CN103366072A - Digital simulation method for blood backflow caused by mitral valve insufficiency - Google Patents

Abstract

A method for digital simulation of blood regurgitation in mitral regurgitation involving the cardiovascular system. 1. According to the equivalent relationship between hemodynamic parameters and circuit parameters, establish a four-chamber lumped-parameter cardiovascular dynamic circuit model equivalent to the pulmonary circulatory system, systemic circulatory system, left cardiac circulatory system, and right cardiac circulatory system; 2. 1. According to the circuit model established in step 1, use the state variable analysis method to analyze the dynamic circuit established, and establish corresponding state equations for relevant nodes in the circuit; 3. According to the needs of simulation, set the corresponding parameters in step 1 and step 2, and According to the circuit model set in step 1 and the state equation set in step 2, solve the state equation to obtain the time curve of each node in the circuit; 4. Calculate the _QM obtained in step 3 to obtain the blood return when mitral valve insufficiency flow V _RM , mitral valve forward output V _FM and mitral valve volume V _M .

Description

A digital simulation method of blood regurgitation in mitral regurgitation

technical field

The invention relates to a cardiovascular system, in particular to a digital simulation method for mitral regurgitation insufficiency blood backflow.

Background technique

Mitral valve insufficiency is one of the common pathological phenomena in cardiovascular diseases. It is caused by the failure of the mitral valve to close normally during systole, and blood flows from the left ventricle to the aorta while part of the blood flows back from the left ventricle to the left atrium. . Mitral valve insufficiency can produce blood regurgitation, which can cause dilation of the left ventricle and dysfunction of the left ventricle, and even lead to heart failure and even death in severe cases. The study of blood regurgitation during mitral valve insufficiency, especially the impact of different degrees of insufficiency on blood regurgitation, has important guiding significance for mitral valve clinical repair and valve replacement surgery.

At present, most of the analysis of human mitral regurgitation is to use color Doppler echocardiography to evaluate the degree of mitral regurgitation. This method relies too much on the experience of doctors and operators, and has a certain degree of subjectivity. (Qiu Junwei, Sun Kun. Research progress in imaging assessment methods for the degree of mitral regurgitation [J]. Chinese Interventional Imaging and Therapeutics, 2010, 7(2):203-206), and this method can only measure a certain individual Due to the constraints of ethics and morality, many experiments cannot be carried out directly on the human body, and different degrees of lesions cannot be achieved, so it is impossible to further study its internal laws. There are also animal experiments for research, but due to differences between animals and humans, animal model experiments cannot fully reflect the characteristics of the human body (Sun Jing, Animal experiments on left ventricular relaxation time constant assessed by continuous Doppler spectrum of mitral valve regurgitation Research [D]. Chinese People's Liberation Army Military Medical Training College, Master's Thesis, 2012). There are also scholars who use mechanical devices, sensors, etc. to establish a physical model to simulate the state of human heart activity through physical simulation (Yan Hongyu, Heart Dynamic Modeling Simulation and Simulation Device Research, Shanghai Jiaotong University, Master's Thesis, 2011), but the establishment of this This kind of physical model is time-consuming and laborious, and the parameters of the model are not easy to adjust. There are also differences between the established model and the actual physiological characteristics of the human body. With the development of computer technology, some scholars adopt digital simulation, that is, according to the equivalent relationship between hemodynamic parameters and circuit parameters, establish equivalent circuit models and mathematical models, and simulate the human cardiovascular system on the computer. Operating status. The digital simulation method has the advantages of saving time, labor, low cost, easy to adjust model parameters, and can realize experiments under extreme conditions, which is convenient for studying its internal laws. However, most of these methods currently simulate the normal conditions of the human cardiovascular system, and some scholars also simulate the conditions of mitral valve insufficiency (Deng Min, Ultrasonic Imaging Simulation of Mitral Regurgitation [D], Sichuan University, Master Dissertation, 2006; Jian Zhang, Ultrasound Simulation Research on Quantitative Calculation of Eccentric Mitral Regurgitation [D], Sichuan University, Master Dissertation, 2007). However, in these simulation methods for mitral regurgitation, there are the following shortcomings:

1) The current mitral regurgitation simulation method does not couple the three circulatory systems of the pulmonary circulatory system, the systemic circulatory system and the cardiac circulatory system. Since the pulmonary circulation, systemic circulation, and cardiac circulatory system all affect mitral valve regurgitation, the influence of these three circulatory systems should be considered when analyzing mitral valve regurgitation. If only the cardiac circulatory system is considered, the simulation calculation of mitral regurgitation will produce large errors.

2) The current mitral regurgitation simulation method cannot quantitatively simulate different degrees of mitral regurgitation, and can only simulate the "existence" or "absence" of mitral regurgitation. Because there are different degrees of mitral valve insufficiency clinically, it is necessary to simulate different degrees of mitral valve insufficiency with a method that can be continuously changed and quantitatively expressed, so as to be closer to the actual phenomenon.

3) The current mitral regurgitation simulation method only simulates the blood regurgitation, but cannot measure left ventricular pressure, left ventricular volume, left atrial pressure, left atrial volume, pulmonary venous pressure, mitral valve flow, and mitral valve volume Changes in relevant physiological parameters. These physiological parameters are also of great significance to the study of mitral regurgitation.

Contents of the invention

The purpose of the present invention is to address the deficiencies of the existing mitral valve insufficiency simulation method, to provide a quantitative simulation of different degrees of mitral regurgitation that can consider the impact of the pulmonary circulatory system, systemic circulatory system and cardiac circulatory system on mitral valve regurgitation , a digital simulation method of blood regurgitation in mitral valve insufficiency by accurately calculating blood regurgitation and other relevant physiological parameters, thereby providing assistance for the study of mitral valve insufficiency.

The present invention comprises the following steps:

1. According to the equivalent relationship between hemodynamic parameters and circuit parameters, establish a four-chamber lumped parameter cardiovascular dynamic circuit model equivalent to the pulmonary circulation system, systemic circulation system, left cardiac circulation system, and right cardiac circulation system;

In step one,

The circuit module M _LH equivalent to the left heart circulatory system is composed of the following method: one end of the resistance R _M is connected to the P _LA node, the other end of the resistance R _M is connected in series with the anode of the diode D _M , and the cathode of the diode D _M is connected to the P _LV node ; The P _LA node and the P _LV node are respectively grounded through the time-varying inverted capacitance E _LA (t) and E _LV (t);

The circuit module _MT equivalent to the body circulatory system is formed in the following manner: one end of the resistance R _AP is connected to the P _AP node, the other end of the resistance R _AP is connected in series with the inductor L _AP , the other end of the inductor L _AP is connected to the resistance R _AD Connected to the P _AD node, the other end of the resistor R _AD is connected to the P _VC node; the P _AP node, P _AD node, and P _PV node in the circuit are grounded through the capacitors C _AP , C _AD , and C _PVC respectively;

The circuit module M _F equivalent to the pulmonary circulation system is composed of the following method: one end of the resistance R _PA is connected to the P _PA node, the other end of the resistance R _PA is connected in series with the inductance L _PA , and the other end of the inductance L _PA is connected to the resistance R _PP Connected to the P _PP node, the other end of the resistor R _PP is connected to the PP _PV node; the three points of the P _PA node, P _PP node, and PP _PV node in the circuit are grounded through the capacitors C _PA , C _PP , and C _PV respectively;

The circuit module M _RH equivalent to the right heart circulatory system is composed of the following method: one end of the resistor _RT is connected to the P _RA node, the other end of the resistor _RT is connected in series with the anode of the diode _DT , and the cathode of the diode _DT is connected to the P _RV node ; The P _RA node and the P _RV node are respectively grounded through the time-varying reverse capacitance E _RA (t) and E _RV (t);

The circuit module _MLH is connected to one end of the resistor _RA , the other end _of the resistor RA is connected in series with the anode of the diode _DA , and the cathode of the diode _DA is connected to the circuit module _MT ; one end of the resistor R _VC is connected to the circuit module MT, and the other end of the resistor R _VC is connected to the circuit module _MT . One end is connected to the circuit module M _RH ; the circuit module M _RH is connected to one end of the resistor R _PT , the other end of the resistor R _PT is connected in series with the anode of the diode D _PT , and the cathode of the diode D _PT is connected to the circuit module M _F ; the circuit module M _F is connected to one end of the resistor R _PV , the other end of the resistor R _PV is connected to the circuit module M _LH ;

The meaning of each component in the circuit and the simulated physiological significance of the representation are shown in Table 1;

Table 1

symbol Simulation of physiological meaning actual physical components R _M mitral valve characteristic impedance resistance R _A Aortic valve characteristic impedance resistance R _T tricuspid characteristic impedance resistance R _PT Pulmonary Valve Characteristic Impedance resistance R _AP proximal aortic characteristic impedance resistance C _AP proximal aortic blood flow compliance capacitance L _AP proximal aortic flow inertia inductance R _AD Distal Aortic Characteristic Impedance resistance C _AD blood flow compliance at the distal end of the aorta capacitance R _VC characteristic impedance of vena cava resistance C _VC vena cava flow inertia capacitance _RPA Pulmonary artery proximal characteristic impedance resistance C _PA Pulmonary artery proximal blood flow compliance capacitance L _PA Pulmonary Artery Proximal Flow Inertia inductance R _PP characteristic impedance of distal pulmonary artery resistance C _PP blood flow compliance at the distal end of the pulmonary artery capacitance R _PV Pulmonary vein characteristic impedance resistance C _PV Inertia of pulmonary vein flow capacitance E _RV (t) Right ventricular time-varying elasticity function time-varying inverting capacitance E _RA (t) Right atrial time-varying elastic function time-varying inverting capacitance E _LV (t) left ventricular time-varying elasticity function time-varying inverting capacitance E _LA (t) left atrial time-varying elastic function time-varying inverting capacitance D _A aortic valve status diode D _T tricuspid valve state diode _PT Pulmonary valve switch status diode D _M degree of mitral regurgitation diode

The E _RV (t), E _RA (t), E _LV (t), E _LA (t) time-varying reciprocal capacitances in the circuit are represented by the following time-varying elastic functions:

(1) The time-varying elastic function at E _LA (t) is:

E _LA (t)＝E _minLA +(E _maxLA -E _minLA )×En(t)

in:

E _maxLA represents the maximum value of the time-varying elastic function of the left atrium,

E _minLA represents the minimum value of the time-varying elastic function of the left atrium,

En(t) is expressed by the following formula:

Where: t represents the time variable, T represents the cardiac cycle, T _ac represents the start time of atrial contraction, T _acp represents the duration of atrial contraction, T _ar represents the start time of atrial diastole, and T _arp represents the duration of atrial active relaxation;

(2) The time-varying elastic function at E _RA (t) is:

E _RA (t)＝E _minRA +(E _maxRA -E _minRA )×En(t)

in:

E _maxRA represents the maximum value of the time-varying elastic function of the right atrium,

E _minRA represents the minimum value of the time-varying elastic function of the right atrium,

The expression method of En(t) is the same as that shown above, that is, expressed by formula (1);

(3) The time-varying elastic function at E _RV (t) is:

E _RV (t)＝E _minRV +(E _maxRV -E _minRV )×En(t)

in:

E _maxRV represents the maximum value of the time-varying elastic function of the right ventricle,

E _minRV represents the minimum value of the time-varying elastic function of the right ventricle,

En(t) is expressed by the following formula:

in:

t表示时间变量，T表示心动周期，T_d表示心室收缩时间；

t represents the time variable, T represents the cardiac cycle, and T _d represents the ventricular systole time;

(4) The time-varying elastic function at E _LV (t) is:

E _LV (t)＝E _minLV +(E _maxLV -E _minLV )×En(t)

in:

E _maxLV represents the maximum value of the time-varying elastic function of the left ventricle,

E _minLV represents the minimum value of the time-varying elastic function of the left ventricle,

The expression method of En(t) is the same as that shown above, that is, expressed by formula (2);

(5) The value of D _M in the circuit is:

${\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; \&Delta;P</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>\mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ~</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; \&Delta;P</span>}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.$

ΔP is expressed as the voltage difference between P _LA and PL _LV ,

When ΔP<0, 0≤D _M <1, D _M represents the degree of mitral regurgitation, which is a parameter that can be continuously changed and can be expressed quantitatively. When D _M is equal to 0, it means that there is no mitral regurgitation. In normal physiological state, the larger the value of D _M is, the more serious the degree of mitral valve insufficiency is.

2. According to the circuit model established in step 1, analyze the dynamic circuit established by the state variable analysis method, and establish corresponding state equations for relevant nodes in the circuit according to the following formula;

$<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; LV</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; AP</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; A</span>}}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; A</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; AP</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; AP</span>}}\frac{\mathrm{<span\; class="notranslate">\; d</span>}{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; AP</span>}}}{\mathrm{<span\; class="notranslate">\; dt</span>}}$

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; AP</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; AD</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; AP</span>}}\frac{\mathrm{<span\; class="notranslate">\; d</span>}{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; AP</span>}}}{\mathrm{<span\; class="notranslate">\; dt</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; AP</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; AP</span>}}$

${\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; AP</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; AD</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; VC</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; AD</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; AD</span>}}\frac{\mathrm{<span\; class="notranslate">\; d</span>}{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; AD</span>}}}{\mathrm{<span\; class="notranslate">\; dt</span>}}$

$<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; AD</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; VC</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; AD</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; VC</span>}}\frac{\mathrm{<span\; class="notranslate">\; d</span>}{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; VC</span>}}}{\mathrm{<span\; class="notranslate">\; dt</span>}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; VC</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; RA</span>}}}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; VC</span>}}}$

$<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; RV</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; PA</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; PT</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PA</span>}}\frac{\mathrm{<span\; class="notranslate">\; d</span>}{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; PA</span>}}}{\mathrm{<span\; class="notranslate">\; dt</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; PA</span>}}$

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; PA</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; PP</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; PA</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; PA</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; PA</span>}}\frac{\mathrm{<span\; class="notranslate">\; d</span>}{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; PA</span>}}}{\mathrm{<span\; class="notranslate">\; dt</span>}}$

${\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; PA</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PP</span>}}\frac{\mathrm{<span\; class="notranslate">\; d</span>}{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; PP</span>}}}{\mathrm{<span\; class="notranslate">\; dt</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; PP</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; PV</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; PP</span>}}$

$<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; PP</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; PV</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; PP</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; PV</span>}}\frac{\mathrm{<span\; class="notranslate">\; d</span>}{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; PV</span>}}}{\mathrm{<span\; class="notranslate">\; dt</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; PV</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; LA</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; PV</span>}}<span\; class="notranslate">\; ;</span>$

3. According to the needs of the simulation, set the corresponding parameters in step 1 and step 2, and solve the state equation according to the circuit model set in step 1 and the state equation set in step 2 to obtain the time curve of each node in the circuit; The set parameters and their meanings are shown in Table 2, and the meanings of the time curves of each node in the circuit are shown in Table 3.

Table 2

symbol Simulation of physiological meaning R _M mitral valve characteristic impedance R _A Aortic valve characteristic impedance R _T tricuspid characteristic impedance R _PT Pulmonary Valve Characteristic Impedance R _AP proximal aortic characteristic impedance C _AP proximal aortic blood flow compliance L _AP proximal aortic flow inertia R _AD Distal Aortic Characteristic Impedance C _AD blood flow compliance at the distal end of the aorta R _VC characteristic impedance of vena cava C _VC Inertia of vena cava flow g _RPA Pulmonary artery proximal characteristic impedance C _PA Pulmonary artery proximal blood flow compliance L _PA Pulmonary Artery Proximal Flow Inertia R _PP characteristic impedance of distal pulmonary artery C _PP blood flow compliance at the distal end of the pulmonary artery R _PV Pulmonary vein characteristic impedance C _PV Pulmonary vein flow inertia g T Cardiac cycle T _d ventricular systolic time _Tac atrial systole onset time T _acp atrial contraction duration _Tar atrial diastolic onset time T _arp duration of active atrial relaxation E _minLA The minimum value of time-varying elastic function of left ventricle E _{max LA} The maximum value of time-varying elastic function of left ventricle E _minRA The minimum value of time-varying elastic function of right ventricle E _maxRA The maximum value of time-varying elastic function of right ventricle E _minLV The minimum value of time-varying elastic function of left atrium E _maxLV The maximum value of time-varying elastic function of left atrium E _minRV The minimum value of time-varying elastic function of right atrium E _maxRV The maximum value of time-varying elastic function of right atrium D _M degree of mitral regurgitation

table 3

node symbol Simulation of physiological meaning P _LV left ventricular pressure _PLA left atrial pressure P _AP Aortic pressure V _LV left atrial volume V _LA left ventricular volume P _PV pulmonary venous pressure Q _M mitral valve flow

4. Calculate the Q _M obtained in step 3 according to the following formula to obtain the blood regurgitation volume V _RM , the mitral valve forward output volume V _FM and the mitral valve volume V _M when the mitral valve is insufficient,

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; RM</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="T"\; filenames="HDA00003626458100032.png,HDA00003626458100033.png"\; state="\{\{state\}\}">T</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}^{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="T"\; filenames="HDA00003626458100032.png,HDA00003626458100033.png"\; state="\{\{state\}\}">T</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; dt</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="T"\; filenames="HDA00003626458100032.png,HDA00003626458100033.png"\; state="\{\{state\}\}">T</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="T"\; filenames="HDA00003626458100032.png,HDA00003626458100033.png"\; state="\{\{state\}\}">T</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; T</span>}$

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; FM</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="T"\; filenames="HDA00003626458100032.png,HDA00003626458100033.png"\; state="\{\{state\}\}">T</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; dt</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="T"\; filenames="HDA00003626458100032.png,HDA00003626458100033.png"\; state="\{\{state\}\}">T</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="T"\; filenames="HDA00003626458100032.png,HDA00003626458100033.png"\; state="\{\{state\}\}">T</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}$

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="T"\; filenames="HDA00003626458100032.png,HDA00003626458100033.png"\; state="\{\{state\}\}">T</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; T</span>}}{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; dt</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="T"\; filenames="HDA00003626458100032.png,HDA00003626458100033.png"\; state="\{\{state\}\}">T</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="T"\; filenames="HDA00003626458100032.png,HDA00003626458100033.png"\; state="\{\{state\}\}">T</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; T</span>}$

In the formula, T ₀ represents the start time of any cardiac cycle, and T represents the cardiac cycle.

A digital simulation method of mitral valve insufficiency blood regurgitation proposed by the present invention replaces the physical model and can observe the simulation results dynamically and in real time. This method shortens the experimental time, reduces the cost, and enhances the flexibility and safety of the experiment. It can simulate some phenomena that cannot be produced on the human body, animals and physical models. The digital simulation method of mitral valve insufficiency blood regurgitation proposed by the present invention overcomes the shortcomings of the existing methods, and combines the three systems of the pulmonary circulation system, the systemic circulation system and the cardiac circulation system, and can continuously change and quantitatively represent the mitral valve The degree of regurgitation can accurately calculate blood regurgitation and other related physiological parameters, which has important guiding significance for clinical research on mitral regurgitation.

Description of drawings

FIG. 1 is a four-chamber lumped-parameter cardiovascular circuit model including a pulmonary circulatory system, a systemic circulatory system and a cardiac circulatory system according to an embodiment of the present invention.

Fig. 2 is a graph showing the simulation results of the left ventricular pressure time curve.

Fig. 3 is a graph showing the simulation results of the volume-time curve of the left ventricle.

Fig. 4 is a simulation result diagram of the left atrial pressure time curve.

Fig. 5 is a graph showing the simulation results of the volume-time curve of the left atrium.

Fig. 6 is a simulation result diagram of the time curve of pulmonary venous pressure.

Fig. 7 is a graph showing the simulation results of the flow time curve of the mitral valve.

Fig. 8 is a graph showing the simulation results of the volume-time curve of the mitral valve.

Detailed ways

The following embodiments will further illustrate the present invention in conjunction with the accompanying drawings.

The concrete steps of the embodiment of the present invention are as follows:

step one,

According to Figure 1, a four-chamber lumped parameter cardiovascular dynamic circuit model was established. The meaning of each component in the circuit and the simulated physiological significance expressed are shown in Table 1.

Step two,

According to the circuit model established in step 1, the established dynamic circuit is analyzed by the state variable analysis method, and the corresponding state equations are established for the relevant nodes in the circuit according to the formula in the specification.

Step 3: Set the corresponding parameters (see Table 4 for details) and solve the state equation, wherein the value of D _M represents the simulated moderate mitral regurgitation according to the following formula.

${\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; \&Delta;P</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>\mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; 0.01</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; \&Delta;P</span>}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.$

Table 4

parameter value R _M 0.007mmHg*s/ml R _A 0.01mmHg*s/ml R _T 0.007mmHg*s/ml R _PT 0.01mmHg*s/ml R _AP 0.230mmHg*s/ml C _AP 1.800ml/mmHg L _AP 0.014mmHg*s2/ml R _AD 1.000mmHg*s/ml C _AD 0.140ml/mmHg R _VC 0.0368mmHg*s/ml C _VC 2.5181ml/mmHg R _PA 0.023mmHg*s/ml C _PA 5.000ml/mmHg L _PA 0.0018mmHg*s2/ml R _PP 0.100mmHg*s/ml C _PP 5.800ml/mmHg R _PV 0.0056mmHg*s/ml C _PV 25.00ml/mmHg E _minLA 0.15mmHg/ml E _{max LA} 0.25mmHg/ml E _minRA 0.15mmHg/ml E _maxRA 0.25mmHg/ml E _minLV 0.06mmHg/ml E _maxLV 3mmHg/ml E _minRV 0.06mmHg/ml E _maxRV 1mmHg/ml T 0.8 _Tac 0.69 T _acp 0.10 _Tar 0.79 T _arp 0.10

The equation of state is solved using the fourth-order Runge-Kutta method. Obtain the time curves of the main state variables (P _LV , V _LV , P _LA , V _LA , P _PV ), as shown in Figures 2-6.

Step 4: Calculate the Q _M obtained in Step 3 according to the formula in the instruction manual, and obtain the blood regurgitation volume V _RM , the mitral valve forward output volume V _FM and the mitral valve volume V _M during mitral regurgitation.

The results are shown in Figures 7 and 8.

Finally, it should be noted that the above examples are only used to illustrate the patented technical solution of the present invention without limitation, although the present invention has been described with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solution of the present invention can be Modifications or equivalent replacements can be made without departing from the spirit and scope of the solutions of the present invention.

Claims (8)

1. the digital simulation method of a mitral valve insufficiency blood reflux is characterized in that may further comprise the steps:

One, according to the equivalent relation between hemodynamic parameter and the circuit parameter, the cardiovascular dynamic circuit model of four chamber lumped parameters of foundation and systemic pulmonary circulation, systemic circulatory system, left heart circulation system, the equivalence of right heart circulation system;

Two, the circuit model of setting up according to step 1 with the dynamic circuit that the State-Variable Analysis Method analysis is set up, is set up corresponding state equation to interdependent node in the circuit;

Three, according to the demand of emulation, the relevant parameter in setting steps one, the step 2, and the state equation that arranges of the circuit model that arranges according to step 1 and step 2 carry out the solving state equation and obtain a node time curve map in the circuit;

Four, the Q that step 3 is obtained _MCalculate blood reflux amount V when obtaining mitral valve insufficiency _RM, bicuspid valve forward direction output quantity V _FMAnd bicuspid valve volume V _M

2. a kind of digital simulation method of mitral valve insufficiency blood reflux as claimed in claim 1 is characterized in that in step 1, the circuit module M of described and the equivalence of left heart circulation system _LHConsisted of by following mode: resistance R _MOne is terminated at P _LANode, resistance R _MThe other end and diode D _MAnodal series connection, diode D _MNegative pole is connected to P _LVNode; P _LANode, P _LVNode respectively by the time become elastance E _LA(t) and E _LV(t) ground connection.

3. a kind of digital simulation method of mitral valve insufficiency blood reflux as claimed in claim 1 is characterized in that in step 1, the circuit module M of described and systemic circulatory system equivalence _TConsisted of by following mode: resistance R _APOne be terminated at P _APNode, resistance R _APThe other end and inductance L _APSeries connection, inductance L _APThe other end and resistance R _ADBe connected in P _ADNode, resistance R _ADThe other end be connected in P _VCNode; P in the circuit _APNode, P _ADNode, P _PVThese 3 of nodes pass through respectively capacitor C _AP, C _AD, C _PVCGround connection.

4. a kind of digital simulation method of mitral valve insufficiency blood reflux as claimed in claim 1 is characterized in that in step 1, the circuit module M of described and systemic pulmonary circulation equivalence _FConsisted of by following mode: resistance R _PAOne be terminated at P _PANode, resistance R _PAThe other end and inductance L _PASeries connection, inductance L _PAThe other end and resistance R _PPBe connected in P _PPNode, resistance R _PPThe other end be connected in P _PVNode; P in the circuit _PANode, P _PPNode, P _PVThese 3 of nodes pass through respectively capacitor C _PA, C _PP, C _PVGround connection.

5. a kind of digital simulation method of mitral valve insufficiency blood reflux as claimed in claim 1 is characterized in that in step 1, the circuit module M of described and the equivalence of right heart circulation system _RHConsisted of by following mode: resistance R _TOne is terminated at P _RANode, resistance R _TThe other end and diode D _TAnodal series connection, diode D _TNegative pole is connected to P _RVNode; P _RANode, P _RVNode respectively by the time become elastance E _RA(t) and E _RV(t) ground connection.

6. a kind of digital simulation method of mitral valve insufficiency blood reflux as claimed in claim 1 is characterized in that in step 1 described circuit module M _LHConnecting resistance R _AOne end, resistance R _AThe other end and diode D _AAnodal series connection, diode D _ANegative pole and circuit module M _TLink to each other; Resistance R _VCOne is terminated at circuit module M _T, resistance R _VCThe other end is connected to circuit module M _RHCircuit module M _RHConnecting resistance R _PTOne end, resistance R _PTThe other end and diode D _PTAnodal series connection, diode D _PTNegative pole and circuit module M _FLink to each other; Circuit module M _FConnecting resistance R _PVOne end, resistance R _PVOther end connection circuit module M _LH

E in the circuit _RV(t), E _RA(t), E _LV(t), E _LA(t) become the time elastance respectively when following the change Elastic Function represent:

(1) E _LA(t) locate the time become Elastic Function into:

E _LA(t)＝E _minLA+(E _maxLA-E _minLA)×En(t)

Wherein:

E _MaxLABecome the Elastic Function maximum occurrences during expression atrium sinistrum,

E _MinLABecome the minimum value of Elastic Function during the expression atrium sinistrum,

En (t) represents with following formula:

Wherein: t represents time variable, and T represents cardiac cycle, T _AcExpression atrial contraction start time, T _AcpThe expression atrial contraction duration, T _ArExpression auricular diastole start time, T _ArpThe expression atrium Active Diastolic duration;

(2) E _RA(t) locate the time become Elastic Function into:

E _RA(t)＝E _minRA+(E _maxRA-E _minRA)×En(t)

Wherein:

E _MaxRABecome the Elastic Function maximum occurrences during expression atrium dextrum,

E _MinRABecome the minimum value of Elastic Function during the expression atrium dextrum,

Shown in the method for expressing of En (t) is the same, namely use formula (1) expression;

(3) E _RV(t) locate the time become Elastic Function into:

E _RV(t)＝E _minRV+(E _maxRV-E _minRV)×En(t)

Wherein:

E _MaxRVBecome the Elastic Function maximum occurrences during expression right ventricle,

E _MinRVBecome the minimum value of Elastic Function during the expression right ventricle,

En (t) represents with following formula:

Wherein:

T represents time variable, and T represents cardiac cycle, T _dThe expression ventricular systole time;

(4) E _LV(t) locate the time become Elastic Function into:

E _LV(t)＝E _minLV+(E _maxLV-E _minLV)×En(t)

Wherein:

E _MaxLVBecome the Elastic Function maximum occurrences during expression left ventricle,

E _MinLVBecome the minimum value of Elastic Function during the expression left ventricle,

Shown in the method for expressing of En (t) is the same, namely use formula (2) expression;

(5) D in the circuit _MValue be:

$D_M=\left\{\begin{array}{c}1,\mathrm{\&Delta;P}\&GreaterEqual;0\\ 0~1,\mathrm{\&Delta;P}<0\end{array}\right.$

Δ P is expressed as P _LAWith P _LVThe voltage difference at place,

When Δ P＜0,0≤D _M＜1, D _MExpression mitral valve insufficiency degree, be one can change continuously, can the quantificational expression parameter, work as D _MEqual to represent not exist the normal physiological state of mitral valve insufficiency pathology at 0 o'clock, D _MThe larger expression mitral valve insufficiency of value degree more serious.

7. a kind of digital simulation method of mitral valve insufficiency blood reflux as claimed in claim 1 is characterized in that in step 2, and the corresponding state equation of described foundation can be according to following Formula:

$(P_{\mathrm{LV}}-P_{\mathrm{AP}})D_A/R_A=Q_{\mathrm{AP}}+C_{\mathrm{AP}}\frac{d{P}_{\mathrm{AP}}}{\mathrm{dt}}$

$P_{\mathrm{AP}}-P_{\mathrm{AD}}=L_{\mathrm{AP}}\frac{d{Q}_{\mathrm{AP}}}{\mathrm{dt}}+Q_{\mathrm{AP}}{R}_{\mathrm{AP}}$

$Q_{\mathrm{AP}}=(P_{\mathrm{AD}}-P_{\mathrm{VC}})/R_{\mathrm{AD}}+C_{\mathrm{AD}}\frac{d{P}_{\mathrm{AD}}}{\mathrm{dt}}$

$(P_{\mathrm{AD}}-P_{\mathrm{VC}})/R_{\mathrm{AD}}=C_{\mathrm{VC}}\frac{d{P}_{\mathrm{VC}}}{\mathrm{dt}}+\frac{P_{\mathrm{VC}}-P_{\mathrm{RA}}}{R_{\mathrm{VC}}}$

$(P_{\mathrm{RV}}-P_{\mathrm{PA}})D_{\mathrm{PT}}/R_{\mathrm{PT}}=C_{\mathrm{PA}}\frac{d{P}_{\mathrm{PA}}}{\mathrm{dt}}+Q_{\mathrm{PA}}$

$P_{\mathrm{PA}}-P_{\mathrm{PP}}=Q_{\mathrm{PA}}{R}_{\mathrm{PA}}+L_{\mathrm{PA}}\frac{d{Q}_{\mathrm{PA}}}{\mathrm{dt}}$

$Q_{\mathrm{PA}}=C_{\mathrm{PP}}\frac{d{P}_{\mathrm{PP}}}{\mathrm{dt}}+(P_{\mathrm{PP}}-P_{\mathrm{PV}})/R_{\mathrm{PP}}$

$(P_{\mathrm{PP}}-P_{\mathrm{PV}})/R_{\mathrm{PP}}=C_{\mathrm{PV}}\frac{d{P}_{\mathrm{PV}}}{\mathrm{dt}}+(P_{\mathrm{PV}}-P_{\mathrm{LA}})/R_{\mathrm{PV}}.$

8. a kind of digital simulation method of mitral valve insufficiency blood reflux as claimed in claim 1 is characterized in that in step 4 the described Q that step 3 is obtained _MCalculate, can calculate according to following formula:

$V_{\mathrm{RM}}=-{\&Integral;}_{T_0+T_d}^{T_0+T}{Q}_M\left(t\right)\mathrm{dt},T_0+T_d\&le;t\&le;T_0+T$

$V_{\mathrm{FM}}={\&Integral;}_{T_0}^{T_0+T_d}{Q}_M\left(t\right)\mathrm{dt},T_0\&le;t\&le;T_0+T_d$

$V_M={\&Integral;}_{T_0}^{T_0+T}{Q}_M\left(t\right)\mathrm{dt},T_0\&le;t\&le;T_0+T$

T in the formula ₀Represent the start time of arbitrary cardiac cycle, T represents cardiac cycle.

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