All Articles from Pilun Kim -Optical Coherence Tomography News

Articles from Pilun Kim

1-20 of 20
1. Dynamic compensation of path length difference in optical coherence tomography by an automatic temperature control system of optical fiber
  
  Explore IEEE Xplore May 5 2020
  
  Optical fiber is widely used in optical coherence tomography (OCT) to propagate light precisely with low attenuation and low dispersion. However, the total optical path length within the optical fiber varies in accordance with changes of the temperature. This leads changes in the total optical travel path of the interfering signals and results in shifting of OCT image position to an unintended depth pixel value. In this paper, we presented the temperature-based automatic path length compensating method in OCT to limit the external temperature effect and control the image position in micro-scale without manual movement of optical components. By utilizing ...
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  Mentions: Jeehyun Kim Kyungpook National University Naresh Kumar Ravichandran
2. An averaged intensity difference detection algorithm for identification of human gingival sulcus in optical coherence tomography images
  
  Explore IEEE Xplore Jun 4 2019
  
  In the past decade, there has been an increase in the development of sensitive, highresolution, non-invasive diagnostic methods for periodontic diseases. Optical coherence tomography (OCT) has attracted considerable attention in clinical settings. In this study, a reliable, robust algorithm for the detection of gingival sulcus in 2D OCT cross-sectional images is proposed. Previously, the measurement of gingival sulcus in OCT images has been performed by manual identification using two-dimensional (2D) cross-sectional images. The automated detection of gingival sulcus continuity in 2D OCT images may help medical practitioners to assess important features of gingival tissues. The Sobel and canny operators have ...
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  Mentions: Jeehyun Kim Kyungpook National University Naresh Kumar Ravichandran
3. Non-Invasive Morphological Characterization of Rice Leaf Bulliform and Aerenchyma Cellular Regions Using Low Coherence Interferometry
  
  Explore MDPI Open Access Journals Platform May 22 2019 NDE/NDT
  
  Non-invasive investigation of rice leaf specimens to characterize the morphological formation and particular structural information that is beneficial for agricultural perspective was demonstrated using a low coherence interferometric method called swept source optical coherence tomography (SS-OCT). The acquired results non-invasively revealed morphological properties of rice leaf, such as bulliform cells; aerenchyma, parenchyma, and collenchyma layer; and vascular bundle. Beside aforementioned morphologic characteristics, several leaf characteristics associated with cytological mechanisms of leaf rolling (leaf inclination) were examined for the pre-identification of inevitable necrosis and atrophy of leaf tissues by evaluating acute angle information, such as angular characteristics of the external bi-directional ...
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  Mentions: Jeehyun Kim Kyungpook National University Ruchire Eranga Wijesinghe
4. Non-ionized, High-resolution Measurement of Internal and Marginal Discrepancies of Dental Prosthesis Using Optical Coherence Tomography
  
  Explore IEEE Xplore Dec 25 2018 Dentistry
  
  An internal and marginal fit between prosthesis and abutment are important factors of the durability of dental prosthesis. In this study we have proposed the use of swept-source optical coherence tomography (SS-OCT) as a novel application for non-ionized and high-resolution measurements of internal and marginal discrepancies at anatomically critical four points, such as occlusal, angle, axial, and margin during prosthesis attachment. A tooth model was fabricated by 3D printing technique and the dental prosthesis was designed using dental CAD software. The cross-sectional images along with intensity peak profile analysis of the sample were acquired using OCT system for measurements of ...
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  Mentions: Kyungpook National University Ruchire Eranga Wijesinghe
5. Clinical Utility of Intraoperative Tympanomastoidectomy Assessment Using a Surgical Microscope Integrated with an Optical Coherence Tomography
  
  Explore Nature Publishing Group Nov 27 2018 Otolaryngology
  
  Significant technical and optical advances are required for intraoperative optical coherence tomography (OCT) to be utilized during otological surgeries. Integrating OCT with surgical microscopy makes it possible to evaluate soft tissue in real-time and at a high resolution. Herein, we describe an augmented-reality, intraoperative OCT/microscope system with an extended working distance of 280 mm, providing more space for surgical manipulation than conventional techniques. We initially performed ex vivo experiments to evaluate system performance. In addition, we validated the system by performing preliminary clinical assessments of tympanomastoidectomy outcomes in six patients with chronic otitis media. The system evaluated residual inflammation ...
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  Mentions: Superlum Ajou University Jeehyun Kim
6. Non-destructive identification of weld-boundary and porosity formation during laser transmission welding by using optical coherence tomography
  
  Explore IEEE Xplore Nov 21 2018 NDE/NDT
  
  Laser transmission welding offers significant benefits over conventional welding techniques enabling single-stage rapid plastic joining. The quality of laser transmission welded products are commonly assessed by measuring the weld penetration depth, hardened weld boundary, and inspecting the formation of porosity. However, existing methods of verification are inevitably accompanied by destruction of the specimen. Thus, non-destructive quality assessment methods for laser transmission welding have gained attention recently. Here, we demonstrated an extended industrial application of 860 nm wavelength based spectral domain optical coherence tomography for the non-destructive inspection of the aforementioned quality parameters of laser transmission welded industrial plastic materials, i ...
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  Mentions: Jeehyun Kim Kyungpook National University Ruchire Eranga Wijesinghe
7. Biophotonic approach for the characterization of initial bitter-rot progression on apple specimens using optical coherence tomography assessments
  
  Explore Nature Publishing Group Oct 31 2018 NDE/NDT , Other Non-Medical
  
  The tremendous advances achieved in the biophotonics technologies have intensified the necessity for non-invasive modalities that can characterize diverse biological materials with increased sensitivity and resolution. Optical coherence tomography (OCT) is one of the techniques that has been applied for biological applications in medicine and agriculture to identify structural properties. Herein, we report the successful incorporation of OCT for the identification of morphological changes that occur as a result of the bitter rot disease, through continuous detection of structural changes. Detailed inner morphological structural changes occurring in fruit specimens were precisely analyzed as a function of the disease incubation period ...
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  Mentions: Jeehyun Kim Kyungpook National University Naresh Kumar Ravichandran
8. Numerical-Sampling-Functionalized Real-Time Index Regulation for Direct k-Domain Calibration in Spectral Domain Optical Coherence Tomography
  
  Explore MDPI Open Access Journals Platform Sep 9 2018
  
  An index-regulation technique functionalized by numerical sampling for direct calibration of the non-linear wavenumber ( k )-domain to a linear domain in spectral domain optical coherence tomography (SD-OCT) is proposed. The objective of the developed method is to facilitate high-resolution identification of microstructures in biomedical imaging. Subjective optical alignments caused by nonlinear sampling of interferograms in the k -domain tend to hinder depth-dependent signal-to-noise ratios (SNR) and axial resolution in SD-OCT. Moreover, the optical-laser-dependent k -domain requires constant recalibrated in accordance with each laser transition, thereby necessitating either hardware or heavy software compensations. As the key feature of the proposed method ...
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  Mentions: Jeehyun Kim Changho Lee Kyungpook National University
9. Non-Destructive Classification of Diversely Stained Capsicum annuum Seed Specimens of Different Cultivars Using Near-Infrared Imaging Based Optical Intensity Detection
  
  Explore MDPI Open Access Journals Platform Aug 1 2018 NDE/NDT
  
  The non-destructive classification of plant materials using optical inspection techniques has been gaining much recent attention in the field of agriculture research. Among them, a near-infrared (NIR) imaging method called optical coherence tomography (OCT) has become a well-known agricultural inspection tool since the last decade. Here we investigated the non-destructive identification capability of OCT to classify diversely stained (with various staining agents) Capsicum annuum seed specimens of different cultivars. A swept source (SS-OCT) system with a spectral band of 1310 nm was used to image unstained control C. annuum seeds along with diversely stained Capsicum seeds, belonging to different cultivar ...
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  Mentions: Medical University of Vienna Jeehyun Kim Kyungpook National University
10. Multiple Wavelength Optical Coherence Tomography Assessments for Enhanced Ex Vivo Intra-Cochlear Microstructural Visualization
  
  Explore MDPI Open Access Journals Platform Jul 31 2018 Otolaryngology
  
  The precise identification of intra-cochlear microstructures is an essential otorhinolaryngological requirement to diagnose the progression of cochlea related diseases. Thus, we demonstrated an experimental procedure to investigate the most optimal wavelength range, which can enhance the visualization of ex vivo intra-cochlear microstructures using multiple wavelengths (i.e., 860 nm, 1060 nm, and 1300 nm) based optical coherence tomography (OCT) systems. The high-resolution tomograms, volumetric, and quantitative evaluations obtained from Basilar membrane, organ of Corti, and scala vestibule regions revealed complementary comparisons between the aforementioned three distinct wavelengths based OCT systems. Compared to 860 nm and 1300 nm wavelengths, 1060 nm ...
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  Mentions: Medical University of Vienna Ajou University Jeehyun Kim
11. Quality assessment of the optical thin films using line field spectral domain optical coherence tomography
  
  Explore ScienceDirect May 29 2018 NDE/NDT
  
  Cross-sectional and three-dimensional images show the effectiveness of the system. In this study, the industrial inspection of optical thin film on touch screen panels was demonstrated using line field spectral domain optical coherence tomography. The conventional Fourier domain optical coherence tomography system requires a single scanner for two-dimensional cross-sectional images and two scanners for volumetric images. Our developed line field spectral domain optical coherence tomography has the advantage of needing only a single scanner for volumetric images, while two-dimensional cross-sectional images are obtained by the parallel acquisition of an illuminated line on a sample using an area camera. Further, the ...
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  Mentions: Medical University of Vienna Jeehyun Kim Kyungpook National University
12. Application of wearable optical coherence tomography (OCT) and Loop-mediated isothermal amplification (LAMP) techniques for In situ real-time field inspection of apple Marssonina blotch disease
  
  Explore Conference Proceedings Apr 22 2017
  
  Here we describe the possible application of optical coherence tomography (OCT) to inspect Marssonina coronaria infected apple blotch disease of in situ apple leaves. To fulfill the in situ field inspection requirement, we developed a compact wearable OCT system. For the confirmation of OCT results, simultaneous experiment was performed in realtime using loop-mediated isothermal amplification (LAMP), which is frequently used in agriculture. LAMP method was developed as an alternative approach for the inspection of disease. We performed field inspection for 30 consecutive days, and all the acquired results from both OCT and lamp were compared to confirm the correlation. A ...
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  Mentions: Jeehyun Kim Kyungpook National University Naresh Kumar Ravichandran
13. In vivo 3D imaging of the human tympanic membrane using a wide-field diagonal-scanning optical coherence tomography probe
  
  Explore OSA | OSA Publishing Feb 27 2017 Otolaryngology , Probes
  
  A wide-field optical coherence tomography (OCT) probe was developed that adapts a diagonal-scanning scheme for three-dimensional (3D) in vivo imaging of the human tympanic membrane. The probe consists of a relay lens to enhance the lateral scanning range up to 7 mm. Motion artifacts that occur with the use of handheld probes were found to be decreased owing to the diagonal-scanning pattern, which crosses the center of the sample to facilitate entire 3D scans. 3D images could be constructed from a small number of two-dimensional OCT images acquired using the diagonal-scanning technique. To demonstrate the usefulness and performance of the ...
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  Mentions: Stephen A. Boppart Harvard University University of Illinois at Urbana-Champaign
14. Optical coherence tomography-integrated, wearable (backpack-type), compact diagnostic imaging modality for in situ leaf quality assessment
  
  Explore OSA | OSA Publishing Feb 17 2017 Other Non-Medical
  
  We developed a compact, wearable diagnostic imaging modality employing optical coherence tomography for in situ plant leaf quality assessments. This system is capable of diagnosing infected leaves at the initial disease stages. Our system is a versatile backpack-type imaging modality with a compact spectrometer, miniature computer, rechargeable power source, and handheld inspection probe. This method enhances real-time in situ specimen inspection through direct implementation of the imaging modality in a plantation. To evaluate the initial performance, field experiments were conducted in apple, pear, and persimmon plantations. Based on the obtained results, we can conclude that the developed imaging modality can ...
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  Mentions: Jeehyun Kim Kyungpook National University Naresh Kumar Ravichandran
15. Optical sensing method to analyze germination rate of Capsicum annum seeds treated with growth-promoting chemical compounds using optical coherence tomography
  
  Explore SPIE | Journal Jan 6 2017 NDE/NDT , Other Non-Medical
  
  Seed germination rate differs based on chemical treatments, and nondestructive measurements of germination rate have become an essential requirement in the field of agriculture. Seed scientists and other biologists are interested in optical sensing technologies-based biological discoveries due to nondestructive detection capability. Optical coherence tomography (OCT) has recently emerged as a powerful method for biological and plant material discoveries. We report an extended application of OCT by monitoring the germination rate acceleration of chemically primed seeds. To validate the versatility of the method, Capsicum annum seeds were primed using three chemical compounds: sterile distilled water (SDW), butandiol, and 1-hexadecene. Monitoring ...
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  Mentions: Jeehyun Kim Kyungpook National University Ruchire Eranga Wijesinghe
16. Dual-path handheld system for cornea and retina imaging using optical coherence tomography
  
  Explore Home - Springer Nov 19 2016 Ophthalmology , Probes
  
  A dual-path handheld system is proposed for cornea and retina imaging using spectral domain optical coherence tomography. The handheld sample arm is designed to acquire two images simultaneously. Both eyes of a person can be imaged at the same time to obtain the images of the cornea of one eye and the retina of the other eye. Cornea, retina, and optic disc images are acquired with the proposed sample arm. Experimental results demonstrate the usefulness of this system for imaging of different eye segments. This system reduces the time required for imaging of the two eyes and is cost effective.
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  Mentions: Jeehyun Kim Kyungpook National University Naresh Kumar Ravichandran
17. Full-Field Optical Coherence Tomography Using Galvo Filter-Based Wavelength Swept Laser
  
  Explore MDPI Open Access Journals Platform Nov 17 2016 Tunable Sources
  
  We report a wavelength swept laser-based full-field optical coherence tomography for measuring the surfaces and thicknesses of refractive and reflective samples. The system consists of a galvo filter–based wavelength swept laser and a simple Michelson interferometer. Combinations of the reflective and refractive samples are used to demonstrate the performance of the system. By synchronizing the camera with the source, the cross-sectional information of the samples can be seen after each sweep of the swept source. This system can be effective for the thickness measurement of optical thin films as well as for the depth investigation of samples in industrial ...
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  Mentions: Jeehyun Kim Kyungpook National University Mansik Jeon
18. Fast Industrial Inspection of Optical Thin Film Using Optical Coherence Tomography
  
  Explore MDPI Open Access Journals Platform Oct 1 2016 NDE/NDT , Other Non-Medical
  
  An application of spectral domain optical coherence tomography (SD-OCT) was demonstrated for a fast industrial inspection of an optical thin film panel. An optical thin film sample similar to a liquid crystal display (LCD) panel was examined. Two identical SD-OCT systems were utilized for parallel scanning of a complete sample in half time. Dual OCT inspection heads were utilized for transverse (fast) scanning, while a stable linear motorized translational stage was used for lateral (slow) scanning. The cross-sectional and volumetric images of an optical thin film sample were acquired to detect the defects in glass and other layers that are ...
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  Mentions: Jeehyun Kim Kyungpook National University Ruchire Eranga Wijesinghe
19. Quantitative monitoring of laser-treated engineered skin using optical coherence tomography
  
  Explore OSA | OSA Publishing Feb 27 2016 Dermatology
  
  Nowadays, laser therapy is a common method for treating various dermatological troubles such as acne and wrinkles because of its efficient and immediate skin enhancement. Although laser treatment has become a routine procedure in medical and cosmetic fields, the prevention of side-effects, such as hyperpigmentation, redness and burning, still remains a critical issue that needs to be addressed. In order to reduce the side-effects while attaining efficient therapeutic outcomes, it is essential to understand the light-skin interaction through evaluation of physiological changes before and after laser therapy. In this study, we introduce a quantitative tissue monitoring method based on optical ...
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  Mentions: University of Ulsan Jeehyun Kim Kyungpook National University
20. Optically deviated focusing method based high-speed SD-OCT for in vivo retinal clinical applications
  
  Explore Home - Springer Nov 29 2015 Ophthalmology
  
  The aim of this study is to provide accurately focused, high-resolution in vivo human retinal depth images using an optically deviated focusing method with spectral-domain optical coherence tomography (SD-OCT) system. The proposed method was applied to increase the retinal diagnosing speed of patients with various values of retinal distances (i.e., the distance between the crystalline eye lens and the retina). The increased diagnosing speed was facilitated through an optical modification in the OCT sample arm configuration. Moreover, the optical path length matching process was compensated using the proposed optically deviated focusing method. The developed system was mounted on a ...
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  Mentions: Korea University Jeehyun Kim Kyungpook National University
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