胸阻抗信号监测心肺复苏质量的方法研究

发布时间：2018-07-06 10:44

本文选题：心脏骤停 + 心肺复苏　；参考：《第三军医大学》2013年博士论文

【摘要】：心脏骤停（cardiac arrest, CA），又称心源性猝死（sudden cardiac death，SCD）是指心脏的机械活动停止，，同时左心室收缩不足或停止收缩。心脏骤停80%以上都发生在院外，又称院外心脏骤停（Out-of-hospital cardiac arrest，OHCA)。据统计，在美国每年约有33万人发生OHCA，在欧洲每年约有35万人，而在中国这一数字则高达55.4万人。心肺复苏（cardiopulmonary resuscitation，CPR）作为全球医学界研究的热点之一，是抢救心脏骤停患者的唯一有效途径。CPR包括胸外按压、人工通气和体外电除颤等。美国心脏协会（American heart association, AHA）在2010年复苏指南中进一步强调，及早进行高质量的胸外按压是提高CPR成功率的关键措施。胸外按压（chest compression，CC）的质量包括按压深度、按压频率和胸廓的回弹程度等。尤其是足够的按压深度，它是保持一定冠状动脉灌注压（coronary perfusionpressure, CPP）的关键。CPP被证实是目前预测能否恢复自主循环（return of spontaneouscirculation，ROSC）的最直接的指标。但是，研究表明许多心脏骤停患者在CPR过程中没有得到有效的胸外按压，主要表现在按压深度不足、按压频率较低以及没有保持适当的循环血流。由于OHCA病人的第一目击者绝大多数是非专业人员，使得院外CPR的质量更加得不到保障，调查显示目前全球总体CPR成功率不到10%。目前监测心肺复苏质量的手段主要有监测CPR实施过程的CPP、按压深度、按压频率等参数。CPP能很好预测心肺复苏成功率，但是由于它需要进行有创监测而无法得到广泛应用。按压深度和频率可以通过在患者胸口上方放置加速度传感器或位移传感器来获得，但需要额外增加器件是它存在的固有缺陷。尽管经胸阻抗（Transthoracicimpedance，TTI）在心肺复苏领域应用广泛，但利用TTI实时监测胸外按压质量的研究仍未见报道，且目前尚未建立TTI变化与CPP和按压深度之间的关系。如何利用TTI信号对心肺复苏质量进行监测并实时反馈，是一项具有重要意义的研究课题。针对上述问题，本论文对以下两个方面内容开展了研究： 1.建立动物实验模型并研究TTI变化值与CPP和按压深度之间的关系。我们通过实验建立了家猪心跳骤停（6分钟室颤）与不同人工心肺复苏质量模型，并通过高质量按压组和低质量按压组进行对照研究。在本实验中，高质量按压组的按压深度不低于胸部前后径幅度的25%（即50mm），低质量按压组的按压深度为高质量按压组的70%（即35mm）。实验结果显示，高质量按压组所有动物均获得ROSC，低质量按压组仅2头动物获得ROSC（100%vs.28.57%, p=0.021）。TTI变化值和按压深度的相关系数为0.89（P0.001），TTI变化值和CPP的相关系数为0.83（P0.001），均具有很好的线性相关性。 2.利用TTI信号监测心肺复苏质量并进行实时反馈。为准确获取TTI信号中包含的TTI变化值、按压频率、按压通气比、按压时间比等反映心肺复苏质量的指标并进行实时反馈，我们设计了基于TTI信号的检测算法。算法主要包括三个部分：（1）通过极值搜索法来检测胸外按压和人工通气的波形，并去除干扰信号。（2）通过特征提取和线性判别式分类，将检测到的信号分为按压波和通气波。（3）计算阻抗变化值、按压频率、按压通气比、按压时间比等参数，评价心肺复苏质量，通过实时显示和反馈以更好地指导救援。我们通过心肺复苏模型的建立，研究并证实了TTI变化值与CPP和按压深度具有显著的正相关性。同时，利用基于TTI信号的检测算法，准确计算出评价心肺复苏质量参数并实时显示，对于指导心肺复苏具有重要意义。由于TTI信号可以通过除颤器的除颤电极来获取，所以不需要额外增加电子器件。因此，基于TTI信号监测心肺复苏质量的方法在心肺复苏领域具有广阔的应用前景。
[Abstract]:Cardiac arrest (cardiac arrest, CA), also known as sudden cardiac death (SCD), refers to the mechanical activity of the heart, and the left ventricular contraction is insufficient or the contraction. More than 80% of the cardiac arrest occurs outside the hospital, also called the cardiac arrest (Out-of-hospital cardiac arrest, OHCA). According to statistics, there are about 330 thousand people in the United States. The incidence of OHCA in Europe is about 350 thousand per year, while in China the figure is as high as 554 thousand.
Cardiopulmonary resuscitation (CPR), as one of the hotspots in the global medical field, is the only effective way to rescue patients with cardiac arrest,.CPR including chest compressions, artificial ventilation and external defibrillation. The American Heart Association (American Heart Association, AHA) further emphasized in the 2010 recovery guide, as early as possible. High quality chest compression is the key step to improve the success rate of CPR.
The mass of chest compression (CC) consists of pressing depth, pressing frequency and the rebound degree of the chest. Especially enough compression depth, it is the key.CPP to maintain a certain coronary artery perfusion pressure (coronary perfusionpressure, CPP), which is confirmed to be able to restore the autonomous circulation (return of spontaneouscirculation) at present. The most direct index of ROSC). However, studies have shown that many cardiac arrest patients have not received effective chest compressions during the CPR process, mainly in the lack of compression depth, low press frequency, and no proper circulation flow. Because the majority of the first eyewitnesses of the OHCA patients are non professionals, the quality of the CPR is made out of the hospital. The volume is far from guaranteed. The survey shows that the overall global CPR success rate is less than 10%..
The main means to monitor the quality of cardiopulmonary resuscitation are CPP monitoring CPR implementation process, compression depth, compression frequency and other parameters.CPP can well predict the success rate of cardiopulmonary resuscitation, but because it needs invasive monitoring, it can not be widely used. Press depth and frequency can pass the acceleration sensor above the chest of the patient, or the acceleration sensor can be placed over the patient's chest. Displacement sensors are obtained, but additional devices are required to be inherent defects. Although Transthoracicimpedance (TTI) is widely used in the field of cardiopulmonary resuscitation, the study of real-time monitoring of the mass of chest compressions with TTI has not been reported, and the relationship between TTI changes and CPP and press depth has not yet been established. It is an important research topic to use TTI signals to monitor the quality of cardiopulmonary resuscitation and feedback in real time.
In view of the above problems, the following two aspects are studied in this paper.
1. the animal experimental model was established and the relationship between the TTI change value and the CPP and the press depth were studied. We established the quality model of the cardiac jump sudden stop (6 minute ventricular fibrillation) and the different artificial cardiopulmonary resuscitation through the experiment, and studied the high mass press group and the low mass press group. In this experiment, the press depth of the high quality press group was deep. The degree was not less than 25% (50mm) of the anterior and posterior diameter of the chest, and the compression depth of the low mass press group was 70% (35mm) of the high mass compression group. The results showed that all the animals in the high quality compression group were ROSC, and only 2 animals in the low mass press group obtained the ROSC (100%vs.28.57%, p=0.021).TTI change and the compression depth of 0.89 (P). 0.001) the correlation coefficient of TTI and CPP is 0.83 (P0.001), and all have good linear correlation.
2. using TTI signal to monitor the quality of cardiopulmonary resuscitation and carry out real-time feedback. In order to accurately obtain the TTI change values included in the TTI signal, press the frequency, pressure and ventilation ratio, press time ratio to reflect the quality of cardiopulmonary resuscitation and real-time feedback, we designed a detection algorithm based on the TTI signal. The algorithm mainly includes three parts: (1) The extreme value search method is used to detect the waveform of chest compressions and artificial ventilation and to remove interference signals. (2) the detected signals are divided into press wave and ventilatory wave through feature extraction and linear discriminant classification. (3) to calculate the change of impedance, press the frequency, pressure and ventilation ratio, press time ratio and so on to evaluate the quality of cardiopulmonary resuscitation. Display and feedback to better guide the rescue.
Through the establishment of the cardiopulmonary resuscitation model, we have studied and confirmed the significant positive correlation between the TTI change value and the CPP and the press depth. At the same time, using the detection algorithm based on TTI signal, the evaluation of the quality parameters of CPR and the real-time display are of great significance for guiding the cardiopulmonary resuscitation. Because TTI signals can be eliminated. The defibrillator electrode is obtained, so there is no need for additional electronic devices. Therefore, the method of monitoring the mass of cardiopulmonary resuscitation based on TTI signals has a broad prospect in the field of cardiopulmonary resuscitation.
【学位授予单位】：第三军医大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：R459.7

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