Showing papers on "Data acquisition published in 1996"

Inter-laboratory note. Laser ablation inductively coupled plasma mass spectrometric transient signal data acquisition and analyte concentration calculation

Abstract: Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) produces complex, time-dependent signals. These require significantly different treatment both during data acquisition and reduction from the more steady-state signals produced by solution sample introduction. This paper discusses, in detail, data acquisition and reduction considerations in LA-ICP-MS analysis. Optimum data acquisition parameters are suggested. Equations are derived for the calculation of sample concentrations and LOD when time-resolved data acquisition is employed, sensitivity calibration is obtained from reference materials with known analyte concentrations and naturally occurring internal standards are used to correct for the multiplicative correction factors of drift, matrix effects and the amount of material ablated and transported to the ICP.

System and method for performing real time data acquisition, process modeling and fault detection of wafer fabrication processes

Abstract: A system and method for detecting faults in wafer fabrication process tools by acquiring real-time process parameter signal data samples used to model the process performed by the process tool. The system includes a computer system including a DAQ device, which acquires the data samples, and a fault detector program which employs a process model program to analyze the data samples for the purpose of detecting faults. The model uses data samples in a reference database acquired from previous known good runs of the process tool. The fault detector notifies a process tool operator of any faults which occur thus potentially avoiding wafer scrap and potentially improving mean time between failures. The fault detector also receives notification of the occurrence of process events from the process tool, such as the start or end of processing a wafer, which the fault detector uses to start and stop the data acquisition, respectively. The fault detector also receives notification of the occurrence of a new process recipe and uses the recipe information to select the appropriate model for modeling the data samples. The fault detector employs a standard data exchange interface, such as DDE, between the fault detector and the model, thus facilitating modular selection of models best suited to the particular fabrication process being modeled. Embodiments are contemplated which use a UPM model, a PCA model, or a neural network model.

LabVIEW for Everyone

Abstract: Preface FUNDAMENTALS 1 Introduction-What in the World Is LabVIEW? What Exactly Is LabVIEW, and What Can It Do for Me? Demonstration Examples Wrap it Up! Additional Activities 2 Virtual Instrumentation: Hooking Your Computer Up to the Real World The Evolution of LabVIEW What Is Data Acquisition? What Is a GPIB? Communication Using the Serial Port Real-World Applications: Why We Analyze A Little Bit about PXI and VXI Connectivity LabVIEW Add-on Toolkits Wrap It Up! 3 The LabVIEW Environment: Building Your Own Workbench Front Panels Block Diagrams The Icon and the Connector Pull-Down Menus Floating Palettes The Toolbar Pop-Up Menus Help! A Word about SubVIs Activity 3-2: Front Panel and Block Diagram Basics Wrap It Up! 4 LabVIEW Foundations Creating Vis-It's Your Turn Now! Basic Controls and Indicators and the Fun Stuff They Do Wiring Up Running Your VI Useful Tips Wrap It Up! Additional Activities 5 Yet More Foundations Loading and Saving VIs VI Libraries Debugging Techniques Creating SubVIs Documenting Your Work A Little about Printing Activity 5-2: Creating SubVIs-Practice Makes Perfect Wrap It Up! Additional Activities 6 Controlling Program Execution with Structures Two Loops Shift Registers Case Structures Sequence Structures The Formula Node Wrap It Up! Additional Activities 7 LabVIEW's Composite Data: Arrays and Clusters What Are Arrays? Creating Array Controls and Indicators Using Auto-Indexing Two-Dimensional Arrays Activity 7-1: Building Arrays with Auto-Indexing Functions for Manipulating Arrays Activity 7-2: Array Acrobatics Polymorphism Activity 7-3: Polymorphism Compound Arithmetic All about Clusters Creating Cluster Controls and Indicators Cluster Order Using Clusters to Pass Data to and from SubVIs Bundling Your Data Replacing a Cluster Element Unbundling Your Clusters Activity 7-4: Cluster Practice Bundling and Unbundling by Name Activity 7-5: More Fun with Clusters Interchangeable Arrays and Clusters Wrap It Up! Additional Activities 8 LabVIEW's Exciting Visual Displays: Charts and Graphs Waveform Charts Activity 8-1: Temperature Monitor Graphs Activity 8-2: Graphing a Sine on a Waveform Graph XY Graphs Chart and Graph Components Activity 8-4: Temperature Analysis Intensity Charts and Graphs-Color as a Third Dimension Waveforms Wrap It Up! Additional Activities 9 Exploring Strings and File I/O More about Strings Using String Functions Activity 9-1: String Construction Parsing Functions Activity 9-2: More String Parsing File Input/Output Activity 9-3: Writing to a Spreadsheet File Activity 9-4: Reading from the Spreadsheet File Wrap It Up! Additional Activities ADVANCED TOPICS Introduction to the Advanced Section 10 Getting Data into and out of Your Computer: Data Acquisition and Instrument Control Acronyms Unlimited How to Connect Your Computer to the Real World Signals Selecting and Configuring DAQ Measurement Hardware Activity 10-2: Measurement System Analysis Installing the Boards Using a GPIB Board Getting Ready for Serial Communications Wrap It Up! Solutions to Activities 11 DAQ and Instrument Control in LabVIEW Definitions, Drivers, and Devices Analog I/O Digital I/O Instrument Control in LabVIEW: VISA, GPIB, and Serial Wrap It Up! 12 Advanced LabVIEW Functions and Structures Local and Global Variables Property Nodes Other LabVIEW Goodies Calling Code from Other Languages Fitting Square Pegs into Round Holes: Advanced Conversions and Typecasting Wrap It Up! 13 Advanced LabVIEW Features Options, Options Configuring Your VI The VI Server Radices and Units Automatically Creating a SubVI from a Section of the Block Diagram A Few More Utilities in LabVIEW Wrap It Up! 14 Connectivity in LabVIEW LabVIEW, Networking, and the Internet An Overview of How the Web Works Publishing and Controlling VIs on the Web Sharing Data over the Network: DataSocket Connectivity to Other Programs and Devices Enterprise Connectivity-The Big Picture Wrap It Up! 15 Advanced File I/O, Printing, and Reports Advanced File I/O Putting It in Writing: Printing with LabVIEW Reports from LabVIEW Wrap It Up! 16 The Art of LabVIEW Programming Why Worry about the Graphical Interface Appearance Arranging, Decorating, Grouping, and Locking Vive l'Art: Importing Pictures Custom Controls and Indicators Adding Online Help Pointers and Recommendations for a "Wow!" Graphical Interface How Do You Do That in LabVIEW? Memory, Performance, and All That Programming with Style Wrap It Up! Concluding Remarks Appendix Resources for LabVIEW GlossaryIndex

Distributed seismic data-gathering system

Abstract: A distributed seismic data acquisition system includes a vast plurality of Autonomous Data Acquisition Modules (ADAM) to each of which are interconnected a subplurality of data-collection channels. Each data collection channel is comprised of an array of seismic sensors for continuously measuring seismic signals. The ADAMs include a GPS satellite receiver for providing geographic coordinates and system clock. Measured seismic signals are quantized and continuously downloaded to the respective interconnected ADAMs from the data-collection channels. The system includes both field testing capability as well means for transmitting the results of self tests. Provision is made for servicing the ADAMs at the end of a multi-day recording session and for harvesting and cataloging the recorded data. The seismic signals gathered by use of the distributed data-gathering system may be processed to provide a subsurface earth model.

Excavator data acquisition and control system and process

Abstract: A data acquisition and control system and process for characterizing the subsurface geology of an excavation site, and for utilizing acquired data to optimize the production performance of a machine an earth penetrating member. A geological information acquisition unit (256) and an optional geographic positioning system (254) are employed to survey a predetermined excavation site or route. A geology characterization unit (260) may be employed to determine the physical characteristics of the subsurface geology. The acquired data are processed to provide geologic and, if applicable, position information for the excavation site which is utilized by a main control unit (250) and a machine controller (255) to modify excavation production performance of the machine.

The Allegro gravitational wave detector: Data acquisition and analysis.

Abstract: We discuss the data acquisition and analysis procedures used on the Allegro gravity wave detector, including a full description of the filtering used for bursts of gravity waves. The uncertainties introduced into timing and signal strength estimates due to stationary noise are measured, giving the windows for both quantities in coincidence searches.

LabVIEW for Everyone : Graphical Programming Made Even Easier

Abstract: Foreword. Preface Good Stuff to Know Before You Get Started. 1. What in the World Is LabVIEW? 2. Virtual Instrumentation: Hooking Your Computer Up to the Real World. Real-World Application: Radio-Linked Environmental Monitoring and Display Systemal Monitoring and Display System Building Your Own Workbench. 4. LabVIEW Foundations. 5. Yet More Foundations. Real-World Application: Next-Generatiion Gas Delivery System for Semiconductor Manufacurers. 6. Controlling Program Execution with Structures. 7. LabVIEW's Composite Data: Arrays and Clusters. 8. LabVIEW's Exciting Visual Displays: Charts and Graphs. 9. Exploring Strings and File I/O. Real-World Application: Preconditioning Automobile Evaporative Canisters Advanced Section. A Bit About the Advanced Section. 10. Getting Data into and out of Your Computer: Data Acquisition and Instrument Control. 11. DAQ and Instrument Control in LabVIEW. Real-World Application: DAQ, SCXI, and LabVIEW Simulate and Test Power Systems. 12. Advanced LabVIEW Functions and Structures. 13. Advanced LabVIEW Features. Real-World Application: Accelerating the Development of Medical Diagnostic Instruments. 14. Communications and Advanced File I/O. 15. The Art of LabVIEW Programming. Real-World Application: High-Speed Remote Process Control. Appendix A. National Instruments Contact Information, Resources, and Toolkits. Appendix B. Troubleshooting and Common Questions. Glossary. Index.

Portable, self-contained data collection systems and methods

Abstract: A portable self-contained data collection system (100) for measuring and collecting vibration data from machines includes an accelerometer (160) which is coupled to the analog input of a data acquisition card (120). The data acquisition card (120) samples and digitizes the analog signal to produce a time domain digital signal. The data acquisition card output (122) is coupled to a battery-powered portable computer (110). The battery-powered portable computer (110) includes a database (220) having machine identifications and associated measurement parameters. The portable computer (110) processes the time domain digital signal according to the measurement parameters associated with a selected machine identification, and produces a frequency domain digital signal by performing a Fast Fourier Transform and other digital signal processing operations. The frequency domain signal is also analyzed in the portable computer (110) to produce predictive maintenance information. A power supply (150) for supplying power to the accelerometer (160) is also included. The accelerometer power supply (150) electrically and mechanically couples the accelerometer (160) to the data acquisition card (120). It supplies power to the accelerometer (160) when the data acquisition card is activated. The portable self-contained data collection system (100) can be used to measure and collect vibration data from machines and to analyze this data to produce predictive maintenance information.

A three-phase sag generator for testing industrial equipment

Abstract: A diesel powered three-phase standby 480 V, 15 kW, 60 Hz synchronous generator has been modified to give controlled three-phase voltage sags. These sags can be controlled in both depth and duration. A 486-based computer with a data acquisition system controls the generator and monitors the system under test. The custom software interface allows the user to select the depth and duration of the each sag. Typically, the user will select a series of sags in selectable increments down to a certain depth. The data acquisition system has both digital and analog inputs, so that data lines, AC and DC voltages and currents, contactors and relays, etc. can be monitored during the tests. The software interface enables the user to select allowable tolerance bands for the monitored signals. If one or more of the signals falls outside the allowable range, the test is suspended. The sag depth and duration that caused the equipment to "fail" the test is then recorded, After testing over a range of sag durations, a CBEMA-type curve is available for the system under test. The sag generator enables the user to systematically determine the sensitivity of the components of an installed process line. This will enable the user to determine cost-effective ride-through enhancement strategies or to test the effectiveness of currently installed equipment. Although this test generator is small, the basic concept can be scaled up to the 2 MVA range.

The SIL Data Acquisition and Monitoring System

Abstract: INTRODUCTION In the past, computerized seismological networks used dedicated telephone lines for continuous telemetering of relatively low-dynamic range, narrow bandwidth data to a central recording facility. These networks have served well the purpose of studying the spatial and temporal distribution of seismicity. However, the high data transmission costs, limitations in dynamic range and bandwidth, and the distortion problems associated with long-distance transfer of analog data have limited the possibility of retrieving the earthquake source information carried by the seismic waves. In the 1980s some networks were designed using microor mini-computers for digitization and data decimation at the observation sites. Event detection is performed in the computer at each site and only the detected events are transferred to the center. Partly due to the relatively high investment cost of these systems, the station spacing within the networks is rather large, limiting the routine analysis to origin time estimation, epicenter location, and...

Predictive maintenance system

Abstract: A predictive maintenance system for a plurality of machines is disclosed. The system includes vibration sensors connected to the machines and a plurality of data acquisition nodes, each node connected to one or more of the vibration sensors. Each node acquires vibration data from the sensors connected thereto during a respective data acquisition interval. A system control computer collects vibration data acquired by the nodes during a polling cycle which is based on the longest of the respective data acquisition cycles of the nodes.

System for effective control of urban environment security

Abstract: A security system for detecting a gunshot event. A communication link, and a number of pole units are arranged in a dense grid. Each one of the pole units includes a microphone and a signal conditioning and thresholding unit coupled to the microphone. The signal conditioning and thresholding unit outputs a detection signal in response to an event when an output signal from the microphone exceeds a peak background average. A data acquisition and signal processing unit is coupled to the signal conditioning and thresholding unit for discriminating gunshot events. The data acquisition and signal processing unit remains in a powered down stand-by mode so as to conserve energy until a detection signal is received. The data acquisition and signal processing unit includes apparatus for identifying a gunshot event by measuring an initial pulse time duration and subsequent pulse pattern features, and a communication interface coupled at an input to the data acquisition and signal processing unit. A central processor is coupled to the communication link so as to receive data from the pole units where the central processor and the pole units operate so as to detect and locate gunshot events sensed by one or more of the pole units.

Examples of resistivity imaging using ME-100 resistivity field acquisition system

Abstract: In spite of dramatic improvement in field acquisition, technology during the past decade (ground penetrating radar - GPR, frequency domain - FEM - and time domain equipment - TEM supported by newly developed techniques for processing and presentation of data, electrical surveying techniques (in particular resistivity) still remain basic tools for examining subsurface features in geological, engineering geological, hydrogeological, environmental and archaeological projects. Conventional resistivity techniques are relatively quick and easy to use and usually provide satisfactory results. Heaviness of this approach appears where detailed survey at small electrode spacings is required - often the amount of data acquired is determined by time constraints rather than more technical considerations. More recently, systems have been developed which employ the use automated switching facilities. These systems allow rapid data acquisition at different electrode spacings to be carried out along the same survey line. The technique has already been applied to variety of geological applications with considerable success.

On-line digital measurement for the quality analysis of power systems under non-sinusoidal conditions

Abstract: This paper presents a digital instrument for the power quality analysis in systems where voltage or current waveforms are non-sinusoidal. It is based on a C40 DSP and on a special high-speed data acquisition system. The analysis is performed by a recursive algorithm which allows the mutable system properties to be tracked. The paper also goes on to discuss the performance of an instrument prototype, both in terms of accuracy specifications and speed of measurement.

Event timing and shape analysis of vibration bursts from power circuit breakers

Abstract: Noninvasive vibration diagnostic techniques are implemented to assess the mechanical condition of power circuit breakers. A diagnostic system, the prototype commercial portable diagnostic system (PCPDS) has been developed Hardware of the PCPDS includes a portable computer, and a data acquisition unit and computer communication cards. Signal processing techniques include the discrete energy statistics envelope, short-time power spectrum, timing extraction algorithm and chi-square based shape test. Decision-making is carried out via a voter program, to which individual results from the timing and shape analysis programs are passed. Statistical and empirical thresholds have been established, that classify the circuit breaker as being in normal-transitional-abnormal (green-yellow-red) condition.

Seismic data compression using high-dimensional wavelet transforms

Abstract: Seismic data have a number of unique characteristics that differentiate them from the still image and video data that are the focus of most lossy coding research efforts. Seismic data occupy three or four dimensions, and have a high degree of anisotropy with substantial amounts of noise. Two-dimensional coding approaches based on wavelets or the DCT achieve only modest compression ratios on such data because of these statistical properties, and because 2D approaches fail to fully leverage the redundancy in the higher dimensions of the data. We describe here a wavelet-based algorithm that operates directly in the highest dimension available, and which has been used to successfully compress geophysical data with no observable loss of geophysical information at compression ratios substantially greater than 100:1. This algorithm was successfully field tested on a vessel in the North Sea in July 1995, demonstrating the feasibility of performing on-board real-time compression and satellite downloading from marine seismic data acquisition platforms.

Optical spray coating monitoring system and method

Abstract: An optical spray coating monitoring system uses a laser displacement sensor and a data acquisition system to monitor a spray gun operator's technique, and display information relating to coating conditions and/or technique. The system includes a laser displacement sensor having a sensor head that is removably attached to a hand held spray gun. The laser displacement sensor measures the distance from the spray nozzle to the surface being coated. The laser displacement sensor also preferably measures the angle of orientation of the spray gun with respect to the surface being coated. The sensor head can also include an infrared temperature sensor. Another embodiment of the invention also uses a second laser displacement sensor. The first sensor measures the distance from the spray gun nozzle to the surface being coated before the coating has been applied to the surface and the second sensor measures the distance after the coating has been applied to the surface, thus allowing determination of the thickness of the wet film on the surface being coated. The measured information is transmitted to the data acquisition system. The data acquisition system provides low level calculations, displays raw data or statistical information, and stores data in memory so that the data can be later downloaded to a computer for further analysis at a later time.

Method and apparatus for providing separate fat and water MRI images in a single acquisition scan

Abstract: A method and apparatus for obtaining three MRI image data in a single data acquisition TR interval for use in constructing separate water and fat images by appropriate processing of the three images data is disclosed. The three image data are obtained in one exemplary embodiment by sandwiching a spin echo between two field echoes. The invention can also be used for multiple-echo and multiple-slice 3D scans.

Virtual navigator, and inertial angular measurement system

Abstract: A position tracker uses an inertial angular measurement system, for measuring orientation and linear translation of a helmet on a human head for the synthesis by a host computer of virtual, directional audio over headphones sensors mounted on the helmut, includes a roll gyro sensor, a pitch gyro sensor, a yaw gyro sensor, an absolute roll tilt sensor coupled to a first universal signal conditioner, an absolute pitch tilt sensor coupled to a second universal signal conditioner, and an absolute yaw compensator. A data acquisition system is coupled between the sensors and the host computer for converting analog signals from the sensors into digital, angular orientation data. Each of the gyro sensors includes angular velocity detectors and solid state electronic devices connected to provide angular velocity signals at a given sample rate.

Performance evaluation of laser communication equipment onboard the ETS-VI satellite

Abstract: Communications Research Laboratory (CRL) developed laser communication equipment (LCE) onboard the engineering test satellite VI(ETS-VI) and a ground system for establishment of basic technologies in optical intersatellite communications. The experiments using a ground-to-space laser link started on December 1994. In the paper, preliminary evaluation for the performance of LCE is presented based on a part of experimental data. Included in the paper are a brief description of operation and data acquisition system, acquisition, tracking and pointing subsystem performance, and communication subsystem performance.

Attribute-based system and method for configuring and controlling a data acquisition task

Abstract: A data acquisition system comprising a computer system, coupled to a data acquisition device, a data acquisition application executing on the computer system, and device interface software with an attribute-based API executing on the computer system. The attribute-based API enables the data acquisition application to perform steps to control the data acquisition device. The steps comprise creating a task for controlling the data acquisition device, setting values of the attributes of the task and device, starting the task acquiring data, and destroying said task. Creating the task comprises allocating an attribute database comprising a plurality of attribute objects corresponding to the attributes of the data acquisition device and an attribute table referencing the plurality of attribute objects. The attribute objects comprise environment data containing values of the attributes and a function for setting the values of the attributes. The attribute table comprises attribute table entries. Each of the attribute table entries references a respective attribute object. The attribute table is indexed by a portion of a unique attribute number associated with each of the attributes. The lookup time associated with invoking the attribute setting function is constant regardless of a number of the attributes. Each attribute has an associated unique number portions of which specifies the datatype and I/O type of the attribute, when the attribute may be set, and the index of the attribute into the appropriate attribute table. A new attribute may be added to the API and existing applications may link to or invoke functions of the new API without modification.

Application of reduced-encoding imaging with generalized-series reconstruction (RIGR) in dynamic MR imaging.

Abstract: Dynamic MRI has proven to be an important tool in studies of transient physiologic changes in animals and humans. High sensitivity and temporal resolution in such measurements are critical for accurate estimation of dynamic information. Fast imaging, often involving expensive hardware, has evolved for use in such cases. We demonstrate herein the possibility of accelerated data acquisition schemes on conventional machines using standard pulse sequences for dynamic studies. This is achieved by combining reduced-encoded dynamic data (typically 30 to 40 phase encodings) with a priori high-resolution data via a novel constrained image reconstruction algorithm. Such an approach reduces image acquisition time significantly (by a factor of 3 to 4 in the examples described here) without loss in the accuracy of information.

3D reconstruction of indoor environments

Abstract: This paper presents a new 3D scene analysis system that automatically reconstructs the 3D model of real-world scenes from multiple range images acquired by a laser range finder on board of a mobile robot. The reconstruction is achieved through an integrated procedure including range data acquisition, geometrical feature extraction, planning the next view, registration and integration of multiple views. The system relies only on the acquired data. Experimental results on real range images are presented in the paper. Direct applications of this technique include 3D reconstruction and/or update of architectural or industrial plans into a CAD model, design verification of buildings, navigation of autonomous robots, and input to virtual reality systems.

Adaptive control of marine seismic streamers

Abstract: A method for controlling the position and shape of marine seismic streamer cables, whereby a plurality of real time signals from a marine seismic data acquisition system and a plurality of threshold parameters from an input device are received. The real time signals are compared to the threshold parameters to determine if the streamer cables should be repositioned. The streamer cables are repositioned when the real time signals exceed the threshold parameters.

DAQ configuration system and method for configuring channels in a data acquisition device

Abstract: A data acquisition configuration system and method for facilitating the creation of data acquisition applications. The present invention enables the user to create channel configurations which include information for a respective DAQ hardware channel, such as the physical phenomena being measured and how the phenomena is being measured. The user then assigns a name to each respective channel configuration. This channel configuration name is then usable in a data acquisition application to specify the channel configuration, thus simplifying application development. After specifying a channel configuration and assigning a name, the user then constructs a program which controls the data acquisition system. The program construction includes providing the assigned name which specifies the channel configuration for the selected channel of the data acquisition device. The program can then be executed to perform a data acquisition operation, wherein the executing includes using the channel configuration referenced by the assigned name in performing the data acquisition operation. The user is thus not required to create code to specify the channel configuration. Further, the program can execute in units of the physical quantity being measured/generated according to the channel configuration, and the user is not required to create code to operate in the units of the physical quantity being measured/generated.

A sinewave fitting procedure for characterizing data acquisition channels in the presence of time base distortion and time jitter

Abstract: A method is proposed to characterize the nonlinear behaviour of a data acquisition channel using a sinewave fitting procedure. Three error sources are considered: the nonlinear (dynamic) behaviour of the data acquisition channel (amplifiers, sample-and-hold, analog-digital-convertor), the time base distortion and the time jitter. Also the time base distortion and the jitter variance are estimated from the same experiment.

Evaluation of GPS for Applications in Precision Agriculture

Abstract: Location coordinate information is needed in precision agriculture to map in-field variability, and to serve as a control input for variable rate application. Differential global positioning system (DGPS) measurement techniques were compared with other independent data sources for sample point location and combine yield mapping operations. Sample point location could be determined to within 1 m (3 ft) 2dRMS using C/A code processing techniques and data from a high-performance GPS receiver. Higher accuracies could be obtained with carrier phase kinematic positioning methods, but this required more time and was a less robust technique with a greater potential for data acquisition problems. Data from a DGPS C/A code receiver was accurate enough to provide combine position information in yield mapping. However, distance data from another source, such as a ground-speed radar or shaft speed sensor, was needed to provide sufficient accuracy in the travel distance measurements used to calculate yield on an area basis.

CHAPTER 12 – A New PET Camera for Noninvasive Quantitation of Physiological Functional Parametric Images: Headtome-V-Dual

Abstract: Headtome-V-Dual is a latest generation positron emission tomography camera system that covers the whole brain and whole myocardium simultaneously. The axial field of view is 15 cm and 10 cm corresponding to the brain and heart scanners, respectively. The heart scanner can move axially to adjust the distance between the brain and the heart in each study. Each gantry consists of 112 units of two-dimensional position-sensitive detector blocks. Detector diameter is 84.7 cm. A unique data acquisition system is implemented, which consists of a large-scale data acquisition memory (1 GB) and a microprocessor that controls the data transfer and the numerical operation, enabling real-time weighted-integration data acquisition either in two- or three-dimensional acquisition modes. Thus, functional parametric images can be calculated rapidly without acquiring the dynamic data. Each microprogram is under control of a UNIX host computer, enabling the software development to be flexible and easy. The coincidence path acceptance is designed to be variable in the axial direction, so that the sensitivity and axial spatial resolution can be optimized in each study protocol. Use of the left ventricular time–activity curve as input function obviates the needs for arterial cannulation, which could be of great advantage in clinical use.

A Holter-type microprocessor-based rehabilitation instrument for acquisition and storage of plantar pressure data in children with cerebral palsy

Abstract: A multichannel, portable data acquisition system has been developed to measure discrete plantar pressures in the rehabilitation of children who have cerebral palsy and planovalgus foot deformity The microprocessor-based system is designed to be lightweight (350 g with batteries) and portable (no umbilicus) in order to minimize encumbrances to gait patterns It provides an improved method for obtaining accurate and reliable data during extended recording and rehabilitative periods that is not available from commercial systems Twelve conductive polymer force (pressure) sensors are used to acquire pressure data, which are then stored in the system memory Plantar pressures are sampled at a rate of 40 Hz from each of the 12 sensors for up to 2 h The system consists of 16 analog amplifiers, a 12 b sampling analog-to-digital converter, an 8 b Dallas semiconductor microprocessor (DS5001FP-16, Dallas, TX), 4 MB of pseudo static RAM, and serial and parallel I/O interfaces The interfaces are used to upload data into a PC for further processing, analysis, and display During subject testing, sensors are located at predetermined anatomic areas under the calcaneus, medial and lateral midfoot, medial and lateral metatarsal heads, and hallux Foot pressure data has been acquired from two pediatric subjects during multiple walking trials to illustrate system application in the normal and planovalgus foot The system is considered to be appropriate for further clinical application and for characterization of event related alterations including rehabilitative, therapeutic, surgical, and nonsurgical treatment