Commercial Data Acquisition System Research Articles

Low-Power Long-Term Ambulatory Electrocardiography Monitor of Three Leads with Beat-to-Beat Heart Rate Measurement in Real Time.

A low-power long-term ambulatory ECG monitor was developed for the acquisition, storage and processing of three simultaneous leads DI, aVF and V2 with a beat-to-beat heart rate measurement in real time. It provides long-term continuous ECG recordings until 84 h. The monitor uses a QRS complex detection algorithm based on the continuous wavelet transform with splines, which automatically selects the scale for the analysis of ECG records with different sampling frequencies. It includes a lead-off detection to continuously monitor the electrode connections and a real-time system of visual and acoustic alarms to alert users of abnormal conditions in its operation. The monitor presented is based in an ADS1294 analogue front end with four channels, 24-bit analog-to-digital converters and programmable gain amplifiers, a low-power dual-core ESP32 microcontroller, a microSD memory for data storage in a range of 4 GB to 32 GB and a 1.4 in thin-film transistor liquid crystal display (LCD) variant with a resolution of 128 × 128 pixels. It has programmable sampling rates of 250, 500 and 1000 Hz; a bandwidth of 0 Hz to 50% of the selected sampling rate; a CMRR of -105 dB; an input margin of ±2.4 V; a resolution of 286 nV; and a current consumption of 50 mA for an average battery life of 84 h. The ambulatory ECG monitor was evaluated with the commercial data-acquisition system BIOPAC MP36 and its module for ECG LABEL SS2LB, simultaneously comparing the morphologies of two ECG records and obtaining a correlation of 91.78%. For the QRS detection in real time, the implemented algorithm had an error less than 5%. The developed ambulatory ECG monitor can be used for the analysis of the dynamics of the heart rate variability in long-term ECG records and for the development of one's own databases of ECG recordings of normal subjects and patients with cardiovascular and noncardiovascular diseases.

Stochastic Memristive Interface for Neural Signal Processing.

We propose a memristive interface consisting of two FitzHugh–Nagumo electronic neurons connected via a metal–oxide (Au/Zr/ZrO2(Y)/TiN/Ti) memristive synaptic device. We create a hardware–software complex based on a commercial data acquisition system, which records a signal generated by a presynaptic electronic neuron and transmits it to a postsynaptic neuron through the memristive device. We demonstrate, numerically and experimentally, complex dynamics, including chaos and different types of neural synchronization. The main advantages of our system over similar devices are its simplicity and real-time performance. A change in the amplitude of the presynaptic neurogenerator leads to the potentiation of the memristive device due to the self-tuning of its parameters. This provides an adaptive modulation of the postsynaptic neuron output. The developed memristive interface, due to its stochastic nature, simulates a real synaptic connection, which is very promising for neuroprosthetic applications.

An open source motorized swivel for in vivo neural and behavioral recordings

In this work we propose an open source, cost-effective motorized swivel for behavioral and neural recordings in small rodents, offering a flexible solution for managing cable twisting and tangling in a variety of experimental settings with minimal human supervision.•The device operates independently of the data acquisition system, and it can be controlled through any popular platform such as Arduino or Raspberry Pi.•All mechanical parts are 3D-printed, allowing to customize the design to fit specific experimental needs, and electromechanical components can be sourced from all major distributors, keeping the cost for the entire system under $500.•The proposed commutator is compatible with commercial or custom data acquisition systems supporting up to 10 data lines (2 for LVDS signals) and 2 power lines.

Signal enhancement due to high-Z nanofilm electrodes in parallel plate ionization chambers with variable microgaps.

We developed a method for measuring signal enhancement produced by high-Z nanofilm electrodes in parallel plate ionization chambers with variable thickness microgaps. We used a laboratory-made variable gap parallel plate ionization chamber with nanofilm electrodes made of aluminum-aluminum (Al-Al) and aluminum-tantalum (Al-Ta). The electrodes were evaporated on 1mm thick glass substrates. The interelectrode air gap was varied from 3μm to 1cm. The gap size was measured using a digital micrometer and it was confirmed by capacitance measurements. The electric field in the chamber was kept between 0.1kV/cm and 1kV/cm for all the gap sizes by applying appropriate compensating voltages. The chamber was exposed to 120kVp X-rays. The current was measured using a commercial data acquisition system with temporal resolution of 600Hz. In addition, radiation transport simulations were carried out to characterize the dose, D(x), high-energy electron current, J(x), and deposited charge, Q(x), as a function of distance, x, from the electrodes. A deterministic method was selected over Monte Carlo due to its ability to produce results with 10nm spatial resolution without stochastic uncertainties. Experimental signal enhancement ratio, SER(G) which we defined as the ratio of signal for Al-air-Ta to signal for Al-air-Al for each gap size, was compared to computations. The individual contributions of dose, electron current, and charge deposition to the signal enhancement were determined. Experimental signals matched computed data for all gap sizes after accounting for several contributions to the signal: (a) charge carrier generated via ionization due to the energy deposited in the air gap, D(x); (b) high-energy electron current, J(x), leaking from high-Z electrode (Ta) toward low-Z electrode (Al); (c) deposited charge in the air gap, Q(x); and (d) the decreased collection efficiency for large gaps (>~500μm). Q(x) accounts for the electrons below 100eV, which are regarded as stopped by the radiation transport code but which can move and form electron current in small gaps (<100μm). While the total energy deposited in the air gap increases with gap size for both samples, the average high-energy current and deposited charge are moderately decreasing with the air gap. When gap sizes are smaller than ~20μm, the contribution to signal from dose approaches zero while contributions from high-energy current and deposited charges give rise to an offset signal. The measured signal enhancement ratio (SER) was 40.0±5.0for the 3μm gap and rapidly decreasing with gap size down to 9.9±1.2 for the 21μm gap and to 6.6±0.3 for the 100μm gap. The uncertainties in SER were mostly due to uncertainties in gap size and data acquisition system. We developed an experimental method to determine the signal enhancement due to high-Z nanolayers in parallel plate ionization chambers with micrometer spatial resolution. As the water-equivalent thicknesses of these air gaps are 3nm to 10μm, the method may also be applicable for nanoscopic spatial resolution of other gap materials. The method may be extended to solid insulator materials with low Z.

Topological detector: measuring continuous dosimetric quantities with few-element detector array

A prototype topological detector was fabricated and investigated for quality assurance of radiation producing medical devices. Unlike a typical array or flat panel detector, a topological detector, while capable of achieving a very high spatial resolution, consists of only a few elements and therefore is much simpler in construction and more cost effective. The key feature allowing this advancement is a geometry-driven design that is customized for a specific dosimetric application. In the current work, a topological detector of two elements was examined for the positioning verification of the radiation collimating devices (jaws, MLCs, and blades etc). The detector was diagonally segmented from a rectangular thin film strip (2.5 cm × 15 cm), giving two contiguous but independent detector elements. The segmented area was the central portion of the strip measuring 5 cm in length. Under irradiation, signals from each detector element were separately digitized using a commercial multichannel data acquisition system. The center and size of an x-ray field, which were uniquely determined by the collimator positions, were shown mathematically to relate to the difference and sum of the two signals. As a proof of concept, experiments were carried out using slit x-ray fields ranging from 2 mm to 20 mm in size. It was demonstrated that, the collimator positions can be accurately measured with sub-millimeter precisions.

Measuring the Noise Cumulative Distribution Function Using Quantized Data

This paper considers the problem of estimating the cumulative distribution function and probability density function of a random variable using data quantized by uniform and non-uniform quantizers. A simple estimator is proposed based on the empirical distribution function that also takes the values of the quantizer transition levels into account. The properties of this estimator are discussed and analyzed at first by simulations. Then by removing all assumptions that are difficult to apply, a new procedure is described that does not require neither the transition levels nor the input sequence used to source the quantizer to be known. The experimental results obtained using a commercial 12-b data acquisition system show the applicability of this estimator to real-world type of problems.

Development and programming of Geophonino: A low cost Arduino-based seismic recorder for vertical geophones

The commercial data acquisition systems used for seismic exploration are usually expensive equipment. In this work, a low cost data acquisition system (Geophonino) has been developed for recording seismic signals from a vertical geophone. The signal goes first through an instrumentation amplifier, INA155, which is suitable for low amplitude signals like the seismic noise, and an anti-aliasing filter based on the MAX7404 switched-capacitor filter. After that, the amplified and filtered signal is digitized and processed by Arduino Due and registered in an SD memory card. Geophonino is configured for continuous registering, where the sampling frequency, the amplitude gain and the registering time are user-defined. The complete prototype is an open source and open hardware system. It has been tested by comparing the registered signals with the ones obtained through different commercial data recording systems and different kind of geophones. The obtained results show good correlation between the tested measurements, presenting Geophonino as a low-cost alternative system for seismic data recording.

Prototypes of self-powered radiation detectors employing intrinsic high-energy current.

The authors experimentally investigate the effect of direct energy conversion of x-rays via selfpowered Auger- and photocurrent, potentially suitable to practical radiation detection and dosimetry in medical applications. Experimental results are compared to computational predictions. The detector the authors consider is a thin-film multilayer device, composed of alternating disparate electrically conductive and insulating layers. This paper focuses on the experiments while a companion paper introduces the fundamental concepts of high-energy current (HEC) detectors. The energy of ionizing radiation is directly converted to detector signal via electric current induced by high-energy secondary electrons generated in the detector material by the incident primary radiation. The HEC electrons also ionize the dielectric and the resultant charge carriers are selfcollected due to the contact potential of the disparate electrodes. Thus, an electric current is induced in the conductors in two different ways without the need for externally applied bias voltage or amplification. Thus, generated signal in turn is digitized by a data acquisition system. To determine the fundamental properties of the HEC detector and to demonstrate its feasibility for medical applications, the authors used a planar geometry composed of multilayer microstructures. Various detectors with up to seven conducting layers with different combinations of materials (250 μm Al, 35 μm Cu, 100 μm Pb) and air gaps (100 μm) were exposed to nearly plane-parallel 60-120 kVp x-ray beams. For the experimental design and verification, the authors performed coupled electron-photon radiation transport computations. The detector signal was measured using a commercial data acquisition system with 24 bits dynamic range, 0.4 fC sensitivity, and 0.9 ms sampling time. Measured signals for the prototype detector varied depending on the number of layers, material type, and incident photon energy, and it was in the range of 30-150 nA/cm(2) for unit air kerma (1 Gy), which is viable for practical applications. The experiments had an excellent agreement with the computations. Within the examined range of 60-120 kVp, the energy dependence of the HEC (normalized to the x-ray tube output) was relatively small. Based on the experimental results for 100 ms sampling time, it would be possible to measure the time dependence of x-ray beams for x-ray tube current of 0.1 mA or higher. Significant advantages of the HEC device are that generation of its signal does not require external power supply, it can be made in any size and shape, including flexible curvilinear forms, and it is inexpensive. It remains to be determined, which of the potential applications in medical dosimetry (both in vivo and external), or radiation protection would benefit from such selfpowered detectors.

Low-Cost System to Evaluate Impact Localization in Composite Plates

The development of composite materials has been following a growing trend, with its use ranging from sporting goods to construction materials and defense. The aerospace industry in particular has observed a minute increase in demand for these materials, since the associated weight reductions promise significant savings in fuel related costs. Composite materials, however, are prone to important and very specific failure modes which are invisible to the naked eye (e.g., delaminations, fiber ruptures, debondings) and occur in response to everyday events such as impacts. Thus, usage of these materials in critical areas of airplanes (e.g. wings and fuselage) is subject to the development of technologies able to continuously and precisely monitor existence, type and extent of failures. Impact localization plays a key role within this paradigm allowing identification of hot spots, that is, areas subjected to potentially damaging phenomena, for further analysis. Several such techniques have already been developed, but anisotropy, precision, robustness and cost are common drawbacks amongst their implementation. The present study was directed to the use of conditioned piezoelectric sensors along with low cost commercial off-the shelf data acquisition system to implement a reliable impact localization method.

SU-E-T-111: Development of Proton Dosimetry System Using Fiber-Optic Cerenkov Radiation Sensor Array

Purpose: We had developed and evaluated a new dosimetric system for proton therapy using array of fiber-optic Cerenkov radiation sensor (FOCRS) which can measure a percent depth dose (PDD) instantly. In this study, the Bragg peaks and spread out Bragg peak (SOBP) of the proton beams measured by FOCRS array were compared with those measured by an ion chamber. Methods & Method: We fabricated an optical fiber array of FOCRS in a handmade phantom which is composed of poly-methyl methacrylate (PMMA). There are 75 holes of 1mm diameter inside the phantom which is designed to be exposed in direction of beam when it is emerged in water phantom. The proton beam irradiation was carried out using IBA cyclotron PROTEUS 235 at national cancer center in Korea and a commercial data acquisition system was used to digitize the analog signal. Results: The measured Bragg peak and SOBP for the proton ranges of 7∼ 20 cm were well matched with the result from ion chamber. The comparison results show that the depth of proton beam ranges and the width of SOBP measured by array of FOCRS are comparable with the measurement from multi-layer ion chamber (MLIC) although there are some uncertainty in the measurement of FOCRS array for some specific beam ranges. Conclusion: The newly developed FOCRS array based dosimetric system for proton therapy can efficiently reduce the time and effort needed for proton beam range measurement compared to the conventional method and has the potential to be used for the proton pencil beam application.

CRionScan: A stand-alone real time controller designed to perform ion beam imaging, dose controlled irradiation and proton beam writing

High resolution ion microbeams, usually used to perform elemental mapping, low dose targeted irradiation or ion beam lithography needs a very flexible beam control system. For this purpose, we have developed a dedicated system (called “CRionScan”), on the AIFIRA facility (Applications Interdisciplinaires des Faisceaux d’Ions en Région Aquitaine). It consists of a stand-alone real-time scanning and imaging instrument based on a Compact Reconfigurable Input/Output (Compact RIO) device from National Instruments™. It is based on a real-time controller, a Field Programmable Gate Array (FPGA), input/output modules and Ethernet connectivity. We have implemented a fast and deterministic beam scanning system interfaced with our commercial data acquisition system without any hardware development. CRionScan is built under LabVIEW™ and has been used on AIFIRA’s nanobeam line since 2009 (Barberet et al., 2009, 2011) [1,2]. A Graphical User Interface (GUI) embedded in the Compact RIO as a web page is used to control the scanning parameters. In addition, a fast electrostatic beam blanking trigger has been included in the FPGA and high speed counters (15MHz) have been implemented to perform dose controlled irradiation and on-line images on the GUI. Analog to Digital converters are used for the beam current measurement and in the near future for secondary electrons imaging. Other functionalities have been integrated in this controller like LED lighting using Pulse Width Modulation and a “NIM Wilkinson ADC” data acquisition.

KTX-산천 열차용 모터 감속기 고정대의 피로 수명 평가

In this study, fatigue life of the motor block bracket units for KTX-Sancheon trains was assessed. Design evaluation for railway structures was performed based on the UIC 566 regulation, and test and evaluation of fatigue life in welded parts was performed in accordance with standard ERRI B 12/RP17 and ERRI B 12/RP60. The actual vehicle dynamic stress testing was executed in KTX-Sancheon service line with the service operating speed. The dynamic stress was measured with commercial data acquisition system (MGC plus). The cumulative damage was evaluated by applying standard BS 7608 - Class F and cycle counting was used rain-flow counting method. As a result, the motor block bracket units for KTX-Sancheon trains was designed to fit the regulation and the safety of fatigue life for 30 years, assuming that KTX-Sancheon trains travels 600,000km annually, were confirmed under current operating conditions.

Fast and low-cost prototype of data logger for photovoltaic water pumping system

In this paper, a special microcontroller-based data-acquisition system (DAQS) for remote photovoltaic (PV) water pumping systems with available components is designed and made. The specific microcontroller was selected in order to produce a fast and low-cost prototype. These data serve to collect field's parameters, such as water flow rate, global irradiation on an inclined and horizontal surface, voltage and current of PV field and ambient temperature. To verify its functioning, some field tests and comparison of this measurement system against two other commercial DAQSs have been carried out.

Controllogger: A remote monitoring system for decentralized renewable energy sources

The development of a remote monitoring and control system for decentralized renewable energy plants is described in the present paper. The system has a microcontroller-based unit for local storing and data transmission to internet by a GSM modem and a database server to store the data. The proposed architecture is easily extended for controlling a decentralized renewable energy plant by a remote operator. Correlations and performance tests are used to compare the data collected by the system prototype with data collected by a commercial data acquisition system. The results indicate that the Root Mean Square Error (RMSE) is 0.103 m/s for the wind speed measurement and the correlation factor is greater than 0.9996. Overall, the low errors rates indicate that the data have been stored in a similar form to what would be expected with the use of a commercial data logger.

Magnetoencephalography using a Multilayer hightc DC SQUID Magnetometer

We describe tests of the use of a multilayer highTc DC SQUID magnetometer for magnetoencephalography (MEG) and compare our measurements with results obtained using a lowTc SQUID sensor. The integration of bias reversal readout electronics for highTc DC SQUID magnetometry into a commercial MEG data acquisition system is demonstrated. Results of measurements performed on a salinefilled head phantom are shown and the detection of an auditory evoked magnetic response of the human cortex elicited by a stimulus is illustrated. Future modifications of highTc DC SQUID sensors for applications in MEG, in order to reach a resolution of 1 fT/√Hz at 77.5 K over a wide frequency band, are outlined.

SU-E-T-147: Scintillating Fiber Array to Determine the Proton Beam Range

Purpose: To develop the scintillating fiber array dosimeter to determine the proton beam range for the purpose of quality assurance of the patient in the proton therapy. Methods: A scintillating fiber dosimeter was composed of a commercial scintillating fiber optically coupled with organic based optical fiber. An array of scintillating fibers was settled inside a water bath. The scintillating light was amplified by photo multiplier tube before being gathered by commercial data acquisition system. Bragg peak and SOBP was measured with scintillating fiber dosimetry. The correction of the signal between the dosimeters and quenching effect of each dosimeter itself were conducted in home-made software. The results were compared with the ion chamber.Results: The signals from each scintillating fiber dosimeter showed randomly distributed along the depth. After calibrating between the dosimeters, the signals showed similar curve to Bragg peak and SOBP. Then correcting the quenching effect made the signal to coincident with the icon chamber results Conclusions: We improved the scintillating fiber optic dosimetry system which is previously developed in scanning type to the array type. The developed dosimetry system can provided more applicable and faster way to determine the proton beam range.

SU‐GG‐T‐347: Determination of Proton Beam Range by Using Scintillating Fiber Optic Dosimetry

Purpose: Scintillating fiber type dosimeter was investigated to determine the proton beam range in a short time for the purpose of quality assurance of the patient in the proton therapy. Degradation of output signal in scintillator has to be overcome for applying the scintillating fiber dosimeter on clinical use. One dimensional dosimeter array was tried to measure the range at a time and required characteristics for this application were evaluated. Methods: The dosimetry system was composed of commercial scintillating fiber optically coupled with organic based optical fiber. Scintillating light was amplified by photo multiplier tube before being gathered by commercial data acquisition system. Bragg peak and SOBP was measured with scintillating fiber dosimetry. One dimensional scintillating fiber array dosimeter was prepared and Bragg peak and SOBP of proton beam were measured and analyzed. Results: The Bragg peak measured by scintillating fiber dosimetry showed degradation of the output signal in high dose region when comparing with the results of the ionization chamber, which is known as quenching effect of scintillator. Quenching effect could corrected by fitting the measured data to quenching equation. However, it didn't show significant degradation of the signal enough to miss the range within sub‐millimeter for the scintillator smaller than the diameter of 0.5 mm. The SOBP curve also showed good agreement with the ionization chamber results after being modified by considering the quenching effect. It can be applied to construct the scintillator array to measure the depth dose distribution at a time. Conclusions: Scintillating fiber optic dosimetry was suitable for measuring depth dose distribution of proton therapy beam and determining its range. Quenching effect of scintillator was dealt with well within our tolerable range by fitting method. One dimensional scintillating fiber array provided more applicable and faster way for applying it to clinical field.

Management of the LHCb Readout Network

The LHCb event building relies on a readout network based on Gigabit Ethernet (GbE). The readout network is extremely performance critical, sophisticated monitoring at all levels is essential for the successful operation of the data acquisition for the experiment. LHCb uses a commercial Supervisory Control and Data Acquisition (SCADA) system called PVSS II for its Experiment Control System (ECS), which consists of varied sub-systems. For the efficient operation of the experiment, it is crucial that all parts of the system are monitored and controlled through the same interface in a coherent way. The network monitoring is implemented in the same framework.We show here how a large scale network can be monitored using tools originally made for industrial supervisory control. The status of the network devices and their ports, their connectivity and the traffic are monitored in this system. Alarms can be issued to inform the experiment operators and online network experts about errors such as dropped packets or broadcast-storms. Reports and longterm monitoring using powerful trending tools are possible.

Guest Editorial: Nanophotonics for Space Applications

The application of cutting-edge photonics technology for improving the performance of space-based assets has resulted in a myriad of success stories. As early as 1981, the first photonics-based active fiber optic data links aboard the NASA Long Duration Exposure Facility (Air Force Experiment, AFWL Experiment 701, Fiber Optic Space Effects), during a 69-month orbital period in the Van Allen radiation belts convincingly demonstrated that optical fibers, III-IV laser diodes and detectors, and other photonics technology to follow would have a major role in reducing the dependency on expensive, complexly-wired system technologies, while reducing weight and volume. The proof-of-concept experiment verified the contention that reduced-size photonic systems could reduce satellite weight and volumes while dramatically increasing the bandwidth, reliability, and survivability of commercial and military satellite communication and data acquisition systems. Most importantly, the experiment provided the first conclusive evidence that properly designed photonic systems could provide excellent resistance to the natural space radiation and temperature environment. More recently, QD and nanostructure-based photovoltaic and nonlinear components and sensor arrays operating from visible wavelengths to far-IR are under investigation for near-term application in space systems. Cutting-edge photonic-nanophotonic components, materials, and systems under investigation include radiation-resistant, QD-based chip-sized nonlinear inertial guidance systems, focal plane arrays, thin film solar cells, polymer detectors, polymer modulators, active-smart optical windows, and specialized coatings, to name but a few applications, several of which are presented in this special section. The recent evolution of exotic photonic technology involving integration of nanotechnology with polymers and new molecular-hybrid nanomaterials have shown a high potential for potentially improving specific extra-terrestrial applications, as discussed in this special section. The diverse potential applications are well represented in this section and include papers on protective optical limiting coatings for spacebased sensors (Sarkar et al.), radiation-resistant properties of photovoltaic solar cells (Hubbard et al.), mitigation of Lunar regolith using nanoparticle smart coatings (Pirich et al.), and evolving radiationresistant EO polymer modulator materials (Zhang and Taylor). Recently announced plans by NASA to return to the Moon in 2020 as well as other potential interplanetary space missions will require lightweight polymer-based shielding materials for crew cabins and the protection of astronauts and components from galactic cosmic rays (GCR) during lunar surface exploration and interplanetary missions. Nanotechnology is expected to play a role in the development of some of these materials. Traditional radiation high-Z shielding materials such as lead and other heavy elements are not suitable for GCR protection since the interaction of GCR with these materials results in the production of secondary radiation which is harmful to humans and can degrade photonic and electronic components. Radiation transport calculations have shown that hydrogen-rich low-Z materials are more effective per unit mass of shield than heavier shielding elements for xor gamma-ray absorption because of their lower cross sections, and because heavier elements can serve as the sources of dose-producing secondary particles such as short-range heavy nuclear fragments and penetrating neutrons. Thus, a challenge to develop new nano-based materials and radiation-resistant photonic components for space applications appears to be well under way. Hopefully the initial sampling of papers presented in this special section on Nanophotonics for Space Applications will be well received and provide new ideas from the readership for addressing the special needs of the photonics space community. Journal of Nanophotonics, Vol. 3, 031899 (19 November 2009)

A microcontroller-based data-acquisition system for meteorological station monitoring

This paper presents a study of feasibility of different existing methodologies linked to field’s data acquisition from remote meteorological stations. The data transmission serves to collect field’s meteorological information, such as temperature, humidity and radiation. In our study the experimental data is registered in a weather station located about 100 km from the University of Almeria. Various existing techniques are studied, especially Radio, GSM (global system of mobile communication) and GPRS (general packet radio service). In the result of these studies has been designed a system of field’s data acquisition (herein referred as Meteologger) which we are going to present in this paper. The system is based on an ATmega 16 microcontroller, which scans 8 sensors together at any programmable intervals. This paper presents the study of the mentioned project, application and some main characteristics of the prototype system and its program. We attempt to implement the system, and subsequently present the performance of tests regarding the mentioned system. To verify its functioning some comparison of this measurement system with two others commercial data-acquisition system (Campbell and Hobo H8) has been carried out.