Browsing by Author "Seong, D"

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Embargo
Comparative quantifications and morphological monitoring of the topical treatment approach for onychomycosis-affected in vivo toenail using optical coherence tomography: A case study
(Elsevier Ltd, 2024-02) Saleah, S.S; Gu, Y; Wijesinghe, R.E; Seong, D; Cho, H; Jeon, M; Kim, J
Onychomycosis is one of the most common toenail fungal infections that affect the quality of life of many patients. Long-term and noninvasive monitoring of morphological changes of onychomycosis-affected nail plate aids the medication process and provides comfort for patients. However, existing medical and dermatological imaging methods have various types of limitations in nail investigation due to low resolution, lack of volumetric data, the necessity of highly trained personnel for image analysis, and the variety of protocols. In this study, qualitative monitoring-based quantitative assessments were performed to assess the morphological changes of onychomycosis-affected toenail for 15 consecutive weeks using high-resolution optical coherence tomography (OCT). Layer intensity and surface roughness measuring algorithms were applied to two-dimensional OCT cross-sectional images to detect gradual changes in the morphological structure of the diseased toenail. A depth intensity profile and the angle formed between the nail plate and nail fold were also used to analyze the thickness and shape of the toenail plates, respectively. The quantitative and morphological monitoring results revealed significant changes in the toenail structure before and during the treatment process, confirming the healing of the diseased toenail. Therefore, the proposed noninvasive optical analysis approach can be applied to monitor nail abnormalities and evaluate the process of diseased toenail medication
Embargo
Comparative quantifications and morphological monitoring of the topical treatment approach for onychomycosis-affected in vivo toenail using optical coherence tomography: A case study
(Elsevier, 2023-10-19) Saleah, S. A; Gu, Y; Wijesinghe, R.E; Seong, D; Cho, H; Jeon, M; Kim, J
Onychomycosis is one of the most common toenail fungal infections that affect the quality of life of many patients. Long-term and noninvasive monitoring of morphological changes of onychomycosis-affected nail plate aids the medication process and provides comfort for patients. However, existing medical and dermatological imaging methods have various types of limitations in nail investigation due to low resolution, lack of volumetric data, the necessity of highly trained personnel for image analysis, and the variety of protocols. In this study, qualitative monitoring-based quantitative assessments were performed to assess the morphological changes of onychomycosis-affected toenail for 15 consecutive weeks using high-resolution optical coherence tomography (OCT). Layer intensity and surface roughness measuring algorithms were applied to two-dimensional OCT cross-sectional images to detect gradual changes in the morphological structure of the diseased toenail. A depth intensity profile and the angle formed between the nail plate and nail fold were also used to analyze the thickness and shape of the toenail plates, respectively. The quantitative and morphological monitoring results revealed significant changes in the toenail structure before and during the treatment process, confirming the healing of the diseased toenail. Therefore, the proposed noninvasive optical analysis approach can be applied to monitor nail abnormalities and evaluate the process of diseased toenail medication.
Open Access
Label-free visualization of internal organs and assessment of anatomical differences among adult Anopheles, Aedes, and Culex mosquito specimens using bidirectional optical coherence tomography
(Elsevier, 2023-08-02) Luna, J.A; Ravichandran, N.K; Saleah, S. A; Wijesinghe, R.E; Seong, D; Choi, K.S; Jung, H.Y; Jeon, M; Kim, J
Mosquitoes transmit several fatal human diseases and constitute a global threat to the fight against infectious diseases. Thus, it is crucial to identify the diseases transmitted by mosquitoes, analyze their internal organs, investigate the life cycles of the viruses and pathogens they carry, and elucidate the anatomical changes they cause inside the host without dissecting them. Here we have demonstrated a method for label-free visualization of the internal organs of adult Anopheles, Aedes, and Culex mosquitoes using swept-source optical coherence tomography (SS-OCT). To overcome the limitation of depth-dependent signal-to-noise ratio (SNR) reduction, imaging was conducted using a dynamic rotational OCT scanner to acquire images of the top and bottom surfaces of the specimens. The internal structure and organ images of all the mosquito specimens had constant resolvability and higher SNR than in those obtained via conventional OCT. Furthermore, a depth profiling algorithm was developed to obtain quantitative information about the internal organs. Several internal organs, such as the salivary glands, heart, midgut, dorsal and ventral crop, and abdominal ganglia, were precisely identified and analyzed noninvasively using OCT. The average thicknesses of the heart, midgut, dorsal and ventral crop, and abdominal ganglia of Anopheles, Aedes, and Culex mosquitoes were 72.1, 107.3, 87.3, and 63.4 μm, respectively. This study demonstrates the applicability of OCT in entomology research for high-resolution microscopic analysis. The findings of this study can guide future studies requiring nondestructive assessment of internal organs to evaluate the morphological differences among various virus-transmitting mosquito specimens.
Embargo
Non-destructive morphological screening for the assessment of postharvest storage effect on pears stored with apples using optical coherence tomography
(Elsevier GmbH, 2024-04) Luna, J.A; Wijesinghe, R.E; Lee, S.Y; Ravichandran, N.K; Saleah, S.A; Seong, D; Jung, H.Y; Jeon, M; Kim, J
The use of a limited and inadequate storage facility for the storage of multiple food items for an extended period of time results in the loss of structural integrity and freshness while storing fruit in confined single storage without adequate individual packaging methods can result in morphological changes and the degradation of the quality of the fruit. In this study, the effects of postharvest storage on pears co-stored with apples were investigated via non-invasive screening of the structural deformation of pears and the respective anatomical changes of the sub-surface. The anatomical changes were monitored for a prolonged time (12 d) under inadequate and confined storage conditions using swept-source optical coherence tomography (SS-OCT) and the results were comparatively analyzed using appropriately stored specimens. In addition, the OCT cross-sectional images were analyzed for the assessment of the dispersed intensity profile using a customized intensity-based image-processing algorithm. The results revealed the internal morphological variations and corresponding intensity fluctuations, thickness variations, and internal gap formations. This confirmed the potential applicability of OCT as a real-time, non-invasive high-resolution assessment technique for determining fruit quality in diverse environments, such as post-harvest storage and transportation systems.
Open Access
Single board computer and adapted 3D-printed case-based low cost and compact optical coherence tomography
(SPIE, 2025) Seong, D; Han, S; Kim, Y; Hong, J; Wijhesinghe, R. E; Jeon, M; Kim, J
Optical coherence tomography (OCT) is a non-invasive, label-free imaging method based on high-resolution interferometric optics that allows real-time visualization of morphological structures and depth-resolved images. The high cost of most commercially available OCT systems limits their widespread use, especially in resource-poor settings. Miniaturization of OCT devices therefore reduces not only size but also cost and has the potential to open new markets for this technology. In this study, we developed a small, portable 3D printed OCT system (SBC-OCT) based on a single-board computer. To reduce the cost to configure the system, the whole case of SBC-OCT is made with 3D-printed architecture. Using an area camera to avoid thermally induced alignment distortions in the spectrometer during system operation, the spectrometer is temperature insensitive, requires no hardware changes or additional components, and requires minimal computational effort. An applied automatic signal correction method was developed. The smaller size, lighter weight, and lower cost of SBC-OCT highlight its significant relevance in medical, industrial, and security applications, showcasing its potential for broad adoption.
Open Access
Three-Dimensional Assessment of Dental Enamel Microcrack Progression After Orthodontic Bracket Debonding Using Optical Coherence Tomography
(Multidisciplinary Digital Publishing Institute (MDPI), 2025-01) Saleah, S.A; Hamdan, A.H; Seong, D; Ravichandran, N. K; Wijesinghe, R.E; Han, S; Kim, J; Jeon, M; Park, H. S
The current study aimed to quantify the length progression of enamel microcracks (EMCs) after debonding metal and ceramic brackets, implementing OCT as a diagnostic tool. The secondary objectives included a three-dimensional assessment of EMC width and depth and the formation of new EMCs. OCT imaging was performed on 16 extracted human premolars before bonding and after debonding. Debonding was conducted with a universal Instron machine, with ARI values recorded. Additionally, 2D and 3D OCT images were employed to detect EMC formation and progression. Enface images quantified the length, width, and number of EMCs, and the length and width were analyzed using Image J (1.54f) and MATLAB (R2014b), respectively. Sagittal cross-sectional images were used for EMC depth analysis. A paired t-test showed significant differences in the length, width, and number of EMCs after debonding (p-value < 0.05), while the Wilcoxon non-parametric test indicated significant EMC depth changes (p-value < 0.05). No significant results were identified for the EMC number in ceramic brackets and EMC depth in metal brackets. Three-dimensional OCT imaging monitored existing EMCs at higher risk of progression and detected new EMCs following orthodontic bracket debonding. This study provides novel insights into EMC progression regarding the length, width, depth, and number after debonding.