Intelligent bone cement injection system of bionic hollow screw and control method

Abstract

The invention discloses an intelligent bone cement injection system of a bionic hollow screw and a control method. An intelligent bone cement injection system of a bionic hollow screw comprises an intelligent profiling interface, a multi-channel independent injection and sensing module, a piezoelectric ceramic micropump, a central control module and a three-dimensional navigation verification module. Loading three-dimensional micropore topological data through a scanning screw, and constructing a personalized perfusion model; and dynamically distributing multi-channel flow based on the model. According to the intelligent bone cement injection system of the bionic hollow screw and the control method, the problems that in the prior art, bone cement injection equipment is not matched with a novel 3D printing screw interface, the injection process is uncontrollable, and directional strategies and real-time feedback are lacked are solved, accurate, uniform and safe filling of bone cement in a complex micropore network is achieved, and the bone cement injection efficiency is improved. The stability, the safety and the predictability of the internal fixation operation of the osteoporotic fracture are obviously improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to an intelligent bone cement injection system and control method for a bionic hollow screw. Background Technology

[0002] With the increasing global trend of population aging, osteoporosis has become a major disease affecting the bone health of middle-aged and elderly people. Osteoporosis leads to decreased bone density, degeneration of bone microstructure, and increased bone fragility, making patients highly susceptible to fractures when subjected to low-energy trauma (such as falls), with pelvic fragility fractures being particularly common. These fractures are characterized by "three highs": high incidence, high disability rate, and high mortality rate, seriously affecting patients' quality of life and imposing a heavy medical burden on society and families.

[0003] Currently, surgical treatment has become the mainstream approach for unstable osteoporotic pelvic fractures. Minimally invasive percutaneous cannulated screw fixation is widely considered the preferred treatment option due to its advantages of minimal trauma, less bleeding, and faster recovery. This technique involves inserting a cannulated screw through a small incision on the skin under image guidance to stabilize the pelvic ring. However, patients with severe osteoporosis experience significant bone loss, resulting in severely insufficient bone-screw interface strength. This leads to unsatisfactory immediate holding force (initial stability) and long-term holding force (resistance to cutting and loosening) of traditional screws, significantly increasing the risk of postoperative internal fixation failure (such as screw cutting, loosening, or displacement).

[0004] To improve the anchoring strength of screws in osteoporotic bone, various reinforcement techniques have been developed in clinical practice. One common method is to inject bone cement (mainly polymethyl methacrylate, PMMA) into the bone through the central channel of a hollow screw, utilizing the "bone cement-bone" composite formed after the cement solidifies to enhance the screw's holding power. Another method is to directly inject bone cement around the screw (within the bone tunnel) to form a reinforcing layer surrounding the screw. While these methods improve stability to some extent, they still suffer from problems such as uncontrollable bone cement distribution, high risk of leakage, and uneven reinforcement effects.

[0005] In recent years, with the widespread application of additive manufacturing (3D printing) technology in the medical device field, a new type of hollow screw with a biomimetic microporous structure has emerged. These screws are typically manufactured using biocompatible materials such as titanium alloys through precision 3D printing. Their core innovation lies in the complex three-dimensional microporous network topology designed within the screw. This structure typically includes a central main channel, several guide channels distributed along the screw's axis, and hundreds of micropores (with pore sizes typically ranging from 200-500 μm) radiating from the guide channels to the screw surface at specific angles (e.g., 45°±5°). During surgery, bone cement is injected into this microporous network. The cement permeates outward through the micropores into the interstices of the bone trabeculae surrounding the screw, solidifying to form countless tiny "anchors" and interwoven "roots," thus firmly locking the screw to the bone tissue, significantly improving pull-out and rotational resistance. This interlocking structure of "screw-bone cement-bone tissue" provides a revolutionary solution for internal fixation in osteoporotic conditions.

[0006] However, the effectiveness of this advanced screw highly depends on the precise, uniform, and complete injection of bone cement of appropriate viscosity and dosage into its complex microporous network. Existing clinical bone cement injection equipment (mostly manual plunger, gun-type, or simple electric pushers) reveals a series of technical bottlenecks that urgently need to be addressed when dealing with this new type of personalized screw:

[0007] 1. Mechanical Interface Incompatibility and Sealing Challenges: To achieve both driving and sealing, 3D-printed bionic hollow screws typically feature specialized mechanical structures at their tails, such as internal hexagonal slots or hexagonal slots for the driving interface, and a precision flared sealing surface. The injection head of a traditional bone cement injector (usually a flat or simple conical head) cannot form an effective and rapid intraoperative connection with these specialized structures. Forced connection can easily lead to misalignment, unstable connection, and, more importantly, an inability to achieve a reliable seal under high injection pressure. This results in bone cement leakage from the interface, contaminating the surgical field, affecting the procedure, and causing cement waste and inaccurate dosage.

[0008] 2. Lack of awareness and control over micropore blockage: The micropores inside the screw are extremely small, almost the same size as the larger polymer particles in bone cement. During injection, bone cement is highly susceptible to blockage due to particle aggregation, local viscosity changes, or air bubbles as it flows through these narrow channels. Traditional injection devices rely entirely on the physician's manual experience and cannot detect pressure changes within the injection pathway in real time. When blockage occurs, physicians often increase the injection force, causing a sudden increase in injection pressure. This can not only damage the delicate microstructure of the screw, but more dangerously, the high pressure may cause bone cement to leak unexpectedly from the fracture line or weak points in the bone. Bone cement leaking into the spinal canal or blood vessels can cause catastrophic complications such as nerve compression and pulmonary embolism. Conversely, if the injection pressure is insufficient due to concerns about leakage, the bone cement may not fully fill the distal micropores, resulting in a significant reduction in the strengthening effect and the screw holding force not meeting expectations.

[0009] 3. Disconnect between infusion strategy and screw topology: The micropore network of a biomimetic screw is a meticulously designed fluid system. Each channel serves a specific area of ​​the micropore group, and the pore diameter may exhibit a gradient change from the tail to the head (e.g., smaller at the tail and larger at the head), with all micropores at a certain angle. Ideal infusion requires the bone cement to simultaneously and uniformly fill all micropores. With the traditional "single-point injection" method, the flow path of the bone cement in the complex network is difficult to predict and control, easily leading to overfilling of some channels or areas of micropores while others are underfilled, resulting in uneven infusion and failing to fully utilize the mechanical advantages of biomimetic design.

[0010] 4. Intraoperative process is invisible and lacks real-time feedback: The microporous network is located inside the screw and bone tissue, making it completely invisible during the procedure. Doctors are essentially "blind men feeling an elephant" during injection, only able to make rough judgments based on limited X-ray fluoroscopy images (usually two-dimensional), unable to understand in real-time and intuitively the specific penetration depth, uniform distribution, and complete filling of the bone cement within the three-dimensional microporous network. The success of the surgery can only be assessed post-operatively via CT scan; once poor filling is detected, it is too late to remedy the situation intraoperatively.

[0011] Therefore, it is necessary to provide a smart bone cement injection system and control method based on a biomimetic hollow screw to solve the above-mentioned technical problems. Summary of the Invention

[0012] In order to overcome the shortcomings of the prior art, the present invention provides a biomimetic hollow screw intelligent bone cement injection system and control method that can achieve rapid and reliable connection and sealing with the screw, sense the fluid state in real time during the injection process, and intelligently control the injection of bone cement according to the geometric topological characteristics of the screw, so as to ensure that the bone cement is uniformly, completely and safely filled in the microporous network of the screw.

[0013] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0014] The biomimetic hollow screw-based intelligent bone cement injection system includes a drive head that precisely mates with the screw's drive groove. For example, if the screw has an internal hexagonal groove, the drive head has an external hexagonal protrusion; if the screw has a hexagonal groove, the drive head has a corresponding hexagonal protrusion. This drive head is typically made of high-strength stainless steel or hard alloy, with dimensional tolerances controlled at the micrometer level, ensuring easy insertion and tight engagement, and assisting in the final tightening of the screw when necessary. The diameter of the drive head (e.g., 2.5 mm) matches the diameter of the screw's central channel, providing a clear central flow path for the bone cement.

[0015] At the rear of the drive head, an integrated flared deformation sealing ring is present. This sealing ring is typically made of medical-grade silicone, fluororubber, or other materials with excellent elasticity, biocompatibility, and chemical resistance. Its front end is designed as a conical or spherical surface that matches the flared surface of the screw tail. When the drive head is inserted into the screw and an appropriate axial locking force is applied, the sealing ring is compressed between the system interface and the screw flared surface, undergoing elastic deformation (the design deformation rate is preferably 10%-20%, for example, 15%). This deformation generates a strong radial sealing force, effectively preventing cement leakage from the interface gap under the high pressure of bone cement injection. The back of the sealing ring usually has a rigid support structure to prevent it from being squeezed into the flow channel under high pressure.

[0016] It also includes a multi-channel independent injection and high-precision sensing module. This module is responsible for distributing the single bone cement flow from the power module to each perfusion path according to control requirements and monitoring the status of each path throughout the process. The multi-channel shunt is a precision fluid distribution component, precision-machined from medical-grade 316L stainless steel or PEEK (polyether ether ketone). Its internal flow channels are optimized using computational fluid dynamics (CFD) to reduce flow resistance and particle deposition. The shunt has one inlet and multiple (typically 2-4, depending on the number of screw guide channels, e.g., 3) outlets. Each outlet is connected to the corresponding flow channel within the intelligent contour interface module via a flexible, radiopaque medical polymer tubing, ultimately guiding the bone cement to the specific guide channel of the screw.

[0017] A miniaturized, high-precision pressure sensor is integrated into the tubing at or immediately adjacent to the outlet of each shunt. This sensor employs piezoresistive or capacitive microelectromechanical systems (MEMS) principles, featuring small size, fast response, and high accuracy (e.g., measurement accuracy up to ±0.5 kPa, sampling frequency up to 100 Hz or higher). Each sensor independently monitors the real-time injection pressure of its respective channel and transmits the voltage signal to the central control module. This forms the basis for the "sensing" function; by analyzing this pressure data, the system can determine the patency of the flow channels, detect blockages, and assess the location of the bone cement flow front.

[0018] Preferably, each channel can also be equipped with a miniature proportional valve or on / off valve, directly driven by the central control module. This enables the system not only to monitor the pressure of each channel, but also to actively and independently control or cut off the flow of bone cement to a specific channel, providing a hardware foundation for implementing more complex infusion strategies (such as time-sequential infusion).

[0019] Preferably, the traditional manual push rod or simple rotary motor propulsion method is abandoned, and a piezoelectric ceramic micropump with extremely fast response speed and high control precision is used as the core power source. Unlike the traditional steady flow, the piezoelectric ceramic micropump easily generates pulsating flow. The system can be programmed to control the pump to operate at a specific frequency (e.g., 1-10 Hz) and a specific waveform (e.g., sine wave, square wave). This pulsating injection has important clinical significance: a) the pulsed pressure wave helps to "impact" the initial blockage or air bubbles that may form at the micropore inlet; b) the intermittent flow can give the high-viscosity bone cement a certain amount of relaxation time, which helps it spread better in the microporous network; c) when an abnormal increase in pressure is detected, a brief reverse suction pulse can be generated immediately to actively clear blockages, a "active clearing" function that traditional pushers cannot achieve. The flow channel part of the pump comes into contact with the bone cement and must be made of biocompatible materials and designed for easy disassembly and cleaning or single use to meet sterility requirements.

[0020] Preferably, it also includes a central control and intelligent processing module, which is the system's computing and control center, integrated into a separate main unit or a high-performance handheld device. Core processor: Employs a high-performance embedded microprocessor (such as an ARM Cortex-A series) or an industrial-grade single-board computer, responsible for running complex real-time control algorithms and graphical interfaces. Data input interface: Identification code reading interface: Supports connection to a 1D / 2D barcode scanner or RFID reader for reading the unique identification code on the screw packaging or the screw itself.

[0021] Screw Parameter Database: The system can access a cloud / LAN database locally or via network. This database stores detailed 3D printing parameters (STL files, bore distribution tables, channel coordinates, etc.) for each batch and each screw. These parameters can be retrieved instantly using an identification code. User Input Interface: Equipped with a touchscreen, allowing doctors to select bone cement type (preset with different viscosity coefficients k), set safety thresholds, manually fine-tune parameters, or perform interventional control.

[0022] Preferably, the control algorithm is as follows:

[0023] Topology path planning algorithm: Converts the discrete micro-hole data of screws into a controllable multi-channel continuous infusion model.

[0024] Pressure warning and blockage diagnosis algorithm: This algorithm analyzes pressure sensor data from each channel in real time. For example, it defines "pressure change rate (dP / dt)" as a key indicator. When the dP / dt of a channel exceeds a positive threshold (e.g., +5 kPa / s) within a short period, it may indicate that a blockage is forming; when it exceeds a negative threshold, it may indicate that the flow channel is suddenly clear or a leak has occurred. Based on the diagnostic results, the algorithm automatically invokes preset response strategies (such as triggering pulses of a specific frequency, adjusting the pump speed, or even closing valves).

[0025] Adaptive PID control algorithm: used to precisely control the output of piezoelectric ceramic micropump, so that the actual injection pressure or flow rate can quickly and smoothly track the set value and suppress external disturbances.

[0026] Output control unit: generates a high-voltage amplified signal to drive the piezoelectric ceramic micropump, as well as switching signals to control the valves in each channel (if equipped).

[0027] Preferably, it also includes a 3D navigation and real-time verification module, which combines medical imaging with computer graphics technology to construct an augmented reality (AR) view of the operating room.

[0028] Image data interface: Supports the standard DICOM 3.0 protocol, and can receive two-dimensional fluoroscopic images or three-dimensional volumetric scan data from intraoperative O-arm, C-arm, CT and other equipment in real time via wired or wireless network.

[0029] Image registration and fusion engine: This is the core technology of this module. The engine first segments the received intraoperative images, identifying the outlines of the screw and bone cement (usually appearing as high brightness on CT). Then, using image registration algorithms (such as feature-based registration or intensity registration), the screw position in the intraoperative images is precisely aligned in three-dimensional space with the pre-loaded, high-precision digital model of the screw. Because the screw is a rigid object and its digital model is known, this registration can achieve very high accuracy.

[0030] 3D Visualization and Heatmap Generation: After successful registration, the system creates a virtual 3D scene containing: a) a semi-transparent digital model of the screw; b) a 3D point cloud of bone cement distribution extracted from intraoperative CT data. The system calculates the overlap between the bone cement point cloud and the screw micropore model in real time. For each micropore or micropore unit, a continuous color value from blue (0% fill) to red (100% fill) is assigned based on the estimated proportion of bone cement filling within it (based on CT grayscale values). Finally, the entire screw model surface or interior is rendered in this "heatmap" format, visually displaying the filling progress and uniformity.

[0031] Intelligent Analysis and Decision-Making Unit: Based on visualization, the software calculates key indicators in real time: overall filling coverage (filled micropore volume / total micropore volume), filling rate of each drainage channel area, and filling rate of high-risk areas (such as micropore opening areas near fracture lines, spinal canals, and blood vessels). These indicators are displayed in numerical and progress bar formats. The system has preset logical rules: for example, "if the overall coverage is <85%, an alarm is triggered and a suggestion to refill is made"; "if the filling rate of high-risk areas is >30%, the highest level alarm is issued and it is recommended to stop injection." More advanced systems can automatically calculate the optimal refill channel and injection parameters based on the distribution of unfilled areas.

[0032] Detailed procedure for controlling directional bone cement injection:

[0033] Phase 1: Preoperative preparation and digital modeling

[0034] Screw identification binding and data retrieval: Before surgery or after screw implantation, the system's scanner reads the screw's QR code. The system immediately retrieves the screw's complete digital file from the database. The file includes at least: the number, spatial coordinates, and orientation of the drainage channels; the three-dimensional coordinates (X, Y, Z), designed aperture (D), and axial tilt angle (θ) of the center point of each micropore; and a topological connection table describing the connection relationship between the drainage channels and the micropores.

[0035] Injection path model construction: The central processing unit (CPU) categorizes all micropores into their corresponding flow channels based on the topology connection table, forming several "injection subtrees." Each "subtree" corresponds to a physical injection channel. The system analyzes the pore size distribution of the micropores within each "subtree," identifying the minimum pore size (d_min) and the corresponding maximum inclination angle (θ_max) along that path. These are the key bottleneck parameters determining flow resistance.

[0036] Safe pressure threshold calculation: The system retrieves the corresponding viscosity coefficient (k) based on the selected bone cement type (e.g., "Palacos® LV"). For each infusion path, the theoretical maximum safe injection pressure P_max is calculated using the formula:

[0037] Pmax = k * (d_min) 2 / cos(θ_max)

[0038] Where d_min is in micrometers (μm) and θ_max is in degrees (°), this formula is based on a simplified capillary flow model. P_max represents the estimated pressure required for bone cement to just begin flowing at the minimum pore size and maximum inclination angle of the path. In practice, the system sets an alarm threshold for the path at a value lower than P_max (e.g., 0.7 to 0.9 times P_max) to provide a safety margin for operation.

[0039] Phase Two: Initial Parameter Setting and Injection Initiation

[0040] Dynamic flow rate allocation: The system calculates the sum of the total cross-sectional areas (S_total) of all micropores downstream of each "infusion subtree". Then, according to the proportion of S_total for each subtree, the total output flow rate of the piezoelectric ceramic micropump is initially allocated to each channel. For example, if the system has three channels with an S_total ratio of 1:1.5:1.2, and the initial total flow rate is set to 0.6 ml / s, then the initial target flow rates for the three channels can be set to 0.6*(1 / 3.7)≈0.16 ml / s, 0.24 ml / s, and 0.20 ml / s. This allocation aims to give bone cement approximately equal "opportunities" to enter each pathway simultaneously.

[0041] Orifice Diameter Zoning and Speed ​​Range Mapping: Based on the screw's geometry, the system divides the micro-orifice into several zones according to diameter and presets a recommended injection speed range for each zone. For example:

[0042] Zone A (pore size 200-300μm): Easily clogged zone, recommended low speed 0.1-0.2 ml / s.

[0043] Zone B (pore size 300-400μm): Transition zone, recommended medium speed 0.2-0.3 ml / s.

[0044] Zone C (pore size 400-500μm): unobstructed zone, high speed of 0.3-0.4 ml / s is recommended to complete filling quickly.

[0045] Initiating Injection: After confirming the parameters on the touchscreen, the doctor presses the start button. The central control module calculates the total set speed / frequency of the piezoelectric ceramic micropump based on the initial flow distribution and issues a start command. Injection officially begins, and the pressure sensors in each channel start transmitting data.

[0046] Phase 3: Intraoperative Real-Time Adaptive Control

[0047] This is the core loop of the method, in which the system completes a closed loop of "perception-decision-execution" within tens of milliseconds.

[0048] Pressure monitoring and forward position estimation: The system continuously analyzes the pressure values ​​(P) and their trends in each channel. Initially, the pressure is low and rises slowly. When the cement forward reaches the bottleneck region (minimum orifice diameter) of a path, the pressure in that channel experiences a relatively significant acceleration. By combining the initial flow rate and pressure rise curves, the system can roughly estimate the progress of the cement forward in each path and determine its current orifice diameter range.

[0049] Aperture gradient adaptive speed regulation:

[0050] When the system determines that the bone cement front of a certain channel has entered the medium-diameter range B from the small-diameter range A, it will automatically increase the target flow rate of that channel from the low-speed range (e.g., 0.15 ml / s) to the medium-speed range (e.g., 0.25 ml / s).

[0051] Similarly, when it is determined that the forward has entered the large aperture range C, it will be further increased to a high speed (e.g., 0.35 ml / s).

[0052] This speed adjustment is "on-demand allocation." In the later stages of injection, channel 1 may have entered the high-speed filling phase, while channel 2 is still in the medium-speed phase, and channel 3, due to its longer path, remains in the low-speed phase. The system can independently control the speed of the three channels based on their respective progress, thereby promoting coordinated progress and striving to complete the filling of all paths almost simultaneously.

[0053] Multi-level pressure safety protection mechanism:

[0054] While adjusting the speed, the system compares the real-time pressure P with the P_max calculated for the current path and performs tiered protection:

[0055] Level 1 Warning (Mild Blockage Risk): When P > 0.7 P_max, the system considers the flow resistance to be too high. It will first attempt "gentle clearing", that is, automatically superimposing a low-frequency (e.g., 2-3 Hz) small pressure pulse on the channel to try to loosen any particles that may have accumulated.

[0056] Level 2 Intervention (Moderate Blockage Risk): If the pressure continues to rise to P > 0.8 P_max, the system determines that the blockage risk is high. At this point, stronger unblocking measures will be triggered, such as switching the injection mode to a high-frequency pulse mode (e.g., 5 Hz), using a stronger alternating pressure differential to clear the blockage. Simultaneously, the baseline flow rate of this channel may be temporarily reduced.

[0057] Level 3 Protection (High Risk or Leakage Warning): If the pressure spikes abnormally, approaching or exceeding P_max, or if the pressure suddenly drops in the high-speed zone (potentially indicating that cement has breached the barrier and entered the cavity or leakage has occurred), the system will immediately activate the highest level of protection. This may include: a) automatically pausing injection in that channel or even all channels; b) triggering a brief reverse aspiration pulse to actively aspirate a small amount of bone cement to reduce distal pressure and assess the situation; c) displaying a prominent red alert on the user interface along with an audible prompt, awaiting the doctor's assessment.

[0058] Real-time 3D visualization feedback: Throughout the injection process, the 3D navigation module operates continuously in the background. Each time the O-arm performs a scan (or continuous fluoroscopy), new image data is fused, and the heatmap is updated accordingly. The doctor can clearly see which areas of the micropores have turned red (well-filled), which are still blue (unfilled), and whether cement has formed "clouds" outside the expected area (indicating leakage risk). The screen sidebar displays the coverage percentage in real time.

[0059] Phase 4: Verification and Decision-Making upon Completion of Infusion

[0060] Completion judgment: Injection continues until one of the following conditions is met, at which point the system will display "Infusion complete":

[0061] The preset total injection volume of bone cement (calculated based on the total volume of the screw micropores) has been delivered.

[0062] The 3D heat map shows that the overall coverage has reached the preset target value (e.g., ≥90%).

[0063] The pressure curves for all channels show that they have entered a stable or declining phase, suggesting that the microporous network may be essentially full.

[0064] Intelligent assessment report: After injection stops, the system automatically generates a brief report, which includes: final overall coverage, coverage of each zone, maximum injection pressure, and whether there are any alarm trigger records.

[0065] Refill Decision Support: If the final coverage does not reach the target (e.g., displayed as 85%), the system analyzes the heatmap to identify the main unfilled area clusters. Then, based on the connection relationship between these clusters and the drainage channels, it automatically plans a "refill plan": suggesting which channel(s), at what slower speed, and how much volume of bone cement to inject to specifically fill the blind spots. Physicians can refer to this plan for secondary injections.

[0066] Safe needle withdrawal: After confirming satisfactory infusion, the doctor issues the needle withdrawal command. The locking mechanism of the system control interface module loosens, allowing the doctor to smoothly separate the injection system from the screw. At this point, the sealing ring elastically recovers, automatically sealing the flow channel on the system side to prevent residual cement from dripping.

[0067] Compared with the prior art, the present invention has the following beneficial effects:

[0068] (1) This invention solves the problem of missing "connector" between novel 3D printed screws and general injection equipment through intelligent contour interface, making the clinical application of advanced screws simple and reliable, and promoting the development of personalized medicine;

[0069] (2) The system of this invention uses high-precision sensors to perceive the fluid state at the injection site in real time and automatically adjusts the action of the actuator through intelligent algorithms, forming a stable feedback control system. This changes the past extensive mode that relied entirely on the doctor's subjective experience and feel, and greatly improves the controllability and repeatability of the process;

[0070] (3) This invention realizes a multi-level pressure protection mechanism and real-time leakage risk warning. It can quickly identify and initially deal with blockage and leakage risks before the human brain can react, minimizing the probability of serious complications;

[0071] (4) Based on the directional perfusion strategy and pore size gradient speed regulation of the screw topology, this invention ensures that the bone cement can be evenly distributed into all micropores according to the designer's intention. This allows each screw to exert its theoretical maximum anchoring efficiency, improves the predictability and consistency of treatment results, and reduces clinical failures caused by poor perfusion;

[0072] (5) The three-dimensional permeation thermal map of this invention transforms the invisible process into an intuitive image, greatly enhancing the doctor's situational awareness. The system not only displays the problem, but also provides data-driven solution suggestions, empowering doctors to make more accurate intraoperative decisions and lowering the technical threshold;

[0073] (6) From scanning codes to retrieve data, to automatic planning and control, and then to generating digital reports, the entire process of this invention embodies the concept of digital healthcare. This helps to collect standardized surgical data, laying the foundation for postoperative efficacy analysis, technological improvement, and even future artificial intelligence applications. Attached Figure Description

[0074] Figure 1 A schematic diagram of the injection device used in the intelligent bone cement injection system provided by the present invention;

[0075] Figure 2 This is a schematic diagram of a partial cross-sectional view of the device;

[0076] Figure 3 This is a flowchart of the steps in the bone cement directional injection control method of the present invention;

[0077] Figure 4 for Figure 3 Schematic diagram of preoperative preparation and digital modeling process;

[0078] Figure 5 for Figure 3 Schematic diagram of initial parameter settings and injection initiation procedure for intraoperative surgery;

[0079] Figure 6 for Figure 3 Schematic diagram of real-time adaptive control process during surgery;

[0080] Figure 7 for Figure 3 A schematic diagram of the verification and decision-making process for the infusion process.

[0081] The corresponding names of the attached figures are: 1-injection cylinder, 3-drive head, 4-multi-channel distributor, 41-channel, 411-flow control valve. Detailed Implementation

[0082] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0083] Example 1:

[0084] like Figure 1-2 As shown, the intelligent bone cement injection system for the bionic hollow screw provided by this invention includes an injection cylinder 1. The front end of the injection cylinder 1 is equipped with a drive head 3 adapted to the tail of the hollow screw disclosed in publication number CN223169799U. The drive head 3 is a hollow tube shape adapted to the hexagonal groove at the tail end of the screw. A multi-channel distributor 4 is integrally provided at the end of the drive head 3, and the multi-channel distributor 4 is inserted into the central hole of the screw from the tail end. Three injection channels 41 are evenly opened on the multi-channel distributor 4, corresponding to the three guide grooves of the hollow screw. An actuator of a flow control valve 411 is provided in each injection channel 41. The flow control valve 411 can be connected to and controlled by the system control program. Furthermore, a pressure detection element should be provided in each channel 41 for real-time pressure detection. Most of the structure of the flow control valve 411 is located inside the injection cylinder 1, with only the actuating end (intercepting block) located inside the injection channel 41, minimizing its size as much as possible. The intercepting block is driven to move by the driving component inside the injection cylinder 1, thereby opening and closing the injection channel 41.

[0085] Example 2:

[0086] like Figure 3-7As shown, the method of using the bone cement injection system is explained using an 83-year-old female patient as an example. This patient was diagnosed with a pelvic fragility fracture (such as a fracture of the left sacral wing or pubic ramus) and a Singh osteoporosis index of grade III. The planned procedure was minimally invasive percutaneous cannulated screw fixation combined with bone cement reinforcement.

[0087] Preoperative preparation and digital modeling:

[0088] Based on the patient's CT data, a biomimetic hollow screw of a specific size was planned and 3D printed preoperatively. The screw parameters are: length 150mm, outer diameter 7.0mm, and central channel diameter 2.5mm. Internally, it features three axial guide channels symmetrically distributed at 120 degrees. Approximately 300 micropores radiate spirally from each channel at a 43° angle, with a gradient in pore size design: 60 micropores near the screw tail (located outside the cortical bone during implantation) have a diameter of 230μm; 180 micropores in the intermediate transition zone have a diameter of 350μm; and 60 micropores near the screw tip (located within the cancellous bone) have a diameter of 480μm. After the screw was manufactured, its unique QR code was activated and stored in the hospital database along with a digital model containing all the aforementioned geometric parameters.

[0089] In the operating room, the main unit, handheld terminal, barcode scanner, foot switch, and other components of the intelligent bone cement injection system of this invention are connected and put into operation for self-test. A sterile packaged bone cement (Palacos® LV, with a preset viscosity coefficient k=0.38, is used in this example) is installed onto the piezoelectric ceramic micropump actuator of the system.

[0090] Intraoperative procedures:

[0091] Under C-arm fluoroscopy guidance, following standard minimally invasive surgical procedures, a hollow screw guide was inserted, and finally, this personalized bionic hollow screw was screwed into the predetermined position. The screw placement was confirmed to be satisfactory.

[0092] The operator removes the sterile cover from the handheld terminal of the intelligent injection system, exposing the intelligent contour interface. The operator aligns the six-star drive head (2.5mm in diameter) at the front of the interface with the six-star slot at the tail of the screw and gently pushes it in until engagement is felt. Then, slight axial force is applied to tighten until a soft "click" is heard or a green indicator light illuminates, indicating that the interface has been mechanically locked and the sealing ring (silicone material) has deformed under pressure (approximately 15%), achieving a seal.

[0093] Initial parameter settings at injection start:

[0094] The assistant uses a sterilized wireless scanner to scan the QR code recorded on the screw packaging or surgical diagnose. The touchscreen immediately displays: "Screw ID: XYZ123456 identified, parameters loading...". After about 2 seconds, the screen displays a 3D wireframe model of the screw and a parameter summary pops up: 3 channels, aperture gradient 230 / 350 / 480μm, tilt angle 43°.

[0095] The scrub nurse prepares the bone cement according to standard procedures (powder and liquid mixing, stirring) and injects it into the system's dedicated syringe, removing air bubbles. The syringe is then installed into the system. The operator selects "Palacos LV" as the bone cement type on the touchscreen and confirms the injection parameters automatically calculated by the system. The interface displays:

[0096] Channel 1 (corresponding to screw guide groove A): initial flow rate 0.16 ml / s, P_max=85 kPa.

[0097] Channel 2 (corresponding to guide channel B): initial flow velocity 0.24 ml / s, P_max=80 kPa.

[0098] Channel 3 (corresponding to guide channel C): initial flow velocity 0.20 ml / s, P_max=88 kPa.

[0099] (P_max is calculated by substituting the minimum aperture of each channel, 230 μm, and the tilt angle, 43° into the formula).

[0100] The operator presses the foot switch to begin the injection.

[0101] Intraoperative real-time adaptive control process:

[0102] 0-30 seconds: In the initial stage of injection, the pressure curves of the three channels rise steadily and slowly, reaching approximately 25, 22, and 28 kPa respectively. The three-dimensional thermogram (based on the preoperative screw model, not yet fused with intraoperative images) shows three red "filling advances" slowly advancing from the screw tail along the three guide channels.

[0103] 30-50 seconds: The pressure rise rate in channel 1 accelerates, reaching 55 kPa. Based on the pressure curve and the initial flow rate model, the system determines that the bone cement front has entered the first densely packed small-aperture zone. The system automatically reduces the flow rate in channel 1 from 0.16 ml / s to 0.14 ml / s to reduce the risk of blockage.

[0104] 55 seconds: The pressure in Channel 1 suddenly accelerates, instantly reaching 68 kPa (>0.8 * 85 kPa). The pressure warning algorithm is immediately triggered. The system: (a) displays a yellow warning message "Channel 1 pressure too high" on the interface; (b) automatically switches the injection mode of Channel 1 to 5Hz pulse mode for 3 seconds. The pressure curve shows that under the action of the pulse, the pressure value oscillates and drops back to 52 kPa, then resumes a steady rise. The alarm is cleared.

[0105] 70-100 seconds: Channels 2 and 3 pass through their small-aperture regions in succession, and the system performs similar flow rate fine-tuning. The pressure in channel 3 reaches 75 kPa upon passage, triggering a 3Hz pulse, which relieves the pressure.

[0106] 100-120 seconds: Based on the inflection points of the pressure rise curves in each channel, the system determines that the bone cement front has essentially passed through the small-diameter zone and entered the medium-diameter transition zone. The system automatically increases the flow rates of the three channels to 0.22 ml / s, 0.28 ml / s, and 0.25 ml / s, respectively.

[0107] 120-150 seconds: During this time, the assistant operates the O-arm (or uses a C-arm) to perform a rapid intraoperative 3D scan. The scan data is transmitted to the system. The 3D navigation module activates, registering the CT data with the screw model. The view on the screen instantly changes from a simple model image to an enhanced view incorporating the actual distribution of bone cement. The heat map shows that the bone cement is mainly distributed at the screw tail and middle, while the screw tip area is still blue.

[0108] 150-180 seconds: The system determines that the bone cement has begun to enter the large-diameter zone of the screw head. The flow rate is further increased to the preset high-speed setting: Channel 1: 0.32 ml / s, Channel 2: 0.38 ml / s, Channel 3: 0.35 ml / s. The pressure curve shows that after entering the large-diameter zone, the pressure rise in each channel slows down significantly, and even decreases slightly.

[0109] 185 seconds: The 3D heatmap dynamically updates, showing the nail tip area quickly being covered in red. The coverage gauge on the side of the screen jumps rapidly from 75% to 89%.

[0110] 195 seconds: The preset injection volume is completed, and the system automatically stops the injection. At this time, the O-arm scans again. The final thermal map after fusion shows that the middle and rear sections of the screw are completely dark red, while the tip area is orange-red to red. The overall coverage is calculated to be 91.2%.

[0111] Infusion completion verification and decision-making:

[0112] The system assessment showed a coverage rate of >90%, meeting the preset target; no abnormally high fill rates were found in high-risk areas. The system interface displayed a green "Injection complete, good results" message and generated a report.

[0113] The surgeon reviewed the heat map and report and confirmed his satisfaction.

[0114] The surgeon presses the unlock button on the handheld terminal, easily separating the injection system from the screw. The interface is checked for cement leakage. After the bone cement has hardened, the surgical sutures are completed as usual.

Claims

1. A biomimetic hollow screw-based intelligent bone cement injection system, characterized in that, include: The intelligent contour interface module is used to detachably connect to the tail of the bionic hollow screw and form a fluid seal, and includes a drive head (3) that cooperates with the screw tail drive structure. The multi-channel independent injection and sensing module includes a multi-channel shunt (4) and multiple pressure sensors. The shunt is used to distribute bone cement flow to multiple channels (41), and each channel (41) corresponds to a pressure sensor for monitoring the injection pressure of its respective channel. The power module is used to provide precisely controllable injection power to the system; The central control and processing module is used to receive and process screw identification information and pressure sensor signals, and generate control commands for the power module and the multi-channel independent injection and sensing module accordingly. The 3D navigation and verification module is used to receive intraoperative medical imaging data, register and fuse it with the digital model of the screw, and generate and display a 3D visualization image of the bone cement penetration in the micropore structure of the screw in real time.

2. The intelligent bone cement injection system for a biomimetic hollow screw according to claim 1 is characterized in that, The drive head (3) is either hexagonal or quincunx-shaped, and its size matches the center channel of the screw.

3. The intelligent bone cement injection system for a bionic hollow screw according to claim 1 is characterized in that the multi-channel independent injection and sensing module further includes an independent flow control valve (411) disposed on each channel (41), and the flow control valve (411) is controlled by the central control and processing module.

4. The intelligent bone cement injection system for a biomimetic hollow screw according to claim 1, characterized in that, The central control and processing module includes: The identification code reading unit is used to obtain the unique identification code of the screw. A data retrieval unit is used to retrieve the microhole topology parameters of the screw from a local or remote database based on the identification code. The control algorithm unit is used to run the pressure warning algorithm and the adaptive flow control algorithm; the pressure warning algorithm is configured to diagnose the blockage risk and trigger the response strategy based on the real-time pressure change rate; the adaptive flow control algorithm is configured to dynamically adjust the injection speed of each channel (41) based on the screw topology parameters and real-time pressure feedback.

5. The intelligent bone cement injection system for a biomimetic hollow screw according to claim 4, characterized in that, The response strategies include one or more of the following: triggering a piezoelectric ceramic micropump to generate a pulse flow of a specific frequency and amplitude, adjusting the injection reference flow rate, triggering a reverse aspiration pulse, or pausing the injection.

6. The intelligent bone cement injection system for a biomimetic hollow screw according to claim 1, characterized in that, The three-dimensional navigation and verification module includes: Image data interface for receiving DICOM format image data from O-arm, C-arm and CT; An image registration engine is used to spatially align the screws in the image data with a preloaded digital model of the screws. A visualization rendering engine for calculating and rendering heat maps of the bone cement filling distribution; The intelligent analysis unit is used to calculate the fill coverage in real time, identify unfilled areas and leakage risk areas, and provide decision prompts based on preset rules.

7. A control method applicable to the intelligent bone cement injection system according to any one of claims 1-6, characterized in that, Includes the following steps: S1: Load the screw micropore topology data, construct a multi-channel injection path model, and calculate the safe pressure threshold for each path; S2: Dynamically allocate the initial injection flow rate based on the total flow cross-sectional area of ​​the downstream micropores of each injection path; S3: Start injection and monitor the pressure of each channel in real time; dynamically adjust the injection speed of each channel according to the pressure feedback and the preset aperture-speed mapping relationship, and perform graded protection actions when the pressure is abnormal; S4: Real-time acquisition and fusion of intraoperative images to generate a three-dimensional thermal map of bone cement penetration for real-time visual monitoring and intelligent assessment.

8. The control method according to claim 7, characterized in that, In step S1, the safe pressure threshold P_max is calculated using the following formula: Pmax=k*(d_min) 2 / cos(θ_max) Where k is the viscosity coefficient of the selected bone cement, d_min is the minimum pore diameter on the current infusion path, and θ_max is the maximum inclination angle of the micropores on the path.

9. The control method according to claim 7, characterized in that, In step S3, the aperture-velocity mapping relationship is as follows: the micropore aperture is divided into at least two intervals, with a lower injection speed level and a higher pressure protection threshold associated with the smaller aperture interval, and a higher injection speed level and a lower pressure protection threshold associated with the larger aperture interval; the graded protection actions include triggering pulse, reducing flow rate, pausing injection, or backflushing.

10. The control method according to claim 7, characterized in that, In step S4, the intelligent evaluation includes: Calculate the overall and zoned bone cement filling coverage; If the overall coverage rate is lower than the first preset threshold, the distribution of unfilled areas will be automatically analyzed and supplementary filling suggestions will be planned. If the filling rate of the leakage risk area is higher than the second preset threshold, an alarm will be triggered and an injection stop operation will be recommended or automatically executed.

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