浅谈心电图的教学方法

心电图是一门以图识病的特殊学科,理论抽象、内容难理解,本文针对当前中等职业卫生教育中心电图难学的问题,提出要注意的几个方面。     

心电图机打印系统的实验教学研究

实验环节是培养高素质生物医学工程人才的重要环节之一。心电图机的打印系统涉及到心电信号的分析,打印机接口的设计,单片机控制程序编写。作为实验教学项目,非常有利于学生学习实践软件、硬件知识,并且与现实有着紧密联系。于是主要集中阐述了心电信号的特点,单片机控制的打印机接口设计,心电图机实验教学的打印系统的设计,单片机控制打印心电图形的程序设计,以及实验指导书的编写。     

木乃伊复活(下)

心电图的线条突然跳了起来,画出一个粗犷、古怪的图形。比森拿起电棒放在心脏上,解除心室纤颤。心电图又呈一条直线。温度又上升1度,心电图上出现了一个完整的心搏,又是一个心搏。紧接着,脑电图的指针也晃动起来。比森抬起头,激动     

流行性出血热141例心电图分析及猝死1例临床探讨

对141例流行性出血热患者的心电图临床资料分析及1例流行性出血热患者猝死的原因和诱因探讨,提出流行性出血热患者心电图变化中的危险信号,以杜绝诱因,防止猝死的发生。     

蒺藜皂甙治疗冠心病150例临床观察

采用蒺藜皂甙(商品名:心脑舒通)治疗冠心病150例,发现该药在改善冠心病主要症状如胸闷、胸痛、心悸和治疗总有效率(达88.67％)方面均较对照组明显为好(P<0.01),改善心电图的有效率为55.77％,较对照组为高(P<0.05).蒺藜皂甙是一个高效、无毒、安全,副作用小,使用方便,适合于临床长期、持续服用的良药.     

心电图机灵敏度改变引起的问题和解决办法

临床心电图机由于各种因素影响其灵敏度经常发生变化,心电图机的灵敏度改变容易引起很多问题及分析产生这些问题的原因,并且指出解决问题的办法。     

急性脑血管病与心电图异常

急性脑血管（ACVD）时常引起心电图改变，临床上称为“脑心综合征”。就我院1994～1996年收治急性脑血管病120例，心电图异常占78例。本文进行了详细分析，心电图的异常改变以窦速或窦缓、早搏、ST－T异常、左室肥大最为多见，其次则为心房纤颤、肢导低电压。发病率从性别方面分析男性多于女性为25：1；从年今上分析多数是在老年前组和老年组，为此提醒老年朋友们必须提早防治，以免造成不必要的痛苦。     

基于Aduc845的心电监测系统的设计

本系统利用Aduc845单片机实现对心电信号的监测和处理.利用基于Labview的虚拟机技术实现对心电信号的显示.完成了心电监测系统的设计与实现.每个模块都能很好地实现相应的功能.从而有利于对心电信号的监测和分析.     

改进的小波阈值去噪法在心电信号中的应用

目的:滤除心电信号中包含的基线漂移、工频干扰、肌电干扰三种主要噪声,获取干净有效的临床心电信号信息。方法:改进阈值处理函数的小波变换阈值去噪法。结论:改进阈值处理函数小波阈值去噪法能更好的弥补了软、硬阈值函数去噪法中存在的不足,得到的去噪效果更优。     

基于LabVIEW的医用体外反博器数据采集和心电波形识别软件设计

本文介绍了基于LabVIEW的体外反搏系统的软件设计方法,该软件通过友好的人机界面、多功能的软件模块使实验操作灵活方便;通过运用计算机强大的数据计算与处理能力,大大提高了数据分析处理能力。     

ARMA模型在远程心电诊断中的应用研究

研究适于远程心电诊断，基于ARMA模型的高精度的心电信号(ECG)直接分类方法．利用ARMA模型系数作为特征对ECG信号进行分类和压缩．在对信号特征分类时，采用了BP神经网络分类的方法．利用文中方法对MIT-BIH标准数据库中的正常窦性心律(NSR)、心房早期收缩(APC)、心室早期收缩(PVC)、心室性心动过速(VT)、室上性心动过速(SVT)和心室纤维性颤动(VF)各300个样本信号进行了测试，获得了96．51％～98．38％的分类精度．     

Biological applications of the “Filtered” Van der Pol oscillator

The present article deals with the development of an oscillatory model, which generates waveforms corresponding to ECG patterns. The present oscillatory system relies on coupling of oscillators derived from the famous VDP oscillator. We demonstrate that inducing a relaxation type of dynamics in the models contributes to their successful generation of ECG like signals. Furthermore, an interesting affinity is found, which associates the present models with a version of the well-known practical Wien Bridge oscillator. The presently discussed system relies on coupled elementary oscillator units. The present coupling is due to merely two units. The model, however, is likely to become even more realistic by coupling in the same manner an assembly of relatively many oscillators.     

MEMSWear-biomonitoring system for remote vital signs monitoring

This paper proposes a remote vital signs monitoring system, which integrates wireless body area network (WBAN) and personal digital assistant (PDA) phone technology. Four different physiological signs, e.g., ECG, SpO₂, temperature and blood pressure, can be continuously acquired or derived from two wireless sensor nodes—ECG sensor and integrated SpO₂/temperature sensor. Once sentinel events happened or the request to real-time display vital signs is confirmed, all physiological signs and critical indices will be immediately transmitted to patient's PDA phone through Bluetooth and further relayed to doctor's PDA phone through global system for mobile communication (GSM) technology. A prototype of such system has been successfully developed and implemented, which will offer high standard of healthcare with a major reduction in cost for our society.     

Wavelet analysis of electrocardiograms to characterize recurrent atrial fibrillation

In a substantial number of patients atrial fibrillation (AF) recurs after successful electrical cardioversion. Recurrence of AF is insufficiently predictable by clinical and echocardiographic parameters used in the clinic procedure. In this study some parameters were extracted from the analysis of electrocardiograms (ECGs), in an effort to predict the maintenance of sinus rhythm after cardioversion in patients with persistent AF. The database under study includes some ECG registers undergoing cardioversion with some additional physiological and anatomical information of each patient. After 12 weeks following cardioversion, only 15 (41.6%) of 34 patients maintained sinus rhythm. The ECG recordings were processed using the continuous wavelet transform (CWT) and the discrete wavelet transform (DWT). The method estimated the predictive power with respect to defibrillation outcome of some parameters extracted with CWT and DWT analysis, such as the main frequency peak frequency and the energy of detail coefficients, respectively. A logistic regression model was constructed, determining the calibration with the Homer–Lemeshow test and the discrimination with the area under the receiver operation characteristic (ROC) curve. The proposed methodology demonstrated a diagnostic capability of 82.4% for the prediction of AF recurrence, contributing to an improved interpretation of AF arrhythmias and their relation with recurrence risk.     

Diagnosis of acute myocardial infarction: CK-MB versus cTn-T in Indian patients

The comparative diagnostic efficacy of two cardiac markers: CK-MB and cTn-T, has scarcely been investigated in Indian patients of acute myocardial infarction. The present study was conducted for the same objective. The present study comprised of 59 patients. Males were 44 (75%) and females were 15 (25 %). The age of patients ranged from 32–84 years with mean age of 62.8 yrs. The mean age of males and females were 60 and 63 yrs respectively. All patients presented with history of chest pain with a 12 leads ECG proven MI (ST Elevation, discordant T-waves). CK-MB was estimated in peripheral blood samples at 0,24,48 and 72 hours by an autoanalyzer. Following 12 hours of admission bed side Troponin-T test was done employing cTn-T marker kit. Initially (0 hr), in 50% patients CK-MB was elevated. By end of 24 hours all the patients were CKMB positive and peak level was attained at 24 hrs. Then it tended to decline over next 48 hrs. There were no false positive or negative results. The cTn-T test was positive only in 22 % of ECG positive infarctions. However, the cTn-T positive cases were always accompanied by a higher CK-MB levels. A significantly lower cTn-T positive cases in Indian patients can only be attributed to some difference in amino acid sequence of Indian cTn-T and occidental cTn-T. A larger study from other Indian cardiac centers can either substantiate or contradict our results.     

Parameters Analysis of Sample Entropy,Permutation Entropy and Permutation Ratio Entropy for RR Interval Time Series

Proper parameters can improve performance of entropy methods for discerning electrocardiogram (ECG) signals. So, we tried to determine proper parameters of three entropy methods i.e., a novel permutation ratio entropy (PRE), sample entropy (SmpE) and permutation entropy (PE) for discerning several typical ECG RR interval recordings i.e., normal sinus rhythm (NSR), congestive heart failure (CHF) and NSR and arrhythmia RR (ARR) interval recordings. The three entropy methods were first calculated for a logistic sequence to evaluate their sensitivity to dynamic property changes within a time series. Their capabilities of distinguishing complexity between NSR and CHF, NSR and ARR, and CHF and ARR RR interval recordings were compared. Statistical differences between the three entropy values for normal (i.e., NSR) and abnormal RR interval recordings (i.e., CHF and ARR) were analysed respectively. Performance of the entropy methods in simultaneously discerning the three groups (i.e., NSR, CHF and ARR groups) were also compared. PRE more accurately reflected logistic sequence changes from period doublings to chaos than SmpE or PE did. In experiments with real data, PRE correctly yielded higher values on NSR RR recordings than on CHF and ARR recordings and exhibited significant differences (p < 0.01) on more parameter pairs than SmpE and PE did.