PACKET TRAFFIC MANAGEMENT IN UBIQUITOUS HEALTHCARE SYSTEM

Chung, Wan-Young,Koay, Su-Lin,Jung, Sang-Joong,Kwon, Tae-Ha National Taiwan University 2012 Biomedical engineering Vol.24 No.2

<P> Recent advances in wireless sensor network (WSN) envisaging ubiquitous healthcare system that simplifies the monitoring and treatment of patients. WSN also pose several challenges to ubiquitous healthcare applications. As healthcare application commonly handle two different types of data such as wave-like data of ECG and linear waveform-independent data of body temperature, blood pressure and oxygen content. As wave-like data requires a higher sampling rate than waveform-independent data, the transmission of wave-like data in WSN causes traffic congestion and, consequently, loss of vital signal in transmission. With the increasing number of sensor nodes involved in the WSN field, network congestion issue is rapidly coming known as a tangible issue in healthcare system that must be addressed in order to maintain data reliability. Sensor nodes have very limited computational resources due to its energy consumption. To reduce traffics in WSN communication, the biomedical data are sent when they had very serious problems. The collaboration among sensors through task mapping based in-network processing is adapted to achieve higher processing power and reduce traffics in WSN. System analysis shows that the data packet loss in the ubiquitous healthcare system is dramatically reduced after the implementation of this process. By adapting fall detection, not only the numbers of packets received by the base station are greatly reduced but also the traffic overload problems in WSN are also resolved. </P>

CHARACTERISTICS of <font>Al2O3</font> GATE pH-ISFET DIFFERENCE OF THERMAL ANNEALING TEMPERATURE

Ryu, Sang-Hyuk,Lee, Sang-Kwon,Sohn, Young-Soo,Son, Won-Ho,Choi, Sie-Young National Taiwan University 2012 Biomedical engineering Vol.24 No.2

<P> We investigated the characteristics of Al2O3 gate pH-ISFET which was fabricated by using the standard complementary metal oxide semiconductor (CMOS)-process techniques. The Al2O3 film used to sensing membrane was deposited by atomic layer deposition (ALD). Then, thermal temperature annealing process of the Al2O3 film was performed in O2 ambient for 40 min at a temperature of 500°C, 600°C, 800°C and 900°C. We measured the I D- V D, I D- V G and transconductance of fabricated FET device in order to confirm stability of device before the fabrication of pH-ISFET. Then, the package process was performed. To investigate the pH response characteristics, we measured the I-V curves of the Al2O3 gate pH-ISFET sensor using a 4155 probe station. Form the measured results, we confirmed that sensitivity, hysteresis, and long-term stability of the Al2O3 pH-ISFET showed the changed characteristics at various annealing temperature. The characteristics of Al2O3 gate pH-ISFET annealed at 600°C indicated the best results of the high sensitivity (56 mV/pH), low hysteresis (0.5 ~ 0.7 mV), and low drift (1.35 mV/h) in comparison to Al2O3 gate pH-ISFETs annealed other conditions. As measured results, we confirmed that sensitivity, hysteresis, and long-term stability of Al2O3 gate pH-ISFET depend on the thermal annealing temperature of Al2O3 film and also it is the very important parameter in the pH-ISFET. </P>

VLC-BASED MEDICAL HEALTHCARE INFORMATION SYSTEM

Ng, Xiao-Wei,Chung, Wan-Young National Taiwan University 2012 Biomedical engineering Vol.24 No.2

<P> Nowadays, wireless communication technologies are employed in medical body area networks to enhance flexibility and convenience for caregivers and patients. However, there is always the risk of disturbance from electromagnetic waves toward precision medical equipment. This study demonstrates a novel design and implementation of a medical healthcare information system using the emerging wireless visible light communication (VLC) technology. VLC technology can be implemented using visible light emitting diodes (LED), which is expected to be the main lighting source in the near future due to its energy efficient characteristic compared to conventional incandescent and fluorescent lighting. By manipulating the fast switching characteristic of LEDs, these lighting devices can be used simultaneously for illumination and wireless data communication. The prototype design of the VLC-based medical healthcare system can be used to provide data service and monitoring in radio frequency restricted hospital areas. High brightness LED (HB-LED) is used in the transmitter module to transmit medical and healthcare information using optical modulation method. High speed photodetector is used to detect the optical signal, then the signal is demodulated and conditioned at the receiver module. Medical caregivers or patients can download the biomedical data and healthcare information using a portable device with attached optical sensor. </P>

SURFACE MODIFICATION OF ALUMINUM OXIDE FOR BIOSENSING APPLICATION

Sin, Eun Jung,Moon, Young-Soon,Lee, Yeon Kyung,Lim, Jeong-Ok,Huh, Jeung-Soo,Choi, Sie-Young,Sohn, Young-Soo National Taiwan University 2012 Biomedical engineering Vol.24 No.2

<P> The surface modification for immobilization of antibodies on the aluminum oxide surface was developed for biosensing application. The aluminum oxide has been received much attention since it has various advantages including low cost, hardness, resistance to organic solvents, and high capacitance. In addition, the aluminum oxide can prevent the leakage current in the electrical detection. For development of the protein anchorable surface, the aluminum oxide chip was treated with oxygen plasma and directly immersed in ethanol and toluene solution of 3-aminopropyltriethoxysilane (APTES). Next, this amine modified chip was immersed in the glutaraldehyde solution that contained sodium cyanoborohydride. Finally, the fluorescent materials, the Alexa 488, and the FITC conjugated anti-IgG were reacted to the aldehyde-modified surface. To verify the modified surface, the intensity of the fluorescence was measured and compared. The higher intensity of the fluorescence was observed when the APTES was dissolved in toluene rather than in ethanol. From the highest intensity of the fluorescence observed, the FITC conjugated anti-IgG was well immobilized on the modified surface of the aluminum oxide with APTES and glutaraldehyde. Thus, the proposed surface modification method can immobilize the proteins including antibodies, and can be applied for the various biological researches including biosensors and biochips. </P>

EFFECT OF PURIFIED ALGINATE MICROCAPSULES ON THE REGENERATION OF CHONDROCYTES

Hwang, Ji Hye,Kim, On You,Kim, A Ram,Bae, Ji Yeon,Jeong, Su Mi,Shim, Jung Bo,Yoon, Kun Ho,Lee, Dongwon,Khang, Gilson National Taiwan University 2012 Biomedical engineering Vol.24 No.3

<P> Adult articular cartilage tissue has poor capability of self-repair. Therefore, a variety of tissue engineering approaches are motivated by the clinical need for articular repair. Alginate has been used as a biomaterial for cartilage regeneration. The alginate is a natural polymer that is extracted from seaweeds and purification. However, the main drawback is the immune rejection in vivo. To overcome this problem, we have developed the biocompability of alginate using modified Korbutt method. After alginate was purified, purified alginate microcapsules were used in cartilage regeneration. Chondrocytes were seeded in purified and nonpurified alginate microcapsules, and then cell viability, proliferation and phenotype were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. Reverse transcriptase-polymerase chain reaction (RT-PCR) was conducted to confirm mRNA expression on collagen type I and collagen type II for chondrocytes phenotype. Hematoxylin and eosin (H&E) and Safranin-O histological staining showed tissue growth at the interface during the first 10 days. In this study, chondrocytes in purified alginate microcapsules had higher cell viability, proliferation and more phenotype expression than those in nonpurified alginate microcapsules. The results suggest that the purified alginate microcapsule is useful for cartilage regeneration. </P>

ATTACHMENT AND PROLIFERATION OF RETINAL PIGMENT EPITHELIAL CELLS ON SMALL INTESTINE SUBMUCOSA POWDER IMPREGNATED POLY(L-LACTIDE-CO-GLYCOLIDE) FILM

Jo, Eun Hye,Lee, Ga Young,Cho, Su Jin,Yoo, Hanna,Kim, On You,Seong, Kyeongyeol,Kang, Young Sun,Lee, Dongwon,Khang, Gilson National Taiwan University 2011 Biomedical engineering Vol.23 No.2

<P> The retinal pigment epithelium (RPE) closely interacts with photoreceptors in the maintenance of visual function. The native RPEs exist as a monolayer structure and have a mottled brown color due to the presence of melanin and other pigments including lipofuscin granules, which accumulate with age. In age-related macular degeneration (AMD), RPE's dysfunction and changes in Bruch's membrane occur. Thus, small intestine submucosa/poly(lactic-co-glycolic acid) (SIS/PLGA) film is a biomimetic transplant consisting of a layer of healthy RPE cells cultured on a support membrane. The goals of this study were to evaluate the effects of attachment and proliferation of RPEs on SIS/PLGA films. Porcine SIS is an acellular tissue and widely used as a biomaterial without immunorejection responses, whereas PLGA is a biodegradable synthetic polymer with acceptable mechanical strength and well-controlled degradation rate. We fabricated SIS/PLGA films using 20 wt% of SIS. We measured MTT to confirm cellular adhesion of cell number attached on film at 1, 3, 5, and 7 days. Morphology of cellular adhesion on films was confirmed by scanning electron microscopy at 1, 3, and 7 days. Further, reverse transcription polymerase chain reaction (RT-PCR) was conducted to confirm messenger RNA expression of RPE65 as RPE's marker and expression of cytokeratin, and RPE65 were determined by AEC immunocytochemical staining. These results suggest that SIS provides suitable surface to RPEs. </P>

DETECTION OF PANCREATIC CANCER CELLS (SUIT-2) USING AN FET-BASED BIOSENSOR WITH AN EXTENDED <font>Au</font> GATE

Cho, Byunghyun,Lee, Hee-Ho,Shin, Jang-Kyoo,Murata, Masaharu,Ohuchida, Kenoki,Hashizume, Makoto National Taiwan University 2012 Biomedical engineering Vol.24 No.2

<P> In this paper, we assess the feasibility of detecting human pancreatic cancer cells using a field effect transistor (FET)-based biosensor with an extended Au gate for medical application. Pancreatic cancer is one of the most fatal cancers, and is very difficult to diagnose in its early stages. Gemcitabine is an anticancer drug, and when used in chemotherapy it induces cell death. During apoptosis, the surface potential of the pancreatic cancer cells is changed by gemcitabine. In the present study, this change was detected using an FET-based biosensor. This biosensor was fabricated with an extended Au gate, whose surface is a sensing area for cancer cells. A null-balancing circuit was used in the measurement system, and the LabVIEW software platform allowed the immune-reaction at the Au gate to be detected as an output voltage. The cancer cells were incubated for one day; during this time, the cancer cells adhered to the Au extended gate surface. As gemcitabine was introduced to the cancer cells in vitro, changes in the output of the biosensor were monitored. Pancreatic cancer cells with a resistance to gemcitabine were used to verify that the change in the output of the biosensor was due only to the interaction between the cancer cells and the gemcitabine. We also investigated the relationship between the starting time of the reaction and the concentration of the anticancer drug. </P>