Dark-field illuminated reflectance fiber bundle endoscopic microscope

Abstract

Abstract. We propose a reflectance fiber bundle microscope using a dark-field illumination configuration for applications in endoscopic medical imaging and diagnostics. Our experiment results show that dark-field illumination can effectively suppress strong specular reflection from the proximal end of the fiber bundle. We realized a lateral resolution of 4.4 μm using the dark-field illuminated fiber bundle configuration. To demonstrate the feasibility of using the system to study cell morphology, we obtained still and video images of two thyroid cancer cell lines. Our results clearly allow differentiation of different cancer cell types. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

Reflectance imaging by fiber bundle endoscope: Vertical reconstruction by multipositional illumination

“…Previously, a fiber-bundle reflectance imaging system using illumination through the imaging fiber itself without any additional illumination system has been introduced. [7][8][9]. Applying these techniques into a multipositional illumination scheme would be desirable for future study.…”

Color reflectance fiber bundle endomicroscopy without back-reflections

“…In 2011, Liu et al suggested an alternative method in which the numerical aperture of the fiber bundle is shared between illumination and collection, a technique conceptually similar to darkfield microscopy. 6 Again this system was demonstrated using cell cultures with an apparently higher SNR.…”

“…Fiber bundles can also be used for fluorescence endomicroscopy under widefield illumination, providing a low-cost alternative to confocal imaging for selected applications. 2 A further possibility, reflectancemode endomicroscopy, has been demonstrated on several occasions, under both confocal 3,4 and widefield 5,6 operation, but has so far failed to have a similar clinical impact.…”

“…7 Simple digital subtraction, while possible, is an unattractive option which results in a low signal-to-noise ratio (SNR) and poor dynamic range. 6 In confocal systems, refractive index matching at the bundle faces allows back-reflections to be shifted away from the focal plane so that they are blocked by the detector pinhole. 3 Alternatively, pulsed laser illumination and time-of-flight measurements can be used to distinguish between the tissue signal and reflections from the proximal tip.…”

Fiber bundle endomicroscopy with multi-illumination for three-dimensional reflectance image reconstruction

“…Our current system has separate illumination fibers and imaging fiber, resulting large size and large invasiveness. The illumination through the imaging fiber itself [12][13][14] may solve the problem.…”