Serhat Tozburun Laboratory

Translational Biophotonics and Optical Imaging

Serhat Tozburun Research Lab.
OVERVIEW

Over the last few decades, the use of modern optics technology for biomedical research and health care has been dramatically growing so fast. It has resulted in increased attention towards the study of Biophotonics, which is a highly cross-disciplinary scientific field. Biophotonics covers a broad range of topics that rises on the generation of laser radiation and interactions between laser light and tissue for minimally invasive manipulation, detection, and monitoring of biological tissues. Besides being a cross-disciplinary research field, the translation of technologies from laser physics, optoelectronics, fiber optics, biophysics, and optical imaging into a common point to aid the development of new generation biomedical instrumentations for point-of-care diagnostics and therapy is the unique and extremely valuable part of Biophotonics.

At Translational Biophotonics and Optical Imaging Lab, our focus is to develop and translate novel optical technologies and methods (using laser-tissue interactions and noninvasive optical coherence imaging modalities) that address challenges in biomedical applications through a multi-disciplinary approach including Electrical Engineering, Optical Engineering, Physics, Biophysics and Biology, and making close professional collaborations with clinicians.

RESEARCH INTERESTS

We envision that future advances in Biophotonics and Optical Imaging will be used as leverage in the development of new generation biomedical instrumentations for point-of-care diagnostics and therapy, resulting in a direct benefit to patients’ quality of life. To help reach this envision, we attach priority to translational and novel R&D through a methodology which is a multi-disciplinary approach including optics, photonics, laser physics, engineering, and biology.

Our research direction spans from basic physics of light-tissue interactions to optical coherence imaging systems. Main topics of our research interests can be summarized as follows: Development of new wavelength-stepped and wavelength-swept laser sources, Swept-source Optical Coherence Tomography, Development of optical laparoscopic probes, and Infrared laser nerve stimulation.

RESEARCH HIGHLIGHTS

1) A Potential Diagnostic Technique: Optical Nerve Stimulation

Optical Nerve Stimulation that uses continuous-wave laser radiation at near-infrared (near-IR) has been reported as a potential alternative to a conventional technique called Electrical Nerves Stimulation. Optical Nerve Stimulation method may have significant advantages compared with Electrical Nerve Stimulation for both scientific studies and clinical applications. First, it is a non-contact method of stimulation because the near-IR laser radiation is delivered in a non-contact mode. Second, spatial selectivity is improved because the laser beam can be focused down smaller than a typical electrode and the problem of the electrical current spreading out in the tissue is eliminated for Optical Nerve Stimulation. Finally, when stimulating a nerve optically and measuring responses electrically, or by another means, electrical stimulation artifacts are eliminated. At Translational Biophotonics and Optical Imaging Lab, we perform development studies of nerve mapping devices and Optical Nerve Stimulation technique, which may be promising for real-time, intra-operative identification and preservation of the nerve bundles during clinic operations.

ONS Photothermal

The figure shows thermal images of the rat cavernous nerve before and during Optical Nerve Stimulation. The temperature of the nerve just before laser irradiation was at a baseline level of 33.9 °C. The nerve reached a peak temperature of 43.3 °C during laser irradiation, which was just above the nerve stimulation threshold.

2) Therapy: Development of Endoscopic Therapy Device

Inflammation in the lining of the esophagus caused by chronic reflux of acid into the esophagus may result in precancerous conditions of the esophagus and may associate with esophageal cancer (adenocarcinoma of the esophagus). There are several treatment options including medication, endoscopic mucosal resection, and endoscopic ablation therapy. However, there is still a need for a device that produces minimally destructive tissue damage in the endoscopic mucosal treatment of esophagus over large areas. Our team works on new designs of endoscopic devices that are able to remove the diseased tissue layer in safe, effective, cost-effective, efficient, single-session, and a reliable manner.

Esophagus

Figure shows an OCT image of swine esophagus taken by newly developed endoscopic probe.

3) Optical Imaging: Swept-Source Optical Coherence Tomography

Swept-Source Optical Coherence Tomography (SS-OCT) systems operating at MHz A-line rates provide higher imaging speeds that offer new capabilities for rapid volumetric OCT angiography and blood flow imaging. With this feature, OCT technology can be leveraged to enable more extensive oversampling of each location to improve flow quantification, or to provide rapid measurement of perfusion and pulsatile dynamics within a volume. Here, we develop an angiographic system composed of a novel swept wavelength source integrated with an MEMs-based fast-axis scanner. This new generation SS-OCT system provides rapid acquisition of volumes on which a range of Doppler and intensity-based angiographic analyses can be performed. Besides the rapid imaging, the laser source and data acquisition computer can be directly phase-locked to provide an intrinsically phase stable imaging system. With this interesting feature, it is possible to support Doppler measurements without the need for individual A-line triggers or post-processing phase calibration algorithms.

OCT System Diagram

The figure shows a schematic of the novel OCT system that provides MHz A-line rates while having phase coherence between each A-lines for a long period of time.

Lab members:

Cutting edge research opportunities are available in the Translational Biophotonics and Optical Imaging Lab at IBG-izmir. We are now looking to recruit highly motivated and enthusiastic graduate students and researchers into our team. Candidates with experience in Electrical Engineering, Physics, Optics and Photonics are strongly invited to apply.

Interested candidates should send their CV accompanied by a cover letter to: serhat.tozburun@deu.edu.tr

Education/Research Experience
2015 – present Assistant Professor
Dokuz Eylul University, Izmir Biomedicine and Genome Institute and Center, Izmir, Turkey.
2012 – 2015 Postdoctoral Research Fellow in Dermatology
Massachusetts General Hospital, Boston, MA.
2012 – 2015 Postdoctoral Research Fellow in Optical Imaging and Biomedical Optics Lab
Harvard Medical School, Boston, MA.
2009-2012 Research Assistant in Neuro-Urology Lab
Johns Hopkins Medical Institution, Baltimore, MD.
2008-2012 Research Assistant in Biomedical Optics Lab
University of North Carolina, Charlotte, NC.
2007-2008 Teaching Assistant in Dept. of Physics and Optical Science
University of North Carolina, Charlotte, NC.
2005-2007 Teaching Assistant in Dept. of Physics
Koç University, Istanbul, Turkey.
2012 Doctor of Philosophy in Optical Science and Engineering
University of North Carolina, Charlotte, NC.
2007 Master of Science in Physics
Koç University, Istanbul, Turkey.
2005 Bachelor of Science in Physics
Middle East Technical University, Ankara, Turkey.
AWARDS AND RECOGNITION
• FABED Eser Tumen Research Award, 2016.
• 2236 Co-Funded Brain Circulation Scheme Fellowship, The Scientific and Technological Research Council of Turkey (TÜBİTAK) and EU 7th Frame Work Marie Curie Actions, Ankara – Turkey, 2016.
• 2232 Re-integration Fellowship, The Scientific and Technological Research Council of Turkey (TÜBİTAK), Ankara – Turkey, 2016.
• Optics and Photonics Scholarship, The international society for optics and photonics – SPIE, Bellingham, WA, 2012.
• Travel Award for 2011 SPIE Photonics West, Center for Biomedical Engineering Systems, Charlotte, NC, 2011.
• Travel Award for 2010 SPIE Photonics West, University of North Carolina, Charlotte, Charlotte, NC, 2010.
• Graduate Student Scholarship, University of North Carolina, Charlotte, Charlotte, NC, 2007-2012.
• Graduate Student Scholarship, Koç University, Istanbul, Turkey, 2005-2007.
• Honor Student Graduation, Middle East Technical University, Ankara, Turkey, 2005.
PUBLICATIONS (selected)
Full list and citations: Google Scholar: Serhat Tozburun
• M. Siddiqui, S. Tozburun, E.Z. Zhang, and B.J. Vakoc, Compensation of spectral and RF errors in swept-source OCT for high extinction complex demodulation”, Opt. Express 23, 5508-5520 (2015).
S. Tozburun, M. Siddiqui, and B.J. Vakoc, A rapid, dispersion-based wavelength-stepped and wavelength-swept laser for optical coherence tomography,” Opt. Express 22, 3414-3424 (2014).•  S. Tozburun, G.A. Lagoda, A.L. Burnett, and N.M. Fried, Infrared laser nerve stimulation as a potential diagnostic method for intra-operative identification and preservation of the prostate cavernous nerves,” IEEE J. Sel. Top. Quant. Electron. 20, 7100515 (2013). (INVITED)
• S. Tozburun, C.D. Stahl, T.C. Hutchens, G.A. Lagoda, A.L. Burnett, and N.M. Fried, Continuous-wave infrared subsurface optical stimulation of the rat prostate cavernous nerves using a 1490-nm diode laser,” Urology 82, 968-973 (2013).
S. Tozburun, T.C. Hutchens, M.A. McClain, G.A. Lagoda, A.L. Burnett, and N.M. Fried, Temperature-controlled optical stimulation of the rat prostate cavernous nerves,” J. Biomed. Opt. 18, 0670001 (2013).
S. Tozburun, G.A. Lagoda, A.L. Burnett, and N.M. Fried, Subsurface near-infrared laser stimulation of the periprostatic cavernous nerves,” J. Biophoton. 5, 793-800 (2012).
S. Tozburun, G.A. Lagoda, A.L. Burnett, and N.M. Fried, “Continuous-wave laser stimulation of the rat prostate cavernous nerves using a compact and inexpensive all single mode optical fiber system,” J. Endourol. 25, 1727-1731 (2011).
S. Tozburun, C.M. Cilip, G.A. Lagoda, A.L. Burnett, and N.M. Fried, Continuous-wave infrared optical nerve stimulation for potential diagnostic applications,” J. Biomed. Opt. 15, (2010).
S. Tozburun, M. Mayeh, G.A. Lagoda, F. Farahi, and N.M. Fried, A compact laparoscopic probe for optical stimulation of the prostate nerves,” IEEE J. Sel. Top. Quant. Electron. 16, 941-945 (2010).
PATENTS
• B.J. Vakoc, S. Tozburun, and M. Siddiqui, “System, apparatus and method utilizing optical dispersion for Fourier-domain optical coherence tomography,” filed July 25. 2014 and published June 9, 2016.
• N.M. Fried and S. Tozburun, “Continuous-wave optical stimulation of nerve tissue,” filed June 22, 2012 and published June 27, 2013.