Disclosure of Invention
The invention provides a manufacturing method of an interventional spring tube assembly, which comprises the following steps:
sleeving a first auxiliary ring and a second auxiliary ring on the knurled section of the inlet cage and the knurled section of the outlet cage respectively;
the inlet tap and the outlet tap are respectively sleeved at different preset positions on the mandrel; the outer diameter of the mandrel is in smooth transition with the inner diameter of the inlet tap and the inner diameter of the outlet tap;
forming an inner tube, a shape memory layer and an outer tube outside the mandrel; the inner tube is sleeved outside the mandrel, the shape memory layer is sleeved outside the inner tube, the outer tube is sleeved outside the shape memory layer, and the inner tube, the shape memory layer and the outer tube are all positioned between the inlet tap and the outlet tap;
removing the first and second auxiliary rings to form a step gap at the knurled section of the inlet and outlet nibs, respectively;
filling an adhesive material through the step gap to cure the spring tube assembly; the maximum outer diameter of the viscous material does not exceed the outer diameter of the outer tube;
removing the mandrel;
and bending and shaping the spring tube assembly.
Preferably, the first auxiliary ring is in interference fit with the knurled section of the inlet tap and the second auxiliary ring is in interference fit with the knurled section of the outlet tap.
Preferably, the first auxiliary ring width is less than or equal to the knurled section width of the inlet tap, and the second auxiliary ring width is less than or equal to the knurled section width of the outlet tap.
Preferably, the first auxiliary ring width is less than the knurled section width of the inlet tap, and the second auxiliary ring width is less than the knurled section width of the outlet tap; and both ends of the inner tube are aligned with the first auxiliary ring and the second auxiliary ring, respectively, or both ends of the inner tube are partially overlapped with the first auxiliary ring and the second auxiliary ring in the axial direction, respectively.
Preferably, the first auxiliary ring width is less than the knurled section width of the inlet tap, and the second auxiliary ring width is less than the knurled section width of the outlet tap; the inner tube is positioned between the inlet tap and the outlet tap, and axial gaps are reserved between the two end faces of the inner tube and the end faces of the inlet tap and the end faces of the outlet tap respectively;
the method further comprises the following steps before forming the shape memory layer:
And thermally fusing thermoplastic materials on the two ends of the inner tube and the surfaces of the first auxiliary ring and the second auxiliary ring.
Preferably, the thermoplastic material covers the gap between the inner tube and the knurled section, the knurled section uncovered by the first and second auxiliary rings, the first and second auxiliary rings; the outer diameter of the thermoplastic material after hot melting is larger than or equal to the inner diameter of the shape memory layer;
the two end surfaces of the shape memory layer are respectively provided with axial gaps with the step end surface of the knurling section of the inlet tap and the step end surface of the knurling section of the outlet tap; or alternatively
The two ends of the shape memory layer are respectively partially overlapped with the knurled section of the inlet cage and the knurled section of the outlet cage in the axial direction, and the shape memory layer is formed when the thermoplastic material is in a molten state and is not solidified.
Preferably, the thermoplastic material covers the gap between the inner tube and the knurled section, the gap between the inner tube and the first and second auxiliary rings; the outer diameter of the thermoplastic material is equal to the outer diameter of the inner tube; and forming the shape memory layer after the thermoplastic material is cured.
Preferably, the first and second auxiliary rings comprise wire-like springs wound around the knurled section.
Preferably, the step of forming the inner tube comprises:
the inner pipe is sleeved outside the mandrel;
a first heat shrinkage pipe is sleeved outside the inner pipe; the length of the first heat shrinkage tube is longer than that of the inner tube;
and performing heat shrinkage shaping on the inner tube through the first heat shrinkage tube.
Preferably, the step of forming the outer tube comprises:
the outer tube is sleeved outside the shape memory layer;
a second heat shrinkage pipe is sleeved outside the outer pipe; the length of the second heat shrinkage tube is longer than that of the outer tube;
and performing heat shrinkage shaping on the outer tube through the second heat shrinkage tube.
Preferably, the temperature of the heat shrinkage shaping is 150-250 ℃.
Preferably, the shape memory layer comprises a wire-shaped spring, the wire-shaped spring is spirally wound outside the inner tube, and the wire-shaped spring is a round wire or a flat wire.
Preferably, the material of the spring comprises nitinol or copper-aluminum alloy.
Preferably, the shape memory layer is a flat wire and made of nickel-titanium alloy.
Preferably, the pitch of the shape memory layer is uniform or the pitch of both ends is smaller than the pitch of the middle part, or the diameter of both ends of the shape memory layer is larger than the diameter of the middle part.
Preferably, the length of the outer tube is greater than the length of the shape memory layer and the outer tube partially coincides with both the knurled section of the inlet tap and the knurled section of the outlet tap in the axial direction.
Preferably, the adhesive material is cured to form a cone shape with a smooth outer surface.
Preferably, the adhesive material comprises epoxy glue, and the curing step is performed at a temperature of 100-150 ℃ for 10-40 min.
Preferably, the step of bending and shaping the intervening spring tube assembly comprises:
arranging the intervention type spring tube assembly in a shaping groove of a shaping die;
performing heat setting treatment on the setting mould; the shaping temperature is 100-150 ℃, and the shaping time is 10-60 min.
Preferably, the knurling is in any one of diamond, zigzag, sinusoidal, thread, ring and irregular shape.
Further, the invention also provides a manufacturing method of the intervention type blood pump, which comprises the intervention type spring tube assembly formed by the manufacturing method of the intervention type spring tube assembly;
the interventional spring tube assembly comprises a housing, a first guide tube, a second guide tube, a motor and a housing, wherein the first guide tube, the interventional spring tube assembly, the housing and the second guide tube are sequentially connected, the motor is arranged inside the housing, and the motor is used for pumping blood from an inlet tap, an inner tube and an outlet tap sequentially.
The invention further provides an interventional spring tube assembly, which comprises a middle section, an inlet tap and an outlet tap, wherein the middle section comprises an inner tube, a shape memory layer and an outer tube, the shape memory layer is sleeved outside the inner tube, the outer tube is sleeved outside the shape memory layer, and the inlet tap and the outlet tap are respectively arranged at two ends of the middle section and are connected through adhesive materials; the inner diameters of the middle section, the inlet tap and the outlet tap are in smooth transition; the two ends of the middle section, which are connected with the inlet cage head and the outlet cage head, are in a multi-stage ladder shape; the joint of the inlet tap and the middle section is provided with a knurling section, and a step gap is arranged at the joint; the joint of the outlet tap and the middle section is provided with a knurling section, and a step gap is arranged at the joint; the step gap is filled with the viscous material; the interventional spring tube assembly is formed by the method of manufacturing an interventional spring tube assembly as set forth in any one of the preceding claims.
Furthermore, the invention also provides an interventional blood pump, which comprises a first catheter, a second catheter, a motor, a housing and an interventional spring tube assembly formed by the manufacturing method of the interventional spring tube assembly in any embodiment, wherein the first catheter, the interventional spring tube assembly, the housing and the second catheter are sequentially connected, the motor is arranged in the housing, and the motor is used for pumping blood from the inlet tap, the inner tube and the outlet tap sequentially.
Compared with the prior art, the technical scheme of the embodiment of the invention has the following beneficial effects:
according to the interventional spring tube assembly, the blood pump and the manufacturing method thereof provided by the embodiment of the invention, the inner tube, the shape memory layer, the outer tube and the viscous material are all formed outside the mandrel in a manufacturing mode of pre-embedding integrated forming of the inlet tap and the outlet tap, so that the outer diameter of the mandrel is smoothly transited with the inner diameters of the inlet tap and the outlet tap, the inner diameter of the finally formed spring tube assembly is smoothly transited with the inner diameters of the inlet tap and the outlet tap, the smooth inner walls of the joints of the inner tube and the inlet tap, the inner tube and the outlet tap are ensured, blood flow is not hindered by an uneven structure in the whole process of flowing out of the inlet tap, the inner tube of the spring tube assembly and the outlet tap finally, hemolysis performance is ensured, and hemolysis risk caused by the uneven problem of the inner wall of the spring tube assembly is eliminated.
Further, the section of the viscous material solidified at the joint surfaces of the middle section of the spring tube assembly and the metal inlet tap and the metal outlet tap at the two ends is in a multistage ladder-shaped structure, so that the adhesive force and strength are higher, and the falling and cracking risks of the rigid and flexible joint of the spring tube assembly can be reduced without increasing the outer diameter of the spring tube assembly.
Further, the joint between the inlet tap and the middle section and the joint between the outlet tap and the middle section are respectively knurled, so that the adhesive force of the solidified adhesive material is further increased, and the bonding strength is enhanced.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The technical scheme of the invention is described in detail below by specific examples. The following embodiments may be combined with each other, and some embodiments may not be repeated for the same or similar concepts or processes.
Currently, in the treatment of heart failure by interventional mechanical circulatory assist techniques, a blood pump is delivered to a target location of a patient's heart by percutaneous puncture. For example, the interventional left ventricle auxiliary pump enters the left ventricle through the aorta, and the impeller is driven by the motor to rotate at high speed, so that blood is pumped into the ascending aorta from the left ventricle through the spring tube, and the perfusion of coronary artery and terminal viscera is maintained and improved, as shown in fig. 1. During the blood pump pushing process, it is necessary to reach a given location through the patient's tortuous path or calcified anatomy, which requires the spring tube to be small in size and soft in texture to reduce trauma to the patient. However, the distal and proximal ends of the flexible tube are connected to the pump inlet and outlet taps, respectively, and under frequent beating of the heart, the connection is easy to fall off at the rigid-flexible joint, and even the risk of breakage exists.
As shown in fig. 2, the conventional technology adopts a reinforcing layer with a thickness of 0.05mm-0.15mm and a length of 2cm for the outer end portion of the spring tube, and the thermal forming of the reinforcing layer at the outer end portion can avoid the falling off and cracking risks of the joint to a certain extent, but the method is carried out at the cost of increasing the outer dimension of the tube body, and is limited by the dimension of the blood vessel, and the method can increase the risk of interventional operation. In addition, the spring tube and the pump body inlet and outlet halters are assembled by adopting a connection mode that finished products of the inlet and outlet halters are sleeved into finished products of the spring tube, and uneven connection steps can appear on the inner surface of a flow channel of the assembled tube body under the influence of the wall thickness of the parts and the tolerance of each machining batch. At high motor speeds, during the pumping of blood by the blood pump, the red blood cells can collide with the steps at the junction due to problems on the inner surface of the flow channel and break, thereby damaging the blood and even causing hemolysis.
In the present invention, as shown in fig. 3, the interventional blood pump includes an interventional spring tube assembly 100, a motor 200, a first catheter 300, and a second catheter 400 (which may be a pigtail catheter). In this embodiment, a housing may be provided outside the motor 200 to obtain a smooth exterior of the assembly. During operation of motor 200 to drive the blood pump, blood flow is shown at 500 from the left ventricle through the internal passageway of spring tube assembly 100 and into the main artery. For better clinical results, it is often desirable for the spring tube assembly 100 to have a larger inner diameter to achieve greater flow gain, and a smaller outer diameter to achieve low risk of intervention.
Specifically, as shown in fig. 4, the spring tube assembly 100 is a multi-layered composite tube structure with both ends having inlet and outlet functions, and the entire assembly is integrally formed, has a certain bending angle α, and has a developing function. In order to fully ensure stable hemodynamics during operation of the blood pump and good hemolysis effect, the inner wall of the whole spring tube assembly 100 is designed to be uniform and smooth, i.e. the middle section of the spring tube assembly 100 has the same inner diameter as the inlet halter 110 and the outlet halter 170 at the two ends of the spring tube assembly.
As shown in fig. 4-7, the spring tube assembly 100 includes, from the inner layer to the outer layer, at least an inner tube 120, a shape memory layer 130 (e.g., a spring), and an outer tube 150. Where development is desired, the spring tube assembly 100 also includes a development mark (mark) 140. The axial length of the inner tube 120 is shorter than the axial length of the outer tube 150, i.e., both ends of the outer tube 150 extend axially beyond both ends of the inner tube 120. At both ends of the spring tube assembly 100 are an inlet tap 110, an outlet tap 170, and an adhesive material (e.g., glue) 160. The outlet of the inlet tap 110 and the inlet of the outlet tap 170 are in a multi-stage 'ladder' structure on the axis, namely, the end face of the outlet of the inlet tap 110 and the inlet of the outlet tap 170 are axially provided with multi-stage steps along the axis, the inner diameter of the multi-stage steps at the outlet of the inlet tap 110 gradually increases from the inlet direction to the outlet direction, and the inner diameter of the multi-stage steps at the inlet of the outlet tap 170 gradually decreases from the inlet direction to the outlet direction. The outlet of the inlet tap 110 and the inlet of the outlet tap 170 are respectively provided with a certain clearance on the axes, and the radial and axial directions of the inner tube 120, the shape memory layer 130 and the outer tube 150 are respectively provided with a knurling section 111 and a knurling section 171, the knurled patterns can be straight lines, twills, reticulation and other lines capable of increasing friction force, preferably reticulation, more particularly diamond, square reticulation and other reticulation. The steps at the outlet of the inlet tap 110 and the inlet of the outlet tap 170 are on the axes, so that the viscous material fills the gap between the joint surfaces of the middle section of the spring tube assembly 100 and the metal inlet tap and the metal outlet tap at the two ends and is solidified, and the section is in a multi-stage step structure, thereby the joint of the spring assembly 100 has larger bonding force and strength, and the falling and cracking risks of the rigid-flexible joint of the spring tube assembly 100 can be reduced without increasing the outer diameter of the spring tube assembly. Further, by knurling the joint between the inlet tap 110 and the spring tube assembly 100 and the joint between the outlet tap 170 and the spring tube assembly 100, respectively, knurled sections 111, 171 are formed, respectively, which further increases the adhesion to the cured adhesive material and enhances the bonding strength.
As shown in fig. 6, the adhesive material 160 is fully filled in the gaps between the spring tube assembly 100 and the inlet and outlet cages 110 and 170, and is tapered on the outside, i.e., the outer diameter of the adhesive material 160 outside the end face of the outer tube 150 and wrapped around the outer walls of the inlet and outlet cages 110 and 170, respectively, is gradually reduced from the end face of the outer tube 150 to the outside in the axial direction, so that the outer wall 161 of the adhesive material 160 therein is smoothly extended to form a conical surface. The outer wall 161 has an outer diameter not exceeding the outer diameter of the outer tube 150, and is connected to the inner walls of the shape memory layer 130 and the outer tube 150, and also to the ends of the inner tube 120, the shape memory layer 130 and the outer tube 150. The stepped interface of the inlet and outlet nibs 110, 170 may be uniform in structure and size.
In some embodiments, the spring tube assembly 100 may not be provided with a developing marker (mark) 140, and instead, the developing function is achieved by providing a developing marker at other components of the interventional blood pump, such as the motor 200, the first catheter 300, the second catheter 400, and the like.
The embodiment of the invention provides a manufacturing method of an interventional spring tube assembly. Fig. 8 is a flowchart of a method for manufacturing an interventional spring tube assembly according to an embodiment of the present invention. As shown in fig. 8, a method for manufacturing a spring tube assembly includes the steps of:
And S110, respectively sleeving the knurled section of the inlet cage and the knurled section of the outlet cage with a first auxiliary ring and a second auxiliary ring.
In an implementation, as shown in fig. 9a, the inlet tap 110 has a knurled section 111 and the outlet tap 170 has a knurled section 171. In some embodiments, the knurls may be diamond-shaped, zigzag, including longitudinal zigzag as shown in fig. 11a and transverse zigzag as shown in fig. 11c, sinusoidal, including longitudinal sinusoidal as shown in fig. 11b and transverse sinusoidal as shown in fig. 11d, any one or combination of thread-shaped as shown in fig. 11e, circular-ring-shaped as shown in fig. 11f, irregular-shaped as shown in fig. 11 g. Furthermore, the knurled shape can be deformed into any shape capable of resisting axial load, so that the falling-off of the joint surfaces can be avoided.
As shown in fig. 9b, the axial width of the knurled section 111 of the inlet tap 110 and the axial width of the knurled section 171 of the outlet tap 170 are each 3mm or less. In some embodiments, the size of the knurled section 111 of the inlet tap 110 and the size of the knurled section 171 of the outlet tap 170 are the same, in particular the inner diameter, the outer diameter, the axial width of the knurled section 111 and the knurled section 171 are each equal, so that the size of the first auxiliary ring 101 and the second auxiliary ring 102 can also be set to be the same. It should be noted that in other embodiments, the size of the knurled section 111 of the inlet tap 110 and the knurled section 171 of the outlet tap 170 may be different, in particular the axial width may be different, such that the widths of the first and second auxiliary rings 101, 102 are set for the respective widths.
The inner diameters of the first auxiliary ring 101 and the second auxiliary ring 102 may be between 4 to 6 mm. The axial width of the first auxiliary ring 101 is less than or equal to the axial width of the knurled section 111 of the inlet tap 110 and the axial width of the second auxiliary ring 102 is less than or equal to the axial width of the knurled section 171 of the outlet tap 170. The first auxiliary ring 101 and the second auxiliary ring 102 may be aligned with the edges of the corresponding knurled sections remote from the intermediate section. In particular, when the axial width of the first auxiliary ring 101 is equal to the axial width of the knurled section 111 of the inlet tap 110 and the axial width of the second auxiliary ring 102 is equal to the axial width of the knurled section 171 of the outlet tap 170, i.e. when the auxiliary ring completely covers the knurling, the bonding strength can be increased at the bonding surface by means of a thermoplastic material or glue or the like. Preferably, the axial width of the first auxiliary ring 101 is smaller than the axial width of the knurled section 111 of the inlet tap 110 and the axial width of the second auxiliary ring 102 is smaller than the axial width of the knurled section 171 of the outlet tap 170.
The first auxiliary ring 101 and the second auxiliary ring 102 may be any ring-shaped material that is not compatible with the inner tube 120, and may be a metallic material or a nonmetallic material, in order to facilitate the subsequent peeling. The first auxiliary ring 101 and the second auxiliary ring 102 have a certain elasticity in the radial direction. Preferably, the first auxiliary ring 101 and the second auxiliary ring 102 are wire-shaped springs to facilitate peeling in a subsequent process flow, and the springs are wound on the knurled sections.
In some embodiments, there is an interference fit between the first auxiliary ring 101 and the knurled section 111 of the inlet tap 110 and between the second auxiliary ring 102 and the knurled section 171 of the outlet tap 170, thereby ensuring coaxiality. Specifically, if the first auxiliary ring 101 and the second auxiliary ring 102 are metal springs, the inner diameter of the springs is required to be slightly smaller than or equal to the outer diameter of the knurls, so that interference can be achieved, and the springs have elasticity, so that the inner diameters of the springs can be expanded. If the inner diameter of the plastic is nonmetal, the plastic can be large or small, the interference can be realized by a heat shrinkage mode, and the plastic can be realized by a plastic elastic expansion mode.
And step S120, respectively sleeving the inlet tap and the outlet tap at different preset positions on the mandrel.
In this embodiment, as shown in fig. 9c, when manufacturing the spring tube assembly, the selection of the mandrel 20 includes: the inner diameter and length of the spring tube assembly 100, i.e., the design size of the inner diameter and the design size of the length thereof, are manufactured according to the need, and the mandrel 20 having the corresponding size is selected according to the inner diameter size of the inlet tap 110 and the inner diameter size of the outlet tap 170, so that the outer diameter of the mandrel 20 smoothly transits with the inner diameter of the inlet tap 110 and the inner diameter of the outlet tap 170, the outer diameter of the mandrel 20 is equal to the design inner diameter of the spring tube assembly 100, and the length of the mandrel 20 depends on the design length of the spring tube assembly 100 as long as it is greater than the design length of the spring tube assembly 100, and the mandrel 20 can be inserted into the inlet tap 110 and the outlet tap 170. Specifically, the outer diameter of the mandrel 20 is equal to the inner diameters of the inlet tap 110 and the outlet tap 170, so that the inner diameter of the inner tube 120 of the finally formed spring tube assembly is equal to the inner diameters of the inlet tap 110 and the outlet tap 170 respectively, smooth inner walls at the joints of the inner tube and the inlet tap, the inner tube and the outlet tap are ensured, and no uneven structure is blocked in the whole process of flowing out from the inlet tap, the inner tube of the spring tube assembly and the outlet tap finally, so that the hemolytic performance is ensured. The inner diameters of the mandrels 20 are axially equal throughout, thereby defining the inner diameters of the various portions of the inner tube of the resulting spring tube assembly that are axially equal, ensuring that blood flow is free of uneven structural obstructions within the inner tube. The inner diameter of the mandrel 20 may also be in a reducing trend, and only the smooth and non-smooth structure of the outer surface of the mandrel 20 needs to be ensured, the outer diameter of one end sleeved with the inlet tap 110 is smoothly connected with the inner diameter of the inlet tap 110, the outer diameter of one end sleeved with the outlet tap 170 is smoothly connected with the inner diameter of the outlet tap 170, so that the inner wall of the inner tube 120 of the finally formed spring tube assembly is smooth, and the joint of the inner tube and the inlet tap 110 and the outlet tap 170 is smoothly transited without a convex or concave structure.
To control the length of the entire spring tube assembly 100 and to facilitate demolding, the outer surface of the mandrel 20 is provided with a Polytetrafluoroethylene (PTFE) lubrication coating and graduation marks for indicating the position of the inlet and outlet nibs 110, 170, which may be based on the length of the middle portion of the spring tube assembly 100. To further facilitate demolding of the mandrel 20, the outer surface of the mandrel 20 may also be coated with a release agent, such as liquid silicone oil.
In step S130, an inner tube, a shape memory layer, a development mark (if needed) and an outer tube are formed outside the mandrel.
In this embodiment, referring to fig. 5, 6 and 9c, the inner tube 120 is sleeved outside the mandrel 20, the shape memory layer 130 and the developing mark 140 are sleeved outside the inner tube 120, and the outer tube 150 is sleeved outside the shape memory layer 130 and the developing mark 140. Axially, the inner tube 120, shape memory layer 130, development mark 140, and outer tube 150 are all located between the inlet and outlet nibs 110, 170. The inner and outer tubes 120, 150 are required to be soft in texture to reduce physical damage to the person during the intervention, and may be polyurethane, silicone or soft polyester materials.
Specifically, the inner tube 120 is formed outside the mandrel 20 by using the mandrel 20 as an inner mold. In some embodiments, the step of forming the inner tube 120 includes steps S131-S133:
Step S131, an inner tube is sleeved outside the mandrel.
Step S132, sleeving a first heat shrinkage tube outside the inner tube; the length of the first heat shrinkage tube is greater than the length of the inner tube.
And S133, performing heat shrinkage shaping on the inner tube through the first heat shrinkage tube.
In a specific implementation, as shown in fig. 9c to 9e, the material of the inner tube 120 is coated outside the mandrel 20, then the first heat shrinkage tube 30 is arranged outside the inner tube 120, the inner tube 120 is heat-shrunk on the surface of the mandrel 20 through the first heat shrinkage tube 30, and the first heat shrinkage tube 30 can be removed after the heat shrinkage shaping of the inner tube 120. After the heat shrinkage treatment, in order to ensure that the inner tube 120 is in smooth transition with the inlet tap 110 and the outlet tap 170 at the connection part, the heat shrinkage shaping temperature can be 150-250 ℃, the material of the first heat shrinkage tube 30 can be poly (perfluoroethylene propylene) or polytetrafluoroethylene, and the heat shrinkage temperature is preferably more than 250 ℃ and 1.5: a heat-shrinkable tube with heat shrinkage ratio of more than 1. The length of the first heat shrinkage tube 30 is greater than the length of the inner tube 120.
In some embodiments, both end surfaces of the inner tube 120 in the axial direction may have a gap with the knurled sections on both sides; it is also possible to partially coincide with the knurled sections on both sides in the axial direction and align with the end faces of the first auxiliary ring 101 and the second auxiliary ring 102, respectively, to cover the knurled sections not covered by the first auxiliary ring 101 and the second auxiliary ring 102; it is also possible to partially coincide with the first auxiliary ring 101 and the second auxiliary ring 102, respectively, and to have a certain clearance with the end faces of the knurled sections on both sides, which are remote from the intermediate section.
In some embodiments, as shown in fig. 9f, in the step of forming the shape memory layer 130 and the developing mark 140, the shape memory layer 130 includes a wire-shaped spring, which is spirally wound outside the inner tube 120, and the spring is a round wire or a flat wire. In some embodiments, the spring material may be nitinol or copper-aluminum alloy. Preferably, the shape memory layer 130 is a flat wire and is made of nickel titanium alloy (NiTi), thereby achieving higher support performance and reducing delamination. In some embodiments, the pitch of the spring in the shape memory layer 130 is uniform or the pitch of the two end portions is smaller than the pitch of the middle portion or the diameter of the two end portions is larger than the diameter of the middle portion, i.e., a variable diameter spring. In some embodiments, the length of the shape memory layer 130 may be greater than the length of the inner tube 120, and both ends of the shape memory layer 130 are partially coated on the outer surfaces of the first auxiliary ring 101 and the second auxiliary ring 102, respectively. In other embodiments, the length of the shape memory layer 130 may be equal to the length of the inner tube 120, and there is a gap between both end surfaces of the shape memory layer 130 in the axial direction and the knurled ends of both ends.
In some embodiments, as shown in fig. 9f, the developing mark 140 has an X-ray developing function, the developing mark 140 is ring-shaped and has an opening to facilitate installation, the inner diameter of the developing mark 140 is smaller than the outer diameter of the inner tube 120, and the axial width of the developing mark 140 is smaller than or equal to the pitch of the shape memory layer 130. Preferably, the development mark 140 is a split ring having an axial length equal to or less than the pitch of the shape memory layer 130. The developing mark 140 may be disposed in a gap of the shape memory layer 130 spring.
Specifically, the outer tube 150 is formed outside the shape memory layer 130 and the development mark 140. In some embodiments, the step of forming the outer tube 150 includes steps S135-S137:
in step S135, the outer tube 150 is sleeved outside the shape memory layer and the development mark.
In step S136, the second heat shrinkage tube 40 is sleeved outside the outer tube 150. The length of the second heat shrink tube 40 is greater than the length of the outer tube 150.
In step S137, the outer tube 150 is heat shrunk and shaped by the second heat shrink tube 40.
In an embodiment, as shown in fig. 9 g-9 i, the shaped outer tube 150 with a specific length is sleeved on the outer layer of the shape memory layer 130, and equidistant axial gaps are left between the outer tube and the steps of the inlet and outlet bridles 110 and 170. The length of the outer tube 150 is greater than the length of the shape memory layer 130, the axial gap between the outer tube 150 and the end surface of the knurled section distal from the intermediate section may be less than 1mm, and the provision of the axial gap may increase the length of the adhesive material extending axially from beyond the end of the outer tube 150 to the interior of the outer tube 150, as much as possible to increase the interface.
In some embodiments, the length of the second heat shrink tube 40 is greater than the length of the outer tube 150, and the second heat shrink tube 40 is sleeved onto the outer layer of the outer tube 150 and completely covers. And then, performing heat shrinkage shaping on the outer tube 150 by using the second heat shrinkage tube 40, wherein the temperature of the heat shrinkage shaping is 150-250 ℃, and the second heat shrinkage tube 40 can be removed after shaping is completed. The heat shrinkage process parameters of the second heat shrinkage tube 40 and the first heat shrinkage tube 30 can be identical, and the two heat shrinkage tubes can be made of the same material or different materials.
In some embodiments, the length of the outer tube 150 is greater than the length of the shape memory layer 130, and the outer tube 150 partially coincides with both the knurled section 111 of the inlet tap 110 and the knurled section 171 of the outlet tap 170 in the axial direction.
Step S140, removing the first auxiliary ring and the second auxiliary ring to form a step gap at the knurled section of the inlet tap and the knurled section of the outlet tap, respectively.
Step S150, filling the adhesive material through the step gap to cure the spring tube assembly. The maximum outer diameter of the viscous material does not exceed the outer diameter of the outer tube.
Step S160, removing the mandrel.
In a specific implementation, as shown in fig. 9j, the first and second auxiliary rings 101 and 102 are removed to form a step gap at both end faces of the intermediate section and the knurled section 111 of the inlet and outlet cages 110 and 171 of the outlet cage 170, respectively. As shown in fig. 9k, the adhesive material 160 is filled in the inner step gap formed by removing the first auxiliary ring 101 and the second auxiliary ring 102, and is formed in a cone shape at the outer wall of the inlet tap 110 and the outer wall of the outlet tap 170 outside the end face of the outer tube 150, so that the maximum outer diameter of the outer wall 161 of the adhesive material 160 does not exceed the outer diameter of the shaped outer layer 150, and then the outer wall is placed in a heat treatment apparatus to be cured. The adhesive material is preferably a high temperature resistant glue, such as an epoxy glue, having a cure temperature of between 100 deg. -150 deg. and a cure time of between 10min-40min, because of the subsequent need to bend the spring tube assembly 100. After curing is complete, mandrel 20 is withdrawn.
And S170, bending and shaping the spring tube assembly.
In the specific implementation, as shown in fig. 9l and 10, the cured straight spring tube assembly 100 is placed in the shaping groove 51 of the shaping mold 50, and the shaping mold 50 is placed in a hot bellows or a heat treatment furnace to be shaped, and cooled and dried to obtain the shaped spring tube assembly 100. Preferably, the bending and shaping temperature is 100-150 degrees, and the shaping time is 10-60 min. The shaping mold 50 may have a plurality of shaping grooves 51 therein so that a plurality of spring tube assemblies 100 may be simultaneously bent and shaped.
The width of the auxiliary ring, the inner tube 120, the shape memory layer 130, the outer tube 150 in the axial direction and the thickness in the radial direction may be variously combined in the present invention. In these embodiments, the first auxiliary ring 101 has an axial width that is less than the width of the knurled section 111 of the inlet tap 110 and the second auxiliary ring 102 has an axial width that is less than the width of the knurled section 171 of the outlet tap 170.
In the first embodiment, as shown in fig. 6 and 9a, 9b, both ends of the inner tube 120 are aligned with the first auxiliary rings 101 and 102, respectively, and the second auxiliary rings. In this embodiment, the end of the inner tube 120 may be a stepped structure with a long inner portion and a short outer portion, the shorter portion abuts against the knurled end, and the longer portion abuts against the auxiliary ring, so as to be clamped with the knurled section, and increase the bonding strength. After the auxiliary ring is peeled off, the position thereof is filled with an adhesive material, thereby further increasing the bonding strength.
Further, the inner tube 120, the shape memory layer 130 and the outer tube 150 are gradually increased in width in the axial direction to form a stepped structure, and a gap is provided between the outer tube 150 and the end surface of the knurled section, which is far from the middle section, so that the viscous material can flow into the stepped structure from the gap, fill between the spring gaps of part of the shape memory layer 130, cover the position where the original auxiliary ring is located, and form a tapered structure with a smooth appearance on the outside.
In the second embodiment, as shown in fig. 12 and 9a, 9b, both ends of the inner tube 120 partially overlap with the first auxiliary ring 101 and the second auxiliary ring 102, respectively, in the axial direction.
Further, the axial width of the inner tube 120 may be equal to the axial width of the outer tube 150 in the axial direction and greater than the width of the shape memory layer in the axial direction, and both sides of the inner tube 120 and the outer tube 150 may have a gap with the end surface of the knurled section far from the middle section, so that glue enters and fills the position of the original auxiliary ring through the gap, and wraps the outer walls of the inlet and outlet nibs 110 and 170 outside the end surface of the outer tube 150, respectively, to form a tapered structure having a smooth appearance.
In a third embodiment, as shown in fig. 13 and 9a, 9b, both ends of the inner tube 120 have axial clearance with the knurled section 111 of the inlet tap 110 and the knurled section 171 of the outlet tap 170, respectively. The method further includes, prior to forming the shape memory layer 130: thermoplastic material is thermally melted at both ends of the inner tube 120 and the surfaces of the first auxiliary ring 101 and the second auxiliary ring 102.
Further, the width of the shape memory layer 130 and the inner tube 120 in the axial direction is equivalent, or the width of the shape memory layer 130 in the axial direction is slightly larger than the width of the inner tube 120 in the axial direction, and both ends of the shape memory layer 130 and the inner tube 120 in the axial direction have axial clearances with the knurled sections 111 of the inlet cage 110 and the knurled section 171 of the outlet cage 170, respectively. The outer tube 150 partially coincides with the knurling section in the axial direction and has a gap with the end surface of the knurling section remote from the intermediate section, the thermoplastic material 180 covers the shape memory layer 130 and the gap between the inner tube 120 and the knurling section, and covers the knurling section and the auxiliary ring not covered by the auxiliary ring, and the outer diameter of the thermoplastic material 180 is greater than or equal to the inner diameter of the shape memory layer 130. The thermoplastic material 180 and the end surface of the knurled section far from the middle section have a gap therebetween, and the width of the gap in the axial direction can be equal to the width of the gap between the outer tube 150 and the end surface of the knurled section far from the middle section, and the adhesive material 160 flows into and fills the original auxiliary ring position from the gap, and wraps the outer walls of the inlet tap 110 and the outlet tap 170 outside the end surface of the outer tube 150 respectively, so as to form a cone shape with smooth appearance.
In other embodiments, as shown in fig. 13 and 9a, 9b, both ends of the inner tube 120 have axial clearance with both the knurled section 111 of the inlet tap 110 and the knurled section 171 of the outlet tap 170, respectively. The method further includes, prior to forming the shape memory layer 130: thermoplastic material 180 is thermally melted at both end portions of the inner tube 120 and the surfaces of the first auxiliary ring 101 and the second auxiliary ring 102.
Further, in the third embodiment, as shown in fig. 13 and 9a, 9b, both ends of the shape memory layer 130 have axial clearances with the knurled section 111 of the inlet tap 110 and the knurled section 171 of the outlet tap 170, respectively. Thermoplastic material 180 covers the gap between inner tube 120 and the knurled section, the knurled section not covered by first auxiliary ring 101 and second auxiliary ring 102, first auxiliary ring 101 and second auxiliary ring 102. The outer diameter of thermoplastic material 180 is greater than or equal to the inner diameter of shape memory layer 130. There is a gap between the thermoplastic material 180 and the end surfaces of the knurled sections distal from the intermediate section, and the thermoplastic material 180, after curing, can be aligned with the end surfaces of the outer tube 150 to form a gap of the same axial width. From this gap, the viscous material 160 flows into and fills the original auxiliary ring and wraps around the outer walls of the inlet and outlet nibs 110, 170, respectively, beyond the end face of the outer tube 150, forming a smooth-looking cone.
Further, in the fourth embodiment, as shown in fig. 14 and 9a, 9b, both ends of the shape memory layer 130 are partially overlapped with the knurled section 111 of the inlet cage 110 and the knurled section 171 of the outlet cage 170, respectively, in the axial direction, and the shape memory layer 130 is formed while the thermoplastic material 180 is uncured in a molten state, and the thermoplastic material 180 is embedded in part of the shape memory layer 130. In this embodiment, the widths of the inner tube 120, the shape memory layer 130 and the outer tube 150 in the axial direction are gradually increased, thereby forming a stepped gap, and the thermoplastic material 180 fills the gap between the inner tube 120 and the shape memory layer 130 and the knurled section and the knurled portion inside the shape memory layer 130 and not covered by the auxiliary ring. There is a gap between the thermoplastic material 180 and the end surfaces of the knurled sections distal from the intermediate section, and the thermoplastic material 180, after curing, can be aligned with the end surfaces of the outer tube 150 to form a gap of the same axial width. From this gap, the viscous material 160 flows into and fills the original auxiliary ring and wraps around the outer walls of the inlet and outlet nibs 110, 170, respectively, beyond the end face of the outer tube 150, forming a smooth-looking cone.
In the fifth embodiment, as shown in fig. 15 and 9a, 9b, the outer diameter of the thermoplastic material 180 is equal to the outer diameter of the inner tube 120, and the thermoplastic material 180 is cured to form the shape memory layer 130. In this embodiment, the thermoplastic material 180 fills the gap between the inner tube and the auxiliary ring, knurled section.
Further, the widths of the inner tube 120, the shape memory layer 130 and the outer tube 150 in the axial direction are gradually increased to form a stepped structure, and a gap is formed between the outer tube 150 and the end surface of the knurled section, which is far away from the middle section, so that viscous material can flow into the stepped structure from the gap, fill between the spring gaps of part of the shape memory layer 130, cover the position where the original auxiliary ring is located, and wrap the outer walls of the inlet tap 110 and the outlet tap 170 outside the end surface of the outer tube 150 respectively to form a tapered structure with a smooth appearance.
It should be understood that, although the steps in the flowchart of fig. 8 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least a portion of the steps in fig. 8 may include a plurality of steps or stages that are not necessarily performed at the same time, but may be performed at different times, and the order of execution of the steps or stages is not necessarily sequential, but may be performed in rotation or alternately with at least a portion of the steps or stages in other steps or other steps.
Further, the present invention also provides an interventional spring tube assembly comprising a middle section, an inlet tap 110 and an outlet tap 170, the middle section comprising an inner tube 120, a shape memory layer 130, a development mark 140 and an outer tube 150. The shape memory layer 130 and the developing mark 140 are sleeved outside the inner tube 120, the outer tube 150 is sleeved outside the shape memory layer 130 and the developing mark 140, and the inlet and outlet taps 110 and 170 are respectively arranged at two ends of the middle section and connected through the adhesive material 160. The inner diameters of the intermediate section, inlet tap 110 and outlet tap 170 transition smoothly. The two ends of the middle section, which are jointed with the inlet cage 110 and the outlet cage 170, are in a multi-stage ladder shape; the joint of the inlet tap 110 and the middle section is provided with a knurled section 111, and the joint is provided with a step gap; the junction of the outlet tap 170 and the intermediate section has a knurled section 171 and the junction is provided with a step gap; the step gap is filled by the viscous material 160. The present invention may further include an interposed spring tube assembly 100 formed by the method of making an interposed spring tube assembly in any of the embodiments described above.
Further, the present invention also provides an interventional blood pump, as shown in fig. 3, which includes a first catheter 300, a second catheter 400, a motor 200, a housing, and an interventional spring tube assembly 100 formed by the method for manufacturing an interventional spring tube assembly according to any of the above embodiments. The first catheter 300, the intervening spring tube assembly 100, the housing and the second catheter 400 are connected in sequence, the motor 200 is disposed inside the housing, and the motor 200 is used to pump blood from the inlet tap 110, the inner tube and the outlet tap 170 in sequence.
The invention also provides a manufacturing method of the intervention type blood pump, which comprises the steps of forming the intervention type spring tube assembly 100 by the manufacturing method of the intervention type spring tube assembly according to any one of the embodiments; a first conduit 300, a second conduit 400, a motor 200, and a housing are provided on the interventional spring tube assembly 100; the first catheter 300, the intervening spring tube assembly 100, the housing and the second catheter 400 are connected in sequence, the motor 200 is disposed inside the housing, and the motor 200 is used to pump blood from the inlet tap 110, the inner tube 120 and the outlet tap 170 in sequence.
In summary, according to the manufacturing method of the interventional spring tube assembly and the blood pump and the interventional blood pump provided by the embodiments of the invention, the inner tube 120, the shape memory layer 130, the developing mark 140, the outer tube 150 and the viscous material 160 are all formed outside the mandrel 20 by integrally forming the spring tube assembly 100, and as the outer diameter of the mandrel 20 is in smooth transition with the inner diameters of the inlet tap 110 and the outlet tap 170 respectively, the inner diameters of all parts in the axial direction of the finally formed spring tube assembly 100 are limited to be in smooth transition, so that the inner wall of the spring tube assembly 100 is smooth and has no convex or concave structure, and the hemolysis risk caused by the problem of unsmooth inner wall of the spring tube can be eliminated. Meanwhile, in the molded spring tube assembly 100, the cross section of the adhesive material 160 solidified at the joint surface of the middle section and the metal inlet and outlet heads 110 and 170 is in a multi-stage ladder-shaped structure, so that the adhesive force and strength are higher, and the falling and cracking risks of the rigid-flexible joint of the spring tube assembly 100 can be reduced without increasing the outer diameter size of the spring tube assembly 100. Further, by knurling the joint between the inlet tap 110 and the spring tube assembly 100 and the joint between the outlet tap 170 and the spring tube assembly 100, respectively, knurled sections 111, 171 are formed, respectively, which further increases the adhesion to the cured adhesive material and enhances the bonding strength. Further, structurally, the shape memory layer 130 formed integrally is embedded in a manner that the sections of the two ends of the assembly are in a multi-stage ladder shape, and a certain gap is reserved at the joint of the inner part, the end part and the inlet tap 110 and the outlet tap 170 after knurling the step surface, so that the assembly has larger bonding force and strength characteristics after being fully filled by flowing adhesive material 160 and thermally cured.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.