128道心外膜电位标测系统的前置放大模块的设计

心电标测是心脏电生理机理研究的主要方法,也是临床精密诊断和对心律失常病灶进行精确定位的重要手段,特别适用于房颤等复杂心律失常电生理机制的研究.该文主要介绍了心外膜电位标测系统中的前置放大模块的设计,并根据实际需要,增加了右腿驱动电路.通过人体与动物实验检测,应用右腿驱动电路后均能得到清楚的心电波形.     

Tutorial. Surface EMG detection,conditioning and pre-processing: Best practices

This tutorial is aimed primarily to non-engineers, using or planning to use surface electromyography (sEMG) as an assessment tool for muscle evaluation in the prevention, monitoring, assessment and rehabilitation fields. The main purpose is to explain basic concepts related to: (a) signal detection (electrodes, electrode–skin interface, noise, ECG and power line interference), (b) basic signal properties, such as amplitude and bandwidth, (c) parameters of the front-end amplifier (input impedance, noise, CMRR, bandwidth, etc.), (d) techniques for interference and artifact reduction, (e) signal filtering, (f) sampling and (g) A/D conversion, These concepts are addressed and discussed, with examples.The second purpose is to outline best practices and provide general guidelines for proper signal detection, conditioning and A/D conversion, aimed to clinical operators and biomedical engineers. Issues related to the sEMG origin and to electrode size, interelectrode distance and location, have been discussed in a previous tutorial. Issues related to signal processing for information extraction will be discussed in a subsequent tutorial.     

Insect electroantennogram responses to semiochemicals recorded with an inexpensive personal computer

ABSTRACT. . A circuit and accompanying program that allow an inexpensive personal computer to replace an expensive storage oscilloscope in displaying electroantennogram (EAG) recording is described. The maximum amplitude of the EAG is calculated automatically by the computer and appears as an alphanumeric display on the monitor screen. Because the entire EAG trace is stored by the computer, parameters of the EAG trace other than the maximum amplitude are also available for analysis, such as voltages at specified times after antennal stimulation.     

YQ—W系列发酵罐溶解氧测定仪的研制

复膜式氧传感器是1956年Clark发明的,可耐高温灭菌的溶氧传感器是70年代才发展起来的,国外已有定型产品,其中以瑞士的Ingold、美国的900型以及日本的DY一2镕氧传感器最为优良。国内也于70年代开始了溶氧传感器的研制工作,80年代达到国际水平。1985年,我们研制成功了YQ－W－I型复合式溶氧传感器及其检测放大器,1987年获得了国家医药管理总局科技进步二等奖。1990年完成了国家“七五”重点科技项目75－7l－08－10《YQ－W－Ⅱ型溶氧传感器及其检测放大器》的研制工作。同年12月6日在轻工部的主持下,通过了技术鉴定,并于12月22日在北京通过了国家级验收。鉴定结论指出：YQ－W－Ⅱ型溶氧传感器属于结构型传感器,结构新颖,采用水冷与压力补偿技术,工作可靠,不易染菌,使用方便．易于维护,主要性能已达到国际上同类产品水平;YQ－w－Ⅱ型溶氧传感器耐高温,稳定性好,工作寿命长,其指标超过了国际上同类产品水平。其配套的检测放大器达到一级精度．工作稳定可靠,线性和恒流特性良好,可与Ⅱ型、Ⅲ型仪表及微机配套使用,构成溶氧的自动记录、自动调节或实时控制系统。1992年．我们又研制成功了YQ－W－Ⅱ型开孔式溶氧传感器、补偿式溶氧传感器和新型溶氧传感器以及与其配套的检测放大器。以上几种产品,获得了天津市技术监督局颁发的生产许可证书,已经投入了生产。本文分别介绍发酵罐溶解氧测定仪包括的溶氧传感器及检测放大器两部分的结构特点。     

New selective amplifier genes containing c-Mpl for hematopoietic cell expansion

We previously developed "selective amplifier genes (SAGs)" which confer a growth advantage to transduced cells. The SAG is a chimeric gene encoding the G-CSF receptor (GCR) and the estrogen or tamoxifen (Tm) receptor and is able to expand transduced hematopoietic cells by treatment with estrogen or Tm. In the current study, we examined the in vitro efficacy of modified SAGs containing the thrombopoietin (TPO) receptor (c-Mpl) gene instead of GCR as a more potent signal generator. In addition, we constructed various mutant Mpl-type SAGs to abolish the responsiveness to endogenous TPO while retaining Tm-dependency. When Ba/F3 cells were retrovirally transduced with the Mpl-type SAGs, the cells showed Tm- and TPO-dependent growth even without IL-3. The Mpl-type SAGs induced more potent proliferation of Ba/F3 and cynomolgus CD34(+) cells than the GCR-type SAG. One mutant Mpl-type SAG (Delta GCRMplTmR) successfully lost the responsiveness to TPO without affecting the Tm-dependence.     

高性能生物电放大器的研制

本室研制了以ＡＤ５２４芯片作前级放大器和有源高通－低通滤波器为主要部件的高性能生物电放大器。其共模抑制比为１１０ｄＢ,输入阻抗１０９Ω,内部噪声低于２．０μｖｐ－ｐ。其滤波器特性为：低通滤波器在其通带截止频率的３倍频处,衰减２０ｄＢ;高通滤波器在其通带截止频率的１／３倍频处,衰减３ｏｄＢ,在１／２倍频处衰减１５６Ｂ以上。该放大器与常用的两种生物电放大器ＡＢ－６２０Ｇ和ＡＶＢ－１０相比较,性能有大幅度提高。对家兔减压神经放电的对照记录说明,本放大器的结果优于其余两种放大器。     

Stable heterometallic fluorinated β-diketonato/alkoxo complexes as precursors for Er-doped luminescence materials

New series of novel heterometallic fluorinated β-diketonato/alkoxo complexes have been synthesized in quantitative yields and characterized by analytical data, FT-IR, NMR and mass spectroscopy. Their thermal behavior was investigated by TGA. The plausible structure of β-diketonato/alkoxo complexes was suggested from the physico-chemical analysis. These complexes have been studied as potential precursors for planar optical amplifiers through the investigation of optical properties and a homogenous thin film spin coating. The volatility of these complexes was reduced by intramolecular hydrogen bonding. The assembling of fluorinated β-diketonato/alkoxo ligands ensures high coordination numbers for coordinated metals and improves their stability in ambient atmosphere.     

Enhancer variants on chromosome 2p14 regulating SPRED2 and ACTR2 act as a signal amplifier to protect against rheumatoid arthritis

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Heterodyne detected nonlinear optical imaging in a lock‐in free manner

We report a compact, cost‐effective tuned amplifier for frequency‐selective amplification of the modulated signal in heterodyne detected nonlinear optical microscopy. Our method improved the signal to noise ratio by an order of magnitude compared to conventional lock‐in detection, as demonstrated through stimulated Raman scattering imaging of live cells and tissues at the speed of 2 μsec/pixel. Application of the tuned amplifier to transient absorption microscopy is also demonstrated. The increased signal to noise ratio allowed epi‐detected in vivo imaging of myelin and blood in rat spinal cord with high spatial resolution. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

An inexpensive and reliable electroantennometer with automatic base line offset and drift canceller

ABSTRACT. An inexpensive and reliable electronic device is described which allows measurement, viewing and recording of electroantennogram (EAG) responses. Potential advantages of the device include low cost, simple operation, suitability for bench or field use, built-in digital readout, separate head amplifier, (+) and (-) peak value memories, and an exclusive automatic offset and drift cancelling circuit which does not introduce distortion. The device is intended for use in EAG recording, where signals with either rapid or slow depolarizations are being measured, bringing important information in the return-to-baseline region, as well as the (+) and (-) peak values of the EAG.