Multi-channel Acquisition System Research Articles

Design and Development of Low Cost Multi-Channel USB Data Acquisition System for the Measurement of Physical Parameters

This paper describes the design and development of low cost USB Data Acquisition System (DAS) for the measurement of physical parameters. Physical parameters such as temperature, humidity, light intensity etc., which are generally slowly varying signals are sensed by respective sensors or integrated sensors and converted into voltages. The DAS is designed using PIC18F4550 microcontroller, communicating with Personal Computer (PC) through USB (Universal Serial Bus). The designed DAS has been tested with the application program developed in Visual Basic, which allows online monitoring in graphical as well as numerical display.

Design Based on Multi-Channel Power Acquisition and Data Teletransmission System of MSP430 Simulating SPI Interface and CS5460A Communication

Real-time acquisition of multi-channel power and data teletransmission is the most frequent important problems in power system to be solved perfectly. SPI, a synchronous serial interface, can connect multiple microcontrollers and all kinds of input-output devices with SPI interface which send and receive independent. However, most microcontrollers usually only with a single SPI interface which seems powerless when it communicates with many chip in need of the way of SPI. This paper taking the three-phase power acquisition and data teletransmission design of power system as an example lays special stress on introducing a design method to well solve the above problems based on the realization of three-phase power collection through MSP430 simulating SPI interface communicating with multi-block CS5460A. The design is simple and low-cost. Moreover, it has a broad prospect of application in the fields of multi-channel data measurement and acquisition and teletransmission communication and so on.

Four Channel, 40 ps Resolution, Fully Integrated Time-to-Amplitude Converter for Time-Resolved Photon Counting

Recently, a growing interest has arisen about the time-correlated single photon counting (TCSPC) technique, that allows the analysis of fast and weak light waveforms with a time resolution in the picosecond order. Since TCSPC basically consists of the measurement of the arrival time of a photon, a high resolution and high linearity time measurement block is of the utmost importance; moreover, the use of multianode Photo Multiplier Tube and of single photon avalanche diode arrays led to the development of multichannel acquisition systems, where the time measurement block has to be integrated to reduce both cost and area. We have designed and fabricated a four channel fully integrated time-to-amplitude converter (TAC), built in 0.35 μm Si-Ge technology, characterized by an excellent time resolution (less than 50 ps full width half maximum), low differential nonlinearity (better than 0.02 LSB peak-peak and 0.0003 LSB rms), high counting rate (16 MHz), low and constant power dissipation (50 mW) and low area occupation (2.58 × 1.28 mm2 ). Moreover, the very low crosstalk ( -115 dB) between channels, together with low power and low area makes the converter suitable for large scale multi-channel acquisition chains.

Design and Implementation of Valve Failure Signal Multi-Channel Acquisition System Based on Acoustic Emission and Pipeline

Designed and implemented acoustic emission signal acquisition system core with microprocessor STM32F103RB. Acquisition system included high sensitivity acoustic emission sensors: PXR20; signal conditioning for acoustic emission, used high-speed ADC AD9225 for A/D conversion; used FIFO module for data buffer; used USB to serial port technology for data communications and transmissions. Central control unit design included gain control of amplifier circuit, clock control of external AD-chip and data cache chip, data acquisition port control, data output port control. Experimental results show that the system implements a multi-channel, parallel, high-precision acquisition and transmission for acoustic emission data.

The Research into the Key Problem of Multi-Channel Video Acquisition and Display System Based on FPGA

Aimed at the problem of the embedded multi-channel video acquisition and display system, a new one based on FPGA is put forward. The configuration of the system is given. The principle and key issue is analyzed. Using of the state shift mechanism, t the controlling time sequence signals of TFT-LCD are produced; The synchronization among multi-channel video acquisition is realized by using time-division multiplexing technology; The problem of conflict between reading and writing frame cache is solved through the two SRAM switch; The frames composition technology is applied to accomplish the change from interlaced scanning to progressive scanning. The result of project application shows the virtues of system, such as good effect of acquisition and display, low cost and low power consumption.

The reconstruction of erectile function with rabbit segmental gracilis musculocutaneous flap

To design an animal model for the reconstruction of penile erectile function with segmental gracilis musculocutaneous flap. The rabbit gracilis muscle was split longitudinally into two approximately equal halves completely according to the principles of muscle compartmentalization. An animal model was designed for the reconstruction of erectile function with segmental musculocutaneous flap based on the anterior gracilis muscle bundle, with a silicone stick implanted as a supporter. A multi-channel physiological signal acquisition and processing system were used to stimulate the reconstructed penis and its CMAP was measured synchronously. When its nerve was electric stimulated, the muscle bundle contracted, which made the reconstructed penis moving accordingly. It satisfactorily simulated the way of a normal penis's erection. The reconstructed penis with rabbit segmental gracilis musculocutaneous flap according to the principles of muscle compartmentalization has achieved the erectile function satisfactorily. It has met the requirements of both improving reconstructive penis's appearance and retaining muscle' s contractive function.

Design of Multi-Channel Temperature Acqusition System Based on MSP430

The design of multi-channel temperature acquisition system based on MSP430 and temperature sensor DS18B20 is presented in this paper. The simulation can be realized by using Proteus. The system has the following advantages: the structure of system is specific; the circuit is simple and it’s easy to control. The system can complete the acquisition and display of multi-channel temperature, it also has other functions such as transferring data to PC, etc. The simulation shows that the system is low cost, high reliability and high practical value.

Characteristics of Electrode Displacement and Force in Resistance Spot Welding

The behaviors of electrode displacement and force during spot welding were studied. Tests were conducted on a 170KVA MFDC spot welder. Data were collected via a multi-channel high speed data acquisition system, and were analyzed with MATLAB. Behaviors of 5182 aluminium and mild steel in spot welding were compared. Results showed that nugget expansion rate did not reach zero for aluminium as it did for mild steel as nugget grew to a certain size. An electrode force peak was observed and was believed relevant to sufficient nugget size.

Development and characterization of a modular acquisition system for a 4D PET block detector

Next generation PET scanners should fulfill very high requirements in terms of spatial, energy and timing resolution. Modern scanner performances are inherently limited by the use of standard photomultiplier tubes . The use of Silicon Photomultiplier (SiPM) matrices is proposed for the construction of a 4D PET module based on LSO continuous crystals, which is envisaged to replace the standard PET block detector. The expected spatial resolution of the module for the photon hit position is below 1 mm, and it will perform at the same time, the Depth Of Interaction (DOI) calculation and the Time Of Flight (TOF) measurement. The use of large area multi-pixel Silicon Photomultiplier (SiPM) detectors requires the development of a multichannel Digital Acquisition system (DAQ) as well as of a dedicated front-end in order not to degrade the intrinsic detector performances. We have developed a flexible and modular DAQ system for the read-out of two modules in time coincidence for Positron Emission Tomography (PET) applications. The DAQ system is based on a previously developed custom front-end ASIC chip (BASIC) which allows to read-out SiPM matrices preserving their spectroscopy and timing capabilities. Here we describe the acquisition system architecture and its characterization measurements.

RATAN-600 radio telescope in the 24th solar-activity cycle. III. System of data acquisition and control of the solar spectral facility

We report the development of a multichannel data acquisition and control system for the Spectral and Polarization High-Resolution Solar Research System, installed at the RATAN-600 radio telescope. This facility provides high-speed registration of signals from 240 channels and controls the preparation for observations and the process of automatic observations. The hardware is made in the form factor of 3U Evromekhanika modules. The measurement facility is controlled by the software based on the QT cross-platform library (the open source version), which can be run both on Linux and Windows operating systems. The data are written to a magnetic carrier and then transferred to the computer network of the Special Astrophysical Observatory for archiving, and can be accessed by external users.

Heme oxygenase-1 transgenic overexpression did not prevent artery injury induced by electric stimulation and pressure overload in mice

Heme oxygenase-1 (HO-1) shows multiple beneficial effects on cardiovascular diseases. However, the effect of HO-1 on the injury of artery has never been identified. In the present study, we established systemic HO-1 overexpression transgenic mice and investigated the effect of HO-1 on the injury of artery induced by electric stimulation and pressure-overload in transgenic mice. Artery injury was induced by electric stimulation and pressure overload. The contractive function, endothelium-dependent and -independent relaxation of arteries were measured through an isometric force transducer connected to a multichannel acquisition and analysis system. Western blot results showed that HO-1 protein level in transgenic mice arteries was significantly higher than that in wild type mice arteries, while no difference of HO-2 protein level in the arteries of transgenic and wild type mice. Arterial reendothelialization after electric injury was accelerated in transgenic mice. No significant difference in contractive function, endothelium-dependent and -independent relaxation of arteries was observed between wild type and transgenic mice at day 7 after electric injury and 4 weeks after pressure overload. We concluded that HO-1 overexpression accelerated the reendothelialization, but did not prevent the functional impairment of injured artery in mice.

A Novel Lead Configuration for Optimal Spatio-Temporal Detection of Intracardiac Repolarization Alternans

Electric alternans is a pattern of variation in the shape of ECG waveform that occurs every other beat. In humans, alternation in ventricular repolarization, known as repolarization alternans (RA), has been associated with increased vulnerability to ventricular tachycardia/fibrillation and sudden cardiac death. This study investigates the spatio-temporal variability of intracardiac RA and its relationship to body surface RA in an acute myocardial ischemia model in swine. We developed a real-time multichannel repolarization signal acquisition, display, and analysis system to record ECG signals from catheters in the right ventricle, coronary sinus, left ventricle, and epicardial surface before and after circumflex coronary artery balloon occlusion. We found that RA is detectable within 4 minutes after the onset ischemia and is most prominently seen during the first half of the repolarization interval. Ischemia-induced RA was detectable on unipolar and bipolar leads (both in near- and far-field configurations) and on body surface leads. Far-field bipolar intracardiac leads were more sensitive for RA detection than body surface leads, with the probability of body surface RA detection increasing as the number of intracardiac leads detecting RA increased, approaching 100% when at least three intracardiac leads detected RA. We developed a novel, clinically applicable intracardiac lead system based on a triangular arrangement of leads spanning the right ventricular and coronary sinus catheters, which provided the highest sensitivity for intracardiac RA detection when compared with any other far-field bipolar sensing configurations. In conclusion, intracardiac alternans, a complex spatio-temporal phenomenon associated with arrhythmia susceptibility and sudden cardiac death, can be reliably detected through a novel triangular right ventricular-coronary sinus lead configuration.

Design of Multi-Channel Signal Acquisition System of the Torsion Spring Based on LabVIEW

This paper presents a torsion spring detection and analysis system which is different from traditional torsion spring detector. The design is based on virtual instrument software with multi-channel signal acquisition. Two characteristic quantities, torsion angle and the torque, are collected and will be analyzed and processed by the computer, which owns large storage capacity and strong analyze ability, to store and display the data as the format of two dimensional graph.

Multichannel Sampling of Multidimensional Parametric Signals

The contribution of this paper is two-fold; first, we present a novel approach for sampling and reconstructing two dimensional signals with parametric structure or namely signals with Finite Rate of Innovation (FRI). The considered signals are bi-level polygons and set of 2-D Diracs and it will be shown that with the use of ACMP method, projection-slice theorem, Radon projections and exponential splines as sampling kernels, such signals can be perfectly reconstructed. Then, we present a possible extension of the theory of sampling multidimensional FRI signals, discussed above, to the case of multichannel acquisition systems. The essential issue of our considered multichannel system is that each channel receives the input signal with an unknown geometric transformation which needs to be estimated. We pose both the synchronization stage and the signal reconstruction stage as a parametric estimation problem and demonstrate that a simultaneous exact synchronization of the channels and reconstruction of the FRI signal is possible.

Multichannel Sampling of Signals With Finite Rate of Innovation

In this letter, we present a possible extension of the theory of sampling signals with finite rate of innovation (FRI) to the case of multichannel acquisition systems. The essential issue of a multichannel system is that each channel introduces different unknown delays and gains that need to be estimated for the calibration of the channels. We pose both the synchronization stage and the signal reconstruction stage as a parametric estimation problem and demonstrate that a simultaneous exact synchronization of the channels and reconstruction of the FRI signal is possible. We also consider the case of noisy measurements and evaluate the Cramer-Rao bounds (CRB) of the proposed system. Numerical results as well as the CRB show clearly that multichannel systems are more resilient to noise than the single-channel ones.

Effects of isosorbide mononitrate on the restoration of injured artery in mice in vivo

The pharmacological basis of isosorbide mononitrate (ISMN), a widely used drug for cardiovascular diseases, is that it is metabolized to nitric oxide (NO). However, NO is a double-edged sword that results in either beneficial or detrimental effect. Vascular injury is the common consequence of many cardiovascular diseases, but it is not determined whether ISMN influences the restoration of injured artery in vivo. Carotid artery injury was induced by electric stimulation in mice. Vasoconstriction and endothelium-dependent and -independent relaxation were recorded by a multichannel acquisition and analysis system. ISMN (10 mg/kg, p.o.) treatment for 1 week and 1 month had no effect on reendothelialization, histology and function of carotid artery injured by electric stimulation. l-arginine (500 mg/kg, p.o.) and Nω-nitro- l-arginine methyl ester (L-NAME) (50 mg/kg, p.o.) treatment for 1 week did not affect the reendothelialization process, but L-NAME treatment induced neointimal hyperplasia and inhibited endothelium-dependent relaxation in electrically injured artery. These results suggest that supplement of exogenous or endogenous NO has no effect on the restoration of injured artery, but inhibition of endogenous NO induces neointimal hyperplasia in injured artery. ISMN treatment does not affect the restoration of injured artery.

Inhibition of 2-Aminoethoxydiphenyl Borate-induced Rat Atrial Ectopic Activity by Anti-arrhythmic Drugs

Background/Aims: 2-aminoethoxydiphenyl borate (2-APB) provokes spontaneous mechanical activity in isolated rat left atria. The present study is to characterize 2-APB-induced ectopic activity in rat atria and to investigate the inhibition of 2-APB-induced ectopic activity by anti-arrhythmic drugs. Methods: 2-APB-induced ectopic activity was measured through an isometric force transducer connected to a multichannel acquisition and analysis system. Intracellular [Ca²⁺]_i was measured with fluorescence laser scanning confocal microscopy. Voltage-dependent L- type Ca²⁺ currents were recorded by using patch-clamp technique. Results: 2-APB dose-dependently increased the ectopic activity of left atria at 1, 5, 10, 20, 50 µM. Anti-arrhythmic drugs, quinidine (10µM), lidocaine (10µM), verapamil (5µM), and amiodarone (50µM,100µM) inhibited 2-APB-induced ectopic activity. 2-APB-induced ectopic activity was inhibited by Ca²⁺-free bath, Na⁺/Ca²⁺ exchanger blockers, 3′,4′-dichlorobenzamil hydrochloride (DHC) and Ni²⁺, not by non-selective cation channel blocker Gd³⁺. 2-APB also induced ectopic contractions in ventricular tissue straps and the ectopic contractions were inhibited by quinidine, verapamil and DHC. Lidocaine, verapamil and DHC inhibited 2-APB-induced increase of intracellular Ca²⁺ concentration in cardiomyocytes. Low molecular weight heparin inhibited phenylephrine (PE)-induced but not 2-APB -induced atria ectopic activity, and the pattern of 2-APB-induced ectopic activity was continuous, distinct from the discontinuous activity induced by PE. Conclusion: 2-APB-induced atria ectopic activity was inhibited by classic anti-arrhythmic drugs quinidine, lidocaine, verapamil, amiodarone, and Na⁺/Ca²⁺ exchanger blockers. It can be used for testing agents able to affect any of Na⁺, Ca²⁺ channel, Na⁺/Ca²⁺ exchanger without selectivity.

Design of Wireless multi-channel surface EMG acquisition system

Design of Wireless multi-channel surface EMG acquisition system

Development of a low-energy X-ray fluorescence system combined with X-ray microscopy

A system for Low Energy X-ray Fluorescence (LEXRF) has been implemented in the TwinMic [1] microscope station operating at Elettra synchrotron facility. The integrated LEXRF is coupled with the STXM operation mode. This allows simultaneous collection of XRF maps, brightfield images and phase contrast images [2], providing complementary information about the sample's chemical specificity and morphology with high spatial resolution. The system is based on a modular setup of multiple Be windowless Silicon Drift Detectors (SDDs), read-out by a custom designed fast multichannel acquisition system [3]. The number of the SDDs (up-to 8 detectors) will be increased in the future in order to minimize the XRF acquisition time (higher count rate and solid angle) and to increase the XRF detection limits, therefore allowing us to acquire XRF maps with sub-micron spatial resolution.

Using the ERT method in tectonically active areas: hints from Southern Apennine (Italy)

Abstract. Electrical Resistivity Tomography (ERT) method has been used to study two tectonically active areas of southern Apennine (Caggiano Faults and Ufita Basin). The main aim of this job was to study the structural setting of the investigated areas, i.e. the geometry of the basins at depth, the location of active faults at surface, and their geometrical characterization. The comparison between ERT and trench/drilling data allowed us to evaluate the efficacy of the ERT method in studying active faults and the structural setting of seismogenic areas. In the Timpa del Vento intermontane basin, high resolution ERT across the Caggiano Fault scarps, with different arrays, electrode spacing (from 1 to 10 m) and penetration depth (from about 5 to 40 m) was carried out. The obtained resistivity models allowed us to locate the fault planes along the hillslope and to gather information at depth, as later confirmed by paleoseismological trenches excavated across the fault trace. In the Ufita River Valley a 3560-m-long ERT was carried out across the basin, joining 11 roll-along multi-channel acquisition system with an electrode spacing of 20 m and reaching an investigation depth of about 170 m. The ERT allowed us to reconstruct the geometry and thickness of the Quaternary deposits filling the Ufita Valley. Our reconstruction of the depositional setting is in agreement with an interpretative geological section based on borehole data.