Miniature Force Transducer for Myocardial Stimulation and Local Tension Measurements

The commercially available transducers for direct measurement of myocardial tension are either large in size or lack the ability of isometric measurement. Moreover, none of them enables measurement of local isometric tension just around the site of electrical stimulation of the heart. A miniature strain gauge transducer was developed in our laboratories and is herewith described. It weighs 150 mg, and consists of two arms with adjustable distance between 1-5 mm. It is applied to the heart by 2 needles which may serve also as stimulating or sensing electrodes. A full bridge made of constantan foil strain gauges ensures low drift. The device enables in vivo measurement of isometric tension of a myocardial segment of the site where the tension is being measured and permits simultaneous recording of the electrogram. Attachment of the gauge to the ventricular wall by means of needles makes simple the transfer of the transducer from one measuring point to another. The performance of the miniature force transducer was compared to that of a standard Walton-Brodie strain gauge arch demonstrating marked similarity of response at low heart rates. At high frequencies however differences in mechanical response of the heart were obtained by the two force transducers.     

Pattern Recognition of Canine Duodenal Contractile Activity

An application of statistical pattern recognition technique to the classification of canine duodenal contractile activity resulting from the ingestion of three different test meals, viz. water, acid, and solid, is described. Feature vectors were extracted from the contractile activities recorded by means of strain gauges, and were based on average duration, number, and intensities of contractions, as well as their frequency and propagational characteristics. Pattern training and classification were performed via the Bayes decision rule. The resuits indicate that the three different meals give rise to three different kinds of contractile activities. An improvement in the classifier's performance was observed when it was updated with correctly classified patterns. The results appear to suggest that pattern analysis techniques add a new dimension to the study of gastrointestinal motility in health and disease. For example, pattern recognition techniques can also be extended to identify contractile patterns altered due to such pathological conditions as irritable bowel syndrome and postoperative diarrhea and, hence, elucidate the underlying relationship between contractile activity and distal propulsion of contents.     

基于迈克尔逊干涉测力传感器装置的设计

基于迈克尔逊干涉原理和弹簧有机结合,自行设计出一种新型的测力传感器装置。采用线阵CCD作为光电传感器件捕捉干涉圆环的光强信号,并通过MSP430单片机对电信号进行处理,再利用设计出的迈克尔逊干涉圆环计数软件自动计算出干涉圆环数目,即可自动精确计算出弹簧的形变量,从而实现对所受的外力进行测量。编写相应的程序将力的大小由低功耗OCM126864-9液晶屏显示。分析表明,该测力装置具有高测量精度和高智能化的特点。     

Measurement of Fetal Movements by Moving-Coil Transducer

A transducer for the detection of fetal movements is described. The transducer is based on a coil moving in a magnetic field. It produces a signal as a result of fetal movements which create changes on the matemal anterior abdomen. The transducer is not affected by slow movements, maternal respiration, and uterine contractions. The sensitivity of the transducer in comparison with other means of fetal movement assessment is discussed.     

军队医院建立应急医学信息服务保障系统的意义

采用电路设计与原理分析相结合的方法对坡莫合金压磁式测力传感器测试系统的交-直变换电路进行了研究.针对坡莫合金压磁式测力传感器的特点,设计了传感器测试系统及交-直变换电路,并对交-直变换电路中的电源、功放、精密整流滤波电路、电压调整器、仪用放大器、低通滤波器等关键组成部件进行了深入探讨.所设计的交-直变换方案保持了传统电桥高灵敏度的优点,测试实验验证了电路的合理性.     

应用原子力显微镜对单晶硅进行纳米级加工

以原子力显微镜（AFM）作为加工工具,基于金刚石针尖对单晶硅进行了纳米加工实验,对纳米加工区域特性,材料在不同垂荷荷下的去除机理及切屑形成特征,进行了系统的研究和分析,提出了一种在纳米尺度下研究加工机理的新方法,在此基础上,应用有限元方法（FEM）对AFM纳米加工中存在于金刚石针尖和被加工材料之间的作用机制进行了计算仿真。     

提高压电换能器导纳圆测量精度的方法研究

不同压电换能器的动态电阻、电容、电感和静态电阻、电容的值不同,这些参数均可从其对应的导纳圆中得到.分析了导纳圆测量中的两个重要影响因素:A/D转换器的量化误差、测量电阻.为提高导纳圆的测量精度,量化误差不变时不同的压电换能器需选择不同的测量电阻以保证所测量的两路正弦信号有适当的幅值比和相位差.测量电阻的值为压电换能器动态电阻值的0.15～3.5倍时,导纳圆半径的相对误差小于0.5％,测量电阻为动态电阻的0.7倍时导纳圆的相对误差最小.     

The Measurement of Fetal Movement Using a Strain-Gauge Transducer

Strain-gauge transducers are a simple and safe means of measuring fetal movement. The transducers do, however, respond to all abdominal movement and thus the measuring instrument must discriminate between maternal and fetal movements. The discrimination may be achieved by choosing an appropriate size for the transducer and also by using an adaptive filter. The success of the adaptive filter is illustrated on real data.     

用于流速测量的微型力传感器的研制

设计并仿真了一种压阻式六自由度力传感器及其测量电桥,采用微电子机械系统(MEMS)加工技术制备了以单晶硅为结构材料的六自由度力传感器,完成了传感器芯片的封帽式封装。压阻式六自由度力传感器的尺寸为5 mm×5 mm×3 mm,由传感器芯片、探测柱和封装外壳组成。基于流体的绕流阻力效应,完成了压阻式六自由度力传感器水流流速检测实验。实验证明,该传感器的量程为0～0.55 m/s,可以灵敏检测到低速水流的波动性变化,并且传感器在水流速度为0.45～0.55 m/s的测量范围内灵敏度较高。利用单晶硅材料易于小型化、滞后极小的特点,该六自由度力传感器响应快、环境适应性强、可批量制造。     

用光电流谱研究多孔硅微腔的光电特性

利用光电流谱对全硅基多孔硅微腔的吸收特性进行了研究 ,在光电流谱中观察到 λ1 =742 nm主峰 .同时也对多孔硅微腔的 PL 谱和单层多孔硅的光电流谱进行了测量 ,结合有效折射率方法和菲涅耳公式 ,对照 PL 谱和单层多孔硅的光电流谱 ,对常温下多孔硅微腔的光电流谱进行解释 .     

用光电流谱研究多孔硅微腔的光电特性

利用光电流谱对全硅基多孔硅微腔的吸收特性进行了研究,在光电流谱中观察到λ1=742nm主峰.同时也对多孔硅微腔的PL谱和单层多孔硅的光电流谱进行了测量,结合有效折射率方法和菲涅耳公式,对照PL谱和单层多孔硅的光电流谱,对常温下多孔硅微腔的光电流谱进行解释.     

PVDF传感器在液体压力激波测试中的应用

针对液体压力激波具有高温、高压和高应变的特点,研制了一种基于聚偏氟乙烯(PVDF)压电薄膜的液体压力激波传感器,并通过霍普金斯(Hopkinson)压杆对压电传感器的压电系数进行了精确标定,在此基础上构建了液体压力激波测试系统.在小压力幅值下,与水听器进行了对比测试试验,测试结果具有很高的吻合性,在满量程(0.1～1.0 MPa)内,与水听器偏差在5%范围内;大压力幅值下,通过对单元和多阵元液体压力激波发生器系统的测试,掌握了激励电压、脉冲频率、阵元个数等对激波的影响规律,为液体压力激波加工系统的改进和工程应用提供了试验依据.     

用于调焦调平测量系统中的硅片表面形貌模型

以硅片表面的平整度(flatness)和硅片表面的全场厚度范围(TTV)等参数为基础,建立了硅片表面的理论形貌模型。根据调焦调平测量系统指标等确定了调焦调平测量系统的有效频带,并设计了相应的滤波器。对硅片表面的理论形貌进行滤波后,得到用于调焦调平测量的硅片表面形貌的模型。由于该模型包括硅片表面在一个曝光视场内的模型和全场模型,并以SEMI标准和ITRS预测的相关参数为基础,因此不受实验条件影响,适用范围广,可用于调焦调平测量系统的模拟测试以及相关光刻工艺的分析。     

单色光光电导衰减法测试硅单晶少子寿命的表面复合修正公式

本文在数值分析和实验数据的基础上，提出了用单色光高频光电导衰减法测量硅单晶少子寿命的表面复合修正公式。     

硅抛光片表面质量测试技术综述

随着硅抛光片尺寸逐渐增大,硅抛光片表面质量测试逐步被人们所关注。表面金属离子含量以及表面颗粒度成为衡量硅抛光片表面质量的重要指标,对表面金属离子含量以及表面颗粒度的测试原理以及设备进展进行了介绍。     

压电薄膜新型测力传感器及其调理电路的研究

以聚偏氟乙烯(PVDF)压电薄膜作为信息采集端并根据实际需要进行结构优化,制成搏击比赛用测力传感器模块。通过对比电荷放大器、射极跟随器、电压跟随器的性质及实际工作特点,最终设计了基于AD744KR运放的电压跟随器作为调理电路。再根据各自工作原理进行等效分析、模拟仿真,并最终实现制成工程样机达到研究目的。     

超声换能器辐射电导测量不确定度分析

利用毫瓦级国家超声功率基准装置对作者研制的标准换能器进行标定.由于测量的结果直接影响超声功率量值传递的准确性,故换能器标定时的准确度要求很高.该文分析了标定过程中超声功率的测量不确定度以及标准换能器辐射电导的不确定度.     

Electrical Activity of Extended Defects in Multicrystalline Silicon

The excess carrier lifetime (τ) distribution in multicrystalline silicon grown by the Bridgman technique from high-purity metallurgical silicon (HPMG-Si) is studied. The features of the variation in τ, caused by the grain-boundary structure of ingots, are revealed. The grain boundaries, dislocations, and impurity microinclusions are studied by electron probe microanalysis (EPMA) and scanning electron microscopy (SEM) using selective acid etching. The electrical activity of extended defects is measured by the electronbeam- induced-current (EBIC) method.     

An OOK Body-Channel Transceiver Front-End ASIC for Distributed Force Measurement

The design and implementation of a fully integrated transceiver front-end for biomedical data is reported. The system targets the transmission of force data from a distributed sensor system for on-body application. A prototype force transducer patch is presented whose parasitic capacitance is exploited as coupling capacitance for body-channel transmission. The transceiver is implemented in 0.35 μm CMOS technology and occupies an area of 0.0178 mm². It consumes 360 μA of current at a supply voltage of 3 V. Measured results further confirm a transmission rate of 54 kb/s making the design suitable for use in a distributed pressure sensing network.     

纳米硅微结构的测量与控制

文章应用电化学方法获得了纳米硅微粒材料。通过TEM的分析测算,知其平均粒度在2－5nm之间。在暗室中,能见其萤光辐射。并在同一溶液中,采用不同电流密度和反应时间,制作了不同的硅微粒薄膜样品;利用基于分形理论和计算机图像处理技术的软件,对样品电镜照片的图像灰度值进行计算及数据处理,求得了相应样品的分形参数,找到了分形参数随微粒大小及密度而变化的规律。提出了获得均匀一致、粒径可控的纳米硅材料的新方法。