Portable Laser Doppler Flowmeter for Microcirculation Detection

Chang-Lin Hu,Meng-Lin Li,Zhan-Sheng Lin,Yen-Yu Chen,Yuan-Hsiang Lin 대한의용생체공학회 2013 Biomedical Engineering Letters (BMEL) Vol.3 No.2

Purpose The microcirculatory system of the human body is closely related to its physiological conditions. The laser Doppler flowmeter can detect symptoms through variations in the microcirculation; however, the present commercial Doppler flowmeter is very expensive, heavy, and inconvenient to carry. Therefore, an inexpensive, small, and portable laser Doppler flowmeter is proposed. Methods In this study, we designed a laser Doppler flowmeter transmitting receiving module based on the fundamental principles of laser Doppler, using a common computer for flow calculation. A self-designed correction system was used to validate the portable laser Doppler flowmeter. Results The coefficient of correlation between the mean frequency offset <ω> of the flowmeter and the actual mimicked blood flow rate reached a high value of R = 0.99, and the variations in microcirculation flow could be accurately measured. Conclusions The results proved that the low-cost portable laser Doppler flowmeter can be used extensively in early symptom detection for disease prevention and control.

A modified random decrement technique for modal identification from nonstationary ambient response data only

Chang-Sheng Lin,Dar-Yun Chiang 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.6

Modal identification is considered from response data of structural system under nonstationary ambient vibration. In a previous paper,we showed that by assuming the ambient excitation to be nonstationary white noise in the form of a product model, the nonstationary response signals can be converted into free-vibration data via the correlation technique. In the present paper, if the ambient excitation can be modeled as a nonstationary white noise in the form of a product model, then the nonstationary cross random decrement signatures of structural response evaluated at any fixed time instant are shown theoretically to be proportional to the nonstationary cross-correlation functions. The practical problem of insufficient data samples available for evaluating nonstationary random decrement signatures can be approximately resolved by first extracting the amplitude-modulating function from the response and then transforming the nonstationary responses into stationary ones. Modal-parameter identification can then be performed using the Ibrahim time-domain technique, which is effective at identifying closely spaced modes. The theory proposed can be further extended by using the filtering concept to cover the case of nonstationary color excitations. Numerical simulations confirm the validity of the proposed method for identification of modal parameters from nonstationary ambient response data.

System Identification of Structures with Severe Closely Spaced Modes Using Parametric Estimation Algorithms Based on Complex Mode Indicator Function with Singular Value Decomposition

Chang-Sheng Lin 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.9

The modal-interference phenomenon usually makes difficulty of parametric estimation, especially for some structural systems with severe modal interference caused from close or even repeated modes. The existence of severe modal interference will degrade the effectiveness of system identification, and may lead to the problem of insufficient model order due to the existence of repeated modes. Multiple input/multiple output modal estimation is therefore usually conducted effectively to meet the sufficient number of measurement channels. In this paper, the Complex Mode Indicator Function (CMIF) is introduced to estimate the number of significant modes of a structure with severe modal interference, and then the singular value decomposition (SVD) is employed to parametric estimation of the major modes of a structural system without additionally evaluating enhanced frequency response function. Numerical simulations and experimental validation of a practical rectangular steel plate confirm the effectiveness of the presented method for parametric estimation of systems with severe closely spaced modes under noisy conditions.

Response-only modal identification using random decrement algorithm with time-varying threshold level

Chang-Sheng Lin,Tse-Chuan Tseng 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.6

Modal Identification from response data only is studied for structural systems under nonstationary ambient vibration. The topic of thispaper is the estimation of modal parameters from nonstationary ambient vibration data by applying the random decrement algorithm withtime-varying threshold level. In the conventional random decrement algorithm, the threshold level for evaluating randomdec signatures isdefined as the standard deviation value of response data of the reference channel. The distortion of randomdec signatures may be, however,induced by the error involved in noise from the original response data in practice. To improve the accuracy of identification, amodification of the sampling procedure in random decrement algorithm is proposed for modal-parameter identification from the nonstationaryambient response data. The time-varying threshold level is presented for the acquisition of available sample time history to performaveraging analysis, and defined as the temporal root-mean-square function of structural response, which can appropriately describea wide variety of nonstationary behaviors in reality, such as the time-varying amplitude (variance) of a nonstationary process in a seismicrecord. Numerical simulations confirm the validity and robustness of the proposed modal-identification method from nonstationary ambientresponse data under noisy conditions.

Frequency-domain approach for the parametric identification of structures with modal interference

Chang-Sheng Lin 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.9

This study aims to improve the accuracy of the parametric estimation of systems with modal interference in the frequency domain. The theory of modal identification states that the frequency response function can be expressed as a rational function form by using the curve fitting technique, and the modal parameters can then be estimated from rational fractional coefficients. The conventional common denominator model only indicates the frequency response function of a single-degree-of-freedom system; thus, it cannot acquire the mode shape information. In this paper, we propose the matrix-fractional coefficient model constructed by the frequency response functions of a multiple-degree-of-freedom system for modal identification. To avoid the phenomenon of omitted modes caused by the distortion from modal interference among the vibration modes of systems during modal estimation, we use a system model with higher-order matrixfractional coefficients, but fictitious modes may be caused by numerical computation. Structural and fictitious modes can be effectively separated by using a different-order constructed stabilization diagram. Modal identification can be implemented by solving the eigenproblem of the companion matrix yielded from least-square estimation. Numerical simulations, including a full model of sedan and onehalf railway vehicle in the form of a linear 2D model, as well as the experimental testing of an actual plate, confirm the validity and robustness of the proposed parametric-estimation method for a system with modal interference under noisy conditions.

The Design and Application of an Automatic Optical Inspection System for the Advanced Fiber Coupler Assembly Manufacturing Process

Chern-Sheng Lin,Jen Min Tsai,Kai-Sheng Chen,Yun-Long Lay,Nin-Chun Chang 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

In this paper an automatic optical inspection system for the advanced fiber coupler assembly manufacturing process is presented. Coupling efficiency variations were compared with axial displacement. The main standard components of light peak fiber couplerswere used in the experiment to determine the corresponding offset and position of the optimal optical coupling efficiency in order toachieve a positioning effect. This study used the parameters of lens curvature, focal length and light source for validation using opticaldesign software. An infrared CCD camera was used to extract the coupled light spot images. The curve fitting method and couplingsimulation database were used for image processing and to calculate optimal coupling efficiency. Under optimal coupling efficiency,the minimum amount of movement of the translation stages was used to calculate the offset of each axle or the coupling efficiencywhen tilted. Moreover, a coupling efficiency database was established. The optical axle center offset in the alignment was calculatedby comparing the data in the database. Finally, the optical axle center offset or tilt direction was identified through the program toachieve the position of optimal coupling efficiency.

Advanced Imaging of Nanometer-Scale Recorded Bits on Super-Resolution Near-Field Optical Disk

Pei Lin Yang,Din Ping Tsai,Cheng Wei Lin,Chih Ching Hsu,Pei Hsin Chang,Tsung Sheng Kao,Wei Chih Lin 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.47 No.1

An advanced imaging technique is demonstrated for fast, non-destructive and high resolution characterizations for nanometer-scale recorded bits on a super-resolution near-field optical disk (super-RENS). For the first time, an array of individual 100 nm recorded marks is imaged and studied by using the conductive-atomic force microscopy (C-AFM) method. Discussions also include comparisons of 300 nm, 200 nm and 100 nm recorded marks on both a super-RENS disk and a commercial DVD disk, and the image results are evidence of the high carrier-to-noise ratio (CNR) value on the super-RENS disk, even though the mark size has been shrunk to less than the diffraction limit.

Efficacy of Epigallocatechin-3-Gallate and Amla (Emblica officinalis) Extract for the Treatment of Diabetic-Uremic Patients

Tung-Sheng Chen,Show-Yih Liou,Hsi-Chin Wu,Fuu-Jen Tsai,Chang-Hai Tsai,Chih-Yang Huang,Yen-Lin Chang 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.7

Uremic patients with diabetes suffer from high levels of oxidative stress due to regular hemodialysis therapy (neutrophil activation induced by hemo-incompatibility between the hemodialyser and blood) and complications associated with diabetes. Several plasma biomarkers were screened in 13 uremic diabetic patients after receiving the mixture of (–)-epigallocatechin gallate (EGCG), a major component of green tea extract, and Amla extract (AE), from Emblica officinalis, the Indian gooseberry, for 3 months. We found that oral administration of a 1:1 mixture of EGCG and AE for 3 months significantly improved antioxidant defense as well as diabetic and atherogenic indices in uremic patients with diabetes. Furthermore, no significant changes in hepatic function, renal function, or inflammatory responses were observed. These results suggest that a 1:1 combination of EGCG and AE is a safe and effective treatment for uremic patients with diabetes.

THE UPDATED ORBITAL PERIOD OF LOW MASS X-ray BINARY 4U 1323-62

CHUANG, PO-SHENG,CHOU, YI,HU, CHIN-PING,YANG, TING-CHANG,SU, YI-HAO,LIAO, NAI-HUI,HSIEH, HUNG-EN,LIN, CHING-PING The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

4U 1323-62, a low mass X-ray binary with an orbital period of 2.94 hr, exhibits periodic X-ray dips, which are due to absorption by the bulge of the outer accretion disk. The purpose of this study is to search for orbital period changes using archived X-ray data over a time span of 20 years. We present our preliminary results from analyzing light curves observed by RXTE, BeppoSAX, XMM-Newton and Suzaku. We used the method proposed by Hu et al. (2008) to estimate dip center time and adopted the Observed - Calculated method to measure changes in period. We obtained an orbital period of 2.941917(36) hr and a period derivative of $\dot{P}_{orb}/P_{orb}=(-9.9{\pm}3.5){\times}10^{-7}yr^{-1}$. The F-test result shows that the quadratic ephemeris is describes the evolution of the dip phases better than the linear ephemeris at a greater than 95% confidence level. More X-ray data collected from the early 80s will be included to further refine the orbital ephemeris.

Professionals’ experiences and attitudes toward use of Traditional Chinese Medicine in hospice palliative inpatient care units: A multicenter survey in Taiwan

Yu-Jia Lin,Hsiao-Ting Chang,Ming-Hwai Lin,Ru-Yih Chen,Ping-Jen Chen,Wen-Yuan Lin,Jyh-Gang Hsieh,Ying-Wei Wang,Chung-Chieh Hu,Yi-Sheng Liou,Tai-Yuan Chiu,Chun-Yi Tu,Yi-Jen Wang,Bo-Ren Cheng,Tzeng-Ji Ch 한국한의학연구원 2021 Integrative Medicine Research Vol.10 No.2

Background: Medical staff may have difficulties in using conventional medicine to manage symptoms among terminally ill patients, including adverse effects of the treatment. Traditional Chinese medicine (TCM) is regarded as a complementary or alternative medicine, and has been increasingly used in the field of palliative medicine in recent years. This study aimed to investigate the experiences of and attitudes toward using TCM among palliative care professionals, and to provide preliminary information about its use in palliative care. Methods: This was a cross-sectional survey study conducted in eight inpatient hospice wards in Taiwan between December 2014 and February 2016. The questionnaire was self-administered, and was analyzed with descriptive statistics including Pearson’s Chi-square test and Fisher’s exact test. Results: A total of 251 palliative care professionals responded to the questionnaire, of whom 89.7% and 88.9% believed that the use of TCM could improve the physical symptoms and quality of life in terminally ill patients, respectively. Overall, 59.8%, of respondents suggested that TCM had rare side effects, and 58.2% were worried that TCM could affect the liver and kidney function of patients. In total, 89.7% and 88.0% of professionals agreed there were no suitable clinical practice guidelines and educational programs, respectively, for TCM use in palliative care. Conclusions: Most of the respondents agreed there was insufficient knowledge, skills-training, and continuing education on the use of TCM in terminally ill patients in Taiwan. These results show that to address patient safety considerations, guidelines about use of TCM in palliative care should be established.