基于经验模式分解的心电特征提取算法

本研究应用基于经验模式分解的心电特征提取方法,利用第一本征模函数(intrinsic mode function,IMF)分量对QRS波进行定位,并通过减少分解层数、筛选次数、处理区域等策略实现了快速算法。利用MIT-BIT心律失常数据库的数据进行算法测试,取得较高的检测率,检测速度也有明显提高。实验结果表明,经验模式分解算法在QRS波定位中具有相当的优越性,临床应用中取得了良好的检测效果。     

Simple two-electrode biosignal amplifier

A simple, cost effective circuit for a two-electrode non-differential biopotential amplifier is proposed. It uses a ‘virtual ground’ transimpedance amplifier and a parallel RC network for input common mode current equalisation, while the signal input impedance preserves its high value. With this innovative interface circuit, a simple non-inverting amplifier fully emulates high CMRR differential. The amplifier equivalent CMRR (typical range from 70–100 dB) is equal to the open loop gain of the operational amplifier used in the transimpedance interface stage. The circuit has very simple structure and utilises a small number of popular components. The amplifier is intended for use in various two-electrode applications, such as Holter-type monitors, defibrillators, ECG monitors, biotelemetry devices etc.     

LCD心电监视器两例

为了给我们研制的便携式急救心电监护仪配上监视器,实现心电波形的连续、实时显示,我们试用了两种LCD显示模块.本文介绍了显示器的软、硬件设计.     

心肌炎患者高频心电图QRS波群的功率谱分析

本文选取６９名心肌炎患者，９４名正常人做为对照。依其年龄不同，共分６组：幼儿心肌炎组，正常幼儿组，学龄心肌炎组，正常学龄组，成人心肌炎组，正常成人组。分别对这６组的Ⅱ导、ａＶＦ导、Ｖ２导、Ｖ５导ＱＲＳ波群０－１０００Ｈｚ、８０－３００Ｈｚ、１００－１０００Ｈｚ３个频段的功率谱（用绝对能量表示）进行了分析。结果提示，不同年龄的心肌炎患者，其心电信号高频频段的能量变化规律不一致。     

基于快速节律性运动的皮层脑电分析

节律运动是人们生活中一种基本的运动形式,与单次运动相区别,快速节律运动在脑电中有特殊的表现形式.本文以两位植入皮层电极的癫痫病人作为受试,在1Hz与2Hz听觉节拍器提示下进行手指节律运动,同时记录皮层脑电数据.对脑电数据的能量和相关性进行离线分析,结果显示节律运动中运动感觉皮层脑电的能量在特定频段上呈下降趋势,相干性呈上升趋势,且运动相关能量与相干性在不同的运动速度下具有明显的统计性差异.对不同功能区之间相干性的分析表明辅助运动区可能是与运动速度有关的皮层功能区.     

A placebo-controlled trial of procaterol: A new long-acting oral beta2-agonist in bronchial asthma

Procaterol hydrochloride, a potent beta 2-adrenergic bronchodilator developed in Japan, was evaluated in a double-blind, placebo-controlled study for efficacy and safety in 45 patients (ages 18 to 55 yr) with chronic documented reversible airway disease. After a 1-week placebo washout period, patients were administered either 0.05 mg or 0.10 mg of procaterol or placebo twice daily for 2 wk. Spirometric determinations, vital signs, and ECGs were obtained at 1/2, 1, 2, 4, 6, and 8 hr after the first dose and at the same time intervals after 1 and 2 wk of treatment. Patients recorded on a daily basis peak flow rates, asthma symptoms, need for supplemental aerosol, concurrent medications, and side effects. Spirometry results indicated significant improvement in pulmonary function with both doses of procaterol compared with placebo (P less than 0.05). The larger dose was generally more effective. Bronchodilatation was evident 1/2 hr after dosing and peaked at 2 hr. At 8 hr after 0.10 mg of procaterol, FEV1 was still above predose values. Daily peak flow rates were significantly higher with 0.10 mg than with 0.05 mg (P less than 0.05) and placebo (P less than 0.001). Tremor and nervousness were the most frequent side effects. They occurred in a dose-related frequency, were mild and transient, and occurred early in treatment. No significant drug-related changes were noted in ECGs, heart rate, blood pressure, or clinical laboratory data. Procaterol was found to be an effective, well-tolerated oral bronchodilator with a long duration of action, especially at 0.10 mg twice daily.     

模糊ART神经网络在心律失常分析中的应用

本研究提出一种用模糊ART神经网络进行心律失常分析的方法。确定用于描述QRS波群特征的若干属性 ,提取其特征 ,模糊化处理后作为神经网络的输入模式矢量。神经网络为三层结构 ,经过竞争学习 ,对QRS波群进行自动分类。分类结果用MIT -BIH数据库进行了检验 ,证明本方法非常有效 ,30min数据的分析时间小于 2s,满足实用要求     

心电信号预处理与心电信号分析

本文介绍了在一种便携式心电监护仪器中是如何对心电数据进行预处理和智能分析的．为了适应便携式仪器的特征，我们在心电信号预处理中采用了FFT滤波和滑动平均滤波的方法去除各种干扰并使图像得以平滑，同时采用了差分阈值法提取特征点，考虑到监护仪器的实用性，在心电信号分析阶段，我们采用了分析特征间期异常情况的方法来替代对病症的智能诊断功能。     

基于PDA的嵌入式ECG监护分析仪

目的为了方便快捷地实时监测心律失常,设计一种基于PDA的嵌入式ECG监护分析仪。方法仪器功能包括低功耗MSP430系列单片机控制心电信号的采集、放大、滤波、转换和在PDA上实时显示、存储和分析,并实现心电数据的远程传输。对仪器工作原理进行分析,把监护分析仪总体结构划分为子模块,并具体介绍各子模块的功能与实现。结果与结论与医院现有的三导全自动心电图机、Holter动态心电图机进行对照,本监护分析仪携带方便、操作简单、接收的心电信号无失真,连续工作时间大于20h等。各高频干扰信号对ECG信号无影响;软件可对心电信号进行实时显示,可连续记录15h的原始心电数据。     

Deleterious effects of low-dose oestrogen theraphy on coronary status in patients with prostatic cancer

The effects of oestrogen therapy and of orchidectomy on coronarystauts, as reflected by exercise ECG-testing before and afteryear of tretment, were assessed in a randomized study of patients(N=100) prostatic cancer. Oestrogen was given as polyestradiolphosphate 80 mg i.m. per month in combination with 150 µgor in pre-traetment exercise test results Twelve months afterstart of therapy the oestrogen group showed a significantlygreater depression of the ST-segment during maximal exercisein leads CH₂ (P<0.0005) and CH⁵)P<0.01) compared withthe pre-treatment depression. Twenty-five per cent (N=13) ofthe patients in the oestrogen group suffered cardiovascularcomplications during the yera the of therapy, whereas no suchcomplications were observed in the orchidectomy group. However,even the patients in the oestrogen group who had not sufferedcardiovascular complications had significantly greater depressionsof the ST-segment during exercise both in lead CH₂ (P<0.0005)and in CH₅ (P<0.05). There was no significant change in theST-segment level in the orchidectomy group twelve months aftersurgery. In summary, we found of an induction of myocardialishaemia during treatment with exogenous oestrogens at low dosagein patients with prostatic. This deleterious effect of oestrogenon the coronary status argues against oestrogen therapy, sinceoedtrogen has not been shown to be more beneficial than orhidectomyagainst prostatic carcinoma.