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Bernard Choi
Arnold and Mabel Beckman Fellow
Beckman Laser Institute
University of California, Irvine
Approaches for Imaging the
Microvasculature in Skin
Abstract
Photothermal and optical imaging techniques are promising methods for
noninvasive or minimally invasive diagnosis of biological tissue. They are
based on quantitative analysis of measurements involving various sources of
optical contrast, such as absorption, reflectance, or fluorescence. In our
work, we are interested in imaging the microvasculature in skin. First, I
will present results obtained with our photothermal imaging system, which is
used to acquire high-speed infrared image sequences of skin after pulsed
laser irradiation. An inversion algorithm is applied to these sequences to
estimate the initial space dependent temperature rise immediately at the end
of the laser pulse. With appropriate selection of laser parameters and image
processing routines, this space dependent temperature rise corresponds to a
1-D depth profile of skin or a 3-D image of the microvasculature. Recent
results obtained using numerical modeling techniques and our photothermal
imaging system on in vitro tissue phantoms and in vivo animal models and
human subjects will be presented. Second, initial results of a low-cost
laser speckle imaging system for noninvasive imaging of blood flow dynamics
will be presented. Finally, I will present results on the use of
hyperosmotic chemical agents to reduce optical scattering in skin, improving
our ability to use light based techniques to probe, image, or treat deeper
structures in tissue. Such an approach can be used to improve optical
imaging or treatment of blood vessels in skin.
Biosketch
Bernard received a B.S. degree in Biomedical Engineering from Northwestern
University in 1996, and M.S.E. and Ph.D. degrees in Biomedical Engineering
from The University of Texas at Austin in 1998 and 2001, respectively. He is
currently an Arnold and Mabel Beckman Fellow at Beckman Laser Institute,
University of California, Irvine. His graduate and postdoctoral research has
focused on the use of biomedical optics for diagnostic and therapeutic
applications in skin.
Wednesday, November 12, 2003
Bourns Hall, Room A171
10:10 a.m.-11:00 p.m.
(Refreshments will be served at 10:00 a.m.) |
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