An artificial heart valve stent

Abstract

The artificial heart valve stent provided in this application includes: a main body segment, the main body segment including an inner network structure formed by multiple metal struts connected in an interlaced manner, the inner network structure being composed of multiple cells arranged circumferentially; wherein, the outflow end of the main body segment is provided with a first passive wireless sensor for detecting aortic static pressure; the sidewall of the main body segment is provided with a second passive wireless sensor for detecting ventricular static pressure; the inflow end of the main body segment is provided with a platform structure, the platform structure extending into the interior of the artificial heart valve stent, the platform structure being parallel to the radial direction, and the platform structure being provided with a third passive wireless sensor for detecting total ventricular pressure.

Description

Technical Field

[0001] This application relates to, but is not limited to, the field of medical device technology, and in particular to an artificial heart valve stent. Background Technology

[0002] Interventional surgery is an option for treating various cardiovascular-related diseases, including valvular heart disease. Natural valves in the body (such as the aortic valve, pulmonary valve, and atrioventricular valve) play a crucial role in the functioning of the circulatory system. Congenital or acquired valvular diseases, such as aortic or mitral valve calcification, can prevent the valves from opening and closing properly, increasing the workload on the heart and affecting blood supply to other organs. Transcatheter valve replacement (TVR) is a treatment for valvular heart disease. Guided by a guidewire, a stent is delivered to the valve region and opens the natural valve, allowing an artificial valve attached to the stent to function. This method avoids open-heart surgery, reducing the trauma of the treatment process, and is suitable for some elderly or physically weak patients.

[0003] After artificial valve implantation, transvalvular pressure and valve flow are the main physiological parameters to be monitored. In traditional monitoring protocols, valve flow is measured by ultrasound, while transvalvular pressure is measured using a pressure guidewire. Both require specialized measuring equipment and operators, necessitating patient visits to the hospital for measurement; furthermore, measuring transvalvular pressure using a pressure guidewire is time-consuming. Therefore, there is an urgent need to improve the equipment used for monitoring transvalvular pressure and valve flow. Summary of the Invention

[0004] This application provides an artificial heart valve stent to solve the problems of time-consuming and complex operation in related technologies for monitoring valve transmural pressure and valve flow.

[0005] The technical solution of this application embodiment is implemented as follows:

[0006] This application provides an artificial heart valve stent, which includes a main body section, the main body section including an inner mesh structure formed by multiple metal struts connected in an interlaced manner, the inner mesh structure being formed by multiple cells arranged along the circumferential and axial directions;

[0007] The main body section is provided with a first passive wireless sensor for detecting aortic static pressure at its outflow end; and / or the main body section is provided with a second passive wireless sensor for detecting ventricular static pressure on its sidewall.

[0008] The main section has a platform structure at its inflow end, which extends into the interior of the artificial heart valve stent. The platform structure is parallel to the radial direction and is equipped with a third passive wireless sensor for detecting total ventricular pressure.

[0009] The artificial heart valve stent provided in this application includes: a main body segment, the main body segment comprising an inner network structure formed by multiple interlocking metal struts, the inner network structure being composed of multiple cells arranged circumferentially and axially; wherein, the outflow end of the main body segment is provided with a first passive wireless sensor for detecting aortic static pressure; the sidewall of the main body segment is provided with a second passive wireless sensor for detecting ventricular static pressure; the difference between the internal aortic static pressure and the ventricular static pressure is the transmural pressure; the inflow end of the main body segment is provided with a platform structure extending into the interior of the artificial heart valve stent, the platform structure... The platform structure is parallel to the radial direction and is equipped with a third passive wireless sensor for detecting the total ventricular pressure. The difference between the total ventricular pressure and the ventricular static pressure is the ventricular dynamic pressure, which is used to convert the dynamic pressure into flow rate. As can be seen, the artificial heart valve stent provided in this application has multiple sensors mounted on it to measure the transmural pressure and valve flow rate. The circuit design is simple, omitting power cords and other devices, reducing the volume and number of implants, improving safety and applicability. At the same time, it monitors the transmural pressure and flow rate in real time, and the obtained parameters can assist doctors in monitoring the patient's condition, enabling early detection of problems and intervention. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the structure of the artificial heart valve stent provided in the embodiments of this application;

[0011] Figure 2 A structural schematic diagram of a portion of the inflow end of the main section provided in an embodiment of this application;

[0012] Figure 3 This is a schematic diagram of the structure of the artificial heart valve stent with sensors mounted on it, provided in an embodiment of this application.

[0013] Figure 4 This is a structural schematic diagram of the main body section and the skirt section provided in the embodiments of this application;

[0014] Figure 5 A schematic diagram of a platform structure with a second passive wireless sensor disposed at the bottom, provided in an embodiment of this application;

[0015] Figure 6 This is a schematic diagram of the structure of the second capacitive sensor provided in an embodiment of this application;

[0016] Figure 7 A cross-sectional view of the structure of a capacitive sensor provided in an embodiment of this application;

[0017] Figure 8 A cross-sectional view of the structure of a resistive sensor provided in an embodiment of this application;

[0018] Figure 9 A schematic diagram of the circuit structure for measuring sensor parameters via a first external antenna after implantation of the stent provided in this application embodiment;

[0019] Figure 10 A schematic diagram of the input impedance argument versus frequency provided for embodiments of this application;

[0020] Figure 11 A schematic diagram of the circuit structure for measuring sensor parameters via a second external antenna and a third external antenna after implantation of the stent provided in this application embodiment;

[0021] Figure 12 A schematic diagram showing the power of the second external antenna as a function of frequency, provided in an embodiment of this application.

[0022] Figure 13 A schematic diagram of the argument curve and power curve obtained by the signal analysis system when multiple sensors work together, as provided in the embodiments of this application;

[0023] Figure 14 A schematic diagram illustrating two winding methods of inductors provided in embodiments of this application;

[0024] Figure 15 This is a schematic diagram showing a stent placed near the sinus, with two sensors measuring the pressure in the ventricle and aorta, respectively, according to an embodiment of this application. Detailed Implementation

[0025] It should be understood that the phrases "embodiments of this application" or "foreign embodiments" throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "embodiments of this application" or "in the foreign embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0028] In this embodiment, the "inflow end" and "outflow end" of the artificial heart valve stent and its components, and the artificial heart valve and its components, are defined according to the blood flow direction during ventricular diastole. The "inflow end" refers to the end closer to the blood inflow side or the ventricular side; the "outflow end" refers to the end closer to the blood outflow side or the aortic side. "Axial" refers to the direction parallel to the line connecting the center of the outflow end and the center of the inflow end. "Radial" refers to the direction perpendicular to or approximately perpendicular to the axial direction. "Circumferential" refers to the direction surrounding the axial direction.

[0029] The artificial heart valve stent has a radially compressed delivery state and a radially expanded natural state. In the delivery state, the artificial heart valve stent is radially compressed by external force, allowing it to be compressed and inserted into a sheath with a small radial dimension, thereby being delivered to the heart via a delivery device. In the natural state, the artificial heart valve stent is not subjected to external force and naturally expands radially. Unless otherwise specified in this application, the structural features of the artificial heart valve stent in its natural state are described.

[0030] This application provides an artificial heart valve stent; see [link to previous document]. Figure 1 , Figure 2 and Figure 3 As shown, the artificial heart valve stent 1 includes:

[0031] Main section 10, the main section includes an inner network structure composed of multiple metal support rods connected in an interlaced manner, the inner network structure being composed of multiple cells arranged along the circumferential and axial directions;

[0032] For example, see Figure 1 As shown, Figure 1 This is a front view of an artificial heart valve stent 1. The shape of the artificial heart valve stent 1 can generally be simplified to something similar to... Figure 1The artificial heart valve stent 1 unfolds radially naturally, its pattern consisting of multiple metal struts interlaced to form quadrilateral cells. These cells are arranged circumferentially and axially to form an inner mesh structure. For example, the cells are also called grids, similar to rhombuses. Along the axial direction, the grid side lengths on the same side are equal, while the grid side lengths on different sides differ. The quadrilateral grids along the circumferential direction have the same shape. Some areas of the main body segment 10 have hollowed-out portions located on the aorta side. The purpose of hollowing out or increasing the grid length in this area is to prevent obstruction of coronary intervention procedures.

[0033] The main body section has a first passive wireless sensor 11 for detecting aortic static pressure at the outflow end 101, and a second passive wireless sensor 12 for detecting ventricular static pressure at the side wall 102.

[0034] In this application, where some areas of the main body section 10 have open spaces, the second passive wireless sensor 12 is placed away from large grid or open areas, and instead placed in the grid area near the inflow end 104 of the main body section to avoid affecting coronary intervention surgery. It should be noted that the first passive wireless sensor 11 is located at the outflow end 101 of the main body section, and the second passive wireless sensor 12 is located on the side wall 102 of the main body section. Both the first passive wireless sensor 11 and the second passive wireless sensor 12 are parallel to the axial direction.

[0035] See Figure 2 As shown, Figure 2 In the diagram, A is a side view of a section near the inflow end of the main body of the artificial heart valve stent 1. Figure 2 In the diagram, B is a top view of a section near the inflow end of the main body of the artificial heart valve stent 1, as shown below. Figure 2 The main section shown has a platform structure 105 at its inflow end 104. The platform structure 105 extends into the interior of the artificial heart valve stent and is parallel to the radial direction. Figure 2 and Figure 5 As shown, the platform structure 105 is equipped with a third capacitive sensor 130 for detecting the total ventricular pressure of the third passive wireless sensor 13. The third capacitive sensor 130 is connected to the inductor coil inside a single cell of the artificial heart valve stent via a wire 107.

[0036] Interventional surgery is an option for treating various cardiovascular-related diseases, including valvular heart disease. Natural valves in the body (such as the aortic valve, pulmonary valve, and atrioventricular valve) play a crucial role in the functioning of the circulatory system. Congenital or acquired valvular diseases, such as aortic or mitral valve calcification, can prevent the valves from opening and closing properly, increasing the workload on the heart and affecting blood supply to other organs. Transcatheter valve replacement (TVR) is a treatment for valvular heart disease. Guided by a guidewire, a stent is delivered to the valve region and opens the natural valve, allowing an artificial valve attached to the stent to function. This method avoids open-heart surgery, reducing the trauma of the treatment process, and is suitable for some elderly or physically weak patients.

[0037] After artificial valve implantation, transvalvular pressure and valve flow are the main physiological parameters to be monitored. In traditional monitoring protocols, valve flow is measured by ultrasound, while transvalvular pressure is measured using a pressure guidewire. Both require specialized measuring equipment and operators, and patients need to come to the hospital for measurement. Furthermore, measuring transvalvular pressure using a pressure guidewire is time-consuming and costly.

[0038] In this embodiment, the artificial heart valve stent provided in this application carries multiple passive wireless sensors on a single artificial heart valve stent, which can measure the transmural pressure and valve flow during the use of the artificial heart valve. For example, the first passive wireless sensor 11 is used to detect aortic static pressure, the second passive wireless sensor 12 is used to detect ventricular static pressure, and the difference between the aortic internal static pressure and the ventricular static pressure is the transmural pressure; the third passive wireless sensor 13 is used to detect ventricular total pressure, and the difference between the ventricular total pressure and the ventricular static pressure is the ventricular dynamic pressure, which is used to convert the ventricular dynamic pressure into flow. The first passive wireless sensor 11, the second passive wireless sensor 12, and the third passive wireless sensor 13 provided in this application affect the original shape and function of the artificial heart valve stent to a small extent. In addition, multiple sensors can be carried on the artificial heart valve stent to measure the transmural pressure or valve flow. As can be seen, the artificial heart valve stent provided in this application has a simple circuit design, omitting power cords and other devices, reducing the size and number of implants, improving safety and applicability, and at the same time, it can monitor transmural pressure and flow in real time. The obtained parameters can assist doctors in monitoring the patient's condition, and can detect problems in advance and intervene.

[0039] The first passive wireless sensor 11, the second passive wireless sensor 12, and the third passive wireless sensor 13 mentioned above all include circuits designed based on the principle of resonant circuit design. The resonant circuit structure used in this application is simple. By mounting a capacitive sensor or a resistive sensor on the resonant circuit, a simple antenna with a sensor can be formed. A radio frequency (RF) antenna can be used to communicate with this simple antenna. By measuring the resonant frequency or bandwidth of the simple antenna, the capacitance or resistance value of the sensor in the resonant circuit can be obtained, thereby inferring the physical value and achieving the purpose of measuring the valve transmural pressure and valve flow.

[0040] In other embodiments of this application, in the first feasible solution, see [link to relevant documentation]. Figure 1 As shown, the outflow end 101 of the main section has a fixed structure 1011, which is parallel to the axial direction. The fixed structure 1011 is provided with a first capacitive sensor 110, which is included in the first passive wireless sensor 11.

[0041] Here, taking the first capacitive sensor 110 being located at the outflow end 101 of the main body section as an example, optionally, the outflow end 101 of the main body section is provided with a fixing structure 1011, and the fixing structure 1011 is provided with the first capacitive sensor 110. Since the metal bracket itself has inductance and resistance, the bracket body and the first capacitive sensor 110 together form a measurement circuit of the first passive wireless sensor. At this time, the first capacitive sensor 110 can be fixed on the fixing structure 1011 by means of laser welding or conductive epoxy resin adhesive, thereby forming an RLC series resonant circuit.

[0042] It should be noted that, see Figure 1 As shown, a first capacitive sensor 110 is installed in the fixing structure 1011. The first capacitive sensor 110 and the stent body together form a first passive wireless sensor 11. Simultaneously, a second passive wireless sensor 12 is also installed on the side wall 102 of the main body section. The fixing structure 1011 is used to fix the artificial heart valve stent to the delivery system and control the release of the artificial heart valve stent. The artificial heart valve stent can be a self-expanding stent made of nitinol alloy.

[0043] In other embodiments of this application, Figure 1 The second passive wireless sensor 12 has a first series resonant circuit, which is included in a single cell of multiple cells, see [link to documentation]. Figure 3 As shown, it consists of a second capacitive sensor 120 and wires ( Figure 3The circuit formed by connecting wires (both the wires wound within the cell and / or the wires wound on the cell's support) is a series resonant circuit. In other words, the first series resonant circuit constituting the second passive wireless sensor 12 can be set within a single cell of multiple cells.

[0044] In other embodiments of this application, see Figure 4 As shown, the artificial heart valve stent 1 also includes:

[0045] The skirt section 30 covers the radially inner and outer sides of the main body section 10, and the skirt section 30 is located between the outflow end 101 and the inflow end 104 of the main body section; for example, Figure 4 The mid-skirt section 30 is located at the bottom of the main section; "bottom" refers to the position near the inflow end 104 of the main section. See also... Figure 4 As shown, some areas of the main section 10 have hollowed-out portions 108 located on the aorta side; the purpose of hollowing out or increasing the grid length of this area is to prevent obstruction of coronary intervention procedures.

[0046] The position of the hollow part 108 may vary depending on the design of the artificial heart valve stent; the bottom of the artificial heart valve stent is covered with a skirt section 30. In this application, the skirt section 30 can be used to prevent leakage and to fix the sensor; the skirt section 30 specifically refers to the area covered by the skirt.

[0047] In the second feasible solution, a scheme is provided in which the first series resonant circuit is set within a single cell. Figure 3 The first type of first series resonant circuit 201 is fixed in Figure 4 On the skirt section 30 shown, as Figure 3 As shown, the structure of the first type of first series resonant circuit 201 is as follows: an inductor is formed by a wire wrapped or coiled in a single cell, and a second capacitive sensor 120 is set in the middle area of ​​the wire wrapping. The two ends of the wire are respectively connected to the electrodes of the second capacitive sensor 120. Combined with the resistance of the wire itself, an RLC series circuit is formed. In this scheme, the inductance value can be adjusted by adjusting parameters such as the radius and number of turns of the inductor wrapping, thereby adjusting the operating frequency range of the RLC series circuit.

[0048] In other embodiments of this application, a third feasible solution is provided, in which a first series resonant circuit is set within a single cell. Figure 3The structures of the second type of first series resonant circuit 202, the third type of first series resonant circuit 203, and the fourth type of first series resonant circuit 204 are as follows: a wire is wound around at least one support rod of a single cell to form a spiral inductor coil, or the wire forms a multi-turn ring coil inductor within a single cell, and the two ends of the wire are respectively connected to the electrodes of the second capacitive sensor 120. Figure 3 The structure of the second type of first series resonant circuit 202 is as follows: a wire is wound around a support rod of a single cell to form an inductor coil, and the two ends of the wire are respectively connected to the electrodes of the second capacitive sensor 120. Figure 3 The third type of first series resonant circuit 203 has the following structure: a wire is wound around two support rods of a single cell to form an inductor coil, and the two ends of the wire are respectively connected to the electrodes of the second capacitive sensor 120. Figure 3 The fourth type of first series resonant circuit 204 has the following structure: a wire is wound around three support rods of a single cell to form an inductor coil, and the two ends of the wire are respectively connected to the electrodes of the second capacitive sensor 120. It can be seen that in the third feasible scheme, within a grid, the wire is wound around the grid boundary, i.e., the support rods of the artificial heart valve stent, to form a coil. The two ends of the wire are respectively connected to the electrodes of the second capacitive sensor 120, and combined with the resistance of the wire itself, an RLC series circuit is formed. It should be noted that in practical applications, depending on the required inductance value, one to three support rods can be wound; furthermore, in this scheme, the inductance value can be adjusted by adjusting parameters such as the number of turns of the wire and the pitch, thereby adjusting the operating frequency range of the RLC series circuit.

[0049] In other embodiments of this application, Figure 1 The second passive wireless sensor 12 has a first series resonant circuit, which is set in two adjacent cells, see [link / reference]. Figure 3 As shown, the first passive wireless sensor has a first series resonant circuit, which is included in two adjacent cells of a plurality of cells.

[0050] Furthermore, in other embodiments of this application, a fourth feasible solution is provided, which involves setting a first series resonant circuit within two adjacent cells. Figure 3 The fifth type of first series resonant circuit 205 has the following structure: a wire is wound around one of two adjacent cells, and a second capacitive sensor 120 is disposed in the other of the two adjacent cells. The two ends of the wire are connected to the electrodes of the second capacitive sensor 120, respectively. See also... Figure 3The fifth type of first series resonant circuit 205 is shown in the figure. The RLC series circuit is placed in the bottom region of the artificial heart valve stent, and the second capacitive sensor 120 is placed in another grid adjacent to the grid where the coil formed by the wire is located.

[0051] Furthermore, in other embodiments of this application, a fifth feasible solution is provided that a first series resonant circuit is set within two adjacent cell units. Figure 3 The sixth type of first series resonant circuit 206 has the following structure: Two inductors are formed by winding wires around the support rods on the same side of two adjacent cells. One end of each inductor is connected via a resistive sensor 22, and the other end is connected via a fixed capacitor 23. (See also...) Figure 3 The sixth type of first series resonant circuit 206 is shown. The RLC series circuit is placed in the bottom region of the artificial heart valve stent. In the fifth feasible scheme, the sensor type is a resistive sensor 22, paired with a fixed capacitor 23. Because the circuit includes a resistive sensor and a fixed capacitor, the circuit in this scheme is set in two adjacent grids. Wires are wound around the support rods on the same side of the two grids to form inductor coils. The resistive sensor and the fixed capacitor are connected using two coils to finally form the RLC series circuit. Adjusting the number of turns of the wire, the pitch, or other parameters, or adjusting the capacitance value of the fixed capacitor 23, can control the resonant frequency of the circuit, thereby adjusting the operating frequency range of the RLC series circuit.

[0052] In other embodiments of this application, Figure 2 The main section shown has a platform structure 105 at its inflow end 104. Figure 2 The platform structure 105 has a third passive wireless sensor 13 at its bottom for detecting total ventricular pressure. Combined with... Figure 5 As shown, the third passive wireless sensor 13 has a second series resonant circuit, which includes a third capacitive sensor 130 and an inductor formed by winding a wire in a single cell of multiple cells and / or on a support rod of a single cell, with the two ends of the wire connected to the electrodes of the third capacitive sensor 130.

[0053] Combination Figure 2 , Figure 5 and Figure 6 As shown, a platform structure 105 is added below the bottom mesh; the platform structure 105 extends into the artificial heart valve stent, and the third capacitive sensor 130 is fixed to the bottom of the platform structure 105 by means of laser welding or epoxy resin adhesive; however, the third capacitive sensor 130 does not form a circuit with the artificial heart valve stent, therefore, two wires are led out from the third capacitive sensor 130; and inductive elements are wound around the wires inside the mesh or on the mesh support rod.

[0054] Furthermore, in other embodiments of this application, in the sixth possible implementation, Figure 6 In the diagram, A represents a wire that wraps around the inside of the grid to form an inductance. The inductance is connected to the wire 107 led out from the third capacitive sensor 130 at the bottom of the platform structure 105 to form an RLC series circuit. The operating frequency range of the RLC series circuit can be adjusted by adjusting parameters such as the number of turns of the wire and the pitch.

[0055] Furthermore, in other embodiments of this application, in the seventh possible implementation, Figure 6 In the diagram, B represents the inductance formed by the wire around the grid support rod. The inductance is connected to the wire leading out from the third capacitive sensor 130 at the bottom of the platform structure 105, forming an RLC series circuit. The operating frequency range of the RLC series circuit can be adjusted by adjusting parameters such as the number of turns of the wire and the pitch.

[0056] Furthermore, in other embodiments of this application, in the eighth possible implementation, Figure 6 The C in the middle combines Figure 6 A and Figure 6 The B wire in the circuit is wound in a way that forms an inductor. The inductor is connected to the wires led out by the capacitive sensor to form an RLC series circuit. The operating frequency range of the RLC series circuit can be adjusted by adjusting parameters such as the number of turns of the wire and the pitch.

[0057] It should be noted that, Figure 5 For ease of description, the third passive wireless sensor 13 is labeled on the platform structure 105. It can be understood that the third passive wireless sensor 13 includes... Figure 5 The third capacitive sensor 130 on the platform structure 105, the two wires 107, and Figure 6 An inductance formed by winding wires within a single cell of multiple cells and / or on the support rod of a single cell.

[0058] Furthermore, the working principle and structure of the capacitive and resistive sensors mounted on the aforementioned artificial heart valve stent will be explained.

[0059] The capacitive sensor used in this application can be a parallel-plate capacitor with electrodes attached to a thin film. Changes in blood pressure cause deformation of the thin film and alter the distance between the parallel plates, resulting in a change in capacitance and thus affecting the resonant frequency of the RLC series circuit. By measuring the resonant frequency of the circuit, the blood pressure value can be deduced. The formula for calculating the capacitance is as follows:

[0060]

[0061] Where C is the capacitance, P is the blood pressure, ε is the vacuum dielectric constant, A is the area of ​​the parallel plates, and d is the distance between the parallel plates, which varies with blood pressure.

[0062] The following describes the possible capacitor structures and their working principles:

[0063] Structure 1: The cross-sectional view of Structure 1 is as follows Figure 7 As shown in Figure A, a hollow substrate is sandwiched between two thin films. A metal film serves as an electrode on the surface of the movable film. The movable film deforms under pressure, changing the distance between the metal films and thus altering the capacitance. The substrate material can be silicon dioxide, such as glass, and the hollow region is created using ion-reactive etching. The movable film is made of silicon wafers, and photolithography is used to etch the wiring electrode circuit onto the silicon wafer surface. Then, metal sputtering is used to fill the etched circuit with conductive metal, forming a metal film on the surface as an electrode. In a vacuum environment, the two silicon wafers with electrodes and the hollow substrate are bonded at high temperature to form a vacuum-sealed cavity with the metal film facing inward. After bonding, chemical etching is used to etch the silicon wafers with electrodes on both sides until the wiring electrode position is reached, obtaining a silicon film. After etching, the wafer is diced and packaged, and the wiring electrode is welded to the coils in the second to fourth, or sixth to eighth feasible schemes mentioned above to form a circuit. The circuit of the wiring electrode can be designed according to the specific wiring scheme to facilitate soldering with the coil.

[0064] Structure 2: The cross-sectional view of Structure 2 is as follows Figure 7 As shown in Figure B, a layer of metal thin-film electrodes is present on the substrate surface. A movable thin film with electrodes is covered above the substrate. The movable thin film deforms under pressure, changing the distance between the metal films and thus altering the capacitance. The substrate material can be silicon dioxide, such as glass. Ion reactive etching is used to etch the wiring electrode circuit. Then, metal sputtering is used to form the metal thin film and wiring electrodes on the substrate surface. The movable thin film is made of silicon wafer. Photolithography is used to etch the cavity and wiring electrode circuit on the silicon wafer. Then, metal sputtering is used to form the wiring electrodes and metal thin film. In a vacuum environment, the silicon wafer and substrate are bonded at high temperature to form a vacuum-sealed cavity with the metal thin film facing inward. After bonding, chemical etching is used to etch the silicon wafer down to the location of the wiring electrodes, obtaining a silicon thin film. After etching, the wafer is diced and packaged. The wiring electrodes are then soldered to coils from the second to fourth, or sixth to eighth feasible schemes mentioned above to form a circuit. The circuit of the wiring electrodes can be designed according to the specific wiring scheme to facilitate soldering with the coils.

[0065] Structure 3: The cross-sectional view of Structure 3 is as follows Figure 7 As shown in C, a metal material is used as the substrate, covered with a movable thin film, and then covered with another metal thin film as an electrode. The substrate material is a conductive metal, specifically a metal material suitable for surgical implants. A cavity is etched into the metal substrate using micro-discharge machining or laser processing techniques. Polyimide is used as the movable thin film and also as the insulating medium. The metal layer is evaporated using an electron beam, then spin-coated and cured onto the polyimide film to create the metal thin film; alternatively, a metal thin film can be formed directly on the polyimide using metal sputtering. Heating is performed in a vacuum environment to bond the polyimide film to the metal substrate, forming a vacuum-sealed cavity. The capacitor in configuration three is used in the first feasible scheme, and by welding the metal substrate to the fixed structure 1011, it can directly form an RLC circuit with the scaffold.

[0066] The fifth feasible solution of this application is a solution using a resistive sensor. Its working principle is based on the piezoresistive effect of semiconductors such as silicon and germanium. When deformation occurs, their resistance changes accordingly. The expression for the change in resistance with pressure is:

[0067]

[0068] Where R is the resistance value; ΔR is the change in resistance; π l ,π t These are the longitudinal and transverse piezoresistive coefficients, respectively; σ l (P),σ t (P) represents the longitudinal and transverse stresses, respectively, and σ l (P),σ t (P) varies with changes in blood pressure.

[0069] In the fifth feasible scheme, the resistive sensor deforms due to changes in blood pressure, thereby altering the resistance and bandwidth of the RLC series circuit; measuring the bandwidth allows for the deduction of the resistance and blood pressure values. The resistive sensor is constructed as follows... Figure 8 As shown, a vacuum cavity and a movable thin film are located above the substrate. The movable thin film is made of semiconductor, and its resistance changes when it deforms under pressure. A silicon wafer is selected, and its conductivity is improved by doping it with trace elements such as phosphorus and boron. A chemical etching technique is used to etch the cavity and form the movable thin film on the silicon wafer. Glass is selected as the substrate, and the silicon wafer and the glass substrate are bonded at high temperature in a vacuum environment to form a vacuum-sealed cavity. The silicon wafer, after being doped with trace elements, becomes conductive, and a circuit can be formed by connecting a wire to the silicon wafer.

[0070] In the second to eighth feasible solutions of this application, the wire is the main source of resistance in the RLC series circuit. It is known that the smaller the resistance, the smaller the bandwidth of the RLC series circuit, making it easier to distinguish the resonant frequency and improve measurement accuracy. Gold and silver have high conductivity, and considering the strength of the wires, they may not be suitable for manufacturing. Therefore, a metal plating or metal spraying process can be used to cover a thin film of gold or silver onto a high-strength wire to improve conductivity. One feature of this application is the ability to accommodate multiple sensors; therefore, the first feasible solution needs to be considered when it is used in conjunction with other solutions on a single support. To prevent coils or wires from other solutions from contacting the support and forming a loop, an insulating coating, such as polytetrafluoroethylene (PTFE), can be added to the surface of the wires or coils to reduce the influence of the coils or wires on the inductance and resistance of the support, ensuring the normal operation of the first feasible solution. Ideally, after covering the wires with a metal coating to improve conductivity, an insulating coating should be added; however, considering economic costs and the already sufficiently small circuit bandwidth, an insulating coating can be added only to the surface of the wires.

[0071] In this application, two characteristic parameters of the RLC series circuit are used to measure physical values: the resonant frequency and the bandwidth. The expression for the resonant frequency f0 is: Where L is the inductance value.

[0072] The expression for bandwidth Δf is:

[0073] like Figure 9 As shown, after the stent is implanted, it can communicate with the passive wireless sensor on the stent via the first external antenna 41, thereby measuring physiological parameters inside the body. The first external antenna 41 is a radio frequency antenna, which is actually an inductor coil. Figure 9 The coil shown is an example; the actual shape can be designed according to the specific circumstances of the actual scenario. The power supply 42 provides current or voltage of different frequencies to the first external antenna 41, thereby generating an alternating electromagnetic field near the radio frequency antenna; the inductor mounted on the bracket generates current under the action of the alternating electromagnetic field and absorbs the energy of the alternating electromagnetic field. Figure 9 The external antenna circuit and internal sensor circuit are shown. Here, La is the inductance of the external antenna, Ls is the coil inductance or the inductance of the support itself in the above scheme, and Lm is the mutual inductance generated when La and Ls are coupled; Rs is the resistance of the coil, the resistance of the support itself, or the resistance of the resistive sensor in the above scheme; Cs is the capacitance of the capacitive sensor or a fixed capacitor in the above scheme. Va is the voltage across La, Vs is the voltage across Ls, Ia is the current flowing through La, and Is is the current flowing through Ls. Based on the characteristics of the mutual inductance coupling circuit, we can obtain:

[0074] Va =sL a I a +sL m I s (1)

[0075] V s =sL m I a +sL s I s (2)

[0076] Where s = j·2π·f,j 2 = -1, where f is the frequency. Based on the characteristics of an RLC series circuit, we can obtain:

[0077]

[0078] By combining equations (1) and (2), we can obtain the relationship between Va and Ia:

[0079]

[0080] Therefore, the input impedance Z of the inductor coil of the external antenna is equal to:

[0081]

[0082] Where k is the mutual inductance coupling parameter, and Q is the quality factor, its expression is:

[0083]

[0084]

[0085] The input impedance Z is a complex number, and the argument of Z reflects the phase difference between the current and the voltage. The phase difference changes with frequency. Differentiating equation (5) reveals that the phase difference has a minimum value with frequency, and the corresponding frequency is the resonant frequency f0. Figure 10 As shown; therefore, by measuring the change of input impedance Z with respect to frequency f, the resonant frequency f0 can be extracted. Based on the relationship between the input impedance argument and frequency, the external antenna circuit is connected to an impedance analyzer to extract the phase difference at different frequencies and perform fitting. Based on the fitting results, f0, k, and Q values ​​can be obtained, where f0 and Q values ​​can be used to measure the parameters of capacitive and resistive sensors, respectively. Therefore, this application can choose to perform signal analysis using impedance analysis. Figure 9 The signal analysis system 43 consists of an impedance analyzer and a computer. After obtaining impedance information through the impedance analyzer, the system is fitted in the computer to extract the resonant frequency and bandwidth.

[0086] As mentioned above, the internal sensor circuit absorbs energy from the external antenna under an alternating electromagnetic field, thereby generating current. After the external antenna is removed, the current still exists and gradually decays under the influence of resistance. Before the current disappears, the sensor circuit generates an alternating electromagnetic field, and analyzing this electromagnetic field can also yield the characteristic parameters of the sensor circuit. For example... Figure 11 As shown, after stimulating the passive wireless sensor using the third external antenna 45, the power is disconnected and the second external antenna 44 is brought close to the sensor. The second external antenna 44 is essentially an inductor coil; under the influence of the alternating electromagnetic field generated by the sensor, it absorbs energy from the alternating electric field and generates current internally. The sensor circuit absorbs and releases the highest power at the resonant frequency. The voltage and current of the second external antenna 44 are measured and converted into electrical power. The change in electrical power with frequency is recorded; the frequency corresponding to the maximum electrical power is the resonant frequency. Figure 12 The power variation curve of the second external antenna 44 is shown. The power reaches its maximum value when the frequency equals the resonant frequency f0. Furthermore, when the power drops to half of the maximum power, there are two corresponding frequencies; the difference between these two frequencies is the bandwidth Δf. In this scheme, the signal analysis system connected to the second external antenna 44 can use an oscilloscope and a computer to record voltage, current, and power data. The computer then performs Fourier transforms to calculate the power at various frequencies, and finally extracts the resonant frequency and bandwidth.

[0087] An RLC series circuit has bandpass filtering characteristics, absorbing or releasing energy within a certain frequency range. Outside this frequency range, the absorbed or released energy is very small, and the phase difference between the current and voltage is close to 90 degrees. Figure 10 and Figure 12 This phenomenon is reflected in all of these. Therefore, the bandpass characteristic of RLC series circuits can be used to perform measurements from multiple sensors, such as... Figure 13 As shown. After determining the pressure measurement range of the sensor, the resonant frequency of the sensor is varied within a certain frequency range by adjusting the capacitance or inductance value. This frequency range is called the operating range. When performing signal analysis on the sensor, it is only necessary to read the resonant frequency or bandwidth within the corresponding operating range, ensuring that multiple sensors will not interfere with each other when working simultaneously.

[0088] refer to Figure 3 The inductor winding scheme in this application can be classified as a spiral coil inductor (e.g., Figure 3 202-204, Figure 3 Zhong 306 and Figure 6 (B) or multi-turn toroidal coil inductance (such as B) Figure 3 201 Figure 3 Zhong 205 and Figure 6 A) in Figure 6The 'C' in this context can be considered as two inductors connected in series. As mentioned above, the operating range of the circuit can be adjusted by changing the inductance value, thereby enabling multiple sensor operating schemes. Inductance adjustment methods include controlling parameters such as the number of inductor turns, wire length, and coil area. The formula for calculating the inductance value of a spiral coil inductor is as follows:

[0089]

[0090] Where, μ r denoted as relative permeability, μ0 as permeability in free space, N as the number of turns in the coil, Area as the cross-sectional area of ​​the coil, and l as the length of the coil.

[0091] The formula for calculating the inductance value of a multi-turn toroidal coil is as follows:

[0092]

[0093] d avg =0.5·(D out +D in )

[0094] ρ=(D out -D in ) / (D out +D in )

[0095] Where, d avg The outer diameter D of the coil out and coil inner diameter D in The average value, ρ is the filling ratio, and c1, c2, c3, and c4 are constants, equal to 1.0, 2.46, 0.0, and 0.20 respectively. Figure 14 Two inductor winding methods are provided. Figure 14 In this context, A represents the inductance of the spiral coil. Figure 14 In this context, B represents the inductance of a multi-turn toroidal coil. Figure 14 In the diagram B, w is the diameter of the wire, s is the gap between the wires, and the number of turns N is determined by the outer diameter D of the coil. out Coil inner diameter D in The diameter w of the conductor and the gap s between the conductors determine the result.

[0096] In the first practical application scenario, the aforementioned sensor mounting scheme and measurement method are used to achieve the function of measuring valve transmural pressure, such as... Figure 2 As shown. To measure the pressure inside the aorta, the first feasible approach involves placing a sensor circuit on one side of the aorta. The sensor's construction is referenced. Figure 7 In C; to measure ventricular pressure, a second feasible approach is adopted, in which an RLC series circuit is mounted within the grid at the bottom of the stent, wherein the sensor construction is referenced Figure 7A or Figure 7 In practice, the second feasible solution can be replaced by the third, fourth, or fifth feasible solution. The skirt section 30 is used to wrap around the mesh at the bottom of the stent and the RLC series circuit, fixing the RLC series circuit within the mesh and preventing direct contact between the circuit and blood.

[0097] During pressure measurement, the external antenna is placed close to the heart region, and the power is turned on. The current or voltage frequency supplied by the power supply covers the operating range of both sensor circuits, generating an alternating electromagnetic field inside the external antenna and exciting the sensor circuits. Using a signal analysis system, the corresponding resonant frequencies are searched within the respective operating ranges of the two sensor circuits. Figure 13 As shown, the data is converted into pressure data to obtain the transvalvular pressure value.

[0098] In the second practical application scenario, the aforementioned sensor mounting scheme and measurement method are used to achieve the function of measuring valve transmural pressure, such as... Figure 15 As shown, the stent is placed near the sinus, and two sensors measure the pressure in the ventricle and aorta respectively. The sensor on the ventricular side is a resistive sensor. To measure the pressure inside the aorta, the first feasible approach involves placing a sensor circuit on the aortic side. The sensor's construction is referenced... Figure 7 In C; to measure ventricular pressure, a fifth feasible approach is adopted, in which an RLC series circuit is mounted within the grid at the bottom of the stent, wherein the sensor construction is referenced Figure 8 The skirt section 30 is used to wrap around the mesh at the bottom of the stent and the RLC series circuit, so that the RLC series circuit is fixed within the mesh and the circuit is prevented from direct contact with blood.

[0099] During pressure measurement, the external antenna is placed close to the heart region, and the power is turned on. The current or voltage frequency provided by the power supply covers the operating range of both sensor circuits, generating an alternating electromagnetic field inside the external antenna and exciting the sensor circuits. Using a signal analysis system, the corresponding resonant frequency is searched within the operating range of the capacitive sensor circuit, and the bandwidth is read within the operating range of the resistive sensor. The resonant frequency and bandwidth are converted into capacitance and resistance values, respectively, to further obtain the aortic pressure and ventricular pressure. The difference between the two is used to calculate the transvalvular pressure.

[0100] In the third practical application scenario, the aforementioned sensor mounting scheme and measurement method are used to achieve the function of measuring flow velocity. One example is measuring blood hydrostatic pressure, which employs the second feasible scheme by placing a sensor circuit within a grid. The sensor construction is referenced... Figure 7 A or Figure 7Option B; another option for measuring total blood pressure, using the sixth feasible approach, involves placing a capacitive sensor on the bottom platform, with the sensor construction referenced. Figure 7 A or Figure 7 B in the diagram is used to form a circuit with coils within the grid. The second feasible solution can be replaced by the third, fourth, or fifth feasible solution; the sixth feasible solution can be replaced by the seventh or eighth feasible solution. The skirt section 30 wraps around the grid at the bottom of the support and the RLC series circuit, fixing the RLC series circuit within the grid and preventing direct contact between the circuit and blood. When blood impacts the sensor at the bottom of the platform, the blood stops on the sensor's surface. At this point, the dynamic pressure is converted into static pressure and acts on the sensor's moving diaphragm. Therefore, the pressure measured at the bottom of the platform is the total blood pressure; while the sensor placed within the grid is not directly impacted by the blood flow, so it measures the static pressure. Total pressure P total static pressure P static and dynamic pressure P dynamic The relationship is as follows:

[0101] P total =P static +P dynamic ,

[0102] During measurement, the external antenna is placed close to the heart region, and the power is turned on. The current or voltage frequency supplied by the power supply covers the operating range of both sensor circuits, generating an alternating electromagnetic field inside the external antenna and exciting the sensor circuits. Using a signal analysis system, the corresponding resonant frequencies are searched within the respective operating ranges of the two sensor circuits, with reference to... Figure 11 As shown, the pressure data is converted and the pressure difference between the two sides is calculated to obtain the dynamic pressure value. Then, according to formula (8), the blood velocity v is calculated; here ρ is the blood density value. The blood density varies from person to person, and a reference value of 1060 kg / m3 is given here. After obtaining the velocity value, the area of ​​the ventricular outlet can be calculated with the help of medical imaging, such as computed tomography (CT), and thus converted into flow data.

[0103] In the fourth practical application scenario, three sensor circuits are set up within the same support to calculate transvalvular pressure and flow velocity. The specific solution is as follows: Figure 1 As shown, three sensors are placed: one inside the bottom grid, one under the bottom platform, and one on the side of the aorta. Figure 1Combining the first and third practical application scenarios, three sensors were placed on the stent using the first, second, and sixth feasible solutions to measure aortic venous pressure, ventricular venous pressure, and total ventricular pressure, respectively. The second feasible solution can be replaced by the third through fifth feasible solutions, and the sixth feasible solution can be replaced by the seventh and eighth feasible solutions. The RLC series circuit at the bottom of the stent is wrapped with a skirt segment 30 to fix the RLC series circuit and prevent direct contact between the circuit and blood. Transvalvular pressure was measured following the operating methods of the first and second practical application scenarios; the flow velocity near the ventricular outlet was measured following the method of the third practical application scenario.

[0104] The artificial heart valve stent provided in this application has the following beneficial effects: The human cardiac cycle is approximately 0.8 seconds, therefore the frequency of blood pressure or flow rate changes is 1-2 Hz. As long as the current and voltage frequency of the RLC series circuit is much higher than the frequency of blood pressure changes, the blood pressure value at a certain moment can be measured before a significant change occurs. Therefore, by setting the operating frequency range of the RLC series circuit to be much higher than 2 Hz, the pressure value corresponding to each moment within a cardiac cycle can be obtained. Thus, this application can detect pressure changes near the valve in real time without the need for interventional devices such as pressure guidewires. This application adopts a passive wireless sensor design, which simplifies the circuit design, eliminates power cords and other devices, reduces the size and number of implants, and improves safety and applicability. This application sets up a scheme where a single stent carries multiple sensors, which can measure the key parameters of concern during the use of the artificial heart valve: transvalvular pressure and flow rate. This application can monitor transvalvular pressure and valve flow rate in real time, and the obtained parameters can assist doctors in monitoring the patient's condition, enabling early detection and intervention of problems.

[0105] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0106] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0107] Furthermore, in the various embodiments of this application, all functional units can be integrated into one processing module, or each unit can be a separate unit, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in a combination of hardware and software functional units. Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0108] The methods disclosed in the several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0109] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0110] The features disclosed in the several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method or device embodiments.

[0111] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A prosthetic heart valve stent, characterized in that, The artificial heart valve stent comprises: a main body section comprising an inner net structure formed by a plurality of metal support rods being staggered connected, the inner net structure being arranged in a circumferential and axial direction by a plurality of unit cells; wherein the outflow end of the main body section is provided with a first passive wireless sensor for detecting aortic static pressure; the side wall of the main body section is provided with a second passive wireless sensor for detecting ventricular static pressure; the inflow end of the main body section is provided with a platform structure extending to the inside of the artificial heart valve stent, the platform structure being radial parallel, the platform structure being provided with a third passive wireless sensor for detecting ventricular total pressure; wherein the outflow end of the main body section has a fixing structure, the fixing structure being axial parallel, the fixing structure being provided with a first capacitive sensor, the first capacitive sensor and the stent body of the artificial heart valve stent forming the first passive wireless sensor; wherein the second passive wireless sensor has a first series resonance circuit, the first series resonance circuit comprising a circuit formed by a second capacitive sensor and a wire connection in a single unit cell of the plurality of unit cells or in adjacent two unit cells; wherein the third passive wireless sensor has a second series resonance circuit, the second series resonance circuit comprising a third capacitive sensor, and an inductance formed by winding a wire on a support rod in a single unit cell of the plurality of unit cells and / or on a support rod of the single unit cell, both ends of the wire being connected with electrodes of the third capacitive sensor.

2. The prosthetic heart valve support of claim 1, wherein, The artificial heart valve stent further comprises: a skirt section covering the radial outside and the radial inside of the main body section, and the skirt section being located between the inflow end of the main body section and the outflow end of the main body section; wherein the first series resonance circuit is fixed on the skirt section, the wire in the single unit cell is wound to form an inductance, and a second capacitive sensor is arranged in the middle region of the wire winding, both ends of the wire being respectively connected with electrodes of the second capacitive sensor.

3. The prosthetic heart valve support of claim 1, wherein, The wire of the first series resonance circuit is wound on at least one support rod of the single unit cell to form a spiral inductance coil, or the wire of the first series resonance circuit forms a multi-turn annular coil inductance in a unit cell, both ends of the wire of the first series resonance circuit being respectively connected with electrodes of the second capacitive sensor.

4. The prosthetic heart valve support of claim 1, wherein, The wire of the first series resonance circuit is wound in one of the adjacent two unit cells, the second capacitive sensor is arranged in the other of the adjacent two unit cells, and both ends of the wire of the first series resonance circuit are respectively connected with electrodes of the second capacitive sensor.

5. The prosthetic heart valve support of claim 1, wherein, The wire of the first series resonance circuit is wound on the support rods on the same side of the adjacent two unit cells to form two inductance coils, one end of the two inductance coils being connected through a resistive sensor, and the other end of the two inductance coils being connected through a constant value capacitor.

6. The prosthetic heart valve support of claim 2 or 4, wherein, The radius and / or the number of turns around which the conductors of the first series resonance circuit are wound are used to adjust the inductance value.

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