12月14日，香港大学Dr. Kevin K.M. Tsia教授来参观我中心并做了题为“TsiaUltrafast all-optical laser-scanning imaging-Enabling deep single-cell imaging and analysis”的学术报告。我中心的老师和学生热烈参与，互相讨论交流，反响甚好。
Abstract:
Studying cell populations, their transition states and functions at the single cell level is critical for understanding in normal tissue development and pathogenesis of disease. However, current platforms for single-cell analysis (SCA) lack the practical combination of throughput and precision that is limited by the prohibitive costs and time in performing SCA, very often involving thousands to millions individual cells – largely explaining the limited applications of SCA to date. For creating new scientific insights and enriching the diagnostic toolsets, it is valuable to explore alternative biomarkers, notably biophysical markers, which maximizes the cost-effectiveness of SCA because of its label-free nature. Also, as it is closely tied with many cellular behaviours, biophysical markers can complement and correlate with the information retrieved by existing biochemical markers with high statistical precision – providing a comprehensive catalogue of single-cell properties. Optical microscopy is an effective tool to visualize cells with high spatiotemporal resolution. However, its full adoption for high-throughput SCA has been hampered by the intrinsic speed limit imposed by the prevalent image capture strategies, which involve the laser scanning technologies (e.g. galvanometric mirrors), and/or the image sensors (e.g. CCD and CMOS). The laser scanning speed is fundamentally limited by the mechanical inertia of the mirrors whereas the image capture rate of CCD/CMOS sensor is fundamentally limited by the required image sensitivity.
To address these challenges, we adopt two related techniques to enable single-cell imaging with the unprecedented combination of imaging resolution and speed. Sharing a common concept of all-optical laser-scanning by ultrafast spatiotemporal encoding of laser pulses, these techniques, time-stretch imaging and free-space angular-chirp-enhanced delay (FACED) imaging enable ultrahigh-throughput single-cell imaging with multiple image contrasts (e.g. quantitative phase and fluorescence imaging) at a line-scan rate beyond 10’s MHz (i.e. an imaging throughput up to ~100,000 cells/sec). Moreover, they also enable quantification of intrinsic biophysical markers of individual cells – a largely unexploited class of single-cell signatures that is known to be correlated with the overwhelmingly investigated biochemical markers. All in all, these ultrafast single-cell imaging platforms could find new potentials in deep machine learning complex biological processes from such an enormous size of image data (from molecular signatures to biophysical phenotypes), especially to unveil the unknown heterogeneity between different single cells and to detect (and even quantify) rare aberrant cells.
Biography:
Kevin Tsia received his Ph.D. degree at the Electrical Engineering Department, at University of California, Los Angeles (UCLA), in 2009. He is currently an Associate Professor in the Department of Electrical and Electronic Engineering, and the Medical Engineering Program, at the University of Hong Kong. His research interest covers a broad range of subject matters, including ultra-fast real-time spectroscopy and microscopy for biomedical applications such as imaging flow cytometry, MHz optical coherence tomography. His pervious researches, such as energy harvesting in silicon photonics and the World’s fastest barcode reader and optical imaging system, have attracted worldwide press coverage and featured in many prestigious science and technology review magazines such as MIT Technology Review, EE Times and Science News. He received Early Career Award 2012-2013 by the Research Grants Council (RGC) in Hong Kong. He also received the Outstanding Young Research Award 2015 at HKU as well as 14th Chinese Science and Technology Award for Young Scientists in 2016. His recent research on ultrafast optofluidic imaging technologies, dubbed “ATOM” and “FACED”, have also been covered by media and scientific magazines. He is author or coauthor of over 140 journal, conference papers and book chapters. He holds 2 granted and 4 pending US patents on ultrafast optical imaging technologies.
