• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.1051-1054
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• 2000

We developed the micro CSF (celebrospinal fluid) shunt valve with surface and bulk micromachining technology in polymer MEMS. This micro CSF shunt valve was formed with four micro check valves to have a membrane connected to the anchor with the four bridges. The up-down movement of the membrane made the CSF on & off and the valve characteristic such as open pressure was controlled by the thickness and shape of the bridge and the membrane. The membrane, anchor and bridge layer were made of the $O_2$ RIE (reactive ion etching) patterned Parylene thin film to be about 5~10 microns in thickness on the silicon wafer. The dimension of the rectangular nozzle is 0.2＊0.2 $\textrm{mm}^2$ and the membrane 0.45 mm in diameter. The bridge width is designed variously from 0.04 mm to 0.12 mm to control the valve characteristics. To protect the membrane and bridge in the CSF flow, we developed the packaging system for the CSF micro shunt valve with the deep RIE of the silicon wafer. Using this package, we can control the gap size between the membrane and the nozzle, and protect the bridge not to be broken in the flow. The total dimension of the assembled system is 2.5＊2.5 $\textrm{mm}^2$ in square, 0.8 mm in height. We could precisely control the burst pressure and low rate of the valve varing the design parameters, and develop the whole CSF shunt system using this polymer MEMS fabricated CSF shunt valve.

• KSBB Journal
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• v.25 no.2
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• pp.116-122
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• 2010

Fermented materials have been used for long time around the world and have been researched according to the excellent effect in the part of medical and food industry. However, when such materials are applied on skin, because of the skin barrier, the most effective ingredients are poorly absorbed. The absorption of the skin is exceedingly limited and the method of increasing skin absorption needs special procedures. The micro-needle therapy is a method used to improve the absorption of drug (solution) in the skin which is called "natural skin rejuvenation therapy". This therapy uses micro-needle which is equipped with very thin, delicate needles smaller than a 0.07 mm thick hair. During this therapy, the micro-needle makes small holes and helps absorb the solution into the skin. This is a very excellent therapy in skin absorption. It can be used in wide regions of the skin without any side effects and no recovery time. In 2007, the micro-needle is permitted to personal care. However, the solutions have not yet been developed professionally, and such skill is needed.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.11
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• pp.83-85
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• 1992

In this paper, the Infant Incubator Consisting of amp lifer, A/D Convert, I/O Expand, Watchdog Timer, Alarm Circuit. Display, and mirco-Computer part was developed. The care of Premature new borns of the required that they be in an environment in which temperature is elevaled and Controlled, because they are unable to regulated their own temperature. The central and processing methods based on micro-processor employ the flexibility, and economy over other conventional system. The system characteristic were as follows 1) system based on micro-processor. 2) Easy-to read, touch-Operate control panel all displays and indicators 3) System flexibility.

• Journal of Biomedical Engineering Research
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• v.31 no.3
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• pp.187-193
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• 2010

In this study we have designed and fabricated an inexpensive micro electronic system that we call Alvitek. It can indirectly but accurately predict and display the partial pressures of alveolar oxygen and carbon dioxide for the patients in the ICU of a hospital. Alvitek consists of both hardware part and software part. Performance of the system is tested by animal experiment with pigs for various $F_{t}e_{2}$ and RR(Respiratory Rate) values under the mechanical ventilation. The predicted alveolar gas partial pressures are cprpared with the approximate alveolar oxygen partial pressures easily calculated by the physician’s bedside formula. As a result, we have concluded that the relative error of A-$aDe_2$ calculated by the bedside formula grows seriously for lower $F_{t}e_{2}$ values. The present prediction method of Alvitek is henceforth believed very meaningful to the physicians. The system hardware and software are described in the text.

• Journal of Power System Engineering
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• v.10 no.1
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• pp.83-89
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• 2006

Recently, the seriousness of high blood pressure was appeared as the most frequent disease of a the whole sickness in the world. However, the treatment of this disease is uncertain and produces an adverse reaction of a medicine therapy. Also, the patients are burdened with a fee for medical treatment. Therefore, in this paper, we studied effectively and financially to execute the treatment of high blood pressure using the Chinese medicine theorem that is recently arousing the great interest of the people. The main theories in this paper are blood vessel theory and acupuncture, respectively. Especially, the composed circuit systems are classified the blood pressure depressor part and the meridian points discrimination part, respectively. The blood pressure depressor part is composed generally of low-frequency generation circuit, charging-discharging circuit, and micro-computer circuit. Finally, this research have the advantage of discrimination parts such as regular voltage generating circuit, stimulus circuit, amplifying circuit, and alarm circuit.

• Journal of Biomedical Engineering Research
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• v.27 no.4
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• pp.189-196
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• 2006

Micro computed tomography (micro-CT) has been used for in vivo animal study owing to its noninvasive and high spatial resolution capability. However, the sizes of existing detectors for micro-CT systems are too small to obtain whole-body images of a small animal object with $\sim$10 micron resolution and a part of its bones or other organs should be extracted. So, we have introduced the zoom-in micro-tomography technique which can obtain high-resolution images of a local region of an live animal object without extracting samples. In order to verify our zoom-in technique, we performed in vivo animal bone study. We prepared some SD (Sprague-Dawley) rats for making osteoporosis models. They were divided into control and ovariectomized groups. Again, the ovariectomized group is divided into two groups fed with normal food and with calcium-free food. And we took 3D tomographic images of their femurs with 20 micron resolution using our zoom-in tomography technique and observed the bone changes for 12 weeks. We selected ROI (region of interest) of a femur image and applied 2D FDT (fuzzy distance transform) to measure the trabecular bone thickness. The measured results showed obvious bone changes and big differences between control and ovariectomized groups. However, we found that the reliability of the measurement depended on the selection of ROI in a bone image for thickness calculation. So, we extended the method to 3D FDT technique. We selected 3D VOI (volume of interest) in the obtained 3D tomographic images and applied 3D FDT algorithm. The results showed that the 3D technique could give more accurate and reliable measurement.

• Molecules and Cells
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• v.39 no.8
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• pp.619-624
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• 2016

Glioblastoma stem cells (GBM-SCs) are believed to be a subpopulation within all glioblastoma (GBM) cells that are in large part responsible for tumor growth and the high grade of therapeutic resistance that is so characteristic of GBM. MicroRNAs (miR) have been implicated in regulating the expression of oncogenes and tumor suppressor genes in cancer stem cells, including GBM-SCs, and they are a potential target for cancer therapy. In the current study, miR-203 expression was reduced in $CD133^+$ GBM-SCs derived from six human GBM biopsies. MicroRNA-203 transfected GBM-SCs had reduced capacity for self-renewal in the cell sphere assay and increased expression of glial and neuronal differentiation markers. In addition, a reduced proliferation rate and an increased rate of apoptosis were observed. Therefore, miR-203 has the potential to reduce features of stemness, specifically in GBM-SCs, and is a logical target for GBM gene therapy.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.424-427
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• 1997

Electrical impedance plethysmography is still be one of the simplest and most convenient methods or non-invasive measurement of blood low, but it has the weak point can not do real-time measurement because of using chart-record or processing after receiving data from analog plethysmography through A/D converter. In this study. we developed hardware system composed of analog part which include auto-balancing circuit and calibration register and digital part which include 80C196KC, keypad, and LCD. we studied the algorithms or extracting parameter to calculate blood low and implemented it using general purpose micro controller.

• Anatomy and Cell Biology
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• v.56 no.3
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• pp.334-341
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• 2023

Anterior talofibular ligament (ATFL) injuries are the most common cause of ankle sprains. To ensure anatomically accurate surgery and ultrasound imaging of the ATFL, anatomical knowledge of the bony landmarks around the ATFL attachment to the distal fibula is required. The purpose of the present study was to anatomically investigate the ATFL attachment to the fibula with respect to bone morphology and attachment structures. First, we analyzed 36 feet using micro-computed tomography. After excluding 9 feet for deformities, the remaining 27 feet were used for chemically debrided bone analysis and macroscopic and histological observations. Ten feet of living specimens were observed using ultrasonography. We found that a bony ridge was present at the boundary between the attachments of the ATFL and calcaneofibular ligament (CFL) to the fibula. These two attachments could be distinguished based on a difference in fiber orientation. Histologically, the ATFL was attached to the anterodistal part of the fibula via fibrocartilage anterior to the bony ridge indicating the border with the CFL attachment. Using ultrasonography in living specimens, the bony ridge and hyperechoic fibrillar pattern of the ATFL could be visualized. We established that the bony ridge corresponded to the posterior margin of the ATFL attachment itself. The ridge was obvious, and the superior fibers of the ATFL have directly attached anteriorly to it. This bony ridge could become a valuable and easy-to-use landmark for ultrasound imaging of the ATFL attachment if combined with the identification of the fibrillar pattern of the ATFL.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.551-557
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• 2009

A development of smart materials is becoming a prominent issue on present industries. A smart material, included in functions, is needed for micro fabrication. A shape memory alloy(SMA) in a smart material is best known material. Ni-Ti alloy, composed of nikel and titanium is one of the best shape memory alloy(SMA). Nitinol SMA is used for a lot of high tech industry such as aero space, medical device, micro actuator, sensor system. However, Ni-Ti SMA is difficult to process to make a shape and fabrications as traditional machining process. Because nitinol SMA, that is contained nikel content more than titanium content, has similar physical characteristics of titanium. In this paper, the characteristics of ECM grooving process for nitinol SMA are investigated by experiments. The experiments in this study are progressed for power, gap distance and machining time. The characteristics are found each part. Fine shape in work piece can be found on conditions; current 6A, duty factor 50%, gap distance 15%, gap distance $15{\mu}m$, machining time 10min.