All Articles from Chia-Wei Sun -Optical Coherence Tomography News

Articles from Chia-Wei Sun

1-11 of 11
1. Differentiation of primary central nervous system lymphoma from glioblastoma using optical coherence tomography based on attention ResNet
  
  Explore SPIE Digital Library Apr 5 2022 Neurology
  
  Significance: Differentiation of primary central nervous system lymphoma from glioblastoma is clinically crucial to minimize the risk of treatments, but current imaging modalities often misclassify glioblastoma and lymphoma. Therefore, there is a need for methods to achieve high differentiation power intraoperatively. Aim: The aim is to develop and corroborate a method of classifying normal brain tissue, glioblastoma, and lymphoma using optical coherence tomography with deep learning algorithm in an ex vivo experimental design. Approach: We collected tumor specimens from ordinal surgical operations and measured them with optical coherence tomography. An attention ResNet deep learning model was utilized to differentiate glioblastoma ...
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2. Signal properties of split-spectrum amplitude decorrelation angiography for quantitative optical coherence tomography-based velocimetry
  
  Explore OSA | OSA Publishing Sep 13 2021
  
  Split-spectrum amplitude-decorrelation angiography (SSADA) is a noninvasive and three-dimensional angiographic technique with a microscale spatial resolution based on optical coherence tomography. The SSADA signal is known to be correlated with the blood flow velocity and the quantitative velocimetry with SSADA has been expected; however, the signal properties of SSADA are not completely understood due to lack of comprehensive investigations of parameters related to SSADA signals. In this study, phantom experiments were performed to comprehensively investigate the relation of SSADA signals with flow velocities, time separations, particle concentrations, signal-to-noise ratios, beam spot sizes, and viscosities, and revealed that SSADA signals reflect ...
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3. Disease activation maps for subgingival dental calculus identification based on intelligent dental optical coherence tomography
  
  Explore Wiley Online Library May 15 2021 Dentistry
  
  During the treatment of periodontitis, removal of dental calculus is essential but still tricky despite developments of several imaging modalities. In this research, we propose a novel approach to provide an intuitive guidance, to automatically detect the present of subgingival calculus, and to identify the site of the lesion in optical coherence tomography images based on convolutional neural network model and the class activation maps technique. Our result shows good visualizations of dental calculus both in B‐scan and in volumetric view. We believe the improvement can break down the technical barrier and finally facilitate the prevalence of dental optical ...
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4. Polarization-Sensitive Optical Coherence Tomography for Brain Tumor Characterization
  
  Explore IEEE Xplore Jan 2 2019 Neurology
  
  Complete removal of brain tumor is of the most interest to a surgeon because the resection area directly relates to recurrence rate. Although there are many biomedical imaging modalities applied to locate the positions of tumors, they lack the spatial resolution to precisely delineate the boundary between brain tumor and normal brain tissues and are also inconvenient to be used intraoperatively. This study aims to examine the feasibility of the label-free, polarization-sensitive optical coherence tomography (PS-OCT) for distinguishing brain tumors from normal brain tissues. Ex vivo samples were obtained from two patients with grade II and II-III glioma; healthy porcine ...
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5. Review: Optical Scanning Probe for Optical Coherence Tomography
  
  Explore jmbe.org.tw May 25 2018 Probes
  
  Optical coherence tomography (OCT) has become an important medical imaging modality. However, low penetration depth limits its application. Therefore, the optical scanning probe plays an important role in OCT systems for clinical applications. This article reviews OCT methodology and the mechanisms of an optical scanning probe. Recent developments of OCT probe and related clinical applications are summerized. Various OCT probe techniques (e.g., side imaging and forward imaging) have been used for measuring optical biopsy of various tissues. OCT probes for early diagnosis applications should be developed and combined with functional OCT modalities, such as Doppler OCT and polarization-sensitive OCT ...
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  Mentions: National Yang-Ming University
6. Systematic Optimization for Optical Coherence Tomographic Imaging
  
  Explore Home Sep 2 2017
  
  Optical coherence tomography is a powerful tool that can effectively provide detail information of biological tissue structure. The axis resolution of optical coherence tomography has achieved sub-micrometer and we are interested in its ultrahigh resolution that can be practically utilized for clinical application. In this article, the basic system calibration is discussed; we systematically demonstrated the detail process in optimization of optical coherence tomography for accurately acquiring data. The systematic optimization for optical coherence tomography imaging is discussed here including system calibration and image post-processing.
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7. Sensing of Tooth Microleakage Based on Dental Optical Coherence Tomography
  
  Explore Hindawi Publishing Corporation Feb 22 2015 Dentistry
  
  This study describes microleakage sensing based on swept-source optical coherence tomography (SS-OCT). With a handheld scanning probe, the SS-OCT system can provide portable real-time imaging for clinical diagnosis. Radiography is the traditional clinical imaging instrument used for dentistry; however, it does not provide good contrast images between filling material and the enamel of treated teeth with microleakage. The results of this study show that microleakage can be detected with oral probing using SS-OCT in vivo . The calculated microleakage length was 401 μ m and the width is 148 μ m, which is consistent with the related histological biopsy measurements. The diagnosis of ...
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8. Review: Optical Scanning Probe for Optical Coherence Tomography
  
  Explore jmbe.bme.ncku.edu.tw May 6 2014
  
  Optical coherence tomography (OCT) has become an important medical imaging modality. However, low penetration depth limits its application. Therefore, the optical scanning probe plays an important role in OCT systems for clinical applications. This article reviews OCT methodology and the mechanisms of an optical scanning probe. Recent developments of OCT probe and related clinical applications are summerized. Various OCT probe techniques (e.g., side imaging and forward imaging) have been used for measuring optical biopsy of various tissues. OCT probes for early diagnosis applications should be developed and combined with functional OCT modalities, such as Doppler OCT and polarization-sensitive OCT ...
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9. Dental Optical Coherence Tomography
  
  Explore MDPI Open Access Journals Platform Jul 12 2013 Dentistry
  
  This review paper describes the applications of dental optical coherence tomography (OCT) in oral tissue images, caries, periodontal disease and oral cancer. The background of OCT, including basic theory, system setup, light sources, spatial resolution and system limitations, is provided. The comparisons between OCT and other clinical oral diagnostic methods are also discussed.
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  Mentions: National Taiwan University National Yang-Ming University
10. Optical scanning probe
  
  Explore uspto.gov Apr 5 2011 Patents , Probes
  
  An optical scanning probe is provided and includes a housing, a diaphragm disposed in the housing, a rotor, a conduit, an optical fiber module, and a reflector disposed on the rotor, wherein the diaphragm and the housing forms a chamber. The rotor is movably disposed in the chamber and has several fans. The conduit is disposed in the housing to conduct fluid into the chamber, thus impelling the fans and the rotor. The optical fiber module is disposed in the housing and through the diaphragm to transmit a light beam. The reflector rotates with the rotor and reflects the light ...
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11. Tissue birefringence of hypercholesterolemic rat liver measured with polarization-sensitive optical coherence tomography
  
  Explore SPIE Digital Library Nov 16 2007
  
  We measure in vitro tissue birefringence in the liver of hypercholesterolemic rats with polarization-sensitive optical coherence tomography. Tissue birefringence is determined by measuring the phase retardation as a function of tissue depth. The birefringence of such a sample is usually due to the narrow fibrous structures that cannot be resolved by a standard optical coherence tomography system. Anisotropic structures are formed in the hypercholesterolemic rat liver, which is quite different from the isotropic nature of healthy liver. Birefringence is evaluated to give an order of magnitude of 4.48×10−4 at 790nmin hypercholesterolemic rat liver. The infiltration ...
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  Mentions: National Taiwan University Chang Gung University
1-11 of 11