A physical intelligent artificial heart and a control method thereof

Abstract

The present application relates to the technical field of artificial heart, and especially relates to a physical intelligent artificial heart and a control method thereof, adopts LCE material to form a double-layer structure LCE balloon, and respectively adds a circuit winding the LCE balloon in the two-layer LCE film, provides power for the jumping of the LCE balloon based on the electrothermal effect, simultaneously combines the aortic valve one-way valve and the mitral valve one-way valve to realize the periodic circulation of pumping blood into or out of the left ventricle, thereby simulating the left ventricular dynamic jumping characteristics participating in the human blood circulation system. The present application has the advantages of high efficiency and convenience through the theoretical simulation analysis of the chaotic self-excitation jumping of the heart, compared with the experimental and observation methods, can quickly simulate the left ventricular dynamic jumping characteristics participating in the human blood circulation system, can promote the application of chaotic dynamics in the field of artificial heart and medical instruments, and provide theoretical support for early diagnosis of cardiovascular diseases.

Description

Technical Field

[0001] This invention relates to the field of artificial heart technology, and in particular to a physically intelligent artificial heart and its control method. Background Technology

[0002] Chaos is ubiquitous in our lives, appearing in everything from flags fluttering in the wind and dripping faucets to chemical reactions and biological systems. In some cases, chaos is essential for normal functioning. In the human circulatory system, the left ventricle plays a crucial role, pumping oxygenated blood from the heart throughout the body. Research shows that a healthy cardiovascular system is nonlinear and complex. Circulatory system diseases can manifest as a reduction in chaos or a greater degree of this nonlinear dynamics. In recent years, researchers have increasingly focused on self-sustaining chaotic systems based on liquid crystal elastomer (LCE) materials. These systems can better mimic natural motion patterns, particularly in heart-related applications. Therefore, research on LCE-based self-sustaining chaotic systems contributes to cardiac and cerebrovascular chaos analysis, cardiovascular disease prevention and treatment, and bionics.

[0003] Currently, with the rapid development of active materials, self-vibrating systems based on active materials have received considerable attention. However, artificial hearts constructed based on self-vibrating systems cannot absorb energy from the external environment to compensate for damping dissipation and maintain continuous beating when faced with theoretical simulation analysis of self-excited beating, and their self-regulation ability is poor. Moreover, the commonly used methods for analyzing heart beating are time-domain analysis and morphological analysis. These two methods lack sufficient sensitivity for analyzing heart beating and are affected by individual differences, making efficient and convenient theoretical analysis difficult. Therefore, how to achieve an efficient and convenient theoretical analysis method is an urgent problem to be solved. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a physically intelligent artificial heart and its control method to solve the technical problems mentioned in the background section.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a physically intelligent artificial heart, comprising a bionic left ventricle manufactured by a mold forming process, and a connection and fixing device for internally installing and stably fixing the bionic left ventricle, wherein the bionic left ventricle comprises an LCE balloon with a double-layer structure composed of a first LCE membrane and a second LCE membrane.

[0006] The physical intelligent artificial heart also includes a systemic circulation system mounted on the LCE balloon to pump blood into it and re-infuse it to achieve periodic circulation, and a power drive system that causes the LCE balloon to contract inward and gradually recover based on periodic electrothermal stimulation.

[0007] Furthermore, the systemic circulation system includes the aorta and mitral valve veins symmetrically arranged on both sides of the LCE balloon and respectively connected to them, as well as a blood circulation device connected to the aorta and mitral valve veins. An aortic valve check valve and a mitral valve check valve are respectively built into the aorta and the mitral valve veins near the LCE balloon. Blood in the LCE balloon is pumped into the aorta through the aortic valve check valve, and then transported into the mitral valve vein through the blood circulation device, and finally flows into the LCE balloon through the mitral valve check valve.

[0008] Furthermore, the power drive system comprises an electrothermal stimulation circuit embedded or wound on the first LCE membrane and the second LCE membrane, as well as contact points and an external power source disposed on the connection and fixing device. When the LCE balloon expands and touches the contact point, the circuit is energized, and the LCE balloon contracts inward due to the electrothermal effect. When the LCE balloon leaves the contact point, the circuit is de-energized, and the LCE balloon stops contracting and gradually recovers.

[0009] Furthermore, the connection and fixing device includes an external main support device, an arc-shaped bracket for fixing and placing the LCE balloon is provided inside the external main support device, and a fixing beam for installing the contact point is provided at the top inside the external main support device, and the contact point is located directly above the LCE balloon.

[0010] Furthermore, this invention proposes a control method for a physically intelligent artificial heart. By calculating the radius of the bionic left ventricle and determining whether it is energized, the method achieves autonomous beating control of the artificial heart under electrothermal action, thereby rapidly simulating the dynamic beating characteristics of the ventricle involved in the human circulatory system. The method includes the following steps:

[0011] S1, Define chest pressure And according to chest pressure Calculate the ventricular pressure as an introduced variable affecting the bionic left ventricular beat. ;

[0012] S2. Determine the temperature difference of the LCE balloon under autonomous power supply or power failure conditions. And solve the electrothermal-driven contractile strain of the biomimetic left ventricle. ;

[0013] S3, Shrinkage strain driven by electrothermal stimulation Calculation of principal stresses within the biomimetic left ventricular plane And based on principal stress Calculation of Laplace stress in a biomimetic left ventricle ;

[0014] S4, based on ventricular pressure and Laplace stress Establish dynamic control equations to realize the autonomous beating of an artificial heart under electrothermal action;

[0015] S5. Solve the dynamic control equations using the fourth-order Runge-Kutta method to obtain the radius of the bionic left ventricle used to regulate the spontaneous beating mode of the artificial heart. According to the radius Determine whether the bionic left ventricle is energized, and update the temperature difference accordingly. The state.

[0016] By employing the above technical solution, the present invention provides a physically intelligent artificial heart and its control method, which has at least the following beneficial effects:

[0017] 1. This invention uses LCE material to construct an LCE balloon with a double-layer structure, and adds circuits wrapped around the LCE balloon to the two LCE membranes respectively. Based on the electrothermal effect, the LCE balloon is powered to beat. At the same time, combined with the aortic valve check valve and the mitral valve check valve, the periodic circulation of blood pumped into or out of the left ventricle is realized, thereby simulating the dynamic beating characteristics of the left ventricle involved in the human circulatory system. This overcomes the shortcomings of traditional artificial hearts, such as insufficient sensitivity and susceptibility to individual differences, and can improve the efficiency and convenience of cardiac self-excited beating analysis.

[0018] 2. This invention has the advantages of high efficiency and convenience in theoretical simulation analysis of chaotic self-excited heart beating. Compared with experimental and observational methods, it can quickly simulate the dynamic beating characteristics of the left ventricle involved in the human circulatory system, which can promote the application of chaotic dynamics in artificial hearts and medical devices, and provide theoretical support for the early diagnosis of cardiovascular diseases. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0020] Figure 1 This is a schematic diagram of the artificial heart structure in Embodiment 1 of the present invention;

[0021] Figure 2 This is a top view of the artificial heart in Embodiment 1 of the present invention;

[0022] Figure 3 This is a schematic diagram showing the change of radius over time when the damping coefficient is 0.03 in Embodiment 2 of the present invention;

[0023] Figure 4 This is the phase diagram for the damping coefficient being 0.03 in Embodiment 2 of the present invention;

[0024] Figure 5This is the Poincaré plot for the damping coefficient of 0.03 in Embodiment 2 of the present invention;

[0025] Figure 6 This is a schematic diagram showing the change of radius over time when the damping coefficient is 0.09 in Embodiment 2 of the present invention;

[0026] Figure 7 This is the phase diagram for the damping coefficient of 0.09 in Embodiment 2 of the present invention;

[0027] Figure 8 The Poincaré plot is shown in Embodiment 2 of the present invention when the damping coefficient is 0.09.

[0028] Figure 9 This is a bifurcation diagram showing the variation of the damping coefficient in Embodiment 2 of the present invention;

[0029] Figure 10 This is a bifurcation diagram showing the variation of the shrinkage coefficient in Embodiment 2 of the present invention;

[0030] Figure 11 This is a bifurcation diagram of the respiratory cycle changes in Embodiment 2 of the present invention;

[0031] Figure 12 This is a bifurcation diagram showing the change in LCE balloon volume in Embodiment 2 of the present invention;

[0032] Figure 13 This is a bifurcation diagram of different dimensionless maximum active pressures in Embodiment 2 of the present invention.

[0033] In the picture:

[0034] 1. Bionic left ventricle; 10. LCE balloon; 11. First LCE membrane; 12. Second LCE membrane;

[0035] 2. Connecting and fixing device; 21. External main support device; 22. Arc-shaped bracket; 23. Fixing beam;

[0036] 3. Systemic circulatory system; 31. Aorta; 32. Mitral valve; 33. Aortic valve check valve; 34. Mitral valve check valve; 35. Blood circulation apparatus;

[0037] 4. Power drive system; 41. Electrothermal stimulation circuit; 42. Contact point. Detailed Implementation

[0038] 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. This will allow for a full understanding of how the present application uses technical means to solve technical problems and achieve technical effects, and to facilitate its implementation.

[0039] Inspired by the human left ventricle, this embodiment presents a novel chaotic beating system modeled on an electrothermally responsive liquid crystal elastomer balloon. To investigate the self-beating characteristics of the liquid crystal elastomer left ventricle, a simplified theoretical framework is established by combining the Joule heat conduction model, the left ventricular circulatory system model, and dynamic principles. Numerical results demonstrate that the left ventricle exhibits two typical self-beating modes: periodic beating and chaotic beating.

[0040] Example 1

[0041] This embodiment proposes a physically intelligent artificial heart, such as... Figure 1 and Figure 2 As shown, the device includes a bionic left ventricle 1 manufactured using a molding process, and a connection and fixation device 2 for internally mounting and securing the bionic left ventricle 1. The bionic left ventricle 1 includes an LCE balloon 10 with a double-layer structure consisting of a first LCE membrane 11 and a second LCE membrane 12. The connection and fixation device 2 includes an external main support device 21, within which is an arc-shaped bracket 22 for fixing the LCE balloon 10. A fixing beam 23 for mounting a contact point 42 is provided at the top of the external main support device 21, with the contact point 42 located directly above the LCE balloon 10. The physically intelligent artificial heart also includes a systemic circulation system 3 mounted on the LCE balloon 10 for pumping blood into and re-infusing it to achieve periodic circulation, and a power drive system 4 that causes the LCE balloon 10 to contract inward and gradually recover based on periodic electrothermal stimulation.

[0042] The systemic circulation system 3 includes an aorta 31 and a mitral valve vein 32 symmetrically arranged on both sides of the LCE balloon 10 and connected to them respectively, and a blood circulation device 35 connected to the aorta 31 and the mitral valve vein 32. An aortic valve check valve 33 and a mitral valve check valve 34 are respectively built into the aorta 31 and the mitral valve vein 32 near the LCE balloon 10. Blood in the LCE balloon 10 is pumped into the aorta 31 through the aortic valve check valve 33, then transported into the mitral valve vein 32 through the blood circulation device 35, and finally flows into the LCE balloon 10 through the mitral valve check valve 34. The blood circulation device 35 is an integrated piping system that may include a pump, check valves, and resistance control components. Its core function is to guide blood from the aorta to the mitral valve vein (left atrial inlet) and maintain a closed-loop circulation through the check valves. The specific design depends on the application scenario (such as medical equipment or experimental models), but essentially it simulates or assists the blood flow path of systemic circulation.

[0043] The power drive system 4 includes an electrothermal stimulation circuit 41 embedded or wound on the first LCE membrane 11 and the second LCE membrane 12, and is composed of a contact point 42 set on the connection and fixing device 2 and an external power source. When the LCE balloon 10 expands and touches the contact point 42, the circuit is energized, and the LCE balloon 10 contracts inward due to the electrothermal effect. When the LCE balloon 10 leaves the contact point 42, the circuit is de-energized, and the LCE balloon 10 stops contracting and gradually recovers.

[0044] This embodiment uses LCE material to construct an LCE balloon with a double-layer structure, and circuits wrapped around the LCE balloon are added to the two LCE membranes respectively. Based on the electrothermal effect, the LCE balloon is powered to beat. At the same time, combined with the aortic valve check valve and the mitral valve check valve, the periodic circulation of blood pumped into or out of the left ventricle is realized, thereby simulating the dynamic beating characteristics of the left ventricle involved in the human circulatory system. This overcomes the shortcomings of traditional artificial hearts, such as insufficient sensitivity and susceptibility to individual differences, and can improve the efficiency and convenience of cardiac self-excited beating analysis.

[0045] Example 2

[0046] This embodiment proposes a control method for the physically intelligent artificial heart proposed in Embodiment 1. By calculating the radius of the bionic left ventricle and determining whether it is energized, the method achieves autonomous beating control of the artificial heart under electrothermal action, thereby rapidly simulating the dynamic beating characteristics of the ventricle involved in the human circulatory system. The method includes the following steps:

[0047] S1, Define chest pressure And according to chest pressure Calculate the ventricular pressure as an introduced variable affecting the bionic left ventricular beat. In this embodiment, the defined chest pressure The thoracic pressure caused by the contraction and expansion of the respiratory muscle groups such as the diaphragm and intercostal muscles is expressed as:

[0048]

[0049] In the formula, A represents the minimum thoracic pressure; A represents the maximum active pressure. This indicates respiratory rate, which is related to the respiratory cycle. The relationship is ; This refers to the self-excitation time of the biomimetic left ventricle.

[0050] Determining chest pressure Based on this, variable ventricular pressure is obtained through calculation. The expression is:

[0051]

[0052] In the formula, The ventricular volume is designed to mimic the left ventricle. , These are the atonic ventricular volumes at the end of diastole and end of systole, respectively.

[0053] In the artificial heart proposed in this embodiment, the ventricular volume , The radius of the biomimetic left ventricle. Its ventricular volume. Aortic blood flow aortic pressure With bionic left ventricular pressure There is a coupling relationship between them. This coupling relationship will be explained in detail in the next step.

[0054] S2. Determine the temperature difference of the LCE balloon under autonomous power supply or power failure conditions. And solve the electrothermal-driven contractile strain of the biomimetic left ventricle. To further simulate the dynamics of the biomimetic left ventricle, it is assumed that heat exchange within the LCE membrane is rapid and the temperature is uniform. According to Joule's law, heat is generated when an electric current passes through a conductor. This embodiment studies temperature differences by establishing an electrojoule heat conduction model. Changes under self-powered and power-off conditions. Therefore, in step S2, the specific process includes the following steps:

[0055] S21. Based on Joule's law, establish an electrojoule heat conduction model to characterize the heat generated by current passing through the LCE balloon. The expression is:

[0056]

[0057]

[0058]

[0059] In the formula, This refers to the characteristic time of heat exchange between the LCE membrane and the environment. This represents the limiting temperature difference of the LCE membrane under long-term energized conditions. The electric heating intensity represents the heat generated per second when an electric current passes through the LCE membrane. Specific heat capacity; The heat transfer coefficient; This refers to the temperature difference.

[0060] S22. Determine the temperature difference of the LCE balloon under autonomous power supply or power failure conditions based on the Joule heat conduction model. ,Right now:

[0061] Temperature difference The state under self-powered conditions is as follows:

[0062]

[0063] Temperature difference The state under power failure is as follows:

[0064]

[0065] In the formula, The radius of the biomimetic left ventricle; This means injecting blood into the stress-free LCE balloon until the radius of the bionic left ventricle reaches a critical state;

[0066] S23. Based on the temperature difference of the LCE balloon under autonomous power supply or power failure conditions. Calculation of electrothermal-driven contractile strain of biomimetic left ventricle For simplicity, assume that electrothermal-driven contraction strain Temperature difference between LCE thin film and environment It is inversely proportional, and the calculation formula is:

[0067]

[0068] In the formula, It is the contractility coefficient of the LCE balloon.

[0069] S3, Shrinkage strain driven by electrothermal stimulation Calculation of principal stresses within the biomimetic left ventricular plane And based on principal stress Calculation of Laplace stress in a biomimetic left ventricle In step S3, the specific process includes:

[0070] Calculation of principal stress within the biomimetic left ventricular plane based on the plane stress assumption. The calculation formula is:

[0071]

[0072] In the formula, The elastic modulus of the LCE balloon material itself; Poisson's ratio; This represents the initial radius of the LCE balloon under stress-free conditions.

[0073] According to principal stress Calculate the Laplace stress generated by the bionic left ventricle under autonomous power supply or power failure conditions. The calculation formula is:

[0074]

[0075] In the formula, The radius of the biomimetic left ventricle; This indicates the thickness of the LCE balloon.

[0076] S4, based on ventricular pressure and Laplace stress A dynamic control equation is established to realize the autonomous beating of the artificial heart under electrothermal action. The expression is as follows:

[0077]

[0078] in:

[0079]

[0080]

[0081] In the formula, This refers to the atmospheric pressure experienced by the biomimetic left ventricle. Let represent the thickness of the LCE balloon. Considering that the thickness of the LCE balloon is much smaller than its radius, and assuming that the LCE balloon is incompressible, where... The volume representing the material structure of the LCE balloon itself; It is the density of the LCE balloon; and These are the radial velocity and acceleration of the left ventricle, respectively. This represents the radial damping coefficient associated with left ventricular deformation; These are one-way valves installed in the aorta and mitral valve, respectively. The resistance of the mitral valve; Blood flow in the aorta; This is a biomimetic representation of left ventricular pressure. This refers to the elastic modulus of the material structure of the LCE balloon itself.

[0082] This embodiment establishes a novel ventricle based on a thermo-responsive liquid crystal elastomer (LCE) sphere, namely a biomimetic left ventricle. To simplify calculations, the biomimetic left ventricle is assumed to be a hollow sphere (LCE balloon), and a tiny volumetric unit is selected for force analysis. The study found that the volumetric unit of the biomimetic left ventricle is mainly subjected to ventricular pressure. Atmospheric pressure and principal stress The generated Laplace stress The impact of ventricular pressure was analyzed. Atmospheric pressure and Laplace stress The influence of key factors on the bionic left ventricle was investigated, and the dynamic control equation for the artificial heart's beating was further derived.

[0083] S5. Solve the dynamic control equations using the fourth-order Runge-Kutta method to obtain the radius of the bionic left ventricle used to regulate the spontaneous beating mode of the artificial heart. According to the radius Determine whether the bionic left ventricle is energized, and update the temperature difference accordingly. The state. In step S5, the specific process includes the following steps:

[0084] S51. Ventricular volume based on biomimetic left ventricle Aortic blood flow aortic pressure With bionic left ventricular pressure The coupling relationship between them is used to establish a biomimetic left ventricle coupled cyclic system including four state equations, namely:

[0085]

[0086]

[0087]

[0088]

[0089] In the formula, Aortic pressure; The resistance of the aortic valve; The characteristic resistance of the aorta; Overall resistance of the arterial system; For the overall compliance of the arterial system; Overall compliance of the pulmonary venous system; The inertia of blood flow in the aorta;

[0090] S52, will Substitute these parameters into the four state equations of the coupled cyclic system and perform dimensionless processing. To simplify the analysis process, reduce computational errors, and improve model stability, all parameters are normalized as follows:

[0091] ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; .

[0092] The dimensionless result is:

[0093]

[0094]

[0095]

[0096]

[0097]

[0098] Dimensionless temperature difference The states under self-powered and power-off conditions are represented as follows:

[0099]

[0100]

[0101] S53. Solve the four dimensionless equations simultaneously and use the fourth-order Runge-Kutta method to obtain the radius of the biomimetic left ventricle. In this embodiment, the radius of the bionic ventricle can be obtained by solving the above equation. However, these equations contain variable coefficient differential equations without analytical solutions. Therefore, the classic fourth-order Runge-Kutta method is used to solve these equations. The initial state of the bionic left ventricle is calculated using the fourth-order Runge-Kutta method, based on the calculated radius. Determine whether the bionic left ventricle is energized, and update the temperature difference accordingly. The state.

[0102] S54, Based on radius Determine whether the bionic left ventricle is energized;

[0103] like The bionic left ventricle is then energized, causing the LCE balloon to contract and the mitral valve to activate. Keep it closed, be aware of ventricular pressure Greater than aortic pressure At that time, the aortic valve one-way valve The ventricle opens, and blood is pumped out of the bionic left ventricle.

[0104] like The bionic left ventricle is in a de-energized state, causing the LCE balloon to inflate and the aortic valve one-way valve to activate. Keep it closed, be aware of ventricular pressure When the pressure is below the atrial pressure, the mitral valve one-way valve The heart opens, blood flows from the atria into the bionic left ventricle, and the ventricular pressure is calculated and updated based on the current state. .

[0105] This embodiment performs small-volume stress analysis on the LCE balloon based on the constructed artificial heart, deriving the dynamic control equation for the biomimetic left ventricular beat. Ventricular pressure is solved by introducing chest pressure, and then an electrojoule heat conduction model is established by assuming rapid and uniform heat exchange within the LCE membrane and that the membrane circuit is a purely resistive circuit. Temperature difference is investigated. The Laplace stress equation is derived more intuitively and clearly by examining the changes under autonomous power supply and power outage conditions. Finally, by studying the coupling relationship between ventricular volume, aortic blood flow, aortic pressure, and bionic left ventricular pressure, four state equations of the ventricular coupled circulatory system are derived, and the variable coefficient differential equations are solved using the fourth-order Runge-Kutta method. Based on the above derivation, it is found that the bionic heart has two beating modes: chaotic beating mode and periodic beating mode. The predicted chaotic phenomenon has a similar pattern to the existing chaotic beating of the heart, thus realizing the simulation calculation of a physically intelligent artificial heart.

[0106] like Figures 3-8 The diagram illustrates the spontaneous beating process of the left ventricle as the damping coefficient increases. Figure 3 As shown, when the damping coefficient is 0.03, the time history curve in the figure has no stable amplitude. The corresponding phase diagram is as follows. Figure 4 As shown, the trajectories on the phase diagram are complex and irregular. For example... Figure 5 As shown, a cyclic chaotic attractor appears on the corresponding Poincaré map. These phenomena indicate that the left ventricle is in a chaotic beating state. When the damping coefficient is 0.09, Figure 6 The time-history curve shows a stable peak. Figure 7 A closed trajectory appears on the corresponding phase diagram. For example... Figure 8 As shown, the corresponding Poincaré diagram contains three fixed points.

[0107] like Figure 9 The diagram shows the bifurcation of the dimensionless variation of the damping coefficient. Adjusting the damping coefficient can alter the spontaneous beating pattern of the left ventricle. Key parameters other than the damping coefficient are set as follows: =0.51, =1, =0.14, A=0.3, =0.051, =0.51, =0.7. It can be seen that the left ventricle exhibits a multi-periodic orbit in the interval β≈[0.02, 0.022]. For the interval β≈[0.022, 0.075], the multi-periodic orbit evolves into a chaotic attractor and undergoes period-doubling bifurcation within the interval. Then, the chaotic attractor splits into three periodic orbits in the interval β≈[0.075, 0.1]. Furthermore, it can be observed that a higher damping coefficient more easily triggers the periodic beating of the left ventricle. This is because a larger damping coefficient leads to a reduction in the net energy received by the left ventricle.

[0108] like Figure 10 The bifurcation diagram shown illustrates how the left ventricular self-beating pattern can be altered by adjusting the left ventricular contractility coefficient. This embodiment provides relevant data for two different beating patterns. Parameters other than the contractility coefficient are set as follows: β = 0.051. = 1, = 0.14, A=0.3, =0.051, =0.51, =0.7. This can be seen from the bifurcation diagram under the change in the contraction coefficient. In the interval... A stable periodic orbit appears within the range ≈[0.2, 0.45]. Within the interval ≈[0.45, 0.6], the chaotic attractor splits into periodic orbits multiple times. In general, the smaller the contraction coefficient, the less energy the left ventricle absorbs, thus the left ventricle tends to beat periodically.

[0109] like Figure 11 The diagram shows the bifurcation pattern during respiratory cycle changes, demonstrating how adjusting the respiratory cycle can alter the left ventricular automatic beat pattern. Parameters other than the respiratory cycle are set as follows: β = 0.051. = 0.51, = 0.14, A = 0.3, =0.051, = 0.51, = 0.7. This is a bifurcation diagram under respiratory cycle variations. For the interval... ≈[0.8,1.1], the chaotic attractor splits into multi-period orbits multiple times, and then evolves into a chaotic attractor. The chaotic attractor eventually resides in the interval [0.8,1.1]. The evolution from a stable multi-period orbit to a single-period orbit is approximately [1.1, 1.2]. Generally, a longer respiratory cycle is more likely to induce periodic beatings of the left ventricle. This is because a longer respiratory cycle slows down the rate of pressure change and work done in the left ventricle, resulting in less energy being available to the left ventricle over the same time span.

[0110] like Figure 12 The diagram shows the bifurcation of the LCE balloon volume. Adjusting the LCE balloon volume can alter the left ventricular autobeat pattern. Parameters other than the balloon volume are set as follows: β = 0.05. = 0.5, =A= 0.3, =0.05, = 0.5, = 0.8. A stable periodic orbit appears in the range. ≈[0.1, 0.106]. In Within the interval ≈[0.106, 0.155], the periodic orbit evolves into a chaotic attractor through a period-doubling bifurcation path. The chaotic attractor then splits into a multi-period orbit. The multi-period orbit loses stability and evolves into a chaotic attractor. The range ≈[0.155,0.2] roughly forms two stable periodic trajectories.

[0111] like Figure 13 The diagram shows the bifurcation of different dimensionless maximum active pressures. Adjusting the maximum active pressure can alter the left ventricular autobeat pattern. Key parameters other than maximum active pressure are set as follows: = 0.51, = 1, =0.14, β= 0.051, = 0.051, = 0.51, = 0.7. In the interval A≈[0.2,0.4], the chaotic attractor repeatedly enters the multi-period orbit, and re-enters the chaotic attractor after instability. In general, as the maximum active pressure increases, the left ventricle tends to beat periodically. This is because the maximum active pressure hinders the beating of the left ventricle, resulting in a reduction in the compensatory energy received by the left ventricle.

[0112] In summary, this invention introduces an electrothermally driven LCE (Left Ventricular Cyclic Emission) system with chaotic self-beating. This system consists of an LCE balloon and a ventricular circulation system. A theoretical model of the system was established based on the Joule heat conduction model, the left ventricular circulation system model, and dynamic principles. By introducing the left ventricular pressure equation and considering the coupling relationship between ventricular volume, aortic blood flow, aortic pressure, and biomimetic left ventricular pressure, a state equation for the ventricular coupled circulation system was constructed, enabling a physically intelligent simulation of the heart. Numerical results show that under electrothermal conditions, the left ventricle exhibits two self-beating modes: periodic beating and chaotic beating.

[0113] The mechanism of periodic beating is due to the balance of work done by various forces within the same time span. The mechanism of chaotic beating is the alternating change of positive and negative work within the same time span. Furthermore, the beating law of the system was studied in depth through parameter discussion and bifurcation diagram analysis. With the increase of damping coefficient, respiratory cycle, maximum active pressure, and minimum thoracic pressure, the beating pattern of the left ventricle shifts from chaotic to periodic beating. With the decrease of contractility coefficient, balloon volume, electric heating intensity, and critical radius, the beating of the left ventricle exhibits a trend towards periodic pulsation. This invention will not only provide insights into the dynamic characteristics of the heart but also promote the development of new medical devices, such as more efficient artificial hearts and adaptive cardiac assist devices. This method overcomes the shortcomings of insufficient sensitivity and susceptibility to individual differences, achieving efficient and convenient theoretical analysis.

[0114] This invention offers the advantages of high efficiency and convenience in theoretical simulation analysis of chaotic self-excited cardiac beating. Compared to experimental and observational methods, it can quickly simulate the dynamic beating characteristics of the left ventricle involved in the human circulatory system, promoting the application of chaotic dynamics in artificial hearts and medical devices, and providing theoretical support for the early diagnosis of cardiovascular diseases.

[0115] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0116] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Since the above embodiments are substantially similar to the method embodiments, their descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0117] The above embodiments provide a detailed description of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A physically intelligent artificial heart, comprising a biomimetic left ventricle (1) manufactured by a molding process, and a connection and fixing device (2) for internally installing and securely fixing the biomimetic left ventricle (1), characterized in that, The bionic left ventricle (1) includes an LCE balloon (10) with a double-layer structure consisting of a first LCE membrane (11) and a second LCE membrane (12). The physical intelligent artificial heart also includes a systemic circulation system (3) installed on the LCE balloon (10) to pump blood into it and re-inject it to achieve periodic circulation, and a power drive system (4) based on periodic electrothermal stimulation to cause the LCE balloon (10) to contract inward and gradually recover. The power drive system (4) includes an electrothermal stimulation circuit (41) embedded or wrapped around the first LCE membrane (11) and the second LCE membrane (12), a contact point (42) set on the connection and fixing device (2), and an external power source. When the LCE balloon (10) expands and touches the contact point (42), the circuit is energized, and the LCE balloon (10) contracts inward due to the electrothermal effect. When the LCE balloon (10) leaves the contact point (42), the circuit is de-energized, and the LCE balloon (10) stops contracting and gradually recovers. The connection and fixing device (2) includes an external main support device (21), an arc-shaped bracket (22) for fixing the LCE balloon (10) is provided inside the external main support device (21), and a fixing beam (23) for installing the contact point (42) is provided at the top inside the external main support device (21), and the contact point (42) is located directly above the LCE balloon (10).

2. The physically intelligent artificial heart according to claim 1, characterized in that, The systemic circulation system (3) includes an aorta (31) and a mitral valve vein (32) symmetrically arranged on both sides of the LCE balloon (10) and connected to them respectively, and a blood circulation device (35) connected to the aorta (31) and the mitral valve vein (32). An aortic valve check valve (33) and a mitral valve check valve (34) are respectively built into one end of the aorta (31) and the mitral valve vein (32) near the LCE balloon (10). Blood in the LCE balloon (10) is pumped into the aorta (31) through the aortic valve check valve (33), and then transported into the mitral valve vein (32) through the blood circulation device (35), and finally flows into the LCE balloon (10) through the mitral valve check valve (34).

3. A control method for the physically intelligent artificial heart described in any one of claims 1-2, characterized in that, The method includes the following steps: S1, Define chest pressure And according to chest pressure Calculate the ventricular pressure as an introduced variable affecting the bionic left ventricular beat. ; S2. Determine the temperature difference of the LCE balloon under autonomous power supply or power failure conditions. And solve the electrothermal-driven contractile strain of the biomimetic left ventricle. ; S3, Shrinkage strain driven by electrothermal stimulation Calculation of principal stresses within the biomimetic left ventricular plane And based on principal stress Calculation of Laplace stress in a biomimetic left ventricle ; S4, based on ventricular pressure and Laplace stress Establish dynamic control equations to realize the autonomous beating of an artificial heart under electrothermal action; S5. Solve the dynamic control equations using the fourth-order Runge-Kutta method to obtain the radius of the bionic left ventricle used to regulate the spontaneous beating mode of the artificial heart. According to the radius Determine whether the bionic left ventricle is energized, and update the temperature difference accordingly. The state.

4. The control method according to claim 3, characterized in that, The chest pressure The thoracic pressure caused by the contraction and expansion of the respiratory muscle groups such as the diaphragm and intercostal muscles is expressed as: ； In the formula, Minimum chest pressure; A represents the maximum active pressure; This indicates respiratory rate, which is related to the respiratory cycle. The relationship is ; This refers to the self-excitation time of the biomimetic left ventricle; Determining chest pressure Based on this, variable ventricular pressure is obtained through calculation. The expression is: ； In the formula, The ventricular volume is designed to mimic the bionic left ventricle. , These are the atonic ventricular volumes at the end of diastole and end of systole, respectively.

5. The control method according to claim 3, characterized in that, In step S2, the specific process includes the following steps: S21. Based on Joule's law, establish an electrojoule heat conduction model to characterize the heat generated by current passing through the LCE balloon. The expression is: ； ； ； In the formula, This refers to the characteristic time of heat exchange between the LCE membrane and the environment. This represents the limiting temperature difference of the LCE membrane under long-term energized conditions. The electric heating intensity represents the heat generated per second when an electric current passes through the LCE membrane. Specific heat capacity; The heat transfer coefficient; For temperature difference; S22. Determine the temperature difference of the LCE balloon under autonomous power supply or power failure conditions based on the Joule heat conduction model. ,Right now: Temperature difference The state under self-powered conditions is as follows: ； Temperature difference The state under power failure is as follows: ； In the formula, The radius of the biomimetic left ventricle; This means injecting blood into the stress-free LCE balloon until the radius of the bionic left ventricle reaches a critical state; S23. Based on the temperature difference of the LCE balloon under autonomous power supply or power failure conditions. Calculation of electrothermal-driven contractile strain of biomimetic left ventricle The calculation formula is: ； In the formula, It is the contractility coefficient of the LCE balloon.

6. The control method according to claim 3, characterized in that, In step S3, the specific process includes: Calculation of principal stress within the biomimetic left ventricular plane based on the plane stress assumption. The calculation formula is: ； In the formula, The radius of the biomimetic left ventricle; The elastic modulus of the LCE balloon material itself; Poisson's ratio; This represents the initial radius of the LCE balloon under stress-free conditions; According to principal stress Calculate the Laplace stress generated by the bionic left ventricle under autonomous power supply or power failure conditions. The calculation formula is: ； In the formula, This indicates the thickness of the LCE balloon.

7. The control method according to claim 6, characterized in that, The expression for the dynamic control equation is: ； in: ； ； In the formula, This refers to the atmospheric pressure experienced by the biomimetic left ventricle. Indicates the thickness of the LCE balloon. The volume representing the material structure of the LCE balloon itself; It is the density of the LCE balloon; and These are the radial velocity and acceleration of the left ventricle, respectively. This represents the radial damping coefficient associated with left ventricular deformation; These are one-way valves installed in the aorta and mitral valve, respectively. The resistance of the mitral valve; Blood flow in the aorta; This is a biomimetic representation of left ventricular pressure. This refers to the elastic modulus of the material structure of the LCE balloon itself.

8. The control method according to claim 7, characterized in that, In step S5, the specific process includes the following steps: S51. Ventricular volume based on biomimetic left ventricle Aortic blood flow aortic pressure With bionic left ventricular pressure The coupling relationship between them is used to establish a biomimetic left ventricle coupled cyclic system including four state equations, namely: ； ； ； ； In the formula, Aortic pressure; The resistance of the aortic valve; The characteristic resistance of the aorta; Overall resistance of the arterial system; For the overall compliance of the arterial system; Overall compliance of the pulmonary venous system; The inertia of blood flow in the aorta; S52, will Substituting these equations into the state equations of the coupled cyclic system and performing dimensionless processing, we obtain: ； ； ； S53. Solve the dimensionless equations of state simultaneously and use the fourth-order Runge-Kutta method to obtain the radius of the biomimetic left ventricle. ; S54, Based on radius Determine whether the bionic left ventricle is energized; like The bionic left ventricle is then energized, causing the LCE balloon to contract and the mitral valve to activate. Keep it closed, and watch for ventricular pressure. Greater than aortic pressure At that time, the aortic valve one-way valve The ventricle opens, and blood is pumped out of the bionic left ventricle. like The bionic left ventricle is in a de-energized state, causing the LCE balloon to inflate and the aortic valve one-way valve to activate. Keep it closed, and watch for ventricular pressure. When the pressure is below the atrial pressure, the mitral valve one-way valve The heart opens, blood flows from the atria into the bionic left ventricle, and the ventricular pressure is calculated and updated based on the current state. .

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