Miniature near-infrared dual-axes confocal microscope utilizing a two-dimensional microelectromechanical systems scanner

Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.
Optics Letters (Impact Factor: 3.29). 03/2007; 32(3):256-8. DOI: 10.1364/OL.32.000256
Source: PubMed


The first, to our knowledge, miniature dual-axes confocal microscope has been developed, with an outer diameter of 10 mm, for subsurface imaging of biological tissues with 5-7 microm resolution. Depth-resolved en face images are obtained at 30 frames per second, with a field of view of 800 x 100 microm, by employing a two-dimensional scanning microelectromechanical systems mirror. Reflectance and fluorescence images are obtained with a laser source at 785 nm, demonstrating the ability to perform real-time optical biopsy.

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    • "The recent advancement in miniaturized scanning mirrors based on microelectromechanical systems (MEMS) technology has enabled the feasibility of fabricating compact fiber-optic-based endomicroscopic probes [23] [24] [25] [26]. In our previous work, we have successfully built an all-optical MEMS-based PAM system using miniature components and achieved imaging of microvasculatures inside a canine bladder wall [27]. "
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    • "More recently, Si et al., Gong et al. and Sheppard et al. reported a theoretical analysis of the divided-pupil configuration with point-scanning, showing improvement in optical sectioning, compared to the full-pupil configuration, under certain detector conditions [14–16]. Liu et al., too, have reported analytical and experimental imaging results, showing stronger sectioning and enhanced contrast in deep tissue with their dual-axes point-scanning design, compared to a conventional single axis [17,18]. The dual axes design mimics the divided-pupil and theta microscope configurations, in which the transmitter and receiver paths are separate and intersect only in the object plane (optical section). "
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    • "Fig. 2 shows three examples of miniature LSMs, and Fig. 3 shows corresponding images acquired in vivo. Fig. 2(a) and (b) are a 10-mm and 5-mm version, respectively, of the dual-axes confocal microscope developed by the Network for Translational Research in Optical Imaging (NTROI) group, Stanford Univeristy [3], [4], [6]. The 10-mm version is hand-held and used for in vivo imaging of skin surfaces and ex vivo imaging of tissue samples, while the 5-mm version fits down the working channel of an endoscope for in vivo imaging of the gastrointestinal tract. "
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