Data Acquisition Interface Research Articles

TELICS—A Telescope Instrument Control System for Small/Medium Sized Astronomical Observatories

ABSTRACTFor any modern astronomical observatory, it is essential to have an efficient interface between the telescope and its back-end instruments. However, for small and medium-sized observatories, this requirement is often limited by tight financial constraints. Therefore a simple yet versatile and low-cost control system is required for such observatories to minimize cost and effort. Here we report the development of a modern, multipurpose instrument control system TELICS (Telescope Instrument Control System) to integrate the controls of various instruments and devices mounted on the telescope. TELICS consists of an embedded hardware unit known as a common control unit (CCU) in combination with Linux-based data acquisition and user interface. The hardware of the CCU is built around the ATmega 128 microcontroller (Atmel Corp.) and is designed with a backplane, master-slave architecture. A Qt-based graphical user interface (GUI) has been developed and the back-end application software is based on C/C++. TELICS provides feedback mechanisms that give the operator good visibility and a quick-look display of the status and modes of instruments as well as data. TELICS has been used for regular science observations since 2008 March on the 2 m, f/10 IUCAA Telescope located at Girawali in Pune, India.

Towards a modular, versatile and portable sensor system for measurements in gaseous environments based on microcantilevers

Microfabricated silicon cantilever sensor arrays represent a powerful platform for sensing applications in physics, chemistry, material science, biology and medicine. The sensor response is mechanical bending due to absorption of molecules. In gaseous environment, polymer-coated microcantilevers are used as electronic nose for characterization of vapors, resulting in cantilever bending due to polymer swelling upon exposure. Medical applications involve fast characterization of exhaled patient's breath samples for detection of diseases, based on the presence of certain chemicals in breath. We present a portable, compact, modular microcantilever setup, which uses a micropump for aspiration and a bluetooth interface for remote data acquisition.

Effect of home-based telemonitoring using mobile phone technology on the outcome of heart failure patients after an episode of acute decompensation: randomized controlled trial.

BackgroundTelemonitoring of patients with chronic heart failure (CHF) is an emerging concept to detect early warning signs of impending acute decompensation in order to prevent hospitalization.ObjectiveThe goal of the MOBIle TELemonitoring in Heart Failure Patients Study (MOBITEL) was to evaluate the impact of home-based telemonitoring using Internet and mobile phone technology on the outcome of heart failure patients after an episode of acute decompensation.MethodsPatients were randomly allocated to pharmacological treatment (control group) or to pharmacological treatment with telemedical surveillance for 6 months (tele group). Patients randomized into the tele group were equipped with mobile phone–based patient terminals for data acquisition and data transmission to the monitoring center. Study physicians had continuous access to the data via a secure Web portal. If transmitted values went outside individually adjustable borders, study physicians were sent an email alert. Primary endpoint was hospitalization for worsening CHF or death from cardiovascular cause.ResultsThe study was stopped after randomization of 120 patients (85 male, 35 female); median age was 66 years (IQR 62-72). The control group comprised 54 patients (39 male, 15 female) with a median age of 67 years (IQR 61-72), and the tele group included 54 patients (40 male, 14 female) with a median age of 65 years (IQR 62-72). There was no significant difference between groups with regard to baseline characteristics. Twelve tele group patients were unable to begin data transmission due to the inability of these patients to properly operate the mobile phone (“never beginners”). Four patients did not finish the study due to personal reasons. Intention-to-treat analysis at study end indicated that 18 control group patients (33%) reached the primary endpoint (1 death, 17 hospitalizations), compared with 11 tele group patients (17%, 0 deaths, 11 hospitalizations; relative risk reduction 50%, 95% CI 3-74%, P = .06). Per-protocol analysis revealed that 15% of tele group patients (0 deaths, 8 hospitalizations) reached the primary endpoint (relative risk reduction 54%, 95% CI 7-79%, P= .04). NYHA class improved by one class in tele group patients only (P< .001). Tele group patients who were hospitalized for worsening heart failure during the study had a significantly shorter length of stay (median 6.5 days, IQR 5.5-8.3) compared with control group patients (median 10.0 days, IQR 7.0-13.0; P= .04). The event rate of never beginners was not higher than the event rate of control group patients.ConclusionsTelemonitoring using mobile phones as patient terminals has the potential to reduce frequency and duration of heart failure hospitalizations. Providing elderly patients with an adequate user interface for daily data acquisition remains a challenging component of such a concept.

Chatter prevention for milling process by acoustic signal feedback

This paper presents how real-time chatter prevention can be realized by feedback of acoustic cutting signal, and the efficacy of the proposed adaptive spindle speed tuning algorithm is verified as well. The conventional approach to avoid chatter is to select a few appropriate operating points according to the stability lobes by experiments and then always use these preset cutting conditions. For most cases, the tremble measurement, obtained by accelerometers or dynamometers, is merely to monitor spindle vibration or detect the cutting force, respectively. In fact, these on-line measures can be more useful, instead of always being passive. Furthermore, most of these old-fashioned methodologies are invasive, expensive, and cumbersome at the milling stations. On the contrary, the acoustic cutting signal, which is fed into the data acquisition interface, Module DS1104 by dSPACE, so that an active feedback loop for spindle speed compensation can be easily established in this research, is non-invasive, inexpensive, and convenient to facilitate. In this research, both the acoustic chatter signal index (ACSI) and spindle-speed compensation strategy (SSCS) are proposed to quantify the acoustic signal and compensate the spindle speed, respectively. By converting the acoustic feedback signal into ACSI, an appropriate spindle speed compensation rate (SSCR) can be determined by SSCS based on real-time chatter level. Accordingly, the compensation command, referred to as added-on voltage (AOV), is applied to actively tune the spindle motor speed. By employing commercial software MATLAB/Simulink and DS1104 interface module to implement the intelligent controller, the proposed chatter prevention algorithm is practically verified by intensive experiments. By inspection on the precision and quality of the workpiece surface after milling, the efficacy of the real-time chatter prevention strategy via acoustic signal feedback is further examined and definitely assured.

Study on the yarn compressive stresses at balloon control ring by signal processing

Process monitoring and online control of each process in textile industry has received significant attention nowadays. Yarn tension plays an important role in ring spinning and there are a few methods for real-time measurement of yarn tension. To obtain machine efficient parameters, it is necessary to understand how operating variables determine yarn tension and balloon dynamic stability. In this study, compressive stresses that are acting on the yarn by balloon control ring are investigated by manipulating of signal processing. An experimental set up is devised for capturing and monitoring the signals through of a data acquisition interface. The results show that decreasing the balloon height or increasing the traveler mass will lead to a decrease in compressive forces acting on yarn at balloon control ring. Analysis of variance, Bonferroni test and linear regression methods were used to evaluate the results. The results have been analyzed in the frequency area as well.

A neural network implemented microcontroller system for quantitative classification of hazardous organic gases in the ambient air

In this study, a microcontroller-based gas mixture classification system is proposed to use real-time analyses of the trichloroethylene and acetone binary mixture. A Feed Forward Neural Network (FFNN) structure is performed for quantitative identification of individual gas concentrations (trichloroethylene and acetone) in their gas mixtures. The phthalocyaninecoated Quartz Crystal Microbalance (QCM) type sensors were used as gas sensors. A calibrated Mass Flow Controller (MFC) was used to control the flow rates of carrier gas and trichloroethylene and acetone gas mixtures streams. The components in the binary mixture were quantified by applying the sensor responses from the QCMs sensor array as inputs to the FFNN. The microcontroller-based gas mixture classification system performs Neural Network (NN)-based estimation, the data acquisition and user interface tasks. This system can estimate the gas concentrations of trichloroethylene and acetone with the average errors of 0.08% and 0.97%, respectively.

Computer-controlled high-temperature single-crystal X-ray diffraction experiments and temperature calibration

This work provides a simple way to operate and calibrate single-crystal gas flow heaters that use heating currents up to 10 A. Devices used for this task are an I-7019R data acquisition interface (ICP DAS Co. Ltd, Hsinchu, Taiwan) and an SDP-2210 power unit (Manson Engineering Industrial Ltd, Hong Kong;Imax= 10 A,Vmax= 20 V), which are both connected to one computer. The presented open source softwarehtcontrol(http://htcontrol.sourceforge.net) is able to control the heating current and to monitor the temperature, which allows automated calibrations. In particular, this work targets Stoe IPDS II diffractometer systems with a Heatstream high-temperature (HT) device. The extra hard- and software enables computer-controlled HT data collection series, which are performed utilizing theWinXposesoftware (Stoe &amp; Cie GmbH, Darmstadt, Germany). New developments inWinXposeallow non-interactive data collections, which are controlled by means of an XML file specifying the measurement conditions.

The Assessment of Stability and Reliability of a Virtual Reality-Based Intravenous Injection Simulator

The aim of this study was to validate the feasibility of a virtual reality-based (without haptic feedback) intravenous injection system as an effective tool for computer-assisted instruction and training. The stability and reliability of the system were assessed. A personal computer, a needle/catheter device, and a data acquisition interface are included in this system. Using Virtual Reality Modeling Language, an interactive virtual environment was developed. Ten participants, ranging from 20 to 28 years of age, were recruited for this study. The self-learning and training procedures encompassed an intravenous catheterization process. The experimental results showed that after a few trials, the change in task time was not obvious in each trial, and the error frequency decreased slightly with more trials. High intraclass correlation coefficients also were obtained for task time and error frequency by analyzing the test-retest reliability. These results indicated that the system was stable and that the system reliability was acceptable.

Activation of Extracellular Signal-Regulated Protein Kinase in Sensory Neurons After Noxious Gastric Distention and Its Involvement in Acute Visceral Pain in Rats

Changes in the properties of visceral sensory neurons contribute to the development of gastrointestinal pain. However, little is known about the molecules involved in mechanosensation from the gastrointestinal tract. We investigated the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), a member of the mitogen-activated protein kinase cascade, in dorsal root ganglion (DRG) and nodose ganglion (NG) neurons by noxious gastric distention (GD) and its involvement in acute visceral pain in rats. Electromyographic responses to gastric balloon distention through gastrostomy were recorded from the acromiotrapezius muscle in rats after splanchnic nerve resection or vagotomy and in control rats. We then examined the phosphorylated-ERK1/2 (p-ERK1/2) labeling in the DRG and NG after GD using immunohistochemistry. Gastric distention induced p-ERK1/2 in DRG and NG neurons with a peak at 2 minutes after stimulation. We found a stimulus intensity-dependent increase in the number of activated neurons, and this activation corresponded well with the incidence of the visceromotor response. Most of these p-ERK1/2-labeled neurons were small- and medium-sized neurons that coexpressed transient receptor potential vanilloid 1 ion channel and acid-sensing ion channel 3. Splanchnic nerve resection, but not vagotomy, affected the visceromotor response, and attenuated the ERK1/2 activation in DRG neurons produced by GD. Furthermore, intrathecal administration of the mitogen-activated protein kinase kinase 1/2 inhibitor, U0126, altered the response to noxious GD. The activation of ERK1/2 pathways in DRG neurons by noxious GD may be correlated with functional activity, and may be involved in acute visceral pain.

Low-cost accelerometers for physics experiments

The implementation of a modern game-console controller as a data acquisition interface for physics experiments is discussed. The investigated controller is equipped with three perpendicular accelerometers and a built-in infrared camera to evaluate its own relative position. A pendulum experiment is realized as a demonstration of the proposed approach.

Improved uncertainty for a modified commercial emissometer

Three techniques were used to improve the measurement uncertainty of a commercial emissometer, which was manufactured by the Devices and Services Company. In order to mitigate the errors from ambient disturbance, the emissometer was put into a thermostat water bath, i.e. a heat sink, and wrapped with insulators. A data acquisition interface was added in the emissiometer system for the purpose of automatic data acquisition. This allows statistical data sampling and accurate analysis can be performed. A secondary standard meter was used to closely monitor both signals from the thermalpile and the output of the standard platinum resistance thermometer (SPRT). Thermal error due to the temperature difference between the water bath and ambient was thus reduced. These new amendments to the emissometer improve the expanded uncertainty of about 160%. A detailed analysis is included in this paper. Results from simulation confirmed that the enhanced thermal insulation forced the major heat current within the emissometer to drain from the heat sink through the electric connectors to the ambient.

Measurement system using ultraviolet and multiband infrared technology for identifying fire behavior

Multisensor-based fire alarm systems have been developed as an automatic fire detection technology. However, only two or three fire signatures do not suffice to recognize a fire. Conventional fire detectors must touch sufficient targets (heat or smoke) so that they respond slowly to the alarm. This article proposes several approaches that use the radiation-sensing technologies to detect fire behaviors. Four features, temperature, hot CO2 gas, flicker, and the UV energy of the flame are adopted in the system to analyze the fire traits. Four kinds of sensors and one IR transducer are used successfully to evaluate these features. Experimental results show that the use of two pyroelectric sensors can accurately “see” the appearance of combustion by detecting the CO2 emission instead of the particle density of smoke. The combination of a blue and an UV sensor is used effectively to pickup the UV component of the flame. The information is presented on a personal computer using LABVIEW software and a data-acquisition interface. Although this article focuses on techniques for measuring IR and UV energies, in off-line work, a trained back-propagation network verifies that the measuring system is effective in collecting the information on fire behaviors. Results of this study provide a valuable reference for designers in developing a novel fire detector.

Micro- and Nano-instrument Power

ABSTRACTFor the last several years, we have been developing and characterizing “mobile” micro- and nano-instruments for use on-site (e.g., in the field). Although such portable, battery-operated instruments are much smaller that their laboratory-scale counterparts, sometimes they provide comparable performance and they often offer improved capabilities. As such, they are expected to cause a paradigm shift in classical chemical analysis by allowing practioners to “bring the lab (or part of it) to the sample”. Two classes of examples will be used as the means with which to illustrate the power of micro- and nano-instruments. One class involves a “patient” as the sample and an ingestible capsule-size spectrometer used for cancer diagnosis of the gastro intestinal tack as (part of) “the lab”. The other involves the “environment” as the sample and a portable, battery-operated, miniaturized instrument that utilizes a PalmPilot™ with a wireless interface for data acquisition and signal processing as (part of) “the lab”. To discuss how to electrically power such miniaturized instruments, mobile energy issues will be addressed. Particular emphasis will be paid to current or anticipated future applications and to the paradigm shifts that may prove essential in powering the next generation of miniaturized instruments.

Improved superfusion technique for rapid cooling or heating of cultured cells under patch-clamp conditions

We have developed an improved technique for fast cooling and heating of solutions superfusing isolated cells under patch-clamp or calcium imaging conditions. The system meets the requirements for studying temperature dependency of all kinds of ion channels, in particular temperature-gated ion channels. It allows the application of temperature changes within a range of 5–60 °C at maximum rates of −40 °C/s to 60 °C/s. Barrels filled with different solutions are connected to a manifold consisting of seven silica capillaries (320 μm inner diameter, i.d.). A common outlet consists of a glass capillary through which the solutions are applied onto the cell surface. The upper part of this capillary is embedded in a temperature exchanger driven by a miniature Peltier device which preconditions the temperature of the passing solution. The lower part of the capillary carries an insulated copper wire, densely coiled over a length of 7 mm, and connected to a dc current source for resistive heating. The Peltier device and the heating element are electrically connected to the headstage probe which is fixed on to a micromanipulator for positioning of the manifold. The temperature of the flowing solution is measured by a miniature thermocouple inserted into the common outlet capillary near to its orifice which is placed at a distance of less than 100 μm from the surface of the examined cell. The temperature is either manually controlled by voltage commands or adjusted via the digital-to-analog converter of a conventional data acquisition interface. Examples are given of using the device in patch-clamp studies on heterologously expressed TRPV1, TRPM8, and on cultured rat sensory neurons.

Simple and versatile data acquisition interface embedded with microprocessor(H8/3069) for fundamental experiment course in physiology

Simple and versatile data acquisition interface embedded with microprocessor(H8/3069) for fundamental experiment course in physiology

Industrial Trials of Paste Drying in Spouted Beds Under QDMC

Spouted bed has been extensively investigated by many authors for years, but the issue of controlling its operation still remains in basic developing stages. The present work consists of the application of an advanced control strategy (QDMC—Quadratic Dynamic Matrix Control) to automate the operation of a large-scale spouted bed dryer. The work on control strategies for spouted bed was motivated by the lack of references on this subject and the encouraging results obtained by Corrêa et al. (Corrêa, N.A.; Freire, J.T.; Corrêa, R.G. Improving operability of spouted beds using a simple optimizing control structure. Brazilian Journal of Chemical Engineering 1999 16 (4), 359–368; Corrêa N.A. Corrêa, R.G.; Freire, J.T. Adaptive control of paste drying in spouted bed using the GPC algorithm. Brazilian Journal of Chemical Engineering 2000 17 (4–7), 639–648; Corrêa, N.A.; Corrêa, R.G.; Freire, J.T. Self-tuning control of egg drying in spouted bed using the GPC algorithm. Drying Technology 2002 20 (4), 813–828.) for a laboratory-scale apparatus. The industrial-scale spouted bed dryer has a height of 4 m and a diameter of 66 cm. The same configuration of data acquisition unit, sensors, and interface developed for the laboratory-scale unit was employed. The dryer is capable of processing up to 20 L/h of pasty material. The powder moisture content (Ys), inferred from measurements of temperature at the exhaustion of the bed bulk, and the powder production rate (Pr), measured on-line by an electronic balance, are the controlled variables. The manipulated variables are: the paste inflow rate (W), regulated by an automatic pump, and the electrical power supply for air heating (P), regulated by a thyristor. The bed pressure drop, the airflow rate, and the information from the environment are monitored by means of an interfaced microcomputer. Experimental runs of drying up to 400 kg/day of an Al2O3 10% aqueous suspension were carried out. The results showed that the QDMC control is robust with respect to the main variables involved and is efficient in maintaining the operation of the bed under the constraints of the system. The major aim concerning the scale-up of spouted bed, which is the determination of the minimum amount of energy required to ensure spout stability, was accomplished by the constrained control strategy.

Uniform management of data acquisition devices with XML

A comprehensive model based on XML technologies to interface data acquisition hardware devices for configuration and control purposes is presented. The model builds upon the use of a unified syntax for describing hardware devices, configuration data, test results and control sequences. An implementation and an evaluation together with an application scenario are presented.

Pyroelectric infrared sensor-based thermometer for monitoring indoor objects

This article describes a system for measuring temperature by monitoring an object’s radiation in the infrared spectrum. Using a measuring device by passing through a data acquisition interface, a long-term observation of the temperature variance of objects on a personal computer by the LabVIEW software is conducted. A special mechanism joined with a pyroelectric infrared (PIR) sensor, optical chopper, and Fresnel lens is presented in this system. This separable architecture makes the lens easily replaceable and portable. In this study, the PIR sensor into a quantitative measurement for long-term and long-distance applications with calibration equipment based on a blackbody and some electrometers was successfully applied. Experimental results show that the measuring device only has an average error rate of 1.21% in the overall range from 40 to 200 °C, and field of view is 4.58°. The results confirm that noncontacted temperature measurement using a PIR sensor is feasible.

Development of a remote-access laboratory: a dc motor control experiment

This paper presents the development of a remote-access control system which allows users to perform control experiments through Internet. A dc motor control module is used as an example to illustrate our design. The system is composed of an internal distributed system and an application system linked by a data acquisition (DAQ) interface card. Web server, video server and Laboratory Virtual Instrument Engineering Workbench (LabVIEW) controller server are designed based on a client–server structure. The experiment can be accessed from http://www.acae.cuhk.edu.hk/∼accl/ibc/.

A portable microelectrode array recording system incorporating cultured neuronal networks for neurotoxin detection

Cultured neuronal networks, which have the capacity to respond to a wide range of neuroactive compounds, have been suggested to be useful for both screening known analytes and unknown compounds for acute neuropharmacologic effects. Extracellular recording from cultured neuronal networks provides a means for extracting physiologically relevant activity, i.e. action potential firing, in a noninvasive manner conducive for long-term measurements. Previous work from our laboratory described prototype portable systems capable of high signal-to-noise extracellular recordings from cardiac myocytes. The present work describes a portable system tailored to monitoring neuronal extracellular potentials that readily incorporates standardized microelectrode arrays developed by and in use at the University of North Texas. This system utilizes low noise amplifier and filter boards, a two-stage thermal control system with integrated fluidics and a graphical user interface for data acquisition and control implemented on a personal computer. Wherever possible, off-the-shelf components have been utilized for system design and fabrication. During use with cultured neuronal networks, the system typically exhibits input referred noise levels of only 4–6 μV RMS, such that extracellular potentials exceeding 40 μV can be readily resolved. A flow rate of up to 1 ml/min was achieved while the cell recording chamber temperature was maintained within a range of 36–37 °C. To demonstrate the capability of this system to resolve small extracellular potentials, pharmacological experiments with cultured neuronal networks have been performed using ion channel blockers, tetrodotoxin and tityustoxin. The implications of the experiments for neurotoxin detection are discussed.