About Instruments Today No. 224


Development and Application Trends of Biophotonics in the Medical Field

Wen-Chuan Kuo

Clinical Trends and Challenges of Optical Coherence Tomography

Sheng-Lung Huang

Optical coherence tomography (OCT) was invented less than 30 years ago, and it has now become a standard of care impacting the treatment of millions of people every year. In biomedical field, it is rare to have such an achievement in such a short period of time. At present, there are more than 100 OCT companies worldwide dedicated to the development of clinical applications as well as technologies. Application wise, there are tremendous clinical and preclinical progresses in ophthalmology, cardiology, dermatology, gastroenterology, neurosurgery, etc. Technology wise, the OCT imaging speed, resolution, and functionality are advancing rapidly due to the breakthroughs in broadband light sources and various optical probes for reaching the deep and/or interior tissues and organs. In the biomedical field, OCT is a successful role model for medical devices. In this article, the basic principles, technologies, applications, as well as the trends and challenges are addressed. Hopefully, it could serve as a guideline for interested readers and inspire the medical image developing teams for making impacts.

Optical Coherence Tomography (OCT): Clinical Applications of Endoscopic Catheter in Gynecology

Meng-Shan Wu, Yi-Chun Wu, Hsiang-Chieh Lee

Optical coherence tomography (OCT) is a non-invasive and high-resolution imaging technology that provides real-time and cross-sectional images of the tissue architectures, suitable for detecting precancerous lesions of the cervix. We have developed a catheter-based OCT system allowing volumetric imaging of the cervical canal, particularly the cervical canal or the vagina. Preliminary imaging results of the human palm and fingertip were shown to demonstrate the imaging capability of the developed imaging system.

Applications of Two-photon Confocal Microscopy for Real-time Imaging of Animal Disease Models

Yu-Chun Cheng, Peilin Chen

In modern biomedical research, living animals are often used as disease models. To observe the disease states, it often requires subcutaneous or intravenous injection to introduce drugs, cells or contrast agents. For long-term observation, it is not practical to conduct biopsy to instantaneously check the status of pathological tissues at different time points. Therefore, it is desirable to utilize noninvasive tools such as intravital imaging to investigate the three-dimensional structure changes in the disease models. In this article, we will discuss the applications of two-photon confocal microscopy for the real-time imaging in live animals. We will focus on disease models based on mouse or chick embryo chorioallantoic membrane (CAM) models.

Introduction of Diffuse Reflectance Spectroscopy-the Core Technology for Optical Wearable Physiological Monitoring Devices

Shih-Yu Tzeng, Chun-Yen Kuo, Nan-Yu Cheng, Sheng-Hao Tseng

Diffuse reflectance spectroscopy (DRS) has been widely used in the field of biomedical optics in recent years. Based on proper theoretical models, DRS not only can be used in quantifying arterial oxygen saturation level, but also used by many groups for developing wearable devices for blood glucose and blood pressure monitoring. In this article, we will introduce the theoretical background of DRS and show its clinical applications in investigating skin collagen concentration, and quantifying neonatal bilirubin and hemoglobin levels.

Introduction of Non-destructive Testing for Wind Turbines

Yi-En Wang, Guan-Lin Chen, Wen-Tse Hsiao, Shih-Feng Tseng

In recent years, the wind power is one of the green energy sources that has attracted worldwide attention due to its low cost of power generation, low ecological impact, low carbon emissions, no air pollution, high stability, etc. Therefore, the visibility of worldwide wind turbines has become much higher. With increasing annual growth of global wind turbines and power generation, the inspection, maintenance, and repair of wind turbines have gradually received attention. Because the wind turbine systems are massive, the maintained components can't be easily disassembled and inspected one by one nor destructively inspected like conventional mechanical devices. Hence, the non-destructive testing (NDT) under various inspection technologies for wind turbines have become the mainstream inspection method. This article will introduce the possible causes of fractures to wind turbines and commonly various non-destructive testing methods. Finally, the advantages and disadvantages of each inspection method are summarized in the conclusion.

The Principle of Gloss Measurement and the Study of Gloss Measurement on the Surface of Dental Prosthesis

Han-Chao Chang, Ming-Ying Hsu, Yen-Yun Wang, Rou-Jhen Chen

When the patient needs to make a dental prosthesis (dental crown) at their own expense, the patient hopes that the color between the dental prosthesis and the real tooth can achieve a color shading aesthetic state. Although the colorimeter can provide the lowest color difference in the crown's color, due to the difference between the material of the crown and the real tooth, there will be a considerable difference in gloss at the actual clinical practice. Commercially available gloss meters mainly measure the coating surfaces of large-area engineering products, and their probes are too large to be measured in the patient's mouth; and the measurement spot size is too large, which may easily cause measurement deviations for a small area of the front teeth. Therefore, this article will explain the gloss measurement principle and use the 60° mirror gloss of the glazed ceramic white porcelain (ASTM C584-81) and Zemax OpticStudio® optical software to perform the small gloss meter light spot with a body thickness of more than 10 mm research on the range and diffraction limit. Based on the optical simulation results of this study and comparing the gloss data between the crown and the real tooth, we determined that the spot range of the micro-gloss meter is between 1 and 3.8 mm, and the optical design is close to point light source, so reduce the aberration of the optical system and improve the parallelism of the collimated light. This research can import gloss measurement into the dental prosthesis gloss measurement to improve the aesthetic quality of the dental prosthesis.

An Iterative Algorithm Base on Feed Rate for Large Aperture Aspherics Polishing Process

Hao-Lun Chang, Ching-Hsiang Kuo, Zong-Ru Yu, Cheng-Fang Ho, Hong-Tsu Young

This study established an iterative algorithm, which based on feed rate, for the CNC bonnet polishing process. This algorithm calculates the corresponding feed rate distribution which eliminates the surface form error based on the relationship between the feed rate and the material removal depth, furthermore, the predicted surface residual will also be calculated and demonstrated. The calculation result shows that in the range of Ø 100 mm, the PV value of surface residual could be converged under 1 nm, and the PV value within Ø 90 mm range could be further converged under 0.5 nm, which sufficiently supports the high convergence of the algorithm constructed in this research.

Chair Professor of Kaohsiung Medical University Dr. Hsin-Su Yu: Problem Solving Must Think About Its Background

Claire Lin, Han-Chao Chang

Find the Right Antidote! Precision Medicine is the Big Trend of the Future

Yu-Hsin Lin, Yi Chiuen Hu

NARLabs i-ONE Instrument Technology Innovation Competition The First Prize of 2019: A Novel Full-field Surface Profilometer Using Diffractive-based Confocal Microscopy

Guo-Wei Wu, Ming-Chun Ching, Hsiu-Wen Liu