• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1796-1797
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• 2011

본 연구에서는 기존 오실로메트리(oscillomatry) 혈압측정에서 가압 커프의 영향을 최소화 하기위하여, 캐패시턴스 센서를 추가하여 혈압측정 동안의 혈압 및 혈류의 변화량을 측정하여 얻은 신호로 수축기 혈압 및 이완기 혈압을 추정하였다. 필터를 적용한 캐패시턴스 센서의 값을 피크의 크기에 따른 알고리즘을 적용하였으며 얻어진 혈압값과 기존의 혈압계의 값을 비교분석 하였다. 피험자의 연령은 $25{\pm}4$세의 15명을 기준으로 실험하였으며 알콜 및 운동 등 혈압에 영향을 미치는 요소들에 대해 제한 시켰으며 측정 전 15분의 안정을 취했다. 결과적으로 피험자 15명에 대해 수축기 혈압에서의 오차범위는 ${\pm}4$ mmHg이하로 나타났으며 평균 및 표준편차는 각각 2.13 mmHg 과 1.36 mmHg이었다. 이완기 혈압에서는 오차범위가 11명에 대해 수축기혈압과 같았으며 4명은 ${\pm}7mmHg$이상 이였고 평균과 표준편차는 4.20 mmHg와 2.24 mmHg 로 수축기 혈압에서 오차 및 분산 모두 이완기혈압 추정보다 비교적 정확한 값을 검출했다.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.34-34
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• 2011

Recently, people have concerned about environmental pollution. This environmental pollution occur due to many reasons such as heavy metal ions and anions. In this regard, many researchers have studied organic materials to monitor above reasons to protect environmental pollution. One of the organic materials for this function is chemosensor. This chemosensor has been studied and reported about monitoring toxic heavy metal ions and anions. In this study, the dye sensor was designed and synthesized through reaction of Rhodamine 6G and 1,3-Indanedion. this dye sensor selective detected $Hg^{2+}$ metal ions while showing red color absorption and yellowish-green strong fluorescence emission compared to other heavy metal ions such as $Cu^{2+}$, $Hg^{2+}$, $Ag^{2+}$, $Zn^{2+}$, $Fe^{2+}$ and $Fe^{3+}$. In this regard, we anticipated that this dye senosr can provide an significant material for monitoring mercury which cause environmental pollution. Thus, We investigated detailed properties of this dye sesnor with using UV-Vis absorption and fluorescent spectrophotometer, Job's plot method for metal binding complex, computational simulated calculation named Material Studio 4.3 suite to approach for electron distribution and HOMO/LUMO.

• Bulletin of the Korean Chemical Society
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• v.26 no.8
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• pp.1293-1296
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• 2005

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.3
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• pp.364-369
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• 1986

Silicon diaphragms, 10 and 20 \ulcorner-thick and 1x1 mm\ulcornerarea, have been fabricated by means of the electrochemical P-N junction etch-stop technique. The P-type diffused resistors were formed on the diaphragm, and the piezoresistance effect was examined. It was been found that the fractional variation of the resistance is dependent on the diaphragm thickness, resistor location, and resistor length, etc. The 1.2 k\ulcornerfull-brige pressure sensor with 10\ulcorner-thick diaphragm exhibits a pressure sensitivity of 42 \ulcorner/V\ulcornermHg with a temperature coefficient of 2.3 mmHg/\ulcorner, and shows a good linearity in the pressure range from 0 to 300 mmHg.

• Journal of Korean Neurosurgical Society
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• v.30 no.2
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• pp.144-149
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• 2001

Objective : Spinal nerve root compression occurs commonly in conditions, such as herniated nucleus pulposus, spinal stenosis, intervertebral foraminal stenosis, and trauma. However, the pathophysiolosy of the symptoms and signs related to spinal nerve root compression is poorly understood. The purpose of the present study was to assess and compare the changes of various pressures of intervertebral foraminal pressure before and after decompression. Method : After laminetomy without foraminotomy was performed, pressure sensor tip of Camino parenchymal type was located at the middle-central portion of the intervertebral foramen and anterior portion of nerve root for the foraminal pressure before decompression of the intervertebral foramen. After laminectomy with foraminotomy, the same method was used for the foraminal pressure after decompression. The authors studied 40 consecutive patients (57 disc spaces) with severe constant root pain to the lower leg, pain unrelived by bed rest, and minimal tension signs, diagnosed by MRI. Results : In patients with intervertebral foraminal stenosis, the intraforaminal pressure was decreased from $86{\pm}2.23mmHg$ to $17.1{\pm}1.51mmHg$ and in patients without stenosis, from $55.9{\pm}1.08mmHg$ to $11.9{\pm}1.25mmHg$. All patients below 20mmHg after decompression showed good outcome, but 4 cases who showed poor outcome had foraminal stenosis, posterolateral type of the herniated disc, and above 30mmHg of foraminal pressure after decompression. Conclusion : These findings suggest that if the foraminal pressure falls below 20mmHg after decompression, good outcome can be anticipated. Central type of the herniated disc shows better outcome compared to the posterolateral type.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.100-105
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• 2017

An 8-hydroxyquinoline compound that was synthesized with 8-hydroxyquinoline-2-carboxaldehyde and 4-aminoantipyrine was investigated for use as the sensing material of a fiber-optic copper ion sensor in an aqueous environment. The experiment was conducted with a fiber-optic measurement system, in order to evaluate the relationship between the absorbance peak and copper ion concentration. The synthesized derivative exhibited a (highly selective) chromogenic phenomenon for copper ions among various metal ions in an aqueous environment and showed a specific absorbance peak at a wavelength of 530 nm for copper ions. The effect of mercury ions was investigated to evaluate the selectivity of the prepared synthesized derivatives toward Cu ions. The absorbance was measured at various concentration ratios of Cu and Hg ions (Cu:Hg ratios from 0.05 to 20), and it was found that the absorbance at 530 nm tended to increase with increasing Cu ion concentration. The experimental results also showed the linear relationship between the logarithmic concentration of copper ions and the specific absorbance peak at a wavelength of 530 nm. These results indicate that the synthesized 8-hydroxyquinoline compound has selectivity for copper ions and can be used as a sensing material for fiber-optic copper ion sensors.

• Journal of Sensor Science and Technology
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• v.17 no.2
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• pp.87-94
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• 2008

Blood pressure (BP), one of the most important vital signs, is used to identify an emergency state and reflects the blood flow characteristics of the cardiovascular system. The conventional noninvasive method of measuring BP is inconvenient because patients must wear a cuff on their arm and the measurement process takes time. This paper proposes an algorithm for estimating the BP using the pulse transit time (PTT) of the photoplethysmography (PPG) and pressure pulse from finger at the same time as a more convenient way to measure the BP. After recording the electrocardiogram (ECG), measuring the pressure pulse, and performing PPG, we calculated the PTT from the acquired signals. Then, we used a multiple regression analysis to measure the systolic and diastolic BP indirectly. Comparing the BP measured indirectly using the proposed algorithm and the real BP measured with a sphygmomanometer, the systolic pressure had a mean error of ${\pm}3.240$ mmHg and a standard deviation of 2.530 mmHg, while the diastolic pressure had a satisfactory result, i.e., a mean error of ${\pm}1.807$ mmHg and a standard deviation of 1.396 mmHg. These results are more superior than existing method estimating blood pressure using the one PTT and satisfy the ANSI/AAMI regulations for certifying a sphygmomanometer i.e., the measurement error should be within a mean error of ${\pm}5$ mmHg and a standard deviation of 8 mmHg. These results suggest the possibility of applying our method to a portable, long-term BP monitoring system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.7
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• pp.407-412
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• 2017

This paper introduces a biocompatible packaging system for implantable medical device having a hermetic sealing, such that a perfect physical and chemical isolation between electronic medical system and human body (including tissue, body fluids, etc.) is obtained. The hermetic packaging includes an electronic MEMS pressure sensor, power charging system, and bluetooth communication system to wirelessly measure variation of capacitance. The packaging was acquired by Quartz direct bonding and $CO_2$ laser welding, with a size of width $ 6cm{\times}length\;10cm{\times}lheight\;3cm$. Hermetic sealing of the packaged system was tested by changing the pressure in a hermetic chamber using a precision pressure controller, from atmospheric to 900 mmHg. We found that the packaged system retained the same count or capacitance values with sensor 1 - 25,500, sensor 2 - 26,000, and sensor 3 - 20,800, at atmospheric as well as 900 mmHg pressure for 5 hours. This result shows that the packaging method has perfect hermetic sealing in any environment of the human body pressure.

• Archives of Plastic Surgery
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• v.41 no.6
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• pp.668-672
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• 2014

Background Negative-pressure wound therapy (NPWT) is believed to accelerate wound healing by altering wound microvascular blood flow. Although many studies using laser Doppler have found that NPWT increases perfusion, recent work using other modalities has demonstrated that perfusion is reduced. The purpose of this study was to investigate the influence of NPWT on tissue oxygenation of the foot, which is the most sensitive region of the body to ischemia. Methods Transcutaneous partial pressure of oxygen ($TcpO_2$) was used to determine perfusion beneath NPWT dressings of 10 healthy feet. The sensor was placed on the tarso-metatarsal area of the foot and the NPWT dressing was placed above the sensor. $TcpO_2$ was measured until it reached a steady plateau state. The readings obtained at the suction-on period were compared with the initial baseline (pre-suction) readings. Results $TcpO_2$ decreased significantly immediately after applying NPWT, but gradually increased over time until reaching a steady plateau state. The decrease in $TcpO_2$ from baseline to the steady state was 2.9 to 13.9 mm Hg (mean, $9.3{\pm}3.6$ mm Hg; $13.5{\pm}5.8%$; P<0.01). All feet reached a plateau within 20 to 65 minutes after suction was applied. Conclusions NPWT significantly decrease tissue oxygenation of the foot by 2.9 to 13.9 mm Hg. NPWT should be used with caution on feet that do not have adequate tissue oxygenation for wound healing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.561-564
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• 2000

Silicon capacitive pressure sensor has been fabricated by using electrochemical etching stop and silicon-to-glass electrostatic bonding technique. A diaphragm structure is designed to compensate the nonlinear response. A cavity is etched into the silicon to the depth of 2$\mu\textrm{m}$ by anisotropic etching in 20wt.% TMAH solution at 80$^{\circ}C$. A fabricated sensor showed 3.3 pF zero-pressure capacitance, 297 pp.m/mmHg sensitivity, and a 7.4 7%F.S. nonlinear response in a 0-1 kgf/cm$^2$pressure range.