Miniature endoscope for simultaneous optical coherence tomography and laser-induced fluorescence measurement

Abstract

We have designed a multimodality system that combines optical coherence tomography (OCT) and laser-induced fluorescence (LIF) in a 2.0-mm-diameter endoscopic package. OCT provides approximately 18-microm resolution cross-sectional structural information over a 6-mm field. LIF spectra are collected sequentially at submillimeter resolution across the same field and provide histochemical information about the tissue. We present the use of a rod prism to reduce the asymmetry in the OCT beam caused by a cylindrical window. The endoscope has been applied to investigate mouse colon cancer in vivo.

Simultaneous optical coherence tomography and laser induced fluorescence imaging in rat model of ovarian carcinogenesis

“…OCT and LIF are non-destructive imaging modalities which can be packaged into a small diameter dual modality device. 36,38 As these characteristics provide the means for in vivo imaging, future work should aim to evaluate in vivo ovarian imaging of animal models serially over time to observe tumor progression from early neoplasms or preneoplastic lesions to better characterize these lesions and further enhance understanding of ovarian tumor carcinogenesis. resulted in a higher 450 nm emission peak from the metabolic activity of the inflammatory cells.…”

“…Ovaries were harvested at three or five months post DMBA treatment and imaged using a 2-mm diameter side-firing catheter that optically combined both the OCT and LIF subsystems, previously described in detail. 36 The OCT subsystem used a superluminescent diode source with a 1,300 nm center wavelength (D1300-HP, Superlum, Moscow, Russia) with axial and lateral resolutions of approximately 14 µm and 18 µm, respectively. The LIF subsystem used a helium cadmium laser source (Kimmon Electric, Englewood, Colorado) with a 325 nm excitation wavelength, which was chosen due to its ability to excite endogenous fluorophores NADH, FAD and collagen.…”

Specialty Fiber Coupler: Fabrications and Applications

“…For the case of the polymer-clad fiber, the DCF coupler, which couples only the inner cladding modes, could be simply implemented. Simply striping out the polymer coating, the outer cladding, and physical contacting two pieces of bare DCFs allowed the implementation of DCF coupler [26][27]. To make effective contact, pair of DCFs were twisted around each other after removing the polymer jackets (the outer cladding) as shown in Fig.…”

The Development of Double Clad Fiber and Double Clad Fiber Coupler for Fiber Based Biomedical Imaging Systems

“…Recently, attempts to combine a fiber optic OCT with a spectroscopy system have been reported [7,8]. Although these hybrid systems have also been implemented mainly with fiber optic devices, the use of bulk optic elements such as dichroic mirrors was unavoidable to handle dual-wavelengths for the hybrid systems [7].…”

“…Although these hybrid systems have also been implemented mainly with fiber optic devices, the use of bulk optic elements such as dichroic mirrors was unavoidable to handle dual-wavelengths for the hybrid systems [7]. In addition, the employment of different kinds of optical fibers was necessary to isolate the fluorescence signal from the OCT signal [8]. In our previous work, we have reported the use of double clad fiber (DCF) and DCF devices to get a common probe for both modalities [9,10].…”