Open AccessDeep-tissue access with confocal fluorescence microendoscopy through hypodermic needles
Author(s) -
Rajesh S. Pillai,
Dirk Lorenser,
David D. Sampson
Publication year - 2011
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.007213
Subject(s) - confocal , galvanometer , optics , materials science , fluorescence lifetime imaging microscopy , confocal microscopy , fluorescence , optical fiber , biomedical engineering , laser , physics , medicine
We report on the design and implementation of a gradient-index microendoscope suitable for accessing tissues deep within the body using confocal fluorescence imaging. The 350-μm diameter microendoscope has a length of 27 mm, which enables it to be inserted through a 22-gauge hypodermic needle. A prototype imaging system is demonstrated to obtain images of tissue samples at depths of ~15 mm with a lateral resolution of ~700 nm. To the best of our knowledge, this is the highest resolution and imaging depth reported for a confocal probe of these dimensions. We employ a scanning arrangement using a lensed fiber that can conveniently control the input beam parameters without causing off-axis aberrations typically present in the optical relay lenses used in galvanometer-mirror scanning systems.