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ABSTRACT: Spectrally encoded confocal microscopy and optical frequency domain imaging are two non-contact optical imaging technologies that provide images of tissue cellular and architectural morphology, which are both used for histopathological diagnosis. Although spectrally encoded confocal microscopy has better transverse resolution than optical frequency domain imaging, optical frequency domain imaging can penetrate deeper into tissues, which potentially enables the visualization of different morphologic features. We have developed a co-registered spectrally encoded confocal microscopy and optical frequency domain imaging system and have obtained preliminary images from human oesophageal biopsy samples to compare the capabilities of these imaging techniques for diagnosing oesophageal pathology.
Journal of Microscopy 08/2010; 239(2):87-91. · 1.63 Impact Factor
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ABSTRACT: Understanding pediatric voice development and laryngeal pathology is predicated on a detailed knowledge of the microanatomy of the layered structure of the vocal fold. Our current knowledge of this microanatomy and its temporal evolution is limited by the lack of pediatric specimen availability. By providing the capability to image pediatric vocal folds in vivo, a noninvasive microscopy technique could greatly expand the existing database of pediatric laryngeal microanatomy and could furthermore make longitudinal studies possible. A variety of natural-contrast optical imaging technologies, including optical frequency domain imaging (OFDI), full-field optical coherence microscopy (FF-OCM), and spectrally encoded confocal microscopy (SECM) have been recently developed for noninvasive diagnosis in adult patients. In this paper, we demonstrate the potential of these three techniques for laryngeal investigation by obtaining images of excised porcine vocal fold samples. In our study, OFDI allowed visualization of the vocal fold architecture deep within the tissue, from the superficial mucosa to the vocalis muscle. The micron-level resolution of SECM allowed investigation of cells and extracellular matrix fibrils from the superficial mucosa to the intermediate layer of the lamina propria (LP) (350 microm penetration depth). The large field of view (up to 700 microm), penetration depth (up to 500 microm), and resolution (2x2x1microm [XxYxZ]) of FF-OCM enabled comprehensive three-dimensional evaluation of the layered structure of the LP. Our results suggest that these techniques provide important and complementary cellular and structural information, which may be useful for investigating pediatric vocal fold maturation in vivo.
Journal of voice: official journal of the Voice Foundation 04/2008; 23(3):269-76. · 0.95 Impact Factor
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ABSTRACT: Imaging large tissue areas with microscopic resolution in vivo may offer an alternative to random excisional biopsy. We present an approach for performing confocal imaging of large tissue surface areas using spectrally encoded confocal microscopy (SECM). We demonstrate a single-optical-fiber SECM apparatus, designed for imaging luminal organs, that is capable of imaging with a transverse resolution of 2.1 microm over a subsurface area of 16 cm2 in less than 1 min. Due to the unique probe configuration and scanning geometry, the speed and resolution of this new imaging technology are sufficient for comprehensively imaging large tissues areas at a microscopic scale in times that are appropriate for clinical use.
Optics Letters 06/2007; 32(9):1102-4. · 3.40 Impact Factor
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ABSTRACT: Spectrally encoded confocal microscopy (SECM) is a technique that allows confocal microscopy to be performed through the confines of a narrow diameter optical fiber probe. We present a novel scheme for performing SECM in which a rapid wavelength swept source is used. The system allows large field of view images to be acquired at rates up to 30 frames/second. Images of resolution targets and tissue specimens acquired ex vivo demonstrate high lateral (1.4 mum) and axial (6 mum) resolution. Imaging of human skin was performed in vivo at depths of up to 350 mum, allowing cellular and sub-cellular details to be visualized in real time.
Optics Express 11/2005; 13(20):8214-21. · 3.59 Impact Factor
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ABSTRACT: We demonstrate a compact high-power rapidly swept wavelength tunable laser source based on a semiconductor optical amplifier and an extended-cavity grating filter. The laser produces excellent output characteristics for biomedical imaging, exhibiting >4-mW average output power, <0.06-nm instantaneous linewidth, and >80-dB noise extinction with its center wavelength swept over 100 nm at 1310 nm at variable repetition rates up to 500 Hz.
IEEE Photonics Technology Letters 01/2004; 16(1):293-295. · 2.19 Impact Factor
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ABSTRACT: Ultrahigh-speed tuning of an extended-cavity semiconductor laser is demonstrated. The laser resonator comprises a unidirectional fiber-optic ring, a semiconductor optical amplifier as the gain medium, and a novel scanning filter based on a polygonal scanner. Variable tuning rates up to 1150 nm/ms (15.7-kHz repetition frequency) are demonstrated over a 70-nm wavelength span centered at 1.32 microm. This tuning rate is more than an order of magnitude faster than previously demonstrated and is facilitated in part by self-frequency shifting in the semiconductor optical amplifier. The instantaneous linewidth of the source is <0.1 nm for 9-mW cw output power and a low spontaneous-emission background of -80 dB.
Optics Letters 10/2003; 28(20):1981-3. · 3.40 Impact Factor
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ABSTRACT: Understanding pediatric voice development and laryngeal pathology is predicated on a detailed knowledge of the microanatomy of the layered structure of the vocal fold. Our current knowledge of this microanatomy and its temporal evolution is limited by the lack of pediatric specimen availability. By providing the capability to image pediatric vocal folds in vivo, a noninvasive microscopy technique could greatly expand the existing database of pediatric laryngeal microanatomy and could furthermore make longitudinal studies possible. A variety of natural-contrast optical imaging technologies, including optical frequency domain imaging (OFDI), full-field optical coherence microscopy (FF-OCM), and spectrally encoded confocal microscopy (SECM) have been recently developed for noninvasive diagnosis in adult patients. In this paper, we demonstrate the potential of these three techniques for laryngeal investigation by obtaining images of excised porcine vocal fold samples. In our study, OFDI allowed visualization of the vocal fold architecture deep within the tissue, from the superficial mucosa to the vocalis muscle. The micron-level resolution of SECM allowed investigation of cells and extracellular matrix fibrils from the superficial mucosa to the intermediate layer of the lamina propria (LP) (350 μm penetration depth). The large field of view (up to 700 μm), penetration depth (up to 500 μm), and resolution (2 × 2 × 1 μm [X × Y × Z]) of FF-OCM enabled comprehensive three-dimensional evaluation of the layered structure of the LP. Our results suggest that these techniques provide important and complementary cellular and structural information, which may be useful for investigating pediatric vocal fold maturation in vivo.
Journal of Voice.
