• 대한의생명과학회지
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• 제12권4호
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• pp.375-383
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• 2006

The physiological responses following stress are different in individual or personality. We performed this study to clarify gender differences in influences of noise stress on physiological factors. 70 healthy subjects, which was divided man (n=30) and woman (n=40) groups, were exposed to 85 decibels of excavator noise for 15 minutes. Cardiac factors such as heart rate (HR), systolic and diastolic blood pressures (SBP and DBP, respectively), and heart rate-systolic pressure product (RPP) were determined. Transcranial Doppler ultrasound (TCD) was used to measure mean blood flow velocity (Vm), pulsatility index (PI), and resistance index (RI) in the middle, anterior and posterior cerebral arteries (MCA, ACA and PCA, respectively) before and during noise exposure. Cortisol level and hematological variables were also measured before (baseline) and immediately after the end of noise exposure. In the both groups HR, SBP, and RPP significantly decreased during noise exposure (P<0.05) but not significantly different between two groups (P>0.05). Vms of three cerebral arteries in man group decreased, whereas Vm of PCA in woman group fell during noise exposure (P<0.05). Vm, PI and RI in MCA and ACA during noise exposure were low in man group compared with woman group (P<0.05). Vm of PCA was low, whereas PI and RI of PCA were high in man group compared with woman group during noise exposure (P<0.05). Total leukocyte and red blood cell (RBC) counts slightly decreased during noise exposure but not significant (P>0.05). Levels in hematological variables decreased but not significant changed following noise exposure. Decreased rate of total leukocyte in man group was higher (P<0.05). Cortisol levels in the both groups decreased immediately after the end of noise exposure, while the decreased rate in man group was greater than that in woman group (p<0.05). These findings indicate that a transient exposure to experimental excavator noise may cause decreased changes in cardiac factors, cerebral hemodynamics and cortisol levels and the changes may be greater in men than in women.

• Journal of Yeungnam Medical Science
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• 제16권2호
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• pp.309-317
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• 1999

만성 신부전증은 지속적인 혈액투석을 하고 있음에도 다양한 형태의 좌심실 기능부전을 보이며, 특히 좌심실 수축기능이 정상이면서 이완기능 장애만으로 임상적인 심부전증 증상인 폐부종 등이 나타나기도 한다. 또한 혈액투석 후 급격한 혈액량의 변화가 생기므로 적정 심박출을 유지하기 위하여 좌심실 이완기능이 중요한 역할을 하는 것으로 알려져 있다. 저자들은 혈액투석이 좌심실의 수축 및 이완기능에 미치는 영향을 알아보기 위해 Doppler 심초음파도 지표들을 이용해 투석 전후에 좌심실 수축 및 이완기능의 변화를 비교분석 하였다. 심초음파 검사상 좌심실 수축기능 부전이 없고(fractional shortening>30%), 심장 판막질환이나 심근 국소벽 운동장애가 없으며 정상 심율동을 가진 만성 신부전증 환자 30명(남자 15명, 연령$45{\pm}10$세)을 대상으로 이면성 심초음파도 검사를 시행하고, 혈액투석 전후의 좌심실 용적, 좌심실 수축기능 및 Doppler 심초음파도를 이용한 좌심실 이완기능 지표들의 변화를 관찰하여 분석하였다. 혈액투석 후 맥박은 약간 증가하는 소견을 보였으나 통계적 유의성은 없었고, 혈압은 수축기 혈압 및 이완기 혈압의 감소가 있었다. 혈액투석 후 좌심방 및 좌심실 확장기 내경의 크기가 감소했으나 좌심실 수축기 내경의 크기는 변화가 없었고, 심실중격 및 좌심실 후벽의 두께는 변화가 없었다. 좌심실 수축기능 지표인 Fractional shortening, 좌심실 구혈율, 좌심실 박출지수, mean VCF은 투석 전후에 유의한 변화를 보이지 않아 혈액투석으로 인한 좌심실 수축지표의 변화는 관찰되지 않았다. 혈액투석 후 좌심실 이완기능지표의 변화로서 peak E velocity는 현저히 감소하였고, peak A velocity의 변화는 통계적 유의성이 없었다. E/A ratio가 감소하였고, IVRT(Isovolumic Relaxation Time)의 증가가 있었으나, DT(Deceleration time)의 변화는 없었다. 수축기 및 이완기 기능 지표로 사용되는 IMP(Index of Myocardial Performance)는 좌심실 구혈율의 증가와 함께 현저히 증가되었다. 이상의 결과로 혈액투석 후 전부하의 감소에 따른 좌심실 이완기능 지표의 변화로서 E파속 및 E/A비의 감소, IVRT 증가가 나타나고 수축기 기능 및 이완기 기능의 지표로 이용되는 IMP의 증가가 발생하므로, 혈액투석 후 흔히 좌심실 이완기능 장애의 악화가 발생하는 것으로 추정된다.

• 대한의생명과학회지
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• 제8권3호
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• pp.143-154
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• 2002

The effect of cardiopulmonary bypass (CPB) on cerebral physiology during heart surgery remains incompletely understood. This study was carried out to investigate changes of cerebral metabolism and the association between the changes and clinical factors during heart surgery. Seventy adult patients (n=70) scheduled for elective cardiac surgery were participated in the present study. Middle cerebral artery blood flow velocity (V$_{MCA}$), cerebral arteriovenous oxygen content difference (C(a-v)O$_2$), cerebral oxygen extraction (COE), and modified cerebral metabolic rate for oxygen (MCMRO$_2$) were measured during six phases of the operation; Pre-CPB, CPB-10 min, Rewarm-1 (nasopharyngeal temperature 34$^{\circ}C$), Rewarm-2 (nasopharyngeal temperature 37$^{\circ}C$), CPB-off, and Post-OP (at skin closure after CPB-off). Each relationship of age, arterial blood gas parameters, or other variables to V$_{MCA}2$, C(a-v)O$_2$, COE, or MCMRO$_2$ was evaluated. V$_{MCA}$ increased (P<0.0001) whereas C(a-v)O$_2$ decreased (P<0.01) throughout the five phases of the operation compared to Pre-CPB value (control). COE diminished at CPB-10, Rewarm-1, and CPB-off (P<0.05) while MCMRO$_2$ reduced at CPB-10 and Rewarm-1 (P<0.05) compared to Pre-CPB value. Positive correlation was found between age and cerebral metabolic parameters (V$_{MCA}$, C(a-v)O$_2$, COE, or MCMRO$_2$) during CPB (range r=0.24 to 0.38, p<0.05). Four cerebral metabolic parameters had partially negative or positive correlation with arterial blood gas parameters and other variables (arterial blood pH, $O_2$ tension, $O_2$ content, $CO_2$ tension, blood pressure, blood flow, temperature, or hematocrit) during the operation. In conclusion, CPB led to marked alterations of cerebral metabolism and age, pH, and $CO_2$ tension profoundly influenced the changes during cardiac surgery.

• 대한한의학회지
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• 제26권1호
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• pp.123-133
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• 2005

Objective : We investigated the sasang constitutional difference of physiological and psychological response in various thermal environmental conditions. Methods: Among 210 volunteers, 30 healthy subjects were selected through the QSCC II (a questionnaire for constitutional discrimination) and the manual examination of a specialist in sasang constitution. Subjects consisted of 10 each Soyang(少陽), Soeum(少陰), and Taeum(太陽). Experimental environments were set by six different conditions to be $23^{\circ}C,\;50\%\;RH,\;0.lm/s;\;25^{\circ}C,\;25\%\;RH,\;0.lm/s;\;25^{\circ}C,\;50\%\;RH,\;0.lm/s;\;25^{\circ}C,\;50\%\;RH,\;0.4m/s;\;25^{\circ}C,\;75\%\;RH,\;0.1m/s;\;and\;27^{\circ}C,\;50\%\;RH,\;0.1m\s$ (respectively temperature, relative humidity, and wind velocity). Skin temperature, core temperature, heart rate variability (HRV), and galvanic skin response (GSR) were measured for each subject Additionally, subjects were asked about comfort through the questionnaire. Results: From the viewpoint of external temperature sensibility, in all experimental environments, generally the Taeum type feels hotter and the Soeum feels colder than other types. In relative comfort, Soeum types were most sensitive to wind velocity change. From the viewpoint of body temperature, Taeum type was lower and Soyang was higher than other types. The measurements of HRV and GSR showed no difference between the types. Conclusion : The four sasang constitution types showed different responses to various thermal environmental conditions. Accordingly, our research could provide basic data for building the optimal thermal conditions for individuals based on sasang constitution. Consequently, it will help to build a healthy environment for everyday life.

• 대한간학회지
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• 제24권4호
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• pp.409-416
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• 2018

Background/Aims: Left ventricular diastolic dysfunction (LVDD) is an early manifestation of cardiac dysfunction in patients with liver cirrhosis (LC). However, the effect of LVDD on survival has not been clarified, especially in decompensated LC. Methods: We prospectively enrolled 70 patients with decompensated LC, including ascites or variceal bleeding, at Daejeon St. Mary's Hospital from April 2013 to April 2015. The cardiac function of these patients was evaluated using 2D echocardiography with tissue Doppler imaging. The diagnosis of LVDD was based on the American Society of Echocardiography guidelines. The primary endpoint was overall survival. Results: Forty-four patients (62.9%) had LVDD. During follow-up (22.3 months), 18 patients died (16 with LVDD and 2 without LVDD). The survival rate was significantly lower in patients with LVDD than in those without LVDD (31.1 months vs. 42.6 months, P=0.01). In a multivariate analysis, the Child-Pugh score and LVDD were independent predictors of survival. Moreover, patients with a ratio of early filling velocity to early diastolic mitral annular velocity (E/e') ${\geq}10$ (LVDD grade 2) had lower survival than patients with E/e' ratio < 10. Conclusions: The presence of LVDD is associated with poor survival in patients with decompensated LC. Therefore, it may be important to monitor and closely follow LVDD patients.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권5호
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• pp.702-712
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• 2016

A wrist watch type wearable cardiovascular monitoring device is proposed for continuous and convenient monitoring of the patient's cardiovascular system. For comprehensive monitoring of the patient's cardiovascular system, the concurrent electrocardiogram (ECG) and arterial pulse wave (APW) sensor front-end are fabricated in $0.18{\mu}m$ CMOS technology. The ECG sensor frontend achieves 84.6-dB CMRR and $2.3-{\mu}Vrms$-input referred noise with $30-{\mu}W$ power consumption. The APW sensor front-end achieves $3.2-V/{\Omega}$ sensitivity with accurate bio-impedance measurement lesser than 1% error, consuming only $984-{\mu}W$. The ECG and APW sensor front-end is combined with power management unit, micro controller unit (MCU), display and Bluetooth transceiver so that concurrently measured ECG and APW can be transmitted into smartphone, showing patient's cardiovascular state in real time. In order to verify operation of the cardiovascular monitoring system, cardiovascular indicator is extracted from the healthy volunteer. As a result, 5.74 m/second-pulse wave velocity (PWV), 79.1 beats/minute-heart rate (HR) and positive slope of b-d peak-accelerated arterial pulse wave (AAPW) are achieved, showing the volunteer's healthy cardiovascular state.

• 산업경영시스템학회지
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• 제32권1호
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• pp.67-71
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• 2009

Using driving simulator, we analyzed the driving behavior of an older driver on intersection and measured the pychological load to HRV. As a results, older drivers started to enter the more complex intersection on a great distance and on low velocity for safety driving. On the other hand, the value of HRV would be lower on more complex intersections. It suggested that an older driver allowed for his own losses of physiological and cognitive function and recognized low level of driving confidence relatively.

• 대한가정학회지
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• 제37권12호
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• pp.193-203
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• 1999

This study was executed to show influence of material and property of sportswear to physiological responses of body and comfort sensation and to supply basic research data about comfortable sportswear Trainning wear was manufactured with cotton(C) and hygroscopically treated polyester material (FP), and its properties of material were measured. Then rectal temperature, skin temperature, heart rate, weight loss, clothing microclimate and subjective sensation was estimated with study of wearing with these sportswear and examined the influence that it got to physiological responses of body and sensation. Health adult men were selected for subjects and executed at climatic chamber of temperature, $20\pm2^{\circ}C and humidity, $60\pm5%$ R.H. Conclusively sportswear of hygroscopically treated polyester is a favorable functional material. So far factor that affect to physiological comfort sensation has been explained mostly by moisture regain but in our experiment, it turned out that air permeability, water absorption velocity and dynamic oater absorption etc. were affecting factors. So according to this result, air permeability and moisture permeability should be considered with transmittance of temperature moisture for development of comfort material.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 추계학술대회
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• pp.217-220
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• 1996

In this paper, we compare three mehods to obtain PSD of HRV - FFT, AR modeling, and residual integration. Using these methods we speculate the balances of the LP and HF powers of HRV at $0^{\circ}$, $45^{\circ}$, $90^{\circ}$ tilt levels of head-up tilt table for young and healthy 24 men. R peaks are located at the highest point of QRS complex detected from modified spacial velocity algorithm. In general FFT is the most fast way to obtain PSD but PSD from FFT has too many peaks and valleies. AR PSD can show frequency of ANS activity effectively but LF component of PSD is often invisible due to interference of VLF power. The residual integration method that decomposes the AR PSD is very efficient way to extract LF component. Applying the above three methods to HRV we can visualize the trend of PSD variations along tilt levels.

• 디지털융복합연구
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• 제15권7호
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• pp.407-414
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• 2017

본 연구는 융복합 유산소운동이 비만 여자대학생의 동맥맥파속도, 호흡순환계 및 신체조성에 미치는 영향을 규명하기 위해 D광역시 Y구에 위치한 D대학교 여자대학생을 대상으로 체지방율 수치가 30% 이상인자, 과거와 현재 특별한 질환이 없고, 규칙적인 신체활동 경험이 없는 26명을 선정하여 실험 목적과 내용을 충분히 설명한 후 참여 동의서를 받음으로써 최종 확정한 뒤, 운동집단(N=13), 통제집단(N=13)으로 무선배정 하고 12주간 유산소운동을 실시하였으며, 다음과 같은 결론을 얻었다. 첫째, 신체조성의 변화는 운동집단에서 체중, 체지방율, 복부지방율이 유의하게 감소를 보였다. 둘째, 호흡순환계의 변화는 운동집단에서 최대산소섭취량, 최대심박수, 최대환기량은 유의한 증가를 보였다. 셋째, 동맥맥파속도의 변화는 운동집단에서 상체(왼손, 오른손), 하체(왼발, 오른발)에서 유의한 감소를 보였다.