Speaker: A. P. Yu Chen (University of Maryland)

Time and Date: 16:00 pm, December 26, 2017

Place: Room 206 of Genetics Building, Handan Campus, Fudan University

Abstract:

Optical Coherence Tomography (OCT) is an established medical imaging technology which is analogous to ultrasound imaging but has significantly higher resolution (~10 mm) to enable 3D imaging of tissue microstructures in situ and in real-time with a penetration depth of ~1-2 mm. OCT can be extended to functional imaging modalities such as Doppler OCT (DOCT) for blood flow detection and polarization-sensitive OCT (PS-OCT) for detection of tissue birefringence. We have developed a forwarding-imaging needle-type OCT probe for avoiding the hemorrhage and guiding neurosurgical interventions. The needle probe has a thin diameter of 0.7 mm. The feasibility of vessel detection and neurosurgical guidance were demonstrated on sheep brain in vivo and human brain ex vivo. In addition, we further reduced the probe size to 0.3 mm using an optical Doppler sensing (ODS) fiber probe that can integrate with microelectrode recording (MER) to detect the blood vessels lying ahead to improve the safety of this procedure. We further combine high-resolution OCT with large-field-of-view magnetic resonance imaging (MRI) to provide multi-scale imaging.

In addition, we have developed a novel mesoscopic 3D optical molecular imaging technique – Fluorescence Laminar Optical Tomography (FLOT), which can achieve ~100 µm resolution and 2-3 mm penetration depth. Biomedical applications of FLOT include tissue engineering, neuroscience, and oncology. For functional mapping of brain activities, we applied FLOT to record 3D neural activities evoked in the whisker system of mice by deflection of a single whisker in vivo.  We utilized FLOT to investigate the cell viability, migration, and bone mineralization within bone tissue engineering scaffolds in situ, which allows depth-resolved molecular characterization of engineered tissues in 3D. Moreover, we investigated the feasibility of the OCT/FLOT multi-modal imaging system to monitor the drug distribution and therapeutic effects during and after photo-immunotherapy (PIT) in situ and in vivo, which can be used to optimize PIT regimen and elucidate PIT mechanism.

Biography:

Dr. Yu Chen received his BS in Physics from Peking University in 1997 and his PhD in Bioengineering from the University of Pennsylvania in 2003. From 2003-2007, he pursued his postdoctoral training at MIT. He became an Assistant Professor of the Fischell Department of Bioengineering at the University of Maryland in College Park in 2007 and became an Associate Professor since 2014. He has mentored 8 PhD students and 7 postdoctoral fellows. He received Teaching Excellence Award from the Fischell Department of Bioengineering of the University of Maryland in 2011, and the National Science Foundation (NSF) CAREER Award in 2012. Dr. Chen has published 1 book, 16 book chapters, and 85 peer-reviewed journal publications. He has been an associate editor of Medical Physics, a guest editor of IEEE Journal of Selected Topics on Quantum Electronics, Journal of Innovative Optical Health Sciences, Neurophotonics, and an Editorial Board member of Scientific Reports. He is a member of IEEE, SPIE, and the Optical Society of America (OSA). He has served as conference program co-chair and general co-chair for OSA Conference on Lasers and Electro-Optics (CLEO): Applications and Technologies, and scientific committee co-chair of Annual World Congress of the Society of Brain Mapping and Therapeutics (SBMT).