A scalable mobility prosthetic heart valve stent and control system thereof

Abstract

A scalable mobility artificial heart valve stent and a control system thereof, comprising: a scalable mobility artificial heart valve stent: having a concave honeycomb cell structure; a strain sensing module: integrated in the stress part of the concave honeycomb cell, real-time acquisition of strain data of each honeycomb cell; a data transmission module: connected with the strain sensing module, the strain data is transmitted to the control module; a control module: in communication connection with the data transmission module, including: a pre-stored mapping model, updating and / or storing the corresponding relationship of compression force-strain-radial shrinkage; a PID control module for calculating the real-time compression force adjustment instruction according to the deviation of real-time strain data and target strain; a force control execution module: arranged at the front end of the delivery catheter, in communication connection with the control module, for applying or reducing local compression force to the corresponding honeycomb cell according to the compression force adjustment instruction. The application adapts to the growth needs of patients and reduces the risk of surgery.

Description

Technical Field

[0001] The present invention relates to the technical field of heart valves, and more particularly to a telescopically movable artificial heart valve stent and a control system thereof. Background Art

[0002] Valvuloplasty is the preferred surgical intervention for aortic valve disease. However, when valvuloplasty fails or valve damage is too severe to repair, aortic valve replacement becomes necessary. Currently available artificial valves on the market are fixed in size and are typically made of non-living tissue or rigid materials.

[0003] However, a key drawback of these valves in the treatment of pediatric aortic valve disease is their lack of growth and remodeling capacity, making them unable to adapt to the needs of children during growth and development, resulting in symptoms such as valvular regurgitation. This mismatch not only affects the normalization of coronary blood flow reserve after surgery but also adversely affects left ventricular function. As a result, children often require multiple valve replacement surgeries before reaching adulthood.

[0004] At the same time, existing heart valves need to be compressed to a small diameter through a catheter during delivery to reduce vascular damage. However, traditional positive Poisson's ratio stents (such as metal mesh or polymer stents) will produce lateral expansion (positive Poisson's ratio effect) due to material properties when compressed, resulting in the stent's minimum outer diameter after compression being limited, requiring the use of a thicker delivery catheter, increasing the risk of surgical trauma.

[0005] In addition, the axial compression force applied by doctors when operating the delivery catheter may vary due to differences in experience or the curvature of the patient's vascular path (e.g., the catheter is squeezed by the vascular wall during pushing, resulting in uneven compression force), which may cause the shrinkage of the honeycomb unit to deviate from the design value (e.g., excessive compression causing the unit to be concave too deeply, or insufficient compression causing insufficient radial shrinkage).

[0006] If local units undergo plastic deformation due to uneven force during compression (such as the angle of a connecting rib deviates from 120°), the stent may experience asymmetric radial expansion (such as local bulges or depressions) after release, affecting the fit between the valve and the native aortic wall, leading to paravalvular leakage or hemodynamic abnormalities.

[0007] Therefore, the problems existing in the prior art need to be further improved and developed. Summary of the Invention

[0008] (1) Purpose of the invention: In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a retractable and movable artificial heart valve stent and its control system.

[0009] (II) Technical solution: In order to solve the above technical problems, this technical solution provides a control system for a retractable and movable artificial heart valve stent, including:

[0010] A retractable and movable artificial heart valve stent: a concave honeycomb unit structure with a negative Poisson's ratio;

[0011] Strain sensing module: integrated in the stress-bearing part of the concave honeycomb unit, used to collect strain data of each honeycomb unit in real time;

[0012] Data transmission module: connected to the strain sensing module, used to transmit the strain data to the control module;

[0013] Control module: communicatively connected to the data transmission module, including: a pre-stored mapping model, updating and / or storing the corresponding relationship between compression force, strain, and radial contraction; a PID control module, for calculating real-time compression force adjustment instructions based on the deviation between real-time strain data and target strain;

[0014] Force control execution module: arranged at the front end of the delivery catheter, communicated with the control module, and used to apply or reduce local compression force to the corresponding honeycomb unit according to the compression force adjustment instruction.

[0015] In the control system of the retractable and movable artificial heart valve stent, the strain sensing module includes a plurality of micro strain sensors discretely distributed along the axial and radial directions of the concave honeycomb unit.

[0016] The control system of the telescopically movable artificial heart valve stent, wherein the data transmission module includes: a wired transmission device and / or a wireless transmission device.

[0017] The control system of the telescopically movable artificial heart valve stent, wherein the pre-stored mapping model is constructed by the following steps:

[0018] The data input layer obtains raw data and standardizes the raw data to obtain standard data; the raw data includes vascular physiological parameters of different ages and different vascular types;

[0019] The computational verification layer establishes a finite element simulation model, and simulates the strain distribution and radial contraction of the retractable and movable artificial heart valve stent under different compressive forces based on the finite element simulation model to obtain simulation data: a corresponding relationship between compression force, strain, and radial contraction;

[0020] The verification calibration layer verifies the obtained corresponding relationship between compression force, strain and radial contraction, and modifies the finite element simulation model according to the verification result to obtain an updated pre-stored mapping model.

[0021] The control system of the retractable and movable artificial heart valve stent, wherein the verification calibration layer verifies the obtained correspondence between compression force, strain and radial contraction, and modifies the finite element simulation model according to the verification result to obtain the updated pre-stored mapping model, specifically includes:

[0022] A simulation verification unit is constructed; the simulation verification unit includes a simulated blood vessel matching different physical classifications, a pulsating pressure pump, a high-speed optical measurement system, and a compression pressure pump; the retractable and movable artificial heart valve stent is implanted into the simulated blood vessel, a compression force consistent with that in the finite element simulation model is applied by the compression pressure pump, and the strain and radial contraction of the surface of the retractable and movable artificial heart valve stent are simultaneously collected;

[0023] Compare the compression force applied by the compression pressure pump, the strain and radial contraction of the surface of the retractable and movable artificial heart valve stent collected, and the corresponding relationship between compression force, strain, and radial contraction obtained by the finite element simulation model with the same compression force, calculate the root mean square error, and obtain the error value. According to the relationship between the error value and the standard error, determine whether the simulation data of the corresponding compression force range needs to be corrected;

[0024] According to the compression force applied by the compression pressure pump and the collected strain and radial contraction of the surface of the telescopically movable artificial heart valve stent, the finite element simulation model is corrected using a particle swarm optimization algorithm to obtain an updated pre-stored mapping model.

[0025] The control system of a retractable and movable artificial heart valve stent, wherein the PID control module includes an adaptive parameter adjustment unit, and the adaptive parameter adjustment unit adjusts the proportional coefficient, integral coefficient and differential coefficient of the PID control module according to the biomechanical characteristic parameters of the target sample.

[0026] The control system of the retractable and movable artificial heart valve stent, wherein the PID control algorithm module calculates the compression force to be adjusted based on the deviation between the real-time strain data and the target strain,

[0027] ΔF=Kp·Δε + Ki·∫Δεdt + Kd·d(Δε) / dt,

[0028] Where ΔF is the compression force that needs to be adjusted; Kp is the proportional coefficient; Δε is the deviation from the target strain, Δε = target strain -Real-time response ; Ki is the integral coefficient; dt is the time increment; Kd is the differential coefficient; d(Δε) / dt is the rate of change of the deviation Δε with time t, d(Δε) / dt=(current deviation - previous moment deviation) / time interval.

[0029] The control system of the retractable and movable artificial heart valve stent, wherein the force control execution module includes a plurality of micro-drive devices circumferentially arranged at the front end of the delivery catheter, each micro-drive device driver corresponds to a honeycomb unit, and the micro-drive device is used to adjust the local compression force of the corresponding honeycomb unit.

[0030] A telescopic and movable artificial heart valve stent, used in the above-mentioned control system, comprises a stent body, a fixing ring and an artificial valve.

[0031] The stent body is a tubular structure and is composed of concave honeycomb units with a negative Poisson's ratio; the fixing ring is located above the stent body and is connected by connecting ribs; the valve is composed of three valve petals of the same shape and equal size, and the valve is fixed in the gap between the stent body and the fixing ring.

[0032] The telescopically movable artificial heart valve stent has a concave honeycomb unit with a length of 6.58 mm and a width of 6.30 mm, and an angle of two connecting ribs in the horizontal direction of the concave honeycomb unit is 120°.

[0033] (3) Beneficial effects: The present invention provides a retractable and movable artificial heart valve stent and its control system. The stent body is composed of an inward-concave honeycomb unit with a negative Poisson's ratio. The diameter and length of the artificial aortic valve are increased by its tensile expansion effect, so that the stent and diameter of the artificial aortic valve can be adjusted to meet the needs of the existing artificial aortic valve during its growth and development. In addition, the strain and radial contraction of the stent body during transportation are simulated, and a reference strategy for pressure adjustment is given in time, reducing the risk of surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic structural diagram of a first-view side view of a telescopically movable artificial heart valve stent according to the present invention;

[0035] Figure 2 A schematic structural diagram of a second perspective side view of a telescopically movable artificial heart valve stent according to the present invention;

[0036] Figure 3 This is a schematic diagram of the structure of a telescopic and movable artificial heart valve stent according to the present invention from a top view;

[0037] Figure 4 This is a schematic structural diagram of a telescopic and movable artificial heart valve stent according to the present invention from a three-dimensional perspective;

[0038] Figure 5 This is a schematic diagram of the flattened structure of a stent body of a telescopically movable artificial heart valve stent according to the present invention after being unfolded;

[0039] Figure 6 This is a schematic diagram of the three-dimensional structure of a telescopic and movable artificial heart valve stent of the present invention after the stent body is unfolded;

[0040] Figure 7 This is a schematic diagram of the structure of a telescopically movable artificial heart valve stent of the present invention, viewed from the left after the stent body is unfolded;

[0041] Figure 8 This is a schematic diagram of the structure of a telescopically movable artificial heart valve stent of the present invention after the stent body is unfolded;

[0042] Figure 9 This is a schematic structural diagram of a first-perspective side view of an artificial valve of a telescopically movable artificial heart valve stent according to the present invention;

[0043] Figure 10 A schematic structural diagram of a second perspective of the side of an artificial valve of a telescopically movable artificial heart valve stent of the present invention;

[0044] Figure 11 This is a schematic structural diagram of an artificial valve of a telescopically movable artificial heart valve stent according to the present invention, viewed from above;

[0045] Figure 12 This is a schematic structural diagram of an artificial valve of a telescopically movable artificial heart valve stent according to the present invention from a three-dimensional perspective;

[0046] Figure 13 This is a schematic structural diagram of a control system for a telescopically movable artificial heart valve stent according to the present invention;

[0047] 101-Stent body; 102-Fixer ring; 103-Artificial valve. DETAILED DESCRIPTION

[0048] The present invention is further described in detail below in conjunction with preferred embodiments. More details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0049] The accompanying drawings are schematic diagrams of embodiments of the present invention. It should be noted that the drawings are merely examples and are not drawn to scale, and should not be used to limit the actual scope of protection claimed in the present invention.

[0050] A scalable mobility artificial heart valve stent and its control system are used for doctors to learn and / or practice artificial heart valve implantation, and can also be used as an auxiliary system to provide force intensity recommendations for compression force.

[0051] A scalable mobility artificial heart valve stent for a control system of a scalable mobility artificial heart valve stent, as shown in the figure, includes a stent body 101, a fixed ring 102, and an artificial valve 103. The stent body 101 is in a tubular structure and is composed of negative Poisson's ratio concave honeycomb cells. The fixed ring 102 is located above the stent body 101 and is connected by connecting ribs. The artificial valve 103 is composed of three valve leaflets that are the same in shape and size. The artificial valve 103 is fixed between the stent body 101 and the fixed ring 102. Figure 1-12

[0052] The lower end of the stent body 101 is circular, and the upper end is composed of three protruding structures, each with an angle of 120° and a height of 11.4 mm. Each protruding structure is the same in geometry, and each protruding structure is symmetric about the central axis of the protruding extension direction.

[0053] The cross-sectional diameter of the tubular structure of the stent body 101 is consistent, i.e., the diameter of the upper end and the lower end of the tubular structure of the stent body 101 is the same. Specifically, the inner diameter of the cross-section of the tubular structure of the stent body 101 is 17.85 mm, the outer diameter is 19.85 mm, the wall thickness is 1 mm, and the height is 18.02 mm.

[0054] The length of the concave honeycomb cell is 6.58 mm, the width is 6.30 mm, and the angle of the two connecting ribs in the horizontal direction of the concave honeycomb cell is 120°.

[0055] The fixed ring 102 is located 0.3 mm above the stent body, and there is a gap between the stent body 101 and the fixed ring 102, which is used to fix the artificial valve 103. The height of the fixed ring is 0.5 mm.

[0056] The diameter of the artificial valve 103 is 17.85 mm, and the height is 11.7 mm. The artificial valve 103 is fixed in the gap between the stent body 101 and the fixed ring 102.

[0057] ​A retractable and movable artificial heart valve stent fixes the artificial valve between a stent body 101 and a fixing ring 102. The stent body 101 is composed of negative Poisson's ratio concave honeycomb units. The diameter and length of the artificial aortic valve can be increased through the negative Poisson's ratio effect of the stent body 101, that is, the tensile expansion effect. Specifically, by applying different external forces to adjust the shape and size of the artificial aortic valve, the stent and diameter of the artificial aortic valve can be adjusted, thereby solving the problem that existing artificial aortic valves cannot increase in size as the child grows.

[0058] A control system for a retractable and movable artificial heart valve stent can be used by doctors to learn and / or practice artificial heart valve implantation surgery, and can also serve as an auxiliary system to provide compression force recommendations. Figure 13 As shown, the control system includes the retractable and movable artificial heart valve stent, strain sensing module, data transmission module, control module and force control execution module. When used for doctors to learn and / or practice artificial heart valve implantation surgery, the control system also includes a first simulation model.

[0059] The retractable and movable artificial heart valve stent comprises a structure with concave honeycomb cells. The strain sensing module is integrated into the stress-bearing portion of the concave honeycomb cells and is used to collect strain data from each honeycomb cell in real time. The data transmission module is connected to the strain sensing module and is used to transmit the strain data to a control module. The control module is communicatively connected to the data transmission module and includes a pre-stored mapping model and a PID control module. The pre-stored mapping model is used to update and / or store the correspondence between compression force, strain, and radial contraction. The PID control module is used to calculate real-time compression force adjustment instructions based on the deviation between real-time strain data and target strain. The force control execution module is located at the front end of the delivery catheter and is communicatively connected to the control module. It is used to apply or reduce local compression force to the corresponding honeycomb cells based on the compression force adjustment instructions. Based on the pre-stored mapping model and real-time strain data, the control module generates adjustment instructions via the PID control module, driving the force control execution module to adjust the compression force until the strain error of each honeycomb cell meets a preset threshold. The first simulation model is used for implanting the artificial heart valve stent and includes models of different ages and different vascular types.

[0060] The control module also includes a display unit configured to display the calculated, real-time compression force adjustment instructions. When the control system functions as an auxiliary system, a physician can use the real-time compression force adjustment instructions displayed on the display unit as a reference for adjusting the compression force intensity, thereby applying or reducing the local compression force on the corresponding cell through the force control execution module.

[0061] The strain sensing module includes a plurality of micro strain sensors discretely distributed along the axial and radial directions of the concave honeycomb unit. The micro strain sensors can be specifically arranged at the midpoints of the connecting ribs and the concave vertices of the concave honeycomb unit to realize real-time collection of strain data of each concave honeycomb unit, and the strain data reflects the local deformation of the honeycomb unit.

[0062] The micro strain sensor can be a micro piezoelectric ceramic sensor, a fiber Bragg grating sensor (FBG), a MEMS piezoresistive sensor, a flexible film sensor, etc. The strain sensing module is connected to the micro wireless transmission module at the bottom of the valve frame via a micro wire. The size is ≤2mm×2mm and the package is biocompatible. It should be noted that the selected micro strain sensor also needs to meet the following conditions:

[0063] The maximum outer dimension is less than the inner diameter of the delivery tube × length;

[0064] The total mass is ≤ 0.5g to avoid imbalance in the bending stiffness of the catheter tip due to excessive actuator weight, which affects the controllability.

[0065] No protruding structures, such as exposed wires that need to be buried to prevent jamming during transportation;

[0066] Force control accuracy ≤ 0.05N, to match the strain error control target of ±0.5% for the flexible and movable artificial heart valve stent (according to the "compression force-strain" mapping model, a 1% strain change typically corresponds to a force change of 0.1N-0.2N);

[0067] The encapsulation layer is polyimide or epoxy resin, with a thickness of ≤0.2mm.

[0068] A specific embodiment of the distribution of the micro strain sensors may be:

[0069] The axial layout positions are the proximal end (1 / 3 length), middle end (1 / 2 length) and distal end (2 / 3 length) of the stent; the radial layout positions are the apex and midpoint of each honeycomb unit; the lateral size of a single sensor is ≤0.2mm and the axial length is ≤2mm to adapt to the spatial constraint of the inner diameter × length of the catheter.

[0070] Traditional solutions cannot monitor the local deformation of honeycomb units in real time. For example, whether a connecting rib is excessively bent due to excessive force, resulting in inconsistent deformation of each unit during compression. The micro strain sensor collects the strain data of each honeycomb unit in real time to reflect whether its actual deformation meets the target value.

[0071] The micro strain sensor preferably uses a micro piezoelectric ceramic sensor, which has a millimeter-level or even submillimeter-level laminated structure, such as 0.5mm×0.5mm×5mm, to adapt to the narrow space at the front end of the catheter. The piezoelectric effect response time of the micro piezoelectric ceramic sensor is in the microsecond level (1μs~100μs), and the response time meets the real-time requirements of the 50ms~100ms control cycle in closed-loop control. The displacement resolution of the micro piezoelectric ceramic sensor is at the nanometer level of 0.1nm~1nm, and the force control accuracy is at the millinewton level of 0.01N~0.1N, meeting the precise control requirements of strain error ≤0.5%. In addition, the micro piezoelectric ceramic sensor is free of electromagnetic interference: piezoelectric ceramics do not rely on magnetic field drive and can still work stably in electromagnetically sensitive environments such as magnetic resonance imaging (MRI).

[0072] The data transmission module includes a wired transmission device and / or a wireless transmission device. The wired transmission device is used for wired transmission and can specifically be a micro coaxial cable. The coaxial cable is coated with a polyimide insulation layer and a metal shielding layer, and the thickness of the metal shielding layer is ≤0.1mm. The wireless transmission device is used for wireless transmission and can specifically be a near-field communication (NFC) module. The operating frequency of the NFC module must avoid electromagnetic interference with medical equipment and can be 13.56MHz.

[0073] The data transmission rate of the data transmission module is ≥100 Hz to meet the real-time strain monitoring requirements of the heart beat cycle (1 Hz to 2 Hz).

[0074] The pre-stored mapping model of the control module is constructed by the following steps:

[0075] Step S1: The data input layer obtains the original data and standardizes the original data to obtain standard data;

[0076] Step S2, establishing a finite element simulation model in the calculation verification layer, and simulating the strain distribution and radial contraction of the retractable and movable artificial heart valve stent under different compressive forces based on the finite element simulation model to obtain simulation data: a corresponding relationship between compression force, strain, and radial contraction;

[0077] Step S3: The verification and calibration layer verifies the simulation data and modifies the finite element simulation model according to the verification result to obtain an updated pre-stored mapping model.

[0078] The raw data include vascular physiological parameters of different ages and different vascular types, including vascular inner diameter, blood flow velocity, vascular three-dimensional geometry (curvature, bifurcation angle), vascular wall thickness, vascular wall elastic modulus (E 血, in MPa) and Poisson's ratio (ν). Vascular physiological parameters for different age groups should include at least those for those aged 0 to 12 years and may also include those for those aged 12 years and above. Vascular physiological parameters for different vascular types should include at least those for coronary and peripheral arteries.

[0079] In step S1, the original data obtained by the data input layer needs to delete abnormal data, such as congenital vascular malformations, calcifications, etc., before being input into the data input layer, so as to ensure the universality of the data.

[0080] In step S1, standardizing the original data to obtain the standard data specifically includes:

[0081] Physically classify the raw data by age and vascular type;

[0082] Obtain the key parameters corresponding to different physical classifications, that is, obtain the standard data corresponding to different physical classifications.

[0083] The key parameters include first geometric parameters and mechanical parameters. The first geometric parameters include the inner diameter of the blood vessel (denoted by the letter d, in mm), the length (denoted by the letter L, in mm), and the bending angle (denoted by the letter θ, in degrees). The mechanical parameters include the elastic modulus of the blood vessel wall (denoted by the letter E 血 expressed in MPa), Poisson's ratio (expressed by ν), and maximum tolerable strain (expressed by ε_max, in %).

[0084] In step S1, the standard data is further stored in a database. Specifically, the key parameters corresponding to different physical classifications are stored in the database, i.e., the key parameters corresponding to different ages and different blood vessel types are stored in the database. The database is preferably a relational database, such as MySQL.

[0085] The finite element simulation model can be established using COMSOL simulation software, ANSYS simulation software, etc.

[0086] In step S3, the verification calibration layer verifies the obtained correspondence between compression force, strain and radial contraction, and modifies the finite element simulation model according to the verification result to obtain an updated pre-stored mapping model. Specifically,

[0087] Step S31, building a simulation verification unit;

[0088] Step S32, comparing the strain and radial contraction of the surface of the telescopically movable artificial heart valve stent of the simulation verification unit with the simulation data of the same compression force of the finite element simulation model to determine whether the finite element simulation model needs to be revised;

[0089] Step S33: using a particle swarm optimization algorithm to modify the finite element simulation model that needs to be modified, to obtain an updated pre-stored mapping model.

[0090] In step S31, the simulation verification unit includes simulated blood vessels matching different physical categories, a pulsating pressure pump, a high-speed optical measurement system, and a compression pressure pump. When constructing the simulation verification unit, the retractable and movable artificial heart valve stent is implanted into the simulated blood vessel. The compression pressure pump applies a compression force consistent with that in the finite element simulation model, and the strain and radial contraction of the surface of the retractable and movable artificial heart valve stent are simultaneously collected to obtain verification results.

[0091] The simulated blood vessels are preferably made of silicone, with an elastic modulus of 1-3 MPa, matching that of human coronary arteries. The pulsating pressure pump simulates a heart rate of 70-90 beats per minute and a peak pressure of 120 mmHg. The high-speed optical measurement system has a resolution of 5 μm and a sampling frequency of 100 Hz. The compression pressure pump applies a compression force consistent with the finite element simulation model to the simulation verification unit.

[0092] When collecting the strain on the surface of the telescopically movable artificial heart valve stent and its radial contraction, the strain can be collected by the micro strain sensor provided on the telescopically movable artificial heart valve stent.

[0093] In the step S32, specifically including:

[0094] In the simulation verification unit, the compression force applied by the compression pressure pump and the micro strain sensor are used to collect the strain and radial contraction of the surface of the telescopic and movable artificial heart valve stent at each monitoring point, and compared with the corresponding relationship of compression force-strain-radial contraction obtained by the finite element simulation model with the same compression force: the root mean square error of the surface strain of the telescopic and movable artificial heart valve stent obtained by the simulation verification unit and the finite element simulation model under the same compression force is calculated to obtain the error value of the strain; the root mean square error of the radial contraction of the telescopic and movable artificial heart valve stent obtained by the simulation verification unit and the finite element simulation model under the same compression force is calculated to obtain the error value of the radial contraction; the error value includes the error value of the strain and the error value of the radial contraction; according to the relationship between the error value and the standard error, it is judged whether the simulation data of the corresponding compression force range needs to be corrected.

[0095] The standard error is a preset value, which may be 3%. The standard error may include the standard error of strain and the standard error of radial shrinkage. The standard error of strain and the standard error of radial shrinkage may be the same or different, and there is no specific limitation here.

[0096] According to the relationship between the error value and the standard error, it is judged whether the simulation data corresponding to the compression force interval needs to be corrected. Specifically: the error value is subtracted from the standard error to obtain a judgment difference: when the judgment difference is less than or equal to zero, the simulation data error corresponding to the compression force interval meets the requirements and does not need to be corrected, that is, the finite element simulation model does not need to be corrected; when the judgment difference is greater than zero, the simulation data error corresponding to the compression force interval is too large and needs to be corrected, that is, the finite element simulation model needs to be corrected.

[0097] When the error value exceeds 3%, the simulation data corresponding to the compression force range needs to be corrected.

[0098] In step S33, based on the compression force applied by the compression pressure pump, the strain and radial contraction of the surface of the telescopically movable artificial heart valve stent collected, that is, the verification results, the finite element simulation model is corrected using a particle swarm optimization algorithm to obtain an updated pre-stored mapping model.

[0099] The modification of the finite element simulation model according to the verification results specifically includes:

[0100] Step S331,

[0101] Obtaining initial benchmark data: In the simulation verification unit, a compression pump applies different compressive forces to the stent body. Simultaneously, a micro-strain sensor collects the surface strain and radial contraction of the stent body under different compressive forces. Standard values ​​under different compressive forces, or the strain and radial contraction corresponding to different compressive forces, are obtained, i.e., the initial benchmark data.

[0102] According to the fitness of the initial benchmark data, the benchmark data with the smallest error is selected from the initial benchmark data to obtain the first benchmark data:

[0103] The fitness of the initial benchmark data is calculated based on the fitness function, and the initial benchmark function and the corresponding fitness are placed in the fitness set. The fitness function is: fitness = W1 × strain error + W2 × radial shrinkage error, where W1 and W2 are preset values, with W1 preferably taking a value of 0.7 and W2 preferably taking a value of 0.3. The strain error is the absolute error or root mean square error between the strain value calculated by the finite element simulation model and the strain value measured by the simulation verification unit. The radial shrinkage error is the absolute error or root mean square error between the shrinkage calculated by the finite element simulation model and the shrinkage measured by the simulation verification unit.

[0104] The initial benchmark data in the fitness set are sorted according to fitness, and the initial benchmark data with fitness values ​​less than the standard fitness are selected as the first benchmark data. The standard fitness is a preset value and can be adjusted as needed.

[0105] The control module stores the optimization parameters and the value range of the optimization parameters. The optimization parameters and the value range of each optimization parameter can be input or modified through the input unit of the control module. The optimization parameters include material parameters and second geometric parameters. The material parameters include hyperelastic material parameters shear modulus and strain hardening exponent , parameter shear modulus and strain hardening exponent Together they determine the elastic deformation curve of the stent body material. Control the stiffness in the small deformation stage, Controls the hardening rate during the large deformation stage. Shear modulus The value range of can be [0.1MPa,5MPa], the strain hardening exponent The value range of can be [1, 5]. The second geometric parameter includes the edge length deviation and angle deviation of the concave honeycomb unit. The edge length deviation is the possible error in processing, and the angle deviation is the possible error in angular processing. The value range of the edge length deviation can be [-0.1mm, +0.1mm], and the value range of the angle deviation can be [-5°, +5°].

[0106] Step S332: Using a particle swarm optimization algorithm to adjust the optimization parameters in the finite element simulation model, and simulating the strain distribution and radial contraction of the retractable artificial heart valve stent under different compressive forces or specified pressures based on the finite element simulation model with the adjusted optimization parameters, to obtain second simulation data:

[0107] Step S3321, randomly select the initial position of the optimization parameter, that is, select the initial value of each optimization parameter, and obtain the optimization parameter combination under the initial position, such as [ , , edge length deviation i , angle deviation i ], each optimization parameter combination is a particle, and i is the i-th particle.

[0108] In step S3322, the optimized parameter combination for the initial position is updated by sequentially increasing or decreasing the corresponding parameter adjustment amount, thereby obtaining multiple optimized parameter combinations, i.e., multiple particles. If any of the optimized parameter combinations falls outside the corresponding value range, the optimization parameter combination for that initial position is stopped and the optimized parameter combination with parameters outside the corresponding value range is deleted. The parameter adjustment amount can be randomly generated or incremented / decremented by a specified amount, and there are no specific limitations here. It should be noted that the parameter adjustment amount for each optimized parameter is less than the difference between the maximum and minimum values ​​in the parameter's value range.

[0109] Repeat steps S3321 to S3322. When the number of obtained optimization parameter combinations (ie, particles) is greater than or equal to N, execute step S3323.

[0110] Step S3323, adjust the parameters of the finite element simulation model according to the optimized parameter combination, and then the finite element simulation model simulates the strain distribution and radial contraction of the retractable and movable artificial heart valve stent under different compression forces or specified pressures based on the adjusted optimized parameter combination to obtain second simulation data.

[0111] Step S333 , calculating the fitness of the second simulation data according to the steps of step S331 , and selecting the optimization parameter combination corresponding to the second simulation data with the smallest fitness as the target optimization parameter combination.

[0112] Step S334 : adjusting the parameters corresponding to the finite element simulation model according to the target optimization parameter combination, correcting the finite element simulation model, and obtaining an updated pre-stored mapping model.

[0113] The PID control module includes an adaptive parameter adjustment unit, which adjusts the proportional coefficient, integral coefficient and differential coefficient of the PID control module according to the biomechanical characteristic parameters of the target sample, the compression force applied by the compression pressure pump in the simulation verification unit, and the strain and radial contraction of the surface of the retractable and movable artificial heart valve stent at each monitoring point collected by the micro strain sensor.

[0114] The PID control algorithm module calculates the compression force to be adjusted based on the deviation between the real-time strain data and the target strain.

[0115] ΔF=Kp·Δε + Ki·∫Δεdt + Kd·d(Δε) / dt,

[0116] Where ΔF is the compression force that needs to be adjusted; Kp is the proportional coefficient; Δε is the deviation from the target strain, Δε = target strain -Real-time response ; Ki is the integral coefficient; dt is the time increment; Kd is the differential coefficient; d(Δε) / dt is the rate of change of the deviation Δε with time t, d(Δε) / dt=(current deviation - previous moment deviation) / time interval.

[0117] The time increment is a small time increment, such as 0.1 second, 1.01 second, etc. The initial value of Kp may be 0.002 N / μm, the initial value of Ki may be 0.0001 N / (μm·s), and the initial value of Kd may be 0.001 N·s / μm.

[0118] The adaptive parameter adjustment unit adjusts the proportional coefficient, integral coefficient and differential coefficient of the PID control module according to the target sample biomechanical characteristic parameter, and the compression force applied by the compression pressure pump and the strain and radial shrinkage of the surface of the stretchable artificial heart valve stent at each monitoring point collected by the micro strain sensor, and the specific process includes,

[0119] When the simulation verification unit, the compression force applied by the compression pressure pump and the strain and radial shrinkage of the surface of the stretchable artificial heart valve stent at each monitoring point collected by the micro strain sensor, in a time increment, collect real-time strain, if the strain deviation is greater than Z1*Δεmax, then the adaptive parameter adjustment unit increases the proportional coefficient Kp by a first increasing amount; if the strain change rate is greater than Z2*reference rate, then the adaptive parameter adjustment unit increases the differential coefficient Kd by a second increasing amount. At this time, the time increment can be 0.1s, Z1 can be 0.8, and Z2 can be 2.

[0120] When the simulation verification unit, the compression force applied by the compression pressure pump and the strain and radial shrinkage of the surface of the stretchable artificial heart valve stent at each monitoring point collected by the micro strain sensor, in a time increment, collect real-time strain, if the strain deviation is greater than Z1*Δεmax, then the adaptive parameter adjustment unit increases the proportional coefficient Kp by a first increasing amount; if the strain change rate is greater than Z2*reference rate, then the adaptive parameter adjustment unit increases the differential coefficient Kd by a second increasing amount. At this time, the time increment can be 0.1s, Z1 can be 0.8, and Z2 can be 2.

[0121] The biomechanical characteristic parameters include the elastic modulus E representing the stiffness of the target sample material (stent body), the strain rate sensitivity coefficient m representing the sensitivity of the target sample material to the compression speed of the stent body, the preset maximum allowed strain deviation Δεmax, and the target strain change rate dε0 / dt.

[0122] The force control execution module includes a plurality of micro drive devices arranged circumferentially on the positioning clamping jaws at the front end of the delivery catheter, each micro drive device driver corresponding to a honeycomb unit, and the micro drive device is used to adjust the local compression force of the corresponding honeycomb unit. The contact end of the micro drive device and the inner recessed honeycomb unit is provided with a flexible gasket such as silicone or polyurethane, and the contact area is ≤2mm². The force output range of the micro drive device is 0.1N~3N, and the force control accuracy is ≤0.05N. The micro drive device can be a piezoelectric ceramic laminated driver, a micro hydraulic push rod or a shape memory alloy (SMA) driver.

[0123] The force execution module is provided with a physical connection structure between the strain sensing module and / or the data transmission module, when the force execution module completes the compression force adjustment task (i.e. the artificial heart valve stent is placed in the target position), the force execution module is separated from the artificial heart valve stent and taken out, and at the same time, the strain sensing module and / or the data transmission module are taken out together with the force execution module through the physical connection structure. The physical connection structure can be a connecting rope or a connecting chain, which is not specifically limited here.

[0124] A scalable mobility artificial heart valve stent and its control system, by adjusting the axial compression force applied to the stent during transportation, the stent shrinks in the transverse direction, and then easily passes through the narrow place. After reaching the target position, the axial compression force is released, and the swelling effect makes the valve frame expand in the transverse direction (thicken), tightly fit the target position (such as the blood vessel wall, the part interface), and stably fix the axial compression force. The swelling effect makes the valve frame expand in the transverse direction (thicken), so as to tightly fit in the target position.

[0125] In addition, during the growth of the user, an axial tension is generated on the scalable mobility artificial heart valve stent, so that the stent expands in the transverse direction (thickens) and fits the thickening of the blood vessel with growth, ensuring the fit of the valve frame in the target position.

[0126] At the same time, the strain and radial shrinkage of the scalable mobility artificial heart valve stent during transportation can be simulated, and the reference strategy for pressure adjustment is given in time, thereby reducing the risk of surgery.

[0127] The above is a description of the preferred embodiments of the present application, which can help those skilled in the art to more fully understand the technical solutions of the present application. However, these embodiments are only illustrative, and the specific implementation of the present application is limited to the description of these embodiments. For those skilled in the art to which the present application belongs, without departing from the concept of the present application, a number of simple deductions and transformations can be made, which should be regarded as falling within the scope of protection of the present application.

Claims

1. A control system for a telescopically movable artificial heart valve stent, characterized in that: include, A retractable and movable artificial heart valve stent: a concave honeycomb unit structure with a negative Poisson's ratio; Strain sensing module: integrated in the stress-bearing part of the concave honeycomb unit, used to collect strain data of each honeycomb unit in real time; Data transmission module: connected to the strain sensing module, used to transmit the strain data to the control module; Control module: communicatively connected to the data transmission module, including: a pre-stored mapping model, updating and / or storing the corresponding relationship between compression force, strain, and radial contraction; a PID control module, for calculating real-time compression force adjustment instructions based on the deviation between real-time strain data and target strain; A force control execution module is provided at the front end of the delivery conduit and is in communication with the control module, and is used to apply or reduce the local compression force on the corresponding honeycomb unit according to the compression force adjustment instruction; The control module generates an adjustment instruction through the PID control module based on the pre-stored mapping model and real-time strain data, and drives the force control execution module to adjust the compression force until the strain error of each honeycomb unit meets a preset threshold; The PID control module includes an adaptive parameter adjustment unit, which adjusts the proportional coefficient, integral coefficient and differential coefficient of the PID control module according to the biomechanical characteristic parameters of the target sample, the compression force applied by the compression pressure pump in the simulation verification unit, and the strain and radial contraction of the surface of the artificial heart valve stent with telescopic mobility at each monitoring point collected by the micro strain sensor; The PID control module calculates the compression force to be adjusted based on the deviation between the real-time strain data and the target strain: ΔF=Kp·Δε + Ki·∫Δεdt + Kd·d(Δε) / dt, Where ΔF is the compression force that needs to be adjusted; Kp is the proportional coefficient; Δε is the deviation from the target strain, Δε = target strain -Real-time response ; Ki is the integral coefficient; dt is the time increment; Kd is the differential coefficient; d(Δε) / dt is the rate of change of the deviation Δε with time t, d(Δε) / dt=(current deviation - previous moment deviation) / time interval.

2. The control system of a telescopically movable artificial heart valve stent according to claim 1, characterized in that: The strain sensing module includes a plurality of micro strain sensors discretely distributed along the axial direction and radial direction of the concave honeycomb unit.

3. The control system of a telescopically movable artificial heart valve stent according to claim 1, characterized in that: The data transmission module includes: a wired transmission device and / or a wireless transmission device.

4. The control system of a telescopically movable artificial heart valve stent according to claim 1, characterized in that: The pre-stored mapping model is constructed by the following steps: The data input layer obtains raw data and standardizes the raw data to obtain standard data; the raw data includes vascular physiological parameters of different ages and different vascular types; The computational verification layer establishes a finite element simulation model, and simulates the strain distribution and radial contraction of the retractable and movable artificial heart valve stent under different compressive forces based on the finite element simulation model to obtain simulation data: a corresponding relationship between compression force, strain, and radial contraction; The verification calibration layer verifies the corresponding relationship between the compression force, strain and radial contraction, and modifies the finite element simulation model according to the verification result to obtain an updated pre-stored mapping model.

5. The control system of a telescopically movable artificial heart valve stent according to claim 4, characterized in that: The verification calibration layer verifies the corresponding relationship between compression force, strain and radial contraction, and modifies the finite element simulation model according to the verification result to obtain an updated pre-stored mapping model. Specifically, A simulation verification unit is constructed; the simulation verification unit includes a simulated blood vessel matching different physical classifications, a pulsating pressure pump, a high-speed optical measurement system, and a compression pressure pump; the retractable and movable artificial heart valve stent is implanted into the simulated blood vessel, a compression force consistent with that in the finite element simulation model is applied by the compression pressure pump, and the strain and radial contraction of the surface of the retractable and movable artificial heart valve stent are simultaneously collected; Compare the compression force applied by the compression pressure pump, the strain and radial contraction of the surface of the retractable and movable artificial heart valve stent collected, and the corresponding relationship between compression force, strain, and radial contraction obtained by the finite element simulation model with the same compression force, calculate the root mean square error, and obtain the error value. According to the relationship between the error value and the standard error, determine whether the simulation data of the corresponding compression force range needs to be corrected; According to the compression force applied by the compression pressure pump and the collected strain and radial contraction of the surface of the telescopically movable artificial heart valve stent, the finite element simulation model is corrected using a particle swarm optimization algorithm to obtain an updated pre-stored mapping model.

6. The control system of a telescopically movable artificial heart valve stent according to claim 1, characterized in that: The force control execution module includes a plurality of micro drive devices circumferentially arranged at the front end of the delivery catheter, each micro drive device driver corresponds to a honeycomb unit, and the micro drive device is used to adjust the local compression force of the corresponding honeycomb unit.

7. The control system of a telescopically movable artificial heart valve stent according to claim 1, characterized in that: The retractable and movable artificial heart valve stent includes a stent body, a fixing ring and an artificial valve. The stent body is a tubular structure and is composed of concave honeycomb units with a negative Poisson's ratio; the fixing ring is located above the stent body and is connected by connecting ribs; the valve is composed of three valve petals of the same shape and equal size, and the valve is fixed in the gap between the stent body and the fixing ring.

8. The control system of a telescopically movable artificial heart valve stent according to claim 1, characterized in that: The length of the concave honeycomb unit is 6.58 mm, the width is 6.30 mm, and the angle between the two connecting ribs in the horizontal direction of the concave honeycomb unit is 120°.

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