生理学教学中蟾蜍心脏起搏点分析与心电图引导的整合设计

蟾蜍心脏起搏点观察和心电图引导是生理学经典实验。传统的蟾蜍心脏起搏点观察实验利用斯氏结扎法配合计数,观察蟾蜍心脏各部分的自律性和等级性;心电图引导是模拟标准肢体Ⅱ导联,引导出蟾蜍心电图,观察心电图的基本波形,理解心电图基本原理。将2个实验有机结合,对实验项目进行重新设计,提高了实验成功率,增加了实验的可视性和启发性,取得良好的教学效果。     

蟾蜍皮下淋巴囊麻醉对心脏功能的影响

目的：研究一种对蟾蜍心脏功能影响较小的固定方式,适用于蛙心起搏点以及蛙心室舒缩与心电图同步记录观察期前收缩和代偿间歇实验的固定方式。方法：将一定数量的蟾蜍平均分为三组,分别为对照组捣毁大脑和脊髓组、乌拉坦皮下淋巴囊麻醉组。模拟Ⅱ导联分别将麻醉组、捣毁组蟾蜍连接RM6240,进入心电图实验模块,观察并记录两组组蟾蜍的处理前后心电图的变化情况,以及两组蟾蜍经过处理后痛觉、肌张力、呼吸的对比情况。快速游离三组蟾蜍的心脏,4%甲醛固定,30%蔗糖溶液脱水,修剪后冰冻固定,切片,苏木精-伊红（HE）染色,通过光学显微镜观查。结果：①乌拉坦皮下淋巴囊麻醉组蟾蜍的固定效果与捣毁大脑和脊髓组蟾蜍相当。②给药前后麻醉组蟾蜍的心电图变化幅度小于捣毁前后捣毁组蟾蜍的心电图。③与对照组蟾蜍的心肌细胞相比乌拉坦皮下淋巴囊麻醉组蟾蜍的心肌细胞破坏程度小于捣毁大脑和脊髓组蟾蜍。结论：在蛙心起搏点以及蛙心室舒缩与心电图同步记录观察期前收缩和代偿间歇实验中对蟾蜍进行乌拉坦皮下淋巴囊麻醉是一种优于捣毁蟾蜍大脑和脊髓的固定方法。     

一套研究机械电反馈的心室压力钳系统

在心脏机械电反馈的研究中准确控制机械刺激是非常重要的。本研究室构建了一套适用于离体家兔心脏的心室压力钳系统。该系统通过计算机控制压力钳,不仅能模拟正常生理条件下左心室的压力波形,还能在心室活动周期的特定时相、以适当波形对心室施加机械刺激。该系统集心脏灌流与起搏、表面心电图记录、单相动作电位记录、心室压力钳制与测定等多种功能于一体,特别适用于器官水平上观察机械电反馈现象并探讨其机制。     

单片机模拟心电图发生器的制作

本文介绍了采用８９Ｇ５１单片机的心电图信号发生器的原理和制作。本仪器小巧,灵便,能模拟产生标准件的十二导联心电图波形信号,可用来调整心电图仪和心电监视器的增益,走纸速度以及检查导联线,病人电极的性能。     

24小时动态心电图检查在起搏器植入心律失常诊断中应用价值分析

目的:分析24 h动态心电图检查在起搏器植入心律失常诊断中的应用价值。方法:选择2013年2月～2016年1月于医院接受起搏器植入术治疗的60例患者作为研究对象,均采用常规12导联及24 h动态心电图进行检查,比较两种不同检查方法对心律失常的诊断价值。结果:①24 h动态心电图对心室过感知、心房感知不良、心室感知不良检出率均高于12导联心电图(P0.05)。②24 h动态心电图心律失常总检出率明显高于12导联心电图(P0.05)。③24 h动态心电图HRV时域指标24 h内所有正常R-R间期标准差(SDNN)、24 h内相邻正常R-R间期之差均方根值(RMSDD)、全程每5 min时间段R-R间期均值标准差(SDANN)均高于12导联心电图(P0.05)。结论:24 h动态心电图对起搏器植入术后起搏功能异常、感知功能异常及心律失常检出率高,且对心率变异性诊断相对敏感,对起搏器植入心律失常诊断的临床应用价值较12导联心电图更高。     

电刺激大鼠蓝斑核区对实验性急性心肌缺血性损伤的影响

本实验在大鼠尾静脉注射垂体后叶素造成急性心肌缺血性损伤,以心电图肢体导联 S-T_Ⅱ段和 T_Ⅱ以及心率为指标,观察了电刺激蓝斑核区对大鼠急性心肌缺血性损伤的影响。实验结果表明蓝斑核区电刺激组的缺血性心电图恢复时间与对照组相比显著提前,前者为18.8±8.31分,后者为67±12.74分(P<0.01)。脑非蓝斑核区电刺激组的缺血性心电图恢复时间为69.2±6.8分。蓝斑核埋藏电极组的恢复时间为44.5±9.97分,与蓝斑核区电刺激组相比,其差异均非常显著(P<0.01)。这些结果说明蓝斑核区的刺激对大鼠急性心肌缺血性模型的恢复有促进作用。     

心电图简介

介绍了有关心电图的基本知识,其中包括心肌细胞静息电位及动作电位的产生原理;描记心电图的导联,包括双极肢体导联、加压单极肢体导联及胸前导联;正常心电图的５个基本波形及其所代表的意义;心电图的临床应用,包括心律失常、心肌肥大、冠心病与心肌梗塞的诊断等。     

女性患者十二导联远程动态心电图与门诊动态心电图对比分析

为探讨十二导联远程动态心电图对基层女性心血管疾病诊断的临床价值,本研究通过观察不同年龄段(青年组,围绝经期组,绝经组)的基层女性患者的远程动态心电图检测指标,与同期我院门诊女性患者相关指标进行比较。研究发现,围绝经期组、绝经组,远程女性患者和门诊女性患者的多项动态心电图指标检出率差异无统计学意义(p0.05),并且异常动态心电图检出率高,表明十二导联远程动态心电图有助于提高基层女性心血管疾病的检出率,进而提高了基层地区女性心血管健康的关注度。另外,三甲医院门诊的青年女性患者动态心电图异常检出率高,青年女性心血管疾病的发病率呈逐年增加的趋势。     

不同导联对动态心电图结果分析的诊断效果评价

目的:使用不同导联方法分析动态心电图(Ambulatory Eletrocrrdiograhy;AECG),评价导联方法在心肌缺血与心律失常检测上的诊断效果.方法:采用随机,平行对照分组的方法对三甲医院门诊及住院患者要求检测动态心电图进行分组:12导联组,3导联组;比较两组动态心电图表现.结果:(1)12导联发生缺血性ST-T下降的病例比例高于3导联(P<0.05),缺血部位明确.(2)12导联和3导联在不同心律失常的心电图表现诊断方面无统计学差异;(3)12导联对室性期前收缩定位存在可行性.结论:12导联(AECG)相对3导联更能及时检出缺血性ST-T改变,并准确定位;对室上性与室性心律失常判定准确;对室性期前收缩的起源定位存在可行性,对提高心电图临床诊断提供了较准确的科学依据.     

远东刺猬正常心电图的描记

本文采用标准双极导联(Ⅰ、Ⅱ、Ⅲ)和加压单极肢导联(aVR、aVL、aVF)对12只成体远东刺猬Erinaceus amurensis进行心电图测定。结果表明,远东刺猬的平均心率为294±46次/min,均为窦性心律。各导联的波形均较规则而稳定,所有导联都有QRS波群和T波,P波只在导联Ⅰ、Ⅱ、aVF中较明显,R′波明显存在于导联Ⅲ中。     

SYD4228型多媒体生理学学生实验系统的研制

本文介绍了ＳＹＤ４２２８型多媒体生理学学生实验系统的研制目的和特色。     

Electrocardiogram Data Compression Techniques for Cardiac Healthcare Systems: A Methodological Review

Objective: Globally, cardiovascular diseases (CVDs) are one of the most leading causes of death. In medical screening and diagnostic procedures of CVDs, electrocardiogram (ECG) signals are widely used. Early detection of CVDs requires acquisition of longer ECG signals. It has triggered the development of personal healthcare systems which can be used by cardio-patients to manage the disease. These healthcare systems continuously record, store, and transmit the ECG data via wired/wireless communication channels. There are many issues with these systems such as data storage limitation, bandwidth limitation and limited battery life. Involvement of ECG data compression techniques can resolve all these issues.Method: In the past, numerous ECG data compression techniques have been proposed. This paper presents a methodological review of different ECG data compression techniques based on their experimental performance on ECG records of the Massachusetts Institute of Technology-Beth Israel Hospital (MIT-BIH) arrhythmia database.Results: It is observed that experimental performance of different compression techniques depends on several parameters. The existing compression techniques are validated using different distortion measures.Conclusion: This study elaborates advantages and disadvantages of different ECG data compression techniques. It also includes different validation methods of ECG compression techniques. Although compression techniques have been developed very widely but the validation of compression methods is still a prospective research area to accomplish an efficient and reliable performance.     

Polygraphic belt with force-sensing expander for physiological tests on cosmonauts.

To study cardiorespiratory and neuromotor functions in cosmonauts a novel belt with embedded polygraphic sensors and a force sensing expander were developed. The sensors are: a three-electrode ECG/impedance plethysmographic system to capture cardiac and respiratory activity, two triaxial accelerometers to record limb micromotions and an IR reflex-sensor to detect peripheral pulse waves. The expander consists of an elastic cable in series with a load cell to measure the extension force and to adjust the extensions by visual feedback. The cable stiffness was chosen rather high (150-200 N/m) in order to induce involuntary limb oscillations at higher extension levels. The equipment was tested in MIR spaceflights and is projected for physiological tests on the ISS.     

Computational Intelligence and Wavelet Transform Based Metamodel for Efficient Generation of Not-Yet Simulated Waveforms

The design and verification of complex electronic systems, especially the analog and mixed-signal ones, prove to be extremely time consuming tasks, if only circuit-level simulations are involved. A significant amount of time can be saved if a cost effective solution is used for the extensive analysis of the system, under all conceivable conditions. This paper proposes a data-driven method to build fast to evaluate, but also accurate metamodels capable of generating not-yet simulated waveforms as a function of different combinations of the parameters of the system. The necessary data are obtained by early-stage simulation of an electronic control system from the automotive industry. The metamodel development is based on three key elements: a wavelet transform for waveform characterization, a genetic algorithm optimization to detect the optimal wavelet transform and to identify the most relevant decomposition coefficients, and an artificial neuronal network to derive the relevant coefficients of the wavelet transform for any new parameters combination. The resulted metamodels for three different waveform families are fully reliable. They satisfy the required key points: high accuracy (a maximum mean squared error of 7.1x10^-5 for the unity-based normalized waveforms), efficiency (fully affordable computational effort for metamodel build-up: maximum 18 minutes on a general purpose computer), and simplicity (less than 1 second for running the metamodel, the user only provides the parameters combination). The metamodels can be used for very efficient generation of new waveforms, for any possible combination of dependent parameters, offering the possibility to explore the entire design space. A wide range of possibilities becomes achievable for the user, such as: all design corners can be analyzed, possible worst-case situations can be investigated, extreme values of waveforms can be discovered, sensitivity analyses can be performed (the influence of each parameter on the output waveform).     

Clinical trials of a dual-sensor diagnostic pacemaker

The results of clinical trials of a dual-sensor diagnostic pacemaker are described. The system monitors and records intraventricular electrical and pressure waveforms using a special lead incorporating bipolar electrodes together with a piezoelectric pressure transducer. The recorded waveforms, which are shown in conjunction with Holter recordings made simultaneously, demonstrate the value of pressure measurements and illustrate several cardiac events, including an ECG pause, bradycardia, a pressure pause, ectopic beats and tachycardia. The pacing function of the device is shown and capture is demonstrated.     

Influence of anoxic selectors on heavy metal removal by activated sludge

The goal of this research is to compare the metal binding characteristics of an anoxic selector activated sludge system and a conventional activated sludge system. Metal biosorption by biomass harvested from experimental systems was determined by a series of batch experiments. Heavy metals studied in this research were zinc, cadmium, and nickel. The sorption isotherm showed that the selector sludge had significantly higher sorption capacity than did the control sludge. Metal biosorption behavior closely followed a Freundlich isotherm model for equilibrium concentrations. ECP contents of biomass estimated by alkali extraction technique showed that ECP levels in the selector sludge significantly higher than that in the sludge harvested from the conventional system, indicating that the higher metal sorption capacity of selector sludge may be due to the selection of the ECP-producing bacteria (i.e., Zoogloca sp.) by the selector system.     

The Eco-efficiency of Lead in China's Lead-Acid Battery System

Improving eco-efficiency can contribute to sustainable development. This article defines the societal services and environmental impacts of the lead-acid battery (LAB) system and offers definitions of eco-efficiency, resource efficiency, and environmental efficiency in the context of LAB systems. Based on the actual lead-flow in the LAB system, we develop a model that considers changes in production, the time interval between production and disposal, direct linkages between the final product and the societal service it provides, and the fiscal year as the statistical period. From this model, equations for eco-efficiency are derived and changes in eco-efficiency are predicted.
The results show, not surprisingly, that increased lead recycling and reduced lead emissions will both improve ecoefficiency. The resource and environmental efficiencies for LAB in China are 119 and 131 kilowatt-hour-years per metric tonne (kWh. yr/t), respectively, versus a value for both of 15, 800 kWh. yr/t in Sweden. The difference results from a lower lead recycling rate (only 0.312 tonne/tonne, which means that nearly 70% of the old lead scrap is not recycled based on official statistics) and higher lead emissions (0.324 tonne/tonne, which means that nearly 33% of the lead inputs used in the LAB system were lost into the environment) in China. Further analysis shows that these problems result from inefficient management of lead scrap, poor quality lead ore, and an abundance of small-scale lead-related plants. Ways to improve eco-efficiency are proposed.