CN103191476B - Single-fulcrum magnetomotive centrifugal blood pump - Google Patents

Abstract

The invention provides a single-fulcrum magnetomotive centrifugal blood pump, which is characterized in that a pump body and a driving device are arranged in a blood pump, wherein the pump body comprises a top cap, a base, an impeller and outer magnetic steel; at least three layers of bosses are arranged on the base; a groove is arranged in the boss at the top end; a rolling ball is placed in the groove; a patchhole is arranged at the center of the bottom of the base; vanes and an annular joint are arranged on the impeller; connecting rods are arranged in the inner circle of the annular joint and gathered around the center of the inner circle of the annular joint; a circular arc central groove is formed at the bottom of the gathering position of connecting rod, and is matched with the rolling ball in the groove in the boss to form a single-fulcrum bearing; the outer magnetic steel is arranged inside the vanes; the driving device comprises a transmission shaft and a driving motor provided with a motor rotor; the motor rotor is sleeved with the transmission shaft; the transmission shaft is inserted into the patchhole; and inner magnetic steel is arranged inside the transmission shaft. The blood pump provided by the invention has the advantages that the incidence rate of thrombus and hemolysis can be effectively reduced as the pre-filling quantity is less; the structure is simple and stable; the mounting is convenient; and the cost is low.

Description

A single fulcrum magnetic power centrifugal blood pump

technical field

The invention relates to the technical field of medical devices, in particular to a single fulcrum magnetic power centrifugal blood pump.

Background technique

Cardiovascular and cerebrovascular diseases have already ranked first in the cause of human death in developed countries, accounting for about 46% of the mortality rate. Statistics in the United States show that the number of heart operations is about 350,000 cases per year. At present, the number of open-heart surgeries in China is about 100,000 per year. With the rapid development of the economy and the continuous improvement of the medical level, the number of heart surgeries in China will inevitably increase. According to statistics, after cardiac surgery, some patients (0.6-2%) cannot maintain the minimum requirements of the body due to severe impairment of cardiac function, even with drug support. These patients have to use assisted circulation equipment to temporarily support the heart function, maintain life, and wait for the heart function to recover. Some of these patients also require the use of long-term circulatory assist devices to replace heart function. In addition, the most effective way to treat chronic irreversible heart failure is heart transplantation, but the shortage of donor hearts limits the general application of heart transplantation therapy in clinical practice, and new treatments such as genetic engineering and cell engineering cannot be carried out on a large scale in the foreseeable future. Therefore, ventricular assist technology has become the only option in many cases.

Blood pump (also known as heart pump) is the core of cardiac assisted circulation device. In recent years, it has been the focus of assisted circulation research in developed countries and has made some progress.

The earliest first-generation blood pump is a pulsating pump modeled on the heart. This type of blood pump uses pneumatic or electric extrusion to squeeze the pump chamber, and beats out blood through the change of the volume of the pump chamber. The second generation of continuous flow impeller blood pumps emerged in the early 1980s. The blades of this type of blood pump are mounted on the blood pump rotor through mechanical bearings. The rotor drives the blades to rotate to push the blood forward along the helical direction. The third-generation blood pump is characterized by levitation technology, so all blood pumps developed using magnetic levitation and/or liquid levitation technology are called third-generation blood pumps.

The third-generation blood pump generally has two systems of suspension and drive: the suspension system suspends the impeller, and the impeller is directly permanent magnetized or embedded with a permanent magnet in the shaped impeller. The stator or pump casing of the blood pump is built with permanent magnets or electromagnetic coils, and the impeller is suspended in the middle of the pump casing through the axial and radial magnetic field interaction between the magnetized impeller and the stator or pump casing; the drive system drives the impeller to rotate. Another set of electromagnetic coils is built into the stator or pump casing, and the change of the electromagnetic coil current generates magnetic force to drive the magnetized impeller to rotate.

The third-generation blood pump has three development stages: the first stage is the stage where the suspension and drive system are separated and the external motor indirectly drives the impeller. The suspension technology of the blood pump is relatively simple. The suspension system is separated from the drive system. The blood pump adopts the external motor drive technology, and the impeller is driven by an independent external motor; Drives the rotation of another suspended magnetized inner impeller; the inner impeller is the main drive part and its rotation drives the blood flow. The second stage is the motor directly driving the impeller stage where the suspension and drive systems are separated, and the blood pump motor directly drives the impeller suspension technology. The suspension system and the drive system are also separated, but the motor cancels the outer impeller, and the suspension impeller is directly used as the rotor of the motor. The motor directly drives the suspension impeller to rotate through the change of magnetic force to promote blood flow. The pump still requires another separate magnetic levitation system to levitate the blood pump impeller. The third stage is the fusion stage of the suspension and drive system, that is, the suspension of the blood pump is integrated with the drive system. The design of the blood pump combines the electromagnetic coils of the suspension and drive system to form a stator, and a stator is used to drive and suspend the impeller. Therefore, the design of the pump is more concise, and its representative blood pump is VentrAssist.

Most of the third-generation blood pumps are designed as centrifugal pumps, and a few are axial-flow pumps. There are several representative third-generation blood pumps, such as: (1) Berlin Heart Incor pump: a magnetic levitation axial-flow pump developed by Berlin Heart , the blood pump is made of titanium alloy. The only moving impeller in the pump body is designed as an Archimedes spiral. The impeller is suspended in the pump casing by axial and radial magnetic force. Through the change of the electromagnetic field, the suspended impeller is driven to rotate axially. (2) HeartWare pump: the impeller of the pump suspends the pump blades through magnetic levitation and liquid levitation technology, and the total stator of the pump is composed of two mutually independent coils. (3) VentrAssist pump: The part of the pump in contact with blood is coated with pyrolytic carbon, which can reduce the incidence of thrombus, but the pump has a long inflow channel, so after implantation, it still needs to be removed. A small pouch is made behind the rectus abdominis sheath or behind the rectus abdominis to place the pump body; (4) NovacorVAD pump: it has a special inflow system, the inflow pipe of the pump is designed parallel to the pump body, and the outside forms a flat shape.

Thrombus is formed by the aggregation and deposition of platelets. In the blood pump, it generally occurs in the stagnation area less washed by blood flow and the low-speed area of the contact surface with blood. Hemolysis refers to the destruction of erythrocytes in the blood by high speed or high pressure generated by turbulent flow or mechanical movement, causing hemoglobin to disperse into plasma, which is mainly caused by irregular flow and high shear stress in the turbulent movement area. Hemolysis and thrombosis are extremely harmful to patients. In clinical applications, thrombus and hemolysis caused by cardiac assisted circulation devices will lead to physiological disorders in patients, which will lead to intraoperative and postoperative complications, and even endanger the lives of patients, especially The impact is greater in patients requiring long-term assisted circulatory support. It can be seen that reducing the occurrence of thrombus and hemolysis in the heart pump is an urgent problem to be solved in the research and development of the auxiliary circulatory system.

Compared with the first and second generation blood pumps, the third-generation blood pump adopts the magnetic levitation technology, the impeller is suspended in the blood pump body, there is no friction and extrusion, the hemolysis is significantly reduced, the incidence of thrombus is significantly reduced, and there is no bearing wear Problems, improve the durability of blood pump use, more suitable for long-term circulation assistance.

However, the structure of the current third-generation blood pump is relatively complicated, and the contact surface with the blood is large, which is prone to produce stagnation areas of blood and cause thrombus. In addition, the blood pump is a disposable product, which should be simple in structure and low in cost; the prefilling volume of the blood pump should be reduced as much as possible; for infants and neonatal patients, it should also have the advantage of low prefilling volume. At present, there is no report about a blood pump with a simpler structure, which can effectively reduce the incidence of thrombus, has a small priming volume, low flow rate, and low cost.

Contents of the invention

The purpose of the present invention is to provide a single fulcrum magnetic power centrifugal blood pump to solve the deficiencies in the prior art.

For realizing above-mentioned object, the technical scheme that the present invention takes is:

A single fulcrum magnetic power centrifugal blood pump is provided with a pump body and a driving device. The pump body includes a top cover, a base, an impeller and an outer magnetic steel. The base is provided with at least three layers of bosses. The boss is provided with a groove, the ball is placed in the groove, and the bottom center of the base is provided with an insertion hole; the impeller is provided with a blade and an annular connection, and the inner ring of the annular connection is provided with Connecting rods, the connecting rods gather in the center, and the bottom forms a circular arc-shaped central groove, and the central groove cooperates with the balls in the groove of the boss to form a single fulcrum bearing; the outer magnetic steel is located on Inside the blade; the drive device includes a drive shaft and a drive motor with a motor rotor, the drive shaft is sleeved on the motor rotor, and inserted into the insertion hole of the base, and the inside of the drive shaft is provided with an inner magnetic steel, The number of the inner magnetic steel and the outer magnetic steel is the same, and the adjacent magnetic poles are arranged in a staggered manner;

The outer magnetic steel is a cuboid or a cylinder;

The inner magnetic steel is a cuboid or a cylinder;

The base is provided with three layers of bosses;

The ball is spherical or hemispherical;

The balls are made of ceramics;

The blades are straight blades or curved backward along the direction of blood flow;

The number of the blades is four or six;

The outside of the drive motor is provided with a pump body placement device, and the pump body placement device is a concave platform.

The present invention has the advantage that:

1. A single fulcrum bearing is used as the rotating shaft. The contact area between the ball bearing and the blood is very small, which reduces the contact surface between the rotating shaft and the blood, thereby reducing the blood stagnation area and effectively reducing the incidence of thrombus;

2. The outer magnetic steel and the blood flow channel are in the same cavity. By placing the outer magnetic steel in the blade and the inner magnetic steel in the transmission shaft, the problem of placing the magnetic steel in the common cavity is solved. At the same time, the blood pump of the present invention is simple in structure and has the advantages of low priming volume, and is suitable for ventricular auxiliary circulation after surgery for children with congenital heart disease, and can also be used in extracorporeal circulation during surgery;

3. The ball is hemispherical, which makes the single fulcrum bearing structure more stable;

4. The base is provided with a boss, which can effectively reduce the pre-charge amount;

5. The base is provided with an insertion hole to facilitate the placement of the transmission shaft;

6. The shape of the impeller is that the front end is bent backward along the direction of blood flow, conforming to the direction of blood flow, which can effectively reduce the shear force on the red blood cells in the blood and reduce the probability of hemolysis;

7. Small size, convenient for surgical implantation, and can significantly reduce costs.

Description of drawings

Accompanying drawing 1 is the assembly diagram of the single fulcrum magnetodynamic centrifugal blood pump of the present invention.

Accompanying drawing 2 is the assembly diagram of the pump body of the single fulcrum magnetic power centrifugal blood pump of the present invention.

Accompanying drawing 3 is the plan view of Fig. 2.

Accompanying drawing 4 is the second isometric view of the impeller of the single fulcrum magnetodynamic centrifugal blood pump of the present invention.

Accompanying drawing 5 is the bottom view of Fig. 4.

Accompanying drawing 6 is the second isometric axis view of the single fulcrum magnetodynamic centrifugal blood pump driving device of the present invention. the

Figure 7 is a second isometric view of another impeller of the single fulcrum magnetodynamic centrifugal blood pump of the present invention.

Accompanying drawing 8 is the second isometric view of another driving device of the single fulcrum magnetic power centrifugal blood pump of the present invention.

Detailed ways

The specific embodiments provided by the present invention will be described in detail below in conjunction with the accompanying drawings.

The reference signs and components involved in the accompanying drawings are as follows:

1. Top cover 101. Entrance

102. Exit 103. Upper wall

104. Outer wall 2. Base

201. The first boss 2011. The top of the first boss

2012. The main body of the first boss 202. The second boss

203. The third boss 204. Groove

205. Ball 206. Insertion hole

3. Impeller 301. Blade

302. Ring connection 303. Connecting rod

304. Central groove 305. Outer magnetic steel

3051. Top surface of outer magnetic steel 306. Joint

4. Drive motor 401. Motor rotor

5. Transmission shaft 501. Inner magnetic steel

6. Pump body placement device

Example 1

Please refer to FIG. 1 . FIG. 1 is an assembly diagram of the single fulcrum magnetodynamic centrifugal blood pump of the present invention. The single fulcrum magnetic power centrifugal blood pump is provided with a pump body and a driving device. The pump body includes a top cover 1, a base 2, an impeller 3 and an outer magnetic steel 305. The driving device includes a driving motor 4, Transmission shaft 5 and inner magnetic steel 501.

Please refer to FIG. 2 . FIG. 2 is an assembly diagram of the single fulcrum magnetodynamic centrifugal blood pump body of the present invention. The top cover 1 is provided with an inlet 101 , an outlet 102 , an upper wall 103 and an outer wall 104 . The outer wall 104 is cylindrical, and the bottom end is provided with an internal thread (not shown); the upper wall 103 is conical and is located at the top of the outer wall 104; the inlet 101 is located at the center of the top of the upper wall 103 Position; the outlet 102 is at right angles to the inlet 101, as can be seen from FIG. 3 (FIG. 3 is a top view of FIG. 2), the outlet 102 is placed on the surface of the outer wall 104 along the tangential direction of the outflow channel.

Referring to FIG. 2 again, the base 2 includes a first boss 201 , a second boss 202 and a third boss 203 . The first boss top 2011 of the first boss 201 is conical, and the center is provided with a groove 204, and a ball 205 is placed in the groove 204, and the ball 205 is hemispherical. The first boss main body 2012 of the first boss 201 is a hollow cylinder; the second boss 202 is also a hollow cylinder, and its outer wall is provided with external threads (not shown), and the second boss 202 The top end is connected to the first boss 201, the bottom end is connected to the top of the third boss 203, the diameter of the second boss 202 is larger than the diameter of the first boss body 2012; the third boss 203 is also a hollow cylinder body, its diameter is greater than the diameter of the second boss 202, and at the same time larger than the diameter of the outer wall 104; the hollow interior of the first boss body 2012, the second boss 202 and the third boss 203 forms an insertion hole 206, that is The bottom of the base 2 is provided with an insertion hole 206 .

Please refer to FIG. 4 . FIG. 4 is a second isometric view of the impeller of the single fulcrum magnetodynamic centrifugal blood pump of the present invention. The impeller 3 is provided with an annular connection 302, the annular connection 302 is an annular ring, and its inner ring is provided with three connecting rods 303, and the three connecting rods 303 gather at the center of the impeller 3 to form a joint 306, the joint part 306 is an annular ring, the central bottom of which is a central groove 304, and the central groove 304 is arc-shaped. The lower end of the annular connection 302 is provided with four blades 301, and the four blades 301 are arranged in an array, and are connected as a whole by the annular connection 302 to form a semi-disc-shaped flow channel. The front ends of the blades 3 flow along the blood The direction is bent backwards. The rear end of the blade 301 is provided with an external magnetic steel 305 inside, and the external magnetic steel 305 is a sheet structure. Please refer to FIG. 5 , which is a bottom view of FIG. 4 , the top surface 3051 of the outer magnet is rectangular, that is, the outer magnet 305 is a cuboid.

Please refer to Fig. 1 again, described drive device comprises drive motor 4 and drive shaft 5, and described drive motor 4 is provided with pump body placement device 6 outside, and described pump body placement device 6 is a concave platform, and its inner diameter It is equal to the outer diameter of the third boss 203 of the base 2 ; the upper end of the drive motor 4 is the motor rotor 401 . Please refer to FIG. 6 . FIG. 6 is a two-isometric view of the single fulcrum magnetodynamic centrifugal blood pump driving device of the present invention. The transmission shaft 5 is sheathed on the motor rotor 401, and the inner magnet steel 501 is placed in the transmission shaft 5, and the inner magnet steel 501 is a circular flake magnet steel, which has the same quantity as the outer magnet steel 305.

Please refer to FIG. 1 , when the single fulcrum magnetic power centrifugal blood pump of the present invention is assembled, the internal thread (not shown) at the bottom of the outer wall 104 is matched with the external thread (not shown) of the second boss 202 , so that the top cover 1 and the base 2 form an internal cavity, the impeller 3 is located in the internal cavity, and is assembled on the first boss 201, the central groove 304 and the ball in the groove 204 205 to form a single fulcrum bearing; the central axis of the impeller 3 coincides with the central axis of the first boss 201, and the rear end of each blade 301 is spaced the same distance from the first boss 201, and is separated from the first boss 201. The tangent direction of the platform 201 is parallel; the outer magnetic steel top surface 3051 of the outer magnetic steel 305 is parallel to the central axis of the first boss 201, and perpendicular to the radial direction of the first boss 201, and the vertical feet are located outside The center of the top surface of the magnetic steel 3051; the number of the inner magnetic steel 501 and the outer magnetic steel 305 are the same and they are placed facing each other, and the adjacent magnetic poles are arranged in a staggered manner. The transmission shaft 5 is inserted into the insertion hole 206 of the base 2, the diameter of the transmission shaft 5 is smaller than the diameter of the insertion hole 206, and the pump body installation device 6 clamps the third boss 203 to fix the entire pump body .

Example 2

The single fulcrum magnetic power centrifugal blood pump of this embodiment is basically the same as that of Embodiment 1, the only difference is: Please refer to Figure 7, which is another impeller second-class measurement of the single fulcrum magnetic power centrifugal blood pump of the present invention. In an axial view, the impeller 3 is provided with six blades 301, and the blades 301 are straight blades.

Example 3

The single fulcrum magnetic power centrifugal blood pump of this embodiment is basically the same as that of Embodiment 1, the only difference is: Please refer to Figure 8, which is another driving device of the single fulcrum magnetic power centrifugal blood pump of the present invention. In the axial view, the inner magnetic steel 501 is a circular sheet magnetic steel. Correspondingly, the top surface 3051 of the outer magnet 305 (not shown) is circular, that is, the outer magnet 305 is a sheet cylinder.

For the above-mentioned embodiments 1-3, it should be noted that:

The arc-shaped central groove 304 cooperates with the hemispherical ball 205 in the groove 204 of the base 2 to form a single fulcrum bearing, and the hemispherical ball 205 plays the role of axially supporting the impeller 3 and radially fixing The role of the impeller 3, the single fulcrum bearing has a simple structure, can effectively reduce the area in contact with blood, thereby reducing the stagnation area of blood, and significantly reducing the incidence of thrombus; the ball 205 is designed to be hemispherical, allowing the base 2 and the impeller 3 to pass through The overall structure formed by the single fulcrum bearing is more stable; the ball 205 can be made of non-abrasive materials, such as ceramics;

The outer magnet 305 is placed in the blade 301, and the inner magnet 501 is placed in the transmission shaft 5 as the driving magnet, which solves the problem of magnet placement when the driving magnet and the blood flow channel are in the same cavity At the same time, the structure of the single fulcrum magnetodynamic centrifugal blood pump of the present invention is simpler; the number of the outer magnets 305 and the inner magnets 501 are the same, and the adjacent magnetic poles are arranged in a staggered manner, which can prevent the loss of synchronization during rotation; The thickness of the outer magnetic steel 305 is 1-2 mm, and its shape is preferably a cuboid; the thickness of the inner magnetic steel 501 is 1-2 mm, and its shape is preferably a cuboid;

The number of blades 301 of the impeller 3 is usually designed as an even number, but not limited to four or six; the distance between the rear end of the blade 301 and the central axis of the impeller 3 is 5-10mm, and the length of the blade 301<30mm; the assembly is completed , the width of the gap between the rear end of the blade 301 and the first boss 201 is 0.5mm; the shape of the blade 301 is preferably such that the front end bends backward along the blood flow direction, which can effectively reduce the impact on the red blood cells in the blood. The shear force prevents hemolysis.

The shape of the central groove 304 is preferably hemispherical; the number of bosses of the base 2 is at least three, but not limited to three, and the design of the bosses can effectively reduce the amount of pre-charge; The connection between the outer wall 104 and the second boss 201 is not limited to threaded connection, any connection method can be used, such as sealing with viscous glue; the outer diameter of the outer wall 104 is 40-60 mm; the pump body placement device 6 is concave and convex with pins , its function is to fix the pump body and prevent the pump body from rotating with the drive shaft 5, so this part can be omitted.

The working principle of the single fulcrum magnetic power centrifugal blood pump of the present invention is as follows: the motor rotor 401 rotates, drives the transmission shaft 5 to rotate, and the inner magnet 501 placed inside the transmission shaft 5 follows the rotation, and then drives the outer magnet 305 to rotate, and then The outer magnetic steel 305 inside the blade 301 drives the impeller to rotate, the blood enters the cavity formed by the top cover 1 and the base from the inlet 101, and flows down from the gap between the connecting rod 303 of the impeller 3, under the centrifugal action of the impeller 3 , pumped out from outlet 102. The single fulcrum magnetic power centrifugal blood pump has the advantages of low prefill volume, which can reach less than 23ml, which can effectively reduce the incidence of thrombus and hemolysis, and at the same time, has a simple and stable structure, convenient installation, and low cost.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the method of the present invention, some improvements and supplements can also be made, and these improvements and supplements should also be considered Be the protection scope of the present invention.

Claims (9)

1. A single fulcrum magnetic power centrifugal blood pump is provided with a pump body, and the pump body includes a top cover, a base, an impeller and an outer magnetic steel, and is characterized in that, The base is provided with at least three layers of bosses, the boss at the top is provided with grooves, balls are placed in the grooves, and the center of the bottom of the base is provided with an insertion hole; the impeller is provided with blades and rings. The inner ring of the annular connection is provided with connecting rods, the connecting rods gather in the center, and the bottom forms an arc-shaped central groove, and the central groove and the ball in the groove of the boss Cooperate to form a single fulcrum bearing; the outer magnetic steel is arranged inside the blade; The single fulcrum magnetic power centrifugal blood pump is also provided with a drive device, the drive device includes a drive shaft and a drive motor with a motor rotor, the drive shaft is sleeved on the motor rotor, and inserted into the base Inserting into the hole, the interior of the transmission shaft is provided with inner magnets, the number of the inner magnets is the same as that of the outer magnets, and the number of the outer magnets is opposite to each other, and the adjacent magnetic poles are arranged in a staggered manner. 2 . The single fulcrum magnetodynamic centrifugal blood pump according to claim 1 , wherein the outer magnetic steel is a cuboid or a cylinder. 3 . 3. The single fulcrum magnetodynamic centrifugal blood pump according to claim 1, wherein the inner magnetic steel is a cuboid or a cylinder. 4. The single fulcrum magnetodynamic centrifugal blood pump according to claim 1, wherein the base is provided with three layers of bosses. 5. The single fulcrum magnetodynamic centrifugal blood pump according to claim 1, wherein the ball is spherical or hemispherical. 6. The single fulcrum magnetic power centrifugal blood pump according to claim 1, wherein the ball is made of ceramics. 7. The single fulcrum magnetodynamic centrifugal blood pump according to claim 1, wherein the blades are straight blades or curved backward along the direction of blood flow. 8. The single fulcrum magnetodynamic centrifugal blood pump according to claim 1, characterized in that the number of said blades is four or six. 9. The single fulcrum magnetodynamic centrifugal blood pump according to claim 1, characterized in that a pump body resting device is provided outside the driving motor, and the pump body resting device is a concave platform.