Interventional pump in-vitro simulation cycle test device

Abstract

The invention discloses an intervention pump in-vitro simulation cycle testing device which comprises a supporting system, a blood pump system, a bionic cardiovascular simulation system, a sensing and measuring system and a control system. The support system is used for bearing and fixing each component and integrating an electric signal input interface and a serial communication interface; the blood pump system comprises a servo motor and a base, and the servo motor rotates to drive the base and the bionic left ventricle model to rotate; the bionic cardiovascular simulation system comprises a bionic left ventricle model, a valve device and a simulated cardiovascular loop, and the sensing and measuring system is used for monitoring hemodynamic parameters of the loop in real time; and the control system is used for receiving the hemodynamic parameters and controlling the servo motor to output motion meeting physiological characteristics. The device is simplified in structure, high in integration level, modular in design, capable of supporting quick disassembly and assembly, improved in maintenance efficiency, capable of reducing operation difficulty and personal errors and capable of reducing blood injury risks at the same time. The system is high in control stability and high in physiological simulation precision.

Description

TECHNICAL FIELD The present application belongs to the technical field of in-vitro simulation circulation device, and particularly relates to an in-vitro simulation circulation test device for an intervention pump. BACKGROUND

[0001] The in-vitro simulation circulation system (MCL) is a test platform for testing and evaluating the performance of a ventricular assist device (VAD), and is widely used in the development, optimization and verification of VAD. The core components of the MCL system include a blood pump, a cardiovascular simulation system, a sensing system and a control system. The blood pump is responsible for introducing circulating fluid into the cardiovascular simulation system. When the circulating fluid circulates in the cardiovascular simulation system, the sensing system extracts relevant data. The control system can achieve closed-loop control of different ventricular assist devices by changing the control strategy. The precision of the MCL system affects the reliability of medical devices and to some extent determines the risk and cost of clinical trials and personalized treatment. Therefore, under the premise of ensuring the stability of the instrument, it is an important task to improve the precision and accuracy of the in-vitro simulation circulation test system.

[0002] To improve the accuracy and reliability of MCL system, researchers have been committed to developing more bionic and integrated in vitro simulation circulatory system to improve the degree of system and actual agreement, while reducing the complexity of operation. Pickard Murphy et al. designed a simulation extracorporeal circulation system to test the artificial heart valve in the patent US4682491A, in which the test chamber and the intake chamber simulate the cardiovascular circuit together. Pressure compensation is provided between the test chamber and the intake chamber, and a data processor is used to monitor and process flow data and control the pump to create the desired waveform. A.Z.M. Khudzari et al. designed a highly simulated extracorporeal simulation circulation system that can accurately control the pressure, flow and resistance of the system (Khudzari AZM, Kadir MRA, Osman K, et al. Mock circulatory loop for cardiovascular assist device testing[J]. Cardiovascular Engineering: Technological Advancements, Reviews, and Applications, 2019: 177-200.). The system transmits square wave signals to the scalable fluid chamber to simulate the pulsatile effect of physiological pulsatility. During systole, air is pressurized to fill the chamber, and is accurately cut off at the end of diastole. In addition, the thick wall (about 2 mm) of the scalable fluid chamber promotes passive filling, which naturally reproduces the original shape of the fluid chamber during diastole. In order to simulate various ranges of cardiac physiological conditions, the fluid chamber is designed to contain 250 mL of water, which is almost twice the normal physiological value, and this design can simulate the left ventricular volume under the condition of dilated cardiomyopathy. However, this system only approaches the real cardiovascular system in terms of pressure, compliance and resistance values, and does not completely reproduce the physiological structure and function of the extracorporeal simulation circulation. Gianfranco Ferrari et al. combined numerical and physical models to obtain a numerical-physical hybrid model connected by an electro-hydraulic interface, which improved the measurement accuracy of MCL system (Ferrari G, De Lazzari C, Kozarski M, et al. A hybrid mock circulatory system: testing a prototype under physiologic and pathological conditions[J]. ASAIO journal, 2002, 48(5): 487-494.). The hybrid model reproduces the function of the ventricle through a variable elastic numerical model.Control of a DC motor driven gear pump was achieved by measuring left atrial and systemic arterial pressures and by solving the corresponding equations to calculate left ventricular output flow. Results obtained under different circulatory conditions demonstrated that the ventricular model output satisfied the pressure-volume loop and successfully predicted the trends of major hemodynamic parameters, comparatively successfully reproducing the physiological characteristics of the simulated cardiovascular circuit. However, the fluid dynamics characteristics of different circulations, different physiological variables and different ventricular assist devices are not easy to analyze, and there may be certain difficulties in actual operation. Researchers such as Zhang Yu designed an extracorporeal simulation circulation system for artificial heart testing in a patent with application number 202010010433.0, which includes a ventricular simulation assembly, a pulmonary circulation simulation assembly, and a systemic circulation simulation assembly, achieving simulation of human blood flow state and organ perfusion state. In the left and right ventricular simulator, the invention simulates the myocardium through a flexible connector, uses an elastic element to simulate the contraction and relaxation of the myocardium, and uses a limit stop to simulate the limit state of myocardial contraction and relaxation, achieving passive adjustment of the ventricular beating state when the preload and afterload of the heart change. At the same time, by simulating different blood flow paths and different organ perfusion levels, the invention can test and optimize various types of "artificial heart" (ventricular assist pump) devices and objectively test and optimize the fluid mechanics performance of the product. Although the system uses a flexible connector to simulate the passive adjustment of the myocardium, the actual mechanical feedback of the heart involves more complex bioelectric-mechanical coupling, and the system cannot fully reproduce dynamic adaptability. At the same time, the system needs to switch paths through a gate valve to adapt to different artificial hearts (such as LVAD / TAH), and frequent operation may introduce human error and the switching efficiency may have some impact on the test results. SUMMARY

[0003] To solve the above technical problems, the present application provides an interventional pump extracorporeal simulation circulation test device with simple structure, convenient carrying and maintenance, flexible and accurate adjustment of blood flow mode, and improved measurement accuracy.

[0004] The technical scheme adopted by the present application is: an interventional pump extracorporeal simulation circulation test device, comprising a support system, a blood pump system, a bionic cardiovascular simulation system, a sensing and measuring system, and a control system; the support system is used to bear and fix each component; the blood pump system comprises a servo motor and a base, the servo motor periodically rotates the base in the horizontal plane through the key on the rotating shaft, thereby driving the bionic left ventricular model in the bionic cardiovascular simulation system to contract or relax; the bionic cardiovascular simulation system comprises a bionic left ventricular model, a valve device, and a simulated cardiovascular circuit, the sensing and measuring system is used to monitor the hemodynamic parameters of the circuit in real time; the control system is used to receive the hemodynamic parameters and control the servo motor to output a motion conforming to the physiological characteristics, so as to reproduce the contraction and relaxation process of the heart.

[0005] The simulation cardiovascular loop of the intervention pump extracorporeal simulation circulation test device is composed of a silica gel hose, a silica gel compliant cavity and a damping valve, the size of the compliant cavity and the resistance of the damping valve can be adjusted to simulate the compliance and flow resistance of the human body blood vessels.

[0006] The support system of the intervention pump extracorporeal simulation circulation test device includes a support base and an upper support, the support base is made of high-strength plastic, a fixing hole is arranged in the middle of the support base for mounting a servo motor, and two fixing holes for fixing the bionic left ventricular model are arranged on the upper support.

[0007] The servo motor of the intervention pump extracorporeal simulation circulation test device includes a body and a protective shell, the body is installed in the protective shell, the protective shell is made of aluminum alloy, a round hole matched with the fixing hole on the support base is arranged on the protective shell, and the protective shell is fixed on the support base by screws.

[0008] The bionic cardiovascular simulation system of the intervention pump extracorporeal simulation circulation test device further includes an upper support, the top of the bionic left ventricular model is fixedly connected with the upper support, the upper support is fixedly installed on the support base, and the bottom of the bionic left ventricular model is fixedly connected with the base.

[0009] The bionic left ventricular model of the intervention pump extracorporeal simulation circulation test device is integrally injection molded according to a real human heart by using a medical-grade polycarbonate, the bionic left ventricular model is provided with a blood inlet and a blood outlet, a valve device is arranged at the blood inlet and the blood outlet, and the valve device can be detached.

[0010] The sensing and measuring system of the intervention pump extracorporeal simulation circulation test device includes a pressure sensor, a flow sensor and a filtering system, the pressure sensor is installed at the port of the bionic left ventricular model, the flow sensor and the filtering system are arranged in the simulation cardiovascular loop, and the pressure in the bionic left ventricular model and the flow parameter in the simulation cardiovascular loop are monitored in real time and accurately.

[0011] The control system of the intervention pump extracorporeal simulation circulation test device is composed of a PLC and an upper computer, the control system controls the motor to realize the output in line with the pressure-volume loop (PV-LOOP), the sensing and measuring system is electrically connected with the PLC, and the PLC is electrically connected with the upper computer.

[0012] The bionic cardiovascular simulation system, the support system and the blood pump system of the intervention pump extracorporeal simulation circulation test device adopt a modular split architecture, and are quickly disassembled based on gap fit.

[0013] The blood inlet and blood outlet interfaces of the bionic left ventricle model are thickened by using a biocompatible polyether ether ketone material, so as to ensure the interface connection accuracy and the loop airtightness.

[0014] Compared with the prior art, the present application has the following advantages: (1) The present application improves the physiological simulation accuracy, with a blood flow waveform reproduction error of less than or equal to 5%, a PV-LOOP matching degree with the real heart mechanical characteristics of greater than or equal to 90%, and the ability to reproduce the blood flow characteristics of normal, heart failure, aortic valve stenosis and other physiological and pathological states, thereby providing a high-fidelity test environment for medical device research and development.

[0015] (2) The present application has a simplified structure, high integration, modular design, supports quick disassembly and assembly, improves maintenance efficiency, reduces operation difficulty and human error, and reduces the risk of blood damage.

[0016] (3) The present application has strong control stability, can effectively suppress overshoot, has good data repeatability, and has an open interface compatible with various ventricular assist devices, is convenient to switch, and is widely applicable.

[0017] (4) The present application has high production feasibility, the core components are easy to purchase, the process is mature, the cost is controllable, and is conducive to industrialization, and can be applied to the fields of medical device research and development, university research, clinical training, etc.

[0018] (5) In terms of cost control, the present application has integrated design, reduces the number of parts, reduces the hardware cost by 25%-30%, modular maintenance reduces downtime and annual maintenance cost, the cavity and replaceable valve device of the present application reduce the cost of consumables. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic diagram of the present application.

[0020] Figure 2 is a schematic diagram of the bionic left ventricle model of the present application.

[0021] Figure 3 is a schematic diagram of the valve device of the present application.

[0022] Figure 4 is a structural schematic diagram of the servo motor of the present application.

[0023] Figure 5 is a structural schematic diagram of the upper support of the present application.

[0024] In the figure: 1. Bionic left ventricle model, 2. Base, 3. Keyway, 4. Valve device, 5. Valve device connection hole, 6. Key, 7. Servo motor top fixing hole, 8. Servo motor, 9. Servo motor fixing hole in the middle of the support, 10. Support, 11. Upper bracket and base connecting column, 12. Upper bracket, 13. Bionic left ventricle model fixing hole at the upper bracket. Detailed Implementation

[0025] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0026] like Figures 1-5 As shown, the present invention includes a support system, a blood pump system, a biomimetic cardiovascular simulation system, a sensing and measurement system, and a control system.

[0027] The support system is used to support and fix the various components, such as Figure 5 As shown. The support system includes a support base 10 and an upper bracket 12. The support base 10 is a ring structure made of high-strength plastic. The support base 10 has four fixing holes 9 in the middle for mounting a servo motor 8. The upper bracket 12 is made of high-strength plastic and fits tightly against the bionic left ventricular model 1. The upper part of the upper bracket 12 has two bionic left ventricular model fixing holes 13 for fixing the bionic left ventricular model 1.

[0028] The blood pump system includes a servo motor 8 and a base 2. The servo motor 8 drives the base 2 to rotate periodically in the horizontal plane via a key 6 on a rotating shaft, thereby causing the bionic left ventricular model 1 in the bionic cardiovascular simulation system to contract or relax.

[0029] like Figure 2 As shown, the biomimetic cardiovascular simulation system includes a biomimetic left ventricular model 1, a valve device 4, and a simulated cardiovascular circuit. The biomimetic left ventricular model 1 is integrally injection molded from medical-grade polycarbonate based on an image of a real human heart. The biomimetic left ventricular model has a blood inlet and a blood outlet, both of which are equipped with detachable valve devices. The blood inlet and blood outlet interfaces of the biomimetic left ventricular model 1 are thickened with biocompatible polyetheretherketone (PEEK) material to ensure accurate interface connections and circuit airtightness.

[0030] The bottom of the bionic left ventricle model 1 is fixed to the base 2 with solid glue. The top of the bionic left ventricle model 1 is fixed to the upper support 12 with bolts. Other fasteners can be optionally added to enhance structural stability. The upper support 12 is fixedly mounted on the support base 10. The upper support 12 is connected to the base 2 with a clearance fit. The interface of the bionic left ventricle model 1 adopts an open design, which allows for adjustment of the position 4 of the bionic valve and the type of simulated cycle testing device that can be connected.

[0031] like Figure 4 As shown, the servo motor 8 includes a base plate, a protective housing, a stator, a mover, a photoelectric encoder, and a programmable driver. The body of the servo motor 8 is installed inside the protective housing. The protective housing is made of aluminum alloy and has a round hole on its top that matches the fixing hole 9 on the support base 10. It is fixed to the support base 10 with screws, and the protective housing is fitted with the bottom of the base 2 with a clearance. The key 6 on the rotating shaft of the servo motor 8 cooperates with the keyway 3 on the base 2 to form a precision transmission interface, driving the bionic left ventricular model 1 to achieve periodic contraction and relaxation functions. The simulated cardiovascular circuit consists of a silicone tubing, a silicone compliance chamber, and a damping valve. The size of the compliance chamber and the resistance of the damping valve are adjustable to simulate the compliance and flow resistance of human blood vessels.

[0032] The sensing and measurement system is used to monitor the hemodynamic parameters of the circuit in real time. The sensing and measurement system includes an access pressure sensor, a flow sensor, and a filtering system. The pressure sensor and flow sensor are used to accurately monitor the pressure in the bionic left ventricular model 1 and the flow parameters in the simulated cardiovascular circuit, respectively. The pressure sensor is installed at the port of the bionic left ventricular model, and the flow sensor and filtering system are set in the simulated cardiovascular circuit.

[0033] The control system receives hemodynamic parameters and controls the servo motor to output motion conforming to physiological characteristics, thereby replicating the contraction and relaxation processes of the heart. The control system consists of a PLC and a host computer, using a PI control algorithm to control the motor position and speed loops to achieve PV-LOOP-compliant output. The sensing and measurement system is electrically connected to the PLC, and the PLC is electrically connected to the host computer. The biomimetic cardiovascular simulation system, support system, and blood pump system adopt a modular, split architecture, enabling rapid assembly and disassembly based on clearance fit.

[0034] like Figure 1 , 2 As shown, in one complete working cycle of this invention, the servo motor 8 drives the bionic left ventricular model 1 to perform bidirectional periodic motion: during the contraction phase, the servo motor 8 rotates forward, the valve device 4 at the blood inlet closes, and a gradient pressure drop is formed in the bionic left ventricular model 1 due to volume change, causing blood to be pumped out from the blood outlet. During the diastolic phase, the servo motor 8 rotates in reverse, the valve device 4 at the blood outlet closes, and blood flows into the bionic left ventricular model 1 from the blood inlet. By adjusting the rotation speed, acceleration time, and rotation of the servo motor 8, accurate simulation of the heart's beating process can be achieved. Furthermore, since the output blood flow mode of this invention simulates the beating blood flow of the heart, compared with traditional methods, it can effectively reduce the shear stress of the blood, helping to protect the physiological activity of the blood and reduce the risk of blood damage. This invention, through precise mechanical coordination and the application of biocompatible materials, achieves modular and detachable maintenance characteristics while ensuring liquid tightness.

[0035] The assembly of this invention adopts a modular bottom-up positioning strategy: First, the support base 10 of this invention is placed on a horizontal reference plane, and the servo motor 8 is connected to the support base 10 by means of screws and nuts. The key 6 on the shaft of the servo motor 8 is embedded in the keyway 3 of the base 2; the bionic left ventricular model 1 and the upper support 12 are fastened with bolts. This design supports rapid maintenance, as the upper support 12 and the support base 10, and the bionic left ventricular model 1 and the base 2 can be directly decoupled, achieving convenient separation and meeting the needs of non-destructive disassembly, cleaning, and consumable replacement in clinical scenarios, improving operational efficiency while ensuring sealing.

Claims

1. An external simulated circulation testing device for an interventional pump, characterized in that: The system includes a support system, a blood pump system, a bionic cardiovascular simulation system, a sensing and measurement system, and a control system. The support system supports and secures the components and integrates an electrical signal input interface and a serial communication interface. The blood pump system includes a servo motor and a base. The servo motor drives the base to rotate periodically in a horizontal plane via a key on a rotating shaft, thereby causing the bionic left ventricular model in the bionic cardiovascular simulation system to contract or relax. The bionic cardiovascular simulation system includes a bionic left ventricular model, a valve device, and a simulated cardiovascular circuit. The sensing and measurement system monitors the hemodynamic parameters of the circuit in real time. The control system receives the hemodynamic parameters and controls the servo motor to output motion that conforms to physiological characteristics to reproduce the heart's contraction and relaxation process.

2. The extracorporeal simulated circulation testing device for interventional pumps according to claim 1, characterized in that: The simulated cardiovascular circuit consists of a silicone tubing, a silicone compliance chamber, and a damping valve. The size of the compliance chamber and the resistance of the damping valve can be adjusted to simulate the compliance and flow resistance of human blood vessels.

3. The extracorporeal simulated circulation testing device for interventional pumps according to claim 1, characterized in that: The support system includes a support base and an upper bracket. The support base is made of high-strength plastic and has a fixing hole in the middle for mounting a servo motor. The upper bracket has two biomimetic left ventricular model fixing holes for fixing the left ventricular model.

4. The extracorporeal simulated circulation testing device for interventional pumps according to claim 3, characterized in that: The servo motor includes a body and a protective housing; the body is installed inside the protective housing; the protective housing is made of aluminum alloy and has round holes that match the fixing holes on the support base, and is fixed to the support base with screws.

5. The extracorporeal simulated circulation testing device for interventional pumps according to claim 3, characterized in that: The bionic cardiovascular simulation system also includes an upper support. The top of the bionic left ventricle model is fixedly connected to the upper support, which is fixedly mounted on a support base. The bottom of the bionic left ventricle model is fixedly connected to the base.

6. The extracorporeal simulated circulation testing device for interventional pumps according to claim 1, characterized in that: The bionic left ventricle model is made of medical-grade polycarbonate and is injection molded in one piece according to the real human heart. The bionic left ventricle model has a blood inlet and a blood outlet, and valve devices are installed at both the blood inlet and the blood outlet. The valve devices can be removed.

7. The extracorporeal simulated circulation testing device for interventional pumps according to claim 1, characterized in that: The sensing and measurement system includes a pressure sensor, a flow sensor, and a filtering system. The pressure sensor is installed at the port of the bionic left ventricular model, and the flow sensor and filtering system are set in the simulated cardiovascular circuit to accurately monitor the pressure in the bionic left ventricular model and the flow parameters in the simulated cardiovascular circuit in real time.

8. The extracorporeal simulated circulation testing device for interventional pumps according to claim 1, characterized in that: The control system consists of a PLC and a host computer. The control system controls the motor to achieve the output conforming to the pressure-volume loop. The sensing and measurement system is electrically connected to the PLC, and the PLC is electrically connected to the host computer.

9. The extracorporeal simulated circulation testing device for interventional pumps according to claim 1, characterized in that: The biomimetic cardiovascular simulation system, support system, and blood pump system adopt a modular and split architecture, which enables rapid assembly and disassembly based on gap fit.

10. The extracorporeal simulated circulation testing device for interventional pumps according to claim 6, characterized in that: The blood inlet and blood outlet interfaces of the biomimetic left ventricle model are reinforced with biocompatible polyetheretherketone material to ensure accurate interface connection and airtight circuit.

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