基于fNIRS与SiPM的脑血氧检测电路设计

脑血氧检测作为大脑功能检测之一,是认知神经科学和生物医学领域必不可少的研究工具。其研究方法之一——功能性近红外光谱技术,利用组织中血液的主要成分对近红外光的良好吸收性和散射性,而获得组织内氧合血红蛋白和脱氧血红蛋白的变化情况,从而实现对脑血氧的检测。硅光电倍增器件是近几年兴起的光电探测器件,具有尺寸小、增益高、工作电压低、对磁场不敏感等特点。为了检测脑血氧的变化,设计一个基于近红外光谱技术与硅光电倍增管的新型脑血氧检测电路,并通过前臂阻断实验验证了电路设计的性能满足需求。     

基于色素谱吸收原理的肝储备功能无创测量系统

肝病一直是我国高发疾病,肝储备功能是肝病诊治中重要的生理参数,医院传统方法采用采血比色法进行肝储备功能测量.利用吲哚氰绿ICG色素指示剂对805 nm波长光的吸光效应,患者注射ICG色素,分别采集0 min、5 min、10 min、15 min的血液样本,通过比色测量,绘制ICG浓度代谢曲线,测量肝储备功能.为了避免采血法对测量结果和病人的不良影响,提出基于色素谱吸收原理的无创肝储备功能测量系统的设计方案.实验证明,利用805 nm和940 nm敏感波长以及吲哚氰绿ICG色素吸光特性,能较好地实现无创肝储备功能测量.     

生物发酵参数相关性及菌体浓度软测量技术的研究

从生物细胞代谢角度,分析了发酵过程中生物代谢参数的相关性,找出了能够表示生物变量大小的代谢参数,然后将这些参数作为输入变量,建立了菌体细胞浓度软测量的神经网络模型。仿真结果表明,该软测量方法较一般的菌体浓度软测量方法具有更高的准确性和鲁棒性。     

基于光体积描述记成像技术的非接触低成本生理信息的检测

在最近几十年,人们对低成本、非接触和普适方法测量生理信息(心率、心率变异性、血氧饱和度等)产生了浓厚的兴趣。传统的临床测量生理信息的方法包括Ag/AgCl电极测量心率和心率变异性,二氧化碳分析仪测量呼吸率状态,脉搏血氧饱和度仪测量血氧饱和度。这些方法虽然可以获得完美的信号,但是他们价格昂贵、使用麻烦、不方便。基于光体积描述记成像技术检测生理信息提供了一个人体生理健康检测的新方法。血流速度、血流量和血压可间接地评估血容量,反过来,血容量间接反映了这些生理参数的变换。光在人体组织的反射或透射可以得到血容量的变化。使用电脑摄像头或手机摄像头扑捉的人体皮肤表面成像,通过对成像光信号的处理和分析,获得一些生理信息,如心率、呼吸率、心率变异性和血氧饱和度等。在本文中,我们回顾使用光体积描述记成像技术在非接触健康检测领域里的最新发展,论述面临的挑战和将来的发展方向。     

基于RBF神经网络的发酵过程菌体浓度的软测量

针对微生物发酵过程中菌体细胞浓度难以实时在线检测的问题,从生物细胞代谢角度分析了发酵过程中生物代谢参数的相关性,找出了能够表示生物变量大小的代谢参数,然后将这些参数作为输入变量,建立了菌体细胞浓度软测量的R B F神经网络模型,为复杂系统中生物量参数的检测提供了一条有效途径。仿真结果表明,该软测量方法具有较高的精度,能很好地应用于生物发酵过程。     

功能性近红外光谱系统及锁相放大器算法的研究

功能性近红外光谱技术是一种新兴的非侵入式光学技术,该技术可以测量脑皮层的功能性活动信息;介绍了单通道fNIRS系统的开发,为了验证系统的性能,2人参与了算数运算任务,获得了氧合血红蛋白和脱氧血红蛋白的浓度变化;锁相放大器在fNIRS系统中可以很好地提取淹没在噪声中微弱的光强信号,但是模拟锁相放大器价格昂贵,对多通道系统来说是很大的负担;设计了数字锁相放大器算法,通过与模拟锁相进行比较,结果表明设计的数字锁相放大器可以取代价格昂贵的模拟锁相放大器。     

基于微加工技术的集成细胞芯片的实验研究

细胞电生理检测芯片已成为后基因时代生物科学研究的重要工具,但是目前的细胞胞外电生理测试工具发展迅速,但存在功能单一化、指标不够稳定的缺点,如信噪比较低,难于重复与对照,且不能实现多参数同时检测,已成为细胞电生理快速分析发展的瓶颈。集成型细胞芯片通过传感器件的网络化和集成化,将细胞的电学信息、化学信息、动力学信息等生理活动信息转换为可检测的信号,并细化为微观信息量进行实时分析,实现快速微量的细胞功能信息和待测物质性质的检测,在细胞生物学、环境监测和药物开发等领域有广泛应用前景。本文设计了一种新型的集成了细胞微电极阵列、电阻抗传感器及光寻址电位传感器三个传感单元的阵列化芯片,首先分析了各单元用于细胞电生理测量的界面模型;在此基础上重点分析了各细胞传感器单元的特性曲线测试、表面处理测试,并初步进行细胞电生理参数的分析。结果显示,MEA加入测试液测试后,噪声水平在80μV左右,且器件适于细胞培养及动作电位测试;IDA器件上培养的肾细胞在药物作用下会引起细胞阻抗变化率12%～16%的变化;LAPS器件的酸化率灵敏度在50.65mV/pH,在肾细胞酸化率测试中,高浓度5-氟尿嘧啶会引起的细胞正常代谢率下降(相对酸化率下降50%)。说明药物浓度越大,作用时间越长,对细胞的活性影响越大,这与IDA器件的测试结果一致。最后得到了在器件特性、系统优化及细胞测试的一些初步结果,对芯片进行了芯片各单元的互补性分析,为细胞传感器的多功能化发展开拓了一个新的应用领域。     

生物医学光声成像技术及其临床应用进展

样品被短脉冲激光照射后会受激产生超声波,这种现象被称为光声效应。随着激光器技术及超声探测技术的进 步,基于此效应的光声成像技术已成为生物医学成像领域发展最快的技术之一。光声成像作为一种混合型的成像方式, 结合了光学成像的高对比度和光谱识别特性,以及超声成像大穿透深度下仍具备较高分辨率的特点。光声成像技术不仅 可对包括血红蛋白、脂肪在内的多种组织成分进行高特异性成像,还能灵敏的反映包括血氧含量、氧代谢率等生理特征 的变化,与超声技术的形态和结构成像具有很强的互补性,已在临床及生物医学研究领域体现出巨大的应用潜力。光声 成像技术的这些特性使其在恶性肿瘤、心血管疾病、微循环异常等疾病的成像诊断和治疗引导中具有重要的应用前景。 文章小结了本课题组在光声成像技术领域最近取得的一些新进展,包括利用解卷积技术进一步提高光声显微成像分辨 率;利用压缩感知技术降低数据采集量,提高光声层析成像的速度;利用自制的纳米探针,实现光声分子成像和光热治 疗。光声成像技术的这些进步使其在癌症、心脑血管疾病等方面的诊断和治疗更具有可行性,文章最后回顾了光声成像 技术在乳腺癌、前哨淋巴结及血管内成像等方面的临床应用和研究进展。     

光纤pH传感器在青霉素测定中的应用

为了实现生物培养过程的计算机在线控制,应尽快地研制出能检测关键代谢参数的传感器。在检测青霉素方面,已报导的方法有电极法和热敏法。前者灵敏度较低,后者热干扰大和设备费用较高不易推广。pH 光极流动注射分析法则具有灵敏度高、成本低等优点因而受到人们的注意。一、实验装置实验pH 光极流动注射分析法测定青霉素的实验装置如图1所示。青霉素酶固定于尼龙管内壁,当含有青霉素的缓冲溶液经过尼龙管时,便发生下列催化反应:     

调控一代谢网络的集成建模与分析方法研究

转录调控网络和代谢网络分别刻画了细胞新陈代谢过程的不同阶段,两个阶段相互作用,影响细胞的生命活动.调控-代谢网络的集成建模是生物网络建模的一个重要方向,通过集成调控-代谢网络可以对整个反应体系而不是单单对代谢网络进行考察,能够获得关于代谢和细胞功能的更全面认识,不仅有助于解释生命现象,同时对于代谢工程和合理选择药物靶标也有很大的意义.随着大规模高通量实验技术的发展,基因组、生物化学和生理学等各方面的信息海量涌现,为重构基因组规模的系统生物学模型提供了可能.介绍了国内外关于转录-调控网络的集成建模和分析方法,并简要评述了目前的研究现状以及可能的发展方向.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。