CN111632217A - A ventricular circulatory aid device with an intermediate impeller - Google Patents

Abstract

The invention relates to the field of medical devices, in particular to an accelerated external drive ventricular circulation auxiliary device, comprising a drive device, a catheter bush, a pump blood vessel, a head-end impeller and an intermediate impeller, wherein the pump blood vessel is hollow inside and open at both ends, The front end of the catheter shaft sleeve is connected with the rear end of the pump blood vessel, and the connection is provided with a head end impeller, the catheter shaft sleeve is provided with an intermediate impeller, and the head end impeller and the intermediate impeller are driven to rotate by a driving device. The invention utilizes the head-end impeller to pump blood from the ventricle into the aorta, utilizes the intermediate impeller to accelerate the blood flow rate in the blood vessel, improves the blood pumping efficiency, or pumps the blood in reverse flow to slow down the distal blood flow to maintain blood pressure, and ensure important organs blood supply.

Description

A ventricular circulatory aid device with an intermediate impeller

technical field

The invention relates to the field of medical instruments, in particular to a ventricular circulation auxiliary device provided with an intermediate impeller.

Background technique

In clinical medicine, when the patient's cardiac function is severely damaged, such as acute myocardial infarction complicated with heart failure and cardiogenic shock, the patient is routinely treated or needs interventional therapy, or complications occur before and after surgery and after surgery, etc. In all cases, circulatory support to the heart is required to enable the patient to pass through the dangerous period.

In order to meet the above-mentioned treatment needs, some ventricular assisted circulation devices have emerged, which usually include structures such as pump blood vessels, catheter bushings, impellers, and driving devices, wherein the driving device is used to drive the impeller to rotate to realize blood pumping. The impeller can be directly driven by the method of being installed in the human body, or the impeller can be driven by external driving through the rotating shaft in the catheter bushing. However, the ventricular assisted circulation device in the prior art is usually only provided with an impeller at the distal end of the catheter, and the blood pumping efficiency has its limit. The catheter is limited and cannot be designed to be too large. If the impeller rotates too high, it can cause the rupture of blood cells, thrombocytopenia or hemolysis, which threatens the life of the patient.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a ventricular circulation auxiliary device provided with an intermediate impeller, which utilizes the head-end impeller to pump blood from the ventricle into the aorta, utilizes the intermediate impeller to accelerate the flow rate of blood in the blood vessel, improves the pumping efficiency, or In severe cases, when blood pressure cannot be maintained, the middle impeller adopts the opposite structure to pump blood in reverse flow to slow down the distal blood flow to maintain blood pressure and ensure the blood supply to important organs.

The purpose of this invention is to realize through the following technical solutions:

A ventricular circulation auxiliary device provided with an intermediate impeller, comprising a driving device, a catheter shaft sleeve, a pump vessel, a head-end impeller and an intermediate impeller, wherein the pump vessel is hollow inside and has open ends at both ends, and the front end of the catheter sleeve is connected to the back of the pump vessel. The ends are connected and a head-end impeller is arranged at the connection, an intermediate impeller is arranged on the conduit sleeve, and the head-end impeller and the intermediate impeller are driven to rotate by a driving device.

The position where the conduit sleeve is provided with the intermediate impeller is provided with a diameter reducing portion and a transition sleeve, one end of the transition sleeve is connected with the diameter reducing portion and an input opening is provided at the connection, and the other end of the transition sleeve passes through the intermediate connecting rod It is connected with the catheter shaft sleeve, and an output opening is formed between adjacent intermediate connecting rods, and an intermediate impeller is arranged in the transition sleeve.

The inner wall of the transition sleeve includes an arc-shaped wall of the transition sleeve and a linear wall of the transition sleeve, and the outer wall of the reduced diameter portion, the input opening and the arc-shaped wall of the transition sleeve are smoothly connected.

A transition sleeve is provided at the position where the intermediate impeller is provided on the conduit sleeve, and both ends of the transition sleeve are respectively connected with the conduit sleeve on the corresponding side through an intermediate connecting rod, and the input is formed between the adjacent intermediate connecting rods at one end. opening, and an output opening is formed between the adjacent intermediate links at the other end.

The front end of the pump blood vessel is provided with a flexible part, and the flexible part is connected with the front end of the pump blood vessel through the first connecting rods evenly distributed along the circumferential direction, and the gap between the two adjacent first connecting rods forms a pumping opening The rear end of the pump blood vessel is connected with the front end of the catheter shaft sleeve through second connecting rods evenly distributed along the circumferential direction, and the gap between two adjacent second connecting rods forms a pumping opening.

The pumping opening at the front end of the pump blood vessel is connected with an expansion head end, and the expansion head end includes an expansion frame made of memory alloy and a diversion membrane sleeved on the expansion frame, and the back end of the pump blood vessel passes through the expansion frame. The second connecting rods evenly distributed along the circumferential direction are connected with the front end of the catheter bushing, and the gap between two adjacent second connecting rods forms a pumping opening.

The expansion frame includes a plurality of support beams made of memory alloy, the rear end of the support beam is connected to the pump blood vessel, the front end of the support beam is a free end, and the guide film is covered and fixed on the support beam .

The rear end of the catheter shaft sleeve is connected with an extracorporeal drive device, the interior of the catheter shaft sleeve is provided with a rotating shaft, and the rotating shaft is driven to rotate by the external drive device, and the head end impeller and the intermediate impeller are arranged on the rotating shaft .

The rotating shaft is a spiral wound tube.

The drive device is an internal drive device, including a head end drive device and an intermediate drive device, the head end drive device and the intermediate drive device are both arranged in the catheter shaft sleeve, and the head end impeller passes through the head end drive device. Driven to rotate, the intermediate impeller is driven to rotate by an intermediate drive device.

The advantages and positive effects of the present invention are:

1. The present invention utilizes the head-end impeller to pump blood from the ventricle into the aorta, utilizes the intermediate impeller to accelerate the flow rate of blood in the blood vessel, improves the pumping efficiency, or utilizes the intermediate impeller to slow down the distal blood flow near one end of the heart, maintaining Blood pressure, in most cases, the middle impeller can adopt the structure of pumped blood flow in the same direction as normal blood flow to improve the pumping efficiency, but if the patient has heart pump failure accompanied by blood pressure drop, the middle impeller is used at this time. The blood flow of the impeller pump is in the opposite direction to the normal blood flow. Through the countercurrent pumping blood, the distal blood flow is slowed down, the blood pressure is maintained, and the blood supply to the important organs is guaranteed.

2. In the present invention, positioning elements are provided on both the pump blood vessel and the transition sleeve to monitor the position in real time, and a pressure sensor and a temperature sensor are also provided on the pump blood vessel and the transition sleeve to monitor parameters such as blood pressure and temperature in real time.

3. The present invention can be provided with an expansion head at the distal end of the pump vessel to guide the blood flow, so as to increase the blood entry area, slow down the blood flow rate, prevent the blood flow rate from affecting the blood hemolysis index and other indicators, and reduce blood cell damage.

Description of drawings

1 is a schematic structural diagram of Embodiment 1 of the present invention,

Fig. 2 is an enlarged view of A in Fig. 1,

Fig. 3 is the three-dimensional schematic diagram of the pump blood vessel in Fig. 2,

Fig. 4 is the enlarged view of B in Fig. 1,

Fig. 5 is the sectional view of the transition sleeve in Fig. 4,

6 is a schematic structural diagram of Embodiment 2 of the present invention,

Fig. 7 is the enlarged view of C in Fig. 6,

Fig. 8 is the working state schematic diagram of embodiment 2 in Fig. 6,

9 is a schematic diagram of the working state of the ventricular circulatory assist device in the prior art,

Fig. 10 is a schematic diagram of the installation position of the head end drive device according to the third embodiment of the present invention,

FIG. 11 is a schematic diagram of the installation position of the intermediate drive device according to Embodiment 3 of the present invention.

Among them, 1 is the pump blood vessel, 101 is the pump inlet opening, 102 is the flexible part, 103 is the pump outlet opening, 104 is the first connecting rod, 105 is the second connecting rod, 2 is the head end impeller, 3 is the middle impeller, 301 302 is the transition sleeve, 303 is the arc-shaped wall of the transition sleeve, 304 is the intermediate connecting rod, 305 is the input opening, 306 is the linear wall of the transition sleeve, 307 is the first intermediate block, 4 is the catheter shaft sleeve, 401 is the rotating shaft, 402 is the block, 5 is the external drive device, 6 is the ventricle, 7 is the aorta, 8 is the expansion head, 801 is the expansion frame, 802 is the diversion membrane, 9 is the head end driving device, 10 is Intermediate drive.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in Figures 1 to 8, the present invention includes a driving device, a catheter shaft sleeve 4, a pump vessel 1, a head end impeller 2 and an intermediate impeller 3, wherein the pump vessel 1 is hollow inside and has openings at both ends, and the front end of the catheter shaft sleeve 4 A head-end impeller 2 is connected to the rear end of the pump vessel 1 and the connection is provided with a head-end impeller 2 , the catheter shaft sleeve 4 is provided with an intermediate impeller 3 , and the head-end impeller 2 and the intermediate impeller 3 are driven to rotate by a driving device.

As shown in FIGS. 1 to 3 , the pump blood vessel 1 is provided with a pump inlet opening 101 at the front end and a pump outlet opening 103 at the rear end. When the present invention works, the head end of the catheter sleeve 4 is connected to the pump blood vessel 1 . The rotation of the impeller 2 causes the blood in the ventricle 6 to enter the pump blood vessel 1 through the pumping opening 101 , and flow out into the aorta 7 through the pumping opening 103 , thereby realizing the blood circulation of the heart.

As shown in FIG. 2 , a blocking block 402 is provided at the front end of the catheter shaft sleeve 4 to isolate the inside of the catheter shaft sleeve 4 from the outside to achieve sealing, so as to ensure that blood in the human body does not enter the catheter shaft sleeve 4, while the blades of the impeller 2 The axle is rotatably mounted on the blocking block 402 through structural support such as a rotating sleeve or a bearing.

As shown in FIG. 1 , one or more intermediate impellers 3 can be arranged on the duct bushing 4 as required. As shown in FIGS. 4 to 5 , the position where the intermediate impellers 3 are arranged on the duct bushing 4 is provided The diameter portion 301 and the transition sleeve 302 are provided with an input opening 305 at the connection between the diameter reducing portion 301 and the transition sleeve 302. The other end of the transition sleeve 302 is provided with an intermediate impeller 3, and the transition sleeve 302 is provided with an intermediate impeller 3. One end of the impeller 3 is connected to the catheter bushing 4 through a plurality of intermediate links 304 , and an output opening is formed between adjacent intermediate links 304 . According to the different conditions of the patient, the intermediate impeller 3 can adopt the structure of the pumped blood flow in the same direction as the normal blood flow, or the structure in the opposite direction of the pumped blood flow and the normal blood flow. In most cases, the intermediate impeller 3. Make the pumped blood flow in the same direction as the normal blood flow to improve the pumping efficiency, but if the patient has heart pump failure accompanied by a drop in blood pressure, etc., the middle impeller 3 is used to pump the blood flow and the normal blood flow direction. Contrary to the structure, it slows down the blood flow at the distal end near the heart through countercurrent pumping, maintains blood pressure, avoids further lowering of blood pressure, and ensures blood supply to important organs. When the intermediate impeller 3 needs to pump blood in the opposite direction, the structure of the intermediate impeller 3 and its related diameter reducing portion 301 , transition sleeve 302 , input opening 305 , output opening and other structures are changed according to the front and rear directions of the longitudinal axis of the catheter bushing 4 . , and the impeller angle is also changed accordingly as required.

As shown in FIG. 5 , the inner wall of the transition sleeve 302 includes a transition sleeve arc-shaped wall 303 and a transition sleeve linear wall 306, wherein the outer wall of the reduced diameter portion 301 is smoothly connected with the transition sleeve arc-shaped wall 303, so that blood flows along the The outer concave surface of the reduced diameter portion 301 flows into the input opening 305 naturally, and flows naturally along the arc shape of the input opening 305 and the arc-shaped wall 303 of the transition sleeve under the action of the intermediate impeller 3 . The input opening 305 and the inner side of the arc-shaped wall 303 of the transition sleeve form an arc-shaped flow channel as gentle as possible to ensure the natural flow of blood along the arc-shaped flow channel. The arc-shaped flow channel is suitable for pumping blood, and the maximum diameter of the intermediate impeller 3 avoids rotational interference with other components.

As shown in FIG. 5 , the diameter reducing portion 301 is provided with a first intermediate block 307 to seal the interior of the catheter shaft sleeve 4 on the front side of the transition sleeve 303 . Similarly, the end portion of the catheter shaft sleeve 4 on the rear side of the transition sleeve 303 A second intermediate blocking block is provided to achieve internal sealing of the rear catheter shaft sleeve 4 .

The transition sleeve 302 can also adopt a structure similar to that of the pump blood vessel 1 shown in FIG. 3 , that is, both ends of the transition sleeve 302 are directly connected to the corresponding catheter shaft sleeve 4 through the intermediate link 304, and one end is adjacent to the middle. The input opening 305 is formed between the connecting rods 304 , and an output opening is formed between the adjacent intermediate connecting rods 304 at the other end.

In order to monitor the position of each part of the present invention, the pump vessel 1 and the transition sleeve 302 can be provided with positioning elements, and the positioning elements can be positioned by using a developing ring or a developing coating in conjunction with a developing device. The developing ring and Developable coatings are well known in the art.

In the present invention, a positioning detection head can also be provided on the pump vessel 1 and the transition sleeve 302 , and the detection field generation system in the prior art can be used to achieve precise positioning of both ends of the pump vessel 1 and the transition sleeve 302 . At present, the commonly used positioning methods in medicine mainly include magnetic field positioning and electric field positioning. The principle of magnetic field positioning is to generate a spatially encoded low-frequency low-power magnetic field outside the human body to form a magnetic field gradient inside the human body. The magnetic sensor detects the magnetic field and reverses the location of the magnetic sensor to determine the position of the medical element. The principle of electric field positioning is usually to use the current electrode to form an orthogonal current field inside the human body. The inductive sensor on the sensor detects the impedance between the electrodes, which in turn shows the path the element has taken. Regardless of the positioning method, a positioning processing system including a computer and a display screen is generally equipped. If the patient's body is in a relatively stable state at this time, the medical element with the sensor will move in the human body. The trajectory can be converted and processed by the positioning processing system and displayed on the display screen for reference and confirmation by the doctor. For example, when positioning the pacing electrode entering the blood vessel, in some parts with obvious anatomical structure features, such as the upper and lower cavities, the tricuspid valve, For the right ventricular outflow tract and other parts, the position of the lead can be judged more accurately based on the doctor's experience. Therefore, the detection field generation system in the present invention may be a magnetic field generation system, in which case the positioning detection head corresponds to a magnetic sensor, and the detection field generation system may also be an electric field generation system, in which case the positioning detection head corresponds to an electric field generation system sensor,

When the positioning detection head is used for positioning, the corresponding part of the human body is placed in the detection field generating system, and then the catheter starts to be lowered. After the present invention enters the human body, the positioning detection head on the pump blood vessel 1 and the transition sleeve 302 sends out signals to the positioning processing system. , the positioning processing system can process the signal and display it on the display screen, and the doctor can confirm the position of the pump blood vessel 1 and the transition sleeve 302 by observing the display screen of the positioning processing system. The positioning detection head, the detection field generation system, and the positioning processing system are all known in the art and are all commercially available products.

In addition, the pump blood vessel 1 and the transition sleeve 302 can also be provided with pressure sensors, temperature sensors and other components to monitor the parameters such as blood pressure and temperature in real time. The pressure sensors and temperature sensors are known in the art and are commercially available products. .

The front end of the pump vessel 1 of the present invention can be designed as a flexible part 102 or an expansion head end 8 as required, and the drive device can be in the form of an external drive device 5 or an internal drive device as required.

Example 1

As shown in Figures 1-3, this embodiment adopts the form of an external drive device 5, and the front end of the pump blood vessel 1 is provided with a flexible part 102 to prevent damage to the internal organs of the human body. The flexible part 102 is a curved soft head, so The curved soft tip can avoid damage to the vessel wall or the ventricular wall.

As shown in FIG. 1 , the rear end of the catheter bushing 4 extends outside the human body and is connected to the extracorporeal driving device 5 . The catheter bushing 4 is internally provided with a rotating shaft 401 , and the rotating shaft 401 is driven to rotate by the extracorporeal driving device 5 , the head end impeller 2 and the intermediate impeller 3 are both driven and rotated by the rotating shaft 401, wherein as shown in FIG. , the axle of the head-end impeller 2 is mounted on the blocking block 402 through the bearing support, and the axle end of the head-end impeller 2 is fixedly connected with the rotating shaft 401, and as shown in FIG. 5, the diameter reduction A first intermediate block 307 is provided in the part 301 to seal the interior of the catheter sleeve 4 on the front side of the transition sleeve 303, and the end of the catheter sleeve 4 on the rear side of the transition sleeve 303 is provided with a second intermediate block to realize the rear catheter. The shaft sleeve 4 is sealed inside, the front axle of the intermediate impeller 3 is mounted on the first intermediate block 307 through the bearing support, and the rear axle of the intermediate impeller 3 is mounted on the second intermediate block through the bearing support. and the front and rear axles of the intermediate impeller 3 are respectively fixed to the rotating shafts 401 in the corresponding side conduit bushings 4 .

In this embodiment, the rotating shaft 401 can be a spirally wound tube, which ensures the rotation of the driving impeller and also has a certain flexibility, and can be deformed with the catheter shaft sleeve 4. The spirally wound tube is a well-known technology in the art and is a commercially available product .

As shown in FIG. 3 , the tail end of the flexible portion 102 is connected to the front end of the pump vessel 1 through a plurality of first connecting rods 104 evenly distributed along the circumferential direction, and a gap is formed between two adjacent first connecting rods 104 Pumping into the opening 101, the rear end of the pump vessel 1 is connected to the front end of the catheter shaft sleeve 4 through a plurality of second connecting rods 105 evenly distributed along the circumferential direction, and the gap between two adjacent second connecting rods 105 is formed When pumping out of the opening 103 , the rotational diameter of the head-end impeller 2 should be smaller than the diameter of the circumference enclosed by the second connecting rods 105 , so as to avoid the rotational interference of the head-end impeller 2 .

The head-end impeller 2, the intermediate impeller 3, the pump blood vessel 1, each block and each connecting rod can be made of medical alloy and other materials.

The working principle of this embodiment is:

As shown in FIG. 9, the ventricular assisting circulation device in the prior art is usually only provided with an impeller at the front end for pumping the blood in the ventricle 6 to the aorta 7. For some patients with severe heart failure, if only The blood is pumped by the impeller at the head end, and the pumping efficiency has its limit.

In this embodiment, as shown in FIG. 1 , in addition to the head-end impeller 2 provided at the front end of the conduit sleeve 4, one or more intermediate impellers 3 can also be arranged on the conduit sleeve 4 as required, and the head-end impeller 2 is mainly used to The blood is pumped into the aorta 7 from the ventricle 6, and according to the different conditions of the patient, the middle impeller 3 can adopt the structure of the pumped blood flow in the same direction as the normal blood flow, or the pumped blood flow can be reversed to the normal blood flow. Directional structure, in most cases, the middle impeller 3 makes the pumped blood flow in the same direction as the normal blood flow to improve the pumping efficiency, but if the patient has heart pump failure accompanied by a drop in blood pressure, the The middle impeller 3 is used to pump the blood flow in the opposite direction to the normal blood flow, so as to slow down the distal blood flow through countercurrent pumping, maintain blood pressure, and ensure the blood supply to important organs. In addition, the flexible portion 102 at the front end of the pump blood vessel 1 can avoid damage to the blood vessel wall or the inner wall of the ventricle.

The implantation process of the lower tube in this embodiment is the same as the implantation process of the lower tube of the ventricular assisting circulation device in the prior art.

Example 2

As shown in Figures 6-8, this embodiment adopts the form of an external drive device 5, but the difference between this embodiment and Embodiment 1 is that the front end of the pump blood vessel 1 is provided with an expansion head 8 to increase the blood entry area, Make the blood flow smoothly and reduce the energy consumption during the pumping process.

As shown in FIGS. 6-8 , the expansion head end 8 includes an expansion stent 801 and a diversion membrane 802 laid on the expansion stent 801 . The opening 101 is fixedly connected, and the front end of the expansion frame 801 can be automatically opened, and the diversion membrane 802 is stretched at the same time to form a nearly trumpet-shaped blood inlet to guide the blood to flow in a certain direction, increase the blood inlet area and make the blood flow at the same time. flow and slow inflow. In this embodiment, the expansion frame 801 includes a plurality of support beams made of memory alloy, the rear ends of the support beams are fixedly connected with the pumping opening 101 , the front ends of the support beams are free ends, and the guide film 802 The cover is fixed on the support beam. The memory alloy is a well-known technology in the art, which is widely used in the medical field. The support beam can be compressed and automatically opened due to the characteristics of the memory alloy. In addition, in this embodiment, the material of the guide film 802 can be made of polymer. , such as polyurethane, etc., has sufficient elasticity and strength, which is a well-known technology in the art, and because the guide film 802 has elasticity and wraps the support beam, it can prevent damage to the blood vessel wall or the inner wall of the ventricle.

In this embodiment, the rear end of the pump blood vessel 1 is connected to the front end of the catheter sleeve 4 through a plurality of second connecting rods 105 evenly distributed along the circumferential direction, and the gap between two adjacent second connecting rods 105 forms the pump Exit opening 103 .

The working principle of this embodiment is:

The blood inlet at the front end of the pump blood vessel of the ventricular assisting circulation device in the prior art is usually small, which limits the blood pumping efficiency and easily leads to an increase in the blood flow rate. As shown in FIG. There is an expansion head end 8, and the expansion head end 8 is in a compressed state by compressing a support beam made of memory alloy when the tube is down, which is convenient for down tube. After entering the ventricle 6, the expansion head end 8 automatically opens due to the characteristics of the memory alloy. The diversion membrane 802 is stretched to form a blood inlet, which increases the blood inlet area and also makes the blood flow gently, reducing the energy consumption in the process of pumping blood. To pump blood against the flow of blood when the heart pump fails and is accompanied by a drop in blood pressure, etc.

The implantation process of the lower tube in this embodiment is basically the same as the implantation process of the lower tube of the ventricular assist circulation device in the prior art, and the difference is only that the expansion head end 8 is compressed when the tube is lowered.

Example 3

As shown in FIGS. 10-11 , this embodiment adopts the form of an in-body drive device, omitting structures such as the rotating shaft 401 .

As shown in FIGS. 10 to 11 , the driving device 5 in this embodiment includes a head-end driving device 9 and an intermediate driving device 10 . The head-end driving device 9 and the intermediate driving device 10 are both micro-motors and are fixed on the catheter shaft In the sleeve 4, as shown in FIG. 10, the axle of the head-end impeller 2 passes through the blocking block 402 and is fixedly connected with the driving end of the head-end driving device 9. As shown in FIG. 11, the front of the intermediate impeller 3 The side axles are mounted on the first intermediate block 307 through bearing support, and the rear axle of the intermediate impeller 3 passes through the second intermediate block and is fixedly connected to the corresponding driving end of the intermediate drive device 10 . The head end driving device 9 and the intermediate driving device 10 are known in the art and are commercially available products.

In this embodiment, a flexible portion 102 or an expansion head end 8 may be provided at the front end of the pump blood vessel 1 as required.

Claims (10)

1. A ventricular circulation assist device provided with a central impeller, characterized in that: including drive arrangement, pipe axle sleeve (4), pump vessel (1), head end impeller (2) and middle impeller (3), wherein pump vessel (1) inside cavity and both ends opening, pipe axle sleeve (4) front end with pump vessel (1) rear end is connected and the junction is equipped with head end impeller (2), be equipped with middle impeller (3) on pipe axle sleeve (4), just head end impeller (2) and middle impeller (3) are rotated through the drive arrangement drive.

2. A ventricular circulation assist device having a central impeller in accordance with claim 1, wherein: the position that pipe axle sleeve (4) was equipped with middle impeller (3) is equipped with undergauge portion (301) and transition cover (302), transition cover (302) one end with undergauge portion (301) link to each other and the junction is equipped with input opening (305), the transition cover (302) other end passes through middle connecting rod (304) and links to each other with pipe axle sleeve (4), and forms output opening between adjacent middle connecting rod (304), be equipped with middle impeller (3) in transition cover (302).

3. A distal dilation ventricular circulation assist device having an intermediate impeller according to claim 2, wherein: the inner wall of the transition sleeve (302) comprises a transition sleeve arc-shaped wall (303) and a transition sleeve linear wall (306), and the outer wall of the reducing portion (301), the input opening (305) and the transition sleeve arc-shaped wall (303) are smoothly connected.

4. A ventricular circulation assist device having a central impeller in accordance with claim 1, wherein: the position that pipe axle sleeve (4) was equipped with middle impeller (3) is equipped with transition cover (302), just transition cover (302) both ends link to each other with pipe axle sleeve (4) that correspond the side through middle connecting rod (304) respectively to form between the adjacent middle connecting rod (304) of one end input opening (305), form between the adjacent middle connecting rod (304) of the other end output opening.

5. A ventricular circulation assist device having a central impeller in accordance with claim 1, wherein: the front end of the pump blood vessel (1) is provided with a flexible part (102), the flexible part (102) is connected with the front end of the pump blood vessel (1) through first connecting rods (104) uniformly distributed along the circumferential direction, a pumping opening (101) is formed in a gap between every two adjacent first connecting rods (104), the rear end of the pump blood vessel (1) is connected with the front end of the guide pipe shaft sleeve (4) through second connecting rods (105) uniformly distributed along the circumferential direction, and a pumping opening (103) is formed in a gap between every two adjacent second connecting rods (105).

6. A ventricular circulation assist device having a central impeller in accordance with claim 1, wherein: the pump is characterized in that a pump pumping opening (101) at the front end of the pump blood vessel (1) is connected with an expansion head end (8), the expansion head end (8) comprises an expansion frame (801) made of memory alloy and a flow guide film (802) sleeved on the expansion frame (801), the rear end of the pump blood vessel (1) is connected with the front end of the catheter shaft sleeve (4) through second connecting rods (105) uniformly distributed along the circumferential direction, and a pump pumping opening (103) is formed in a gap between every two adjacent second connecting rods (105).

7. A ventricular circulation assist device having a medial impeller in accordance with claim 6, wherein: the expansion frame (801) comprises a plurality of support beams made of memory alloy, the rear ends of the support beams are connected with the pump blood vessel (1), the front ends of the support beams are free ends, and the flow guide films (802) are covered and fixedly arranged on the support beams.

8. A ventricular circulation assist device having a central impeller in accordance with claim 1, wherein: the utility model discloses a catheter tube, including catheter shaft sleeve (4), external drive arrangement (5), catheter shaft sleeve (4) inside is equipped with pivot (401), and pivot (401) are passed through external drive arrangement (5) drive is rotatory, head end impeller (2) and middle impeller (3) are located on pivot (401).

9. A ventricular circulation assist device having a central impeller in accordance with claim 8, wherein: the rotating shaft (401) is a spiral winding pipe.

10. A ventricular circulation assist device having a central impeller in accordance with claim 1, wherein: the driving device is an in-vivo driving device and comprises a head end driving device (9) and an intermediate driving device (10), the head end driving device (9) and the intermediate driving device (10) are arranged in a conduit shaft sleeve (4), the head end impeller (2) is driven to rotate by the head end driving device (9), and the intermediate impeller (3) is driven to rotate by the intermediate driving device (10).

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