1. Articles from Yao-Chun Shen

    1-7 of 7
    1. Deformation velocity imaging using optical coherence tomography and its applications to the cornea

      Deformation velocity imaging using optical coherence tomography and its applications to the cornea

      Optical coherence tomography (OCT) can monitor human donor corneas non-invasively during the de-swelling process following storage for corneal transplantation, but currently only resultant thickness as a function of time is extracted. To visualize and quantify the mechanism of de-swelling, we present a method exploiting the nanometer sensitivity of the Fourier phase in OCT data to image deformation velocities. The technique was demonstrated by non-invasively showing during de-swelling that osmotic flow through an intact epithelium is negligible and removing the endothelium approximately doubled the initial flow at that interface. The increased functional data further enabled the validation of a mathematical model ...

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      Mentions: Yalin Zheng
    2. Investigating Intra-Tablet Coating Uniformity With Spectral-Domain Optical Coherence Tomography

      Investigating Intra-Tablet Coating Uniformity With Spectral-Domain Optical Coherence Tomography

      Spectral domain optical coherence tomography (SD-OCT) has recently attracted a lot of interest in the pharmaceutical industry as a fast and non-destructive modality for direct quantification of thin film coatings that cannot easily be resolved with other techniques. While previous studies with SD-OCT have estimated the intra-tablet coating uniformity, the estimates were based on limited number of B-scans. In order to obtain a more accurate estimate, a greater number of B-scans are required that can quickly lead to an overwhelming amount of data. To better manage the data so as to generate a more accurate representation of the intra-tablet coating ...

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    3. Scan-Less Line Field Optical Coherence Tomography, with Automatic Image Segmentation, as a Measurement Tool for Automotive Coatings

      Scan-Less Line Field Optical Coherence Tomography, with Automatic Image Segmentation, as a Measurement Tool for Automotive Coatings

      The measurement of the thicknesses of layers is important for the quality assurance of industrial coating systems. Current measurement techniques only provide a limited amount of information. Here, we show that spectral domain Line Field (LF) Optical Coherence Tomography (OCT) is able to return to the user a cross sectional B-Scan image in a single shot with no mechanical moving parts. To reliably extract layer thicknesses from such images of automotive paint systems, we present an automatic graph search image segmentation algorithm. To show that the algorithm works independently of the OCT device, the measurements are repeated with a separate ...

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      Mentions: Yalin Zheng
    4. Investigating Intra-Tablet Coating Uniformity With Spectral-Domain Optical Coherence Tomography

      Investigating Intra-Tablet Coating Uniformity With Spectral-Domain Optical Coherence Tomography

      Spectral domain optical coherence tomography (SD-OCT) has recently attracted a lot of interest in the pharmaceutical industry as a fast and non-destructive modality for direct quantification of thin film coatings that cannot easily be resolved with other techniques. While previous studies with SD-OCT have estimated the intra-tablet coating uniformity, the estimates were based on limited number of B-scans. In order to obtain a more accurate estimate, a greater number of B-scans are required that can quickly lead to an overwhelming amount of data. To better manage the data so as to generate a more accurate representation of the intra-tablet coating ...

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    5. High resolution corneal and single pulse imaging with line field spectral domain optical coherence tomography

      High resolution corneal and single pulse imaging with line field spectral domain optical coherence tomography

      We report the development of a Spectral Domain Line Field Optical Coherence Tomography (LF-OCT) system, using a broad bandwidth and spatial coherent Super-Continuum (SC) source. With conventional quasi-Continuous Wave (CW) setup we achieve axial resolutions up to 2.1 μm in air and 3D volume imaging speeds up to 213 kA-Scan/s. Furthermore, we report the use of a single SC pulse, of 2 ns duration, to temporally gate an OCT B-Scan image of 70 A-Scans. This is the equivalent of 35 GA-Scans/s. We apply the CW setup for high resolution imaging of the fine structures of a human ...

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      Mentions: Yalin Zheng
    6. Nondestructive analysis of automotive paints with spectral domain optical coherence tomography

      Nondestructive analysis of automotive paints with spectral domain optical coherence tomography

      We have demonstrated for the first time, to our knowledge, the use of optical coherence tomography (OCT) as an analytical tool for nondestructively characterizing the individual paint layer thickness of multiple layered automotive paints. A graph-based segmentation method was used for automatic analysis of the thickness distribution for the top layers of solid color paints. The thicknesses measured with OCT were in good agreement with the optical microscope and ultrasonic techniques that are the current standard in the automobile industry. Because of its high axial resolution (5.5 μm), the OCT technique was shown to be able to resolve the ...

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      Mentions: Yalin Zheng
    7. Non-Destructive Evaluation of Polymer Coating Structures on Pharmaceutical Pellets Using Full-Field Optical Coherence Tomography

      Non-Destructive Evaluation of Polymer Coating Structures on Pharmaceutical Pellets Using Full-Field Optical Coherence Tomography

      Full-field optical coherence tomography (FF-OCT) using a conventional light-emitting diode and a complementary metal-oxide semiconductor camera has been developed for characterising coatings on small pellet samples. A set of en-face images covering an area of 700 × 700 μm 2 was taken over a depth range of 166 μm. The three-dimensional structural information, such as the coating thickness and uniformity, was subsequently obtained by analysis of the recorded en-face images. Drug-loaded pharmaceutical sustained-release pellets with two coating layers and of a sub-millimetre diameter were studied to demonstrate the usefulness of the developed system. We have shown that both coatings can be ...

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    1-7 of 7
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    Non-Destructive Evaluation of Polymer Coating Structures on Pharmaceutical Pellets Using Full-Field Optical Coherence Tomography Nondestructive analysis of automotive paints with spectral domain optical coherence tomography High resolution corneal and single pulse imaging with line field spectral domain optical coherence tomography Investigating Intra-Tablet Coating Uniformity With Spectral-Domain Optical Coherence Tomography Scan-Less Line Field Optical Coherence Tomography, with Automatic Image Segmentation, as a Measurement Tool for Automotive Coatings Investigating Intra-Tablet Coating Uniformity With Spectral-Domain Optical Coherence Tomography Deformation velocity imaging using optical coherence tomography and its applications to the cornea Postdoctoral Associate Position at Duke Vision and Image Processing Laborator Anterior segment optical coherence tomography angiography Refining percutaneous coronary intervention: intracoronary imaging, haemodynamics, P2Y12 antagonists, and public outcomes reporting Optical Coherence Tomography/Fluorescence Imaging: Fiber assembly enables efficient multimodal endoscopy Optical Fabrication: Glassblowing technique creates arrays of axicon lenses