Biological microsystem for measuring uric acid in biological fluids

This paper describes a biological microsystem (bio-system) for measuring uric acid concentration in serum, plasma or urine. Its operation is based on optical absorption in a well-defined part of the visible spectrum. The bio-system is composed by two dies: one is fabricated in polystyrene and contains the microchannels and the other is fabricated in a CMOS standard process and contains the photodetector and readout electronics. The uric acid concentration is measured by using a mixture of 14 μl of infinity™ uric acid reagent with 0.25 μl of sample. The achieved sensitivity is 0.33 mg/dl (±0.6% of the value in urine of a healthy person), with a 1 mm lightpath. Using an optical absorption method, a maximum peak at wavelength λ=494 nm, is detected. This bio-system can be included in the group of low-cost disposable devices for biological fluids analysis.     

手机支付双界面卡的接触式与非接触式接口标准的研究

针对双界面卡实现手机支付涉及接触式和非接触式两种相异的通信方式,目前尚没有形成关于双界面卡开发的统一标准的问题,通过对SIMpass方案的介绍,以及对双界面卡中用到的ISO/IEC7816和ISO/IEC14443标准的详细分析,得到在双界面卡的设计过程中应依据的标准和规范.指出当前双界面卡发展存在的问题,为下一步双界面卡的设计实现做好了理论准备.     

A dielectrophoretic barrier-based microsystem for separation of microparticles

This paper presents a microfluidic system for separation of microparticles based on the use of dielectrophoretic barriers, which are constructed by aligning two layers of microelectrode structure face-to-face on the top and bottom sides of the microchannel. The energized barriers tend to prevent the particles in the flow from passing through. However, particles may penetrate the barriers if a sufficiently high flow rate is used. The flow velocity at which the particles begin to penetrate the barrier is defined as threshold velocity. Different particles are of different threshold velocities so that they can be separated. In this paper, the electrodes are configured with open ends and aligned with a certain angle to the direction of the flow. Polystyrene microbeads of different sizes (i.e., 9.6 and 16 μm in diameter) are studied in the tests. Under the experimental conditions, two particle trajectories are observed: the 9.6 μm beads penetrate the barriers and move straightly toward the fluidic outlet, while the 16 μm beads snake their way along the electrode edges at a relatively low speed. The two subpopulations of particles are separated into spatial distance of ∼10 mm within tens of seconds. The system presents a rapid and dynamic separation process within a continuous flow.     

A straightforward determination of fluid viscosity and density using microcantilevers: From experimental data to analytical expressions

Vibrating microcantilevers are used to measure the density and the viscosity of surrounding fluids. The classical procedure involves experimental acquisition of the deflection spectrum of the beam, but a systematic calibration step is mandatory for obtaining viscosity and density. In the present study, a method is proposed to facilitate these measurements for Newtonian fluids with only one calibration step in air during the cantilever lifetime. Our approach relies on a complete theoretical analysis allowing to approximate semi-analytically the deflection spectrum with a second-order transfer function and to determine an analytical relationship between viscosity, density and the parameters of the transfer function. Fluid parameter determination results are shown for validation and discussed.     

Review of methods for determination of total protein and peptide concentration in biological samples

Clinical proteomics can be defined as the use of proteomic technologies to identify and measure biomarkers in fluids and tissues. The current work is intended to review various methods used for the determination of the total concentration of protein or peptide in fluids and tissues and the application of such methods to clinical proteomics. Specifically, this article considers the approaches to the measurement of total protein concentration, not the measurement of the concentration of a specific protein or group of proteins in a larger mixture of proteins. The necessity of understanding various concepts such as fit-for-use, quality-by-design, and other regulatory elements is discussed, as is the significance of using suitable standards for the protein quality of various samples.     

Optimal design and performance analysis of solar power microsystem for mini-grid application

Microsystem Technologies - Universally, solar power microsystem for mini-grid is acceptable as a new approach to solve the global energy problem. Improving population lifestyle as well as the...     

非接触式电站高温预警系统设计

配电站中的故障电气设备的工作温度会处于高于其正常工作温度的状态,易造成火灾。设计了一种非接触式的实时高温预警系统。系统利用长波红外相机对被测试目标进行非接触式灰度成像,基于LabVIEW上位机实时采集图像并对图像数据进行处理,从而得到所拍摄电气设备实时工作温度。若此温度值高于电气设备安全工作的最高温度值,下位机报警,工作人员可根据系统所成图像确定故障位置,进而提前排除安全隐患。测试结果表明：系统运行稳定、操作简便。系统能够有效地对电站中的电气设备运行状态进行实时监测和精确预警,极大程度地降低了工作人员的安全风险,提高了工作效率。     

Manufacturing and packaging of sensors for their integration in avertical MCM microsystem for biomedical applications

Demonstrates the feasibility of integrating fragile micromachined chips into a complex three-dimensional (3-D) multichip module (MCM) microsystem for a biomedical application. The system is based on the vertical integration of the different parts: micropumps and valves, a multisensor chip for on-line control of the system and a signal-processing chip. In this paper, packaging of the microsystem is studied in order to minimize the induced stress that can affect the integrity of the different micromachined parts of the system. Standard commercially available components and materials were used so as to minimize costs for the case of high volume packaging. For testing the approach, a multisensor chip which includes thin silicon membrane-based devices has been used as the main test structure to compare different packaging materials. In addition, for the fabrication of such a sensor chip in an efficient mode, technological modules needed to fabricate sensors on complementary metal-oxide-semiconductor (CMOS) wafers are discussed. The definition of standardized "add-on" sensor modules to the CMOS process of a foundry is intended to limit the development cost of smart sensors     

Towards a GC-based microsystem for benzene and 1,3 butadiene detection: Pre-concentrator characterization

The performance of a gas pre-concentrator/gas chromatographic column/gas sensor system was studied step by step towards benzene vapor in presence of 1,3 butadiene vapor. The pre-concentrator, based on an activated carbon of high adsorption capacity, was first characterized using a GC/FID system. By this way, the adsorption capacity of each pollutant was evaluated, first separately, then mixed with different proportions in air. It was shown that the affinity of the pre-concentrator for benzene was higher than for butadiene. Once the optimal pre-concentration parameters were adjusted, we replaced the FID detector by a metal oxide gas sensor. The use of such gas pre-concentrator allowed decreasing the detection limit of the system towards benzene in presence of butadiene by at least ten times.     

A non-contact method of capturing low-resolution text for OCR

Document recognition is a lively research area with much effort concentrated on optical character recognition. Less attention is paid to locating and extracting text from the general (non-desktop, non-scanner) environment. Such contact-free extraction of text from a general scene has applications in the context of wearable computing, robotic vision, point and click document capture, or as an aid for visually handicapped people. Here, a novel automatic text reading system is introduced using an active camera focused on text regions already located in the scene (using our recent work). Initially, a located region of text is analysed to determine the optimal zoom that would foveate onto it. Then a number of images are captured over the text region to construct a high-resolution mosaic composite of the whole region. This magnified image of the text is suitable for reading by humans or for recognition by OCR, or even for text-to speech synthesis. Although we employed a low resolution camera, we still obtained very good results. ID="A1"Correspondance and offprint requests to: Dr M. Mirmehdi, Department of Computer Science, University of Bristol, Bristol BS8 1UB, UK. Email: majid@cs.bris.ac.uk     

Controlling microdrop shape and position for biotechnology using micropatterned rings

Photolithographic micropatterning is used to achieve topographic rather than chemical control of the static shape and position of microdrops on solid substrates in a gaseous ambient. Micrometer cross-section, millimeter-diameter circular rings with steep sidewalls strongly and robustly pin contact lines of nanoliter to 100 μl liquid drops, increasing the maximum stable drop volume and eliminating contact line motion due to transient accelerations. Physical and chemical processes involving two-phase transport within these drops are more reproducible, and automated image analysis of the evolving drop contents is greatly simplified. This technique has particular promise for high-throughput protein solution screening in structural genomics and drug discovery. This work was funded by the National Institutes of Health (R01 GM65981).     

A wireless microsystem for the remote sensing of pressure, temperature, and relative humidity

This work presents a microsystem that utilizes inductive power and data transfer through a backscatter-modulated carrier and a transducer interface that monitors its environment through embedded capacitive transducers. Formed on a single chip, transducers for temperature, pressure, and relative humidity are realized using a silicon-on-glass process that combines anodic bonding and a silicon-gold eutectic to realize vacuum-sealed cavities with low-impedance (6 /spl Omega/) electrical feedthroughs. Temperature is sensed capacitively using a row of Si/Au bimorph beams that produce a sensitivity of 15 fF//spl deg/C from 20 to 100/spl deg/C. The absolute pressure sensors have a sensitivity of 15 fF/torr and a range from 500 to 1200 torr, while the relative humidity sensor responds with 39 fF/%RH from 20 to 95%RH. A relaxation oscillator implements low-power capacitance-to-frequency conversion on a second chip with a sensitivity of 750 Hz/pF at 10 kHz, forming a 341 /spl mu/W transducer interface. The system is remotely powered by a 3-MHz carrier and has a volume of 32 mm/sup 3/, including the hybrid antenna wound around the perimeter of the system.     

高压气瓶非接触压力测量系统设计

常规状态下气瓶压力测量,在气瓶出口管路上开口进行引压测量,对于高压气瓶在长期贮存的情况下,开口引压存在开口部位压力泄漏的隐患。为克服气瓶开口引压泄漏问题,对气瓶非接触压力测量系统进行分析研究,基于气瓶壁在压力下产生形变的情况,通过对气瓶壁进行应变测量关键技术,建立气瓶壁的应变量与内部压力之间的关系计算模型,经多次实验验证,积累不同温度及压力下的相关数据参数,通过数据模型拟合具有温度补偿的压力计算公式,通过编程写进便携式测试仪,实现对高压气瓶在不接触介质的情况下非接触压力测量的目的,并满足了气瓶在高压下进行长期贮存时随机测量的应用需求。     

Development of a vision non-contact sensing system for telerobotic applications

The study presented here describes a novel vision-based motion detection system for telerobotic operations such as distant surgical procedures. The system uses a CCD camera and image processing to detect the motion of a master robot or operator. Colour tags are placed on the arm and head of a human operator to detect the up/down, right/left motion of the head as well as the right/left motion of the arm. The motion of the colour tags are used to actuate a slave robot or a remote system. The determination of the colour tags’ motion is achieved through image processing using eigenvectors and colour system morphology and the relative head, shoulder and wrist rotation angles through inverse dynamics and coordinate transformation. A program is used to transform this motion data into motor control commands and transmit them to a slave robot or remote system through wireless internet. The system performed well even in complex environments with errors that did not exceed 2?pixels with a response time of about 0.1?s. The results of the experiments are available at: http://www.youtube.com/watch?v=yFxLaVWE3f8 and http://www.youtube.com/watch?v=_nvRcOzlWHw     

非接触式温度测量系统中固体摄像器件的选择

非接触式温度测量由于不受被测对象的条件限制,具有十分优越的特点。如何选择能符合温度测量要求的固体摄像器件是值得重视的问题。基于辐射理论和CCD器件成像原理,指出了辐射式测温系统中的固体摄像器件必须具备的性能和选择CCD摄像器件时应考虑的主要问题。     

基于颜色识别的肠道出血诊疗微系统设计

提出了一种可自动识别肠道出血区域并具有药物释放功能的微系统方案,设计了基于颜色传感器的出血检测模块和可用于粘附肠道血液的特殊吸附性薄片.引入HSL(色相Hue、饱和度Saturation、亮度Light)颜色空间法,根据出血与非出血区域色相H值的差异来实现肠道出血的智能识别,针对微量出血和较大量出血2种情况提出了不同的...     

非接触光电式速度传感器的研究与应用

讨论了光电式速度传感器光学系统对路面模型的处理，硅光电池转换光电信号的原理以及对实际路面的分析，阐述了光电式速度传感器获取光电信号，跟踪滤波输出的随机窄带基波信号，波形预处理及应用。     

Statistical methods for detecting latent periodicity patterns in biological sequences: The case of small-size samples

An original spectral-statistical approach for detecting latent periodicity in biological sequences is proposed. This approach can be applied under conditions of limited statistical sample. It allows one to avoid redundancy and instability when identifying the latent periodicity structure. The optimality of the periodicity-pattern-size estimates obtained for approximate tandem repeats on the basis of the spectral-statistical approach is demonstrated in practical examples. Maria Borisovna Chaley was born in 1963 and graduated from the Moscow Institute of Physics and Technology in 1988 (M.Sc.). She received her PhD in biophysics in 1993 and became a docent in bioinformatics in 2003. At the present time, she is a senior research fellow at the Institute of Mathematical Biology Problems of the Russian Academy of Sciences. Her research interests include bioinformatics, genetic text analysis, and molecular evolution. She is the author of over 40 research publications, including 14 journal articles. Nafisa Nailovna Nazipova was born in 1960 and graduated from the Department of Computational Mathematics and Cybernetics of Lenin Kazan State University in 1982 (MSc.). She received her PhD in physics and mathematics (mathematic modeling, numerical methods, and program complexes) in 2002. At the present time, she is the head of the bioinformatics laboratory at the Institute of Mathematical Biology Problems of the Russian Academy of Sciences. Her research interests include bioinformatics and the structural and functional organization of genetic sequences. She is the author of over 35 research publications, including 9 papers in refereed journals and 2 book chapters. Vladimir Andreyevich Kutyrkin was born in 1952 and graduated from the Department of Mechanics and Mathematics of Lomonosov Moscow State University in 1974 (MSc.). He received his PhD in physics and mathematics in 1995. At the present time, he is a docent of Bauman Moscow State Technical University. His research interests include applied mathematical statistics, computational and discrete mathematics, and bioinformatics. He is the author of over 20 research publications, including 11 journal papers.     

Modified glassy carbon electrode with multiwall carbon nanotubes as a voltammetric sensor for determination of noscapine in biological and pharmaceutical samples

A simple and highly sensitive method is described for direct voltammetric determination of noscapine in blood and pharmaceutical sample. Glassy carbon electrode with effective method is modified with multiwall carbon nanotubes (MWNTs) to cause activation of multiwall carbon nanotubes structures for electrocatalyzes of noscapine oxidation. The cyclic voltammetric (CV) results indicated that MWNTs remarkably enhances electrocatalytic activity toward the oxidation of noscapine, which is leading to considerable improvement of anodic peak current for noscapine, and allows the development of a highly sensitive voltammetric sensor for detection of noscapine in pharmaceutical and clinical samples. Under the optimum condition, the calibration curve was linear in the concentration range 4.0 × 10⁻⁷–1.0 × 10⁻⁴ mol L⁻¹ with the detection limit of 8.0 × 10⁻⁸ mol L⁻¹ and relative standard deviation (R.S.D.%) lower than 1.0% (n = 5). Finally, some kinetic parameters were determined and multistep mechanism for oxidation of noscapine for first time was proposed.