Conduit pump assembly and method of processing thereof

Abstract

The application relates to the technical field of medical devices, in particular to a catheter pump assembly and a processing method thereof. The catheter pump assembly comprises a blood flow channel, a blood inflow cage and a blood outflow cage. The blood flow channel comprises a spring body support which is coiled by a shape memory alloy wire. The inner side of the spring body support is covered with an inner layer film, and the outer side is covered with an outer layer film. The two ends of the inner layer film and the outer layer film respectively extend to the two ends close to the spring body support, so that at least part of the spring body support is located at the connecting part of the blood flow channel, the blood inflow cage and the blood outflow cage. According to the technical scheme provided by the application, the connecting part of at least part of the blood flow channel, the blood inflow cage and the blood outflow cage is supported by the spring body support, thereby improving the bending resistance of the connecting part of the blood inflow cage, the blood outflow cage and the blood flow channel, overcoming the risk of breakage or falling of the connecting part, and ensuring the reliability of the catheter pump in use.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a catheter pump assembly and its processing method. Background Technology

[0002] As a type of ventricular assist device, a catheter pump can be introduced into the heart percutaneously and can be configured to assist or replace the natural heart pumping function by pumping blood through circulation or continuous pumping, providing hemodynamic support for cardiogenic shock and acute heart failure.

[0003] A catheter pump typically includes a blood inlet cage located in the left ventricle, a blood outlet cage located in the aorta, and a blood flow channel between the blood inlet and blood outlet cages for blood flow.

[0004] During percutaneous insertion or removal, existing catheter pumps have encountered situations where the connection between the blood flow channel and the blood inlet or outlet cage breaks or detaches, resulting in some components of the catheter pump being left in the ventricle or aorta, causing serious medical accidents. Summary of the Invention

[0005] The purpose of this invention is to provide a catheter pump assembly that overcomes the defect in the prior art where the connection between the blood flow channel and the blood inlet cage or blood outlet cage may break or fall off, thus ensuring the reliability of the catheter pump during use.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A catheter pump assembly includes a blood flow channel, a blood inlet cage disposed at the distal end of the blood flow channel and a blood outlet cage disposed at the proximal end of the blood flow channel, wherein the blood flow channel includes a spring body support made of shape memory alloy wire, the inner side of the spring body support is covered with an inner film and the outer side is covered with an outer film.

[0008] The inner and outer films extend to their respective ends near the ends of the spring body support, such that at least a portion of the spring body support is located at the connection between the blood flow channel and the blood inflow cage and the blood outflow cage.

[0009] In a further technical solution, the two ends of the inner film and the outer film extend to the two ends of the spring body support, and are fixedly connected as one unit at the end sides of the spring body support.

[0010] In a further technical solution, the winding density of the shape memory alloy wires at both ends of the spring body support is greater than the winding density of the shape memory alloy wires at the middle position.

[0011] In a further technical solution, the shape memory alloy wire is selected from one of nickel-titanium alloy, titanium-nickel-copper alloy, titanium-nickel-iron alloy, and titanium-nickel-chromium alloy.

[0012] In a further technical solution, the inner film and the outer film are each independently selected from at least one of polyethylene, polyurethane, polycarbonate and thermoplastic elastomer.

[0013] In a further technical solution, the outer surface of the spring body stent is coated with a radiopaque ring to show its insertion location in the heart.

[0014] In a further technical solution, the blood inflow cage and the blood outflow cage are respectively provided with shallow threads or knurling at the ends near the blood flow channel.

[0015] The present invention also provides a method for processing the above-mentioned conduit pump assembly, the method comprising the following steps:

[0016] (1) A shape memory alloy wire is wound into a spring shape on the surface of a mandrel to form a spring body support, wherein the pitch of the proximal end and the distal end of the spring body support is smaller than the pitch between the proximal end and the distal end.

[0017] (2) Heat-treat the wound spring body bracket together with the mandrel to shape the spring body bracket into a predetermined shape.

[0018] (3) Use an ion sputtering instrument to sputter a layer of Pt or Pd metal on the outer surface of the spring body support to form a developing ring;

[0019] (4) A thin film is applied to the inner and outer surfaces of the spring body support to form an inner film and an outer film, the two ends of the inner film and the outer film extending to the two ends near the spring body support, so that at least part of the spring body support is located at the connection between the blood flow channel and the blood inflow cage and the blood outflow cage.

[0020] (5) Use adhesives or fixing elements to fix the blood inflow cage to the distal end of the spring body support and fix the blood outflow cage to the proximal end of the spring body support to obtain the catheter pump assembly.

[0021] In a further technical solution, in step (1), the mandrel is a stainless steel round bar with both ends bent at a certain angle, and the two ends of the spring body bracket are fixed on the mandrel using a clamp.

[0022] In a further technical solution, in step (2), the heat treatment conditions include holding the product at a temperature of 450-550℃ for 15-25 minutes and then cooling it to room temperature.

[0023] Compared with the prior art, the present invention has the following technical effects:

[0024] The catheter pump assembly provided by this invention features an inner film covering the inner surface of a spring body support and an outer film covering the outer surface. Furthermore, the ends of both the inner and outer films extend close to the ends of the spring body support, such that at least a portion of the spring body support is positioned at the connection between the blood flow channel and the blood inlet and outlet cages. This ensures that at least a portion of the connection between the blood flow channel and the blood inlet and outlet cages is supported by the spring body support, thereby improving the bending strength at the connection points between the blood inlet and outlet cages and the blood flow channel. This overcomes the risk of breakage or detachment at the connection points of the blood inlet and outlet cages and the blood flow channel in existing technologies, thus ensuring the reliability of the catheter pump during use.

[0025] Other features and advantages of the present invention will be described in detail in the following specific embodiments. Attached Figure Description

[0026] Figure 1 The diagram shows a structural schematic of a conduit pump assembly according to a specific embodiment of the present invention;

[0027] Figure 2 Shown as Figure 1 An enlarged view of position A in the middle;

[0028] Figure 3 Shown as Figure 1 An enlarged view of position B in the middle;

[0029] The numbers in the diagram are explained as follows: 10, blood flow channel; 101, spring body support; 102, outer membrane; 11, first section; 12, second section; 13, third section; 20, blood inflow cage; 30, blood outflow cage; 40, imaging ring. Detailed Implementation

[0030] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further explained below with reference to the specific accompanying drawings.

[0031] It should be noted that in the field of medical devices, the side closer to the operator and farther from the heart is usually defined as the proximal end, and the side farther from the operator and closer to the heart is defined as the distal end.

[0032] As previously described, the present invention provides a catheter pump assembly, including a blood flow channel, a blood inlet cage disposed at the distal end of the blood flow channel, and a blood outlet cage disposed at the proximal end of the blood flow channel. The blood flow channel includes a spring body support made of shape memory alloy wire, the inner surface of the spring body support being covered with an inner film, and the outer surface being covered with an outer film.

[0033] The inner and outer films extend to their respective ends near the ends of the spring body support, such that at least a portion of the spring body support is located at the connection between the blood flow channel and the blood inflow cage and the blood outflow cage.

[0034] In the technical solution provided by this invention, an inner thin film is provided on the inner side of the spring body support constituting the blood flow channel, and an outer thin film is provided on the outer side. The two ends of the inner and outer thin films are extended to near the two ends of the spring body support, so that at least a portion of the spring body support is located at the connection between the blood flow channel and the blood inlet and outlet cages. This ensures that at least a portion of the connection between the blood flow channel and the blood inlet and outlet cages is supported by the spring body support, thereby improving the bending strength at the connection between the blood inlet and outlet cages and the blood flow channel. This overcomes the risk of breakage or detachment at the connection between the blood inlet and outlet cages and the blood flow channel in the prior art, thus ensuring the reliability of the catheter pump during use.

[0035] It should be noted that in this invention, only the part of the spring body bracket needs to be located at the connection between the blood flow channel and the blood inlet cage and the blood outlet cage to improve the bending strength at the connection between the blood inlet cage and the blood flow channel, thereby reducing the probability of the aforementioned connection breaking or falling off during subsequent use.

[0036] In a preferred embodiment of the present invention, the two ends of the aforementioned inner and outer films are respectively flush with the two end faces of the spring body support. In this case, the connection between the blood flow channel and the blood inflow cage and blood outflow cage is entirely supported by the spring body support, thus ensuring that the aforementioned connection portion obtains the best bending resistance.

[0037] In a more preferred embodiment, the inner and outer membranes extend to the two ends of the spring-body stent respectively, and are fixedly connected as a single unit at the ends of the spring-body stent. In this embodiment, the inner and outer membranes located at both ends of the spring-body stent are fixed together to prevent the ends of the spring-body stent from being exposed, thus avoiding damage to the patient's vascular wall during surgery.

[0038] According to the conduit pump assembly provided by the present invention, the winding density of the shape memory alloy wires at both ends of the spring body support is greater than that at the middle position. That is, the spring pitch at both ends of the spring body support is smaller than the spring pitch at the middle position. This further improves the bending strength at the connection between the blood inflow cage and the blood outflow cage and the blood flow channel, avoiding the problem of breakage or detachment at the connection.

[0039] like Figure 1As shown, for ease of description, the distal end of the blood flow channel 10 is defined as the first segment 11, the proximal end of the blood flow channel 10 is defined as the third segment 13, and the blood flow channel 10 also has a second segment 12 located between the first segment 11 and the third segment 13.

[0040] The first section 11 of the blood flow channel 10 serves as the connection with the blood inflow cage 20, and the third section 13 of the blood flow channel 10 serves as the connection with the blood outflow cage 30. To prevent the "connection" from breaking or falling off, the inner film (not shown in the figure) and the outer film 102 extend to the ends near the ends of the spring body support 101, so that at least a portion of the spring body support 101 is located at the "connection" between the blood flow channel 10 and the blood inflow cage 20 and the blood outflow cage 30. This ensures that a portion of the spring body support 101 is located within the first section 11 and the third section 13, thereby providing support for the aforementioned "connection" and preventing breakage or falling off.

[0041] In the preferred embodiment, the two ends of the inner and outer films 102 are flush with the two end faces of the spring body support 101, respectively. At this time, the frame of the spring body support 101 is filled to the entire first section 11 and the third section 13, respectively, so that the "connection" between the blood flow channel 10 and the blood inflow cage 20 and the blood outflow cage 30 is fully supported by the spring body support 101, thus better avoiding the occurrence of breakage or detachment.

[0042] More preferably, the inner and outer films 102 extend to the two ends of the spring body support 101 and are fixedly connected to each other at the ends of the spring body support 101. That is, the frame of the spring body support 101 not only fills the first section 11 and the third section 13 respectively, but the films covering the inner and outer sides of the spring body support 101 are also fixedly connected to each other at their ends. This ensures support for the aforementioned "connection part" while preventing the exposed frame part at the end of the spring body support 101 from damaging the inner wall of the patient's blood vessels during the operation.

[0043] In a further preferred embodiment, combined with Figure 2 , 3 As shown, the shape memory alloy wire of the spring body support 101 constituting the blood flow channel 10 has a higher winding density in the first section 11 and the third section 13 than in the second section 12. This significantly enhances the bending strength of the blood flow channel 10 at the connection with the blood inflow cage 20 and the blood outflow cage 30, further preventing breakage or detachment at this point and ensuring the reliability of the catheter pump assembly in subsequent use.

[0044] Furthermore, in combination Figure 1As shown, in this invention, in order to adapt to the physiological structure of the ascending aorta and the left ventricle, the aforementioned second segment 12 has a certain degree of curvature. More specifically, the curvature of the second segment 12 is 130-150°.

[0045] In this invention, the blood flow channel needs to pass through the heart valves to enter the left ventricle in order to transport blood from the left ventricle to the aorta. In order to reduce damage to the heart valves, the blood flow channel is required to be relatively soft. However, if it is made of a very soft material, it will result in a lack of support, which is not conducive to the percutaneous insertion of the catheter pump. Furthermore, when the soft blood flow channel is connected to the metal blood inlet and outlet cages, it may be subjected to large torsional and tensile forces, which may cause the blood flow channel itself or the connection to break. Therefore, this invention uses shape memory alloy wire to wind and form a spring body support, and coats the inner and outer sides of the spring body support to form the blood flow channel, which has a certain supporting strength.

[0046] Shape memory alloys are materials composed of two or more metallic elements that exhibit shape memory effects through thermoelasticity and martensitic phase transformation and its inverse. In this invention, the shape memory alloy constituting the shape memory alloy wire can be one commonly used by those skilled in the art; specifically, the shape memory alloy wire is selected from one of nickel-titanium alloy, titanium-nickel-copper alloy, titanium-nickel-iron alloy, and titanium-nickel-chromium alloy.

[0047] According to the conduit pump assembly provided by the present invention, the inner film and the outer film can be made of the same or different plastic materials. Specifically, the inner film and the outer film are each independently selected from at least one of polyethylene, polyurethane, polycarbonate and thermoplastic elastomer.

[0048] In this invention, the connection methods between the blood inflow cage and the blood outflow cage and the blood flow channel include, but are not limited to, adhesive bonding and fixing, or fixing and connecting with fixing elements.

[0049] Among these methods, using adhesives for fixing and connecting is a common connection method used by those skilled in the art. Furthermore, to improve the connection strength between the blood flow channel and the blood inlet and outlet cages, the ends of the blood inlet and outlet cages near the blood flow channel are respectively provided with shallow threads or knurled patterns. More specifically, the surfaces at the connection points between the blood inlet and outlet cages and the blood flow channel are machined to have shallow threads, or knurled to have knurled patterns, thereby increasing the amount of adhesive applied and making the connection between the blood flow channel and the blood inlet and outlet cages more secure.

[0050] Furthermore, in this invention, combined with Figure 1As shown, the outer surface of the spring-loaded stent is coated with a radiopaque ring 40 to indicate its insertion position within the heart. This facilitates the positioning of the catheter pump after percutaneous insertion.

[0051] The present invention also provides a method for processing the above-mentioned conduit pump assembly, the method comprising the following steps:

[0052] (1) A shape memory alloy wire is wound into a spring shape on the surface of a mandrel to form a spring body support, wherein the pitch of the proximal end and the distal end of the spring body support is smaller than the pitch between the proximal end and the distal end.

[0053] (2) Heat-treat the wound spring body support together with the mandrel to shape the spring body support into a predetermined shape.

[0054] (3) Use an ion sputtering instrument to sputter a layer of Pt or Pd metal on the outer surface of the spring body support to form a developing ring;

[0055] (4) A thin film is applied to the inner and outer surfaces of the spring body support to form an inner film and an outer film, the two ends of the inner film and the outer film extending to the two ends near the spring body support, so that at least part of the spring body support is located at the connection between the blood flow channel and the blood inflow cage and the blood outflow cage.

[0056] (5) Use adhesives or fixing elements to fix the blood inflow cage to the distal end of the spring body support and fix the blood outflow cage to the proximal end of the spring body support to obtain the catheter pump assembly.

[0057] Furthermore, according to the method provided by the present invention, the mandrel is a stainless steel round bar with both ends bent at a certain angle, and the two ends of the spring body bracket are fixed on the mandrel using a clamp.

[0058] According to the method provided by the present invention, the shape memory alloy wire wound on the mandrel can be shaped according to a predetermined shape by heat treatment. Furthermore, the inventors of this application have discovered that by keeping the wound spring body support together with the mandrel at a temperature of 450-550°C for 15-25 minutes and then cooling it to room temperature, the problem of wire breakage and cracking of the shape memory alloy wire during heat treatment can be effectively avoided, and the shaped spring body support can be ensured to have a certain strength.

[0059] According to the method provided by the present invention, the width of the imaging ring can be selected within a certain range, but in order to facilitate the positioning of the blood flow channel in actual use, the width of the imaging ring is 1-5mm.

[0060] The foregoing has shown and described the basic principles, main features, and characteristics of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A catheter pump assembly, comprising a blood flow channel, a blood inlet cage disposed at the distal end of the blood flow channel, and a blood outlet cage disposed at the proximal end of the blood flow channel, characterized in that, The blood flow channel includes a spring body support made of shape memory alloy wire, the inner side of which is covered with an inner film and the outer side is covered with an outer film. The inner and outer films extend to the two ends of the spring body support respectively, and are fixedly connected to each other at the end of the spring body support. The winding density of the shape memory alloy wires at both ends of the spring body support is greater than that of the shape memory alloy wires at the middle position. The blood inflow cage and the blood outflow cage are respectively provided with shallow threads or knurling at the ends near the blood flow channel.

2. The conduit pump assembly according to claim 1, characterized in that, The shape memory alloy wire is selected from one of nickel-titanium alloy, titanium-nickel-copper alloy, titanium-nickel-iron alloy, and titanium-nickel-chromium alloy.

3. The duct pump assembly according to claim 1, characterized in that, The inner and outer films are each independently selected from at least one of polyethylene, polyurethane, polycarbonate, and thermoplastic elastomers.

4. The duct pump assembly according to claim 1, characterized in that, The outer surface of the spring-loaded stent is coated with a radiopaque ring to show its insertion location within the heart.

5. A method for processing the conduit pump assembly according to any one of claims 1-4, characterized in that, The method includes the following steps: (1) A shape memory alloy wire is wound into a spring shape on the surface of a mandrel to form a spring body support, wherein the pitch of the proximal end and the distal end of the spring body support is smaller than the pitch between the proximal end and the distal end. (2) Heat-treat the wound spring body bracket together with the mandrel to shape the spring body bracket into a predetermined shape. (3) Use an ion sputtering instrument to sputter a layer of Pt or Pd metal on the outer surface of the spring body support to form a developing ring; (4) A thin film is applied to the inner and outer surfaces of the spring body support to form an inner film and an outer film, the two ends of the inner film and the outer film extending to the two ends near the spring body support, so that at least part of the spring body support is located at the connection between the blood flow channel and the blood inflow cage and the blood outflow cage. (5) Use adhesives or fixing elements to fix the blood inflow cage to the distal end of the spring body support and fix the blood outflow cage to the proximal end of the spring body support to obtain the catheter pump assembly.

6. The method according to claim 5, characterized in that, In step (1), the mandrel is a stainless steel round bar with both ends bent at a certain angle, and the two ends of the spring body bracket are fixed on the mandrel using a clamp.

7. The method according to claim 5, characterized in that, In step (2), the heat treatment conditions include holding the product at 450-550℃ for 15-25 minutes and then cooling it to room temperature.

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