Medical multi-material printing device

Abstract

The invention provides a medical multi-material printing device, which comprises a multi-axis mechanical arm, a plurality of printing nozzles and a control unit, the plurality of printing nozzles comprise: a bone meal mixed slurry printing nozzle for printing a bone model by using a mixed slurry of bone meal and bone cement; the bone powder mixed slurry printing spray head is used for printing a bone powder mixed slurry, the supporting material printing spray head is used for printing a supporting material for supporting the model, the control unit alternately controls the bone powder mixed slurry printing spray head and the supporting material printing spray head to print the bone model during printing, and the bone powder mixed slurry printing spray head is further provided with a refrigeration part for cooling the mixed slurry in the printing container. According to the invention, the model can be directly and quickly printed on the human skeleton so as to adapt to specific skeleton defects, enhance the mechanical strength and the living activity, contribute to reducing the occurrence of rejection reaction, and also can be widely applied to the fields of bone repair and plastic surgery and cosmetology.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a medical multi-material printing device. Background Art

[0002] Currently, some implantable devices on the market are made of non-degradable metal materials. When these non-degradable metal devices are implanted in the human body, some metals may cause allergic reactions, leading to local inflammation and pain. At the same time, although most metals have good biocompatibility, in some rare cases the patient's body may produce an immune response and reject the implant.

[0003] Over time and after long-term use, these non-degradable metal implants may experience wear or metal fatigue, and regular medical follow-up is required during the implant period to ensure that the implant is functioning properly and there is no inflammation.

[0004] After a non-degradable metal device is implanted in the human body, the patient may go to certain extreme environments (for example, extremely cold or hot environments). Since metal has good thermal conductivity, it may cause local discomfort in the human body.

[0005] However, bone powder and bone cement are materials used in the medical field and are often used in bone repair and reconstruction surgery. As a bone transplant material (bone filling material), it can be used to fill bone defects and promote the formation and integration of new bones. Bioactive bone powder can be used as a substitute for autologous bone (the patient's own bone) to treat fractures, bone defects and other bone-related diseases. Some specially processed bone powders are osteoinductive and can guide and promote bone formation, which is very useful for bone regeneration and repair.

[0006] In addition, hydrogels made of calcium phosphate polymer composites, silicate-based materials, silk protein-based materials, polymer composites, gelatin and sodium alginate are all biomaterials that can be used for bone regeneration and repair. These biomaterials can improve their mechanical properties and retain good biodegradability, and can be formed by various methods such as 3D printing. In addition, this material can maintain good spatial structure and mechanical properties in the early stage of degradation, and has good bone conduction, which can effectively repair bone defects.

[0007] Or allogeneic bone transplantation can be used, but allogeneic bone is a type of allogeneic transplantation, which is generally divided into two types: structural bone grafting and filling bone grafting. It can be used in the fields of repairing fractures and soft tissues. At the same time, its source is wide and its usage is not restricted. When doing structural bone grafting, it is necessary to find a structure similar to the patient's resected bone. After bone grafting, the patient may also experience rejection reactions, absorption of allogeneic bone and slower healing.

[0008] At the same time, the choice of prostheses in traditional plastic surgery is often limited, and it is difficult to fully meet the needs of patients. 3D printing technology can customize prostheses according to the facial features and needs of patients. Customized prostheses can not only improve the effect of surgery, but also reduce rejection after surgery. At the same time, facial reconstruction surgery is difficult and the effect is uncertain. 3D printing technology can accurately print the prostheses required for reconstruction based on the three-dimensional data of the injured part and restore the patient's facial structure.

[0009] However, it is still a difficult problem in the industry to make bone powder and bone cement match the patient's injury implant precisely, especially when facing some complex and irregular implants. Now a new structural 3D printing solution can solve the above problems. Summary of the invention

[0010] In view of the above problems, the present invention provides a medical multi-material printing device with a new structure, which utilizes a mixed slurry of bone powder and bone cement mixed in proportion and a degradable supporting material to combine and print models through a multi-axis robotic arm. The device can quickly print models directly on human bones to adapt to specific bone defects, enhance mechanical strength and vitality, help reduce the occurrence of rejection reactions, and can also be widely used in the fields of bone repair and plastic surgery.

[0011] In order to achieve the above-mentioned purpose, the medical multi-material printing device of the present invention includes a multi-axis robotic arm; a plurality of printing nozzles installed at the front end of the multi-axis robotic arm; and a control unit for controlling the multi-axis robotic arm and the plurality of printing nozzles, wherein the plurality of printing nozzles include: a bone powder mixed slurry printing nozzle, which uses a mixed slurry of bone powder and bone cement to print a bone model; and a supporting material printing nozzle, which prints a degradable supporting material for supporting the model, and the control unit alternately controls the bone powder mixed slurry printing nozzle and the supporting material printing nozzle to print the bone model during printing, and the bone powder mixed slurry printing nozzle and the supporting material printing nozzle respectively have: a nozzle for spraying printing material; and a printing container for containing the printing material connected to the nozzle, and the bone powder mixed slurry printing nozzle also has a refrigeration component for cooling the mixed slurry in the printing container.

[0012] In some embodiments, the control unit controls the temperature of the mixed slurry in the printing container of the bone powder mixed slurry printing nozzle within a range of -20°C to 20°C via the refrigeration component.

[0013] In some embodiments, the refrigeration component is a semiconductor refrigeration device.

[0014] In some embodiments, a storage component is further included, which stores the mixed slurry before printing and maintains the mixed slurry in the range of -20°C to 0°C, and is configured to supply the mixed slurry to the printing container of the bone meal mixed slurry printing nozzle.

[0015] In some embodiments, the plurality of print heads each have an extrusion device, and the extrusion device includes: an extrusion component for extruding the printing material in the print container from the nozzle; and a driving component for driving the extrusion component.

[0016] In some embodiments, the extrusion component is a piston, and the driving component is a push rod motor capable of pushing the piston.

[0017] In some embodiments, the plurality of print heads each have a remaining amount detection unit, which is disposed outside or inside the print container and is used to detect the remaining amount of material in the print container, and an alarm is issued when the detection value of the remaining amount detection unit is lower than a preset value.

[0018] In some implementations, the remaining amount detection unit is a remaining amount sensor that detects the remaining amount using laser or infrared rays.

[0019] In some embodiments, a heating device is further included, which uses hot air to heat the mixed slurry just ejected from the nozzle of the bone powder mixed slurry printing nozzle.

[0020] In some embodiments, the support material printing nozzle further comprises a heating component for heating the support material in the printing container.

[0021] In some embodiments, the printing containers and the nozzles in the plurality of printing heads are detachable for replacement or sterilization.

[0022] In some embodiments, it also includes a signal receiving device, which receives signals about printing paths and telecontrol instructions generated based on the three-dimensional model of the skeleton, and the control unit controls the multi-axis robotic arm and the multiple printing nozzles based on the signals.

[0023] In some embodiments, the medical multi-material printing device is disposed in an operating room or a sterile room.

[0024] In some embodiments, the support material is soluble in saline.

[0025] In some embodiments, a nozzle for supplying the physiological saline solution is further included, and the control unit controls the nozzle to remove the support material after the model printing is completed.

[0026] The beneficial effects of the present invention are as follows:

[0027] The present invention utilizes a bone powder mixed slurry in which bone powder and bone cement are mixed in proportion and a degradable supporting material to print a model through a multi-axis robotic arm. Thus, the model can be quickly printed directly on the human skeleton to adapt to specific bone defects, enhance mechanical strength and life activity, help reduce the occurrence of rejection reactions, and can also be widely used in the fields of bone repair and plastic surgery.

[0028] Moreover, the present invention is not only provided with a bone powder mixed slurry printing nozzle for printing a skeletal model using a mixed slurry of bone powder and bone cement, but also provided with a support material printing nozzle for printing support materials. Therefore, it is capable of coping with the printing of skeletal models whose geometric shapes cannot support themselves during the printing process or models with suspended parts.

[0029] In addition, since the bone powder mixed slurry reacts faster at higher temperatures, this may cause the slurry to solidify before printing, thereby affecting the accuracy and quality of printing. By providing a refrigeration component to cool the mixed slurry in the printing container of the bone powder mixed slurry printing nozzle, the temperature inside the printing container can be slowed down, the reaction speed of the bone powder mixed slurry can be effectively controlled, and it is ensured that it maintains appropriate fluidity and printability during the printing process, thereby improving the accuracy and quality of printing.

[0030] In addition, by setting the above-mentioned refrigeration component as a vibration-free, small-sized and light-weight semiconductor refrigeration device, the mixed slurry in the printing container of the bone meal mixed slurry printing nozzle can be appropriately cooled without affecting the accuracy and quality of printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The following is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings. The accompanying drawings are only exemplary and do not limit the embodiments. In the accompanying drawings, the same reference numerals refer to the same elements, wherein:

[0032] Figure 1 It is a stereoscopic view showing a medical multi-material printing device according to an embodiment of the present invention.

[0033] Figure 2 It is a stereoscopic view showing a bone powder mixed slurry printing nozzle of the medical multi-material printing device according to the present embodiment.

[0034] Figure 3 It is a three-dimensional diagram showing a support material printing nozzle of the medical multi-material printing device according to the present embodiment.

[0035] It should be understood that, for the sake of simplicity and / or clarity of illustration, the elements shown in the drawings are not necessarily drawn to scale. For example, for the sake of clarity, the sizes of some elements may be exaggerated relative to other elements. In addition, in order to make the concept of the present invention easier to understand, elements known in the art are omitted in the drawings. The sizes of the drawings do not represent the exact sizes and / or size ratios of the various elements described herein.

[0036] Description of Reference Numerals

[0037] 100: Medical multi-material printing device, 1: Multi-axis robotic arm, 2: Bone powder mixed slurry printing nozzle, 21: Nozzle, 22: Printing container, 23: Refrigeration component, 24: Extrusion component, 25: Driving component, 3: Support material printing nozzle, 31: Nozzle, 32: Second printing container, 33: Heating component, 34: Extrusion component, 35: Driving component. DETAILED DESCRIPTION

[0038] In the following description, several specific details are set forth. However, the embodiments described herein can be implemented without certain specific details. In specific embodiments, in order to avoid unclear understanding of the specification, well-known structures and technologies are not shown in detail.

[0039] In addition, the phrases "in one embodiment," "in an embodiment," and / or "in some embodiments" may be used repeatedly herein. The phrases generally do not refer to the same embodiment; however, they may refer to the same embodiment. Unless the context indicates otherwise, the terms "including," "having," and "comprising" are synonymous. The phrases "A or B" and "A / B" mean "(A), (B), or (A and B)."

[0040] It should be understood that ordinal adjectives such as "first", "second", "third", etc. may be used in this document to refer to elements. Unless otherwise specified, these are only used to distinguish different elements and do not imply that the mentioned elements must be in a given order in time, space, or other aspects.

[0041] In addition, it should be understood that the words "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", etc. may be used in this document to describe the position of components. This is only for the convenience of explaining the relative position relationship between components, and the use of these words does not limit the components.

[0042] In addition, it should also be understood that the word "about" or "approximately" may be used herein to modify a numerical value, which means within the normal tolerance range in this field. For example, "about" or "approximately" can be understood as within 1% of the modified numerical value.

[0043] Below, first, refer to Figure 1 , describing a medical multi-material printing device 100 according to an embodiment of the present invention. The medical multi-material printing device 100 comprises: a multi-axis robot arm 1; a plurality of printing heads mounted at the front end of the multi-axis robot arm 1; and a control unit (not shown) for controlling the multi-axis robot arm 1 and the plurality of printing heads.

[0044] In this embodiment, the multi-axis robot arm 1 uses a 6-axis robot arm, but the present invention is not limited thereto, and a 4-axis or 5-axis robot arm can be selected according to the needs to meet the printing of the model.

[0045] The plurality of printing nozzles include: a bone powder mixed slurry printing nozzle 2, which uses a mixed slurry of bone powder and bone cement to print a bone model; and a supporting material printing nozzle 3, which prints a degradable supporting material for supporting the model. In addition, the plurality of printing nozzles are not limited to only including the bone powder mixed slurry printing nozzle 2 and the supporting material printing nozzle 3, and may also include a printing nozzle for printing other required materials.

[0046] The control unit consists of a central controller and multiple joint controllers. The central controller receives sensor information and generates control instructions according to preset tasks. The joint controller controls the joints of the multi-axis robot 1 according to the instructions of the central controller. The motor rotates or moves to a specific position according to the instructions. The central controller calculates and adjusts the position and speed of each axis in real time based on dynamic analysis, inverse kinematics, forward kinematics, etc. In addition, when printing, the control unit controls the movement of the multi-axis robot 1 while alternately controlling the bone powder mixed slurry printing nozzle 2 and the support material printing nozzle 3 to print the bone model.

[0047] like Figure 2 As shown, the bone meal mixed slurry printing nozzle 2 has: a nozzle 21 for spraying the mixed bone meal mixed slurry; a printing container 22 for containing the bone meal mixed slurry connected to the nozzle 21; and a refrigeration component 23 arranged on both sides of the printing container 22 in a manner of surrounding the printing container 22. There is good heat conduction between the refrigeration component 23 and the printing container 22, so as to effectively cool the bone meal mixed slurry in the printing container 22. In addition, as needed, a monitoring unit for monitoring the internal temperature of the printing container 22 can also be provided. The control unit can adjust the power of the refrigeration component 23 according to the monitoring data of the monitoring unit to maintain a suitable temperature range. In addition, considering the problem of condensed water that may be generated during the refrigeration process of the refrigeration component 23, a collection unit for collecting condensed water can also be provided as needed to prevent it from affecting the normal operation of the equipment.

[0048] The refrigeration component 23 is, for example, a semiconductor refrigeration device. Since the semiconductor refrigeration device has the advantages of no vibration, small size, and light weight, by using the semiconductor refrigeration device, the mixed slurry in the printing container 22 of the bone powder mixed slurry printing nozzle 2 can be properly cooled without affecting the accuracy and quality of printing. In addition, the present invention is not limited to this, for example, a device with a refrigeration method such as air cooling or water cooling can also be used.

[0049] The control unit controls the temperature of the mixed slurry in the print container 22 of the bone meal mixed slurry print nozzle 2 within the range of -20°C to 20°C, preferably 10°C, via the refrigeration component 23, to alleviate the environmental temperature and accelerate the chemical reaction. In addition, when the mixed slurry in the print container 22 is squeezed out of the nozzle 21, since the mixed slurry is still in a fluid state and has a certain fluidity, in order to accelerate the chemical reaction of the mixed slurry to accelerate its curing process, the printing environment needs to be heated to 30°C to 50°C, preferably 40°C, to accelerate the chemical reaction of the material in the mixture and accelerate the curing speed to finally accumulate into a model. Therefore, it is preferred that a heating device (not shown) is also provided, which uses, for example, hot air to heat the mixed slurry just ejected from the nozzle 21 of the bone meal mixed slurry print nozzle 2.

[0050] In addition, the medical multi-material printing device 100 may also include a storage component (not shown), which stores the mixed bone powder slurry and keeps the bone powder slurry in the range of -20°C to 0°C, and is configured to supply the bone powder slurry to the printing container 22 of the bone powder slurry printing nozzle 2. Before printing, the mixed slurry is frozen in the range of -20°C to 0°C (preferably -18 to -12°C, more preferably -15°C). The purpose of this step is to further slow down the reaction speed of the bone powder slurry to prevent it from solidifying prematurely before printing. At the same time, freezing can also help the bone powder slurry better maintain its shape and accuracy during the printing process.

[0051] In addition, the bone powder mixed slurry printing nozzle 2 also has an extrusion device, such as Figure 2 As shown, the extrusion device includes: an extrusion component 24 for extruding the bone powder mixed slurry in the printing container 22 from the nozzle 21; and a driving component 25 for driving the extrusion component 24. Here, as an example, the extrusion component 24 is a piston that can move in the printing container 22, and the driving component is a push rod motor that can push the piston. However, the present invention is not limited to this, for example, a screw or the like can also be used to extrude the bone powder mixed slurry from the nozzle 21.

[0052] like Figure 3As shown, the support material printing nozzle 3 has: a nozzle 31 for ejecting the support material; a printing container 32 for containing the support material connected to the nozzle 31; and a heating component 33 arranged on both sides of the printing container 32 in a manner of surrounding the printing container 32. The heating component 33 heats the support material in the printing container 32. Since the support material needs to be removed after the printing of the bone model is completed, a degradable material is used. The support material is made of a mixture of, for example, honey, salt, starch materials and washable and removable materials. Since the solidification temperature of honey is about 15 degrees and most starch materials begin to gelatinize at 55 degrees, it is necessary to use the heating component 33 for heating to ensure that the support material can flow out of the nozzle normally under the action of the extrusion component described later. Here, it is preferred that the support material can be dissolved in physiological saline.

[0053] Similar to the bone powder mixed slurry printing nozzle 2, the support material printing nozzle 3 also has an extrusion device, such as Figure 3 As shown, the extrusion device includes: an extrusion component 34 for extruding the support material in the printing container 32 from the nozzle 31; and a driving component 35 for driving the extrusion component 34. Here, as an example, the extrusion component 34 is a piston that can move in the printing container 32, and the driving component is a push rod motor that can push the piston. However, the present invention is not limited to this, for example, a screw or the like can also be used to extrude the bone powder mixed slurry from the nozzle 31.

[0054] In addition, the plurality of print heads also have a residual amount detection unit (not shown), which is arranged outside or inside the print container 22, 32, and is used to detect the residual amount of the printing material in the print container 22, 32. When the detection value of the residual amount detection unit is lower than the preset value, a remote communication prompt or a light and a buzzer prompt that the residual amount of the material is low is given, so that the operator can add the printing material in time to avoid affecting the continuous printing of the model. In addition, the control unit can also control the addition of printing material automatically when the detection value of the residual amount detection unit is lower than the preset value.

[0055] In addition, the printing containers 22 and 32 preferably use syringes, which can accurately control the flow and distribution of the printing material. By adjusting parameters such as the extrusion speed and pressure of the syringe, the shape, size and structure of the printed part can be accurately controlled.

[0056] In addition, since the printed model needs to be used on the human body, the disinfection of the printing device is particularly important. The printing container 22 (syringe) for containing the bone cement mixed slurry, the printing container 32 (syringe) for containing the support material, and the corresponding nozzles 21 and 31 (needles) can be disposable printing containers (syringes) and nozzles (needles), or printing containers (syringes) and nozzles (needles) that can be reused after disinfection to avoid cross infection of bacteria to the patient. Therefore, in the present invention, it is preferred that the printing containers and nozzles in the multiple printing nozzles are detachable for replacement or disinfection.

[0057] In addition, the medical multi-material printing device 100 may also include a signal receiving device that receives signals about the printing path and telecontrol instructions generated based on the three-dimensional model of the skeleton. The control unit controls the multi-axis robotic arm and multiple printing nozzles based on the signal. Specifically, the patient is first subjected to MRI magnetic resonance imaging to generate detailed internal body images. At the same time, the Dicom format images generated by MRI can be read with the help of commonly used medical image file format conversion software including 3D Slicer, ITK-SNAP, OsiriX, etc. Doctors can manually edit and mark images according to personalized needs, use rigid and non-rigid algorithms to fuse and co-register data, and segment the images to view the complete three-dimensional view, and then use three-dimensional visualization tools such as MIMICS, Amira, Avizo, ORS VisuaI, etc. to extract specific information (such as bones) and generate triangular meshes, and finally save them as STL format. STL format files can be read and sliced ​​by slicing software. The slicing software will also generate the printing path and motion instructions (printing parameters such as extrusion speed, pressure, path planning, etc.) for each layer based on the slicing data. Finally, the signal is read by the control unit on the robotic arm to control the drive motor to move and print the model.

[0058] In addition, the printing environment is an operating room or a sterile room (clean room), and the sterility of the printing space needs to be ensured, including disinfection and sterilization of the robotic arm to prevent intraoperative infection of the patient during the printing process. Therefore, it is preferred that the medical multi-material printing device of the present invention is arranged in an operating room or a sterile room.

[0059] The beneficial effects of the present invention are as follows:

[0060] The present invention utilizes a bone powder mixed slurry in which bone powder and bone cement are mixed in proportion and a degradable supporting material to print a model through a multi-axis robotic arm. Thus, the model can be quickly printed directly on the human skeleton to adapt to specific bone defects, enhance mechanical strength and life activity, help reduce the occurrence of rejection reactions, and can also be widely used in the fields of bone repair and plastic surgery.

[0061] Moreover, the present invention is not only provided with a bone powder mixed slurry printing nozzle for printing a skeletal model using a mixed slurry of bone powder and bone cement, but also provided with a support material printing nozzle for printing support materials. Therefore, it is capable of coping with the printing of skeletal models whose geometric shapes cannot support themselves during the printing process or models with suspended parts.

[0062] In addition, since the bone powder mixed slurry reacts faster at higher temperatures, this may cause the slurry to solidify before printing, thereby affecting the accuracy and quality of printing. By providing a refrigeration component to cool the mixed slurry in the printing container of the bone powder mixed slurry printing nozzle, the temperature inside the printing container can be slowed down, the reaction speed of the bone powder mixed slurry can be effectively controlled, and it is ensured that it maintains appropriate fluidity and printability during the printing process, thereby improving the accuracy and quality of printing.

[0063] In addition, by setting the above-mentioned refrigeration component as a vibration-free, small-sized and light-weight semiconductor refrigeration device, the mixed slurry in the printing container of the bone meal mixed slurry printing nozzle can be appropriately cooled without affecting the accuracy and quality of printing.

[0064] In addition, the bone powder mixed slurry used in the present invention preferably includes biological bone powder with biological activity and bone cement, wherein the biological bone powder is made of one or more of autologous bone, allogeneic bone or animal bone, and the bone cement includes powder and liquid, the mass ratio of biological bone powder to bone cement is 1:1 to 1:12, and the mass ratio of bone cement powder to bone cement liquid is 0.5:1 to 1.5:1.

[0065] The 3D bone-printed prosthesis is a porous scaffold structure constructed by powder and liquid of bone cement, and biological bone powder with biological activity is present in the porous structure, thereby forming a biologically active structure. The present invention uses biological bone powder with biological activity as a raw material, has good biocompatibility with biological tissues, and retains biologically active cells, can induce the growth of osteocytes, and is more likely to achieve good bone ingrowth and bone integration with surrounding bone tissues, promote secondary growth of bones, improve the biocompatibility of 3D bone printing materials, and is conducive to reducing the biological inertness between bone cement materials and bone tissues.

[0066] By adjusting the solid-liquid ratio of bone cement powder and liquid, the extrusion performance and porosity of the material can be adjusted. And the content of biological bone powder in the material can be adjusted according to the load-bearing characteristics and bone density requirements of the printed bone structure.

[0067] In addition, by controlling the temperature of the mixed slurry of the above-mentioned bioactive biological bone powder and bone cement in the printing container of the bone powder mixed slurry printing nozzle within the range of -20°C to 20°C through a refrigeration component, the reaction rate of the bone powder mixed slurry can be further effectively controlled, ensuring that it maintains appropriate fluidity and printability during the printing process, thereby improving the accuracy and quality of printing.

[0068] In some preferred embodiments, the mass ratio of bone cement powder to bone cement liquid is 0.8:1 to 1.2:1. By controlling the solid-liquid ratio of bone cement powder and liquid, it is possible to ensure that bone cement has good bonding properties and flow properties, and has good extrusion properties. The printed material can be suitable for 3D printing equipment. At the same time, by adjusting the ratio of the two, the porosity of the printed material support structure can be regulated, thereby adjusting the density of the printed material, and the curing time as a binder can also be adjusted, which is more conducive to the control of the printing process. In some preferred embodiments, the mass ratio of biological bone powder to bone cement is 1:3 to 1:10. Due to the different functions of bones in different positions, the load-bearing capacity, strength and bone density required by bones are also different. In addition to being regulated by a porous support structure, it can also be regulated by the bone powder content present in the porous structure. Changes in bone powder content also affect the fluidity, extrudability and formability of bone printing materials, thereby affecting the stability of the formed bone structure.

[0069] In some preferred embodiments, the mass ratio of bone cement powder to bone cement liquid is 0.9:1 to 1.1:1. When the solid-liquid ratio of bone cement is too high, the material is too viscous and cannot be smoothly formed. When the solid-liquid ratio of bone cement is too low, the mixed slurry formed is too thin and difficult to form. In some preferred embodiments, the mass ratio of biological bone powder to bone cement is 1:4 to 1:10. When the bone powder content is too low, the bone density is low and the biological inertness of the bone cement material cannot be effectively reduced. When the bone powder content is too high, the material formed is not stable enough due to the influence of the bonding properties of bone cement.

[0070] In some preferred embodiments, the biological bone powder is preferably made of autologous bone. When autologous bone is used as the raw material, compared with bone powder raw materials from other sources, the patient is less likely to have an immune rejection reaction, making the transplantation process safer and having a higher success rate. The autologous bone selected is generally a bone in the human body that only has a decorative effect and does not affect the normal function of the human body.

[0071] In some embodiments, biological bone powder is obtained by removing the periosteum from fresh bones after in vitro pulverization. The bone powder used in the commonly used 3D bone printing often needs to be subjected to various complex treatments, including but not limited to defatting and deproteinization under high temperature, high pressure and various chemical reagents. These treatment processes are not only complicated, but also make the obtained bone powder lose its biological activity. Utilizing the material of the present invention, biological bone powder with biological activity is obtained only by simple operations of simple periosteum removal and crushing, and the cell activity of bone powder can be maintained to the greatest extent. The use of these biological bone powders with biological activity does not require the additional cultivation of active bone marrow cells and the increase of corresponding nutrients. Only simple treatment is required to activate the biological activity of bones, promote secondary growth of bones, and form a more stable bone structure. The operation is simple, safe and fast. The simple and fast processing method improves the efficiency of 3D bone printing and wins precious treatment time for rescuing patients with acute bone injuries.

[0072] In some embodiments, the particle size of the biological bone powder is controlled to be 50 to 200 μm. Considering the uniformity of the mixture of bone powder and bone cement, the particle size of the bone powder needs to be reasonably selected. If the particle sizes of the two do not match, the mixing uniformity will decrease, thereby causing the mechanical properties to decrease.

[0073] In some embodiments, the bone cement powder may include polymethyl methacrylate, and the bone cement liquid may include methyl methacrylate monomer. The present invention uses PMMA bone cement as a binder. It is known that PMMA bone cement is a traditional acrylic bone cement, which can achieve rapid coagulation at room temperature through polymerization reaction between powder and liquid.

[0074] In some embodiments, the 3D bone printing material may further include additives, which may include one or more of a developer, polylactic acid, degradable polyester, a solubilizer, and artificial bone powder. Thus, by selectively adding, the imaging performance, solubility, degradability, and biocompatibility of the material may be improved, and the mechanical properties of the material may be increased.

[0075] In some preferred embodiments, the developer may include barium sulfate or zirconium oxide to enhance the imaging visibility of the bone prosthesis formed after 3D printing. In some preferred embodiments, polylactic acid is polymerized from lactic acid in renewable resources (such as corn starch or sugarcane) and has excellent biocompatibility and biodegradability. In some preferred embodiments, the degradable polyester may include one or more of polyurethane, polycaprolactone, polyglycolide, polyanhydride, polyphosphate, polycarbonate, polyhydroxybutyrate, polydioxanone, and polyglycolic acid, which has a good Young's modulus, so that the mechanical properties of 3D bone printing materials are more matched with native bones, and the stress shielding effect can also be effectively reduced to prevent bone loss. In some preferred embodiments, the solubilizer may include polyvinyl pyrrolidone (PVP), which is soluble in water and most organic solvents, has excellent physiological inertness, does not participate in human metabolism, and has excellent biocompatibility. In some preferred embodiments, artificial bone powder includes hydroxyapatite, tricalcium phosphate, calcium phosphate composite material, bioglass, collagen, and lactic acid-glycolic acid copolymer. It can improve the regenerative ability of biological bone powder, which is beneficial to the growth of new bone. At the same time, it forms a good synergistic effect with biological bone powder and bone cement, improves the mechanical properties and processing properties of the material, and improves the stability of the bone prosthesis formed after printing.

[0076] In some preferred embodiments, the mass percentage of the additive can be 0-5%. The type and amount of the additive can be selected according to the specific location of the bone prosthesis to be printed and the type of prosthesis, so as to selectively improve the imaging performance, solubility, degradability, biocompatibility and mechanical properties of the prosthesis material formed after printing.

[0077] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above implementation modes, those skilled in the art should understand that they can still modify the technical solutions described in the above implementation modes, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the implementation modes of the present application.

Claims

1. A medical multi-material printing device, It is characterized in that include: Multi-axis robotic arm; A plurality of printing nozzles mounted on the front end of the multi-axis robotic arm; and a control unit for controlling the multi-axis robotic arm and the plurality of print heads, The plurality of print heads include: Bone powder mixed slurry printing nozzle, which uses a mixed slurry of bone powder and bone cement to print a bone model; and A support material printing nozzle, which prints a degradable support material for supporting the model, The control unit alternately controls the bone powder mixed slurry printing nozzle and the support material printing nozzle to print the bone model during printing. The bone powder mixed slurry printing nozzle and the support material printing nozzle respectively have: a nozzle for ejecting printing material; and a printing container for accommodating the printing material connected to the nozzle, The bone meal mixed slurry printing nozzle also has a refrigeration component for cooling the mixed slurry in the printing container.

2. The medical multi-material printing device according to claim 1, Features: The control unit controls the temperature of the mixed slurry in the printing container of the bone powder mixed slurry printing nozzle within a range of -20°C to 20°C via the refrigeration component.

3. The medical multi-material printing device according to claim 1, Features: The refrigeration component is a semiconductor refrigeration device.

4. The medical multi-material printing device according to claim 1, Features: It also includes a storage component, which stores the mixed slurry before printing and keeps the mixed slurry in the range of -20°C to 0°C, and is configured to supply the mixed slurry to the printing container of the bone powder mixed slurry printing nozzle.

5. The medical multi-material printing device according to claim 1, Features: The plurality of printing nozzles are respectively provided with an extrusion device, The extrusion device comprises: an extrusion component for extruding the printing material in the printing container from the nozzle; and A driving component for driving the extrusion component.

6. The medical multi-material printing device according to claim 5, Features: The extrusion component is a piston, The driving component is a push rod motor capable of pushing the piston.

7. The medical multi-material printing device according to claim 1, Features: The plurality of printing nozzles are respectively provided with a residual amount detection unit, and the residual amount detection unit is arranged outside or inside the printing container and is used to detect the residual amount of the material in the printing container, and an alarm is issued when the detection value of the residual amount detection unit is lower than a preset value.

8. The medical multi-material printing device according to claim 7, Features: The remaining amount detection unit is a remaining amount sensor that detects the remaining amount using laser or infrared rays.

9. The medical multi-material printing device according to claim 1, Features: It also includes a heating device, which uses hot air to heat the mixed slurry just ejected from the nozzle of the bone powder mixed slurry printing nozzle.

10. The medical multi-material printing device according to claim 1, Features: The support material printing nozzle also has a heating component for heating the support material in the printing container.

11. The medical multi-material printing device according to claim 1, Features: The printing containers and the nozzles in the plurality of printing heads are detachable for replacement or sterilization.

12. The medical multi-material printing device according to claim 1, Features: The system also includes a signal receiving device, which receives signals about a printing path and teleoperation instructions generated based on the three-dimensional model of the bone. The control unit controls the multi-axis robot arm and the plurality of print heads based on the signal.

13. The medical multi-material printing device according to claim 1, Features: The medical multi-material printing device is arranged in an operating room or a sterile room.

14. The medical multi-material printing device according to claim 1, Features: The support material can be dissolved in physiological saline.

15. The medical multi-material printing device according to claim 14, Features: It also includes a nozzle for supplying the physiological saline solution, and the control unit controls the nozzle to remove the support material after the model printing is completed.

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