1. Ruikang K. Wang

    0 Comments Leave a Comment

    1-15 of 151 1 2 3 4 5 6 7 8 9 10 »
    1. Mentioned In 151 Articles

    2. Platform to investigate aqueous outflow system structure and pressure-dependent motion using high-resolution spectral domain optical coherence tomography

      Platform to investigate aqueous outflow system structure and pressure-dependent motion using high-resolution spectral domain optical coherence tomography

      The aqueous outflow system (AOS) is responsible for maintaining normal intraocular pressure (IOP) in the eye. Structures of the AOS have an active role in regulating IOP in healthy eyes and these structures become abnormal in the eyes with glaucoma. We describe a newly developed system platform to obtain high-resolution images of the AOS structures. By incorporating spectral domain optical coherence tomography (SD-OCT), the platform allows us to systematically control, image, and quantitate the responses of AOS tissue to pressure with a millisecond resolution of pulsed flow. We use SD-OCT to image radial limbal segments from the surface of the ...

      Read Full Article
    3. Shear wave elastography method combining phase-sensitive optical coherence tomography and coded acoustic radiation force

      Shear wave elastography method combining phase-sensitive optical coherence tomography and coded acoustic radiation force

      We combined phase-sensitive optical coherence tomography (PhS-OCT) and acoustic radiation force (ARF) to develop a shear wave elastography (SWE) method that could be used for ophthalmic applications. SWE measures tissue stiffness from the speed of shear waves propagating through tissue. Assessing the elastic properties of the cornea and the intraocular lens can, for example, help the management of refractive surgeries (myopia or presbyopia correction). OCT is a non-contact imaging method easily applicable in vivo that provides micron-scale resolution particularly suitable for characterizing ocular tissues. ARF is commonly used to remotely induce shear waves in tissue by emitting short (∼100 µs ...

      Read Full Article
    4. Shear wave elastography of ex vivo human corneas using phase-sensitive optical coherence tomography

      Shear wave elastography of ex vivo human corneas using phase-sensitive optical coherence tomography

      Assessing the biomechanical properties of the cornea can provide clinically valuable information in addition to structural images for better management of pathologies (e.g. glaucoma) or refractive surgeries. OCT provides a micron scale and high sensitivity that are ideal for ophthalmic applications. We propose a shear wave elastography (SWE) method for the cornea based on phase-sensitive optical coherence tomography (PhS-OCT). SWE consists in launching a propagating shear wave in tissues and retrieving tissue elasticity from the shear wave speed. We used a piezo-electric actuator in contact with the cornea to induce shear waves that were then tracked using a PhSOCT ...

      Read Full Article
    5. Simultaneous estimation of bidirectional particle flow and relative flux using MUSIC-OCT: phantom studies

      Simultaneous estimation of bidirectional particle flow and relative flux using MUSIC-OCT: phantom studies

      In an optical coherence tomography (OCT) scan from a living tissue, red blood cells (RBCs) are the major source of backscattering signal from moving particles within microcirculatory system. Measuring the concentration and velocity of RBC particles allows assessment of RBC flux and flow, respectively, to assess tissue perfusion and oxygen/nutrition exchange rates within micro-structures. In this paper, we propose utilizing spectral estimation techniques to simultaneously quantify bi-directional particle flow and relative flux by spectral estimation of the received OCT signal from moving particles within capillary tubes embedded in tissue mimicking phantoms. The proposed method can be directly utilized for ...

      Read Full Article
    6. Swept-Source OCT Angiography of Macular Telangiectasia Type 2

      Swept-Source OCT Angiography of Macular Telangiectasia Type 2

      BACKGROUND AND OBJECTIVE: To evaluate the central macular microvascular network in patients with macular telangiectasia type 2 (MacTel2) using optical coherence tomography (OCT)-based microangiography (OMAG). PATIENTS AND METHODS: Prospective, observational study of patients with MacTel2 evaluated using a swept-source OCT (SS-OCT) prototype. OMAG was performed using a 3 mm × 3 mm central foveal raster scan. The algorithm segmented the retina into three layers. Microvascular distribution was depicted as en face images, and qualitative information was compared to fluorescein angiography (FA) images. RESULTS: OMAG detected abnormal microvasculature in all MacTel2 eyes, predominantly in the middle retinal layers with neovascularization in ...

      Read Full Article
    7. Segmentation and quantification of blood vessels for OCT-based micro-angiograms using hybrid shape/intensity compounding

      Segmentation and quantification of blood vessels for OCT-based micro-angiograms using hybrid shape/intensity compounding

      Optical coherence tomography (OCT) based microangiography is capable of visualizing 3D functional blood vessel networks within microcirculatory tissue beds in vivo. To provide the quantitative information of vasculature from the microangiograms such as vessel diameter and morphology, it is necessary to develop efficient vessel segmentation algorithms. In this paper, we propose to develop a hybrid Hessian/intensity based method to segment and quantify shape and diameter of the blood vessels innervating capillary beds that are imaged by functional OCT in vivo. The proposed method utilizes multi-scale Hessian filters to segment tubular structures such as blood vessels, but compounded by the ...

      Read Full Article
    8. Volumetric cutaneous microangiography of human skin in vivo by VCSEL swept-source optical coherence tomography

      Volumetric cutaneous microangiography of human skin in vivo by VCSEL swept-source optical coherence tomography

      We demonstrate volumetric cutaneous microangiography of the human skin in vivo that utilises 1.3-μm high-speed sweptsource optical coherence tomography (SS-OCT). The swept source is based on a micro-electro-mechanical (MEMS)-tunable vertical cavity surface emission laser (VCSEL) that is advantageous in terms of long coherence length over 50 mm and 100 nm spectral bandwidth, which enables the visualisation of microstructures within a few mm from the skin surface. We show that the skin microvasculature can be delineated in 3D SS-OCT images using ultrahigh-sensitive optical microangiography (UHS-OMAG) with a correlation mapping mask, providing a contrast enhanced blood perfusion map with ...

      Read Full Article
    9. User-guided segmentation for volumetric retinal optical coherence tomography images

      User-guided segmentation for volumetric retinal optical coherence tomography images

      Despite the existence of automatic segmentation techniques, trained graders still rely on manual segmentation to provide retinal layers and features from clinical optical coherence tomography (OCT) images for accurate measurements. To bridge the gap between this time-consuming need of manual segmentation and currently available automatic segmentation techniques, this paper proposes a user-guided segmentation method to perform the segmentation of retinal layers and features in OCT images. With this method, by interactively navigating three-dimensional (3-D) OCT images, the user first manually defines user-defined (or sketched) lines at regions where the retinal layers appear very irregular for which the automatic segmentation method ...

      Read Full Article
    10. In vivo imaging of functional microvasculature within tissue beds of oral and nasal cavities by swept-source optical coherence tomography with a forward/side-viewing probe

      In vivo imaging of functional microvasculature within tissue beds of oral and nasal cavities by swept-source optical coherence tomography with a forward/side-viewing probe
      ...a forward/side-viewing probe Woo June Choi and Ruikang K. Wang »View Author Affiliations Woo June Choi and Ruikang K. Wang^* ^Department of Bioengineering, University of Washington, 3720 15th NE, Seattle, WA 98195, ...
      Read Full Article
    11. Method and apparatus for quantitative imaging of blood perfusion in living tissue

      Method and apparatus for quantitative imaging of blood perfusion in living tissue

      Embodiments provide methods and systems for quantitative imaging of blood perfusion in living tissue. A method provides for obtaining an optical microangiography (OMAG) image of a sample, wherein the image has an OMAG background sample; digitally reconstructing a homogeneous ideal static background tissue; replacing the OMAG background sample with the digitally reconstructed homogeneous ideal static background tissue; correlating two or more neighboring A-lines with the digitally reconstructed homogeneous ideal static background tissue; and measuring a phase difference between the two or more neighboring A-lines to quantify blood perfusion in the sample. Methods using digital reconstruction to reduce random phase noise ...

      Read Full Article
    12. Optical coherence tomography microangiography for monitoring the response of vascular perfusion to external pressure on human skin tissue

      Optical coherence tomography microangiography for monitoring the response of vascular perfusion to external pressure on human skin tissue
      ...vely assessing tissue microcirculation in the locally pressed tissue in vivo. Woo June Choi ; Hequn Wang and Ruikang K. Wang "Optical coherence tomography microangiography for monitoring the response of vascular perfus...
      Read Full Article
    13. Full anterior segment biometry with extended imaging range spectral domain optical coherence tomography at 1340 nm

      Full anterior segment biometry with extended imaging range spectral domain optical coherence tomography at 1340 nm

      We demonstrate an extended-imaging-range anterior-segment optical coherence tomography (eAS-OCT) system for the biometric assessment of full AS in human eye. This newly developed eAS-OCT operating at 1340-nm wavelength band is simultaneously capable of an imaging speed of 120 kHz A-line scan rate, an axial resolution of 7.2 μ m, and an extended imaging range of up to 16 mm in air. Imaging results from three healthy subjects and one subject with a narrow-angle demonstrate the instrument’s utility. With this system, it can provide anatomical dimensions of AS, including central corneal thickness, anterior chamber width, anterior chamber depth, crystalline lens ...

      Read Full Article
    14. 1-15 of 151 1 2 3 4 5 6 7 8 9 10 »
  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. About Ruikang K. Wang

    Ruikang K. Wang

    Ruikang K. Wang is a professor in the biomedical engineering department at Washington University. He interests include: High resolution functional optical imaging using coherence gating and confocal gating techniques as applied to healthcare, Optical biopsy and functional imaging in tissue engineering, Photoacoustic imaging, and Light propagation in biological tissue.