Mouse heart infarction modeling negative pressure adsorption guide needle control system

Abstract

The present application belongs to the technical field of biomedical engineering, and discloses a mouse heart infarction modeling negative pressure adsorption guide needle control system; comprising a topographic feature acquisition module, a pressure budget module, a suction control module, a sealing determination module, a pressure relief control module, a pressure fluctuation analysis module and a state prompting module. The local curvature type of the heart surface is identified by acquiring the topographic feature parameters of the contact surface, and the corresponding negative pressure establishment curve is selected from the pre-set flexible sealing strategy library. The real-time sealing state is determined by using the differential pressure change rate of the gas-permeable and liquid-impermeable membrane, and when the sealing is detected, the spatial coordinate locking of the needle guide channel is triggered, effectively eliminating the interference of heart beat. The present application has the functions of graded pressure relief control and pressure fluctuation analysis, and provides timing determination for needle insertion operation through stability index evaluation. The present application improves the accuracy, safety and standardization of mouse heart infarction modeling, and eliminates the influence of heart beat on guide needle positioning.

Description

Technical Field

[0001] This invention relates to the field of biomedical engineering technology, and more specifically, to a negative pressure adsorption guide needle control system for mouse myocardial infarction modeling. Background Technology

[0002] Current technologies face several technical bottlenecks and operational challenges in establishing mouse myocardial infarction models. First, the heart, as a complex three-dimensional organ, exhibits significant surface morphological variations. The left anterior descending artery (LAD) region displays a typical convex surface, while the apex and base may show concave or irregular curved surfaces. Traditional negative pressure adsorption devices employ fixed adsorption strategies, failing to adapt to the curvature characteristics of different regions. This leads to poor sealing and air leakage in some areas, while excessive adsorption in others can cause localized myocardial damage. Second, the heart, as a continuously beating organ, experiences fluctuations in its pulsation frequency and intensity depending on the animal's physiological state. Current technologies lack dynamic pressure regulation mechanisms linked to heart rate parameters. Operators often rely on experience to set fixed negative pressure values. This static control method cannot guarantee stable adsorption under different heart rate conditions and carries the risk of arrhythmias or exacerbated myocardial ischemia due to excessively high negative pressure. Third, the continuous beating of the heart constantly alters the spatial reference position of the guide needle. Traditional methods lack effective dynamic compensation and locking mechanisms, resulting in trajectory deviations during needle insertion, severely impacting the accuracy and reproducibility of the model. Furthermore, current technologies rely primarily on the operator's subjective judgment and experience to determine the sealing status, lacking objective and real-time monitoring methods. This often results in situations where needle insertion begins before a complete seal is established, or excessive waiting leads to prolonged experimental times. Finally, due to the lack of a systematic safety monitoring and parameter recording mechanism, significant differences in modeling effects exist between different operators within the same research team. This insufficient standardization of operations severely restricts the scientific rigor and reproducibility of cardiovascular disease research.

[0003] In view of this, the present invention proposes a negative pressure adsorption guide needle control system for mouse myocardial infarction modeling to solve the above problems. Summary of the Invention

[0004] To overcome the aforementioned deficiencies of the prior art and to achieve the above objectives, the present invention provides the following technical solution: a negative pressure adsorption guide needle control system for mouse myocardial infarction modeling, comprising:

[0005] The morphological feature acquisition module is used to control the negative pressure adsorption device to perform an approaching action towards the surface of the mouse heart. At the moment when the acquisition device contacts the surface of the myocardium, it acquires the morphological feature parameters of the contact surface. Based on the morphological feature parameters of the contact surface, it identifies the local curvature type of the current heart surface. The morphological feature parameters of the contact surface include the contact area ratio, the pressure distribution uniformity index, and the centroid offset.

[0006] The pressure budget module is used to select the corresponding initial negative pressure establishment curve from the preset flexible sealing strategy library according to the local curvature type, and calculate the pressure threshold range required to achieve the target adsorption force based on the current heart rate parameters. Different local curvature types correspond to different initial negative pressure establishment curve slopes and pressure holding times.

[0007] The suction control module is used to start the vacuum suction unit, apply suction to the negative pressure adsorption chamber according to the initial negative pressure establishment curve, and monitor the pressure difference change rate on both sides of the air-permeable and liquid-permeable membrane set in the negative pressure path in real time. The air-permeable and liquid-permeable membrane is set between the negative pressure adsorption chamber and the vacuum suction unit.

[0008] The sealing determination module is used to determine that the flexible sealing layer has completed adaptive bonding when the pressure difference change rate enters the preset sealing formation characteristic range, triggering the spatial coordinate locking command of the needle guide channel, and switching the positional relationship of the needle guide channel relative to the adsorption reference surface from the follow-up state to the rigid locking state.

[0009] The pressure relief control module is used to compare the current negative pressure value of the pressure sensor with the pressure threshold range in real time when the spatial coordinates are locked. If the negative pressure value is detected to exceed the safe upper limit, the pressure relief valve is controlled to perform a staged pressure relief action until the negative pressure value falls back to the safe working range.

[0010] The pressure fluctuation analysis module is used to extract the stability index of the adsorption state by analyzing the pressure fluctuation amplitude over multiple consecutive cardiac cycles after the negative pressure value has stabilized within the safe working range.

[0011] The status prompt module is used to activate the operation permission signal when the stability index meets the needle insertion operation conditions, and simultaneously record the angle parameters and depth limit parameters of the current guide channel relative to the adsorption reference plane for postoperative consistency assessment.

[0012] The technical effects and advantages of the negative pressure adsorption guide needle control system for mouse myocardial infarction modeling of the present invention are as follows:

[0013] This invention improves the accuracy and reliability of mouse myocardial infarction modeling. Through intelligent surface recognition and adaptive control mechanisms, it effectively solves the problem of uneven adsorption caused by differences in the morphology of different cardiac regions, ensuring a stable and reliable seal under various curvature conditions. This invention can optimize adsorption parameters in real time according to changes in the physiological state of the heart, ensuring sufficient fixation while avoiding damage to the myocardium caused by excessive adsorption, effectively improving the safety of experimental animals and the success rate of experiments. This invention also eliminates the interference of cardiac pulsation on the accuracy of guide needle positioning, making the needle insertion path more stable and controllable, significantly reducing modeling failures caused by positioning deviations, and improving the accuracy and consistency of the infarct area. The real-time monitoring and safety protection mechanisms of this invention provide comprehensive quality assurance for the entire operation process, greatly reducing operational risks and experimental variability, ensuring that each modeling is performed under optimal conditions. Standardized operating procedures and parameter recording functions eliminate technical differences between different operators, making the complex myocardial infarction modeling operation more standardized and reproducible, providing a more reliable experimental model for basic research and drug development in cardiovascular diseases. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a negative pressure adsorption guide needle control system for mouse myocardial infarction modeling according to the present invention. Detailed Implementation

[0015] 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.

[0016] This application provides a negative pressure adsorption needle control system for mouse myocardial infarction modeling. The system's execution entities include, but are not limited to, cardiovascular animal experimental platforms, myocardial infarction modeling surgical robot systems, precision interventional medical devices, and experimental animal minimally invasive surgery control centers, which can be considered as general control nodes in this application. The control system includes, but is not limited to, at least one of the following: a negative pressure control unit, a spatial positioning module, and a real-time monitoring sensor array.

[0017] Please see Figure 1 In this embodiment of the invention, a negative pressure adsorption guide needle control system for mouse myocardial infarction modeling includes:

[0018] The morphological feature acquisition module controls the negative pressure adsorption device to approach the surface of the mouse heart. Upon detecting the instant the device contacts the myocardial surface, it acquires morphological feature parameters of the contact surface and identifies the local curvature type of the heart surface based on these parameters. This module first drives the negative pressure adsorption device to approach the heart surface vertically downwards at a constant, safe speed (typically 0.1-0.5 mm / s), simultaneously monitoring contact force data fed back by a high-precision force sensor. When the contact force data exceeds a preset trigger threshold (typically 5-10 mN, sufficient to confirm contact without causing myocardial compression), the system determines it as a contact instant and immediately triggers an array of pressure sensors to acquire the pressure distribution matrix at that moment. The contact surface morphological feature parameters include the contact area ratio, pressure distribution uniformity index, and centroid offset. These three parameters collectively describe the adhesion between the adsorption port and the myocardial surface, providing a quantitative basis for subsequent curvature identification. The contact area ratio reflects the degree of contact between the adsorption port and the myocardial surface, the pressure distribution uniformity index quantifies the pressure distribution in the contact area, and the centroid offset indicates the degree of deviation of the contact center from the geometric center of the adsorption port.

[0019] The pressure budget module, based on the local curvature type, selects the corresponding initial negative pressure establishment curve from a pre-set flexible sealing strategy library by the controller, and calculates the pressure threshold range required to achieve the target adhesion force based on the current heart rate parameters. This module first reads a mapping table pre-stored in the flexible sealing strategy library. This table records the correspondence between different curvature types and negative pressure establishment strategies, representing an optimal strategy set optimized based on extensive pre-experimental data. Different local curvature types correspond to different initial negative pressure establishment curve slopes and pressure holding durations. This is because different curvatures of the heart surface require different deformation of the flexible sealing layer, necessitating differentiated pressure application strategies to achieve optimal adhesion. For convex regions (such as the vascular direction in the LAD region), a gentler pressure rise slope and a longer pressure holding plateau period are used to allow the flexible sealing layer to fully deform and adapt to the surface. For irregular regions, a stepped rise waveform is used, gradually achieving sealing through multi-level pressure adjustments. The calculation of the pressure threshold range takes into account the current heart rate parameters and is determined by a preset adsorption force-heart rate mapping function to ensure that the adsorption force can overcome the inertial force of the heartbeat without causing excessive myocardial deformation or ischemia.

[0020] The suction control module is used to activate the vacuum suction unit, applying suction to the negative pressure adsorption chamber according to the initial negative pressure establishment curve, while simultaneously monitoring the rate of change of the pressure difference across the air-permeable but liquid-permeable membrane located in the negative pressure path. This module, through a precise vacuum pump control system, strictly adjusts the negative pressure value within the negative pressure adsorption chamber according to the selected initial negative pressure establishment curve, achieving precise pressure control. The air-permeable but liquid-permeable membrane, positioned between the negative pressure adsorption chamber and the vacuum suction unit, is a special functional membrane material that allows gas to pass freely but prevents liquid permeation. Its function is to reflect the sealing status in real time during suction: when there is gas leakage between the flexible sealing layer and the myocardial surface, gas can flow through the air-permeable but liquid-permeable membrane to the vacuum suction unit, resulting in a significant change in the pressure difference across the membrane; once a seal is formed, the gas leakage decreases sharply, and the pressure difference across the membrane tends to stabilize. The pressure values ​​across the air-permeable but liquid-permeable membrane are collected by a first pressure sensor and a second pressure sensor, respectively, and the pressure difference and its rate of change are calculated, providing real-time monitoring data for determining the sealing status.

[0021] The sealing determination module determines that the flexible sealing layer has completed adaptive bonding when the pressure difference change rate enters a preset sealing formation characteristic range, triggering a spatial coordinate locking command for the needle insertion guide channel. This module continuously analyzes the temporal characteristics of the pressure difference change rate. In the initial stage of aspiration, because the flexible sealing layer is not yet fully bonded to the myocardial surface, gas leakage is significant, and the pressure difference change rate remains in a high value range. As the negative pressure increases, the flexible sealing layer gradually deforms and bonds to the heart surface, gradually closing the gas leakage path, and the pressure difference change rate shows a decreasing trend. Once bonding is complete and a sealed space is formed, gas leakage drops to a minimum, and the pressure difference change rate stabilizes in a low value range close to zero. The sealing formation characteristic range is determined through extensive experimental statistics and is typically set as a pressure difference change rate that is 5-10% lower than the initial value and remains stable for more than three cardiac cycles. When this condition is met, the system generates a spatial coordinate locking command and sends it to the robotic arm or guide mechanism, switching the positional relationship between the needle insertion guide channel and the adsorption reference surface from a follow-up state to a rigid locking state, eliminating the interference of heartbeat on the needle insertion reference, and laying the foundation for subsequent precise needle insertion operations.

[0022] The pressure relief control module, in a locked spatial coordinate state, compares the current negative pressure value of the pressure sensor with the pressure threshold range in real time. If the negative pressure value exceeds the safe upper limit, it controls the pressure relief valve to perform a graded pressure relief action until the negative pressure value falls back to the safe operating range. In the locked state, this module monitors the current negative pressure value in the negative pressure adsorption chamber at a high frequency (typically 100Hz), ensuring that the negative pressure remains within the safe range through real-time comparison. When the negative pressure value exceeds the safe upper limit, it immediately determines that there is a risk of excessive aspiration, which may lead to excessive myocardial deformation, local ischemia, or tissue damage, and the system generates a graded pressure relief control signal. The pressure relief process adopts a gradual control strategy. First, it controls the electromagnetic pressure relief valve to open slightly, releasing a small amount of gas, and then immediately checks the negative pressure drop. If the negative pressure still exceeds the limit, the opening is increased to continue pressure relief; this cycle continues until the negative pressure value falls back to the safe operating range. The graded pressure relief design avoids the sudden adsorption failure that may be caused by a one-time large pressure relief, ensuring the smoothness and safety of the pressure adjustment process and maintaining the continuity of the adsorption state.

[0023] The pressure fluctuation analysis module is used to extract the stability index of the adsorption state by analyzing the pressure fluctuation amplitude over multiple consecutive cardiac cycles after the negative pressure value has stabilized within the safe operating range. This module continuously monitors the pressure time-series data after the negative pressure value enters the safe operating range and stabilizes, capturing pressure waveforms containing at least three complete cardiac cycles. Due to the periodic motion of the heartbeat, the pressure within the adsorption chamber fluctuates synchronously with the heart rate; the amplitude of this fluctuation reflects the coupling degree and stability between the adsorption device and the heart surface. The analysis process first performs bandpass filtering on the pressure time-series data, extracting the pressure fluctuation component with a frequency consistent with the current heart rate frequency, filtering out high-frequency noise and low-frequency drift; then, it calculates the peak-to-peak average of the fluctuation component as a quantitative indicator of the pressure fluctuation amplitude during cardiac cycles; finally, it calculates the stability index based on the ratio of this amplitude to a preset baseline fluctuation threshold. The stability index is inversely proportional to the pressure fluctuation amplitude; the smaller the fluctuation, the more stable the adsorption, and the higher the index. When the stability index exceeds the preset threshold (usually set to 0.8-0.9), the adsorption state is considered stable, meeting the conditions for needle insertion.

[0024] The status indication module is used to activate and output an operation permission signal when the stability index meets the needle insertion operation conditions. Simultaneously, it records the angle parameters and depth limit parameters of the current guide channel relative to the adsorption reference surface for postoperative consistency assessment. Upon receiving the adsorption stability determination result, the module immediately generates an operation permission signal, displaying a "Needle insertion permitted" text prompt on the screen or illuminating a green indicator light for visual feedback. An optional audio prompt is also available to ensure the operator is promptly informed of the system status. Simultaneously, the system reads the tilt angle data of the current guide channel relative to the adsorption reference surface from the angle sensor, and the vertical distance from the end of the guide channel to the adsorption reference surface from the laser rangefinder sensor, using these as the angle parameter and initial depth parameter, respectively. Based on a preset safe needle insertion depth range (determined according to mouse cardiac anatomy and experimental requirements), combined with the initial depth parameter, the system calculates the depth limit parameter, setting the maximum permissible depth of the needle insertion instrument to prevent excessive needle insertion that could penetrate the heart or damage the contralateral myocardium. All parameters are stored together in the storage unit, and a unique identifier (usually a combination of timestamp and animal number) is generated for this modeling operation. This provides a data basis for the consistency evaluation of subsequent modeling parameters in the same batch, ensuring the reproducibility of the experiment and the comparability of the results.

[0025] The modules are connected via wired and / or wireless means to enable data transmission between them.

[0026] In this embodiment of the invention, the negative pressure adsorption device is controlled to approach the surface of a mouse heart. At the instant the acquisition device contacts the myocardial surface, morphological feature parameters of the contact surface are collected. Detailed implementation steps for identifying the local curvature type of the current heart surface based on these contact surface morphological feature parameters include:

[0027] The negative pressure adsorption device is controlled to vertically descend towards the heart surface at a preset speed, while simultaneously monitoring the contact force data fed back by the force sensor. The approach process is driven by a precision servo motor, with speed control accuracy reaching ±0.01 mm / s, ensuring the smoothness and controllability of the approach process. The selection of the preset speed comprehensively considers operational efficiency and safety; too fast a speed may cause damage to the heart surface due to impact, while too slow a speed would prolong the operation time and increase the animal's burden. The force sensor uses a high-sensitivity strain gauge or piezoelectric sensor, typically with a range of 0-100 mN and a resolution better than 0.1 mN, capable of accurately capturing minute force changes at the moment of contact. The monitoring process acquires force data in real time at a high sampling frequency (typically ≥1 kHz), and high-frequency noise is removed through a digital filtering algorithm to extract the true contact force signal.

[0028] When the contact force data reaches the trigger threshold, it is determined to be a moment of contact, triggering the array-type pressure sensor to collect the pressure distribution matrix at that moment. The trigger threshold is set based on the mechanical characteristics and safety considerations of the mouse heart, ensuring reliable contact detection while avoiding excessive compression of the myocardium. The array-type pressure sensor is placed around the adsorption port of the negative pressure adsorption device, employing flexible pressure sensor array technology, containing multiple independent sensing units (typically 16-64), with a spatial resolution of 1-2 mm, capable of finely capturing the pressure distribution details of the contact area. At the moment the trigger signal is generated, the system simultaneously collects the pressure values ​​of all sensing units, forming a two-dimensional pressure distribution matrix. This matrix completely records the spatial distribution information of the pressure in contact between the adsorption port and the myocardial surface, providing raw data for subsequent morphological feature extraction.

[0029] The pressure distribution matrix is ​​binarized and contour extracted. The ratio of the contact area to the theoretical area of ​​the adsorption port is calculated as the contact area ratio, and the pressure distribution uniformity index is calculated based on the variance of the pressure distribution. Binarization employs an adaptive threshold segmentation method, automatically determining the segmentation threshold based on the statistical characteristics of the pressure distribution, converting the pressure matrix into a binary image. Areas above the threshold are marked as contact areas, and areas below the threshold are marked as non-contact areas. Contour extraction uses an edge detection algorithm to accurately determine the boundaries of the contact areas, calculate the number of pixels in the contact areas, and convert this to the actual area based on the sensor's spatial resolution. The theoretical area of ​​the adsorption port is the designed geometric area of ​​the adsorption port. The formula for calculating the contact area ratio is:

[0030] ; in, This refers to the contact area ratio. This represents the actual contact area. This represents the theoretical area of ​​the adsorption port. A ratio closer to 1 indicates a more complete fit, while a ratio that is too low indicates poor contact or curvature mismatch. The pressure distribution uniformity index is calculated based on the variance of the pressure values ​​within the contact area; a smaller variance indicates a more uniform pressure distribution and better fit quality. The uniformity index is calculated using normalized variance to eliminate the influence of absolute pressure values. The formula is: ; in, The pressure distribution uniformity index. The standard deviation of the pressure values ​​in the contact area. This represents the average pressure value in the contact area. The index value ranges from [0, 1], with a larger value indicating better uniformity.

[0031] The distance between the centroid of the pressure distribution and the geometric center of the adsorption port is calculated as the centroid offset. The contact area ratio, pressure distribution uniformity index, and centroid offset are input into a pre-trained curvature classification model. The pressure distribution centroid is calculated using a weighted centroid algorithm, with the following formula: , ; in, The centroid coordinates of the pressure distribution are... For position The pressure value at that location, The coordinates of this location are given. The geometric center of the adsorption port is the coordinate of the center point of the adsorption port's geometry, and the centroid offset is calculated as the Euclidean distance between the two points. A larger offset indicates that the center of contact pressure deviates from the center of the adsorption port, reflecting the asymmetry of the local curvature of the heart surface or the deviation of the adsorption position. The three feature parameters are combined into a feature vector, which is input into a pre-trained curvature classification model. This model is trained based on machine learning algorithms (such as support vector machines, random forests, or neural networks), and the training data comes from labeled samples of different curvature regions in a large number of pre-experiments. The model can automatically identify the curvature type based on the combination pattern of the feature vectors.

[0032] The local curvature type labels output by the curvature classification model are obtained. These labels include convex, concave, or irregular types. Convex types characterize the surface curvature features of the LAD region along the direction of blood vessel course. The model output uses a multi-classification format, with each category corresponding to a confidence score. The category with the highest confidence score is taken as the final identification result. Convex types typically correspond to the LAD (left anterior descending artery) blood vessel course region on the surface of the left ventricle of a mouse heart, exhibiting an arc-shaped convexity along the vessel direction. Concave types correspond to grooves in the heart or concave regions near the apex. Irregular types correspond to transitional regions or diseased areas with complex curvature changes. Accurate identification of the curvature type provides a crucial basis for the selection of subsequent pressure control strategies, ensuring that the adsorption process adapts to the actual geometric features of the heart surface, thereby improving the adsorption success rate and safety.

[0033] In this embodiment of the invention, the detailed implementation steps of the controller selecting the corresponding initial negative pressure to establish a curve from a preset flexible sealing strategy library according to the local curvature type, and calculating the pressure threshold range required to achieve the target adsorption force based on the current heart rate parameters include:

[0034] The system reads a mapping table pre-stored in a flexible sealing strategy library. This table records the correspondence between different curvature types and negative pressure establishment strategies. The flexible sealing strategy library is the core knowledge base of the system, established through offline experiments and simulation optimization, and contains optimal pressure control strategies for various curvature types. The mapping table is organized using a lookup table or decision tree structure. The input is a curvature type label, and the output is the corresponding set of pressure control parameters, including key parameters such as pressure rise slope, pressure holding plateau, and holding time. The strategy library is established based on a flexible material mechanical model and cardiac surface contact mechanics analysis. Through parametric simulation and experimental verification, the pressure application curve that achieves the best sealing effect for each curvature type is determined.

[0035] When the local curvature type is convex, a first negative pressure establishment curve is selected. This curve is configured to use a linear rising segment with a first slope in the initial stage, followed by a first-duration pressure holding plateau period after reaching the pre-adsorption pressure. This allows the flexible sealing layer to deform and adapt to the surface. The characteristic of convex curvature is that the flexible sealing layer needs to bend inward to conform to the heart surface; this deformation requires time and appropriate pressure. The first slope is typically set to a gentle slope (e.g., -0.5 to -1.0 kPa / s) to avoid excessively rapid pressure rise leading to localized stress concentration or tearing of the sealing layer. The pre-adsorption pressure is set to 60-80% of the pressure corresponding to the target adsorption force. At this pressure, the sealing layer has initially deformed but is not yet fully bonded. The first-duration pressure holding plateau period (typically 3-5 seconds) allows the material to continue creeping deformation under constant pressure, gradually eliminating local gaps and achieving full bonding. This two-stage strategy balances deformation rate and quality, ensuring the reliability of the seal.

[0036] When the local curvature is irregular, a second negative pressure establishment curve is selected, configured as a stepped upward waveform. Irregular curvature is characterized by complex cardiac surface geometry; a linear increase with a single slope is insufficient to adapt to changes in local curvature, easily leading to over-adsorption in some areas and poor sealing in others. The stepped upward waveform divides the pressure establishment process into multiple stages, each containing a rapid rise and a brief holding period, gradually achieving a complete seal through multiple progressive adjustments. A typical configuration includes 3-5 steps, with each step's pressure increment being 20-30% of the total pressure range, and a holding time of 1-2 seconds. This strategy simulates a manual adjustment process, finding the optimal sealing state through multiple trial adjustments, adapting to changes in complex curvature, and improving the sealing success rate.

[0037] The system acquires the current heart rate parameters, calculates the target adsorption force based on a preset adsorption force-heart rate mapping function, and determines the upper and lower limits of the pressure threshold range based on the target adsorption force. The pressure threshold range is configured to limit the negative pressure value to a range that does not cause excessive myocardial deformation. Heart rate parameters are acquired in real-time via electrocardiogram (ECG) monitoring equipment, reflecting the frequency and intensity of heartbeats. The adsorption force-heart rate mapping function is established based on a cardiac mechanics model, considering the inertial force and acceleration generated by heartbeats: the higher the heart rate, the greater the inertial force generated by the heartbeat, requiring a larger adsorption force to maintain stable adsorption. The mapping function is typically in linear or quadratic form, derived from fitting extensive experimental data. After calculating the target adsorption force, the corresponding target negative pressure value is determined through the force-pressure conversion relationship of the adsorption device (depending on the adsorption port area and sealing efficiency). The pressure threshold range sets upper and lower limits based on the target negative pressure value: the lower limit ensures the adsorption force is sufficient to overcome heartbeats, typically 90-95% of the target value; the upper limit restricts the maximum negative pressure to prevent excessive myocardial deformation, local ischemia, or tissue damage, typically 105-110% of the target value. This range is set by taking into account both adsorption stability and safety, providing a benchmark for subsequent pressure relief control.

[0038] In this embodiment of the invention, the detailed implementation steps of activating the vacuum suction unit, applying suction to the negative pressure adsorption chamber according to the initial negative pressure establishment curve, and simultaneously monitoring the rate of change of pressure difference across the air-permeable and liquid-permeable membrane set in the negative pressure path in real time include:

[0039] The vacuum suction unit establishes a curve based on the selected initial negative pressure to increase the negative pressure value within the negative pressure adsorption chamber. The vacuum suction unit employs a precision vacuum pump or negative pressure generator, equipped with a proportional control valve and a pressure feedback loop, forming a closed-loop pressure control system. The control process is implemented using a PID (Proportional-Integral-Derivative) control algorithm. Based on the target pressure curve and actual pressure feedback, the opening of the control valve or the pump speed is dynamically adjusted to ensure that the actual pressure accurately follows the set curve. The control accuracy typically reaches ±0.1 kPa, with a response time of less than 100 ms, enabling accurate reproduction of complex pressure curves. During suction, the gas within the negative pressure adsorption chamber is gradually extracted, causing the internal pressure to gradually decrease (the negative pressure value increases), driving the flexible sealing layer to deform and adhere to the heart surface.

[0040] A first pressure sensor collects the pressure value on the side of the air-permeable, liquid-permeable membrane near the negative pressure adsorption chamber, while a second pressure sensor collects the pressure value on the side of the membrane near the vacuum suction unit. Both pressure sensors are of the same specification and model to ensure measurement consistency, with a typical range of -100 kPa to 0 kPa (relative to atmospheric pressure) and an accuracy better than ±0.5% of full scale. The first pressure sensor is installed close to the negative pressure adsorption chamber to accurately reflect the pressure state within the chamber, including suction pressure and pressure fluctuations due to leakage. The second pressure sensor is installed on the other side of the membrane, near the vacuum suction unit, reflecting the pressure state after membrane filtration. Sampling by both sensors is performed synchronously, with a sampling frequency typically between 100-500 Hz to ensure the capture of rapid pressure changes.

[0041] The difference between the first and second pressure values ​​is calculated as the pressure difference across the membrane, and the change in pressure difference at adjacent sampling times is calculated using a preset sampling frequency. The pressure difference calculation is achieved through simple numerical subtraction, but sensor time synchronization and signal delay compensation must be considered to ensure that the two pressure values ​​correspond to measurements taken at the same time. The physical meaning of the pressure difference is the pressure gradient across the gas-permeable but liquid-permeable membrane, driving gas flow through the membrane. In cases of poor sealing, due to gas leakage, a large amount of gas flows through the membrane, resulting in a large pressure difference across the membrane; in cases of good sealing, the amount of gas leakage decreases, the amount of gas flowing through the membrane decreases, and the pressure difference decreases. The change in pressure difference is calculated by subtracting the pressure difference values ​​at adjacent sampling points, reflecting the temporal trend of the pressure difference.

[0042] The rate of change of pressure difference is calculated based on the change in pressure difference and the sampling time interval. This rate of change characterizes the change in gas flux through a gas-permeable but liquid-impermeable membrane. The formula for calculating the rate of change of pressure difference is the change in pressure difference divided by the sampling time interval, with units of kPa / s. This indicator is a key parameter for determining the sealing status and has a clear physical meaning: In the initial stage of aspiration, the gap between the flexible sealing layer and the myocardial surface is large, resulting in a large gas leakage, high gas flux through the membrane, rapid changes in the pressure difference across the membrane, and a high rate of change of pressure difference. As the sealing layer gradually adheres, the leakage gap narrows, the gas flux decreases, the pressure difference tends to stabilize, and the rate of change of pressure difference decreases. When the seal is complete, the leakage is essentially eliminated, the pressure difference reaches a steady state, and the rate of change of pressure difference approaches zero. Therefore, the temporal characteristics of the rate of change of pressure difference directly reflect the dynamic process of seal formation, providing a real-time and sensitive monitoring method for seal determination.

[0043] In this embodiment of the invention, when the differential pressure change rate is detected to enter a preset sealing formation characteristic range, it is determined that the flexible sealing layer has completed adaptive bonding, and the detailed implementation steps of triggering the spatial coordinate locking command of the needle guide channel include:

[0044] In the initial stage of suction, the rate of change of pressure difference remains high as the gas flows. This initial stage corresponds to the beginning of the negative pressure establishment curve. At this time, the negative pressure is small, the flexible sealing layer has just begun to contact the heart surface but has not yet deformed and adhered, and there is a clear gas leakage channel around the adsorption port. Gas enters the adsorption chamber from the external environment through the leakage channel, and then flows to the vacuum suction unit through the gas-permeable but liquid-permeable membrane, forming a continuous gas flow. Due to the large leakage and high gas flow rate through the membrane, the pressure difference across the membrane is large and adjusts rapidly with changes in suction pressure, maintaining a high rate of change of pressure difference (usually greater than 5-10 kPa / s). This stage is the normal seal establishment process, and the system continuously monitors the rate of change of pressure difference, waiting for it to begin to decrease.

[0045] The pressure difference rate of change is continuously monitored. When the pressure difference rate of change decreases and stabilizes within the preset sealing formation characteristic range, it is determined that a sealed space has been formed between the flexible sealing layer and the myocardial surface, and the gas leakage is below a preset threshold. The monitoring process employs a sliding window statistical method to calculate the average and standard deviation of the pressure difference rate of change within the most recent time window (e.g., 1-2 seconds) in real time, assessing its decreasing trend and stability. The sealing formation characteristic range is set based on experimental statistical analysis, typically defined as an average pressure difference rate of change below 10% of the initial stage and a standard deviation below a set threshold (e.g., 0.2 kPa / s), indicating that the pressure difference change has become gradual and stable. When this condition is met, it indicates that the flexible sealing layer has fully deformed and adhered to the heart surface, the leakage channel is essentially sealed, effective pressure isolation is formed inside and outside the adsorption chamber, and the gas leakage is reduced to a minimum. At this point, the leakage mainly comes from microscopic permeation of the material and tiny gaps at the joints, and its impact on maintaining the adsorption force is negligible.

[0046] At the moment when adaptive bonding is determined to be complete, a spatial coordinate locking command is generated and sent to the robotic arm or guide mechanism. This controls the spatial position, angle, and depth of the needle guide channel relative to the adsorption reference surface to stop floating and enter a rigid locking state, thus eliminating the interference of heartbeats on the needle guide surface. Before sealing is complete, to adapt to positional changes caused by heartbeats, the needle guide channel is usually in a follow-up state, maintaining its relative position to the heart surface through flexible connections or active following mechanisms. However, during needle insertion, the spatial position of the guide channel must be fixed; otherwise, heartbeats will cause the needle path to deviate, affecting the modeling accuracy. After the locking command is triggered, the locking mechanism of the robotic arm or guide mechanism (such as an electromagnetic brake, mechanical locking pin, or hydraulic clamping device) immediately actuates, locking all degrees of freedom of the guide channel, including its three-dimensional spatial position (X, Y, Z coordinates), tilt angle relative to the adsorption reference surface (pitch and yaw angles), and axial rotation angle. Once locked, the guide channel and the adsorption device form a rigid whole. Even if the heart continues to beat, the positional relationship between the guide channel and the heart surface remains unchanged because the adsorption device is fixed to the heart surface by negative pressure and moves synchronously with the heart, providing a stable and reliable spatial reference for needle insertion.

[0047] In this embodiment of the invention, under the spatial coordinate locking state, the current negative pressure value of the pressure sensor is compared with the pressure threshold range in real time. If the negative pressure value is detected to exceed the safety upper limit, the detailed implementation steps for controlling the pressure relief valve to perform a staged pressure relief action include:

[0048] In the locked state, the current negative pressure value within the negative pressure adsorption chamber is read at a preset monitoring frequency. The preset monitoring frequency is typically set to 100Hz to ensure timely detection of pressure anomalies. High-frequency monitoring is necessary because mice have a high heart rate (typically 300-600 beats / minute) and a cardiac cycle of only 0.1-0.2 seconds. Under such high-frequency heartbeats, the negative pressure value may fluctuate drastically on a millisecond timescale. If the sampling frequency is insufficient (e.g., below 10Hz), transient events of pressure exceeding limits may be missed. Therefore, a high-frequency monitoring of 100Hz is required to ensure safety. Pressure reading is implemented using hardware interrupts or high-priority tasks to ensure real-time monitoring and reliability. The read negative pressure value undergoes digital filtering to remove sensor noise and high-frequency interference, retaining the true pressure signal.

[0049] The current negative pressure value is compared with the safe upper limit of the pressure threshold range. This comparison is achieved through simple numerical judgment, but the effects of measurement error and short-term fluctuations must be considered to avoid false alarms triggered by transient noise. A continuous exceedance judgment strategy is typically adopted, meaning that a true exceedance event is only considered when the negative pressure values ​​at N consecutive sampling points (e.g., N=3-5) all exceed the safe upper limit, thus improving the reliability of the judgment. The safe upper limit is determined based on the pressure threshold range and represents the maximum permissible negative pressure value. Exceeding this value may lead to excessive myocardial deformation, local tissue damage, or blood flow obstruction, posing a safety risk.

[0050] If the current negative pressure exceeds the safe upper limit, an over-absorption risk is identified, and a graded pressure relief control signal is generated. Over-absorption may be caused by: vacuum pump control errors leading to actual aspiration exceeding the set value; sealing quality exceeding expectations resulting in actual leakage below expectations; or changes in heart position causing a decrease in the adsorption chamber volume. Regardless of the cause, once over-absorption is detected, pressure relief measures must be taken immediately to avoid damage to the myocardium. The graded pressure relief control signal includes a target pressure (usually the median or lower limit of the pressure threshold range) and a pressure relief rate limit (to prevent excessively rapid pressure relief from causing sudden adsorption failure), providing detailed parameters for the control of the pressure relief valve.

[0051] The electromagnetic pressure relief valve, located in the negative pressure path, opens and performs a micro-pressure relief action according to a preset opening-time curve. This micro-pressure relief action is configured to immediately detect the negative pressure drop after releasing a small amount of gas. The electromagnetic pressure relief valve uses proportional control or pulse width modulation (PWM) control, enabling precise control of the opening degree and opening time to achieve accurate release of small amounts of gas. The preset opening-time curve is calculated based on the system volume, leakage characteristics, and pressure response model. A small-opening, short-duration pulse-type pressure relief strategy is typically employed: the valve is opened for 10-50ms each time, with an opening degree of 5-20% of the maximum opening. After releasing a small amount of gas, the valve is immediately closed, and then the pressure change is monitored. The design concept of the micro-pressure relief action is gradual adjustment, gradually reducing the pressure to a safe range through multiple small-amplitude pressure reliefs, avoiding the sudden pressure drop and adsorption failure that may result from a large-scale pressure relief at once. After each micro-pressure relief, the system immediately reads the current negative pressure value, evaluates the pressure relief effect, and decides whether to continue pressure relief based on the actual pressure drop.

[0052] If the negative pressure value is detected to have fallen back to the pressure threshold range, the electromagnetic pressure relief valve is closed to maintain the current adsorption state. The pressure drop determination also employs a continuous sampling strategy. When the negative pressure values ​​at N consecutive sampling points are all within the safe range, the pressure relief is considered successful, and the pressure relief operation stops. At this point, the electromagnetic pressure relief valve is closed, restoring the sealed state. Dynamic equilibrium is achieved through continuous suction from the vacuum unit and minimal leakage from the system, maintaining stable negative pressure. If the pressure still exceeds the limit after the initial micro-pressure relief, the system will repeat the micro-pressure relief action until the pressure falls back to the safe range. The entire pressure relief process is completed within hundreds of milliseconds, with minimal impact on adsorption stability, ensuring a balance between safety and operational continuity.

[0053] In this embodiment of the invention, after the negative pressure value stabilizes within a safe operating range, the detailed implementation steps for extracting the stability index of the adsorption state by analyzing the pressure fluctuation amplitude over multiple consecutive cardiac cycles include:

[0054] After the negative pressure value stabilizes, time-series pressure monitoring data containing at least three complete cardiac cycles are extracted. The starting point for the time-series data extraction is the moment when the negative pressure value enters the safe operating range and stabilizes. The extraction length is dynamically determined based on the current heart rate to ensure sufficient cardiac cycles are included to obtain statistical significance. Three cardiac cycles are the minimum requirement; typically, 5-10 cycles are extracted to improve the reliability of the stability assessment. Cardiac cycle identification is achieved through ECG signal synchronization or extraction of the periodic features of the pressure signal itself. Peak detection or frequency domain analysis methods are used to determine the start and end points of each cycle. The extracted time-series data includes periodic pressure fluctuations caused by heartbeats, as well as random noise and inherent system fluctuations, providing raw material for subsequent analysis.

[0055] Bandpass filtering is applied to the time-series pressure monitoring data to extract pressure fluctuation components with frequencies consistent with the heart rate. The bandpass filter is designed with the frequency corresponding to the current heart rate as the center frequency, typically 5-10 Hz (corresponding to a heart rate of 300-600 beats / minute), and the passband width is set to ±20-30% of the center frequency to allow for physiological fluctuations in heart rate. Butterworth, Chebyshev, or elliptic filters can be used, balancing passband flatness, transition band steepness, and phase distortion. The filtering process removes high-frequency noise above the heart rate frequency (such as sensor noise and electromagnetic interference) and low-frequency drift below the heart rate frequency (such as temperature changes and system creep), retaining the pressure fluctuation components synchronized with the heartbeat. The extracted fluctuation components accurately reflect the mechanical coupling state between the adsorption device and the heart surface: when coupling is good, the adsorption device moves synchronously with the heart, and the pressure fluctuations are regular and of moderate amplitude; when coupling is poor, phase delay, amplitude abnormalities, or waveform distortion may occur.

[0056] The average peak-to-peak value of the pressure fluctuation component is calculated as the pressure fluctuation amplitude during the cardiac cycle. The peak-to-peak value is the difference between the maximum and minimum pressure fluctuation values ​​within each cardiac cycle, directly reflecting the range of pressure variation within that cycle. The calculation process first identifies each cardiac cycle, then finds the maximum and minimum values ​​of the pressure fluctuation component within that cycle, and calculates the difference to obtain the peak-to-peak value. The arithmetic mean of the peak-to-peak values ​​for all cycles is taken to obtain the average peak-to-peak value, which serves as a quantitative indicator of the pressure fluctuation amplitude during the cardiac cycle. The physical meaning of this indicator is the degree of response of the adsorption system to the heartbeat: an excessively large amplitude indicates insufficient rigidity in the connection between the adsorption device and the heart surface, resulting in relative slippage or elastic deformation; an excessively small amplitude may indicate excessive adsorption leading to localized myocardial fixation; a moderate amplitude indicates stable adsorption with minimal impact on the myocardium, representing the ideal adsorption state.

[0057] The stability index is calculated based on the ratio of the cardiac cycle pressure fluctuation amplitude to a baseline fluctuation threshold, where the stability index is inversely proportional to the cardiac cycle pressure fluctuation amplitude. The baseline fluctuation threshold is determined through extensive preliminary experiments and represents the typical pressure fluctuation amplitude under optimal adsorption conditions, typically ranging from 0.5 to 1.5 kPa. The formula for calculating the stability index is: ; in, As a stability index, As the benchmark fluctuation threshold, This represents the measured amplitude of cardiac cycle pressure fluctuations. The value is a small constant (e.g., 0.01) to prevent the denominator from being zero. The stability index ranges to positive real numbers; a larger value indicates more stable adsorption. When the measured fluctuation amplitude is close to the baseline threshold, the stability index is close to 1, indicating good adsorption. When the measured fluctuation amplitude is significantly less than the baseline threshold, the stability index is greater than 1, indicating very stable adsorption but over-adsorption should be noted. When the measured fluctuation amplitude is significantly greater than the baseline threshold, the stability index is less than 1, indicating insufficient adsorption stability, which may affect the needle insertion accuracy.

[0058] When the stability index exceeds a preset threshold, the adsorption state is considered stable, meeting the conditions for needle insertion. The preset threshold is typically set between 0.8 and 0.9, taking into account both adsorption stability and myocardial safety. When the stability index exceeds this threshold, it indicates that the connection between the adsorption device and the heart surface is stable and reliable, pressure fluctuations are within acceptable limits, the spatial positioning accuracy of the needle insertion guide channel meets requirements, and the myocardium has not been excessively compressed or damaged, thus meeting all the conditions for safe needle insertion. At this point, the system generates a "needle insertion permitted" signal, activates the status prompt module, and notifies the operator that needle insertion can begin, entering a crucial step in the modeling process.

[0059] In this embodiment of the invention, when the stability index meets the needle insertion operation conditions, the activation status prompt module outputs an operation permission signal and simultaneously records the detailed implementation steps of the current guide channel's angle parameters and depth limit parameters relative to the adsorption reference surface, including:

[0060] The system generates an operation permission signal, displaying a prompt that needle insertion is permitted on the screen or through visual signals such as indicator lights. The operation permission signal employs a multimodal prompting method to ensure operators are promptly and accurately informed of the system status. The screen display combines text, graphics, and animation, showing the text "Adsorption stable, needle insertion permitted," while simultaneously highlighting the current system status in green. Optional displays include real-time pressure curves, stability index values, and other detailed information. The indicator lights use LEDs; a green light indicates needle insertion is permitted, while a red light indicates a risk-free state, providing rapid status identification. Optional audio prompts use a buzzer or speech synthesizer to emit short beeps or a voice prompt "needle insertion permitted," suitable for situations where operators cannot directly view the screen. This multimodal prompt design improves the reliability of information transmission and operational safety.

[0061] The tilt angle data of the current guide channel relative to the adsorption reference plane, fed back by the angle sensor, is used as the angle parameter. The angle sensor, employing a dual-axis or tri-axis tilt sensor, is installed at a fixed point on the needle insertion guide channel. It measures the tilt angle of the guide channel axis relative to the adsorption reference plane (usually defined as the adsorption port plane or a local tangent plane of the heart surface), including pitch and yaw angles. The sensor accuracy is typically ±0.1°, with a resolution better than 0.01°, accurately reflecting the spatial attitude of the guide channel. The angle data is transmitted to the controller in real time via a digital interface (such as SPI, I2C, or CAN bus). The reading process is executed simultaneously with the generation of the operation permission signal, ensuring that the recorded angle parameter is completely consistent with the actual state at the moment of needle insertion. The angle parameter is a key element of the needle insertion path, directly affecting the direction and depth of needle insertion. Accurate recording of this parameter provides important evidence for postoperative evaluation and consistency comparison in subsequent experiments.

[0062] The initial depth parameter is obtained by reading the vertical distance from the end of the guide channel to the adsorption reference surface, fed back by the laser rangefinder. The laser rangefinder, employing laser triangulation or time-of-flight (TOF) principles, is installed at the end or side of the guide channel to measure the vertical distance from the end of the guide channel (needle insertion start point) to the adsorption reference surface. The sensor's range is typically 5-20 mm, with an accuracy better than ±0.01 mm, enabling precise measurement of minute distance changes. The measurement process is performed in a locked state, where the guide channel position is fixed, ensuring stable and reliable measurement results. The initial depth parameter represents the initial position of the needle insertion instrument before needle insertion and serves as the reference point for calculating the needle insertion depth. Accurate measurement of this parameter is crucial for controlling the needle insertion depth and avoiding excessively deep or shallow insertions, directly affecting the accuracy and success rate of modeling.

[0063] Based on the preset safe depth range and initial depth parameters, the depth limit parameter is calculated. The safe depth range is predetermined based on the anatomical structure of the mouse heart, the thickness of the heart wall, and experimental requirements, and is typically about 1 mm deep relative to the heart surface, ensuring that the needle reaches the middle layer of the myocardium to form an effective infarction without penetrating the heart wall. The formula for calculating the depth limit parameter is: ; in, For depth limit parameters, This is the initial depth parameter (the distance from the end of the guide channel to the adsorption reference surface). The safe needle insertion depth (relative to the adsorption reference plane) is defined by a depth limit parameter. This parameter represents the maximum allowable distance the needle insertion instrument can advance. When the position sensor of the instrument detects that the advance distance has reached this limit, the system will automatically stop the needle insertion or issue a warning to prevent excessive needle insertion that could cause cardiac perforation or contralateral myocardial damage. This parameter provides a reliable safety mechanism for needle insertion operations.

[0064] Angle parameters and depth limit parameters are associated and stored in a storage unit, generating a unique identifier for each modeling operation to ensure consistency of parameters within the same batch during subsequent operations. The storage unit uses non-volatile memory (such as EEPROM, Flash, or SD card) to ensure long-term data retention. The stored data structure includes key parameters such as timestamp, animal ID, angle parameters (pitch and yaw angles), initial depth parameters, depth limit parameters, pressure threshold range, and stability index, forming a complete modeling operation record. The unique identifier is generated by combining a timestamp (accurate to seconds or milliseconds) with the animal ID, such as "20251215143025_M001," ensuring globally unique identification for each operation. This data record provides a complete reference for postoperative consistency assessment: by comparing modeling parameters of different animals in the same batch or at different time points, the consistency and repeatability of the operation can be evaluated; by analyzing the correlation between parameters and modeling results (such as infarct area and changes in cardiac function), the modeling protocol and parameter settings can be optimized. The data can also be used for operational training, quality control, and experimental reporting, improving the standardization and traceability of experiments.

[0065] In this embodiment of the invention, after identifying the local curvature type of the current cardiac surface based on the contact surface morphology feature parameters, the method further includes: If the identification result is a high-risk curvature type, an adjustment suggestion signal is output. High-risk curvature types include those with a contact area ratio lower than a preset safe contact threshold. High-risk curvature types represent situations where the adsorption device does not adhere well to the heart surface, has difficulty sealing, or has insufficient adsorption force. These mainly include: a contact area ratio that is too low (e.g., below 0.6), indicating insufficient contact area between the adsorption port and the heart surface, failing to form an effective seal; a pressure distribution uniformity index that is too low, indicating severely uneven contact pressure distribution, with localized excessive compression or localized suspension; and a centroidal offset that is too large (e.g., exceeding 30% of the adsorption port radius), indicating that the adsorption position is severely deviated from the target area and may not be able to cover the target blood vessel or modeling site. In these cases, forcibly performing adsorption and needle insertion operations has a low success rate and high risk, potentially leading to adsorption failure, myocardial damage, or modeling position deviation. Once the system identifies a high-risk curvature type, it immediately generates an adjustment suggestion signal and outputs specific adjustment suggestions through the display screen or voice prompts, such as "Insufficient contact area, it is recommended to adjust the adsorption position to move left / right / up / down by X mm" or "Curvature mismatch, it is recommended to change the adsorption head specification," providing operators with clear directions for improvement.

[0066] If no position adjustment operation is detected within the preset waiting time after the adjustment suggestion signal is output, the vacuum suction unit will enter standby mode, prohibiting subsequent suction actions. The preset waiting time is typically set to 30-60 seconds, giving the operator sufficient time to react and adjust. During the waiting period, the system continuously monitors the position and force sensors of the adsorption device to detect any position adjustment operations (such as robotic arm movement or adsorption head repositioning). If a significant change in position or contact force is detected within the waiting time, it indicates that the operator is making an adjustment, and the system resets the waiting timer and reassesses the contact state. If no adjustment operation is detected after the waiting time, it indicates that the operator may not have received the suggestion or has chosen to ignore the warning. To avoid adverse consequences caused by high-risk operations, the system automatically controls the vacuum suction unit to enter standby mode, shuts down the vacuum pump, opens the pressure relief valve to release the established negative pressure, and prohibits subsequent suction and needle insertion actions. At the same time, the system displays a warning message "High-risk operation has been terminated, please adjust and restart" on the display screen and records the event in the log. This safety mechanism effectively prevents high-risk operations caused by operator negligence or misjudgment, improves the safety and reliability of the system, and ensures that each molding operation is carried out under optimal conditions.

[0067] In this embodiment of the invention, the spatial coordinate locking command for the needle guide channel is configured as follows:

[0068] Upon receiving the spatial coordinate locking command, the connection between the needle guide channel and the heart-pulse follow-up mechanism is released, and the electromagnetic damper or mechanical locking mechanism is activated to fix the needle guide channel at the current spatial coordinates. The heart-pulse follow-up mechanism is an auxiliary device used during adsorption establishment. Through flexible connections (such as springs, flexible rods, or active follower motors), it allows the needle guide channel to make small-amplitude position adjustments with the heartbeat, avoiding excessive contact force or adsorption device detachment due to heart movement. However, during needle insertion, the guide channel position must be fixed to provide a stable needle insertion reference. After receiving the spatial coordinate locking command, the control system first sends a signal to the follower mechanism to trigger the disconnection action: for passive follower mechanisms, this is achieved by releasing the latch or disengaging from the flexible element; for active follower mechanisms, this is achieved by disabling the follower control algorithm and locking the motor. After disconnection, the guide channel loses its coupling with the heartbeat, but because the adsorption device has been fixed to the heart surface through negative pressure adsorption, the rigid connection between the guide channel and the adsorption device ensures that the guide channel is fixed to the heart along with the adsorption device, maintaining its position relative to the heart surface. To further enhance the rigidity of the locking mechanism, the system employs a specialized electromagnetic damper or mechanical locking mechanism: the electromagnetic damper increases the damping of the guide channel's movement by applying a magnetic field, significantly suppressing vibration and minute displacements; the mechanical locking mechanism directly locks the joints or sliding parts of the guide channel through locking pins, clamping devices, or threaded locking, achieving complete rigid fixation. After locking, the spatial position and orientation of the guide channel are completely determined, providing a stable and reliable reference for needle insertion operations.

[0069] The needle guide channel is configured to allow only axial movement of the needle insertion instrument, restricting radial displacement and axial rotational freedom to ensure that the needle insertion path coincides with the axis of the guide channel. The mechanical structure of the needle guide channel is designed as a precision linear guide mechanism, typically employing cylindrical guides, linear bearings, or precision sleeve structures. Through its interaction with the guide channel, the needle insertion instrument is strictly limited to axial movement: it can freely advance or retract in the axial direction (along the guide channel axis) to control the insertion depth; its radial direction (in a plane perpendicular to the guide channel axis) is constrained by the inner wall of the guide mechanism, with clearance controlled within 0.01-0.05 mm to prevent radial offset; axial rotational freedom is restricted by keyways, flat sections, or anti-rotation pins to prevent rotation of the needle insertion instrument during advancement, ensuring the needle tip direction remains consistent. The advantages of this single-degree-of-freedom design are: it greatly simplifies the control complexity of needle insertion, requiring only the operator or automated needle insertion device to control a single axial advance; it ensures high precision and repeatability of the needle insertion path, with the needle trajectory strictly following the axis of the guide channel, unaffected by operator hand tremors or other interference; and it guarantees the accuracy of the needle insertion depth. Combined with depth limit parameters, the needle can be precisely controlled to reach the predetermined depth, achieving standardized modeling. The axial direction of the guide channel is precisely positioned relative to the heart surface upon locking, thus accurately determining the relationship between the needle insertion path and the cardiac anatomy, ensuring that each needle insertion accurately reaches the target blood vessel or myocardial region, significantly improving the success rate and consistency of modeling.

[0070] In this embodiment of the invention, the needle guide channel is also configured with a curved needle insertion mode, the detailed implementation steps of which include:

[0071] During the needle insertion instrument installation phase, the system automatically detects the type of needle insertion instrument through the instrument identification module. Identification methods include: reading the instrument's coding information via RFID tags to automatically identify it as a straight or curved needle; detecting the instrument's geometric contour using optical sensors to identify the curved features of a curved needle; or allowing the operator to manually select the instrument type on the control interface. When a curved needle is detected, the system automatically switches to curved needle insertion mode, removing restrictions on axial rotational freedom and activating the rotary drive mechanism.

[0072] The core principle of the curved needle insertion mode is that the curved needle has a preset radius of curvature. During the insertion process, if it only advances axially without rotating, the needle will deviate laterally due to the curvature, making it impossible to puncture along a straight path. By controlling the rotation of the curved needle around its own axis, the needle tip can move along an arc trajectory, precisely controlling the spatial shape of the puncture path. By simultaneously controlling the rotation angle and the insertion depth, straight puncture, arc puncture, or complex three-dimensional path puncture can be achieved to meet different modeling needs.

[0073] The rotary drive mechanism is located near the needle guide channel and includes a precision rotary motor, a rotary encoder, an axial feed driver, and a synchronization controller. The rotary motor, using a stepper motor or servo motor, has a resolution better than 0.1°, enabling precise control of the bending needle's rotation angle. The rotary encoder provides real-time feedback on the bending needle's current rotation angle, forming a closed-loop control. The axial feed driver, using a linear motor or precision lead screw mechanism, controls the bending needle's axial feed depth with a positioning accuracy better than 0.01mm. The synchronization controller operates based on the bending needle's geometric parameters (radius of curvature). Calculate the rotation angle based on the arc length, target needle depth, and other parameters. With depth of advancement The synchronous control curve.

[0074] For achieving a straight puncture path (i.e., the curved needle tip advances in a straight line along the axis of the guide channel), the calculation of the synchronization control curve is based on the following geometric relationship: ; in, This is the angle (in radians) that the bent needle needs to rotate. For axial thrust depth, Let be the radius of curvature of the bend. This formula shows that for the bend tip to advance along a straight trajectory, the rotation angle must be proportional to the advance depth, with the proportionality coefficient being the reciprocal of the radius of curvature. The controller synchronously drives the rotary motor and the advance driver at a high frequency (typically 100-500Hz) to ensure that their movements are strictly coordinated according to the calculated curve.

[0075] For cases requiring an arc-shaped puncture path, the operator can preset the target puncture arc (e.g., 30° off-axis). The system then adjusts the ratio of rotation angle to insertion depth based on the target arc and needle depth, enabling the needle tip to move along the set arc. This flexible path control capability allows the system to adapt to complex anatomical structures and diverse experimental needs.

[0076] During needle advancement, the non-uniform resistance of the myocardial tissue disturbs the needle's trajectory. Factors such as myocardial fiber orientation, tissue density, and water content lead to significant differences in puncture resistance in different areas. This uneven resistance can cause unexpected deflection or rotation of the needle during advancement, resulting in the actual trajectory deviating from the theoretically calculated curve.

[0077] When a sudden increase in axial resistance is detected, the feed speed is appropriately reduced and the rotation angle compensation is increased to prevent the bending needle from being axially compressed or bent due to resistance. When an abnormal rotation torque is detected, the rotation speed is adjusted or an additional rotation torque is applied to overcome the resistance of the tissue to the rotation of the bending needle. By comparing the actual rotation angle (encoder feedback) with the theoretical rotation angle (control curve) in real time, the deviation is calculated and dynamically corrected by the PID controller to ensure that the actual trajectory always closely follows the preset path.

[0078] The compensation control algorithm employs an adaptive control strategy, optimizing control parameters in real time based on historical data and current feedback to improve trajectory tracking accuracy. Experimental verification shows that, through real-time compensation, the trajectory error of the bent needle can be controlled within ±0.1mm, meeting the requirements for precise mold making.

[0079] In the curved needle insertion mode, the calculation of the depth limit parameter needs to consider the arc-shaped trajectory characteristics of the curved needle. Because the tip of the curved needle moves along an arc, there is a geometric relationship between its axial advance depth and the actual puncture depth (measured along the arc): ; In straight-line puncture mode, the arc depth equals the axial depth, and the calculation method for the depth limit parameter is the same as for straight needle. In arc-shaped puncture mode, it is necessary to calculate the mapping relationship between the actual puncture depth and the axial advance depth based on the target arc path, and set the corresponding limit parameters.

[0080] The safety protection mechanisms include: when abnormally high resistance (exceeding a preset threshold, such as 5N) is detected during the needle bending process, the system immediately stops the bending and issues a warning to prevent the needle from breaking or myocardial tearing; when the rotation angle or the depth of the bending exceeds the safe range, an emergency stop is triggered and the system automatically retracts.

[0081] The straight needle insertion mode is suitable for situations where the target area is located in the superficial layer of the heart and there are no important anatomical structures obstructing the puncture path. It is simple to operate and intuitive to control, making it the preferred option for routine modeling. The curved needle insertion mode is suitable for complex situations that require bypassing surface blood vessels, reaching deep myocardium, or puncturing at a specific angle. The curved trajectory can avoid important structures, reduce collateral damage, and improve the safety and flexibility of modeling.

[0082] The system supports seamless switching between two modes, allowing operators to select the appropriate needle insertion instrument and mode based on specific experimental needs, fully leveraging their respective advantages to adapt to diverse myocardial infarction modeling scenarios. All operating parameters, trajectory data, and biomechanical feedback are recorded in real time, providing comprehensive data support for postoperative evaluation and protocol optimization.

[0083] This invention, through morphological feature acquisition, adaptive pressure control, sealing determination, coordinate locking, and stability verification, can adapt to different cardiac surface curvatures. The air-permeable and liquid-impermeable membrane monitoring technology enables real-time and accurate determination of the sealing status, and the spatial coordinate locking mechanism eliminates cardiac pulsation interference, providing a stable and reliable needle insertion benchmark for mouse myocardial infarction modeling, significantly improving the accuracy, safety, and repeatability of the modeling operation.

[0084] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0085] It should be noted that all formulas in this manual are calculated by removing dimensions and taking their numerical values. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters and thresholds in the formulas are set by those skilled in the art according to the actual situation.

[0086] Although embodiments of the invention have been shown and described, those skilled in the art will understand 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 claims and their equivalents.

Claims

1. A negative pressure adsorption guide needle control system for mouse myocardial infarction modeling, characterized in that, include: The morphological feature acquisition module is used to control the negative pressure adsorption device to perform an approaching action towards the surface of the mouse heart. At the moment when the acquisition device contacts the surface of the myocardium, the morphological feature parameters of the contact surface are acquired. Based on the morphological feature parameters of the contact surface, the local curvature type of the current heart surface is identified. The morphological feature parameters of the contact surface include the contact area ratio, the pressure distribution uniformity index, and the centroid offset. The pressure budget module is used to select the corresponding initial negative pressure from the preset flexible sealing strategy library to establish a curve according to the local curvature type, and calculate the pressure threshold range required to achieve the target adsorption force based on the current heart rate parameters. The suction control module is used to start the vacuum suction unit, apply suction to the negative pressure adsorption chamber according to the initial negative pressure establishment curve, and monitor the pressure difference change rate on both sides of the air-permeable and liquid-permeable membrane set in the negative pressure path in real time. The air-permeable and liquid-permeable membrane is set between the negative pressure adsorption chamber and the vacuum suction unit. The sealing determination module is used to determine that the flexible sealing layer has completed adaptive bonding when the pressure difference change rate is detected to enter the preset sealing formation characteristic range, trigger the spatial coordinate locking command of the needle guide channel, and switch the positional relationship of the needle guide channel relative to the adsorption reference surface from the follow-up state to the rigid locking state. The pressure relief control module is used to compare the current negative pressure value of the pressure sensor with the pressure threshold range in real time when the spatial coordinates are locked. If the negative pressure value is detected to exceed the safety upper limit, the pressure relief valve is controlled to perform a graded pressure relief action until the negative pressure value falls back to the safe working range. The pressure fluctuation analysis module is used to extract the stability index of the adsorption state by analyzing the pressure fluctuation amplitude over multiple consecutive cardiac cycles after the negative pressure value has stabilized within the safe working range. The status prompt module is used to activate the status prompt module to output an operation permission signal when the stability index meets the needle insertion operation conditions, and simultaneously record the angle parameters and depth limit parameters of the current guide channel relative to the adsorption reference surface.

2. The system according to claim 1, characterized in that, The controlled negative pressure adsorption device performs an approaching motion towards the surface of the mouse heart. At the instant the acquisition device contacts the myocardial surface, it collects the morphological features of the contact surface. Based on these morphological features, it identifies the local curvature type of the current heart surface, including: The negative pressure adsorption device is controlled to approach the heart surface vertically downward at a preset speed, while the contact force data fed back by the force sensor is monitored. When the contact force data reaches the trigger threshold, it is determined to be the moment of contact, and the array pressure sensor is triggered to collect the pressure distribution matrix at the current moment; The pressure distribution matrix is ​​binarized and its contour is extracted. The ratio of the contact area to the theoretical area of ​​the adsorption port is calculated as the contact area ratio. The pressure distribution uniformity index is calculated based on the variance of the pressure distribution. The distance between the centroid of the pressure distribution and the geometric center of the adsorption port is calculated as the centroid offset. The contact area ratio, pressure distribution uniformity index, and centroid offset are then input into a pre-trained curvature classification model. Obtain the local curvature type label output by the curvature classification model. The local curvature type label includes convex, concave or irregular.

3. The system according to claim 1, characterized in that, The step of selecting a corresponding initial negative pressure from a preset flexible sealing strategy library to establish a curve based on the local curvature type, and calculating the pressure threshold range required to achieve the target adsorption force based on the current heart rate parameters, includes: Read the mapping table pre-stored in the flexible sealing strategy library, which records the correspondence between different curvature types and negative pressure establishment strategies; When the local curvature type is convex, a first negative pressure establishment curve is selected. The first negative pressure establishment curve is configured to use a linear rising segment with a first slope in the initial stage, and to perform a pressure holding plateau period of a first duration after reaching the pre-adsorption pressure, so as to allow the flexible sealing layer to deform and adapt to the curved surface. When the local curvature type is irregular, a second negative pressure establishment curve is selected, and the second negative pressure establishment curve is configured as a stepped rising waveform. The current heart rate parameter is obtained, the target adsorption force is calculated based on the preset adsorption force-heart rate mapping function, and the upper and lower limits of the pressure threshold range are determined according to the target adsorption force. The pressure threshold range is configured to limit the negative pressure value to a range that does not cause excessive myocardial deformation.

4. The system according to claim 1, characterized in that, The vacuum suction unit is activated to apply suction to the negative pressure adsorption chamber according to the initial negative pressure establishment curve, while simultaneously monitoring the rate of change of pressure difference across the air-permeable but liquid-permeable membrane in the negative pressure path in real time, including: The vacuum suction unit is controlled to establish a curve according to the selected initial negative pressure to increase the negative pressure value in the negative pressure adsorption chamber; The first pressure value of the air-permeable and liquid-impermeable membrane near the negative pressure adsorption chamber is collected by the first pressure sensor, and the second pressure value of the air-permeable and liquid-impermeable membrane near the vacuum suction unit is collected by the second pressure sensor. The difference between the first pressure value and the second pressure value is calculated as the pressure difference across the membrane, and the change in pressure difference at adjacent sampling times is calculated at a preset sampling frequency. The rate of change of pressure difference is calculated based on the change in pressure difference and the sampling time interval.

5. The system according to claim 4, characterized in that, When the differential pressure change rate is detected to enter the preset sealing formation characteristic range, it is determined that the flexible sealing layer has completed adaptive bonding, triggering a spatial coordinate locking command for the needle guide channel, including: During the initial stage of aspiration, the differential pressure change rate is continuously monitored. When the differential pressure change rate decreases and stabilizes within the preset sealing formation characteristic range, it is determined that a sealed space has been formed between the flexible sealing layer and the myocardial surface, and the gas leakage is lower than the preset threshold. When the adaptive bonding is determined to be complete, a spatial coordinate locking command is generated and sent to the robotic arm or guide mechanism to control the spatial position, angle and depth of the needle guide channel relative to the adsorption reference surface to stop floating and enter a rigid locking state.

6. The system according to claim 1, characterized in that, In the spatial coordinate locked state, the current negative pressure value of the pressure sensor is compared with the pressure threshold range in real time. If the negative pressure value is detected to exceed the safety upper limit, the pressure relief valve is controlled to perform a staged pressure relief action, including: In the locked state, the current negative pressure value in the negative pressure adsorption chamber is read at a preset monitoring frequency; Compare the current negative pressure value with the safe upper limit of the pressure threshold range; If the current negative pressure value is greater than the safety upper limit value, it is determined that there is a risk of excessive suction, and a graded pressure relief control signal is generated. The electromagnetic pressure relief valve set in the negative pressure passage is opened, and a micro-pressure relief action is performed according to the preset opening degree-time curve. The micro-pressure relief action is configured to detect the negative pressure drop immediately after releasing a small amount of gas. If the negative pressure value is detected to fall back to the pressure threshold range, the electromagnetic pressure relief valve is closed to maintain the current adsorption state.

7. The system according to claim 1, characterized in that, After the negative pressure value stabilizes within the safe operating range, the stability index of the adsorbed state is extracted by analyzing the pressure fluctuation amplitude over multiple consecutive cardiac cycles, including: After the negative pressure value stabilizes, extract the time series data of pressure monitoring containing at least three complete cardiac cycles; The pressure monitoring time series data is subjected to bandpass filtering to extract the pressure fluctuation component with the same frequency as the heart rate. Calculate the peak-to-peak average of the pressure fluctuation components as the cardiac cycle pressure fluctuation amplitude; The stability index is calculated based on the ratio of the cardiac cycle pressure fluctuation amplitude to the baseline fluctuation threshold. When the stability index is greater than a preset threshold, the adsorption state is determined to be stable, and the conditions for needle insertion are met.

8. The system according to claim 1, characterized in that, When the stability index meets the needle insertion operation conditions, the activation status prompt module outputs an operation permission signal and simultaneously records the angle parameters and depth limit parameters of the current guide channel relative to the adsorption reference surface, including: Generate an operation permission signal, displaying a prompt that allows needle insertion on the screen or illuminating an indicator light to output a visual signal; Read the tilt angle data of the current guide channel relative to the adsorption reference plane, and use it as the angle parameter; Read the vertical distance from the end of the guide channel to the adsorption reference surface, and use it as the initial depth parameter; Based on the preset needle insertion depth safety range and the initial depth parameter, the depth limit parameter is calculated; The angle parameter and depth limit parameter are associated and stored in the storage unit, and a unique identifier code for this modeling operation is generated.

9. The system according to claim 1, characterized in that, After identifying the local curvature type of the current cardiac surface based on the contact surface morphology feature parameters, the method further includes: If the identification result is a high-risk curvature type, an adjustment suggestion signal is output, wherein the high-risk curvature type includes types with a contact area ratio lower than a preset safe contact threshold; If no position adjustment operation is detected within a preset waiting time after the adjustment suggestion signal is output, the vacuum suction unit is controlled to enter standby mode, and subsequent suction operations are prohibited.

10. The system according to claim 1, characterized in that, The spatial coordinate locking command for the needle insertion guide channel is configured as follows: Upon receiving the spatial coordinate locking command, the connection between the needle insertion guide channel and the heartbeat follow-up mechanism is released, and the electromagnetic damper or mechanical locking mechanism is activated to fix the needle insertion guide channel at the current spatial coordinate. The needle insertion guide channel is configured to allow the needle insertion instrument to move only along the axial direction, restricting radial displacement and axial rotational degrees of freedom.

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