Emerging Biomedical Technologies

Modulating Chemotaxis of Cancer Cells by Using Direct-Current Electric Fields in a Microfluidic Chip [ 下載 PDF ]

Yu-Chiu Kao, Meng-Hua Hsieh, Chung-Chun Liu, Huei-Jyuan Pan, Wei-Yu Liao, Ji-Yen Cheng, Po-Ling Kuo, Chau-Hwang Lee

The migration of cancer cells is affected by many physical or chemical factors. For example, the signalling pathways induced by epidermal growth factor (EGF) have been verifi ed to be related to the metastasis of various types of cancer cells. The electrotaxis of cancer cells could also play significant roles in cancer metastasis. We employed direct-current electric fields (dcEFs) to modulate the chemotaxis of lung cancer cells in a microfluidic cell culture device that incorporates both stable concentration gradients and dcEFs. We found that the chemotaxis of lung cancer cells induced by a 0.5 µM/mm concentration gradient of EGF can be nearly compensated by a 360 mV/mm dcEF. When the effect of chemical stimulation was balanced by the electric field, the cells migrated randomly, and the path lengths were reduced. We also demonstrated electrically modulated chemotaxis of two types of lung cancer cells with opposite directions of electrotaxis in this device.

Three-Dimensional Refractive Index Microscopy and Its Application [ 下載 PDF ]

Jing-Wei Su, Wei-Chen Hsu, Kung-Bin Sung

Refractive index (RI) fluctuations in biological cells and tissue provide an intrinsic source of imaging contrast without external labels. The intrinsic phase contrast not only avoids morphological and functional alterations of biosamples but also enables long term observation of living specimens. Compared to more conventional phase contrast and differential interference contrast microscopies and emerging two-dimensional quantitative phase microscopy, imaging of the three-dimensional (3D) RI distribution provides more structural information of heterogeneities in bio-samples. As a result, 3D quantitative RI microscopy has attracted increasing attention in the field of biomedical optics recently. In this manuscript, we review the principle and development history of 3D RI microscopy and associated reconstruction algorithms. Validation of reconstruction algorithms and two optical setups, one based on a Mach-Zehnder interferometer and the other based on a common-path confi guration, developed in our laboratory is provided. Finally, an example of live-cell imaging is demonstrated and potential biomedical applications are discussed.

Brainwave Diopter of Myopia Detecting Device [ 下載 PDF ]

Der-Chin Chen, Chien-Hung Chiu, Peng-Yuan Chen, Lee Siak Lim, Chih-Chi Lin

Brainwave diopter of myopia detecting can rapidly and correctly measure the diopters of myopic patients. In the brainwave single pole device, used for capturing under test persons wearing correction lenses before and after the brainwave signals, that signals were sent to the signal processor to do myopia diopters instant analysis of the attention and meditation value changing. When the measured by the brainwave signals meditation value is rising and attention value is decreasing, that detect out of the corresponding to under test persons the vision are optimal value by the diopter correction lenses. Therefore, this device having brainwave detect is more objectively and accurately with apply to the poor expression ability patients. This device according to personal vision demand to make adjustments, after visual acuity correction the expected value is (V.A.) 0.8–1.2.

Continua ECG Device Solutions: An x73-PHD Bluetooth Adaptor and An x73-PHD ZigBee Adaptor [ 下載 PDF ]

Yuan-Fa, Lee

With the increase of aging population and the threat of cardiovascular disease, ECG monitoring system becomes important healthcare equipment. However, current ECG monitoring systems are private communication systems. There is a necessary need for intercommunication and exchange measurement data among the various ECG devices and application hosting devices within a single system. The study proposes two designs: one is for the x73-PHD Bluetooth adaptor and the other is for the x73-PHD ZigBee adaptor. Both x73-PHD adaptors act as agent of ECG device. The x73-PHD adaptor collects the measured data and transmits them compliant with the international standard 11073 data format via a Bluetooth Health Device Profile (HDP) or ZigBee Health Care Profile (HCP) interface. The design for the x73-PHD Bluetooth adaptor proposed in this paper is based on the MSP430F5529 and Stollmann chipsets as well as the x73-PHD ZigBee adaptor is based on the Freescale ZigBee chipset. Each of the adaptors adopts the ISO/IEEE 11073 standards, which functions as a bridge between the application hosting device and the ECG device. The x73-PHD adaptor converts vital sign data from the connecting ECG device, and then transmits these data (waveform or heart rate) to the application hosting device in compliance with ISO/IEEE 11073 personal health device data format and protocol standards via the Bluetooth HDP or ZigBee HCP interface. Based on the testing results, users can transmit ECG waveform or heart rate data to any application host device certifi ed by Continua Health Alliance over the Bluetooth HDP or ZigBee HCP interface successfully.

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"Applications of Scanning Kelvin Probe Microscopy on the Analysis of Cu(In, Ga)Se₂ Thin Films" [ 下載 PDF ]

Wei-Chung Tang, Wei-Sheng Lin, Jen-Chuan Chang, Tung-Po Hsieh, Mao-Nan Chang

This article introduces the applications of surface potential analysis on investigating the factors influencing the short-circuit current of a CIGS solar cell. For the CIGS thin fi lm grown by a three-stage co-evaporation process, we employed scanning Kelvin probe microscopy (SKPM) to obtain the depth distribution of the surface potential of a CIGS thin film. With the elemental depth profi les provided by X-ray photoelectron spectroscopy (XPS), one can study the relation between the surface potential variations and the energy gaps as well as the built-in electric field in a CIGS thin film. Furthermore, the factors infl uencing the short-circuit current of a CIGS solar cell can be studied.

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Investigation of Nonlinear Scattering in A Single Gold Nanoparticle and Its Application to Superresolution Microscopy [ 下載 PDF ]

Hsuan Lee, Yen-Ta Huang, Shi-Wei Chu

Conventionally, the resolution of optical microscopy is limited to about half of wavelength, due to diffraction barrier. During the past two decades, super-resolution imaging was realized by several innovative approaches, which were based on manipulating the on/off switching of fluorophores, or by saturation of fluorescence emission. However, fluorescence exhibits a severe issue of bleaching, significantly preventing long-term observation. To prevent the photobleaching of fluorophores, we demonstrate novel super-resolution imaging based on saturation of scattering from plasmonic particles, for the first time. From spectral studies, we have confi rmed the saturation is directly linked to surface plasmon resonance effect. With the aid of saturation excitation microscopy, we have achieved optical resolution below 80-nm based on scattering, which is continuously observable without bleaching. Our study will open up a completely new paradigm for not only nano-plasmonics but also super-resolution microscopy.

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Multifunctional White Light Emitting Diode Packaging [ 下載 PDF ]

Jung-Chieh Su

The thin film optical components with a functionality of omni-directional reflection are used to package the multifunctional white light emitting diodes (LEDs). For example, an omni-directional reflector (ODR) is used in UV-pumped white LEDs to omni-directionally reflect the UV light in certain spectrum range and the UV photons are multiple reflected between the ODR and phosphor resin. This mechanism can enhance the phosphor conversion efficiency and the uniformity of the emitted light pattern. The same concept can be used to manufacture other multifunctional LED packaging, such as color tunable white light LEDs which are packaged by combining ODR, UV, purple and blue pumping LEDs.

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A Rapid Detection System for Emulsion Stability [ 下載 PDF ]

Yung-Sheng Lin, Wei-Lung Chou, Cheng-You Chen, Hui-shun Huang, Yu-Hsin Lin, Yu-Ya Huang

This study presents an electrical impedance sensing device to determine the stability of emulsion. We used the traditional visual observation, conductivity, and electrical impedance sensing device to detect the effects of emulsifiers on emulsion stability. Experimental results confirmed that the proposed electrical impedance sensing device has advantages of a smaller detection volume, faster detection, and better sensitivity than traditional methods.

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Plasmonic Energy Transformation in Room Temperature Water Treatment of Armonium Pollutions [ 下載 PDF ]

Hung-Ji Huang, Bo-Heng Liu

The spinning disk reactor and plasmonic photocatalytic reactions are very important research topics in the recent years. The room-temperature ammonium oxidization was done by a home-made spinning disk reactor. The processing efficiency was boosted with applying the catalyst of a platinum thin film and even further enhanced by shinning with a wide-band light source. The energy transformation from light to plasmon and chemical energy was observed.