1. Articles from Hyeon-Cheol Park

    1-6 of 6
    1. Ultra-sensitive optical coherence elastography using a high-dynamic-range force loading scheme for cervical rigidity assessment

      Ultra-sensitive optical coherence elastography using a high-dynamic-range force loading scheme for cervical rigidity assessment

      An ultra-sensitive, wide-range force loading scheme is proposed for compression optical coherence elastography (OCE) that allows for the quantitative analysis of cervical tissue elasticity ex vivo . We designed a force loading apparatus featuring a water sink for minuscule incremental loading through a volume-controlled water droplet, from which the Young’s modulus can be calculated by fitting the stress-strain curve. We validated the performance of the proposed OCE system on homogenous agar phantoms, showing the Young’s modulus can be accurately estimated using this scheme. We then measured the Young’s modulus of rodent cervical tissues acquired at different gestational ages ...

      Read Full Article
    2. Ultralow-voltage electrothermal MEMS based fiber-optic scanning probe for forward-viewing endoscopic OCT

      Ultralow-voltage electrothermal MEMS based fiber-optic scanning probe for forward-viewing endoscopic OCT

      We report an ultralow-voltage, electrothermal (ET) micro-electro-mechanical system (MEMS) based probe for forward-viewing endoscopic optical coherence tomography (OCT) imaging. The fully assembled probe has a diameter of 5.5 mm and a length of 55 mm, including the imaging optics and a 40 mm long fiber-optic cantilever attached on a micro-platform of the bimorph ET MEMS actuator. The ET MEMS actuator provides a sufficient mechanical actuation force as well as a large vertical displacement, achieving up to a 3 mm optical scanning range with only a 3

      Read Full Article
    3. Broadband rotary joint for high-speed ultrahigh-resolution endoscopic OCT imaging at 800  nm

      Broadband rotary joint for high-speed ultrahigh-resolution endoscopic OCT imaging at 800  nm

      We report the development of a broadband rotary joint for high-speed ultrahigh-resolution endoscopic optical coherence tomography (OCT) imaging in the 800 nm spectral range. This rotary joint features a pair of achromatic doublets in order to achieve broadband operation for a 3 dB bandwidth over 150 nm. The measured one-way throughput of the rotary joint is greater than 80%, while the fluctuation of the double-pass coupling efficiency during 360 deg rotation is less than ± 5 % ±5% at a near video-rate speed of 20 revolutions/s (rps). The rotary joint is used in conjunction with a diffractive-optics-based endoscope and 800 nm ...

      Read Full Article
    4. Lissajous fiber scanning for forward viewing optical endomicroscopy using asymmetric stiffness modulation

      Lissajous fiber scanning for forward viewing optical endomicroscopy using asymmetric stiffness modulation

      We report a fully packaged and compact forward viewing endomicroscope by using a resonant fiber scanner with two dimensional Lissajous trajectories. The fiber scanner comprises a single mode fiber with additional microstructures mounted inside a piezoelectric tube with quartered electrodes. The mechanical cross-coupling between the transverse axes of a resonant fiber with a circular cross-section was completely eliminated by asymmetrically modulating the stiffness of the fiber cantilever with silicon microstructures and an off-set fiber fragment. The Lissajous fiber scanner was fully packaged as endomicroscopic catheter passing through the accessory channel of a clinical endoscope and combined with spectral domain optical ...

      Read Full Article
    5. Feature Of The Week 8/19/12: Recent Results on Miniature OCT MEMS Endoscopes from Korea Advanced Institute of Science and Technology

      Feature Of The Week 8/19/12: Recent Results on Miniature OCT MEMS Endoscopes from Korea Advanced Institute of Science and Technology

      Optical coherence tomography (OCT) has been intensively studied for advanced bioimaging microscopy.   Among the areas for exciting research and commercial opportunities is the miniaturization of endoscopic imaging probes.  MEMS technology is of great interest to enable miniaturized laser scanning probes for endoscopic optical biopsy.   Below is a summary of some exciting work by the Korea Advanced Institute of Science and Technology (KAIST).This work reports a fully packaged MEMS endoscopic catheter for forward imaging optical coherence tomography. Two dimensional optical scanning of Lissajous patterns was realized by the orthogonal movement of two commercial aspherical glass lenses laterally mounted on two ...

      Read Full Article
    6. Forward imaging OCT endoscopic catheter based on MEMS lens scanning

      Forward imaging OCT endoscopic catheter based on MEMS lens scanning

      This Letter reports a fully packaged microelectromechanical system (MEMS) endoscopic catheter for forward imaging optical coherence tomography (OCT). Two-dimensional optical scanning of Lissajous patterns was realized by the orthogonal movement of two commercial aspherical glass lenses laterally mounted on two resonating electrostatic MEMS microstages at low operating voltages. The MEMS lens scanner was integrated on a printed circuit board and packaged with an aluminum housing, a gradient index fiber collimator, and an objective lens. A home-built spectral-domain OCT system with 60 kHz A-line acquisition rate was combined with the endoscopic MEMS catheter. Three-dimensional images of 256×256×995 voxels were ...

      Read Full Article
    1-6 of 6
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Topics in the News

    1. (3 articles) Johns Hopkins University
    2. (3 articles) Korea Advanced Institute of Science and Technology
    3. (3 articles) Ki-Hun Jeong
    4. (3 articles) Xingde Li
    5. (2 articles) Cheol Song
    6. (1 articles) University of Florida
    7. (1 articles) Huikai K. Xie
    8. (1 articles) ESPCI ParisTech
    9. (1 articles) Michalina J. Góra
    10. (1 articles) Claude Boccara
    11. (1 articles) Cylite
    12. (1 articles) LLTech
  3. Popular Articles

  4. Picture Gallery

    Forward imaging OCT endoscopic catheter based on MEMS lens scanning Feature Of The Week 8/19/12: Recent Results on Miniature OCT MEMS Endoscopes from Korea Advanced Institute of Science and Technology Lissajous fiber scanning for forward viewing optical endomicroscopy using asymmetric stiffness modulation Broadband rotary joint for high-speed ultrahigh-resolution endoscopic OCT imaging at 800  nm Ultralow-voltage electrothermal MEMS based fiber-optic scanning probe for forward-viewing endoscopic OCT Ultra-sensitive optical coherence elastography using a high-dynamic-range force loading scheme for cervical rigidity assessment Full-field optical coherence tomography: novel imaging technique for extemporaneous high-resolution analysis of mucosal architecture in human gut biopsies Simon Poole, Cylite co-founder, elected as Fellow of Australian Academy of Science Influence of neoatherosclerosis on prognosis and treatment response in patients with in-stent restenosis Tracking the invasion of breast cancer cells in paper-based 3D cultures by OCT motility analysis Coronary Artery Occlusion Caused by Intramural Hematoma Due to In-Stent Dissection Ocular biometric repeatability using a new high-resolution swept-source optical coherence tomographer