Browsing by Author "Wang, Chun-Yang"

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Dental Calculus Image Based on Optical Coherence Tomography
(2011)
Hsieh, Yao-Sheng
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Ho, Yi-Ching
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Lee, Shyh-Yuan
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Chuang, Ching-Cheng
;
Wang, Chun-Yang
In this study, the dental calculus was characterized and imaged by means of swept-source optical coherence tomography (SSOCT). The refractive indices of enamel, dentin, cementum and calculus were measured as 1.625+/-0.024, 1.534+/-0.029, 1.570+/-0.021 and 1.896+/-0.085, respectively. The dental calculus lead strong scattering property and thus the region can be identified under enamel with SSOCT imaging. An extracted human tooth with calculus was covered by gingiva tissue as in vitro sample for SSOCT imaging.
Diffuse Optical Multipatch Technique for Tissue Oxygenation Monitoring: Clinical Study in Intensive Care Unit
(2012-01-01)
Wang, Chun-Yang
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Chuang, Ming-Lung
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Liang, Shinn-Jye
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Tsai, Jui-che
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Chuang, Ching-Cheng
Diffuse optical multipatch technique is used to assess spatial variations in absorption and scattering in biological tissue, by monitoring changes in the concentration of oxyhemoglobin and deoxyhemoglobin. In our preliminary study, the temporal tracings of tissue oxygenation are measured using diffuse optical multipatch measurement and a venous occlusion test, employing normal subjects and ICU patients suffering from sepsis and heart failure. In experiments, obvious differences in tissue oxygenation signals were observed among all three groups. This paper discusses the physiological relevance of tissue oxygenation with respect to disease.
Hemodynamic analysis of patients in intensive care unit based on diffuse optical spectroscopic imaging system
(2010)
Hsieh, Yao-Sheng
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Wang, Chun-Yang
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Ling, Yo-Wei
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Chuang, Ming-Lung
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Chuang, Ching-Cheng
Diffuse optical spectroscopic imaging (DOSI) is a technique to assess the spatial variation in absorption and scattering properties of the biological tissues and provides the monitoring of changes in concentrations of oxy-hemoglobin and deoxy-hemoglobin. In our preliminary study, the temporal tracings of hemodynamic oxygenation are measured with DOSI and venous occlusion test (VOT) from normal subjects, patients with heart failure and patients with sepsis in intensive care unit (ICU). In experiments, the obvious differences of hemodynamic signals can be observed among the three groups. The physiological relevance of VOT hemodynamics with respect to diseases is also discussed in this paper.
Near-Infrared Brain Volumetric Imaging Method: A Monte Carlo Study
(2012-05-01)
Chuang, Ching-Cheng
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Wang, Pei-Ning
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Chen, Wei-Ta
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Lan, Tsuo-Hung
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Chen, Chung-Ming
"The symptom of brain volumetric changes may provide significant biomarker to predict progressive dementia. The brain volumetric changes of prefrontal cortex are highly associated with many neurodegenerative diseases. Besides, brain atrophy reveals the expanded interhemispheric fissure and the concomitant increasing cerebrospinal fluid volume. Thus, the quantitative assessment of brain volumetric changes is an important consideration for clinical studies of neurodegenerative diseases. In this study, we first proposed an approach that uses near-infrared brain volumetric imaging to detect brain volumetric changes. The healthy, aged, and typical Alzheimer's disease (AD) brains were modeled with different characterization of brain volumetric changes from in vivo MRI data based on time-resolved 3-D Monte Carlo simulation. In the results, the significant difference of prefrontal cortex structure can be observed among healthy, aged, and AD brain with various source-detector separations in sagittal view. Our study shows that the near-infrared brain volumetric imaging can be an indicator of brain atrophy for clinical application of neurodegenerative diseases with patient-oriented measurement."
Subgingival calculus imaging based on swept-source optical coherence tomography
(2011-07-01)
Hsieh, Yao-Sheng
;
Ho, Yi-Ching
;
Lee, Shyh-Yuan
;
Lu, Chih-Wei
;
Jiang, Cho-Pei
We characterized and imaged dental calculus using swept-source optical coherence tomography (SS-OCT). The refractive indices of enamel, dentin, cementum, and calculus were measured as 1.625 +/- 0.024, 1.534 +/- 0.029, 1.570 +/- 0.021, and 2.097 +/- 0.094, respectively. Dental calculus leads strong scattering properties, and thus, the region can be identified from enamel with SS-OCT imaging. An extracted human tooth with calculus is covered with gingiva tissue as an in vitro sample for tomographic imaging. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3602851]
The utility of far-infrared illumination in oxygenation dynamics as measured with near-infrared spectroscopy
(2012-10-01)
Wang, Chun-Yang
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Chuang, Ming-Lung
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Chuang, Ching-Cheng
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Hsieh, Yao-Sheng
;
Sun, Chia-Wei
Near-infrared spectroscopy (NIRS) is a noninvasive method for measuring the oxygenation in muscle and other tissues in vivo. For quantitative NIRS measurement of oxygenation dynamics, the vessel-occlusion test was usually applied as physiological intervention. There are several drawbacks of the vessel-occlusion method that include skin contact, uncomfortable and microcirculation block of patients. Thus, we propose the far-infrared (FIR) illumination as a new physiological intervention method in this paper. Our preliminary result shows a linear correlation of oxygenation dynamic signals between FIR illumination and arterial-occlusion test (AOT) that implies the FIR illumination could be applied for hemodynamic response measurement in clinical diagnosis. ((c) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)