1. Articles from Jing-gao Zheng

    1-10 of 10
    1. Feature Of The Week 2/2/14: Tsinghua University.Demonstrates Linear-in-Wavenumber Swept Laser with an Acousto-Optic Deflector for OCT

      Feature Of The Week 2/2/14: Tsinghua University.Demonstrates Linear-in-Wavenumber Swept Laser with an Acousto-Optic Deflector for OCT

      Compared to the conventional time domain OCT, the frequency domain (FD) detection techniques enable a dramatic increase in imaging speed. Spectrometer-based FD-OCT (SD-OCT) systems are already widely used, especially for ophthalmic application in the 800 nm wavelength range. Alternatively, the application of FD-OCT systems based on a rapidly swept, narrowband light source, i.e. swept source OCT (SS-OCT) offers the additional advantages of dual balance detection, potentially longer ranging depth and higher imaging speeds. However, a general disadvantage of most FD-OCT systems is the requirement to resample and recalibrate the detected OCT interference fringe prior to fast Fourier transformation, in ...

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    2. Linear-in-wavenumber swept laser with an acousto-optic deflector for optical coherence tomography

      Linear-in-wavenumber swept laser with an acousto-optic deflector for optical coherence tomography

      We report a novel linear-in-wavenumber ( k -linear) swept laser source based on an acousto-optic deflector (AOD). The AOD-based optical filter includes an acousto-optic deflector and a reflection grating. The laser may tune k linearly in wavenumber over time due to its appropriate configuration and is favorable for fast imaging because it avoids data resampling and recalibration, as are required in conventional swept source optical coherence tomography (SS-OCT). We achieved k -linearity with Pearson’s r correlation coefficients of 0.99995 without and 0.99997 with optimization. The laser has a tuning range of 50 nm, a 3 dB swept range ...

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    3. Feature Of The Week 10/13/13: Tsinghua University Demonstrates a Tiny OCT Endoscopic Probe Using a Hollow Ultrasonic Motor

      Feature Of The Week 10/13/13: Tsinghua University Demonstrates a Tiny OCT Endoscopic Probe Using a Hollow Ultrasonic Motor

      Optical coherence tomography (OCT) is an emerging modality for obtaining cross-sectional images. Due to limitation of the light penetration, small and high resolution probes for endoscopic OCT have been regarded as powerful tools in examining internal organs. Among them, circumferential probes are utilized extensively for imaging within hollow tissues, such as arteries, esophagus, and colon. In recent years, distal scanning is of high interest, as the whole fiber remains stationary in this case. The twisting and nonuniformity in the conventional proximal scanning are avoided. However, some problems emerge such as the wire-shadow effect and the relative large size of the ...

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    4. Tiny endoscopic optical coherence tomography probe driven by a miniaturized hollow ultrasonic motor

      Tiny endoscopic optical coherence tomography probe driven by a miniaturized hollow ultrasonic motor

      We present an endoscopic probe for optical coherence tomography (OCT) equipped with a miniaturized hollow ultrasonic motor that rotates the objective lens and provides an internal channel for the fiber to pass through, enabling 360 deg unobstructed circumferential scanning. This probe has an outer diameter of 1.5 mm, which is ultra-small for motorized probes with an unobstructed view in distal scanning endoscopic OCT. Instead of a mirror or prism, a customized aspheric right-angle lens is utilized, leading to an enlargement of the numerical aperture and thus high transverse resolution. Spectral-domain OCT imaging of bio-tissue and a phantom are demonstrated ...

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    5. Noninvasive three-dimensional live imaging methodology for the spindles at meiosis and mitosis

      Noninvasive three-dimensional live imaging methodology for the spindles at meiosis and mitosis

      The spindle plays a crucial role in normal chromosome alignment and segregation during meiosis and mitosis. Studying spindles in living cells noninvasively is of great value in assisted reproduction technology (ART). Here, we present a novel spindle imaging methodology, full-field optical coherence tomography (FF-OCT). Without any dye labeling and fixation, we demonstrate the first successful application of FF-OCT to noninvasive three-dimensional (3-D) live imaging of the meiotic spindles within the mouse living oocytes at metaphase II as well as the mitotic spindles in the living zygotes at metaphase and telophase. By post-processing of the 3-D dataset obtained with FF-OCT, the ...

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    6. OCT News 2013 Student Paper Awarded to Jing-gao Zheng from Tsinghua University

      OCT News 2013 Student Paper Awarded to Jing-gao Zheng from Tsinghua University

      Jing-Gao Zheng from Tsinghua University was a winner of the 2013 OCT News Student Paper Award for his submission “Understanding early patterning and polarity of preimplantation mouse embryos with full-field optical coherence tomography.” Below is a summary of his work:  Morphogenetic relationship between early patterning and the polarity formation is of fundamental interest and remains controversial issues in mammalian preimplantation development. Label-free subcellular 3D live imaging technique is very helpful to its related studies. We have developed a novel system of full-field optical coherence tomography (FF-OCT) for non-invasive 3D sub-cellular live imaging of preimplantation mouse embryos with no need of ...

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    7. Understanding three-dimensional spatial relationship between the mouse second polar body and first cleavage plane with full-field optical coherence tomography

      Understanding three-dimensional spatial relationship between the mouse second polar body and first cleavage plane with full-field optical coherence tomography

      he morphogenetic relationship between early patterning and polarity formation is of fundamental interest and remains a controversial issue in preimplantation embryonic development. We use a label-free three-dimensional (3-D) imaging technique of full-field optical coherence tomography (FF-OCT) successfully for the first time to study the dynamics of developmental processes in mouse preimplantation lives. Label-free 3-D subcellular time-lapse images are demonstrated to investigate 3-D spatial relationship between the second polar body (2PB) and the first cleavage plane. By using FF-OCT together with quantitative study, we show that only 25% of the predicted first cleavage planes, defined by the apposing plane of two ...

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    8. Feature Of The Week 7/22/12: Label-Free Subcellular 3D Live Imaging of Preimplantation Mouse Embryos With Full-Field Optical Coherence Tomography

      Feature Of The Week 7/22/12: Label-Free Subcellular 3D Live Imaging of Preimplantation Mouse Embryos With Full-Field Optical Coherence Tomography

      arly patterning and polarity is of fundamental interest in preimplantation embryonic development. Label-free subcellular 3D live imaging is very helpful to its related studies. We have developed a novel system of full-field optical coherence tomography (FF-OCT) for noninvasive 3D subcellular live imaging of preimplantation mouse embryos with no need of dye labeling. 3D digitized embryos can be obtained by image processing. Label-free 3D live imaging is demonstrated for the mouse embryos at various typical preimplantation stages with a spatial resolution of 0.7 µm and imaging rate of 24 fps. Factors that relate to early patterning and polarity, such as ...

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    9. Compressed sensing with linear-in-wavenumber sampling in spectral-domain optical coherence tomography

      Compressed sensing with linear-in-wavenumber sampling in spectral-domain optical coherence tomography

      We propose a novel method called compressed sensing with linear-in-wavenumber sampling (k -linear CS) to retrieve an image for spectral-domain optical coherence tomography (SD-OCT). An array of points that is evenly spaced in wavenumber domain is sampled from an original interferogram by a preset k -linear mask. Then the compressed sensing based on l1 norm minimization is applied on these points to reconstruct an A-scan data. To get an OCT image, this method uses less than 20% of the total data as required in the typical process and gets rid of the spectral calibration with numerical interpolation in traditional CS-OCT ...

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    10. Label-free subcellular 3D live imaging of preimplantation mouse embryos with full-field optical coherence tomography

      Label-free subcellular 3D live imaging of preimplantation mouse embryos with full-field optical coherence tomography

      Early patterning and polarity is of fundamental interest in preimplantation embryonic development. Label-free subcellular 3D live imaging is very helpful to its related studies. We have developed a novel system of full-field optical coherence tomography (FF-OCT) for noninvasive 3D subcellular live imaging of preimplantation mouse embryos with no need of dye labeling. 3D digitized embryos can be obtained by image processing. Label-free 3D live imaging is demonstrated for the mouse embryos at various typical preimplantation stages with a spatial resolution of 0.7 µm and imaging rate of 24 fps. Factors that relate to early patterning and polarity, such as ...

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    1-10 of 10
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  2. Topics in the News

    1. (10 articles) Tsinghua University
    2. (10 articles) Jing-gao Zheng
    3. (10 articles) Ping Xue
    4. (9 articles) Chengming Wang
    5. (9 articles) Tianyuan Chen
    6. (9 articles) Ning Zhang
    7. (2 articles) Peking University
    8. (2 articles) Massachusetts General Hospital
    9. (1 articles) Massachusetts Institute of Technology
    10. (1 articles) Harvard University
    11. (1 articles) The Chinese University of Hong Kong
    12. (1 articles) University of Miami
    13. (1 articles) VU University Amsterdam
    14. (1 articles) David A. Boas
    15. (1 articles) Brett E. Bouma
    16. (1 articles) Johannes F. de Boer
    17. (1 articles) Frank D. Verbraak
    18. (1 articles) Apollo Medical Optics
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    Label-free subcellular 3D live imaging of preimplantation mouse embryos with full-field optical coherence tomography Compressed sensing with linear-in-wavenumber sampling in spectral-domain optical coherence tomography Feature Of The Week 7/22/12: Label-Free Subcellular 3D Live Imaging of Preimplantation Mouse Embryos With Full-Field Optical Coherence Tomography Understanding three-dimensional spatial relationship between the mouse second polar body and first cleavage plane with full-field optical coherence tomography OCT News 2013 Student Paper Awarded to Jing-gao Zheng from Tsinghua University Noninvasive three-dimensional live imaging methodology for the spindles at meiosis and mitosis Tiny endoscopic optical coherence tomography probe driven by a miniaturized hollow ultrasonic motor Feature Of The Week 10/13/13: Tsinghua University Demonstrates a Tiny OCT Endoscopic Probe Using a Hollow Ultrasonic Motor Linear-in-wavenumber swept laser with an acousto-optic deflector for optical coherence tomography Feature Of The Week 2/2/14: Tsinghua University.Demonstrates Linear-in-Wavenumber Swept Laser with an Acousto-Optic Deflector for OCT Optical Coherence Tomography: Critical Tool to Manage Expectations after Cataract Extraction Improving the characterization of ex vivo human brain optical properties using high numerical aperture optical coherence tomography by spatially constraining the confocal parameters