12导联心电图P波检测算法

本文提出了一种心电信号中P波检测方法.首先分析了小波变换方法和翼形函数(wings function)方法检测P波的特点,然后提出了一种应用小波变换初步判定有无P波后,在原始信号上再应用翼形函数方法精确检测P波峰点、判定P波形态的方法,最后给出P波单导联和12导联整体起点、终点的确定方法.经上海市第六人民医院随机采样的320例心电图检测验证,P波正确检率达到98%.     

正交导联高频心电图对Ⅲ导联病理性Q波的鉴别诊断意义

为应用正交导联高频心电图，鉴别Ⅲ导联病理性Ｑ波（ＱⅢ）系下壁心肌梗塞灶瘢痕挛缩后所遗留，拟或非梗塞性ＱⅢ波，对陈旧性下壁心肌梗塞仅留有ＱⅢ的患者１８例和非梗塞ＱⅢ的受试者２３例进行了高频心电图检测。结果显示：两组高频切迹数差别有极显著意义（Ｐ＜０．００１），且切迹分布导联有明显差别。提示正交导联高频心电图用于Ⅲ导联病理性Ｑ波的鉴别诊断，可能优于其它方法。     

正常人头胸导联和常规导联右胸异常Q波的比较

目的:比较常规导联心电图及头胸导联心电图所记录的正常人右胸导联Q波的特征.材料与方法:采用导联心电图机及头胸导联心电图机分别检查50个正常成人(30名男性,20名女性)的右胸心电图,记录Q波出现的频率及幅度.结果:头胸导联所记录到的Q波数及Q波幅度均显著低于常规导联心电图.结论:正常人头胸导联心电图较常规心电图较少出现右胸假性异常Q波.     

不同心电图导联时QRS波起始点的比较

进行无创性心功能检查(特别是心缩间期测定)常需记录ECG。能否正确确定QRS复合波的最早起始点,是影响测量准确性的重要因素之一。以往测定心缩间期时常选用Ⅱ导,但Ⅱ导QRS波的起始点常迟于右胸前导联。近年来国内有关心缩间期测定     

P波最大时限及P波离散度预测阵发性房颤的价值

心房纤颤（房颤）是临床常见的心律失常之一,大多转律后易反复发作,部分成为永久性房颤。P波离散度（Pdispersion,Pd）是近年来被广泛研究作为体表心电图预测阵发性房颤的新指标,指测定同步记录的12导心电图各导联中尸波最大时限（Pmax）与P波最小时限的差值。     

心电P波的形状比较法

在临床及基础生理研究中常常需要对ECG进行定量比较,这种比较一般都用相关系数和均方根误差作为诊断指征。相关系数一般用于研究与信号时序有关的各种变异,它对波形幅度不敏感,但要受到形状变化的影响,均方根误差则以比较幅度变异,但也受到时相的影响。这两种方法都缺乏足够的灵敏性。本文介绍了一种选择性比较方法,可以同时比较两个信号幅度、时相及波形的变异。它考虑了随机的和系统变化的影响,可以进行绝对的或相对的比较,并可在小容量内存的计算机系     

尿毒症患者血液透析对P波离散度的影响

目的:比较尿毒症患者血液透析前后P波离散度(Pd)的变化。方法:选择2019年1月至12月在东莞市大朗医院长期进行血液透析的尿毒症患者20例作为血液透析组,并选择同期在本院进行体检的20例健康人作为对照组。比较对照组患者与尿毒症患者血液透析前P波离散度变化,及尿毒症患者血液透析前后P波离散度和血液生化指标变化,从而探讨血液透析对尿毒症患者P波离散度的影响。结果:尿毒症患者进行血液透析可以降低血液尿素氮、肌酐、K~+、Mg~(2+)、P~(2+)和Cl~-含量,并增加血液Ca~(2+)和Na~+水平。尿毒症患者进行血液透析前P波最大时限(P_(max))和Pd高于健康对照组(P0.05),P波最小时限(P_(min))差异无统计学意义(P0.05)。尿毒症患者血液透析后可以增加P_(max)和Pd(P0.05),但对P_(min)无明显影响(P0.05)。结论:尿毒症患者进行长期血液透析可能引起血液电解质紊乱,P_(max)和Pd异常增加,增加其阵发性房颤的风险。     

aVR导联T波直立:心尖肥厚的心电图特征

目的胸前导联T波倒置与左室高电压为心尖肥厚最常见的心电图表现,我们预测aVR导联T波直立为心尖肥厚的另一重要心电图特征。方法回顾分析63例左室肥厚患者的临床资料,根据是否存在心尖肥厚分为心尖肥厚组(n=24, 13例单纯心尖肥厚, 11例混合性心肌肥厚)和非心尖肥厚组(n=39, 19例单纯室间隔肥厚, 20例多部位心肌肥厚)。分析比较两组患者的心电图与超声心动图特点。结果结果显示,相比较于非心尖肥厚组, aVR导联T波直立与胸前导联T波倒置更多见于心尖肥厚组。aVR导联T波直立在两组间的比例为83.3%vs. 30.8%(P0.000 1),胸前导联T波倒置为83.3%vs. 59.0%(P=0.004)。结论研究表明, aVR导联T波直立与胸前导联T波倒置为心尖肥厚的重要心电图表现,可提高心尖肥厚的诊断。     

一种双导联融合心电QRS波检测算法

目的:心电图的检测与分析是临床上诊断心血管疾病的主要依据,QRS波是心电信号中最重要的特征波,它的准确检测是心电信号自动分析的前提和基础。为了提高单导联检测QRS波的灵敏度和准确率,本文提出一种新的双导联融合心电QRS波检测的算法。方法:原始心电信号通过单导联预检波进行QRS波定位后,由双导联决策方法来决定采用单导联检波还是双导联融合检波。单导联检波直接采用第一或第二导联检测结果;双导联融合检波由双导联融合方法和导联判断规则判别。以窗时间为时间单位,不断更新双导联决策算法。本算法包括方差、幅值、模板匹配以及阈值比较等方法。结果:采用MIT-BIH心律失常数据库的48组两导联心电记录进行验证,统计得到平均灵敏度和准确率分别为99.87%、99.81%。其漏检数和误检数比第一导联分别降低了23.26%、18.27%,比第二导联分别降低了88.21%、95.11%。结论:本算法实时高效地提高单导联QRS波检测的灵敏度和准确率,且优于部分算法的检测结果,因而在心电信号自动分析中具有良好的应用前景和较高的实用价值。     

新的P波检测系统的研究食道P波的前置放大和硬件提取

一、提取P波的必要性及其难度:心房波的有无及其形态,以及心房波与心室波间距(即P—R间距)的大小及其变化,也就是说P波在心电图中的有无及其相对位置对心律不齐的诊断极为重要.但体表心电图之P波由于测试点不易靠近心房,故其幅度远小于R波,而在心律不齐病例中P波相对位置不固定,而且常被淹没在R波或T波之中,造成诊断上的困难.因食道靠近心房,故食道P波幅度远大于体表P波,因而有利于心电图的临床诊断.但是单极食道心电图的QRS波幅度往往远大于P波,而且由于受食道蠕动等可能因素的影响,造成单极食道心电图基线漂移很大,且波形复杂,仍不能满足临床诊断的需要,特别是不适于计算机自动识别、测量,因而难于     

基于小波变换和神经网络的心电信号P波检测

为了提高P波检测准确率,利用小波变换模极大值对在多尺度上的变化规律能表征信号突变点的性质,结合人体生理特性的检测策略进行心电信号P波的跨尺度检测。同时,引入反向传播神经网络对已检出的准P渡再次进行确认与识别。经MIT数据库实验表明,P波检测准确率达到97％。     

用小波变换结合神经网络检测ECG信号的P波

通过小波变换对ＥＧＣ信号进行分解,然后采用神经网络检测ＥＣＧ信号的Ｐ波,该方法作为一种辅助检测手段,效果良好。将其用于心率变异性分析具有重要意义。     

P波离散度预测扩张型心肌病伴阵发性心房颤动的价值

目的探讨P波离散度(Pd)预测扩张型心肌病(DCM)伴阵发性心房颤动(PAF)的价值。方法44例DCM伴阵发性Af者(Af组),44例DCM无Af者(对照组)。通过体表12导联心电图测定P波最大持续时间(Pmax)与最小持续时间(Pmin),计算Pd(Pd=Pmax-Pmin)。比较Af组与对照组的Pd与Pmax。同时测量左房内径(LAD)。结果Af组Pd为49.54ms±12.7ms,Pmax为125.84±14.8ms,与对照组Pd为33.6±10.5ms,Pmax为111.4±12.4ms相比有较显著延长(P<0.01)。Af组LAD40.5±5.5mm,对照组LAD39.4±6.2mm,两组相比无显著差异(P<0.01)。取Pmax≥120ms,Pd≥40ms以及两者相结合,预测PAF其敏感性分别为87%﹑91%﹑75%,特异性分别为82%﹑84%﹑91%,阳性预测值分别为86%﹑88%﹑89%。结论Pd﹑Pmax可作为预测DCM并发阵发性Af的可靠指标。     

Association of Increased Arterial Stiffness and P Wave Dispersion with Left Ventricular Diastolic Dysfunction

Background: The association between increased arterial stiffness and left ventricular diastolic dysfunction (LVDD) may be influenced by left ventricular performance. P wave dispersion is not only a significant determinant of left ventricular performance, but is also correlated with LVDD. This study is designed to compare left ventricular diastolic function among patients divided by brachial-ankle pulse wave velocity (baPWV) and corrected P wave dispersion (PWDC) and assess whether the combination of baPWV and PWDC can predict LVDD more accurately.Methods: This cross-sectional study enrolled 270 patients and classified them into four groups according to the median values of baPWV and PWDC. LVDD was defined as impaired relaxation and pseudonormal/restrictive mitral inflow patterns.Results: The ratio of transmitral E wave velocity to early diastolic mitral annulus velocity (E/Ea) was higher in group with higher baPWV and PWDC than in the other groups (all p <0.001). The prevalence of LVDD was higher in group with higher baPWV and PWDC than in the two groups with lower baPWV (p ≤ 0.001). The baPWV and PWDC were correlated with E/Ea and LVDD in multivariate analysis (p ≤ 0.030). The addition of baPWV and PWDC to a clinical mode could significantly improve the R square in prediction of E/Ea and C statistic and integrated discrimination index in prediction of LVDD (p ≤ 0.010).Conclusions: This study showed increased baPWV and PWDC were correlated with high E/Ea and LVDD. The addition of baPWV and PWDC to a clinical model improved the prediction of high E/Ea and LVDD. Screening patients by means of baPWV and PWDC might help identify the high risk group of elevated left ventricular filling pressure and LVDD.     

P and R Wave Detection in Complete Congenital Atrioventricular Block

Complete atrioventricular block (type III AVB) is characterized by an absence of P wave transmission to ventricles. This implies that QRS complexes are generated in an autonomous way and are not coordinated with P waves. This work introduces a new algorithm for the detection of P waves for this type of pathology using noninvasive electrocardiographic surface leads. The proposed algorithm is divided into three stages. In the first stage, the R waves located by a QRS detector are used to generate the RR series and time references for the other stages of the algorithm. In the second stage, the ventricular activity (QT segment) is removed by using an adaptive filter that obtains an averaged pattern of the QT segment. In the third stage, a new P wave detector is applied to the residual signal obtained after QT cancellation in order to detect P wave locations and get the PP time series. Eight Holter records from patients with congenital type III AVB were used to verify the proposed algorithm. Although further improvements should be made to improve the algorithm’s performance, the results obtained show high average values of sensitivity (90.52%) and positive prediction (90.98%).     

基于心电和脉搏波数据融合的呼吸率估计

本研究提出了一种通过心电和脉搏波提取呼吸信号并基于卡尔曼滤波的多路数据融合估计呼吸率的算法。算法分别从心电的RR间期、R波的绝对高度和脉搏波搏动周期中提取呼吸信号,利用AR模型估计呼吸率,根据信号波形、节律和频谱特征获得反映信号质量高低的质量指数,然后基于信号质量指数和卡尔曼滤波残差进行数据融合,获得融合呼吸率。14名志愿者参加了实验。结果表明,融合呼吸率比单独从心电或脉搏信号提取的呼吸率更好地反映了呼吸率的变化。与压阻式呼吸传感器提供的参考呼吸率相比,融合呼吸率误差为(-0.03±2.78)次/min,而从心电RR间期、R波的绝对高度和脉搏法提取的呼吸率的误差分别为(0.62±3.30)、(0.42±3.47)和(-0.17±2.69)次/min。总体认为,基于多路数据融合的方法可以有效避免干扰的影响,较准确地估计呼吸率。     

C-terminal hydrophobic region leads PRSV P3 protein to endoplasmic reticulum

P3 protein is one of the least characterized potyviral proteins in both functions and sub-cellular localization. In this study, we examined the sub-cellular localization of PRSV P3 and its intermediate, P3-6K1 by expressing their GFP fusion proteins in onion epidermal cells. Our results showed that both P3- and P3-6K1 GFP fusion proteins were localized at the endoplasmic reticulum. Deletion analysis indicated that C-terminal of P3 protein contained localization signal, and a 19 amino acids hydrophobic domain from this region was able to target the GFP fusion protein to endoplasmic reticulum. C-terminal of P3 proteins has been suggested to be involved in both viability and pathogenicity of the potyvirus. Therefore, our result suggests that localization of P3 protein at endoplasmic reticulum is essential for functionality of P3 protein.     

P300 and Slow Wave in a Message Consisting of Two Events

This study is concerned with P300 and Slow Wave in an experimental paradigm in which information is transmitted by a combination of two successive events (a ‘message’). Each event delivered essential information for understanding the message, but the meaning of the message could not be determined until occurrence of the second event. The amount of information in each event was varied by varying its perceptual difficulty. Increasing perceptual difficulty causes an information loss, termed equivocation. A positive Slow Wave was elicited by both events. Slow wave was clearly increased in amplitude by equivocation in the eliciting event, and less clearly increased in amplitude by equivocation in the other event. The first event elicited a small P290 component. It could not be determined whether this component corresponded to P300. The second event elicited a large P300. This component was much reduced in amplitude by equivocation in the second event, but was only moderately reduced in amplitude by equivocation in the first event.     

脑波治疗对青少年期精神分裂症患者认知功能的影响

目的探讨脑波治疗对青少年期精神分裂症患者认知功能的影响。方法随机将年龄在12-18岁之间符合DSM-IV精神分裂症标准患者46例,分为单纯应用奥氮平治疗组（实验组1）及应用脑波联合奥氮平治疗组（实验组2）,选择23例健康者作为对照组。实验组予奥氮平治疗8周前后予《简明精神状况检查量表》（BPRS）评分,各组分别予P300检测,分别比较P300潜伏期及波幅的差异。结果实验组1、实验组2PZ点潜伏期均比对照组延长,实验组1、实验组2FZ、CZ、PZ、OZ点波幅均比对照组降低（P〈0.05及0.01）。治疗后,实验组1、实验组2PZ点潜伏期均比治疗前缩短（P〈0.01）;实验组1、实验组2FZ、CZ、PZ、OZ点波幅均比治疗前升高（P〈0.05及0.01）。实验组2PZ点潜伏期比实验组1缩短（P〈0.05）;实验组2FZ、CZ、PZ、OZ点波幅均比实验组1升高（P〈0.05及0.01）。治疗后,实验组1BPRS评分高于实验组2（P〈0.01）,实验组2显效率及总有效率明显高于实验组1（P〈0.01）。结论脑波治疗通过调节、平衡人体的脑电活动及兴奋水平,具有辅助改善青少年期精神分裂症患者认知功能的作用。