Virtual instruments in undergraduate biomedical engineering laboratories

It is anticipated that many undergraduate biomedical engineering (BME) students will seek jobs in industry following graduation. Therefore, it is imperative that BME programs establish a learning environment that exposes students to modem tools and equipment that best prepare them for an industrial setting. BME laboratory courses using PC-based virtual instruments can prepare students for real-world experience with minimal cost and risk. This article details various approaches for incorporating undergraduate BME laboratories in the curriculum and the use of virtual instruments. In particular, we discuss the motivations for and approaches to implementing virtual instruments and also describe a number of virtual instrument applications.     

虚拟实验室的构建

介绍了虚拟仪器技术软件的构成原理和优势,探讨了构建虚拟实验室的可行性.提出了将虚拟仪器技术应用于构建虚拟实验室中,设计了一套虚拟实验系统,并在此基础上对各种实验进行了仿真.实验结果表明,应用虚拟技术构建的电子虚拟实验室与传统的电子实验室相比,优势显著.为电子实验教学提供了一种全新的解决方案.     

基于LabVIEW的梁分布动载荷识别系统设计与实现

分布动载荷识别是结构动力学分析中的难点之一,在工程应用中具有重要的意义。从工程实践需求出发,设计了一款通用的分布动载荷识别系统。分布动载荷识别系统基于LabVIEW虚拟仪器平台进行模块化设计和开发,以Bernoulli Euler梁为主要研究对象,利用模态坐标变换的分布动载荷识别技术,设计和实现了可用于工程应用的动载荷识别系统。系统有效利用了虚拟仪器强大的数据处理分析以及动态链接库等能力,具有良好的人机交互界面,通用性以及可扩展性等优点。并通过应用实例,来证明所设计的梁分布动载荷识别系统的可靠性和实用性。     

Stand-alone laboratory sessions in sensors and signal processing

Real laboratory experiments can help students to gain a better understanding of theoretical problems. Great efforts are needed, however, to improve the quality of laboratory sessions, and a large number of tutors are usually required. Moreover, students may lose time because of hardware failure or an inefficient experimental setup. Several educational tools (based on virtual instruments) have been developed allowing for optimized time scheduling and remote access to laboratory sessions. Drawbacks related to hardware failure have not, however, been seriously addressed. This paper proposes an educational tool made up of a user-friendly interface controlling experimental boards. It basically consists of an array of optical sensing devices connected to suitable conditioning circuits, which are interfaced to a virtual instrument by means of a data acquisition system. To solve the previously mentioned drawbacks, a solution based on both pre-cabled hardware and PC-based measurement stations has been adopted. Moreover, the ability to configure self-educational tasks optimizes time scheduling for students during laboratory activities. The proposed system allows students to improve their knowledge in the field of optical sensing devices, virtual instrumentation, data acquisition systems, and signal processing. The paper describes an application of the tool as a simple system for surface recognition. This application is one of the laboratory tasks performed in measurement classes during this engineering course at the University of Catania, Catania, Italy.     

Virtual Laboratory for Creative Control Design Experiments

This paper proposes a two-step strategy for the computer-aided learning of control. A virtual Web-based laboratory for control design experiments (http://www.hl1.uni-mb.si), which supports a two-step strategy, is based on the MATLAB Web server (MWS) and consists of two virtual laboratories. The first virtual laboratory, called ldquoWeb sisotool,rdquo supports computer-aided control design and structured hands-on experiments. Computer-aided control design is welcome as a design tool while structured hands-on experiments are welcome for the visualization of hard-to-grasp concepts. The second virtual laboratory offers students an unstructured MATLAB-like environment, called ldquoM-file application,rdquo that allows students to create and design control design experiments by writing MATLAB M-files of their own and executing them on MWS. The presented virtual laboratory for control design experiments is cost effective and has already been successfully used for the learning of control. Student feedback is also presented.     

Development of a Web-Based Control Laboratory for Automation Technicians: The Three-Tank System

This paper introduces a Web-based control laboratory for experimentation on a nonlinear multiple-input-multiple-output (MIMO) system: the three-tank plant. Using this application, automation technician students can learn in a practical way many fundamental aspects of control processes. The client-side of the virtual laboratory has been developed using the programming support provided by Easy Java Simulations (EJS), an open-source tool for teachers with limited programming skills who want to create Java applications and applets. The lab has been integrated in the collaborative Web-based experimentation environment eMersion which provides more flexibility for the students performing the laboratory experiments.     

基于虚拟仪器的开放式虚拟实验室系统的研究和实现

本文对构建基于虚拟仪器的开放式虚拟实验室系统的设计思想进行了描述,论述了该系统的关键技术,如动态网页技术、数据库技术、多媒体技术和虚拟仪器技术等,选择了适合本系统内容和特点的技术方案.根据系统的整体设计原则,结合虚拟仪器的实验要求,设计了系统的整体框架和功能模块,将系统划分为6个主要模块:虚拟仪器技术、LabVIEW、HP VEE、虚拟仪器中心(虚拟仪器实验室) 、软件下载和交流园地.系统中根据各个模块的特点分别采用了Dreamweaver、Flash、ASP、数据库和虚拟仪器技术实现了不同模块的功能.本系统大量采用了层叠样式表单(cascading style sheets,CSS)技术,使整个站点的HTML文件在风格上保持一致,方便修改和使用;并且采用Remote Panel技术实现了虚拟仪器的网络化;最后以虚拟电压表的设计与实现为例给出了虚拟仪器系统的具体实现方法.     

基于LabVIEW的数字信号处理虚拟实验室构建

本文首先简要介绍了当前数字信号处理教学的现状,并针对目前实验室的具体情况,分析了研究虚拟实验室的必要性及意义。并在此基础上使用LabVIEW构建了数字信号处理虚拟实验室。该系统界面友好,维护简单等优点。此外,用户可以根据需要对典型的数字信号处理实验参数进行设置。实验证明该系统具有很好的教学实验效果。     

基于LabVIEW的智能照明网络虚拟实验系统设计

随着网上教育的广泛应用,基于网络的虚拟实验研究逐渐被人们关注。虚拟实验是现代创新教育的重要手段,是实现教学资源共享与优化配置的重要方式。以智能照明控制系统为例,以LabVIEW软件为平台,以办公室环境为对象设计了智能照明网络虚拟实验系统。该系统能满足远程场景控制、移动探测器控制、照度控制、现场控制、时间控制等多种控制要求,实现照明自动控制,以满足智能照明虚拟实验的需求。所建立的智能照明网络虚拟实验系统解决方案,可实现对高校智能建筑实验室现有实验系统的补充,具有较强的实际应用价值。     

300MW火电机组RB控制策略的改进与实施

以某电厂300 MW机组控制系统为例,在分析其辅机故障减负荷(RB)各种工况的基础上,设计了1套完整的RB工况下的控制策略。经实际应用表明,该控制策略设计完善、可靠,满足电厂机组安全运行的要求。     

基于LabVIEW软件的数据采集与分析系统设计

为降低传统实验仪器成本,扩充数据分析功能,设计了一套数据采集与分析系统。通过LabJack数据采集卡实时采集信号,利用LabVIEW图形化编程语言开发了虚拟示波器和虚拟电能质量分析仪软件系统。结果表明,该系统能取代传统示波器,完成基本数据采集和基本电能质量分析功能,可广泛应用于实验室虚拟实验平台和工业领域。     

A novel unconstrained cardiorespiratory monitoring system during sleep

As one of the basic means of assessing human health conditions, cardiorespiratory monitoring during sleep has been widely used in diagnosis of sleep disorders. In this paper, a novel method for unconstrained and non-invasive measurement of respiration and heartbeat is proposed. The method is based on the intelligent combination of two sensor systems for respiratory and pulse monitoring. In order to wear comfortable, polyvinylidene fluoride (PVDF) film was taken as the sensor material. For improving the sensor sensitivity, a “double-sided arch” spring and a “thin-shell” spring were designed as the substrate of respiratory sensor and pulse sensor, respectively. To obtain clear cardiorespiratory responses from the sensor probe, hardware filter circuit is applied for further data filtering. Relative cardiorespiratory signal parameters such as respiratory cycle (RC) and heart rate (HR) could be displayed by LabVIEW. The fabrication steps and some experiments results for human monitoring system are described. The results show that respiration and pulse signal can be obtained accurately and the method lays the foundation for medical diagnosis.     

基于虚拟仪器技术的巨磁阻抗测量系统

Co基非晶和Fe基纳米微晶材料中观察到巨磁阻抗效应（GMI），在传感器技和磁记录技术中具有巨大的应用潜能，受国内外专家的广泛关注。为了对该效应的应用和开发作进一步研究，我们自行设计和制作了一套基于虚拟仪器技术的GMI测量系统。测试结果表明，该系统能够满足各类材料测定巨磁阻抗的要求。     

Noninvasive measurement of instantaneous, radial artery blood pressure

A new prototype system for the noninvasive measurement of instantaneous blood pressure (BP) in the human radial artery has been developed. The system is based on the volume-compensation method, but several components were newly designed, namely, a disk-type cuff for local pressurization and a nozzle-flapper-type electro-pneumatic converter (EPC) for the cuff-pressure control. Results of experiments indicated that, using the disk-type cuff, the radial artery could be completely compressed, and the newly devised EPC had sufficient frequency response for BP measurement in humans. It was also found that the prototype system comprising these components was capable of noninvasively measuring instantaneous BP in the human radial artery, not only under rest conditions but also in a stressful condition, such as during the cold pressor test. In conclusion, the newly developed local pressurization technique appears promising as a useful and helpful means for instantaneous BP monitoring over longer periods of time than have previously been possible. Using this method, it is possible to construct an instrument that is more compact and more comfortable for the subject to use than a conventional commercial instrument. Finally, it has been reported that it may be possible to monitor cardiac output continuously by BP waveform analysis. Thus, continuous cardiac output monitoring might be another potential and important application of the newly designed instrument.     

面向航天员虚拟训练的人机交互系统研制和测试

根据航天员地面虚拟训练的需求,设计了一套面向航天员虚拟训练的人机交互系统,研制了具有真实感与临场感的多自由度手臂力反馈设备,实现了航天员虚拟训练环境中的抓握、推拉等带力觉感受的各种交互操作,增强虚拟仿真环境的沉浸感受,提高仿真训练的逼真度。面向航天员虚拟训练的人机交互系统包括手臂力反馈设备、硬件系统以及软件系统。手臂力反馈设备具有7个运动自由度,包括三自由度平动、三自由度转动以及食指运动的自由度;硬件系统主要是下位机采集光电编码器的信号发送给上位机以解算力反馈设备末端位置,以及接收上位机的力反馈执行参数以控制力反馈执行器;软件系统基于Unity3D平台,搭建了虚拟空间舱训练环境,并且实现了上位机与下位机的接口通讯以及位置和力的解算。还提出了基于磁流变液控制的力反馈方法,独立设计了一种新型的磁流变液阻尼器作为力反馈执行器。整个系统工作空间可达0.4 m×0.4 m×0.5 m,位置测量精度高达3 mm。系统结构设计上的创新实现了机械解耦、力和力矩的解耦,整个系统工作空间大、安全性能高、输出力大、位置测量精度高,并且还可广泛应用于康复医疗、虚拟手术等领域,应用面广泛。     

Brain-computer communication: motivation, aim, and impact of exploring a virtual apartment.

The step away from a synchronized or cue-based brain-computer interface (BCI) and from laboratory conditions towards real world applications is very important and crucial in BCI research. This work shows that ten naive subjects can be trained in a synchronous paradigm within three sessions to navigate freely through a virtual apartment, whereby at every junction the subjects could decide by their own, how they wanted to explore the virtual environment (VE). This virtual apartment was designed similar to a real world application, with a goal-oriented task, a high mental workload, and a variable decision period for the subject. All subjects were able to perform long and stable motor imagery over a minimum time of 2 s. Using only three electroencephalogram (EEG) channels to analyze these imaginations, we were able to convert them into navigation commands. Additionally, it could be demonstrated that motivation is a very crucial factor in BCI research; motivated subjects perform much better than unmotivated ones.     

Brain–Computer Communication: Motivation, Aim, and Impact of Exploring a Virtual Apartment

The step away from a synchronized or cue-based brain-computer interface (BCI) and from laboratory conditions towards real world applications is very important and crucial in BCI research. This work shows that ten naive subjects can be trained in a synchronous paradigm within three sessions to navigate freely through a virtual apartment, whereby at every junction the subjects could decide by their own, how they wanted to explore the virtual environment (VE). This virtual apartment was designed similar to a real world application, with a goal-oriented task, a high mental workload, and a variable decision period for the subject. All subjects were able to perform long and stable motor imagery over a minimum time of 2 s. Using only three electroencephalogram (EEG) channels to analyze these imaginations, we were able to convert them into navigation commands. Additionally, it could be demonstrated that motivation is a very crucial factor in BCI research; motivated subjects perform much better than unmotivated ones.     

An Open Source Power System Virtual Laboratory: The PSAT Case and Experience

This paper describes the authors' experience in the assessment of laboratory activities based on an open source software package for power system analysis, namely, Power System Analysis Toolbox (PSAT). PSAT is currently used in several universities for both undergraduate and graduate courses. PSAT has also its own Web forum, which provides support to students and researchers all around the world, thus resulting in an almost unique example of ldquovirtual laboratoryrdquo over the Internet. This paper attempts to answer through a variety of real-life examples the following open questions: What are the practical and pedagogical advantages of using an open source software with respect to proprietary software for power system analysis? What happens if a power system virtual laboratory is freely available on the Web? What is the difference between a class-based and a Web-based virtual laboratory?     

基于Unity3D的《电机拖动》虚拟实验室设计与开发

虚拟现实技术（VR）是近年来最炙手可热的前沿技术。本文结合《电机拖动》课程的实验和虚拟现实技术,针对普通高校实验中存在的问题,提出了一种虚拟实验室的解决方案。该平台的设计采用Unity3d引擎和3Dmax三维绘图软件,并使用到了虚拟现实技术、电机原理建模技术、三维建模技术和数据库技术。该实验平台包括用户登录、实验室漫游、虚拟实验3个子系统,实现了用户信息管理、参观实验室和电机仿真实验等功能。通过测试可知：该系统运行稳定、可靠,达到预期效果。     

Design and modeling of SMES based SAPF for pulsed power load demands

In this article, a Superconducting Magnetic Energy Storage (SMES) based Shunt Active Power Filter (SAPF) topology is proposed to compensate high power pulsating load demands in a power system. The SMES based SAPF is designed and modeled to realize as an efficient compensator for the compensation of pulsed power load demands. The conventional SAPF is efficient to mitigate the power quality problems in a power system unless there is high power pulsating load demands, transient conditions or power fluctuations. Particularly, a Modified Synchronous Reference Frame (MSRF) control algorithm has been implemented to generate proper switching signals for the three-phase Voltage Source Converter (VSC) of the SMES based SAPF. In the simulation, it has been seen that the SAPF is incompetent under high power pulsating load demands whereas the SMES based SAPF has shown excellent performance under such load conditions. Moreover, a comparative analysis has been made between the conventional SAPF and the SMES based SAPF under pulsating load conditions, to check the effectiveness of the SMES based SAPF. The performance of the proposed system is presented by using Sim Power System (SPS)/MATLAB Simulink and real-time digital simulator laboratory (RTDS-Lab).