CN115570787A

CN115570787A - On-site 3D printing device and printing method

Info

Publication number: CN115570787A
Application number: CN202211301001.0A
Authority: CN
Inventors: 邵惠锋; 朱佳华; 张涛; 黄智强; 史金元; 年志恒; 景卓荦; 龚友平
Original assignee: Hangzhou Dianzi University
Current assignee: Hangzhou Dianzi University
Priority date: 2022-10-24
Filing date: 2022-10-24
Publication date: 2023-01-06

Abstract

The invention discloses an on-site 3D printing device suitable for repairing an invagination defect of a bone, which comprises a rack, a three-degree-of-freedom motion platform, a multi-degree-of-freedom suspension movable arm, an extrusion printing mechanism, a scanning mechanism and a surgical bed vehicle, wherein the three-degree-of-freedom motion platform is installed at the top of the rack, the multi-degree-of-freedom suspension movable arm is installed on the three-degree-of-freedom motion platform, the extrusion printing mechanism is installed on the multi-degree-of-freedom suspension movable arm, the scanning mechanism is installed at the middle end of the rack, and the rack is installed on the surgical bed vehicle. The device can accomplish to carry out on-line scanning to the disease wound, utilizes the parcel to print the technique and restores the printing to the bone defect, and the process is succinct, does not need too much manpower, can also accomplish the defective printing problem of irregular caved-in bone.

Description

On-site 3D printing device and printing method

Technical Field

The invention relates to the technical field of medical equipment, in particular to an on-site 3D printing device and method suitable for repairing an invagination defect of a bone.

Background

Bone defect is a common orthopedic disease, the causes of which are various, thus the sizes and the serious conditions of the bone defect shapes are different, the complicated and changeable disease conditions make the clinical treatment very difficult, and the clinical treatment is usually accompanied by various problems such as long treatment period, large surgical wound, various complicating diseases and the like. When the traditional repair operation is carried out, the shape of the bone defect needs to be scanned, and then the obtained image needs to be analyzed and processed by professional personnel for modeling. After the model is established, the artificial bone is prepared in vitro, then the doctor repeatedly prunes the model according to the experience and the judgment of the wound shape of the patient, and then the model is matched with the patient after pruning. The whole process is tedious, the operation cycle is long, too much manpower is needed, the precision cannot be guaranteed, the treatment effect is poor, the flow needs to be carried out again, the materials and the time are wasted, and secondary trauma can be brought to patients.

Disclosure of Invention

According to the defects of the prior art, the invention provides the on-site 3D printing device and the printing method, so that the wound of a patient can be scanned on line, the bone defect can be repaired and printed by using a package printing technology, the process is simple, too much labor is not needed, and the printing problem of the irregular invaginated bone defect can be solved.

In order to solve the technical problems, the technical scheme of the invention is as follows:

the utility model provides an on-spot 3D printing device, includes frame, three degree of freedom motion platform, multi freedom hangs the digging arm, extrudes printing mechanism, scanning mechanism and operation bed car, three degree of freedom motion platform installation is at the frame top, multi freedom hangs on the digging arm installation three degree of freedom motion platform, extrude printing mechanism and install on multi freedom hangs the digging arm, scanning mechanism installs in the frame middle-end, on the frame mounting operation bed car.

Preferably, the three-degree-of-freedom motion platform comprises a longitudinal linear motor module, a transverse linear motor module and a short vertical short linear module, the longitudinal linear motor module is arranged at the top of the frame in parallel, a longitudinal sliding block is arranged on the longitudinal linear motor module in a sliding manner, two longitudinal sliding blocks are fixed at two ends of the transverse linear motor module, a transverse sliding block is arranged on the transverse linear motor module in a sliding manner, the vertical short linear module is fixedly arranged on the transverse sliding block, a vertical sliding block is arranged on the vertical short linear module in a sliding manner, and the multi-degree-of-freedom suspension movable arm is arranged on the vertical sliding block.

Preferably, the longitudinal linear motor module comprises a servo motor, a transmission belt and a slide rail, the longitudinal sliding block is slidably mounted on the slide rail, the servo motor is arranged at one end of the slide rail, the other end of the slide rail is provided with a rolling shaft, the transmission belt is wound on an output shaft and the rolling shaft of the servo motor, the transmission belt is fixedly connected with the longitudinal sliding block, and the transverse linear motor module and the short vertical short linear module are identical in structure to the longitudinal linear motor module.

Preferably, the multi-degree-of-freedom suspension movable arm comprises a first connecting rod, a first air cylinder, a second connecting rod, a second air cylinder and a third connecting rod, wherein one end of the first connecting rod is fixedly installed on the vertical sliding block, the other end of the first connecting rod is hinged to the top end of the second connecting rod through a hinge, the top of the first air cylinder is fixedly connected to the middle position of the first connecting rod, the power output end of the first air cylinder is hinged to the middle position of the second connecting rod through the hinge, the top end of the third connecting rod is hinged to the bottom end of the second connecting rod, the top of the second air cylinder is fixedly installed on the second connecting rod, the power output end of the second air cylinder is hinged to the third connecting rod through the hinge, and the extrusion printing mechanism is installed at the bottom end of the third connecting rod.

As preferred, scanning mechanism includes position control mechanism and image acquisition unit, position control mechanism includes sharp module, first motor, gear wheel, pinion, ball screw and screw-nut slider, two straight line module parallel arrangement is in the middle part position of frame, the structure of sharp module is the same with vertical linear motor module, sliding connection has link block, two on the sharp module the opposite side of link block is fixed respectively and is provided with first connecting plate, two horizontal installation has fixed long plate between the first connecting plate, the upper surface at fixed long plate is installed to first motor, ball screw is located the below of fixed long plate, and ball screw's both ends pass through swivel bearing rotatable coupling to two first connecting plates, the gear wheel is fixed to be set up the output at first motor, pinion fixed mounting is on ball screw, gear wheel and pinion intermeshing, screw-nut slider threaded connection is on ball screw, the image acquisition unit is installed on screw-nut slider.

Preferably, the image acquisition unit comprises a binocular camera and a grating projector, the binocular camera is installed on the screw nut slider, a telescopic support is arranged on the side wall of the screw nut slider, the grating projector is installed on the telescopic support through a two-degree-of-freedom connecting piece, and the grating projector is matched with the binocular camera.

Preferably, the bottom end of the third link is provided with a universal connector, and the extrusion printing mechanism is mounted to the bottom end of the third link through the universal connector.

As preferred, universal joint includes second connecting plate, spherical gear, mount pad and actuating mechanism, one side center department fixed connection of second connecting plate is to the bottom of third connecting rod, two the mount pad is symmetrical structure and installs the meso position at second connecting plate opposite side, spherical gear installs between two mount pads, two actuating mechanism is symmetrical structure and sets up in spherical gear both sides, actuating mechanism is including fixing motor mounting panel, the box fixing base on the second connecting plate, install the slewing gear box on the box fixing base, be provided with drive mechanism in the slewing gear box, install the second motor on the motor mounting panel, the second motor passes through drive mechanism power output to spherical gear, extrude the fixed surface that sets up at spherical gear of printing mechanism.

As preferred, drive mechanism includes monopole gear, transition straight-toothed gear, little straight-toothed gear, second bevel gear, first bevel gear and slew bearing, second bevel gear fixed mounting is at the output of second motor, first bevel gear passes through the connecting axle and installs the inner wall at the slew gear box, first bevel gear and second bevel gear intermeshing, little straight-toothed gear and the coaxial setting of first bevel gear, the transition gear passes through the rotatable installation of connecting axle in the slew gear box, little straight-toothed gear and transition gear meshing, the transition gear passes through slew bearing power transmission straight monopole gear, unipolar gear meshing to spherical gear.

The invention also provides a field 3D printing method, which comprises the following steps:

1) A target bone defect patient lies on the operating bed trolley, a binocular camera and a grating projector on the scanning mechanism are driven by a linear motor module and a lead screw nut slide block to reach the position above the bone defect position of the patient, then pose adjustment of the binocular camera and the grating projector is completed by a two-degree-of-freedom connecting piece and a telescopic device, a binocular imaging area and a projection area are overlapped, scanning and imaging are complete, the bone defect shape is scanned through binocular stereo vision, the obtained data is transmitted to a computer for 3D modeling, and a three-dimensional model of the bone defect shape is established after the scanning data is analyzed and processed by the computer;

2) Carrying out layered slicing processing on the entity data of the model through layered software to form corresponding codes, inputting the corresponding codes into a 3D printing device, and then printing the codes in real time by an extrusion printing device;

3) The three-freedom-degree motion platform drives the multi-freedom-degree suspension movable arm to reach the position of the bone defect part of the patient through three-dimensional motion, then three connecting rods of the multi-freedom-degree suspension movable arm are driven by two cylinders to move relatively to drive the extrusion printing device to achieve a more accurate and proper pose, then the extrusion printing device starts to work, the spherical gear part connected with the extrusion printing device can rotate at any angle according to the function of the spherical gear part, so that the extrusion printing device can print in multiple directions, and the repair printing of the complex bone defect shape is completed.

The invention has the following characteristics and beneficial effects:

according to the on-site 3D printing device for repairing the defect of the invaginated bone, the extrusion printing device is driven by the spherical gear joint to move, so that the direction of the printing needle tube can be changed according to the actual printing requirement, the limitation of the traditional printing is solved, and the difficulty that the printing cannot be carried out on the defect of a hole on the side surface is solved.

The method of the invention is simple, easy to operate and low in cost, the whole structure adopts a double-layer duplex structure, the scanning module and the printing module are positioned on different motion planes, and the movement of each part of the equipment is very flexible. The multi-degree-of-freedom suspension movable arm has enough movement space on the plane, and cannot interfere with the movement of the scanning module, the requirement of any space movement of the printing head can be met by using the multi-degree-of-freedom suspension movable arm mechanism, and the six-degree-of-freedom mechanical arm with higher use cost can be avoided to achieve corresponding effect.

When the device is applied to a bone defect repair operation, 3D printing can be carried out in real time according to the field state, the operation period is helped, and the device can be adjusted according to the field condition, so that the success rate of the operation is effectively improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an on-site 3D printing apparatus of the present invention.

Fig. 2 is a schematic mechanism diagram of the three-degree-of-freedom motion platform of the present invention.

Fig. 3 is a schematic diagram of the mechanism of the multi-degree-of-freedom suspension movable arm of the invention.

Fig. 4 is a mechanism diagram of the scanning mechanism of the present invention.

Fig. 5 is another view structure diagram of fig. 4.

Fig. 6 is a schematic structural view of a spherical gear joint of the present invention.

Fig. 7 is a schematic structural view of the extrusion printing apparatus of the present invention.

FIG. 8 is a flow chart illustrating the present invention method of printing in situ.

Fig. 9 is a diagram showing a printing example of the on-site 3D printing apparatus according to the present invention.

In the figure: 1-a frame, 2-a three-freedom-degree motion platform, 3-a three-freedom-degree suspension movable arm, 4-a scanning mechanism, 5-an extrusion printing mechanism, 6-a surgical bed trolley, 7-a longitudinal linear motor module, 8-a transverse linear motor module, 9-a vertical short linear module, 10-a first connecting rod, 11-a first cylinder, 12-a second connecting rod, 13-a third connecting rod, 14-a second cylinder, 15-a first motor, 16-a large gear, 17-a linear module, 18-a first connecting plate, 19-a fixed long plate, 20-a small gear, 21-a ball screw, 22-a screw nut slide block, 23-a binocular camera and 24-a grating projector, 25-two-degree-of-freedom connecting piece, 26-telescopic bracket, 27-spherical gear, 28-single-pole gear, 29-transition straight gear, 30-small straight gear, 31-second bevel gear, 32-first bevel gear, 33-rotary gear box body, 34-rotary bearing, 35-mounting seat, 36-box body fixing seat, 37-motor mounting plate, 38-second motor, 39-second connecting plate, 40-light connecting piece, 41-penetrating motor, 42-printing cylinder bottom cover, 43-printing cylinder, 44-fourth bevel gear, 45-third bevel gear, 46 small shaft, 47-fourth connecting rod, 48-fifth connecting rod, 49-piston and 50-printing nozzle.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referred device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The invention provides an on-site 3D printing device, which comprises a rack 1, a three-degree-of-freedom motion platform 2, a multi-degree-of-freedom suspension movable arm 3, an extrusion printing mechanism 5, a scanning mechanism 4 and an operating bed trolley 6, wherein the three-degree-of-freedom motion platform is connected with the rack 1 through a connecting rod; the three-degree-of-freedom motion platform 2 is arranged at the upper end of the frame 1; the multi-degree-of-freedom suspension movable arm 3 is arranged on the three-degree-of-freedom motion platform 2; the extrusion printing mechanism 5 is arranged on the multi-degree-of-freedom suspension movable arm 3; the scanning mechanism 4 is arranged at the middle end of the frame 1; the operation bed vehicle 6 is fixed at the bottom of the frame 1.

Among the above-mentioned technical scheme, can accomplish to carry out on-line scanning to the disease wound, utilize parcel printing technique to restore the printing to the defective scene situation of bone.

In a further configuration of the present invention, as shown in fig. 2, the three-degree-of-freedom motion platform 2 includes longitudinal linear motor modules 7 installed on two sides of the rack, a transverse linear motor module 8 installed on the longitudinal linear motor module 7, and a vertical short linear module 9 installed on the transverse linear motor module 8. The servo motors of the longitudinal linear motor modules 7 on the two sides are started, the self rotary motion is converted into linear motion to drive the transverse linear motor module 8 to complete the longitudinal motion, similarly, the transverse linear motor module 8 drives the vertical short linear module 9 to complete the transverse motion, and the vertical short linear module 9 can drive the multi-degree-of-freedom suspension movable arm 3 arranged on the vertical short linear module to complete the vertical up-and-down motion. Therefore, the multi-degree-of-freedom suspension movable arm 3 can complete simple three-dimensional motion.

Specifically, the longitudinal linear motor module comprises a servo motor, a transmission belt and a slide rail, the longitudinal sliding block is slidably mounted on the slide rail, the servo motor is arranged at one end of the slide rail, the other end of the slide rail is provided with a rolling shaft, the transmission belt is wound on an output shaft and the rolling shaft of the servo motor, the transmission belt is fixedly connected with the longitudinal sliding block, and the transverse linear motor module and the short vertical short linear module are identical in structure to the longitudinal linear motor module.

In this embodiment, other structures are applicable to convert the rotational motion of the device itself into the linear motion.

Further, as shown in fig. 3, the multi-degree-of-freedom suspension movable arm 3 includes a first connecting rod 10 installed on the above three-degree-of-freedom motion platform 2, a first cylinder 11 installed on the first connecting rod 10, a second connecting rod 12 hinged to the first cylinder 11, a second cylinder 14 installed on the second connecting rod 12, a third connecting rod 13 hinged to the second cylinder 14, a second connecting plate 18 installed on the third connecting rod 13, an installation seat 35 installed on the connecting plate 39, a spherical gear 27 installed on the installation seat 35, a single-stage gear 28 engaged with the spherical gear 27, a transition spur gear 29 engaged with the single-stage gear 28, a small spur gear 30 engaged with the transition spur gear 29, a first bevel gear 32 coaxially connected with the small spur gear 30, a second bevel gear 31 engaged with the first bevel gear 32, a rotary gear box 33 fixedly connected with the second bevel gear 31, a motor 37 installed on the box 36, and a motor 38 installed on the installation seat 36.

In the above technical solution, the first cylinder 11 can drive the second connecting rod 12 and the first connecting rod 10 to move relatively to realize bending, the second cylinder 14 drives the third connecting rod 13 and the second connecting rod 12 to move relatively to complete bending, meanwhile, the third connecting rod 13 drives the second connecting plate 18, the second connecting plate 18 drives the mounting seat 35, the mounting seat 35 drives the spherical gear 27 to complete two-dimensional movement on the XOZ plane, the motor 38 drives the bevel gear No. two 31 and the rotary gear box 33 to rotate synchronously, the bevel gear No. two 31 drives the bevel gear No. one 32 to perform meshing transmission, the bevel gear No. one 32 drives the small spur gear 30 to perform coaxial transmission, the small spur gear 30 drives the transition spur gear 29 to perform meshing transmission, the transition spur gear 29 drives the single-pole gear 28 to perform meshing transmission, the rotary gear box 33 drives the single-pole gear 28 to perform synchronous rotation, and the single-pole gear 28 drives the spherical gear 27 to perform meshing transmission and rotation.

Further, as shown in fig. 7, the extrusion printing mechanism 5 includes a light connecting member 40 mounted on the spherical gear 27, a printing cylinder bottom cover 42 fixed on the light connecting member 40, a through motor 41 mounted on the printing cylinder bottom cover 42, a third bevel gear 45 mounted on an output shaft of the through motor 41, a fourth bevel gear 44 engaged with the third bevel gear 45, a small shaft 46 fixed in the fourth bevel gear 44, a fourth connecting rod 47 connected with the small shaft 46, a fifth connecting rod 48 hinged with the fourth connecting rod 47, a piston 49 hinged with the fifth connecting rod 48, an extrusion printing cylinder 43 engaged with the piston 49, and a nozzle 50 mounted on the extrusion printing cylinder 43.

The motor 41 drives the third bevel gear 45 to operate, the third bevel gear 45 drives the fourth bevel gear 44 and the small shaft 46 to rotate, the small shaft 46 drives the fourth connecting rod 47 to do circular motion, the fourth connecting rod 47 drives the fifth connecting rod 48 to move, the fifth connecting rod 48 drives the piston 49 to do linear motion, and the piston 49 extrudes and prints the slurry from the needle tube of the printing head 50.

As shown in fig. 4 and 5, the scanning mechanism 4 of the present invention further includes linear motor modules 17 mounted on two sides of the frame, a first connecting plate 18 mounted on the linear motor modules 17, a motor fixed long plate 19 mounted on the first connecting plate 18, a motor 15 mounted on the motor fixed long plate 19, a large spur gear 16 mounted on an output shaft of the motor 15, a small spur gear 20 engaged with the large spur gear 16, a ball screw 21 fixedly connected to the small spur gear 20, a screw nut slider 22 engaged with the ball screw 21, a two-degree-of-freedom connecting member 25 and a telescopic device 26 mounted on the screw nut slider 22, a binocular camera 23 mounted on the two-degree-of-freedom connecting member 25, and a grating projector 24 mounted on the telescopic device 26.

The servo motors of the linear motor modules 17 on the two sides drive the ball screw 21 and the screw nut slide block 22 to move longitudinally, the motor 15 drives the ball screw 21 to rotate, the ball screw 21 drives the screw nut slide block 22 to move transversely, the screw nut slide block 22 drives the binocular camera 23 and the grating projector 24 to move transversely, the telescopic device 26 drives the grating projector 24 to move horizontally to adjust the horizontal distance between the telescopic device and the binocular camera 23, and the two-degree-of-freedom connecting piece 25 can drive the binocular camera 23 and the grating projector 24 to complete two-degree-of-freedom spatial deflection to adjust the scanning and projection range coincidence and scanning dead angles.

In the technical scheme, the scanning mechanism 4 at the middle end of the rack drives the binocular camera 23 and the grating projector 24 to move to the bone defect part of a patient through the linear motor and the ball screw slide block 22, the arrangement of the position angles of the binocular camera 23 and the grating projector 24 is completed through the two-degree-of-freedom connecting piece 25 and the telescopic device 26, the binocular imaging area and the projection area are overlapped, the bone defect shape is scanned through binocular stereo vision, and modeling is performed. The obtained data is processed by a computer to be sliced, information is transmitted to the multi-freedom-degree suspension movable arm 3, meanwhile, the multi-freedom-degree suspension movable arm 3 is moved to the position above the defect part of the patient bone by the three-freedom-degree motion platform 2, then the multi-freedom-degree suspension movable arm 3 drives the extrusion printing device 5 to be adjusted to the position capable of being accurately printed according to the scanned data through the spherical gear joint, finally, the extrusion printing device 5 starts to work, and meanwhile, the multi-freedom-degree suspension movable arm 3 is matched with the extrusion printing device 5 in real time until the printing is completed.

The invention provides a field 3D printing method suitable for repairing an invaginated bone defect, which adopts a field 3D printing device and comprises the following steps as shown in figure 8:

1) A target bone defect patient lies on the operating bed vehicle 6, a binocular camera 23 and a grating projector 24 on the scanning mechanism 4 move to the position above the bone defect position of the patient through a two-dimensional plane of a linear motor module 17 and a screw nut slide block 22, then the accurate adjustment of the poses of the binocular camera 23 and the grating projector 24 is completed through the space rotation of a two-degree-of-freedom connecting piece 25 and a telescopic device 26, so that a binocular imaging area and a projection area are coincided, the bone defect shape is scanned through binocular stereo vision, the obtained data is transmitted to a computer for 3D modeling, and a three-dimensional model of the bone defect shape is established after the analysis processing of the scanned data by the computer;

2) The three-degree-of-freedom motion platform 2 drives the multi-degree-of-freedom suspension movable arm 3 to move above a target bone defect through the motion of an xyz shaft, transmits three-dimensional model data of the shape of the bone defect established by the scanning mechanism 4 into layering software for layering and slicing processing, forms a corresponding code and inputs the code into a printing device;

3) The multi-degree-of-freedom suspension movable arm 3 starts to work according to codes: firstly, according to the defect position and the model height, the initial printing height is accurately adjusted through the rotation of three connecting rods driven by an air cylinder, then, a spherical gear joint at the tail end of a multi-freedom-degree suspension movable arm 3 works to drive an extrusion printing device 5 to rotate and adjust to a vertical printing posture, then, printing is started according to three-dimensional model data, conventional printing is carried out, when an invagination defect is met, an extrusion printing mechanism is driven by the spherical joint to rotate and adjust to an optimal printing posture to print the internal defect, when an extrusion printing needle tube 50 is about to contact with the upper edge of the defect, the multi-freedom-degree suspension movable arm 3 outwards displaces a defect space through a three-freedom-degree motion platform 2, then, the spherical gear joint at the tail end of the multi-freedom-degree suspension movable arm 3 works to rotate the extrusion printing device 5 for 90 degrees and then form a horizontal direction, then, the air cylinder drives the connecting rods to rotate to enable the extrusion printing device to be lifted upwards to a horizontal printing height, meanwhile, the extrusion printing device is in a position higher than a previous printing structure, then, the multi-freedom-degree suspension movable arm 3 drives the extrusion printing device 5 to slowly move into the defect in the horizontal direction, and then, the subsequent printing is carried out, and the subsequent printing is carried out until the subsequent needle tube printing is completed.

In step 3), the slurry is bio-ink that can be extruded, such as bio-ink formed by mixing polyvinyl alcohol and ceramic powder in proportion, or other liquid that can be extruded.

In practical applications, the following embodiments are provided in combination with the 3D printing apparatus and the printing method

Example (b):

preparation of the biomaterial of this example: as an example of a three-dimensional structure formed by mixing polyvinyl alcohol and magnesium-doped calcium silicate powder, a polyvinyl alcohol solution (5.1 g) was prepared in an amount of 6 wt%, and calcium silicate powder (4 g) was uniformly mixed.

As shown in fig. 1-8, the procedure for repairing the bone defect shown in fig. 9 is as follows:

step 1, a target bone defect patient lies on the operating bed trolley, a binocular camera and a grating projector on a scanning mechanism achieve the position above the bone defect position of the patient through two-dimensional plane motion of a linear motor module and a screw nut slide block, then accurate adjustment of poses of the binocular camera and the grating projector is completed through space rotation of a two-degree-of-freedom connecting piece and a telescopic device, a binocular imaging area is enabled to be coincident with a projection area, the bone defect shape is scanned through binocular stereo vision, obtained data are transmitted to a computer for 3D modeling, a three-dimensional model of the bone defect shape is established after analysis processing of the scanned data is conducted through the computer, meanwhile, a three-degree-of-freedom motion platform drives a multi-freedom suspension movable arm to reach the position above the target bone defect through xyz shaft motion, three-dimensional model data of the bone defect shape established by the scanning mechanism are transmitted into layering software for layering slicing processing, corresponding codes are formed and input into an extrusion printing device;

and 2, starting the multi-degree-of-freedom suspension movable arm to work according to the codes: firstly, accurately adjusting initial printing height through rotation of three connecting rods driven by a cylinder according to a defect position and a model height, then driving an extrusion printing device to rotate and adjust to a vertical printing posture through a spherical gear joint at the tail end of a multi-degree-of-freedom suspension movable arm, and then starting to print each block area divided according to three-dimensional model data and finishing a part of preliminary block printing, as shown in FIG. 9A;

step 3, driving the extrusion printing device to move to the next block area (the wall surface is concave) by the multi-degree-of-freedom suspension movable arm, driving the extrusion printing device to rotate by a certain angle by the spherical gear to achieve the optimal printing posture, and then continuing extrusion printing, as shown in fig. 9B;

step 4, when the remaining defect part is in quick contact with the extrusion printing device, the multi-degree-of-freedom suspension movable arm drives the extrusion printing device to move out by a specified distance, the spherical gear drives the extrusion printing device to rotate to a horizontal pose, and then the printing work of the part is started, as shown in fig. 9C;

and 5, driving the extrusion printing device to move to the next area by the multi-degree-of-freedom suspension movable arm, rotating the spherical gear by a certain angle according to the data to enable the extrusion printing device to be perpendicular to the printing area (the optimal printing position), and printing again, wherein as shown in fig. 9D, all parts of the on-site 3D printing device for repairing the defect of the invaginated bone return to the initial positions and stop working after printing is completed.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments, including components thereof, without departing from the principles and spirit of the invention, and still fall within the scope of the invention.

Claims

1. The field 3D printing device is characterized by comprising a rack, a three-degree-of-freedom motion platform, a multi-degree-of-freedom suspension movable arm, an extrusion printing mechanism, a scanning mechanism and a surgical bed trolley, wherein the three-degree-of-freedom motion platform is installed at the top of the rack, the multi-degree-of-freedom suspension movable arm is installed on the three-degree-of-freedom motion platform, the extrusion printing mechanism is installed on the multi-degree-of-freedom suspension movable arm, the scanning mechanism is installed at the middle end of the rack, and the rack is installed on the surgical bed trolley.

2. The on-site 3D printing device according to claim 1, wherein the three-degree-of-freedom motion platform comprises a longitudinal linear motor module, a transverse linear motor module and a short vertical short linear module, the two longitudinal linear motor modules are arranged on the top of the frame in parallel, a longitudinal slide block is slidably mounted on the longitudinal linear motor module, two longitudinal slide blocks are fixed at two ends of the transverse linear motor module, a transverse slide block is slidably mounted on the transverse linear motor module, the vertical short linear module is fixedly mounted on the transverse slide block, a vertical slide block is slidably mounted on the vertical short linear module, and the multi-degree-of-freedom suspension movable arm is mounted on the vertical slide block.

3. The on-site 3D printing device according to claim 1, wherein the longitudinal linear motor module comprises a servo motor, a transmission belt and a slide rail, the longitudinal sliding block is slidably mounted on the slide rail, the servo motor is arranged at one end of the slide rail, a roller is arranged at the other end of the slide rail, the transmission belt is wound on an output shaft and a roller shaft of the servo motor, the transmission belt is fixedly connected with the longitudinal sliding block, and the transverse linear motor module and the short vertical short linear motor module are identical in structure to the longitudinal linear motor module.

4. The on-site 3D printing device according to claim 2, wherein the multi-degree-of-freedom suspension movable arm includes a first connecting rod, a first cylinder, a second connecting rod, a second cylinder and a third connecting rod, one end of the first connecting rod is fixedly mounted on the vertical slider, the other end of the first connecting rod is hinged to the top end of the second connecting rod through a hinge, the top of the first cylinder is fixedly connected to the middle position of the first connecting rod, the power output end of the first cylinder is hinged to the middle position of the second connecting rod through a hinge, the top end of the third connecting rod is hinged to the bottom end of the second connecting rod, the top of the second cylinder is fixedly mounted on the second connecting rod, the power output end of the second cylinder is hinged to the third connecting rod through a hinge, and the extrusion printing mechanism is mounted at the bottom end of the third connecting rod.

5. The on-site 3D printing device according to claim 3, wherein the scanning mechanism comprises a position adjusting mechanism and an image collecting unit, the position adjusting mechanism comprises a linear module, a first motor, a gear wheel, a pinion, a ball screw and a screw nut slider, the linear module is arranged in the middle of the rack in parallel, the linear module is identical to the longitudinal linear motor module in structure, the linear module is connected with a connecting slider in a sliding manner, the two opposite sides of the connecting slider are respectively and fixedly provided with a first connecting plate, a fixed long plate is horizontally arranged between the two first connecting plates, the first motor is arranged on the upper surface of the fixed long plate, the ball screw is positioned below the fixed long plate, the two ends of the ball screw are rotatably connected to the two first connecting plates through a rotating bearing, the gear wheel is fixedly arranged at the output end of the first motor, the pinion is fixedly arranged on the ball screw, the gear wheel is meshed with the pinion, the screw nut slider is in threaded connection with the ball screw, and the image collecting unit is arranged on the screw nut slider.

6. The on-site 3D printing device according to claim 5, wherein the image acquisition unit comprises a binocular camera and a grating projector, the binocular camera is mounted on a screw-nut slider, a telescopic bracket is arranged on a side wall of the screw-nut slider, the grating projector is mounted on the telescopic bracket through a two-degree-of-freedom connecting piece, and the grating projector is matched with the binocular camera.

7. The on-site 3D printing device according to claim 4, wherein a bottom end of the third link is provided with a universal connection, and the extrusion printing mechanism is mounted to the bottom end of the third link through the universal connection.

8. The on-site 3D printing device according to claim 7, wherein the universal connecting piece comprises a second connecting plate, a spherical gear, two mounting seats and two driving mechanisms, the center of one side of the second connecting plate is fixedly connected to the bottom end of the third connecting rod, the two mounting seats are symmetrically mounted at the middle position of the other side of the second connecting plate, the spherical gear is mounted between the two mounting seats, the two driving mechanisms are symmetrically arranged on two sides of the spherical gear, each driving mechanism comprises a motor mounting plate and a box fixing seat which are fixed on the second connecting plate, a rotary gear box body is mounted on the box fixing seat, a transmission mechanism is arranged in the rotary gear box body, a second motor is mounted on the motor mounting plate, the second motor is output to the spherical gear through the power of the transmission mechanism, and the printing mechanism is fixedly arranged on the surface of the spherical gear.

9. The on-the-spot 3D printing device according to claim 8, wherein the transmission mechanism includes a single-pole gear, a transition spur gear, a small spur gear, a second bevel gear, a first bevel gear and a rotary bearing, the second bevel gear is fixedly installed at an output end of the second motor, the first bevel gear is installed on an inner wall of the rotary gear box body through a connecting shaft, the first bevel gear and the second bevel gear are meshed with each other, the small spur gear is coaxially arranged with the first bevel gear, the transition gear is rotatably installed in the rotary gear box body through the connecting shaft, the small spur gear is meshed with the transition gear, the transition gear is in power transmission with the single-pole gear through the rotary bearing, and the single-pole gear is meshed with the spherical gear.

10. An on-site 3D printing method, characterized in that the on-site 3D printing device according to any one of claims 1 to 9 is adopted, comprising the steps of:

1) A target bone defect patient lies on the operating bed trolley, a binocular camera and a grating projector on the scanning mechanism are driven by a linear motor module and a lead screw nut slide block to reach the position above the bone defect position of the patient, then the pose adjustment of the binocular camera and the grating projector is completed by a two-degree-of-freedom connecting piece and a telescopic device, so that a binocular imaging area and a projection area are overlapped, the completeness of scanning and imaging is ensured, the bone defect shape is scanned through binocular stereo vision, the obtained data is transmitted to a computer for 3D modeling, and a three-dimensional model of the bone defect shape is established after the scanning data is analyzed and processed by the computer;