CN118022165B

CN118022165B - Interventional axial blood pump

Info

Publication number: CN118022165B
Application number: CN202410367266.3A
Authority: CN
Inventors: 胡佳; 翁孟坤; 王朋; 周志鹏; 文泽军
Original assignee: Wuhan Wanzhida Intelligent Technology Co ltd; Once Top Motor Manufacture Co ltd
Current assignee: Wuhan Wanzhida Intelligent Technology Co ltd; Once Top Motor Manufacture Co ltd
Priority date: 2024-03-28
Filing date: 2024-03-28
Publication date: 2024-09-17
Anticipated expiration: 2044-03-28
Also published as: CN118022165A

Abstract

The invention discloses an interventional axial flow blood pump, which comprises an impeller mounting cylinder, a stator assembly, an optical fiber type pressure sensor and a tail wrapping and sealing device, wherein the stator assembly comprises a stator shell, a magnetic conduction stator and a stator winding; the tail wrapping and sealing device comprises a right sealing cover, a guide wire and an outer casing pipe, wherein a through hole and a blind hole are formed in the right end of the right sealing cover, a liquid through pipe is connected at the through hole of the right sealing cover in a sealing mode, the guide wire is connected with the blind hole of the right sealing cover in a sealing mode, and the right ends of a power line, an optical fiber and the liquid through pipe penetrate through the right sealing cover and then enter the outer casing pipe. According to the invention, the optical fiber type pressure sensor is placed by arranging the groove on the surface of the stator shell, so that extra use space is not increased, the phenomenon that the power output is influenced due to occupation of the internal structure of the blood pump is avoided, and the power line, the optical fiber, the liquid-passing tube and the guide wire can be well wrapped by the outer sleeve to realize packaging.

Description

Interventional axial blood pump

Technical Field

The invention belongs to the field of interventional medical instruments, and particularly relates to an interventional axial flow blood pump.

Background

In recent years, the performance of a continuous blood flow left ventricular assist device (an artificial blood pump) has been greatly improved, and the implantation amount has been increased year by year, but complications caused after implantation often afflict postoperative patients and affect the life quality of the patients, and the occurrence of the complications has a close relationship with poor blood pressure control. For an interventional type artificial blood pump with miniaturized structure, how to integrate the blood pressure monitoring function into a product becomes an important expression of the product in practical use. The interventional artificial blood pump monitors cardiovascular internal pressure generally by installing a miniature pressure sensor, and the data monitoring achieves real-time accurate control, so that the interventional artificial blood pump has great significance for smooth progress in the operation process and life support in the postoperative recovery period.

In the prior art, a pressure sensor and an optical fiber are adhered to the outer surface of a miniature blood pump, and are covered and fixed by biocompatible glue, so that the installation process is inconvenient and the local bulge of the surface of the blood pump occupies space. In addition, the tail pipe of the tail part of some miniature blood pumps adopts locking parts such as locking rings and the like to be arranged on the blood pump body, blood is easy to remain in gaps and edges of the locking parts to be coagulated in long-term use, the cleaning is difficult, and the pushing and supporting effects of the tail pipe on the blood pump body are also poor, so that the blood pump body is inconvenient to move in blood vessels.

Disclosure of Invention

Aiming at the defects or improvement demands of the prior art, the invention provides an interventional axial flow blood pump, which reliably installs an optical fiber pressure sensor on the premise of not influencing the performance of the axial flow blood pump, and conveniently and effectively gathers and wraps the optical fiber of the optical fiber pressure sensor and other pipelines and wires, so that the function of the axial flow blood pump is more perfect.

In order to achieve the above object, according to the present invention, there is provided an interventional axial flow blood pump, comprising an impeller mounting cylinder, a stator assembly, an optical fiber type pressure sensor and a tail wrapping and sealing device, wherein the stator assembly comprises a stator shell, a magnetic conducting stator and a stator winding which are sequentially connected from outside to inside, the stator winding is connected with the left end of a power line, the impeller mounting cylinder is mounted at the left end of the stator shell, and a blood outlet is arranged on the impeller mounting cylinder, and a groove is arranged on the outer side wall of the stator shell, wherein:

The optical fiber type pressure sensor is arranged in the groove and used for measuring the pressure of blood flowing out of the blood outlet, the optical fiber type pressure sensor does not exceed the outer side wall of the stator shell, the optical fiber type pressure sensor is provided with an optical fiber, the optical fiber extends along the groove, and the right end of the optical fiber exceeds the right end of the groove;

The tail wrapping and sealing device comprises a right sealing cover, a guide wire, a liquid passing pipe and an outer wrapping sleeve, wherein the left end of the right sealing cover is in sealing connection with the right end of the stator shell, the right end of the right sealing cover is in sealing connection with the outer wrapping sleeve, the right end of the right sealing cover is provided with a through hole and a blind hole, the liquid passing pipe is in sealing connection with the through hole of the right sealing cover, the left end of the liquid passing pipe stretches into an inner cavity of the right sealing cover so as to be used for introducing high-pressure liquid into the stator shell, the blind hole of the right sealing cover is in sealing connection with the left end of the guide wire, the right end of the power wire, the right end of the optical fiber and the right end of the liquid passing pipe all penetrate through the right sealing cover and then enter the outer wrapping sleeve, the power wire, the optical fiber, the liquid passing pipe and the guide wire are wrapped on the side wall of the right sealing cover, so that the optical fiber stretches into the right sealing cover and then enters the outer wrapping sleeve, and the wire passing hole adopts biocompatible sealing glue;

The right seal cover comprises an outer cover, an inner cover and a tail cover, and the stator shell comprises an outer shell, wherein:

The left end of the inner cover is fixedly connected with the right end of the outer shell, the left end of the tail cover is fixedly connected with the right end of the inner cover, the right end of the tail cover is provided with the through hole and the blind hole, the through hole of the tail cover is clamped with the liquid through pipe, the left end of the liquid through pipe stretches into the inner cavity of the tail cover, and the left end of the guide wire is clamped into the blind hole of the tail cover;

the left end of the outer cover is fixedly connected to the right end of the outer shell, the inner cover and the tail cover are both positioned in the outer cover, and the wiring hole is formed in the outer cover;

The power line, the optical fiber and the liquid through pipe all penetrate through the outer cover, and the right end of the outer cover is connected with the outer packaging sleeve in a sealing mode.

Preferably, the grooves are covered with biocompatible glue for completely fixing the probe head and the optical fiber of the optical fiber type pressure sensor, and the gaps and edges of the grooves are filled and covered with the biocompatible glue so as to avoid residual blood coagulation.

Preferably, the liquid-passing tube is made of biocompatible plastic and has a straightened length of 1.3-2 m, and the guide wire is made of biocompatible nickel-titanium wire material and has a straightened length of 1.3-1.8 m.

Preferably, the right ends of the power wire, the optical fiber, the liquid passing tube and the guide wire do not exceed the outer sleeve.

Preferably, the fiber optic pressure sensor further has a probe head connected to the optical fiber;

for the groove, the groove depth of the part for placing the probe is 0.06-0.25 mm, and the groove depth of the part for placing the optical fiber is 0.06-0.15 mm.

Preferably, the rotor assembly of the interventional axial flow blood pump comprises a rotating shaft, a permanent magnet and a rotor sleeve which are sequentially connected from inside to outside, and the stator shell further comprises a left sealing cover connected to the left end of the shell;

The interventional axial flow blood pump further comprises a left end bearing, a right end bearing, an impeller and a pre-tightening spring, wherein the left end bearing and the right end bearing are ball bearings, an outer ring of the right end bearing is fixedly arranged on the right sealing cover, and the pre-tightening spring is arranged on the rotating shaft in a penetrating manner;

The left sealing cover is provided with a horizontal step hole, the step hole is a through hole and comprises a first hole, a second hole and a third hole which are sequentially arranged from left to right and have diameters from small to large, the first step of the inner wall of the left sealing cover forms the first hole and the second hole, the second step of the inner wall of the left sealing cover forms the second hole and the third hole, the left end of the rotating shaft penetrates through the left sealing cover from the step hole and is then connected with the impeller, a first gap is formed between the hole wall of the first hole and the rotating shaft, the first gap is used as an outlet of high-pressure liquid which is introduced into a motor shell, the outer ring of the left end bearing is fixedly arranged on the hole wall of the third hole and is abutted against the second step, the outer diameter of the inner ring of the left end bearing is smaller than the aperture of the second hole, the inner ring of the left end bearing is matched with the permanent magnet to clamp the pre-tightening spring, and the pre-tightening spring exerts elastic force on the inner ring of the left end bearing;

A second gap and a third gap are formed between the inner ring of the left end bearing and the inner ring of the right end bearing and the rotating shaft respectively, the second gap enables the inner ring of the left end bearing to reciprocate along the axial direction of the rotating shaft under the elasticity of the pre-tightening spring and enables the inner ring of the left end bearing and the rotating shaft to still synchronously rotate, the third gap enables the inner ring of the right end bearing and the rotating shaft to still synchronously rotate, a force transmission piece is fixedly arranged on the rotating shaft and rightwards applies force on the inner ring of the right end bearing under the elasticity of the pre-tightening spring;

The impeller mounting cylinder is fixedly mounted on the left sealing cover and surrounds the impeller, the inner cavity of the impeller mounting cylinder is communicated with the first gap, and the side wall of the impeller mounting cylinder is provided with the blood outlet at a position corresponding to the impeller.

Preferably, the first step is provided with a chamfer so as to form a flare with a gradually decreasing diameter in the direction from the second hole to the first hole, so that high-pressure liquid flows into the first gap from the second hole to fill the first gap, thereby reducing the risk of blood flowing backward into the stator housing.

Preferably, the angle of the chamfer is 20-40 degrees, namely the included angle with the central line of the rotating shaft is 20-40 degrees.

Preferably, the first gap is 5-15 μm, the second gap is 1-3 μm, and the third gap is 1-3 μm.

In general, the above technical solutions conceived by the present invention, compared with the prior art, enable the following beneficial effects to be obtained:

1) According to the interventional axial flow blood pump, the optical fiber pressure sensor is placed by arranging the groove on the surface of the stator shell, so that extra use space is not increased, and the phenomenon that the power output is influenced due to occupation of the internal structure of the blood pump motor is avoided. Through setting up optical fiber type pressure sensor to blood pressure data's real-time supervision, realized the accurate control to in the art, postoperative.

2) According to the interventional axial flow blood pump, the right sealing cover which can be used for fixing the guide wire and the liquid passing pipe is arranged at the right end (tail part) of the stator shell, so that loosening of the guide wire and leakage of the liquid passing pipe can be effectively prevented. In the pushing process of the blood pump, the flexible support of the guide wire in the outer sleeve is beneficial to the pushing of the axial blood pump in the arterial vessel.

3) The optical fiber of the optical fiber type pressure sensor of the interventional axial flow blood pump is converged in the outer casing pipe at the right end (tail part) of the stator shell, and is furled and wrapped by the outer casing pipe together with the liquid passing pipe, the guide wire and the motor power wire, so that the product has good integrity.

4) The invention relates to an interventional axial flow blood pump, wherein a right end bearing at an inlet of high-pressure liquid on a stator shell and a left end bearing at an outlet of the stator shell are matched with a rotating shaft by adopting ball bearings, a second gap is reserved between an inner ring of the left end bearing and the rotating shaft, but the two bearings are not independently supported and cannot form a completely suspended and non-contact matched form, and the second gap is mainly used for enabling the inner ring of the left end bearing to axially move under the pretightening force of a pretightening spring so as to compensate the play of the left end bearing. Because the second clearance between the two bearings is very small and the two bearings are in a non-independent supporting matching mode, the inner ring of the left end bearing and the rotating shaft synchronously rotate together (the two bearings are relatively static), and friction and abrasion cannot be generated. The right end bearing is also a ball bearing, a third gap is also formed between the right end bearing and the rotating shaft, and the rotating shaft and the inner ring of the right end bearing are relatively static as the left end bearing, so that friction and abrasion cannot be generated. Therefore, the invention reduces the uncertainty risk caused by the change of the friction state condition and can prevent the blood component from entering the blood pump motor to solidify by adopting the ball bearings at the left end and the right end and having gaps between the inner ring and the rotating shaft.

5) According to the interventional axial blood pump, as the second gap exists between the inner ring of the left end bearing and the rotating shaft, a certain elastic force (axial pretightening force) is generated by the pretightening spring to act on the inner ring of the left end bearing, the inner ring of the ball bearing can move relatively freely along the axial direction under the pretightening force, the outer ring of the left end bearing bears the axial force of the second step opposite to the direction of the corresponding inner ring, so that the inner ring and the outer ring of the left end bearing can be mutually misplaced along the axial direction, rolling elements in the left end bearing are clamped by the inner ring and the outer ring and are tightly attached to raceways of the inner ring and the outer ring, noise and vibration abrasion cannot be generated due to tiny jump, and therefore, the pretightening force of the pretightening spring and the design of the second gap between the inner ring of the left end bearing and the rotating shaft can timely compensate tiny play generated by the abrasion of the left end bearing, and the axial blood pump can keep a stable running state in the working process.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic illustration of the present invention with a portion of the outer casing broken away;

FIG. 3 is an exploded view of the present invention;

FIG. 4 is an enlarged schematic view at A in FIG. 3;

FIG. 5 is a schematic view of the present invention with the outer casing removed from the outer cover;

FIG. 6 is an enlarged schematic view at B in FIG. 5;

FIG. 7 is a schematic view of the outer cover of the present invention;

FIG. 8 is a partial schematic view of the present invention;

FIG. 9 is an enlarged schematic view at C in FIG. 8;

FIG. 10 is a cross-sectional view of the invention with a portion of the tail wrap seal removed;

FIG. 11 is an enlarged schematic view at D in FIG. 10;

FIG. 12 is a schematic view of a left closure of the present invention;

FIG. 13 is a force diagram of the left end bearing of the present invention;

Fig. 14a to 14c are schematic views of various shapes of the pretensioned spring in the present invention.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

Referring to the drawings, an interventional axial flow blood pump comprises an impeller mounting cylinder 7, a stator assembly 1, an optical fiber type pressure sensor 8 and a tail wrapping and sealing device 9, wherein the stator assembly 1 comprises a stator shell 11, a magnetic conducting stator and a stator winding which are sequentially connected from outside to inside, the stator winding is connected with the left end of a power wire 117, the impeller mounting cylinder 7 is mounted at the left end of the stator shell 11, a blood outlet 71 is arranged on the impeller mounting cylinder 7, a groove 1110 is arranged on the outer side wall of the stator shell 11, and the interventional axial flow blood pump comprises the following components:

The optical fiber type pressure sensor 8 is arranged in the groove 1110 for measuring the pressure of the blood flowing out of the blood outlet 71, the optical fiber type pressure sensor 8 is not integrally protruded beyond the outer side wall of the stator shell 11, namely, the optical fiber type pressure sensor 8 is not protruded relative to the outer side wall of the stator shell 11, the optical fiber type pressure sensor 8 is provided with an optical fiber 81, the optical fiber 81 is used for transmitting a pressure signal, the optical fiber 81 extends along the groove 1110, and the right end of the optical fiber 81 is protruded beyond the right end of the groove 1110; the grooves 1110 are covered with biocompatible glue for completely fixing the probe 82 and the optical fiber 81 of the optical fiber type pressure sensor 8, and the gaps and edges of the grooves 1110 are filled with the biocompatible glue to avoid residual blood coagulation.

The tail wrapping and sealing device 9 comprises a right sealing cover 113, a guide wire 91, a liquid passing pipe 93 and an outer wrapping sleeve 92, wherein the left end of the right sealing cover 113 is in sealing connection with the right end of the stator shell 11, the right end of the right sealing cover 113 is in sealing connection with the outer wrapping sleeve 92, the right end of the right sealing cover 113 is provided with a through hole 1134 and a blind hole 1135, the through hole 1134 of the right sealing cover 113 is in sealing connection with the liquid passing pipe 93, the left end of the liquid passing pipe 93 stretches into the inner cavity of the right sealing cover 113 so as to be used for introducing high-pressure liquid into the stator shell 11, the high-pressure liquid in the liquid passing pipe 93 is pumped by the high-pressure pump, the blind hole 1135 of the right sealing cover 113 is in sealing connection with the guide wire 91, the right end of the power wire 117, the right end of the optical fiber 81 and the right end of the liquid passing pipe 93 penetrate through the right sealing cover 113 and then enter the outer wrapping sleeve 92, the power wires 117, 81, the liquid passing pipe 93 and the guide wire 91 are in sealing cover 113, the right end face of the optical fiber 113 is provided with a wire 1136, and the optical fiber 1136 extends into the outer wrapping sleeve 92 along the right end face of the stator shell 11, and the end face of the optical fiber 113 is formed by stretching into the right sealing cover 113, and the end face of the outer wrapping sleeve 81 is provided with the right sealing cover 113, and the right end face of the optical fiber 113 is provided with the right end face of the sealing cover 113, and the end face is provided with the sealing cover 6. The right ends of the power cord 117, the optical fiber 81, the liquid passing tube 93 and the guide wire 91 do not go beyond the outer sheath 92, i.e. they are all wrapped inside the outer sheath 92.

Further, the right cover 113 includes an outer cover 1133, an inner cover 1131, and a tail cover 1132, and the stator housing 11 includes an outer case 111, in which:

The left end of inner cup 1131 with the right-hand member fixed connection of shell 111, the left end fixed connection of tail cap 1132 is in the right-hand member of inner cup 1131, the right-hand member of tail cap 1132 sets up through-hole 1134 and blind hole 1135, the through-hole 1134 department joint of tail cap 1132 lead to liquid pipe 93, the left end of leading to liquid pipe 93 stretches into the inner chamber of tail cap 1132, the left end card of seal wire 91 is gone into in tail cap 1132's the blind hole 1135. The left end of the outer cover 1133 is fixedly connected to the right end of the outer casing 111, the inner cover 1131 and the tail cover 1132 are both located in the outer cover 1133, and the routing holes 1136 are formed in the outer cover 1133. The power cord 117, the optical fiber 81 and the liquid passing tube 93 all pass through the outer cover 1133, and the right end of the outer cover 1133 is connected with the outer casing 92 in a sealing manner. The right cover 113 is divided into a plurality of structures of an outer cover 1133, an inner cover 1131 and a tail cover 1132, which facilitate connection with the stator housing 11 and threading. The tail cap 1132 is mainly used for installing the liquid through pipe 93 and the guide wire 91, the outer cap 1133 is mainly used for installing the outer sleeve 92, and the right end bearing 4 can be installed inside the inner cap 1131 to support the rotor assembly 2. The optical fiber 81 extends from the routing hole 1136 into the outer cover 1133, and then passes through the outer cover 1133 directly into the outer casing 92, instead of passing through the inner cover 1131 and the tail cover 1132, outside the inner cover 1131 and the tail cover 1132.

Further, the rotor assembly 2 of the interventional axial blood pump comprises a rotating shaft 21, a permanent magnet 22 and a rotor sleeve 23 which are sequentially connected from inside to outside, and the stator housing 11 further comprises a left cover 112 connected to the left end of the outer housing 111.

The interventional axial flow blood pump further comprises a left end bearing 3, a right end bearing 4, an impeller 5 and a pre-tightening spring 6, wherein the left end bearing 3 and the right end bearing 4 are ball bearings, and are preferably deep groove ball bearings subjected to pure radial stress. The outer ring of the right end bearing 4 is fixedly installed on the right sealing cover 113, the pre-tightening spring 6 is installed on the rotating shaft 21 in a penetrating mode, the outer ring of the right end bearing 4 is preferably installed on the inner cover 1131, a limiting boss is arranged on the inner cover 1131, and the tail cover 1132 presses the outer ring of the right end bearing 4 on the limiting boss.

The left cover 112 has a horizontal step hole 114, the step hole 114 is a through hole and comprises a first hole 1141, a second hole 1142 and a third hole 1143 which are sequentially arranged from left to right and have diameters from small to large, namely, the aperture of the first hole 1141 is smaller than the aperture of the second hole 1142 is smaller than the aperture of the third hole 1143, the first hole 1141 and the third hole 1143 are directly communicated with the external environment of the left cover 112, the first step 115 of the inner wall of the left cover 112 forms the first hole 1141 and the second hole 1142, the second step 116 of the inner wall of the left cover 112 forms the second hole 1142 and the third hole 1143, the left end of the rotating shaft 21 passes through the left cover 112 from the step hole 114 and is connected with the impeller 5, a first gap 1144 is formed between the wall of the first hole 1141 and the rotating shaft 21, namely, the two gaps are in clearance fit, the first gap 1144 is used as an outlet (overflow port) of high-pressure liquid flowing into the stator housing 11, the high-pressure pump is pumped in the stator housing 11 from the inside to the outside of the high-pressure liquid, and is used for preventing blood outside the stator housing 11 from flowing back into the blood pump, the outer ring of the left end bearing 3 is fixedly arranged on the hole wall of the third hole 1143 and abuts against the second step 116, the outer diameter of the inner ring of the left end bearing 3 is smaller than the hole diameter of the second hole 1142, so that the high-pressure liquid in the stator housing 11 flows out of the left end bearing 3 and then enters the second hole 1142, and is prevented from scraping the second step 116 when the inner ring of the left end bearing 3 rotates, the high-pressure liquid flows out of the left sealing cover 112 through the first gap 1144 communicated with the second hole 1142, a second gap 5 exists between the inner ring of the left end bearing 3 and the rotating shaft 21, the inner ring of the left end bearing 3 and the permanent magnet 22 cooperate to clamp the pre-tightening spring 6, the pre-tightening spring 6 applies elastic force (pre-tightening force) on the inner ring of the left end bearing 3, the second gap 1145 enables the inner ring of the left end bearing 3 to reciprocate along the axial direction of the rotating shaft 21 under the elastic force of the pre-tightening spring 6 and enables the inner ring of the left end bearing 3 to still rotate synchronously with the rotating shaft 21, the rotating shaft 21 is fixedly provided with a force transmission piece 26, and the force transmission piece 26 applies right force on the inner ring of the right end bearing 4 under the elastic force of the pre-tightening spring 6. The force-transmitting member 26 may be a spring member (which is held by the permanent magnet 22 and the inner race of the right-end bearing 4), or a sleeve made of biocompatible plastic.

A third gap exists between the inner ring of the right end bearing 4 and the rotating shaft 21, and the inner ring of the right end bearing 4 and the rotating shaft 21 can still rotate synchronously through the third gap. Therefore, the second gap and the third gap are small, and the line contact of the inner ring of the left end bearing 3 and the inner ring of the right end bearing 4 with the rotating shaft 21 is larger than the point contact friction force of the balls with the raceways, so that the balls preferentially generate relative movement. The fit clearance between the rotating shaft 21 and the inner ring is very small, molecular adsorption (and viscosity of water molecules of high-pressure liquid) exists in microscopic level, and relative rotation between the inner ring and the rotating shaft 21 can not be generated, so that the inner ring and the rotating shaft 21 synchronously rotate, and the circumferential directions of the rotating shaft 21 and the inner ring of the bearing are hardly worn.

The right end bearing 4 is also in clearance with the rotating shaft 21 like the left end bearing 3, the left end bearing 3 and the right end bearing 4 do not need to be in a transitional or interference fit mode, so that the assembling is troublesome, the rotating shaft 21 is easy to bend under the stress, and scraps are easy to generate in the fit process, so that the cleaning is difficult.

In fact, when using a ball bearing, friction exists only between the rolling elements and the raceway, for example, the ball bearing is in point contact with the raceway, and the friction is rolling friction, and the wear is very small. Because the axial flow blood pump of the invention has very small size, the roller bearing or the needle bearing is unlikely to be used in practical situations, and because the contact of the roller and the needle is linear contact, compared with the ball point contact of the ball bearing, the contact area of the roller, the needle and the rollaway nest is large, the friction is large, and relative rotation exists between the inner ring of the bearing and the rotating shaft 21 so as to increase abrasion easily.

In addition, since the rotating shaft 21 has a gap with both the inner ring of the left end bearing 3 and the inner ring of the right end bearing 4, the rotating shaft 21 may generate axial play. If there is axial float, it means that there is an external force, but the pre-tightening force of the pre-tightening spring 6 needs to resist the external force, so long as the pre-tightening force is slightly greater than the external force, the whole rotor assembly 2 is stable, the external force is mainly applied to the acting force of the impeller 5 by the blood (fluid) (because the inside of the stator shell 11 is filled with high-pressure fluid, the flow of the high-pressure fluid is very small, and the disturbance of the high-pressure fluid is basically negligible), after the impeller 5 rotates, a force pulling the rotor assembly 2 to the left is formed, but the force fluctuates in a certain range under the disturbance of the blood, and the pre-tightening force of the pre-tightening spring 6 can counteract the fluctuation of the acting force of the blood (fluid) on the impeller 5, so as to prevent the axial float of the rotating shaft 21 along the self axis. In addition, the axial sliding of the rotating shaft 21 relative to the inner rings of the left end bearing 3 and the right end bearing 4 takes very little time in the whole life cycle, and the inner rings only have very small axial movement when the ball bearings generate small play due to self wear, so that the axial wear is almost eliminated.

The impeller mounting cylinder 7 is fixedly mounted on the left cover 112 and surrounds the impeller 5, the inner cavity of the impeller mounting cylinder 7 communicates with the first gap 1144, and the side wall of the impeller mounting cylinder 7 is provided with the blood outlet 71 at a position corresponding to the impeller 5.

The rotating shaft 21 is supported left and right by adopting the left and right ball bearings, the rolling friction of the ball bearings is obviously reduced compared with the friction abrasion of the existing sliding bearings, the generation of abrasion particles is reduced, and the rotor assembly 2 and the impeller 5 on the rotor assembly can keep a stable running state for a long time. The high-pressure liquid in the motor circulates in the stator shell 11, sequentially passes through the inside of the right end bearing 4, the gap between the stator assembly 1 and the rotor assembly 2 and the inside of the left end bearing 3, then enters into a first gap 1144 between the left end bearing 3 and the left sealing cover 112, then flows out of the micro motor from the first gap 1144 (radial gap, the size is 5-15 μm), enters into a space (the interval is 0.03-0.03 mm.15 mm) formed by the impeller 5 and the left sealing cover 112, and continuously gushes out from the blood outlet 71 into human blood. The chamfer 1151 of the edge of the first step 115 is α and α=20° to 40 °, so that a flare with a gradually smaller diameter is formed along the direction from the second hole 1142 to the first hole 1141, so that the high-pressure liquid flows into the first gap 1144 from the second hole 1142 to fill the first gap 1144, thereby being beneficial to filling the first gap 1144 with the high-pressure liquid and reducing the risk of blood backflow. Due to the continuous injection of high pressure liquid, the liquid pressure in the space inside the stator housing 11, the first gap 1144, the impeller 5 and the left cover 112 may be greater than the adjacent blood pressure, and blood components may not enter these areas to cause coagulation clogging. The left cover 112 material is a biocompatible metal (stainless steel or titanium alloy).

Because the pre-tightening spring 6 is sleeved on the rotating shaft 21, one end of the pre-tightening spring 6 is abutted with the inner ring of the left end bearing 3, and the other end of the pre-tightening spring is pressed on the left pouring sealant 24 of the rotor. The pre-tightening spring 6 is in a compressed state after being installed, namely, the pre-tightening spring 6 can generate certain elastic force (axial pre-tightening force, F ₁ is 0.1N-1N) to act on the inner ring of the left end bearing 3, and the outer ring of the left end bearing 3 bears axial force F ₂ opposite to the corresponding inner ring, so that the inner ring and the outer ring of the left end bearing 3 are mutually staggered along the axial direction, and the balls are tightly attached to the inner ring and the outer ring roller paths, so that noise and vibration abrasion cannot be generated due to tiny runout. It is obvious that the ball bearing itself has a small amount of wear, but for long service life, the bearing play increase due to the accumulation of wear needs to be taken into account. In order to keep the axial blood pump in a stable running state all the time in the working process, the inner ring of the left end bearing 3 needs to move relatively freely along the axial direction under the action of the pretightening force so as to timely compensate the tiny play generated by the self-abrasion of the left end bearing 3, so that the inner ring of the left end bearing 3 is in clearance fit with the rotating shaft 21, and a second clearance 1145 (radial clearance, the size of which is 1-3 μm) is formed between the inner ring of the left end bearing 3 and the rotating shaft. The inner ring of the right end bearing 4 and the rotating shaft 21 have a third gap (radial gap, the size is 1 μm-3 μm), and the stress and movement condition of the inner ring of the right end bearing 4 refer to the left end bearing 3.

The outer side wall of the stator housing 11 is provided with a groove 1110 along the axial direction for placing the probe 82 and the optical fiber 81 of the optical fiber type pressure sensor 8. It should be noted that the probe 82 of the fiber-optic pressure sensor 8 needs to be placed near the blood outlet 71 of the impeller mounting cylinder 7 to reflect the real-time blood pressure information, so that the groove 1110 for placing the probe 82 may be provided on the left cover 112 or on the surface of the housing 111, depending on the actual situation. The groove depth of the portion of the groove 1110 for placing the probe 82 is 0.06 to 0.25mm, and the groove depth of the portion of the groove 1110 for placing the optical fiber 81 is 0.06 to 0.15mm. By providing a suitable size of the groove 1110, the fiber-optic pressure sensor 8 is ensured to be difficult to slip in the process of installation and to be accurate in placement position. A small amount of biocompatible glue is covered in the groove 1110 to completely fix the probe 82 and the optical fiber 81, and simultaneously the gaps and edges of the groove 1110 are filled and covered to avoid residual blood coagulation. The optical fiber 81 is usually composed of a plurality of functional sub-wires, and the wire diameter is very small and is easy to break, so when the optical fiber 81 extends to the right end (tail end) of the axial flow pump, the optical fiber 81 needs to be hidden and enter the inside of the outer cover 1133, and is wrapped by the outer wrapping sleeve 92 to extend outwards, and the extension length of the optical fiber 81 is 1.3-1.8 meters.

The liquid pipe 93 is made of biocompatible plastic (such as PA), and the length after being straightened is 1.3-2 meters. The guide wire 91 can be inserted into the blind hole 1135 and filled with biocompatible glue for fixation, the guide wire 91 is made of biocompatible nickel titanium wires, the straightened guide wire is 1.3-1.8 m long, and the guide wire has excellent toughness and metal memory function. After the axial flow blood pump is provided with the optical fiber type pressure sensor 8, the guide wire 91 and the liquid passing pipe 93, the axial flow blood pump and the power wire 117 electrically connected with the magnetic conduction winding of the blood pump motor are converged at the right end (tail end) of the axial flow blood pump, and then the outer cover 1133 is sleeved.

The optical fiber 81 is gathered into the inside through the wiring hole 1136 on the side surface of the outer cover 1133, the position of the wiring hole 1136 is covered by adopting biocompatible glue, the glue must be uniformly smeared, the surface is round, and the opening edge of the outer cover 1133 must be coated, so as to reduce the risks of blood cell damage, residual blood coagulation and the like. Both ends of the outer cover 1133 are opened and communicated with the inside, and the biocompatible pouring sealant is injected into the inside through the wiring hole 1136 to fill the internal gap, so that the root parts of the guide wire 91, the liquid through pipe 93, the power line 117 and the optical fiber 81 can be better fixed and protected.

The outer side wall of the outer cover 1133 is provided with a horn-shaped rotating surface 1137, a cylindrical light surface 1138 and a rough cylindrical surface 1139 which are sequentially connected from left to right, the outer diameter of the cylindrical light surface 1138 is larger than that of the rough cylindrical surface 1139, and the rough cylindrical surface 1139 is formed by roughening the cylindrical surface by knurling or laser and is used for sleeving the outer sleeve 92. The outer sleeve 92 is made of biocompatible plastic, has certain toughness, and the inner circular surface of the outer sleeve 92 is matched with the rough cylindrical surface 1139 of the outer cover 1133. The diameter of the inner circular surface of the outer sleeve 92 is slightly smaller than the diameter of the rough cylindrical surface 1139 of the outer cover 1133, and the design is favorable for the outer sleeve 92 to tightly hold the rough cylindrical surface 1139 of the outer cover 1133, and then the outer sleeve 92 is bonded by being assisted by biocompatible glue, so that the outer sleeve can be reliably connected. In other embodiments, the roughened cylindrical surface 1139 of the outer cover 1133 may be designed with an inverted cone structure to more reliably prevent the outer casing 92 from loosening. More importantly, the design of the outer casing 92 enables the outer diameter of the outer casing 92 in place to be basically consistent with the diameter of the smooth cylindrical surface of the outer cover 1133, and the end face of the outer casing 92 is flat, so that a smooth transition state is formed, and blood is prevented from being solidified at tiny corners and gaps.

The outer sleeve 92 wraps the guide wire 91, the liquid passing pipe 93, the power line 117 and the pressure sensor optical fiber 81 inside the outer sleeve 92, and has better toughness under the supporting effect of the guide wire 91. The front end (generally called the proximal end) of the axial blood pump is sleeved with a metal spiral braided catheter, an impeller mounting cylinder 7 with a blood inlet structure and an outlet structure, and a pigtail (not shown in the figure). Because the interventional pump is usually penetrated through the inguinal artery of a human body, a certain distance needs to be pushed in an arterial blood vessel, and finally, the proximal end structure of the axial flow blood pump is positioned in the left ventricle, the axial flow blood pump is positioned in the aorta, and the oxygenated blood of the left ventricle is directly pumped into the main artery for auxiliary circulation under the action of the axial flow blood pump. During this surgical advancement, the malleable support of the guidewire 91 facilitates advancement of the axial blood pump within the arterial vessel. In addition, the outer surface of the outer sleeve 92 is printed with uniformly spaced graduation strips and numbers that enable the physician to assist in determining the distance of the axial flow pump during the procedure by marking the graduation strips and numbers. Meanwhile, doctors can judge the torsion condition of the axial blood pump in the pushing process according to the continuous marking lines along the axial direction.

It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims

1. The utility model provides an intervention formula axial flow blood pump, its characterized in that, includes impeller installation section of thick bamboo, stator module, optic fibre pressure sensor and afterbody parcel sealing device, stator module is including stator shell, magnetic conduction stator and the stator winding that links together in proper order from outside to interior, the left end of power cord is connected to the stator winding, impeller installation section of thick bamboo is installed the left end of stator shell, and be provided with the blood outlet on the impeller installation section of thick bamboo, be equipped with the slot on the lateral wall of stator shell, wherein:

2. An interventional axial blood pump according to claim 1, wherein the grooves are covered with a biocompatible glue for completely securing the probe and the optical fiber of the optical fiber type pressure sensor, and wherein the biocompatible glue fills and covers the gaps and edges of the grooves to avoid residual blood coagulation.

3. The interventional axial blood pump of claim 1, wherein the liquid-passing tube is made of biocompatible plastic and has a straightened length of 1.3-2 meters, and the guide wire is made of biocompatible nickel-titanium wire material and has a straightened length of 1.3-1.8 meters.

4. An interventional axial blood pump according to claim 1, wherein the right end of the power cord, optical fiber, fluid tube and guidewire do not extend beyond the outer sheath.

5. The interventional axial blood pump of claim 1, wherein said fiber optic pressure sensor further has a probe connected to the optical fiber;

6. The interventional axial blood pump of claim 1, wherein the rotor assembly of the interventional axial blood pump comprises a rotating shaft, a permanent magnet and a rotor sleeve which are sequentially connected from inside to outside, and the stator housing further comprises a left cover connected to the left end of the housing;

7. An interventional axial blood pump according to claim 6, wherein the first step is provided with a chamfer to form a flare of progressively smaller diameter in the direction from the second bore to the first bore so that high pressure liquid flows from the second bore into the first gap to fill the first gap to reduce the risk of blood flowing back into the stator housing.

8. An interventional axial blood pump according to claim 7, wherein the chamfer angle is 20 ° -40 °, i.e. 20 ° -40 ° from the centre line of the shaft.

9. The interventional axial blood pump of claim 6, wherein the first gap is 5-15 μm, the second gap is 1-3 μm, and the third gap is 1-3 μm.