CN116870356A - Catheter pump assembly and control system thereof - Google Patents

Abstract

The invention aims to provide a catheter pump assembly and a control system thereof, which can not damage blood vessels and reduce hemolysis on the premise that the blood volume of a pump meets the requirement, wherein the proximal end of a motor is connected with a catheter, the distal end of the motor is connected with a pumping unit through a motor shaft, the pumping unit comprises a foldable impeller, an expandable/contractible bracket body is arranged on the periphery of the foldable impeller in a covering way, and the bracket body can axially slide relative to the foldable impeller. The impeller is of a collapsible structure, is contracted into the sheath tube during insertion and withdrawal, has a small outer diameter, is withdrawn from the body by a restraining force, and is expanded to a large size, thereby enabling a larger flow of blood to be pumped. Compared with the existing catheter pump, under the condition that the blood volume of the pump is the same, the impeller is large in size, so that the rotating speed of the motor is required to be low, and limit damage to blood is much smaller; the motor shaft of the motor is hard connected with the impeller by adopting a mode of built-in motor, the impeller is directly driven to rotate, and the energy transmission efficiency of the motor is high.

Description

Catheter pump assembly and control system thereof

Technical Field

The invention relates to the technical field of medical instruments, in particular to a catheter pump assembly and a control system thereof.

Background

Catheter pumps, as one of the ventricular assist devices, may be introduced percutaneously into the heart and may be configured to assist or replace the natural heart pump function by circulatory pumping or continuous pumping of blood, providing hemodynamic support for cardiogenic shock and acute heart failure. Taking a left ventricular catheter pump as an example, as shown in fig. 1, the catheter pump includes a catheter 1 connected to an external support device, a motor 2, an impeller 3, a sleeve 4, a pigtail 5, a blood inflow port 6, a blood outflow port 7, and the like. When in use, the pigtail 5 and the part of the sleeve 4 with the blood inflow port 6 extend into the left ventricle, the blood outflow port 7, the motor 2 and other parts are positioned in the main vessel, and the motor 2 works to drive the impeller 3 to rotate so as to convey the blood in the left ventricle into the main vessel.

Wherein the pumping volume of the catheter pump is related to the rotational speed of the motor 2 and the size of the impeller 3, a high power motor 2 and/or a large size impeller 3 are required to ensure a sufficient pumping volume. However, the diameter of the high-power motor 2 is usually oversized, and the catheter pump is inserted into the heart through a blood vessel, so that the catheter pump is limited by the blood vessel, the diameter of the motor 2 cannot be oversized, otherwise bleeding can be caused during insertion, the rotating speed of the high-power motor 2 is high, and the high rotating speed can cause the increase of the hemolysis probability. Therefore, how to ensure that the blood vessel is not damaged and the hemolysis can be reduced on the premise that the blood volume of the pump meets the requirement is a difficult problem to be solved in the industry.

Disclosure of Invention

It is an object of the present invention to provide a catheter pump assembly that reduces both vascular damage and hemolysis, provided that the amount of blood pumped is satisfactory.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the utility model provides a catheter pump assembly, includes the motor, and the proximal end and the pipe of motor link to each other, and the distal end passes through the motor shaft to be connected its characterized in that with pumping unit: the pumping unit comprises a foldable impeller, an expandable/contractible bracket body is arranged on the periphery of the foldable impeller, and the bracket body can axially slide relative to the foldable impeller.

The inner layer and/or the outer layer and/or the interlayer of the bracket body are/is covered with a film, the inner cavity of the film forms a blood cavity, and the film is provided with a blood outflow opening.

The proximal end of the bracket body is fixed on the periphery of the distal end of the motor shell, the distal end of the bracket body is connected with the sleeve through a metal connecting piece, and the metal connecting piece and the foldable impeller form axial sliding and circumferential running fit.

The metal connecting piece comprises an outer ring and an inner cylinder which are coaxially arranged, the outer ring and the inner cylinder are fixed through a connecting column, the outer ring is fixedly connected with a sleeve, the far end of a bracket body is fixed on the inner cylinder in a welded mode, a motor shaft penetrates through a hub of the foldable impeller and is inserted into an inner cavity of the inner cylinder, and the end face of the far end of the inner cylinder is sealed.

The support body is a grid-shaped structure made of shape memory alloy materials, the support body comprises a middle cylindrical section and conical cylindrical sections at two ends, the cross section of the support body is circular or oval under the condition that the support body is forced or not forced, and the distal end of the film covers the outside of the sleeve.

The foldable impeller comprises a hub and blades around the hub, wherein the hub is made of hard materials, the blades are made of flexible materials, and gaps are reserved between the outer edges of the blades and the inner wall of the bracket body when the blades are in an expansion state.

The inner part and the outer part of the bracket body are covered with films, and the blood outflow opening is arranged at the position of the proximal end of the film.

The sleeve comprises a spring body support, an inner layer film and an outer layer film which are covered on the inner side and the outer side of the spring body support, the spring body support is of a spiral structure wound by shape memory alloy wires, and the winding density of the shape memory alloy wires at the two ends of the spring body support is greater than that of the shape memory alloy wires at the middle position.

The proximal end of the sleeve is connected with the distal end of the blood inflow cage, and the proximal end of the blood inflow cage is provided with a pigtail.

The motor is provided with a Hall sensor, and the Hall sensor monitors the rotating speed and the load signal of the feedback motor in real time and transmits the signals to the control unit.

It is another object of the present invention to provide a control system for a catheter pump assembly that reduces both vascular damage and hemolysis, provided that the amount of blood pumped is satisfactory.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a control system of a catheter pump assembly comprises the catheter pump assembly, the control system comprises a display interaction unit, a driving control unit, a flushing control unit and a data acquisition unit, wherein,

the data acquisition unit acquires signals such as real-time pressure, real-time temperature and motor rotation speed data of blood pressure and transmits the signals to the drive control unit;

the driving control unit is used for controlling the start and stop of the motor and the rotating speed of the motor according to the signals acquired by the data acquisition unit;

the flushing control unit controls the flushing system to squeeze flushing liquid into a flushing channel in the motor in a sequential extrusion mode according to the signals acquired by the data acquisition unit;

and the display interaction unit is used for displaying various data information of the catheter pump assembly in real time and providing the information and the operation command which can be further input by an operator according to the processing result.

The scheme at least has the following beneficial effects:

1. the impeller is of a collapsible structure, is contracted into the sheath tube during insertion and withdrawal, has a small outer diameter, is withdrawn from the body by a restraining force, and is expanded to a large size, thereby enabling a larger flow of blood to be pumped.

2. Compared with the conventional catheter pump, the invention has the advantages that the impeller has large size, so that the rotating speed of the motor is required to be low, and the limit damage to blood is much smaller.

3. The motor shaft of the motor is hard connected with the impeller by adopting a mode of built-in motor, the impeller is directly driven to rotate, and the energy transmission efficiency of the motor is high.

Drawings

FIG. 1 is a schematic illustration of a prior art catheter pump assembly;

FIG. 2 is a schematic view of a catheter pump assembly of the present invention;

FIG. 3 is a partially enlarged schematic illustration of FIG. 2;

FIG. 4 is a perspective view of the metal connector of FIG. 2;

FIG. 5 is a schematic view of the structure of the bracket body in FIG. 2;

FIG. 6 is a schematic view of the internal structure of the removed bracket body of FIG. 2;

FIG. 7 is a schematic structural view of a film;

FIG. 8 is a schematic view of a collapsible impeller;

fig. 9 is a block diagram of a control system.

Detailed Description

For ease of understanding, we first define the orientations referred to hereinafter: "proximal", "proximal" refers to the side proximal to the operator/physician and "distal" refers to the side distal to the operator/physician, i.e., the side proximal to the heart, as discussed in further detail below in connection with fig. 2-8.

A catheter pump assembly comprises a motor 10, wherein the proximal end of the motor 10 is connected with a catheter 20, the distal end of the motor is connected with a pumping unit 30 through a motor shaft 11, the pumping unit 30 comprises a foldable impeller 31, the periphery of the foldable impeller 31 is covered with an expandable/contractible bracket body 32, and the bracket body 32 can axially slide relative to the foldable impeller 31. The impeller is constructed in a collapsible structure, and is contracted in the sheath tube during insertion and withdrawal, and has a small outer diameter, and the restraining force is removed during the in-vivo operation, so that the collapsible impeller 31 is expanded to a large size, thereby enabling pumping of a larger flow rate of blood. In the present invention, since the foldable impeller 31 has a large size, the rotation speed of the motor 10 is required to be low, and mechanical damage to blood is significantly smaller, compared with the conventional catheter pump, when the amount of blood pumped is the same. By adopting a mode of built-in motor, the motor shaft 11 of the motor 10 is hard connected with the foldable impeller 31, the foldable impeller 31 is directly driven to rotate, and the energy transmission efficiency of the motor 10 is high.

In order to form a blood channel, a membrane 33 is covered on the inner layer and/or the outer layer and/or the interlayer of the bracket body 32, the inner cavity of the membrane 33 forms a blood cavity, and a blood outflow opening 34 is arranged on the membrane 33. The 3 structures are included, namely, the film 33 is coated only on the outer part of the bracket body 32, and the film 33 is coated on the outer part and the inner part of the bracket body 32.

As shown in fig. 2, the proximal end of the bracket body 32 is fixed on the outer periphery of the distal end of the housing of the motor 10/the motor shaft 11, the distal end of the bracket body 32 is connected with the sleeve 40 through the metal connecting piece 41, and the metal connecting piece 41 and the foldable impeller 31 form an axial sliding and circumferential rotating fit. In the contracted state of the support body 32, the outer diameter of the support body 32 is smaller than or equal to the outer diameter of the motor 10, and in the expanded state of the support body 32, the outer diameter of the support body 32 is larger than the outer diameter of the motor 10. In this structure, the holder 32 is provided only around the outer periphery of the foldable impeller 31, and one end thereof is fixed to the casing of the motor 10 and the other end thereof is connected to the sleeve 40. It should be emphasized here that the former is preferred because the axial length of the holder body 32 becomes longer when it is contracted, and therefore, it is required that the metal connector 41 and the foldable impeller 31 are axially slidably engaged, circumferentially rotated, or that the metal connector 41 and the sleeve 40 can be axially slidably engaged.

Specifically, as shown in fig. 3 and 4, the metal connector 41 includes an outer ring 411 and an inner cylinder 412 that are coaxially arranged, the outer ring 411 and the inner cylinder 412 are fixed by a connecting post 413, a gap between the outer ring 411, the inner cylinder 412 and the connecting post 413 is used for blood to flow through, the outer ring 411 is fixedly connected with the sleeve 40, and the distal end of the bracket body 32 is fixed on the inner cylinder 412 by welding. The motor shaft 11 is inserted into the inner cavity of the inner cylinder 412 after passing through the hub 311 of the foldable impeller 31, the proximal end of the motor shaft 11 is provided with a motor support, the distal end is provided with an inner cylinder 412 support, and the rotation is more stable; more importantly, when the support body 32 is contracted, the axial length of the support body is prolonged, the inner cylinder 412 has a certain length, the motor shaft 11 can axially move in the inner cylinder 412 to adapt to the contraction and expansion of the support body 32, and in addition, the distal end face of the inner cylinder 412 is arranged in a closed manner, so that blood can be prevented from entering the inner cylinder 412 to cause blood damage and thrombus. In addition, since the surface of the sleeve 40 is made of a non-metal material and the bracket body 32 is made of a metal material, the arrangement of the metal connecting piece 41 also increases the reliability of the connection between the sleeve 40 and the bracket body 32.

As shown in fig. 5, the support body 32 is a mesh-like structure made of a shape memory alloy material, the support body 32 includes a middle cylindrical section and two tapered cylindrical sections at two ends, and the support body 32 has a circular or oval cross section in both the forced and non-forced states. That is, the support body 32 preferably can be radially expanded and contracted without being axially bent, or can be slightly bent under the condition of external force to adapt to physiological structures of human bodies, and has certain rigidity under the natural state that the external force is removed, so that the support body 32 is prevented from being bent under the normal working state of the catheter pump assembly, and the foldable impeller 31 is prevented from colliding with the support body 32 to cause mechanical hemolysis.

As shown in fig. 8, the foldable impeller 31 includes a hub 311 and blades 312 circumferentially arranged thereon, the hub 311 is made of a hard material and is reliably fixed to the motor shaft 11, the blades 312 are made of a flexible material, when constrained, the whole outer diameter is very small, after the external constraint force is removed, the blades 312 are unfolded, the blades 312 can be in a state of maximum size or not, when the foldable impeller 31 rotates, the blades 312 are expanded to a state of maximum size due to the centrifugal force, and when the blades 312 are in an expanded state, gaps are reserved between the outer edges of the blades 312 and the inner wall of the bracket body 32, so that the blades 312 are prevented from colliding with the inner wall of the bracket body 32 in the rotating process, and the damage to blood is reduced.

As a preferred embodiment of the present invention, as shown in fig. 7, the stent body 32 is covered with the membrane 33 on the inside and the outside, and the membrane 33 is also expanded and contracted, so that it is ensured that the blood channel is formed while simultaneously expanding or contracting with the stent body 32, and the blood outlet 34 is disposed at the proximal end position of the membrane 33, thereby avoiding the existence of a blood recirculation region, i.e., the blood flowing from the blood channel to the nearest end region and then back out of the blood outlet 34, which may cause energy loss.

The sleeve 40 needs to pass through the heart valve and enter the left ventricle as a blood flow path part to convey the blood in the left ventricle to the aorta, in order to reduce damage to the heart valve, the blood flow path is required to be relatively soft, but if made of very soft materials, the lack of support is caused to be unfavorable for the percutaneous insertion of the catheter pump, and the blood flow path itself or the joint is broken due to the possibility of bearing large twisting force and stretching force, the sleeve 40 comprises a spring body bracket and an inner layer film and an outer layer film which are covered on the inner side and the outer side of the spring body bracket, and has certain support strength, and certain soft characteristics while meeting the strength requirement of the percutaneous insertion of the catheter pump. The spring body support is of a spiral structure wound by the shape memory alloy wire, and the bending degree of the spring body support is adapted to the physiological structure of the left ventricle. The winding density of the shape memory alloy wires at the two ends of the spring body support is greater than that of the shape memory alloy wires at the middle position, in other words, the spring pitch at the two ends of the spring body support is smaller than that at the middle position, so that the bending strength of the two ends of the sleeve 40 is further improved, and the problem that the connecting part breaks or falls off is avoided.

Further, the proximal end of the cannula 40 is connected to the distal end of the blood inflow cage 50, and the proximal end of the blood inflow cage 50 is provided with a pigtail 60. The catheter pump assembly is introduced through the femoral, subclavian arteries and after passing through the arteries, the pigtail 60 and the portion of the cannula 40 with the blood inflow cage 50 extend into the left ventricle, the pumping assembly 30, motor 10, i.e., the portion of the cannula 40, are positioned in the main vessel, and the motor 10 is operated to rotate the collapsible impeller 31 to deliver blood from the left ventricle into the main vessel. The pigtail 60 abuts against the inner wall of the ventricle preventing aspiration.

At present, the conduit pump has errors in rotating speed measurement and calculation through reaction electromotive force, so that the common impeller is of a rigid structure, and the rotating speed error range is also met through judgment of the common impeller, but the conventional mode is unfavorable for judgment of the foldable impeller, so that the motor 10 is provided with the Hall sensor, the Hall sensor monitors and feeds back the rotating speed and load signals of the motor 10 in real time, and the signals are transmitted to the control unit, so that the precision is higher.

A control system of a catheter pump assembly comprises a display interaction unit, a driving control unit, a flushing control unit and a data acquisition unit, wherein,

the data acquisition unit acquires signals such as real-time pressure, real-time temperature and motor rotation speed data of blood pressure and transmits the signals to the drive control unit;

the driving control unit is used for controlling the start and stop of the motor and the rotating speed of the motor according to the signals acquired by the data acquisition unit;

the flushing control unit controls the flushing system to squeeze flushing liquid into a flushing channel in the motor in a sequential extrusion mode according to the signals acquired by the data acquisition unit; because there are inevitably gaps between the shaft of the motor 10 and the housing, and between the shaft and the bearing, there are gaps into which blood enters to coagulate into thrombus when the collapsible impeller 31 pumps blood, blocking the rotation of the shaft, and thus the flushing system is provided to back flush the gap to prevent blood from entering, the flushing control unit is provided to control the start and stop of the flushing system and the flow rate.

And the display interaction unit is used for displaying various data information of the catheter pump assembly in real time and providing the information and the operation command which can be further input by an operator according to the processing result.

The foregoing has outlined and described the basic principles, main features and features of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made therein without departing from the spirit and scope of the invention, which is defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (10)

1. Catheter pump assembly, including motor (10), the proximal end of motor (10) links to each other with catheter (20), and the distal end passes through motor shaft (11) and is connected with pumping unit (30), its characterized in that: the pumping unit (30) comprises a foldable impeller (31), an expandable/contractible bracket body (32) is arranged on the periphery of the foldable impeller (31), the bracket body (32) can axially slide relative to the foldable impeller (31), the distal end of the bracket body (32) is connected with a sleeve (40), the distal end of the sleeve (40) is connected with the distal end of a blood inflow cage (50), and a pigtail tube (60) is arranged at the distal end of the blood inflow cage (50).

2. A catheter pump assembly according to claim 1, wherein: the inner layer and/or the outer layer and/or the interlayer of the bracket body (32) is covered with a film (33), the inner cavity of the film (33) forms a blood cavity, and the film (33) is provided with a blood outflow port (34).

3. A catheter pump assembly according to claim 1, wherein: the proximal end of the bracket body (32) is fixed on the periphery of the distal end of the motor (10) shell, the distal end of the bracket body (32) is connected with the sleeve (40) through the metal connecting piece (41), and the metal connecting piece (41) and the foldable impeller (31) form axial sliding and circumferential running fit.

4. A catheter pump assembly according to claim 3, wherein: the metal connecting piece (41) comprises an outer ring (411) and an inner cylinder (412) which are coaxially arranged, wherein the outer ring (411) and the inner cylinder (412) are fixed through a connecting column (413), the outer ring (411) is fixedly connected with the sleeve (40), the far end of the bracket body (32) is fixed on the inner cylinder (412) in a welding mode, the motor shaft (11) penetrates through the hub (311) of the foldable impeller (31) and then is inserted into the inner cavity of the inner cylinder (412), and the end face of the far end of the inner cylinder (412) is sealed.

5. A catheter pump assembly according to claim 1, wherein: the support body (32) is a grid-shaped structure made of a shape memory alloy material, the support body (32) comprises a middle cylindrical section and conical cylindrical sections at two ends, the cross section of the support body (32) is circular or elliptical under the condition that the support body is applied with force or not applied with force, and the distal end of the film (33) is covered outside the sleeve (40).

6. A catheter pump assembly according to claim 1, wherein: the foldable impeller (31) comprises a hub (311) and blades (312) in the circumferential direction, wherein the hub (311) is made of hard materials, the blades (312) are made of flexible materials, and gaps are reserved between the outer edges of the blades (312) and the inner wall of the bracket body (32) when the blades (312) are in an expanded state.

7. A catheter pump assembly according to claim 2, wherein: the inner part and the outer part of the bracket body (32) are covered with films (33), and the blood outflow opening (34) is arranged at the position near the films (33).

8. A catheter pump assembly according to claim 3, wherein: the sleeve (40) comprises a spring body support, an inner layer film and an outer layer film which are covered on the inner side and the outer side of the spring body support, the spring body support is of a spiral structure wound by shape memory alloy wires, and the winding density of the shape memory alloy wires at the two ends of the spring body support is greater than that of the shape memory alloy wires at the middle position.

9. A catheter pump assembly according to claim 1, wherein: the motor (10) is provided with a Hall sensor, and the Hall sensor monitors and feeds back the rotating speed and the load signal of the motor (10) in real time and transmits the signal to the control unit.

10. A control system for a catheter pump assembly comprising the catheter pump assembly of claims 1-9, characterized in that: the control system comprises a display interaction unit, a drive control unit, a flushing control unit and a data acquisition unit, wherein,

the data acquisition unit acquires signals such as real-time pressure, real-time temperature of blood pressure, rotating speed data of the motor (10) and the like, and transmits the signals to the drive control unit;

the driving control unit is used for controlling the start and stop of the motor (10) and the rotating speed of the motor according to the signals acquired by the data acquisition unit;

the flushing control unit controls the flushing system to squeeze flushing liquid into a flushing channel in the motor (10) in a sequential extrusion mode according to the signals acquired by the data acquisition unit;

and the display interaction unit is used for displaying various data information of the catheter pump assembly in real time and providing the information and the operation command which can be further input by an operator according to the processing result.