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IEEE Symposium (IUS) Ultrasonics

作者： B.M. Shapo J.R. Crowe A.R. Skovoroda M.J. Eberle N.A. Cohn M. O'Donnell Electrical Engineering and Computer Science Department and Bioengineerin Program University of Michigan Ann Arbor MI USA Institute of Mathematical Problems of Biology Russian Academy of Science Pushchino Russia Endosonics Corporation Rancho Cordova CA USA

Tissue elasticity can be estimated from displacement and strain images acquired under controlled deformation. We extend this approach for coronary arteries, deformed and imaged by an integrated angioplasty balloon and ultrasonic imaging probe. Because the lumen cross section of a severely occluded artery is generally not circular, we have also developed a technique to perform all motion computations in the reference frame of the lumen's geometric center. This coordinate system is independent of the imaging catheter, and consequently referencing to this frame removes artifacts associated with probe motion within the balloon during deformation. Displacements and strains estimated by phase-sensitive correlation-based speckle tracking were used to distinguish arterial plaques in simulated coronary arteries of differing elastic moduli: hard, soft, and homogenous. We have also applied these methods to images of a homogeneous gelatin phantom collected with the integrated probe. The spatial dependence of these quantities shows good agreement with theoretically predicted values.

关键词： Capacitive sensors Ultrasonic imaging Arteries Probes Elasticity Displacement control Strain control Angioplasty Catheters Phase estimation

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A Model For The Relative Environmental Stability Of A Series Of Polyimide Capacitance Humidity Sensors

A Model For The Relative Environmental Stability Of A Series...

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International Conference on Solid State Sensors and Actuators (TRANSDUCERS)

作者： A.R.K. Ralston C.F. Klein P.E. Thomas D.D. Denton Central Research Johnson Controls Inc. Milwaukee WI USA Materials Science Program Department of Electrical and Computer Engineering and Department of Chemistry University of Wisconsin Madison Madison WI USA

A capacitance humidity sensor is used as a test de- vice to characterize the performance of thirteen polyimide films in relative humidity sensing applications. This sensor has a multilayer, free-standing film construction. It consists of a humidity sensitive polyinfide dielectric core and conductive layers consisting of carbon filled polysul- fone on each side of the polyimide film to form a capacitor. Thirteen polyimide films, including commercial polyimides and films of novel chemistry, are investigated to determine the long term stability of sensors using the films exposed to 85'C/85% RH for a total of 28 days. Differences in film chemistry are used to interpret trends in the environmental stability of the films.

关键词： Stability Polyimides Capacitance Humidity Sensor phenomena and characterization Chemical sensors Chemistry Capacitive sensors Aging Conductive films

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Microemboli characterization by determination of Legendre coefficients of phase function

Microemboli characterization by determination of Legendre co...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： Jungkuk Kim J.C. Lin L.O. Reynolds BioEngineering Program University of Illinois Chicago Chicago IL USA Electrical Engineering and Computer Science Department University of Illinois Chicago Chicago IL USA University of Illinois Chicago Chicago IL USA

The characterization of microemboli located in whole blood is attempted by determining the Legendre coefficients of phase function from the scattered light distribution around the medium. In the radiative transport equation, a microembolus is represented as a secondary source and assumed to have a spherical form and the first order transport approximate solution of the equation is used to describe the scattered intensity distribution. After the scattered intensities are determined at the surfaces of the medium, the orthogonal property of Legendre polynomial is used to extract the coefficients out of the intensities. From the obtained coefficients, the size and complex index of refraction of microemboli are determined.

关键词： Particle scattering Red blood cells Laboratories Cells (biology) Equations Electrical capacitance tomography Polynomials Position measurement computer simulation Slabs

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Gas desorption from FEA-phosphor screen pairs

Gas desorption from FEA-phosphor screen pairs

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IEEE International Conference on Vacuum Microelectronics (IVMC)

作者： M.E. Malinowski K.D. Stewart D.A.A. Ohlberg T.E. Felter A.G. Chakhovskoi C. Hunt L.E. Shea B.E. Russ J.B. Talbot J. McKittrick Sandia National Laboratories Livermore CA USA Department of Electrical and Computer Engineering University of California Davis CA USA Materials Science Program and Department of AMES University of California San Diego La Jolla CA USA

Gas desorption from a field emitter array (FEA) cathode and phosphor screen anode in a flat panel display must be controlled so that outgassing products produced during display operation do not change cathode electron emission and degrade display performance and uniformity. In order to help understand such desorption processes and to help define pumping requirements in FEA displays, we have determined the major species outgassing from two phosphor screen-FEA cathode systems. The screens were made from YAG:Cr and ZnGa/sub 2/O/sub 4/, candidate materials for use as low voltage phosphors. The YAG:Cr phosphor screen has spectral output primarily in the red, the ZnGa/sub 2/O/sub 4/, in the blue. Outgassing products were measured outside the line-of-sight of both the FEA and phosphor screens. Therefore, if the FEA-screen pairs studied were in a flat panel display, the products detected would be those pumped by appendage pumps mounted on the flat panel. In the current study, we do not measure the source of the products (FEA or screen).

关键词： Phosphors Flat panel displays Field emitter arrays Cathodes Current measurement Vacuum systems Anodes Glass Indium tin oxide Gases

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Synthetic phased array imaging of coronary arteries with an intraluminal array

Synthetic phased array imaging of coronary arteries with an ...

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IEEE Symposium (IUS) Ultrasonics

作者： M. O'Donnell M.J. Eberle D.N. Stephens J.L. Litzza K. San Vicente B.M. Shapo Dept. of Electr. Eng. & Comput. Sci. Michigan Univ. Ann Arbor MI USA Endosonics Corporation Rancho Cordova CA USA Electrical Engineering and Computer Science Department and Bioengineering Program University of Michigan Ann Arbor MI USA

Previous synthetic array methods for intraluminal imaging of coronary arteries have been greatly extended. First, a 64 element, high efficiency, ceramic piezoelectric, array transducer operating at 20 MHz has been constructed. The array is mounted on the surface of a 1.2 mm diameter catheter appropriate for coronary artery applications. Second, integrated into the catheter tip is a custom analog chip set permitting complete data capture from the array. That is, on each firing any combination of array elements can be selected independently as transmitter or receiver. Using data acquired in this way, a complete phased array aperture (i.e. independent transmit and receive apertures) can be reconstructed. To create real-time images, a beam former based on a custom application specific integrated circuit (ASIC) has been designed and built. Beam forming coefficients were derived using an optimal filtering approach accounting for the circular geometry of the array.

关键词： Phased arrays Arteries Catheters Apertures Application specific integrated circuits Ceramics Piezoelectric transducers Transmitters Image reconstruction Filtering

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PARALLEL AND DISTRIBUTED TLM COMPUTATION WITH SIGNAL-PROCESSING FOR ELECTROMAGNETIC-FIELD MODELING

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INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS 1995年第3-4期8卷 169-185页

作者： SO, PPM ESWARAPPA, C HOEFER, WJR NSERC/MPR Teltech Research Chair in RF Engineering Department of Electrical and Computer Engineering University of Victoria Victoria British Columbia V8W 3P6 Canada Poman So received his B.Sc. degree in computer science and physics from the University of Toronto Toronto Onatario Canada in 1985. He obtained his B.A. Sc. and M.A.Sc. degrees in electrical engineering (summa cum laude) from the University of Ottawa Ottawa Ontario Canada in 1987 and 1989 respectively. Mr So was a research engineer in the University of Ottawa from January 1989 to October 1991 his research interests included CAD techniques of microwave circuits and numerical methods for electromagnetic wave modelling. He specialized in the development of electromagnetic engineering CAD software and successfully implemented a number of electromagnetic wave simulators based on the two-dimensional and three-dimensional transmission-line matrix methods. From August 1990 to February 1991 he accompanied Professor W. J. R. Hoefer to Rome Italy and Sophia Antiopolas France. During that time he implemented a parallel version of the 3D-TLM simulator for the CM-2 Connection Machine using C-Star and X Windows Library. He is a research engineer and a Ph.D. student at the University of Victoria Victoria British Columbia Canada. He ported the 2D- and 3D-TLM simulators to DECmpp 1200 massively parallel computer using MPL C and C++. He also combined OSA90/hope a commercially available microwave CAD program with a 2D-TLM simulation module for geometry optimization using the Datapipe technique of OSA90/hope. Recently he has developed a distributed client-server computing technique for the TLM method this technique could accelerate the TLM simulation by more than an order of magnitude. Channabasappa Eswarappa received the M.Tech. degree in electrical engineering from the Indian Institute of Technology Kanpur India in 1983 and Ph. D. degree from the University of Ottawa Canada in 1990. He worked as an Assistant Executive Engineer and later as

This paper describes the implementation of transmission-line matrix (TLM) method algorithms on a massively parallel computer (DECmpp 12000), the technique of distributed computing in the UNIX environment, and the combination of TLM analysis with Prony's method as well as with autoregressive moving average (ARMA) digital signal processing for electromagnetic field modelling. By combining these advanced computation techniques, typical electromagnetic field modelling of microwave structures by TLM analysis can be accelerated by a few orders of magnitude.

关键词： Mathematical models

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A DISTRIBUTED MEDIA ACCESS PROTOCOL FOR PACKET RADIO NETWORKS AND PERFORMANCE ANALYSIS .2. NETWORK SET-UP TIME AND DATA RATE

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 1995年第1期8卷 49-63页

作者： POND, LC LI, VOK Communication Sciences Electrical Engineering Systems University of Southern California Los Angeles CA 90089-2565 U.S.A. Lawrence C. Pond received the M.Sc. and Ph.D. degrees in electrical engineering from the University of Southern California in 1983 and 1990 respectively. Dr. Pond is currently a scientist at Hughes Space and Communications Company having joined in 1980. He has worked in the fields of communication system design mobile communication network and spacecraft payload design. He is currently working on the development of satellite-based ATM transport and switching architectures for BISDN and Defense Information System Network amlications. Dr. Pond is a member of IEEE. Victor O. K. Li was born in Hong Kong in 1954. He received his SB SM and Sc.D. degrees in Electrical Engineering and Computer Science from the Massachusetts Institute of Technology Cambridge Massachusetts in 1977 1979 and 1981 respectively. Since February 1981 he has been with the University of Southern California (USC) LOS Angeles California where he is Professor of Electrical Engineering and Director of the USC Communication Sciences Institute. He has published 150 technical papers and has lectured and consulted extensively around the world. His research interests include high-speed communication networks personal communication networks intelligent networks distributed databases queueing theory graph theory and applied probability. Dr. Li is very active in the Institute of Electrical and Electronic Engineers (IEEE) having been a member of the Computer Communications Technical Committee since 1983 and having served as Chairman from 1987–1989. He served as Chairman of the Los Angeles Chapter of the IEEE Information Theory Group from 1983–1985. He is the Steering Committee Chair of the International Conference on Computer Communications and Networks (IC3 N) General Chair of the 1st Annual IC3N held in San Diego California in June 1992 General Chair and Technical Program Chair of the 4th IEEE Workshop on Comp

In this, the second part of a two-part paper, the required time for establishing a mobile packet radio network using the virtual circuit and time division multiple access protocol developed in Part 1 is analysed. Tools are developed to determine the virtual circuit and network set-up times in terms of the channel bandwidth allocated to establish and maintain the network. The tools are then extended to include the effects of user mobility. Then these results are combined with the network capacity results of Part 1 to analyse the trade-off between the data rate and set-up time of the network. Next a hierarchical architecture is proposed and the network data rate versus set-up time trade-off of this architecture is analysed using these tools. This architecture is shown to both provide a higher data rate and establish faster than flat networks of the same number of nodes.

关键词： PACKET RADIO NETWORK EPLRS DISTRIBUTED NETWORK TDMA VIRTUAL CIRCUITS MULTIHOP NETWORK BOUNDED DELAY MOBILITY NETWORK SET-UP TIME HIERARCHICAL NETWORK NETWORK DATA RATE

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Book reviews

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Minds and Machines 1995年第1期5卷 109-155页

作者： Weiss, Eric A. Leiber, Justin Duchan, Judith Felson Selfridge, Mallory Dietrich, Eric Facione, Peter A. Day, Timothy Joseph Lammens, Johan M. Feenberg, Andrew Johnson, Deborah G. Levine, Daniel S. Warfield, Ted A. Annals of the History of Computing Kailua U.S.A. Department of Philosophy University of Houston Houston U.S.A. Department of Communicative Disorders and Sciences and Center for Cognitive Science State University of New York at Buffalo Buffalo USA Department of Computer Science and Engineering The University of Connecticut Storrs U.S.A. Program in Philosophy Computers and Systems Science Department of Philosophy State University of New York at Binghamton Binghamton USA College of Arts and Sciences Santa Clara University Santa Clara U.S.A. Department of Philosophy University of Alabama at Birmingham Birmingham U.S.A. Scuola Superiore S. Anna ARTS Lab Pisa Italy Department of Philosophy San Diego State University San Diego U.S.A. Department of Science and Technology Studies Rensselaer Polytechnic Institute Troy U.S.A. Department of Mathematics University of Texas at Arlington Arlington U.S.A. Department of Philosophy Rutgers The State University of New Jersey New Brunswick U.S.A.

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A Sophisticated Ground Water Analytical Tool

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Groundwater Monitoring & Remediation 1995年第2期15卷 134-139页

作者： Tonjes, David J. Heil, James H. Black, John A. David J. Tonjes is a doctoral candidate in coastal oceanography at the Marine Sciences Research Center University at Stony Brook through its Waste Management Institute (Waste Management Institute Marine Sciences Research Center University at Stony Brook 11794–5000). Under a grant from the Town Board he is a technical adviser to the commissioner of waste management of the town of Brookhaven New York in solid waste planning regulatory compliance and environmental site monitoring. Tonjes has a B.A. in liberal arts from St. John's College an M.S. in computer science from New York Institute of Technology and an M.S. in technological systems management from the University at Stony Brook. James H. Heil is commissioner of waste management for the town of Brookhaven (Department of Waste Management Town of Brookhaven 3233 Rte. 112 Medford NY 11763). Heil received a B.S. from Manhattan College and an M.S. from New York University in civil engineering and is a licensed professional engineer in New York. He is a former president of the New York State Solid Waste Management Association. John A. Black is the coordinator of the environmental science program at Suffolk County Community College (Environmental Science Program Suffolk County Community College Selden NY 11784). He is currently the chair of the Ecology Committee of the Pine Barrens Advisory Committee for Suffolk County and is a member of the Suffolk County Pine Barrens Review Commission. Black received a B.S. in chemistry from Adephi University an M.S. in public administration from the University at Stony Book an M. S. from Hofstra University and a Ph. D. from Adlephi in marine sciences.

Stiff diagrams arc a multivariate method of analysis used to describe the chemical state of ground water. The use of Stiff diagrams to describe multiconstituent contamination sites, such as landfills, has distinct advantages over single constituent analyses. Problems associated with traditional Stiff diagram analyses, such as diagram attentuation, can be addressed by allowing the scale of the diagram to vary with the ionic strength of the analyzed sample. The use of these sliding scale Stiff diagrams reveals the chemical slate of the ground water over wide ranges of constituent concentrations and thus allows for sensitive and sophisticated depictions of complicated contamination sites in a fashion that is extremely difficult to replicate with single constituent analyses. This approach has possible applications for understanding and tracing the mixing and chemical changes in uncontaminated settings. Copyright © 1995, Wiley Blackwell. All rights reserved

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Semi-automatic construction of 3D medical image-segmentation processes

Semi-automatic construction of 3D medical image-segmentation...

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Visualization in Biomedical Computing 1994

作者： Higgins, William E. Reinhardt, Joseph M. Sharp, Werner L. Departments of Electrical Engineering Computer Science and Engineering and the Bioengineering Program Pennsylvania State University University ParkPA16802 United States

We describe a GUI-based system called INTERSEG that can define 3D radiological image-segmentation processes. Using INTERSEG's GUI interface, the user first defines interactively some problem cues, which specify a segmentation task. Then, INTERSEG uses the cues to automatically construct a process for the task. The process consists of automatic image-processing operations, such as image enhancement, image segmentation, shape analysis, and measurement. With other systems, the user must resort to trial-and-error experimentation to construct such processes. © 1994 SPIE. All rights reserved.

关键词： Image enhancement

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