Fall 2011:
IPRPI Workshop on Diffusion Optical Imaging
October 27 & 28, 2011
Workshop Description: Diffuse optical tomography (DOT) is a noninvasive imaging modality that makes use of the light in the nearinfrared (NIR) spectrum. The inverse problem in DOT involves reconstruction of spatially varying absorption and scattering properties as well as fluorophore lifetime and yield in tissues from boundary measurements. These fundamental quantities can be utilized to obtain tissue oxy and deoxyhemoglobin concentrations, blood oxygen saturation, water, fat and fluorophore uptake in tissue.
The unique physiological and biochemical information offered by DOT is very valuable for practical applications such as breast cancer diagnosis, cognitive activity monitoring, brain tumor and hemorrhage detection, functional muscle imaging with a growing list of applications in fluorescence tomographic imaging.
This workshop is aimed at highlighting the challenging and new medical applications where diffuse optical imaging can potentially play a major role and the recent developments in instrumentation and the solutions of PDE based nonlinear inverse problems, thereby providing a discussion forum in identifying new directions in diffuse optical imaging research.
This workshop is supported by the Division of Mathematical Sciences at the National Science Foundation, NSF DMS0852516.
Program for the Workshop: The proposed workshop will run for two days, and will consist of nine 45 minute talks each followed by a 20 minute short discussion session. At the end of the first day there will be a Panel Discussion. On the second day there will be a one hour and twenty minute poster session during the lunch break.
Organizer:
Dr. Birsen Yazici, Electrical, Computer and Systems Engineering, RPI
Dr. Xavier Intes, Department of Biomedical Engineering, RPI
IPRPI Workshop on Biomechanical Imaging
August 27 & 28, 2011
Workshop Description: Recent advances in biomedical imaging have made it possible to image mechanical properties of tissues. These include properties such as the Young’s modulus, nonlinear elastic properties and viscoelastic and poroelastic properties. Simultaneously, it has been established that the mechanical properties of tissue are altered if it is diseased. For example, cancers often present as lumps that are stiffer than their surroundings. Based on this, medical practitioners are now evaluating the potential of biomechanical images in the detection and diagnosis of several diseases such as breast and prostate cancer, atherosclerosis, deep vein thrombosis and liver cirrhosis. In addition, biomechanical images may also be used to generate patientspecific models for surgical training and planning and to test fundamental hypotheses on the effect of mechanics on biology (mechanobiology).
Almost all techniques in biomechanical imaging involve “watching” the tissue deform using a standard imaging modality such as ultrasound or MRI, and then using the pre and postdeformation images to estimate the interior displacement of tissue. This displacement data is then used along with an appropriate mechanical model (say linear elastic) to determine the spatial distribution of the desired mechanical property. The problem of determining the spatial map of the mechanical property given the interior displacement data is naturally posed as an inverse problem. What makes this inverse problem special is (1) The availability of (incomplete) interior data. Though displacements are known in the interior of the tissue they are typically known only over a subset of the total domain, or only a single displacement component is known. (2) In solving the problem more than one material property may be sought. For example one may want to image both the linear elastic and viscoelastic parameters. (3) While it may be possible to gather data over a large subset of the domain, it is very hard to generate more than a few (23) independent measurements. All these factors (incomplete interior data, multiple solution variables and few independent measurements) make the resulting inverse problem very different from typical inverse problems found in imaging. With this as background, we are proposing a workshop where a few (say five) leaders from the field of biomechanical imaging will present the state of that art and pressing needs in their areas to an audience comprising mainly of applied mathematicians and computational scientists. The hope is that through this interaction the group will identify open problems and in the long term this would lead to greater progress in this new and exciting area of medical imaging.
Program for the Workshop: The workshop will run for one and a half days. The workshop will begin at lunch time on the first day and will end at 6 p.m. on the second day. There will be six invited talks, a poster session, and two tutorials.
Organizer:
Dr. Assad Oberai, Mechanical Engineering, RPI
Schedule and Invited Speakers:
(Download Schedule)
Summer 2010:
IPRPI Workshop on Microlocal Analysis in Imaging
August 2 & 3, 2010
Workshop Description:
Microlocal analysis is the mathematical study of singularities and associated highfrequency structures. It encompasses the theory of Fourier integral operators and their action on functions with singularities. This is important in imaging for two reasons: 1) The forward operators in synthetic aperture imaging, and in many other linearized imaging problems, are Fourier integral operators. Microlocal analysis shows how to construct approximate inverse operators for these operators; and 2) One example of a type of singularity is a jump discontinuity. Such jump discontinuities describe the boundaries between different objects in space and also the boundaries between different objects (edges) in images. Thus it is precisely attention to singularities that is important in imaging.
There is now increasing agreement in many quarters that the mathematics and engineering communities would both benefit by more interaction. Engineering has become highly mathematical, yet many of the mathematical techniques developed by engineers are unknown in the mathematics community. Conversely, techniques and theory such as microlocal analysis that have been developed within the mathematics community are directly relevant to problems in engineering, and yet many mathematicians are unaware of potential applications and are not thinking about how to communicate their ideas to anyone outside their own ingrown community. This workshop is aimed at bringing the mathematics and engineering communities together in a workshop that focuses on the use of microlocal analysis in imaging problems. .
Program for the Workshop:
The proposed workshop will run for two days, with a short 23 hour tutorial in the afternoon of August 2nd, 2010 and a fullday workshop on August 3rd, 2010 which will consist of six 45 minute talks each followed by a 30 minute short discussion session. At the end of the second day there will be a one hour poster session and a discussion session.
Organizers:
Dr. Birsen Yazici, Electrical, Computer and Systems Engineering, RPI
Dr. Margaret Cheney, Mathematical Sciences, RPI
Spring 2010:
IPRPI Workshop on Seismic Waveform Tomography
April 27 & 28, 2010
Workshop Description:
Because seismograms of elastic waves provide the highest resolution and least ambiguous images of the subsurface, seismologists have been motivated for many years to develop increasingly sophisticated techniques to exploit the information in seismic waveforms. Historically, seismic imaging techniques have evolved from two end member approaches: full waveform techniques capable of modeling mildly heterogeneous media, and ray or infinite frequency techniques that migrate coherent phases in a strongly heterogeneous media but ignore the details of the waveform. The former techniques generally have been employed by passive source seismologists, as large earthquakes can generate the required large amplitude, long wavelength signals. The latter have been used extensively by active source seismologists, who generate short wavelength signals from artificial sources to resolve fine details of near surface structure. The challenge for seismic imaging over the past decade has been to close the gap between these approaches, either by analytically adapting long wavelength techniques to smaller scales or using numerical techniques to recover the information in high frequency waveforms.
Technical developments over the past several years have brought about a remarkable increase in both the quantity and quality of seismic data, as well as tremendous advances in computing capabilities. Seismologists from both the active and passive source communities have been taking advantage of these advances to develop techniques that extend the analysis of waveforms to progressively higher frequencies. The most promising applications, which can be collectively categorized as seismic waveform tomography attempt to take advantage of the entire seismic wavetrain in constructing an image. The applications are diverse, in part because the seismologists who propose them have a particular application in mind. Nevertheless, all of these researchers are in a real sense trying to solve the same problem: how to image the physical properties of the subsurface using the waveform of a recorded vibration. Hence, there should be opportunities for crossfertilization that can result in significant advances in both active and passive source imaging. A principle motivation for this workshop is to invite several key researchers from both the active and passive source sides of seismology to discuss and compare their approaches and discover how we might benefit from each others’ experiences.
Program for the Workshop:
The proposed workshop will run for two days, the first day being devoted to active source techniques and the second to passive source techniques. Each day will consist of five 45 minute talks followed by a 15 minute short discussion session, with a a one hour discussion session at the end of the day.
Organizer:
Dr. Steven W. Roecker, Earth and Environmental Sciences Department, RPI
IPRPI Symposium on Inverse Problems and System Identification of Geosystems
March 29 & 30, 2010
Workshop Description:
Inverse problem and system identification techniques play an important role in the characterization and modeling of the response of geosystems. These techniques are expected to have in the future an ever growing impact on the ways we monitor, model, analyze and design geosystems. The Inverse Problem Center at RPI (IPRPI, www.iprpi.rpi.edu) is organizing a twoday workshop to discuss recent developments and the role of Inverse Problems and System Identification of geosystems in advancing our understanding and modeling of geosystems.
Organizer:
Mourad Zeghal, Department of Civil and Environmental Engineering, RPI
Workshop on Inverse Problems
and System Identification of GeoSystems
March 24, 2008
Workshop Description:
Inverse problem and system identification techniques play an important role in the characterization and modeling of the response of geosystems. These techniques are expected to have in the future an ever growing impact on the ways we monitor, model, analyze and design geosystems. The Inverse Problem Center at RPI (IPRP, www.iprpi.rpi.edu) is planning a daylong workshop to discuss recent developments and the role of Inverse Problems and System Identification of Geo Systems in advancing the current state of knowledge in Geomechanics. The workshop will consist of 5 comprehensive talks with ample time for discussions
Organizer:
Mourad Zeghal, Department of Civil and Environmental Engineering, RPI
Workshop on Inverse Problems
Radar Waveform Design and Imaging
May 19, 2005
Workshop Description:
This workshop will bring together researchers
interested in fundamental and practical issues related to radar
waveform design and imaging. We anticipate participants from both
academia and national research laboratories.
Organizers:
Margaret Cheney and Birsen Yazici
Background:
The Radar Waveform Design and Imaging
Workshop is one of IPRPI's signature events where focused, interactive
research discussion and presentation enables and encourages cross
disciplinary exchanges of ideas. Both senior and early career researchers
are encouraged to participate. Prior events of this type were the
Geophysical Imaging Workshop, held on January 30, 2004 and the Solid
Mechanics Workshop, held on March 24, 2004.
Workshop on Geophysics
January,
2004
Workshop
Description:
The focus will be on seismic imaging,
both active and passive, with an aside to magnetotellurics (MT)
and the potential for integrating MT and seismic investigations.
Organizer:
Steve Roecker
Background:
During the inaugural year for the newly
established IPRPI center, we are organizing daylong workshops to
discuss inverse problems (or "imaging") in a number of
disciplines. The first in this series is devoted to Geophysical
Imaging.
Workshop on Solid Mechanics
March, 2004
Workshop Description:
Here we focus on a number of rapidly
advancing inverse problems fields including medical imaging through
elastography, inverse problems for multiscale stochastic models,
methods for inverse problems in nanomechanics and multiscale mechanics.
Organizer:
Antoinette Maniatty
Background:
During the inaugural year for the newly
established IPRPI center, we are organizing daylong workshops to
discuss inverse problems in a number of disciplines. The first in
this series was devoted to Geophysical Imaging and was held on January
30, 2004. The second of these is the one described here, devoted
to parameter identification problems in solid mechanics, which will
be held on March 24, 2004. In addition, there will be an IPRPI Center
Opening Conference at Rensselaer, April 57, 2004.
Opening Conference
April 2004
Background:
During the inaugural year for the newly
established IPRPI center, we host Interdisciplinary Inverse Problems:
Opening Conference for IPRPI during April 57. The topics covered
in this conference reflect the active research areas of center participants
including: geophysical imaging, biomedical imaging, radar imaging,
time reversal problems, earthquake dynamics inverse problems, ocean
acoustics inverse problems, and photonics.
Plenary Speakers and Panelists:
George Papanicoleao, Stanford University
Mathias Fink, ESPCI, Paris
Gunther Uhlmann, University of Washington
Maarten DeHoop, Colorado School of Mines
William Symes, Rice University
Erkki Somersalo, Helsinki
William Rundell, NSF DMS Director
Albert Tarantola, Institut de Physique du Globe
de Paris
Omar Ghattas, Carnegie Mellon University
