Digital Signal Acquisition Research Articles

Digital signal acquisition system for complex nuclear reaction experiments

Digital signal acquisition system for complex nuclear reaction experiments

A pediatric telecardiology system that facilitates integration between hospital-based services and community-based primary care

IntroductionTelecardiology has emerged as a vital field within telemedicine, fostering collaboration between hospital and community medicine. This pilot study introduces an innovative pediatric telecardiology system, comprising a telecardiology system seamlessly integrated with a hospital telemedicine platform. A smooth flow of ECG execution, transmission, and reporting between Primary Care Pediatrician clinics and the hospital was tested as the primary objective. User experience surveys were also considered. MethodsThe study involved three Primary Care Pediatrician clinics, and the enrollment of children took place consecutively from January to July 2023. We integrated a digital electrocardiographic signal acquisition unit and online information transmission-capable tablets, that were provided to the pediatricians, with a telemedicine multitenant platform that facilitated the transmission of the patient's ECG data from the community to the Hospital Pediatric Cardiologist. ResultsA total of 158 children (80 M/78F, 8.9 ± 2.8 yrs) underwent ECG recording (78.5 % medical certificates, 21.5 % presence of symptoms) The transmission and reporting of ECGs were successfully completed in all cases, without technical issues. Normal findings on the ECG were demonstrated in 94.9 % of children. 70.8 % of respondents completed all parts of the survey. Respondents had a high level of education (90 %) and demonstrated excellent or good competence in using digital technologies (89 %). 51 % of respondents were not familiar with the term “Telemedicine” and 81 % of the cases had no previous telemedicine experience. 90 % of users were very satisfied or satisfied with the service. Connection problems (2.8 %) and concerns about the service's reliability compared to standard care (3.7 %) were mentioned as possible limitations of the telecardiology. ConclusionsOur pediatric telecardiology system offers a valuable diagnostic tool to enhance patient management in the community.

Development of a high-speed digital pulse signal acquisition and processing system based on MTCA for liquid scintillator neutron detector on EAST

Development of a high-speed digital pulse signal acquisition and processing system based on MTCA for liquid scintillator neutron detector on EAST

Laser Additive Remanufacturing Cladding Thickness Detection System

As an important parameter in laser additive remanufacturing technology, cladding thickness is related to the quality of remanufacturing. Thickness detection during the cladding process can help improve the cladding quality and facilitate manual adjustment of parameters in real time to optimize the cladding thickness. This system develops a set of cladding thickness detection system based on laser displacement sensor. The system consists of hardware and software parts. The hardware part includes laser displacement sensor, mounting plate, digital signal acquisition device and laser cladding system. The software part a set of data acquisition software is developed according to Visual Studio. The system uses two methods to measure, and eliminates the error caused by the tilt factor of the worktable, and realizes the online measurement of cladding thickness.

Development of a wide-range and fast-response digitizing pulse signal acquisition and processing system for neutron flux monitoring on EAST

The neutron count rate fluctuation reaches six orders of magnitude between the ohmic plasma scenario and high power of auxiliary heating on an experimental advanced superconducting tokamak (EAST). The measurement result of neutron flux monitoring (NFM) is a significant feedback parameter related to the acquisition of radiation protection-related information and rapid fluctuations in neutron emission induced by plasma magnetohydrodynamic activity. Therefore, a wide range and high time resolution are required for the NFM system on EAST. To satisfy these requirements, a digital pulse signal acquisition and processing system with a wide dynamic range and fast response time was developed. The present study was conducted using a field-programmable gate array (FPGA) and peripheral component interconnect extension for instrument express (PXIe) platform. The digital dual measurement modes, which are composed of the pulse-counting mode and AC coupled square integral’s Campbelling mode, were designed to expand the measurement range of the signal acquisition and processing system. The time resolution of the signal acquisition and processing system was improved from 10 to 1 ms owing to utilizing high-speed analog-to-digital converters (ADCs), a high-speed PXIe communication with a direct memory access (DMA) mode, and online data preprocessing technology of FPGA. The signal acquisition and processing system was tested experimentally in the EAST radiation field. The test results showed that the time resolution of NFM was improved to 1 ms, and the dynamic range of the neutron counts rate was expanded to more than 10^{6} counts per second. The Campbelling mode was calibrated using a multipoint average linear fitting method; subsequently, the fitting coefficient reached 0.9911. Therefore, the newly developed pulse signal acquisition and processing system ensures that the NFM system meets the requirements of high-parameter experiments conducted on EAST more effectively.

Study on Synthetic Aperture Focusing Technique (SAFT)

The Synthetic Aperture Focussing Technique (SAFT) restores ultrasonic images obtained from either B or C scans having focusing distortion. With the help of SAFT, improvement in image resolution was obtained without the use of traditional ultrasonic lenses. The images from both the B and the C scans have a lateral resolution limited by the focus of ultrasonic transducers. The techniques commonly used to improve the lateral resolution include using additional lenses or by using synthetic focus. The use of lenses makes the beams more collimated but introduces a considerable loss in transmitted signals. The use of the SAFT is efficient since it does not introduce any additional losses, but it can only be used in a digital signal acquisition system. The use of SAFT brings significant benefits to mechanized ultrasonic testing. In addition to the more precise defect localization and the better separation of neighbouring defect indications, the improvement of the structure-related signal-to-noise ratio (SNR) is an important reason for the use of SAFT. It can be used for defect analysis and offers a high degree of robustness when configured correctly. Sufficient computing power is required to carry out the SAFT analysis. In order to reduce the computing effort, the data from an ultrasonic test can be evaluated separately for each layer using 2D-SAFT. Although these results are volume related and can be displayed in three dimensions (and are therefore sometimes misleadingly referred to as 3D SAFT), some of the benefits of SAFT remain untapped

Primary calibration system for digital accelerometers

Accelerometers with a digital signal output are widely used for the motion sensing of internet of things devices, vibration monitoring in industries, or scientific observations. Calibrating their frequency response is essential in extracting the correct information from measurements. However, the dynamic calibration method of a digital sensor has not yet been established. This study develops a simple synchronized data acquisition system for digital and analog signals and implements it in the primary calibration system of accelerometers. Using the constructed system, response of a digital accelerometer, including both sensitivity modulus and phase shift, is accurately determined. The measurement uncertainty was evaluated in detail, and the estimated values for the sensitivity modulus and the phase shift were below 0.2% and 0.1°, respectively. The uncertainty source component specific to the digital signal acquisition system was negligible compared to the total uncertainty.

High sampling rate or high resolution in a sub-Nyquist sampling system

A digital signal acquisition system consists of two steps: sampling and quantization. Sampling maps a continuous signal to a digital signal, which then is quantized into a finite number of bits. Generally, a high sampling rate can ensure robustness to noise, while high resolution means less distortion. However, an analog-to-digital converter (ADC) cannot provide a high sampling rate and high resolution simultaneously. The bit rate is constrained, and there is a tradeoff between sampling rate and resolution. In this paper, we investigate the signal reconstruction in the framework of a compressed sensing based sub-Nyquist sampling system. We also study the noise introduced in the sampling stage and the quantization stage and evaluate the recovered signal-to-noise ratio (RSNR) with respect to the sampling rate and resolution. Considering potential application, we study the tradeoff involved in choosing the sampling rate and number of quantization bits according to the input SNR. Finally, we derive a relationship between RSNR and signal sparsity order, sampling rate, and number of quantization bits.

Development of A Low-Cost Arduino-Based 12-Lead Ecg Acquisition System And Accompanied Labview Application

In this paper, the design of a real-time digital multi--channel ECG signal acquisition system is presented. With the purpose of fabrication towards a simple, compact and low-cost tool for bioelectrical signal processing laboratories, the system is developed to acquire the 12 leads EGC signals and converted to numerical data based on an Arduino module named as Leonardo equipped 12 channels ADC. To observe the EGC waves, the ECG signals are amplified through designed amplifiers with the gain of 60 dB. To reduce the effects from the DC component as well as the baseline wandering and the high frequency noise, the active analog bandpass filter ranged in 0,05 Hz to 100 Hz was designed. The power line noise of 50 Hz also decreased with an active analog bandstop filter with attenuation -38 dB. Under the PC application was built using Labview programing, the low-cost digital ECG signal acquisition system was demonstrated with the requirement of observation in real-time. To clarify the small wave in the digital EGG signal, the limitation of the analog signal processing is improved through the digital filters parameterized in the software to increase the SNR from 1.4 dB to 27.6 dB. Practically, the system is evaluated through a series of experiments on a volunteer person resulting the ECG data is recorded and stored in a TDMS file. Since the system is designed as opened-system, a series of developments towards various applications in biomedical diagnosis based on digital signal analysis techniques is promised to be feasible in the near future.

Design and Verification of a Dry Sensor-Based Multi-Channel Digital Active Circuit for Human Brain Electroencephalography Signal Acquisition Systems.

A brain–computer interface (BCI) is a type of interface/communication system that can help users interact with their environments. Electroencephalography (EEG) has become the most common application of BCIs and provides a way for disabled individuals to communicate. While wet sensors are the most commonly used sensors for traditional EEG measurements, they require considerable preparation time, including the time needed to prepare the skin and to use the conductive gel. Additionally, the conductive gel dries over time, leading to degraded performance. Furthermore, requiring patients to wear wet sensors to record EEG signals is considered highly inconvenient. Here, we report a wireless 8-channel digital active-circuit EEG signal acquisition system that uses dry sensors. Active-circuit systems for EEG measurement allow people to engage in daily life while using these systems, and the advantages of these systems can be further improved by utilizing dry sensors. Moreover, the use of dry sensors can help both disabled and healthy people enjoy the convenience of BCIs in daily life. To verify the reliability of the proposed system, we designed three experiments in which we evaluated eye blinking and teeth gritting, measured alpha waves, and recorded event-related potentials (ERPs) to compare our developed system with a standard Neuroscan EEG system.

Localization and Frequency Identification of Large-Range Wide-Band Electromagnetic Interference Sources in Electromagnetic Imaging System

The identification and localization of large-range, wide-band electromagnetic interference (EMI) sources have always been both costly and time-consuming. The measurements at different times and places are often required before a typical system can locate a target. In this paper, we proposed a 2D electromagnetic imaging system to localize interference sources and identify the EMI frequency in real time. In this system, an offset paraboloid with a diameter of three meters is designed for large-range EMI imaging, while a multi-channel digital signal acquisition system is developed for wide-band EMI localization. The located interference source is segmented by the maximum entropy method based on particle swarm optimization, and the modified generalized regression neural network (MGRNN) is applied to identify the EMI frequency effectively by excluding misleading effects of outliers. The experiment which has been completed on our dataset indicates that our approach not only increases accuracy by 5% compared with the standard generalized regression neural network approaches for identification, but also exerts a large-range wide-band localization of the EMI source detection method.

American Clinical Neurophysiology Society Guideline 4: Recording Clinical EEG on Digital Media.

Digital EEG recording systems are now widely available and relatively inexpensive. They offer multiple advantages over previous analog/paper systems, such as higher fidelity recording, signal postprocessing, automated detection, and efficient data storage. This document provides guidance for the creation of digital EEG recordings including (1) documentation of patient information, (2) notation of information during the recording, (3) digital signal acquisition parameters during the recording, (4) storage of digital information, and (5) display of digital EEG signals.

Modified compressive sensing approach for GNSS signal reception in the presence of interference

Pre-processing traditional navigation signals in global navigation satellite system (GNSS) receivers includes the conversion of an analog-to-digital sample and acquisition following the basic principle of Nyquist sampling theory. This condition inevitably increases the system computation time and cost of a modern wideband receiver. In recent years, the compressive sensing (CS) approach has been proven to effectively reduce the number of measurement samples required for digital signal acquisition systems. This method gives new potential to this modern design. In this study, a modified compressive sensing algorithm for the acquisition of a GNSS signal that is contaminated by an interfering signal is presented. The proposed method attempts to combine CS demodulation and the subspace projecting method to enhance GNSS signal acquisition performance with interference present. First, the received signal is sub-sampled and aliased from a compressive sampling process. This operation maintains the restricted isometry property (RIP) condition of the second sampling process using a Toeplitz-structured sensing matrix, which replaces a conventional random sensing matrix. The matrix ensures that distances between desired signals on the set of sparse space are not influenced by the sampling process. Next, the interference is eliminated through the orthogonal feature between the interference signal and the desired signal using the subspace projecting method. This also preserves the RIP of the projecting matrix to ensure that the original structure of the linear projection of the signal is preserved. After this, an iterative least-square method is utilized to recover the correlator output from the reception samples taken by the CS demodulator. In addition, the signal detection performance in the presence of co-channel interference using a CS demodulator is analyzed and evaluated. Finally, the relationships between signal detection probability, compressive factor and signal bandwidth are also illustrated. Several numerical results are presented to verify the theory.

The Design and Realization of Airborne Electrical Equipments’ Online Test System in the Environments of Mechanics

Current OTS (Online Test System, OTS) of airborne electrical equipments in the environments of mechanics is only able to test statically but dynamically. To solve the problem, a new kind of dynamic test system based on PXI bus is designed. In the design, modular instrument resources that used in the third generation of ATE (Auto Test System, ATE) commonly is adopted to prove the system’s reusability, extensibility and standard ability, digital signal acquisition is replaced with analog signal acquisition to realize dynamic test, support from the method of process monitoring is drew to get the capability to detect the reversible failure in UUT (Unit Under Test, UTT), VC++ language is used as the software development tool to control the system and record test data. In the special mechanics environment such as centrifuge, drawing lessons from the experience of the new concept dynamic test, the system architecture of remote control acquisition is used to prove the stability and efficiency of the test system greatly. The experimental result shows that the system runs well and has more advantages such as high efficiency of auto-test and reliability of failure diagnosis results, meeting new demand of the airborne electrical equipments’ online test in the environments of mechanics.

Recovery error bounds on compressed sensing of noisy signals

SummaryCompressed sensing is an emerging technique in the field of digital signal acquisition. It promises almost exact recovery of high‐dimensional signals from a very small set of measurements. However, this technique is challenged by the task of recovering signals immersed in noise. In this paper, we derive upper and lower bounds on mean squared recovery error of noisy signals. These bounds are valid for any number of acquired measurements and at any signal‐to‐noise ratio. This work is highly useful for the design of any compressed sensing‐based real world application by quantifying recovery error entailed with realistic digital signal acquisition scenarios. Copyright © 2013 John Wiley & Sons, Ltd.

Development of Diagnostic Equipment for ECU Parts Used in Electric Vehicles

Electric vehicles use lots of ECU controllers in the CAN network, the quality of ECU parts used in vehicles is closely related to safe driving. This paper develops a kind of fault diagnostic equipment for electric vehicles ECU controllers. This device has designed digital input signal acquisition module, the output switch signal module, power supply module and fault simulation module based on CAN bus communication principle. Then we use LabVIEW developing computer program in order to monitor and control the whole system.

PC104 Interface Recommended for High Speed Data Acquisition Systems

The interface presented in this paper performs a synchronized sampling of all eight common-mode or differential analog inputs with a high sampling rate. This is a low cost interface, entirely controlled by the PC104 CPU. The paper is focused on design and operation aspects of the synchronized analog-to-digital conversion module. This interface is recommended for high speed data acquisition systems and finds its utility in energetic systems, for monitoring the power quality and for recording different specific transient events. Some programmable electronic modules which perform analog and digital signal acquisition in energetic systems already contain a PC104 interface with synchronized sampling of analog inputs; some experimental results are also presented in this paper.

PC104 Interface Recommended for High Speed Data Acquisition Systems

The interface presented in this paper is recommended for high speed data acquisition systems; it performs a synchronized sampling of all common-mode or differential analog inputs with a high sampling rate. This is a low cost interface, entirely controlled by the PC104 CPU. Programmable electronic modules that contain such PC104 interfaces can be found running in the energetic system from Romania; these dedicated equipments perform the analog and digital signal acquisition for monitoring and recording different specific transient events. Some experimental results obtained using the disturbance monitoring device PC-08/104 are also presented in this paper.

Regime Change: Bit-Depth Versus Measurement-Rate in Compressive Sensing

The recently introduced compressive sensing (CS) framework enables digital signal acquisition systems to take advantage of signal structures beyond bandlimitedness. Indeed, the number of CS measurements required for stable reconstruction is closer to the order of the signal complexity than the Nyquist rate. To date, the CS theory has focused on real-valued measurements, but in practice measurements are mapped to bits from a finite alphabet. Moreover, in many potential applications the total number of measurement bits is constrained, which suggests a tradeoff between the number of measurements and the number of bits per measurement. We study this situation in this paper and show that there exist two distinct regimes of operation that correspond to high/low signal-to-noise ratio (SNR). In the measurement compression (MC) regime, a high SNR favors acquiring fewer measurements with more bits per measurement; in the quantization compression (QC) regime, a low SNR favors acquiring more measurements with fewer bits per measurement. A surprise from our analysis and experiments is that in many practical applications it is better to operate in the QC regime, even acquiring as few as 1 bit per measurement.

Design of the Underwater Acoustic Signal Acquisition System Based on the Pipelined Twin-AD

In order to improve the accuracy of the underwater acoustic detection effectively, the digital signal acquisition circuxcA`\\it is a necessary deceive, which must have enough high data acquisition rate. Therefore the high frequency operating clock is employed in the traditional digital signal acquisition circuit. However, the high frequency operating clock will bring troubles to the design of hardware and software, and the power consumption and interference of the system are both increased. According to the principle of the pipelined system, the operation of AD deceive is divided into two process, including the conversion starting and data reading. The FPGA is employed to produce control signals which make twin-AD work in proper state. The design of the underwater acoustic signal acquisition system based on the pipelined twin-AD is presented here. On the base of the system design, simulation, implementation, the hardware experiments are completed. The results show: driven by the operating clock with same frequency, the underwater acoustic signal acquisition system based on the pipelined twin-AD can obtain the acquisition rate which is twice as the traditional data acquisition system.