无透镜微流控成像流动细胞检测与计数系统

在未来面向个人化的生物医疗诊断中,实时的细胞检测与计数具有重要需求.现有的细胞检测和计数系统例如流式细胞仪和血细胞计数器不适用于小型化流动细胞实时检测和计数.通过将CMOS图像传感器芯片和微流控芯片结合,提出了一种用于流动细胞检测和计数的无透镜微流控成像系统,与用于计数静态细胞的其它无透镜微流控成像系统不同,该系统可以通过基于时域差分的运动检测算法检测和计数微流体通道中连续流动的细胞样本.测试结果表明:该系统可以对微流控通道中流动的人体骨髓基质细胞实现自动检测和计数,并具有-6.53％的低统计错误率.该系统提供了面向未来即时应用的细胞检测和计数解决方案.     

基于SPR干涉成像传感法检测大蒜素刺激胃癌细胞的响应

针对细胞响应传感的要求,提出了SPR干涉成像传感细胞响应的方法,设计制作新颖的微流体池,构建用于活细胞水平分子传感和检测的系统。在此基础上,先检测和分析细胞在微流体池中的培养状态,再检测大蒜素对人胃癌细胞系BGC823刺激响应。实验结果表明,胃癌细胞贴附生长良好,微流体池可提供细胞生存的微环境;6 h后大蒜素刺激和对照的SPR信号响应值分别为0.15 RIRF和0.35 RIRF,大蒜素对胃癌细胞系BGC823细胞具有明显抑制作用。在持续提高精度、可靠性以及丰富有关工艺技术后,有可能建立完整的药物刺激细胞响应检测技术平台,为药物发现和临床化疗方案优化做出贡献。     

微悬臂梁矩阵细胞牵引力测量传感器研制

提出一种采用聚碳酸酯核孔膜为模版来制作高深宽比聚二甲基硅氧烷微悬臂梁矩阵的新方法,用来作为生物微机电系统传感器探测细胞微纳力学及在体外研究细胞的机械特性,并对其制作工艺进行研究.通过选择不同的膜,可以便捷制作不同规格的微悬臂梁矩阵来满足不同精度的测量需求.细胞贴附在经表面处理后的微悬臂梁矩阵顶端生长并延展迁移,造成微悬臂梁弯曲形变.通过对形变共焦荧光显微图像处理,可以精确描绘出细胞牵引力分布.实验结果表明该制作方法有效,测量精度达到nN/μm.     

微小尺度射流流量传感器的设计与仿真分析

在许多新型传感器和微系统中均存在微量流体自动、精确地驱动和控制问题,而这有赖于微小尺度下对流量的精确测量。基于射流振荡原理设计了一种新型的无反馈通道微小尺度流量传感器,采用计算流体动力学(CFD)方法对该流量传感器的测量特性进行了仿真研究。通过观测振荡腔内部流场,分析了振荡器内部流动形态和射流振荡过程。通过对监测点压力变化曲线的分析,获得了不同入口速度下流体振荡频率,建立了流体流速与振荡频率的函数关系。研究结果表明,该微小尺度射流振荡器振荡平稳,主射流切换灵活,在较宽的流速范围内,流速与振荡频率具有线性关系,具有0.3%的较低的相对压力损失并可达到较小的测量下限,易于加工成型。     

基于微透镜阵列的多通道光寻址电位传感器研

为了提高化学和生物图像传感器的成像速度和简化成像系统,提出了一种基于微透镜阵列的多通道光寻址电位传感器.利用微透镜阵列把单束激光转化成点阵,通过多频率斩波器,得到不同频率的光点阵列用作光寻址电位传感器的光源,从而实现多点同时检测.实验结果表明该系统具有良好的频域分辨率,通过数字补偿技术可获得各个检测点的电流电压特性曲线,证明可实现多点同时检测.该系统可以用于光寻址电位传感器和扫描光感阻抗传感器的快速成像,以及多通道化学生物图像检测.     

基于微流控技术的体外多参数快速诊断POCT系统的设计

针对传统的体外快速诊断系统(POCT)精度低、参数单一等问题,设计了一种基于微纳传感结合微流控技术的多参数体外快速诊断POCT系统.本文研究了传感器与微流控芯片的制备工艺、传感器微弱信号的采集与提取、多通道参考电极的多维度抗干扰校正算法以及多参数POCT系统的优化设计,保证了POCT系统具有检测精度高、抗干扰性能好、多参数集成等特点.通过系统测试和临床实际样本的基本性能测试,实验结果表明,本文提出的多参数体外诊断快速检测POCT系统能够综合检测血糖、血酮等多项指标,具备快速,精确,多参数测量的特点,将为基层医疗机构的生化指标检测提供一种新型实用的技术和仪器.     

高于室温环境的热式气体微流量传感器性能分析

为了探索平板微热管的传热特性,了解微热管内不同温度区间的蒸汽传输特性,开展了热式气体微流量传感器及其检测系统的设计。设计了一种便于探索最佳温度测量点的热式微流量传感器结构,利用MEMS工艺进行加工制作,在不同环境温度下对其性能进行了测试,得到了环境温度与热式微流量传感器性能的关系。基于MSP430单片机和C＃语言自主开发了流量传感器检测系统,可对一定范围内的流量进行实时检测,并实时绘制流速随时间的变化曲线。研究表明,采用本文设计的热式微流量传感器结构,可以检测高于室温环境下的微流量气体,并可通过提高加热器温度或改变测温电阻对的测量位置来提高测量灵敏度。     

Si基微环谐振腔化学传感检测方法研究

提出了一种非标记光化学传感检测方法：光波导谐振谱检测,通过感应环形波导表面有效折射率变化进行化学传感;理论分析,并结合光学测试系统,利用此方法实现了微环谐振腔结构对NaCl离子、结晶紫分子溶液的在线浓度测量,实验得到：其检测灵敏度分别达181.47 pm/10－2,227 nm/（ mol·L－1）,证明了该方法可以应用于化学溶液检测领域。     

微电极阵列细胞阻抗传感器研究

贴壁生长在微电极表面的细胞可引起贴壁电极界面阻抗的改变,从而可以获得细胞生理功能相关的生物信息.本研究采用微机械加工技术,在硅基底上设计了直径为20～50 μm的20通道金微电极阵列(micro-electrode array,MEA),用以构建能实时、连续、定量跟踪哺乳动物细胞形态和增殖分化改变的细胞阻抗测试传感器(electric cell-substrate impedance sens-ing,ECIS),用于细胞与电极间的阻抗测试研究.通过对培养在微电极表面24 h的成骨细胞Saos-2细胞系的阻抗谱测量发现,其阻抗值增加集中在中频102～10<'4>Hz之间,本结果符合细胞阻抗传感测量的理论模型分析.因此,该微电极阵列细胞阻抗传感器的研究,为进一步的细胞生理和药物分析等研究奠定了良好的基础.     

基于电容式传感测头的电容检测系统的设计

针对纳米尺寸测量领域的不同测量要求,尝试开发一种基于电容传感器的微触觉测头及其电容检测系统。阐述了测头的结构原理和电容传感器的工作原理,研制了基于电容传感器的微触觉测头。测头的测量原理表明:微小电容检测电路是整个电容检测系统的关键部分。该微小电容检测电路选用电容/数字转换器(CDC)AD7747芯片,分别编写了单片机与该芯片的I2C通信程序和单片机与上位机间的串行通信程序,实现了微小电容的采集和处理,简单进行了电容式传感测头的轴向性能的测试实验。实验表明:电容式微触觉测头的分辨率为0.02μm,重复性较好,证实了此电容式微触觉测头的可行性。     

Distributed partitioning algorithms for multi-agent networks with quadratic proximity metrics and sensing constraints

We consider a class of Voronoi-like partitioning problems, in which a multi-agent network seeks to subdivide a subset of an affine space into a finite number of cells in the presence of sensing constraints. The cell of this subdivision that is assigned to a particular agent consists exclusively of points that can be sensed by this agent and are closer to it than to any other agent that can also sense them. The proximity between an agent and an arbitrary point is measured in terms of a non-homogeneous quadratic (generalized) distance function, which does not, in general, enjoy the triangle inequality and the symmetry property. One of the consequences of this fact is that the structure of the sublevel sets of the utilized proximity metric does not conform with that of the sensing region of an agent. Due to this mismatch, it is possible that a point may be assigned to an agent which is different from its “nearest” agent simply because the nearest agent cannot sense this point, unless special care is taken. We propose a distributed partitioning algorithm that enables each agent to compute its own cell independently from the other agents when the only information available to it is the positions and the velocities of the agents that lie inside its sensing region. The algorithm is based on an iterative process that adjusts the size of the sensing region of each agent until the associated cell of the latter corresponds to the intersection of its sensing region with the cell that would have been assigned to it in the absence of sensing constraints. The correctness of the proposed distributed algorithm, which successfully handles the aforementioned issues, is studied in detail.     

可用于机械臂控制的小脑脉冲神经元网络研究与FPGA实现

小脑对运动的调控和对环境的适应性是人体完成快速精准运动的关键,模拟并研究小脑的运行机制将为控制复杂多变的机器人模型提供更有效的方法.鉴于此,遵循神经元数量的真实生物比率,构建大规模小脑脉冲神经网络模型,模拟大脑中小脑的真实结构、信息传递方式和学习机制,实现对机械臂的误差纠正控制,同时依据系统在不同控制任务下的控制结果,得到不同突触可塑性对小脑网络控制效果的影响规律.为了进一步增加小脑控制系统的生物真实性,以更贴近人脑的并行运算方式在现场可编程门阵列(field programmable gate array,FPGA)平台上实现所构建的模型,并进行相应的资源优化,增加可实现的网络规模.FPGA实现结果显示,系统能够成功完成基于小脑误差纠正功能的自适应类脑机械臂控制,可以验证小脑的真实细胞动力学和大规模颗粒层提供的高容错性,并提供兼顾小脑应用功能实现和理论研究的平台.     

Highly integrated polymeric microliquid flow controller for droplet microfluidics

Microfluidic applications demand accurate control and measurement of small fluid flows and volumes, and the majority of approaches found in the literature involve materials and fabrication methods not suitable for a monolithic integration of different microcomponents needed to make a complex Lab-on-a-Chip (LoC) system. The present work leads to a design and manufacturing approach for problem-free monolithic integration of components on thermoplastics, allowing the production of excellent quality devices either as stand-alone components or combined in a complex structures. In particular, a polymeric liquid flow controlling system (LFCS) at microscale is presented, which is composed of a pneumatic microvalve and an on-chip microflow sensor. It enables flow regulation between 30 and 230 μl/min with excellent reproducibility and accuracy (error lower than 5%). The device is made of a single Cyclic Olefin Polymer (COP) piece, where the channels and cavities are hot-embossed, sealed with a single COP membrane by solvent bonding and metalized, after sealing, to render a fully functional microfluidic control system that features on-chip flow sensing. In contrast with commercially available flow control systems, the device can be used for high-quality flow modulation in disposable LoC devices, since the microfluidic chip is low cost and replaceable from the external electronic and pneumatic actuators box. Functionality of the LFCS is tested by connecting it to a microfluidic droplet generator, rendering highly stable flow rates and allowing generation of monodisperse droplets over a wide range of flow rates. The results indicate the successful performance of the LFCS with significant improvements over existing LFCS devices, facing the possibility of using the system for biological applications such as generating distinct perfusion modes in cell culture, novel digital microfluidics. Moreover, the integration capabilities and the reproducible fabrication method enable straightforward transition from prototype to product in a way that is lean, cost-effective and with reduced risk.     

RFID-based sensing system for context information management using P2P network architecture

An RFID-based sensing system using a P2P network can play an important role in a ubiquitous environment. We developed a network capable of managing its own computing and network resources by combining computing devices with a wide variety of sensors. Context awareness is required to deliver the functionality of the sensing network described in this paper. We designed an RFID-based sensing system that receives contextual information about the user via a P2P network. The proposed system includes the basic RFID equipment needed to use and test an RFID system, which consists of a reader, 30 sample tags, and a sample middleware application for reading, writing, and testing RFID tags. It is able to recognize users entering and leaving a location, as well as determine the distance of a user from itself. It can also recognize the condition of the sensor installation. We designed, implemented, and analyzed a system that provides practical services with real-world educational applications. There were statistically significant differences between the control and test groups for user satisfaction, content learned, learning content composition, and user interface.     

MEDA芯片菊花链的自动容错设计

微点阵生物芯片MEDA biochip将微电子和微流体结合,是最近出现的一种新型数字微流控芯片,它基于微点阵思想,每个微点阵单元都包含驱动电路和检测电路,从而实现对生化实验的实时监测。为减少外部引脚,MEDA芯片的所有微单元由菊花链串联,以实现对芯片的准确控制。作为MEDA芯片的关键数据通路,菊花链上即使只有一个单元发生故障,也会导致整条链失效,因此必须对菊花链进行有效的容错设计。为MEDA芯片设计了具有自测试和容错功能的菊花链结构,该结构由测试响应触发菊花链故障单元的自动容错。当菊花链的某个单元出现故障时,其测试响应产生异常,从而触发故障单元的自动修复,若修复失败,则异常的测试响应会再次触发该单元的旁路,从而实现自动容错。实验结果表明,该结构可以在测试和诊断故障的同时进行有效的容错,并在容错失败时将其永久旁路。     

Hybrid paper-based microfluidics: combination of paper-based analytical device (µPAD) and digital microfluidics (DMF) on a single substrate

Microfluidics found its place in point of care diagnostics. Microfluidic devices on paper substrate are proposed on both channel-based and digital microfluidics (DMF). But fluid flow controlling on microfluidics paper-based analytical devices (µPADs) and post-processing on DMF devices have limitations. In this work a new hybrid paper-based device is proposed with the aim of resolving these limitations and expanding the microfluidics capabilities in point of care diagnostics. The hybrid paper-based microfluidics (HPMF) device is composed of a DMF device following a µPAD in a single substrate, in which the DMF part performs the preprocessing steps of the test on droplets and transfers the resulting droplet to the µPAD part of the device for post-processing steps. The fabrication process of the device is rapid and very low cost due to use of paper substrate and out of clean-room processes. The results show that the proposed HPMF device can perform droplet operations: moving, mixing, and splitting.     

基于小波内插的遥感图象超分辨率增强

基于小波内插的超分辨率增强方法,利用多幅遥感图象的交错采样结构,将同一场景的多幅遥感图象序列中的信息,在像素级上内插到一幅遥感图象中,得到一幅信息量更加丰富、分辨率更高的遥感图象。该文介绍了该方法及相应遥感图象预处理方法,文中实验显示了该方法的有效性。     

Computer-Aided Design and Test for Digital Microfluidics

This article discusses several aspects of design and test methodology centered on digital microfluidics, including modeling, simulation, synthesis, test, and reconfiguration. The automated design methods for digital electronics and adaption of them to droplet-based microfluidics are explained. The test methodology detects both catastrophic and parametric faults by electrically controlling and tracking the motion of the test stimuli droplets and also facilitates concurrent testing, in which fault testing and biomedical assays run simultaneously on a microfluidic system.     

基于PLC的电气—液压精确控制的研究

本文针对液压传动系统中的零超调以及精确控制难的问题,基于经典控制理论和PLC技术,提出了电气—液压精确控制的解决方案,并通过相应的理论算法设计和PLC程序设计,实现了电气控制对液压系统的零超调的精确控制,运行测试的各指标均满足要求。     

无线传感器网络中基于Voronoi覆盖及Delaunay三角剖分图的最小刚性拓扑控制算法

为同时满足覆盖与节能应用需求,本文提出了无线传感器网络中一种最小刚性拓扑控制算法MRTc（Minimal rigid topology control algorithm based on Voronoi coverage and Delaunay triangulation）.该算法基于Voronoi覆盖机制,准确控制节点工作状态,实现活动节点对目标区域的完全覆盖.在此基础上,MRTc利用Delaunay三角剖分图的特点,构建出适用于无线传感器网络的最小刚性拓扑结构.该结构有效约束了网络平均节点度,且同时具有容错性、覆盖性和稀疏性.此外,MRTc引入节点功率控制策略,在维持网络完全覆盖的基础上最小化节点能耗.仿真结果进一步验证了本文提出的MRTc算法的有效性.