External evaluation equipment and evaluation method for near-physiological pulsation fluid of heart valve prosthesis

Abstract

The invention discloses an artificial heart valve near-physiological pulsation fluid external evaluation device and method, and relates to the technical field of heart valve testing.The artificial heart valve near-physiological pulsation fluid external evaluation device comprises a supporting frame, a driving unit, a tested valve installation unit and an artery and peripheral loop unit, the driving unit provides power for liquid flowing, and the tested valve installation unit is used for fixing an artificial heart valve; and a liquid volume assembly and a resistance assembly of the artery and peripheral loop unit can simulate the compliance and resistance of aorta blood vessels and peripheral artery blood vessels, so that the pressure waveform simulation of the systemic circulation loop is more accurate. On the basis of the air cavity, the elastic corrugated pipes with different frequency responses are arranged, the compliance and rebound resilience of the aorta are simulated, a device for rapidly replacing the tested valve is designed, and the mechanical property of the simulated human body aorta is adjusted by adjusting the parameters such as the output frequency and the vibration amplitude of the driving unit; real pressure and flow waveforms under different physiological / pathological conditions are simulated, and a more accurate and convenient detection environment is realized.

Description

Technical Field

[0001] This invention relates to the field of heart valve testing technology, and in particular to an artificial heart valve near-physiological pulsatile fluid external evaluation device and evaluation method. Background Technology

[0002] In the systemic circulation loop, research on simulating the mechanical properties of the human aorta has always been an important topic in the field of medical devices. Currently, the existing device for simulating the mechanical properties of the human aorta is an air chamber. This air chamber mainly works based on the principle of air compressibility. In the systemic circulation loop, when the pressure increases, some of the pressure can be stored by compressing the air in the air chamber. When the loop pressure decreases, the pressure stored in the air chamber is automatically released. In this way, the functions of arteries in storing and releasing pressure and maintaining blood pressure can be simulated to a certain extent, that is, the simulation of arterial compliance can be achieved.

[0003] However, existing air chambers that rely solely on compressed air to simulate arterial vascular functions have significant limitations. They cannot accurately simulate pressure waveforms, especially in details such as the inability to simulate dicrotic waves (i.e., vascular resilience). This leads to inaccurate evaluation results in applications such as artificial valve pulsatile fluid external assessment, failing to meet higher requirements for artificial valve performance evaluation and consequently affecting the accuracy and reliability of the entire medical device evaluation. Therefore, improvements are needed to better serve the functional realization of artificial valve pulsatile fluid external assessment devices. Summary of the Invention

[0004] The purpose of this invention is to provide an in vitro evaluation device and method for near-physiological pulsatile fluid in artificial heart valves, so as to solve the problems existing in the prior art and improve the accuracy of in vitro evaluation of artificial heart valves.

[0005] To achieve the above objectives, the present invention provides the following solution: In a first aspect, the present invention provides an external evaluation device for near-physiological pulsating fluid in artificial heart valves, comprising: The drive unit includes a linear motor and a cylinder. The linear motor drives the piston rod of the cylinder to perform reciprocating linear motion. The cylinder has a first exhaust valve and an inlet valve that communicate with the rodless chamber of the cylinder on its side wall.

[0006] The valve installation unit under test includes a first connecting tube, a valve fixing mechanism, and a second connecting tube connected sequentially from top to bottom. The bottom end of the second connecting tube communicates with the rodless chamber of the cylinder. The bottom end of the first connecting tube is detachably connected to the top end of the second connecting tube, and the top end of the first connecting tube is closed. The valve fixing mechanism is installed at the top end of the second connecting tube and is used to clamp the artificial heart valve to be tested.

[0007] An arterial and peripheral circuit unit; the arterial and peripheral circuit unit includes a reservoir, a liquid capacity assembly, a reflux assembly, and a resistance assembly. The reservoir is connected to the first connecting pipe via a third connecting pipe. The liquid capacity assembly includes a first bellows and a second bellows, both of which are closed at one end and open at the other. The open ends of the first and second bellows are respectively connected to the third connecting pipe, and the second bellows is closer to the reservoir than the first bellows. The reflux assembly includes a fifth connecting pipe connected sequentially from top to bottom. The system includes a tube, an atrial valve fixing mechanism, and a sixth connecting tube. The bottom end of the fifth connecting tube is detachably connected to the top end of the sixth connecting tube. The atrial valve fixing mechanism is installed at the bottom end of the fifth connecting tube and is used to clamp the atrial valve. The fifth connecting tube is connected to the liquid storage container via a fourth connecting tube, and the sixth connecting tube is connected to the rodless chamber of the cylinder via a seventh connecting tube. The first resistance valve of the resistance assembly is located between the first bellows and the second bellows, and the second resistance valve of the resistance assembly is located between the second bellows and the liquid storage container.

[0008] The measurement and control unit includes a controller, a flow meter, a pre-valve pressure sensor, and a post-valve pressure sensor. The linear motor, the pre-valve pressure sensor, and the post-valve pressure sensor are respectively signal-connected to the controller. The flow meter is disposed on the third connecting pipe and is located between the first connecting pipe and the first bellows. The second connecting pipe is provided with a pre-valve pressure measuring port communicating with the second connecting pipe, and the first connecting pipe is provided with a post-valve pressure measuring port communicating with the first connecting pipe. The pre-valve pressure sensor is installed on the pre-valve pressure measuring port, and the post-valve pressure sensor is installed on the post-valve pressure measuring port.

[0009] Support frame; the linear motor and cylinder are respectively fixed on the support frame.

[0010] Preferably, the measurement and control unit further includes an atrial valve pressure sensor that is signal-connected to the controller, and the fifth connecting tube is provided with an atrial valve pressure measuring port, and the atrial valve pressure sensor is installed on the atrial valve pressure measuring port; the top end of the first connecting tube is provided with an observation window and a second exhaust valve.

[0011] Preferably, the liquid storage container is equipped with a heating device and a temperature measuring device, wherein the heating device is capable of heating the test liquid in the liquid storage container to a temperature close to that of human blood.

[0012] Preferably, the drive unit further includes a linear guide rail fixed on the support frame and a slider that slides with the linear guide rail, the output end of the linear motor is fixedly connected to the slider, and the slider is fixedly connected to the piston rod of the cylinder through a coupling.

[0013] Preferably, the second connecting pipe is connected to the rodless chamber of the cylinder via a three-way pipe, with one port of the three-way pipe connected to the second connecting pipe, another port connected to the rodless chamber of the cylinder, and yet another port connected to the end of the seventh connecting pipe away from the sixth connecting pipe.

[0014] Preferably, the linear guide rod is further provided with a grating ruler for monitoring the displacement of the slider, and the grating ruler is signal-connected to the controller.

[0015] Preferably, the linear motor is a voice coil motor; the cylinder is a rolling diaphragm cylinder; and the first connecting pipe is connected to the second connecting pipe via a quick-connect coupling. The specific structure of the motor and cylinder in this invention is not limited. Besides a voice coil motor, other motors capable of achieving the functions required by this invention can be used, such as iron-core motors, ironless motors, rod-shaped linear motors, arc-shaped ironless linear motors, and long stator linear motors. The cylinder can be not only a rolling diaphragm cylinder, but also other types of cylinders capable of achieving the functions required by this invention, such as oscillating cylinders or magnetic cylinders.

[0016] Preferably, the valve fixation mechanism includes a first sleeve and a first pressure ring, the first sleeve is fixedly and sealingly connected to the top of the first connecting tube, and the top cover is threadedly and sealingly connected to the top of the first sleeve.

[0017] Two symmetrically arranged axial connecting rods are fixedly provided on the inner bottom wall of the first sleeve. The first pressure ring is fixedly provided at the end of the axial connecting rod away from the first sleeve. The axial connecting rod and the first pressure ring can extend into the first connecting pipe and are located at the connection position of the first connecting pipe and the second connecting pipe. A first support ring is fixedly connected at the end of the first pressure ring away from the axial connecting rod. The first pressure ring is used to cooperate with the first support ring to clamp the edge of the artificial heart valve to be tested.

[0018] Preferably, the atrial valve fixation mechanism includes a second sleeve and a second pressure ring, the second sleeve being fixedly and sealingly connected to the top of the fifth connecting tube, and the top of the second sleeve being threadedly and sealingly connected to a top cover.

[0019] The inner bottom wall of the second sleeve is fixedly provided with two symmetrically arranged axial connecting rods. The end of the axial connecting rod away from the second sleeve is fixedly provided with the second pressure ring. The axial connecting rod and the second pressure ring can extend into the fifth connecting pipe and are located at the connection position of the fifth connecting pipe and the sixth connecting pipe. The end of the second pressure ring away from the axial connecting rod is fixedly connected with the second support ring. The second pressure ring is used to cooperate with the second support ring to clamp the edge of the artificial heart valve to be tested.

[0020] Secondly, the present invention provides an evaluation method based on the aforementioned artificial heart valve near-physiological pulsating fluid external evaluation device, comprising: Test liquid is injected into the rodless chamber of the cylinder and the container / unit / component connected to the cylinder through the inlet valve on the side wall of the cylinder until the artificial heart valve pulsating fluid external evaluation device is full of test liquid; the heating device is activated to heat the temperature of the test liquid in the storage container to close to the temperature of human blood.

[0021] The artificial heart valve to be tested is installed in the valve fixation mechanism.

[0022] Based on the controller in the measurement and control unit, the motion parameters of the linear motor are set; the motion parameters are used to determine the reciprocating motion law of the piston rod in the cylinder; the piston rod in the cylinder is used to simulate the aortic pressure waveform of a set frequency through reciprocating motion; the linear motor is a voice coil linear motor; the motion parameters include: initial motor position, voice coil motor point-to-point running position, motor stop position, voice coil motor periodic running waveform, voice coil motor periodic running amplitude, voice coil motor periodic running frequency, voice coil single-machine periodic running offset, and voice coil motor periodic running phase offset.

[0023] Start the linear motor to drive the piston rod to perform linear reciprocating motion, and check the opening and closing of the valve during fluid flow and record the working status of the artificial heart valve.

[0024] Acquire pressure data and fluid flow data before and after the artificial heart valve in the prevalence and postvalence pressure sensors at the aortic and mitral valves; the pressure data includes the prevalence and postvalence pressure of the aortic or mitral valve being measured, the maximum peak systolic pressure of the aorta, the maximum end-diastolic pressure, the aortic pressure, the maximum ventricular pressure, the ventricular pressure, the maximum atrial pressure, and the atrial pressure.

[0025] Based on the category of the simulation experiment and the fluid dynamics performance verification guidelines in the international standard ISO 5840, the standard flow rate value for the artificial heart valve near-physiological pulsating fluid external evaluation device was determined during operation.

[0026] Based on the flow meter, the actual flow value of the artificial heart valve near-physiological pulsating fluid external evaluation device is obtained, and the output amplitude of the reciprocating pump is adjusted to make the actual flow value equal to the standard flow value.

[0027] The pressure values ​​of the aorta, left ventricle, and left atrium of the artificial heart valve near-physiological pulsating fluid external evaluation device are monitored.

[0028] When the mean aortic pressure and mean left ventricular pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device are greater than the maximum values ​​of the mean aortic pressure and mean left ventricular pressure in the fluid dynamics performance verification guidelines of the international standard ISO 5840, the resistance value of the first or second resistance valve is reduced until the mean aortic pressure and mean left ventricular pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meet the fluid dynamics performance verification guidelines of the international standard ISO 5840.

[0029] When the mean aortic pressure and mean left ventricular pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device are less than the minimum values ​​of the mean aortic pressure and mean left ventricular pressure in the fluid dynamics performance verification guidelines of the international standard ISO 5840, the resistance value of the first or second resistance valve is increased until the mean aortic pressure and mean left ventricular pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meet the fluid dynamics performance verification guidelines of the international standard ISO 5840.

[0030] When the average aortic pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840, and the fluctuation range of the average aortic pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device is greater than the maximum value of the fluctuation range of the average aortic pressure in the fluid dynamics performance verification guidelines in the international standard ISO 5840, a portion of the air in the liquid container component is extracted by the air extraction device until the fluctuation range of the average aortic pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840.

[0031] When the mean pressure of the aorta meets the fluid dynamics performance verification guidelines in ISO 5840, and the fluctuation range of the mean pressure of the aorta is less than the minimum value of the fluctuation range of the mean pressure of the aorta in ISO 5840, air is injected into the liquid container component through the air injection device until the fluctuation range of the mean pressure of the aorta in the artificial heart valve near-physiological pulsation fluid external evaluation device meets the fluid dynamics performance verification guidelines in ISO 5840.

[0032] When the minimum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device are all higher than the maximum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure as specified in the international standard ISO 5840 fluid dynamics performance verification guidelines, liquid is drawn from the reservoir to lower the liquid level until the minimum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meet the fluid dynamics performance verification guidelines of the international standard ISO 5840.

[0033] When the maximum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device are all lower than the minimum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure in the fluid dynamics performance verification guidelines of the international standard ISO 5840, then liquid is continuously injected into the reservoir to raise the liquid level in the reservoir until the maximum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meet the fluid dynamics performance verification guidelines of the international standard ISO 5840.

[0034] When the pressure values ​​of the left ventricle and left atrium of the artificial heart valve near-physiological pulsating fluid external evaluation device both meet the fluid dynamics performance verification guidelines in the international standard ISO 5840, and the pressure value of the aorta of the artificial heart valve near-physiological pulsating fluid external evaluation device is lower than the fluid dynamics performance verification guidelines in the international standard ISO 5840, then the resistance value of the resistance valve is increased until the pressure value of the aorta of the artificial heart valve near-physiological pulsating fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840.

[0035] When the pressure values ​​of the left ventricle and left atrium of the artificial heart valve near-physiological pulsating fluid external evaluation device both meet the fluid dynamics performance verification guidelines in the international standard ISO 5840, and the pressure value of the aorta of the artificial heart valve near-physiological pulsating fluid external evaluation device is higher than the fluid dynamics performance verification guidelines in the international standard ISO 5840, then the resistance value of the first or second resistance valve is reduced until the pressure value of the aorta of the artificial heart valve near-physiological pulsating fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840.

[0036] The pressure change data and fluid flow rate data in the near-physiological pulsating fluid external evaluation device of the artificial heart valve are acquired, and the average flow rate, stroke volume, average aortic pressure, average transvalvular pressure gradient of the tested artificial valve, regurgitation flow rate of the tested artificial valve, and effective opening area of ​​the tested valve are calculated; the regurgitation flow rate includes closure volume, leakage volume, and closure transvalvular pressure gradient of the tested artificial valve.

[0037] The present invention achieves the following technical effects compared to the prior art: The artificial heart valve pulsating fluid external evaluation device and its evaluation method of the present invention incorporate two bellows in the systemic circulation tubing. The bellows are elastic and can extend and retract axially, simulating the compliance and resilience of the aorta and peripheral arteries. This makes the simulation of the aortic pressure waveform in the systemic circulation loop more accurate, and can realize details such as dicrotic waves, thereby improving the accuracy of the in vitro evaluation of artificial heart valves, meeting the higher requirements for artificial valve performance evaluation, and thus improving the accuracy and reliability of the entire medical device evaluation.

[0038] Furthermore, the measurement and control unit is equipped with prevalence pressure sensors, postvalence pressure sensors, and an optional atrial valve pressure sensor, each installed on its corresponding pressure measurement port, and all of these sensors are connected to the controller. This allows the device to monitor the pressure conditions before and after the artificial heart valve, as well as at the atrial valve (if needed), in real time and accurately. The controller can adjust the device's operating parameters based on the monitored pressure data, further ensuring the accuracy of pressure conditions during the evaluation process and providing strong support for the precise evaluation of artificial heart valve performance.

[0039] Furthermore, the equipment is equipped with a complete fluid circuit consisting of multiple components, including the valve installation unit under test, a reservoir, a liquid storage assembly, and a reflux assembly. For example, the first and second bellows in the liquid storage assembly can act similarly to the elasticity of blood vessels during fluid flow. The first bellows can simulate the compliance of the aorta, and the first resistance valve can simulate the resistance of the aorta. The second bellows can simulate the compliance of peripheral arteries, and the second resistance valve can simulate the resistance of peripheral arteries. In conjunction with other connecting pipes and valves, it more comprehensively simulates the flow, storage, and pressure changes of blood in the human cardiovascular system. Compared with existing simulation methods that rely solely on air cavities, it can provide testing conditions that are closer to the real physiological environment of the human body for artificial heart valves. The reservoir is equipped with a heating device and a temperature measuring device. The heating device can use an electric heating wire or an electric heating element, and the temperature measuring device can use a thermometer or a temperature sensor, which can heat the test liquid in the reservoir to the same temperature as human blood.

[0040] Furthermore, the drive unit uses a linear motor to drive the piston rod of the cylinder to perform reciprocating linear motion. This drive method can more accurately simulate the beating action of the heart, providing power for the entire fluid circuit, so that the fluid flows in the circuit at a rhythm similar to the human heart pumping blood, thereby allowing the artificial heart valve to be evaluated in a dynamic environment that is more in line with the actual physiological state.

[0041] Furthermore, in the valve installation unit under test, the bottom end of the first connecting tube and the top end of the second connecting tube are detachably connected to the valve fixing mechanism, and in the reflux assembly, the bottom end of the fifth connecting tube and the top end of the sixth connecting tube are detachably connected to the atrial valve fixing mechanism. This detachable connection method facilitates the installation and removal of artificial heart valves and atrial valves (if applicable), and allows for quick replacement when testing valves of different specifications or models, improving the versatility and operational efficiency of the equipment.

[0042] Furthermore, an observation window and a second vent valve are provided at the top of the first connecting pipe. The observation window allows operators to visually observe the internal fluid conditions during testing, while the second vent valve helps to expel excess gas during initial commissioning or operation, ensuring the normal operation of the fluid circuit. These auxiliary components all contribute to improving the ease of use and operability of the equipment.

[0043] Furthermore, a flow meter, a first resistance valve, and a second resistance valve are installed on the third connecting pipe. By adjusting these components, the flow rate and resistance of the fluid can be flexibly controlled to adapt to the evaluation needs of different types and performance requirements of artificial heart valves. This allows the equipment to adjust parameters according to the specific evaluation object, improving its applicability.

[0044] Furthermore, the linear guide rod is equipped with a grating ruler for monitoring the slider displacement, and the grating ruler is connected to the controller signal. The linear motor can be of different types, such as a voice coil motor. The grating ruler can provide real-time feedback on the slider displacement, allowing the controller to precisely control the linear motor's operation based on this information. The controller can also select the appropriate motor type according to actual needs, further enabling flexible adjustment of equipment operating parameters to better adapt to different testing scenarios and the characteristics of artificial heart valves.

[0045] Furthermore, by selecting the materials, wave pitch, wave thickness, and wave depth coefficient k of the two bellows, the compliance of the aorta and peripheral arteries can be simulated. By using elastic bellows with different frequency responses, the compliance of the aorta and peripheral arteries can be simulated. In addition, by combining the output frequency, vibration amplitude, and other parameters of the output device, the simulated mechanical properties of the human aorta can be adjusted to simulate the real pressure and flow waveforms under different physiological / pathological conditions, providing a more accurate detection environment for artificial valves (more accurate waveform simulation, capable of realizing details such as dicrotic waves). Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of the structure of the artificial heart valve near-physiological pulsating fluid external evaluation device of the present invention.

[0048] Figure 2 This is a schematic diagram of the valve fixation mechanism of the artificial heart valve near-physiological pulsating fluid external evaluation device in this invention.

[0049] Figure 3 This is a three-dimensional structural diagram of the valve fixation mechanism in this invention.

[0050] Figure 4 This is a schematic diagram of the atrial valve fixation mechanism in the artificial heart valve near-physiological pulsating fluid external evaluation device of the present invention.

[0051] Figure 5 This is a three-dimensional structural diagram of the central atrial valve fixing mechanism of the present invention.

[0052] Figure 6 This is a diagram of the voice coil motor control software interface of the present invention.

[0053] Figure 7 This is a flowchart of the motor control software of the present invention.

[0054] Figure 8 This is a circuit design diagram of the pressure amplifier of the present invention.

[0055] Figure 9 The waveform diagram is shown when the cardiac output is 2L / min according to the present invention.

[0056] Figure 10 The waveform diagram is shown when the cardiac output is 5L / min according to the present invention.

[0057] Figure 11 The waveform diagram is shown when the cardiac output is 8L / min according to the present invention.

[0058] In the diagram: 1. Support frame; 2. Linear motor; 3. Slider; 4. Linear guide rail; 5. Grating ruler; 6. Coupling; 7. Piston rod; 8. Cylinder; 9. T-connector; 10. Second connecting pipe; 11. First connecting pipe; 12. Observation window; 13. Inlet valve; 14. First exhaust valve; 15. Top cover; 16. Third connecting pipe; 17. First bellows; 18. Flow meter; 19. First resistance valve; 20. Second resistance valve; 21. Liquid storage container; 22. Fourth connecting pipe; 3. Fifth connecting tube; 24. Sixth connecting tube; 25. Prevalence pressure sensor; 26. Postvalence pressure sensor; 27. Valve fixation mechanism; 28. Atrial valve fixation mechanism; 29. ​​Atrial valve pressure sensor; 30. Second bellows; 31. First sleeve; 32. First support ring; 33. First pressure ring; 34. First threaded hole; 35. Second sleeve; 36. Second support ring; 37. Second pressure ring; 38. Second threaded hole; 39. Heating device; 40. Temperature measuring device. Detailed Implementation

[0059] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] The purpose of this invention is to provide an in vitro evaluation device and method for near-physiological pulsatile fluid in artificial heart valves, so as to solve the problems existing in the prior art and improve the accuracy of in vitro evaluation of artificial heart valves.

[0061] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0062] Example 1 like Figures 1 to 5 As shown, this embodiment provides a near-physiological pulsatile fluid external evaluation device for artificial heart valves, including: The drive unit includes a linear motor 2 and a cylinder 8. The linear motor 2 drives the piston rod 7 of the cylinder 8 to perform reciprocating linear motion. The side wall of the cylinder 8 is provided with a first exhaust valve 14 and a liquid inlet valve 13 that communicate with the rodless chamber of the cylinder 8.

[0063] The valve installation unit includes a first connecting tube 11, a valve fixing mechanism 27, and a second connecting tube 10 connected sequentially from top to bottom. The bottom end of the second connecting tube 10 is connected to the rodless chamber of the cylinder 8. The bottom end of the first connecting tube 11 is detachably connected to the top end of the second connecting tube 10 via a clamp or quick connector. The top end of the first connecting tube 11 is closed. The valve fixing mechanism 27 is installed at the top end of the second connecting tube 10 and is used to clamp the artificial heart valve to be tested. The artificial heart valve that can be tested by this invention is not limited and can be either the mitral valve or the aortic valve, so it can be used to test the average transvalvular pressure gradient of the mitral valve or the average transvalvular pressure gradient of the aortic valve, respectively. The specific choice can be flexibly made according to the actual test plan. Regardless of which valve is used, accurate testing can be achieved.

[0064] The arterial and peripheral circuit unit includes a reservoir 21, a liquid container assembly, a reflux assembly, and a resistance assembly. The reservoir 21 is connected to the first connecting pipe 11 via a third connecting pipe 16 to simulate the left atrium. A heating device 39 and a temperature measuring device 40 are provided at the reservoir 21. The heating device 39 and the temperature measuring device 40 are signal-connected to existing control devices such as a computer. The heating device 39 can be activated based on the temperature reading from the temperature measuring device 40. The heating device 39 can be a heating wire or a heating element, etc. The temperature measuring device 40... 0 can use a thermometer or temperature sensor. The heating device 39 can heat the test liquid in the storage container 21 to the same or close to the temperature of human blood, thereby making the simulation more realistic. The liquid container assembly includes a first corrugated tube 17 and a second corrugated tube 30, used to simulate the compliance of the aorta and other arteries. Both the first corrugated tube 17 and the second corrugated tube 30 are closed at one end and open at the other end. The open end of the first corrugated tube 17 and the open end of the second corrugated tube 30 are respectively connected to the third connecting tube 16, and the third... The second corrugated pipe 30 is closer to the reservoir than the first corrugated pipe 17; the reflux assembly includes a fifth connecting pipe 23, an atrial valve fixing mechanism 28, and a sixth connecting pipe 24 connected sequentially from top to bottom. The bottom end of the fifth connecting pipe 23 is detachably connected to the top end of the sixth connecting pipe 24 via a clamp or quick connector. The atrial valve fixing mechanism 28 is installed at the bottom end of the fifth connecting pipe 23 and is used to clamp the atrial valve. The fifth connecting pipe 23 is connected to the reservoir 21 via the fourth connecting pipe 22, and the sixth connecting pipe 24 is connected to the reservoir 21 via the first connecting pipe 23. The seventh connecting pipe is connected to the rodless chamber of the cylinder 8; the resistance assembly includes a first resistance valve 19 and a second resistance valve 20, which are used to simulate peripheral resistance. The first resistance valve 19 is located between the first bellows 17 and the second bellows 30, and the second resistance valve 20 is located between the second bellows 30 and the liquid storage container. By adjusting these components, the resistance of the fluid can be flexibly controlled to adapt to the evaluation needs of artificial heart valves of different types and performance requirements, so that the equipment can adjust the parameters according to the specific evaluation object and improve the applicability of the equipment.

[0065] The measurement and control unit includes a controller, a pre-valve pressure sensor 25, and a post-valve pressure sensor 26. The linear motor 2, the pre-valve pressure sensor 25, and the post-valve pressure sensor 26 are respectively connected to the controller via signals. A flow meter is installed on the third connecting pipe, which is located between the first connecting pipe 11 and the first bellows 17. A pre-valve pressure measuring port is provided on the second connecting pipe 10, and a post-valve pressure measuring port is provided on the first connecting pipe 11. The pre-valve pressure sensor 25 is installed on the pre-valve pressure measuring port, and the post-valve pressure sensor 26 is installed on the post-valve pressure measuring port.

[0066] Support frame 1; linear motor 2 and cylinder 8 are respectively fixed on support frame 1.

[0067] The artificial heart valve pulsation fluid external evaluation device in this embodiment simulates the systemic circulation circuit of the human body through the rodless chamber of cylinder 8, the valve installation unit under test, the third connecting pipe 16, the liquid container assembly, the liquid storage container 21, the fourth connecting pipe 22, the reflux assembly, and the seventh connecting pipe. The device incorporates a first corrugated pipe 17 and a second corrugated pipe 30 into the systemic circulation circuit. These corrugated pipes are elastic and capable of axial expansion and contraction, simulating the compliance of the aorta and peripheral arteries. This results in a more accurate simulation of the aortic pressure waveform in the systemic circulation circuit, enabling details such as dicrotic waves to be realized. This improves the accuracy of the external evaluation of the artificial heart valve, meets the higher requirements for artificial valve performance evaluation, and ultimately enhances the accuracy and reliability of the entire medical device evaluation.

[0068] In the valve installation unit under test, the top ends of the first connecting tube 11 and the second connecting tube 10 are detachably connected, and in the reflux assembly, the top ends of the fifth connecting tube 23 and the sixth connecting tube 24 are detachably connected. This detachable connection method facilitates the installation and removal of artificial heart valves and atrial valves (if applicable), and allows for quick replacement when testing valves of different specifications or models, thus improving the versatility and operational efficiency of the equipment.

[0069] It is worth noting that the artificial heart valve pulsating fluid external evaluation device in this embodiment does not have a drain valve, because all the components are connected by pipelines. After use, the liquid inside the device can be drained by disassembling the pipelines. Of course, in practical applications, it is also possible to set a drain valve in the device for easy drainage.

[0070] In an optional embodiment, a preferred embodiment features a top cover 15 at the top of the first connecting pipe 11. The top cover 15 is made of transparent material and has a smooth, transparent sealing layer in the center, which forms an observation window 12. The observation window 12 allows operators to easily observe the internal fluid conditions during testing. The second exhaust valve helps to expel excess gas during initial equipment commissioning or operation, ensuring the normal operation of the fluid circuit. These auxiliary components all contribute to improving the ease of use and operability of the equipment.

[0071] In an optional embodiment, a preferred embodiment includes an atrial valve pressure sensor 29 connected to the controller. An atrial valve pressure measuring port is provided on the fifth connecting pipe 23, and the atrial valve pressure sensor 29 is installed on the atrial valve pressure measuring port. The control unit is equipped with a prevalence pressure sensor 25, a postvalence pressure sensor 26, and an optional atrial valve pressure sensor 29, each installed on its corresponding measuring port, and all these sensors are connected to the controller. This allows the device to monitor the pressure conditions before and after the artificial heart valve and at the atrial valve (if needed) in real time and accurately. The controller can adjust the device's operating parameters based on the monitored pressure data, further ensuring the accuracy of pressure conditions during the evaluation process and providing strong support for accurate evaluation of artificial heart valve performance.

[0072] In the optional embodiments of this example, a heating device 39 and a temperature measuring device 40 are provided at the liquid storage container 21. The heating device 39 can heat the temperature of the test liquid in the liquid storage container 21 to close to the temperature of human blood.

[0073] In an optional embodiment, a preferred embodiment includes a linear guide rail 4 fixed to the support frame 1 and a slider 3 slidably engaged with the linear guide rail 4. The output end of the linear motor 2 is fixedly connected to the slider 3, and the slider 3 is fixedly connected to the piston rod 7 of the cylinder 8 via a coupling 6. The drive unit uses the linear motor 2 to drive the piston rod 7 of the cylinder 8 in reciprocating linear motion. This driving method can more accurately simulate the beating action of the heart, providing power to the entire fluid circuit and causing the fluid to flow in the circuit at a rhythm similar to the pumping action of a human heart, thus allowing the artificial heart valve to be evaluated in a dynamic environment that more closely matches actual physiological conditions.

[0074] In the optional scheme of this embodiment, it is more preferred that the second connecting pipe 10 is connected to the rodless cavity of the cylinder 8 through the three-way pipe 9. One port of the three-way pipe 9 is connected to the second connecting pipe 10, another port is connected to the rodless cavity of the cylinder 8, and yet another port is connected to the end of the seventh connecting pipe away from the sixth connecting pipe 24.

[0075] In an optional embodiment, a preferred embodiment includes a grating ruler 5 on the linear guide rod for monitoring the displacement of the slider 3. The grating ruler 5 is connected to the controller via a signal connection. The grating ruler 5 can provide real-time feedback on the displacement of the slider 3, allowing the controller to precisely control the operation of the linear motor 2 based on this information. Furthermore, the controller can select the appropriate motor type according to actual needs, further enabling flexible adjustment of the equipment's operating parameters to better adapt to different testing scenarios and the characteristics of artificial heart valves.

[0076] In the optional schemes of this embodiment, a preferred option is that the linear motor 2 is a voice coil motor. Voice coil motors have the characteristics of fast response speed and high precision, which can more accurately drive the reciprocating motion of the piston rod 7 of the cylinder 8, thereby better simulating the regular movement of the heart valves in the body with the heartbeat, ensuring the accuracy and stability of the test. The cylinder 8 is a rolling diaphragm cylinder. The rolling diaphragm cylinder has good sealing and stability during operation, which can effectively prevent gas or liquid leakage and ensure the stability of the test environment, thereby improving the accuracy and reliability of the test. The first connecting pipe 11 is connected to the second connecting pipe 10 through a quick-connect coupling.

[0077] In the optional embodiments of this example, the valve fixation mechanism 27 preferably includes a first sleeve 31 and a first pressure ring 33. The bottom outer wall of the first sleeve 31 is provided with an ear plate, which has a connecting hole and a bolt. The ear plate and bolt structure can be fixedly connected to the ear plate on the top side wall of the first connecting tube 11. In order to improve the sealing performance, a sealing ring is provided at the contact position between the bottom of the first sleeve 31 and the top of the first connecting tube 11, that is, the bottom of the first sleeve 31 and the top of the first connecting tube 11 are fixedly and sealed by a sealing ring.

[0078] An axial connecting rod is fixedly provided on the inner bottom wall of the first sleeve 31. The axial connecting rod is arranged along the axial direction of the first sleeve 31. A first pressure ring 33 is fixedly connected to the bottom of the axial connecting rod. The first pressure ring 33 has two first threaded holes 34. Bolts in the first threaded holes 34 can be used to fix it to the first support ring 32. Thus, the first pressure ring 33 and the first support ring 32 cooperate to clamp the edge of the artificial heart valve to be tested. The outer side of the first pressure ring 33 is in sealing contact with the inner side wall of the first connecting tube 11. A sealing ring can also be provided between the two to achieve a seal. In another embodiment, one connecting tube can be removed, that is, the first connecting tube 11 and the second connecting tube 10 can be made into an integrally formed connecting tube structure. The axial connecting rod and the first pressure ring 33 are located in the integral connecting tube structure, which can also achieve the above functions.

[0079] In the optional embodiments of this example, it is preferred that the valve fixing mechanism 27 and the atrial valve fixing mechanism 28 have the same structure. The atrial valve fixing mechanism 28 includes a second sleeve 35 and a second pressure ring 37. The bottom outer wall of the second sleeve 35 is provided with an ear plate, which is provided with a connecting hole and a bolt. The ear plate and bolt structure can be fixedly connected to the ear plate on the top side wall of the fifth connecting tube 23. In order to improve the sealing performance, a sealing ring is provided at the contact position between the bottom of the second sleeve 35 and the top of the fifth connecting tube 23. That is, the bottom of the second sleeve 35 and the top of the fifth connecting tube 23 are fixedly and sealed by a sealing ring.

[0080] An axial connecting rod is fixedly provided on the inner bottom wall of the second sleeve 35. The axial connecting rod is arranged along the axial direction of the second sleeve 35. A second pressure ring 37 is fixedly connected to the bottom of the axial connecting rod. The second pressure ring 37 has two second threaded holes 38. Bolts in the second threaded holes 38 can be used to fix it to the second support ring 36. Thus, the second pressure ring 37 and the second support ring 36 cooperate to clamp the edge of the artificial heart valve to be tested. The outer side of the second pressure ring 37 is in sealing contact with the inner side wall of the fifth connecting tube 23. A sealing ring can also be provided between the two to achieve a seal. In another embodiment, one connecting tube can be removed, that is, the fifth connecting tube 23 and the sixth connecting tube 24 can be made into an integrally formed connecting tube structure. The axial connecting rod and the second pressure ring 37 are located in the integral connecting tube structure, which can also achieve the above function. A top cover 15 is threadedly sealed to the top of the first sleeve 31 and the top of the second sleeve 35. An observation window is provided at the top cover 15. To improve sealing, a groove can be made on the side wall of the second support ring 36 and the first support ring 32, and a sealing ring can be installed in the groove. The sealing ring is fixedly and sealed to the inner wall of the corresponding connecting pipe. That is, the first support ring 32 is fixedly and sealed to the inner wall of the first connecting pipe 11 through its sealing ring, and the second support ring 36 is sealed to the inner wall of the fifth connecting pipe 23 through its sealing ring.

[0081] The specific working principle of the artificial heart valve near-physiological pulsating fluid external evaluation device in this embodiment is as follows: (1) Power generation and fluid drive The drive unit is the power source for the entire device. The linear motor 2 is fixed on the support frame 1, and it drives the piston rod 7 of the cylinder 8 to perform reciprocating linear motion. When the linear motor 2 is working, it drives the slider 3 (the slider 3 is fixed to the piston rod 7 of the cylinder 8 through the coupling 6) to slide on the linear guide rail 4, causing the piston rod 7 of the cylinder 8 to perform reciprocating motion.

[0082] The cylinder 8 has a first exhaust valve 14 and an inlet valve 13 communicating with the rodless chamber. During the reciprocating motion of the piston rod 7, the volume of the rodless chamber of the cylinder 8 changes periodically. When the volume of the rodless chamber increases, liquid is drawn in from the outside through the inlet valve 13; when the volume of the rodless chamber decreases, the liquid is compressed, thereby providing power for the flow of liquid in the entire circulation pipeline.

[0083] (2) Fluid circulation process and valve test After the liquid flows out of the rodless chamber of cylinder 8, it enters the valve installation unit under test through the second connecting tube 10. The second connecting tube 10 is detachably connected to the first connecting tube 11, and the artificial heart valve to be tested is held in the valve fixing mechanism 27 between them. The liquid flows from the second connecting tube 10 through the artificial heart valve into the first connecting tube 11.

[0084] The top end of the first connecting pipe 11 is closed, and it is connected to the liquid storage container 21 through the third connecting pipe 16, allowing liquid to flow back from the first connecting pipe 11 to the liquid storage container 21. During this process, the liquid storage assembly (including the first bellows 17 and the second bellows 30) is connected to the third connecting pipe 16. Both the first bellows 17 and the second bellows 30 are closed at one end and open at the other. The open end of the first bellows 17 and the open end of the second bellows 30 are respectively connected to the third connecting pipe 16. The first bellows 17 and the second bellows 30 can elastically deform according to changes in liquid pressure and flow rate, thus buffering and regulating liquid pressure and flow rate, simulating the elastic characteristics of blood vessels.

[0085] After the liquid flows out of the storage container 21, part of the liquid enters the reflux assembly through the fourth connecting pipe 22. The atrial valve fixing mechanism 28 in the reflux assembly clamps the atrial valve, and after passing through the atrial valve, the liquid returns to the rodless chamber of the cylinder 8 through the seventh connecting pipe, completing a complete liquid cycle.

[0086] (3) Pressure monitoring and control The measurement and control unit plays a crucial role in monitoring and controlling the equipment during operation. The prevalence pressure sensor 25 is installed on the prevalence pressure measuring port of the second connecting tube 10, and the postvalence pressure sensor 26 is installed on the postvalence pressure measuring port of the first connecting tube 11, which can monitor the pressure changes before and after the artificial heart valve in real time.

[0087] The controller is connected to the linear motor 2, the prevalvular pressure sensor 25, and the postvalvular pressure sensor 26. When the prevalvular and postvalvular pressure sensors 26 detect pressure changes, they transmit signals to the controller. Based on these signals, the controller can adjust the operating state of the linear motor 2, such as changing its speed or stroke, thereby regulating the rate and amplitude of volume change in the rodless chamber of the cylinder 8, and thus controlling the flow rate and pressure of the fluid. This enables testing of the artificial heart valve under different pressure and flow conditions. The tested pressure change data includes the maximum peak systolic pressure of the aorta, the maximum end-diastolic pressure, the mean aortic pressure, the real-time aortic pressure, the mean ventricular pressure, the highest ventricular pressure, the real-time ventricular pressure, the mean atrial pressure, the highest atrial pressure, the real-time atrial pressure, and the mean transvalvular pressure gradient. The measured fluid flow data includes the mean transvalvular pressure gradient, the mean flow rate, and the stroke volume. In different embodiments, when the artificial heart valve being tested is a mitral valve, the mean transvalvular pressure gradient is the same as the mean transvalvular pressure gradient of the mitral valve; when the artificial heart valve being tested is an aortic valve, the mean transvalvular pressure gradient is the same as the mean transvalvular pressure gradient of the aortic valve.

[0088] If the measurement and control unit also includes an atrial valve pressure sensor 29 (installed on the atrial valve pressure measuring port), it can also monitor the pressure before and after the atrial valve, further improving the control and regulation of pressure in the entire circulation pipeline.

[0089] (4) Flow and resistance regulation A flow meter, a first resistance valve 19, and a second resistance valve 20 are installed on the third connecting pipe. The flow meter is located between the first connecting pipe 11 and the first bellows 17. The first resistance valve 19 is located between the first bellows 17 and the second bellows 30. The second resistance valve 20 is located between the second bellows 30 and the liquid storage container. The flow meter 18 can measure the flow rate of the liquid in real time, and the first resistance valve 19 and the second resistance valve 20 can adjust the flow resistance of the liquid.

[0090] By adjusting the opening degree of the first resistance valve 19 and the second resistance valve 20, the resistance of the liquid in the circulation pipeline can be changed. Combined with the measurement data of the flow meter 18, the flow rate of the liquid can be further precisely controlled, providing different working environments for the artificial heart valve and more comprehensively evaluating its performance.

[0091] Example 2 This embodiment provides an evaluation method based on the aforementioned artificial heart valve near-physiological pulsating fluid external evaluation device, including: Test liquid is injected into the rodless chamber of cylinder 8 and the container / unit / component connected to cylinder 8 through the liquid inlet valve 13 on the side wall of cylinder 8 until the artificial heart valve pulsating fluid external evaluation device is full of test liquid; the heating device 39 is activated to heat the temperature of the test liquid in the liquid storage container 21 to close to the temperature of human blood.

[0092] The artificial heart valve to be tested is installed in the valve fixation mechanism 27.

[0093] Based on the controller in the measurement and control unit, the motion parameters of the linear motor 2 are set; the motion parameters are used to determine the reciprocating motion law of the piston rod 7 in the cylinder 8; the piston rod in the cylinder is used to simulate the aortic pressure waveform of a set frequency through reciprocating motion; the linear motor is a voice coil linear motor; the motion parameters include: initial motor position, voice coil motor point-to-point running position, motor stop position, voice coil motor periodic running waveform, voice coil motor periodic running amplitude, voice coil motor periodic running frequency, voice coil single-machine periodic running offset, and voice coil motor periodic running phase offset.

[0094] Start the linear motor 2 to drive the piston rod 7 to perform linear reciprocating motion, and check the opening and closing of the valve during the fluid flow process and record the working status of the artificial heart valve.

[0095] The pressure data and fluid flow data before and after the artificial heart valves are acquired by the prevalence pressure sensor 25 and postvalence pressure sensor 26 at the aortic and mitral valves. The pressure data includes the prevalence and postvalence pressures of the aortic or mitral valve being measured, the maximum peak systolic pressure of the aorta, the maximum end-diastolic pressure, the aortic pressure, the maximum ventricular pressure, the ventricular pressure, the maximum atrial pressure, and the atrial pressure.

[0096] Based on the category of the simulation experiment and the fluid dynamics performance verification guidelines in the international standard ISO 5840, the standard flow rate value for the artificial heart valve near-physiological pulsating fluid external evaluation device was determined during operation.

[0097] Based on the flow meter, the actual flow value of the artificial heart valve near-physiological pulsating fluid external evaluation device is obtained, and the output amplitude of the reciprocating pump is adjusted to make the actual flow value equal to the standard flow value.

[0098] The pressure values ​​of the aorta, left ventricle, and left atrium of the artificial heart valve near-physiological pulsating fluid external evaluation device are monitored.

[0099] When the mean aortic pressure and mean left ventricular pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device are greater than the maximum values ​​of the mean aortic pressure and mean left ventricular pressure in the fluid dynamics performance verification guidelines of the international standard ISO 5840, the resistance value of the first or second resistance valve is reduced until the mean aortic pressure and mean left ventricular pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meet the fluid dynamics performance verification guidelines of the international standard ISO 5840.

[0100] When the mean aortic pressure and mean left ventricular pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device are less than the minimum values ​​of the mean aortic pressure and mean left ventricular pressure in the fluid dynamics performance verification guidelines of the international standard ISO 5840, the resistance value of the first or second resistance valve is increased until the mean aortic pressure and mean left ventricular pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meet the fluid dynamics performance verification guidelines of the international standard ISO 5840.

[0101] When the average aortic pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840, and the fluctuation range of the average aortic pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device is greater than the maximum value of the fluctuation range of the average aortic pressure in the fluid dynamics performance verification guidelines in the international standard ISO 5840, a portion of the air in the liquid container component is extracted by the air extraction device until the fluctuation range of the average aortic pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840.

[0102] When the mean pressure of the aorta meets the fluid dynamics performance verification guidelines in ISO 5840, and the fluctuation range of the mean pressure of the aorta is less than the minimum value of the fluctuation range of the mean pressure of the aorta in ISO 5840, air is injected into the liquid container component through the air injection device until the fluctuation range of the mean pressure of the aorta in the artificial heart valve near-physiological pulsation fluid external evaluation device meets the fluid dynamics performance verification guidelines in ISO 5840.

[0103] When the minimum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device are all higher than the maximum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure as specified in the international standard ISO 5840 fluid dynamics performance verification guidelines, liquid is drawn from the reservoir to lower the liquid level until the minimum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meet the fluid dynamics performance verification guidelines of the international standard ISO 5840.

[0104] When the maximum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device are all lower than the minimum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure in the fluid dynamics performance verification guidelines of the international standard ISO 5840, then liquid is continuously injected into the reservoir to raise the liquid level in the reservoir until the maximum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meet the fluid dynamics performance verification guidelines of the international standard ISO 5840.

[0105] When the pressure values ​​of the left ventricle and left atrium of the artificial heart valve near-physiological pulsating fluid external evaluation device both meet the fluid dynamics performance verification guidelines in the international standard ISO 5840, and the pressure value of the aorta of the artificial heart valve near-physiological pulsating fluid external evaluation device is lower than the fluid dynamics performance verification guidelines in the international standard ISO 5840, then the resistance value of the resistance valve is increased until the pressure value of the aorta of the artificial heart valve near-physiological pulsating fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840.

[0106] When the pressure values ​​of the left ventricle and left atrium of the artificial heart valve near-physiological pulsating fluid external evaluation device both meet the fluid dynamics performance verification guidelines in the international standard ISO 5840, and the pressure value of the aorta of the artificial heart valve near-physiological pulsating fluid external evaluation device is higher than the fluid dynamics performance verification guidelines in the international standard ISO 5840, then the resistance value of the first or second resistance valve is reduced until the pressure value of the aorta of the artificial heart valve near-physiological pulsating fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840.

[0107] The pressure change data and fluid flow rate data in the near-physiological pulsating fluid external evaluation device of the artificial heart valve are acquired, and the average flow rate, stroke volume, average aortic pressure, average transvalvular pressure gradient of the tested artificial valve, regurgitation flow rate of the tested artificial valve, and effective opening area of ​​the tested valve are calculated; the regurgitation flow rate includes closure volume, leakage volume, and closure transvalvular pressure gradient of the tested artificial valve.

[0108] In this embodiment, the PID self-feedback process of the evaluation method is performed during the adjustment of test conditions to achieve the target evaluation state. The PID (proportional-integral-derivative) self-feedback process in this evaluation method is mainly used to precisely control and adjust the working state of the linear motor and the opening degree of the first and second resistance valves, thereby achieving fine adjustment of the resistance of the test fluid in the circulation pipeline and simulating the actual working conditions of the artificial heart valve under different working environments.

[0109] The specific process is as follows: 1. After starting the linear motor and driving the piston rod to perform linear reciprocating motion, real-time pressure data before and after the artificial heart valve is obtained through the prevalence pressure sensor and postvalence pressure sensor.

[0110] Second, compare the acquired pressure data with the preset target pressure data (i.e., the pressure value expected under the working environment of the artificial heart valve) and calculate the deviation value.

[0111] Third, based on the PID control algorithm, the adjustment amount of the linear motor's operating state (such as speed, acceleration, etc.) or the adjustment amount of the resistance valve opening is calculated according to the deviation value. The PID control algorithm responds quickly to the deviation through the proportional term, eliminates static deviation through the integral term, and predicts the deviation change trend through the derivative term, thereby achieving precise control of the deviation.

[0112] Fourth, based on the calculated adjustment amount, the working state of the linear motor or the opening degree of the first and second resistance valves are adjusted by the controller in the measurement and control unit, thereby realizing the adjustment of the resistance of the test liquid in the circulation pipeline.

[0113] 5. Repeat the above steps until the obtained pressure data matches the preset target pressure data, that is, the artificial heart valve is in the target evaluation state.

[0114] 6. After reaching the target evaluation state, record and calculate the working status data, pressure change data, and fluid flow data of the artificial heart valve, and evaluate its performance.

[0115] In this embodiment, a voice coil motor is selected as the drive source, and its operating curve can be easily programmed and preset via computer. By combining it with the adjustment of fluid resistance and fluid capacity in the fluid circuit, a pulsating flow close to the physiological state can be generated; at the same time, the low-friction cylinder used in conjunction has the characteristics of fast response and large diameter, which can meet the high flow rate requirements in heart valve testing.

[0116] The linear module of the voice coil motor, model L445-S19-1.0UM-000, has a peak thrust of 445 N and a continuous thrust of 145 N, with a maximum stroke of 38 mm. The low-friction cylinder adopts the FCS single-acting ejection type, with a cylinder diameter of 80 mm, a stroke of 108 mm, an operating pressure range of 0.01-0.7 MPa, and an operating temperature range of 0-60℃.

[0117] Utilizing a voice coil motor as the drive source, combined with a low-friction cylinder, the system perfectly meets testing requirements in terms of drive control and flow regulation. The voice coil motor platform is equipped with a servo controller and a grating position feedback system. Employing its PVT mode, it can precisely control the motor's trajectory, thereby precisely controlling the ejection of liquid from the cylinder. Combined with fluid resistance and capacity adjustments in the hydraulic circuit, it can generate a pulsating flow close to physiological conditions.

[0118] Specifically, regarding voice coil motor control: The control of a voice coil motor mainly consists of a voice coil motor, a Copley motor driver, a CAN card, and a PC. Communication is via an RS-232 serial port and CANOpen. A serial-to-USB cable is used to connect the USB end to the computer and the serial end to the RS-232 port of the Copley digital servo motor driver.

[0119] A CAN-PCI card for CAN bus communication is inserted inside the computer chassis. The DB9 port of the CAN card is then connected to the CAN bus communication interface of the copley driver. The amplifier output of the driver is connected to the voice coil motor, and the optical encoder on the voice coil motor (used for position feedback during motor operation) is connected to the feedback signal input of the copley driver. When multiple voice coil motors need to be controlled, multiple copley motor drivers are connected to the CAN bus, with each driver driving one voice coil motor.

[0120] like Figure 6 As shown, the voice coil motor control software was developed using the C++Builder 5.0 platform and the software development kit (CMO.dll). CMO library introduction: The software development kit used for voice coil motor control is the CMO.dll (version 2.18) development tool provided by Copley. CMO.dll is packaged as a COM component, which can be used by all software development tools that support COM components.

[0121] Control Mode Used: The control program for the voice coil motor primarily utilizes the PVT control mode from the CMO library. This involves continuously sending a series of position (P), speed (V), and time (T) points to the copley driver's RAM via CanOpen communication. Once the motor completes its cycle, the program sends the next series of PVT points, thus achieving uninterrupted cyclic operation of the motor. Specifically... Figure 7 As shown.

[0122] The main functions of the voice coil motor control software include: initializing the motor position (Home), setting the point-to-point running position of the voice coil motor, setting the motor stop position, setting the periodic running waveform of the voice coil motor, setting the periodic running amplitude of the voice coil motor, setting the periodic running frequency of the voice coil motor, setting the periodic running offset of the voice coil motor, and setting the periodic running phase offset of the voice coil motor.

[0123] The pre-valve pressure sensor and post-valve pressure sensor use ZXP410 pressure sensor with a pressure range of 40 kPa. Its main specifications are: model: ZXP 410, accuracy class: 0.15, nonlinearity: 0.15%FS, repeatability and hysteresis: 0.1%FS, output resistance: 5 kΩ, insulation resistance: >20 MΩ / 50V, power supply: 6 V, operating temperature: -10~70 ℃, allowable overload: 1.5 times.

[0124] Pressure amplifier circuit design, such as Figure 8 As shown, an LM317 two-stage voltage regulator circuit is used to output a 6V regulated power supply, ensuring a 1.5A output current, a linear regulation rate of 0.01%, an 80dB ripple rejection ratio, output short-circuit protection, and overcurrent and overheat protection. This allows the 6V output to simultaneously power four sensors. The preamplifier uses an AD8221 precision instrumentation amplifier; the amplifier gain can be adjusted by adjusting R5. The OPA2277 is a high-precision dual operational amplifier; the first stage is configured as a second-order low-pass filter, and the second stage is a non-inverting proportional amplifier. Adjusting potentiometer W1 can achieve zero-point setting of the sensors.

[0125] The USB data acquisition card uses the Advantech USB-4711A-AE model USB data acquisition board, whose main specifications are as follows: AD channels: 16 SE / 8 DI, resolution: 12 bit, sampling rate: 150 KS / s, on-board FIFO: 1024 samples (can hold 1024 sample values), input voltage range from +0.625V to +10V, accuracy from 0.4% to 0.1% (FSR), input impedance: 1GΩ; DA channels: 2, resolution: 12 bit, output voltage range: unipolar 0~5V and 0~10V, bipolar +5V and +10V, accuracy +1LSB; digital I / O channels: 8 inputs and 8 outputs, counter: 1 channel.

[0126] This AD / DA board performs the conversion of pressure and temperature. Its resolution, accuracy, and conversion speed meet the requirements for analog signal acquisition.

[0127] Specifically, the selected test and control chassis has 4-channel pressure amplifiers, a USB AD conversion module, 2-channel voice coil motor drivers, and a lighting power interface.

[0128] The system's test parameters include: peak systolic blood pressure ≥130 mmHg (adjustable to 110-150 mmHg), end-diastolic blood pressure ≥85 mmHg (adjustable to 60-90 mmHg), mean blood pressure ≥100 mmHg (adjustable to 80-120 mmHg); output volume 2-8 L / min (75 bpm), maximum stroke volume ≥150 mL; heart rate range 4-120 bpm; supports testing of mechanical valves, bioprosthetic valves, and implanted valves; suitable for valve sizes 15-35; can generate near-physiological aortic and ventricular pressure and flow waveforms; can observe and record valve opening and closing status; can measure or calculate mean transvalvular pressure gradient, mean flow, stroke volume, aortic and ventricular pressure, and record 10 consecutive cycles of aortic / ventricular / flow curves.

[0129] like Figure 9 Figures 10 and 11 show the system waveforms at cardiac output of 2 L / min, 5 L / min, and 8 L / min, respectively (red represents ventricular pressure, and black represents aortic pressure). Specifically, Figure 9 The aortic pressure systolic / average / diastolic pressure was 117 / 97 / 91 mmHg, and the maximum ventricular pressure was 124 mmHg. Figure 10 The aortic pressure systolic / average / diastolic pressure was 140 / 100 / 79 mmHg, and the maximum ventricular pressure was 144 mmHg. Figure 11 The aortic pressure shown in the figure is systolic / average / diastolic pressure of 169 / 98 / 56 mmHg, and the maximum ventricular pressure is 173 mmHg.

[0130] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An external evaluation device for near-physiological pulsating fluid in artificial heart valves, characterized in that, include: A drive unit, comprising a linear motor and a cylinder, wherein the linear motor drives the piston rod of the cylinder to perform reciprocating linear motion; The cylinder is provided with a first exhaust valve and an inlet valve that communicate with the rodless chamber of the cylinder. The valve installation unit under test includes a first connecting tube, a valve fixing mechanism, and a second connecting tube connected sequentially from top to bottom. The bottom end of the second connecting tube communicates with the rodless chamber of the cylinder. The bottom end of the first connecting tube is detachably connected to the top end of the second connecting tube, and the top end of the first connecting tube is closed. The valve fixing mechanism is installed at the top end of the second connecting tube and is used to clamp the artificial heart valve to be tested. An arterial and peripheral circuit unit; the arterial and peripheral circuit unit includes a reservoir, a liquid capacity assembly, a reflux assembly, and a resistance assembly. The reservoir is connected to the first connecting pipe via a third connecting pipe. The liquid capacity assembly includes a first bellows and a second bellows, both of which are closed at one end and open at the other. The open ends of the first and second bellows are respectively connected to the third connecting pipe, and the second bellows is closer to the reservoir than the first bellows. The reflux assembly includes a fifth connecting pipe connected sequentially from top to bottom. The system includes a tube, an atrial valve fixing mechanism, and a sixth connecting tube. The bottom end of the fifth connecting tube is detachably connected to the top end of the sixth connecting tube. The atrial valve fixing mechanism is installed at the bottom end of the fifth connecting tube and is used to clamp the atrial valve. The fifth connecting tube is connected to the liquid storage container via a fourth connecting tube, and the sixth connecting tube is connected to the rodless chamber of the cylinder via a seventh connecting tube. The first resistance valve of the resistance assembly is located between the first bellows and the second bellows, and the second resistance valve of the resistance assembly is located between the second bellows and the liquid storage container. The measurement and control unit includes a controller, a flow meter, a pre-valve pressure sensor, and a post-valve pressure sensor. The linear motor, the pre-valve pressure sensor, and the post-valve pressure sensor are respectively connected to the controller via signals. The flow meter is mounted on the third connecting pipe and is located between the first connecting pipe and the first bellows. The second connecting pipe has a pre-valve pressure measuring port communicating with the second connecting pipe, and the first connecting pipe has a post-valve pressure measuring port communicating with the first connecting pipe. The pre-valve pressure sensor is mounted on the pre-valve pressure measuring port, and the post-valve pressure sensor is mounted on the post-valve pressure measuring port. Support frame; the linear motor and cylinder are respectively fixed on the support frame.

2. The artificial heart valve near-physiological pulsating fluid external evaluation device according to claim 1, characterized in that: The measurement and control unit also includes an atrial valve pressure sensor that is signal-connected to the controller. An atrial valve pressure measuring port is provided on the fifth connecting tube, and the atrial valve pressure sensor is installed on the atrial valve pressure measuring port. A top cover is provided at the top of the first connecting tube. The top cover is made of transparent material and can form an observation window.

3. The artificial heart valve near-physiological pulsating fluid external evaluation device according to claim 1, characterized in that: The liquid storage container is equipped with a heating device and a temperature measuring device. The heating device can heat the temperature of the test liquid in the liquid storage container to close to the temperature of human blood.

4. The artificial heart valve near-physiological pulsating fluid external evaluation device according to claim 1, characterized in that: The drive unit also includes a linear guide rail fixed on the support frame and a slider that slides with the linear guide rail. The output end of the linear motor is fixedly connected to the slider, and the slider is fixedly connected to the piston rod of the cylinder through a coupling.

5. The artificial heart valve near-physiological pulsating fluid external evaluation device according to claim 1, characterized in that: The second connecting pipe is connected to the rodless chamber of the cylinder via a three-way pipe. One port of the three-way pipe is connected to the second connecting pipe, another port is connected to the rodless chamber of the cylinder, and yet another port is connected to the end of the seventh connecting pipe away from the sixth connecting pipe.

6. The artificial heart valve near-physiological pulsating fluid external evaluation device according to claim 4, characterized in that: The linear guide rod is also equipped with a grating ruler for monitoring the displacement of the slider, and the grating ruler is connected to the controller signal.

7. The artificial heart valve near-physiological pulsating fluid external evaluation device according to claim 1, characterized in that: The linear motor is a voice coil motor; the cylinder is a rolling diaphragm cylinder; the first connecting pipe is connected to the second connecting pipe through a quick-connect coupling.

8. The artificial heart valve near-physiological pulsating fluid external evaluation device according to claim 2, characterized in that: The valve fixation mechanism includes a first sleeve and a first pressure ring. The first sleeve is fixedly and sealed to the top of the first connecting tube, and the top cover is threadedly and sealed to the top of the first sleeve. Two symmetrically arranged axial connecting rods are fixedly provided on the inner bottom wall of the first sleeve. The first pressure ring is fixedly provided at the end of the axial connecting rod away from the first sleeve. The axial connecting rod and the first pressure ring can extend into the first connecting pipe and are located at the connection position of the first connecting pipe and the second connecting pipe. A first support ring is fixedly connected at the end of the first pressure ring away from the axial connecting rod. The first pressure ring is used to cooperate with the first support ring to clamp the edge of the artificial heart valve to be tested.

9. The artificial heart valve near-physiological pulsating fluid external evaluation device according to claim 1, characterized in that: The atrial valve fixation mechanism includes a second sleeve and a second pressure ring. The second sleeve is fixedly and sealed to the top of the fifth connecting tube, and a top cover is threadedly and sealed to the top of the second sleeve. The inner bottom wall of the second sleeve is fixedly provided with two symmetrically arranged axial connecting rods. The end of the axial connecting rod away from the second sleeve is fixedly provided with the second pressure ring. The axial connecting rod and the second pressure ring can extend into the fifth connecting pipe and are located at the connection position of the fifth connecting pipe and the sixth connecting pipe. The end of the second pressure ring away from the axial connecting rod is fixedly connected with the second support ring. The second pressure ring is used to cooperate with the second support ring to clamp the edge of the artificial heart valve to be tested.

10. A method for evaluating an artificial heart valve near-physiological pulsating fluid external evaluation device according to any one of claims 1-9, characterized in that, include: Test liquid is injected into the rodless chamber of the cylinder and the container / unit / component connected to the cylinder through the inlet valve on the side wall of the cylinder until the artificial heart valve pulsating fluid external evaluation device is filled with test liquid; the heating device is activated to heat the temperature of the test liquid in the storage container to close to the temperature of human blood. The artificial heart valve to be tested is installed in the valve fixation mechanism; Based on the controller in the measurement and control unit, the motion parameters of the linear motor are set; the motion parameters are used to determine the reciprocating motion law of the piston rod in the cylinder; The piston rod in the cylinder is used to simulate aortic pressure waveforms at a set frequency through reciprocating motion. The linear motor is a voice coil linear motor; the motion parameters include: initial motor position, voice coil motor point-to-point running position, motor stop position, voice coil motor periodic running waveform, voice coil motor periodic running amplitude, voice coil motor periodic running frequency, voice coil single-machine periodic running offset, and voice coil motor periodic running phase offset. Start the linear motor to drive the piston rod to perform linear reciprocating motion, and check the opening and closing of the valve during the fluid flow process and record the working status of the artificial heart valve. Acquire pressure data and fluid flow data before and after the artificial heart valve in the prevalence and postvalence pressure sensors at the aortic and mitral valves; the pressure data includes the prevalence and postvalence pressure of the aortic or mitral valve being measured, the maximum peak systolic pressure of the aorta, the maximum end-diastolic pressure, the aortic pressure, the maximum ventricular pressure, the ventricular pressure, the maximum atrial pressure, and the atrial pressure. Based on the category of the simulation experiment and the fluid dynamics performance verification guidelines in the international standard ISO 5840, the standard flow rate value for the artificial heart valve near-physiological pulsating fluid external evaluation device was determined during operation. Based on the flow meter, the actual flow value of the artificial heart valve near-physiological pulsating fluid external evaluation device is obtained, and the output amplitude of the reciprocating pump is adjusted to make the actual flow value equal to the standard flow value; The pressure values ​​of the aorta, left ventricle, and left atrium of the artificial heart valve near-physiological pulsating fluid external evaluation device were monitored; When the mean aortic pressure and mean left ventricular pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device are greater than the maximum values ​​of the mean aortic pressure and mean left ventricular pressure in the fluid dynamics performance verification guidelines of the international standard ISO 5840, the resistance value of the first or second resistance valve is reduced until the mean aortic pressure and mean left ventricular pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meet the fluid dynamics performance verification guidelines of the international standard ISO 5840. When the mean aortic pressure and mean left ventricular pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device are less than the minimum mean aortic pressure and mean left ventricular pressure values ​​in the fluid dynamics performance verification guidelines of the international standard ISO 5840, the resistance value of the first or second resistance valve is increased until the mean aortic pressure and mean left ventricular pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meet the fluid dynamics performance verification guidelines of the international standard ISO 5840. When the average aortic pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840, and the fluctuation range of the average aortic pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device is greater than the maximum value of the fluctuation range of the average aortic pressure in the fluid dynamics performance verification guidelines in the international standard ISO 5840, a portion of the air in the liquid container component is extracted by the air extraction device until the fluctuation range of the average aortic pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840; When the mean pressure of the aorta meets the fluid dynamics performance verification guidelines in the international standard ISO 5840, and the fluctuation range of the mean pressure of the aorta is less than the minimum value of the fluctuation range of the mean pressure of the aorta in the fluid dynamics performance verification guidelines in the international standard ISO 5840, air is injected into the liquid container component through the air injection device until the fluctuation range of the mean pressure of the aorta of the artificial heart valve near-physiological pulsation fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840; When the minimum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device are all higher than the maximum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure in the fluid dynamics performance verification guidelines of the international standard ISO 5840, then liquid is drawn from the reservoir to lower the liquid level in the reservoir until the minimum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meet the fluid dynamics performance verification guidelines of the international standard ISO 5840. When the maximum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device are all lower than the minimum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure in the fluid dynamics performance verification guidelines of the international standard ISO 5840, then liquid is continuously injected into the reservoir to raise the liquid level in the reservoir until the maximum values ​​of the aortic pressure, left ventricular pressure, and left atrial pressure of the artificial heart valve near-physiological pulsating fluid external evaluation device meet the fluid dynamics performance verification guidelines of the international standard ISO 5840; When the pressure values ​​of the left ventricle and left atrium of the artificial heart valve near-physiological pulsating fluid external evaluation device both meet the fluid dynamics performance verification guidelines in the international standard ISO 5840, and the pressure value of the aorta of the artificial heart valve near-physiological pulsating fluid external evaluation device is lower than the fluid dynamics performance verification guidelines in the international standard ISO 5840, then the resistance value of the resistance valve is increased until the pressure value of the aorta of the artificial heart valve near-physiological pulsating fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840; When the pressure values ​​of the left ventricle and left atrium of the artificial heart valve near-physiological pulsating fluid external evaluation device both meet the fluid dynamics performance verification guidelines in the international standard ISO 5840, and the pressure value of the aorta of the artificial heart valve near-physiological pulsating fluid external evaluation device is higher than the fluid dynamics performance verification guidelines in the international standard ISO 5840, then the resistance value of the first or second resistance valve is reduced until the pressure value of the aorta of the artificial heart valve near-physiological pulsating fluid external evaluation device meets the fluid dynamics performance verification guidelines in the international standard ISO 5840; The pressure change data and fluid flow rate data in the near-physiological pulsating fluid external evaluation device of the artificial heart valve are acquired, and the average flow rate, stroke volume, average aortic pressure, average transvalvular pressure gradient of the tested artificial valve, regurgitation flow rate of the tested artificial valve, and effective opening area of ​​the tested valve are calculated; the regurgitation flow rate includes closure volume, leakage volume, and closure transvalvular pressure gradient of the tested artificial valve.

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