameter 11 which comprises a tapered section 13 and a gradually-expanded section 14, so that the flow loss caused by reduction of the flow cross-sectional area can be reduced, and the reliability of the blood pump under extreme conditions can be improved. Compared with the traditional blood pump driven by a magnetic conductive material in a rotor and an electromagnetic coil outside a sleeve, the blood pump directly driven by a micro motor improves the output efficiency of the blood pump, has better stability and reduces the difficulty of installation and processing. The streamline adaptive structural design of the outflow port 10 can effectively reduce the resistance and disturbance when blood flows out, and further improve the mechanical efficiency of the blood pump.

As shown in fig. 1 and 4, a tooth-shaped sealing structure 12 is arranged between the rotor hub 4 and the back guide impeller hub 6, so that the lubrication effect is achieved, the damage of blood cells is avoided, and the reliability of the blood pump is remarkably enhanced.

As shown in fig. 2 and 3, the rotor hub 4, the rear guide vane hub 6, the rotor blades 5 and the rear guide vane blades 7 of the blood pump all adopt an integrated streamline design, so that the resistance and disturbance of blood flowing through the rotor and the rear guide vanes can be effectively reduced, and the mechanical efficiency of the blood pump is improved.

Fig. 5 and fig. 6 respectively show a convergent section curve and a divergent section curve obtained by optimization under the conditions of pressure at the inlet of the sleeve being 10000Pa and flow rate being 4L/min, wherein the convergent section curve and the divergent section curve satisfy the following conditions:

the minimum sectional area is the same as the sectional area of the flow field area in the middle of the rotor;

secondly, the curve is smooth as a whole, and the derivative at the beginning and the end is 0;

thirdly, setting sleeve inlet pressure 10000Pa and flow 4L/min by using FLUENT simulation, and finally obtaining the optimal curve based on the minimum energy loss of the whole tapered sectionThe curve y of the tapered section is 0.6468x²-0.1467x³-0.0258x⁴. The gradual expansion section curve is optimized based on the constant of the flow field sectional area, namely the inner diameter of the sleeve is gradually increased along with the increase of the diameter of the rotor hub, the flow field sectional area is ensured to be basically constant, the energy loss caused by the change of the sectional area is avoided, and the gradual expansion section curve y is finally obtained as 1-0.2132x²+0.0441x³-0.0016x⁴(ii) a In the formula, x represents an axial coordinate, and x ═ 0 represents the position where the curve starts, and the unit is mm; y represents the reduction of the inner diameter in mm.

The gradual change internal diameter of sleeve entrance design can effectively reduce the energy loss because of the sectional area brings, and the streamline self-adaptation structure of the outflowing port can further promote the work efficiency of the blood pump, can improve 30% finally; therefore, only the rotating speed is set to 20000-30000 r/min, the flow rate not less than 4L/min and the pressure rise not less than 80-100 mmHg can be generated, and the blood is driven to circularly flow. Meanwhile, due to the reduction of the rotating speed and the existence of the toothed sealing structure between the rotor hub and the rear guide impeller hub, the damage of the blood pump to blood cells can be further reduced, and the reliability of the blood pump is obviously enhanced.