CN110757799B - Equipment and manufacturing process suitable for preparing nerve conduit - Google Patents

Abstract

The embodiment of the invention discloses equipment suitable for preparing nerve conduits, which comprises a machine base and an upright post, wherein a transmission belt, a coarse adjustment hand wheel, a fixed seat connecting plate and a tailstock sliding seat are transversely arranged on the upper surface of the machine base; the extrusion hole of the extrusion head of the screw extruder is correspondingly arranged with the forming shaft, the screw extruder is arranged on the Y-axis module of the extruder through the Y-axis slide of the extruder, the Y-axis module of the extruder is connected with the X-axis slide of the extruder, the X-axis slide of the extruder is arranged on the X-axis slide table of the extruder, and the X-axis slide table of the extruder is fixed at the top of the upright post. The device and the corresponding process are suitable for preparing the nerve conduit, the problems of support, smoothness and difficult forming during the manufacturing of the thin-wall long tube nerve conduit by the traditional additive manufacturing process are solved, and the printed conduit has high strength and can be repeatedly and individually customized.

Description

A device and manufacturing process suitable for preparing a nerve conduit

Technical Field

The present invention relates to the field of additive manufacturing, and in particular to a device and a manufacturing process suitable for preparing a nerve conduit.

Background Art

Currently, the safer and more effective methods for treating severe defects at both ends of peripheral nerves are autologous nerve transplantation and allogeneic nerve transplantation, but both have major problems. Autologous nerve transplantation faces problems such as difficulty in matching transplanted nerves and loss of sensory function in the donor area. Allogeneic nerve transplantation is mainly used to repair long-segment nerve defects, but immunosuppressants are required after surgery, increasing the patient's chance of infection and inflammation. In view of the limitations of nerve transplantation, the manufacture of nerve conduits to repair peripheral nerve defects has become a current research hotspot.

At present, the manufacturing of nerve catheters is mostly based on the electrospinning process. Since the electrospinning process requires a relatively high voltage, which must reach several thousand volts, the equipment cost and usage cost are relatively expensive, and it is not suitable for industrial production. In addition, since the electrospinning process is affected by many factors such as polymer parameters, solvent parameters, solution parameters, process control parameters and environmental parameters, the manufacturing process is difficult to control and has low repeatability, which affects the effect of manufacturing nerve catheters.

The nerve conduit is a thin-walled long tube. When printing the nerve conduit using the traditional additive manufacturing process, if it is placed horizontally for printing, it is necessary to print supports inside and outside the nerve conduit. The subsequent removal of the supports is likely to reduce the smoothness of the inner and outer walls of the nerve conduit, and since the nerve conduit is a thin-walled structure, the removal of the supports is likely to destroy its integrity; if it is printed vertically, since the traditional additive manufacturing process is contact-type layer-by-layer printing, the upper layer needs to be in contact with the lower layer during printing, and the nerve conduit is a thin-walled long tube. During printing, the upper layer is likely to scrape the lower layer, causing printing drift and affecting the printing quality. The nerve conduit is subjected to axial force during use. Since the layer-by-layer printing method is used, the interlayer strength of the printed nerve conduit is insufficient and it is easy to break, so the traditional additive manufacturing process is limited.

Summary of the invention

The technical problem to be solved by the embodiments of the present invention is that the electrospinning process is used to manufacture nerve conduits, which is expensive, cannot be industrialized, the manufacturing process is difficult to control, and the repeatability is low. The traditional additive manufacturing process is used to print nerve conduits, which easily destroys their integrity and is not strong enough and is easy to break. A device and a manufacturing process suitable for preparing nerve conduits are proposed.

In order to solve the above technical problems, on the one hand, an embodiment of the present invention provides an apparatus suitable for preparing a nerve catheter, comprising a frame and a screw extruder; the frame comprises a machine base and a column vertically connected to the machine base, a transmission belt is horizontally installed on the upper surface of the machine base, the transmission belt is connected to a coarse adjustment handwheel, two coarse adjustment handwheels are provided, which are respectively installed at two ends of the machine base, a fixed seat connecting plate and a tail seat slide are both arranged on the transmission belt and slidably connected to the transmission belt, a tail seat fixing rod is provided on the tail seat slide, the tail seat fixing rod controls the loosening and fixing of the tail seat slide on the transmission belt, a top shaft tail stock and a fine adjustment handwheel are installed on the tail seat slide, the fine adjustment handwheel is connected to the end of the top shaft tail stock, a fixed seat fixing rod is provided on the fixed seat connecting plate, the fixed seat fixing rod controls the loosening and fixing of the fixed seat connecting plate on the transmission belt, a fixed seat is fixedly installed on the fixed seat connecting plate, a clamping disk is installed on one end of the fixed seat facing the top shaft tail stock, and a clamping disk is installed on the end of the fixed seat facing the top shaft tail stock. A forming shaft is clamped on the tightening disk, and one end of the forming shaft away from the clamping disk is tightly fitted with the top shaft tailstock. The clamping disk rotating motor is fixed on the fixed seat, and its motor shaft passes through the fixed seat and is connected with the clamping disk, driving the clamping disk and the forming shaft to rotate; the top and bottom of the screw extruder are respectively connected with the extruder motor and the extrusion head, and the extrusion hole of the extrusion head is arranged correspondingly to the forming shaft up and down, the screw extruder is installed on the extruder Y-axis module through the extruder Y-axis slide, the extruder Y-axis module is connected with the extruder X-axis slide, the extruder X-axis slide is installed on the extruder X-axis slide, the extruder X-axis slide is fixed on the top of the column, one end of the extruder X-axis slide is connected with the extruder X-axis motor, the motor shaft of the extruder X-axis motor is connected with the extruder X-axis slide, the fine-tuning hand wheel is connected with one end of the top shaft tailstock away from the forming shaft, and a bayonet is arranged on the top shaft tailstock, and the end of the forming shaft is inserted into the bayonet and tightly pressed against the top shaft tailstock.

There are two columns, which are installed on the machine base at intervals and in parallel, and the tops of the two columns are fixedly connected to the two ends of the X-axis slide of the extruder respectively.

Among them, a sleeve is provided outside the forming shaft, and a plurality of tiny gaps are arranged axially on the sleeve. When installed on the forming shaft, the gaps on the sleeve are expanded but do not affect the forming of the material. After printing is completed, the sleeve is removed from the forming shaft, and the gaps on the sleeve shrink and become smaller, making it convenient to remove the printed nerve conduit.

The sleeve is made of polytetrafluoroethylene material and has self-lubricating properties inside.

In order to solve the above technical problems, on the other hand, an embodiment of the present invention further provides a manufacturing process for preparing a nerve conduit, based on the above-mentioned device for preparing a nerve conduit, comprising the following steps:

Step 1: The control system sends control information to drive the extruder X-axis motor, extruder motor, extruder Y-axis module and the clamping disk rotation motor to start;

Step 2: The control system moves the extruder head to a suitable position to prepare for printing according to the wall thickness requirements of the designed nerve conduit, and drives the extruder head to extrude the nerve conduit forming material;

Step 3: Manually adjust the tailstock fixing rod, the fixing rod of the fixing seat, the coarse adjustment hand wheel and the fine adjustment hand wheel to accurately locate the printing position of the forming axis;

Step 4: After the extruder extrude the nerve conduit forming material, the material is coated on the sleeve of the forming shaft. As the forming shaft rotates at a low speed and the extruder reciprocates at a high speed in the X-axis direction, the material extruded by the extruder makes an axial spiral motion in the axial direction of the forming shaft;

Step 5: After printing is completed, remove the entire sleeve from the forming shaft, and then remove the printed nerve conduit.

Among them, by adjusting the rotation direction of the forming shaft and the moving direction of the extruder head, a mesh-structured nerve conduit can be printed after several cycles; by adjusting the rotation speed of the forming shaft and the moving speed of the extruder head, nerve conduits with different axial inclination angles can be printed; by controlling the distance between the extrusion hole on the extruder head and the forming shaft, the wall thickness of the printed nerve conduit can be controlled; by selecting the appropriate axial diameter of the forming shaft and its sleeve, nerve conduits with different specifications of inner diameter can be printed; by controlling the extruder head to coat back and forth through the control system, multi-layer and multi-material nerve conduits can be produced; by controlling the extrusion volume of the extruder, hollow grid forming can be achieved, which is beneficial to nerve growth.

The implementation of the embodiments of the present invention has the following beneficial effects: the equipment and manufacturing process for preparing nerve conduits overcome the problem of high voltage required for electrospinning process manufacturing, so the equipment cost and use cost are low and suitable for industrial production; the electrospinning process is affected by multiple factors such as polymer parameters, solvent parameters, solution parameters, process control parameters and environmental parameters, and the manufacturing process of this process method is easy to control; the problems of support, roughness and difficulty in forming when manufacturing thin-walled long-tube nerve conduits by traditional additive manufacturing processes are overcome, and the forming shaft and sleeve are used to provide support, and no printing support is required. The forming shaft and sleeve rotate, which is easier to form during the printing process; the problem that the interlayer strength of the nerve conduit is insufficient and easy to break caused by printing with traditional additive manufacturing processes is overcome, and a nerve conduit with high axial strength is printed through the new process; due to the stability of the mechanical structure of the equipment and the high precision of the control system, the equipment has both high repeatability and can be customized; due to the high editability of the code of the control system in the equipment, the settings can be easily changed to achieve multi-specification and multi-material forming, which overcomes the defects of high professionalism and low controllability of electrospinning equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a front view schematic diagram of a device for preparing a nerve conduit provided by the present invention;

FIG2 is a schematic side view of a device for preparing a nerve conduit provided by the present invention;

FIG3 is a schematic diagram of a top view of a device for preparing a nerve conduit provided by the present invention;

Figure 4 shows the printing track when the forming shaft rotates clockwise and the extruder moves to the right;

FIG5 is a printing track in which the forming shaft rotates counterclockwise and the extruder moves leftward after the action in FIG4;

FIG6 is a diagram showing the trajectory of the first layer of material printed on the surface of the forming shaft;

FIG. 7 shows the trajectory of the second layer of material printed on the surface of the forming shaft.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Please refer to Figures 1-3, Figure 1 is a front view structural schematic diagram of a device suitable for preparing a nerve catheter provided by the present invention; Figure 2 is a side view structural schematic diagram of a device suitable for preparing a nerve catheter provided by the present invention; Figure 3 is a top view structural schematic diagram of a device suitable for preparing a nerve catheter provided by the present invention; the device and manufacturing process suitable for preparing a nerve catheter include: an extruder X-axis motor 1, an extruder X-axis slide 2, an extruder motor 3, a screw extruder 4, an extruder head 5, a column 6, an extruder X-axis slide 7, an extruder Y-axis module 8, an extruder Y-axis slide 9, a machine base 10, a transmission belt 11, a fine-tuning hand wheel 12, a top shaft tailstock 13, a tailstock fixing rod 14, a tailstock slide 15, a forming shaft 16, a clamping disk 17, a fixing seat 18, a coarse adjustment hand wheel 19, a fixing seat fixing rod 20, a fixing seat connecting plate 21 and a clamping disk rotating motor 22.

The device for preparing a nerve conduit comprises a frame and a screw extruder 4 .

The frame includes a base 10 and a column 6 vertically connected to the base 10. A transmission belt 11 is horizontally installed on the upper surface of the base 10. The transmission belt 11 is connected to a coarse adjustment handwheel 19. Two coarse adjustment handwheels 19 are provided and are respectively installed at both ends of the base 10. In this embodiment, the connection between the coarse adjustment handwheel and the conveyor belt adopts the existing technology. One end of the coarse adjustment handwheel is a handwheel, and the other end has a toothed shaft, which is inserted into the toothed hole of the pulley. Rotating the coarse adjustment handwheel can make the coarse adjustment handwheel drive the pulley to rotate. The pulley is connected to the conveyor belt to drive the conveyor belt to move.

The fixed seat connecting plate 21 and the tailstock slide 15 are both arranged on the transmission belt 11 and are slidably connected with the transmission belt 11; a tailstock fixing rod 14 is arranged on the tailstock slide 15, and the tailstock fixing rod 14 controls the loosening and fixing of the tailstock slide 15 on the transmission belt 11, and a top shaft tailstock 13 and a fine-tuning handwheel 12 are installed on the tailstock slide 15, and the fine-tuning handwheel 12 is connected to one end of the top shaft tailstock 13 away from the forming shaft 16, and a bayonet 131 is arranged on the top shaft tailstock 13; in this embodiment, the connection between the fine-tuning handwheel and the top shaft tailstock adopts the existing technology, and the fine-tuning handwheel has a section of external threaded shaft, which is installed in the internal threaded hole of the top shaft tailstock. By rotating the fine-tuning handwheel, the external threaded shaft of the fine-tuning handwheel can be extended from the bayonet at the other end of the top shaft tailstock, and the forming shaft can be tightened as needed.

A fixed seat fixing rod 20 is provided on the fixed seat connecting plate 21, and the fixed seat fixing rod 20 controls the loosening and fixing of the fixed seat connecting plate 21 on the transmission belt 11. A fixed seat 18 is fixedly installed on the fixed seat connecting plate 21, and a clamping plate 17 is installed on the end of the fixed seat 18 facing the top shaft tail seat 13. A forming shaft 16 is clamped on the clamping plate 17, and the end of the forming shaft 16 away from the clamping plate 17 is inserted into the bayonet 131 and pressed against the top shaft tail seat 13; the clamping plate rotating motor 22 is fixed on the fixed seat 18 The motor shaft passes through the fixing seat 18 and is connected with the clamping disk 17, driving the clamping disk 17 and the forming shaft 16 to rotate; the outer sleeve of the forming shaft 16 is provided with a sleeve 161, which is made of polytetrafluoroethylene material and has self-lubricating properties inside. A plurality of tiny gaps are axially arranged on the sleeve 161. When installed on the forming shaft 16, the gaps on the sleeve 161 are expanded but do not affect the forming of the material. After printing is completed, the sleeve 161 is removed from the forming shaft 16, and the gaps on the sleeve 161 shrink and become smaller, making it convenient to remove the printed nerve conduit.

The top and bottom of the screw extruder 4 are respectively connected with an extruder motor 3 and an extrusion head 5, the extrusion hole of the extrusion head 5 is arranged correspondingly to the forming shaft 16 up and down, and a heating rod and a temperature sensor are installed in the extrusion hole 5 for temperature control and feedback; the screw extruder 4 is installed on the extruder Y-axis module 8 through the extruder Y-axis slide 9, the extruder Y-axis module 8 is connected to the extruder X-axis slide 7, the extruder X-axis slide 7 is installed on the extruder X-axis slide 2, the extruder X-axis slide 2 is fixed on the top of the column 6, one end of the extruder X-axis slide 2 is connected with the extruder X-axis motor 1, and the motor shaft of the extruder X-axis motor 1 is connected to the extruder X-axis slide 7; in other embodiments, the screw extruder 4 can be any kind of extrusion equipment.

In this embodiment, two columns 6 are provided, which are installed on the machine base 10 in parallel and at intervals, and the tops of the two columns 6 are fixedly connected to the two ends of the extruder X-axis slide 2 respectively.

The present invention also provides a manufacturing process suitable for preparing a nerve conduit, based on the above-mentioned device suitable for preparing a nerve conduit, comprising the following steps:

Step 1: The control system sends control information to drive the extruder X-axis motor, extruder motor, extruder Y-axis module and clamping disk rotation motor to start; the above motors include but are not limited to servo motors.

Step 2: The control system moves the extruder head to a suitable position to prepare for printing according to the wall thickness requirements of the designed nerve conduit, and drives the extruder head to extrude the nerve conduit forming material;

Step 3: Manually adjust the tailstock fixing rod, the fixing rod of the fixing seat, the coarse adjustment hand wheel and the fine adjustment hand wheel to accurately locate the printing position of the forming axis;

Step 4: After the extruder extrude the nerve conduit forming material, the material is coated on the sleeve of the forming shaft. As the forming shaft rotates at a low speed and the extruder reciprocates at a high speed in the X-axis direction, the material extruded by the extruder makes an axial spiral motion in the axial direction of the forming shaft;

Step 5: After printing is completed, remove the entire sleeve from the forming shaft, and then remove the printed nerve conduit.

Please refer to Figures 4-7 for the printing process (the dotted line in each figure is the center line of the rotating shaft). Figure 4 shows the printing trajectory of the forming shaft rotating clockwise and the extruder moving to the right; Figure 5 shows the printing trajectory of the forming shaft rotating counterclockwise and the extruder moving to the left after the action in Figure 4; Figure 6 shows the trajectory of the first layer of material on the surface of the forming shaft after the actions in Figures 4 and 5 are cycled multiple times; Figure 7 shows the trajectory of the second layer of material on the surface of the forming shaft after the action in Figure 6, the forming shaft rotates counterclockwise, the extruder moves to the right, and then the forming shaft rotates clockwise, the extruder moves to the left, and after multiple cycles, the printing is completed.

In this production process, according to the actual situation of the patient, by adjusting the rotation direction of the forming shaft and the moving direction of the extruder head, a mesh-structured nerve conduit can be printed after several cycles; by adjusting the rotation speed of the forming shaft and the moving speed of the extruder head, nerve conduits with different axial inclination angles can be printed; by controlling the distance between the extrusion hole on the extruder head and the forming shaft, the wall thickness of the printed nerve conduit can be controlled; by selecting the appropriate axial diameter of the forming shaft and its sleeve, nerve conduits with different specifications of inner diameter can be printed; by controlling the extruder head to coat back and forth through the control system, multi-layer and multi-material nerve conduits can be produced; by controlling the extrusion volume of the extruder, hollow grid forming can be achieved, which is beneficial to nerve growth.

The implementation of the embodiments of the present invention has the following beneficial effects: the equipment and manufacturing process for preparing nerve conduits overcome the problem of high voltage required for electrospinning process manufacturing, so the equipment cost and use cost are low and suitable for industrial production; the electrospinning process is affected by multiple factors such as polymer parameters, solvent parameters, solution parameters, process control parameters and environmental parameters, and the manufacturing process of this process method is easy to control; the problems of support, roughness and difficulty in forming when manufacturing thin-walled long-tube nerve conduits by traditional additive manufacturing processes are overcome, and the forming shaft and sleeve are used to provide support, and no printing support is required. The forming shaft and sleeve rotate, and it is easier to form during the printing process; the problem that the interlayer strength of the nerve conduit is insufficient and easy to break caused by printing with traditional additive manufacturing processes is overcome, and a nerve conduit with high axial strength is printed through the new process; due to the stability of the mechanical structure of the equipment and the high precision of the control system, the equipment has both high repeatability and can be customized; due to the high editability of the code of the control system in the equipment, the settings can be easily changed to achieve multi-specification and multi-material forming, which overcomes the defects of high professionalism and low controllability of electrospinning equipment.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (6)

1. An apparatus suitable for preparing a nerve conduit, the apparatus comprising a housing and a screw extruder;

The machine frame comprises a machine seat and an upright post vertically connected to the machine seat, a transmission belt is transversely arranged on the upper surface of the machine seat, the transmission belt is connected with a coarse adjustment hand wheel, two coarse adjustment hand wheels are arranged, the coarse adjustment hand wheels are respectively arranged at two ends of the machine seat, a fixed seat connecting plate and a tailstock sliding seat are both arranged on the transmission belt and are in sliding connection with the transmission belt, a tailstock fixing rod is arranged on the tailstock sliding seat, the tailstock fixing rod controls the tailstock sliding seat to be loosened and fixed on the transmission belt, a top shaft tailstock and a fine adjustment hand wheel are arranged on the tailstock sliding seat, the fine adjustment hand wheel is connected with the end part of the top shaft tailstock, a fixed seat fixing rod is arranged on a fixed seat connecting plate, a fixed seat is fixedly arranged on the fixed seat connecting plate, one end of the fixed seat facing the top shaft tailstock is provided with a clamping disc, the clamping disc is clamped on the clamping disc, one end of the forming shaft far away from the top shaft is tightly contacted with the top shaft of the motor, and the clamping disc is rotatably connected with the clamping disc through the fixing seat;

The screw extruder is characterized in that an extruder motor and an extrusion head are respectively connected to the top and the bottom of the screw extruder, an extrusion hole of the extrusion head is correspondingly arranged up and down with the forming shaft, the screw extruder is arranged on an extruder Y-axis module through an extruder Y-axis sliding seat, the extruder Y-axis module is connected with an extruder X-axis sliding seat, the extruder X-axis sliding seat is arranged on an extruder X-axis sliding table, the extruder X-axis sliding table is fixed at the top of the upright post, one end of the extruder X-axis sliding table is connected with the extruder X-axis motor, a motor shaft of the extruder X-axis motor is connected with the extruder X-axis sliding seat, a fine adjustment hand wheel is connected with one end of the top-axis tailstock far away from the forming shaft, a bayonet is arranged on the top-axis tailstock, and the end of the forming shaft is inserted into the bayonet and is tightly propped against the top-axis tailstock.

2. The apparatus for preparing a nerve conduit according to claim 1, wherein two stand columns are arranged on the base at intervals and in parallel, and the tops of the two stand columns are fixedly connected with two ends of the X-axis sliding table of the extruder respectively.

3. The apparatus for preparing a nerve conduit according to claim 1, wherein the forming shaft is sleeved with a sleeve, a plurality of tiny gaps are axially arranged on the sleeve, when the sleeve is installed on the forming shaft, the gaps on the sleeve are expanded to be larger, but the forming of materials is not affected, the sleeve is taken down from the forming shaft after printing is finished, the gaps on the sleeve are contracted to be smaller, and the printed nerve conduit is convenient to take down.

4. A device suitable for use in the preparation of nerve conduits according to claim 3, wherein the sleeve is made of polytetrafluoroethylene material and is self-lubricating internally.

5. A manufacturing process suitable for the preparation of nerve conduits, based on an apparatus suitable for the preparation of nerve conduits according to any one of claims 1-4, characterized in that it comprises the following steps:

Step one: the control system sends out control information to drive the X-axis motor of the extruder, the extruder motor, the Y-axis module of the extruder and the rotating motor of the clamping disc to start;

Step two: the control system enables the extrusion head to move to a proper position for printing according to the wall thickness requirement of the designed nerve conduit, and drives the extrusion head to extrude the nerve conduit forming material;

Step three: the printing position of the forming shaft is accurately positioned through a manual adjustment tailstock fixing rod, a fixing seat fixing rod, a rough adjustment hand wheel and a fine adjustment hand wheel;

Step four: when the extrusion head extrudes the nerve conduit forming material, the material is coated on a sleeve of the forming shaft, and the extrusion head axially and spirally moves along with the low-speed rotation of the forming shaft and the high-speed back and forth reciprocating movement of the extrusion head in the X-axis direction;

step five: and after printing, the whole sleeve is taken down from the forming shaft, and then the printed nerve conduit is taken down.

6. The manufacturing process for preparing nerve conduit according to claim 5, wherein the nerve conduit having a net structure can be printed after several cycles by adjusting the rotation direction of the forming shaft and the movement direction of the extrusion head; by adjusting the rotation speed of the forming shaft and the moving speed of the extrusion head, nerve conduits with different axial dip angles can be printed; controlling the wall thickness of the nerve conduit printing by controlling the distance between the extrusion hole on the extrusion head and the forming shaft; the nerve conduits with different specification inner diameters can be printed out by selecting proper forming shafts and shaft diameters of the sleeves of the forming shafts; the extrusion head is controlled by the control system to be coated back and forth in a reciprocating way, so that the multilayer multi-material nerve conduit can be manufactured; the formation of the air-break grid can be realized by controlling the extrusion amount of the extruder, which is beneficial to the nerve growth.