Showing papers on "Data acquisition published in 2006"

Advanced Methods And Tools for ECG Data Analysis

Abstract: This cutting-edge resource provides you with a practical and theoretical understanding of state-of-the-art techniques for electrocardiogram (ECG) data analysis. Placing an emphasis on the fundamentals of signal etiology, acquisition, data selection, and testing, this comprehensive volume presents guidelines to help you design, implement, and evaluate algorithms used for the analysis of ECG and related data. Additionally, explanations of open source software and related databases for signal processing are given. The book focuses on the modeling, classification, and interpretation of features derived from advanced signal processing and artificial intelligence techniques. Key topics covered include physiological origin, hardware acquisition and filtering, time-frequency quantification of the ECG and derived signals (including heart rate variability and respiration), analysis of noise and artifact, models for ECG and RR interval processes, linear and nonlinear filtering techniques, and adaptive algorithms such as neural networks. Much of the book is devoted to deriving robust, clinically meaningful parameters such as the QRS axis, QT-interval, the ST-level, and T-wave alternan metrics. Methods for applying these metrics to clinical classification are also discussed, together with supervised and unsupervised classification techniques. Including over 190 illustrations, the book offers you a solid grounding in the relevant basics of physiology, data acquisition and database design, and addresses the practical issues of improving existing data analysis methods and developing new applications.

Send-On-Delta Concept: An Event-Based Data Reporting Strategy

Abstract: : The paper addresses the issue of the send-on-delta data collecting strategy to capture information from the environment. Send-on-delta concept is the signal-dependent temporal sampling scheme, where the sampling is triggered if the signal deviates by delta defined as the significant change of its value. It is an attractive scheme for wireless sensor networking due to effective energy consumption. The quantitative evaluations of send-on-delta scheme for a general type continuous-time bandlimited signal are presented in the paper. The bounds on the mean traffic of reports for a given signal, and assumed sampling resolution, are evaluated. Furthermore, the send-on-delta effectiveness, defined as the reduction of the mean rate of reports in comparison to the periodic sampling for a given resolution, is derived. It is shown that the lower bound of the send-on-delta effectiveness (i.e. the guaranteed reduction) is independent of the sampling resolution, and constitutes the built-in feature of the input signal. The calculation of the effectiveness for standard signals, that model the state evolution of dynamic environment in time, is exemplified. Finally, the example of send-on-delta programming is shown.

LabVIEW for Everyone: Graphical Programming Made Easy and Fun

Abstract: About the Authors xxix Preface xxxi Acknowledgments xli 1 What in the World Is LabVIEW? 3 2 Virtual Instrumentation: Hooking Your Computer Up to the Real World 21 3 The LabVIEW Environment 41 4 LabVIEW Foundations 101 5 Yet More Foundations 147 6 Controlling Program Execution with Structures 185 7 LabVIEW's Composite Data: Arrays and Clusters 245 8 LabVIEW's Exciting Visual Displays: Charts and Graphs 301 9 Exploring Strings and File I/O 379 10 Signal Measurement and Generation: Data Acquisition 419 11 Data Acquisition in LabVIEW 465 12 Instrument Control in LabVIEW 523 13 Advanced LabVIEW Structures and Functions 553 14 Advanced LabVIEW Data Concepts 673 15 Advanced LabVIEW Features 721 16 Connectivity in LabVIEW 799 17 The Art of LabVIEW Programming 853 Appendix A CD Contents 891 Appendix B Add-on Toolkits for LabVIEW 893 Appendix C Open Source Tools for LabVIEW: OpenG 897 Appendix D LabVIEW Object-Oriented Programming 901 Appendix E Resources for LabVIEW 921 Appendix F LabVIEW Certification Exams 925 Glossary 931 Index 959

Multiple-gradient array measurements for multichannel 2D resistivity imaging

Abstract: Two-dimensional resistivity imaging using multiple gradient, Wenner and dipole-dipole electrode arrays was carried out at two field sites in Sweden and one in Nicaragua, with the objective of confirming the practical applicability of results obtained with numerical modelling. The results support earlier numerical modelling studies that concluded that the gradient array, using multiple current electrode combinations, has resolution as good as or better than the commonly used Wenner array. The array behaved well in terms of sensitivity to noise at the test sites, and the results obtained generally agree with dipole-dipole array results, although the latter at two of the sites gave resistivities that differed significantly from the other arrays in the deeper parts of the inverted models. A formula proposed for pseudosection plotting works well for data quality assessment, where it can be an advantage to make separate plots for each m-factor (the distance between the midpoints of the current and potential electrode pairs) or for each a-spacing. The gradient array is well suited for multichannel data acquisition, and can significantly increase the speed of data acquisition in the field and at the same time give higher data density, but it is also an attractive option for single-channel data acquisition. The Wenner array, on the other hand, is not suitable for measuring in more than one channel. Compared to the dipole-dipole array, it offers lower sensitivity to noise which may be a major advantage in real data acquisition, and the remote electrode needed for the pole-dipole array is avoided, which is often a significant advantage for field logistics.

Step-and-shoot data acquisition and reconstruction for cardiac x-ray computed tomography

Abstract: Coronary artery imaging with x-ray computed tomography (CT) is one of the most recent advancements in CT clinical applications. Although existing ''state-of-the-art'' clinical protocols today utilize helical data acquisition, it suffers from the lack of ability to handle irregular heart rate and relatively high x-ray dose to patients. In this paper, we propose a step-and-shoot data acquisition protocol that significantly overcomes these shortcomings. The key to the proposed protocol is the large volume coverage (40 mm) enabled by the cone beam CT scanner, which allows the coverage of the entire heart in 3 to 4 steps. In addition, we propose a gated complementary reconstruction algorithm that overcomes the longitudinal truncation problem resulting from the cone beam geometry. Computer simulations, phantom experiments, and clinical studies were conducted to validate our approach.

Data acquisition and processing software package for Medipix2

Abstract: The semiconductor pixel detector Medipix2 [1] (256×256 square pixels, 55×55 μm2 each) is a superior imaging device in terms of spatial resolution, linearity and dynamic range. This makes it suitable for various applications such as radiography, neutronography, and micro–tomography. The software package for acquisition and data processing has been developed to control and manage complex measurements. The solution features an open and very flexible modular architecture with custom made plugin support. Plugins can control parts of the acquisition system as well as perform real-time data processing and use these results as feedback for controlling further steps of measurements. This allows us to control, e.g. data acquisition, position and rotation of the sample (stepper motors), source parameters, temperature, etc. in a synchronized way. An example is the adaptive tomography plugin which adaptively controls the measurement and benefits from preprocessing performed by other plugins such as the beam-hardening correction of measured projections.

X-ray ct apparatus

Abstract: A data acquisition device, which has an X-ray detector including a plurality of channel widths at which channels at its central portion are fine and channels at its peripheral portions are coarse or rough, and a plurality of data acquisition ranges including a data acquisition range wide in a channel direction and a data acquisition range narrow in the channel direction, and which is capable of performing switching among the data acquisition ranges for each data acquisition, is used to perform data acquisition on the channels fine at the central portion in the data acquisition range narrow in the channel direction, whereby an X-ray CT apparatus is provided which is capable of performing high-resolution imaging and brings about more satisfactory image quality.

Design and evaluation of the clear-PEM scanner for positron emission mammography

Abstract: The design and evaluation of the imaging system Clear-PEM for positron emission mammography, under development by the PEM Consortium within the framework of the Crystal Clear Collaboration at CERN, is presented. The proposed apparatus is based on fast, segmented, high atomic number radiation sensors with depth-of-interaction measurement capabilities, and state-of-the-art data acquisition techniques. The camera consists of two compact and planar detector heads with dimensions 16.5/spl times/14.5 cm/sup 2/ for breast and axilla imaging. Low-noise integrated electronics provide signal amplification and analog multiplexing based on a new data-driven architecture. The coincidence trigger and data acquisition architecture makes extensive use of pipeline processing structures and multi-event memories for high efficiency up to a data acquisition rate of one million events/s. Experimental validation of the detection techniques, namely the basic properties of the radiation sensors and the ability to measure the depth-of-interaction of the incoming photons, are presented. System performance in terms of detection sensitivity, count-rates and reconstructed image spatial resolution were also evaluated by means of a detailed Monte Carlo simulation and an iterative image reconstruction algorithm.

System and method for programmatically generating a graphical program based on a sequence of motion control, machine vision, and data acquisition (DAQ) operations

Abstract: A user may utilize a prototyping environment to create a sequence of motion control, machine vision, and/or data acquisition (DAQ) operations, e.g., without needing to write or construct code in any programming language. For example, the environment may provide a graphical user interface (GUI) enabling the user to develop/prototype the sequence at a high level, by selecting from and configuring a sequence of operations using the GUI. The prototyping environment application may then be operable to automatically, i.e., programmatically, generate graphical program code implementing the sequence. For example, the environment may generate a standalone graphical program operable to perform the sequence of operations.

Synchronized and noise-robust audio recordings during realtime magnetic resonance imaging scans.

Abstract: This letter describes a data acquisition setup for recording, and processing, running speech from a person in a magnetic resonance imaging (MRI) scanner. The main focus is on ensuring synchronicity between image and audio acquisition, and in obtaining good signal to noise ratio to facilitate further speech analysis and modeling. A field-programmable gate array based hardware design for synchronizing the scanner image acquisition to other external data such as audio is described. The audio setup itself features two fiber optical microphones and a noise-canceling filter. Two noise cancellation methods are described including a novel approach using a pulse sequence specific model of the gradient noise of the MRI scanner. The setup is useful for scientific speech production studies. Sample results of speech and singing data acquired and processed using the proposed method are given.

Sensemble: a wireless, compact, multi-user sensor system for interactive dance

Abstract: We describe the design of a system of compact, wireless sensor modules meant to capture expressive motion when worn at the wrists and ankles of a dancer. The sensors form a high-speed RF network geared toward real-time data acquisition from multiple devices simultaneously, enabling a small dance ensemble to become a collective interface for music control. Each sensor node includes a 6-axis inertial measurement unit (IMU) comprised of three orthogonal gyroscopes and accelerometers in order to capture local dynamics, as well as a capacitive sensor to measure close range node-to-node proximity. The nodes may also be augmented with other digital or analog sensors. This paper describes application goals, presents the prototype hardware design, introduces concepts for feature extraction and interpretation, and discusses early test results.

Visual navigation system for endoscopic surgery

Abstract: An endoscopic surgical navigation system comprises a data acquisition subsystem, a tracking subsystem, a registration subsystem, a data processing subsystem and a user interface subsystem. The data acquisition subsystem inputs intra-operative scan data from a medical scanning device during an endoscopic procedure. The tracking subsystem captures data representing positions and orientations of a flexible endoscope during the endoscopic procedure. The registration subsystem determines transformation parameters for coregistering the intra-operative scan data and the data indicative of positions and orientations of the endoscope. The data processing subsystem coregisters the intra-operative scan data and the data indicative of positions and orientations of the endoscope based on the transformation parameters and generates real-time image data representing 3D internal views of a body that are coregistered with live video from an endoscopic video camera. The user interface subsystem receives input from a user for controlling the system and provides output to the user.

A VLSI analog computer/digital computer accelerator

Abstract: The design of a single-chip VLSI analog computer fabricated in a 0.25-/spl mu/m CMOS process is described. It contains 80 integrators, 336 other linear and nonlinear analog functional blocks, switches for their interconnection, and circuitry to enable the system's programing and control. The IC is controlled, programmed and measured by a PC via a data acquisition card. This arrangement has been used to simulate ordinary differential equations (ODEs), partial differential equations, and stochastic differential equations with moderate accuracy, significantly faster than a modern workstation. Techniques for using the digital computer to refine the solution from the analog computer are presented. Solutions from the analog computer have been used to accelerate a digital computer's solution of the periodic steady state of an ODE by more than 10/spl times/. The IC occupies 1 cm/sup 2/ and consumes 300 mW. An analysis has been done showing that the analog computer dissipates 0.02% to 1% of the energy of a general purpose digital microprocessor and about 2% to 20% of the energy of a digital signal processor, when solving the same differential equation.

Hardware and software design for an electromagnetic induction tomography (EMT) system for high contrast metal process applications

Abstract: This paper presents the latest development of an EMT system designed for use in the metal production industry such as imaging molten steel flow profiles during continuous casting. The system that has been developed is based on a commercial data acquisition board residing in a PC host computer and programmed in the LabView graphical language. The paper reviews the new EMT hardware electronics and software. The noise effects and the detectability limits of the system are given in the paper followed by the system sensitivity map analysis. Optimal image reconstructions, including the simultaneous iterative reconstruction technique (SIRT) and non-iterative Tikhonov regularization, truncated singular value decomposition (TSVD), are also discussed and applied for the system. The system has been demonstrated in real time (10 frames s−1 for 5 kHz excitation) with test phantoms that represent typical metal flow profiles such as central, annular stream and multiple streams.

Practical Issues in Implementing Analog-to-Information Converters

Abstract: The stability and programmability of digital signal processing systems has motivated engineers to move the analog-to-digital conversion (ADC) process closer and closer to the front end of many signal processing systems in order to perform as much processing as possible in the digital domain. Unfortunately, many important applications, including radar and communication systems, involve wideband signals that seriously stress modern ADCs; sampling these signals above the Nyquist rate is in some cases challenging and in others impossible. While wideband signals by definition have a large bandwidth, often the amount of information they carry per second is much lower; that is, they are compressible in some sense. The first contribution of this paper is a new framework for wideband signal acquisition purpose-built for compressible signals that enables sub-Nyquist data acquisition via an analog-to-information converter (AIC). The framework is based on the recently developed theory of compressive sensitng in which a small number of non-adaptive, randomized measurements are sufficient to reconstruct compressible signals. The second contribution of this paper is an AIC implementation design and study of the tradeoffs and nonidealities introduced by real hardware. The goal is to identify and optimize the parameters that dominate the overall system performance.

Automated robotic measuring system

Abstract: An automated coordinate measuring system comprising a measuring arm used for acquisition of geometry data that incorporates an exoskeletal structure resilient to physical perturbations including thermal changes and vibrations which may affect coordinate data acquisition. The system may be adapted to a portable platform allowing for convenient positioning and alignment of the measuring arm in a wide variety of environments.

Estimation of Vehicle Speed Based on Asynchronous Data from a Silicon Retina Optical Sensor

Abstract: This work presents an embedded optical sensory system for traffic monitoring and vehicles speed estimation based on a neuromorphic "silicon-retina" image sensor, and the algorithm developed for processing the asynchronous output data delivered by this sensor. The main purpose of these efforts is to provide a flexible, compact, low-power and low-cost traffic monitoring system which is capable of determining the velocity of passing vehicles simultaneously on multiple lanes. The system and algorithm proposed exploit the unique characteristics of the image sensor with focal-plane analog preprocessing. These features include sparse asynchronous data output with high temporal resolution and low latency, high dynamic range and low power consumption. The system is able to measure velocities of vehicles in the range 20 to 300 km/h on up to four lanes simultaneously, day and night and under variable atmospheric conditions, with a resolution of 1 km/h. Results of vehicle speed measurements taken from a test installation of the system on a four-lane highway are presented and discussed. The accuracy of the speed estimate has been evaluated on the basis of calibrated light-barrier speed measurements. The speed estimation error has a standard deviation of 2.3 km/h and near zero mean

Autocalibrated coil sensitivity estimation for parallel imaging.

Abstract: Parallel imaging has proven to be a robust solution to the problem of acquisition speed in MRI. These methods are based on extracting spatial information from an array of multiple surface coils in order to speed up image acquisition. One of the most essential elements of any parallel imaging method is the information describing the coil sensitivity distribution throughout the sample. This paper covers some of the advanced methods to obtain coil sensitivity-related information, focusing particularly on the class of methods referred to as autocalibrating. These methods all acquire the data for coil sensitivity estimation directly before, during or directly after the reduced data acquisition. After a review of standard methods for coil sensitivity estimation, some of the basic and advanced autocalibrating methods are reviewed, and some example applications shown.

Image processing techniques for a video based traffic monitoring system and methods therefor

Abstract: The present disclosure relates to a number of inventions directed, generally, to the application of image processing techniques to traffic data acquisition using video images. The inventions reside in a traffic monitoring system, the basic function of which is for traffic data acquisition and incident detection. More specifically, the application of image processing techniques for the detection of vehicle, from sequence of video images, as well as the acquisition of traffic data and detection of traffic incident. In one aspect, the present invention provides a method of processing images received from a video based traffic monitoring system. In another aspect, the present invention is directed to a Region Of Interest (ROI) for detection of a moving vehicle and a further aspect is directed to a method of detecting day or night status in a traffic monitoring system. It's The application of various algorithms to a video based traffic monitoring system is also considered inventive. Other inventive aspects of the present traffic monitoring system are outlined in the claims.

A localization method using 3-axis magnetoresistive sensors for tracking of capsule endoscope.

Abstract: In this paper, we propose a non-invasive tracking method, which has the potential to be used for localization of the capsule endoscope. The tracking system consists of a magnetic marker, a sensor array, amplifiers, data acquisition devices and a signal processing unit. The marker is modeled as a magnetic dipole to simplify the theoretical expression of the magnetic field distribution. By minimizing the squared error of the field values between the calculation and measurements using Levenberg-Marquardt optimization method, the 5 localization parameters of the dipole can be determined. Real time experiments were carried out to test the feasibility of the method. It is demonstrated that, the accuracy of the localization is related to the number of sensors. For the sensor array including 16 3-axis magnetoresistive sensors, the average position error is 3.3 mm and the average orientation error is about 3 degrees, when the magnetic marker is 100 mm above the sensor array plane.

Design and implementation of a multifrequency near-infrared diffuse optical tomography system

Abstract: The design and implementation of a multifrequency and multispectral diffuse optical tomography system is described. Four wavelengths are utilized: 665, 785, 808, and 830 nm. The system is based on a network analyzer, which provides rf modulation signals for the laser diodes, as well as measures the amplitude and the phase of the detected signals. Six different modulation frequencies ranging from 110 to 280 MHz are used. The details of instrumentation, calibration, data acquisition, and performance of the system are given. A finite element algorithm is used to solve the diffusion equation, and an inverse solver based on this forward solver is implemented to calculate the absorption and scattering maps from the acquired data. Data acquisition for one wavelength is completed in less than 2.5 min for a single modulation frequency. The measurement repeatability is 0.5% in ac intensity and 0.2 deg in phase. The performance of the system is evaluated with phantom studies. A multifrequency reconstruction algorithm is used, in which a single absorption and scattering image pair is obtained using the whole dataset obtained at different modulation frequencies. It is shown that the multifrequency reconstruction approach provides superior image quality compared to the single frequency counterpart.

Method and apparatus of radiographic imaging with an energy beam tailored for a subject to be scanned

Abstract: A method and apparatus for tailoring the profile of an x-ray beam for radiographic imaging for a specific subject is disclosed. The invention includes a filter assembly having a pair of filters, each of which may be dynamically controlled by a motor assembly during data acquisition. The filters are positionable in the x-ray beam so as to shape the intensity profile of the x-ray beam. In one exemplary embodiment, the filters are dynamically positioned during CT data acquisition based on the shape of the subject. A method of determining the shape of the subject prior to CT data acquisition is also disclosed.

Capturing high-frequency phenomena using a bandwidth-limited sensor network

Abstract: Small-form-factor, low-power wireless sensors-motes-are convenient to deploy, but lack the bandwidth to capture and transmit raw high-frequency data, such as human voices or neural signals, in real time. Local filtering can help, but we show that the right filter settings depend on changing ambient conditions and network effects such as congestion, which makes them dynamic and unpredictable. Mote collection systems for high-frequency data must support iteratively-tuned, deployment-specific filter settings as well as fast samplin.VANGO, our software system for high-frequency data collection, achieves these goals via integrated processing across network tiers. Bandwidth-limited sensor nodes reduce data in network but rely on microservers, which have greater computational capabilities and a wider scope of observation, to plan how. VANGO provides a cross-platform library for data transformation, measurement, and classification; a fast and low-jitter data acquisition system for motes; and a mechanism to control mote and microserver signal processing. With VANGO we have developed new applications: the first acoustic collection system for motes responsive to changing environmental conditions and user interests, and the first neural spike acquisition application capable of supporting a network of nodes.

Modeling and Control System Design for a UAV Helicopter

Abstract: We present in this paper a linearized hovering model of a UAV helicopter obtained using the in-flight data generated through a perturbation method. The UAV helicopter is constructed from a radio-controlled helicopter by integrating an onboard system, which includes a data processing unit, a data acquisition system, a wireless communications and all necessary sensors. A flight control law is then designed using a newly developed nonlinear control technique, i.e. the composite nonlinear feedback control. Actual flight testing shows that the design is successful.

Systems and Method of Network Operation and Information Processing, Including Data Acquisition, Processing and Provision, Including Data Acquisition, Processing and Provision and/or Interoperability Features

Abstract: According to some embodiments of the present invention, a system (100), apparatus and method of network operation and information processing, including data acquisition, data processing, data provision, and/or data interoperability features is presented In some exemplary embodiments, the method includes registering users logging-on to a computer network (170) and gathering user-related information from users (121) In one or more embodiments, user-profile and location-centric information for each user may be gathered and/or processed in connection with processing targeting and content information