Johns Hopkins University, Department of Biomedical Engineering, Baltimore, MD 21205, USA.
J Biomed Opt. 2010 Nov-Dec;15(6):060506. doi: 10.1117/1.3523234.
A miniature fiber optic endomicroscope with built-in dynamic focus scanning capability is developed for the first time for 3-D two-photon fluorescence (TPF) imaging of biological samples. Fast 2-D lateral beam scanning is realized by resonantly vibrating a double-clad fiber cantilever with a tubular piezoactuator. Slow axial scanning is achieved by moving the distal end of the imaging probe with an extremely compact electrically driven shape memory alloy (SMA). The 10-mm-long SMA allows 150-μm contractions with a driving voltage varying only from 50 to 100 mV. The response of the SMA contraction with the applied voltage is nonlinear, but repeatable and can be accurately calibrated. Depth-resolved imaging of acriflavine-stained biological tissues and unstained white paper with the endomicroscope is performed, and the results demonstrate the feasibility of 3-D nonlinear optical imaging with the SMA-based scanning fiber-optic endomicroscope.
首次研制出一种带有内置动态聚焦扫描功能的微型光纤内窥显微镜，用于生物样本的三维双光子荧光（TPF）成像。通过共振振动带有管状压电执行器的双包层光纤悬臂梁实现快速 2D 横向光束扫描。通过使用极其紧凑的电驱动形状记忆合金（SMA）移动成像探头的远端来实现缓慢的轴向扫描。10mm 长的 SMA 允许以 50 至 100mV 的驱动电压进行 150μm 的收缩。SMA 收缩与施加电压的响应是非线性的，但可重复且可准确校准。用内窥镜对吖啶黄素染色的生物组织和未染色的白纸进行深度分辨成像，结果表明基于 SMA 的扫描光纤内窥镜进行三维非线性光学成像的可行性。
