title: Handheld subcellular-resolution single-fiber confocal microscope using high-reflectivity two-axis vertical combdrive silicon microscanner.
abstract: We introduce a handheld single-fiber laser-scanning confocal microscope, incorporating a high-reflectivity two-axis silicon vertical combdrive microscanner, aimed at in vivo early detection of epithelial precancers. The approach adopted is motivated by need for a portable, economical, biopsy-free, early precancer screening technology in low-infrastructure environments. Our microelectromechanical system (MEMS) based handheld probe integrates the microscanners with miniature objective lens system and flexible electrical routing in a forward-imaging configuration, with 4.8 mm distal probe tip outer diameter for unrestricted imaging access in biological sites such as the oral cavity and cervix. Reflectance confocal videos of a USAF 1951 resolution target and biological samples were obtained over 200 microm x 110 microm field of view, with 0.80 and 9.55 microm lateral and axial resolution, at 3.5-5.0 frames per second. With improvements to objective numerical aperture, our probe can enable precise evaluation of nuclear size, density, nucleus-to-cytoplasm ratio and cell density, which are important visual identifiers of epithelial precancers.
authors.affiliation: Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, TX, 78712, USA. kkumar@mail.utexas.edu
authors.forename: Karthik
authors.initials: K
authors.lastname: Kumar
authors.forename: Kazunori
authors.initials: K
authors.lastname: Hoshino
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Zhang
mesh_terms: D004867:Equipment Design / Q000295:instrumentation; D005336:Fiber Optic Technology / Q000295:instrumentation*; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D008846:Micromanipulation / Q000295:instrumentation*; D018613:Microscopy, Confocal / Q000295:instrumentation* / Q000379:methods; D008904:Miniaturization / Q000295:instrumentation*; D012825:Silicon / Q000737:chemistry
chemical_list: D012825:Silicon