用于多脑区神经环路解析的新型光电极阵列

光遗传技术已被广泛用于神经环路的精确解析,帮助人们深入理解神经精神疾病的发病机制。然而在活体水平实现多脑区的光遗传调控和电生理记录仍然极具挑战。文章介绍了一种制备多脑区光电极阵列的方法。这种光电极阵列包含微电极支架和步进装置,可以同时对小鼠 4 个脑区的自发电生理信号(包括神经元放电和场电位)和光遗传调控后诱发的电生理变化进行记录。此外,还采用电化学修饰技术,显著降低了电极界面阻抗,提高了电生理记录信号的质量和稳定性。文章利用该光电极阵列对光遗传调控前后不同脑区之间神经元的同步化关系进行了分析,通过 4'', 6-二脒基-2-苯基吲哚染色确定了光电极的植入位点。实验结果表明,这种多脑区光电极阵列适用于多脑区水平的研究,并且容易与其他在体研究方法结合,实现对特定神经环路的精确解析。     

脑-机接口用微传感器设计与制造方法研究

神经微传感器是脑-机接口系统中的关键器件,通过对神经组织多个区域进行生物电信号记录和施加电刺激,探索神经系统顽疾的治疗方法。建立了神经微传感器与神经组织相互作用的电路模型;从生理、物理、工程等角度出发,设计了微传感器的机械结构,并确定了探针臂的几何参数;将两片二维电极插接在支撑基板上,并安装隔板加以固定,从而组装成三维结构,能在创伤度最小的情况下实现稳定、可靠的三维测点定位。单通道动作电位检测实验证明：此神经微传感器具有良好的神经信号提取能力。     

绝缘层参数对非接触电极心电检测性能的影响研究

心电图广泛用于人体心脏电活动特性研究和心脏相关疾病的诊断。常规的接触式湿电极普遍 使用导电膏,容易造成受试者的负担感和不适感,且存在皮肤过敏的风险,也不利于心电信号的长期监测。针对这个问题,该文设计了一种通过皮肤与电极感应层之间的容性耦合来获取心电信号的非接触电极,并搭建了基于 ADS1299 的生理信号采集系统,可实现无需导电膏、无需与皮肤直接接触的心电测量。在此基础上,该文全面研究了介于非接触电极和皮肤之间的绝缘层材料及厚度对心电信号的影响。研究结果表明,非接触电极可获取高质量的心电信号,且绝缘层参数对心电信号质量具有显 著的影响：棉布材料作为绝缘层时,心电信号质量最好;绝缘层厚度越小,心电信号质量越好。该研究结果可为非接触电极在移动健康监护中的进一步广泛应用提供重要的实验基础和理论依据。     

L-半胱氨酸自组装金电极测定鲜橙多中抗坏血酸的含量

该文用循环伏安法研究了抗坏血酸在以L-半胱氨酸作为修饰剂的自组装金电极表面上的电化学行为,并对实验条件进行了优化.实验结果表明,在pH=4.43的HAc-NaAc缓冲溶液中,在-0.2～0.8V扫描电位范围内,相对裸金电极,抗坏血酸在自组装金电极表面出现一对稳定的氧化还原峰.且该氧化峰的峰电流与抗坏血酸的浓度在1.09×10-6～2.13×10-3 mol/L呈良好的线性关系,检测限为1.0×10-7mol/L.此外,该自组装膜电极还具有一定的抗干扰能力和较好的稳定性与重现性,用该自组装膜金电极对实际样品鲜橙多中抗坏血酸的含量进行测定,结果令人满意.     

ka频段片式一体化发射组件的设计与实现

介绍了一种ka频段片式一体化发射组件的研制方法和关键技术。为满足一体化片式组件小型化且工作频率高的要求,提出了一种集成天线辐射单元与射频模块三维垂直互联的方法,同时结合多功能芯片 (MFC)技术、多芯片组装(MCM)技术实现组件高密度集成。研制的一体化组件尺寸为48 mm×48 mm×6.3 mm、质量不超过100g,集成16个发射通道,每个通道包含6位数控移相器和5位数控衰减器。该组件集成度高、较传统组件在尺寸和重量上具有较大的优势。     

心血管病人出入量记录误差控制技术研究

由于传统程序人工操作过多,导致出入量记录误差较大,无法满足临床工作需求,提出了心血管病人出入量记录误差控制技术。充分考虑语言使用环境,选择C++作为程序编译语言构造新词素,实现程序的动态编译。根据动态编译结果,集合全部数据,分析出入量记录结构,确定各个结构之间的逻辑关系,改善人工操作方式。以该结构逻辑关系为基础设计误差控制界面,为出入量记录数据与处理提供快捷误差控制界面和必要图表。由实验结果可知,该设计方法成功避免了人工记录出现误差的行为,使程序最高运行效率达到92%,能够满足临床工作需求。     

面向课程群的递进式教学案例库一体化设计

针对新工科项目式教学中存在的问题,提出面向课程群的递进式教学项目案例库设计方法,重点介绍支撑课程群的递进式教学项目案例库设计的方法,分析递进式教学项目案例库的一体化设计过程,为新工科背景下学生技能的培养提供新的思路和方法。     

新型电化学CO气体传感器的研制

研制了一种用于测定CO的新型电化学式气体传感器,即把多壁碳纳米管自组装到铂微电极上,制备多壁碳纳米管粉末微电极,其电极在氧化过电位为+700mV时,对CO具有显著的电化学催化效应。以其电极为工作电极,Ag/AgCl为参比电极,Pt丝为对比电极,多孔聚四氟乙烯膜作为透气膜制成传感器。其传感器响应时间短、重复性好,能用于环境监测和控制。     

一种新的心肌细胞电生理模型的描述方法

心肌细胞电生理模型是心脏仿真研究的基础工具，现有的模型描述方法存在着通用性、兼容性差的问题。应用CellML语言描述心肌细胞电生理模型，可以有效地解决以上的问题，该文介绍了CellML语言的结构，描述了心肌细胞电生理模型以及该模型在心肌细胞仿真中的实验结果。     

基于柔性印刷工艺的表面肌电电极阵列装置的设计

设计了一种基于柔性印刷工艺的表面肌电电极阵列装置。该电极阵列由12个直径1.2mm的镀金圆电极分成两列组成,内部电极间距为3mm。电极载体材料(聚酰亚胺,厚50μm)具有较高的机械柔性,表面镀金(厚度2μm)的电极具有较低的阻抗,特制的聚酯双面胶带用于可重复使用的电极阵列装置的固定。在单指力量输出任务时记录指浅屈肌的多通道表面肌电(surface Electromyogram,sEMG)信号的实验中得到了稳定的基线和较好的sEMG信号。初步的实验结果表明,设计的这种低成本、体积小的高密度电极阵列装置能用于表面肌肉空间sEMG信号的检测。     

Computer aided EDM electrode design

A large number of EDM electrodes are used in die and mold manufacturing. However, the electrode design is very time consuming. This paper introduces a computer-aided electrode design system for die and mold manufacturing. Using this system, when the electrode boundaries are selected, the electrode tool, its holder, and a work coordinate system are created automatically. An algorithm of sharp corner uncut detection for electrode design is also developed. With this algorithm, sharp corner uncut can be detected by calculating the surface angles at their common edges. The system has been tested and proved to be able to shorten the electrode design lead-time significantly.     

面向化学气相沉积生长单晶金刚石的高导热嵌入型 基片托盘设计及其高质量生长工艺研究

针对高功率密度微波等离子体化学气相沉积法生长单晶金刚石过程中,金刚石籽晶表面温度容易发生漂移的问题,提出了一种新的基片托盘结构设计方法.基片托盘中间采用通孔结构,以避免籽晶底部与钼托盘的直接接触,在基片托盘与水冷台之间、籽晶和水冷台之间添加高导热材料氮化铝片,以保证外延沉积金刚石所需的均匀温度场环境.实验结果显示,利用新型基片托盘可以连续工作48 h,并获得生长厚度达1.66 mm的单晶金刚石,经过多次反复生长可实现厚度3 mm的高质量单晶金刚石制备.新型基片托盘能有效地抑制生长过程中石墨等大颗粒煤烟沉积引起的温度漂移现象,满足不同条件下金刚石单晶的同质外延生长,抑制籽晶边沿处多晶金刚石的生成,从而保证金刚石单晶在高功率密度下长时间稳定生长,获得高质量、大尺寸的化学气相沉积单晶金刚石.     

Enhancing displacement of lead-zirconate-titanate (PZT) thin-film membrane microactuators via a dual electrode design

A common design of piezoelectric microactuators adopts a membrane structure that consists of a base silicon diaphragm, a layer of bottom electrode, a layer of piezoelectric thin film, and a layer of top electrode. In particular, the piezoelectric thin film is often made of lead-zirconate-titanate (PZT) for its high piezoelectric constants. When driven electrically, the PZT thin film extends or contracts flexing the membrane and generating an out-of-plane displacement. Many manufacturing defects, however, could significantly reduce the designed actuator displacement. Examples include residual stresses, warping, non-uniform etching of the silicon diaphragm, and misalignment between the top electrode and the silicon diaphragm. The purpose of this paper is to develop a dual top-electrode design to enhance the actuator displacement. In this design, the top electrode consists of two disconnected (thus independent) electrode areas, while a continuous bottom electrode serves as the ground. The two top electrodes are located in two regions with opposite curvature when the diaphragm deflects. When the two top electrodes are driven in an out-of-phase manner, the actuator displacement is enhanced. Finite element analyses and experimental measurements both confirm the feasibility of this design. When manufacturing defects are present, experimental results indicate that the actuator displacement can be optimized by adjusting the phase difference between the dual top electrodes.     

Multivariate spectral methods for the analysis of event-related brain potentials

The purpose of this article is to present some useful mathematical models for the analysis of multiple electrode event-related brain potential (ERP) experiments. We describe a multivariate spectral method for eye-movement removal and we also describe a multivariate spectral method for the analysis of multiple lead repeated measures data. The complex T2 and the complex Behrens-Fisher Problem are also discussed. All of the above methods are applied to experimental ERP data for four electrodes, two groups and two repeated factors.     

Fabrication and mathematical analysis of an electrochemical microactuator (ECM) using electrodes coated with platinum nano-particles

This paper reports the design, fabrication, modeling, and analysis of an electrochemical microactuator (ECM). The driving mechanism of the ECM is based on the reversible electrolysis process of water. The expansion and shrinkage of gas bubbles generated in a micro electrochemical chamber during a reversible electrolysis process can be used for actuation in microfluidic systems. The fluidic components of the ECM were fabricated on a glass substrate using UV lithography of SU-8. Two electrodes were used, with one Pt black (coated with platinum nanoparticles) as working and auxiliary electrode and the other Ag/AgCl coated as reference. The nano particles coated on the working electrode help to boost the surface-to-volume ratio of the electrode and to obtain higher operation frequency. Pulse electropotentials were supplied for active control of expansion and shrinkage of gas bubbles using reproducible electrochemical reactions. The theoretical volume change rate of gas bubbles was simulated as a function of time using the ideal gas law and compared with the measured volume change. The experimental results show the electrode coated with platinum nanoparticles helped to enhance the reversible electrolysis process significantly. The results also show that the dynamic model can be used to simulate the dynamic behaviors of the ECM actuator. The ECM can be used in microfluidic applications such as pumping or valves.     

电导法原油含水率测量传感器的模型优化与仿真

电导法原油含水率测量是基于阵列电极传感器的一种测量方法,电极系的结构与参数对传感器性能有着重要影响.拟研究电极系传感器结构的优化设计方法,在建立传感器电场分布理论模型的基础上,利用ANSYS有限元软件仿真电极系传感器不同参数下的电场分布,分析电极环宽度、激励电极对间距、测量电极间距等参数对传感器性能的影响.依据仿真结果,确定传感器的优化参数,并对传感器进行了灵敏度的模拟测试,测试结果显示:传感器灵敏度仿真结果与实际测试结果一致性较好;在高含水(大于85%)的油水两相流含水率测试精度可达3%.测试结果验证了传感器理论和仿真分析方法的有效性,为优化设计传感器提供一种有效的方法.     

井间ERT电极阵列优化及监测实验系统设计与开发

为了开发用于地层中CO2运移监测的井间ERT系统,研究了ERT电极阵列和工作模式优化设计方法并研制了井间ERT监测模拟实验系统。基于COMSOL平台构建了模拟井间ERT测量响应的有限元数值模型,利用数值模型分析了电极间距和宽度等参数对监测区域电场灵敏度的影响规律以及不同电极阵列工作模式下场域灵敏度的分布特征,确定了井间ERT实验系统中最优的电极参数,即电极间距、宽度与监测范围的比值分别为0.200、0.025,电极阵列的工作模式为AM-BN。在对实验系统进行功能需求分析、总体设计以及上述优化设计的基础上,分别对系统硬件部分和软件部分进行了开发,采用多路切换开关并配合精密电桥仪实现了对电阻抗参数的测量,利用以LabVIEW为平台开发的测控软件实现了对实验系统的自动化控制。以埋放绝缘物体来模拟注入地层CO2的方式开展了实验测试,结果显示测量到的电阻抗数据可以灵敏地反映出监测区域电参数的变化且能够用于定位绝缘物体的位置,从而验证了所开发系统的可用性。所建立的电极阵列优化设计方法以及开发的井间ERT监测模拟实验系统为下一步深入研究基于复电导率参数的CO2饱和度评价模型和开发现场适用的井间ERT监测系统提供了实验平台。     

A novel integrated silicon capacitive microphone-floating electrode“electret” microphone (FEEM)

A novel principle “electret” microphone, i.e., floating electrode electret microphone, is proposed and implemented in this study. Single-chip fabrication and corrugation technique are used in the design and fabrication of the microphone. The floating electrode is encapsulated by highly insulated materials to ensure that there is no electric-leakage passage between the floating electrode and the electrodes of the microphone. Net-free electronic charges (not “bonded” charges as in traditional electret) in the floating electrode can excite the electric field, which is similar to that of the traditional electret. The floating electrode can be easily charged by use of the “hot” electron technique, available using the avalanche breakdown of the p⁺-n junction. Therefore, the electret microphone is rechargeable, which can greatly increase the lifetime of the device. The preamplifier has been on-chip integrated in a junction-field-effect transistor (JFET) source-follower type with resistors by use of ion implantation. Electret charges are banded in a deep potential trap, thus, this microphone can operate at a high temperature (as high as 300°C) and has high stability and reliability. Experiments show that the prototype has a 3-mV/Pa sensitivity and a larger than 21-kHz frequency bandwidth in a 1 mm ×1-mm diaphragm area. Microphone performance can be further improved by optimized process and design. The fabrication is completely integrated-circuit (IC) compatible, hence, the microphone shows promise in integrated acoustic systems     

基于超高输入阻抗放大电路的生物传感器设计

脑电与心电信号作为2种重要的生物电信号,长期以来一直被用作重要的生理、心理指标。从技术角度分类,此类医疗传感器的电极可以分为两大类：湿电极和干电极,其中后者又可以进一步分为接触式干电极和非接触式干电极。目前绝大部分场合仍使用传统的湿电极,有诸多不便和弊端。对于干电极的研究现在成为全世界的热门课题,主流的方向集中在采用微针穿透技术的接触式干电极,为了实现基于超高输入阻抗放大电路的接触式干电极,将重点引入正反馈阻抗提高技术,并给出电路的设计和分析。     

Kernel current source density method

Local field potentials (LFP), the low-frequency part of extracellular electrical recordings, are a measure of the neural activity reflecting dendritic processing of synaptic inputs to neuronal populations. To localize synaptic dynamics, it is convenient, whenever possible, to estimate the density of transmembrane current sources (CSD) generating the LFP. In this work, we propose a new framework, the kernel current source density method (kCSD), for nonparametric estimation of CSD from LFP recorded from arbitrarily distributed electrodes using kernel methods. We test specific implementations of this framework on model data measured with one-, two-, and three-dimensional multielectrode setups. We compare these methods with the traditional approach through numerical approximation of the Laplacian and with the recently developed inverse current source density methods (iCSD). We show that iCSD is a special case of kCSD. The proposed method opens up new experimental possibilities for CSD analysis from existing or new recordings on arbitrarily distributed electrodes (not necessarily on a grid), which can be obtained in extracellular recordings of single unit activity with multiple electrodes.