CN106512117B

CN106512117B - Flexible transmission system, percutaneous auxiliary blood pumping device and intravascular thrombus aspiration system

Info

Publication number: CN106512117B
Application number: CN201610880612.3A
Authority: CN
Inventors: 唐智荣; 郑淇文; 杨海; 王涛
Original assignee: Fengkaili Medical Instrument Shanghai Co ltd
Current assignee: Fengkaili Medical Instrument Shanghai Co ltd
Priority date: 2016-10-09
Filing date: 2016-10-09
Publication date: 2023-08-04
Anticipated expiration: 2036-10-09
Also published as: CN106512117A

Abstract

The invention discloses a flexible transmission system, a percutaneous auxiliary blood pumping device and an intravascular thrombus suction system, wherein the flexible transmission system comprises a flexible driving shaft positioned at an inner layer and a sheath pipe positioned at the outer side of the flexible driving shaft, perfusate is filled between the flexible driving shaft and the sheath pipe, the flexible driving shaft is braided stranded wires formed by braiding at least 2 strands of metal wires, and the sheath pipe consists of a hollow metal spiral pipe, a high polymer pipe or a composite pipe. And two ends of the flexible transmission system are respectively connected with an external motor and a blood pumping impeller. When the motor rotates at a high speed, the vibration of the transmission system is small, so that a patient can feel more comfortable and safe when using the motor.

Description

Flexible transmission system, percutaneous auxiliary blood pumping device and intravascular thrombus aspiration system

Technical Field

The invention belongs to the field of medical instruments, and particularly relates to a flexible transmission system, a percutaneous auxiliary blood pumping device and an intravascular thrombus suction system.

Background

The heart is a power source for maintaining the effective blood circulation and oxygen delivery of the whole body, and if the heart function is reduced due to Acute Myocardial Infarction (AMI), heart Failure (HF), cardiogenic Shock (CS) and the like, the requirement of tissue metabolism cannot be met, and the life of a patient is endangered. Methods of treatment for these patients can be generally divided into two aspects, causal treatment and supportive treatment, but causal treatment and circulatory support are closely related during the course of treatment. Generally, the etiology analysis takes time and the treatment takes time, but the circulatory support often has instant effect on the recovery of the hemodynamics, and the key is that the time can be won for the etiology treatment. Therefore, mechanical methods have been sought to replace part or all of the heart's function, to allow the heart to rest and reduce oxygen consumption, to improve the blood supply to the heart muscle, and to promote heart recovery.

Over the past decades, a number of auxiliary devices (collectively referred to in this section as "blood pumps") have been developed for use in place of cardiac pumping. In the early stage, a diaphragm pump with a bionic property is adopted, but due to the volume, the clinical use is large in wound, the complications are more, and the operation prognosis is poor. The advent of continuous flow blood pumps in the 80 s of the 20 th century has enabled the reduction of blood volume, and since the 90 s, surgical implantation of left ventricular assist devices (Left ventricular assistant device, LVAD) has improved effectiveness, safety and reduced complications, and for patients with severe and drug-refractory heart failure, surgical implantation of ventricular assist devices has become a beneficial supplement to heart transplant surgery in europe and america.

However, the implantation and withdrawal of the surgical implantation ventricular assist device are very complex, and the surgical implantation of the ventricular assist device is limited when applied to a scene where rapid stabilization of hemodynamics is required, or where heart function is theoretically recoverable, and convenient withdrawal is required after temporary circulatory support is completed. Therefore, percutaneous insertion of a left ventricular assist device is required.

US5,911,685 discloses in vivo motor-driven percutaneous implantation of left ventricular assist product technology for rapid stabilization of hemodynamics in cardiogenic shock patients.

The existence of the in-vivo motor increases the length of the in-vivo rigid body, on the other hand, the motor causes the risk of blood temperature rise when rotating at high speed, and if the motor leaks electricity, the motor can cause an electric shock event which damages the heart.

When the drive motor of the LVAD is located outside the body, the motor and the blood pumping component-impeller cannot be connected through a rigid shaft generally due to the vascular anatomy, the product is generally used in the process of penetrating through femoral artery, through abdominal aorta, thoracic aorta and aortic arch into the left ventricle, the outer diameter of the blood pumping component is within 14F to meet the requirement of penetration implantation, at the diameter, the flow of 2.5L/min is required, the rotating speed of the impeller is more than 1 ten thousand revolutions per minute, more limited, and the rotating speed is possibly more than 5 ten thousand revolutions per minute. The primary function of the flexible drive shaft is to transmit the torque of the motor to a rotary working mechanism, such as a blood pumping impeller or the like. During this process, the flexible drive shaft is subjected to a shear force, and if the actual shear strength to which the flexible drive shaft is subjected is greater than the ultimate shear strength of the material, the flexible drive shaft will fracture.

The flexible transmission system is positioned between the external motor and the impeller. The ratio of the long diameter of the flexible transmission system is more than 160 times. The flexible transmission system is composed of a flexible driving shaft and a sheath tube, wherein the flexible driving shaft is positioned at the inner layer, the sheath tube is positioned at the outer side of the flexible driving shaft, the sheath tube at least comprises a layer of hollow sheath tube, and the sheath tube can be a polymer tube material which is extruded continuously, can also be a hollow tube material woven by metal wires or polymer fibers, or is formed by compounding the materials.

The flexible drive shaft is prone to severe vibration in the flexible drive system when rotated at high speeds within the sheath. The cause of the vibration is: on the one hand, friction between the flexible driving shaft and the sheath tube when rotating, and on the other hand, the flexible coefficient of the flexible driving shaft is very high, and when rotating, very large swinging is generated, and the flexible driving shaft knocks or impacts the sheath tube when swinging, so that a transmission system comprising a stator generates vibration with certain amplitude and frequency.

The existence of the filling liquid can effectively reduce the friction between the flexible driving shaft and the sheath tube so as to reduce the vibration and noise caused by the friction, but the vibration generated by the collision of the flexible driving shaft with the sheath tube during the swing cannot be solved. When the amplitude of the transmission system exceeds a certain range for a long time, the patient will be unacceptable, and adverse events such as plaque falling off, interlayer and the like in the blood vessel of the aorta may be caused.

Patent CN105682602 discloses a flexible drive design that uses a hollow helical tube with local filling hardening at the proximal and distal ends as the drive shaft to reduce its vibration load. This solution is very complex to implement, and in particular in the case of partial fill hardening solutions, the outer diameter of the drive shaft inevitably increases.

Therefore, there is a need for a new flexible drive shaft configuration that satisfies the long-term, high rotational speed, high torque operating requirements without the need for localized stiffening.

Disclosure of Invention

The invention aims to solve the technical problem of providing a flexible transmission system, a percutaneous auxiliary blood pumping device and an intravascular thrombus suction system, which can safely transmit torque and reduce the vibration amplitude of the transmission system during rotation so as to make a patient feel more comfortable during use.

The technical scheme adopted by the invention for solving the technical problems is to provide a flexible transmission system which comprises a flexible driving shaft positioned at an inner layer and a sheath pipe positioned at the outer side of the flexible driving shaft, wherein perfusate is filled between the flexible driving shaft and the sheath pipe, the flexible driving shaft is a braided twisted wire formed by braiding at least 2 strands of metal wires, and the sheath pipe consists of a hollow metal spiral pipe, a high polymer pipe or a composite pipe. .

The flexible transmission system, wherein the diameter of the flexible driving shaft ranges from 0.15mm to 0.53mm.

The flexible transmission system, wherein the diameter of the flexible driving shaft ranges from 0.36mm to 0.51mm, and the flexible driving shaft is a round strand braided twisted wire.

The flexible drive system described above wherein the flexible drive shaft is a braided structure of 3*1, 5*1, 6*1, 7*1, 8*1, 9*1, 12 x 1 or 37 x 1.

The flexible transmission system, wherein the mass ratio of the sheath tube to the flexible driving shaft is 6-351.

The flexible transmission system, wherein a gap between the flexible driving shaft and the sheath tube is 0.05mm-0.41mm.

The invention provides a percutaneous auxiliary blood pumping device which aims at solving the technical problems and comprises a driving module, a control module and a blood pumping catheter which can be implanted into a human body through the skin, wherein the driving module is arranged outside the body and is separated from the blood pumping catheter, the far end of the driving module is connected with the blood pumping catheter through a flexible transmission system, and the near end of the driving module is connected with the control module through a signal wire, wherein the flexible transmission system is the flexible transmission system.

The percutaneous auxiliary blood pumping device, wherein the blood pumping impeller comprises a hub and blades, and the hub is composed of a distal axial flow hub section and a proximal diagonal flow hub section; the axial-flow hub section comprises an axial-flow hub front section and an axial-flow hub rear section, the outer diameter of the axial-flow hub front section gradually increases from the far end to the near end to be the same as the diameter of the axial-flow hub rear section, the hub diameter of the diagonal-flow hub section gradually increases from the far end to the near end, the diameter of the far end of the diagonal-flow hub section is the same as the hub diameter in the axial-flow hub rear section, and the diameter of the near end of the diagonal-flow hub section is the same as the outer diameter of the impeller.

The percutaneous auxiliary blood pumping device, wherein the length ratio range of the axial flow hub section and the diagonal flow hub section in the axial direction is 9:1-1:1, the diagonal flow diffusion structure at the proximal end of the diagonal flow hub section and the outflow window are matched to form an outflow channel, and the length ratio range of the diagonal flow hub section and the outflow window in the axial direction is 0.5:1 to 3:1, a step of; the hub ratio in the rear section of the axial flow hub is 0.25-0.6; the outer diameter of the blood pumping impeller is smaller than 10mm.

The percutaneous auxiliary blood pumping device comprises at least one continuous blade, wherein the continuous blade comprises an axial flow blade and an oblique flow blade from a far end to a near end, the axial flow blade is correspondingly arranged on a hub of the axial flow section, the oblique flow blade is correspondingly arranged on the hub of the oblique flow hub section, the axial flow blade comprises an axial flow inlet blade and an axial flow main body blade from the far end to the near end, and the blade angle of the continuous blade is gradually increased from the far end to the near end.

In the percutaneous auxiliary blood pumping device, the blade angle range of the axial flow inlet blade is 5-65 degrees, the blade angle range of the axial flow main body blade is 30-70 degrees, and the blade angle range of the diagonal flow blade is 55-85 degrees.

The percutaneous auxiliary blood pumping device, wherein the blade angles of each section of the continuous blades are continuously changed, the blade angle of the proximal end of the axial flow inlet blade is the same as the blade angle of the distal end of the axial flow main body blade, and the blade angle of the distal end of the diagonal flow blade is the same as the blade angle of the proximal end of the main body section.

The invention provides a third technical scheme adopted for solving the technical problems, which is to provide an intravascular thrombus suction system, comprising a suction catheter which can be implanted into a human body through skin and a driving module positioned outside the body, wherein the suction catheter comprises a blood inlet, a blood flow channel and a bleeding port, a filter screen is arranged in the blood flow channel of the suction catheter, and an impeller is arranged between the filter screen and the bleeding port or at the bleeding port; the impeller is connected with the driving module; the distal end of the driving module is connected with the suction catheter through a flexible transmission system, and the proximal end of the driving module is connected with the control module through a signal wire; the flexible transmission system is the flexible transmission system, and the flexible driving shaft is connected with the impeller through a bridging structure.

The intravascular thrombus aspiration system comprises the drive module, the drive motor and the bridging structure, wherein the drive module comprises a support shell, the drive motor and the bridging structure, the distal end of the drive module bridging structure is connected with a flexible drive shaft in the flexible transmission system, and the proximal end of the drive module bridging structure is connected with a rotating shaft of the drive motor.

The intravascular thrombus suction system comprises a driving motor, wherein the driving motor is a pneumatic motor, a cooling structure, a speed measuring structure, an exhaust structure and a noise reduction structure are further arranged in a supporting shell, the control module outputs a control signal to the driving module to control the output air pressure of an air source to control the rotating speed of a steam turbine, and meanwhile the speed measuring structure feeds back the actual rotating speed of the steam turbine to form closed-loop control.

The intravascular thrombus aspiration system is characterized in that the driving motor is an electric motor, a cooling structure is further arranged in the supporting shell, the control module provides a driving signal machine power supply for the driving module, and the driving module feeds back the running state of the motor.

The intravascular thrombus aspiration system comprises a control module, a control module and a control module, wherein the control module comprises a controller main body, an electrical system and system software carried by the controller, and is provided with a human-computer interaction interface; the controller main body is connected with the driving module through a signal wire, and the controller main body transmits and receives the operation parameters of the motor in the driving module; the system software is used for setting system operation parameters, controlling system operation and monitoring the operation state of the suction catheter in real time.

The intravascular thrombus aspiration system described above, wherein the mesh area of the filter mesh is in the range of 0.1mm ² -16mm ² 。

Compared with the prior art, the invention has the following beneficial effects: the flexible transmission system, the percutaneous auxiliary blood pumping device and the intravascular thrombus suction system provided by the invention are characterized in that the flexible rotating shaft of the flexible transmission system is arranged into the braided twisted wires formed by braiding at least two strands of metal wires, and the diameter of the flexible transmission shaft is designed to be generally not smaller than the diameter of the rotating shaft of a motor, for example, the outer diameter of the rotating shaft of the motor is 1.0mm, and the outer diameter of the transmission rotating shaft is generally at least 1.0mm. Compared with the existing circular monofilament structure, the braided twisted wire with the same outer diameter can meet the tasks of long-time, high-rotating-speed and stable transmission, the mass ratio of the sheath tube to the flexible driving shaft is controlled, and the vibration of the flexible transmission system can be reduced, in the invention, the sheath tube is considered to be controlled to be as small as possible to reduce the damage to the blood vessel of a human body, the weight ratio is controlled to be between 6 and 351, the vibration is not felt when the catheter runs, and when the braided structure of 3*1, 5*1, 6*1, 7*1, 7*7, 8*1, 9*1 or 37 x 1 is adopted, even if the mass ratio of the sheath tube to the flexible driving shaft is as low as 6, the effect of reducing the vibration load can be very good.

The average curvature radius of a normal adult aortic arch is about 47.5mm, but the curvature radius of each individual is different, in addition, for a flexible transmission system rotating at a high speed for a long time, certain bending can happen due to unexpected stress outside the body, certain current signal disturbance is generated to a motor, the disturbance can influence the estimation of flow, when the gap between a flexible driving shaft and a sheath tube is controlled to be 10% -90% of the diameter of the driving shaft, or 0.05mm-0.41mm, the curvature radius of the transmission system is even as low as 35mm, no obvious influence is caused to the current signal of the motor, and most of the conditions in clinical application are met. Therefore, the invention can control the mass ratio between the sheath tube and the driving shaft through the material structure design of the flexible driving shaft and the sheath tube and the matching design between the flexible driving shaft and the sheath tube, in particular the gap between the sheath tube and the driving shaft, so that the vibration of the transmission system can not be felt when the motor rotates at high speed, and the patient can feel more comfortable and safer when using the motor.

Drawings

FIG. 1 is a schematic diagram of a flexible drive system with an electric motor coupled thereto in an embodiment of the invention;

FIGS. 2-1, 2-2, 2-3, 2-4, 2-5 are schematic cross-sectional views of braided skeins using the braid structures 2*1, 3*1, 7*1, 12 x 1, 37 x 1, respectively, of embodiments of the present invention;

FIG. 3 is a schematic diagram of a percutaneous assisted pumping device according to an embodiment of the invention;

FIG. 4 is a schematic diagram illustrating connection control of a percutaneous assisted blood pumping device according to an embodiment of the present invention;

FIG. 5 is a schematic cross-sectional view of a hub of a blood pumping impeller according to an embodiment of the present invention;

FIG. 6 is a schematic view of the overall structure of a blood pumping impeller according to an embodiment of the present invention;

FIG. 7 is a schematic view showing a blade plane of a blood pumping impeller according to an embodiment of the present invention;

FIG. 8 is a schematic illustration of a hub and flow field variation of the present invention;

FIG. 9 is a schematic view of a segmented progressive continuous vane of a blood pumping impeller in accordance with an embodiment of the present invention;

FIG. 10 is a flow-head comparison of a pump impeller of the present invention with a conventional impeller;

FIG. 11 is a schematic view of a blade angle definition;

FIG. 12 is a schematic view showing the structure of an intravascular thrombus aspiration system of the present invention;

fig. 13 is a schematic view showing the operation of the intravascular thrombus aspiration system of the present invention.

In the figure:

1 Pump catheter 2 drive Module 3 control Module

4 flexible transmission system 5 signal wire 6 axial flow wheel hub section

7 diagonal flow hub section 8 continuous blade 9 axial flow blade

10 diagonal flow vane 11 blood flow channel 12 blood pumping impeller

13 in-vivo inner joint 14 outflow window

21 drive motor 22 support housing 23 motor

31 controller 32 electrical system

41 sheath 42 drive shaft 43 constraining layer

61 axial flow hub front section 62 axial flow hub rear section

91 axial inlet blade 92 axial body blade

100 suction catheter 200 screen 300 impeller

101 blood inlet 102 blood outlet 103 blood flow channel

400 sheath 41 500 blood vessel 600 thrombus

700 blood

Detailed Description

The invention is further described below with reference to the drawings and examples.

Referring to fig. 1, the flexible transmission system provided by the invention comprises a flexible driving shaft 42 positioned at an inner layer and a sheath 41 positioned at the outer side of the flexible driving shaft 42, wherein perfusate is filled between the flexible driving shaft 42 and the sheath 41, and the flexible driving shaft 42 is a round strand woven twisted wire formed by weaving at least 2 strands of metal wires, preferably 6-37 strands of metal wires; the sheath 41 is composed of a hollow metal spiral pipe, a polymer pipe or a composite pipe. The diameter of the flexible driving shaft ranges from 0.15mm to 0.6mm; preferably 0.36mm-0.51mm, the structure of the round strand braided twisted wire is described by the number of strands (M) and the number of wires (N), the braided structure is expressed by m×n, the braided twisted wire has M (M is an integer greater than or equal to 2) strands, each strand has N (N is an integer greater than or equal to 1) wires, such as 3*1, 5*1, 6*1, 7*1, 7*7, 8*1, 9*1 or 37×1, etc., and the cross-sectional structures of 2*1, 3*1, 7*1, 12×1, 37×1 are respectively listed in fig. 2-1 to 2-5.

The flexible transmission system provided by the invention has the mass ratio of the sheath tube 41 to the flexible driving shaft 42 of 6-351, preferably 9-34; the gap between the flexible drive shaft 42 and the sheath 41 is preferably 0.05mm-0.41mm.

Example 1

The flexible transmission system 4 is formed by taking an L605 twisted wire with the diameter of 0.15mm and the length of 1100mm and the 3*1 as a weaving structure as a driving shaft 42, taking a sheath tube 41 with the inner diameter of 0.2mm, the outer diameter of 3.0mm and the length matched with the driving shaft 42, wherein the sheath tube 41 is formed by a hollow spiral tube and an outer layer closed polymer tube. The two ends of the transmission system are respectively connected with the external driving module 2 and the blood pumping impeller 12, the driving module 2 can be a motor 23, and the flexible transmission system 4 is filled with perfusate. The weight of the drive shaft 42 is about 0.15g, the weight of the sheath 41 is about 54g, and the weight ratio of the sheath 41 to the drive shaft 42 is about 351; after the motor 23 climbs to 50000 rpm at 2000 rpm, the continuous running vibration is small, the vibration of the flexible transmission system 4 is not perceived, and the vibration displacement is less than 0.001mm.

Example 2

The flexible transmission system 4 is formed by taking an L605 twisted wire with the diameter of 0.36mm and the length of 1200mm and a braided structure of 7*1 as a driving shaft 42, taking a PTFE tube with the inner diameter of 0.56mm and the outer diameter of 2.1mm and the length of the driving shaft 42 matched with the driving shaft 42 as a sheath tube 41. The two ends of the flexible transmission system 4 are respectively connected with an external motor 23 and a blood pumping impeller 12, and the flexible transmission system 4 is filled with perfusate. The weight of the drive shaft 42 is about 0.97g, the weight of the sheath 41 is about 8.9g, and the weight ratio of the sheath 41 to the drive shaft 42 is about 9; after the motor 23 climbs to 40000 rpm at 2000 rpm, the continuous running vibration was small, the vibration of the flexible transmission system 4 was not perceived, and the vibration displacement was less than 0.001mm.

Example 3

The flexible transmission system 4 is formed by taking a 304 stainless steel wire with the diameter of 0.46mm and the length of 1400mm and a 12 x 1 as a weaving structure as a driving shaft 42, taking a sheath tube 41 with the inner diameter of 0.87mm and the outer diameter of 3.0mm and the length matched with the shaft 42 of the driving shaft 42, wherein the sheath tube 41 has a two-layer structure, the inner layer is a spiral tube formed by processing 304 stainless steel, and the outer layer is a PU tube. Two ends of the flexible transmission system 4 are respectively connected with an external motor and a blood pumping impeller, and the flexible transmission system 4 is filled with perfusion fluid. The weight of the drive shaft 42 is about 1.85g, the weight of the sheath 41 is about 63.4g, and the weight ratio of the sheath 41 to the drive shaft 42 is about 34; after the motor 23 climbs to 45000 rpm at 2000 rpm, the continuous running vibration is small, the vibration of the flexible transmission system 4 is not perceived, and the vibration displacement is less than 0.001mm.

Example 4

The flexible transmission system 4 is formed by taking MP35N twisted wires with the diameter of 0.52mm and the length of 1300mm and taking 37 x 1 as a weaving structure as a driving shaft 42, taking a sheath tube 41 with the inner diameter of 0.57mm and the outer diameter of 2.7mm and the length of the driving shaft 42 being matched with the driving shaft 42, wherein the sheath tube 41 has a two-layer structure, the inner layer is a spiral tube formed by processing 304 stainless steel, and the outer layer is a PU tube. The two ends of the flexible transmission system 4 are respectively connected with an external motor 23 and a blood pumping impeller 12, and the flexible transmission system 4 is filled with perfusate. The weight of the drive shaft 42 is about 2.2g, the weight of the sheath 41 is about 28.4g, and the weight ratio of the sheath 41 to the drive shaft 42 is about 13; after the motor 23 climbs to 45000 rpm at 2000 rpm, the continuous running vibration is small, the vibration of the flexible transmission system 4 is not perceived, and the vibration displacement is less than 0.001mm.

Example 5

The flexible transmission system 4 is formed by taking an L605 twisted wire with the diameter of 0.46mm and the length of 1200mm and taking 37 x 1 as a weaving structure as a driving shaft 42, taking a PTFE tube with the inner diameter of 0.50mm and the outer diameter of 2.2mm and the length of the driving shaft 42 matched with the driving shaft 42 as a sheath tube 41. The two ends of the flexible transmission system 4 are respectively connected with an external motor 23 and a blood pumping impeller 12, and the flexible transmission system 4 is filled with perfusate. The weight of the drive shaft 42 is about 1.58g, the weight of the sheath 41 is about 9.9g, and the weight ratio of the sheath 41 to the drive shaft 42 is about 6.2; after the motor 23 climbs to 40000 rpm at 2000 rpm, the continuous running vibration was small, the vibration of the flexible transmission system 4 was not perceived, and the vibration displacement was less than 0.002mm.

Example 6

The flexible transmission system 4 is formed by taking MP35N twisted wires with the diameter of 0.6mm and the length of 1200mm and taking 37 x 1 as a weaving structure as a driving shaft 42, taking a sheath tube 41 with the inner diameter of 0.66mm and the outer diameter of 2.7mm and the length of the driving shaft 42 being matched with the driving shaft 42, wherein the sheath tube 41 has a two-layer structure, the inner layer is a spiral tube formed by processing 304 stainless steel, and the outer layer is a PU tube. The two ends of the flexible transmission system 4 are respectively connected with an external motor 23 and a blood pumping impeller 12, and the flexible transmission system 4 is filled with perfusate. The weight of the drive shaft 24 is about 2.69g, the weight of the sheath 41 is about 25.92g, and the weight ratio of the sheath 41 to the drive shaft 42 is about 9.6; after the motor 23 climbs to 45000 rpm at 2000 rpm, the continuous running vibration is small, the vibration of the flexible transmission system 4 is not perceived, and the vibration displacement is less than 0.001mm.

Example 7

The flexible transmission system 4 is formed by taking MP35N twisted wires with diameters of 0.6mm and lengths of 1200mm and different braiding structures as a driving shaft 42, taking a sheath tube 41 with inner diameter of 0.66mm and outer diameter of 2.8mm and the lengths of the driving shaft 42 being matched with the driving shaft 42, wherein the sheath tube 41 is a PTFE tube. The two ends of the flexible transmission system 4 are respectively connected with an external motor 23 and a blood pumping impeller 12, and the flexible transmission system 4 is filled with perfusate. The weight of the drive shaft 42 is about 2.69g, the weight of the sheath 41 is about 16.04g, and the weight ratio of the sheath 41 to the drive shaft 42 is about 6; the motor 23 is continuously operated after climbing up to 45000 rpm at 2000 rpm, the knitting structures are 2*1, 3*1, 5*1, 6*1, 7*1, 8*1, 9*1, 12×1 and 37×1, the vibration displacement of the flexible transmission system 4 using 2*1 knitting twisted wires as the driving shaft 42 is about 0.005mm, and the vibration displacement of the flexible transmission system 4 using other knitting twisted wires as the driving shaft 42 is less than 0.002mm.

Example 8

The flexible transmission systems 4 in examples 1-6 are sequentially and partially put into semicircular models with the curvature radiuses of 35mm, 40mm and 55mm, and run at the rotation speed of 33000 r/min, and the average current in the motor Hall sensor during running is recorded, wherein the change of the curvature radiuses of examples 1-4 and example 6 is less than 10% of the disturbance on the motor current, and the change of the curvature radiuses of example 5 is about 15% of the disturbance on the motor current.

In the above embodiment, the flexible driving shaft 42 may be coated with a coating layer with a lubrication function, such as PTFE or Parylene, and a constraining layer 43 may be disposed in the sheath 41, where the constraining layer 43 is mainly used to limit the swing amplitude of the flexible driving shaft 42.

The flexible transmission system 4 provided by the invention can be applied to a percutaneous auxiliary blood pumping device with a driving module positioned outside the body and an intravascular thrombus aspiration system, and the details are respectively described below.

FIG. 3 is a schematic diagram of a percutaneous assisted blood pumping device according to the present invention; fig. 4 is a schematic diagram illustrating connection control of a percutaneous assisted blood pumping device according to an embodiment of the invention.

Referring to fig. 3 and 4, the percutaneous assisted pumping device provided by the present invention includes a percutaneous implantable pumping catheter 1, an extracorporeal driving module 2 and an extracorporeal control module 3. The pumping catheter 1 is a miniature blood pump implantable through femoral artery, and comprises a blood flow channel 11 for communicating the left ventricle and the aorta of a patient and a pumping structure (a pumping impeller 12) containing impellers, and the tail end of the pumping catheter 1 is connected with the driving module 2 through a flexible transmission system 4. When in use, the driving module 2 is positioned outside the body and comprises a driving motor 21, the far end of the driving module 2 is connected with the blood pumping catheter 1 through the flexible transmission system 4, and the near end of the driving module 2 is connected with the control module 3 through the signal wire 5; when in use, the control module 3 is positioned outside the body and comprises an embedded controller 31 and an electrical system 32, the driving module 2 is connected with the control module 3 through a signal wire 5, and control system software is loaded in the driving module and a man-machine interaction interface is provided.

The percutaneous auxiliary blood pumping device provided by the invention has the following working processes: when the intelligent control system starts to be used, control parameters are input to the control module 3 through a man-machine interface and are converted into operation parameters by the embedded controller 31; the embedded controller 31 sends a driving signal to the driving module 2 through the signal line 5 during operation, and controls the driving motor 21 in the driving module 2 to operate according to the set operation parameters; the driving module 2 transmits the rotation torque to a blood pumping impeller 12 in the blood pumping catheter 1 through a flexible transmission system 4, and the blood pumping impeller 12 rotates under the drive of the flexible transmission system 4 to pump blood in the left ventricle into the aorta; finally, the driving module 2 feeds back the actual running state signal of the motor to the control module 3 for forming closed loop control and monitoring the running state of the blood pump in real time.

The blood pumping catheter 1 comprises a blood flow inlet, a blood flow channel 11, a blood pumping impeller 12, a blood flow outlet and a bridging structure. Wherein the blood flow inlet, the blood flow channel 11 and the blood flow outlet form a valve crossing channel through which blood flows; the valve-crossing channel and the blood pumping impeller 12 in the channel form a miniature blood pump, and blood can be actively induced to be sucked in through the blood flow inlet through the impeller rotation and pumped out through the blood flow outlet after flowing through the blood flow channel 11; the blood pumping impeller 12 is connected with a driving shaft 42 in the flexible transmission system 4 through a bridging structure, and rotates under the driving of the driving shaft 42.

The flexible transmission system 4 is a torque transmission structure between the driving module 2 and the pumping catheter 1, and comprises a driving shaft 42 and a sheath 41 from a bridge joint in the driving module 2 to the bridge joint of the pumping catheter 1. The sheath 41 is a rear catheter providing a transmission lumen for the drive shaft 42, and the drive shaft 42 is the braided wire provided in examples 1-8. The flexible drive system 4 preferably has a length in the range of 80cm to 200cm, which is effective for transmitting drive torque even in an irregular complete condition.

The drive module 2 comprises a support housing 22, a drive motor 21 and a bridging structure. The support housing 22 includes cooling structure therein while providing a fixed space for the drive motor 21 and bridging structure. The distal end of the bridge structure is connected to a drive shaft 42 in the flexible drive train 4 and the proximal end of the bridge structure is connected to the distal shaft of the drive motor 21. In operation, the bridge structure is driven by the drive motor 21 to rotate and drive the drive shaft 42. The driving motor 21 is a terminal power source for driving the blood pumping impeller 12 to rotate, and can be an electric motor or a pneumatic motor; the control module 3 includes an embedded controller 31, an electrical system 32, and system software mounted on the controller 31. The embedded controller 31 is connected with the driving module 2 through a signal wire 5, and transmits and receives the operation parameters of the motor in the driving module 2; the system software is used for setting system operation parameters, controlling the system to operate and displaying the operation state of the pump blood conduit 1 in real time.

The pumping impeller 12, including hub and blades, may be an axial flow impeller, a diagonal flow impeller, or a combination of an axial flow impeller and a diagonal flow impeller; in an embodiment, please refer to fig. 5 and 6, the hub is formed by matching an axial flow hub section 6 and an oblique flow hub section 7 according to a certain length proportion in the axial direction of the impeller, when the impeller rotates to pump blood, the front end of the impeller is sucked in an axial flow manner, the rear end of the impeller is pumped out in an oblique flow manner, the pump blood flow and the lift are ensured by applying work to the blood through two modes of axial pressure difference at the front end and rear end centrifugation, meanwhile, an oblique flow diffusion structure at the rear end of the oblique flow hub section 7 is matched with an outflow window 14 to form an outflow channel, so that the blood is stably transited in an oblique flow manner from the axial flow direction and pumped out from two sides of the pump body to ensure the blood compatibility of the miniature blood pump. The length matching proportion range of the axial flow hub section 6 and the diagonal flow hub section 7 in the axial direction is preferably 9:1-1:1; preferably, the length matching ratio of the diagonal flow hub section 7 and the outflow window 14 in the axial direction is 0.5:1-3:1, preferably 1.2:1-1.5:1. The hub is preferably a three-section hub structure, namely the axial flow hub section 6 comprises an axial flow hub front section 61 and an axial flow hub rear section 62, and the hub ratio of the axial flow hub rear section 62 is 0.25-0.6, preferably 0.35-0.45; the diameter of the diagonal flow hub section 7 gradually increases from the distal end to the proximal end, the diameter of the diagonal flow hub section 7 can be linearly gradually changed, or the diameter of the diagonal flow hub section 7 can be gradually increased along a specific curve of a certain formula, the distal end diameter of the diagonal flow hub section 7 is the same as the hub diameter of the axial flow hub rear section 62, and the diameter of the diagonal flow hub section 7 is increased to the maximum value at the proximal end and is the same as the impeller outer diameter D. The axial-flow hub front section 61 serves as an inlet-section hub, and the outer diameter of the axial-flow hub front section 61 gradually increases from the distal end to the proximal end to be the same as the diameter of the axial-flow hub rear section 62, and the axial-flow hub front section 61 may be a bullet-shaped tip, a linear gradual-change-type tip, a spherical dome, or a tip of an approximately spherical dome obtained by rounding the outer edge of a cylinder. The bullet-shaped tip refers to a dome-shaped conical tip.

Referring to fig. 6-9, the vane structure of the impeller 12 is comprised of at least one vane having a continuous distal axial flow section to a proximal diagonal flow section and a smooth transition in vane angle. Firstly, the continuous blades 8 are divided into an axial flow section (axial flow blades 9) and a rear guide vane section (diagonal flow blades 10) which respectively correspond to the axial flow hub section 6 and the diagonal flow hub section 7 in the hub structure, and secondly, the axial flow blades 9 are formed by matching an inlet section and a main body section in an axial direction according to a certain length proportion. Thus, from distal to proximal, the continuous blade 8 is preferably divided into an axial inlet blade 91, an axial main blade 92, and a diagonal flow blade 10, with the blade angle increasing gradually.

Referring to fig. 11, the blade angle is the angle between the tangential line of the blade bone line along the direction of the liquid flow in the impeller and the direction of the peripheral velocity, and different blade angles provide the blades with different fluid characteristics, as shown in fig. 7. The small blade angle at the far end of the impeller prevents cavitation, blood is sucked into the impeller through a more stable flow field, and the blade angle range of the inlet section axial flow inlet blade 91 is 5-65 degrees; the main section axial flow main body blades 92 form a main flow channel, do work on blood, and the blade angle range of the axial flow main body blades 92 is 30-70 degrees; the tail end rear guide vane section diagonal flow blade 10 converts the rotational kinetic energy of the blood pumped by the main body section into pressure energy, and the blade angle range of the diagonal flow blade 10 is 55-85 degrees. The blade angles of each segment can be fixed or continuously variable. The engagement angle is based on the angle of the axial flow main body blade 92 when the blade angle is continuously gradually changed, and the blade angle of the proximal end of the axial flow inlet blade 91 is the same as the blade angle of the distal end of the axial flow main body blade 92, and the blade angle of the distal end of the diagonal flow blade 10 is the same as the blade angle of the proximal end of the axial flow main body blade 92. The manner in which the blade angle is tapered may be a linear taper or an exponential taper. The thickness of the continuous blade 8 may be constant or have certain airfoil characteristics; preferably, the blade thickness is no more than 0.8mm; the hub can be loaded with 1 or more than 1 continuous blade 8, and the preferable number of blades is 2-4. The hub structure provides superior pumping efficiency in the micro blood pump field relative to conventional pure axial flow and diagonal flow impellers. Meanwhile, the flow field characteristics of the axial flow suction diagonal flow pump are more in line with the structural characteristics of the miniature blood pump based on catheter implantation, so that more stable flow field distribution and more excellent blood compatibility are provided while the blood pumping efficiency is ensured. The vane structure simplifies the whole structure, reduces the processing difficulty, ensures the blood pumping efficiency, and improves the blood compatibility of the impeller.

The percutaneous auxiliary blood pumping device actively assists heart blood pumping of a patient through the blood pumping catheter 1 implanted in the body, and improves blood circulation of the patient before, during and after operation. The system realizes the pumping catheter driven by the external active driving module through the flexible driving system 4 and the torque transmission structure, completely avoids the biocompatibility risk caused by the active components entering the body, and transfers a rigid structure in the pumping catheter to the outside, which significantly influences the operation difficulty. Meanwhile, the driving module located outside the body relaxes the volume limitation, larger driving power can be realized through larger motor specifications, the complexity and cost of the driving module are obviously reduced due to the amplification of the module volume, and meanwhile, the running stability is improved. Finally, the driving module located outside the patient does not need to consider the influence of running heat dissipation on the blood environment in the patient, and meanwhile, a more effective heat dissipation structure with a more indirect structure can be adopted, so that the system cost is reduced, the temperature state of the motor is effectively controlled, and further, the more stable running performance is obtained.

Example 9

The driving motor 21 adopts an electric motor, the control module 3 provides a driving signal machine power supply for the driving module 2, and the driving module 2 feeds back the running state of the motor, such as the rotating speed of a rotor and the current, for forming closed-loop control; the control module 3 adopts an embedded hardware platform, is carried by an operating system, can be operated by a human-computer interaction interface monitoring system, and comprises the operation state of the driving module 2 and the auxiliary blood pumping flow of the blood pumping catheter 1. The embedded controller 31 is driven by an ac power supply, and supplies dc power to the drive module 2 and the pump catheter 1. The driving module 2 is connected with the control module 3 through a signal wire 5, and the near end of the signal wire 5 is a quick connector which is connected with a signal port on the controller 31. The controller 31 supplies a driving power source and a control signal to the driving module 2 through the signal line 5. In the driving module 2, the signal wire 5 is directly connected with a motor to drive the motor to rotate. In this embodiment, the driving motor is a direct current hollow cup motor with hall, and is loaded in the fixed structure of the driving module 2, and drives the transmission structure to rotate under the driving of the control signal, and meanwhile, the hall signal is fed back to the control module 3 through the signal line 5 to enable the controller 31 to estimate the actual rotation speed so as to form closed loop control. In the control module 3, a quick connection structure is arranged between the transmission structure and the flexible transmission system 4, when the motor in the driving module 2 runs, the transmission guide wire in the flexible transmission system 4 is driven to rotate, torque is transmitted to the blood pumping catheter 1, and the blood pumping impeller 12 in the blood pumping catheter 1 is driven to rotate, so that an auxiliary blood pumping function is realized.

Example 10

The driving motor 21 adopts a pneumatic motor, the support shell 22 also comprises an additional speed measuring structure, an exhaust structure and a noise reduction structure, the control module 3 outputs a control signal to the driving module 2 for controlling the output air pressure of the air source to control the rotating speed of the steam turbine, and meanwhile, the speed measuring structure feeds back the actual rotating speed of the steam turbine to form closed loop control. In this embodiment, the driving module 2 is composed of a driving turbine, an air source, an electromagnetic valve, a speed measuring structure and a noise reducing structure. The air source provides driving power, the controller 31 controls air supply air pressure of the air source by controlling the switch of the electromagnetic valve so as to adjust the rotating speed of the steam turbine, the speed measuring structure adopts laser speed measuring to send, the real-time rotating speed is fed back to the controller 31 so as to form closed-loop control, and the steam turbine is connected with the flexible transmission system 4 through the switching structure so as to drive the blood pumping impeller 12 in the blood pumping conduit 1 to realize the auxiliary blood pumping function.

Example 11

In this embodiment, a 4mm miniature blood pump impeller employs 6:1, a hub ratio of 0.4, a three-section continuous blade with blade angles of 30 degrees, 60 degrees and 85 degrees, and a length ratio of the diagonal flow section to the outflow window of 1:1. under the condition of 60mmHg pressure difference in CFD simulation, pump blood flows of 1.0L/min, 2.5L/min and 3.5L/min can be respectively realized at 3 ten thousand rpm, 4 ten thousand rpm and 5 ten thousand rpm.

Under the same impeller specification and CFD simulation conditions, a hub with a traditional axial flow structure and a single 60-degree axial flow blade are adopted, but the hub with an oblique flow section and gradual change is provided with a contrast impeller with a back expansion section, and the blood flow of pumps of 0.5L/min, 1.0L/min and 2.0L/min can be respectively realized at 3 ten thousand rpm, 4 ten thousand rpm and 5 ten thousand rpm.

Under the same impeller specification and CFD simulation conditions, a hub with a traditional axial flow structure, a single 60-degree axial flow blade and another control impeller without an oblique flow section are adopted, and the blood flow of 0.2L/min, 0.7L/min and 1.8L/min can be respectively realized at 3 ten thousand rpm, 4 ten thousand rpm and 5 ten thousand rpm.

In the above embodiment, the flow-lift curves of the impeller and the control impeller at different rotation speeds are compared with each other, as shown in fig. 10, and the flow-lift curves of the impeller at 50000 rpm, 40000rpm and 30000rpm are respectively from top to bottom in fig. 10. Under the same rotation speed and pressure difference conditions, the pumping performance of the impeller is respectively improved to 250% and 357% of the design of the control impeller under the operating state of 40000rpm by comparing the axial flow impeller adopting the post-expansion section hub with the traditional axial flow impeller.

Example 12

In the embodiment, the miniature blood pump impeller adopts a three-section type hub structure and three-section type variable blades, the pump impeller flows out of the side face matched with the blood flow channel, the front end of the axial flow section adopts a bullet type gradual change diameter, and the diameter of the oblique flow section is converted into a backward expansion curve according to an exponential curve. The impeller adopts 6:1, a hub ratio of 0.4, a three-section continuous gradual change blade with blade angles of 20 degrees, 60 degrees and 85 degrees, and a length ratio of an oblique flow section to an outflow window of 1.3:1. in CFD simulation, pump blood flows of 1.4L/min, 2.3L/min and 3.5L/min were respectively achieved at 3 ten thousand rpm, 4 ten thousand rpm and 5 ten thousand rpm under a pressure difference of 60 mmHg.

Under the same impeller specification and CFD simulation conditions, the same hub structural design is adopted, the blades are continuous blades with fixed blade angles, and the pump blood flow of 1.0L/min, 1.6L/min and 2.5L/min can be respectively realized at 3 ten thousand rpm, 4 ten thousand rpm and 5 ten thousand rpm.

In the embodiment, under the conditions of the same rotating speed and pressure difference, the impeller pump blood performance of the invention is compared with the impeller design adopting the same hub structure to fix the blade angle, and the pump blood performance is increased to 144% of the compared impeller design under the operating state of 40000 rpm.

Example 13

Fig. 12 is a schematic view showing the structure of the intravascular thrombus aspiration system of the present invention.

Referring to fig. 12, the intravascular thrombus aspiration system provided in this embodiment includes an aspiration catheter 100 that can be percutaneously implanted in a human body and a driving module 2 located outside the body, the aspiration catheter 100 includes a blood inlet 101, a blood flow channel 103 and a bleeding port 102, a filter screen 200 is disposed in the blood flow channel 103 of the aspiration catheter 100, and a rotatable impeller 300 is disposed between the filter screen 200 and the bleeding port 102 or at the bleeding port 102; the impeller 300 is connected to the drive module 2. Preferably, the mesh area of the filter screen 200 is in the range of 0.1mm ² -16mm ² 。

In the intravascular thrombus aspiration system provided in this embodiment, the driving module 2 is located outside the body and is separately disposed from the aspiration catheter 100, the impeller 300 is driven by the driving module 2, the distal end of the driving module 2 is connected to the aspiration catheter 100 through the flexible transmission system 4, and the proximal end of the driving module 2 is connected to the control module through the signal line. The flexible drive system 4 comprises a drive shaft 42 and a sheath 41 providing a drive chamber for the drive shaft 42, the drive shaft 42 being connected to the impeller 300 by a bridging structure. Preferably, the length of the flexible transmission system 4 ranges from 80cm to 200cm, and the drive shaft 42 is the braided skein provided in embodiments 1-8. The drive module 2 comprises a support housing, a drive motor and a bridging structure, the distal end of the drive module bridging structure is connected with a drive shaft 42 in the flexible transmission system 4, and the proximal end of the drive module bridging structure is connected with the rotating shaft of the drive motor.

In this embodiment, the driving motor may be an air motor or an electric motor, when the driving motor is an air motor, a cooling structure, a speed measuring structure, an exhaust structure and a noise reduction structure are further disposed in the supporting housing, the control module outputs a control signal to the driving module to control the output air pressure of the air source to control the turbine speed, and meanwhile, the speed measuring structure feeds back the actual turbine speed to form closed-loop control. When the driving motor is an electric motor, a cooling structure is further arranged in the supporting shell, the control module provides a driving signal machine power supply for the driving module, and the driving module feeds back the running state of the motor.

The control module comprises a controller main body, an electrical system and system software carried by the controller, and is provided with a man-machine interaction interface; the controller main body is connected with the driving module through a signal wire, and the controller main body transmits and receives the operation parameters of the motor in the driving module; the system software is used for setting system operation parameters, controlling system operation and monitoring the operation state of the suction catheter in real time.

Referring to fig. 13, when the operation is started, control parameters are input to the controller through the human-computer interface and converted into operation parameters by the controller; the controller sends a driving signal to the driving module through a signal line during operation, and controls a motor in the driving module to operate according to the set operation parameters; the drive module transmits rotational torque to the impeller 300 in the aspiration catheter 100 through the flexible transmission system, the impeller 300 rotates, blood is sucked from the blood inlet 101 together with the thrombus 600, and when passing through the filter screen 200, the blood normally flows out of the blood outlet 102 and enters the blood circulation system, and the thrombus 600 remains on the filter screen 200. As the aspiration catheter 100 is moved out of the body, the thrombus 600 follows the aspiration catheter 100 out of the body.

Thus, aspiration catheter 100 is percutaneously advanced into a thrombosed artery or vein. When the driving device rotates at a high speed, the impeller 300 is driven to rotate at a high speed, a negative pressure area is formed at the blood inlet 101, blood containing thrombus 600 is sucked into the suction catheter 100, and when the blood passes through the filter screen 200, the blood 700 can pass through, but the thrombus 600 larger than the mesh of the filter screen 200 cannot pass through, so that the thrombus 600 and the blood 700 can be separated, and the blood 700 returns to the blood vessel 500 through the bleeding opening 102. Compared with the thrombus taking modes such as a balloon stent, the intravascular thrombus sucking system provided by the embodiment does not need to block blood flow, adopts a negative pressure sucking mode, is safer to take, and does not worry about rupture and falling. Compared with the prior art of aspiration catheter, when the intravascular thrombus aspiration system provided by the present embodiment is used, the blood of the patient returns to the blood circulation after passing through the filter screen 200 without blood loss, and the thrombus is removed together when the aspiration catheter 100 is withdrawn from the body.

While the invention has been described with reference to the preferred embodiments, it is not intended to limit the invention thereto, and it is to be understood that other modifications and improvements may be made by those skilled in the art without departing from the spirit and scope of the invention, which is therefore defined by the appended claims.

Claims

1. The percutaneous auxiliary blood pumping device comprises a driving module, a control module and a blood pumping catheter which can be implanted into a human body through the skin, wherein the driving module is arranged outside the body and is separated from the blood pumping catheter, the distal end of the driving module is connected with the blood pumping catheter through a flexible transmission system, and the proximal end of the driving module is connected with the control module through a signal wire;

the flexible driving shaft is connected with a blood pumping impeller in the blood pumping catheter through a bridging structure, the blood pumping impeller comprises a hub and blades, and the hub is composed of a distal axial flow hub section and a proximal diagonal flow hub section; the axial flow hub section comprises an axial flow hub front section and an axial flow hub rear section, the outer diameter of the axial flow hub front section is gradually increased from the far end to the near end to be the same as the diameter of the axial flow hub rear section, the hub diameter of the diagonal flow hub section is gradually increased from the far end to the near end, the diameter of the far end of the diagonal flow hub section is the same as the hub diameter in the axial flow hub rear section, and the diameter of the near end of the diagonal flow hub section is the same as the outer diameter of the impeller;

The blade is at least one continuous blade, the continuous blade comprises an axial flow blade and an oblique flow blade from a far end to a near end, the axial flow blade is correspondingly arranged on a hub of the axial flow hub section, the oblique flow blade is correspondingly arranged on the hub of the oblique flow hub section, the axial flow blade comprises an axial flow inlet blade and an axial flow main body blade from the far end to the near end, and the blade angle of the continuous blade is gradually increased from the far end to the near end.

2. The percutaneous auxiliary blood pumping device of claim 1, wherein the flexible drive shaft has a diameter in the range of 0.15mm to 0.6mm.

3. The percutaneous auxiliary blood pumping device of claim 2, wherein the flexible drive shaft has a diameter in the range of 0.36mm to 0.51mm and is a round strand braided twisted wire.

4. The percutaneous assisted pumping device of claim 1, wherein the flexible drive shaft is in a braided configuration of 3*1, 5*1, 6*1, 7*1, 8*1, 9*1, or 37 x 1.

5. The percutaneous assisted pumping device of claim 1, wherein the sheath and flexible drive shaft have a mass ratio of 6-351:1.

6. the percutaneous auxiliary blood pumping device of claim 1, wherein a gap between the flexible drive shaft and the sheath is 0.05mm to 0.41mm.

7. The percutaneous assisted pumping device of claim 1, wherein the axial flow hub section and the diagonal flow hub section have a length ratio in the axial direction ranging from 9:1 to 1:1, the diagonal flow hub section proximal diagonal flow diffusion structure and the outflow window cooperate to form an outflow channel, and the diagonal flow hub section and the outflow window have a length ratio in the axial direction ranging from 0.5:1 to 3:1, a step of; the hub ratio in the rear section of the axial flow hub is 0.25-0.6: 1, a step of; the outer diameter of the blood pumping impeller is smaller than 10mm.

8. The percutaneous auxiliary blood pumping apparatus according to claim 1, wherein the axial flow inlet blades have a blade angle in the range of 5 ° to 65 °, the axial flow main body blades have a blade angle in the range of 30 ° to 70 °, and the diagonal flow blades have a blade angle in the range of 55 ° to 85 °.

9. The percutaneous auxiliary pumping device of claim 1, wherein the blade angles of the successive blade segments are continuously variable, the blade angle at the proximal end of the axial flow inlet blade being the same as the blade angle at the distal end of the axial flow body blade, and the blade angle at the distal end of the diagonal flow blade being the same as the blade angle at the proximal end of the body segment.

10. An intravascular thrombus sucking system comprises a sucking catheter which can be implanted into a human body through skin and a driving module which is positioned outside the human body, wherein the sucking catheter comprises a blood inlet, a blood flow channel and a bleeding port, a filter screen is arranged in the blood flow channel of the sucking catheter, and an impeller is arranged between the filter screen and the bleeding port or at the bleeding port; the impeller is connected with the driving module; the distal end of the driving module is connected with the suction catheter through a flexible transmission system, and the proximal end of the driving module is connected with the control module through a signal wire; the flexible transmission comprises a flexible driving shaft positioned at an inner layer and a sheath pipe positioned at the outer side of the flexible driving shaft, wherein perfusate is filled between the flexible driving shaft and the sheath pipe, the flexible driving shaft is a braided twisted wire formed by braiding at least 2 strands of metal wires, and the sheath pipe consists of a hollow metal spiral pipe, a high polymer pipe or a composite pipe; the flexible driving shaft is connected with the impeller through a bridging structure;

The driving module comprises a supporting shell, a driving motor and a bridging structure, wherein the distal end of the driving module bridging structure is connected with a flexible driving shaft in the flexible transmission system, and the proximal end of the driving module bridging structure is connected with a rotating shaft of the driving motor.

11. The endovascular thrombus aspiration system of claim 10, wherein the drive motor is an air motor, a cooling structure, a speed measurement structure, an exhaust structure and a noise reduction structure are further disposed in the support housing, the control module outputs a control signal to the drive module to control the output air pressure of the air source to control the turbine speed, and the speed measurement structure feeds back the actual turbine speed to form a closed loop control.

12. The intravascular thrombus aspiration system of claim 10 wherein the drive motor is an electric motor and a cooling structure is further disposed within the support housing, the control module providing drive signal power to the drive module, the drive module feeding back the operating state of the motor.

13. The endovascular thrombus aspiration system of claim 10, wherein the control module comprises a controller body, an electrical system, and controller-onboard system software, and has a human-machine interface; the controller main body is connected with the driving module through a signal wire, and the controller main body transmits and receives the operation parameters of the motor in the driving module; the system software is used for setting system operation parameters, controlling system operation and monitoring the operation state of the suction catheter in real time.

14. The endovascular thrombus aspiration system of claim 10 wherein the screen has a mesh area in the range of 0.1mm ² -16mm ² 。

15. The endovascular thrombus aspiration system of claim 10, wherein the flexible drive shaft has a diameter in the range of 0.15mm to 0.6mm.

16. The endovascular thrombus aspiration system of claim 15 wherein the flexible drive shaft has a diameter in the range of 0.36mm to 0.51mm and is a round strand braided wire.

17. The endovascular thrombus aspiration system of claim 10, wherein the flexible drive shaft adopts a braided structure of 3*1, 5*1, 6*1, 7*1, 8*1, 9*1 or 37 x 1.

18. The intravascular thrombus aspiration system of claim 10 wherein the mass ratio of sheath to flexible drive shaft is 6-351:1.

19. the endovascular thrombus aspiration system of claim 10, wherein the gap between the flexible drive shaft and the sheath is 0.05mm-0.41mm.