WO2014019274A1

WO2014019274A1 - Single-fulcrum magnetomotive centrifugal blood pump

Info

Publication number: WO2014019274A1
Application number: PCT/CN2012/081203
Authority: WO
Inventors: 王伟; 韩露; 俞晓青; 丁文祥; 杨明; 张海波
Original assignee: 上海交通大学医学院附属上海儿童医学中心
Priority date: 2012-08-03
Filing date: 2012-09-10
Publication date: 2014-02-06
Also published as: CN103191476B; CN103191476A

Abstract

A single-fulcrum magnetomotive centrifugal blood pump is provided with a pump body and a driving device. The pump body comprises a top cap (1), a base (2), an impeller (3) and outer magnetic steel (305); the base (2) is provided with at least three layers of bosses (201, 202, 203); the boss (201) at the top end is provided with a groove (204); a rolling ball (205) is placed in the groove (204); a patchhole (206) is arranged at the center of the bottom of the base (2); vanes (301) and an annular joint (302) are arranged on the impeller (3); connecting rods (303) are arranged in the inner circle of the annular joint (302) and gathered around the center of the inner circle of the annular joint (302); a circular arc central groove (304) is formed at the bottom of the gathering position of the connecting rods, and is matched with the rolling ball (205) in the groove (204) in the boss to form a single-fulcrum bearing; the outer magnetic steel (305) is arranged inside the vanes (301); the driving device comprises a transmission shaft (5) and a driving motor (4) provided with a motor rotor (401); the motor rotor (401) is sleeved with the transmission shaft (5); the transmission shaft (5) is inserted into the patchhole (206); and inner magnetic steel (501) is arranged inside the transmission shaft (5). The blood pump can effectively reduce the incidence rate of thrombus and hemolysis as the pre-filling quantity is less; the structure is simple and stable; the mounting is convenient; and the cost is low.

Description

Single-point magnetic centrifugal blood pump

Technical field

The present invention relates to the field of medical device technology, and more particularly to a single-point magnetic powered centrifugal blood pump.

Background technique

Cardiovascular and cerebrovascular diseases have long been the leading cause of human death in developed countries, accounting for 46% of deaths. US statistics show that the number of heart surgeries per year is about 350,000. At present, the number of open-heart surgery in the country is about 100,000 per year. With the rapid development of the economy and the continuous improvement of medical standards, the number of domestic cardiac surgery is bound to increase. According to statistics, some patients (0.6-2%) have severe heart function damage after cardiac surgery, and they cannot maintain the minimum body requirements even with drug support. This part of the patient had to use the auxiliary circulation device to temporarily support the heart function, maintain life, and wait for the heart function to recover. Some of these patients also need to use long-term circulation aids to replace heart function. In addition, the most effective method for the treatment of chronic irreversible heart failure is heart transplantation, but the lack of donor heart restricts the universal application of heart transplantation therapy, and new therapies such as genetic engineering and cell engineering cannot be carried out in a wide range in the foreseeable future. Therefore, ventricular assistive technology has become the only choice in many cases.

The blood pump (also known as the heart pump) is the core of the 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 was a pulse pump developed in the same way as the heart. This type of blood pump uses a pneumatic or electric squeeze pump chamber to beat the blood through the change of the pump chamber volume. The second generation of continuous flow impeller blood pumps was launched in the early 1980s. The blades of such blood pumps are mounted on the blood pump rotor by mechanical bearings. The rotor drives the blades to rotate to push the blood forward or backward along the radial or axial spiral. . The third-generation blood pump is characterized by suspension technology, so all blood pumps developed using magnetic levitation and/or liquid suspension technology are called third-generation blood pumps.

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

The third generation of blood pumps has three stages of development: The first stage is the indirect drive of the impeller stage by the outer motor of the suspension and drive system separation. The suspension technology of the blood pump is relatively simple. The suspension system is separated from the drive system. The blood pump uses an external motor drive technology. The impeller is driven by a separate external motor. The outer motor is connected to the magnetized outer impeller through a mechanical bearing. The outer impeller passes the magnetic force. Driving another suspended magnetized inner impeller to rotate; the inner impeller is the primary drive portion whose rotation drives blood flow. The second stage is the direct drive of the impeller stage by the suspension and drive system separation motor. The blood pump motor directly drives the impeller suspension technology. The suspension system is also separated from the drive system, but the motor cancels the outer leaf The wheel directly uses the suspension impeller as the rotor of the motor. The motor directly drives the suspended impeller to rotate the blood to promote blood flow. The pump still requires an additional magnetic suspension system to suspend the blood pump impeller. The third stage is the fusion phase of the suspension and drive system, that is, the suspension of the blood pump is combined with the drive system. The blood pump design combines the suspension and the electromagnetic coil of the drive system to form the stator, and uses one stator to function as the drive and suspension impeller. Therefore, the design of the pump is more concise, and it represents the blood pump as Ventr Assist.

The third-generation blood pumps are mostly 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 suspension axial flow pump developed by Berlin Heart The blood pump is made of titanium alloy, and 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, and the suspended impeller is axially rotated by the change of the electromagnetic field. Thereby pushing the blood forward; (2) HeartWare pump: The impeller of the pump suspends the pump blade by magnetic suspension and liquid suspension technology. The total stator of the pump is composed of two independent coils. When running, two coils can be simultaneously Work, can also work alone; (3) VentrAssist pump: The pump is in contact with the blood with a pyrolytic carbon coating, which can reduce the incidence of thrombosis, but the pump has a long inflow path, so it still needs to be after the implantation. rectus abdominis rectus sheath or pouches made after pump _placement; (4) No VaCO rVAD pump: a special flow into the system, the pump and the pump body parallel to the inflow conduit design, a flat formed outer Like.

Thrombosis is formed by the accumulation and deposition of platelets, which are commonly found in stagnant areas that are less subject to blood flow and low-velocity areas that are in contact with blood. Hemolysis refers to the high speed or high pressure generated by turbulent motion or mechanical movement that destroys red blood cells in the blood, causing hemoglobin to disperse into the plasma, mainly caused by irregular flow and high shear stress in the turbulent motion zone. Hemolysis and thrombosis are extremely harmful to patients. In clinical applications, thrombosis and hemolysis caused by cardiac assisted circulation devices can cause physiological disturbances in patients, which can lead to complications during and after surgery, and even endanger the lives of patients, especially It has a greater impact on patients who require long-term assisted circulation 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 development of the auxiliary circulation system.

Compared with the first and second generation blood pumps, the third generation blood pump is suspended in the blood pump body due to the application of magnetic levitation technology. Without friction and extrusion, the hemolysis is significantly reduced, the incidence of thrombus is significantly reduced, and there is no bearing wear. The problem is that the durability of the blood pump is improved, and it is more suitable for long-term circulation assistance.

At present, the structure of the third-generation blood pump is still relatively complicated, and the contact surface with the blood is large, and it is easy to generate a blood stagnant area and cause a blood clot. In addition, the blood pump is a disposable product, which should be simple in structure and low in cost; for infants and newborns, the pre-charge of the blood pump should also be minimized. At present, blood pumps with simpler structure, effective reduction of thrombus rate, small pre-charge, low flow rate and low cost have not been reported.

Summary of the invention

SUMMARY OF THE INVENTION The object of the present invention is to provide a single-point magnetic powered centrifugal blood pump in view of the deficiencies in the prior art.

In order to achieve the above object, the technical solution adopted by the present invention is: The utility model relates to a single-point magnetic power centrifugal blood pump, which is provided with a pump body and a driving device. The pump body comprises a top cover, a base, an impeller and an outer magnetic steel, and the base is provided with at least three layers of bosses, the top end The boss is provided with a groove, the groove is disposed in the groove, and the center of the bottom 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 a connecting rod, the connecting rod is collected at the center, the bottom portion forms a circular arc-shaped central groove, and the central groove cooperates with the ball in the groove of the boss to form a single-point bearing; the outer magnetic steel is disposed at The driving device comprises a transmission shaft and a driving motor provided with a motor rotor, wherein the transmission shaft is sleeved on the rotor of the motor and inserted into the insertion hole of the base, and the inner part of the transmission shaft is provided with inner magnetic steel. The inner magnetic steel and the outer magnetic steel have the same number of positively facing pairs, and the adjacent magnetic poles are staggered;

The outer magnetic steel is a rectangular parallelepiped or a cylinder;

The inner magnetic steel is a rectangular parallelepiped or a cylinder;

The base is provided with three layers of bosses;

The balls are spherical or hemispherical;

The balls are made of ceramic;

The blade is a straight blade or curved backward in the direction of blood flow;

The number of the blades is four or six;

The pump motor is externally provided with a pump body mounting device, and the pump body mounting device is a concave platform.

The advantages of the invention are:

1. The single-point 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 retention zone 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 placing the inner magnetic steel in the transmission shaft, the magnetic steel placement problem of the common cavity is solved. At the same time, the blood pump of the invention has the advantages of simple structure and low pre-charge, and is suitable for assisting circulation after pediatric congenital heart disease surgery, and can also be used for extracorporeal circulation during surgery;

3. The ball is spherical or hemispherical, which makes the single-point bearing structure more stable;

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

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 in the direction of blood flow, conforming to the direction of blood flow, can effectively reduce the shearing force on red blood cells in the blood, and reduce the incidence of hemolysis;

7, small size, easy for surgical implantation, while significantly reducing costs.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an assembly view of a single-point magnetic powered centrifugal blood pump of the present invention.

Figure 2 is a view showing the assembly of the single-point magnetic power centrifugal blood pump body of the present invention. Figure 3 is a plan view of Figure 2.

4 is a second-class axis view of the single-point magnetic power centrifugal blood pump impeller of the present invention.

Figure 5 is a bottom view of Figure 4.

Figure 6 is a second axis view of the single-point magnetic power centrifugal blood pump driving device of the present invention.

Figure 7 is a second axial view of another impeller of a single-point magnetic powered centrifugal blood pump of the present invention.

Figure 8 is a second axis view of another driving device of the single-point magnetic power centrifugal blood pump of the present invention;

detailed description

The specific embodiments provided by the present invention are described in detail below with reference to the accompanying drawings.

The reference numerals and components referred to in the drawings are as follows:

1. top cover 101. entrance

102. Export 103. Upper wall

104. outer wall 2. base

201. First boss 2011. The first boss top

2012. First boss body 202. Second boss

203. Third boss 204. Groove

205. Ball 206. Insert hole

3. Impeller 301. Blade

302. Ring connection 303. Connecting rod

304. Central groove 305. External magnetic steel

3051. External magnetic steel top surface 306. Joint

4. Drive motor 401. Motor rotor

5. Drive shaft 501. Inner magnetic steel

6. Pump body installation device

Example 1

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

Please refer to FIG. 2. FIG. 2 is a view showing the assembly of the single-point magnetic 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 internal threads (not shown); the upper wall 103 is tapered and disposed at the top end of the outer wall 104; the inlet 101 is located at the center of the top end of the upper wall 103. Position; the outlet 102 is at a right angle to the inlet 101, as shown in Figure 3 (Figure 3 is a top view of Figure 2 It can be seen that the outlet 102 is placed on the surface of the outer wall 104 in 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 portion 2011 of the first boss 201 is tapered, and a groove 204 is disposed at the center. The groove 204 is disposed with a ball 205, 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 the outer wall thereof is provided with an external thread (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 end of the third boss 203, and 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. The diameter of the body is larger than the diameter of the second boss 202 and 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 form 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-class axis view of the single-point magnetic power centrifugal blood pump impeller of the present invention. The impeller 3 is provided with an annular connection 302. The annular connection 302 is an annular ring, and the inner ring is provided with three connecting rods 303. The three connecting rods 303 are assembled at the center of the impeller 3 to form a joint portion. 306, the joint portion 306 is an annular ring, the central bottom of which is a central groove 304, and the central groove 304 has a circular arc shape. The lower end of the annular connection 302 is provided with four blades 301, and the four blades 301 are discharged in an array, and are connected by an annular connection 302 as a whole to form a half-disc flow passage, and the front end of the blade 3 flows along the blood. The direction is bent backwards. An outer magnetic steel 305 is disposed inside the rear end of the vane 301, and the outer magnetic steel 305 is a sheet-like structure. Referring to FIG. 5, FIG. 5 is a bottom view of FIG. 4, wherein the outer magnetic steel top surface 3051 is rectangular, that is, the outer magnetic steel 305 is a rectangular parallelepiped.

Referring to FIG. 1 , the driving device includes a driving motor 4 and a transmission shaft 5 . The driving motor 4 is externally provided with a pump body mounting device 6 . The pump body mounting device 6 is a concave table and has an inner diameter. The outer diameter of the third boss 203 of the base 2 is equal; the upper end of the drive motor 4 is the motor rotor 401. Please refer to FIG. 6. FIG. 6 is a second axis view of the single-point magnetic power centrifugal blood pump driving device of the present invention. The drive shaft 5 is jacketed on the motor rotor 401. The inner magnet 501 is placed in the drive shaft 5. The inner magnet 501 is a circular sheet-shaped magnetic steel, which is the same as the outer magnet 305.

Referring to FIG. 1, when the single-point magnetic power centrifugal blood pump of the present invention is assembled, the internal thread (not shown) at the bottom end of the outer wall 104 cooperates with the external thread (not shown) of the second boss 202. The top cover 1 and the base 2 form an internal cavity, and the impeller 3 is located in the internal cavity and is mounted on the first boss 201. The central groove 304 and the ball in the groove 204 The 205 is matched 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 apart from the first boss 201 by the same distance, and the first convex The tangential direction of the table 201 is parallel; the outer magnetic steel top surface 3051 of the outer magnet 305 is parallel to the central axis of the first boss 201, and is perpendicular to the radial direction of the first boss 201, and the foot is located outside. The center of the top surface 3051 of the magnetic steel; the inner magnetic steel 501 and the outer magnetic steel 305 have the same number and are placed facing each other, and the adjacent magnetic poles are staggered. The transmission shaft 5 is inserted into the insertion hole 206 of the base 2, and the diameter of the transmission shaft 5 is smaller than the diameter of the insertion hole 206. The pump body mounting device 6 is engaged with the third boss 203 to fix the entire pump body.

Example 2

The single-point magnetic power centrifugal blood pump of this embodiment is basically the same as that of the first embodiment, except that: FIG. 7 is another second-stage measurement of the impeller of the single-point magnetic centrifugal blood pump of the present invention. In the axial view, the impeller 3 is provided with six blades 301, and the blades 301 are straight blades.

Example 3

The single-point magnetic power centrifugal blood pump of this embodiment is basically the same as that of the first embodiment, except that: FIG. 8 is a second-class driving device of the single-point magnetic centrifugal blood pump of the present invention. In the axial view, the inner magnetic steel 501 is a circular piece of magnetic steel. Correspondingly, the outer magnetic steel top surface 3051 of the outer magnetic steel 305 (not shown) is circular, that is, the outer magnetic steel 305 is a sheet-shaped cylinder.

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

The circular arc-shaped central groove 304 cooperates with the hemispherical ball 205 in the groove 204 of the base 2 to form a single-point bearing, and the hemispherical ball 205 axially supports the impeller 3 and is radially fixed. The action of the impeller 3, the single-point bearing has a simple structure, can effectively reduce the contact area with blood, thereby reducing the blood retention zone, 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 The overall structure of the single-point bearing is more stable; the ball 205 can be made of a material that is not easy to wear, such as ceramics;

The outer magnetic steel 305 is placed in the blade 301, and the inner magnetic steel 501 is placed in the drive shaft 5 as a driving magnetic steel, which solves the magnetic steel placement when the driving magnetic steel and the blood flow channel are in the same cavity. The problem is that the structure of the single-point magnetic power centrifugal blood pump of the present invention is simpler; the outer magnetic steel 305 and the inner magnetic steel 501 are disposed in the same direction, and the adjacent magnetic poles are staggered to prevent the synchronization from being lost during rotation; The outer magnetic steel 305 has a thickness of l-2 mm, and the shape thereof is preferably a rectangular parallelepiped; the inner magnetic steel 501 has a thickness of l-2 mm, and the shape thereof is preferably a rectangular parallelepiped;

The number of the blades 301 of the impeller 3 is generally designed to be an even number, but not limited to four or six; the rear end of the blade 301 is 5-10 mm from the central axis of the impeller 3, and the length of the blade 301 is <30 mm; The width of the gap between the rear end of the blade 301 and the first boss 201 is 0.5 mm; the shape of the blade 301 is preferably that the front end is bent backward in the blood flow direction, which can effectively reduce red blood cells in the blood. Shear force to prevent hemolysis.

The shape of the central groove 304 is preferably hemispherical; the number of the bosses of the base 2 is at least three, but not limited to three, the design of the boss can effectively reduce the pre-charge; The outer wall 104 and the second boss 201 are not limited to the screw connection, and any connection manner may be used, such as adhesive glue sealing; the outer wall 104 has an outer diameter of 40-60 mm; the pump body mounting device 6 has a bump pin. Its function is to fix the pump body and prevent the pump body from rotating with the drive shaft 5, so the part can be omitted. The working principle of the single-point magnetic power centrifugal blood pump of the invention is as follows: the rotor 401 of the motor rotates to drive the transmission shaft 5 to rotate, and the inner magnetic steel 501 placed inside the transmission shaft 5 follows the rotation, thereby driving the outer magnetic steel 305 to rotate. The outer magnetic steel 305 inside the blade 301 drives the impeller to rotate, and the blood enters into the cavity formed by the top cover 1 and the base from the inlet 101, and flows down from the gap between the connecting rods 303 of the impeller 3, under the centrifugal action of the impeller 3. , pumped out from the outlet 102. The single-point magnetic centrifugal blood pump has the advantages of low pre-charge, and the pre-charge can reach 23 ml, which can effectively reduce the incidence of thrombus and hemolysis, and has the advantages of simple and stable structure, convenient installation and low cost.

Claims

Rights request

A single-point magnetic-powered centrifugal blood pump provided with a pump body and a driving device, characterized in that

The pump body comprises a top cover, a base, an impeller and an outer magnetic steel, the base is provided with at least three layers of bosses, the top end of the boss is provided with a groove, and the groove is disposed in the groove, the base The bottom of the bottom is provided with an insertion hole; the impeller is provided with a blade and an annular connection, and the annularly connected inner ring is provided with a connecting rod, the connecting rod is collected at the center, and the bottom forms a circular arc-shaped center a groove, the central groove cooperates with a ball in the groove of the boss to form a single-point bearing; the outer magnetic steel is disposed inside the blade;

The driving device comprises a transmission shaft and a driving motor provided with a motor rotor, the transmission shaft is sleeved on the rotor of the motor and inserted into the insertion hole of the base, and the inner part of the transmission shaft is provided with inner magnetic steel, The inner magnetic steel is the same as the outer magnetic steel, and the adjacent magnetic poles are staggered.

2. The single-point magnetic power centrifugal blood pump according to claim 1, wherein the outer magnetic steel is a rectangular parallelepiped or a cylinder.

The single-point magnetic power centrifugal blood pump according to claim 1, wherein the inner magnetic steel is a rectangular parallelepiped or a cylinder.

4. The single-point magnetic power centrifugal blood pump according to claim 1, wherein the base is provided with a three-layer boss.

The single-point magnetic power centrifugal blood pump according to claim 1, wherein the balls are spherical or hemispherical.

The single-point magnetic power centrifugal blood pump according to claim 1, wherein the balls are made of ceramic.

The single-point magnetic-powered centrifugal blood pump according to claim 1, wherein the blade is a straight blade or curved backward in a blood flow direction.

The single-point magnetic power centrifugal blood pump according to claim 1, wherein the number of the blades is four or six.

9. The single-point magnetic power centrifugal blood pump according to claim 1, wherein the driving motor is provided with a pump body mounting device, and the pump body mounting device is a recess.