• 대한의용생체공학회:의공학회지
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• 제30권4호
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• pp.341-346
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• 2009

Cutaneous electrogastrography is the measurement of electrical activity of the stomach on the abdominal surface. The validity of cutaneous electrogastrography is dependent upon the quality of the recording technique. The locations of electrodes are an important issue. We examined the influences of the inter-electrode distance of bipolar leads on electrogastrography measurements. The sensitivity distributions of EGG leads were calculated based on a 2D body fat model and evaluated according to the region of interest sensitivity ratio (ROISR). We simulated the ROISR of the inter-electrode distance in relation to various body fat thicknesses. The distance between the electrodes was proportional to the distance between the ROI and the surface of the abdomen. The results imply that inter-electrode distance can be applied in electrogastrography according to human body fat thickness.

• 자원환경지질
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• 제14권3호
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• pp.111-122
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• 1981

This study is a model analysis for an effective application of the geophysical prospecting to the investigation of geological structures or useful resources, and the purpose of it is to research a property of the electrical resistivity prospecting, especially by using a Three-Point electrode array method. In using the Three-Point electrode array method, it is theoretically assumed to choose the infinite for a distance between the two current electrodes, however it is impossible in applying to the practical field prospecting. Therefore this study was conducted for determination and presentation of a minimum appropriate distance between the two current electrodes by making a study on prospecting effect in the variation of distance between both the electrodes. In case that the ratios of the distance between the two current electrodes to that between the two potential electrodes are respectively chosen for 40, 400, 5,000, the experimental data of this study showed that the minimum appropriate distance between the two current electrodes is forty times as much as that between two potential electrodes. In order to make clear a problem about prospecting depth which is essential to the data processing, it had been chosen equally to the distance between two potential electrodes. As a result of it, it was shown that the anomaly is appeared along the position of an assumed ore body. Consequently it was found out that the prospecting depth of the Three-Point electrode array method is the same as the distance between the two potential electrodes. From the model experiment on the sheeting ore body(or linear structure) of horizontal, dipping of $30^{\circ}$, $60^{\circ}$ and vertical on the basis of above experimental condition, it was found out that the position and dip of assumed ore body could be inferred from the aspects of the equiresistivity curve. In consequence of performing out the simultaneous Normal and Reversal electrode movement, it was shown that the electrode movement of the Reversal forms the anomaly more clearly than that of Normal when the sheeting ore body is situated obliquely, therefore it could be ascertained that the electrode movement have to be performed simultaneously in the manner of Normal and Reversal. It was also exhibited that the aspect of the equiresistivity curve forms symmetrically when an assumed ore body (or linear structure) is situated horizontally or vertically, that is, symmetrically, and moreover that the aspect of the equiresistivity curve forms unsymmetrically when an assumed ore body (or linear structure) is situated obliquely. On the basis of these experimental analysis it is thought that it can be inferred from the aspect of equiresistivity curve whether an assumed ore body is obliquely situated or not.

• 한국기계가공학회지
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• 제15권3호
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• pp.28-35
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• 2016

Forging operations are non-stationary processes occurring because of indirect pressure, generally, under conditions of three-dimensional stress and deformation. Furthermore, due to friction and the constraints of die geometry, deformation is not homogeneous. Material flow and deformation are largely determined by the shape of the tools. It is well known that net-shape forging can improve the mechanical strength of the final product as well as reduce material waste. Oxygen-free copper that is used for electrical and electronic components has excellent electrical and thermal conductivity. Oxygen-free copper parts have a low productivity in cutting process. Thus, the forging process is performed in order to improve the low productivity in cutting process. The forging of oxygen-free copper for electrode body parts was modeled using finite element simulation and forging experiments that were conducted for producing electrode body parts at room temperature. In order to reduce the cost of cutting products, the forging was performed in a closed cavity to obtain near-net or net-shape parts.

• 한국세라믹학회지
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• 제23권1호
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• pp.60-66
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• 1986

The effect of composition size of sintered body and electrode on resonant characteristics of the system $Pb(Mn_{1/3}Nb_{2/3})O_3 PbTiO_3-PbZrO_3$ has been decribed. Composition ranged from X=40 to X=55 diameter of sintered body ranged from D=6.5 to D=12.5(mm) and diameter of electrode ranged from De=5.5 to De=11 (mm) In the composition of morphotropic phase boundary antiresonant frequency (fa) dcreased slowly whereas resonant frequency (fr) decreased rapidly on the ground of this Δf(fa-fr) and electromechanical coupling fractor Kp increased and Qm showed low value. On the contrary in toward the composition of tetragonal and rhombo-hedral fa increased slowly whereas fr increased rapidly on the ground of this Δf and Kp decreased and Qm increased abruptly. Substance of the above statements have no concern with size of sintered body and ele-ctrode. The other side as the size of electrode decreased Qm fr, fa and Δf increased. Cm and Co dominantly affect the resonant frequency and antiresonant frequency.

• ETRI Journal
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• 제44권5호
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• pp.859-874
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• 2022

This paper presents a low-power and lightweight human body communication (HBC) receiver with an embedded dummy electrode for improved signal acquisition. The clock data recovery (CDR) circuit in the receiver operates with a low supply voltage and utilizes a clock phase inversion scheme. The receiver is equipped with a main electrode and dummy electrode that strengthen the capacitive-coupled signal at the receiver frontend. The receiver CDR circuit exploits a clock inversion scheme to allow 0.9-V operation while achieving a shorter lock time than at 3.3-V operation. In experiments, a receiver chip fabricated using 130-nm complementary metal-oxide-semiconductor technology was demonstrated to successfully receive the transmitted signal when the transmitter and receiver are placed separately on each hand of the user while consuming only 4.98 mW at a 0.9-V supply voltage.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 학술대회 논문집
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• pp.305-308
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• 2004

There are ground facility of maintenance in house electric facility of infra maintenance electric home appliances having used multifariousness in house, that use electric energy of common source for equipment. The body of building such as the reinforced concrete construction is structurally united, and the electric resistance is also small. It is possible that those foundations have contacted the ground at large surface area and that it substitutes the building construction body for the earth electrode. This is called "the structure earthing". This method has been defined at electrical facilities technical standards and KS in our country, and it has been used in various quarters practically. However, in our country, there is no example of using the foundation of the house as substitution earth electrode practically, and the means of the evaluation as electrode has not been established either. Then, in this paper, basic research for utilizing foundation of the house as substitution earth electrode is carried out.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.1023-1026
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• 2006

가정이나 병원 등 해상에서 위급한 환자를 모니터링 할 때 현재의 심전도 측정기의 전극센서가 불편할 경우가 많다. 구급차량 내에서나 선박에서 환자를 측정시 흔들림이 심하기 때문에 전극이 떨어져 측정이 쉽지가 않으며 또 환자의 몸에 지방분이나 습기가 많을 경우를 쉽게 붙어있지 않아 측정이 더욱 힘들어진다. 본 연구에서는 환자가 언제든지 전극을 붙이고 화장실이나 외출까지도 자유롭게 할 수가 있도록 하였으며 또 흉부에 쉽게 착용이 용이하도록 부드러운 벤드 형태로 설계되었다. 심전도의 전극소재로는 전기저항특성이 우수하고 피부 트러블이 거의 없는 금을 소재로 한 제품을 적용하였으며 광전용적맥파 및 말초체온 등을 추가로 설계하여 다중생체신호를 모니터링 할 수 있도록 구현하였다. 본 실험에서는 가승이나 늑골부위에서는 생체신호전달이 좋았으며, 환자의 복부부위에서는 생체신호가 아주 작게 검출되었다. 전극소재로 금 전극을 사용하여 일반적인 전극을 이용할 때 보다 신호 검출이 우수하다는 결과를 얻었으며. 일반적인 전극은 단순1회용으로 끝나지만 금 전극센서는 반영구적이면서도 환자가 이동시 접촉력이 우수하여 보다 정확한 데이터를 얻을 수가 있었다.

• 대한의용생체공학회:의공학회지
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• 제35권6호
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• pp.203-210
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• 2014

Wearable medical device has been a resurgence of interest thanks to the development of technology and propagation of smart phone in recent years. Various types of wearable devices have been introduced and available in market. Capacitive coupled electrode which measures electrocardiogram over cloth is able to be applied wearable device. In previous approaches of capacitive electrode, they need proper pressure for stable contact of the electrode to body surface. However, wearable device that gives pressure on body surface is not suitable for long-term monitoring. In this study, we proposed adhesive polyurethane-based capacitive electrode for patch-type wearable electrocardiogram (ECG) monitoring device. Self-adhesive polyurethane make the electrode and whole system be adhered to the surface of skin without any pressure. The patch-type system is consisted of analog filter, analog-to-digital converter and wireless transmission module and designed to be attached on the body as a patch. To validate the feasibility of the developed system, we measured ECG signal in stable and active state and extracted heart rate. Therefore, we observed skin response after long-term attachment for biocompatibility of the adhesive polyurethane and adhesive strength of it. The result shows the possibility of applying the developed system for ECG monitoring in real-life.

• ETRI Journal
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• 제17권4호
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• pp.1-12
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• 1996

A novel body-tied silicon-on-insulator(SOI) n-channel metal-oxide-semiconductor field-effect transistor with grounded body electrode named GBSOI nMOSFET has been developed by wafer bonding and etch-back technology. It has no floating body effect such as kink phenomena on the drain current curves, single-transistor latch and drain current overshoot inherent in a normal SOI device with floating body. We have characterized the interface trap density, kink phenomena on the drain current ($I_{DS}-V_{DS}$) curves, substrate resistance effect on the $I_{DS}-V_{DS}$ curves, subthreshold current characteristics and single transistor latch of these transistors. We have confirmed that the GBSOI structure is suitable for high-speed and low-voltage VLSI circuits.

• 대한의용생체공학회:의공학회지
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• 제29권3호
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• pp.249-253
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• 2008

The indirect-contact ECG (IDC-ECG) was introduced by a prior study for daily non-intrusive measurements. To improve the signal quality and to extend the application area of IDC-ECG, close study of the frequency characteristics of the IDC-ECG is necessary. In this study, the frequency response of the active electrode for several sample clothes was measured under conditions of actual IDC-ECG measurement with human body. Higher gain in low frequency range than expected by prior study was observed. In addition to it, wide variation in gain according to the cloth type in the low frequency range was observed. Variation in gain caused by moisture variation in the clothes was also observed. This study shows that the parallel R-C connection is proper for electrode model and the resistive factor is influenced by moisture in the clothes. This study is the first that provides the frequency response of the electrode in the actual indirect-contact ECG measurement and it is expected that the results will be helpful to improve the indirect-contact ECG method.