家兔离体心脏希氏束电图记录方法

家兔离体心脏希氏束电图记录方法张玲玲，焦晓惠，刘北英，单若明，钮伟真（首都医学院心血管生理研究室北京１０００５４）当应用Ｌａｎｇｅｎｄｏ─ｆｆ心脏灌流法研究心脏传导系统尤其是房室结的生理特性时，常需记录希氏束电位。通常可将记录电极直接安放在相当于希氏...     

旁道电生理及旁道鉴别

一、旁道电生理:515:调搏频率>200次/min为1,1房室传导,提示存在旁道。二、旁道的鉴别:如下表Kent束Jame。束Mahaim束常规心电图P一R间期《0.125有a波QRS)0.125P一R间期‘Q.125无a波QRS正常典里者:P一R间期正常成稍姗坦有古波.QRS增宽不典组者:①体表心电图正常 ②QRS起始部仅徽小挂钝 ③呈束支吸滞班 ④V:呈R型或RS型,QRS不 宽 A一H间期正常常规希氏A一V间期短束图H一V间期姐或H在V 中A一H间期短A一V间期正常H一V间期正常A一H间期正常A一V间期短H一V间期短或固定或不一定V波增宽经食管心房洲搏时<160ms且固定SR不完全…     

从体表电生理信号中提取希氏束信号的分析系统

背景:传统的希氏束检测方法是对体表心电信号进行数百次叠加或者经食道检测以及心内导管检测得到,研制从体表心电信号提取希氏束信号不但有利于临床诊断,也有利于动物药物实验。目的:从体表心电信号中提取希氏束信号,并开发体表希氏束信号分析系统。方法:以家兔体表心电信号作为待分析信号,以其心内希氏束电图作为对照信号,采用随机共振、小波变换、叠加平均和耦合累加等分析方法,对体表心电信号进行分析。结果与结论:小波变换后得到的信号,可以从体表心电信号中检测出希氏束信号,但并不是所有希氏束信号都能被识别,心内信号经过小波变换后,个别希氏束信号反而消失。随机共振方法从体表心电中检测出的希氏束信号识别率要高于小波分析方法,随机共振方法与小波分析相同之处是,心内信号经过处理后,个别希氏束信号反而消失。本文提出的耦合叠加算法能够从体表心电信号提取出希氏束信号,与经典叠加方法比较,其优点是希氏束信号明显,叠加次数远远少于经典叠加方法。提示实验采用的随机共振、小波变换、耦合累加等分析方法,能够有效抑制噪声、提取希氏束信号,开发研制的体表希氏束信号分析系统具有较强的实用价值。     

T波交替的研究进展

T波交替是指在心电图T波的幅度、形态的逐搏交替变化。作为一项新的无创心电检测方法，T波交替已成为预测室性心律失常及心脏性猝死等疾病的有效手段。较全面地阐述了T波交替的产生机理、检测方法及临床研究等方面的内容，并指出了T波交替的研究方向和发展前景。     

迟电位研究进展

迟电位(Late Potentials)是出现在QRS波群终末与ST段的高频低幅值心脏电活动,它与心肌梗塞后室性心律失常的发生有密切关系。自1978年Berbari和Fontaine等报导采用计算机平均叠加技术从体表记录迟电位获得成功以来,迟电位的研究才明显深化。一、体表检测技术迟电位信号非常微弱,从心外膜直接记录时一般在1mV以下,从体表记录时为微伏数量级。由于骨骼肌活动、电极和放大器噪声及工频干扰的引入,即使在理想情况     

基于质子束激发热声信号的布拉格峰定位

目的:使用质子束激发热声信号对质子束的布拉格峰定位，分析其在质子治疗中应用的可行性。方法:通过Kwave工具包模拟质子束在水中的传播过程，使用放置的传感器接收质子束激发产生的γ波走时数据，再将走时数据进行反演得到布拉格峰位置的修正量，从而完成对布拉格峰定位。结果:在均匀介质中，当初始的布拉格峰位置在目标布拉格峰位置5 cm范围内，使用Kwave模拟得到的走时数据进行定位，无噪声的情况下，定位误差在1.3 mm以内，对其进行加噪处理后，定位误差仍在3 mm以内。使用波前扩展的线性走时插值射线追踪算法得到的走时数据进行反演，能完成零误差定位。结论:使用质子束激发热声信号，仅需要少量的传感器就能对质子束的布拉格峰进行实时定位，走时数据的准确性对定位算法有一定的影响。但是通过加噪实验发现，本算法具有较好的稳定性和收敛性。     

希氏束电位在体表的分布及空间平均法体表希氏束图合理导联方法研究

通过对体表希氏束电位的分布进行测量和分析,探索空间平均法体表希氏束电图的合理导联位置和空间平均方法。为此工作专门研制了一套IBM-pC XT(AT)控制的多导ECG系统,它较通常的ECG系统具有高得多的分辨率。测量是在通常环境下对十名健康者进行的。对希氏束体表电位的分布和正负极值点连线方向采用PQ段等电位图法加以研究并由此导出合理的导联位置和空间平均方法。这些新的导联方法被进一步在空间平均法体表逐拍希氏束测量中加以检验。该工作对空间平均法的导联方法提出了新的见解和依据。     

酚妥拉明阻断去甲肾上腺素对大鼠束旁核痛反应神经元电活动的影响

目的：去甲肾上腺素及其α受体阻断剂酚妥拉明对大鼠束旁核痛反应神经元电活动的影响。方法：以串刺激右侧坐骨神经为伤害性刺激，用玻璃微电极细胞外记录大鼠束旁核痛反应神经元电活动。结果：脑室去甲肾上腺素抑制旁核束旁核痛兴奋神经元放电，促进痛抑制神经元放电，此作用可被酚妥拉明阻断。结论：酚妥拉明阻断去甲肾上腺素对大鼠束旁核痛反应神经元电活动的抑制作用，提示去甲肾上腺素的镇痛作用与α肾上腺素能受体关系密切。     

心室迟电位及其临床意义

近年来应用微型电子计算机采集体表心电信号,经过增幅、平均迭加以提高信噪比,降依噪声干扰后,可以记录到QRS波群末段的高频成份中有一微小的电活动,称为心室迟电位(Late PotenrtiaL; LP)。Rozens ki, Simson, Preithardt, Denes等先后报告在伴有持续性室性心动过速的心肌梗塞患者和左心室壁瘤病人,应用体表QRS波群信号迭加,可以记录到心室迟电位(LP),认     

自回归分析法应用于在体表和浆膜上对人胃的测试结果

一、导言很长时间以来,人们就认识到研究人体的电活动,对于不同组织和器官的认识方面是具有重要价值的。脑电图和心电图的成功应用就是研究工作已应用于临床的两个例子。人体的其它部分也表现出电活动,胃肠道就是这样一个区域。人体的胃肠道是有很多电活动是持续存在的,因而使人们认为这与肠管的肌肉活动有关。本篇论文报道,在人胃脏体表和浆膜上测量结果的比较研究中应用自回归技术。主要目的在于鉴别两种方法记录的不同之处。我们假定在其应用中,信息是由于线性滤波器作用而产生的影响,可用滤波器的特征方程来做比较。从大多数的体表记录中可以观察到,有可能识别出主要的干扰源。在人胃中,这些干扰波相应于呼吸引起的伪迹和有些每分钟9～10个周期的电活动。     

融合CNN和BiLSTM的心律失常心拍分类模型

为更加准确地从动态心电中提取异常心拍,设计一种融合卷积神经网络(CNN)和多层双边长短时记忆网络(BiLSTM)的心律失常心拍分类模型。心电信号首先被分割成0.75 s和4 s两种不同尺度大小的心拍信号,然后利用11层CNN网络和3层BiLSTM网络分别对小/大尺度心拍信号进行特征提取与合并,并使用3层全连接网络对合并特征进行降维,最后利用softmax函数实现分类。针对MIT心律失常数据库异常心拍类型分布不均衡的问题,采用添加随机运动噪声和基线漂移噪声的样本扩展方法,降低模型的过拟合。采用基于患者的5折交叉检验进行模型验证。MIT心律失常数据库116 000个心拍的分类结果表明:所建立的模型针对4类心拍(正常、房性早搏、室性早搏、未分类)的识别准确率为90.42%,比单独使用CNN(76.45%)和BiLSTM(83.28%)的模型分别提高13.97%和7.14%。所提出的融合CNN和BiLSTM的心律失常心拍分类模型,相比单一基于CNN模型或者BiLSTM模型的机器学习算法,有更好的异常心拍分类准确率。     

Assessment, Learning, and Retention of Heart Beat Discrimination

In order to answer questions about the stability, trainability, and maintenance of heart beat discrimination, 32 subjects were given tests of heart beat discrimination on 2 days before and on 2 days after discrimination training, and 28 of those subjects were again tested at a mean of 34 days following the fifth consecutive session. Subjects were tested in a successive discrimination procedure in which they chose whether signal trains were contingent or noncontingent upon heart beats. On successive blocks of trials noncontingent signals were either of variable or invariant interpulse interval in order to determine if relative pulse train variability could provide a basis for correct choices. During training half of the subjects reached a pre-established criterion, and these subjects maintained higher levels of discrimination for the next 3 sessions. Relative pulse train variability was not a useful basis of judgment initially, although it may have aided subjects in the fifth session. Reliability of discrimination scores was low and discussion centers around this and other problems inherent in procedures reported to assess cardiac perception.     

Intrarenal red cell and plasma volumes in the non-diuretic rat

Summary Transmembrane action potentials were recorded from fibers of the atrioventricular region of the rabbit heart.Displacement of the recording microelectrode from the A.V. node towards the distal segment of the bundle of His revealed that the rate of rise and amplitude of the action potentials increased gradually along the bundle. According to these characteristics and to the site from which the action potentials were recorded, they were classified in three groups: upper His (UH), middle His (MH) and lower His (LH).The effects of some specific blocking agents of the ionic fluxes were studied on the electrical activity of the fibers of the bundle of His. Tetrodotoxin (5 g/ml) and high KCl (18.9 and 27.0 mM/l) were used to abolish the fast excitatory current, and MnCl₂ (5 mM/l) to block the slow inward current.The present results indicate that both the fast and the slow inward currents participate in the generation of the action potentials of the bundle of His. The proportion of each current varies, depending on the segment of the bundle of His in which the action potentials were originated. In the cells of the upper bundle the upstroke of the action potentials is determined mainly by the activation of the slow inward current with a negligible contribution from the fast sodium current. Along the bundle of His the participation of the fast inward current increases progressively.     

基于模糊推理的心拍分类

心拍分类对于临床心律失常自动化检测非常重要。临床上对心拍分类的诊断标准存在一定的不确定性,模糊推理可以较好地表达心拍分类过程中的不确定性,而隶属度函数的设计是模糊推理系统的关键问题。本研究提取较为精确的QRS复合波间期和RR间期特征组成模糊输入量;通过对MIT-BIH心律失常心电数据库的所有正常拍和室性早搏模糊输入量进行统计分析,提出了一种设计隶属度函数的具体思路,并实现了一个用于心拍分类的模糊推理系统。通过对MIT-BIH心律失常心电数据库测试,该系统心拍分类结果较好,具有临床应用价值。     

Amusic does not mean unmusical: Beat perception and synchronization ability despite pitch deafness

Pitch deafness, the most commonly known form of congenital amusia, refers to a severe deficit in musical pitch processing (i.e., melody discrimination and recognition) that can leave time processing—including rhythm, metre, and “feeling the beat”—preserved. In Experiment 1, we show that by presenting musical excerpts in nonpitched drum timbres, rather than pitched piano tones, amusics show normal metre recognition. Experiment 2 reveals that body movement influences amusics’ interpretation of the beat of an ambiguous drum rhythm. Experiment 3 and a subsequent exploratory study show an ability to synchronize movement to the beat of popular dance music and potential for improvement when given a modest amount of practice. Together the present results are consistent with the idea that rhythm and beat processing are spared in pitch deafness—that is, being pitch-deaf does not mean one is beat-deaf. In the context of drum music especially, amusics can be musical.     

肾上腺素受体阻断剂对腺苷延长豚鼠希氏束电图A—H间期的影响

本实验采用导管电极记录豚鼠希氏束电图(HBE)、玻璃微电极记录家兔、豚鼠心室肌(VM)细胞动作电位(AP)的方法,以不同浓度腺苷对其作用为观察指标、观察了肾上腺素受体阻断剂—酚妥拉明、酚苄明、心得安等对腺苷作用的影响。结果表明:1.腺苷使HBE A-H间期延长。2.腺苷可改变VM细胞AP复极时程(APD)。3.肾上腺素受体阻断剂部分或全部阻断腺苷的作用。结果提示腺苷可能通过激活细胞膜肾上腺素受体而发挥作用。     

Deriving the Standard 12-lead ECGbased on Weighed Epicardial Potential

INTRODUCTION　　 Many methods are routinely used in diagnosing and locating myocardial ischemiaand myocardial infarction,such as the standard 1 2 -lead ECG and body surfaceisopotential maps.All of them are to measure multi-pointbody surface potentialsnoni…     

基于最大散度的特征搜索算法用于心搏分类的研究

在对心电图进行离散小波变换获得特征空间的基础上,提出了基于最大散度的特征搜索算法.对特征空间进行搜索得到不同维数下的优化特征组合,通过研究这些优化特征组合的散度值随维数的变化趋势,最终确定特征向量的特征构成,并以此特征向量训练BP神经网络.取自MIT-BIH数据库的四类心电图(正常心搏、左束支传导阻滞心搏、右束支传导阻滞心搏和起搏心搏)的分类正确率达到93.9%,检出率较高.     

一种基于复合编码的心电数据压缩算法

本文提出了一种复合心电数据压缩方法，该算法根据ECG数据的特征变化，提取出每路ECG的心搏模板，从而把信号分成三部分；心搏模板，残差，位置参数，在保证恢复信号低失真的情况下，先对残余误差进行LADT编码，再利用Huffman的无损压缩方法进行全部数据二次压缩，与其它压缩方法相比，在同样的信息损伤下，该算法可获得更高的数据压缩比，本文提出的方法，也可应用到图像数据和其它数据的压缩中。     

Tracking EEG changes in response to alpha and beta binaural beats

A binaural beat can be produced by presenting two tones of a differing frequency, one to each ear. Such auditory stimulation has been suggested to influence behaviour and cognition via the process of cortical entrainment. However, research so far has only shown the frequency following responses in the traditional EEG frequency ranges of delta, theta and gamma. Hence a primary aim of this research was to ascertain whether it would be possible to produce clear changes in the EEG in either the alpha or beta frequency ranges. Such changes, if possible, would have a number of important implications as well as potential applications. A secondary goal was to track any observable changes in the EEG throughout the entrainment epoch to gain some insight into the nature of the entrainment effects on any changes in an effort to identify more effective entrainment regimes. Twenty two healthy participants were recruited and randomly allocated to one of two groups, each of which was exposed to a distinct binaural beat frequency for ten 1-minute epochs. The first group listened to an alpha binaural beat of 10 Hz and the second to a beta binaural beat of 20 Hz. EEG was recorded from the left and right temporal regions during pre-exposure baselines, stimulus exposure epochs and post-exposure baselines. Analysis of changes in broad-band and narrow-band amplitudes, and frequency showed no effect of binaural beat frequency eliciting a frequency following effect in the EEG. Possible mediating factors are discussed and a number of recommendations are made regarding future studies, exploring entrainment effects from a binaural beat presentation.