We report an objective-lens-free endomicroscopic catheter for compact Lissajous scanned confocal endomicroscopic system using a scanning lensed-fiber. The fiber scanner comprises a single-mode fiber (SMF) spliced with a coreless silica fiber segment and quadrupole piezoelectric tube. An objective lens was directly formed at the distal end of an SMF using a fusion splicer. The lensed fiber eliminates the need for conventional beam focusing elements such as a gradient index rod lens and precise optical alignment, allowing low cost and facile fabrication of an exceptionally short endomicroscopic catheter. The endomicroscopic scanner was fully packaged within a stainless tube of 2.6 mm in outer diameter and 20 mm in length, which can be easily inserted through the working channel of conventional laparoscope or colonoscope. The microscopic images of a stained kidney section and ear of a mouse were successfully obtained with the Lissajous scanning confocal endomicroscope. The compact Lissajous scanning lensed fiber can provide a new route for diverse in vivo endomicroscopic applications.
Three-dimensional (3D) endoscopes provide depth information and help determining the surgical sites more accurately. Among the conventional 3D endoscopic techniques, efforts on implementation of structured illumination method into 3D imaging system was actively made due to the potential of light environmental robustness and miniaturization. However, structured illumination methods are suffering from the low resolution, which is affected by the light patterns density and uniformity with minimized projector.
In this work, we demonstrate switchable pattern projector module using rotational offsets of double microlens arrays (MLAs) for 3D endoscopic imaging with structured illumination method. The pattern projector module includes diffractive optical element part of double MLAs with rotational offsets for double diffraction pattern generation and the switchable light source part of fiber bundle comprised of the GRIN fiber for collimating laser at the center and other surrounding fibers for white-light illumination. The double MLAs was fabricated using double-sided photolithography on 4-inch borosilicate wafer, thermal reflow with hydrophobic nano film, and parylene-c coating. The period, curvature and rotational offset angle of double MLAs were determined to have high density and uniformity of the projected dot array patterns. The calculated disparity map of non-textured 3D object showed increase on resolution and robustness on surrounding light environment compared to the disparity map with stereoscopic imaging method. The 3D imaging system using the projector module can provide depth information with miniaturized system and lead to various applications for medical imaging as well as other imaging applications in industrial and military fields.
KEYWORDS: Imaging systems, Confocal microscopy, Scanners, In vivo imaging, Endomicroscopy, Microscopes, Indocyanine green, Luminescence, Field programmable gate arrays, Active optics
This work presents a fully packaged confocal endomicroscopic system using Lissajous fiber scanner for in-vivo imaging. The confocal endomicroscopic system consists of a scanning probe part, an optical part, and an electrical part. The scanning probe uses resonant Lissajous fiber scanner based on a piezoelectric tube. The scanner successfully achieves 10 frame rate with ~ 1 kHz scanning frequencies. The probe was fully packaged for waterproofing and disinfection of medical instruments into the outer diameter of 3.4 mm. The endomicroscopic system and successfully obtained 2D reflectance imaging results, human ex-vivo imaging results and a real-time in-vivo imaging results.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.