Confocal foveated endomicroscope for the detection of esophageal carcinoma

Abstract

By mimicking the variable resolution of the human eye, a newly designed foveated endomicroscopic objective shows the potential to improve current endoscopic based techniques of identifying abnormal tissue in the esophagus and colon. The prototype miniature foveated objective is imaged with a confocal microscope to provide large field of view images combined with a high resolution central region to rapidly observe morphological structures associated with cancer development in a mouse model.

Development of a multimodal foveated endomicroscope for the detection of oral cancer

“…The complete design, fabrication and performance of the foveated miniature objective were reported previously [29]. Briefly, the intentional introduction of distortion into the optical design of the objective provides variability in the magnification and numerical aperture across the field.…”

“…The performance of the objective was observed by imaging a 1951 United States Air Force resolution target across the entire field by relaying the image from the foveated objective to a commercial Zeiss Primostar microscope. The final validation of the objective was performed by combining it with a confocal microscope for imaging ex vivo mouse colon with colorectal lesions dyed with proflavine [29]. From these images it was possible to observe the presence of dysplastic tissue and demonstrate that morphology compared well to that observed in histology images.…”

“…4. The custom confocal microscope was reported previously [29]. Briefly, the microscope incorporates a 455nm handheld laser pointer, commercial optics, miniature galvanometer mirrors, a spatial filter, and a photomultiplier tube to scan and collect a diffraction limited point across the region of interest.…”

“…We previously validated the miniature foveated objective by imaging ex vivo mouse colon tissue with a confocal microscope [29]. We have now combined the foveated objective with a vibrating fiber bundle to relay the image from the objective to both a confocal microscope and an image mapping spectrometer (IMS).…”

Design and fabrication of a miniature objective consisting of high refractive index zinc sulfide lenses for laser surgery

“…This material, zinc sulfide (ZnS), has been used considerably in IR imaging applications 13–16 and successfully incorporated into a miniature objective. 17 To further reduce complexity of the optical system and to relax assembly tolerances, all optical components were manufactured using diamond turning technology, a prototyping method that allows for the production of spherical and aspherical components without an increase of cost and manufacturing time. To provide a distance invariant object field, the lens is telecentric in the sample space.…”