Preparation method of micro pump head

Abstract

The present invention provides a method for preparing a micro pump head, which relates to the technical field of pump head preparation. The method for preparing a micro pump head includes the steps of preparing a pump head impeller, and the steps of preparing the pump head impeller include: spirally arranging an impeller skeleton wire between a proximal fixing ring and a distal fixing ring; using an impeller blade mold and an elastic raw material to prepare an impeller blade; fixing the distal fixing ring, rotating the proximal fixing ring along the spiral direction of the impeller skeleton wire, pre-tightening the impeller skeleton wire to a multi-cycle spiral shape, and then putting the impeller blade onto the pre-tightened impeller skeleton surface and releasing the pre-tightening force, so that the impeller skeleton wire recovers at least a periodic spiral shape under the action of its own elasticity, and pushes the impeller blade outward to form a spiral impeller. The preparation method provided by the present invention can obtain a micro pump head with elasticity, thereby improving the safety and work efficiency of the left ventricular assist device.

Description

Technical Field

[0001] The invention relates to the technical field of pump head preparation, in particular to a method for preparing a micro pump head. Background Art

[0002] Existing interventional left ventricular assist devices mainly use a micropump head equipped with a non-deformable rigid impeller. Due to the size of the non-deformable rigid impeller, the auxiliary flow rate generated by this micropump head is small and often cannot achieve the expected blood supply effect. In the process of using an interventional left ventricular assist device with a constant impeller size, in order to provide patients with sufficient auxiliary blood flow, the commonly adopted solution is to increase the impeller speed. However, the high-speed rotation of the impeller will inevitably cause excessive shear force inside the blood, leading to changes in red blood cell permeability and irreversible cell damage, thereby increasing the risk of hemolysis in patients. Therefore, the preparation of a foldable flexible impeller has become a problem that needs to be solved. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for preparing a micro pump head to obtain an elastic micro pump head, thereby improving the safety and working efficiency of a left ventricular assist device.

[0004] To solve the above technical problems, the present invention provides a method for preparing a micro pump head, including the steps of preparing a pump head impeller, wherein the steps of preparing the pump head impeller include:

[0005] Preparation of impeller skeleton: The impeller skeleton comprises a proximal fixing ring, a distal fixing ring and an impeller skeleton wire, and the impeller skeleton wire is spirally arranged between the proximal fixing ring and the distal fixing ring;

[0006] Impeller blade preparation: Use impeller blade mold and elastic raw materials to prepare impeller blade;

[0007] The impeller skeleton and the impeller blade are assembled: fix the distal fixing ring, rotate the proximal fixing ring along the spiral direction of the impeller skeleton wire, pre-tighten the impeller skeleton wire to a multi-cycle spiral shape, put the impeller blade onto the pre-tightened impeller skeleton wire surface and release the pre-tightening force, so that the impeller skeleton wire can restore at least a periodic spiral shape under the action of its own elasticity, and push the impeller blade outward to form a spiral impeller.

[0008] In one embodiment, the impeller skeleton preparation includes:

[0009] Selecting nickel-titanium alloy wire, preferably, the nickel-titanium ratio of the nickel-titanium alloy wire is 53:47-60:40, more preferably 56:44;

[0010] Pre-shaping and fixing the nickel-titanium alloy wire using a mold with a spiral groove;

[0011] The mold is placed in a heating device for heating. The heating method is preferably constant temperature heating. The constant temperature heating temperature is preferably 450° C. to 550° C., more preferably 500° C., and the heating time is preferably 10 minutes to 30 minutes, more preferably 15 minutes.

[0012] After heating, taking a mold to obtain the impeller skeleton wire; and

[0013] The distal end and the proximal end of the impeller skeleton wire are respectively assembled with the distal fixing ring and the proximal fixing ring in a form-locking manner, and biocompatible glue is applied to the assembly positions for bonding and fixing.

[0014] In one embodiment, the impeller skeleton is prepared by metal 3D printing in an integrated manner.

[0015] In one embodiment, the impeller skeleton preparation includes:

[0016] Using nickel-titanium powder as raw material, modeling and printing are performed according to the design dimensions. The nickel-titanium ratio in the nickel-titanium powder is preferably 53:47-60:40, more preferably 56:44. The design dimensions preferably include the pitch, spiral radius, and spiral height.

[0017] Fixing the impeller skeleton with a mold that matches the size of the impeller skeleton to prevent the impeller skeleton from being deformed by heat during the heat treatment process;

[0018] The mold is placed in a heating device for heating. Preferably, the heating method is constant temperature heating. The constant temperature heating temperature is preferably 450° C. to 550° C., more preferably 500° C., and the heating time is preferably 10 minutes to 30 minutes, more preferably 15 minutes; and

[0019] After heating, the mold is taken to obtain the impeller skeleton with mechanical properties and geometrical morphology meeting the requirements.

[0020] In one embodiment, the impeller skeleton is prepared by cutting a nickel-titanium alloy tube through a femtosecond laser.

[0021] In one embodiment, the impeller skeleton preparation includes:

[0022] A nickel-titanium alloy tube is selected and processed using a femtosecond laser according to the design drawings to obtain an impeller skeleton in a folded state, wherein the nickel-titanium ratio of the nickel-titanium alloy tube is preferably 53:47-60:40, more preferably 56:44;

[0023] Twisting the impeller skeleton to an unfolded state, and fixing the impeller skeleton in the unfolded state using a mold having a size that meets the requirements;

[0024] The mold is placed in a heating device for heating. Preferably, the heating method is constant temperature heating. The constant temperature heating temperature is preferably 450° C. to 550° C., more preferably 500° C., and the heating time is preferably 10 minutes to 30 minutes, more preferably 15 minutes; and

[0025] After heating, the mold is taken to obtain the impeller skeleton with mechanical properties and geometrical morphology meeting the requirements.

[0026] In one embodiment, the method for preparing the micro pump head further includes the step of preparing a pump head transmission assembly, wherein the pump head transmission assembly passes through the pump head impeller, the distal end of the pump head transmission assembly is fixedly connected to the distal end of the pump head impeller, the pump head transmission assembly includes a top sleeve, a top shaft sleeve, a top shaft bearing, a top collar, a top shaft, a core shaft sleeve, and a core shaft collar, and the steps of preparing the pump head transmission assembly include:

[0027] Prepare the top sleeve, top shaft sleeve, top sleeve ring, and core shaft sleeve ring by metal 3D printing of stainless steel;

[0028] The mandrel is prepared by cutting a super-hard high-speed steel round bar; and

[0029] The mandrel sleeve was prepared by cutting stainless steel capillary tubing.

[0030] In one embodiment, the preparation of the impeller blade surface includes:

[0031] Configure a material with mechanical properties that meet the requirements, preferably a biocompatible medical silicone raw material;

[0032] Pouring the medical silica gel raw material into a mold, wherein the shape of the mold is preferably a circular tube;

[0033] The mold is placed in a heating device for heating. The heating method is preferably constant temperature heating. The constant temperature heating temperature is preferably 40° C. to 80° C., more preferably 60° C., and the constant temperature heating time is preferably in the range of 15 minutes to 60 minutes, more preferably 30 minutes; and

[0034] After natural cooling, the impeller blade surface is obtained by taking out the mold.

[0035] In one embodiment, the method for preparing the micro pump head further comprises:

[0036] The proximal end and the distal end of the impeller blade are bonded and fixed to the proximal fixing ring and the distal fixing ring respectively by using biocompatible glue.

[0037] In one embodiment, the method for preparing the micro pump head further includes the step of preparing a pump head protection assembly, wherein the pump head protection assembly coaxial cover is arranged outside the pump head impeller and includes a top cover tip, an anchor bracket skeleton, an anchor bracket membrane and a bracket protection cover connecting ring, and the step of preparing the pump head protection assembly includes:

[0038] Prepare the top sleeve tip by metal 3D printing stainless steel;

[0039] Prepare the bracket protective sleeve connecting ring by cutting the copper sleeve;

[0040] Prepare the anchoring stent skeleton by laser cutting a nickel-titanium alloy tube; and

[0041] The anchoring stent membrane is prepared by casting a medical silicone material.

[0042] The above solution of the present invention includes at least the following beneficial effects:

[0043] The preparation method of the micro pump head provided by the above scheme of the present invention includes the steps of preparing a pump head impeller, and the steps of preparing the pump head impeller include: preparing an impeller skeleton, preparing an impeller blade surface, and assembling the impeller skeleton and the impeller blade surface; the impeller skeleton includes a proximal fixing ring, a distal fixing ring, and an impeller skeleton wire, and the impeller skeleton wire is spirally arranged between the proximal fixing ring and the distal fixing ring; using an impeller blade surface mold and an elastic material to prepare the impeller blade surface; fixing the distal fixing ring, rotating the proximal fixing ring along the spiral direction of the impeller skeleton wire, pre-tightening the impeller skeleton wire to a multi-cycle spiral shape, putting the impeller blade surface onto the pre-tightened impeller skeleton surface and releasing the pre-tightening force, so that the impeller skeleton wire recovers at least a periodic spiral shape under the action of its own elasticity, and pushes the impeller blade surface outward to form a spiral impeller. The elastic pump head impeller obtained by the above method of the present invention can facilitate the adjustment of the outer diameter of the pump head impeller in the micro pump head during specific use, thereby improving the use safety and work efficiency of the left ventricular assist device. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a flow chart of preparing a pump head impeller in a method for preparing a micro pump head provided by an embodiment of the present invention;

[0045] Figure 2 is a schematic diagram of preparing a pump head impeller provided by an optional embodiment of the present invention;

[0046] Figure 3 is a flow chart of preparing an impeller skeleton by using nickel-titanium alloy wire provided by an optional embodiment of the present invention;

[0047] Figure 4 is a schematic diagram of preparing an impeller skeleton using nickel-titanium alloy wire according to an optional embodiment of the present invention;

[0048] Figure 5 is a flow chart of preparing an impeller skeleton using nickel-titanium powder provided by an optional embodiment of the present invention;

[0049] Figure 6 is a schematic diagram of preparing an impeller skeleton using nickel-titanium powder according to an optional embodiment of the present invention;

[0050] Figure 7 A process for preparing an impeller skeleton using a nickel-titanium alloy tube is provided in an optional embodiment of the present invention;

[0051] Figure 8 is a schematic diagram of preparing an impeller skeleton using a nickel-titanium alloy tube, provided by an optional embodiment of the present invention;

[0052] Figure 9 is a flow chart of preparing an impeller blade surface provided by an optional embodiment of the present invention;

[0053] Figure 10 is a schematic diagram of preparing an impeller blade surface provided by an optional embodiment of the present invention;

[0054] Figure 11 is a flow chart of preparing a pump head protection assembly provided by an optional embodiment of the present invention;

[0055] Figure 12 is an assembly flow chart of a micro pump head in a method for preparing a micro pump head provided by an optional embodiment of the present invention;

[0056] Figure 13 is a cross-sectional schematic diagram of a left ventricular assist device provided by an optional embodiment of the present invention;

[0057] Figure 14 is a schematic structural diagram of an impeller skeleton provided by an optional embodiment of the present invention;

[0058] Figure 15 is a schematic structural diagram of an impeller blade surface provided by an optional embodiment of the present invention;

[0059] Figure 16 is a schematic structural diagram of a pump head impeller in a folded state provided by an optional embodiment of the present invention;

[0060] Figure 17 is a schematic structural diagram of a pump head impeller in an expanded state provided by an optional embodiment of the present invention;

[0061] Figure 18 is an exploded view of a pump head impeller in an expanded state provided by an optional embodiment of the present invention;

[0062] Figure 19 is an exploded view of a pump head protection assembly provided by an optional embodiment of the present invention;

[0063] Figure 20 It is an exploded view of a pump head transmission assembly provided by an optional embodiment of the present invention.

[0064] Description of Figure Numbers:

[0065] 100. Left ventricular assist device;

[0066] 10. Drive control mechanism; 101. Protective cover drive module; 102. Twisting shell drive module; 103. Mandrel drive module;

[0067] 20. Micro pump head;

[0068] 30. Drive shaft;

[0069] 1. Pump head protection assembly; 11. Top sleeve tip; 12. Anchor bracket skeleton; 13. Anchor bracket membrane; 14. Bracket protection sleeve connecting ring;

[0070] 2. Pump head impeller; 21. Impeller frame; 211. Distal fixing ring; 212. Impeller frame wire; 213. Proximal fixing ring; 22. Impeller blade; 23. Twisting connector;

[0071] 3. Pump head transmission assembly; 31. Top sleeve; 32. Top shaft sleeve; 33. Top shaft bearing; 34. Top sleeve ring; 35. Top shaft; 36. Core shaft sleeve; 37. Core shaft sleeve ring. DETAILED DESCRIPTION

[0072] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0073] First, it should be noted that the micro pump head 20 prepared by the preparation method provided in the following embodiment is applied to the left ventricular assist device 100. Figure 13As shown, the left ventricular assist device 100 also includes a transmission shaft 30 and a drive control mechanism 10, wherein the micro pump head 20 includes a pump head impeller 2, a pump head transmission component 3 and a pump head protection component 1 (the pump head transmission component 3 passes through the pump head impeller 2, and the pump head protection component 1 is coaxially covered outside the pump head impeller 2); the transmission shaft 30 includes a protective sleeve, a twisting shell and a core shaft (the twisting shell can be movably sleeved outside the core shaft, and the protective sleeve can be slidably sleeved outside the twisting shell); the drive control mechanism 10 includes a protective sleeve drive module 101, a twisting shell drive module 102 and a core shaft drive module 103 (protection The sleeve drive module 101, the twisting shell drive module 102 and the core shaft drive module 103 are arranged in sequence, and the twisting shell drive module 102 and the core shaft drive module 103 are detachably connected); the proximal end of the pump head impeller 2 is transmission-connected to the twisting shell drive module 102 of the drive control mechanism 10 through the twisting shell; the distal end of the pump head transmission assembly 3 is fixedly connected to the distal end of the pump head impeller 2, and the proximal end of the pump head transmission assembly 3 is transmission-connected to the core shaft drive module 103 of the drive control mechanism 10 through the core shaft; the proximal end of the pump head protection assembly 1 is transmission-connected to the protection sleeve drive module 101 of the drive control mechanism 10 through the protective sleeve;

[0074] When the left ventricular assist device 100 is used, the entire micro pump head 20 directly enters the patient's body; the core shaft driving module 103 drives the core shaft and the twisting shell to rotate synchronously to drive the distal and proximal ends of the pump head impeller 2 to rotate together, and the pump head impeller 2 as a whole rotates in a single direction with a fixed outer diameter, and the twisting shell driving module 102 drives the twisting shell to rotate relative to the core shaft to drive the proximal end of the pump head impeller 2 to rotate relative to the distal end, and the pump head impeller 2 folds or unfolds to adjust the outer diameter of the pump head impeller 2; the protective sleeve driving module 103 drives the protective sleeve to slide on the twisting shell to control the relative distance between the proximal and distal ends of the pump head protection component 1, and then controls the pump head protection component 1 to fold or unfold to adjust the outer diameter of the pump head protection component 1 and match the increase or decrease in the outer diameter of the pump head impeller 2.

[0075] During use, the blood supply performance of the left ventricular assist device 100 is largely determined by the size and shape of the pump head impeller 2 of the micropump head 20, which directly interacts with the blood. Therefore, the micropump head 20 prepared according to the method provided by the present invention is flexible, allowing the entire micropump head 20 to be folded and unfolded, thereby facilitating flexible adjustment of the outer diameter of the micropump head 20. This not only facilitates implantation of the micropump head 20 into a patient through minimally invasive interventional surgery, but also improves the blood supply efficiency and safety of the left ventricular assist device 100.

[0076] The embodiment of the present invention provides a method for preparing a micro pump head 20, which includes the steps of preparing a pump head impeller 2, wherein the pump head impeller 2 includes: an impeller skeleton 21 and an impeller blade 22, wherein the impeller blade 22 is coated on the impeller skeleton 21; Figure 1 As shown, the specific steps of preparing the pump head impeller 2 include:

[0077] Step 1, preparation of impeller skeleton 21: Figure 14 As shown, the impeller skeleton 21 includes a proximal fixing ring 213, a distal fixing ring 211 and an impeller skeleton wire 212. This step includes spirally arranging the impeller skeleton wire 212 between the proximal fixing ring 213 and the distal fixing ring 211;

[0078] Step 2, preparing the impeller blade surface 22: using an impeller blade surface mold and elastic raw materials to prepare the impeller blade surface 22;

[0079] Step 3, assembling the impeller skeleton 21 and the impeller blade 22: fix the distal fixing ring 211, rotate the proximal fixing ring 213 along the spiral direction of the impeller skeleton wire 212, pre-tighten the impeller skeleton wire 212 to a multi-cycle spiral shape, put the impeller blade 22 onto the surface of the pre-tightened impeller skeleton wire 212 and release the pre-tightening force, so that the impeller skeleton wire 212 can restore at least a periodic spiral shape under its own elasticity, and push the impeller blade 22 outward to form a spiral impeller;

[0080] like Figure 18 As shown, preferably, the pump head impeller 2 may further include a twisting connector 23, and the specific steps of preparing the pump head impeller 2 may further include:

[0081] Step 4: Prepare a twisting connector 23 by metal 3D printing stainless steel; the distal end of the twisting connector 23 is plugged into the proximal end of the proximal fixing ring 213, and the proximal end of the twisting connector 23 is fixedly connected to the distal end of the twisting shell; preferably, the distal end of the twisting connector 23 can be provided with multiple rotation limiting bosses, and the proximal outer edge of the proximal end of the proximal fixing ring 213 is correspondingly provided with multiple limiting grooves. The twisting connector 23 and the proximal fixing ring 213 are rotationally limited by plugging the rotation limiting bosses and limiting grooves. The assembly connection of the rotation limiting bosses and limiting grooves between the twisting connector 23 and the proximal fixing ring 213 can better transmit the twisting torque to the impeller skeleton 21 through the twisting connector 23, so as to realize the one-step twisting and folding of the pump head impeller 2.

[0082] In this embodiment, the impeller skeleton 21 can be made by integrally forming the proximal fixing ring 213, the distal fixing ring 211 and the impeller skeleton wire 212, or by assembling the prepared proximal fixing ring 213, the distal fixing ring 211 and the impeller skeleton wire 212;

[0083] Here, a plurality of impeller skeleton wires 212 can be provided, and the plurality of impeller skeleton wires 212 are connected in parallel between the proximal fixing ring 213 and the distal fixing ring 211 to form a few-period spiral impeller skeleton 21; the few-period spiral impeller skeleton 21 is the normal state (expanded state) of the impeller skeleton 21 in the micro pump head 2, and the few-period spiral can be a single spiral period or a double spiral period; the spiral outer edge of the few-period spiral impeller skeleton 21 extends outward, and at this time the outer diameter of the entire impeller skeleton 21 is larger;

[0084] Further, such as Figure 2 As shown, the proximal fixing ring 213 is rotated relative to the distal fixing ring 211 in the spiral direction, so that the few-period spiral impeller skeleton wire 212 is pre-tightened and shrinks inwardly into a cylindrical shape, thereby obtaining a multi-period spiral impeller skeleton 21 (folded state). The multi-period spiral impeller skeleton 21 is also cylindrical as a whole, and the spiral outer edge of the multi-period spiral impeller skeleton 21 shrinks inwardly. At this time, the outer diameter of the entire impeller skeleton 21 is smaller;

[0085] After obtaining the multi-period spiral impeller skeleton 21, the prepared impeller blade 22 is coated on the multi-period spiral impeller skeleton 21 to obtain the pump head impeller 2 in a folded state (such as Figure 16 At this time, the preload force of the folded pump head impeller 2 is released, so that the impeller skeleton wire 212 recovers at least one periodic spiral shape under its own elastic action. Since the impeller blade surface 22 is made of elastic material, the impeller blade surface 22 can be pushed outward by the less periodic spiral impeller skeleton 21 to form a spiral impeller, thereby obtaining the following: Figure 17 The pump head impeller 2 shown is in an expanded state with a larger outer diameter; the distal end and the proximal end of the impeller blade 22 can be respectively bonded and fixed to the distal fixing ring 211 and the proximal fixing ring 213 of the impeller skeleton 21 to ensure that the impeller blade 22 will not fall off during the folding and auxiliary blood supply process of the pump head impeller 2; in a feasible example, the distal end and the proximal end of the impeller blade 22 can be respectively bonded and fixed to the distal fixing ring 211 and the proximal fixing ring 213 of the impeller skeleton 21 by biocompatible glue to ensure safety during use.

[0086] The pump head impeller 2 prepared by the above method can realize the folding and expanding function, so as to control the outer diameter of the micro pump head 20, and help to realize that the micro pump head 20 is implanted in a designated position in the human body in a folded state through minimally invasive interventional surgery. Subsequently, the pump head impeller 2 can be deformed and expanded into a spiral shape with a larger outer diameter in the human body, so that the left ventricular assist device 100 has the ability to provide the patient with sufficient auxiliary blood flow at a low speed, thereby improving the blood supply efficiency and safety of use of the assist device; in addition, the pump head impeller 2 with the folding and expanding function helps to reduce the resistance of the micro pump head 20 when entering and passing through the catheter, which is more conducive to the rapid and safe deployment and recovery of the left ventricular assist device 100.

[0087] Preferably, the number of blades of the pump head impeller 2 can be 2, the blade helix angle of the pump head impeller 2 can be 22°, the length of the entire pump head impeller 2 can be 12 mm, and the diameter of the pump head impeller 2 can be 16 mm.

[0088] In an optional embodiment of the present invention, referring to Figure 3 and Figure 4 The preparation of the impeller skeleton 21 in step 1 may include:

[0089] Step 11a, selecting a nickel-titanium alloy wire, preferably, the nickel-titanium ratio of the nickel-titanium alloy wire is 53:47-60:40, more preferably 56:44;

[0090] Step 12a, pre-shaping and fixing the nickel-titanium alloy wire using a mold with a spiral groove;

[0091] Step 13a, placing the mold into a heating device for heating;

[0092] Step 14a, after heating, taking out a mold to obtain the impeller skeleton wire 212;

[0093] In step 15a, the distal and proximal ends of the impeller skeleton wire 212 are assembled with the distal fixing ring 211 and the proximal fixing ring 213, respectively, in a form-locking manner, and biocompatible glue is applied to the assembly points for adhesive fixation. In this embodiment, nickel-titanium alloy wire with a certain nickel-titanium mass fraction ratio is selected and then processed in subsequent steps to obtain an impeller skeleton 21 that meets the mechanical property and geometric morphology requirements. At the same time, the impeller skeleton 21 also provides a certain rigidity for the expanded pump head impeller 2, ensuring the stability of the pump head impeller 2 during use.

[0094] Here, the spiral groove of the mold should match the few-period spiral of the few-period spiral impeller skeleton wire 212 to obtain the impeller skeleton wire 212 that meets the size and shape requirements.

[0095] Since the impeller skeleton wire 212 with a few-period spiral shape is prepared from nickel-titanium alloy wire, the mold with the nickel-titanium alloy wire wrapped inside is subjected to heat treatment to obtain the impeller skeleton wire 212 with mechanical properties (superelasticity) and geometric morphology (few-period spiral shape) that meet the requirements; here, the heating method is preferably constant temperature heating in a muffle furnace, the constant temperature heating temperature is preferably 450°C-550°C, more preferably 500°C, and the heating time is preferably 10 minutes-30 minutes, more preferably 15 minutes, so as to prepare the impeller skeleton wire 212 that meets the use requirements.

[0096] Here, the proximal fixing ring 213 and the distal fixing ring 211 can both be prepared by metal 3D printing stainless steel; when the distal end and proximal end of the few-period spiral impeller skeleton wire 212 are fixedly connected to the distal fixing ring 211 and the proximal fixing ring 213 respectively, preferably, the distal end and proximal end of the few-period spiral impeller skeleton wire 212 can be respectively inserted into the proximal corresponding assembly hole of the distal fixing ring 211 and the distal corresponding assembly hole of the proximal fixing ring 213, and biocompatible glue can be applied at the assembly point for bonding and fixing, and the biocompatible glue can also avoid causing harm to the human body.

[0097] In an optional embodiment of the present invention, the impeller skeleton 21 is prepared by metal 3D printing integrally formed. When prepared by metal 3D printing integrally formed, refer to Figure 5 and Figure 6 The preparation of the impeller skeleton 21 in step 1 may include:

[0098] Step 11b, using nickel-titanium powder as raw material, modeling and printing according to design dimensions, wherein the nickel-titanium ratio in the nickel-titanium powder is preferably 53:47-60:40, more preferably 56:44, and the design dimensions preferably include a screw pitch, a screw radius, and a screw height;

[0099] Step 12b, using a mold that matches the size of the impeller skeleton 21 to fix it to prevent the impeller skeleton 21 from being deformed by heat during the heat treatment process;

[0100] Step 13b, placing the mold into a heating device for heating;

[0101] Step 14b: After heating, a mold is taken to obtain an impeller skeleton 21 with mechanical properties and geometrical morphology that meet the requirements.

[0102] In this embodiment, nickel-titanium powder with a certain nickel-titanium mass fraction ratio is selected and then processed in subsequent steps to obtain an impeller skeleton 21 that meets the mechanical property and geometric morphology requirements. At the same time, the impeller skeleton 21 can also provide a certain rigidity for the pump head impeller 2 in the expanded state, ensuring the stability of the pump head impeller 2 during use;

[0103] Optionally, in step 11b, nickel-titanium powder is 3D modeled and printed according to a pre-designed pitch, spiral radius, and spiral height to obtain an integrally formed impeller skeleton 21; the pre-designed pitch, spiral radius, and spiral height can be set according to the specific value of the spiral period corresponding to the short-period spiral impeller skeleton wire 212;

[0104] Furthermore, in step 13b, the mold to which the impeller skeleton 21 is fixed is subjected to a heat treatment to obtain an impeller skeleton 21 having mechanical properties (superelasticity) and geometric morphology (few-period spiral) that meet the requirements; here, the heating method is preferably constant temperature heating in a muffle furnace, the constant temperature heating temperature is preferably 450°C-550°C, more preferably 500°C, and the heating time is preferably 10 minutes-30 minutes, more preferably 15 minutes, so as to prepare an impeller skeleton 21 that meets the use requirements.

[0105] In an optional embodiment of the present invention, the impeller skeleton 21 can also be prepared by cutting the nickel-titanium alloy tube by femtosecond laser. When the impeller skeleton 21 is prepared by cutting the nickel-titanium alloy tube by femtosecond laser, refer to Figure 7 and Figure 8 The preparation of the impeller skeleton 21 in step 1 may include:

[0106] Step 11c: Select a nickel-titanium alloy tube and use a femtosecond laser to process it according to the design drawing to obtain the impeller skeleton 21 in a folded state. The nickel-titanium ratio of the nickel-titanium alloy tube is preferably 53:47-60:40, more preferably 56:44;

[0107] Step 12c, twisting the impeller skeleton 21 to an unfolded state, and fixing the unfolded impeller skeleton 21 using a mold with a size that meets the requirements;

[0108] Step 13c, placing the mold into a heating device for heating;

[0109] Step 14c: After heating, a mold is taken to obtain an impeller skeleton 21 having mechanical properties and geometrical morphology that meet the requirements.

[0110] Optionally, in step 11c, a nickel-titanium alloy tube having a certain nickel-titanium mass fraction ratio is selected, and then processed in subsequent steps to obtain an impeller skeleton 21 that meets the mechanical property and geometric morphology requirements. At the same time, the impeller skeleton 21 can also provide a certain rigidity for the pump head impeller 2 in the expanded state, ensuring the stability of the pump head impeller 2 during use;

[0111] Here, the design drawing includes a cutting pitch, a cutting spiral radius, and a cutting spiral height; preferably, the cutting pitch, the cutting spiral radius, and the cutting spiral height can be set according to the specific values ​​of the spiral period corresponding to the impeller skeleton 21 in the multi-period spiral folded state; further, the multi-period spiral folded state impeller skeleton 21 is twisted into a multi-period spiral unfolded state and fixed with a corresponding mold to prevent the impeller skeleton 21 from being deformed by heat during the heat treatment process;

[0112] Furthermore, in step 13c, the mold to which the impeller skeleton 21 is fixed is subjected to a heat treatment to obtain an impeller skeleton 21 having mechanical properties (superelasticity) and geometric morphology (few-period spiral) that meet the requirements; here, the heating method is preferably constant temperature heating in a muffle furnace, the constant temperature heating temperature is preferably 450°C-550°C, more preferably 500°C, and the heating time is preferably 10 minutes-30 minutes, more preferably 15 minutes, so as to prepare an impeller skeleton 21 that meets the use requirements.

[0113] During femtosecond laser cutting, a complete tube section of a preset length is reserved at the proximal end and the distal end of the nickel-titanium alloy tube to serve as the proximal fixing ring 213 and the distal fixing ring 211 of the impeller frame 21 .

[0114] In an optional embodiment of the present invention, referring to Figure 9 and Figure 10 The preparation of the impeller blade surface 22 in step 2 may include:

[0115] Step 21, preparing a material with mechanical properties that meet the requirements, preferably a biocompatible medical silicone raw material;

[0116] Step 22: pouring the medical silicone raw material into a mold, wherein the shape of the mold is preferably a circular tube;

[0117] Step 23, placing the mold into a heating device for heating;

[0118] Step 24 , after natural cooling, the mold is taken to obtain the impeller blade surface 22 .

[0119] Optionally, in step 21, an elastic material having mechanical properties that meet the requirements is first prepared. Preferably, the elastic material is a biocompatible medical silicone raw material. Preferably, the medical silicone material can be prepared by mixing DragonSkin silicone and Slic Thinner diluent in a mass ratio of 2:1 at room temperature, stirring, and heating to form a film. The medical silicone material has good elastic deformation ability, with a 100% Young's modulus of 21.75 kPa, a maximum strain of 1328.2%, and a maximum stress of 675.3 kPa, which can meet the needs of the pump head impeller 2 during use.

[0120] Optionally, in step 22, the prepared medical silicone raw material is poured into a cylindrical impeller blade mold;

[0121] Optionally, in step 23, the impeller blade mold cast with the medical silicone raw material is subjected to a heating treatment, wherein the heating treatment is preferably constant temperature heating, more preferably constant temperature heating in a low-temperature oven, the constant temperature heating temperature is preferably 40° C.-80° C., more preferably 60° C., and the constant temperature heating time is preferably in the range of 15 minutes-60 minutes, more preferably 30 minutes;

[0122] Optionally, in step 24, after constant temperature heating for a period of time and natural cooling, the following Figure 15 The impeller blades 22 are shown to be elastic and in a tubular shape.

[0123] In an optional embodiment of the present invention, the method for preparing the micro pump head 20 further includes step 5 of preparing a pump head transmission assembly 3, wherein the pump head transmission assembly 3 passes through the pump head impeller 2, and the distal end of the pump head transmission assembly 3 is fixedly connected to the distal end of the pump head impeller 2, such as Figure 20 As shown, the pump head transmission assembly 3 includes a top sleeve 31, a top shaft sleeve 32, a top shaft bearing 33, a top collar 34, a top shaft 35, a core sleeve 36, and a core collar 37, and the steps of preparing the pump head transmission assembly 3 may include:

[0124] Step 51: Prepare the top sleeve 31, top shaft sleeve 32, top sleeve ring 34, and mandrel sleeve ring 37 by metal 3D printing stainless steel; prepare the top shaft 35 by cutting an ultra-hard high-speed steel round bar; and prepare the mandrel sleeve 36 by cutting a stainless steel capillary tube. Here, the top shaft bearing 33 can be customized and purchased according to the specifications of the other prepared components;

[0125] In an optional embodiment of the present invention, the method for preparing the micro pump head 20 further includes step 6 of preparing the pump head protection component 1, wherein, Figure 19 As shown, the pump head protection assembly 1 is coaxially covered outside the pump head impeller 2, and the pump head protection assembly 1 includes a top sleeve tip 11, an anchor bracket skeleton 12, an anchor bracket membrane 13 and a bracket protection sleeve connecting ring 14, as well as a reference Figure 11 , step 6 of preparing the pump head protection component 1 includes:

[0126] Step 61, preparing the top sleeve tip 11 by metal 3D printing of stainless steel;

[0127] Step 62, preparing the bracket protective sleeve connecting ring 14 by cutting the copper sleeve;

[0128] Step 63, preparing the anchoring stent skeleton 12 by laser cutting the nickel-titanium alloy tube;

[0129] Step 64, preparing the anchoring stent membrane 13 by casting a medical silicone material;

[0130] In this embodiment, Figure 19As shown, the anchor support frame 12 can be configured as a lantern shape and coaxially covered on the outside of the pump head impeller 2. The specific process of preparing the anchor support frame 12 by laser cutting the nickel-titanium alloy tube can refer to the specific process of preparing the impeller frame 21 by using femtosecond laser cutting the nickel-titanium alloy tube, which will not be described in detail here.

[0131] Preferably, the anchoring bracket membrane 13 and the anchoring bracket skeleton 12 can be bonded by biocompatible glue; the anchoring bracket membrane 13 can be prepared by molding medical silicone material to reduce the contact stress between the pump head protection component 1 and the blood vessel when the micro pump head 20 is anchored in the patient's body to pump blood; preferably, the medical silicone material can be prepared by stirring and mixing Dragon Skin silicone and Slic Thinner diluent in a mass ratio of 2:1 at room temperature, and heating and curing to form a film; the medical silicone material has good elastic deformation ability, its 100% Young's modulus is 21.75kPa, the maximum strain that can be achieved is 1328.2%, and the maximum stress that can be withstood is 675.3kPa, so as to meet the needs of the pump head protection component 1 during use.

[0132] Reference Figure 12 The specific process of assembling the micro pump head 20 prepared in the embodiment of the present invention is as follows:

[0133] Step 71: Slide the mandrel collar 37 onto the mandrel sleeve 36 and secure them together by gluing them together while ensuring that the proximal end surfaces of the mandrel sleeve 36 and the mandrel collar 37 are aligned. Subsequently, slide the pump head impeller 2 onto the mandrel sleeve 36 and axially position the pump head impeller 2 using the distal end surface of the mandrel collar 37. Finally, secure the distal fixing ring 211 to the mandrel sleeve 36 by gluing them together.

[0134] Step 72, insert the top shaft 35 into the core shaft sleeve 36 to a specific position and glue the two together, then successively put the top collar 34 onto the core shaft sleeve 36, and the top shaft bearing 33 onto the top shaft 35, and use the distal end of the core shaft sleeve 36 to axially position the top shaft bearing 33; then put the top shaft sleeve 32 onto the top shaft 35, and glue the top shaft sleeve 32 and the top shaft 35 together on the basis of axially positioning the top shaft sleeve 32 by the distal end of the top shaft bearing 33; finally, put the top sleeve 31 onto the top shaft bearing 33, and under the condition that the distal end surface of the top sleeve 31 is in contact with the top shaft bearing 33 and the proximal end surface of the top collar 34 is in contact with the top shaft bearing 33, glue the top sleeve 31 and the top collar 34 together;

[0135] Step 73, put the annular proximal end of the anchoring support frame 12 onto the support protective sleeve connecting ring 13, and under the condition that the distal end face of the support protective sleeve connecting ring 13 is flush with the distal end face of the annular proximal end of the anchoring support frame 12, the proximal end of the anchoring support frame 12 is bonded and fixed to the support protective sleeve connecting ring 13; then put the protective sleeve of the transmission shaft 30 onto the proximal end of the support protective sleeve connecting ring 13, and under the condition that the distal end face of the protective sleeve is in contact with the proximal end face of the annular proximal end of the anchoring support frame 12, successively bond the protective sleeve to the support protective sleeve connecting ring 13 and the anchoring support frame 12; assemble the proximal end of the twisting connector 23 to the distal end of the twisting shell of the transmission shaft 30, and bond and fix the assembly; insert the core shaft of the transmission shaft 30 into the core shaft sleeve 36 until the distal end face of the core shaft contacts the proximal end face of the top shaft 35, and bond and fix the core shaft sleeve 36 and the core shaft;

[0136] Step 74, insert the core shaft into the twisting shell, plug and assemble the distal end of the twisting connector 23 to the proximal end of the proximal fixing ring 213, and glue and fix the assembly; while inserting the twisting shell into the protective sleeve, put the annular distal end of the anchor bracket skeleton 12 onto the distal end of the top sleeve 31, and glue and fix the distal end of the anchor bracket skeleton 12 to the top sleeve 31; finally, assemble the top sleeve tip 11 to the distal end of the top sleeve 31, and glue and fix the top sleeve tip 11 to the top sleeve 31; at this point, the transmission shaft 30 and the micro pump head 20 are assembled.

[0137] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a micro pump head, characterized in that: The micro pump head is used in a left ventricular assist device. The method for preparing the micro pump head comprises the steps of preparing a pump head impeller (2). The steps of preparing the pump head impeller (2) comprise: Preparation of an impeller skeleton (21): the impeller skeleton (21) comprises a proximal fixing ring (213), a distal fixing ring (211), and an impeller skeleton wire (212); the impeller skeleton wire (212) is spirally arranged between the proximal fixing ring (213) and the distal fixing ring (211); Preparation of impeller blade surface (22): using an impeller blade surface mold and an elastic material to prepare the impeller blade surface (22); The impeller skeleton (21) and the impeller blade (22) are assembled by fixing the distal fixing ring (211), rotating the proximal fixing ring (213) along the spiral direction of the impeller skeleton wire (212), pre-tightening the impeller skeleton wire (212) to a multi-cycle spiral shape, and sleeve the impeller blade (22) onto the surface of the pre-tightened impeller skeleton wire (212) and releasing the pre-tightening force, so that the impeller skeleton wire (212) recovers at least a periodic spiral shape under the action of its own elasticity, and pushes the impeller blade (22) outward to form a spiral impeller.

2. The method for preparing a micro pump head according to claim 1, wherein: The preparation of the impeller skeleton (21) includes: Select nickel-titanium alloy wire; Pre-shaping and fixing the nickel-titanium alloy wire using a mold with a spiral groove; The mold is placed in a heating device for heating, and the heating method is constant temperature heating; After heating, taking a mold to obtain the impeller skeleton wire (212); and The distal end and the proximal end of the impeller skeleton wire (212) are respectively assembled with the distal fixing ring (211) and the proximal fixing ring (213) in a form-locking manner, and biocompatible glue is applied to the assembly locations for bonding and fixing.

3. The method for preparing a micro pump head according to claim 2, wherein: The nickel-titanium ratio of the nickel-titanium alloy wire is 53:47-60:

40.

4. The method for preparing a micro pump head according to claim 3, characterized in that: The nickel-titanium ratio of the nickel-titanium alloy wire is 56:

44.

5. The method for preparing a micro pump head according to claim 2, wherein: The constant temperature heating temperature is 450°C-550°C.

6. The method for preparing a micro pump head according to claim 5, characterized in that: The constant temperature heating temperature is 500°C.

7. The method for preparing a micro pump head according to claim 2, wherein: The constant temperature heating time is 10 minutes to 30 minutes.

8. The method for preparing a micro pump head according to claim 7, characterized in that: The constant temperature heating time is 15 minutes.

9. The method for preparing a micro pump head according to claim 1, wherein: The impeller skeleton (21) is prepared by metal 3D printing in an integrated manner.

10. The method for preparing a micro pump head according to claim 9, characterized in that: The preparation of the impeller skeleton (21) includes: Using nickel-titanium powder as raw material, modeling and printing are carried out according to the designed dimensions; Fixing the impeller skeleton (21) with a mold that matches the size of the impeller skeleton (21) to prevent the impeller skeleton (21) from being deformed by heat during the heat treatment process; placing the mold in a heating device for heating, wherein the heating method is constant temperature heating; and After heating, a mold is taken to obtain the impeller skeleton (21) having mechanical properties and geometrical morphology that meet the requirements.

11. The method for preparing a micro pump head according to claim 10, characterized in that: The design dimensions include pitch, spiral radius and spiral height.

12. The method for preparing a micro pump head according to claim 10, characterized in that: The nickel-titanium ratio in the nickel-titanium powder is 53:47-60:

40.

13. The method for preparing a micro pump head according to claim 12, characterized in that: The nickel-titanium ratio in the nickel-titanium powder is 56:

44.

14. The method for preparing a micro pump head according to claim 10, characterized in that: The constant temperature heating temperature is 450°C-550°C.

15. The method for preparing a micro pump head according to claim 14, characterized in that: The constant temperature heating temperature is 500°C.

16. The method for preparing a micro pump head according to claim 10, characterized in that: The constant temperature heating time is 10 minutes to 30 minutes.

17. The method for preparing a micro pump head according to claim 16, characterized in that: The constant temperature heating time is 15 minutes.

18. The method for preparing a micro pump head according to claim 1, characterized in that: The impeller skeleton (21) is prepared by cutting a nickel-titanium alloy tube through a femtosecond laser.

19. The method for preparing a micro pump head according to claim 18, characterized in that: The preparation of the impeller skeleton (21) includes: A nickel-titanium alloy tube is selected and processed using a femtosecond laser according to the design drawing to obtain an impeller skeleton in a folded state (21); Twisting the impeller skeleton (21) to an unfolded state, and fixing the impeller skeleton (21) in the unfolded state using a mold having a size that meets the requirements; placing the mold in a heating device for heating, wherein the heating method is constant temperature heating; and After heating, a mold is taken to obtain the impeller skeleton (21) having mechanical properties and geometrical morphology that meet the requirements.

20. The method for preparing a micro pump head according to claim 19, characterized in that: The nickel-titanium ratio of the nickel-titanium alloy tube is 53:47-60:

40.

21. The method for preparing a micro pump head according to claim 20, characterized in that: The nickel-titanium ratio of the nickel-titanium alloy tube is 56:

44.

22. The method for preparing a micro pump head according to claim 19, wherein: The constant temperature heating temperature is 450°C-550°C.

23. The method for preparing a micro pump head according to claim 22, characterized in that: The constant temperature heating temperature is 500°C.

24. The method for preparing a micro pump head according to claim 19, wherein: The constant temperature heating time is 10 minutes to 30 minutes.

25. The method for preparing a micro pump head according to claim 24, characterized in that: The constant temperature heating time is 15 minutes.

26. The method for preparing a micro pump head according to claim 1, characterized in that: The method for preparing the micro pump head further comprises the step of preparing a pump head transmission assembly (3), wherein the pump head transmission assembly (3) penetrates the pump head impeller (2), the distal end of the pump head transmission assembly (3) is fixedly connected to the distal end of the pump head impeller (2), the pump head transmission assembly (3) comprises a top sleeve (31), a top shaft sleeve (32), a top shaft bearing (33), a top sleeve ring (34), a top shaft (35), a core shaft sleeve (36), and a core shaft sleeve ring (37), and the steps of preparing the pump head transmission assembly (3) comprise: The top sleeve (31), the top shaft sleeve (32), the top sleeve ring (34), and the core shaft sleeve ring (37) are prepared by metal 3D printing of stainless steel; The top shaft (35) is prepared by cutting a super-hard high-speed steel round bar; and The mandrel sleeve (36) is prepared by cutting a stainless steel capillary tube.

27. The method for preparing a micro pump head according to claim 1, characterized in that: The preparation of the impeller blade surface (22) includes: Configure materials with mechanical properties that meet the requirements; pouring the material into a mold; placing the mold in a heating device for heating, wherein the heating method is constant temperature heating; and After natural cooling, the impeller blade surface (22) is obtained by taking a mold.

28. The method for preparing a micro pump head according to claim 27, characterized in that: The material is biocompatible medical silicone raw material.

29. The method for preparing a micro pump head according to claim 27, wherein: The shape of the mold is a circular tube.

30. The method for preparing a micro pump head according to claim 27, wherein: The temperature of the constant temperature heating is 40°C-80°C.

31. The method for preparing a micro pump head according to claim 30, characterized in that: The temperature of the constant temperature heating is 60°C.

32. The method for preparing a micro pump head according to claim 27, wherein: The constant temperature heating time is 15 minutes to 60 minutes.

33. The method for preparing a micro pump head according to claim 27, wherein: The constant temperature heating time is 30 minutes.

34. The method for preparing a micro pump head according to claim 1, characterized in that: The preparation method of the micro pump head further includes: The proximal end and the distal end of the impeller blade surface (22) are bonded and fixed to the proximal fixing ring (213) and the distal fixing ring (211) respectively by using biocompatible glue.

35. The method for preparing a micro pump head according to claim 1, characterized in that: The method for preparing the micro pump head further comprises the step of preparing a pump head protection assembly (1), wherein the pump head protection assembly (1) is coaxially covered outside the pump head impeller (2) and comprises a top cover tip (11), an anchoring support frame (12), an anchoring support membrane (13) and a support protection cover connecting ring (14), and the step of preparing the pump head protection assembly (1) comprises: The top sleeve tip (11) is prepared by metal 3D printing of stainless steel; Prepare the bracket protective sleeve connecting ring (14) by cutting the copper sleeve; The anchoring stent skeleton (12) is prepared by laser cutting a nickel-titanium alloy tube; and The anchoring stent membrane (13) is prepared by molding medical silicone material.

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