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Short Courses for the 2003 IEEE International Ultrasonics Symposium
| Course #1: |
Fundamentals of Ultrasonic Waves |
| Instructor: |
David Cheeke
Concordia University
Montreal, Quebec, Canada |
Time: 8:00 am - noon, October 5, 2003.
Abstract: The objective of this course is to provide a sound physical basis for understanding the propagation
of acoustic waves in solids. The course is aimed at newcomers to the field with at least BSc level in Physics
or Engineering and also to those with experience in practical ultrasonics but who lack a theoretical basis.
The material is divided into four equally balanced parts. The first deals with the propagation of bulk waves
in infinite media, the wave equation, and the relation of acoustic properties to the appropriate material
parameters. This is followed by a detailed treatment of the solid-liquid interface, with emphasis on the
partial reflection and transmission of acoustic waves. This leads into a discussion of surface acoustic
(Rayleigh) waves in the third section. These concepts are extended in the final section to a consideration
of guided waves (Lamb, Love, SH, etc.) in various multilayer structures. Where appropriate, applications
of these modes will be discussed.
David Cheeke received the Bachelors and Masters degree in Engineering Physics from UBC, Vancouver, in 1959
and 1961, respectively, followed by the PhD in Low Temperature Physics from Nottingham University in 1965.
He then joined the Low Temperature Laboratory, CNRS, Grenoble, also as a Professor of Physics at the
University of Grenoble. In 1975, he moved to the Université de Sherbrooke, Canada, where he set up an
ultrasonics laboratory, specialized in physical acoustics, acoustic microscopy, and acoustic sensors.
In 1990, he joined the Physics Department at Concordia University, Montreal, where he is Head of an
Ultrasonics Laboratory and was Chair of the Department 1992-2000. He has published over 120 papers
on various aspects of ultrasonics. He is senior member of the IEEE, a member of the ASA, and an Associate
Editor of the IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control.
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| Course #2 |
Medical Ultrasound Transducers |
| Instructors: |
Douglas G. Wildes and L. Scott Smith
GE Global Research Center
Niskayuna, NY |
Time: 8:00 am - noon, October 5, 2003.
Abstract: This course will provide an introduction to the design, fabrication, and testing of medical
ultrasound transducers. Starting from an overview of the basic types of phased-array transducers
(linear, convex, sector), we will discuss how the design for a probe is derived from its target application
and how equivalent-circuit, finite-element, and acoustic field models can be used to optimize the design
and accurately predict performance. A discussion of the structure of an ultrasound probe will lead to a
survey of the different types of materials used in probes and their critical properties. Typical
fabrication processes will be introduced and common problems in probe manufacturing will be summarized.
Methods for evaluating completed transducers will be discussed. We will conclude with some examples of
newer probe technology, e.g. multi-row arrays, single crystal piezoelectrics and cMUT transducers, and
will discuss performance advantages and fabrication difficulties which may be associated with each.
Douglas G. Wildes is a physicist with GE Global Research. He earned an A.B. in physics and mathematics
from Dartmouth College and a Ph.D. in low-temperature physics from Cornell University, then joined GE
in 1985. Since 1991, Dr. Wildes' research has focused on aperture design, fabrication processes, and
high-density interconnect technology for multi-row transducers for medical ultrasound. The results of
his work are reflected in GE's growing line of Matrix Array probes, for which he has received several
GE awards. Dr. Wildes has 16 issued patents and 18 external publications. He is a member of the American
Physical Society and the IEEE.
L. Scott Smith is a physicist with GE Global Research. He earned B.S. and Ph.D. degrees in physics from
the University of Rochester and the University of Pennsylvania respectively. Joining GE in 1976, he
developed phased array probes for medical ultrasound. More recently, he examined novel probe materials
and led projects on pediatric endoscopes and adaptive acoustics. Dr. Smith has 32 issued patents and
over 30 refereed publications. He is a member of the American Physical Society and a Senior Member of
the IEEE where he serves as Vice Chair for Transducers and Transducer Materials on the Ultrasonics
Symposium's Technical Program Committee.
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| Course 3: |
Recent Trends in Beamformation in Medical Ultrasound |
| Instructor: |
Kai E. Thomenius
General Electric's Corporate R&D
Niskayuna, NY |
Time: 8:00 am - noon, October 5, 2003.
Abstract: The goal of this short course is to review analytical methods used in developing the design of
a typical beamformer in use in diagnostic ultrasound today. Two specific methods, angular spectrum and
spatial impulse response, will be discussed in some detail. The key points to be covered deal with
methods of analysis of arrays and beamformers, the interaction of transmit and receive beams with
clinically relevant targets, and how this interaction is used in image formation. The means by which
these analytical methods contribute to a beamformer design and the trade-offs involved are reviewed.
The techniques developed for such analysis will be applied to current topics involving beamformation
such as elevation focusing, sparse arrays, harmonic imaging, and phase aberration correction. Heavy
use of graphical techniques will be made to illustrate the concepts.
Kai E. Thomenius is the Manager for the Ultrasound Program at General Electric's Corporate R&D facility
in Niskayuna, NY. Previously, he has worked at ATL Ultrasound, Inc. and Interspec Inc. as well as several
other ultrasound companies. Dr. Thomenius' academic background is in electrical engineering with a minor
in physiology; all of his degrees are from Rutgers University. His current interests are in beamformation,
propagation of acoustic waves in inhomogeneous media, generation of harmonic energy during acoustic
propagation, the potential of bioeffects due to those acoustic beams, and retrieval of additional
diagnostic information from the echoes that arise from such beams.
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| Course #4: |
Recent Advances in Acoustic Microscopy |
| |
Course #4 has been cancelled. |
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| Course #5: |
Micromachined Ultrasonic Sensors and Actuators |
| Instructors: |
Amit Lal
Cornell University
Ithaca, N.Y.
Richard M. White
University of California
Berkeley, CA |
Time: 1:00 pm - 5:00 pm, October 5, 2003
Abstract: The goal of this course is to introduce the fundamentals of micromachining and the way they
affect the design and performance of ultrasonic sensors and actuators. The first part (~1.5 hours) of
this course will cover established micromachining techniques, such as bulk micromachining and surface
micromachining on silicon. It will also cover new techniques such as XeF2 etching and PDMS soft
micromachining. The relevant acoustic and ultrasonic properties of materials used in MEMS will be discussed
for predictable device design. In the remaining time, the following topics will be discussed with the
help of case studies: (1) Electrostatic actuation of micromachined membranes: Nonlinearities and effective
electromechanical coupling, (2) Comparison of PZT and thin-film piezoelectric actuation of silicon bulk
and surface micromachined structures: silicon horn design, microphones, speakers, impact/spalling actuation
of MEMS (3) Flexural plate waves and bulk waves in micromachined devices: the role of internal stresses
and material properties on waves, (4) Nonlinear ultrasound in microfluidic devices.
Amit Lal is an assistant professor of electrical and computer engineering at Cornell University. He
received his Ph. D. in electrical engineering from the University of California, Berkeley in 1996,
and the B.S. degree from the California Institute of Technology in 1990. He was at the University of
Wisconsin-Madison as an assistant professor from 1998-2002.
Amit Lal is the leader of the SonicMEMS group at Cornell University, which focuses on ultrasonics,
micromachining, modeling of piezoelectric systems, and design and analysis of integrated circuits.
He has published papers on ultrasonic sensors and actuators at conferences in ultrasonics and
micromachining. He serves on the Technical Committee on Physical Acoustics in the IEEE Ultrasonics,
Ferroelectrics, and Frequency Control Society. He holds patents on micromachined acoustic sources/receivers,
and silicon-based high-intensity ultrasonic actuators. He is also the recipient of the NSF CAREER award for
research on applications of ultrasonic pulses to MEMS.
Richard M. White is a professor of electrical engineering and computer sciences at the University of
California, Berkeley. He is also a founding co-director of the Berkeley Sensor & Actuator Center,
an NSF/Industry/University Cooperative Research Center. White received his university education at Harvard,
completing the Ph.D. in applied physics. After
five years at the General Electric Microwave Laboratory in Palo Alto, he joined the faculty of the
University of California at Berkeley. There he has been primarily concerned with teaching and
research in solid-state electronics, with particular emphasis in ultrasonic and sensors.
White's publications and patented inventions concern sensors, ultrasonic phenomena and devices,
thermoelastic effects and microwave electronics. He has co-authored three books: Electrical
Engineering Uncovered, Prentice-Hall, 1997 (an introductory text); Acoustic Wave Sensors, Academic
Press, 1997 (a reference book); and Solar Cells: From Basics to Advanced Systems, McGraw-Hill, 1984
(a reference and text). He is an IEEE Fellow, recipient of the IEEE Cledo Brunetti award and the
Cady award, a Guggenheim fellowship, and the IEEE Society's Achievement Award for contributions to
the field of ultrasonics in photoacoustics, surface acoustic wave devices, and sensors. In 1994
White was elected to the National Academy of Engineering and made a Fellow of the American Association
for the Advancement of Science, and in 1996 he was made a Chancellor's Professor at Berkeley.
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| Course #6: |
Ultrasound contrast agents: Theory and experimental results. |
| Instructors: |
Nico de Jong
Erasmas University
Rotterdam, the Netherlands
Michiel Versluis
University of Twente
Enschede, The Netherlands |
Time: 1:00 pm - 5:00 pm, October 5, 2003
Abstract: The course consists of 6 mean topics:
a) First an overview will be presented of the (clinical and pre-clinical available) contrast agents,
including the properties and characteristics of the gas inside the bubble and the shell surrounding it.
b) Models of the behavior of small bubbles in a ultrasound field will be discussed. Simple models based
on a one dimensional mass-spring system and more complicated models including gas and shell properties.
c) Experimental ultrasound methods for UCA will be presented for characterizing the bubbles in a UCA,
like harmonic and subharmonic scattering, absorption and attenuation. Also the influence of ambient
pressure, temperature and gas concentration will be discussed.
d) Experimental optical methods for characterizing individual bubbles.
e) Imaging methods for contrast agents, like fundamental, harmonic, subharmonic and superharmonic and
multi-pulse methods like pulse inversion, power modulation etc. and new methods like chirp excitation.
f) Ultrasound mediated drug delivery: Interaction between mammalian cells and ultrasound in the vicinity
of bubbles will be discussed.
Nico de Jong graduated from Delft University of Technology, The Netherlands, in 1978. He got his M.Sc.
in the field of pattern recognition. Since 1980, he has been a staff member of the Thoraxcenter of the
Erasmus University Medical Center, Rotterdam, The Netherlands. At the Dept. of Biomedical Engineering,
he developed linear and phased array ultrasonic probes for medical diagnosis, especially compound and
transesophageal transducers. In 1986 his interest in ultrasound applications shifted toward the theoretical
and practical background of ultrasound contrast agents. In 1993 he received his Ph.D. for "Acoustic
properties of ultrasound contrast agents." Currently he is interested in the development of 3-D transducers
and fast framing camera systems. De Jong is the project leader of STW and FOM projects on ultrasound
contrast imaging and drug delivery systems. Together with Folkert ten Cate, MD, he is organizer of
the annual European Symposium on Ultrasound Contrast Imaging, held in Rotterdam and attended by
approximately 175 scientists from all over the world.
Michel Versluis graduated in Physics in 1988 at the University of Nijmegen, the Netherlands, with a special
interest in Molecular Physics and Astrophysics. Later, he specialized in the application of intense tunable
UV lasers for flame diagnostics resulting in a successful defense of his PhD thesis in 1992. Michel Versluis
is now a lecturer at the University of Twente, the Netherlands, in the Physics of Fluids group working on the
experimental study of bubbles and jets in multiphase flows and granular flows. He also works on the use of
microbubbles as a tool for medical diagnosis and therapy. Dr. Versluis teaches various courses in Fluid Mechanics,
one of them focusing on the physics of bubbles.
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| Course #7: |
Synthetic Aperture Ultrasound Systems |
| Instructor: |
Jørgen Arendt Jensen, Svetoslav I. Nikolov and Kim L. Gammelmark
Technical University of Denmark
Lyngby, Denmark |
Time: 6:00 pm - 10:00 pm, October 5, 2003
Abstract: The objective of this course is to give a basic introduction to synthetic aperture (SA)
ultrasound systems. The course is divided into three parts. First the basics of SA data acquisition
and beamformation are described, when synthesizing either the transmitting or receiving aperture.
Equations for the obtainable resolution and side lobe levels are given, and the compromise between
number of emissions and resolution are explained. The second part describes the methods implementation
for clinical imaging. Issues regarding signal-to-noise ratio, the use of coded excitation and aspects of
focusing will be explained. The concept of recursive imaging will be introduced, and it will be shown how
very fast imaging in two and three-dimensions can be obtained. The final part of the course describes
velocity imaging using SA techniques. It is shown how SA systems can acquire data suitable for flow imaging,
and that many of the problems encountered in current flow systems can be solved using SA imaging. This
includes problems with stationary echo canceling, limited precision, and finding the correct velocity
magnitude without angle correction.
The course is intended for Ph.D. students and researchers interested in the signal processing involved
in synthetic aperture ultrasound system for two and three-dimensional imaging for visualizing both anatomy
and the blood flow in the human body.
Jørgen Arendt Jensen earned his Master of Science in electrical engineering in 1985 and the Ph.D.degree
in 1989, both from the Technical University of Denmark. He received the Dr.Techn. from the university in
1996. He has published a number of papers on signal processing and medical ultrasound and the book
"Estimation of Blood Velocities Using Ultrasound", Cambridge University Press in 1996. He has been a visiting
scientist at Duke University, Stanford University, and the University of Illinois at Urbana-Champaign. He is
currently full professor of Biomedical Signal Processing at the Technical University of Denmark at the
Ørsted*DTU and head of Center for Fast Ultrasound Imaging. He has given courses on blood velocity estimation
at both Duke University and University of Illinois and teaches biomedical signal processing and medical
ultrasound imaging at the Technical University of Denmark. His research interest are currently focused on
fast ultrasound imaging using synthetic aperture techniques for anatomic and flow imaging.
Svetoslav Ivanov Nikolov got his Master of Science in electrical engineering and Master of Business and
Administration in international business relations from the Technical University, Sofia in 1996 and 1997,
respectively. In 2001 he got a Ph.D. degree from the Technical University of Denmark, Lyngby.
His dissertation explored approaches for synthetic aperture tissue and flow imaging and their applicability
for real-time 3D imaging. He is currently an assistant professor at the Technical University of Denmark at
the Ørsted*DTU, where he teaches courses in digital design and software development. His research interests
are currently focused on ultrasound 3D real time imaging.
Kim L. Gammelmark was born in Fakse, Denmark on May 1st, 1975. He received his M.S. degree in Electrical
Engineering from the Technical University of Denmark, Kgs. Lyngby, Denmark, in August 2001. He is currently
a Ph.D. student in Biomedical Engineering at the Ørsted*DTU department at the Technical University of Denmark.
His major research interests are the application of synthetic aperture techniques in medical ultrasound
imaging, and synthetic aperture radar techniques.
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| Course 8: |
Finite Element Modeling of Electromechanical Transducers |
| Instructor: |
Reinhard Lerch and Manfred Kaltenbacher
University of Erlangen
Erlangen, Germany |
Time: 6:00 pm - 10:00 pm, October 5, 2003
Abstract: The development of electromechanical transducers, such as piezoelectric ultrasound transducers,
micromachined silicon sensors or, actuators based on electromagnetic transducing principles, e.g.
electroacoustic magnetic transducers (EMATs), is a difficult task in general. Due to their high number of
free parameters which have to be chosen right in order to come to an optimum design, precise computer
simulations based on finite elements (FE) or boundary elements (BE) are often utilized within the design
process. In the first part of that course, the theory of appropriate FE and BE schemes allowing the
modeling of electromechanical coupled field problems as well as basic examples for piezoelectric, electrostatic
and magnetomechanical transducers will be reviewed. The second part will focus on present real life
applications. Therefore, the practical computer aided design of piezoelectric sensors and actuators,
especially ultrasound antennas for imaging purposes, smart piezoelectric structures, micromachined
capacitive sensors and actuators, micromachined capacitive ultrasound transducers (cMuts), micromechanical
systems (MEMS) and, electromagnetic transducers like electrodynamic loudspeakers or EMATs will be
demonstrated. The main goal of this course is to give a basic understanding of finite element transducer
modeling as well as the know-how for its practical application to modern transducer design. A brief
report on latest research regarding the determination of material parameters is also presented. Here,
recent approaches based on a combination of measurements and simulations have led to significant
enhancements. Finally, practical examples will be performed on a PC, therewith demonstrating that with
nowadays simulation software even complex simulation tasks can be performed within reasonable time on
low-cost hardware.
Reinhard Lerch received his master degree in 1977 and his Ph.D. degree in 1980 in Electrical Engineering
from the Technical University of Darmstadt, Germany. From 1981 to 1991, he was employed at the Research
Center of Siemens AG, where he introduced new computer tools supporting the design and development of
piezoelectric transducers. Dr. Lerch is author or coauthor of more than 100 papers in the field of
electromechanical sensors and actuators, acoustics and, signal processing. He received several scientific
awards for his innovative work in the field of computer modeling of electromechanical transducers. From
1991 to 1999, he had a full professorship for Mechatronics at the University of Linz, Austria. Since
September 1999 he is head of the Department of Sensor Technology at the University of Erlangen-Nuremberg.
His current research is directed towards establishing a computer aided design environment for
electromechanical sensors and actuators, including all major transducing principles. Dr. Lerch is serving on
Technical Program Committees of several Technical Conferences. He is a member of the IEEE, the German
Society of Electrical Engineers (VDE), the German Acoustical Society (DEGA), as well as the Acoustical
Society of America (ASA).
Manfred Kaltenbacher received his Dipl.-Ing. in Electrical Engineering from the Technical University of
Graz, Austria in 1992 and his Ph.D. in Technical Science from the Johannes Kepler University of Linz,
Austria in 1996. He is currently an Associate Professor at the Department of Sensor Technology at the
Friedrich-Alexander University of Erlangen. Dr. Kaltenbacher is author and coauthor of more than 30
papers in the field of numerical simulation techniques for coupled field problems and the identification
of material parameters. His research interests are Computer Aided Engineering of electromechanical
sensors and actuators with special emphasis on numerical simulation techniques such as multigrid methods.
Furthermore, he is working on numerical algorithms that enable a precise and automatic reconstruction of
material parameters from relatively simple measurements. Dr. Kaltenbacher is a member of the IEEE Society,
ÖVE Society and the International Compumag Society.
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| Course #9: |
Elasticity Imaging |
| Instructor: |
Stanislav Emelianov
University of Texas
Austin, Texas |
Time: 6:00 pm - 10:00 pm, October 5, 2003
Abstract: Elasticity imaging is rapidly evolving into a new diagnostic and treatment-aid tool. The primary purpose
of this course is to provide both a broad overview and comprehensive understanding of elasticity imaging,
and, as such, it is well suited for both newcomers and active researchers in the field. Following a brief
historical introduction to elasticity imaging, the analysis begins with a discussion of both the equation
of equilibrium and the wave equation to lay a foundation for static (reconstructive) and dynamic (shear
wave) approaches in elasticity imaging, respectively. The theory of elasticity is presented in the
context of the mechanical properties of soft tissues. Then, practical and experimental aspects of
elasticity imaging will be discussed with emphasis on data capture and measurements of internal tissue
motion induced by either internal or surface applied forces. Motion tracking algorithms will be introduced,
and methods to increase and optimize signal-to-noise ratio in strain imaging will be overviewed. Finally,
techniques to map elasticity and other mechanical properties of tissue will be presented and discussed.
The course will conclude with a review of commonly used elasticity imaging techniques, including a discussion
of the advantages and limitations of each approach, and a presentation of current and potential clinical
applications.
Stanislav Emelianov received the B.S. and M.S. degrees in physics and acoustics in 1986 and 1989,
respectively, from the Moscow State University, and the Ph.D. degree in physics in 1993 from Moscow
State University, and the Institute of Mathematical Problems of Biology of the Russian Academy of
Sciences, Russia. In 1989, he joined the Institute of Mathematical Problems of Biology, where he was
engaged in both mathematical modeling of soft tissue biomechanics and experimental studies of
noninvasive visualization of tissue mechanical properties. Following his graduate work, he moved to
the University of Michigan, Ann Arbor, as a post-Doctoral Fellow in the Bioengineering Program, and
Electrical Engineering and Computer Science Department. From 1996 to 2002, Dr. Emelianov was a
Research Scientist at the Biomedical Ultrasonics Laboratory at the University of Michigan. During his
tenure at Michigan, Dr. Emelianov was involved primarily in the theoretical and practical aspects of
elasticity imaging. Dr. Emelianov is currently an Assistant Professor of Biomedical Engineering at
the University of Texas, Austin. His research interests are in the areas of medical imaging for
therapeutics and diagnostic applications, ultrasound microscopy, elasticity imaging, opto-acoustical
imaging, acousto-mechanical imaging, and radiation pressure imaging.
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