Download High Resolution Biomedical Imaging with Light and Sound

Photoacoustic Microscopy: High Resolution
Biomedical Imaging with Light and Sound
Takashi Buma
Department of Electrical & Computer Engineering, Union College
High resolution imaging systems are invaluable tools for biomedical research and clinical
practice. Photoacoustic microscopy (PAM) is an emerging hybrid technique that can overcome
the limitations of conventional optical and ultrasonic imaging modalities. A pulsed laser
illuminates tissue, where optical absorption and transient thermal expansion leads to ultrasound
emission. Image contrast is based on the naturally occurring (endogenous) optical absorption in
tissue. Spatial resolution and penetration depth are determined by the ultrasonic properties of
tissue. Performing PAM at multiple laser wavelengths can produce valuable spectroscopic
information that differentiates various tissue types. The Biomedical Ultrasonics & Biophotonics
Laboratory (BUBL) at Union College is developing rapidly tunable pulsed lasers for high-speed
spectroscopic PAM. We are currently investigating nonlinear fiber optics, particularly stimulated
Raman scattering and four wave mixing, to produce a multi-color output from a single
wavelength laser. We have demonstrated multi-color pulsed lasers operating at visible and nearinfrared wavelengths for potential applications in mapping blood oxygenation in capillaries and
visualizing atherosclerotic plaques.
Takashi Buma received his B.S.E. in Electrical Engineering with a certificate in Engineering
Physics from Princeton University in 1995. He received his Ph.D. in Applied Physics from the
University of Michigan in 2002, where his research in the Biomedical Ultrasonics Laboratory
explored optical techniques to generate and receive high frequency ultrasound. He then joined
the Center for Ultrafast Optical Science at the University of Michigan to perform research in
time-domain terahertz imaging systems. He was an Assistant Professor of Electrical and
Computer Engineering at the University of Delaware from 2005 to 2011. In the fall of 2011, he
joined the faculty of Union’s ECE Department and Bioengineering Program. His research
interests include photoacoustic microscopy, device and systems development for high frequency
ultrasound imaging, and optical coherence tomography.