Pump body assembly of intrusive axial flow blood pump

Abstract

The utility model discloses a pump body assembly of an intrusive axial flow blood pump. The pump body assembly comprises a pump shell, a supporting frame and a thin film pipe. The pump shell body is of a cylindrical structure, and the pump shell comprises a first connecting part and a second connecting part. The supporting frame is formed by winding a metal round wire and is provided with a fixed section and an expansion section connected with the fixed section. A plurality of positioning columns are arranged on the first connecting part of the pump shell and are inserted into a groove in the end part of the in-vivo motor to form an outflow hole of the blood pump; and the fixed section of the support frame is embedded in a plurality of groups of grooves in the surface of the second connecting part of the pump shell. In addition, the film pipe sleeves the fixed section of the support frame and the surface of the second connecting part of the pump shell, so that the connection between the support frame and the pump shell is reinforced and restrained. By adopting the support frame wound by the metal round wire, the risk that the inner wall of a blood vessel is scratched by burrs on the surface of the support frame can be reduced; and the second connecting part of the pump shell is in embedded connection with the fixed section of the supporting frame, so that the connecting strength of the supporting frame and the pump shell can be improved, and the risk that the supporting frame falls off is reduced.

Description

Technical Field

[0001] This application relates to the field of medical device technology, specifically to a pump body assembly of an interventional axial flow blood pump. Background Technology

[0002] Mechanical circulatory support is a clinical device that replaces or assists cardiac function, provides organ blood perfusion, and improves the patient's hypoxic state. It can provide short- to medium-term ventricular assist support, help patients through acute dangerous periods, and is used in bridging heart transplants or high-risk PCI. Among these, implanting a miniature axial flow pump in the descending aorta can treat acute decompensated heart failure. The accelerated blood flow within the pump promotes blood flow outside the pump, thereby increasing the overall downward velocity of blood flow within the vessel, promoting renal artery perfusion, reducing proximal aortic resistance, increasing distal aortic flow, and ultimately reducing left ventricular load and improving cardiac output.

[0003] Because the blood pump is located within the descending aorta, a stent structure is needed to anchor it within the blood vessel to prevent movement during operation. Previously, the pump housing and support frame were machined as a single piece using laser cutting, followed by heat setting to expand and fix the support frame. However, this method results in burrs on the cut metal surface, which are difficult to clean completely and pose a risk of scratching the patient's blood vessels. Utility Model Content

[0004] The purpose of this invention is to solve the above-mentioned technical problems by providing a pump body assembly for an interventional axial flow blood pump, thereby reducing the risk of the metal laser-cut support frame scratching the inner wall of the blood vessel and improving the connection strength between the support frame and the pump housing.

[0005] An invasive axial flow blood pump assembly is characterized by comprising a pump housing, a support frame, and a diaphragm tube. The pump housing is primarily cylindrical and includes a first connecting portion and a second connecting portion. The support frame is made of wound metal wire and includes a fixed section and an expansion section connected to the fixed section. The first connecting portion of the pump housing has multiple positioning posts that are inserted into the end groove of an in vivo motor to form the outflow port of the blood pump. The fixed section of the support frame is embedded in multiple grooves on the surface of the second connecting portion of the pump housing. Furthermore, the diaphragm tube is sleeved on the fixed section of the support frame and the surface of the second connecting portion of the pump housing, reinforcing the connection between the support frame and the pump housing.

[0006] Biocompatible adhesive is applied between the contact surfaces of the membrane tube and the support frame and the outer surface of the pump casing.

[0007] The first connecting portion of the pump housing is provided with a plurality of positioning posts located on the proximal end face of the pump housing, the number of which is 3-6; wherein, the base of the positioning post is provided with an arc chamfer, and the head of the positioning post is provided with a semi-circular surface. The positioning posts are inserted into the end groove of the internal motor, and the pump housing is connected to the internal motor by welding.

[0008] Multiple sets of U-shaped grooves are evenly arranged circumferentially on the surface of the second connecting part of the pump casing.

[0009] The outer diameter of the first connecting part is equal to the maximum outer diameter of the internal motor and the tail end cap, and smaller than the outer diameter of the second connecting part; the first connecting part and the second connecting part are provided with a transition arc to reduce the risk of thrombus deposition on the surface of the blood pump.

[0010] The cross-section of the U-shaped groove has two shapes: semi-circular or semi-elliptical.

[0011] Biocompatible adhesive is applied to the U-shaped groove, and the support frame fixing section is semi-embedded or fully embedded in the U-shaped groove for connection.

[0012] The support frame is made of round wires of metal materials such as nickel-titanium alloy or cobalt-chromium alloy, and the fixed section and the expansion section are connected by an arc transition; wherein, the wire diameter of the support frame is in the range of 0.2-0.5 mm, the length of the fixed section is in the range of 6-7 mm, and the total length of the support frame is in the range of 18-21 mm.

[0013] The beginning and end joints of the support frame metal wires need to be located in the fixed section to prevent the support frame from breaking during release and retraction.

[0014] The support frame is provided with multiple circumferentially evenly arranged petals, the number of which ranges from 3 to 5; wherein each petal is composed of a first support rod, a second support rod and an outer ring, and the circumferential distance between the first support rod and the second support rod gradually increases along the outward expansion direction.

[0015] The beneficial effects of this utility model are as follows: The pump body assembly of the interventional axial flow blood pump of this utility model adopts a support frame made of metal round wire and is fitted and connected to the surface of the pump shell, and then constrained and fixed by a membrane tube, thereby reducing the risk of the support frame cut by metal laser scratching the inner wall of blood vessels and improving the connection strength between the support frame and the pump shell. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0017] Figure 1 This is a schematic diagram of an axial flow blood pump;

[0018] Figure 2 yes Figure 1 Cross-sectional view of the pump body assembly;

[0019] Figure 3 This is a schematic diagram showing the connection between the axial flow blood pump motor and the pump body assembly;

[0020] Figure 4 yes Figure 3 Exploded view of the axial flow blood pump motor and pump body assembly;

[0021] Figure 5 This is a schematic diagram of the pump casing;

[0022] Figure 6 This is a side view of the groove section of the semi-circular cross-section of the pump casing;

[0023] Figure 7 This is a side view of the groove section of the semi-elliptical cross-section of the pump casing.

[0024] Figure 8 This is a schematic diagram of the semi-embedded structure of the support frame and pump casing.

[0025] Figure 9 This is a schematic diagram of a fully embedded structure of the support frame and pump casing.

[0026] Figure 10 This is a front view of the support frame;

[0027] Figure 11 yes Figure 10 Top view of the central support frame. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0029] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application, and are not specific positions that the device or structure referred to must have, and therefore should not be construed as a limitation of this application.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0031] In this utility model application, the terms "proximal" and "distal" are relative to the operator of the interventional axial flow blood pump. The direction closer to the operator is defined as "proximal," while the direction farther from the operator is defined as "distal."

[0032] See Figure 1 As shown, Figure 1 An invasive axial flow blood pump assembly is provided, including an in vivo motor 11, an impeller 12, a tail end cap 13, a sleeve 14, a pump housing 15, a support frame 16, and a diaphragm tube 17. The pump housing 15 is mainly cylindrical and includes a first connecting portion 151 and a second connecting portion 152. The support frame 16 is made of wound metal wire and has a fixed section 161 and an expansion section 162 connected to the fixed section. The first connecting portion 151 of the pump housing 15 has multiple positioning posts 1511, which are inserted into the end groove 111 of the in vivo motor 11 to form the outflow hole of the blood pump. The fixed section of the support frame 16 is embedded in multiple grooves 1521 on the surface of the second connecting portion of the pump housing. In addition, the diaphragm tube 17 is sleeved on the surface of the fixed section of the support frame 16 and the second connecting portion of the pump housing to strengthen the connection between the support frame and the pump housing. The output end of the internal motor 11 is connected to an impeller 12, which is located inside the pump casing. A tail end cap 13 is connected to the proximal end of the internal motor 11, and the tail end cap 13 is connected to a sleeve 14. The internal motor 11 drives the impeller 12 to rotate at high speed, causing blood to flow through the blood pump and, through the conversion of mechanical energy into pressure potential energy, discharge blood at a certain pressure through the outflow hole to the distal end and branches of the aorta. The direction closer to the support frame 16 is designated as the "distal end," and the direction closer to the sleeve 14 is designated as the "proximal end."

[0033] See Figure 2 As shown, the support frame 16 is in an open state under natural, unloaded conditions, with the diaphragm tube 17 covering the outside of the support frame 16. The diaphragm tube 17 fixes the support frame 16 to the outer surface of the pump housing 15 by means of bonding or thermoplasticizing. The contact surface 171 can be coated with glue or directly contact the pump housing 15 and the support frame 16, ensuring that there are no air bubbles on the contact surface 171.

[0034] See Figure 3 and Figure 4As shown, the pump housing 15 includes a first connecting portion 151 and a second connecting portion 152. The first connecting portion 151 is connected to the internal motor 11 and forms a blood outflow hole A with the motor end cap; the second connecting portion 152 is connected to the support frame 16. Specifically, the first connecting portion 151 of the pump housing 15 is connected to the end groove 111 of the internal motor 11, and the fixing section 161 of the support frame 16 is fitted into the surface of the second connecting portion 152.

[0035] See Figure 5 As shown, the first connecting part 151 of the pump housing 15 is provided with a plurality of positioning posts 1511, the number of which is 3-6, and they are evenly distributed circumferentially on the near end face of the pump housing 15. The length of the positioning posts 1511 ranges from 3 to 5 mm. A semi-circular surface 1512 is provided at the head of the positioning post 1511, and the root is smoothly transitioned by an arc chamfer 1513, the purpose of which is to reduce mechanical damage to the blood and improve the blood compatibility of the blood pump. In the process of connecting the pump housing 15 to the in vivo motor 11, the positioning posts 1511 need to be inserted into the end groove 111 of the motor, and the in vivo motor 11 and the pump housing 15 are fixed together by welding. Preferably, the outer shell of the in vivo motor 11 and the pump housing 15 are made of the same metal material, such as titanium alloy, 316LVM, etc. The outer diameter of the first connecting part 151 is consistent with the outer diameter of the in vivo motor 11 and the tail end cap 13, and is smaller than the outer diameter of the second connecting part 152. A transition arc 1522 is provided between the two parts. Multiple sets of grooves 1521 are uniformly provided circumferentially on the surface of the second connecting part 152, and the grooves are U-shaped.

[0036] The 1521 groove has two cross-sectional shapes, which can be as follows: Figure 6 The semi-circular cross section 1521a, or as... Figure 7 The semi-elliptical cross section 1521b. Among them, the semi-circular cross section 1521a structure is used, such as... Figure 8 This allows the support frame 16 to be partially embedded on the outer surface of the pump housing 15; it adopts a semi-elliptical cross-section 1521b structure, such as... Figure 9 This allows the support frame 16 to be fully embedded in the outer surface of the pump housing 15. The choice of cross-section depends on the outer diameter of the pump housing 15 and the support frame 16, as well as the wire diameter of the support frame 16. In addition, the cross-sectional dimensions of the U-shaped groove 1521 should be equal throughout the entire path, with the diameter r1 being 0.05-0.1 mm greater than the wire diameter of the support frame 16.

[0037] In traditional structures, the pump housing 15 and support frame 16 are typically machined as a single piece using metal laser cutting. However, the cut surfaces often contain burrs that are difficult to clean, which can easily scratch the inner wall of blood vessels. Figure 10As shown, in this application, the support frame 16 is made by individually winding metal round wire; the diameter of the metal round wire in the support frame 16 is selected between 0.2-0.5 mm, and the material is usually nickel-titanium alloy or cobalt-chromium alloy, etc. The support frame 16 is divided into two parts: a fixed section 161 and an expansion section 162, which are integrally wound in a mold. Since the materials of the support frame 16 and the pump housing 15 may differ, and the wire diameter of the support frame 16 is relatively thin, it is difficult to fix them by welding. Figure 5 and Figure 10 As shown, bio-adhesive is applied to the groove 1521 of the pump housing 15, and the fixing section 161 of the support frame 16 is embedded in the corresponding groove. The final connection effect is as follows. Figure 3 As shown.

[0038] The fixed section 161 of the support frame 16 is composed of multiple sets of parallel columns, connected at the bottom by a semi-circular arc segment with radius R1. The radius R1 of the semi-circular arc is selected within the range of 0.75-1.5 mm, and the length h1 of the fixed section 161 is selected within the range of 6-7 mm. The starting and ending joint 1611 of the support frame 16 should be located within the fixed section 161, where no movement displacement occurs, and should be avoided in the area of ​​the expansion section 162 to prevent the risk of breakage during the release and retraction of the support frame 16. An arc-shaped transition connection 1621 is provided between the fixed section 161 and the expansion section 162 to reduce local stress and improve the reliability of the support frame 16. The overall length h2 of the support frame 16 is set within the range of 18-21 mm. (See reference...) Figure 11 As shown, the expansion section 162 of the support frame 16 has multiple circumferentially evenly arranged lobes, with 3-5 lobes in total; each lobe consists of a first support rod 1622a, a second support rod 1622b, and an outer ring 1623. Figure 11 Viewed from above, the circumferential distance between the first support rod 1622a and the second support rod 1622b gradually increases from the center of the support frame 16 outwards, and is finally connected by an outer ring; wherein, the maximum diameter D of the outer edge of the support frame 16 is in the range of 20-30 mm, while the minimum diameter d of the fixed section 16 is equal to the outer diameter of the second connecting part 152 of the pump housing 15.

[0039] In this embodiment, the membrane tube 17 is made of a polymer material that is biocompatible, and can be selected from polyurethane, FEP (perfluoroethylene propylene copolymer), silicone, PET (polyethylene terephthalate), etc. The wall thickness of the membrane tube 17 is in the range of 0.1-0.2 mm, and its length is equal to the length of the second connecting part 152 of the pump housing 12, and it can completely cover the fixing section 161 of the support frame 16.

Claims

1. A pump body assembly of an interventional axial flow blood pump, characterized by: The pump shell is a cylindrical structure, and the pump shell comprises a first connecting part and a second connecting part, the support frame is made of a metal round wire, and is provided with a fixed section and an expansion section connected with the fixed section, the first connecting part of the pump shell is provided with a plurality of positioning columns and is inserted into an end groove of an in-vivo motor to form an outflow hole of the blood pump, the fixed section of the support frame is embedded in a plurality of groups of grooves on the surface of the second connecting part of the pump shell, and in addition, the diaphragm tube is sleeved on the surface of the fixed section of the support frame and the second connecting part of the pump shell.

2. The pump body assembly of an interventional axial flow blood pump according to claim 1, wherein, Biocompatible glue is applied between the contact surface of the diaphragm tube and the outer surface of the support frame and the pump shell.

3. The pump body assembly of an interventional axial flow blood pump according to claim 1, wherein, The first connecting part of the pump shell is provided with a plurality of positioning columns located on the proximal end surface of the pump shell, and the number of the positioning columns is 3-6; wherein the root of the positioning column is provided with a circular arc chamfer, and the head of the positioning column is provided with a semicircular surface, the positioning column is inserted into the end groove of the in-vivo motor, and the pump shell and the in-vivo motor are connected by welding.

4. The pump body assembly of an interventional axial flow blood pump according to claim 3, wherein, A plurality of groups of U-shaped grooves are uniformly arranged on the surface of the second connecting part of the pump shell.

5. The pump body assembly of an interventional axial flow blood pump according to claim 3, wherein, The outer diameter of the first connecting part is equal to the maximum outer diameter of the in-vivo motor and the tail end cover, and is smaller than the outer diameter of the second connecting part; the first connecting part and the second connecting part are provided with a transition arc to reduce the risk of thrombus deposition on the surface of the blood pump.

6. The pump body assembly of an interventional axial flow blood pump according to claim 4, wherein, The cross section of the U-shaped groove has two shapes, which are semicircular or semi-elliptical.

7. The pump body assembly of an interventional axial flow blood pump according to claim 6, characterized in that Biocompatible glue is applied in the U-shaped groove, and the fixed section of the support frame is semi-embedded or completely embedded in the U-shaped groove.

8. The pump body assembly of an interventional axial flow blood pump according to claim 1, wherein, The support frame is made of a nickel-titanium alloy or a cobalt-chromium alloy metal material round wire, and the fixed section and the expansion section are connected through an arc transition; wherein the wire diameter of the support frame is 0.2-0.5 mm, the length of the fixed section is 6-7 mm, and the total length of the support frame is 18-21 mm.

9. The pump body assembly of an interventional axial flow blood pump according to claim 8, characterized in that The beginning and end joints of the metal wire of the support frame need to be arranged in the fixed section.

10. The pump body assembly of an interventional axial flow blood pump according to claim 9, characterized in that The support frame is provided with a plurality of circumferentially uniformly arranged leaflets, and the number of the leaflets ranges from 3 to 5; wherein each leaflet is composed of a first support rod, a second support rod and an outer ring, and the circumferential distance between the first support rod and the second support rod gradually increases in the outward expansion direction.

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