1. Articles from Michael R. Wang

    1-15 of 15
    1. Improving lateral resolution and image quality of optical coherence tomography by the multi-frame superresolution technique for 3D tissue imaging

      Improving lateral resolution and image quality of optical coherence tomography by the multi-frame superresolution technique for 3D tissue imaging

      The multi-frame superresolution technique is introduced to significantly improve the lateral resolution and image quality of spectral domain optical coherence tomography (SD-OCT). Using several sets of low resolution C-scan 3D images with lateral sub-spot-spacing shifts on different sets, the multi-frame superresolution processing of these sets at each depth layer reconstructs a higher resolution and quality lateral image. Layer by layer processing yields an overall high lateral resolution and quality 3D image. In theory, the superresolution processing including deconvolution can solve the diffraction limit, lateral scan density and background noise problems together. In experiment, the improved lateral resolution by ~3 times ...

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    2. Handheld non-contact evaluation of fastener flushness and countersink surface profiles using optical coherence tomography

      Handheld non-contact evaluation of fastener flushness and countersink surface profiles using optical coherence tomography

      We report the use of spectral domain optical coherence tomography (SD-OCT) for non-contact optical evaluation of fastener flushness and countersink surface profile. Using a handheld galvanometer scanner of only 0.5 lb in weight the SD-OCT can perform line scan surface profile measurement of fastener and countersink without demanding accurate scan center alignment. It demonstrates fast measurement of fastener flushness, radius, slant angle, as well as countersink edge radius and surface angle within 90 ms suitable for handheld operation. With the use of a broadband light source at 840 nm center wavelength and 45 nm spectral bandwidth and a lens ...

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    3. Improving lateral resolution of optical coherence tomography for imaging of skins

      Improving lateral resolution of optical coherence tomography for imaging of skins

      We report on improving lateral resolution of optical coherence tomography (OCT) for imaging of skins using multiframe superresolution technique. Through introduction of suitable slight transverse positional shifts among a series of C-scans, the superresolution processing of the lateral low resolution images at each axial depth reconstructs a high resolution image. Superresolution processing of all depth layers yields a high resolution 3D image. Using known resolution photomasks, 3 times lateral resolution improvement has been confirmed for both low and high numerical aperture OCT imaging. The superresolution processed OCT 3D skin image provides much more feature details for all subsurface depth layers ...

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    4. Integrated optical coherence tomography and reflectometry system for ocular anterior segment imaging and tear film thickness evaluation

      Integrated optical coherence tomography and reflectometry system for ocular anterior segment imaging and tear film thickness evaluation

      We report an integrated optical coherence tomography (OCT) and reflectometry system for ophthalmology imaging. The dual-functional device provides a complementary high-resolution tear film evaluation by reflectometry and anterior segment imaging by OCT, offering a more comprehensive anterior segment examination. The imaging measurement capabilities have been demonstrated on a human eye as well as on a model eye. The minimum measured tear film thickness is 0.3 μ m with measurement resolution of less than ± 0.58 % of film thickness yet the OCT anterior segment offers a depth resolution of 7 μ m with a 45-nm bandwidth superluminescent light source at 840-nm center ...

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    5. Anterior Segment Biometry during Accommodation Imaged with Ultralong Scan Depth Optical Coherence Tomography

      Anterior Segment Biometry during Accommodation Imaged with Ultralong Scan Depth Optical Coherence Tomography

      Purpose: To measure by ultralong scan depth optical coherence tomography (UL-OCT) dimensional changes in the anterior segment of human eyes during accommodation.Design: Evaluation of diagnostic test or technology.Participants: Forty-one right eyes of healthy subjects with a mean age of 34 years (range, 22–41 years) and a mean refraction of −2.5±2.6 diopters were imaged in 2 repeated measurements at minimal and maximal accommodations.Methods: A specially adapted and designed UL-OCT instrument was used to image from the front surface of the cornea to the back surface of the crystalline lens. Custom software corrected the optical ...

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    6. Ultra-high resolution optical coherence tomography for monitoring tear meniscus volume in dry eye after topical cyclosporine treatment

      Ultra-high resolution optical coherence tomography for monitoring tear meniscus volume in dry eye after topical cyclosporine treatment

      Purpose: This study was designed to determine the ability of ultra-high-resolution optical coherence tomography (UHR-OCT) to monitor tear meniscus volume after dry eye treatment with Restasis® (0.05% cyclosporine). Methods: UHR-OCT was used to image the upper and lower tear menisci (height and volume) in 14 consecutive dry eye patients at baseline. The treatment group was initiated on daily Restasis and measurements were repeated at 1 and 2 months while on treatment. All measurements were performed immediately after a blink. Results: The baseline tear meniscus volumes were 0.40 ± 0.19 µL (upper) and 0.43 ± 0.18 µL (lower ...

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    7. Visualization of the Precorneal Tear Film Using Ultrahigh Resolution Optical Coherence Tomography in Dry Eye

      Visualization of the Precorneal Tear Film Using Ultrahigh Resolution Optical Coherence Tomography in Dry Eye

      Purpose: To visualize the precorneal tear film (PCTF) in dry eye patients using ultrahigh resolution optical coherence tomography (UHR-OCT). Methods: A custom-built UHR-OCT with ultrahigh resolution (~3 [mu]m) was used to image the PCTF at the vertical meridian. Eighteen right eyes of 18 previously diagnosed dry eye patients (9 men and 9 women, age, 47.8+/-20.7 years) with aqueous tear deficiency were studied. Images were taken during normal and delayed blinking. The visualized PCTF was measured directly. An indirect calculation was used to obtain the thickness in cases where the PCTF could not be visualized. Results: During ...

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    8. Broadband superluminescent diode–based ultrahigh resolution optical coherence tomography for ophthalmic imaging

      Broadband superluminescent diode–based ultrahigh resolution optical coherence tomography for ophthalmic imaging

      Spectral domain optical coherence tomography (SD-OCT) with ultrahigh resolution can be used to measure precise structures in the context of ophthalmic imaging. We designed an ultrahigh resolution SD-OCT system based on broadband superluminescent diode (SLD) as the light source. An axial resolution of 2.2 μm in tissue, a scan depth of 1.48 mm, and a high sensitivity of 93 dB were achieved by the spectrometer designed. The ultrahigh-resolution SD-OCT system was employed to image the human cornea and retina with a cross-section image of 2048 × 2048 pixels. Our research demonstrated that ultrahigh -resolution SD-OCT can be achieved using ...

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    9. Micrometer-Scale Contact Lens Movements Imaged by Ultrahigh-resolution Optical Coherence Tomography

      Micrometer-Scale Contact Lens Movements Imaged by Ultrahigh-resolution Optical Coherence Tomography

      Purpose To dynamically evaluate contact lens movement and ocular surface shape using ultrahigh-resolution and ultralong-scan-depth optical coherence tomography (OCT). Design Clinical research study of a laboratory technique. Methods Four different types of soft contact lenses were tested on the left eye of 10 subjects (6 male and 4 female). Lens edges at primary gaze and temporal and nasal gazes were imaged by ultrahigh-resolution OCT. Excursion lag was obtained as the distance between the lens edge at primary gaze and immediately after the eye was quickly turned either nasally or temporally. The inferior lens edges were imaged continuously to track vertical ...

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    10. Extended scan depth optical coherence tomography for evaluating ocular surface shape

      Extended scan depth optical coherence tomography for evaluating ocular surface shape

      Spectral domain optical coherence tomography (SD-OCT) with extended scan depth makes it possible for quantitative measurement of the entire ocular surface shape. We proposed a novel method for ocular surface shape measurement using a custom-built anterior segment SD-OCT, which will serve on the contact lens fitting. A crosshair alignment system was applied to reduce the misalignment and tilting of the eye. An algorithm was developed to automatically segment the ocular surface. We also described the correction of the image distortion from the segmented dataset induced by the nontelecentric scanning system and tested the accuracy and repeatability. The results showed high ...

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    11. Characterization of soft contact lens edge fitting using ultra-high resolution and ultra-long scan depth optical coherence tomography

      Characterization of soft contact lens edge fitting using ultra-high resolution and ultra-long scan depth optical coherence tomography
      Objective: To characterize the edge fitting of soft contact lenses using ultra-high resolution (UHR-OCT) and ultra-long scan depth (UL-OCT) optical coherence tomography. Methods: A total of 20 participants (11 males, 9 females, mean age 32.3 years) were recruited. Four different types of soft contact lenses were randomly fitted to both eyes of each subject on two separate visits. After 30 minutes, the horizontal meridians of the corneal center, mid-periphery, and limbus were imaged by UHR-OCT. UL-OCT imaged each lens in vitro and the ocular surface of a physical model eye. Results: Angle-edged lenses had significantly less conjunctival buildup than ...
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    12. SD-OCT with Prolonged Scan Depth for Imaging the Anterior Segment of the Eye

      SD-OCT with Prolonged Scan Depth for Imaging the Anterior Segment of the Eye

      An 840-nm wavelength spectral domain optical coherence tomography (SD-OCT) with prolonged scan depth was developed and mounted onto a conventional slit lamp for imaging the anterior segment of the eye. X-Y cross aiming was applied to align the SD-OCT scanning position during imaging. An internal fixation target displayed on a miniature LCD monitor was provided. The SD-OCT instrument had an axial resolution of 6 µm and a prolonged scan depth of 7.2 mm. High-quality SD-OCT images, consisting of 2,048 × 2,048 pixels, were acquired of the entire anterior chamber and entire crystalline lens from a healthy subject. The ...

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    13. Detection of Magnetic Particles in Live DBA/2J Mouse Eyes Using Magnetomotive Optical Coherence Tomography

      Detection of Magnetic Particles in Live DBA/2J Mouse Eyes Using Magnetomotive Optical Coherence Tomography

      Objectives: To demonstrate in vivo molecular imaging of the eye using spectral-domain magnetomotive optical coherence tomography (MMOCT).Methods: A custom-built, high-speed, and high-resolution MMOCT was developed for imaging magnetic particle-coupled molecules in living mouse eyes by applying an external dynamic magnetic field gradient during optical coherence tomography (OCT) scanning. The magnetomotive signals were tested in vitro by scanning magnetic beads embedded within an agarose gel (1.5%) and in vivo in the anterior segment of a mouse eye.Results: Cross-sectional OCT images of the gel and the anterior segment of the eye were acquired by regular OCT structural scanning. Magnetomotive ...

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    14. Entire Contact Lens Imaged In Vivo and In Vitro With Spectral Domain Optical Coherence Tomography

      Objectives: To demonstrate the capability of directly visualizing the entire ocular surface and the entire contact lens on the eye using spectral domain optical coherence tomography (SD-OCT).Methods: A custom-built, high-speed, and high-resolution SD-OCT was developed with extended scan depth and width. The eye was imaged before and after wearing a toric soft contact lens (PureVision; Bausch & Lomb). A lubricant eye drop (Soothe; Bausch & Lomb) was instilled in the eye to enhance the image contrast on the lens. The same toric soft contact lens immersed in the contact lens solution was also imaged with a contrast enhancement medium (0.5% Intralipid).Results: Cross-sectional OCT images of ...

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    1-15 of 15
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  2. Topics in the News

    1. (15 articles) University of Miami
    2. (14 articles) Michael R. Wang
    3. (10 articles) Jianhua Wang
    4. (10 articles) Meixiao Shen
    5. (7 articles) Wenzhou Medical College
    6. (3 articles) National Institutes of Health
    7. (2 articles) Bausch & Lomb
    8. (1 articles) Zhejiang University
    9. (1 articles) Yimin Wang
    10. (1 articles) Sonia H. Yoo
    11. (1 articles) Medical University of Vienna
    12. (1 articles) Columbia University
    13. (1 articles) University of Iowa
    14. (1 articles) University of Rochester
    15. (1 articles) National Eye Institute
    16. (1 articles) Peter E. Andersen
    17. (1 articles) Mona K. Garvin
    18. (1 articles) Santec
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    Detection of Magnetic Particles in Live DBA/2J Mouse Eyes Using Magnetomotive Optical Coherence Tomography SD-OCT with Prolonged Scan Depth for Imaging the Anterior Segment of the Eye Characterization of soft contact lens edge fitting using ultra-high resolution and ultra-long scan depth optical coherence tomography Extended scan depth optical coherence tomography for evaluating ocular surface shape Broadband superluminescent diode–based ultrahigh resolution optical coherence tomography for ophthalmic imaging Micrometer-Scale Contact Lens Movements Imaged by Ultrahigh-resolution Optical Coherence Tomography Visualization of the Precorneal Tear Film Using Ultrahigh Resolution Optical Coherence Tomography in Dry Eye Ultra-high resolution optical coherence tomography for monitoring tear meniscus volume in dry eye after topical cyclosporine treatment Anterior Segment Biometry during Accommodation Imaged with Ultralong Scan Depth Optical Coherence Tomography Vitreous Seeding in Retinocytoma: Importance of Optical Coherence Tomography Utility of Spectral-Domain Optical Coherence Tomography in Differentiating Papilledema From Pseudopapilledema: A Prospective Longitudinal Study Visualizing and quantifying cutaneous microvascular reactivity in humans using optical coherence tomography: Impaired dilator function in diabetes