hzeng@bccrc.ca

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Department:	Cancer Imaging (@ the BCCRC since 1990)
Research Role:	Senior Scientist
Postdoctoral Fellows:	Michael Short Anthony Lee Yasser Fawzy
Graduate Students:	Hequn Wang Shuang Wang Yingqiu (Edward) Yu
Other lab members:	Jianhua Zhao Wei Zhang Lioudmila Tchvialeva Naiyan Huang
Education:	Ph.D. (Medical Physics), University of British Columbia, 1993 M.Sc. (Electronic Physics & Devices), Institute of Electronics, Academia Sinica, 1986 B.Sc. (Electronic Physics), Peking (Beijing) University, 1983
Birthplace:	Hunan, China
Phone:	604-675-8083
Fax:	604-675-8099

Research Interests:

My research interests are centered on the optical properties of biological tissues and light-tissue interaction as well as their applications in medical diagnosis and therapy. Biological tissues are optically inhomogeneous and multi-layered turbid media. When light interacts with tissue, it is scattered and absorbed, and the tissue may produce fluorescence. These interactions and the optical properties of tissue determine the distribution of incoming light inside the tissue, which is important for generation of any biological effects and for therapeutic applications. On the other hand, the optical properties and the effects of tissue on light are determined by the chemical composition, morphological structure, and physiological state of the tissue. Therefore, pathological changes in tissue affect the re-emitted optical signal detected when shining a beam of light on the tissue. Through many years of research, we have demonstrated that tissue pathology can be detected in vivo by optical methods non-invasively or minimum invasively through endoscopy. Several clinically relevant devices have been successfully developed for early cancer detection in skin, lung, and gastrointestinal tract.

We are currently exploring a couple of different types of optical measurement modalities for diagnostic applications:

• Diffuse Reflectance Spectroscopy and Multi-spectral Imaging, which explores elastic light scattering and light absorption by tissue chromophores such as melanin, hemoglobin, bilirubin, and water.

• Fluorescence Spectroscopy and Imaging, which explore molecular electronic energy transition-related light emission of certain biomolecules in tissue such as tyrosine, tryptophan, NADH, collagen, and elastin.

• Raman Spectroscopy, which explores inelastic light scattering to give fingerprint-like spectral signatures of molecular vibrations. Molecules in tissue that have unique Raman signatures include proteins, DNA, lipids, glucose, and melanin.

• In-Vivo Confocal Microscopy, which provides sectional images of tissue at micron spatial resolution, allowing us to visualize cellular structures and micro-circulation in real time on living tissue. Imaging mechanisms we are exploring include elastic scattering (reflectance), two-photon excitation fluorescence (TPEF), and second harmonic generation (SHG).

• Laser Speckle Imaging, which analyzes interference patterns from light reflected off skin surfaces.

These researches may also lead to non-invasive assessment of treatment progress. We are applying optical methods to study the pharmacokinetics of photodynamic therapy (PDT) as well as to improve dosimetry for various phototherapy modalities including PDT.

In addition, we are applying MEMS (micro-electro-mechanical systems) technologies to miniaturize our optical devices for endoscopy uses and for point-of-care diagnostic applications. We are also applying nanotechnologies to enhance various light-tissue interactions for diagnostic and therapeutic applications, for example, using metal nanoparticle based SERS (surface enhanced Raman scattering) spectroscopy for diagnostics and developing nanoparticle based photo-thermal therapy

Teaching:

 http://www.phas.ubc.ca/~hzeng/index.html

• SPIE SC 823 - Diagnostic Endoscopy  http://spie.org/x1145.xml?course_id=M000892

Software:

 http://www.flintbox.com/technology.asp?page=3553

See Also:

• Tissue Optics
• Raman Spectroscopy