【作者】 李恒；

【导师】 李特；

【作者基本信息】 大连理工大学 ， 机械电子工程， 2022， 硕士

【摘要】 心力衰竭是一种严重危害人体健康的心血管疾病。体外模拟循环系统是体外研究心血管疾病病理特征的重要手段,为心血管患者病理的血流动力学研究、心血管设备的评估提供可靠的体外平台。本文针对当前体外模拟循环系统存在的模拟精度低、模拟耗时长、模拟范围小等问题,开展面向心衰患者的体外模拟循环系统智能控制与试验研究。具体研究内容如下所述:基于人体血液循环系统的生理学基础,设计了自动可控的体外模拟循环系统。首先,简要介绍了人体血液循环系统的生理学知识;然后,根据血液循环系统各部分的主要特征,设计了体外模拟循环系统总体方案;最后,设计了体外模拟循环系统的左心室模拟器、动脉顺应室和储液室,并设计了一种顺应性自动调节方法。为了模拟特定心衰患者的动脉生理特征,提出了一种基于SAC的体外模拟循环系统智能控制方法。首先,简要介绍了SAC算法的基础知识;然后,建立了体外模拟循环系统的数值模型,基于基尔霍夫定律推导了状态方程;其次,在数值模型基础上,设计了基于SAC的智能控制方法的状态空间、动作空间和奖励函数;最后,对智能控制方法进行了数值训练,测试了智能控制方法在数值模型上的模拟范围、模拟精度和抗干扰能力。为了验证提出的智能控制方法模拟特定心衰患者动脉生理特征的能力,开发了体外模拟循环系统并开展了试验研究。首先,开发了体外模拟循环系统的液压系统和控制系统;然后,将在数值模型上训练好的智能控制方法迁移到试验系统进行训练;最后,根据医学资料设计了几种典型心衰患者的生理特征,验证了智能控制方法模拟特定心衰患者动脉特征的能力,大量试验测试了其模拟范围和模拟精度,并测试了智能控制方法的抗干扰能力。试验结果表明,本文提出的基于SAC的体外模拟循环系统智能控制方法可以在10分钟内大范围重现特定心衰患者的动脉压力和平均流量,动脉收缩压的模拟偏差不超过±2mm Hg,动脉舒张压的模拟偏差不超过±2mm Hg,动脉平均流量的模拟偏差不超过±0.2L/min。本文提出的智能控制方法可以快速、高精度、大范围的模拟特定心衰患者动脉压力和平均流量,并具有良好的抗干扰能力,为体外模拟循环系统的研究提供了一种新思路和新方法。更多还原

【Abstract】 Heart failure is a cardiovascular disease that seriously endangers human health.The mock circulatory system is an important tool to study the pathological characteristics of cardiovascular diseases in vitro,providing a reliable in vitro platform for the hemodynamic study of cardiovascular patient pathology and the evaluation of cardiovascular devices.This paper addresses the problems of low simulation accuracy,long simulation time,and small simulation range of current mock circulatory systems,and conducts intelligent control and experimental research on in vitro mock circulatory system for heart failure patients.The details of the study are described as follows:Based on the physiological basis of the human blood circulation system,an automatically controllable mock circulatory system is designed.Firstly,the physiology of human blood circulation system is briefly introduced;then,the overall scheme of the mock circulatory system is designed based on the main characteristics of each part of the blood circulation system;finally,the left ventricular simulator,arterial compliance chamber and reservoir of the mock circulatory system are designed,and a compliance automatic adjustment method is designed.In order to simulate the arterial physiological characteristics of a specific heart failure patient,an intelligent control method of the mock circulatory system based on SAC is proposed.First,the basics of the SAC algorithm are briefly introduced;then,a numerical model of the mock circulatory system is established,and the state equation is derived based on Kirchhoff’s law;next,based on the numerical model,the state space,action space and reward function of the SAC-based intelligent control method are designed;finally,the intelligent control method is trained in numerical model,and the simulation range,simulation accuracy and interference resistance of the intelligent control method on the numerical model are tested.In order to verify the ability of the proposed intelligent control method to simulate the arterial physiological characteristics of specific heart failure patients,a mock circulatory system is developed and the experimental study is carried out.First,the hydraulic system and control system of the mock circulatory system are developed;then,the intelligent control method trained on the numerical model is migrated to the experimental system for training;finally,several physiological characteristics of typical heart failure patients are designed based on medical literature,and the ability of the intelligent control method to simulate the arterial characteristics of specific heart failure patients is verified.A large number of experiments test its simulation range and simulation accuracy,and the anti-interference ability of the intelligent control method is tested.The experimental results show that the intelligent control method of the SAC-based mock circulatory system proposed in this paper can reproduce the arterial pressure and mean flow of specific heart failure patients in a wide range within 10 minutes,and the simulation deviation of the arterial systolic pressure is no more than ±2 mm Hg,the simulation deviation of the arterial diastolic pressure is no more than ±2mm Hg,and the simulation deviation of the arterial mean flow is no more than ±0.2 L/min.The intelligent control method proposed in this paper can simulate arterial pressure and mean flow for specific heart failure patients with fast,high accuracy and large range,and has good anti-interference ability,which provides a new idea and method for the study of mock circulatory system.更多还原