People

Emily McDowell

Currently working at Intel in Portland, Oregon.

Webpage

Education

PhD Bioengineering, California Institute of Technology, 2009
B.S.E., Biomedical Engineering, Duke University, May 2005

Awards

NSF Graduate Research Fellowship, 2006
NIH Ruth L. Kirschstein National Research Service Award, 2006

Caltech Research

In the fall of 2009, I wrapped up a body of work aimed at evaluating the effect of 1/f noise in low signal optical detection schemes, including spectrometer-based FDOCT and 3x3 homodyne OCT, as well as direct detection schemes utilizing sensitive detectors such as PMTs and APDs. We developed a generalized noise variance analysis model that utilizes the information contained in the noise power spectrum to predict the noise variance and SNR of a measurement. These predictions find good agreement with experimental SNR measurements in the above systems, and are useful for determining appropriate system parameters for achieving optimal detection sensitivity.

Additionally, I worked on developing a technique termed turbidity suppression through optical phase conjugation (TSOPC). This technique allows information to be passed through highly scattering media by ‘time reversing' the scattered wavefront. The time reversed or phase conjugate light field is forced to retrace its path through the scattering material, effectively eliminating the effects of scattering. This technique has several promising applications, including highly efficient schemes for photodynamic therapy (PDT) as well as the potential for directing a large amount of light to implantable photovoltaics. In addition to optimizing the existing setup for both freshly excised and in vivo tissue samples, we worked to demonstrate these potential applications. The technique also holds promise for deep tissue optical imaging schemes.

Previous Research

As an undergraduate at Duke University, I had the opportunity to work in the Izatt Biophotonics Lab. My work focused on the use of spectral domain phase microscopy (SDPM) for investigating the mechanical properties of the cytoskeleton of eukaryotic cells, specifically human breast cancer cells. SDPM is a functional extension of spectral domain OCT that allows for the detection of cellular motions and displacements with nanometer-scale sensitivity in real time. We were able to use SDPM to monitor the response of the cell to a controlled external force, fit the resulting cell data to several models for cytoskeletal rheology, and show a correlation between the cellular response and certain physical characteristics of individual cells.

Journal Publications

E. J. McDowell, M. V. Sarunic, and C. Yang. 1/f noise in spectrometer-based Fourier domain optical coherence tomography. Opt. Exp. (In preparation)

E. J. McDowell, J. Ren, and C. Yang. Fundamental sensitivity limit imposed by 1/f noise in the low optical signal detection regime. Opt. Exp. (Under review)

E. J. McDowell, Z. Yaqoob, M. V. Sarunic, and C. Yang, SNR enhancement through phase dependent signal reconstruction algorithms for phase separated interferometric signals. Opt. Exp. 15(16), 10103-10122 (2007)

E. J. McDowell, A. K. Ellerbee, M. A. Choma, B. E. Applegate, and J. A. Izatt. Spectral domain phase microscopy for local measurements of cytoskeletal rheology in single cells. J. Biomed. Opt. 12, 044008 (2007)

E. J. McDowell, Z. Yaqoob, and C. Yang. A generalized noise variance analysis model and its application to the characterization of 1/f noise. Opt. Exp. 15(7), 3833-3848 (2007)

X. Heng, X. Cui, D. W. Knapp, J. Wu, Z. Yaqoob, E. J. McDowell, D. Psaltis, and C. Yang. Characterization of light collection through a subwavelength aperture from a point source. Opt. Express, 14(22), 10410-10425 (2006)

Z. Yaqoob, J. Wu, E. J. McDowell, X. Heng, and C. Yang. Methods and application areas of endoscopic optical coherence tomography. J. Biomed. Opt. 11(6), 063001 (2006)

Z. Yaqoob, E. J. McDowell, J. Wu, J. Fingler, X. Heng, and C. Yang. Molecular contrast optical coherence tomography: A pump-probe scheme using indocyanine green as a contrast agent. J. Biomed. Opt. 11(5), 054017 (2006)

Conference Presentations and Publications

E. J. McDowell, Z. Yaqoob, V. Senekerimyan, and C. Yang, Turbidity suppression through optical phase conjugation: Results and applications, Poster presentation, OSA Biomedical Optics Topical Meeting, St. Petersburg, FL (2008)

E. J. McDowell, M. V. Sarunic, and C. Yang, 1/f noise in spectrometer-based optical coherence tomography, Poster presentation, OSA Biomedical Optics Topical Meeting, St. Petersburg, FL (2008)

E. J. McDowell, M. V. Sarunic, and C. Yang. The impact of 1/f noise in spectrometer-based optical coherence tomogaphy. Photonics West Conference (BIOS), San Jose, CA (2008)

Z. Yaqoob, E. J. McDowell, G. Zheng, S. Tseng, M. S. Feld, D. Psaltis, and C. Yang. Time reversal optical phase conjugation for tissue turbidity suppression. Photonics West Conference (BIOS), San Jose, CA (2008)

E. J. McDowell, Z. Yaqoob, M. V. Sarunic, and C. Yang. Choice of image reconstruction algorithm impacts signal to noise ratio in 3x3 fiber coupler based homodyne optical coherence tomography. Photonics West Conference (BIOS), San Jose, CA (2007)

E. J. McDowell, Z. Yaqoob, and C. Yang. Pump probe molecular contrast optical coherence tomography utilizing the photodegradation of SDC5712. OSA Biomedical Optics Topical Meeting, Ft. Lauderdale, FL (2006)

Z. Yaqoob, E. J. McDowell, J. Wu, and C. Yang. Pump-probe optical coherence tomography using indocyanine green as a contrast agent. Photonics West Conference (BIOS), San Jose, CA (2006)

A. K. Ellerbee, M. A. Choma, E. J. McDowell, A. L. Creazzo, and J. A. Izatt. Characterizing cellular contractility and cytoplasmic flow using spectral domain phase microscopy. Photonics West Conference (BIOS), San Jose, CA (2005)

E. J. McDowell, M. A. Choma, A. K. Ellerbee, and J. A. Izatt. Spectral domain phase microscopy: a new tool for measuring cellular dynamics and cytoplasmic flow. Poster Presentation, Photonics West Conference (BIOS), San Jose, CA (2005)