1. Articles from zhijia yuan

    1-15 of 15
    1. Optical imaging apparatus, optical imaging method, apparatus for setting characteristics of a light source, and method for setting characteristics of a light source

      Optical imaging apparatus, optical imaging method, apparatus for setting characteristics of a light source, and method for setting characteristics of a light source

      An embodiment provides a method for setting the characteristics of the light to be output from a light source unit for optical coherence tomography, using a computer. This method is performed by using relation information in which a representative wavelength, a wavelength range including said representative wavelength, and the light loss amount due to absorption by a medium are related to each other. This method includes the following steps: setting each value of a first parameter and a second parameter among the representative wavelength, the wavelength range, and the light loss amount; acquiring a value of a third parameter among ...

      Read Full Article
    2. Detection Of Missampled Interferograms In Frequency Domain OCT With A K-CLOCK

      Detection Of Missampled Interferograms In Frequency Domain OCT With A K-CLOCK

      Optical coherence tomography light sources can be non-linear and attempts to linearize them can lead to asynchrony between the light source and A-line scans and missampling in the scans causing signal noise. Accordingly, a system and methods are provided herein to detect missampling by obtaining a plurality of interferograms; providing at least two wavenumber reference signals at different wavenumbers, wherein the wavenumber reference signals comprise attenuated or enhanced portions of each of the plurality of interferograms; aligning each of the plurality of interferograms according to one of the at least two wavenumber reference signals; and for each of the plurality ...

      Read Full Article
    3. Optical imaging method and optical imaging apparatus using optical coherence tomography

      Optical imaging method and optical imaging apparatus using optical coherence tomography

      An optical imaging method in an embodiment includes: a scanning step to scan each of a plurality of A-lines of an object with a signal light while alternately changing the phase difference between the signal light and a reference light to two preset phase differences; a detection step to detect the interference light of the signal light passing through the A-line and the reference light; and an imaging step to generate a complex interference spectrum based on the detection results of the interference lights corresponding to the plurality of A-lines sequentially obtained in the detection step according to the scanning ...

      Read Full Article
    4. Optical imaging method and optical imaging apparatus

      Optical imaging method and optical imaging apparatus

      An optical imaging method is provided that can realize, at low cost, the extension of the imaging depth range. An optical imaging apparatus 400 is an apparatus that forms a tomographic image of an object using FD-OCT, and performs a scanning step, detection step and imaging step. In the scanning step, the object is scanned with a signal light while alternately changing the phase difference between the signal light and a reference light to two preset phase differences. In the detection step, interference light of the signal light passing through the object and the reference light is detected. In the ...

      Read Full Article
    5. Characterization of dynamic physiology of the bladder by optical coherence tomography

      Characterization of dynamic physiology of the bladder by optical coherence tomography

      Because of its high spatial resolution and noninvasive imaging capabilities, optical coherence tomography has been used to characterize the morphological details of various biological tissues including urinary bladder and to diagnose their alternations (e.g., cancers). In addition to static morphology, the dynamic features of tissue morphology can provide important information that can be used to diagnose the physiological and functional characteristics of biological tissues. Here, we present the imaging studies based on optical coherence tomography to characterize motion related physiology and functions of rat bladder detrusor muscles and compared the results with traditional biomechanical measurements. Our results suggest that ...

      Read Full Article
    6. Enhancing Detection of Bladder Carcinoma In Situ by 3-Dimensional Optical Coherence Tomography

      Enhancing Detection of Bladder Carcinoma In Situ by 3-Dimensional Optical Coherence Tomography
      Purpose: We examined the usefulness of 3-dimensional optical coherence tomography to enhance the diagnosis of urothelial carcinoma in situ.Materials and Methods: By expressing SV40T antigen with uroplakin II promoter, carcinoma in situ readily develops in SV40T transgenic mice at about ages 8 to 20 weeks and then frank high grade papillary carcinoma develops in bladder epithelium. We examined 10 control and 40 SV40T mice during weeks 8 to 20 after birth by parallel en face white light imaging and 3-dimensional optical coherence tomography, and compared results with histology findings. We applied quantitative analysis of computer aided detection to 3-dimensional ...
      Read Full Article
    7. On the possibility of time-lapse ultrahigh-resolution optical coherence tomography for bladder cancer grading

      has been recently demonstrated that the cellular details of bladder epithelium embedded in speckle noise can be uncovered with time-lapse ultrahigh-resolution optical coherence tomography (TL-uOCT) by proper time-lapse frame averaging that takes advantage of cellular micromotion in fresh biological tissue ex vivo. Here, spectral-domain 3-D TL-uOCT is reported to further improve the image fidelity, and new experimental evidence is presented to differentiate normal and cancerous nuclei of rodent bladder epithelia. Results of animal cancer study reveal that despite a slight overestimation (e.g., <10%) of nuclear size (DN) to histological evaluation, TL-uOCT is capable of distinguishing normal (DN7 µm) and ...
      Read Full Article
    8. Diagnosis of Bladder Cancer With Microelectromechanical Systems-based Cystoscopic Optical Coherence Tomography

      Objectives To examine the utility and potential limitations of microelectromechanical systems-based spectral-domain cystoscopic optical coherence tomography (COCT) so as to improve the diagnosis of early bladder cancer. Methods An optical coherence tomography catheter was integrated into the single instrument channel of a 22F cystoscope to permit white-light-guided COCT over a large field of view (4.6 mm wide and 2.1 mm deep per scan at 8 frames/s) and 10-μm resolution. Intraoperative COCT diagnosis was performed in 56 patients, with a total of 110 lesions examined and compared with biopsied histology. Results The overall sensitivity of COCT (94%) was ...
      Read Full Article
    9. Noninvasive and High-resolution Optical Monitoring of Healing of Diabetic Dermal Excisional Wounds Implanted with Biodegradable in situ Gelable Hydrogels

      Closure of diabetic dermal chronic wounds remains a clinical challenge. Implant-assisted healing is emerging as a potential class of therapy for dermal wound closure; this advancement has not been paralleled by the development in complementary diagnostic techniques to objectively monitor the wound healing process in conjunction with assessing/monitoring of implant efficacy. Biopsies provide the most objective morphological assessments of wound healing; however, they not only perpetuate the wound presence but also increase the risk of infection. A non-invasive and high-resolution imaging technique is highly desirable to provide objective longitudinal diagnosis of implant-assisted wound healing. We investigated the feasibility of ...
      Read Full Article
    10. A digital frequency ramping method for enhancing doppler flow imaging in Fourier-domain optical coherence tomography

      A digital frequency ramping method for enhancing doppler flow imaging in Fourier-domain optical coherence tomography
      A digital frequency ramping method (DFRM) is proposed to improve the signal-to-noise ratio (SNR) of Doppler flow imaging in Fourier -domain optical coherence tomography (FDOCT). To examine the efficacy of DFRM for enhancing flow detection, computer simulation and tissue phantom study were conducted for phase noise reduction and flow quantification. In addition, the utility of this technique was validated in our in vivo clinical bladder imaging with endoscopic FDOCT. The Doppler flow images reconstructed by DFRM were compared with the counterparts by traditional Doppler FDOCT. The results demonstrate that DFRM enables real-time Doppler FDOCT imaging at significantly enhanced sensitivity without ...
      Read Full Article
    11. Quantification of cocaine-induced cortical blood flow changes using laser speckle contrast imaging and Doppler optical coherence tomography

      Quantification of cocaine-induced cortical blood flow changes using laser speckle contrast imaging and Doppler optical coherence tomography

      We present a dual-imaging technique combining laser speckle contrast imaging and spectral-domain Doppler optical coherence tomography to enable quantitative characterization of local cerebral blood flow (CBF) changes in rat cortex in response to drug stimulus (e.g., cocaine) at high spatiotemporal resolutions. To examine the utility of this new technique, animal experiments were performed to study the influences of anesthetic regimes (e.g., isoflurane, α-chloralose) on the pharmadynamic effects of acute cocaine challenge. The results showed that cocaine-evoked CBF patterns (e.g., increases in α-chloralose and decreases in isoflurane regimes) were quantitatively characterized, thus rendering it a potentially useful tool ...

      Read Full Article
    12. Enhancing Doppler Flow Imaging in Fourier-domain Optical Coherence Tomography

      Enhancing Doppler Flow Imaging in Fourier-domain Optical Coherence Tomography

      A digital frequency ramping method (DFRM) is proposed to improve the signal-to-noise ratio (SNR) of Doppler flow imaging in Fourier-domain optical coherence tomography (FDOCT). To examine the efficacy of DFRM for enhancing flow detection, computer simulation and tissue phantom study were conducted ... [Opt. Express 17, 3951-3963 (2009)]

      Read Full Article
    13. High-resolution imaging diagnosis and staging of bladder cancer: comparison between optical coherence tomography and high-frequency ultrasound

      Zhijia Yuan, Zhenguo Wang, Rubin Pan et al. A comparative study between 1.3-[mu]m optical coherence tomography (OCT) and 40-MHz high-frequency ultrasound (HFUS) is presented to enhance imaging of bladder cancers ex vivo. A standard rat bladder cancer model in which transitional cell carcinoma (TCC) was induced by intravesical instillation of ... [J. Biomed. Opt. 13, 054007 (2008)] published Fri Sep 12, 2008.
      Read Full Article
    14. Optical coherence Doppler tomography quantifies laser speckle contrast imaging for blood flow imaging in the rat cerebral cortex

      Optical coherence Doppler tomography quantifies laser speckle contrast imaging for blood flow imaging in the rat cerebral cortex

      A dual-imaging modality is demonstrated for high-resolution quantitative imaging of local cerebral blood flow in the rat cortex by combining simultaneous spectral-domain Doppler optical coherence tomography (SDOCT) and full-field laser speckle contrast imaging (LSCI). Preliminary studies in tissue flow phantom and cocaine-induced cerebral blood flow changes indicated that by correlating coregistered cortical arterial blood flow, the relative measurement of flow changes by LSCI could be accurately calibrated by the absolute flow imaging provided by SDOCT (least square fit, r2≈0.96). Quantitative LSCI of cerebral blood flow is crucial to the quantitative analyses of the spatiotemporal hemodynamics of functional brain ...

      Read Full Article
    15. Assessment of Dermal Wound Repair after Collagen Implantation with Optical Coherence Tomography

      We present an animal study to examine the utility and potential limitations of optical coherence tomography (OCT) for noninvasive evaluation of biomaterial scaffold–assisted wound healing. The transverse and axial resolutions of the OCT system at the wavelength of 1.3 μm were 12 and 10 μm, respectively. A murine full-thickness transcutaneous wound model was employed, in which a 10 mm full-thickness wound was created on the back of each male Balb/cJ mouse and a porous collagen scaffold was implanted in the wound bed followed by coverage with a TegadermTM film. Sequential cross-sectional OCT scans were performed at different ...
      Read Full Article
    1-15 of 15
  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. (10 articles) SUNY at Stony Brook
    2. (10 articles) Yingtian Pan
    3. (4 articles) Congwu Du
    4. (4 articles) Topcon Medical Systems
  3. Popular Articles

  4. Picture Gallery

    Optical coherence Doppler tomography quantifies laser speckle contrast imaging for blood flow imaging in the rat cerebral cortex Enhancing Doppler Flow Imaging in Fourier-domain Optical Coherence Tomography Quantification of cocaine-induced cortical blood flow changes using laser speckle contrast imaging and Doppler optical coherence tomography A digital frequency ramping method for enhancing doppler flow imaging in Fourier-domain optical coherence tomography Enhancing Detection of Bladder Carcinoma In Situ by 3-Dimensional Optical Coherence Tomography Optical coherence tomography in an eyelid lesion due to Molluscum contagiosum Lung adenocarcinoma choroidal metastasis studied by optical coherence tomography angiography Early detection of enamel demineralization by optical coherence tomography Deep spectral learning for label-free optical imaging oximetry with uncertainty quantification AS-OCT Guided Treatment Of Diffuse Conjunctival Squamous Cell Carcinoma With Resection ... The Eyes Behind Surgical Robots Ophthalmology/Functional Imaging: OCT + AO for functional imaging