Automatic mixing and injection system for bone cement

Abstract

The application belongs to the technical field of medical bone repair materials and medical devices, and discloses a bone cement automatic mixing and injection integrated system, which comprises a storage module, a mixing module, a conveying module and a control module. The bone cement automatic mixing and injection integrated system is designed with double-cavity reciprocating butt, single-cavity reciprocating flow or reciprocating short rotation in the mixing module, so that the solid powder and the liquid component form high-strength reciprocating or circulating flow in the closed cavity. The problems of uneven shearing, local dry powder aggregation or uneven liquid distribution in manual or simple mechanical stirring can be effectively overcome, the material can be fully infiltrated and dispersed on the micro level, the prepared bone cement slurry has highly consistent composition and microstructure, and the predictability of subsequent solidification behavior, and the uniformity and reliability of the mechanical properties and biological properties of the final hardened body are directly ensured.

Description

Technical Field

[0001] This invention relates to the field of medical bone repair materials and medical devices, specifically an integrated system for automatic mixing and injection of bone cement. Background Technology

[0002] Calcium phosphate bone cement, as an injectable bone repair material, is widely used in bone defect repair, bone filling and minimally invasive orthopedic surgery due to its good biocompatibility, bioactivity and similarity to natural bone tissue. Existing calcium phosphate bone cement is usually prepared by mixing solid powder and liquid components on-site before use and the injection operation needs to be completed within a limited working time. In current clinical practice, manual stirring, single-chamber stirrers, or double-syringe mixing are commonly used to complete the mixing process. Among these methods, manual or semi-automatic methods are cumbersome, rely on the operator's experience, and make it difficult to guarantee the uniformity of mixing and the consistency of injection. While double-syringe mixing can improve the uniformity of mixing to some extent, it still has the problems of being time-consuming and laborious, and making it difficult to achieve accurate measurement and automatic injection. The above operations are highly dependent on the user's experience. Differences in solid-liquid ratio control, stirring sequence, stirring intensity, and stirring time may all lead to insufficient mixing or insufficient mixing consistency, thereby affecting the curing behavior, mechanical properties, and injection performance of bone cement. In addition, ceramicized calcium phosphate bone cement usually has a high solid content and a short workable time window. If the mixing is uneven or the operation is delayed, the bone cement is prone to rapid increase in viscosity, decrease in fluidity, or even premature local solidification before or during injection, which will lead to a significant increase in injection resistance, increase the difficulty of clinical operation, and even affect the safety of surgery. Existing devices for bone cement injection mainly focus on the material delivery function and have limited control over the solid-liquid mixing process itself. They are difficult to reliably open and fully mix the solid and liquid components under closed conditions, as well as effectively distinguish between the mixing and injection stages. In actual use, the mixture may also have the risk of backflow, backflow, or contamination, which further affects the safety and stability of clinical use. Therefore, there is an urgent need for a calcium phosphate bone cement mixing and injection system that can achieve quantitative mixing, automatic control, and direct injection output while ensuring mixing uniformity. This would reduce the complexity of clinical operations, improve mixing consistency and controllability of the injection process, and be particularly suitable for ceramicized calcium phosphate bone cement systems with high requirements for operating window and mixing quality. Summary of the Invention

[0003] The purpose of this invention is to provide an integrated automatic mixing and injection system for bone cement, in order to solve the problems of cumbersome operation, reliance on manual experience, difficulty in ensuring mixing uniformity and consistency, difficulty in achieving precise and controllable quantitative mixing and injection within a narrow operating window, and the risk of backflow and contamination in the existing mixing and injection methods.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an integrated automatic mixing and injection system for bone cement, comprising: The storage module is used to hold the solid powder and liquid components of bone cement and to quantitatively input them into the next module. A mixing module for forming a bone cement slurry from the solid powder and liquid components during the mixing stage, and configured to allow the bone cement slurry to flow back and forth in at least one chamber; The delivery module is used to deliver the mixed bone cement slurry out of the injection port during the injection stage; The control module is used to drive the storage module, mixing module and delivery module, and control the system to switch between the mixing stage and the injection stage.

[0005] Preferably, the mixing module includes at least two interconnected chambers, and the bone cement slurry forms a reciprocating countercurrent flow mixing between the at least two chambers.

[0006] Preferably, the mixing module includes a single mixing chamber in which the bone cement slurry forms a controlled reciprocating flow mixing.

[0007] Preferably, the mixing module and the delivery module form an integrated cavity structure, and the bone cement slurry is mixed in the delivery module by controlled forward and reverse driving to form a reciprocating short swirling flow.

[0008] Preferably, under the drive of the control module, the conveying module causes the conveying mechanism in the conveying module to rotate forward, rotate backward, or reciprocate slightly. During the mixing phase, the bone cement slurry is controlled to prevent delivery to the injection port; During the injection phase, the bone cement slurry is stably delivered out of the injection port through forward rotation.

[0009] Preferably, the conveying mechanism includes at least one of a screw conveying mechanism, a gear pump conveying mechanism, a piston conveying mechanism, and a pump conveying mechanism.

[0010] Preferably, the control module is configured to execute the mixing stage, stage switching, and injection stage sequentially according to preset control logic.

[0011] Preferably, the conditions for completing the mixing stage include any one or a combination of the following: The preset mixing time has been reached; To achieve the preset number of reciprocating strokes or reciprocating volume; The drive load has been detected to have entered a stable range.

[0012] Preferably, the control module is configured to control the injection volume and injection speed, and the control module is configured to perform at least one of the following operations when an abnormal load is detected: reducing the drive speed, pausing the drive, or reversing the material ejection.

[0013] Preferably, the mixing module and the conveying module are housed in a disposable sealed cartridge, and the control module and the drive structure are housed in a reusable handle.

[0014] Compared with the prior art, the beneficial effects of the present invention are: the integrated automatic mixing and injection system for bone cement: 1. The system uses a mixing module design with various mixing methods such as dual-cavity reciprocating counter-current, single-cavity reciprocating flow, or reciprocating short vortex to create high-intensity reciprocating or circulating flow of solid powder and liquid components within a closed cavity. This actively controlled fluid motion effectively overcomes common problems in manual or simple mechanical stirring, such as uneven shear force, local dry powder agglomeration, or uneven liquid distribution. This ensures that the material is fully wetted and dispersed at the microscopic level, resulting in a bone cement paste with a highly consistent composition and microstructure. This directly guarantees the predictability of subsequent curing behavior and the uniformity and reliability of the mechanical and biological properties of the final hardened body. It is especially beneficial for leveraging the performance advantages of ceramicized calcium phosphate bone cement. 2. The system is uniformly coordinated by the control module and can automatically complete the entire process from quantitative material output, start of mixing, to completion of mixing and switching to injection output. This design completely eliminates the cumbersome and error-prone links in the traditional method, such as relying on the operator's subjective judgment of the mixing endpoint and manually changing syringes. The automated switching not only reduces the operation steps and time, but more importantly, it avoids the risk of bone cement thickening and solidifying prematurely in the syringe or needle due to human operation delays. The systematic process ensures that the transition from mixing to injection is completed within the operable time window, which significantly reduces the clinical risk of sudden increase in injection resistance or needle blockage caused by material deformation, and improves the safety and controllability of the operation. 3. The system's storage module enables pre-quantitative packaging or measurement of solid and liquid components, ensuring the accuracy of the solid-liquid ratio from the source. This is a fundamental key factor affecting the various properties of bone cement. During the injection stage, a screw-type delivery mechanism is used, which can achieve precise and stable control of the output flow and pressure of the slurry by controlling the speed and direction of the screw. This combination of "quantitative mixing" and "stable delivery" ensures that the slurry injected into the bone defect site maintains a high degree of consistency in quantity, quality, and fluidity, reducing the differences in results caused by different operator techniques and strengths. This makes the clinical effect more standardized and repeatable, which is conducive to improving the stability of treatment quality. 4. It offers multiple mixing methods and adjustable parameters, enabling it to flexibly adapt to different formulations and dosage requirements of bone cement. In particular, it provides a reliable solution for ceramicized calcium phosphate bone cement with short operating windows and high performance requirements. The modular design also allows the system to be used with different injection accessories, making it suitable for various minimally invasive surgical scenarios such as dentistry, orthopedics, and neurosurgery. It has broad clinical applicability and promotional value. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the integrated system of the present invention; Figure 2 This is a schematic diagram of the overall cross-sectional three-dimensional structure of Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the overall cross-sectional three-dimensional structure of Embodiment 2 of the present invention; Figure 4 This is a schematic diagram of the overall cross-sectional three-dimensional structure of Embodiment 3 of the present invention; Figure 5 This is a schematic diagram of the system composition of the present invention; Figure 6 This is a schematic diagram of the system composition and operation process according to Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the implementation process of Embodiment 2 of the present invention; Figure 8 This is a schematic diagram of the structure and function of Embodiment 3 of the present invention.

[0016] In the diagram: 1. Control module; 2. Mixing module; 3. Conveying module; 4. Storage module. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Please see Figure 1 - Figure 8 The present invention provides a technical solution: an integrated system for automatic mixing and injection of bone cement.

[0019] Example 1: Dual-cavity reciprocating counter-impact hybrid implementation method The system includes a first storage compartment and a second storage compartment, as well as an interconnecting channel between the two compartments. After entering the mixing module 2, the solid and liquid phases form a bone cement slurry. Under the driving action, the slurry forms a reciprocating countercurrent flow between the first and second storage compartments, achieving full mixing of the solid and liquid phases. The interconnection channel is a circular tube, with its two ends connected to the outlets of the first and second storage bins, respectively. Under the action of the connecting rod piston, the material can pass back and forth between the first and second storage bins to achieve uniform mixing of the material. The connecting rod piston should be matched with the storage bins, and its thickness and connecting rod are not limited. During the mixing stage, the bone cement slurry flows back and forth between the first and second storage bins according to a set volume and number of times to achieve a counter-mixing effect. During the mixing phase, control module 1 controls mixing module 2 to isolate the injection outlet to prevent bone cement slurry from entering the injection channel during the mixing process. After mixing is completed, control module 1 controls mixing module 2 to switch to the connected state and enter the injection phase. Example 2: Single-cavity reciprocating flow mixing implementation method There is at least one unidirectional channel between the first storage bin and the second storage bin, which allows only the liquid phase to flow into the solid phase. The material is reciprocated and mixed to form bone cement slurry by the displacement of the connecting rod perforated plate in the first storage bin. Then, the bone cement slurry is sent into the conveying module 3 by the connecting rod piston. The connecting rod perforated plate is made of plastic or metal (thickness 1-5mm), with at least one full-layer through hole (diameter 0.1-5mm), the hole shape is not limited, and at least one push-pull rod is connected to the center of the connecting rod perforated plate and passes through the center of the connecting rod piston. The reciprocating flow and mixing of materials is achieved by the displacement of the push-pull rod. Reciprocating flow can be achieved by alternating forward and reverse driving. The specific driving parameters can be adjusted according to the bone cement system and clinical needs, but should not be construed as a limitation of the present invention. Example 3: Single-cavity reciprocating short-rotation mixing implementation method The outlets of the first and second storage compartments are respectively connected to the conveying cavity, allowing controlled material output. This forms an integrated cavity structure where the mixing module 2 and the conveying module 3 are combined. During the mixing stage, the control module 1 controls the conveying module 3 to perform alternating forward and reverse short rotation drives, causing the bone cement slurry to form a reciprocating short rotation mixing within the conveying module 3, thereby completing the mixing without the need for an additional mixing cavity. In the above three embodiments, during the injection stage, the control module 1 controls the delivery module 3 to only perform forward drive, delivering the mixed bone cement slurry out of the injection outlet.

[0020] Example 4: Functional Division of Control Module 1 Control module 1 is configured to perform at least the following functions to achieve the phased control objectives: Mixing phase control function: During the mixing phase, the mixing module 2 is controlled to cause the bone cement slurry to flow back and forth in at least one mixing chamber, and the injection outlet is isolated. Stage switching control function: After detecting that the mixing completion conditions are met, control module 1 switches to the injection state; Injection stage control function: Control delivery module 3 to deliver the mixed bone cement slurry out of the injection outlet; Parameter control and metering functions: control the mixing volume, mixing time, injection volume, and injection speed; Control module 1 operates in a state machine manner, including at least: standby state, mixed state, switching state and injection state; In standby mode, control module 1 keeps storage module 4, mixing module 2 and delivery module 3 in a non-working state, and controls valve control module to be in a closed or isolated state of injection outlet; During the mixing process, control module 1 drives storage module 4 and mixing module 2 to create a reciprocating flow of bone cement slurry within or between mixing chambers. Simultaneously, it controls the isolation injection outlet to prevent bone cement slurry from entering the injection channel during the mixing phase. The mixing process can be terminated based on any of the following conditions or a combination thereof: The preset mixing time is reached; To achieve the preset number of reciprocating strokes or reciprocating volume; The drive load has been detected to have entered a stable range. In the switching state, the control module 1 controls the mixing module 2 to switch from the isolated state to the connected injection outlet state, and calibrates or pre-drives the delivery module 3 to eliminate system gaps or initial resistance. During injection, the control module 1 drives the delivery module 3 to deliver the mixed bone cement slurry out of the injection outlet, and controls the injection speed and injection dosage according to preset parameters. Control module 1 is also configured to monitor the system's operating status, including at least drive load, drive displacement, drive speed, and operating time. When any of the following abnormal conditions are detected, control module 1 is configured to perform at least one safety control operation: The drive load exceeds a preset threshold; Abnormal rate of change of drive load; Injection time exceeded the preset maximum value; Safety control operations include, but are not limited to: Reduce drive speed; Pause the driver; Reverse drive to achieve material removal; Output alarm signal; The value of this part lies in the fact that the control module 1 can be implemented in the form of hardware, software or a combination of hardware and software, or set up as an independent control unit, and can also communicate with the storage module 4, the hybrid module 2 and the transmission module 3 through wired or wireless means.

[0021] Example 5: Study on the Influence of Different Mixing Methods on Bone Cement Mixing To verify the effect of different mixing methods of the present invention on the mixing uniformity of calcium phosphate bone cement, the bone cement paste properties of manual stirring method and double syringe flushing method were compared with those of the three mixing methods of the present invention. Experimental conditions: In this embodiment, all groups of calcium phosphate bone cement were prepared using the same raw material composition and solid-liquid ratio. After mixing, the bone cement slurry was cured under the same conditions. The test items included the flow properties of the slurry, working time, curing time, and the porosity and compressive strength of the cured bone cement. The composition and experimental conditions of the bone cement described above are merely illustrative examples of the present invention and do not constitute a limitation thereof.

[0022] Experimental results: As shown in the table above, compared with manual stirring and traditional double-injector counter-flushing mixing, the calcium phosphate bone cement slurry prepared by the mixing method of the present invention shows a stable trend in terms of fluidity, curing time, porosity and compressive strength after curing. Among them, the bone cement slurry prepared by the double-cavity reciprocating counter-flushing mixing method has relatively high fluidity and compressive strength, indicating that this mixing method is beneficial to reducing the generation of gas entrainment during the mixing process, thereby helping to obtain calcium phosphate bone cement slurry with better mixing uniformity. In addition, the single-cavity reciprocating mixing method and the single-cavity reciprocating short-spinning mixing method can also obtain relatively stable mixing effects, further demonstrating that the mixing method of the present invention can improve the mixing uniformity of bone cement under different structural implementation forms. In the above embodiments, the shape, volume, and driving parameters of the mixing chamber, including but not limited to driving speed, number of reciprocations, and working time, can be adjusted according to the specific bone cement formula and usage requirements. The above parameters are only preferred examples and should not be construed as limiting the scope of protection of the present invention.

[0023] In each embodiment, the control module 1 can monitor the status of the mixing and injection processes. When abnormal load or abnormal operating conditions are detected, the control module 1 can perform safety control operations such as reducing the drive speed, pausing the drive, or reversing the material ejection to improve the safety of system operation.

[0024] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An integrated automatic mixing and injection system for bone cement, characterized in that, include: Storage module (4) is used to hold the solid powder and liquid components of bone cement and to quantitatively input them into the next module; A mixing module (2) is used to form a bone cement slurry from the solid powder and liquid components during the mixing stage, and is configured to allow the bone cement slurry to flow back and forth in at least one chamber. Delivery module (3) is used to deliver the mixed bone cement slurry out of the injection outlet during the injection stage; The control module (1) is used to drive the storage module (4), the mixing module (2) and the delivery module (3), and to control the system to switch between the mixing stage and the injection stage.

2. The integrated automatic mixing and injection system for bone cement according to claim 1, characterized in that: The mixing module (2) includes at least two interconnected chambers, and the bone cement slurry forms a reciprocating countercurrent flow mixing between the at least two chambers.

3. The integrated automatic mixing and injection system for bone cement according to claim 1, characterized in that: The mixing module (2) includes a single mixing chamber in which the bone cement slurry forms a controlled reciprocating flow mixing.

4. The automated mixing and injection integrated system according to claim 1, characterized in that: The mixing module (2) and the delivery module (3) form an integrated cavity structure. The bone cement slurry is mixed in the delivery module (3) by controlled forward and reverse driving to form a reciprocating short swirling flow.

5. The integrated automatic mixing and injection system for bone cement according to claim 1, characterized in that: Driven by the control module (1), the conveying module (3) causes the conveying mechanism in the conveying module (3) to rotate forward, rotate backward, or reciprocate slightly. During the mixing phase, the bone cement slurry is controlled to prevent delivery to the injection port; During the injection phase, the bone cement slurry is stably delivered out of the injection port through forward rotation.

6. The integrated automatic mixing and injection system for bone cement according to claim 5, characterized in that: The conveying mechanism includes at least one of the following: screw conveying mechanism, gear pump conveying mechanism, piston conveying mechanism, and pump conveying mechanism.

7. The integrated automatic mixing and injection system for bone cement according to claim 1, characterized in that: The control module (1) is configured to execute the mixing stage, stage switching, and injection stage sequentially according to preset control logic.

8. The integrated automatic mixing and injection system for bone cement according to claim 7, characterized in that: The conditions for the completion of the hybrid phase include any one or a combination of the following: The preset mixing time has been reached; To achieve the preset number of reciprocating strokes or reciprocating volume; The drive load has been detected to have entered a stable range.

9. The integrated automatic mixing and injection system for bone cement according to claim 1, characterized in that: The control module (1) is configured to control the injection volume and injection speed, and the control module (1) is configured to perform at least one of the following operations when an abnormal load is detected: reducing the drive speed, pausing the drive, or reversing the material ejection.

10. The integrated automatic mixing and injection system for bone cement according to claim 1, characterized in that: The mixing module (2) and the conveying module (3) are housed in a single-use sealed cartridge, and the control module (1) and the drive structure are housed in a reusable handle.

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