3D printing hollowed-out external fixing brace and preparation method thereof

Abstract

The invention provides a 3D printing hollowed-out external fixation brace and a preparation method thereof, and belongs to the technical field of medical instruments, the 3D printing hollowed-out external fixation brace comprises a brace body, a medicine applying opening is reserved in the brace body, a brace block is arranged in the medicine applying opening, and a supporting column is connected with the brace body through a connecting piece; the connecting piece comprises a connecting piece, an upper connecting module and a lower connecting module; the upper connection module is arranged on the connection sheet, the upper connection module comprises an inner column, a shell and a stop unit, the inner column is arranged in the shell, and the stop unit is arranged in the inner column; the lower connecting module is arranged on the brace body, the lower connecting module comprises a lower connecting cylinder, a connecting sleeve and a traction unit, and the lower connecting cylinder is arranged on the outer wall surface of the brace body. The problems that at present, a traumatic external fixing support is adopted for fixing, infection, inconvenient movement and amyotrophy are likely to be caused, meanwhile, patient experience is poor, and certain medical risks exist are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a 3D printed hollow external fixation brace and a preparation method thereof. Background Art

[0002] When a patient has a serious fracture, they need to undergo orthopedic surgery to reduce the fracture, and after the surgery, they need to be fixed with an external fixator. The external fixator is a damaging fixation method that requires steel pins to pass through both ends of the bone for fixation.

[0003] At present, damaging external fixators are used for fixation, which are prone to infection, difficulty in movement, muscle atrophy, and poor patient experience. If not properly cared for, it is easy to cause complications such as pin tract infection and loosening, causing unnecessary pain to patients. In addition to pin tract infection, external fixators may also cause complications such as delayed fracture healing, nonunion, and joint stiffness. These complications need to be discovered and treated by doctors in a timely manner, otherwise they will affect the healing of fractures and the recovery of limb function, and there are certain medical risks. Summary of the invention

[0004] The present invention provides a 3D printed hollow external fixation brace and a preparation method thereof, which aims to solve the problem that currently a damaging external fixation bracket is used for fixation, which is prone to infection, inconvenience in movement, muscle atrophy, and poor patient experience. If improper care is given, it is easy to cause complications such as needle tract infection and loosening, which bring unnecessary pain to the patient. In addition to needle tract infection, the external fixation bracket may also cause complications such as delayed fracture healing, bone nonunion, joint stiffness, etc. These complications need to be discovered and treated by doctors in a timely manner, otherwise they will affect the healing of fractures and the recovery of limb function, and there are certain medical risks.

[0005] The embodiment of the present invention provides a 3D printed hollow external fixation brace, comprising a brace body, a medicine-applying opening is reserved on the brace body, a brace block is arranged in the medicine-applying opening, a plurality of pillars are fixedly connected to the outer side of the brace block, and the pillars are connected to the brace body via a connector;

[0006] The connecting piece includes a connecting piece, an upper connecting module and a lower connecting module;

[0007] The upper connection module is installed on the connection piece, and the upper connection module comprises an inner column, an outer shell and a stop unit, wherein the inner column is installed in the outer shell, and the stop unit is installed in the inner column;

[0008] The lower connecting module is installed on the brace body, and the lower connecting module comprises a lower connecting tube, a connecting sleeve and a traction unit. The lower connecting tube is installed on the outer wall surface of the brace body, the connecting sleeve is installed in the lower connecting tube, and the connecting sleeve is installed above the traction unit.

[0009] A connecting seat 1 is arranged around the connecting piece;

[0010] The two ends of the inner column pass through the connecting seat 1, and the inner column is reserved with a strip groove, a through-hole, channel 1, channel 2 and channel 3. The strip groove is reserved on both sides of the inner column, the through-hole intersects with the vertical center line of the inner column, and the two ends of the through-hole respectively pass through the corresponding strip groove, and the lower end of the through-hole reserves channel 2, and channel 1 is reserved between the through-hole and channel 2, and channel 1 connects the through-hole and channel 2, and channel 3 is reserved on the side of the inner column, and channel 3 and channel 2 are connected to each other;

[0011] The outer shell is provided with a second connecting seat, a movable sheet and a spiral beryllium copper wire. The second connecting seat is provided on both sides of the outer shell, and the movable sheet is provided on both sides of the inner shell. The movable sheet and the strip groove are movably connected. The spiral beryllium copper wire is provided between the outer shell and the connecting seat. A U-shaped opening is reserved on the second connecting seat, and a restraining groove is reserved on the movable sheet.

[0012] Further, the stop unit comprises a stop bar, a movable column, a rotating disc, a rotating shell and two spiral beryllium copper wires, the stop bar is movably connected to the through-hole, the movable column is movably connected to the first channel, the rotating disc is screwed to the second channel, the inner wall surface of the rotating shell is screwed to the inner column, and the second spiral beryllium copper wire is arranged between a pair of stop bars;

[0013] The end of the stop bar farther from the spiral beryllium copper wire is reserved with a wedge-shaped surface.

[0014] Furthermore, the rotating disc is provided with an inclined mouth 1 and a connecting rod, the inclined mouth 1 is reserved on the rotating disc, the inclined mouth 1 is movably connected to the movable column, the connecting rod is movably connected to the channel 3, and the rotating disc and the rotating shell are connected via the connecting rod.

[0015] Furthermore, cavity one, cavity two, a square groove, a circular groove, a strip opening, a connecting opening and a circular strip are arranged on the lower connecting tube. Cavity one is reserved at an end of the lower connecting tube close to the upper connecting module, and cavity two is reserved at an end of the lower connecting tube farther from the upper connecting module. Cavity one and cavity two are connected to each other. The circular strip is arranged at the position where cavity one and cavity two are connected. The square groove is reserved on the inner wall of cavity one. The square groove and connecting seat two are adapted to each other. The circular groove is reserved in the inner wall of the lower connecting tube. The circular groove and the square groove are connected to each other. The strip opening is reserved on the inner wall of cavity two. The circular groove and the strip opening are connected via the connecting opening.

[0016] Furthermore, the connecting sleeve and the annular groove are screwed together, and a circular opening, a docking opening and a second skewed opening are reserved on the connecting sleeve. The circular opening is reserved in the middle of the connecting sleeve, the docking opening is reserved on both sides of the circular opening, and the second skewed opening is reserved on the connecting sleeve.

[0017] Furthermore, the traction unit includes a connecting strip, a traction column and a movable seat. The middle of the connecting strip is screwed to the side wall of the strip-shaped opening, the bottom of the connecting strip passes through the strip-shaped opening, the traction column is installed on the top of the connecting strip, the traction column passes through the connecting opening and the second skewed opening, and the movable seat and cavity two are movably connected.

[0018] Furthermore, circular sheet one, circular sheet two, a connecting frame and spiral beryllium copper wire three are installed on the movable seat, circular sheet one is installed at one end of the movable seat close to the upper connecting module, circular sheet two is installed below circular sheet one, the connecting frame is installed between circular sheet one and circular sheet two, and spiral beryllium copper wire three is installed between circular sheet two and the bottom wall of cavity two; a wedge-shaped surface two is reserved on the side wall of the connecting frame, and the wedge-shaped surface two is in contact with the side wall of the bottom of the connecting strip.

[0019] A method for preparing a 3D printed hollow external fixation brace, comprising the above-mentioned 3D printed hollow external fixation brace, further comprising the following steps:

[0020] Step M1: Obtain medical imaging information of fracture and soft tissue injury sites;

[0021] Step M2: importing medical imaging information into a 3D reconstruction system to obtain a preliminary 3D model;

[0022] Step M3: Perform biomechanical analysis of the preliminary three-dimensional model using the finite element method and according to the first strength theory;

[0023] Step M4: Based on biomechanical analysis, the preliminary three-dimensional model information of the 3D printed medical external fixation brace is updated to obtain a final three-dimensional model;

[0024] Step M5: performing layered slicing and printing path planning on the final 3D model;

[0025] Step M6: The processed final three-dimensional model is printed using polylactic acid printing consumables through a 3D printing process to obtain a brace body;

[0026] Step M7: Print the brace block through the 3D printing process according to the specifications of the medicine port, then print the pillar on the brace block, then print the components of the connector, and then assemble the parts into an upper connector module and a lower connector module, and then adhere the lower connector module and the connector piece to the brace body and the pillar respectively, and finally, assemble the brace body and the brace block together through the upper connector module and the lower connector module.

[0027] Furthermore, the finite element analysis method in step M3 comprises the following steps:

[0028] Step M31: meshing, importing the preliminary three-dimensional model into finite element analysis software to mesh the model;

[0029] Step M32: material property definition, create a new material after importing the model, and assign elastic modulus, Poisson's ratio and density;

[0030] Step M33: Create and assign sections;

[0031] Step M34: setting loads and boundary conditions, and applying corresponding loads and boundary conditions to the outer surface of the brace according to the actual use of the brace and based on biomechanical analysis;

[0032] Step M35: Analysis and solution. After completing the load application and boundary condition setting for the model, create and set a static analysis step for analysis and simulation. Finally, create a new job, submit it and wait for the software to run and the results to be output.

[0033] Furthermore, the biomechanical analysis in step M4 comprises the following steps:

[0034] Step M41: Obtaining an optimization model, and obtaining an optimization model for biomechanical optimization design according to the finite element analysis results of the model under the conditions of step M3;

[0035] Step M42: Setting the optimization response form, setting a single response or a combined response according to the required optimization content;

[0036] Step M43: Setting optimization parameters and setting the optimization parameters in detail. After obtaining the optimization model of the optimal design, the optimization parameters of the model need to be specifically set;

[0037] Step M44: Analysis and solution. After completing all optimization parameter settings for the model, submit and wait for the software to run and the final results to be output.

[0038] The beneficial effects of the present invention are:

[0039] The 3D printed hollow external fixation brace of the present invention replaces the external fixation bracket under specific circumstances (the specific circumstances here specifically refer to no other open wounds, that is, no other large-area wound surface except the surgical incision) to fix the injured part with the surgical incision. A medicine application port is reserved on the brace body, and then a brace block is assembled at the medicine application port. When it is necessary to change the dressing, the brace block is disassembled and taken out, and the medicine application port is opened to change the dressing. The lower connecting module on the outer wall of the brace body is provided with a support, a connecting piece and an upper connecting module on the brace block, so that the brace body and the brace block can be quickly assembled. After the upper connecting module is facing the lower connecting module, it is pressed downward to achieve the purpose of tightening the connection. When the dressing is to be changed, When removing the brace block, only the rotating shell needs to be rotated to cancel the fastening connection. The connection and assembly are very convenient, and the brace block can be quickly disassembled to open the medicine port for dressing change. There is no need to drill holes on the skin of the upper and lower ends of the limb or fracture to fix it, which reduces the difficulty and risk of the operation. At the same time, the operation site can be isolated from the outside world, thereby reducing the risk of infection at the surgical incision. The entire external fixation brace is prepared by 3D printing, has a high aesthetics, and is convenient for daily work and life. The surgical incision is on the inner side of the brace, which is not easy to touch and does not cause pain in the wound. It improves the patient's medical experience and avoids the medical risks brought by traditional external fixators.

[0040] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0042] Figure 1 The main structure of the embodiment of the present invention is shown in FIG. Figure 1 ;

[0043] Figure 2 The main structure of the embodiment of the present invention is shown in FIG. Figure 2 ;

[0044] Figure 3 This is a schematic diagram of the cross-sectional structure of the medicine application port of an embodiment of the present invention;

[0045] Figure 4 A schematic diagram of the structure of an upper connection module and a lower connection module according to an embodiment of the present invention;

[0046] Figure 5This is a schematic diagram of the disassembled structure of the lower connection module according to an embodiment of the present invention;

[0047] Figure 6 This is a schematic diagram of the disassembled structure of the upper connection module according to an embodiment of the present invention;

[0048] Figure 7 This is a schematic diagram of the inner column structure of an embodiment of the present invention;

[0049] Figure 8 A schematic diagram of the housing structure of an embodiment of the present invention;

[0050] Fig. 9 A schematic diagram of the structure of a rotating shell according to an embodiment of the present invention;

[0051] Fig.10 A schematic diagram of the connection structure between the upper connection module and the lower connection module according to an embodiment of the present invention;

[0052] Fig.11 The displacement cloud diagram of the finite element analysis of the embodiment of the present invention;

[0053] Fig.12 This is a model diagram before the biomechanical optimization design of the embodiment of the present invention;

[0054] Fig.13 A model diagram after biomechanical optimization design of an embodiment of the present invention;

[0055] Fig.14 The maximum tensile stress diagram in the X direction of the embodiment of the present invention;

[0056] Fig.15 The maximum tensile stress diagram in the Y direction of the embodiment of the present invention;

[0057] Fig.16 It is a diagram of the maximum tensile stress in the Z direction of an embodiment of the present invention;

[0058] Figure numerals: 1. brace body; 2. medicine port; 3. brace block; 4. pillar; 5. connector; 51. connector piece; 52. upper connector module; 521. inner column; 522. outer shell; 523. stop unit; 53. lower connector module; 531. lower connector tube; 532. connector sleeve; 533. traction unit; 511. connector seat 1; 5211. strip groove; 5212. through-hole; 5213. channel 1; 5214. channel 2; 5215. channel 3; 5221. connector seat 2; 5222. movable piece; 5223. spiral beryllium copper wire 1; 5224. U-shaped mouth; 5225. constraint groove; 5231. stop strip; 5232. movable column; 5233, rotating disc; 5234, rotating shell; 5235, spiral beryllium copper wire II; 5236, skewed mouth I; 5237, connecting rod; 5238, wedge-shaped surface I; 5311, cavity I; 5312, cavity II; 5313, square groove; 5314, circular groove; 5315, strip mouth; 5316, connecting mouth; 5317, circular strip; 5321, circular mouth; 5322, docking mouth; 5323, skewed mouth II; 5331, connecting strip; 5332, traction column; 5333, movable seat; 5334, circular disc I; 5335, circular disc II; 5336, connecting frame; 5337, spiral beryllium copper wire III; 5338, wedge-shaped surface II. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the technical solution of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described in conjunction with the drawings of specific embodiments of the present invention. The same figure marks in the drawings represent the same parts. It should be noted that the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] See also Figure 1-Figure 10 The embodiment of the present invention provides a 3D printed hollow external fixation brace, comprising a brace body 1, a medicine opening 2 is reserved on the brace body 1, a brace block 3 is arranged in the medicine opening 2, a plurality of pillars 4 are fixedly connected to the outer side of the brace block 3, and the pillars 4 are connected to the brace body 1 via a connector 5.

[0061] See also Figure 1 and Figure 2 The medicine opening 2 can be round, plum blossom-shaped, etc., and the support block 3 is adapted to the medicine opening 2.

[0062] See also Figure 3-Figure 5 The connecting member 5 includes a connecting piece 51 , an upper connecting module 52 and a lower connecting module 53 .

[0063] The upper connecting module 52 is mounted on the connecting piece 51. The upper connecting module 52 includes an inner column 521, an outer shell 522 and a stop unit 523. The inner column 521 is mounted in the outer shell 522. The stop unit 523 is mounted in the inner column 521. The outer shell 522 is used to connect and fasten with the lower connecting module 53. The stop unit 523 fastens the outer shell 522 and the inner column 521 when connected. When disassembled, the outer shell 522 and the inner column 521 can also be disassembled through the stop unit 523.

[0064] The lower connecting module 53 is installed on the brace body 1, and the lower connecting module 53 includes a lower connecting tube 531, a connecting sleeve 532 and a traction unit 533. The lower connecting tube 531 is installed on the outer wall surface of the brace body 1, and the connecting sleeve 532 is installed in the lower connecting tube 531. The connecting sleeve 532 is installed above the traction unit 533; the traction unit 533 pulls the connecting sleeve 532 to rotate, and the traction unit 533 is pulled and moved by the inner column 521.

[0065] When assembling the brace block 3, the inner column 521 is connected to the lower connecting module 53. The inner column 521 pulls the traction unit 533 to move, and then the traction unit 533 pulls the connecting sleeve 532 to rotate, so as to achieve the purpose of connecting the connecting sleeve 532 and the outer shell 522. When the inner column 521 is embedded in the lower end of the lower connecting module 53, the stop unit 523 fastens the inner column 521 and the outer shell 522 to complete the connection with each other. When disassembling, the stop unit 523 is controlled to disassemble the inner column 521 and the outer shell 522, and the upper connecting module 52 and the lower connecting module 53 are disassembled by themselves.

[0066] See also Figure 4-Figure 10 Among them, a connecting seat 511 is arranged around the connecting piece 51, which is used to fix a spiral beryllium copper wire 5223.

[0067] Among them, both ends of the inner column 521 pass through the connecting seat 1 511, and the inner column 521 is reserved with a strip groove 5211, a through-port 5212, a channel 1 5213, a channel 2 5214 and a channel 3 5215. The strip groove 5211 is reserved on both sides of the inner column 521, the through-port 5212 intersects with the vertical center line of the inner column 521, and both ends of the through-port 5212 pass through the corresponding strip groove 5211, and the lower end of the through-port 5212 is reserved with a channel 2 5214, and the channel 1 5213 is reserved between the through-port 5212 and the channel 2 5214, and the channel 1 5213 connects the through-port 5212 and the channel 2 5214, and the channel 3 5215 is reserved on the side of the inner column 521, and the channel 3 5215 and the channel 2 5214 are connected to each other;

[0068] The strip groove 5211 is reserved at the head end of the inner column 521 , and the channel two 5214 and the channel three 5215 are reserved at the tail end of the inner column 521 .

[0069] Among them, the outer shell 522 is provided with a second connecting seat 5221, a movable sheet 5222 and a spiral beryllium copper wire 5223. The second connecting seat 5221 is provided on both sides of the outer shell 522, and the movable sheet 5222 is provided on both sides of the inner shell 522. The movable sheet 5222 is movably connected to the strip groove 5211. The spiral beryllium copper wire 5223 is provided between the outer shell 522 and the first connecting seat 511. A U-shaped opening 5224 is reserved on the second connecting seat 5221, and a restraining groove 5225 is reserved on the movable sheet 5222.

[0070] The movable piece 5222 and the strip groove 5211 are adapted to each other to ensure that the inner column 521 cannot rotate in the outer shell 522, and the U-shaped opening 5224 on the connecting seat 5221 and the lower connecting module 53 are adapted to achieve the purpose of connection; the constraint groove 5225 is used to cooperate with the stop unit 523 to achieve the purpose of tightening the outer shell 522 and the inner column 521.

[0071] The stop unit 523 includes a stop bar 5231, a movable column 5232, a rotating disc 5233, a rotating shell 5234 and a second spiral beryllium copper wire 5235. The stop bar 5231 is movably connected to the through hole 5212, the movable column 5232 is movably connected to the first channel 5213, the rotating disc 5233 is screwed to the second channel 5214, the inner wall of the rotating shell 5234 is screwed to the inner column 521, and the second spiral beryllium copper wire 5235 is arranged between a pair of stop bars 5231; a wedge-shaped surface 1 5238 is reserved at the end of the stop bar 5231 that is farther from the second spiral beryllium copper wire 5235;

[0072] The stop strip 5231 is used to tighten the housing 522 when connected. At the beginning, the shape of the spiral beryllium copper wire 2 5235 does not change, the movable column 5232 is located at the end of the channel 1 5213 that is farther from the vertical center line of the rotating disc 5233, the wedge surface 1 5238 passes through the through opening 5212, and the angle between the wedge surface 1 5238 and the stop strip 5231 close to the connecting seat 1 511 is less than ninety degrees.

[0073] Among them, the rotating disc 5233 is provided with an inclined opening 1 5236 and a connecting rod 5237, the inclined opening 1 5236 is reserved on the rotating disc 5233, the inclined opening 1 5236 and the movable column 5232 are movably connected, the connecting rod 5237 and the channel 3 5215 are movably connected, and the rotating disc 5233 and the rotating shell 5234 are connected via the connecting rod 5237;

[0074] The connecting lines at both ends of the skewed opening 5236 deviate from the radius of the rotating disc 5233. At the beginning, the movable column 5232 is located at the end of the skewed opening 5236 that is farther from the vertical center line of the rotating disc 5233. When the rotating shell 5234 is rotated, the movable column 5232 is brought close to the vertical center line of the rotating disc 5233 through the skewed opening 5236, and then the stop bar 5231 is retracted into the through opening 5212. At this moment, the spiral beryllium copper wire 5235 is compressed and shortened. When the rotating shell 5234 is released, the spiral beryllium copper wire 5235 returns to its original state, and the stop bar 5231 passes through the through opening 5212 again.

[0075] The lower connecting tube 531 is provided with a cavity 1 5311, a cavity 2 5312, a square groove 5313, a circular groove 5314, a strip opening 5315, a connection opening 5316 and a circular strip 5317. The cavity 1 5311 is reserved at one end of the lower connecting tube 531 close to the upper connecting module 52, and the cavity 2 5312 is reserved at one end of the lower connecting tube 531 far from the upper connecting module 52. The cavity 1 5311 and the cavity 2 5312 are connected to each other, and the circular strip 5317 is provided. At the position where cavity one 5311 and cavity two 5312 are connected, a square groove 5313 is reserved on the inner wall of cavity one 5311, the square groove 5313 and connecting seat two 5221 are adapted to each other, annular groove 5314 is reserved in the inner wall of the lower connecting tube 531, the annular groove 5314 and the square groove 5313 are connected to each other, and a strip opening 5315 is reserved on the inner wall of cavity two 5312, and the annular groove 5314 and the strip opening 5315 are connected via a connecting opening 5316.

[0076] The connecting sleeve 532 and the circular groove 5314 are screwed together. The connecting sleeve 532 is reserved with a circular opening 5321, a docking opening 5322 and a second skewed opening 5323. The circular opening 5321 is reserved in the middle of the connecting sleeve 532, the docking opening 5322 is reserved on both sides of the circular opening 5321, and the second skewed opening 5323 is reserved on the connecting sleeve 532.

[0077] The structure of the docking interface 5322 and the square groove 5313 are adapted to the structure of the connecting seat 5221. Initially, the docking interface 5322 and the square groove 5313 overlap, and the connecting lines at both ends of the skewed mouth 5323 deviate from the vertical center line of the connecting sleeve 532. Initially, the head of the skewed mouth 5323 at one end farther from the vertical center line of the connecting sleeve 532 overlaps with the connecting port 5316.

[0078] The traction unit 533 includes a connection bar 5331, a traction column 5332 and a movable seat 5333. The middle of the connection bar 5331 is screwed to the side wall of the strip-shaped opening 5315. The bottom of the connection bar 5331 passes through the strip-shaped opening 5315. The traction column 5332 is installed on the top of the connection bar 5331. The traction column 5332 passes through the connection opening 5316 and the second skewed opening 5323. The movable seat 5333 is movably connected to the second cavity 5312.

[0079] At the beginning, the traction column 5332 is located at the end of the connecting port 5316 and the second inclined port 5323 that is farther from the vertical center line of the lower connecting tube 531, and the lower wall surface of the bottom of the connecting strip 5331 is parallel to the lower wall surface of the strip port 5315; when the connecting strip 5331 rotates around its rotation center, the traction column 5332 rotates in the connecting port 5316, and then the traction column 5332 moves in the second inclined port 5323, and then the connecting sleeve 532 is pulled to rotate.

[0080] Among them, circular sheet 1 5334, circular sheet 2 5335, connecting frame 5336 and spiral beryllium copper wire 3 5337 are installed on the movable seat 5333. Circular sheet 1 5334 is installed at one end of the movable seat 5333 close to the upper connecting module 52, circular sheet 2 5335 is installed below circular sheet 1 5334, connecting frame 5336 is installed between circular sheet 1 5334 and circular sheet 2 5335, and spiral beryllium copper wire 3 5337 is installed between circular sheet 2 5335 and the bottom wall of cavity 2 5312; wedge-shaped surface 2 5338 is reserved on the side wall of connecting frame 5336, and wedge-shaped surface 2 5338 contacts the side wall of the bottom of connecting strip 5331;

[0081] The circular piece 2 5335 is used to assemble the spiral beryllium copper wire 3 5337 and pull the connecting bar 5331 back to its original position. The connecting frame 5336 is used to pull the connecting bar 5331 to rotate. At the beginning, the shape of the spiral beryllium copper wire 3 5337 does not change, and the lower wall surface at the bottom of the connecting bar 5331 contacts the circular piece 2 5335. The installation of the wedge surface 2 5338 requires that when the movable seat 5333 moves downward, it can pull the top of the connecting bar 5331 and the traction column 5332 to rotate around the rotation center toward the vertical center line of the connecting tube 531.

[0082] When the support block 3 is used, it is only necessary to make the connecting seat 2 5221 face the square groove 5313, and embed the upper connecting module 52 into the lower connecting module 53. When the bottom of the outer shell 522 and the circular strip 5317 are in contact, the outer shell 522 stops moving downward. At this time, the bottom of the inner column 521 and the circular piece 1 5334 are in contact, and the upper connecting module 52 is pressed downward. At this time, only the inner column 521 continues to move downward, and the traction movable seat 5333 presses the spiral beryllium copper wire 3 5337. During this period, the wedge surface 2 5338 presses one end of the bottom of the connecting strip 5331, so that the traction column 5332 is in contact with the inclined mouth 2 5334. 323 and the vertical center line of the downward connecting tube 531 in the connecting port 5316 change, and then the connecting sleeve 532 is pulled to rotate, and then the docking port 5322 and the U-shaped port 5224 are moved apart, so that the connecting sleeve 532 tightens the outer shell 522. When the inner column 521 is embedded to the bottom, the traction column 5332 is at one end of the vertical center line of the skewed port 5323 close to the connecting sleeve 532, and the wedge-shaped surface 1 5238 on the stop strip 5231 is pressed by the movable sheet 5222 and pressed into the constraint groove 5225, so as to achieve the purpose of tightening the inner column 521 and the outer shell 522. At this moment, the support block 3 is assembled. When changing the dressing, the brace block 3 is removed, and the upper connecting module 52 on the connecting piece 51 and the lower connecting module 53 on the brace block 3 are sequentially unlocked. It is only necessary to rotate the rotating shell 5234 to unlock the stop bar 5231 and the restraining groove 5225. Under the cooperation of the spiral beryllium copper wire 1 5223 and the spiral beryllium copper wire 3 5337, the inner column 521 moves toward the side farther from the lower connecting module 53, and the circular piece 2 5335 presses the bottom of the connecting strip 5331 to make the connecting strip 5331 return to its original position, and then pulls the connecting sleeve 532 back to its original position, so that the purpose of disassembling the upper connecting module 52 and the lower connecting module 53 can be achieved. The same action is performed on the remaining upper connection modules 52 in sequence, so that the purpose of disassembling the brace block 3 can be achieved, and then the dressing of the affected area can be changed. After applying the medicine, the brace block 3 can be assembled according to the above steps. There is no need to drill holes on the skin of the upper and lower ends of the limb or the fracture for fixation, which reduces the difficulty and risk of the operation. At the same time, the operation site can be isolated from the outside world, thereby reducing the risk of infection at the surgical incision. The entire external fixation brace is prepared by 3D printing, has a high aesthetics, and is convenient for daily work and life. The surgical incision is on the inner side of the brace, which is not easy to touch and is not easy to cause pain at the wound.

[0083] A method for preparing a 3D printed hollow external fixation brace comprises the following steps:

[0084] Step M1: Obtain medical imaging information of fracture and soft tissue injury sites;

[0085] Collect relevant medical imaging information of medical 3D printed personalized external fixation braces, which can be obtained through MRI or other three-dimensional imaging technologies.

[0086] Step M2: importing medical imaging information into a 3D reconstruction system to obtain a preliminary 3D model;

[0087] Open the 3D reconstruction system, select the "Import Image Information" function, and then follow the system prompts to import the medical image information into the system, pre-process the medical image information, including alignment and segmentation, to ensure data quality in preparation for 3D reconstruction. After the pre-processing is completed, start the 3D reconstruction. According to the system and algorithm used, generate a preliminary 3D model from the 2D image data. The preliminary 3D model needs to be further optimized and adjusted, including smoothing the surface, repairing holes, and optimizing the geometric structure to improve its quality. After completing the above steps, export the preliminary 3D model to stl or obj format for use in finite element analysis software, which involves saving the preliminary 3D model as a file and directly viewing it in the system or performing further analysis and processing.

[0088] Step M3: Perform biomechanical analysis of the preliminary three-dimensional model using the finite element method and according to the first strength theory;

[0089] The finite element analysis method comprises the following steps:

[0090] Step M31: Meshing, importing the preliminary three-dimensional model into finite element analysis software (such as ANSYS, ABAQUS), meshing the model. In principle, the meshing should be done with a suitable mesh type and size to ensure a balance between calculation accuracy and efficiency. If there is no problem after inspection, proceed to the subsequent steps. If there is a problem, re-mesh the model.

[0091] Step M32: Material property definition. Create a new material after importing the model and assign elastic modulus, Poisson's ratio and density. The values ​​are 2000MPa, 0.34 and 1.25e respectively. -9 T / mm 3 , these values ​​are the basic properties of PLA polylactic acid materials;

[0092] Step M33: Create and assign sections. Create a "shell" section with the type "mean". Select the area to which the interface is to be assigned. Select the entire model with the mouse in the window. Click Finish. Select the shell section created in the previous step as the section of the entire model. Fill in the thickness value of 4mm according to the actual size of the model.

[0093] Step M34: Set the load and boundary conditions. According to the actual use of the brace and based on biomechanical analysis, apply corresponding loads and boundary conditions to the outer surface of the brace, such as simulating the brace to be subjected to the gravity of the human body, the maximum single arm / leg force squeezing, etc. According to the description in "Study on the Maximum Strength Characteristics of Different Body Parts of Adult Male Residents in my country": the maximum upper limb strength is 148.9±29.0b, and the maximum single arm strength can be obtained to be approximately 33.77+6.58kg, and the maximum lower limb strength is 260.9b±53.2b, and the maximum single leg strength can be obtained to be approximately 59.53+12.06kg. In the analysis, this load is used for analysis to simulate the biomechanical environment of the actual use of the brace;

[0094] Step M34: Analysis and solution. After applying loads and setting boundary conditions on the model, create and set a static analysis step for analysis and simulation. Finally, create a new job, submit it and wait for the software to run and the results to be output.

[0095] After the calculation is completed, the obtained data can be analyzed in the result interface, mainly analyzing the calculated stress cloud map and displacement cloud map.

[0096] In the stress cloud diagram, the stress distribution of the model can be determined, and the location and magnitude of the maximum stress can be obtained. By comparing it with the yield strength of the material, it can be determined whether there is a risk of yield or failure, and whether the model has mechanical strength and stability.

[0097] The biomechanical analysis of the preliminary three-dimensional model according to the first strength theory is as follows:

[0098] The maximum tensile stress of the model in three directions is read from the finite element analysis results and compared with the tensile fracture strength of the material. This is used as the basis for determining whether the model is damaged. This type of analysis is more in line with the strength and damage of the model itself.

[0099] The maximum tensile stresses in the three directions are: the maximum tensile stress in the X direction is 8.897MPa, the maximum tensile stress in the Y direction is 5.648MPa, and the maximum tensile stress in the Z direction is 0 (because in this analysis the model is mainly under compression and there is no tension in the Z direction);

[0100] Depend on Fig.14 , Fig.15 and Fig.16 It can be seen that the maximum tensile stress in the three directions is less than the tensile fracture strength of the PLA material (40-60MPa), so the model will not be damaged under the action of the load, and the branch has mechanical strength and stability;

[0101] The failure form of the hollow brace printed with PLA is brittle failure, and the fourth strength theory is mainly aimed at the yield failure of materials, which is not suitable for the finite element analysis of brittle failure. Therefore, the first strength theory, namely the maximum tensile stress theory, which is a strength theory for brittle failure, is selected in the analysis process to improve the accuracy of the analysis results.

[0102] In the displacement cloud diagram, determine the distribution of model displacement, read the position and size of the maximum displacement, evaluate the deformation degree of the model based on the maximum displacement, and determine the impact of the generated deformation on the use function;

[0103] Reference Fig.11 , where the maximum displacement position is the bright area in the figure, that is, the proximal edge of the brace, and the maximum displacement is 10.89mm, which is less than 5% of the overall size of the brace and can be ignored. Therefore, the deformation of the brace under this load will not affect its use function;

[0104] In summary, the results of finite element analysis can verify the design safety, and the design model can be further optimized based on the results of finite element analysis.

[0105] Step M4: Based on biomechanical analysis, the preliminary three-dimensional model information of the 3D printed medical external fixation brace is updated to obtain a final three-dimensional model;

[0106] The biomechanical analysis comprises the following steps:

[0107] Step M41: Obtaining an optimization model, and obtaining an optimization model for biomechanical optimization design according to the finite element analysis results of the model under the conditions of step M3;

[0108] Step M42: Set the optimization response form. Set a single response or a combined response according to the required optimization content. In the optimization design used in this patent, the specific optimization type is "topology optimization". In order to ensure the accuracy of the overall model, choose to freeze the load area and boundary condition area of ​​the optimization model (that is, ensure that these two areas will not be optimized to cause changes in loads and boundary conditions);

[0109] Step M43: Setting optimization parameters. After obtaining the optimization model of the optimal design, the optimization parameters of the model should be specifically set. Based on the analysis of biomechanics, one or more specific parameters of the model, such as strain energy, strain, stress, volume and displacement, are constrained. For example, the optimization constraint is that the value change of strain energy is ≤ 150% of the strain energy under the initial value load, and the volume size optimization is ≥ 50% of the initial volume, so as to control the optimization result.

[0110] Step M44: Analysis and solution. After completing all optimization parameter settings for the model, submit and wait for the software to run and the final results to be output.

[0111] The optimization result is obtained based on the result of the finite element analysis before the optimization process in step M41 and the specific optimization parameter constraints in step M43, according to the model diagram before biomechanical optimization design and the model diagram after biomechanical optimization design. Fig.12 and Fig.13 The optimization result has greatly optimized the volume size of the model (mainly in thickness) while keeping the strain energy within the constraint value (i.e. ensuring that the model will not be damaged). This optimization makes the patented product more excellent in mechanical properties and further enhances the stability of the product. The optimized product has greatly reduced its volume and weight, and improved the use effect of the brace and the comfort of the patient.

[0112] On the basis of the biomechanical analysis in the above steps, the existing preliminary three-dimensional model data is used for the next step of analysis and design; the preliminary three-dimensional model data is processed and adjusted in the digital modeling software using the principle of 3D printing technology; the objects printed by the 3D printing process need to be simulated and analyzed in the modeling software, and the preliminary three-dimensional model data is adjusted according to the simulation results and the needs of biomechanical analysis, including changing the shape and structure of the brace to optimize the biomechanical properties and adaptability of the brace. After repeated simulation and adjustment, the three-dimensional model data of the brace is finally determined; this step needs to ensure that the model data meets all design requirements and can complete the preparation of the brace in the 3D printing equipment.

[0113] Step M5: performing layered slicing and printing path planning on the final 3D model;

[0114] First, import the final 3D model into the slicing software. After the model is imported, it needs to be adjusted, such as scaling, rotating or translating, to better adapt to the printing needs of the printer. Before starting slicing, it is necessary to set some basic printing parameters, such as printing temperature, layer height, wall thickness, and filling density. These parameters will affect the printing quality and printing time, so they need to be adjusted according to actual needs and printer performance. Then the model is layered. The software will divide the model from top to bottom into a series of layers. Each layer corresponds to the printing plane of the printer. The thickness of the layer is determined by the "layer height" in the printing parameters, because the rationality of the layering will directly affect the printing quality and printing efficiency. After the model is layered, the software will generate a printing path for each layer. These paths indicate how the printer should move when printing each layer, including when to move to a new position and when to fill. After generating the printing path, the software will optimize the printing path to improve printing efficiency and reduce printing errors. At the same time, users can preview the entire printing process to see if there is anything that needs to be adjusted. Finally, export the slice data to the printer GCODE format to obtain the final 3D model after processing.

[0115] Step M6: The processed final three-dimensional model is printed using polylactic acid printing consumables through a 3D printing process to obtain a brace body 1;

[0116] When printing begins, the printer prints out the brace layer by layer according to the final three-dimensional model after processing; during the 3D printing process, it is necessary to set conventional printing parameters such as filling density, layer height, wall thickness, printing temperature, etc., which affect the final shape and performance of the brace; after printing is completed, the brace body 1 is obtained; finally, the brace body 1 is quality inspected, including the inspection of the shape of the brace body 1 and the measurement of the size, and the qualified brace is used for external fixation of the affected part.

[0117] Step M7: Print the brace block 3 by 3D printing process according to the specifications of the medicine port 2, then print the pillar 4 on the brace block 3, then print the components of the connector 5, and then assemble the components into an upper connector module 52 and a lower connector module 53, and then adhere the lower connector module 53 and the connector piece 51 to the brace body 1 and the pillar 4 respectively. Finally, assemble the brace body 1 and the brace block 3 together through the upper connector module 52 and the lower connector module 53.

[0118] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A 3D printed hollow external fixation brace, comprising a brace body (1), characterized in that: The brace body (1) is provided with a medicine-applying opening (2), a brace block (3) is arranged in the medicine-applying opening (2), a plurality of pillars (4) are fixedly connected to the outer side of the brace block (3), and the pillars (4) are connected to the brace body (1) via a connecting piece (5); The connecting member (5) comprises a connecting piece (51), an upper connecting module (52) and a lower connecting module (53); The upper connection module (52) is installed on the connection piece (51), and the upper connection module (52) comprises an inner column (521), an outer shell (522) and a stop unit (523), wherein the inner column (521) is installed in the outer shell (522), and the stop unit (523) is installed in the inner column (521); The lower connecting module (53) is mounted on the brace body (1), and the lower connecting module (53) comprises a lower connecting cylinder (531), a connecting sleeve (532) and a traction unit (533); the lower connecting cylinder (531) is mounted on the outer wall surface of the brace body (1), the connecting sleeve (532) is mounted in the lower connecting cylinder (531), and the connecting sleeve (532) is mounted above the traction unit (533); A connecting seat (511) is arranged around the connecting piece (51); The two ends of the inner column (521) pass through the connecting seat 1 (511), and the inner column (521) is reserved with a strip groove (5211), a through-port (5212), a channel 1 (5213), a channel 2 (5214) and a channel 3 (5215). The strip groove (5211) is reserved on both sides of the inner column (521), and the through-port (5212) intersects with the vertical center line of the inner column (521). The two ends of the through-port (5212) respectively pass through Corresponding to the strip-shaped groove (5211), the lower end of the through-opening (5212) reserves a second channel (5214), the first channel (5213) is reserved between the through-opening (5212) and the second channel (5214), the first channel (5213) connects the through-opening (5212) and the second channel (5214), the third channel (5215) is reserved on the side of the inner column (521), and the third channel (5215) and the second channel (5214) are connected to each other; The outer shell (522) is provided with a second connecting seat (5221), a movable sheet (5222) and a spiral beryllium copper wire (5223); the second connecting seat (5221) is provided on both sides of the outer shell (522); the movable sheet (5222) is provided on both sides of the inner shell (522); the movable sheet (5222) and the strip groove (5211) are movably connected; the spiral beryllium copper wire (5223) is provided between the outer shell (522) and the first connecting seat (511); a U-shaped opening (5224) is reserved on the second connecting seat (5221); and a restraining groove (5225) is reserved on the movable sheet (5222).

2. A 3D printed hollow external fixation brace according to claim 1, characterized in that: The stop unit (523) comprises a stop bar (5231), a movable column (5232), a rotating disc (5233), a rotating shell (5234) and a second spiral beryllium copper wire (5235); the stop bar (5231) and the through hole (5212) are movably connected; the movable column (5232) and the first channel (5213) are movably connected; the rotating disc (5233) and the second channel (5214) are screwed together; the inner wall surface of the rotating shell (5234) and the inner column (521) are screwed together; and the second spiral beryllium copper wire (5235) is arranged between a pair of stop bars (5231); The end of the stop bar (5231) that is farther from the spiral beryllium copper wire (5235) reserves a wedge-shaped surface (5238).

3. A 3D printed hollow external fixation brace according to claim 2, characterized in that: The rotating disc (5233) is provided with an inclined opening 1 (5236) and a connecting rod (5237); the inclined opening 1 (5236) is reserved on the rotating disc (5233); the inclined opening 1 (5236) and the movable column (5232) are movably connected; the connecting rod (5237) and the channel 3 (5215) are movably connected; the rotating disc (5233) and the rotating shell (5234) are connected via the connecting rod (5237).

4. A 3D printed hollow external fixation brace according to claim 3, characterized in that: The lower connecting tube (531) is provided with cavity one (5311), cavity two (5312), a square groove (5313), a circular groove (5314), a strip-shaped opening (5315), a connection opening (5316) and a circular strip (5317); the cavity one (5311) is reserved at an end of the lower connecting tube (531) close to the upper connecting module (52); the cavity two (5312) is reserved at an end of the lower connecting tube (531) far from the upper connecting module (52); the cavity one (5311) and the cavity two (5312) are connected to each other; the circular strip (5317) is arranged at At the position where cavity one (5311) and cavity two (5312) are connected, the square groove (5313) is reserved on the inner wall of cavity one (5311), the square groove (5313) and connecting seat two (5221) are adapted to each other, the annular groove (5314) is reserved in the inner wall of the lower connecting tube (531), the annular groove (5314) and the square groove (5313) are connected to each other, and the strip opening (5315) is reserved on the inner wall of cavity two (5312), and the annular groove (5314) and the strip opening (5315) are connected via the connecting opening (5316).

5. A 3D printed hollow external fixation brace according to claim 4, characterized in that: The connecting sleeve (532) and the annular groove (5314) are screwed together, and a circular opening (5321), a docking opening (5322) and a second skewed opening (5323) are reserved on the connecting sleeve (532). The circular opening (5321) is reserved in the middle of the connecting sleeve (532), the docking opening (5322) is reserved on both sides of the circular opening (5321), and the second skewed opening (5323) is reserved on the connecting sleeve (532).

6. A 3D printed hollow external fixation brace according to claim 5, characterized in that: The traction unit (533) comprises a connecting strip (5331), a traction column (5332) and a movable seat (5333); the middle of the connecting strip (5331) is screwed to the side wall of the strip-shaped opening (5315); the bottom of the connecting strip (5331) passes through the strip-shaped opening (5315); the traction column (5332) is installed on the top of the connecting strip (5331); the traction column (5332) passes through the connecting opening (5316) and the second skewed opening (5323); and the movable seat (5333) and the second cavity (5312) are movably connected.

7. A 3D printed hollow external fixation brace according to claim 6, characterized in that: The movable seat (5333) is provided with a circular sheet 1 (5334), a circular sheet 2 (5335), a connecting frame (5336) and a spiral beryllium copper wire 3 (5337); the circular sheet 1 (5334) is arranged at one end of the movable seat (5333) close to the upper connecting module (52); the circular sheet 2 (5335) is arranged below the circular sheet 1 (5334); the connecting frame (5336) is arranged between the circular sheet 1 (5334) and the circular sheet 2 (5335); the spiral beryllium copper wire 3 (5337) is arranged between the circular sheet 2 (5335) and the bottom wall of the cavity 2 (5312); a wedge-shaped surface 2 (5338) is reserved on the side wall of the connecting frame (5336); the wedge-shaped surface 2 (5338) contacts the side wall of the bottom of the connecting strip (5331).

8. A method for preparing a 3D printed hollow external fixation brace, comprising the 3D printed hollow external fixation brace according to claim 1, characterized in that: It also includes the following steps: Step M1: Obtain medical imaging information of fracture and soft tissue injury sites; Step M2: importing medical imaging information into a 3D reconstruction system to obtain a preliminary 3D model; Step M3: Perform biomechanical analysis of the preliminary three-dimensional model using the finite element method and according to the first strength theory; Step M4: Based on biomechanical analysis, the preliminary three-dimensional model information of the 3D printed medical external fixation brace is updated to obtain a final three-dimensional model; Step M5: performing layered slicing and printing path planning on the final 3D model; Step M6: The processed final three-dimensional model is printed using polylactic acid printing consumables through a 3D printing process to obtain a brace body (1); Step M7: Print the brace block (3) by 3D printing process according to the specifications of the medicine port (2), then print the pillar (4) on the brace block (3), then print the components of the connecting piece (5), and then assemble the components into an upper connecting module (52) and a lower connecting module (53), and then adhere the lower connecting module (53) and the connecting piece (51) to the brace body (1) and the pillar (4), respectively. Finally, assemble the brace body (1) and the brace block (3) together through the upper connecting module (52) and the lower connecting module (53).

9. The method for preparing a 3D printed hollow external fixator according to claim 8, characterized in that: The finite element analysis method in step M3 comprises the following steps: Step M31: meshing, importing the preliminary three-dimensional model into finite element analysis software to mesh the model; Step M32: material property definition, create a new material after importing the model, and assign elastic modulus, Poisson's ratio and density; Step M33: Create and assign sections; Step M34: setting loads and boundary conditions, and applying corresponding loads and boundary conditions to the outer surface of the brace according to the actual use of the brace and based on biomechanical analysis; Step M35: Analysis and solution. After applying loads and setting boundary conditions on the model, create and set a static analysis step for analysis and simulation. Finally, create a new job, submit it and wait for the software to run and the results to be output.

10. The method for preparing a 3D printed hollow external fixator according to claim 9, characterized in that: The biomechanical analysis in step M4 comprises the following steps: Step M41: Obtaining an optimization model, and obtaining an optimization model for biomechanical optimization design according to the finite element analysis results of the model under the conditions of step M3; Step M42: Setting the optimization response form, setting a single response or a combined response according to the required optimization content; Step M43: Setting optimization parameters and setting the optimization parameters in detail. After obtaining the optimization model of the optimal design, the optimization parameters of the model need to be specifically set; Step M44: Analysis and solution. After completing all optimization parameter settings for the model, submit and wait for the software to run and the final results to be output.

Images