Browsing by Author "Lee, Chia-Yen"

Now showing 1 - 10 of 10

A feasibility study on non-invasive oxidative metabolism detection and acoustic assessment of human vocal cords by using optical technique
(2017-12-05)
Lin, Tzu-Chieh
;
Chen, Jung-Chih
;
Liu, Chih-Hsien
;
Lee, Chia-Yen
;
Tsou, Yung-An
Voice disorder such as vocal fatigue is a common and complex multifaceted clinical problem that presents a significant impact on quality of life. In this study, the functional near-infrared diffuse optical technique (fNIRS-DOT) was proposed as a novel approach for human vocal cords oxidative metabolism detection and acoustic assessment simultaneously to provide a multidimensional assessment of voice disorder. A totally of 60 healthy subjects included 30 male and 30 female adults of age-matched were recruited and performed a vocal loading task to trigger a mild inflammation of the vocal cords in this study. In the results of oxidative metabolism, the vocal cords expressed hypoxia after vocal loading task in both male and female groups that could provide relevant information on the relationship between tissue oxygen consumption and supply for vocal cords diagnosis. Additionally, the results of optical acoustic assessment revealed the worse/changes voice quality after vocal loading task. Therefore, integration of non-invasive oxidative metabolism detection and acoustic assessment by using optical technique could provide more relevant information for diagnosis of voice disorders. The multi-functional vocal cords detection system could provide a good feasibility for clinical applications such as diagnosis and therapeutic monitoring of voice disorder.
A Modified Harris Corner Detection for Breast IR Image
(2014)
Lee, Chia-Yen
;
Wang, Hao-Jen
;
Chen, Chung-Ming
;
Chuang, Ching-Cheng
;
Chang, Yeun-Chung
Harris corner detectors, which depend on strong invariance and a local autocorrelation function, display poor detection performance for infrared (IR) images with low contrast and nonobvious edges. In addition, feature points detected by Harris corner detectors are clustered due to the numerous nonlocal maxima. This paper proposes a modified Harris corner detector that includes two unique steps for processing IR images in order to overcome the aforementioned problems. Image contrast enhancement based on a generalized form of histogram equalization (HE) combined with adjusting the intensity resolution causes false contours on IR images to acquire obvious edges. Adaptive nonmaximal suppression based on eliminating neighboring pixels avoids the clustered features. Preliminary results show that the proposed method can solve the clustering problem and successfully identify the representative feature points of IR breast images.
Automated Segmentation of Dental Calculus in Optical Coherence Tomography Images
(2018-01-01)
Lee, Chia-Yen
;
Chuang, Ching-Cheng
;
Chen, Guan-Jie
;
Huang, Chih-Chia
;
Lee, Shyh-Yuan
The presence of dental calculus is highly correlated with the formation and advancement of periodontal disease. The occurrence and relapse of periodontal disease can be prevented only if dental calculus is completely removed. In this study, optical coherence tomography (OCT) is used to obtain two-dimensional cross-sectional images of tooth samples, in conjunction with a segmentation technique that enables automatic identification of dental calculus. We propose the vertical intensity transform function to correct the nonuniform instrument signal intensity caused by OCT. Afterwards, the detection ranges are defined by K-means or the Markov random field (MRF), and the candidate range is selected on the basis of mathematical morphology (MM). Finally, the features (thickness gradient, texture, and tooth surface slope) are quantified, and dental calculus is recognized and segmented. In the preliminary result, the sensitivity is 87.5%. The mean distance between the boundaries generated by the proposed algorithm and the corresponding manually delineated boundaries is 2.52 +/- 3.54 pixels. Our proposed algorithm assists physicians to determine dental calculus more easily. Doctors no longer need to rely solely on their experiences to recognize dental calculus, but can refer to specific data to assist in diagnosis.
Cross-section and feasibility study on the non-invasive evaluation of muscle hemodynamic responses in Duchenne muscular dystrophy by using a near-infrared diffuse optical technique
(2018-10-01)
Weng, Wen-Chin
;
Chen, Jung-Chih
;
Lee, Chia-Yen
;
Lin, Chia-Wei
;
Lee, Wang-Tso
Duchenne muscular dystrophy (DMD) is an X-linked debilitating muscular disease that may decrease nitric oxide (NO) production and lead to functional muscular ischemia. Currently, the 6-minute walk test (6-MWT) and the North Star Ambulatory Assessment (NSAA) are the primary outcome measures in clinical trials, but they are severely limited by the subjective consciousness and mood of patients, and can only be used in older and ambulatory boys. This study proposed using functional near-infrared spectroscopy (fNIRS) to evaluate the dynamic changes in muscle hemodynamic responses (gastrocnemius and forearm muscle) during a 6-MWT and a venous occlusion test (VOT), respectively. Muscle oxygenation of the forearm was evaluated non-invasively before, during and after VOT in all participants (included 30 DMD patients and 30 age-matched healthy controls), while dynamic muscle oxygenation of gastrocnemius muscle during 6-MWT was determined in ambulatory participants (n = 18) and healthy controls (n = 30). The results reveal that impaired muscle oxygenation was observed during 6-MWT in DMD patients that may explain why the DMD patients walked shorter distances than healthy controls. Moreover, the results of VOT implied that worsening muscle function was associated with a lower supply of muscle oxygenation and may provide useful information on the relationship between muscular oxygen consumption and supply for the clinical diagnosis of DMD. Therefore, the method of fN1RS with VOT possesses great potential in future evaluations of DMD patients that implies a good feasibility for clinical application such as for monitoring disease severity of DMD. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Diffuser-Aided Diffuse Optical Imaging for Breast Tumor: A Feasibility Study Based on Time-Resolved Three-Dimensional Monte Carlo Modeling
(2012-05-01)
Chuang, Ching-Cheng
;
Lee, Chia-Yen
;
Chen, Chung-Ming
;
Hsieh, Yao-Sheng
;
Liu, Tsan-Chi
This study proposed diffuser-aided diffuse optical imaging (DADOI) as a new approach to improve the performance of the conventional diffuse optical tomography (DOT) approach for breast imaging. The 3-D breast model for Monte Carlo simulation is remodeled from clinical MRI image. The modified Beer-Lambert's law is adopted with the DADOI approach to substitute the complex algorithms of inverse problem for mapping of spatial distribution, and the depth information is obtained based on the time-of-flight estimation. The simulation results demonstrate that the time-resolved Monte Carlo method can be capable of performing source-detector separations analysis. The dynamics of photon migration with various source-detector separations are analyzed for the characterization of breast tissue and estimation of optode arrangement. The source-detector separations should be less than 4 cm for breast imaging in DOT system. Meanwhile, the feasibility of DADOI was manifested in this study. In the results, DADOI approach can provide better imaging contrast and faster imaging than conventional DOT measurement. The DADOI approach possesses great potential to detect the breast tumor in early stage and chemotherapy monitoring that implies a good feasibility for clinical application.
Diffuser-aided time-domain diffuse optical imaging
(2014-01-01)
Chuang, Ching-Cheng
;
Lee, Chia-Yen
;
分子醫學與生物工程研究所
;
Institute of Molecular Medicine and Bioengineering
We present the first experimental results of time-resolved diffuser-aided diffuse optical imaging (DADOI) method in this letter. A self-manufactured diffuser plate was inserted between the optode and the surface of a scattering medium. The diffuser was utilized to enhance multiple scattering that destroys image information for baseline measurement of turbid medium. Therefore, the abnormality can be detected with the modified optical density calculation. The time-domain DADOI method can provide better imaging contrast and more simply imaging than the conventional DOT measurement. Besides, it also reveals rich depth information with temporal responses. Therefore, the DADOI offers a great potential to detect the breast tumor and chemotherapy monitoring in clinical diagnosis.
Diffuser-aided time-domain diffuse optical imaging: a phantom study
(2014-04-01)
Sun, Chia-Wei
;
Chuang, Ching-Cheng
;
Lee, Chia-Yen
;
Chen, Chung-Ming
;
光電工程學系
We present the first experimental results of time-resolved diffuser-aided diffuse optical imaging (DADOI) method in this paper. A self-manufactured diffuser plate was inserted between the optode and the surface of a scattering medium. The diffuser was utilized to enhance the multiple scattering that destroys the image information for baseline measurement of turbid medium. Therefore, the abnormality can be detected with the modified optical density calculation. The time-domain DADOI method can provide better imaging contrast and simpler imaging than the conventional diffuse optical tomography measurement. Besides, it also reveals rich depth information with temporal responses. Therefore, the DADOI offers a great potential to detect the breast tumor and chemotherapy monitoring in clinical diagnosis. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)
Discriminant analysis of functional optical topography for schizophrenia diagnosis
(2014-01-01)
Chuang, Ching-Cheng
;
Nakagome, Kazuyuki
;
Pu, Shenghong
;
Lan, Tsuo-Hung
;
Lee, Chia-Yen
Abnormal prefrontal function plays a central role in the cognition deficits of schizophrenic patients; however, the character of the relationship between discriminant analysis and prefrontal activation remains undetermined. Recently, evidence of low prefrontal cortex (PFC) activation in individuals with schizophrenia has also been found during verbal fluency tests (VFT) and other cognitive tests with several neuroimaging methods. The purpose of this study is to assess the hemodynamic changes of the PFC and discriminant analysis between schizophrenia patients and healthy controls during VFT task by utilizing functional optical topography. A total of 99 subjects including 53 schizophrenic patients and 46 age- and gender-matched healthy controls were studied. The results showed that the healthy group had larger activation in the right and left PFC than in the middle PFC. Besides, the schizophrenic group showed weaker task performance and lower activation in the whole PFC than the healthy group. The result of the discriminant analysis showed a significant difference with P value <0.001 in six channels (CH 23, 29, 31, 40, 42, 52) between the schizophrenic and healthy groups. Finally, 68.69% and 71.72% of subjects are correctly classified as being schizophrenic or healthy with all 52 channels and six significantly different channels, respectively. Our findings suggest that the left PFC can be a feature region for discriminant analysis of schizophrenic diagnosis. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
Study on dynamics of photon migration in human breast based on three-dimensional Monte Carlo modeling
(2010-01-01)
Chuang, Ching-Cheng
;
Chen, Chung-Ming
;
Lee, Chia-Yen
;
Tsai, Jui-che
;
Lu, Chih-Wei
The scattering and absorption properties of human breast are very important for cancer diagnosis based on diffuse optical tomography (DOT). In this study, the dynamics of photon migration in three-dimensional human breast model with various source-detector separations is simulated based on a Monte Carlo algorithm. The three-dimensional human breast structure is obtained from in vivo MRI image. The breast model consists of skin, fatty tissue, glandular tissue, sternum and ribcage. The backscattered diffuse photons from each layer in breast are recorded by marking the deepest layer which every photon can reach. The experimental results indicate that the re-emitted photons contain more information from deep tissue regions with the source-detector separations because of the strong dependence to the resolution and sensitivity in DOT imaging. The geometric position of the source-detector separations were optimized in this study. The different sizes of breast tumor were modeled to analysis of optical image characterizations. Finally, the tumor images from different deep information were obtained with temporal profiles.
Visible light absorption spectroscopy for rapid screening of synovial fluid
(2014-01-01)
Guo, Han Wen
;
Yu, Chao Yuan
;
Wang, Hsing Wen
;
Lee, Chia-Yen
;
Sun, Chia-Wei
In diagnosis of arthritis, severity level of synovial inflammation is one of important information to discriminate arthritis types. In this study, we measured the visible absorption spectra of synovial fluid from arthritis patients and found a stronger absorption band between 380 to 450 nm. Then, the measured optical density (OD) of synovial fluid at 420 nm (OD420) was used to estimate severity level of synovial inflammation and compare with clinical classification of inflammation synovial fluid by counting white blood cells (WBCs) number of synovial fluid. In our experimental result, OD420 of synovial fluid concomitantly increased with the severity level of synovial inflammatory. Therefore, we suggest the optical detection of OD420 of synovial fluid can be an indicator to determine severity level of synovial inflammation.