News/2008-05-19

MEMS Seminar by Dr. Wibool Piyawattanametha
2008-05-19†

MEMS Seminar Information

Schedule: Monday May 19th, 2008, from 16:00 to 17:00
Location: IIS Lounge-C (Kasaoka-Lounge), Bldg-C, East Wing, 2nd floor
Registration: no needed. Free of charge.
Speaker Info: See below

Advanced Endoscopy & Microscopy

Wibool Piyawattanametha, Ph.D.
Research Associate
Stanford University

Departments of Applied Physics, Biological Sciences, Electrical Engineering
Microbiology & Immunology Radiology, and Pediatrics
James H. Clark Center (Bio-X)
318 Campus Drive, Stanford, CA 94305

Biomedical research truly needs new advances in imaging. Existing modalities of in vivo imaging, such as magnetic resonance imaging (MRI) or ultrasound, lack the spatiotemporal resolution required to image the fundamental building block of living tissue, namely the cells. By contrast, existing high-resolution techniques for imaging cells and their sub-cellular features are technologies that are best suited for in vitro experiments in tissue slices. Yet, the ability to make direct connections between human pathological symptoms/behavior and the underlying cells and molecules responsible for such behavior requires in vivo techniques that can image cellular constituents. My research aim is to develop novel high-resolution optical endoscopes (1 to 10 mm diameter) to satisfy unmet needs in the clinical environment. These differ from medical endoscopes, which are generally larger and designed to image macroscopic abnormalities. Most importantly, this novel optical endoscopic imaging might suggest new approaches to disease diagnosis and treatment. This talk will be focused on the development two novel imaging modalities based on microelectromechanical systems (MEMS) technology and their imaging applications.

The first imaging modality is dual-axes confocal (DAC) fluorescence microscopy. Due to the DAC architecture, it offers several advantages over the traditional single-axis confocal (SAC) architecture such as simplicity in miniaturization from deploying low numerical aperture (NA) lenses and aberration-free beam scanning from post-objective scanning configuration. The other important advantage is the ability to achieve a much superior optical sectioning compared to the SAC design. The microscopes are miniaturized into two form factors (5-mm and 10-mm diameter). Miniaturization of the microscope is achieved by using a two-dimensional (2-D) MEMS scanner and miniature-optics. The imaging head consists of two optical fiber collimators for illumination and collection beams, a parabolic mirror, and a fused-silica solid immersion lens (SIL). The imaging demonstrations of the probe will be on both ex vivo human tissues (skin, colon, esophagus, and stomach) and in vivo human and mice skin.

The second imaging modality is two-photon fluorescence microendoscopy. Two-photon microscope is especially well suited for imaging deep inside biological tissue. Towards overcoming the size limitations of conventional two-photon fluorescence microscopy for brain imaging in freely moving animals, I will introduce a portable laser-scanning two-photon microendoscope based on a 2-D MEMS scanner, compound gradient refractive index (GRIN) micro-lenses, and a photonic bandgap fiber (PBF). The imaging aim is to correlate freely moving animal brain cellular activities with motor or cognitive functions without anesthesia. The acquired in vivo/ex vivo images are from cortical and hippocampal areas of the mice brains.

Dear Lab + colleague in LIMMS and MEMS CR

Delighted to announce a MEMS seminar on OCT bio-imaging by Dr. Wibool Piyawattanametha scheduled on Monday May 19th from 16:00 to 17:00 at Lounge-C (Kasaoka Lounge) in Bldg-C, East-wing 2nd floor.

Dr. Piyawattanameetha is an old friend of mine since my stay at UCLA, and he is currently a research associate within Professor Olav Solgaard's group at Stanford University. He is giving a talk at a conference in Kyoto, and will take this opportunity to stop by the IIS to give us his up-to-date talk on the MEMS optical scanner and its application to fiber optic coherent tomography (OCT) system for in vivo bio tissue imaging.

Best regards,

Hiroshi TOSHIYOSHI

皆様

私の友人のWibool Piyawattanametha (ウィブール・ピヤワッタナメタ）氏が、ＭＥＭＳスキャナのＯＣＴ光断層計測ファイバ内視鏡応用のセミナー講演をします。日時は５月１９日（月曜）４時、笠岡ラウンジ（Ｃ棟２階）です。同氏は私のＵＣＬＡでの共同研究者で、現在は、スタンフォード大のSolgaard先生のラボで研究員（助教, Researcher）をしています。ＯＣＴでは有名なＭＩＴのフジモト先生とも内視鏡の共同開発を遂行中。今回は、京都の学会の帰りに生研に立ち寄って、わりと気軽な感じの講演をしてくれることになりました。みなさま、お誘い合わせの上、おこし下さい。

年吉　洋