Interventional catheter pumpTechnical Field
The invention relates to the technical field of medical appliances, in particular to an interventional catheter pump.
Background
Acute heart failure refers to a condition in which the heart fails to discharge the whole amount of heart blood due to the development of an organic heart disease to a decrease in myocardial contractility, and the heart stroke volume decreases, resulting in serious insufficiency of blood supply to the pulmonary venous stasis arterial system. Because of the sudden and severe nature of acute heart failure, there is a need for a therapeutic approach that can rapidly provide support to patients, and thus, interventional catheter pumps are the mainstay of treatment for acute heart failure.
The interventional catheter pump does not need complex open chest operation, can enter the heart chamber of a patient along blood vessels, increases blood flow, enhances blood perfusion, reduces myocardial oxygen consumption, helps acute heart failure patients to enhance heart pumping function in a short period, and lightens heart burden of the patients. Due to the special implantation of the interventional catheter pump, the size of the interventional catheter pump has to be small, which places high demands on the core component of the interventional catheter pump, the motor.
Currently, the motors of interventional catheter pumps are generally divided into two types, an in-vivo motor and an in-vitro motor. The external motor is large and needs to be connected with an impeller of the catheter pump connected into the body through a long flexible shaft so as to drive the impeller to rotate, thereby realizing the blood pumping function, but the flexible shaft has low transmission efficiency and short service life, so that the internal motor structure becomes a main stream product of the prior interventional catheter pump.
However, there are many pain points in the in-vivo motor, because of the size limitation of the interventional catheter pump, the diameter of the in-vivo motor is generally not more than 6mm, and because of the size of the interventional catheter pump, the diameter of the impeller is also very small, so that in order to achieve the purpose of relieving the heart burden of a patient and enhancing the blood pumping of the heart, the rotating speed of the in-vivo motor must reach a rotating speed of tens of thousands of revolutions per minute, and the high rotating speed can cause the temperature of the motor to rise, thereby threatening the life safety of the patient. Therefore, the in-vivo motors are all provided with a perfusion system, and perfusion liquid such as anti-coagulation water is pumped into the in-vivo motors from outside the body through a pipeline so as to reduce the heating temperature of the motors and reduce the probability of coagulation.
However, the existing perfusion system has some defects, in order to realize the sealing of the motor in the body and prevent blood from entering the motor, the existing perfusion mode is to flow the perfusion liquid into the motor and flow out from between the bearing and the rotating shaft, and overcome the pressure and flow resistance of the blood. Therefore, this presents a higher challenge for the motor, which must have a strong waterproof capacity, greatly increasing the manufacturing costs of the intervention pump. Meanwhile, because the pressure of the perfusion fluid is large, the bearing pressure of the perfusion system is also required to be high, the situation that the catheter is propped and exploded by the perfusion fluid pressure and the perfusion fluid leaks easily occurs, and the safety of a patient can be seriously threatened.
Disclosure of Invention
The invention aims to solve the problem of providing an interventional catheter pump so as to overcome the defects that the existing interventional catheter pump has high motor waterproof requirement, short service life and large perfusion pressure and is easy to cause safety accidents.
The technical scheme includes that the interventional catheter pump comprises a blood pumping system and a perfusion system, wherein the blood pumping system comprises a motor, an impeller, a blood pumping catheter, a blood inlet and a blood outlet, the blood inlet and the blood outlet are formed in two ends of the blood pumping catheter, the impeller is arranged on the motor, the motor is used for driving the impeller to rotate to do work so as to pump blood into the blood pumping catheter from the blood inlet and flow out of the blood outlet, the perfusion system comprises a perfusion tube connected to the motor, the motor comprises a motor shell and a motor stator, the motor stator is arranged in the motor shell, a perfusion flow channel is formed between the motor shell and the motor stator, one end of the motor shell is provided with a perfusion hole communicated with the perfusion flow channel, and the perfusion tube is communicated with the blood outlet through the perfusion hole and the perfusion flow channel, so that a perfusion channel is formed.
As a further improvement of the invention, the motor housing is a hollow column, one end of the motor housing is provided with a first end cover, one end of the motor stator is connected with the first end cover in a sealing way, the outer diameter of the motor stator is smaller than the inner diameter of the motor housing, the pouring flow channel is formed by a gap between the inner peripheral surface of the motor housing and the outer peripheral surface of the motor stator, and the pouring hole is arranged on the first end cover.
As a further improvement of the invention, the motor further comprises a motor rotor which is coaxially arranged in the motor stator in a rotating way, wherein the motor rotor is provided with a rotating shaft, and one end of the rotating shaft extends out of the motor shell and is fixedly connected with the impeller.
As a further improvement of the invention, a second end cover is arranged at the other end of the motor shell, a through hole is arranged on the second end cover, the rotating shaft is in clearance fit in the through hole, and the perfusion flow channel is communicated with the blood outlet through a clearance between the rotating shaft and the second end cover.
As a further improvement of the invention, a dynamic sealing element is arranged between the other end of the motor stator and the rotating shaft.
As a further improvement of the invention, the dynamic sealing element comprises a sealing shell with a hollow inside and magnetic fluid, wherein the sealing shell is connected with the other end of the motor stator in a sealing way and sleeved on the rotating shaft, and the magnetic fluid is contained in the sealing shell and wraps the peripheral surface of the corresponding part of the rotating shaft.
As a further improvement of the invention, the motor rotor is also provided with rotor magnetic steel distributed around the rotating shaft, and the rotor magnetic steel is formed by arranging a plurality of permanent magnets in a Halbach array mode.
As a further improvement of the invention, a wire guide channel is arranged between the motor shell and the motor stator, one end of the motor shell is also provided with a wire guide hole communicated with the wire guide channel, and the perfusion tube is communicated with the wire guide hole.
As a further improvement of the invention, the distal end of the blood pumping catheter is fixedly connected with an inlet pipe, the blood inlet is arranged on the inlet pipe, the distal end of the inlet pipe is provided with a pigtail pipe, an impeller shell is fixedly connected between the proximal end of the blood pumping catheter and the motor shell, the impeller is arranged in the impeller shell, and the blood outlet is arranged on the impeller shell.
As a further development of the invention, the interventional catheter pump further comprises a catheter fixedly connected to the motor housing, the irrigation tube being arranged in the catheter, while a cable for powering the motor is also arranged in the catheter.
The beneficial effects of the invention are as follows:
1. According to the interventional catheter pump, the perfusion flow channel is arranged between the motor shell and the motor stator, the perfusion liquid firstly enters the perfusion flow channel through the perfusion hole and then flows out of the motor and enters blood from the blood outlet, the flowing perfusion liquid not only can take away heat generated when the motor rotates at a high speed, but also can bring heparin water in the perfusion liquid into the blood, so that an anticoagulation effect is achieved;
2. Because the perfusion liquid flows along the perfusion flow channel between the motor shell and the motor stator instead of the inside of the motor, the waterproof performance requirement of the motor is greatly reduced, the service life of the motor is prolonged, the area of the perfusion flow channel is increased, the perfusion pressure of the perfusion liquid is greatly reduced, the bearing force of a perfusion system is reduced, the risk of leakage of the perfusion liquid caused by the explosion of the perfusion pipe by the perfusion liquid pressure is avoided, the use safety is improved, and the long-term implantation assistance of the interventional catheter pump is possible;
3. According to the invention, the dynamic sealing element is arranged between the motor stator and the rotating shaft, and the characteristics of the magnetic fluid are utilized, so that the rotating shaft is still full of the sealing shell in the rotating process, and the rotating shaft is always wrapped by the magnetic fluid, so that blood and perfusate cannot enter the motor through a gap between the rotating shaft and the front end of the motor stator, the dynamic sealing function is realized, the waterproof requirement and the cost of the motor are reduced, and the service life of the motor is prolonged;
4. The rotor magnetic steel is formed by arranging a plurality of permanent magnets in a Halbach array mode, so that the magnetic force on the outer side of a motor rotor can be greatly enhanced, the efficiency of the motor is improved, the rotating speed of the motor can be reduced under the same power requirement, and the service lives of the motor and the interventional catheter pump are further prolonged.
Drawings
FIG. 1 is a perspective view of an interventional catheter pump of the present invention;
FIG. 2 is a perspective view of the motor, impeller and impeller housing assembly of the interventional catheter pump of the present invention;
FIG. 3 is an exploded view of the motor, impeller and impeller housing of the interventional catheter pump of the present invention;
FIG. 4 is a cross-sectional view of the motor, impeller and impeller housing of the interventional catheter pump of the present invention;
FIG. 5 is an enlarged view of portion A of FIG. 4 in accordance with the present invention;
FIG. 6 is a cross-sectional view of a catheter of an interventional catheter pump of the present invention and an irrigation tube and cable inside thereof;
FIG. 7 is a perspective view of a rotor magnet steel of an interventional catheter pump of the present invention;
FIG. 8 is a perspective view of another embodiment of a rotor magnet steel of an interventional catheter pump of the present invention;
FIG. 9 is a perspective view of a further embodiment of a rotor magnet steel of an interventional catheter pump of the present invention;
FIG. 10 is a schematic illustration of the application of the interventional catheter pump of the present invention to the heart;
The direction indicated by the arrow in fig. 4 represents the flow direction of the perfusate.
The following description is made with reference to the accompanying drawings:
1. Motor, 11, motor housing, 111, first end cap, 112, second end cap, 1121, through hole, 12, motor stator, 121, convex rib, 13, pouring runner, 14, pouring hole, 15, motor rotor, 151, rotating shaft, 152, rotor magnetic steel, 16, dynamic seal piece, 161, sealing shell, 162, magnetic fluid, 17, guide wire channel, 18, guide wire hole, 19, bearing, 2, impeller, 3, pumping conduit, 4, inlet pipe, 41, blood inlet, 5, impeller housing, 51, blood outlet, 6, pouring pipe, 7, pig tail pipe, 8, conduit, 9, cable.
Detailed Description
A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
It should be noted that the terms "proximal", "distal", "anterior", "posterior" are used herein with respect to a physician manipulating an interventional catheter pump. The terms "proximal", "posterior" and "distal" refer to portions relatively closer to the physician, and the terms "distal" and "anterior" refer to portions relatively farther from the physician. For example, the extracorporeal portion of the catheter 8 is located at the proximal or rear end, while the pumping system is located at the distal or front end. It should be understood that these orientations of "proximal", "distal", "anterior" and "posterior" are defined for purposes of illustration, and that the interventional catheter pump may be used in a variety of orientations and positions, and therefore these terms of relative positional relationships are not limiting and absolute.
Referring to fig. 1-10, the present invention provides an interventional catheter pump including a blood pumping system and a perfusion system. The blood pumping system comprises a motor 1, an impeller 2, a blood pumping conduit 3, and a blood inlet 41 and a blood outlet 51 which are arranged at two ends of the blood pumping conduit 3.
Specifically, in the present embodiment, the distal end of the blood pumping catheter 3 is fixedly connected to the inlet tube 4, and the blood inlet 41 is formed by a plurality of grid holes opened in the circumferential direction of the inlet tube 4. The distal end fixed mounting of entry pipe 4 has tail pipe 7, and tail pipe 7 can reduce the scraping damage to blood vessel inner wall and corresponding tissue at the in-process of implantation intervention catheter pump, reduces the risk of complication, also helps keeping specific position in the heart simultaneously, is difficult for taking place to remove, guarantees the steady operation of intervention catheter pump. An impeller shell 5 is fixedly connected between the proximal end of the blood pumping catheter 3 and a motor shell 11 of the motor 1, the impeller shell 5 is tubular, the impeller 2 is positioned in the impeller shell 5 and connected with the motor 1, and a blood outlet 51 is formed by a plurality of grid holes formed in the impeller shell 5 along the circumferential direction.
When the motor 1 is operated, the impeller 2 can be driven to rotate to do work, and blood is pumped into the blood pumping conduit 3 from the blood inlet 41 and flows out from the blood outlet 51 under the action of centrifugal force generated by the impeller 2.
Illustratively, the pump catheter 3 may employ an artificial blood vessel.
Further, the irrigation system comprises an irrigation tube 6, the distal end of the irrigation tube 6 being connected to the motor 1. The motor 1 comprises a motor shell 11 and a motor stator 12 arranged in the motor shell 11, a perfusion flow channel 13 is arranged between the motor shell 11 and the motor stator 12, a perfusion hole 14 communicated with the perfusion flow channel 13 is arranged at the rear end of the motor shell 11, and the perfusion tube 6 is led to a blood outlet 51 through the perfusion hole 14 and the perfusion flow channel 13, so that a perfusion passage is formed.
After the interventional catheter pump is implanted in the body, the perfusion tube 6 can be used for pumping perfusion fluid into the interventional catheter pump, the perfusion fluid passes through the perfusion hole 14 and enters the perfusion flow channel 13 between the motor shell 11 and the motor stator 12, then flows out of the motor 1 and enters blood from the blood outlet 51, and the flowing perfusion fluid can not only take away heat generated when the motor 1 rotates at a high speed, but also can bring heparin water in the perfusion fluid into the blood to play a role of anticoagulation. Meanwhile, because the perfusate flows along the perfusate channel 13 between the motor shell 11 and the motor stator 12, but not inside the motor 1 (between the motor stator 12 and the motor rotor 15), the waterproof performance requirement of the motor 1 is greatly reduced, and the service life of the motor 1 is prolonged; in addition, compared with the traditional mode of arranging the pouring runner 13 inside the motor shell 11, the invention greatly increases the area of the pouring runner 13, thereby greatly reducing the pouring pressure of the pouring liquid, simultaneously reducing the bearing force of a pouring system, avoiding the risk of pouring liquid leakage caused by the explosion of the pouring pipe 6 by the pouring liquid pressure, improving the use safety and enabling the long-term implantation assistance of the interventional catheter pump to be possible.
In the invention, the interventional catheter pump further comprises a catheter 8, the distal end of the catheter 8 is fixedly connected to the rear end of the motor housing 11, the perfusion tube 6 is arranged in the catheter 8, and meanwhile, a cable 9 for supplying power to the motor 1 is also arranged in the catheter 8.
Referring to fig. 2 to 4, the motor housing 11 is of a hollow cylindrical shape, the motor stator 12 is also of a hollow cylindrical shape, the motor stator 12 is coaxially fixed in the motor housing 11, the outer diameter of the motor stator 12 is smaller than the inner diameter of the motor housing 11, and the pouring flow channel 13 is formed by a gap between the inner peripheral surface of the motor housing 11 and the outer peripheral surface of the motor stator 12.
The rear end of the motor housing 11 is provided with a first end cover 111, and the rear end of the motor stator 12 is connected to the inner side of the first end cover 111 in a sealing manner, so that the rear end position inside the motor 1 is sealed. The pouring aperture 14 is provided on the first end cap 111.
Preferably, in this embodiment, a plurality of ribs 121 are axially disposed on the outer peripheral surface of the motor stator 12, and the plurality of ribs 121 are fixedly connected with the inner peripheral surface of the motor housing 11, so as to enhance the structural strength of the assembly of the two. The plurality of ribs 121 are distributed at equal intervals in the circumferential direction to equally divide the pouring flow channel 13 into a plurality of flow channels, and a plurality of pouring holes 14 which are communicated with the flow channels in a one-to-one correspondence manner are correspondingly arranged on the first end cover 111, and the pouring tube 6 is communicated with the pouring holes 14.
Referring to fig. 4 and 5, the motor 1 further includes a motor rotor 15, and the motor rotor 15 is coaxially rotatably disposed within the motor stator 12. The motor rotor 15 is provided with a rotating shaft 151, the rear end and the middle part of the rotating shaft 151 are respectively rotatably arranged in the motor stator 12 through two bearings 19, and the front end of the rotating shaft 151 extends out of the motor shell 11 and is fixedly connected with the impeller 2.
In the invention, the front end of the motor shell 11 is provided with a second end cover 112, the middle part of the second end cover 112 is provided with a through hole 1121, a rotating shaft 151 is in clearance fit in the through hole 1121, and the perfusion flow channel 13 is communicated with the blood outlet 51 through the clearance between the rotating shaft 151 and the second end cover 112.
It should be noted that the dynamic seal 16 is installed between the front end of the motor stator 12 and the rotating shaft 151 to realize the front end position seal inside the motor 1.
Specifically, the dynamic seal 16 includes a seal housing 161 that is hollow in the interior and a magnetic fluid 162. In this embodiment, the seal housing 161 may be a cake with a certain thickness, and the middle part of the seal housing 161 is provided with a central hole slightly larger than the diameter of the rotating shaft 151, the rear side of the seal housing 161 is connected to the front end of the motor stator 12 in a sealing manner, meanwhile, the seal housing 161 is further sleeved on the rotating shaft 151, the rotating shaft 151 coaxially passes through the central hole on the seal housing 161, the magnetic fluid 162 is contained in the seal housing 161 and wraps the peripheral surface of the corresponding part of the rotating shaft 151, and the magnetic fluid 162 is still filled in the seal housing 161 and always wraps the rotating shaft 151 in the rotating process by utilizing the characteristic of the magnetic fluid 162, so that blood and perfusate cannot enter the motor 1 through a gap in the bearing 19 between the rotating shaft 151 and the front end of the motor stator 12, thereby realizing a dynamic sealing function, reducing the waterproof requirement and cost of the motor 1, and increasing the service life of the motor 1.
In addition, the motor rotor 15 of the present invention is further provided with rotor magnetic steels 152, and the rotor magnetic steels 152 are distributed around the rotating shaft 151 and fixedly connected with the rotating shaft 151. The rotor magnetic steel 152 is used for generating torque under the action of a magnetic field generated when the motor stator 12 is electrified so as to drive the rotating shaft 151 to rotate.
It should be noted that, the rotor magnetic steel 152 in the present invention is formed by arranging a plurality of permanent magnets in a Halbach array manner, and has a ring column shape.
Specifically, the rotor magnetic steel 152 includes a first magnetic shoe and a second magnetic shoe, the sections of the first magnetic shoe and the second magnetic shoe are sector-shaped, and the number of the first magnetic shoe and the second magnetic shoe is the same and is 2N, where N is a natural number greater than or equal to 1. The first magnetic shoes are magnetized along the radial direction, namely the magnetic polarities of the first magnetic shoes are distributed on the inner ring and the outer ring, the second magnetic shoes are magnetized along the circumferential direction, namely the magnetic polarities of the second magnetic shoes are distributed on two ends along the circumferential direction, and meanwhile, the magnetic polarities of one end of the second magnetic shoes, which is abutted against the first magnetic shoes, are the same as the magnetic polarities of the outer ring of the first magnetic shoes. In the circumferential direction, the first magnetic shoes and the second magnetic shoes are alternately arranged, so that the rotor magnetic steel 152 is spliced.
It can be appreciated that the number of magnetic poles of the rotor magnetic steel 152 formed by splicing the first magnetic shoe and the second magnetic shoe in different numbers is different, that is, the number of magnetic poles on the outer circumferential surface of the rotor magnetic steel 152 may have 2N magnetic poles.
Fig. 7 shows an embodiment of a rotor magnetic steel 152 according to the present invention, which includes two first magnetic shoes and two second magnetic shoes, wherein the magnetizing directions of the two first magnetic shoes are opposite, the magnetizing directions of the two second magnetic shoes are opposite, and the two first magnetic shoes and the two second magnetic shoes are alternately arranged along the circumferential direction to be spliced into the rotor magnetic steel 152 with the magnetic pole number of 2.
Fig. 8 shows another embodiment of a rotor magnetic steel 152 according to the present invention, which is formed by alternately arranging and splicing four first magnetic shoes and four second magnetic shoes along the circumferential direction, wherein the number of poles of the rotor magnetic steel 152 is 4.
Fig. 9 shows another embodiment of the rotor magnetic steel 152 according to the present invention, which is formed by alternately arranging and splicing six first magnetic shoes and six second magnetic shoes along the circumferential direction, wherein the number of magnetic poles of the rotor magnetic steel 152 is 6.
Because the rotor magnetic steel 152 is formed by arranging a plurality of permanent magnets in a Halbach array mode, the structure can greatly strengthen the magnetic force on the outer side of the motor rotor 15, thereby improving the efficiency of the motor 1, reducing the rotating speed of the motor 1 and prolonging the service lives of the motor 1 and the interventional catheter pump under the same power requirement.
In order to facilitate the physician's implantation of the interventional catheter pump into the patient's ventricle along the blood vessel, the present invention also provides a guidewire channel 17 between the motor housing 11 and the motor stator 12. As shown in fig. 3, in this embodiment, the guide wire channel 17 may be regarded as being formed by a groove provided in one of the ribs 121 in the axial direction. Meanwhile, a wire guide hole 18 communicating with the wire guide passage 17 is correspondingly provided on the first end cover 111 of the motor housing 11.
It should be noted that the guide wire is an auxiliary component of the interventional catheter pump of the present application when applied to the heart, and is not included in the scope of the present application, and thus, it is not described in detail.
It should be noted that, the pouring tube 6 is also communicated with the guide wire hole 18, so that the guide wire channel 17 can also be used as one of the pouring liquid channels, thereby improving the heat dissipation effect and further increasing the flow channel area of the pouring liquid.
Before the interventional catheter pump is implanted in the body, the guide wire needs to be penetrated into the guide wire hole 18 through the perfusion tube 6, and the guide wire is led to the distal end along the guide wire channel 17 and the blood pumping catheter 3 until reaching the tail pipe 7, then the guide wire is inserted into the left ventricle, and after the interventional catheter pump is implanted into the left ventricle along the guide wire, the guide wire is extracted.
As shown in fig. 10, the pump catheter 3 is stuck in the active valve with the blood inlet 41 in the left ventricle and the blood outlet 51 in the aorta. When the interventional catheter pump is operated, blood in the left ventricle is pumped into the aorta from the blood outlet 51 along the blood pumping catheter 3 via the blood inlet 41, thereby realizing the heart assist function and reducing the heart burden.
Therefore, the invention provides the interventional catheter pump, the perfusion flow channel 13 is arranged between the motor shell 11 and the motor stator 12, the perfusion fluid firstly enters the perfusion flow channel 13 through the perfusion hole 14 and flows out of the motor 1, and enters blood from the blood outlet 51, the flowing perfusion fluid not only can take away heat generated when the motor 1 rotates at a high speed, but also can bring heparin water in the perfusion fluid into the blood to play an anticoagulant role, and the perfusion fluid in the interventional catheter pump flows along the perfusion flow channel 13 between the motor shell 11 and the motor stator 12 instead of the inside of the motor 1, thereby greatly reducing the waterproof performance requirement of the motor 1, enhancing the service life of the motor 1, simultaneously increasing the area of the perfusion flow channel 13, further greatly reducing the perfusion pressure of the perfusion fluid, reducing the bearing pressure of a perfusion system, avoiding the risk of leakage of the perfusion fluid caused by explosion of the perfusion tube 6 by the perfusion fluid pressure, improving the use safety, and enabling long-term implantation assistance of the interventional catheter pump to be possible. Further, according to the invention, the dynamic seal 16 is arranged between the motor stator 12 and the rotating shaft 151, and the characteristics of the magnetic fluid 162 are utilized, so that the rotating shaft 151 is still full of the seal shell 161 in the rotating process, and the rotating shaft 151 is always wrapped by the magnetic fluid 162, so that blood and perfusate cannot enter the motor 1 through a gap between the rotating shaft 151 and the front end of the motor stator 12, the dynamic seal function is realized, the waterproof requirement and cost of the motor 1 are reduced, and the service life of the motor 1 is prolonged. In addition, the rotor magnetic steel 152 is formed by arranging a plurality of permanent magnets in a Halbach array mode, so that the magnetic force on the outer side of the motor rotor 15 can be greatly enhanced, the efficiency of the motor 1 is improved, the rotating speed of the motor 1 can be reduced under the same power requirement, and the service lives of the motor 1 and the interventional catheter pump are further prolonged.
In the above description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The foregoing description is only of a preferred embodiment of the invention, which can be practiced in many other ways than as described herein, so that the invention is not limited to the specific implementations disclosed above. While the foregoing disclosure has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes and modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. Any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention without departing from the technical solution of the present invention still falls within the scope of the technical solution of the present invention.