Bio-Photonics: IR-Laser Nerve Stimulation, Intrinsically Phase-stable OCT, and Apparatus for GI-Tract Treatment

22 December 2015

Serhat TOZBURUN, Ph.D.,

Postdoctoral Research Fellow, Harvard Medical School  & Wellman Center for Photomedicine, Massachusetts General Hospital

22 December 2015 (Tuesday);   14.00 – 15.00 

Institute of Biomedical Engineering, AZ-19, Boğaziçi University Kandilli Campus, Istanbul

About the Seminar:

The field of biophotonics is a highly cross-disciplinary science and technology platform merging life sciences, physics, and engineering. Here three research projects are described in the sub-biophotonics areas of neurons and photons, photoablation therapy in gastrointestinal (GI) tract, and optical micro-angiography. The first project builds upon optical nerve stimulation (ONS) technique. This technique, using infrared laser energy, has been developed recently as a potential alternative to conventional electrical nerve stimulation. More recently, the ability of ONS in pre-clinical studies as an intra-operative diagnostic method for identifying the prostate Cavernous nerves has been demonstrated in in-vivo rat studies. Several milestone advances have been achieved for the first time. (i) Continuous-wave IR laser nerve stimulation; (ii) subsurface optical stimulation of the prostate nerves underlying a thin layer of fascia; and (iii) temperature control operation of ONS system. The second project is expansions of recently developed dispersion-based swept-wavelength laser source for 4D Doppler optical coherence tomography (OCT). Current OCT systems are able to provide inter-frame angiographic imaging and also require the use of highly accurate triggering hardware or implementation of post-processing phase calibration algorithms. The presented angiographic system is comprised from a novel 18.9 MHz swept wavelength source integrated with a MEMs-based 23.7 kHz fast-axis scanner. The system provides rapid acquisition of frames and volumes on which a range of Doppler and intensity-based angiographic analyses can be performed. Interestingly, the source and 1.8 Gigasample per sec acquisition card can be directly phase-locked to provide an intrinsically phase stable imaging system supporting volumetric Doppler measurements without the need for individual A-line triggers or post-processing phase calibration algorithms. The third project is to develop a method using novel apparatus for treatment of Barrett’s esophagus, which is a precancerous condition f esophagus and associated with esophageal cancer (adenocarcinoma of esophagus). At the point of care, there is a need for a device that enables a single-session and minimally destructive tissue damage in endoscopic mucosal treatment of Barrett’s esophagus over large areas. The primary objective of the project is to configure a prototype endoscopic mucosal ablation device that ablate (damage) the mucosa layer of the esophagus to a depth sufficient to eliminate the lesion, but not sufficient deep to induce residual thermal effects within the deeper tissue layers. By delivering negative-pressure (a vacuum), the device basically extends the mucosa layer above and away from its underlying layers to achieve a well confined therapeutic effect. In other words, the target tissue is pulled into the recessed region of the device through a vacuum force using elasticity feature of mucosal layers. Notably, these three translational research projects utilize concepts from interactions of laser light with biological tissues and optical coherence imaging modalities. With further developments, they can levered in future works to be enabling technologies for clinical trials.

About the Speaker:

Serhat Tozburun has been working as a postdoctoral research fellow in the Harvard Medical School and in the Wellman Center for Photomedicine at the Massachusetts General Hospital since summer 2012. He received his B.S. degree in Physics from Middle East Technical University in 2005, M.S. degree in Physics from Koc University in 2007, and Ph.D. degree in the Optical Science and Engineering from the University of North Carolina, Charlotte in 2012, respectively. His research interests lie in the fields of optical science and engineering, biomedical optics, biophotonics, and optical frequency domain imaging. He mainly develops and implements various optical technologies and methods that address challenges in biomedical applications. Dr. Tozburun serves as a reviewer of the Journal of Biomedical Optics, Optics Express, Biomedical Optics Express, Optics Letter, and Current Molecular Imaging. He is also a member of the Institute of Electrical and Electronics Engineers - IEEE, the Optical Society of America - OSA, and the International Society for Optics and Photonics - SPIE. He has been awarded a 2012 Optics and Photonics Scholarship by SPIE for his potential contributions to the fields of optics, photonics, or related field. Dr. Tozburun holds two U.S. patents. He is a first-author of more than 20 papers published in refereed scientific journals and conference proceedings, and presented more than 15 abstracts and conference presentations.