• Journal of Magnetics
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• 제16권4호
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• pp.449-452
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• 2011

A wrist wearable cuffless pulsimeter with a portable and small size apparatus using Hall effect is fabricated. The analysis of the pulse wave measured by the testing product of pulsimeter is done to measure the pulse rate and blood pressure. The blood pressure obtained by the puslimeter is compared with the practical values measured by electronic or mercury liquid blood pressure meters. The detail analysis of a pulse wave measured by a wrist wearable cuffless pulsimeter detecting the changes of the magnetic field can be used to develop a new diagnostic algorithm of blood pressure applying for oriental medical apparatus.

• Journal of Photoscience
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• 제12권2호
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• pp.101-107
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• 2005

Infrared multiphoton dissociation of $CHCl_2F$ was studied using $CO_2$ laser excitation. Three products, $C_2Cl_2F_2$, $C_2ClF_3$, and $C_2HClF_2$, were identified by the analysis of the gas mixture from the photoreaction of $CHCl_2F$. The dependence of the reaction probability on added Ar gas pressure and excitation laser pulse energy was investigated. At low pressure (< 10 torr), the reaction probability increased as Ar pressure increased due to the rotational hole-filling effect, while it diminished with the increase of Ar pressure at high pressure (> > 20 torr) due to the collisional deactivation. The ratio of two products $(C_2ClF_3/C_2Cl_2F_2)$ decreased at low pressure (< 10 torr) and increased at high pressure (> 20 torr) with the increase of Ar pressure. The log-log plot of the reaction probability vs. laser pulse energy (${\\phi}$) was found to have a linear relationship, and its slope decreased as the added Ar pressure was increased. The reaction mechanisms for product formation have been suggested and validated by experimental evidences and considering the energetics. Fluorine-chlorine exchange reaction in the intermediate complex has been suggested to explain the formation of $C_2ClF_3$.

• 한국자기학회지
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• 제20권3호
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• pp.106-113
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• 2010

비가압 상태에서 혈압 및 맥박을 정확하게 측정한 값를 얻기 위하여 안정시 휴대성과 소형화가 가능한 자성 홀소자를 이용한 손목 착용형 맥진기의 시제품을 개발하였다. 본 시제품을 이용하여 맥진파를 분석한 13명의 임상시험 데이터로 상관인자를 정하여 혈압추정 알고리즘의 회귀식을 구하였다. 5초간 비가압 맥진기로 맥진파를 수집한 혈압추정값과 전자혈압계나 수은혈압계로 측정한 혈압값을 비교하였다. 비가압 맥진기로 추정한 최고혈압과 최저혈압의 표준편차는 혈압국제규격 허용치 범위 안에 있는 12.1과 5.9로 각각 나타났다.

• Bulletin of the Korean Chemical Society
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• 제11권3호
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• pp.214-220
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• 1990

We have studied the Infrared Multiphoton Dissociation (IRMPD) of 1-bromo-3-chloropropane by using the pulsed $CO_2$ laser. The product yields and the HCl/HBr branching ratios in IRMPD of $BrCH_2CH_2CH_2Cl$ are studied under the focused beam geometry as a function of buffer gas (He) pressure, laser energy, and photolysing wavelength. It is observed that the total dissociation yield has a laser energy dependence of 1.8-2.0 power order and the branching ratio is very slightly dependent on the pulse energy for the laser lines employed. The dependences of total dissociation yield and branching ratio on the buffer gas pressures show that the dissociation yield monotonically decreases and the branching ratio slightly decreases with the increase of the buffer gas pressure. The Energy-Grained Master Equation (EGME) was applied to explain the laser pulse energy and the buffer gas pressure(He) dependence of the dissociation yield and the branching ratio.

• 한국융합학회논문지
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• 제10권8호
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• pp.53-58
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• 2019

최근 만성질환자 건강관리의 목적으로 혈압측정에 대한 접근성을 높이는 제품 연구가 지속적으로 이루어지고 있다. 기존 연구에서는 심전도(ECG)와 광전용전맥파(PPG)를 분석하여 수축기혈압과 이완기 혈압을 산출하는 방식을 사용하고 있다. 주 과제는 정확도와 재현성을 위한 분석 알고리즘 개발이다. 본 연구에서는 초소형 혈압측정장치를 개발하는 단계에서 장치의 크기를 줄이고 측정방법도 간단히 하는 동시에 알고리즘도 두 개의 PPG만을 이용하여 최고혈압(SBP)을 추출하고 이에 따른 최저혈압(DBP)을 구하고자 하였다. 이를 위해 두 개의 PPG에서 얻은 측정값과 SBP, DBP 관계를 통계적으로 추적하여 상호관계를 분석하였다. PPG의 차이 값인 DF_P는 SBP와 반비례 관계가 있으며, DBP와는 비례적 관계가 성립되어 알고리즘에 의해 혈압값을 유추할 수 있으며, SBP를 통해 DBP를 추적할 수 있다.

• 대한간호학회지
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• 제28권4호
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• pp.980-991
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• 1998

The purpose of this study was to examnin the effect of slow stroke back massage(SSBM) on anxiety and immune response in patients undergoing open heart surgery and to compare the effect of 5-minutes with 10-minutes SSBM. Among the sixty-four patient subjects, twenty-one were one experimental group receiving massage for 10-minutes, twenty for the other experimental group receiving massage for 5-minutes and twenty-three for the control group. Subjects were admitted at Hospitals in Inchon and Puchon for open heart surgery. This study was carried out from October 10, 1997 to May 10, 1998. The levels of anxiety were measured by the Visual Analogue Scale(VAS), Trait anxiety scale, systolic and diastolic blood pressure, pulse rate, blood cortisol and the levels of immune response were measured by the blood T-lymphocyte and Natural killer cell. Study measurements were taken before and after SSBM on the 1st post operative day. Data were analyzed using x$^2$ test, oneway ANOVA, paired t-test, t-test and Pearson product moment correlation. The results were summarized as follows : 1. After SSBM, VAS anxiety level, systolic and diastolic blood pressure and pulse rate of the experimental group were decreased significantly than those measurements before the SSBM. After SSBM, significant difference in the VAS anxiety level, systolic blood pressure and pulse rate between the experimental and control groups were found. 2. After SSBM, the blood cortisol of the experimental and control groups were increased significantly compared with before SSBM. But the significant difference in blood cortisol between the two groups was not found. 3. After SSBM, the blood T-lymphocyte percentages of the experimental and control groups were decreased signigicantly and blood Natural killer cell percentages of the two groups were increased compared with before SSBM. But significant difference in blood T-lymphocyte and Natural killer cell percentages between the two groups was not found. 4. Significant difference in VAS anxiety level, systolic and diastolic blood pressure, pulse rate, blood cortisol, blood T-lymphocyte and Natural killer cell percentages between SSBM for 5 minutes and SSBM for 10 minutes were not found. Based upon the results, this study concludes that the slow stroke back massage for 5 minutes is a useful intervention that decreases anxiety and produces relaxation in patients undergoing open heart surgery.

• 대한핵의학회지
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• 제27권2호
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• pp.203-209
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• 1993

Dipyridamole은 정맥주사시 매우 안전한 것으로 알려져 있으며 일반적으로그 약물효과는 혈압강하와 심계항진에 의한 증상이 대부분이다. 저자들은 dipyridamole 부하 심근 SPECT를 시행한 847명 환자에서 dipyridamole에 대한 반응양상과 부작용에 대해 조사하였다. 대상환자는 847명으로 이들 중 혈압과 맥박수의 측정기록이 있는 702명에서 심근의 관류결손부위에 따른 헐압과 맥박수의 곱과 곱의 비를 분석하여 dipyridamole에 대한 반응을 조사하였다. 1) Dipyridamole 투여후 나타난 부작용으로는 흉통이나 흉부불쾌감(20.3%)이 가장 많았고 두통이 14.8%, 숨이 차다고 한 예가 4.6%, 복통이 4.3%, 어지러움이 2.2%의 빈도를 보였다. 2) Dipyridamole 투여후 대부분의 환자에서 혈압감소를 보여 93.6%에서 혈압이 감소하였고, 0.9에서 혈압의 변동이 없었고, 5.5%에서는 오히려 혈압이 증가하였다. 3) Dipyridamole 부하전의 맥박수에 비해 10%이상의 증가를 보이지 않은 경우는 전체 대상환자의 8.3%였다. 당뇨환자의 16.9%, 비당뇨환자의 6.7%에서 맥박수의 증가를 보이지 않았다(p<0.005). 4)심근 SPECT상 관류결손이 없는 234명에서 연령과 RPPr의 관계는 연령이 증가함에 따라 RPPs/RPPr는 감소하는 경향을 보였다. 관류결손이 있는 환자 468 명에서도 연령과 RPPs, RPPs/RPPr이 같은 결과를 보이고 있다. 5) 휴식기 심근의 관류결손이 있는 환자군에서 심근의 관류결손의 크기와 RPPr과 RPPs/RPPr은 관련이 없었다. Dipyridamole에 의한 반응으로 비전형적인 반응을 보인 경우는 혈압증가가 5.5%, 맥박의 증가가 없는 경우가 8.3% 였다. 혈압과 맥박수의 곱 또는 곱의 비와 연령과의 관계는 휴식기 심장부하가 많은 고령의 환자에서 증가되어 있었으며 dipyridamole부하에 의한 심장부하량은 나이가 많은 환자에서 적어짐을 시사하였다. 관류결손이 있는 환자와 없는 환자에서 dipyridamole부하로 인한 심장부하량에는 유의한 차이가 없었다. Dipyridamole에 의한 부작용은 흉통, 두통, 복통 등의 순이었고 전예에서 호전되었으며 생명에 위험을 초래할 수 있는 정도의 심장마비나 심부정맥은 한 예에서도 없었다. 결론적으로 dipyridamole은 약물부하 심근 SPECT 검사에 안전하게 사용할 수 있는 약물로 사료된다.

• 한국대기환경학회지
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• 제11권1호
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• pp.77-84
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• 1995

To prevent or reduce air pollutant from methanol fueled vehicles, methanol oxidation reaction was carried out using a heteropoly acid catalysts. Catalytic activities of catalysts have been experimented at atmospheric pressure in a fixed bed flow reactor. Catalysts were characterized by XRD, IR, thermal analysis, N $H_{3}$-TPD and GC pulse technique. Acidities of catalysts were highly affected by poly-atoms. Methanol conversion was much higher on catalyst with W than on catalyst with Mo as a poly-atoms. With the increase of copper content(X) in C $u_{x}$ $H_{{3-2x}}$PMo catalyst, acidity was decreased and oxidation ability was increased. Methanol conversion and product distribution were affected by the acidity and oxidation ability of catalyst. Especially, supported PdSiW(1wt%) catalyst has a very good methanol conversion and C $O_{2}$ selectivity as high as a commertial 3-way catalyst.t.

• 한국해안해양공학회지
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• 제7권3호
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• pp.265-276
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• 1995

본 논문에서는 실시간 해황예보 시스템 개발의 일환으로 수행된 회선적분법을 이용한 신속 표층유속 재현에 대하여 다룬다. 바람응력은 공간적으로 균일하고 대 기압은 무시된다. Data Base 구축을 위하여 4방향의 바람(북서, 북동, 남서, 남동)을 고려하여 각 지점의 회선적분의 가중치를 Galerkin-FEM 모형에 의해 계산하였다. 시간에 따른 바람응력이 주어지면 구성된 Data Base를 이용하여 회선적분법에 의해 신속한 예보가 가능하다. 시간적으로 변하는 임의의 바람응력은 6시간 단위로 정의되는 wind pulse의 연속으로 표현되며 총 12개의 pulse(즉, 72시간전)가 convolution product에 사용된다. 회선적분법의 적용 가능성을 확인하기 위하여 황해 이상화한 해역과 황해와 동지나해에 이르는 실제 해역에서의 수치실험이 수행되었다. 고려한 바람응력은 역풍류 생성 확인을 위하여 시간에 따라 sin 함수적으로 변하는 북풍을 고려하였고, 실험 결과 역풍류 생성의 화인과 회선적분법을 이용한 신속 표층해류 예측 가능성을 확인할 수 있었다.

• Journal of Chest Surgery
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• 제54권2호
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• pp.81-87
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• 2021

Background: Artificial grafts such as polyethylene terephthalate (Dacron) and expanded polytetrafluoroethylene (ePTFE) are used for various cardiovascular surgical procedures. The compliance properties of prosthetic grafts could affect hemodynamic energy, which can be measured using the energy-equivalent pressure (EEP) and surplus hemodynamic energy (SHE). We investigated changes in the hemodynamic energy of prosthetic grafts. Methods: In a simulation test, the changes in EEP for these grafts were estimated using COMSOL MULTIPHYSICS. The Young modulus, Poisson ratio, and density were used to analyze the grafts' material properties, and pre- and post-graft EEP values were obtained by computing the product of the pressure and velocity. In an in vivo study, Dacron and ePTFE grafts were anastomosed in an end-to-side fashion on the descending thoracic aorta of swine. The pulsatile pump flow was fixed at 2 L/min. Real-time flow and pressure were measured at the distal part of each graft, while clamping the other graft and the descending thoracic aorta. EEP and SHE were calculated and compared. Results: In the simulation test, the mean arterial pressure decreased by 39% for all simulations. EEP decreased by 42% for both grafts, and by around 55% for the native blood vessels after grafting. The in vivo test showed no significant difference between both grafts in terms of EEP and SHE. Conclusion: The post-graft hemodynamic energy was not different between the Dacron and ePTFE grafts. Artificial grafts are less compliant than native blood vessels; however, they can deliver pulsatile blood flow and hemodynamic energy without any significant energy loss.